blob: 10163887c5ebe317cda14be5d5875959504887b1 [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 Gleixner157e1182020-11-03 10:27:20 +010017 select GENERIC_VDSO_32
Thomas Gleixner117ed452019-04-14 18:00:08 +020018 select HAVE_DEBUG_STACKOVERFLOW
Thomas Gleixner157e1182020-11-03 10:27:20 +010019 select KMAP_LOCAL
Ingo Molnar341c7872016-11-15 10:04:55 +010020 select MODULES_USE_ELF_REL
21 select OLD_SIGACTION
Brian Gerst2ca408d2020-11-30 17:30:59 -050022 select ARCH_SPLIT_ARG64
Sam Ravnborgdaa93fa2007-11-12 20:54:30 +010023
24config X86_64
Jan Beulich3120e252012-09-10 12:41:45 +010025 def_bool y
26 depends on 64BIT
Ingo Molnard94e0682016-11-15 10:11:57 +010027 # Options that are inherently 64-bit kernel only:
Alexandre Ghiti4eb07162019-05-13 17:19:04 -070028 select ARCH_HAS_GIGANTIC_PAGE
Ard Biesheuvelc12d3362019-11-08 13:22:27 +010029 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
Ingo Molnard94e0682016-11-15 10:11:57 +010030 select ARCH_USE_CMPXCHG_LOCKREF
31 select HAVE_ARCH_SOFT_DIRTY
32 select MODULES_USE_ELF_RELA
Christoph Hellwigf616ab52018-05-09 06:53:49 +020033 select NEED_DMA_MAP_STATE
Christoph Hellwig09230cb2018-04-24 09:00:54 +020034 select SWIOTLB
Al Viro7facdc42020-06-13 23:03:25 -040035 select ARCH_HAS_ELFCORE_COMPAT
Kefeng Wang63703f32021-06-30 18:52:20 -070036 select ZONE_DMA32
Sam Ravnborg1032c0b2007-11-06 21:35:08 +010037
Steven Rostedt (VMware)518049d2019-05-10 12:05:46 -040038config FORCE_DYNAMIC_FTRACE
39 def_bool y
40 depends on X86_32
41 depends on FUNCTION_TRACER
42 select DYNAMIC_FTRACE
43 help
44 We keep the static function tracing (!DYNAMIC_FTRACE) around
45 in order to test the non static function tracing in the
46 generic code, as other architectures still use it. But we
47 only need to keep it around for x86_64. No need to keep it
48 for x86_32. For x86_32, force DYNAMIC_FTRACE.
Ingo Molnard94e0682016-11-15 10:11:57 +010049#
50# Arch settings
51#
52# ( Note that options that are marked 'if X86_64' could in principle be
53# ported to 32-bit as well. )
54#
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +010055config X86
Harvey Harrison3c2362e2008-01-30 13:31:03 +010056 def_bool y
Ingo Molnarc763ea22016-11-15 10:26:39 +010057 #
58 # Note: keep this list sorted alphabetically
59 #
Ingo Molnar6471b822015-06-03 10:00:13 +020060 select ACPI_LEGACY_TABLES_LOOKUP if ACPI
61 select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI
Yury Norov942fa982018-05-16 11:18:49 +030062 select ARCH_32BIT_OFF_T if X86_32
Thomas Gleixner2a21ad52018-09-17 14:45:35 +020063 select ARCH_CLOCKSOURCE_INIT
Anshuman Khandual1e866972021-05-04 18:38:21 -070064 select ARCH_ENABLE_HUGEPAGE_MIGRATION if X86_64 && HUGETLB_PAGE && MIGRATION
Anshuman Khandual91024b32021-05-04 18:38:17 -070065 select ARCH_ENABLE_MEMORY_HOTPLUG if X86_64 || (X86_32 && HIGHMEM)
66 select ARCH_ENABLE_MEMORY_HOTREMOVE if MEMORY_HOTPLUG
Anshuman Khandualcebc7742021-06-30 18:51:58 -070067 select ARCH_ENABLE_SPLIT_PMD_PTLOCK if (PGTABLE_LEVELS > 2) && (X86_64 || X86_PAE)
Anshuman Khandual1e866972021-05-04 18:38:21 -070068 select ARCH_ENABLE_THP_MIGRATION if X86_64 && TRANSPARENT_HUGEPAGE
Ingo Molnarc763ea22016-11-15 10:26:39 +010069 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
Anshuman Khandualc2280be2021-05-04 18:38:09 -070070 select ARCH_HAS_CACHE_LINE_SIZE
Laura Abbottfa5b6ec2017-01-10 13:35:40 -080071 select ARCH_HAS_DEBUG_VIRTUAL
Anshuman Khandual399145f2020-06-04 16:47:15 -070072 select ARCH_HAS_DEBUG_VM_PGTABLE if !X86_PAE
Dan Williams21266be2015-11-19 18:19:29 -080073 select ARCH_HAS_DEVMEM_IS_ALLOWED
Douglas Andersonb1a57bb2020-05-07 13:08:42 -070074 select ARCH_HAS_EARLY_DEBUG if KGDB
Ingo Molnar6471b822015-06-03 10:00:13 +020075 select ARCH_HAS_ELF_RANDOMIZE
Linus Torvalds72d93102014-09-13 11:14:53 -070076 select ARCH_HAS_FAST_MULTIPLIER
Dave Hansen316d0972018-04-20 15:20:28 -070077 select ARCH_HAS_FILTER_PGPROT
Daniel Micay6974f0c2017-07-12 14:36:10 -070078 select ARCH_HAS_FORTIFY_SOURCE
Riku Voipio957e3fa2014-12-12 16:57:44 -080079 select ARCH_HAS_GCOV_PROFILE_ALL
Peter Zijlstra0f1441b2020-06-12 16:05:26 +020080 select ARCH_HAS_KCOV if X86_64 && STACK_VALIDATION
Thiago Jung Bauermann0c9c1d52019-08-06 01:49:14 -030081 select ARCH_HAS_MEM_ENCRYPT
Mathieu Desnoyers10bcc802018-01-29 15:20:18 -050082 select ARCH_HAS_MEMBARRIER_SYNC_CORE
Daniel Borkmann0ebeea82020-05-15 12:11:16 +020083 select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
Ingo Molnarc763ea22016-11-15 10:26:39 +010084 select ARCH_HAS_PMEM_API if X86_64
Robin Murphy17596732019-07-16 16:30:47 -070085 select ARCH_HAS_PTE_DEVMAP if X86_64
Laurent Dufour3010a5e2018-06-07 17:06:08 -070086 select ARCH_HAS_PTE_SPECIAL
Dan Williams0aed55a2017-05-29 12:22:50 -070087 select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64
Dan Williamsec6347b2020-10-05 20:40:16 -070088 select ARCH_HAS_COPY_MC if X86_64
Daniel Borkmannd2852a22017-02-21 16:09:33 +010089 select ARCH_HAS_SET_MEMORY
Rick Edgecombed253ca02019-04-25 17:11:34 -070090 select ARCH_HAS_SET_DIRECT_MAP
Laura Abbottad21fc42017-02-06 16:31:57 -080091 select ARCH_HAS_STRICT_KERNEL_RWX
92 select ARCH_HAS_STRICT_MODULE_RWX
Mathieu Desnoyersac1ab122018-01-29 15:20:16 -050093 select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
Brian Gerst25c619e2020-03-13 15:51:42 -040094 select ARCH_HAS_SYSCALL_WRAPPER
Andrey Ryabininc6d30852016-01-20 15:00:55 -080095 select ARCH_HAS_UBSAN_SANITIZE_ALL
Zong Li7e01ccb2020-06-03 16:03:58 -070096 select ARCH_HAS_DEBUG_WX
Kefeng Wang63703f32021-06-30 18:52:20 -070097 select ARCH_HAS_ZONE_DMA_SET if EXPERT
Ingo Molnar6471b822015-06-03 10:00:13 +020098 select ARCH_HAVE_NMI_SAFE_CMPXCHG
99 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
Mark Salter77fbbc82013-10-07 22:18:07 -0400100 select ARCH_MIGHT_HAVE_PC_PARPORT
Mark Salter5e2c18c2014-01-01 11:34:16 -0800101 select ARCH_MIGHT_HAVE_PC_SERIO
Thomas Gleixner3599fe12019-04-25 11:45:22 +0200102 select ARCH_STACKWALK
Arnd Bergmann2c870e62018-07-24 11:48:45 +0200103 select ARCH_SUPPORTS_ACPI
Ingo Molnar6471b822015-06-03 10:00:13 +0200104 select ARCH_SUPPORTS_ATOMIC_RMW
Mike Rapoport5d6ad662020-12-14 19:10:30 -0800105 select ARCH_SUPPORTS_DEBUG_PAGEALLOC
Ingo Molnar6471b822015-06-03 10:00:13 +0200106 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
Thomas Gleixner14df3262020-11-18 20:48:41 +0100107 select ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP if NR_CPUS <= 4096
