blob: 7101ac64bb209d31966ca255e07a2ddf704397e7 [file] [log] [blame]
Greg Kroah-Hartmanb2441312017-11-01 15:07:57 +01001# SPDX-License-Identifier: GPL-2.0
Sam Ravnborgdaa93fa2007-11-12 20:54:30 +01002# Select 32 or 64 bit
3config 64BIT
Masahiro Yamada104daea2018-05-28 18:21:40 +09004 bool "64-bit kernel" if "$(ARCH)" = "x86"
5 default "$(ARCH)" != "i386"
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09006 help
Sam Ravnborgdaa93fa2007-11-12 20:54:30 +01007 Say yes to build a 64-bit kernel - formerly known as x86_64
8 Say no to build a 32-bit kernel - formerly known as i386
9
10config X86_32
Jan Beulich3120e252012-09-10 12:41:45 +010011 def_bool y
12 depends on !64BIT
Ingo Molnar341c7872016-11-15 10:04:55 +010013 # Options that are inherently 32-bit kernel only:
14 select ARCH_WANT_IPC_PARSE_VERSION
15 select CLKSRC_I8253
16 select CLONE_BACKWARDS
Thomas Gleixner117ed452019-04-14 18:00:08 +020017 select HAVE_DEBUG_STACKOVERFLOW
Ingo Molnar341c7872016-11-15 10:04:55 +010018 select MODULES_USE_ELF_REL
19 select OLD_SIGACTION
Vincenzo Frascino7ac87072019-06-21 10:52:49 +010020 select GENERIC_VDSO_32
Sam Ravnborgdaa93fa2007-11-12 20:54:30 +010021
22config X86_64
Jan Beulich3120e252012-09-10 12:41:45 +010023 def_bool y
24 depends on 64BIT
Ingo Molnard94e0682016-11-15 10:11:57 +010025 # Options that are inherently 64-bit kernel only:
Alexandre Ghiti4eb07162019-05-13 17:19:04 -070026 select ARCH_HAS_GIGANTIC_PAGE
Ard Biesheuvelc12d3362019-11-08 13:22:27 +010027 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
Ingo Molnard94e0682016-11-15 10:11:57 +010028 select ARCH_USE_CMPXCHG_LOCKREF
29 select HAVE_ARCH_SOFT_DIRTY
30 select MODULES_USE_ELF_RELA
Christoph Hellwigf616ab52018-05-09 06:53:49 +020031 select NEED_DMA_MAP_STATE
Christoph Hellwig09230cb2018-04-24 09:00:54 +020032 select SWIOTLB
Sam Ravnborg1032c0b2007-11-06 21:35:08 +010033
Steven Rostedt (VMware)518049d2019-05-10 12:05:46 -040034config FORCE_DYNAMIC_FTRACE
35 def_bool y
36 depends on X86_32
37 depends on FUNCTION_TRACER
38 select DYNAMIC_FTRACE
39 help
40 We keep the static function tracing (!DYNAMIC_FTRACE) around
41 in order to test the non static function tracing in the
42 generic code, as other architectures still use it. But we
43 only need to keep it around for x86_64. No need to keep it
44 for x86_32. For x86_32, force DYNAMIC_FTRACE.
Ingo Molnard94e0682016-11-15 10:11:57 +010045#
46# Arch settings
47#
48# ( Note that options that are marked 'if X86_64' could in principle be
49# ported to 32-bit as well. )
50#
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +010051config X86
Harvey Harrison3c2362e2008-01-30 13:31:03 +010052 def_bool y
Ingo Molnarc763ea22016-11-15 10:26:39 +010053 #
54 # Note: keep this list sorted alphabetically
55 #
Ingo Molnar6471b822015-06-03 10:00:13 +020056 select ACPI_LEGACY_TABLES_LOOKUP if ACPI
57 select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI
Yury Norov942fa982018-05-16 11:18:49 +030058 select ARCH_32BIT_OFF_T if X86_32
Thomas Gleixner2a21ad52018-09-17 14:45:35 +020059 select ARCH_CLOCKSOURCE_INIT
Ingo Molnarc763ea22016-11-15 10:26:39 +010060 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
Laura Abbottfa5b6ec2017-01-10 13:35:40 -080061 select ARCH_HAS_DEBUG_VIRTUAL
Anshuman Khandual399145f2020-06-04 16:47:15 -070062 select ARCH_HAS_DEBUG_VM_PGTABLE if !X86_PAE
Dan Williams21266be2015-11-19 18:19:29 -080063 select ARCH_HAS_DEVMEM_IS_ALLOWED
Douglas Andersonb1a57bb2020-05-07 13:08:42 -070064 select ARCH_HAS_EARLY_DEBUG if KGDB
Ingo Molnar6471b822015-06-03 10:00:13 +020065 select ARCH_HAS_ELF_RANDOMIZE
Linus Torvalds72d93102014-09-13 11:14:53 -070066 select ARCH_HAS_FAST_MULTIPLIER
Dave Hansen316d0972018-04-20 15:20:28 -070067 select ARCH_HAS_FILTER_PGPROT
Daniel Micay6974f0c2017-07-12 14:36:10 -070068 select ARCH_HAS_FORTIFY_SOURCE
Riku Voipio957e3fa2014-12-12 16:57:44 -080069 select ARCH_HAS_GCOV_PROFILE_ALL
Peter Zijlstra0f1441b2020-06-12 16:05:26 +020070 select ARCH_HAS_KCOV if X86_64 && STACK_VALIDATION
Thiago Jung Bauermann0c9c1d52019-08-06 01:49:14 -030071 select ARCH_HAS_MEM_ENCRYPT
Mathieu Desnoyers10bcc802018-01-29 15:20:18 -050072 select ARCH_HAS_MEMBARRIER_SYNC_CORE
Daniel Borkmann0ebeea82020-05-15 12:11:16 +020073 select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
Ingo Molnarc763ea22016-11-15 10:26:39 +010074 select ARCH_HAS_PMEM_API if X86_64
Robin Murphy17596732019-07-16 16:30:47 -070075 select ARCH_HAS_PTE_DEVMAP if X86_64
Laurent Dufour3010a5e2018-06-07 17:06:08 -070076 select ARCH_HAS_PTE_SPECIAL
Dan Williams0aed55a2017-05-29 12:22:50 -070077 select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64
Dan Williams092b31a2018-07-08 13:46:17 -070078 select ARCH_HAS_UACCESS_MCSAFE if X86_64 && X86_MCE
Daniel Borkmannd2852a22017-02-21 16:09:33 +010079 select ARCH_HAS_SET_MEMORY
Rick Edgecombed253ca02019-04-25 17:11:34 -070080 select ARCH_HAS_SET_DIRECT_MAP
Laura Abbottad21fc42017-02-06 16:31:57 -080081 select ARCH_HAS_STRICT_KERNEL_RWX
82 select ARCH_HAS_STRICT_MODULE_RWX
Mathieu Desnoyersac1ab122018-01-29 15:20:16 -050083 select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
Brian Gerst25c619e2020-03-13 15:51:42 -040084 select ARCH_HAS_SYSCALL_WRAPPER
Andrey Ryabininc6d30852016-01-20 15:00:55 -080085 select ARCH_HAS_UBSAN_SANITIZE_ALL
Zong Li7e01ccb2020-06-03 16:03:58 -070086 select ARCH_HAS_DEBUG_WX
Ingo Molnar6471b822015-06-03 10:00:13 +020087 select ARCH_HAVE_NMI_SAFE_CMPXCHG
88 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
Mark Salter77fbbc82013-10-07 22:18:07 -040089 select ARCH_MIGHT_HAVE_PC_PARPORT
Mark Salter5e2c18c2014-01-01 11:34:16 -080090 select ARCH_MIGHT_HAVE_PC_SERIO
Thomas Gleixner3599fe12019-04-25 11:45:22 +020091 select ARCH_STACKWALK
Arnd Bergmann2c870e62018-07-24 11:48:45 +020092 select ARCH_SUPPORTS_ACPI
Ingo Molnar6471b822015-06-03 10:00:13 +020093 select ARCH_SUPPORTS_ATOMIC_RMW
Ingo Molnar6471b822015-06-03 10:00:13 +020094 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
95 select ARCH_USE_BUILTIN_BSWAP
Ingo Molnar6471b822015-06-03 10:00:13 +020096 select ARCH_USE_QUEUED_RWLOCKS
97 select ARCH_USE_QUEUED_SPINLOCKS
Mark Brown2ce0d7f2020-04-16 19:24:02 +010098 select ARCH_USE_SYM_ANNOTATIONS
Andy Lutomirskice4a4e562017-05-28 10:00:14 -070099 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
Daniel Borkmann81c22042019-12-09 16:08:03 +0100100 select ARCH_WANT_DEFAULT_BPF_JIT if X86_64
Ingo Molnarc763ea22016-11-15 10:26:39 +0100101 select ARCH_WANTS_DYNAMIC_TASK_STRUCT
Alexandre Ghiti3876d4a2019-06-27 15:00:11 -0700102 select ARCH_WANT_HUGE_PMD_SHARE
Huang Ying38d8b4e2017-07-06 15:37:18 -0700103 select ARCH_WANTS_THP_SWAP if X86_64
Shile Zhang10916702019-12-04 08:46:31 +0800104 select BUILDTIME_TABLE_SORT
Ingo Molnar6471b822015-06-03 10:00:13 +0200105 select CLKEVT_I8253
Ingo Molnar6471b822015-06-03 10:00:13 +0200106 select CLOCKSOURCE_VALIDATE_LAST_CYCLE
107 select CLOCKSOURCE_WATCHDOG
Ingo Molnar6471b822015-06-03 10:00:13 +0200108 select DCACHE_WORD_ACCESS
Linus Torvalds45471cd2015-06-24 19:52:06 -0700109 select EDAC_ATOMIC_SCRUB
110 select EDAC_SUPPORT
Ingo Molnar6471b822015-06-03 10:00:13 +0200111 select GENERIC_CLOCKEVENTS
112 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
113 select GENERIC_CLOCKEVENTS_MIN_ADJUST
114 select GENERIC_CMOS_UPDATE
115 select GENERIC_CPU_AUTOPROBE
Thomas Gleixner61dc0f52018-01-07 22:48:01 +0100116 select GENERIC_CPU_VULNERABILITIES
Ingo Molnar6471b822015-06-03 10:00:13 +0200117 select GENERIC_EARLY_IOREMAP
Thomas Gleixner27d6b4d2020-07-23 00:00:04 +0200118 select GENERIC_ENTRY
Ingo Molnar6471b822015-06-03 10:00:13 +0200119 select GENERIC_FIND_FIRST_BIT
120 select GENERIC_IOMAP
Thomas Gleixnerc7d6c9d2017-06-20 01:37:46 +0200121 select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP
Thomas Gleixner0fa115d2017-09-13 23:29:38 +0200122 select GENERIC_IRQ_MATRIX_ALLOCATOR if X86_LOCAL_APIC
Thomas Gleixnerad7a9292017-06-20 01:37:33 +0200123 select GENERIC_IRQ_MIGRATION if SMP
Ingo Molnar6471b822015-06-03 10:00:13 +0200124 select GENERIC_IRQ_PROBE
Thomas Gleixnerc201c912017-10-17 09:54:59 +0200125 select GENERIC_IRQ_RESERVATION_MODE
Ingo Molnar6471b822015-06-03 10:00:13 +0200126 select GENERIC_IRQ_SHOW
127 select GENERIC_PENDING_IRQ if SMP
Steven Price2ae27132020-02-03 17:36:24 -0800128 select GENERIC_PTDUMP
Ingo Molnar6471b822015-06-03 10:00:13 +0200129 select GENERIC_SMP_IDLE_THREAD
130 select GENERIC_STRNCPY_FROM_USER
131 select GENERIC_STRNLEN_USER
132 select GENERIC_TIME_VSYSCALL
Vincenzo Frascino7ac87072019-06-21 10:52:49 +0100133 select GENERIC_GETTIMEOFDAY
Dmitry Safonov550a77a2019-11-12 01:27:11 +0000134 select GENERIC_VDSO_TIME_NS
Christoph Hellwig39656e82019-07-11 20:56:49 -0700135 select GUP_GET_PTE_LOW_HIGH if X86_PAE
Hans de Goede17e58882020-01-23 22:02:42 +0100136 select HARDIRQS_SW_RESEND
Thomas Gleixner7edaeb62017-08-15 09:50:13 +0200137 select HARDLOCKUP_CHECK_TIMESTAMP if X86_64
Ingo Molnar6471b822015-06-03 10:00:13 +0200138 select HAVE_ACPI_APEI if ACPI
139 select HAVE_ACPI_APEI_NMI if ACPI
140 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
Ingo Molnar6471b822015-06-03 10:00:13 +0200141 select HAVE_ARCH_AUDITSYSCALL
142 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE
143 select HAVE_ARCH_JUMP_LABEL
Ard Biesheuvelb34006c2018-09-18 23:51:41 -0700144 select HAVE_ARCH_JUMP_LABEL_RELATIVE
Andrey Ryabinind17a1d92017-11-15 17:36:35 -0800145 select HAVE_ARCH_KASAN if X86_64
Daniel Axtens0609ae02019-11-30 17:55:00 -0800146 select HAVE_ARCH_KASAN_VMALLOC if X86_64
Ingo Molnar6471b822015-06-03 10:00:13 +0200147 select HAVE_ARCH_KGDB
Daniel Cashman9e08f572016-01-14 15:20:06 -0800148 select HAVE_ARCH_MMAP_RND_BITS if MMU
149 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT
Dmitry Safonov1b028f72017-03-06 17:17:19 +0300150 select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT
Ard Biesheuvel271ca782018-08-21 21:56:00 -0700151 select HAVE_ARCH_PREL32_RELOCATIONS
Ingo Molnar6471b822015-06-03 10:00:13 +0200152 select HAVE_ARCH_SECCOMP_FILTER
Kees Cookf7d83c12017-08-16 13:26:03 -0700153 select HAVE_ARCH_THREAD_STRUCT_WHITELIST
Alexander Popovafaef012018-08-17 01:16:58 +0300154 select HAVE_ARCH_STACKLEAK
Ingo Molnar6471b822015-06-03 10:00:13 +0200155 select HAVE_ARCH_TRACEHOOK
156 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
Matthew Wilcoxa00cc7d2017-02-24 14:57:02 -0800157 select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
Peter Xub64d8d12020-04-20 18:13:45 -0700158 select HAVE_ARCH_USERFAULTFD_WP if X86_64 && USERFAULTFD
Andy Lutomirskie37e43a2016-08-11 02:35:23 -0700159 select HAVE_ARCH_VMAP_STACK if X86_64
Ingo Molnarc763ea22016-11-15 10:26:39 +0100160 select HAVE_ARCH_WITHIN_STACK_FRAMES
Masahiro Yamada2ff2b7e2019-08-19 14:54:20 +0900161 select HAVE_ASM_MODVERSIONS
Ingo Molnar6471b822015-06-03 10:00:13 +0200162 select HAVE_CMPXCHG_DOUBLE
163 select HAVE_CMPXCHG_LOCAL
164 select HAVE_CONTEXT_TRACKING if X86_64
165 select HAVE_C_RECORDMCOUNT
166 select HAVE_DEBUG_KMEMLEAK
Akinobu Mita9c5a3622014-06-04 16:06:50 -0700167 select HAVE_DMA_CONTIGUOUS
Steven Rostedt677aa9f2008-05-17 00:01:36 -0400168 select HAVE_DYNAMIC_FTRACE
Masami Hiramatsu06aeaae2012-09-28 17:15:17 +0900169 select HAVE_DYNAMIC_FTRACE_WITH_REGS
Steven Rostedt (VMware)562955f2019-11-08 13:11:39 -0500170 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
Wang YanQing03f57812018-05-03 14:10:43 +0800171 select HAVE_EBPF_JIT
Johannes Berg58340a02008-07-25 01:45:33 -0700172 select HAVE_EFFICIENT_UNALIGNED_ACCESS
Christoph Hellwig6630a8e2018-11-15 20:05:37 +0100173 select HAVE_EISA
Jiri Slaby5f56a5d2016-05-20 17:00:16 -0700174 select HAVE_EXIT_THREAD
Christoph Hellwig67a929e2019-07-11 20:57:14 -0700175 select HAVE_FAST_GUP
Steven Rostedt (VMware)644e0e82017-03-23 10:33:52 -0400176 select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE
Ingo Molnar6471b822015-06-03 10:00:13 +0200177 select HAVE_FTRACE_MCOUNT_RECORD
Ingo Molnar6471b822015-06-03 10:00:13 +0200178 select HAVE_FUNCTION_GRAPH_TRACER
179 select HAVE_FUNCTION_TRACER
Emese Revfy6b90bd42016-05-24 00:09:38 +0200180 select HAVE_GCC_PLUGINS
K.Prasad0067f122009-06-01 23:43:57 +0530181 select HAVE_HW_BREAKPOINT
Ingo Molnar6471b822015-06-03 10:00:13 +0200182 select HAVE_IDE
183 select HAVE_IOREMAP_PROT
Ingo Molnar6471b822015-06-03 10:00:13 +0200184 select HAVE_IRQ_TIME_ACCOUNTING
185 select HAVE_KERNEL_BZIP2
186 select HAVE_KERNEL_GZIP
187 select HAVE_KERNEL_LZ4
188 select HAVE_KERNEL_LZMA
189 select HAVE_KERNEL_LZO
190 select HAVE_KERNEL_XZ
Nick Terrellfb46d052020-07-30 12:08:39 -0700191 select HAVE_KERNEL_ZSTD
Ingo Molnar6471b822015-06-03 10:00:13 +0200192 select HAVE_KPROBES
193 select HAVE_KPROBES_ON_FTRACE
Masami Hiramatsu540adea2018-01-13 02:55:03 +0900194 select HAVE_FUNCTION_ERROR_INJECTION
Ingo Molnar6471b822015-06-03 10:00:13 +0200195 select HAVE_KRETPROBES
196 select HAVE_KVM
197 select HAVE_LIVEPATCH if X86_64
Frederic Weisbecker01027522010-04-11 18:55:56 +0200198 select HAVE_MIXED_BREAKPOINTS_REGS
Josh Poimboeufee9f8fc2017-07-24 18:36:57 -0500199 select HAVE_MOD_ARCH_SPECIFIC
Joel Fernandes (Google)9f132f72019-01-03 15:28:41 -0800200 select HAVE_MOVE_PMD
Petr Mladek42a0bb32016-05-20 17:00:33 -0700201 select HAVE_NMI
Ingo Molnar6471b822015-06-03 10:00:13 +0200202 select HAVE_OPROFILE
203 select HAVE_OPTPROBES
204 select HAVE_PCSPKR_PLATFORM
205 select HAVE_PERF_EVENTS
Frederic Weisbeckerc01d4322010-05-15 22:57:48 +0200206 select HAVE_PERF_EVENTS_NMI
Nicholas Piggin92e5aae2017-08-18 15:15:51 -0700207 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
Christoph Hellwigeb01d422018-11-15 20:05:32 +0100208 select HAVE_PCI
Jiri Olsac5e63192012-08-07 15:20:36 +0200209 select HAVE_PERF_REGS
Jiri Olsac5ebced2012-08-07 15:20:40 +0200210 select HAVE_PERF_USER_STACK_DUMP
Peter Zijlstraff2e6d722020-02-03 17:37:02 -0800211 select MMU_GATHER_RCU_TABLE_FREE if PARAVIRT
Thomas Gleixner00998082020-07-30 12:14:07 +0200212 select HAVE_POSIX_CPU_TIMERS_TASK_WORK
Ingo Molnar6471b822015-06-03 10:00:13 +0200213 select HAVE_REGS_AND_STACK_ACCESS_API
Jiri Slaby6415b382018-05-18 08:47:13 +0200214 select HAVE_RELIABLE_STACKTRACE if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION
Masami Hiramatsu3c88ee194c2018-04-25 21:20:57 +0900215 select HAVE_FUNCTION_ARG_ACCESS_API
Masahiro Yamadad148eac2018-06-14 19:36:45 +0900216 select HAVE_STACKPROTECTOR if CC_HAS_SANE_STACKPROTECTOR
Ingo Molnarc763ea22016-11-15 10:26:39 +0100217 select HAVE_STACK_VALIDATION if X86_64
Mathieu Desnoyersd6761b82018-06-02 08:43:58 -0400218 select HAVE_RSEQ
Ingo Molnar6471b822015-06-03 10:00:13 +0200219 select HAVE_SYSCALL_TRACEPOINTS
Ingo Molnar6471b822015-06-03 10:00:13 +0200220 select HAVE_UNSTABLE_SCHED_CLOCK
Avi Kivity7c68af62009-09-19 09:40:22 +0300221 select HAVE_USER_RETURN_NOTIFIER
Vincenzo Frascino7ac87072019-06-21 10:52:49 +0100222 select HAVE_GENERIC_VDSO
Thomas Gleixner05736e42018-05-29 17:48:27 +0200223 select HOTPLUG_SMT if SMP
Thomas Gleixnerc01858082011-02-07 02:24:08 +0100224 select IRQ_FORCED_THREADING
Christoph Hellwig86596f02018-04-05 09:44:52 +0200225 select NEED_SG_DMA_LENGTH
Christoph Hellwig2eac9c22018-11-15 20:05:33 +0100226 select PCI_DOMAINS if PCI
Sinan Kaya625210c2019-01-21 23:19:58 +0000227 select PCI_LOCKLESS_CONFIG if PCI
Ingo Molnar6471b822015-06-03 10:00:13 +0200228 select PERF_EVENTS
Prarit Bhargava3195ef52013-02-14 12:02:54 -0500229 select RTC_LIB
Arnd Bergmannd6faca42016-06-01 16:46:23 +0200230 select RTC_MC146818_LIB
Ingo Molnar6471b822015-06-03 10:00:13 +0200231 select SPARSE_IRQ
Pranith Kumar83fe27e2014-12-05 11:24:45 -0500232 select SRCU
Ingo Molnar6471b822015-06-03 10:00:13 +0200233 select SYSCTL_EXCEPTION_TRACE
Andy Lutomirski15f4eae2016-09-13 14:29:25 -0700234 select THREAD_INFO_IN_TASK
Ingo Molnar6471b822015-06-03 10:00:13 +0200235 select USER_STACKTRACE_SUPPORT
236 select VIRT_TO_BUS
Ingo Molnar3b02a052020-04-13 09:44:39 +0200237 select HAVE_ARCH_KCSAN if X86_64
Ingo Molnar6471b822015-06-03 10:00:13 +0200238 select X86_FEATURE_NAMES if PROC_FS
Aubrey Li0c608da2019-06-06 09:22:35 +0800239 select PROC_PID_ARCH_STATUS if PROC_FS
Nayna Jain9e2b4be2020-03-08 20:57:51 -0400240 imply IMA_SECURE_AND_OR_TRUSTED_BOOT if EFI
Balbir Singh7d8330a2008-02-10 12:46:28 +0530241
Ingo Molnarba7e4d12009-06-06 13:58:12 +0200242config INSTRUCTION_DECODER
Jan Beulich3120e252012-09-10 12:41:45 +0100243 def_bool y
244 depends on KPROBES || PERF_EVENTS || UPROBES
Ingo Molnarba7e4d12009-06-06 13:58:12 +0200245
Linus Torvalds51b26ad2009-04-26 10:12:47 -0700246config OUTPUT_FORMAT
247 string
248 default "elf32-i386" if X86_32
249 default "elf64-x86-64" if X86_64
250
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100251config LOCKDEP_SUPPORT
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100252 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100253
254config STACKTRACE_SUPPORT
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100255 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100256
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100257config MMU
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100258 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100259
Daniel Cashman9e08f572016-01-14 15:20:06 -0800260config ARCH_MMAP_RND_BITS_MIN
261 default 28 if 64BIT
262 default 8
263
264config ARCH_MMAP_RND_BITS_MAX
265 default 32 if 64BIT
266 default 16
267
268config ARCH_MMAP_RND_COMPAT_BITS_MIN
269 default 8
270
271config ARCH_MMAP_RND_COMPAT_BITS_MAX
272 default 16
273
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100274config SBUS
275 bool
276
277config GENERIC_ISA_DMA
Jan Beulich3120e252012-09-10 12:41:45 +0100278 def_bool y
279 depends on ISA_DMA_API
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100280
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100281config GENERIC_BUG
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100282 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100283 depends on BUG
Jan Beulichb93a5312008-12-16 11:40:27 +0000284 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
285
286config GENERIC_BUG_RELATIVE_POINTERS
287 bool
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100288
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100289config ARCH_MAY_HAVE_PC_FDC
Jan Beulich3120e252012-09-10 12:41:45 +0100290 def_bool y
291 depends on ISA_DMA_API
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100292
Sam Ravnborg1032c0b2007-11-06 21:35:08 +0100293config GENERIC_CALIBRATE_DELAY
294 def_bool y
295
venkatesh.pallipadi@intel.com9a0b8412008-01-31 17:35:06 -0800296config ARCH_HAS_CPU_RELAX
297 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100298
Pekka Enberg1b27d052008-04-28 02:12:22 -0700299config ARCH_HAS_CACHE_LINE_SIZE
300 def_bool y
301
Dave Hansen316d0972018-04-20 15:20:28 -0700302config ARCH_HAS_FILTER_PGPROT
303 def_bool y
304
Mike Travisdd5af902008-01-30 13:33:32 +0100305config HAVE_SETUP_PER_CPU_AREA
Brian Gerst89c9c4c2009-01-27 12:56:48 +0900306 def_bool y
travis@sgi.comb32ef632008-01-30 13:32:51 +0100307
Tejun Heo08fc4582009-08-14 15:00:49 +0900308config NEED_PER_CPU_EMBED_FIRST_CHUNK
309 def_bool y
310
311config NEED_PER_CPU_PAGE_FIRST_CHUNK
Tejun Heo11124412009-02-20 16:29:09 +0900312 def_bool y
313
Johannes Berg801e4062007-12-08 02:12:39 +0100314config ARCH_HIBERNATION_POSSIBLE
315 def_bool y
Johannes Berg801e4062007-12-08 02:12:39 +0100316
Johannes Bergf4cb5702007-12-08 02:14:00 +0100317config ARCH_SUSPEND_POSSIBLE
318 def_bool y
Johannes Bergf4cb5702007-12-08 02:14:00 +0100319
Steve Capper53313b22013-04-30 08:03:42 +0100320config ARCH_WANT_GENERAL_HUGETLB
321 def_bool y
322
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100323config ZONE_DMA32
Jan Beuliche0fd24a2015-02-05 15:39:34 +0000324 def_bool y if X86_64
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100325
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100326config AUDIT_ARCH
Jan Beuliche0fd24a2015-02-05 15:39:34 +0000327 def_bool y if X86_64
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100328
Akinobu Mita6a11f752009-03-31 15:23:17 -0700329config ARCH_SUPPORTS_DEBUG_PAGEALLOC
330 def_bool y
331
Andrey Ryabinind6f2d752015-07-02 12:09:38 +0300332config KASAN_SHADOW_OFFSET
333 hex
334 depends on KASAN
335 default 0xdffffc0000000000
336
Shane Wang69575d32009-09-01 18:25:07 -0700337config HAVE_INTEL_TXT
338 def_bool y
Kees Cook6ea30382012-10-02 11:16:47 -0700339 depends on INTEL_IOMMU && ACPI
Shane Wang69575d32009-09-01 18:25:07 -0700340
Sam Ravnborg6b0c3d42008-01-30 13:32:27 +0100341config X86_32_SMP
342 def_bool y
343 depends on X86_32 && SMP
344
345config X86_64_SMP
346 def_bool y
347 depends on X86_64 && SMP
348
Tejun Heoccbeed32009-02-09 22:17:40 +0900349config X86_32_LAZY_GS
350 def_bool y
Masahiro Yamada8458f8c2018-06-14 19:36:43 +0900351 depends on X86_32 && !STACKPROTECTOR
Tejun Heoccbeed32009-02-09 22:17:40 +0900352
Srikar Dronamraju2b144492012-02-09 14:56:42 +0530353config ARCH_SUPPORTS_UPROBES
354 def_bool y
355
Rob Herringd20642f2014-04-18 17:19:54 -0500356config FIX_EARLYCON_MEM
357 def_bool y
358
Kirill A. Shutemov94d49eb2018-05-18 14:30:28 +0300359config DYNAMIC_PHYSICAL_MASK
360 bool
361
Kirill A. Shutemov98233362015-04-14 15:46:14 -0700362config PGTABLE_LEVELS
363 int
Kirill A. Shutemov77ef56e2017-07-17 01:59:54 +0300364 default 5 if X86_5LEVEL
Kirill A. Shutemov98233362015-04-14 15:46:14 -0700365 default 4 if X86_64
366 default 3 if X86_PAE
367 default 2
368
Masahiro Yamada2a61f472018-05-28 18:22:00 +0900369config CC_HAS_SANE_STACKPROTECTOR
370 bool
371 default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT
372 default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC))
373 help
374 We have to make sure stack protector is unconditionally disabled if
375 the compiler produces broken code.
376
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100377menu "Processor type and features"
378
Randy Dunlap5ee71532012-01-16 11:57:18 -0800379config ZONE_DMA
380 bool "DMA memory allocation support" if EXPERT
381 default y
382 help
383 DMA memory allocation support allows devices with less than 32-bit
384 addressing to allocate within the first 16MB of address space.
385 Disable if no such devices will be used.
386
387 If unsure, say Y.
388
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100389config SMP
390 bool "Symmetric multi-processing support"
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900391 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100392 This enables support for systems with more than one CPU. If you have
Robert Graffham4a474152014-01-23 15:55:29 -0800393 a system with only one CPU, say N. If you have a system with more
394 than one CPU, say Y.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100395
Robert Graffham4a474152014-01-23 15:55:29 -0800396 If you say N here, the kernel will run on uni- and multiprocessor
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100397 machines, but will use only one CPU of a multiprocessor machine. If
398 you say Y here, the kernel will run on many, but not all,
Robert Graffham4a474152014-01-23 15:55:29 -0800399 uniprocessor machines. On a uniprocessor machine, the kernel
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100400 will run faster if you say N here.
401
402 Note that if you say Y here and choose architecture "586" or
403 "Pentium" under "Processor family", the kernel will not work on 486
404 architectures. Similarly, multiprocessor kernels for the "PPro"
405 architecture may not work on all Pentium based boards.
406
407 People using multiprocessor machines who say Y here should also say
408 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
409 Management" code will be disabled if you say Y here.
410
Mauro Carvalho Chehabcb1aaeb2019-06-07 15:54:32 -0300411 See also <file:Documentation/x86/i386/IO-APIC.rst>,
Mauro Carvalho Chehab4f4cfa62019-06-27 14:56:51 -0300412 <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100413 <http://www.tldp.org/docs.html#howto>.
414
415 If you don't know what to do here, say N.
416
Josh Triplett9def39be2013-10-30 08:09:45 -0700417config X86_FEATURE_NAMES
418 bool "Processor feature human-readable names" if EMBEDDED
419 default y
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900420 help
Josh Triplett9def39be2013-10-30 08:09:45 -0700421 This option compiles in a table of x86 feature bits and corresponding
422 names. This is required to support /proc/cpuinfo and a few kernel
423 messages. You can disable this to save space, at the expense of
424 making those few kernel messages show numeric feature bits instead.
425
426 If in doubt, say Y.
427
Yinghai Lu06cd9a72009-02-16 17:29:58 -0800428config X86_X2APIC
429 bool "Support x2apic"
Jan Kiszka19e3d602015-05-04 17:58:01 +0200430 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900431 help
Yinghai Lu06cd9a72009-02-16 17:29:58 -0800432 This enables x2apic support on CPUs that have this feature.
433
434 This allows 32-bit apic IDs (so it can support very large systems),
435 and accesses the local apic via MSRs not via mmio.
436
Yinghai Lu06cd9a72009-02-16 17:29:58 -0800437 If you don't know what to do here, say N.
438
Yinghai Lu6695c852008-06-19 12:13:09 -0700439config X86_MPPARSE
Bin Gao6e87f9b72012-10-25 09:35:44 -0700440 bool "Enable MPS table" if ACPI || SFI
Jan Beulich7a527682008-10-30 10:38:24 +0000441 default y
Ingo Molnar5ab74722008-07-10 14:42:03 +0200442 depends on X86_LOCAL_APIC
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900443 help
Yinghai Lu6695c852008-06-19 12:13:09 -0700444 For old smp systems that do not have proper acpi support. Newer systems
445 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
Yinghai Lu6695c852008-06-19 12:13:09 -0700446
Jun Nakajimaddd70cf2013-01-21 17:23:09 +0000447config GOLDFISH
Krzysztof Kozlowskib03b0162019-11-21 04:21:09 +0100448 def_bool y
449 depends on X86_GOLDFISH
Jun Nakajimaddd70cf2013-01-21 17:23:09 +0000450
David Woodhouse76b04382018-01-11 21:46:25 +0000451config RETPOLINE
452 bool "Avoid speculative indirect branches in kernel"
453 default y
Peter Zijlstrad5028ba2018-02-06 09:46:13 +0100454 select STACK_VALIDATION if HAVE_STACK_VALIDATION
David Woodhouse76b04382018-01-11 21:46:25 +0000455 help
456 Compile kernel with the retpoline compiler options to guard against
457 kernel-to-user data leaks by avoiding speculative indirect
458 branches. Requires a compiler with -mindirect-branch=thunk-extern
459 support for full protection. The kernel may run slower.
460
Johannes Weinere6d42932019-01-29 17:44:36 -0500461config X86_CPU_RESCTRL
462 bool "x86 CPU resource control support"
Babu Moger6fe07ce2018-11-21 20:28:39 +0000463 depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
Thomas Gleixner59fe5a72016-11-15 15:17:12 +0100464 select KERNFS
Chen Yue79f15a2020-01-15 17:28:51 +0800465 select PROC_CPU_RESCTRL if PROC_FS
Fenghua Yu78e99b42016-10-22 06:19:53 -0700466 help
Johannes Weinere6d42932019-01-29 17:44:36 -0500467 Enable x86 CPU resource control support.
Babu Moger6fe07ce2018-11-21 20:28:39 +0000468
469 Provide support for the allocation and monitoring of system resources
470 usage by the CPU.
471
472 Intel calls this Intel Resource Director Technology
473 (Intel(R) RDT). More information about RDT can be found in the
474 Intel x86 Architecture Software Developer Manual.
475
476 AMD calls this AMD Platform Quality of Service (AMD QoS).
477 More information about AMD QoS can be found in the AMD64 Technology
478 Platform Quality of Service Extensions manual.
Fenghua Yu78e99b42016-10-22 06:19:53 -0700479
480 Say N if unsure.
481
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800482if X86_32
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800483config X86_BIGSMP
484 bool "Support for big SMP systems with more than 8 CPUs"
485 depends on SMP
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900486 help
Randy Dunlape133f6e2019-12-03 16:06:47 -0800487 This option is needed for the systems that have more than 8 CPUs.
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800488
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800489config X86_EXTENDED_PLATFORM
490 bool "Support for extended (non-PC) x86 platforms"
491 default y
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900492 help
Ingo Molnar06ac8342009-01-27 18:11:43 +0100493 If you disable this option then the kernel will only support
494 standard PC platforms. (which covers the vast majority of
495 systems out there.)
496
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800497 If you enable this option then you'll be able to select support
498 for the following (non-PC) 32 bit x86 platforms:
Ben Hutchingscb7b8022013-06-24 01:05:25 +0100499 Goldfish (Android emulator)
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800500 AMD Elan
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800501 RDC R-321x SoC
502 SGI 320/540 (Visual Workstation)
Alessandro Rubini83125a32012-04-04 19:40:21 +0200503 STA2X11-based (e.g. Northville)
Thomas Gleixner3f4110a2009-08-29 14:54:20 +0200504 Moorestown MID devices
Ingo Molnar06ac8342009-01-27 18:11:43 +0100505
506 If you have one of these systems, or if you want to build a
507 generic distribution kernel, say Y here - otherwise say N.
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800508endif
Ingo Molnar06ac8342009-01-27 18:11:43 +0100509
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800510if X86_64
511config X86_EXTENDED_PLATFORM
512 bool "Support for extended (non-PC) x86 platforms"
513 default y
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900514 help
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800515 If you disable this option then the kernel will only support
516 standard PC platforms. (which covers the vast majority of
517 systems out there.)
518
519 If you enable this option then you'll be able to select support
520 for the following (non-PC) 64 bit x86 platforms:
Steffen Persvold44b111b52011-12-06 00:07:26 +0800521 Numascale NumaChip
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800522 ScaleMP vSMP
523 SGI Ultraviolet
524
525 If you have one of these systems, or if you want to build a
526 generic distribution kernel, say Y here - otherwise say N.
527endif
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800528# This is an alphabetically sorted list of 64 bit extended platforms
529# Please maintain the alphabetic order if and when there are additions
Steffen Persvold44b111b52011-12-06 00:07:26 +0800530config X86_NUMACHIP
531 bool "Numascale NumaChip"
532 depends on X86_64
533 depends on X86_EXTENDED_PLATFORM
534 depends on NUMA
535 depends on SMP
536 depends on X86_X2APIC
Daniel J Bluemanf9726bf2012-12-07 14:24:32 -0700537 depends on PCI_MMCONFIG
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900538 help
Steffen Persvold44b111b52011-12-06 00:07:26 +0800539 Adds support for Numascale NumaChip large-SMP systems. Needed to
540 enable more than ~168 cores.
541 If you don't have one of these, you should say N here.
Nick Piggin03b48632009-01-20 04:36:04 +0100542
Ingo Molnar6a485652009-01-27 18:29:13 +0100543config X86_VSMP
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800544 bool "ScaleMP vSMP"
Borislav Petkov6276a072013-03-04 21:20:21 +0100545 select HYPERVISOR_GUEST
Ingo Molnar6a485652009-01-27 18:29:13 +0100546 select PARAVIRT
547 depends on X86_64 && PCI
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800548 depends on X86_EXTENDED_PLATFORM
Shai Fultheimead91d42012-04-16 10:39:35 +0300549 depends on SMP
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900550 help
Ingo Molnar6a485652009-01-27 18:29:13 +0100551 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
552 supposed to run on these EM64T-based machines. Only choose this option
553 if you have one of these machines.
554
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800555config X86_UV
556 bool "SGI Ultraviolet"
557 depends on X86_64
558 depends on X86_EXTENDED_PLATFORM
Jack Steiner54c28d22009-04-03 15:39:42 -0500559 depends on NUMA
Andrew Morton1ecb4ae2016-02-11 16:13:20 -0800560 depends on EFI
Suresh Siddha9d6c26e2009-04-20 13:02:31 -0700561 depends on X86_X2APIC
Ingo Molnar1222e562015-05-06 06:23:59 +0200562 depends on PCI
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900563 help
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800564 This option is needed in order to support SGI Ultraviolet systems.
565 If you don't have one of these, you should say N here.
566
567# Following is an alphabetically sorted list of 32 bit extended platforms
568# Please maintain the alphabetic order if and when there are additions
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100569
Jun Nakajimaddd70cf2013-01-21 17:23:09 +0000570config X86_GOLDFISH
Krzysztof Kozlowskib03b0162019-11-21 04:21:09 +0100571 bool "Goldfish (Virtual Platform)"
572 depends on X86_EXTENDED_PLATFORM
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900573 help
Jun Nakajimaddd70cf2013-01-21 17:23:09 +0000574 Enable support for the Goldfish virtual platform used primarily
575 for Android development. Unless you are building for the Android
576 Goldfish emulator say N here.
577
Thomas Gleixnerc751e172010-11-09 12:08:04 -0800578config X86_INTEL_CE
579 bool "CE4100 TV platform"
580 depends on PCI
581 depends on PCI_GODIRECT
Jiang Liu6084a6e2014-06-09 16:19:46 +0800582 depends on X86_IO_APIC
Thomas Gleixnerc751e172010-11-09 12:08:04 -0800583 depends on X86_32
584 depends on X86_EXTENDED_PLATFORM
Dirk Brandewie37bc9f52010-11-09 12:08:08 -0800585 select X86_REBOOTFIXUPS
Sebastian Andrzej Siewiorda6b7372011-02-22 21:07:37 +0100586 select OF
587 select OF_EARLY_FLATTREE
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900588 help
Thomas Gleixnerc751e172010-11-09 12:08:04 -0800589 Select for the Intel CE media processor (CE4100) SOC.