Nathan Chancellor583bfd42021-04-29 16:26:12 -0700108 select ARCH_SUPPORTS_LTO_CLANG
109 select ARCH_SUPPORTS_LTO_CLANG_THIN
Ingo Molnar6471b822015-06-03 10:00:13 +0200110 select ARCH_USE_BUILTIN_BSWAP
Anshuman Khandualdce44562021-04-29 22:55:15 -0700111 select ARCH_USE_MEMTEST
Ingo Molnar6471b822015-06-03 10:00:13 +0200112 select ARCH_USE_QUEUED_RWLOCKS
113 select ARCH_USE_QUEUED_SPINLOCKS
Mark Brown2ce0d7f2020-04-16 19:24:02 +0100114 select ARCH_USE_SYM_ANNOTATIONS
Andy Lutomirskice4a4e562017-05-28 10:00:14 -0700115 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
Daniel Borkmann81c22042019-12-09 16:08:03 +0100116 select ARCH_WANT_DEFAULT_BPF_JIT if X86_64
Ingo Molnarc763ea22016-11-15 10:26:39 +0100117 select ARCH_WANTS_DYNAMIC_TASK_STRUCT
Nick Desaulniers51c2ee62021-06-21 16:18:22 -0700118 select ARCH_WANTS_NO_INSTR
Alexandre Ghiti3876d4a2019-06-27 15:00:11 -0700119 select ARCH_WANT_HUGE_PMD_SHARE
Nathan Chancellor59612b22020-11-19 13:46:56 -0700120 select ARCH_WANT_LD_ORPHAN_WARN
Huang Ying38d8b4e2017-07-06 15:37:18 -0700121 select ARCH_WANTS_THP_SWAP if X86_64
Balbir Singhb5f06f62021-04-26 21:42:30 +0200122 select ARCH_HAS_PARANOID_L1D_FLUSH
Shile Zhang10916702019-12-04 08:46:31 +0800123 select BUILDTIME_TABLE_SORT
Ingo Molnar6471b822015-06-03 10:00:13 +0200124 select CLKEVT_I8253
Ingo Molnar6471b822015-06-03 10:00:13 +0200125 select CLOCKSOURCE_VALIDATE_LAST_CYCLE
126 select CLOCKSOURCE_WATCHDOG
Ingo Molnar6471b822015-06-03 10:00:13 +0200127 select DCACHE_WORD_ACCESS
Linus Torvalds45471cd2015-06-24 19:52:06 -0700128 select EDAC_ATOMIC_SCRUB
129 select EDAC_SUPPORT
Ingo Molnar6471b822015-06-03 10:00:13 +0200130 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
131 select GENERIC_CLOCKEVENTS_MIN_ADJUST
132 select GENERIC_CMOS_UPDATE
133 select GENERIC_CPU_AUTOPROBE
Thomas Gleixner61dc0f52018-01-07 22:48:01 +0100134 select GENERIC_CPU_VULNERABILITIES
Ingo Molnar6471b822015-06-03 10:00:13 +0200135 select GENERIC_EARLY_IOREMAP
Thomas Gleixner27d6b4d2020-07-23 00:00:04 +0200136 select GENERIC_ENTRY
Ingo Molnar6471b822015-06-03 10:00:13 +0200137 select GENERIC_FIND_FIRST_BIT
138 select GENERIC_IOMAP
Thomas Gleixnerc7d6c9d2017-06-20 01:37:46 +0200139 select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP
Thomas Gleixner0fa115d2017-09-13 23:29:38 +0200140 select GENERIC_IRQ_MATRIX_ALLOCATOR if X86_LOCAL_APIC
Thomas Gleixnerad7a9292017-06-20 01:37:33 +0200141 select GENERIC_IRQ_MIGRATION if SMP
Ingo Molnar6471b822015-06-03 10:00:13 +0200142 select GENERIC_IRQ_PROBE
Thomas Gleixnerc201c912017-10-17 09:54:59 +0200143 select GENERIC_IRQ_RESERVATION_MODE
Ingo Molnar6471b822015-06-03 10:00:13 +0200144 select GENERIC_IRQ_SHOW
145 select GENERIC_PENDING_IRQ if SMP
Steven Price2ae27132020-02-03 17:36:24 -0800146 select GENERIC_PTDUMP
Ingo Molnar6471b822015-06-03 10:00:13 +0200147 select GENERIC_SMP_IDLE_THREAD
148 select GENERIC_STRNCPY_FROM_USER
149 select GENERIC_STRNLEN_USER
150 select GENERIC_TIME_VSYSCALL
Vincenzo Frascino7ac87072019-06-21 10:52:49 +0100151 select GENERIC_GETTIMEOFDAY
Dmitry Safonov550a77a2019-11-12 01:27:11 +0000152 select GENERIC_VDSO_TIME_NS
Christoph Hellwig39656e82019-07-11 20:56:49 -0700153 select GUP_GET_PTE_LOW_HIGH if X86_PAE
Hans de Goede17e58882020-01-23 22:02:42 +0100154 select HARDIRQS_SW_RESEND
Thomas Gleixner7edaeb62017-08-15 09:50:13 +0200155 select HARDLOCKUP_CHECK_TIMESTAMP if X86_64
Ingo Molnar6471b822015-06-03 10:00:13 +0200156 select HAVE_ACPI_APEI if ACPI
157 select HAVE_ACPI_APEI_NMI if ACPI
158 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
Ingo Molnar6471b822015-06-03 10:00:13 +0200159 select HAVE_ARCH_AUDITSYSCALL
160 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE
161 select HAVE_ARCH_JUMP_LABEL
Ard Biesheuvelb34006c2018-09-18 23:51:41 -0700162 select HAVE_ARCH_JUMP_LABEL_RELATIVE
Andrey Ryabinind17a1d92017-11-15 17:36:35 -0800163 select HAVE_ARCH_KASAN if X86_64
Daniel Axtens0609ae02019-11-30 17:55:00 -0800164 select HAVE_ARCH_KASAN_VMALLOC if X86_64
Alexander Potapenko1dc0da62021-02-25 17:18:57 -0800165 select HAVE_ARCH_KFENCE
Ingo Molnar6471b822015-06-03 10:00:13 +0200166 select HAVE_ARCH_KGDB
Daniel Cashman9e08f572016-01-14 15:20:06 -0800167 select HAVE_ARCH_MMAP_RND_BITS if MMU
168 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT
Dmitry Safonov1b028f72017-03-06 17:17:19 +0300169 select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT
Ard Biesheuvel271ca782018-08-21 21:56:00 -0700170 select HAVE_ARCH_PREL32_RELOCATIONS
Ingo Molnar6471b822015-06-03 10:00:13 +0200171 select HAVE_ARCH_SECCOMP_FILTER
Kees Cookf7d83c12017-08-16 13:26:03 -0700172 select HAVE_ARCH_THREAD_STRUCT_WHITELIST
Alexander Popovafaef012018-08-17 01:16:58 +0300173 select HAVE_ARCH_STACKLEAK
Ingo Molnar6471b822015-06-03 10:00:13 +0200174 select HAVE_ARCH_TRACEHOOK
175 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
Matthew Wilcoxa00cc7d2017-02-24 14:57:02 -0800176 select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
Peter Xub64d8d12020-04-20 18:13:45 -0700177 select HAVE_ARCH_USERFAULTFD_WP if X86_64 && USERFAULTFD
Axel Rasmussen7677f7f2021-05-04 18:35:36 -0700178 select HAVE_ARCH_USERFAULTFD_MINOR if X86_64 && USERFAULTFD
Andy Lutomirskie37e43a2016-08-11 02:35:23 -0700179 select HAVE_ARCH_VMAP_STACK if X86_64
Kees Cookfe950f62021-04-01 16:23:45 -0700180 select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
Ingo Molnarc763ea22016-11-15 10:26:39 +0100181 select HAVE_ARCH_WITHIN_STACK_FRAMES
Masahiro Yamada2ff2b7e2019-08-19 14:54:20 +0900182 select HAVE_ASM_MODVERSIONS
Ingo Molnar6471b822015-06-03 10:00:13 +0200183 select HAVE_CMPXCHG_DOUBLE
184 select HAVE_CMPXCHG_LOCAL
185 select HAVE_CONTEXT_TRACKING if X86_64
Frederic Weisbeckerd1f250e2020-11-17 16:16:37 +0100186 select HAVE_CONTEXT_TRACKING_OFFSTACK if HAVE_CONTEXT_TRACKING
Ingo Molnar6471b822015-06-03 10:00:13 +0200187 select HAVE_C_RECORDMCOUNT
Sami Tolvanen6dafca92020-08-06 15:15:02 -0700188 select HAVE_OBJTOOL_MCOUNT if STACK_VALIDATION
Ingo Molnar6471b822015-06-03 10:00:13 +0200189 select HAVE_DEBUG_KMEMLEAK
Akinobu Mita9c5a3622014-06-04 16:06:50 -0700190 select HAVE_DMA_CONTIGUOUS
Steven Rostedt677aa9f2008-05-17 00:01:36 -0400191 select HAVE_DYNAMIC_FTRACE
Masami Hiramatsu06aeaae2012-09-28 17:15:17 +0900192 select HAVE_DYNAMIC_FTRACE_WITH_REGS