590 This option compiles in support for the CE4100 SOC for settop
591 boxes and media devices.
592
David Cohen4cb9b002013-12-16 17:37:26 -0800593config X86_INTEL_MID
Alan Cox43605ef2011-07-12 17:49:29 +0100594 bool "Intel MID platform support"
Alan Cox43605ef2011-07-12 17:49:29 +0100595 depends on X86_EXTENDED_PLATFORM
David Cohenedc6bc72014-01-21 10:41:39 -0800596 depends on X86_PLATFORM_DEVICES
Alan Cox1ea7c672011-11-10 13:29:14 +0000597 depends on PCI
Andy Shevchenko3fda5bb2016-01-15 22:11:07 +0200598 depends on X86_64 || (PCI_GOANY && X86_32)
Alan Cox1ea7c672011-11-10 13:29:14 +0000599 depends on X86_IO_APIC
Alan Cox7c9c3a12011-12-29 14:43:16 +0000600 select SFI
David Cohen4cb9b002013-12-16 17:37:26 -0800601 select I2C
Alan Cox7c9c3a12011-12-29 14:43:16 +0000602 select DW_APB_TIMER
Alan Cox1ea7c672011-11-10 13:29:14 +0000603 select APB_TIMER
Mika Westerberg54b34aa2020-04-16 11:15:33 +0300604 select INTEL_SCU_PCI
Mika Westerberg15a713d2012-01-26 17:35:05 +0000605 select MFD_INTEL_MSIC
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900606 help
David Cohen4cb9b002013-12-16 17:37:26 -0800607 Select to build a kernel capable of supporting Intel MID (Mobile
608 Internet Device) platform systems which do not have the PCI legacy
609 interfaces. If you are building for a PC class system say N here.
Alan Cox1ea7c672011-11-10 13:29:14 +0000610
David Cohen4cb9b002013-12-16 17:37:26 -0800611 Intel MID platforms are based on an Intel processor and chipset which
612 consume less power than most of the x86 derivatives.
Alan Cox43605ef2011-07-12 17:49:29 +0100613
Bryan O'Donoghue8bbc2a12015-01-30 16:29:39 +0000614config X86_INTEL_QUARK
615 bool "Intel Quark platform support"
616 depends on X86_32
617 depends on X86_EXTENDED_PLATFORM
618 depends on X86_PLATFORM_DEVICES
619 depends on X86_TSC
620 depends on PCI
621 depends on PCI_GOANY
622 depends on X86_IO_APIC
623 select IOSF_MBI
624 select INTEL_IMR
Andy Shevchenko9ab6eb52015-03-05 17:24:04 +0200625 select COMMON_CLK
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900626 help
Bryan O'Donoghue8bbc2a12015-01-30 16:29:39 +0000627 Select to include support for Quark X1000 SoC.
628 Say Y here if you have a Quark based system such as the Arduino
629 compatible Intel Galileo.
630
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000631config X86_INTEL_LPSS
632 bool "Intel Low Power Subsystem Support"
Sinan Kaya5962dd22019-01-02 18:10:37 +0000633 depends on X86 && ACPI && PCI
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000634 select COMMON_CLK
Mathias Nyman0f531432013-09-13 17:02:29 +0300635 select PINCTRL
Andy Shevchenkoeebb3e82015-12-12 02:45:06 +0100636 select IOSF_MBI
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900637 help
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000638 Select to build support for Intel Low Power Subsystem such as
639 found on Intel Lynxpoint PCH. Selecting this option enables
Mathias Nyman0f531432013-09-13 17:02:29 +0300640 things like clock tree (common clock framework) and pincontrol
641 which are needed by the LPSS peripheral drivers.
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000642
Ken Xue92082a82015-02-06 08:27:51 +0800643config X86_AMD_PLATFORM_DEVICE
644 bool "AMD ACPI2Platform devices support"
645 depends on ACPI
646 select COMMON_CLK
647 select PINCTRL
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900648 help
Ken Xue92082a82015-02-06 08:27:51 +0800649 Select to interpret AMD specific ACPI device to platform device
650 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
651 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
652 implemented under PINCTRL subsystem.
653
David E. Boxced3ce72014-09-17 22:13:50 -0700654config IOSF_MBI
655 tristate "Intel SoC IOSF Sideband support for SoC platforms"
656 depends on PCI
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900657 help
David E. Boxced3ce72014-09-17 22:13:50 -0700658 This option enables sideband register access support for Intel SoC
659 platforms. On these platforms the IOSF sideband is used in lieu of
660 MSR's for some register accesses, mostly but not limited to thermal
661 and power. Drivers may query the availability of this device to
662 determine if they need the sideband in order to work on these
663 platforms. The sideband is available on the following SoC products.
664 This list is not meant to be exclusive.
665 - BayTrail
666 - Braswell
667 - Quark
668
669 You should say Y if you are running a kernel on one of these SoC's.
670
David E. Boxed2226b2014-09-17 22:13:51 -0700671config IOSF_MBI_DEBUG
672 bool "Enable IOSF sideband access through debugfs"
673 depends on IOSF_MBI && DEBUG_FS
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900674 help
David E. Boxed2226b2014-09-17 22:13:51 -0700675 Select this option to expose the IOSF sideband access registers (MCR,
676 MDR, MCRX) through debugfs to write and read register information from
677 different units on the SoC. This is most useful for obtaining device
678 state information for debug and analysis. As this is a general access
679 mechanism, users of this option would have specific knowledge of the
680 device they want to access.
681
682 If you don't require the option or are in doubt, say N.
683
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800684config X86_RDC321X
685 bool "RDC R-321x SoC"
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100686 depends on X86_32
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800687 depends on X86_EXTENDED_PLATFORM
688 select M486
689 select X86_REBOOTFIXUPS
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900690 help
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800691 This option is needed for RDC R-321x system-on-chip, also known
692 as R-8610-(G).
693 If you don't have one of these chips, you should say N here.
694
Ingo Molnare0c7ae32009-01-27 18:43:09 +0100695config X86_32_NON_STANDARD
Ingo Molnar9c398012009-01-27 18:24:57 +0100696 bool "Support non-standard 32-bit SMP architectures"
697 depends on X86_32 && SMP
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800698 depends on X86_EXTENDED_PLATFORM
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900699 help
H. Peter Anvinb5660ba2014-02-25 12:14:06 -0800700 This option compiles in the bigsmp and STA2X11 default
701 subarchitectures. It is intended for a generic binary
702 kernel. If you select them all, kernel will probe it one by
703 one and will fallback to default.
Yinghai Lud49c4282008-06-08 18:31:54 -0700704
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800705# Alphabetically sorted list of Non standard 32 bit platforms
Yinghai Lud49c4282008-06-08 18:31:54 -0700706
Linus Torvaldsd949f362009-09-26 09:35:07 -0700707config X86_SUPPORTS_MEMORY_FAILURE
Jan Beulich6fc108a2010-04-21 15:23:44 +0100708 def_bool y
Linus Torvaldsd949f362009-09-26 09:35:07 -0700709 # MCE code calls memory_failure():
710 depends on X86_MCE
711 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
Linus Torvaldsd949f362009-09-26 09:35:07 -0700712 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
713 depends on X86_64 || !SPARSEMEM
714 select ARCH_SUPPORTS_MEMORY_FAILURE
Linus Torvaldsd949f362009-09-26 09:35:07 -0700715
Alessandro Rubini83125a32012-04-04 19:40:21 +0200716config STA2X11
717 bool "STA2X11 Companion Chip Support"
718 depends on X86_32_NON_STANDARD && PCI
Alessandro Rubini83125a32012-04-04 19:40:21 +0200719 select SWIOTLB
720 select MFD_STA2X11
Linus Walleij01450712016-06-02 14:20:18 +0200721 select GPIOLIB
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900722 help
Alessandro Rubini83125a32012-04-04 19:40:21 +0200723 This adds support for boards based on the STA2X11 IO-Hub,
724 a.k.a. "ConneXt". The chip is used in place of the standard
725 PC chipset, so all "standard" peripherals are missing. If this
726 option is selected the kernel will still be able to boot on
727 standard PC machines.
728
Shérab82148d12010-09-25 06:06:57 +0200729config X86_32_IRIS
730 tristate "Eurobraille/Iris poweroff module"
731 depends on X86_32
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900732 help
Shérab82148d12010-09-25 06:06:57 +0200733 The Iris machines from EuroBraille do not have APM or ACPI support
734 to shut themselves down properly. A special I/O sequence is
735 needed to do so, which is what this module does at
736 kernel shutdown.
737
738 This is only for Iris machines from EuroBraille.
739
740 If unused, say N.
741
Ingo Molnarae1e9132008-11-11 09:05:16 +0100742config SCHED_OMIT_FRAME_POINTER
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100743 def_bool y
744 prompt "Single-depth WCHAN output"
Ken Chena87d0912008-11-06 11:10:49 -0800745 depends on X86
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900746 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100747 Calculate simpler /proc/<PID>/wchan values. If this option
748 is disabled then wchan values will recurse back to the
749 caller function. This provides more accurate wchan values,
750 at the expense of slightly more scheduling overhead.
751
752 If in doubt, say "Y".
753
Borislav Petkov6276a072013-03-04 21:20:21 +0100754menuconfig HYPERVISOR_GUEST
755 bool "Linux guest support"
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900756 help
Borislav Petkov6276a072013-03-04 21:20:21 +0100757 Say Y here to enable options for running Linux under various hyper-
758 visors. This option enables basic hypervisor detection and platform
759 setup.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100760
Borislav Petkov6276a072013-03-04 21:20:21 +0100761 If you say N, all options in this submenu will be skipped and
762 disabled, and Linux guest support won't be built in.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100763
Borislav Petkov6276a072013-03-04 21:20:21 +0100764if HYPERVISOR_GUEST
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100765
Eduardo Pereira Habkoste61bd942008-01-30 13:33:32 +0100766config PARAVIRT
767 bool "Enable paravirtualization code"
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900768 help
Eduardo Pereira Habkoste61bd942008-01-30 13:33:32 +0100769 This changes the kernel so it can modify itself when it is run
770 under a hypervisor, potentially improving performance significantly
771 over full virtualization. However, when run without a hypervisor
772 the kernel is theoretically slower and slightly larger.
773
Juergen Grossc00a2802018-08-28 09:40:21 +0200774config PARAVIRT_XXL
775 bool
776
Borislav Petkov6276a072013-03-04 21:20:21 +0100777config PARAVIRT_DEBUG
778 bool "paravirt-ops debugging"
779 depends on PARAVIRT && DEBUG_KERNEL
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900780 help
Borislav Petkov6276a072013-03-04 21:20:21 +0100781 Enable to debug paravirt_ops internals. Specifically, BUG if
782 a paravirt_op is missing when it is called.
783
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700784config PARAVIRT_SPINLOCKS
785 bool "Paravirtualization layer for spinlocks"
Kees Cook6ea30382012-10-02 11:16:47 -0700786 depends on PARAVIRT && SMP
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900787 help
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700788 Paravirtualized spinlocks allow a pvops backend to replace the
789 spinlock implementation with something virtualization-friendly
790 (for example, block the virtual CPU rather than spinning).
791
Raghavendra K T4c4e4f62013-10-21 21:35:08 +0530792 It has a minimal impact on native kernels and gives a nice performance
793 benefit on paravirtualized KVM / Xen kernels.
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700794
Raghavendra K T4c4e4f62013-10-21 21:35:08 +0530795 If you are unsure how to answer this question, answer Y.
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700796
Zhao Yakuiecca25022019-04-30 11:45:23 +0800797config X86_HV_CALLBACK_VECTOR
798 def_bool n
799
Borislav Petkov6276a072013-03-04 21:20:21 +0100800source "arch/x86/xen/Kconfig"
801
802config KVM_GUEST
803 bool "KVM Guest support (including kvmclock)"
804 depends on PARAVIRT
805 select PARAVIRT_CLOCK
Marcelo Tosattia1c44232019-07-03 20:51:29 -0300806 select ARCH_CPUIDLE_HALTPOLL
Vitaly Kuznetsovb1d40572020-05-25 16:41:23 +0200807 select X86_HV_CALLBACK_VECTOR
Borislav Petkov6276a072013-03-04 21:20:21 +0100808 default y
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900809 help
Borislav Petkov6276a072013-03-04 21:20:21 +0100810 This option enables various optimizations for running under the KVM
811 hypervisor. It includes a paravirtualized clock, so that instead
812 of relying on a PIT (or probably other) emulation by the
813 underlying device model, the host provides the guest with
814 timing infrastructure such as time of day, and system time
815
Marcelo Tosattia1c44232019-07-03 20:51:29 -0300816config ARCH_CPUIDLE_HALTPOLL
Krzysztof Kozlowskib03b0162019-11-21 04:21:09 +0100817 def_bool n
818 prompt "Disable host haltpoll when loading haltpoll driver"
819 help
Marcelo Tosattia1c44232019-07-03 20:51:29 -0300820 If virtualized under KVM, disable host haltpoll.
821
Maran Wilson77336072018-12-10 11:07:28 -0800822config PVH
823 bool "Support for running PVH guests"
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900824 help
Maran Wilson77336072018-12-10 11:07:28 -0800825 This option enables the PVH entry point for guest virtual machines
826 as specified in the x86/HVM direct boot ABI.
827
Borislav Petkov6276a072013-03-04 21:20:21 +0100828config PARAVIRT_TIME_ACCOUNTING
829 bool "Paravirtual steal time accounting"
830 depends on PARAVIRT
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900831 help
Borislav Petkov6276a072013-03-04 21:20:21 +0100832 Select this option to enable fine granularity task steal time
833 accounting. Time spent executing other tasks in parallel with
834 the current vCPU is discounted from the vCPU power. To account for
835 that, there can be a small performance impact.
836
837 If in doubt, say N here.
838
Gerd Hoffmann7af192c2008-06-03 16:17:29 +0200839config PARAVIRT_CLOCK
840 bool
Gerd Hoffmann7af192c2008-06-03 16:17:29 +0200841
Jan Kiszka4a362602017-11-27 09:11:46 +0100842config JAILHOUSE_GUEST
843 bool "Jailhouse non-root cell support"
Arnd Bergmannabde5872018-01-15 16:51:20 +0100844 depends on X86_64 && PCI
Jan Kiszka87e65d02017-11-27 09:11:48 +0100845 select X86_PM_TIMER
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900846 help
Jan Kiszka4a362602017-11-27 09:11:46 +0100847 This option allows to run Linux as guest in a Jailhouse non-root
848 cell. You can leave this option disabled if you only want to start
849 Jailhouse and run Linux afterwards in the root cell.
850
Zhao Yakuiec7972c2019-04-30 11:45:24 +0800851config ACRN_GUEST
852 bool "ACRN Guest support"
853 depends on X86_64
Zhao Yakui498ad392019-04-30 11:45:25 +0800854 select X86_HV_CALLBACK_VECTOR
Zhao Yakuiec7972c2019-04-30 11:45:24 +0800855 help
856 This option allows to run Linux as guest in the ACRN hypervisor. ACRN is
857 a flexible, lightweight reference open-source hypervisor, built with
858 real-time and safety-criticality in mind. It is built for embedded
859 IOT with small footprint and real-time features. More details can be
860 found in https://projectacrn.org/.
861
Borislav Petkov6276a072013-03-04 21:20:21 +0100862endif #HYPERVISOR_GUEST
Jeremy Fitzhardinge97349132008-06-25 00:19:14 -0400863
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100864source "arch/x86/Kconfig.cpu"
865
866config HPET_TIMER
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100867 def_bool X86_64
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100868 prompt "HPET Timer Support" if X86_32
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900869 help
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100870 Use the IA-PC HPET (High Precision Event Timer) to manage
871 time in preference to the PIT and RTC, if a HPET is
872 present.
873 HPET is the next generation timer replacing legacy 8254s.
874 The HPET provides a stable time base on SMP
875 systems, unlike the TSC, but it is more expensive to access,
Michael S. Tsirkin4e7f9df2016-02-11 01:05:01 +0200876 as it is off-chip. The interface used is documented
877 in the HPET spec, revision 1.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100878
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100879 You can safely choose Y here. However, HPET will only be
880 activated if the platform and the BIOS support this feature.
881 Otherwise the 8254 will be used for timing services.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100882
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100883 Choose N to continue using the legacy 8254 timer.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100884
885config HPET_EMULATE_RTC
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100886 def_bool y
Bernhard Walle9d8af782008-02-06 01:38:52 -0800887 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100888
Jacob Panbb24c472009-09-02 07:37:17 -0700889config APB_TIMER
Krzysztof Kozlowskib03b0162019-11-21 04:21:09 +0100890 def_bool y if X86_INTEL_MID
891 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
892 select DW_APB_TIMER
893 depends on X86_INTEL_MID && SFI
894 help
895 APB timer is the replacement for 8254, HPET on X86 MID platforms.
896 The APBT provides a stable time base on SMP
897 systems, unlike the TSC, but it is more expensive to access,
898 as it is off-chip. APB timers are always running regardless of CPU
899 C states, they are used as per CPU clockevent device when possible.
Jacob Panbb24c472009-09-02 07:37:17 -0700900
David Rientjes6a108a12011-01-20 14:44:16 -0800901# Mark as expert because too many people got it wrong.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100902# The code disables itself when not needed.
Thomas Petazzoni7ae93922008-04-28 02:14:14 -0700903config DMI
904 default y
Ard Biesheuvelcf074402014-01-23 15:54:39 -0800905 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
David Rientjes6a108a12011-01-20 14:44:16 -0800906 bool "Enable DMI scanning" if EXPERT
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900907 help
Thomas Petazzoni7ae93922008-04-28 02:14:14 -0700908 Enabled scanning of DMI to identify machine quirks. Say Y
909 here unless you have verified that your setup is not
910 affected by entries in the DMI blacklist. Required by PNP
911 BIOS code.
912
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100913config GART_IOMMU
Andi Kleen38901f12013-10-04 14:37:56 -0700914 bool "Old AMD GART IOMMU support"
Christoph Hellwig2f9237d2020-07-08 09:30:00 +0200915 select DMA_OPS
Christoph Hellwiga4ce5a42018-04-03 15:47:59 +0200916 select IOMMU_HELPER
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100917 select SWIOTLB
Andreas Herrmann23ac4ae2010-09-17 18:03:43 +0200918 depends on X86_64 && PCI && AMD_NB
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900919 help
Ingo Molnarced3c422013-10-06 11:45:20 +0200920 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
921 GART based hardware IOMMUs.
922
923 The GART supports full DMA access for devices with 32-bit access
924 limitations, on systems with more than 3 GB. This is usually needed
925 for USB, sound, many IDE/SATA chipsets and some other devices.
926
927 Newer systems typically have a modern AMD IOMMU, supported via
928 the CONFIG_AMD_IOMMU=y config option.
929
930 In normal configurations this driver is only active when needed:
931 there's more than 3 GB of memory and the system contains a
932 32-bit limited device.
933
934 If unsure, say Y.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100935
Mike Travis1184dc22008-05-12 21:21:12 +0200936config MAXSMP
Samuel Thibaultddb0c5a2010-08-21 21:32:41 +0200937 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
Kees Cook6ea30382012-10-02 11:16:47 -0700938 depends on X86_64 && SMP && DEBUG_KERNEL
Mike Travis36f51012008-12-16 17:33:51 -0800939 select CPUMASK_OFFSTACK
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900940 help
Samuel Thibaultddb0c5a2010-08-21 21:32:41 +0200941 Enable maximum number of CPUS and NUMA Nodes for this architecture.
Mike Travis1184dc22008-05-12 21:21:12 +0200942 If unsure, say N.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100943
Ingo Molnaraec64872018-02-10 12:36:29 +0100944#
945# The maximum number of CPUs supported:
946#
947# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
948# and which can be configured interactively in the
949# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
950#
951# The ranges are different on 32-bit and 64-bit kernels, depending on
952# hardware capabilities and scalability features of the kernel.