Steven Rostedt (VMware)02a474c2020-10-27 10:55:55 -0400193 select HAVE_DYNAMIC_FTRACE_WITH_ARGS if X86_64
Steven Rostedt (VMware)562955f2019-11-08 13:11:39 -0500194 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
Wang YanQing03f57812018-05-03 14:10:43 +0800195 select HAVE_EBPF_JIT
Johannes Berg58340a02008-07-25 01:45:33 -0700196 select HAVE_EFFICIENT_UNALIGNED_ACCESS
Christoph Hellwig6630a8e2018-11-15 20:05:37 +0100197 select HAVE_EISA
Jiri Slaby5f56a5d2016-05-20 17:00:16 -0700198 select HAVE_EXIT_THREAD
Christoph Hellwig67a929e2019-07-11 20:57:14 -0700199 select HAVE_FAST_GUP
Steven Rostedt (VMware)644e0e82017-03-23 10:33:52 -0400200 select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE
Ingo Molnar6471b822015-06-03 10:00:13 +0200201 select HAVE_FTRACE_MCOUNT_RECORD
Ingo Molnar6471b822015-06-03 10:00:13 +0200202 select HAVE_FUNCTION_GRAPH_TRACER
203 select HAVE_FUNCTION_TRACER
Emese Revfy6b90bd42016-05-24 00:09:38 +0200204 select HAVE_GCC_PLUGINS
K.Prasad0067f122009-06-01 23:43:57 +0530205 select HAVE_HW_BREAKPOINT
Ingo Molnar6471b822015-06-03 10:00:13 +0200206 select HAVE_IOREMAP_PROT
Thomas Gleixner624db9e2021-02-10 00:40:51 +0100207 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
Ingo Molnar6471b822015-06-03 10:00:13 +0200208 select HAVE_IRQ_TIME_ACCOUNTING
209 select HAVE_KERNEL_BZIP2
210 select HAVE_KERNEL_GZIP
211 select HAVE_KERNEL_LZ4
212 select HAVE_KERNEL_LZMA
213 select HAVE_KERNEL_LZO
214 select HAVE_KERNEL_XZ
Nick Terrellfb46d052020-07-30 12:08:39 -0700215 select HAVE_KERNEL_ZSTD
Ingo Molnar6471b822015-06-03 10:00:13 +0200216 select HAVE_KPROBES
217 select HAVE_KPROBES_ON_FTRACE
Masami Hiramatsu540adea2018-01-13 02:55:03 +0900218 select HAVE_FUNCTION_ERROR_INJECTION
Ingo Molnar6471b822015-06-03 10:00:13 +0200219 select HAVE_KRETPROBES
220 select HAVE_KVM
221 select HAVE_LIVEPATCH if X86_64
Frederic Weisbecker01027522010-04-11 18:55:56 +0200222 select HAVE_MIXED_BREAKPOINTS_REGS
Josh Poimboeufee9f8fc2017-07-24 18:36:57 -0500223 select HAVE_MOD_ARCH_SPECIFIC
Joel Fernandes (Google)9f132f72019-01-03 15:28:41 -0800224 select HAVE_MOVE_PMD
Kalesh Singhbe37c982020-12-14 19:07:40 -0800225 select HAVE_MOVE_PUD
Petr Mladek42a0bb32016-05-20 17:00:33 -0700226 select HAVE_NMI
Ingo Molnar6471b822015-06-03 10:00:13 +0200227 select HAVE_OPTPROBES
228 select HAVE_PCSPKR_PLATFORM
229 select HAVE_PERF_EVENTS
Frederic Weisbeckerc01d4322010-05-15 22:57:48 +0200230 select HAVE_PERF_EVENTS_NMI
Nicholas Piggin92e5aae2017-08-18 15:15:51 -0700231 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
Christoph Hellwigeb01d422018-11-15 20:05:32 +0100232 select HAVE_PCI
Jiri Olsac5e63192012-08-07 15:20:36 +0200233 select HAVE_PERF_REGS
Jiri Olsac5ebced2012-08-07 15:20:40 +0200234 select HAVE_PERF_USER_STACK_DUMP
Peter Zijlstraff2e6d722020-02-03 17:37:02 -0800235 select MMU_GATHER_RCU_TABLE_FREE if PARAVIRT
Thomas Gleixner00998082020-07-30 12:14:07 +0200236 select HAVE_POSIX_CPU_TIMERS_TASK_WORK
Ingo Molnar6471b822015-06-03 10:00:13 +0200237 select HAVE_REGS_AND_STACK_ACCESS_API
Jiri Slaby6415b382018-05-18 08:47:13 +0200238 select HAVE_RELIABLE_STACKTRACE if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION
Masami Hiramatsu3c88ee194c2018-04-25 21:20:57 +0900239 select HAVE_FUNCTION_ARG_ACCESS_API
Thomas Gleixnercd1a41c2021-02-10 00:40:52 +0100240 select HAVE_SOFTIRQ_ON_OWN_STACK
Masahiro Yamadad148eac2018-06-14 19:36:45 +0900241 select HAVE_STACKPROTECTOR if CC_HAS_SANE_STACKPROTECTOR
Ingo Molnarc763ea22016-11-15 10:26:39 +0100242 select HAVE_STACK_VALIDATION if X86_64
Josh Poimboeufe6d6c072020-08-18 15:57:44 +0200243 select HAVE_STATIC_CALL
Josh Poimboeuf1e7e4782020-08-18 15:57:45 +0200244 select HAVE_STATIC_CALL_INLINE if HAVE_STACK_VALIDATION
Michal Hocko6ef869e2021-01-18 15:12:19 +0100245 select HAVE_PREEMPT_DYNAMIC
Mathieu Desnoyersd6761b82018-06-02 08:43:58 -0400246 select HAVE_RSEQ
Ingo Molnar6471b822015-06-03 10:00:13 +0200247 select HAVE_SYSCALL_TRACEPOINTS
Ingo Molnar6471b822015-06-03 10:00:13 +0200248 select HAVE_UNSTABLE_SCHED_CLOCK
Avi Kivity7c68af62009-09-19 09:40:22 +0300249 select HAVE_USER_RETURN_NOTIFIER
Vincenzo Frascino7ac87072019-06-21 10:52:49 +0100250 select HAVE_GENERIC_VDSO
Thomas Gleixner05736e42018-05-29 17:48:27 +0200251 select HOTPLUG_SMT if SMP
Thomas Gleixnerc01858082011-02-07 02:24:08 +0100252 select IRQ_FORCED_THREADING
Christoph Hellwig86596f02018-04-05 09:44:52 +0200253 select NEED_SG_DMA_LENGTH
Christoph Hellwig2eac9c22018-11-15 20:05:33 +0100254 select PCI_DOMAINS if PCI
Sinan Kaya625210c2019-01-21 23:19:58 +0000255 select PCI_LOCKLESS_CONFIG if PCI
Ingo Molnar6471b822015-06-03 10:00:13 +0200256 select PERF_EVENTS
Prarit Bhargava3195ef52013-02-14 12:02:54 -0500257 select RTC_LIB
Arnd Bergmannd6faca42016-06-01 16:46:23 +0200258 select RTC_MC146818_LIB
Ingo Molnar6471b822015-06-03 10:00:13 +0200259 select SPARSE_IRQ
Pranith Kumar83fe27e2014-12-05 11:24:45 -0500260 select SRCU
Josh Poimboeuf1e7e4782020-08-18 15:57:45 +0200261 select STACK_VALIDATION if HAVE_STACK_VALIDATION && (HAVE_STATIC_CALL_INLINE || RETPOLINE)
Ingo Molnar6471b822015-06-03 10:00:13 +0200262 select SYSCTL_EXCEPTION_TRACE
Andy Lutomirski15f4eae2016-09-13 14:29:25 -0700263 select THREAD_INFO_IN_TASK
Ingo Molnar6471b822015-06-03 10:00:13 +0200264 select USER_STACKTRACE_SUPPORT
265 select VIRT_TO_BUS
Ingo Molnar3b02a052020-04-13 09:44:39 +0200266 select HAVE_ARCH_KCSAN if X86_64
Ingo Molnar6471b822015-06-03 10:00:13 +0200267 select X86_FEATURE_NAMES if PROC_FS
Aubrey Li0c608da2019-06-06 09:22:35 +0800268 select PROC_PID_ARCH_STATUS if PROC_FS
Nayna Jain9e2b4be2020-03-08 20:57:51 -0400269 imply IMA_SECURE_AND_OR_TRUSTED_BOOT if EFI
Balbir Singh7d8330a2008-02-10 12:46:28 +0530270
Ingo Molnarba7e4d12009-06-06 13:58:12 +0200271config INSTRUCTION_DECODER
Jan Beulich3120e252012-09-10 12:41:45 +0100272 def_bool y
273 depends on KPROBES || PERF_EVENTS || UPROBES
Ingo Molnarba7e4d12009-06-06 13:58:12 +0200274
Linus Torvalds51b26ad2009-04-26 10:12:47 -0700275config OUTPUT_FORMAT
276 string
277 default "elf32-i386" if X86_32
278 default "elf64-x86-64" if X86_64
279
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100280config LOCKDEP_SUPPORT
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100281 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100282
283config STACKTRACE_SUPPORT
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100284 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100285