953#
954# ( If MAXSMP is enabled we just use the highest possible value and disable
955# interactive configuration. )
956#
957
958config NR_CPUS_RANGE_BEGIN
959 int
960 default NR_CPUS_RANGE_END if MAXSMP
961 default 1 if !SMP
962 default 2
963
964config NR_CPUS_RANGE_END
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800965 int
966 depends on X86_32
Ingo Molnaraec64872018-02-10 12:36:29 +0100967 default 64 if SMP && X86_BIGSMP
968 default 8 if SMP && !X86_BIGSMP
969 default 1 if !SMP
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800970
Ingo Molnaraec64872018-02-10 12:36:29 +0100971config NR_CPUS_RANGE_END
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800972 int
973 depends on X86_64
Scott Wood1edae1a2019-10-12 02:00:54 -0500974 default 8192 if SMP && CPUMASK_OFFSTACK
975 default 512 if SMP && !CPUMASK_OFFSTACK
Ingo Molnaraec64872018-02-10 12:36:29 +0100976 default 1 if !SMP
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800977
Ingo Molnaraec64872018-02-10 12:36:29 +0100978config NR_CPUS_DEFAULT
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800979 int
980 depends on X86_32
Ingo Molnaraec64872018-02-10 12:36:29 +0100981 default 32 if X86_BIGSMP
982 default 8 if SMP
983 default 1 if !SMP
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800984
Ingo Molnaraec64872018-02-10 12:36:29 +0100985config NR_CPUS_DEFAULT
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800986 int
987 depends on X86_64
Ingo Molnaraec64872018-02-10 12:36:29 +0100988 default 8192 if MAXSMP
989 default 64 if SMP
990 default 1 if !SMP
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800991
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100992config NR_CPUS
Mike Travis36f51012008-12-16 17:33:51 -0800993 int "Maximum number of CPUs" if SMP && !MAXSMP
Ingo Molnaraec64872018-02-10 12:36:29 +0100994 range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
995 default NR_CPUS_DEFAULT
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900996 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100997 This allows you to specify the maximum number of CPUs which this
Josh Boyerbb61ccc2013-11-05 09:37:29 -0500998 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
Kirill A. Shutemovcad14bb2015-05-08 13:25:26 +0300999 supported value is 8192, otherwise the maximum value is 512. The
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001000 minimum value which makes sense is 2.
1001
Ingo Molnaraec64872018-02-10 12:36:29 +01001002 This is purely to save memory: each supported CPU adds about 8KB
1003 to the kernel image.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001004
1005config SCHED_SMT
Thomas Gleixnerdbe73362018-11-25 19:33:37 +01001006 def_bool y if SMP
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001007
1008config SCHED_MC
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001009 def_bool y
1010 prompt "Multi-core scheduler support"
Borislav Petkovc8e56d22015-06-04 18:55:25 +02001011 depends on SMP
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001012 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001013 Multi-core scheduler support improves the CPU scheduler's decision
1014 making when dealing with multi-core CPU chips at a cost of slightly
1015 increased overhead in some places. If unsure say N here.
1016
Tim Chende966cf2016-11-29 10:43:27 -08001017config SCHED_MC_PRIO
1018 bool "CPU core priorities scheduler support"
Ingo Molnar0a21fc12016-11-30 08:33:54 +01001019 depends on SCHED_MC && CPU_SUP_INTEL
1020 select X86_INTEL_PSTATE
1021 select CPU_FREQ
Tim Chende966cf2016-11-29 10:43:27 -08001022 default y
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001023 help
Ingo Molnar0a21fc12016-11-30 08:33:54 +01001024 Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1025 core ordering determined at manufacturing time, which allows
1026 certain cores to reach higher turbo frequencies (when running
1027 single threaded workloads) than others.
Tim Chende966cf2016-11-29 10:43:27 -08001028
Ingo Molnar0a21fc12016-11-30 08:33:54 +01001029 Enabling this kernel feature teaches the scheduler about
1030 the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1031 scheduler's CPU selection logic accordingly, so that higher
1032 overall system performance can be achieved.
Tim Chende966cf2016-11-29 10:43:27 -08001033
Ingo Molnar0a21fc12016-11-30 08:33:54 +01001034 This feature will have no effect on CPUs without this feature.
Tim Chende966cf2016-11-29 10:43:27 -08001035
Ingo Molnar0a21fc12016-11-30 08:33:54 +01001036 If unsure say Y here.
Tim Chen5e76b2a2016-11-22 12:23:55 -08001037
Thomas Gleixner30b8b002015-01-15 21:22:39 +00001038config UP_LATE_INIT
Krzysztof Kozlowskib03b0162019-11-21 04:21:09 +01001039 def_bool y
1040 depends on !SMP && X86_LOCAL_APIC
Thomas Gleixner30b8b002015-01-15 21:22:39 +00001041
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001042config X86_UP_APIC
Jan Beulich50849ee2015-02-05 15:31:56 +00001043 bool "Local APIC support on uniprocessors" if !PCI_MSI
1044 default PCI_MSI
Bryan O'Donoghue38a1dfd2015-01-22 22:58:49 +00001045 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001046 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001047 A local APIC (Advanced Programmable Interrupt Controller) is an
1048 integrated interrupt controller in the CPU. If you have a single-CPU
1049 system which has a processor with a local APIC, you can say Y here to
1050 enable and use it. If you say Y here even though your machine doesn't
1051 have a local APIC, then the kernel will still run with no slowdown at
1052 all. The local APIC supports CPU-generated self-interrupts (timer,
1053 performance counters), and the NMI watchdog which detects hard
1054 lockups.
1055
1056config X86_UP_IOAPIC
1057 bool "IO-APIC support on uniprocessors"
1058 depends on X86_UP_APIC
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001059 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001060 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1061 SMP-capable replacement for PC-style interrupt controllers. Most
1062 SMP systems and many recent uniprocessor systems have one.
1063
1064 If you have a single-CPU system with an IO-APIC, you can say Y here
1065 to use it. If you say Y here even though your machine doesn't have
1066 an IO-APIC, then the kernel will still run with no slowdown at all.
1067
1068config X86_LOCAL_APIC
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001069 def_bool y
Thomas Petazzoni0dbc6072013-10-03 11:59:14 +02001070 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
Jiang Liub5dc8e62015-04-13 14:11:24 +08001071 select IRQ_DOMAIN_HIERARCHY
Jiang Liu52f518a2015-04-13 14:11:35 +08001072 select PCI_MSI_IRQ_DOMAIN if PCI_MSI
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001073
1074config X86_IO_APIC
Jan Beulichb1da1e72015-02-05 15:35:21 +00001075 def_bool y
1076 depends on X86_LOCAL_APIC || X86_UP_IOAPIC
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001077
Stefan Assmann41b9eb22008-07-15 13:48:55 +02001078config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
1079 bool "Reroute for broken boot IRQs"
Stefan Assmann41b9eb22008-07-15 13:48:55 +02001080 depends on X86_IO_APIC
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001081 help
Stefan Assmann41b9eb22008-07-15 13:48:55 +02001082 This option enables a workaround that fixes a source of
1083 spurious interrupts. This is recommended when threaded
1084 interrupt handling is used on systems where the generation of
1085 superfluous "boot interrupts" cannot be disabled.
1086
1087 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
1088 entry in the chipset's IO-APIC is masked (as, e.g. the RT
1089 kernel does during interrupt handling). On chipsets where this
1090 boot IRQ generation cannot be disabled, this workaround keeps
1091 the original IRQ line masked so that only the equivalent "boot
1092 IRQ" is delivered to the CPUs. The workaround also tells the
1093 kernel to set up the IRQ handler on the boot IRQ line. In this
1094 way only one interrupt is delivered to the kernel. Otherwise
1095 the spurious second interrupt may cause the kernel to bring
1096 down (vital) interrupt lines.
1097
1098 Only affects "broken" chipsets. Interrupt sharing may be
1099 increased on these systems.
1100
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001101config X86_MCE
Andi Kleenbab9bc62009-07-09 00:31:38 +02001102 bool "Machine Check / overheating reporting"
Chen, Gong648ed942015-08-12 18:29:34 +02001103 select GENERIC_ALLOCATOR
Borislav Petkove57dbaf2011-09-13 15:23:21 +02001104 default y
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001105 help
Andi Kleenbab9bc62009-07-09 00:31:38 +02001106 Machine Check support allows the processor to notify the
1107 kernel if it detects a problem (e.g. overheating, data corruption).
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001108 The action the kernel takes depends on the severity of the problem,
Andi Kleenbab9bc62009-07-09 00:31:38 +02001109 ranging from warning messages to halting the machine.
Andi Kleen4efc0672009-04-28 19:07:31 +02001110
Tony Luck5de97c92017-03-27 11:33:03 +02001111config X86_MCELOG_LEGACY
1112 bool "Support for deprecated /dev/mcelog character device"
1113 depends on X86_MCE
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001114 help
Tony Luck5de97c92017-03-27 11:33:03 +02001115 Enable support for /dev/mcelog which is needed by the old mcelog
1116 userspace logging daemon. Consider switching to the new generation
1117 rasdaemon solution.
1118
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001119config X86_MCE_INTEL
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001120 def_bool y
1121 prompt "Intel MCE features"
Andi Kleenc1ebf832009-07-09 00:31:41 +02001122 depends on X86_MCE && X86_LOCAL_APIC
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001123 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001124 Additional support for intel specific MCE features such as
1125 the thermal monitor.
1126
1127config X86_MCE_AMD
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001128 def_bool y
1129 prompt "AMD MCE features"
Yazen Ghannamf5382de2016-11-17 17:57:27 -05001130 depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001131 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001132 Additional support for AMD specific MCE features such as
1133 the DRAM Error Threshold.
1134
Andi Kleen4efc0672009-04-28 19:07:31 +02001135config X86_ANCIENT_MCE
Jan Beulich6fc108a2010-04-21 15:23:44 +01001136 bool "Support for old Pentium 5 / WinChip machine checks"
Andi Kleenc31d9632009-07-09 00:31:37 +02001137 depends on X86_32 && X86_MCE
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001138 help
Hidetoshi Setocd13adcc2009-05-27 16:57:31 +09001139 Include support for machine check handling on old Pentium 5 or WinChip
Masanari Iida5065a702013-11-30 21:38:43 +09001140 systems. These typically need to be enabled explicitly on the command
Hidetoshi Setocd13adcc2009-05-27 16:57:31 +09001141 line.
Andi Kleen4efc0672009-04-28 19:07:31 +02001142
Andi Kleenb2762682009-02-12 13:49:31 +01001143config X86_MCE_THRESHOLD
1144 depends on X86_MCE_AMD || X86_MCE_INTEL
Jan Beulich6fc108a2010-04-21 15:23:44 +01001145 def_bool y
Andi Kleenb2762682009-02-12 13:49:31 +01001146
Andi Kleenea149b32009-04-29 19:31:00 +02001147config X86_MCE_INJECT
Borislav Petkovbc8e80d2017-06-13 18:28:30 +02001148 depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
Andi Kleenea149b32009-04-29 19:31:00 +02001149 tristate "Machine check injector support"
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001150 help
Andi Kleenea149b32009-04-29 19:31:00 +02001151 Provide support for injecting machine checks for testing purposes.
1152 If you don't know what a machine check is and you don't do kernel
1153 QA it is safe to say n.
1154
Andi Kleen4efc0672009-04-28 19:07:31 +02001155config X86_THERMAL_VECTOR
1156 def_bool y
Andi Kleen5bb38ad2009-07-09 00:31:39 +02001157 depends on X86_MCE_INTEL
Andi Kleen4efc0672009-04-28 19:07:31 +02001158
Peter Zijlstra07dc9002016-03-29 14:30:35 +02001159source "arch/x86/events/Kconfig"
Kan Liange633c652016-03-20 01:33:36 -07001160
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001161config X86_LEGACY_VM86
Ingo Molnar1e642812015-09-05 08:58:10 +02001162 bool "Legacy VM86 support"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001163 depends on X86_32
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001164 help
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001165 This option allows user programs to put the CPU into V8086
1166 mode, which is an 80286-era approximation of 16-bit real mode.
1167
1168 Some very old versions of X and/or vbetool require this option
1169 for user mode setting. Similarly, DOSEMU will use it if
1170 available to accelerate real mode DOS programs. However, any
1171 recent version of DOSEMU, X, or vbetool should be fully
1172 functional even without kernel VM86 support, as they will all
Ingo Molnar1e642812015-09-05 08:58:10 +02001173 fall back to software emulation. Nevertheless, if you are using
1174 a 16-bit DOS program where 16-bit performance matters, vm86
1175 mode might be faster than emulation and you might want to
1176 enable this option.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001177
Ingo Molnar1e642812015-09-05 08:58:10 +02001178 Note that any app that works on a 64-bit kernel is unlikely to
1179 need this option, as 64-bit kernels don't, and can't, support
1180 V8086 mode. This option is also unrelated to 16-bit protected
1181 mode and is not needed to run most 16-bit programs under Wine.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001182
Ingo Molnar1e642812015-09-05 08:58:10 +02001183 Enabling this option increases the complexity of the kernel
1184 and slows down exception handling a tiny bit.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001185
Ingo Molnar1e642812015-09-05 08:58:10 +02001186 If unsure, say N here.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001187
1188config VM86
Krzysztof Kozlowskib03b0162019-11-21 04:21:09 +01001189 bool
1190 default X86_LEGACY_VM86
H. Peter Anvin34273f42014-05-04 10:36:22 -07001191
1192config X86_16BIT
1193 bool "Enable support for 16-bit segments" if EXPERT
1194 default y
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07001195 depends on MODIFY_LDT_SYSCALL
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001196 help
H. Peter Anvin34273f42014-05-04 10:36:22 -07001197 This option is required by programs like Wine to run 16-bit
1198 protected mode legacy code on x86 processors. Disabling
1199 this option saves about 300 bytes on i386, or around 6K text
1200 plus 16K runtime memory on x86-64,
1201
1202config X86_ESPFIX32
1203 def_bool y
1204 depends on X86_16BIT && X86_32
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001205
H. Peter Anvin197725d2014-05-04 10:00:49 -07001206config X86_ESPFIX64
1207 def_bool y
H. Peter Anvin34273f42014-05-04 10:36:22 -07001208 depends on X86_16BIT && X86_64
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001209
Andy Lutomirski1ad83c82014-10-29 14:33:47 -07001210config X86_VSYSCALL_EMULATION
Krzysztof Kozlowskib03b0162019-11-21 04:21:09 +01001211 bool "Enable vsyscall emulation" if EXPERT
1212 default y
1213 depends on X86_64
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001214 help
Andy Lutomirski1ad83c82014-10-29 14:33:47 -07001215 This enables emulation of the legacy vsyscall page. Disabling
1216 it is roughly equivalent to booting with vsyscall=none, except
1217 that it will also disable the helpful warning if a program
1218 tries to use a vsyscall. With this option set to N, offending
1219 programs will just segfault, citing addresses of the form
1220 0xffffffffff600?00.
1221
1222 This option is required by many programs built before 2013, and
1223 care should be used even with newer programs if set to N.
1224
1225 Disabling this option saves about 7K of kernel size and
1226 possibly 4K of additional runtime pagetable memory.
1227
Thomas Gleixner111e7b12019-11-12 21:40:33 +01001228config X86_IOPL_IOPERM
1229 bool "IOPERM and IOPL Emulation"
Thomas Gleixnera24ca992019-11-11 23:03:29 +01001230 default y
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001231 help
Thomas Gleixner111e7b12019-11-12 21:40:33 +01001232 This enables the ioperm() and iopl() syscalls which are necessary
1233 for legacy applications.
1234
Thomas Gleixnerc8137ac2019-11-11 23:03:28 +01001235 Legacy IOPL support is an overbroad mechanism which allows user
1236 space aside of accessing all 65536 I/O ports also to disable
1237 interrupts. To gain this access the caller needs CAP_SYS_RAWIO
1238 capabilities and permission from potentially active security
1239 modules.
1240
1241 The emulation restricts the functionality of the syscall to
1242 only allowing the full range I/O port access, but prevents the
Thomas Gleixnera24ca992019-11-11 23:03:29 +01001243 ability to disable interrupts from user space which would be
1244 granted if the hardware IOPL mechanism would be used.
Thomas Gleixnerc8137ac2019-11-11 23:03:28 +01001245
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001246config TOSHIBA
1247 tristate "Toshiba Laptop support"
1248 depends on X86_32
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001249 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001250 This adds a driver to safely access the System Management Mode of
1251 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1252 not work on models with a Phoenix BIOS. The System Management Mode
1253 is used to set the BIOS and power saving options on Toshiba portables.
1254
1255 For information on utilities to make use of this driver see the
1256 Toshiba Linux utilities web site at:
1257 <http://www.buzzard.org.uk/toshiba/>.
1258
1259 Say Y if you intend to run this kernel on a Toshiba portable.
1260 Say N otherwise.
1261
1262config I8K
Pali Rohár039ae582015-05-14 13:16:37 +02001263 tristate "Dell i8k legacy laptop support"
Jean Delvare949a9d72011-05-25 20:43:33 +02001264 select HWMON
Pali Rohár039ae582015-05-14 13:16:37 +02001265 select SENSORS_DELL_SMM
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001266 help
Pali Rohár039ae582015-05-14 13:16:37 +02001267 This option enables legacy /proc/i8k userspace interface in hwmon
1268 dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1269 temperature and allows controlling fan speeds of Dell laptops via
1270 System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1271 it reports also power and hotkey status. For fan speed control is
1272 needed userspace package i8kutils.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001273
Pali Rohár039ae582015-05-14 13:16:37 +02001274 Say Y if you intend to run this kernel on old Dell laptops or want to
1275 use userspace package i8kutils.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001276 Say N otherwise.
1277
1278config X86_REBOOTFIXUPS
Jan Beulich9ba16082008-10-15 22:01:38 -07001279 bool "Enable X86 board specific fixups for reboot"
1280 depends on X86_32
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001281 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001282 This enables chipset and/or board specific fixups to be done
1283 in order to get reboot to work correctly. This is only needed on
1284 some combinations of hardware and BIOS. The symptom, for which
1285 this config is intended, is when reboot ends with a stalled/hung
1286 system.
1287
1288 Currently, the only fixup is for the Geode machines using
Florian Fainelli5e3a77e2008-01-30 13:33:36 +01001289 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001290
1291 Say Y if you want to enable the fixup. Currently, it's safe to
1292 enable this option even if you don't need it.
1293 Say N otherwise.
1294
1295config MICROCODE
Borislav Petkov9a2bc332015-10-20 11:54:44 +02001296 bool "CPU microcode loading support"
1297 default y
Borislav Petkov80030e32013-10-13 18:36:29 +02001298 depends on CPU_SUP_AMD || CPU_SUP_INTEL
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001299 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001300 If you say Y here, you will be able to update the microcode on
Borislav Petkov5f9c01a2016-02-03 12:33:29 +01001301 Intel and AMD processors. The Intel support is for the IA32 family,
1302 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
1303 AMD support is for families 0x10 and later. You will obviously need
1304 the actual microcode binary data itself which is not shipped with
1305 the Linux kernel.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001306
Borislav Petkov5f9c01a2016-02-03 12:33:29 +01001307 The preferred method to load microcode from a detached initrd is described
Mauro Carvalho Chehabcb1aaeb2019-06-07 15:54:32 -03001308 in Documentation/x86/microcode.rst. For that you need to enable
Borislav Petkov5f9c01a2016-02-03 12:33:29 +01001309 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
1310 initrd for microcode blobs.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001311
Benjamin Gilbertc508c462018-01-23 18:06:32 -08001312 In addition, you can build the microcode into the kernel. For that you
1313 need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1314 config option.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001315
Peter Oruba8d86f392008-07-28 18:44:21 +02001316config MICROCODE_INTEL
Borislav Petkove43f6e62012-08-01 19:17:01 +02001317 bool "Intel microcode loading support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001318 depends on MICROCODE
1319 default MICROCODE
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001320 help
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001321 This options enables microcode patch loading support for Intel
1322 processors.
Peter Oruba8d86f392008-07-28 18:44:21 +02001323
Alanb8989db2014-01-20 18:01:56 +00001324 For the current Intel microcode data package go to
1325 <https://downloadcenter.intel.com> and search for
1326 'Linux Processor Microcode Data File'.
Peter Oruba8d86f392008-07-28 18:44:21 +02001327
Peter Oruba80cc9f12008-07-28 18:44:22 +02001328config MICROCODE_AMD
Borislav Petkove43f6e62012-08-01 19:17:01 +02001329 bool "AMD microcode loading support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001330 depends on MICROCODE
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001331 help
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001332 If you select this option, microcode patch loading support for AMD
1333 processors will be enabled.