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100286config MMU
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100287 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100288
Daniel Cashman9e08f572016-01-14 15:20:06 -0800289config ARCH_MMAP_RND_BITS_MIN
290 default 28 if 64BIT
291 default 8
292
293config ARCH_MMAP_RND_BITS_MAX
294 default 32 if 64BIT
295 default 16
296
297config ARCH_MMAP_RND_COMPAT_BITS_MIN
298 default 8
299
300config ARCH_MMAP_RND_COMPAT_BITS_MAX
301 default 16
302
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100303config SBUS
304 bool
305
306config GENERIC_ISA_DMA
Jan Beulich3120e252012-09-10 12:41:45 +0100307 def_bool y
308 depends on ISA_DMA_API
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100309
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100310config GENERIC_BUG
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100311 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100312 depends on BUG
Jan Beulichb93a5312008-12-16 11:40:27 +0000313 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
314
315config GENERIC_BUG_RELATIVE_POINTERS
316 bool
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100317
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100318config ARCH_MAY_HAVE_PC_FDC
Jan Beulich3120e252012-09-10 12:41:45 +0100319 def_bool y
320 depends on ISA_DMA_API
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100321
Sam Ravnborg1032c0b2007-11-06 21:35:08 +0100322config GENERIC_CALIBRATE_DELAY
323 def_bool y
324
venkatesh.pallipadi@intel.com9a0b8412008-01-31 17:35:06 -0800325config ARCH_HAS_CPU_RELAX
326 def_bool y
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100327
Dave Hansen316d0972018-04-20 15:20:28 -0700328config ARCH_HAS_FILTER_PGPROT
329 def_bool y
330
Mike Travisdd5af902008-01-30 13:33:32 +0100331config HAVE_SETUP_PER_CPU_AREA
Brian Gerst89c9c4c2009-01-27 12:56:48 +0900332 def_bool y
travis@sgi.comb32ef632008-01-30 13:32:51 +0100333
Tejun Heo08fc4582009-08-14 15:00:49 +0900334config NEED_PER_CPU_EMBED_FIRST_CHUNK
335 def_bool y
336
337config NEED_PER_CPU_PAGE_FIRST_CHUNK
Tejun Heo11124412009-02-20 16:29:09 +0900338 def_bool y
339
Johannes Berg801e4062007-12-08 02:12:39 +0100340config ARCH_HIBERNATION_POSSIBLE
341 def_bool y
Johannes Berg801e4062007-12-08 02:12:39 +0100342
Andy Shevchenkod7109fe2021-08-26 18:03:17 +0300343config ARCH_NR_GPIO
344 int
345 default 1024 if X86_64
346 default 512
347
Johannes Bergf4cb5702007-12-08 02:14:00 +0100348config ARCH_SUSPEND_POSSIBLE
349 def_bool y
Johannes Bergf4cb5702007-12-08 02:14:00 +0100350
Steve Capper53313b22013-04-30 08:03:42 +0100351config ARCH_WANT_GENERAL_HUGETLB
352 def_bool y
353
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100354config AUDIT_ARCH
Jan Beuliche0fd24a2015-02-05 15:39:34 +0000355 def_bool y if X86_64
Sam Ravnborg8d5fffb2007-11-06 23:30:30 +0100356
Andrey Ryabinind6f2d752015-07-02 12:09:38 +0300357config KASAN_SHADOW_OFFSET
358 hex
359 depends on KASAN
360 default 0xdffffc0000000000
361
Shane Wang69575d32009-09-01 18:25:07 -0700362config HAVE_INTEL_TXT
363 def_bool y
Kees Cook6ea30382012-10-02 11:16:47 -0700364 depends on INTEL_IOMMU && ACPI
Shane Wang69575d32009-09-01 18:25:07 -0700365
Sam Ravnborg6b0c3d42008-01-30 13:32:27 +0100366config X86_32_SMP
367 def_bool y
368 depends on X86_32 && SMP
369
370config X86_64_SMP
371 def_bool y
372 depends on X86_64 && SMP
373
Srikar Dronamraju2b144492012-02-09 14:56:42 +0530374config ARCH_SUPPORTS_UPROBES
375 def_bool y
376
Rob Herringd20642f2014-04-18 17:19:54 -0500377config FIX_EARLYCON_MEM
378 def_bool y
379
Kirill A. Shutemov94d49eb2018-05-18 14:30:28 +0300380config DYNAMIC_PHYSICAL_MASK
381 bool
382
Kirill A. Shutemov98233362015-04-14 15:46:14 -0700383config PGTABLE_LEVELS
384 int
Kirill A. Shutemov77ef56e2017-07-17 01:59:54 +0300385 default 5 if X86_5LEVEL
Kirill A. Shutemov98233362015-04-14 15:46:14 -0700386 default 4 if X86_64
387 default 3 if X86_PAE
388 default 2
389
Masahiro Yamada2a61f472018-05-28 18:22:00 +0900390config CC_HAS_SANE_STACKPROTECTOR
391 bool
392 default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT
393 default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC))
394 help
395 We have to make sure stack protector is unconditionally disabled if
Andy Lutomirski3fb0fdb2021-02-13 11:19:44 -0800396 the compiler produces broken code or if it does not let us control
397 the segment on 32-bit kernels.
Masahiro Yamada2a61f472018-05-28 18:22:00 +0900398
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100399menu "Processor type and features"
400
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100401config SMP
402 bool "Symmetric multi-processing support"
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900403 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100404 This enables support for systems with more than one CPU. If you have
Robert Graffham4a474152014-01-23 15:55:29 -0800405 a system with only one CPU, say N. If you have a system with more
406 than one CPU, say Y.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100407
Robert Graffham4a474152014-01-23 15:55:29 -0800408 If you say N here, the kernel will run on uni- and multiprocessor
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100409 machines, but will use only one CPU of a multiprocessor machine. If
410 you say Y here, the kernel will run on many, but not all,
Robert Graffham4a474152014-01-23 15:55:29 -0800411 uniprocessor machines. On a uniprocessor machine, the kernel
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100412 will run faster if you say N here.
413
414 Note that if you say Y here and choose architecture "586" or
415 "Pentium" under "Processor family", the kernel will not work on 486
416 architectures. Similarly, multiprocessor kernels for the "PPro"
417 architecture may not work on all Pentium based boards.
418
419 People using multiprocessor machines who say Y here should also say
420 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
421 Management" code will be disabled if you say Y here.
422
Mauro Carvalho Chehabcb1aaeb2019-06-07 15:54:32 -0300423 See also <file:Documentation/x86/i386/IO-APIC.rst>,
Mauro Carvalho Chehab4f4cfa62019-06-27 14:56:51 -0300424 <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100425 <http://www.tldp.org/docs.html#howto>.