Peter Oruba80cc9f12008-07-28 18:44:22 +02001334
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001335config MICROCODE_OLD_INTERFACE
Borislav Petkovc02f48e2019-04-05 06:28:11 +02001336 bool "Ancient loading interface (DEPRECATED)"
1337 default n
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001338 depends on MICROCODE
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001339 help
Borislav Petkovc02f48e2019-04-05 06:28:11 +02001340 DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface
1341 which was used by userspace tools like iucode_tool and microcode.ctl.
1342 It is inadequate because it runs too late to be able to properly
1343 load microcode on a machine and it needs special tools. Instead, you
1344 should've switched to the early loading method with the initrd or
Mauro Carvalho Chehabcb1aaeb2019-06-07 15:54:32 -03001345 builtin microcode by now: Documentation/x86/microcode.rst
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001346
1347config X86_MSR
1348 tristate "/dev/cpu/*/msr - Model-specific register support"
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001349 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001350 This device gives privileged processes access to the x86
1351 Model-Specific Registers (MSRs). It is a character device with
1352 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1353 MSR accesses are directed to a specific CPU on multi-processor
1354 systems.
1355
1356config X86_CPUID
1357 tristate "/dev/cpu/*/cpuid - CPU information support"
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001358 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001359 This device gives processes access to the x86 CPUID instruction to
1360 be executed on a specific processor. It is a character device
1361 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1362 /dev/cpu/31/cpuid.
1363
1364choice
1365 prompt "High Memory Support"
Jan Beulich6fc108a2010-04-21 15:23:44 +01001366 default HIGHMEM4G
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001367 depends on X86_32
1368
1369config NOHIGHMEM
1370 bool "off"
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001371 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001372 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1373 However, the address space of 32-bit x86 processors is only 4
1374 Gigabytes large. That means that, if you have a large amount of
1375 physical memory, not all of it can be "permanently mapped" by the
1376 kernel. The physical memory that's not permanently mapped is called
1377 "high memory".
1378
1379 If you are compiling a kernel which will never run on a machine with
1380 more than 1 Gigabyte total physical RAM, answer "off" here (default
1381 choice and suitable for most users). This will result in a "3GB/1GB"
1382 split: 3GB are mapped so that each process sees a 3GB virtual memory
1383 space and the remaining part of the 4GB virtual memory space is used
1384 by the kernel to permanently map as much physical memory as
1385 possible.
1386
1387 If the machine has between 1 and 4 Gigabytes physical RAM, then
1388 answer "4GB" here.
1389
1390 If more than 4 Gigabytes is used then answer "64GB" here. This
1391 selection turns Intel PAE (Physical Address Extension) mode on.
1392 PAE implements 3-level paging on IA32 processors. PAE is fully
1393 supported by Linux, PAE mode is implemented on all recent Intel
1394 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1395 then the kernel will not boot on CPUs that don't support PAE!
1396
1397 The actual amount of total physical memory will either be
1398 auto detected or can be forced by using a kernel command line option
1399 such as "mem=256M". (Try "man bootparam" or see the documentation of
1400 your boot loader (lilo or loadlin) about how to pass options to the
1401 kernel at boot time.)
1402
1403 If unsure, say "off".
1404
1405config HIGHMEM4G
1406 bool "4GB"
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001407 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001408 Select this if you have a 32-bit processor and between 1 and 4
1409 gigabytes of physical RAM.
1410
1411config HIGHMEM64G
1412 bool "64GB"
Matthew Whitehead69b8d3f2018-02-15 11:54:55 -05001413 depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001414 select X86_PAE
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001415 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001416 Select this if you have a 32-bit processor and more than 4
1417 gigabytes of physical RAM.
1418
1419endchoice
1420
1421choice
David Rientjes6a108a12011-01-20 14:44:16 -08001422 prompt "Memory split" if EXPERT
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001423 default VMSPLIT_3G
1424 depends on X86_32
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001425 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001426 Select the desired split between kernel and user memory.
1427
1428 If the address range available to the kernel is less than the
1429 physical memory installed, the remaining memory will be available
1430 as "high memory". Accessing high memory is a little more costly
1431 than low memory, as it needs to be mapped into the kernel first.
1432 Note that increasing the kernel address space limits the range
1433 available to user programs, making the address space there
1434 tighter. Selecting anything other than the default 3G/1G split
1435 will also likely make your kernel incompatible with binary-only
1436 kernel modules.
1437
1438 If you are not absolutely sure what you are doing, leave this
1439 option alone!
1440
1441 config VMSPLIT_3G
1442 bool "3G/1G user/kernel split"
1443 config VMSPLIT_3G_OPT
1444 depends on !X86_PAE
1445 bool "3G/1G user/kernel split (for full 1G low memory)"
1446 config VMSPLIT_2G
1447 bool "2G/2G user/kernel split"
1448 config VMSPLIT_2G_OPT
1449 depends on !X86_PAE
1450 bool "2G/2G user/kernel split (for full 2G low memory)"
1451 config VMSPLIT_1G
1452 bool "1G/3G user/kernel split"
1453endchoice
1454
1455config PAGE_OFFSET
1456 hex
1457 default 0xB0000000 if VMSPLIT_3G_OPT
1458 default 0x80000000 if VMSPLIT_2G
1459 default 0x78000000 if VMSPLIT_2G_OPT
1460 default 0x40000000 if VMSPLIT_1G
1461 default 0xC0000000
1462 depends on X86_32
1463
1464config HIGHMEM
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001465 def_bool y
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001466 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001467
1468config X86_PAE
Jan Beulich9ba16082008-10-15 22:01:38 -07001469 bool "PAE (Physical Address Extension) Support"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001470 depends on X86_32 && !HIGHMEM4G
Christoph Hellwigd4a451d2018-04-03 16:24:20 +02001471 select PHYS_ADDR_T_64BIT
Christian Melki9d99c712015-10-05 17:31:33 +02001472 select SWIOTLB
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001473 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001474 PAE is required for NX support, and furthermore enables
1475 larger swapspace support for non-overcommit purposes. It
1476 has the cost of more pagetable lookup overhead, and also
1477 consumes more pagetable space per process.
1478
Kirill A. Shutemov77ef56e2017-07-17 01:59:54 +03001479config X86_5LEVEL
1480 bool "Enable 5-level page tables support"
Kirill A. Shutemov18ec1ea2019-09-13 12:54:52 +03001481 default y
Kirill A. Shutemoveedb92a2018-02-14 14:16:50 +03001482 select DYNAMIC_MEMORY_LAYOUT
Kirill A. Shutemov162434e2018-02-14 14:16:54 +03001483 select SPARSEMEM_VMEMMAP
Kirill A. Shutemov77ef56e2017-07-17 01:59:54 +03001484 depends on X86_64
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001485 help
Kirill A. Shutemov77ef56e2017-07-17 01:59:54 +03001486 5-level paging enables access to larger address space:
1487 upto 128 PiB of virtual address space and 4 PiB of
1488 physical address space.
1489
1490 It will be supported by future Intel CPUs.
1491
Kirill A. Shutemov6657fca2018-02-14 21:25:42 +03001492 A kernel with the option enabled can be booted on machines that
1493 support 4- or 5-level paging.
Kirill A. Shutemov77ef56e2017-07-17 01:59:54 +03001494
Mauro Carvalho Chehabcb1aaeb2019-06-07 15:54:32 -03001495 See Documentation/x86/x86_64/5level-paging.rst for more
Kirill A. Shutemov77ef56e2017-07-17 01:59:54 +03001496 information.
1497
1498 Say N if unsure.
1499
Ingo Molnar10971ab2015-03-05 08:18:23 +01001500config X86_DIRECT_GBPAGES
Luis R. Rodrigueze5008ab2015-03-04 17:24:12 -08001501 def_bool y
Vlastimil Babka2e1da132019-08-07 15:02:58 +02001502 depends on X86_64
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001503 help
Ingo Molnar10971ab2015-03-05 08:18:23 +01001504 Certain kernel features effectively disable kernel
1505 linear 1 GB mappings (even if the CPU otherwise
1506 supports them), so don't confuse the user by printing
1507 that we have them enabled.
Nick Piggin9e899812008-10-22 12:33:16 +02001508
Thomas Gleixner5c280cf2018-09-17 16:29:12 +02001509config X86_CPA_STATISTICS
1510 bool "Enable statistic for Change Page Attribute"
1511 depends on DEBUG_FS
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001512 help
Ingo Molnarb75baaf2019-11-20 15:57:04 +01001513 Expose statistics about the Change Page Attribute mechanism, which
Colin Ian Kinga9432452019-04-16 11:57:51 +01001514 helps to determine the effectiveness of preserving large and huge
Thomas Gleixner5c280cf2018-09-17 16:29:12 +02001515 page mappings when mapping protections are changed.
1516
Tom Lendacky7744ccd2017-07-17 16:10:03 -05001517config AMD_MEM_ENCRYPT
1518 bool "AMD Secure Memory Encryption (SME) support"
1519 depends on X86_64 && CPU_SUP_AMD
David Rientjes82fef0a2020-04-14 17:05:01 -07001520 select DMA_COHERENT_POOL
Kirill A. Shutemov94d49eb2018-05-18 14:30:28 +03001521 select DYNAMIC_PHYSICAL_MASK
Ard Biesheuvelce9084b2019-02-02 10:41:17 +01001522 select ARCH_USE_MEMREMAP_PROT
Tom Lendacky9087c372019-07-10 19:01:19 +00001523 select ARCH_HAS_FORCE_DMA_UNENCRYPTED
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001524 help
Tom Lendacky7744ccd2017-07-17 16:10:03 -05001525 Say yes to enable support for the encryption of system memory.
1526 This requires an AMD processor that supports Secure Memory
1527 Encryption (SME).
1528
1529config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
1530 bool "Activate AMD Secure Memory Encryption (SME) by default"
1531 default y
1532 depends on AMD_MEM_ENCRYPT
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001533 help
Tom Lendacky7744ccd2017-07-17 16:10:03 -05001534 Say yes to have system memory encrypted by default if running on
1535 an AMD processor that supports Secure Memory Encryption (SME).
1536
1537 If set to Y, then the encryption of system memory can be
1538 deactivated with the mem_encrypt=off command line option.
1539
1540 If set to N, then the encryption of system memory can be
1541 activated with the mem_encrypt=on command line option.
1542
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001543# Common NUMA Features
1544config NUMA
Randy Dunlape133f6e2019-12-03 16:06:47 -08001545 bool "NUMA Memory Allocation and Scheduler Support"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001546 depends on SMP
H. Peter Anvinb5660ba2014-02-25 12:14:06 -08001547 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1548 default y if X86_BIGSMP
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001549 help
Randy Dunlape133f6e2019-12-03 16:06:47 -08001550 Enable NUMA (Non-Uniform Memory Access) support.
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001551
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001552 The kernel will try to allocate memory used by a CPU on the
1553 local memory controller of the CPU and add some more
1554 NUMA awareness to the kernel.
1555
Ingo Molnarc280ea52008-11-08 13:29:45 +01001556 For 64-bit this is recommended if the system is Intel Core i7
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001557 (or later), AMD Opteron, or EM64T NUMA.
1558
H. Peter Anvinb5660ba2014-02-25 12:14:06 -08001559 For 32-bit this is only needed if you boot a 32-bit
David Rientjes7cf6c942014-02-11 18:11:13 -08001560 kernel on a 64-bit NUMA platform.
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001561
1562 Otherwise, you should say N.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001563
Hans Rosenfeldeec1d4f2010-10-29 17:14:30 +02001564config AMD_NUMA
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001565 def_bool y
1566 prompt "Old style AMD Opteron NUMA detection"
Tejun Heo5da0ef92011-07-11 10:34:32 +02001567 depends on X86_64 && NUMA && PCI
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001568 help
Hans Rosenfeldeec1d4f2010-10-29 17:14:30 +02001569 Enable AMD NUMA node topology detection. You should say Y here if
1570 you have a multi processor AMD system. This uses an old method to
1571 read the NUMA configuration directly from the builtin Northbridge
1572 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1573 which also takes priority if both are compiled in.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001574
1575config X86_64_ACPI_NUMA
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001576 def_bool y
1577 prompt "ACPI NUMA detection"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001578 depends on X86_64 && NUMA && ACPI && PCI
1579 select ACPI_NUMA
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001580 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001581 Enable ACPI SRAT based node topology detection.
1582
1583config NUMA_EMU
1584 bool "NUMA emulation"
Tejun Heo1b7e03e2011-05-02 17:24:48 +02001585 depends on NUMA
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001586 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001587 Enable NUMA emulation. A flat machine will be split
1588 into virtual nodes when booted with "numa=fake=N", where N is the
1589 number of nodes. This is only useful for debugging.
1590
1591config NODES_SHIFT
Linus Torvaldsd25e26b2008-08-25 14:15:38 -07001592 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
David Rientjes51591e32010-03-25 15:39:27 -07001593 range 1 10
1594 default "10" if MAXSMP
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001595 default "6" if X86_64
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001596 default "3"
1597 depends on NEED_MULTIPLE_NODES
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001598 help
Mike Travis1184dc22008-05-12 21:21:12 +02001599 Specify the maximum number of NUMA Nodes available on the target
Matt LaPlante692105b2009-01-26 11:12:25 +01001600 system. Increases memory reserved to accommodate various tables.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001601
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001602config ARCH_FLATMEM_ENABLE
1603 def_bool y
Tejun Heo3b166512011-04-01 11:15:12 +02001604 depends on X86_32 && !NUMA
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001605
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001606config ARCH_SPARSEMEM_ENABLE
1607 def_bool y
Kees Cook6ea30382012-10-02 11:16:47 -07001608 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001609 select SPARSEMEM_STATIC if X86_32
1610 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1611
Tejun Heo3b166512011-04-01 11:15:12 +02001612config ARCH_SPARSEMEM_DEFAULT
Mike Rapoport6ad57f72019-04-24 16:24:11 +03001613 def_bool X86_64 || (NUMA && X86_32)
Tejun Heo3b166512011-04-01 11:15:12 +02001614
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001615config ARCH_SELECT_MEMORY_MODEL
1616 def_bool y
Christoph Lameterb2632952008-01-30 13:30:47 +01001617 depends on ARCH_SPARSEMEM_ENABLE
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001618
1619config ARCH_MEMORY_PROBE
Toshi Kania0842b72013-07-19 11:47:48 -06001620 bool "Enable sysfs memory/probe interface"
Jan Beulich3120e252012-09-10 12:41:45 +01001621 depends on X86_64 && MEMORY_HOTPLUG
Toshi Kania0842b72013-07-19 11:47:48 -06001622 help
1623 This option enables a sysfs memory/probe interface for testing.
Mauro Carvalho Chehabcb1aaeb2019-06-07 15:54:32 -03001624 See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
Toshi Kania0842b72013-07-19 11:47:48 -06001625 If you are unsure how to answer this question, answer N.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001626
Tejun Heo3b166512011-04-01 11:15:12 +02001627config ARCH_PROC_KCORE_TEXT
1628 def_bool y
1629 depends on X86_64 && PROC_KCORE
1630
Avi Kivitya29815a2010-01-10 16:28:09 +02001631config ILLEGAL_POINTER_VALUE
Krzysztof Kozlowskib03b0162019-11-21 04:21:09 +01001632 hex
1633 default 0 if X86_32
1634 default 0xdead000000000000 if X86_64
Avi Kivitya29815a2010-01-10 16:28:09 +02001635
Dan Williams7a678322015-08-19 00:34:34 -04001636config X86_PMEM_LEGACY_DEVICE
1637 bool
1638
Christoph Hellwigec776ef2015-04-01 09:12:18 +02001639config X86_PMEM_LEGACY
Dan Williams7a678322015-08-19 00:34:34 -04001640 tristate "Support non-standard NVDIMMs and ADR protected memory"
Dan Williams9f53f9f2015-06-09 15:33:45 -04001641 depends on PHYS_ADDR_T_64BIT
1642 depends on BLK_DEV
Dan Williams7a678322015-08-19 00:34:34 -04001643 select X86_PMEM_LEGACY_DEVICE
Dan Williams7b27a862020-02-16 12:01:16 -08001644 select NUMA_KEEP_MEMINFO if NUMA
Dan Williams9f53f9f2015-06-09 15:33:45 -04001645 select LIBNVDIMM
Christoph Hellwigec776ef2015-04-01 09:12:18 +02001646 help
1647 Treat memory marked using the non-standard e820 type of 12 as used
1648 by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1649 The kernel will offer these regions to the 'pmem' driver so
1650 they can be used for persistent storage.
1651
1652 Say Y if unsure.
1653
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001654config HIGHPTE
1655 bool "Allocate 3rd-level pagetables from highmem"
Jan Beulich6fc108a2010-04-21 15:23:44 +01001656 depends on HIGHMEM
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001657 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001658 The VM uses one page table entry for each page of physical memory.
1659 For systems with a lot of RAM, this can be wasteful of precious
1660 low memory. Setting this option will put user-space page table
1661 entries in high memory.
1662
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001663config X86_CHECK_BIOS_CORRUPTION
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001664 bool "Check for low memory corruption"
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001665 help
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001666 Periodically check for memory corruption in low memory, which
1667 is suspected to be caused by BIOS. Even when enabled in the
1668 configuration, it is disabled at runtime. Enable it by
1669 setting "memory_corruption_check=1" on the kernel command
1670 line. By default it scans the low 64k of memory every 60
1671 seconds; see the memory_corruption_check_size and
1672 memory_corruption_check_period parameters in
Mauro Carvalho Chehab8c27ceff32016-10-18 10:12:27 -02001673 Documentation/admin-guide/kernel-parameters.rst to adjust this.
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001674
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001675 When enabled with the default parameters, this option has
1676 almost no overhead, as it reserves a relatively small amount
1677 of memory and scans it infrequently. It both detects corruption
1678 and prevents it from affecting the running system.
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001679
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001680 It is, however, intended as a diagnostic tool; if repeatable
1681 BIOS-originated corruption always affects the same memory,
1682 you can use memmap= to prevent the kernel from using that
1683 memory.
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001684
Jeremy Fitzhardingec885df52008-09-07 02:37:32 -07001685config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001686 bool "Set the default setting of memory_corruption_check"
Jeremy Fitzhardingec885df52008-09-07 02:37:32 -07001687 depends on X86_CHECK_BIOS_CORRUPTION
1688 default y
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001689 help
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001690 Set whether the default state of memory_corruption_check is
1691 on or off.
Jeremy Fitzhardingec885df52008-09-07 02:37:32 -07001692
H. Peter Anvin9ea77bd2010-08-25 16:38:20 -07001693config X86_RESERVE_LOW
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001694 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1695 default 64
1696 range 4 640
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001697 help
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001698 Specify the amount of low memory to reserve for the BIOS.
Ingo Molnarfc381512008-09-16 10:07:34 +02001699
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001700 The first page contains BIOS data structures that the kernel
1701 must not use, so that page must always be reserved.
Ingo Molnarfc381512008-09-16 10:07:34 +02001702
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001703 By default we reserve the first 64K of physical RAM, as a
1704 number of BIOSes are known to corrupt that memory range
1705 during events such as suspend/resume or monitor cable
1706 insertion, so it must not be used by the kernel.
Ingo Molnarfc381512008-09-16 10:07:34 +02001707
H. Peter Anvind0cd7422010-08-24 17:32:04 -07001708 You can set this to 4 if you are absolutely sure that you
1709 trust the BIOS to get all its memory reservations and usages
1710 right. If you know your BIOS have problems beyond the
1711 default 64K area, you can set this to 640 to avoid using the
1712 entire low memory range.
1713
1714 If you have doubts about the BIOS (e.g. suspend/resume does
1715 not work or there's kernel crashes after certain hardware
1716 hotplug events) then you might want to enable
1717 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1718 typical corruption patterns.
1719
1720 Leave this to the default value of 64 if you are unsure.
Ingo Molnarfc381512008-09-16 10:07:34 +02001721
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001722config MATH_EMULATION
1723 bool
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07001724 depends on MODIFY_LDT_SYSCALL
Arnd Bergmann87d60212019-10-01 16:23:35 +02001725 prompt "Math emulation" if X86_32 && (M486SX || MELAN)
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001726 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001727 Linux can emulate a math coprocessor (used for floating point
1728 operations) if you don't have one. 486DX and Pentium processors have
1729 a math coprocessor built in, 486SX and 386 do not, unless you added
1730 a 487DX or 387, respectively. (The messages during boot time can
1731 give you some hints here ["man dmesg"].) Everyone needs either a
1732 coprocessor or this emulation.
1733
1734 If you don't have a math coprocessor, you need to say Y here; if you
1735 say Y here even though you have a coprocessor, the coprocessor will
1736 be used nevertheless. (This behavior can be changed with the kernel
1737 command line option "no387", which comes handy if your coprocessor
1738 is broken. Try "man bootparam" or see the documentation of your boot
1739 loader (lilo or loadlin) about how to pass options to the kernel at
1740 boot time.) This means that it is a good idea to say Y here if you
1741 intend to use this kernel on different machines.
1742
1743 More information about the internals of the Linux math coprocessor
1744 emulation can be found in <file:arch/x86/math-emu/README>.
1745
1746 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1747 kernel, it won't hurt.
1748
1749config MTRR
Jan Beulich6fc108a2010-04-21 15:23:44 +01001750 def_bool y
David Rientjes6a108a12011-01-20 14:44:16 -08001751 prompt "MTRR (Memory Type Range Register) support" if EXPERT
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001752 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001753 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1754 the Memory Type Range Registers (MTRRs) may be used to control
1755 processor access to memory ranges. This is most useful if you have
1756 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1757 allows bus write transfers to be combined into a larger transfer
1758 before bursting over the PCI/AGP bus. This can increase performance
1759 of image write operations 2.5 times or more. Saying Y here creates a
1760 /proc/mtrr file which may be used to manipulate your processor's
1761 MTRRs. Typically the X server should use this.
1762
1763 This code has a reasonably generic interface so that similar
1764 control registers on other processors can be easily supported
1765 as well:
1766
1767 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1768 Registers (ARRs) which provide a similar functionality to MTRRs. For
1769 these, the ARRs are used to emulate the MTRRs.
1770 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1771 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1772 write-combining. All of these processors are supported by this code
1773 and it makes sense to say Y here if you have one of them.
1774
1775 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1776 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1777 can lead to all sorts of problems, so it's good to say Y here.
1778
1779 You can safely say Y even if your machine doesn't have MTRRs, you'll
1780 just add about 9 KB to your kernel.
1781
Mauro Carvalho Chehabcb1aaeb2019-06-07 15:54:32 -03001782 See <file:Documentation/x86/mtrr.rst> for more information.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001783
Yinghai Lu95ffa242008-04-29 03:52:33 -07001784config MTRR_SANITIZER
Yinghai Lu2ffb3502008-09-30 16:29:40 -07001785 def_bool y
Yinghai Lu95ffa242008-04-29 03:52:33 -07001786 prompt "MTRR cleanup support"
1787 depends on MTRR
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001788 help
Thomas Gleixneraba37282008-07-15 14:48:48 +02001789 Convert MTRR layout from continuous to discrete, so X drivers can
1790 add writeback entries.
Yinghai Lu95ffa242008-04-29 03:52:33 -07001791
Thomas Gleixneraba37282008-07-15 14:48:48 +02001792 Can be disabled with disable_mtrr_cleanup on the kernel command line.
Matt LaPlante692105b2009-01-26 11:12:25 +01001793 The largest mtrr entry size for a continuous block can be set with
Thomas Gleixneraba37282008-07-15 14:48:48 +02001794 mtrr_chunk_size.
Yinghai Lu95ffa242008-04-29 03:52:33 -07001795
Yinghai Lu2ffb3502008-09-30 16:29:40 -07001796 If unsure, say Y.
Yinghai Lu95ffa242008-04-29 03:52:33 -07001797
1798config MTRR_SANITIZER_ENABLE_DEFAULT
Yinghai Luf5098d62008-04-29 20:25:58 -07001799 int "MTRR cleanup enable value (0-1)"
1800 range 0 1
1801 default "0"
Yinghai Lu95ffa242008-04-29 03:52:33 -07001802 depends on MTRR_SANITIZER
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001803 help
Yinghai Luf5098d62008-04-29 20:25:58 -07001804 Enable mtrr cleanup default value
Yinghai Lu95ffa242008-04-29 03:52:33 -07001805
Yinghai Lu12031a62008-05-02 02:40:22 -07001806config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1807 int "MTRR cleanup spare reg num (0-7)"
1808 range 0 7
1809 default "1"
1810 depends on MTRR_SANITIZER
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001811 help
Yinghai Lu12031a62008-05-02 02:40:22 -07001812 mtrr cleanup spare entries default, it can be changed via
Thomas Gleixneraba37282008-07-15 14:48:48 +02001813 mtrr_spare_reg_nr=N on the kernel command line.
Yinghai Lu12031a62008-05-02 02:40:22 -07001814
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001815config X86_PAT
Jan Beulich6fc108a2010-04-21 15:23:44 +01001816 def_bool y
David Rientjes6a108a12011-01-20 14:44:16 -08001817 prompt "x86 PAT support" if EXPERT
Ingo Molnar2a8a2712008-04-26 10:26:52 +02001818 depends on MTRR
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001819 help
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001820 Use PAT attributes to setup page level cache control.
Venki Pallipadi042b78e2008-03-24 14:22:35 -07001821
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001822 PATs are the modern equivalents of MTRRs and are much more
1823 flexible than MTRRs.
1824
1825 Say N here if you see bootup problems (boot crash, boot hang,
Venki Pallipadi042b78e2008-03-24 14:22:35 -07001826 spontaneous reboots) or a non-working video driver.
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001827
1828 If unsure, say Y.
1829
Venkatesh Pallipadi46cf98c2009-07-10 09:57:37 -07001830config ARCH_USES_PG_UNCACHED
1831 def_bool y
1832 depends on X86_PAT
1833
H. Peter Anvin628c6242011-07-31 13:59:29 -07001834config ARCH_RANDOM
1835 def_bool y
1836 prompt "x86 architectural random number generator" if EXPERT
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001837 help
H. Peter Anvin628c6242011-07-31 13:59:29 -07001838 Enable the x86 architectural RDRAND instruction
1839 (Intel Bull Mountain technology) to generate random numbers.
1840 If supported, this is a high bandwidth, cryptographically
1841 secure hardware random number generator.
1842
H. Peter Anvin51ae4a22012-09-21 12:43:10 -07001843config X86_SMAP
1844 def_bool y
1845 prompt "Supervisor Mode Access Prevention" if EXPERT
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001846 help
H. Peter Anvin51ae4a22012-09-21 12:43:10 -07001847 Supervisor Mode Access Prevention (SMAP) is a security
1848 feature in newer Intel processors. There is a small
1849 performance cost if this enabled and turned on; there is
1850 also a small increase in the kernel size if this is enabled.
1851
1852 If unsure, say Y.
1853
Babu Mogerb9718802019-11-05 21:25:32 +00001854config X86_UMIP
Ricardo Neri796ebc82017-11-13 22:29:42 -08001855 def_bool y
Babu Mogerb9718802019-11-05 21:25:32 +00001856 prompt "User Mode Instruction Prevention" if EXPERT
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001857 help
Babu Mogerb9718802019-11-05 21:25:32 +00001858 User Mode Instruction Prevention (UMIP) is a security feature in
1859 some x86 processors. If enabled, a general protection fault is
1860 issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are
1861 executed in user mode. These instructions unnecessarily expose
1862 information about the hardware state.
Ricardo Neri796ebc82017-11-13 22:29:42 -08001863
1864 The vast majority of applications do not use these instructions.
1865 For the very few that do, software emulation is provided in
1866 specific cases in protected and virtual-8086 modes. Emulated
1867 results are dummy.
Ricardo Neriaa35f892017-11-05 18:27:54 -08001868
Dave Hansen35e97792016-02-12 13:02:00 -08001869config X86_INTEL_MEMORY_PROTECTION_KEYS
Babu Moger38f3e772020-05-28 11:08:23 -05001870 prompt "Memory Protection Keys"
Dave Hansen35e97792016-02-12 13:02:00 -08001871 def_bool y
Dave Hansen284244a2016-02-12 13:02:28 -08001872 # Note: only available in 64-bit mode
Babu Moger38f3e772020-05-28 11:08:23 -05001873 depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD)
Ingo Molnar52c8e602016-11-15 10:15:03 +01001874 select ARCH_USES_HIGH_VMA_FLAGS
1875 select ARCH_HAS_PKEYS
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001876 help
Dave Hansen284244a2016-02-12 13:02:28 -08001877 Memory Protection Keys provides a mechanism for enforcing
1878 page-based protections, but without requiring modification of the
1879 page tables when an application changes protection domains.
1880
Mauro Carvalho Chehab1eecbcd2019-06-07 15:54:31 -03001881 For details, see Documentation/core-api/protection-keys.rst
Dave Hansen284244a2016-02-12 13:02:28 -08001882
1883 If unsure, say y.
Dave Hansen35e97792016-02-12 13:02:00 -08001884
Michal Hockodb616172019-10-23 12:35:50 +02001885choice
1886 prompt "TSX enable mode"
1887 depends on CPU_SUP_INTEL
1888 default X86_INTEL_TSX_MODE_OFF
1889 help
1890 Intel's TSX (Transactional Synchronization Extensions) feature
1891 allows to optimize locking protocols through lock elision which
1892 can lead to a noticeable performance boost.
1893
1894 On the other hand it has been shown that TSX can be exploited
1895 to form side channel attacks (e.g. TAA) and chances are there
1896 will be more of those attacks discovered in the future.
1897
1898 Therefore TSX is not enabled by default (aka tsx=off). An admin
1899 might override this decision by tsx=on the command line parameter.
1900 Even with TSX enabled, the kernel will attempt to enable the best
1901 possible TAA mitigation setting depending on the microcode available
1902 for the particular machine.
1903
1904 This option allows to set the default tsx mode between tsx=on, =off
1905 and =auto. See Documentation/admin-guide/kernel-parameters.txt for more
1906 details.
1907
1908 Say off if not sure, auto if TSX is in use but it should be used on safe
1909 platforms or on if TSX is in use and the security aspect of tsx is not
1910 relevant.
1911
1912config X86_INTEL_TSX_MODE_OFF
1913 bool "off"
1914 help
1915 TSX is disabled if possible - equals to tsx=off command line parameter.
1916
1917config X86_INTEL_TSX_MODE_ON
1918 bool "on"
1919 help
1920 TSX is always enabled on TSX capable HW - equals the tsx=on command
1921 line parameter.
1922
1923config X86_INTEL_TSX_MODE_AUTO
1924 bool "auto"
1925 help
1926 TSX is enabled on TSX capable HW that is believed to be safe against
1927 side channel attacks- equals the tsx=auto command line parameter.
1928endchoice
1929
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001930config EFI
Jan Beulich9ba16082008-10-15 22:01:38 -07001931 bool "EFI runtime service support"
Huang, Ying5b836832008-01-30 13:31:19 +01001932 depends on ACPI
Sergey Vlasovf6ce5002013-04-16 18:31:08 +04001933 select UCS2_STRING
Ard Biesheuvel022ee6c2014-06-26 12:09:05 +02001934 select EFI_RUNTIME_WRAPPERS
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001935 help
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001936 This enables the kernel to use EFI runtime services that are
1937 available (such as the EFI variable services).
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001938
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001939 This option is only useful on systems that have EFI firmware.
1940 In addition, you should use the latest ELILO loader available
1941 at <http://elilo.sourceforge.net> in order to take advantage
1942 of EFI runtime services. However, even with this option, the
1943 resultant kernel should continue to boot on existing non-EFI
1944 platforms.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001945
Matt Fleming291f3632011-12-12 21:27:52 +00001946config EFI_STUB
Ard Biesheuvel8f24f8c2019-12-24 16:10:12 +01001947 bool "EFI stub support"
1948 depends on EFI && !X86_USE_3DNOW
1949 depends on $(cc-option,-mabi=ms) || X86_32
1950 select RELOCATABLE
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001951 help
Ard Biesheuvel8f24f8c2019-12-24 16:10:12 +01001952 This kernel feature allows a bzImage to be loaded directly
Matt Fleming291f3632011-12-12 21:27:52 +00001953 by EFI firmware without the use of a bootloader.
1954
Mauro Carvalho Chehab4f4cfa62019-06-27 14:56:51 -03001955 See Documentation/admin-guide/efi-stub.rst for more information.
Matt Fleming0c759662012-03-16 12:03:13 +00001956
Matt Fleming7d453ee2014-01-10 18:52:06 +00001957config EFI_MIXED
1958 bool "EFI mixed-mode support"
1959 depends on EFI_STUB && X86_64
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001960 help
Matt Fleming7d453ee2014-01-10 18:52:06 +00001961 Enabling this feature allows a 64-bit kernel to be booted
1962 on a 32-bit firmware, provided that your CPU supports 64-bit
1963 mode.
1964
1965 Note that it is not possible to boot a mixed-mode enabled
1966 kernel via the EFI boot stub - a bootloader that supports
1967 the EFI handover protocol must be used.
1968
1969 If unsure, say N.
1970
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001971config SECCOMP
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001972 def_bool y
1973 prompt "Enable seccomp to safely compute untrusted bytecode"
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001974 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001975 This kernel feature is useful for number crunching applications
1976 that may need to compute untrusted bytecode during their
1977 execution. By using pipes or other transports made available to
1978 the process as file descriptors supporting the read/write
1979 syscalls, it's possible to isolate those applications in
1980 their own address space using seccomp. Once seccomp is
Alexey Dobriyan9c0bbee2008-09-09 11:01:31 +04001981 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001982 and the task is only allowed to execute a few safe syscalls
1983 defined by each seccomp mode.
1984
1985 If unsure, say Y. Only embedded should say N here.
1986
Masahiro Yamada8636a1f2018-12-11 20:01:04 +09001987source "kernel/Kconfig.hz"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001988
1989config KEXEC
1990 bool "kexec system call"
Dave Young2965faa2015-09-09 15:38:55 -07001991 select KEXEC_CORE
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001992 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001993 kexec is a system call that implements the ability to shutdown your
1994 current kernel, and to start another kernel. It is like a reboot
1995 but it is independent of the system firmware. And like a reboot
1996 you can start any kernel with it, not just Linux.
1997
1998 The name comes from the similarity to the exec system call.
1999
2000 It is an ongoing process to be certain the hardware in a machine
2001 is properly shutdown, so do not be surprised if this code does not
Geert Uytterhoevenbf220692013-08-20 21:38:03 +02002002 initially work for you. As of this writing the exact hardware
2003 interface is strongly in flux, so no good recommendation can be
2004 made.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002005
Vivek Goyal74ca3172014-08-29 15:18:46 -07002006config KEXEC_FILE
2007 bool "kexec file based system call"
Dave Young2965faa2015-09-09 15:38:55 -07002008 select KEXEC_CORE
Vivek Goyal74ca3172014-08-29 15:18:46 -07002009 select BUILD_BIN2C
Vivek Goyal74ca3172014-08-29 15:18:46 -07002010 depends on X86_64
2011 depends on CRYPTO=y
2012 depends on CRYPTO_SHA256=y
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002013 help
Vivek Goyal74ca3172014-08-29 15:18:46 -07002014 This is new version of kexec system call. This system call is
2015 file based and takes file descriptors as system call argument
2016 for kernel and initramfs as opposed to list of segments as
2017 accepted by previous system call.
2018
AKASHI Takahirob799a092018-04-13 15:35:45 -07002019config ARCH_HAS_KEXEC_PURGATORY
2020 def_bool KEXEC_FILE
2021
Jiri Bohac99d5cadf2019-08-19 17:17:44 -07002022config KEXEC_SIG
Vivek Goyal8e7d8382014-08-08 14:26:13 -07002023 bool "Verify kernel signature during kexec_file_load() syscall"
Vivek Goyal74ca3172014-08-29 15:18:46 -07002024 depends on KEXEC_FILE
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002025 help
Jiri Bohac99d5cadf2019-08-19 17:17:44 -07002026
2027 This option makes the kexec_file_load() syscall check for a valid
2028 signature of the kernel image. The image can still be loaded without
2029 a valid signature unless you also enable KEXEC_SIG_FORCE, though if
2030 there's a signature that we can check, then it must be valid.
2031
2032 In addition to this option, you need to enable signature
2033 verification for the corresponding kernel image type being
2034 loaded in order for this to work.
2035
2036config KEXEC_SIG_FORCE
2037 bool "Require a valid signature in kexec_file_load() syscall"
2038 depends on KEXEC_SIG
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002039 help
Vivek Goyal8e7d8382014-08-08 14:26:13 -07002040 This option makes kernel signature verification mandatory for
Borislav Petkovd8eb8942015-03-13 14:04:37 +01002041 the kexec_file_load() syscall.
Vivek Goyal8e7d8382014-08-08 14:26:13 -07002042
Vivek Goyal8e7d8382014-08-08 14:26:13 -07002043config KEXEC_BZIMAGE_VERIFY_SIG
2044 bool "Enable bzImage signature verification support"
Jiri Bohac99d5cadf2019-08-19 17:17:44 -07002045 depends on KEXEC_SIG
Vivek Goyal8e7d8382014-08-08 14:26:13 -07002046 depends on SIGNED_PE_FILE_VERIFICATION
2047 select SYSTEM_TRUSTED_KEYRING
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002048 help
Vivek Goyal8e7d8382014-08-08 14:26:13 -07002049 Enable bzImage signature verification support.
2050
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002051config CRASH_DUMP
Pavel Machek04b69442008-08-14 17:16:50 +02002052 bool "kernel crash dumps"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002053 depends on X86_64 || (X86_32 && HIGHMEM)
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002054 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002055 Generate crash dump after being started by kexec.
2056 This should be normally only set in special crash dump kernels
2057 which are loaded in the main kernel with kexec-tools into
2058 a specially reserved region and then later executed after
2059 a crash by kdump/kexec. The crash dump kernel must be compiled
2060 to a memory address not used by the main kernel or BIOS using
2061 PHYSICAL_START, or it must be built as a relocatable image
2062 (CONFIG_RELOCATABLE=y).
Mauro Carvalho Chehab330d4812019-06-13 15:21:39 -03002063 For more details see Documentation/admin-guide/kdump/kdump.rst
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002064
Huang Ying3ab83522008-07-25 19:45:07 -07002065config KEXEC_JUMP
Kees Cook6ea30382012-10-02 11:16:47 -07002066 bool "kexec jump"
Huang Yingfee7b0d2009-03-10 10:57:16 +08002067 depends on KEXEC && HIBERNATION
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002068 help
Huang Ying89081d12008-07-25 19:45:10 -07002069 Jump between original kernel and kexeced kernel and invoke
2070 code in physical address mode via KEXEC
Huang Ying3ab83522008-07-25 19:45:07 -07002071
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002072config PHYSICAL_START
David Rientjes6a108a12011-01-20 14:44:16 -08002073 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
H. Peter Anvinceefccc2009-05-11 16:12:16 -07002074 default "0x1000000"
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002075 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002076 This gives the physical address where the kernel is loaded.
2077
2078 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2079 bzImage will decompress itself to above physical address and
2080 run from there. Otherwise, bzImage will run from the address where
2081 it has been loaded by the boot loader and will ignore above physical
2082 address.
2083
2084 In normal kdump cases one does not have to set/change this option
2085 as now bzImage can be compiled as a completely relocatable image
2086 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2087 address. This option is mainly useful for the folks who don't want
2088 to use a bzImage for capturing the crash dump and want to use a
2089 vmlinux instead. vmlinux is not relocatable hence a kernel needs
2090 to be specifically compiled to run from a specific memory area
2091 (normally a reserved region) and this option comes handy.
2092
H. Peter Anvinceefccc2009-05-11 16:12:16 -07002093 So if you are using bzImage for capturing the crash dump,
2094 leave the value here unchanged to 0x1000000 and set
2095 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
2096 for capturing the crash dump change this value to start of
2097 the reserved region. In other words, it can be set based on
2098 the "X" value as specified in the "crashkernel=YM@XM"
2099 command line boot parameter passed to the panic-ed
Mauro Carvalho Chehab330d4812019-06-13 15:21:39 -03002100 kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst
H. Peter Anvinceefccc2009-05-11 16:12:16 -07002101 for more details about crash dumps.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002102
2103 Usage of bzImage for capturing the crash dump is recommended as
2104 one does not have to build two kernels. Same kernel can be used
2105 as production kernel and capture kernel. Above option should have
2106 gone away after relocatable bzImage support is introduced. But it
2107 is present because there are users out there who continue to use
2108 vmlinux for dump capture. This option should go away down the
2109 line.