426
427 If you don't know what to do here, say N.
428
Josh Triplett9def39be2013-10-30 08:09:45 -0700429config X86_FEATURE_NAMES
430 bool "Processor feature human-readable names" if EMBEDDED
431 default y
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900432 help
Josh Triplett9def39be2013-10-30 08:09:45 -0700433 This option compiles in a table of x86 feature bits and corresponding
434 names. This is required to support /proc/cpuinfo and a few kernel
435 messages. You can disable this to save space, at the expense of
436 making those few kernel messages show numeric feature bits instead.
437
438 If in doubt, say Y.
439
Yinghai Lu06cd9a72009-02-16 17:29:58 -0800440config X86_X2APIC
441 bool "Support x2apic"
Jan Kiszka19e3d602015-05-04 17:58:01 +0200442 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900443 help
Yinghai Lu06cd9a72009-02-16 17:29:58 -0800444 This enables x2apic support on CPUs that have this feature.
445
446 This allows 32-bit apic IDs (so it can support very large systems),
447 and accesses the local apic via MSRs not via mmio.
448
Yinghai Lu06cd9a72009-02-16 17:29:58 -0800449 If you don't know what to do here, say N.
450
Yinghai Lu6695c852008-06-19 12:13:09 -0700451config X86_MPPARSE
Andy Shevchenko4590d982021-02-11 15:40:02 +0200452 bool "Enable MPS table" if ACPI
Jan Beulich7a527682008-10-30 10:38:24 +0000453 default y
Ingo Molnar5ab74722008-07-10 14:42:03 +0200454 depends on X86_LOCAL_APIC
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900455 help
Yinghai Lu6695c852008-06-19 12:13:09 -0700456 For old smp systems that do not have proper acpi support. Newer systems
457 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
Yinghai Lu6695c852008-06-19 12:13:09 -0700458
Jun Nakajimaddd70cf2013-01-21 17:23:09 +0000459config GOLDFISH
Krzysztof Kozlowskib03b0162019-11-21 04:21:09 +0100460 def_bool y
461 depends on X86_GOLDFISH
Jun Nakajimaddd70cf2013-01-21 17:23:09 +0000462
David Woodhouse76b04382018-01-11 21:46:25 +0000463config RETPOLINE
464 bool "Avoid speculative indirect branches in kernel"
465 default y
466 help
467 Compile kernel with the retpoline compiler options to guard against
468 kernel-to-user data leaks by avoiding speculative indirect
469 branches. Requires a compiler with -mindirect-branch=thunk-extern
470 support for full protection. The kernel may run slower.
471
Johannes Weinere6d42932019-01-29 17:44:36 -0500472config X86_CPU_RESCTRL
473 bool "x86 CPU resource control support"
Babu Moger6fe07ce2018-11-21 20:28:39 +0000474 depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
Thomas Gleixner59fe5a72016-11-15 15:17:12 +0100475 select KERNFS
Chen Yue79f15a2020-01-15 17:28:51 +0800476 select PROC_CPU_RESCTRL if PROC_FS
Fenghua Yu78e99b42016-10-22 06:19:53 -0700477 help
Johannes Weinere6d42932019-01-29 17:44:36 -0500478 Enable x86 CPU resource control support.
Babu Moger6fe07ce2018-11-21 20:28:39 +0000479
480 Provide support for the allocation and monitoring of system resources
481 usage by the CPU.
482
483 Intel calls this Intel Resource Director Technology
484 (Intel(R) RDT). More information about RDT can be found in the
485 Intel x86 Architecture Software Developer Manual.
486
487 AMD calls this AMD Platform Quality of Service (AMD QoS).
488 More information about AMD QoS can be found in the AMD64 Technology
489 Platform Quality of Service Extensions manual.
Fenghua Yu78e99b42016-10-22 06:19:53 -0700490
491 Say N if unsure.
492
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800493if X86_32
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800494config X86_BIGSMP
495 bool "Support for big SMP systems with more than 8 CPUs"
496 depends on SMP
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900497 help
Randy Dunlape133f6e2019-12-03 16:06:47 -0800498 This option is needed for the systems that have more than 8 CPUs.
Randy Dunlapa0d0bb42018-02-09 16:51:03 -0800499
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800500config X86_EXTENDED_PLATFORM
501 bool "Support for extended (non-PC) x86 platforms"
502 default y
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900503 help
Ingo Molnar06ac8342009-01-27 18:11:43 +0100504 If you disable this option then the kernel will only support
505 standard PC platforms. (which covers the vast majority of
506 systems out there.)
507
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800508 If you enable this option then you'll be able to select support
509 for the following (non-PC) 32 bit x86 platforms:
Ben Hutchingscb7b8022013-06-24 01:05:25 +0100510 Goldfish (Android emulator)
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800511 AMD Elan
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800512 RDC R-321x SoC
513 SGI 320/540 (Visual Workstation)
Alessandro Rubini83125a32012-04-04 19:40:21 +0200514 STA2X11-based (e.g. Northville)
Thomas Gleixner3f4110a2009-08-29 14:54:20 +0200515 Moorestown MID devices
Ingo Molnar06ac8342009-01-27 18:11:43 +0100516
517 If you have one of these systems, or if you want to build a
518 generic distribution kernel, say Y here - otherwise say N.
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800519endif
Ingo Molnar06ac8342009-01-27 18:11:43 +0100520
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800521if X86_64
522config X86_EXTENDED_PLATFORM
523 bool "Support for extended (non-PC) x86 platforms"
524 default y
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900525 help
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800526 If you disable this option then the kernel will only support
527 standard PC platforms. (which covers the vast majority of
528 systems out there.)
529
530 If you enable this option then you'll be able to select support
531 for the following (non-PC) 64 bit x86 platforms:
Steffen Persvold44b111b52011-12-06 00:07:26 +0800532 Numascale NumaChip
Ravikiran G Thirumalai84250912009-02-20 16:59:11 -0800533 ScaleMP vSMP
534 SGI Ultraviolet
535
536 If you have one of these systems, or if you want to build a
537 generic distribution kernel, say Y here - otherwise say N.
538endif
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800539# This is an alphabetically sorted list of 64 bit extended platforms
540# Please maintain the alphabetic order if and when there are additions
Steffen Persvold44b111b52011-12-06 00:07:26 +0800541config X86_NUMACHIP
542 bool "Numascale NumaChip"
543 depends on X86_64
544 depends on X86_EXTENDED_PLATFORM
545 depends on NUMA
546 depends on SMP
547 depends on X86_X2APIC
Daniel J Bluemanf9726bf2012-12-07 14:24:32 -0700548 depends on PCI_MMCONFIG
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900549 help
Steffen Persvold44b111b52011-12-06 00:07:26 +0800550 Adds support for Numascale NumaChip large-SMP systems. Needed to
551 enable more than ~168 cores.
552 If you don't have one of these, you should say N here.
Nick Piggin03b48632009-01-20 04:36:04 +0100553
Ingo Molnar6a485652009-01-27 18:29:13 +0100554config X86_VSMP
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800555 bool "ScaleMP vSMP"
Borislav Petkov6276a072013-03-04 21:20:21 +0100556 select HYPERVISOR_GUEST
Ingo Molnar6a485652009-01-27 18:29:13 +0100557 select PARAVIRT
558 depends on X86_64 && PCI
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800559 depends on X86_EXTENDED_PLATFORM
Shai Fultheimead91d42012-04-16 10:39:35 +0300560 depends on SMP
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900561 help
Ingo Molnar6a485652009-01-27 18:29:13 +0100562 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
563 supposed to run on these EM64T-based machines. Only choose this option
564 if you have one of these machines.
565
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800566config X86_UV
567 bool "SGI Ultraviolet"
568 depends on X86_64
569 depends on X86_EXTENDED_PLATFORM
Jack Steiner54c28d22009-04-03 15:39:42 -0500570 depends on NUMA
Andrew Morton1ecb4ae2016-02-11 16:13:20 -0800571 depends on EFI
Ingo Molnarc2209ea2021-04-20 09:47:42 +0200572 depends on KEXEC_CORE
Suresh Siddha9d6c26e2009-04-20 13:02:31 -0700573 depends on X86_X2APIC
Ingo Molnar1222e562015-05-06 06:23:59 +0200574 depends on PCI
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900575 help
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800576 This option is needed in order to support SGI Ultraviolet systems.