2110
2111 Don't change this unless you know what you are doing.
2112
2113config RELOCATABLE
H. Peter Anvin26717802009-05-07 14:19:34 -07002114 bool "Build a relocatable kernel"
2115 default y
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002116 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002117 This builds a kernel image that retains relocation information
2118 so it can be loaded someplace besides the default 1MB.
2119 The relocations tend to make the kernel binary about 10% larger,
2120 but are discarded at runtime.
2121
2122 One use is for the kexec on panic case where the recovery kernel
2123 must live at a different physical address than the primary
2124 kernel.
2125
2126 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2127 it has been loaded at and the compile time physical address
Kees Cook8ab38202013-10-10 17:18:14 -07002128 (CONFIG_PHYSICAL_START) is used as the minimum location.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002129
Kees Cook8ab38202013-10-10 17:18:14 -07002130config RANDOMIZE_BASE
Baoquan Hee8581e32016-04-20 13:55:43 -07002131 bool "Randomize the address of the kernel image (KASLR)"
Kees Cook8ab38202013-10-10 17:18:14 -07002132 depends on RELOCATABLE
Ingo Molnar6807c842017-04-18 11:08:12 +02002133 default y
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002134 help
Baoquan Hee8581e32016-04-20 13:55:43 -07002135 In support of Kernel Address Space Layout Randomization (KASLR),
2136 this randomizes the physical address at which the kernel image
2137 is decompressed and the virtual address where the kernel
2138 image is mapped, as a security feature that deters exploit
2139 attempts relying on knowledge of the location of kernel
2140 code internals.
Kees Cook8ab38202013-10-10 17:18:14 -07002141
Kees Cooked9f0072016-05-25 15:45:33 -07002142 On 64-bit, the kernel physical and virtual addresses are
2143 randomized separately. The physical address will be anywhere
2144 between 16MB and the top of physical memory (up to 64TB). The
2145 virtual address will be randomized from 16MB up to 1GB (9 bits
2146 of entropy). Note that this also reduces the memory space
2147 available to kernel modules from 1.5GB to 1GB.
2148
2149 On 32-bit, the kernel physical and virtual addresses are
2150 randomized together. They will be randomized from 16MB up to
2151 512MB (8 bits of entropy).
Kees Cook8ab38202013-10-10 17:18:14 -07002152
Baoquan Hee8581e32016-04-20 13:55:43 -07002153 Entropy is generated using the RDRAND instruction if it is
2154 supported. If RDTSC is supported, its value is mixed into
2155 the entropy pool as well. If neither RDRAND nor RDTSC are
Kees Cooked9f0072016-05-25 15:45:33 -07002156 supported, then entropy is read from the i8254 timer. The
2157 usable entropy is limited by the kernel being built using
2158 2GB addressing, and that PHYSICAL_ALIGN must be at a
2159 minimum of 2MB. As a result, only 10 bits of entropy are
2160 theoretically possible, but the implementations are further
2161 limited due to memory layouts.
Kees Cookda2b6fb2013-12-10 12:27:45 -08002162
Ingo Molnar6807c842017-04-18 11:08:12 +02002163 If unsure, say Y.
Kees Cook8ab38202013-10-10 17:18:14 -07002164
2165# Relocation on x86 needs some additional build support
H. Peter Anvin845adf72009-05-05 21:20:51 -07002166config X86_NEED_RELOCS
2167 def_bool y
Kees Cook8ab38202013-10-10 17:18:14 -07002168 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
H. Peter Anvin845adf72009-05-05 21:20:51 -07002169
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002170config PHYSICAL_ALIGN
Kees Cooka0215062013-07-08 09:15:17 -07002171 hex "Alignment value to which kernel should be aligned"
Kees Cook8ab38202013-10-10 17:18:14 -07002172 default "0x200000"
Kees Cooka0215062013-07-08 09:15:17 -07002173 range 0x2000 0x1000000 if X86_32
2174 range 0x200000 0x1000000 if X86_64
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002175 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002176 This value puts the alignment restrictions on physical address
2177 where kernel is loaded and run from. Kernel is compiled for an
2178 address which meets above alignment restriction.
2179
2180 If bootloader loads the kernel at a non-aligned address and
2181 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2182 address aligned to above value and run from there.
2183
2184 If bootloader loads the kernel at a non-aligned address and
2185 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2186 load address and decompress itself to the address it has been
2187 compiled for and run from there. The address for which kernel is
2188 compiled already meets above alignment restrictions. Hence the
2189 end result is that kernel runs from a physical address meeting
2190 above alignment restrictions.
2191
Kees Cooka0215062013-07-08 09:15:17 -07002192 On 32-bit this value must be a multiple of 0x2000. On 64-bit
2193 this value must be a multiple of 0x200000.
2194
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002195 Don't change this unless you know what you are doing.
2196
Kirill A. Shutemoveedb92a2018-02-14 14:16:50 +03002197config DYNAMIC_MEMORY_LAYOUT
2198 bool
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002199 help
Kirill A. Shutemoveedb92a2018-02-14 14:16:50 +03002200 This option makes base addresses of vmalloc and vmemmap as well as
2201 __PAGE_OFFSET movable during boot.
2202
Thomas Garnier0483e1f2016-06-21 17:47:02 -07002203config RANDOMIZE_MEMORY
2204 bool "Randomize the kernel memory sections"
2205 depends on X86_64
2206 depends on RANDOMIZE_BASE
Kirill A. Shutemoveedb92a2018-02-14 14:16:50 +03002207 select DYNAMIC_MEMORY_LAYOUT
Thomas Garnier0483e1f2016-06-21 17:47:02 -07002208 default RANDOMIZE_BASE
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002209 help
Thomas Garnier0483e1f2016-06-21 17:47:02 -07002210 Randomizes the base virtual address of kernel memory sections
2211 (physical memory mapping, vmalloc & vmemmap). This security feature
2212 makes exploits relying on predictable memory locations less reliable.
2213
2214 The order of allocations remains unchanged. Entropy is generated in
2215 the same way as RANDOMIZE_BASE. Current implementation in the optimal
2216 configuration have in average 30,000 different possible virtual
2217 addresses for each memory section.
2218
Ingo Molnar6807c842017-04-18 11:08:12 +02002219 If unsure, say Y.
Thomas Garnier0483e1f2016-06-21 17:47:02 -07002220
Thomas Garnier90397a42016-06-21 17:47:06 -07002221config RANDOMIZE_MEMORY_PHYSICAL_PADDING
2222 hex "Physical memory mapping padding" if EXPERT
2223 depends on RANDOMIZE_MEMORY
2224 default "0xa" if MEMORY_HOTPLUG
2225 default "0x0"
2226 range 0x1 0x40 if MEMORY_HOTPLUG
2227 range 0x0 0x40
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002228 help
Thomas Garnier90397a42016-06-21 17:47:06 -07002229 Define the padding in terabytes added to the existing physical
2230 memory size during kernel memory randomization. It is useful
2231 for memory hotplug support but reduces the entropy available for
2232 address randomization.
2233
2234 If unsure, leave at the default value.
2235
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002236config HOTPLUG_CPU
Thomas Gleixnerbebd0242019-03-26 17:36:06 +01002237 def_bool y
Stephen Rothwell40b31362013-05-21 13:49:35 +10002238 depends on SMP
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002239
Fenghua Yu80aa1df2012-11-13 11:32:39 -08002240config BOOTPARAM_HOTPLUG_CPU0
2241 bool "Set default setting of cpu0_hotpluggable"
Kees Cook2c922cd2013-01-22 13:01:19 -08002242 depends on HOTPLUG_CPU
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002243 help
Fenghua Yu80aa1df2012-11-13 11:32:39 -08002244 Set whether default state of cpu0_hotpluggable is on or off.
2245
2246 Say Y here to enable CPU0 hotplug by default. If this switch
2247 is turned on, there is no need to give cpu0_hotplug kernel
2248 parameter and the CPU0 hotplug feature is enabled by default.
2249
2250 Please note: there are two known CPU0 dependencies if you want
2251 to enable the CPU0 hotplug feature either by this switch or by
2252 cpu0_hotplug kernel parameter.
2253
2254 First, resume from hibernate or suspend always starts from CPU0.
2255 So hibernate and suspend are prevented if CPU0 is offline.
2256
2257 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2258 offline if any interrupt can not migrate out of CPU0. There may
2259 be other CPU0 dependencies.
2260
2261 Please make sure the dependencies are under your control before
2262 you enable this feature.
2263
2264 Say N if you don't want to enable CPU0 hotplug feature by default.
2265 You still can enable the CPU0 hotplug feature at boot by kernel
2266 parameter cpu0_hotplug.
2267
Fenghua Yua71c8bc2012-11-13 11:32:51 -08002268config DEBUG_HOTPLUG_CPU0
2269 def_bool n
2270 prompt "Debug CPU0 hotplug"
Kees Cook2c922cd2013-01-22 13:01:19 -08002271 depends on HOTPLUG_CPU
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002272 help
Fenghua Yua71c8bc2012-11-13 11:32:51 -08002273 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2274 soon as possible and boots up userspace with CPU0 offlined. User
2275 can online CPU0 back after boot time.
2276
2277 To debug CPU0 hotplug, you need to enable CPU0 offline/online
2278 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2279 compilation or giving cpu0_hotplug kernel parameter at boot.
2280
2281 If unsure, say N.
2282
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002283config COMPAT_VDSO
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002284 def_bool n
2285 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
Ingo Molnar953fee12016-11-15 10:22:52 +01002286 depends on COMPAT_32
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002287 help
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002288 Certain buggy versions of glibc will crash if they are
2289 presented with a 32-bit vDSO that is not mapped at the address
2290 indicated in its segment table.
Randy Dunlape84446d2009-11-10 15:46:52 -08002291
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002292 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2293 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2294 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
2295 the only released version with the bug, but OpenSUSE 9
2296 contains a buggy "glibc 2.3.2".
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002297
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002298 The symptom of the bug is that everything crashes on startup, saying:
2299 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2300
2301 Saying Y here changes the default value of the vdso32 boot
2302 option from 1 to 0, which turns off the 32-bit vDSO entirely.
2303 This works around the glibc bug but hurts performance.
2304
2305 If unsure, say N: if you are compiling your own kernel, you
2306 are unlikely to be using a buggy version of glibc.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002307
Kees Cook3dc33bd2015-08-12 17:55:19 -07002308choice
2309 prompt "vsyscall table for legacy applications"
2310 depends on X86_64
Andy Lutomirski625b7b72019-06-26 21:45:07 -07002311 default LEGACY_VSYSCALL_XONLY
Kees Cook3dc33bd2015-08-12 17:55:19 -07002312 help
2313 Legacy user code that does not know how to find the vDSO expects
2314 to be able to issue three syscalls by calling fixed addresses in
2315 kernel space. Since this location is not randomized with ASLR,
2316 it can be used to assist security vulnerability exploitation.
2317
2318 This setting can be changed at boot time via the kernel command
Andy Lutomirskibd49e162019-06-26 21:45:03 -07002319 line parameter vsyscall=[emulate|xonly|none].
Kees Cook3dc33bd2015-08-12 17:55:19 -07002320
2321 On a system with recent enough glibc (2.14 or newer) and no
2322 static binaries, you can say None without a performance penalty
2323 to improve security.
2324
Andy Lutomirskibd49e162019-06-26 21:45:03 -07002325 If unsure, select "Emulate execution only".
Kees Cook3dc33bd2015-08-12 17:55:19 -07002326
Kees Cook3dc33bd2015-08-12 17:55:19 -07002327 config LEGACY_VSYSCALL_EMULATE
Andy Lutomirskibd49e162019-06-26 21:45:03 -07002328 bool "Full emulation"
Kees Cook3dc33bd2015-08-12 17:55:19 -07002329 help
Andy Lutomirskibd49e162019-06-26 21:45:03 -07002330 The kernel traps and emulates calls into the fixed vsyscall
2331 address mapping. This makes the mapping non-executable, but
2332 it still contains readable known contents, which could be
2333 used in certain rare security vulnerability exploits. This
2334 configuration is recommended when using legacy userspace
2335 that still uses vsyscalls along with legacy binary
2336 instrumentation tools that require code to be readable.
2337
2338 An example of this type of legacy userspace is running
2339 Pin on an old binary that still uses vsyscalls.
2340
2341 config LEGACY_VSYSCALL_XONLY
2342 bool "Emulate execution only"
2343 help
2344 The kernel traps and emulates calls into the fixed vsyscall
2345 address mapping and does not allow reads. This
2346 configuration is recommended when userspace might use the
2347 legacy vsyscall area but support for legacy binary
2348 instrumentation of legacy code is not needed. It mitigates
2349 certain uses of the vsyscall area as an ASLR-bypassing
2350 buffer.
Kees Cook3dc33bd2015-08-12 17:55:19 -07002351
2352 config LEGACY_VSYSCALL_NONE
2353 bool "None"
2354 help
2355 There will be no vsyscall mapping at all. This will
2356 eliminate any risk of ASLR bypass due to the vsyscall
2357 fixed address mapping. Attempts to use the vsyscalls
2358 will be reported to dmesg, so that either old or
2359 malicious userspace programs can be identified.
2360
2361endchoice
2362
Tim Bird516cbf32008-08-12 12:52:36 -07002363config CMDLINE_BOOL
2364 bool "Built-in kernel command line"
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002365 help
Tim Bird516cbf32008-08-12 12:52:36 -07002366 Allow for specifying boot arguments to the kernel at
2367 build time. On some systems (e.g. embedded ones), it is
2368 necessary or convenient to provide some or all of the
2369 kernel boot arguments with the kernel itself (that is,
2370 to not rely on the boot loader to provide them.)
2371
2372 To compile command line arguments into the kernel,
2373 set this option to 'Y', then fill in the
Sébastien Hinderer69711ca2015-07-08 00:02:01 +02002374 boot arguments in CONFIG_CMDLINE.
Tim Bird516cbf32008-08-12 12:52:36 -07002375
2376 Systems with fully functional boot loaders (i.e. non-embedded)
2377 should leave this option set to 'N'.
2378
2379config CMDLINE
2380 string "Built-in kernel command string"
2381 depends on CMDLINE_BOOL
2382 default ""
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002383 help
Tim Bird516cbf32008-08-12 12:52:36 -07002384 Enter arguments here that should be compiled into the kernel
2385 image and used at boot time. If the boot loader provides a
2386 command line at boot time, it is appended to this string to
2387 form the full kernel command line, when the system boots.
2388
2389 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2390 change this behavior.
2391
2392 In most cases, the command line (whether built-in or provided
2393 by the boot loader) should specify the device for the root
2394 file system.
2395
2396config CMDLINE_OVERRIDE
2397 bool "Built-in command line overrides boot loader arguments"
Anders Roxell645e6462020-01-24 12:46:15 +01002398 depends on CMDLINE_BOOL && CMDLINE != ""
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002399 help
Tim Bird516cbf32008-08-12 12:52:36 -07002400 Set this option to 'Y' to have the kernel ignore the boot loader
2401 command line, and use ONLY the built-in command line.
2402
2403 This is used to work around broken boot loaders. This should
2404 be set to 'N' under normal conditions.
2405
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07002406config MODIFY_LDT_SYSCALL
2407 bool "Enable the LDT (local descriptor table)" if EXPERT
2408 default y
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002409 help
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07002410 Linux can allow user programs to install a per-process x86
2411 Local Descriptor Table (LDT) using the modify_ldt(2) system
2412 call. This is required to run 16-bit or segmented code such as
2413 DOSEMU or some Wine programs. It is also used by some very old
2414 threading libraries.
2415
2416 Enabling this feature adds a small amount of overhead to
2417 context switches and increases the low-level kernel attack
2418 surface. Disabling it removes the modify_ldt(2) system call.
2419
2420 Saying 'N' here may make sense for embedded or server kernels.
2421
Seth Jenningsb700e7f2014-12-16 11:58:19 -06002422source "kernel/livepatch/Kconfig"
2423
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002424endmenu
2425
Michal Hocko3072e412017-09-08 16:11:39 -07002426config ARCH_HAS_ADD_PAGES
2427 def_bool y
2428 depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
2429
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002430config ARCH_ENABLE_MEMORY_HOTPLUG
2431 def_bool y
2432 depends on X86_64 || (X86_32 && HIGHMEM)
2433
Gary Hade35551052008-10-31 10:52:03 -07002434config ARCH_ENABLE_MEMORY_HOTREMOVE
2435 def_bool y
2436 depends on MEMORY_HOTPLUG
2437
Lee Schermerhorne534c7c2010-05-26 14:44:58 -07002438config USE_PERCPU_NUMA_NODE_ID
Tejun Heo645a7912011-01-23 14:37:40 +01002439 def_bool y
Lee Schermerhorne534c7c2010-05-26 14:44:58 -07002440 depends on NUMA
2441
Kirill A. Shutemov94918462013-11-14 14:31:10 -08002442config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2443 def_bool y
2444 depends on X86_64 || X86_PAE
2445
Naoya Horiguchic177c812014-06-04 16:05:35 -07002446config ARCH_ENABLE_HUGEPAGE_MIGRATION
2447 def_bool y
2448 depends on X86_64 && HUGETLB_PAGE && MIGRATION
2449
Naoya Horiguchi9c670ea2017-09-08 16:10:53 -07002450config ARCH_ENABLE_THP_MIGRATION
2451 def_bool y
2452 depends on X86_64 && TRANSPARENT_HUGEPAGE
2453
Bjorn Helgaasda85f862008-11-05 13:37:27 -06002454menu "Power management and ACPI options"
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002455
2456config ARCH_HIBERNATION_HEADER
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002457 def_bool y
Zhimin Gu44556532018-09-21 14:27:29 +08002458 depends on HIBERNATION
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002459
2460source "kernel/power/Kconfig"
2461
2462source "drivers/acpi/Kconfig"
2463
Feng Tangefafc8b2009-08-14 15:23:29 -04002464source "drivers/sfi/Kconfig"
2465
Andi Kleena6b68072008-01-30 13:32:49 +01002466config X86_APM_BOOT
Jan Beulich6fc108a2010-04-21 15:23:44 +01002467 def_bool y
Paul Bolle282e5aa2011-11-17 11:41:31 +01002468 depends on APM
Andi Kleena6b68072008-01-30 13:32:49 +01002469
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002470menuconfig APM
2471 tristate "APM (Advanced Power Management) BIOS support"
Ingo Molnarefefa6f2008-07-10 16:09:50 +02002472 depends on X86_32 && PM_SLEEP
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002473 help
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002474 APM is a BIOS specification for saving power using several different
2475 techniques. This is mostly useful for battery powered laptops with
2476 APM compliant BIOSes. If you say Y here, the system time will be
2477 reset after a RESUME operation, the /proc/apm device will provide
2478 battery status information, and user-space programs will receive
2479 notification of APM "events" (e.g. battery status change).
2480
2481 If you select "Y" here, you can disable actual use of the APM
2482 BIOS by passing the "apm=off" option to the kernel at boot time.
2483
2484 Note that the APM support is almost completely disabled for
2485 machines with more than one CPU.
2486
2487 In order to use APM, you will need supporting software. For location
Mauro Carvalho Chehab151f4e22019-06-13 07:10:36 -03002488 and more information, read <file:Documentation/power/apm-acpi.rst>
Michael Witten2dc98fd2011-07-08 21:11:16 +00002489 and the Battery Powered Linux mini-HOWTO, available from
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002490 <http://www.tldp.org/docs.html#howto>.
2491
2492 This driver does not spin down disk drives (see the hdparm(8)
2493 manpage ("man 8 hdparm") for that), and it doesn't turn off
2494 VESA-compliant "green" monitors.
2495
2496 This driver does not support the TI 4000M TravelMate and the ACER
2497 486/DX4/75 because they don't have compliant BIOSes. Many "green"
2498 desktop machines also don't have compliant BIOSes, and this driver
2499 may cause those machines to panic during the boot phase.
2500
2501 Generally, if you don't have a battery in your machine, there isn't
2502 much point in using this driver and you should say N. If you get
2503 random kernel OOPSes or reboots that don't seem to be related to
2504 anything, try disabling/enabling this option (or disabling/enabling
2505 APM in your BIOS).
2506
2507 Some other things you should try when experiencing seemingly random,
2508 "weird" problems:
2509
2510 1) make sure that you have enough swap space and that it is
2511 enabled.
2512 2) pass the "no-hlt" option to the kernel
2513 3) switch on floating point emulation in the kernel and pass
2514 the "no387" option to the kernel
2515 4) pass the "floppy=nodma" option to the kernel
2516 5) pass the "mem=4M" option to the kernel (thereby disabling
2517 all but the first 4 MB of RAM)
2518 6) make sure that the CPU is not over clocked.
2519 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2520 8) disable the cache from your BIOS settings
2521 9) install a fan for the video card or exchange video RAM
2522 10) install a better fan for the CPU
2523 11) exchange RAM chips
2524 12) exchange the motherboard.
2525
2526 To compile this driver as a module, choose M here: the
2527 module will be called apm.
2528
2529if APM
2530
2531config APM_IGNORE_USER_SUSPEND
2532 bool "Ignore USER SUSPEND"
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002533 help
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002534 This option will ignore USER SUSPEND requests. On machines with a
2535 compliant APM BIOS, you want to say N. However, on the NEC Versa M
2536 series notebooks, it is necessary to say Y because of a BIOS bug.
2537
2538config APM_DO_ENABLE
2539 bool "Enable PM at boot time"
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002540 help
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002541 Enable APM features at boot time. From page 36 of the APM BIOS
2542 specification: "When disabled, the APM BIOS does not automatically
2543 power manage devices, enter the Standby State, enter the Suspend
2544 State, or take power saving steps in response to CPU Idle calls."
2545 This driver will make CPU Idle calls when Linux is idle (unless this
2546 feature is turned off -- see "Do CPU IDLE calls", below). This
2547 should always save battery power, but more complicated APM features
2548 will be dependent on your BIOS implementation. You may need to turn
2549 this option off if your computer hangs at boot time when using APM
2550 support, or if it beeps continuously instead of suspending. Turn
2551 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2552 T400CDT. This is off by default since most machines do fine without
2553 this feature.
2554
2555config APM_CPU_IDLE
Len Browndd8af072013-02-09 21:10:04 -05002556 depends on CPU_IDLE
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002557 bool "Make CPU Idle calls when idle"
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002558 help
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002559 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2560 On some machines, this can activate improved power savings, such as
2561 a slowed CPU clock rate, when the machine is idle. These idle calls
2562 are made after the idle loop has run for some length of time (e.g.,
2563 333 mS). On some machines, this will cause a hang at boot time or
2564 whenever the CPU becomes idle. (On machines with more than one CPU,
2565 this option does nothing.)
2566
2567config APM_DISPLAY_BLANK
2568 bool "Enable console blanking using APM"
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002569 help
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002570 Enable console blanking using the APM. Some laptops can use this to
2571 turn off the LCD backlight when the screen blanker of the Linux
2572 virtual console blanks the screen. Note that this is only used by
2573 the virtual console screen blanker, and won't turn off the backlight
2574 when using the X Window system. This also doesn't have anything to
2575 do with your VESA-compliant power-saving monitor. Further, this
2576 option doesn't work for all laptops -- it might not turn off your
2577 backlight at all, or it might print a lot of errors to the console,
2578 especially if you are using gpm.
2579
2580config APM_ALLOW_INTS
2581 bool "Allow interrupts during APM BIOS calls"
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002582 help
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002583 Normally we disable external interrupts while we are making calls to
2584 the APM BIOS as a measure to lessen the effects of a badly behaving
2585 BIOS implementation. The BIOS should reenable interrupts if it
2586 needs to. Unfortunately, some BIOSes do not -- especially those in
2587 many of the newer IBM Thinkpads. If you experience hangs when you
2588 suspend, try setting this to Y. Otherwise, say N.
2589
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002590endif # APM
2591
Dave Jonesbb0a56e2011-05-19 18:51:07 -04002592source "drivers/cpufreq/Kconfig"
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002593
2594source "drivers/cpuidle/Kconfig"
2595
Andy Henroid27471fd2008-10-09 11:45:22 -07002596source "drivers/idle/Kconfig"
2597
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002598endmenu
2599
2600
2601menu "Bus options (PCI etc.)"
2602
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002603choice
2604 prompt "PCI access mode"
Ingo Molnarefefa6f2008-07-10 16:09:50 +02002605 depends on X86_32 && PCI
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002606 default PCI_GOANY
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002607 help
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002608 On PCI systems, the BIOS can be used to detect the PCI devices and
2609 determine their configuration. However, some old PCI motherboards
2610 have BIOS bugs and may crash if this is done. Also, some embedded
2611 PCI-based systems don't have any BIOS at all. Linux can also try to
2612 detect the PCI hardware directly without using the BIOS.
2613
2614 With this option, you can specify how Linux should detect the
2615 PCI devices. If you choose "BIOS", the BIOS will be used,
2616 if you choose "Direct", the BIOS won't be used, and if you
2617 choose "MMConfig", then PCI Express MMCONFIG will be used.
2618 If you choose "Any", the kernel will try MMCONFIG, then the
2619 direct access method and falls back to the BIOS if that doesn't
2620 work. If unsure, go with the default, which is "Any".
2621
2622config PCI_GOBIOS
2623 bool "BIOS"
2624
2625config PCI_GOMMCONFIG
2626 bool "MMConfig"
2627
2628config PCI_GODIRECT
2629 bool "Direct"
2630
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002631config PCI_GOOLPC
Daniel Drake76fb6572010-09-23 17:28:04 +01002632 bool "OLPC XO-1"
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002633 depends on OLPC
2634
Andres Salomon2bdd1b02008-06-05 14:14:41 -07002635config PCI_GOANY
2636 bool "Any"
2637
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002638endchoice
2639
2640config PCI_BIOS
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002641 def_bool y
Ingo Molnarefefa6f2008-07-10 16:09:50 +02002642 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002643
2644# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2645config PCI_DIRECT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002646 def_bool y
Shaohua Li0aba4962011-05-27 14:59:39 +08002647 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002648
2649config PCI_MMCONFIG
Jan Kiszkab45c9f32018-03-07 08:39:16 +01002650 bool "Support mmconfig PCI config space access" if X86_64
2651 default y
Jan Kiszka8364e1f2018-03-07 08:39:17 +01002652 depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST)
Jan Kiszkab45c9f32018-03-07 08:39:16 +01002653 depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002654
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002655config PCI_OLPC
Andres Salomon2bdd1b02008-06-05 14:14:41 -07002656 def_bool y
2657 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002658
Alex Nixonb5401a92010-03-18 16:31:34 -04002659config PCI_XEN
2660 def_bool y
2661 depends on PCI && XEN
2662 select SWIOTLB_XEN
2663
Jan Kiszka8364e1f2018-03-07 08:39:17 +01002664config MMCONF_FAM10H
2665 def_bool y
2666 depends on X86_64 && PCI_MMCONFIG && ACPI
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002667
Ira W. Snyder3f6ea842010-04-01 11:43:30 -07002668config PCI_CNB20LE_QUIRK
David Rientjes6a108a12011-01-20 14:44:16 -08002669 bool "Read CNB20LE Host Bridge Windows" if EXPERT
Kees Cook6ea30382012-10-02 11:16:47 -07002670 depends on PCI
Ira W. Snyder3f6ea842010-04-01 11:43:30 -07002671 help
2672 Read the PCI windows out of the CNB20LE host bridge. This allows
2673 PCI hotplug to work on systems with the CNB20LE chipset which do
2674 not have ACPI.
2675
Bjorn Helgaas64a5fed2011-01-06 10:12:30 -07002676 There's no public spec for this chipset, and this functionality
2677 is known to be incomplete.
2678
2679 You should say N unless you know you need this.
2680
William Breathitt Gray3a495512016-05-27 18:08:27 -04002681config ISA_BUS
William Breathitt Gray17a2a122017-12-29 15:14:46 -05002682 bool "ISA bus support on modern systems" if EXPERT
William Breathitt Gray3a495512016-05-27 18:08:27 -04002683 help
William Breathitt Gray17a2a122017-12-29 15:14:46 -05002684 Expose ISA bus device drivers and options available for selection and
2685 configuration. Enable this option if your target machine has an ISA
2686 bus. ISA is an older system, displaced by PCI and newer bus
2687 architectures -- if your target machine is modern, it probably does
2688 not have an ISA bus.
William Breathitt Gray3a495512016-05-27 18:08:27 -04002689
2690 If unsure, say N.
2691
David Rientjes1c00f012011-03-22 16:34:59 -07002692# x86_64 have no ISA slots, but can have ISA-style DMA.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002693config ISA_DMA_API
David Rientjes1c00f012011-03-22 16:34:59 -07002694 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2695 default y
2696 help
2697 Enables ISA-style DMA support for devices requiring such controllers.
2698 If unsure, say Y.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002699
Linus Torvalds51e68d02016-05-21 10:25:19 -07002700if X86_32
2701
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002702config ISA
2703 bool "ISA support"
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002704 help
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002705 Find out whether you have ISA slots on your motherboard. ISA is the
2706 name of a bus system, i.e. the way the CPU talks to the other stuff
2707 inside your box. Other bus systems are PCI, EISA, MicroChannel
2708 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2709 newer boards don't support it. If you have ISA, say Y, otherwise N.
2710
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002711config SCx200
2712 tristate "NatSemi SCx200 support"
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002713 help
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002714 This provides basic support for National Semiconductor's
2715 (now AMD's) Geode processors. The driver probes for the
2716 PCI-IDs of several on-chip devices, so its a good dependency
2717 for other scx200_* drivers.
2718
2719 If compiled as a module, the driver is named scx200.
2720
2721config SCx200HR_TIMER
2722 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
John Stultz592913e2010-07-13 17:56:20 -07002723 depends on SCx200
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002724 default y
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002725 help
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002726 This driver provides a clocksource built upon the on-chip
2727 27MHz high-resolution timer. Its also a workaround for
2728 NSC Geode SC-1100's buggy TSC, which loses time when the
2729 processor goes idle (as is done by the scheduler). The
2730 other workaround is idle=poll boot option.
2731
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002732config OLPC
2733 bool "One Laptop Per Child support"
Thomas Gleixner54008972011-02-23 09:50:15 +01002734 depends on !X86_PAE
Andres Salomon3c554942009-12-14 18:00:36 -08002735 select GPIOLIB
Thomas Gleixnerdc3119e702011-02-23 10:08:31 +01002736 select OF
Daniel Drake45bb1672011-03-13 15:10:17 +00002737 select OF_PROMTREE
Grant Likelyb4e51852011-12-16 15:50:17 -07002738 select IRQ_DOMAIN
Lubomir Rintel0c3d9312019-05-13 09:56:37 +02002739 select OLPC_EC
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002740 help
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002741 Add support for detecting the unique features of the OLPC
2742 XO hardware.
2743
Daniel Drakea3128582011-06-25 17:34:10 +01002744config OLPC_XO1_PM
2745 bool "OLPC XO-1 Power Management"
Borislav Petkovfa112cf2018-10-05 15:13:07 +02002746 depends on OLPC && MFD_CS5535=y && PM_SLEEP
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002747 help
Daniel Drake97c4cb72011-06-25 17:34:11 +01002748 Add support for poweroff and suspend of the OLPC XO-1 laptop.
Daniel Drakebf1ebf02010-10-10 10:40:32 +01002749
Daniel Drakecfee9592011-06-25 17:34:17 +01002750config OLPC_XO1_RTC
2751 bool "OLPC XO-1 Real Time Clock"
2752 depends on OLPC_XO1_PM && RTC_DRV_CMOS
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002753 help
Daniel Drakecfee9592011-06-25 17:34:17 +01002754 Add support for the XO-1 real time clock, which can be used as a
2755 programmable wakeup source.
2756
Daniel Drake7feda8e2011-06-25 17:34:12 +01002757config OLPC_XO1_SCI
2758 bool "OLPC XO-1 SCI extras"
Arnd Bergmann92e830f2018-04-04 14:44:54 +02002759 depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
Randy Dunlaped8e47f2012-12-18 12:22:17 -08002760 depends on INPUT=y
Daniel Draked8d01a62011-07-24 18:33:21 +01002761 select POWER_SUPPLY
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002762 help
Daniel Drake7feda8e2011-06-25 17:34:12 +01002763 Add support for SCI-based features of the OLPC XO-1 laptop:
Daniel Drake7bc74b32011-06-25 17:34:14 +01002764 - EC-driven system wakeups
Daniel Drake7feda8e2011-06-25 17:34:12 +01002765 - Power button
Daniel Drake7bc74b32011-06-25 17:34:14 +01002766 - Ebook switch
Daniel Drake2cf2bae2011-06-25 17:34:15 +01002767 - Lid switch
Daniel Drakee1040ac2011-06-25 17:34:16 +01002768 - AC adapter status updates
2769 - Battery status updates
Daniel Drake7feda8e2011-06-25 17:34:12 +01002770
Daniel Drakea0f30f52011-06-25 17:34:18 +01002771config OLPC_XO15_SCI
2772 bool "OLPC XO-1.5 SCI extras"
Daniel Draked8d01a62011-07-24 18:33:21 +01002773 depends on OLPC && ACPI
2774 select POWER_SUPPLY
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002775 help
Daniel Drakea0f30f52011-06-25 17:34:18 +01002776 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2777 - EC-driven system wakeups
2778 - AC adapter status updates
2779 - Battery status updates
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002780
Ed Wildgoosed4f3e352011-09-20 14:00:12 -07002781config ALIX
2782 bool "PCEngines ALIX System Support (LED setup)"
2783 select GPIOLIB
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002784 help
Ed Wildgoosed4f3e352011-09-20 14:00:12 -07002785 This option enables system support for the PCEngines ALIX.
2786 At present this just sets up LEDs for GPIO control on
2787 ALIX2/3/6 boards. However, other system specific setup should
2788 get added here.
2789
2790 Note: You must still enable the drivers for GPIO and LED support
2791 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2792
2793 Note: You have to set alix.force=1 for boards with Award BIOS.
2794
Philip Prindevilleda4e3302012-03-05 15:05:15 -08002795config NET5501
2796 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2797 select GPIOLIB
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002798 help
Philip Prindevilleda4e3302012-03-05 15:05:15 -08002799 This option enables system support for the Soekris Engineering net5501.
2800
Philip A. Prindeville31970592012-01-14 01:45:39 -07002801config GEOS
2802 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2803 select GPIOLIB
2804 depends on DMI
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002805 help
Philip A. Prindeville31970592012-01-14 01:45:39 -07002806 This option enables system support for the Traverse Technologies GEOS.
2807
Vivien Didelot7d029122013-01-04 16:18:14 -05002808config TS5500
2809 bool "Technologic Systems TS-5500 platform support"
2810 depends on MELAN
2811 select CHECK_SIGNATURE
2812 select NEW_LEDS
2813 select LEDS_CLASS
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002814 help
Vivien Didelot7d029122013-01-04 16:18:14 -05002815 This option enables system support for the Technologic Systems TS-5500.
2816
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002817endif # X86_32
2818
Andreas Herrmann23ac4ae2010-09-17 18:03:43 +02002819config AMD_NB
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002820 def_bool y
Borislav Petkov0e152cd2010-03-12 15:43:03 +01002821 depends on CPU_SUP_AMD && PCI
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002822
David Herrmanne3263ab2013-08-02 14:05:22 +02002823config X86_SYSFB
2824 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2825 help
2826 Firmwares often provide initial graphics framebuffers so the BIOS,
2827 bootloader or kernel can show basic video-output during boot for
2828 user-guidance and debugging. Historically, x86 used the VESA BIOS
2829 Extensions and EFI-framebuffers for this, which are mostly limited
2830 to x86.
2831 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2832 framebuffers so the new generic system-framebuffer drivers can be
2833 used on x86. If the framebuffer is not compatible with the generic
Nikolas Nybye3a5dc02018-08-25 19:10:54 -04002834 modes, it is advertised as fallback platform framebuffer so legacy
David Herrmanne3263ab2013-08-02 14:05:22 +02002835 drivers like efifb, vesafb and uvesafb can pick it up.
2836 If this option is not selected, all system framebuffers are always
2837 marked as fallback platform framebuffers as usual.
2838
2839 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2840 not be able to pick up generic system framebuffers if this option
2841 is selected. You are highly encouraged to enable simplefb as
2842 replacement if you select this option. simplefb can correctly deal
2843 with generic system framebuffers. But you should still keep vesafb
2844 and others enabled as fallback if a system framebuffer is
2845 incompatible with simplefb.
2846
2847 If unsure, say Y.
2848
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002849endmenu
2850
2851
Christoph Hellwig15724972018-07-31 13:39:30 +02002852menu "Binary Emulations"
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002853
2854config IA32_EMULATION
2855 bool "IA32 Emulation"
2856 depends on X86_64
Ingo Molnar39f88912016-11-15 10:22:52 +01002857 select ARCH_WANT_OLD_COMPAT_IPC
Randy Dunlapd1603992013-06-18 12:33:40 -07002858 select BINFMT_ELF
Roland McGratha97f52e2008-01-30 13:31:55 +01002859 select COMPAT_BINFMT_ELF
Ingo Molnar39f88912016-11-15 10:22:52 +01002860 select COMPAT_OLD_SIGACTION
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002861 help
H. J. Lu5fd92e62012-02-19 10:40:03 -08002862 Include code to run legacy 32-bit programs under a
2863 64-bit kernel. You should likely turn this on, unless you're
2864 100% sure that you don't have any 32-bit programs left.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002865
2866config IA32_AOUT
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002867 tristate "IA32 a.out support"
2868 depends on IA32_EMULATION
Borislav Petkoveac61652019-03-05 15:47:51 +01002869 depends on BROKEN
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002870 help
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002871 Support old a.out binaries in the 32bit emulation.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002872
H. Peter Anvin0bf62762012-02-27 14:09:10 -08002873config X86_X32
Kees Cook6ea30382012-10-02 11:16:47 -07002874 bool "x32 ABI for 64-bit mode"
Brian Gerst9b540502015-06-22 07:55:21 -04002875 depends on X86_64
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002876 help
H. J. Lu5fd92e62012-02-19 10:40:03 -08002877 Include code to run binaries for the x32 native 32-bit ABI
2878 for 64-bit processors. An x32 process gets access to the
2879 full 64-bit register file and wide data path while leaving
2880 pointers at 32 bits for smaller memory footprint.
2881
2882 You will need a recent binutils (2.22 or later) with
2883 elf32_x86_64 support enabled to compile a kernel with this
2884 option set.
2885
Ingo Molnar953fee12016-11-15 10:22:52 +01002886config COMPAT_32
2887 def_bool y
2888 depends on IA32_EMULATION || X86_32
2889 select HAVE_UID16
2890 select OLD_SIGSUSPEND3
2891
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002892config COMPAT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002893 def_bool y
H. Peter Anvin0bf62762012-02-27 14:09:10 -08002894 depends on IA32_EMULATION || X86_X32
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002895
Jan Beulich3120e252012-09-10 12:41:45 +01002896if COMPAT
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002897config COMPAT_FOR_U64_ALIGNMENT
Jan Beulich3120e252012-09-10 12:41:45 +01002898 def_bool y
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002899
2900config SYSVIPC_COMPAT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002901 def_bool y
Jan Beulich3120e252012-09-10 12:41:45 +01002902 depends on SYSVIPC
Jan Beulich3120e252012-09-10 12:41:45 +01002903endif
David Howellsee009e4a02011-03-07 15:06:20 +00002904
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002905endmenu
2906
2907
Keith Packarde5beae12008-11-03 18:21:45 +01002908config HAVE_ATOMIC_IOMAP
2909 def_bool y
2910 depends on X86_32
2911
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002912source "drivers/firmware/Kconfig"
2913
Avi Kivityedf88412007-12-16 11:02:48 +02002914source "arch/x86/kvm/Kconfig"
Jason A. Donenfeld5e8ebd82020-03-26 17:00:58 +09002915
2916source "arch/x86/Kconfig.assembler"