577 If you don't have one of these, you should say N here.
578
579# Following is an alphabetically sorted list of 32 bit extended platforms
580# Please maintain the alphabetic order if and when there are additions
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100581
Jun Nakajimaddd70cf2013-01-21 17:23:09 +0000582config X86_GOLDFISH
Krzysztof Kozlowskib03b0162019-11-21 04:21:09 +0100583 bool "Goldfish (Virtual Platform)"
584 depends on X86_EXTENDED_PLATFORM
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900585 help
Jun Nakajimaddd70cf2013-01-21 17:23:09 +0000586 Enable support for the Goldfish virtual platform used primarily
587 for Android development. Unless you are building for the Android
588 Goldfish emulator say N here.
589
Thomas Gleixnerc751e172010-11-09 12:08:04 -0800590config X86_INTEL_CE
591 bool "CE4100 TV platform"
592 depends on PCI
593 depends on PCI_GODIRECT
Jiang Liu6084a6e2014-06-09 16:19:46 +0800594 depends on X86_IO_APIC
Thomas Gleixnerc751e172010-11-09 12:08:04 -0800595 depends on X86_32
596 depends on X86_EXTENDED_PLATFORM
Dirk Brandewie37bc9f52010-11-09 12:08:08 -0800597 select X86_REBOOTFIXUPS
Sebastian Andrzej Siewiorda6b7372011-02-22 21:07:37 +0100598 select OF
599 select OF_EARLY_FLATTREE
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900600 help
Thomas Gleixnerc751e172010-11-09 12:08:04 -0800601 Select for the Intel CE media processor (CE4100) SOC.
602 This option compiles in support for the CE4100 SOC for settop
603 boxes and media devices.
604
David Cohen4cb9b002013-12-16 17:37:26 -0800605config X86_INTEL_MID
Alan Cox43605ef2011-07-12 17:49:29 +0100606 bool "Intel MID platform support"
Alan Cox43605ef2011-07-12 17:49:29 +0100607 depends on X86_EXTENDED_PLATFORM
David Cohenedc6bc72014-01-21 10:41:39 -0800608 depends on X86_PLATFORM_DEVICES
Alan Cox1ea7c672011-11-10 13:29:14 +0000609 depends on PCI
Andy Shevchenko3fda5bb2016-01-15 22:11:07 +0200610 depends on X86_64 || (PCI_GOANY && X86_32)
Alan Cox1ea7c672011-11-10 13:29:14 +0000611 depends on X86_IO_APIC
David Cohen4cb9b002013-12-16 17:37:26 -0800612 select I2C
Alan Cox7c9c3a12011-12-29 14:43:16 +0000613 select DW_APB_TIMER
Alan Cox1ea7c672011-11-10 13:29:14 +0000614 select APB_TIMER
Mika Westerberg54b34aa2020-04-16 11:15:33 +0300615 select INTEL_SCU_PCI
Mika Westerberg15a713d2012-01-26 17:35:05 +0000616 select MFD_INTEL_MSIC
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900617 help
David Cohen4cb9b002013-12-16 17:37:26 -0800618 Select to build a kernel capable of supporting Intel MID (Mobile
619 Internet Device) platform systems which do not have the PCI legacy
620 interfaces. If you are building for a PC class system say N here.
Alan Cox1ea7c672011-11-10 13:29:14 +0000621
David Cohen4cb9b002013-12-16 17:37:26 -0800622 Intel MID platforms are based on an Intel processor and chipset which
623 consume less power than most of the x86 derivatives.
Alan Cox43605ef2011-07-12 17:49:29 +0100624
Bryan O'Donoghue8bbc2a12015-01-30 16:29:39 +0000625config X86_INTEL_QUARK
626 bool "Intel Quark platform support"
627 depends on X86_32
628 depends on X86_EXTENDED_PLATFORM
629 depends on X86_PLATFORM_DEVICES
630 depends on X86_TSC
631 depends on PCI
632 depends on PCI_GOANY
633 depends on X86_IO_APIC
634 select IOSF_MBI
635 select INTEL_IMR
Andy Shevchenko9ab6eb52015-03-05 17:24:04 +0200636 select COMMON_CLK
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900637 help
Bryan O'Donoghue8bbc2a12015-01-30 16:29:39 +0000638 Select to include support for Quark X1000 SoC.
639 Say Y here if you have a Quark based system such as the Arduino
640 compatible Intel Galileo.
641
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000642config X86_INTEL_LPSS
643 bool "Intel Low Power Subsystem Support"
Sinan Kaya5962dd22019-01-02 18:10:37 +0000644 depends on X86 && ACPI && PCI
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000645 select COMMON_CLK
Mathias Nyman0f531432013-09-13 17:02:29 +0300646 select PINCTRL
Andy Shevchenkoeebb3e82015-12-12 02:45:06 +0100647 select IOSF_MBI
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900648 help
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000649 Select to build support for Intel Low Power Subsystem such as
650 found on Intel Lynxpoint PCH. Selecting this option enables
Mathias Nyman0f531432013-09-13 17:02:29 +0300651 things like clock tree (common clock framework) and pincontrol
652 which are needed by the LPSS peripheral drivers.
Mika Westerberg3d48aab2013-01-18 13:45:59 +0000653
Ken Xue92082a82015-02-06 08:27:51 +0800654config X86_AMD_PLATFORM_DEVICE
655 bool "AMD ACPI2Platform devices support"
656 depends on ACPI
657 select COMMON_CLK
658 select PINCTRL
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900659 help
Ken Xue92082a82015-02-06 08:27:51 +0800660 Select to interpret AMD specific ACPI device to platform device
661 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
662 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
663 implemented under PINCTRL subsystem.
664
David E. Boxced3ce72014-09-17 22:13:50 -0700665config IOSF_MBI
666 tristate "Intel SoC IOSF Sideband support for SoC platforms"
667 depends on PCI
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900668 help
David E. Boxced3ce72014-09-17 22:13:50 -0700669 This option enables sideband register access support for Intel SoC
670 platforms. On these platforms the IOSF sideband is used in lieu of
671 MSR's for some register accesses, mostly but not limited to thermal
672 and power. Drivers may query the availability of this device to
673 determine if they need the sideband in order to work on these
674 platforms. The sideband is available on the following SoC products.
675 This list is not meant to be exclusive.
676 - BayTrail
677 - Braswell
678 - Quark
679
680 You should say Y if you are running a kernel on one of these SoC's.
681
David E. Boxed2226b2014-09-17 22:13:51 -0700682config IOSF_MBI_DEBUG
683 bool "Enable IOSF sideband access through debugfs"
684 depends on IOSF_MBI && DEBUG_FS
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900685 help
David E. Boxed2226b2014-09-17 22:13:51 -0700686 Select this option to expose the IOSF sideband access registers (MCR,
687 MDR, MCRX) through debugfs to write and read register information from
688 different units on the SoC. This is most useful for obtaining device
689 state information for debug and analysis. As this is a general access
690 mechanism, users of this option would have specific knowledge of the
691 device they want to access.
692
693 If you don't require the option or are in doubt, say N.
694
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800695config X86_RDC321X
696 bool "RDC R-321x SoC"
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100697 depends on X86_32
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800698 depends on X86_EXTENDED_PLATFORM
699 select M486
700 select X86_REBOOTFIXUPS
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900701 help
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800702 This option is needed for RDC R-321x system-on-chip, also known
703 as R-8610-(G).
704 If you don't have one of these chips, you should say N here.
705
Ingo Molnare0c7ae32009-01-27 18:43:09 +0100706config X86_32_NON_STANDARD
Ingo Molnar9c398012009-01-27 18:24:57 +0100707 bool "Support non-standard 32-bit SMP architectures"
708 depends on X86_32 && SMP
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800709 depends on X86_EXTENDED_PLATFORM
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900710 help
H. Peter Anvinb5660ba2014-02-25 12:14:06 -0800711 This option compiles in the bigsmp and STA2X11 default
712 subarchitectures. It is intended for a generic binary
713 kernel. If you select them all, kernel will probe it one by
714 one and will fallback to default.
Yinghai Lud49c4282008-06-08 18:31:54 -0700715
Ravikiran G Thirumalaic5c606d2009-02-09 18:18:14 -0800716# Alphabetically sorted list of Non standard 32 bit platforms
Yinghai Lud49c4282008-06-08 18:31:54 -0700717
Linus Torvaldsd949f362009-09-26 09:35:07 -0700718config X86_SUPPORTS_MEMORY_FAILURE
Jan Beulich6fc108a2010-04-21 15:23:44 +0100719 def_bool y
Linus Torvaldsd949f362009-09-26 09:35:07 -0700720 # MCE code calls memory_failure():
721 depends on X86_MCE
722 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
Linus Torvaldsd949f362009-09-26 09:35:07 -0700723 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
724 depends on X86_64 || !SPARSEMEM
725 select ARCH_SUPPORTS_MEMORY_FAILURE
Linus Torvaldsd949f362009-09-26 09:35:07 -0700726
Alessandro Rubini83125a32012-04-04 19:40:21 +0200727config STA2X11
728 bool "STA2X11 Companion Chip Support"
729 depends on X86_32_NON_STANDARD && PCI
Alessandro Rubini83125a32012-04-04 19:40:21 +0200730 select SWIOTLB
731 select MFD_STA2X11
Linus Walleij01450712016-06-02 14:20:18 +0200732 select GPIOLIB
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900733 help
Alessandro Rubini83125a32012-04-04 19:40:21 +0200734 This adds support for boards based on the STA2X11 IO-Hub,
735 a.k.a. "ConneXt". The chip is used in place of the standard
736 PC chipset, so all "standard" peripherals are missing. If this
737 option is selected the kernel will still be able to boot on
738 standard PC machines.
739
Shérab82148d12010-09-25 06:06:57 +0200740config X86_32_IRIS
741 tristate "Eurobraille/Iris poweroff module"
742 depends on X86_32
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900743 help
Shérab82148d12010-09-25 06:06:57 +0200744 The Iris machines from EuroBraille do not have APM or ACPI support
745 to shut themselves down properly. A special I/O sequence is
746 needed to do so, which is what this module does at
747 kernel shutdown.
748
749 This is only for Iris machines from EuroBraille.
750
751 If unused, say N.
752
Ingo Molnarae1e9132008-11-11 09:05:16 +0100753config SCHED_OMIT_FRAME_POINTER
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100754 def_bool y
755 prompt "Single-depth WCHAN output"
Ken Chena87d0912008-11-06 11:10:49 -0800756 depends on X86
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900757 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100758 Calculate simpler /proc/<PID>/wchan values. If this option
759 is disabled then wchan values will recurse back to the
760 caller function. This provides more accurate wchan values,
761 at the expense of slightly more scheduling overhead.
762
763 If in doubt, say "Y".
764
Borislav Petkov6276a072013-03-04 21:20:21 +0100765menuconfig HYPERVISOR_GUEST
766 bool "Linux guest support"
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900767 help
Borislav Petkov6276a072013-03-04 21:20:21 +0100768 Say Y here to enable options for running Linux under various hyper-
769 visors. This option enables basic hypervisor detection and platform
770 setup.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100771
Borislav Petkov6276a072013-03-04 21:20:21 +0100772 If you say N, all options in this submenu will be skipped and
773 disabled, and Linux guest support won't be built in.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100774
Borislav Petkov6276a072013-03-04 21:20:21 +0100775if HYPERVISOR_GUEST
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100776
Eduardo Pereira Habkoste61bd942008-01-30 13:33:32 +0100777config PARAVIRT
778 bool "Enable paravirtualization code"
Juergen Grossa0e2bf72021-03-11 15:23:09 +0100779 depends on HAVE_STATIC_CALL
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900780 help
Eduardo Pereira Habkoste61bd942008-01-30 13:33:32 +0100781 This changes the kernel so it can modify itself when it is run
782 under a hypervisor, potentially improving performance significantly
783 over full virtualization. However, when run without a hypervisor
784 the kernel is theoretically slower and slightly larger.
785
Juergen Grossc00a2802018-08-28 09:40:21 +0200786config PARAVIRT_XXL
787 bool
788
Borislav Petkov6276a072013-03-04 21:20:21 +0100789config PARAVIRT_DEBUG
790 bool "paravirt-ops debugging"
791 depends on PARAVIRT && DEBUG_KERNEL
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900792 help
Borislav Petkov6276a072013-03-04 21:20:21 +0100793 Enable to debug paravirt_ops internals. Specifically, BUG if
794 a paravirt_op is missing when it is called.
795
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700796config PARAVIRT_SPINLOCKS
797 bool "Paravirtualization layer for spinlocks"
Kees Cook6ea30382012-10-02 11:16:47 -0700798 depends on PARAVIRT && SMP
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900799 help
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700800 Paravirtualized spinlocks allow a pvops backend to replace the
801 spinlock implementation with something virtualization-friendly
802 (for example, block the virtual CPU rather than spinning).
803
Raghavendra K T4c4e4f62013-10-21 21:35:08 +0530804 It has a minimal impact on native kernels and gives a nice performance
805 benefit on paravirtualized KVM / Xen kernels.
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700806
Raghavendra K T4c4e4f62013-10-21 21:35:08 +0530807 If you are unsure how to answer this question, answer Y.
Jeremy Fitzhardingeb4ecc122009-05-13 17:16:55 -0700808
Zhao Yakuiecca25022019-04-30 11:45:23 +0800809config X86_HV_CALLBACK_VECTOR
810 def_bool n
811
Borislav Petkov6276a072013-03-04 21:20:21 +0100812source "arch/x86/xen/Kconfig"
813
814config KVM_GUEST
815 bool "KVM Guest support (including kvmclock)"
816 depends on PARAVIRT
817 select PARAVIRT_CLOCK
Marcelo Tosattia1c44232019-07-03 20:51:29 -0300818 select ARCH_CPUIDLE_HALTPOLL
Vitaly Kuznetsovb1d40572020-05-25 16:41:23 +0200819 select X86_HV_CALLBACK_VECTOR
Borislav Petkov6276a072013-03-04 21:20:21 +0100820 default y
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900821 help
Borislav Petkov6276a072013-03-04 21:20:21 +0100822 This option enables various optimizations for running under the KVM
823 hypervisor. It includes a paravirtualized clock, so that instead
824 of relying on a PIT (or probably other) emulation by the
825 underlying device model, the host provides the guest with
826 timing infrastructure such as time of day, and system time
827
Marcelo Tosattia1c44232019-07-03 20:51:29 -0300828config ARCH_CPUIDLE_HALTPOLL
Krzysztof Kozlowskib03b0162019-11-21 04:21:09 +0100829 def_bool n
830 prompt "Disable host haltpoll when loading haltpoll driver"
831 help
Marcelo Tosattia1c44232019-07-03 20:51:29 -0300832 If virtualized under KVM, disable host haltpoll.
833
Maran Wilson77336072018-12-10 11:07:28 -0800834config PVH
835 bool "Support for running PVH guests"
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900836 help
Maran Wilson77336072018-12-10 11:07:28 -0800837 This option enables the PVH entry point for guest virtual machines
838 as specified in the x86/HVM direct boot ABI.
839
Borislav Petkov6276a072013-03-04 21:20:21 +0100840config PARAVIRT_TIME_ACCOUNTING
841 bool "Paravirtual steal time accounting"
842 depends on PARAVIRT
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900843 help
Borislav Petkov6276a072013-03-04 21:20:21 +0100844 Select this option to enable fine granularity task steal time
845 accounting. Time spent executing other tasks in parallel with
846 the current vCPU is discounted from the vCPU power. To account for
847 that, there can be a small performance impact.
848
849 If in doubt, say N here.
850
Gerd Hoffmann7af192c2008-06-03 16:17:29 +0200851config PARAVIRT_CLOCK
852 bool
Gerd Hoffmann7af192c2008-06-03 16:17:29 +0200853
Jan Kiszka4a362602017-11-27 09:11:46 +0100854config JAILHOUSE_GUEST
855 bool "Jailhouse non-root cell support"
Arnd Bergmannabde5872018-01-15 16:51:20 +0100856 depends on X86_64 && PCI
Jan Kiszka87e65d02017-11-27 09:11:48 +0100857 select X86_PM_TIMER
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900858 help
Jan Kiszka4a362602017-11-27 09:11:46 +0100859 This option allows to run Linux as guest in a Jailhouse non-root
860 cell. You can leave this option disabled if you only want to start
861 Jailhouse and run Linux afterwards in the root cell.
862
Zhao Yakuiec7972c2019-04-30 11:45:24 +0800863config ACRN_GUEST
864 bool "ACRN Guest support"
865 depends on X86_64
Zhao Yakui498ad392019-04-30 11:45:25 +0800866 select X86_HV_CALLBACK_VECTOR
Zhao Yakuiec7972c2019-04-30 11:45:24 +0800867 help
868 This option allows to run Linux as guest in the ACRN hypervisor. ACRN is
869 a flexible, lightweight reference open-source hypervisor, built with
870 real-time and safety-criticality in mind. It is built for embedded
871 IOT with small footprint and real-time features. More details can be
872 found in https://projectacrn.org/.
873
Borislav Petkov6276a072013-03-04 21:20:21 +0100874endif #HYPERVISOR_GUEST
Jeremy Fitzhardinge97349132008-06-25 00:19:14 -0400875
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100876source "arch/x86/Kconfig.cpu"
877
878config HPET_TIMER
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100879 def_bool X86_64
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100880 prompt "HPET Timer Support" if X86_32
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +0900881 help
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100882 Use the IA-PC HPET (High Precision Event Timer) to manage
883 time in preference to the PIT and RTC, if a HPET is
884 present.
885 HPET is the next generation timer replacing legacy 8254s.
886 The HPET provides a stable time base on SMP
887 systems, unlike the TSC, but it is more expensive to access,
Michael S. Tsirkin4e7f9df2016-02-11 01:05:01 +0200888 as it is off-chip. The interface used is documented
889 in the HPET spec, revision 1.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100890
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100891 You can safely choose Y here. However, HPET will only be
892 activated if the platform and the BIOS support this feature.
893 Otherwise the 8254 will be used for timing services.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100894
Ingo Molnar8f9ca472009-02-05 16:21:53 +0100895 Choose N to continue using the legacy 8254 timer.
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100896
897config HPET_EMULATE_RTC
Harvey Harrison3c2362e2008-01-30 13:31:03 +0100898 def_bool y
Anand K Mistry3228e1d2021-02-04 18:32:32 +1100899 depends on HPET_TIMER && (RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
Sam Ravnborg506f1d072007-11-09 21:56:54 +0100900
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
Peter Zijlstra07dc9002016-03-29 14:30:35 +02001155source "arch/x86/events/Kconfig"
Kan Liange633c652016-03-20 01:33:36 -07001156
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001157config X86_LEGACY_VM86
Ingo Molnar1e642812015-09-05 08:58:10 +02001158 bool "Legacy VM86 support"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001159 depends on X86_32
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001160 help
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001161 This option allows user programs to put the CPU into V8086
1162 mode, which is an 80286-era approximation of 16-bit real mode.
1163
1164 Some very old versions of X and/or vbetool require this option
1165 for user mode setting. Similarly, DOSEMU will use it if
1166 available to accelerate real mode DOS programs. However, any
1167 recent version of DOSEMU, X, or vbetool should be fully
1168 functional even without kernel VM86 support, as they will all
Ingo Molnar1e642812015-09-05 08:58:10 +02001169 fall back to software emulation. Nevertheless, if you are using
1170 a 16-bit DOS program where 16-bit performance matters, vm86
1171 mode might be faster than emulation and you might want to
1172 enable this option.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001173
Ingo Molnar1e642812015-09-05 08:58:10 +02001174 Note that any app that works on a 64-bit kernel is unlikely to
1175 need this option, as 64-bit kernels don't, and can't, support
1176 V8086 mode. This option is also unrelated to 16-bit protected
1177 mode and is not needed to run most 16-bit programs under Wine.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001178
Ingo Molnar1e642812015-09-05 08:58:10 +02001179 Enabling this option increases the complexity of the kernel
1180 and slows down exception handling a tiny bit.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001181
Ingo Molnar1e642812015-09-05 08:58:10 +02001182 If unsure, say N here.
Andy Lutomirski5aef51c2015-07-10 08:34:23 -07001183
1184config VM86
Krzysztof Kozlowskib03b0162019-11-21 04:21:09 +01001185 bool
1186 default X86_LEGACY_VM86
H. Peter Anvin34273f42014-05-04 10:36:22 -07001187
1188config X86_16BIT
1189 bool "Enable support for 16-bit segments" if EXPERT
1190 default y
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07001191 depends on MODIFY_LDT_SYSCALL
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001192 help
H. Peter Anvin34273f42014-05-04 10:36:22 -07001193 This option is required by programs like Wine to run 16-bit
1194 protected mode legacy code on x86 processors. Disabling
1195 this option saves about 300 bytes on i386, or around 6K text
1196 plus 16K runtime memory on x86-64,
1197
1198config X86_ESPFIX32
1199 def_bool y
1200 depends on X86_16BIT && X86_32
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001201
H. Peter Anvin197725d2014-05-04 10:00:49 -07001202config X86_ESPFIX64
1203 def_bool y
H. Peter Anvin34273f42014-05-04 10:36:22 -07001204 depends on X86_16BIT && X86_64
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001205
Andy Lutomirski1ad83c82014-10-29 14:33:47 -07001206config X86_VSYSCALL_EMULATION
Krzysztof Kozlowskib03b0162019-11-21 04:21:09 +01001207 bool "Enable vsyscall emulation" if EXPERT
1208 default y
1209 depends on X86_64
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001210 help
Andy Lutomirski1ad83c82014-10-29 14:33:47 -07001211 This enables emulation of the legacy vsyscall page. Disabling
1212 it is roughly equivalent to booting with vsyscall=none, except
1213 that it will also disable the helpful warning if a program
1214 tries to use a vsyscall. With this option set to N, offending
1215 programs will just segfault, citing addresses of the form
1216 0xffffffffff600?00.
1217
1218 This option is required by many programs built before 2013, and
1219 care should be used even with newer programs if set to N.
1220
1221 Disabling this option saves about 7K of kernel size and
1222 possibly 4K of additional runtime pagetable memory.
1223
Thomas Gleixner111e7b12019-11-12 21:40:33 +01001224config X86_IOPL_IOPERM
1225 bool "IOPERM and IOPL Emulation"
Thomas Gleixnera24ca992019-11-11 23:03:29 +01001226 default y
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001227 help
Thomas Gleixner111e7b12019-11-12 21:40:33 +01001228 This enables the ioperm() and iopl() syscalls which are necessary
1229 for legacy applications.
1230
Thomas Gleixnerc8137ac2019-11-11 23:03:28 +01001231 Legacy IOPL support is an overbroad mechanism which allows user
1232 space aside of accessing all 65536 I/O ports also to disable
1233 interrupts. To gain this access the caller needs CAP_SYS_RAWIO
1234 capabilities and permission from potentially active security
1235 modules.
1236
1237 The emulation restricts the functionality of the syscall to
1238 only allowing the full range I/O port access, but prevents the
Thomas Gleixnera24ca992019-11-11 23:03:29 +01001239 ability to disable interrupts from user space which would be
1240 granted if the hardware IOPL mechanism would be used.
Thomas Gleixnerc8137ac2019-11-11 23:03:28 +01001241
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001242config TOSHIBA
1243 tristate "Toshiba Laptop support"
1244 depends on X86_32
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001245 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001246 This adds a driver to safely access the System Management Mode of
1247 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1248 not work on models with a Phoenix BIOS. The System Management Mode
1249 is used to set the BIOS and power saving options on Toshiba portables.
1250
1251 For information on utilities to make use of this driver see the
1252 Toshiba Linux utilities web site at:
1253 <http://www.buzzard.org.uk/toshiba/>.
1254
1255 Say Y if you intend to run this kernel on a Toshiba portable.
1256 Say N otherwise.
1257
1258config I8K
Pali Rohár039ae582015-05-14 13:16:37 +02001259 tristate "Dell i8k legacy laptop support"
Jean Delvare949a9d72011-05-25 20:43:33 +02001260 select HWMON
Pali Rohár039ae582015-05-14 13:16:37 +02001261 select SENSORS_DELL_SMM
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001262 help
Pali Rohár039ae582015-05-14 13:16:37 +02001263 This option enables legacy /proc/i8k userspace interface in hwmon
1264 dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1265 temperature and allows controlling fan speeds of Dell laptops via
1266 System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1267 it reports also power and hotkey status. For fan speed control is
1268 needed userspace package i8kutils.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001269
Pali Rohár039ae582015-05-14 13:16:37 +02001270 Say Y if you intend to run this kernel on old Dell laptops or want to
1271 use userspace package i8kutils.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001272 Say N otherwise.
1273
1274config X86_REBOOTFIXUPS
Jan Beulich9ba16082008-10-15 22:01:38 -07001275 bool "Enable X86 board specific fixups for reboot"
1276 depends on X86_32
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001277 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001278 This enables chipset and/or board specific fixups to be done
1279 in order to get reboot to work correctly. This is only needed on
1280 some combinations of hardware and BIOS. The symptom, for which
1281 this config is intended, is when reboot ends with a stalled/hung
1282 system.
1283
1284 Currently, the only fixup is for the Geode machines using
Florian Fainelli5e3a77e2008-01-30 13:33:36 +01001285 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001286
1287 Say Y if you want to enable the fixup. Currently, it's safe to
1288 enable this option even if you don't need it.
1289 Say N otherwise.
1290
1291config MICROCODE
Borislav Petkov9a2bc332015-10-20 11:54:44 +02001292 bool "CPU microcode loading support"
1293 default y
Borislav Petkov80030e32013-10-13 18:36:29 +02001294 depends on CPU_SUP_AMD || CPU_SUP_INTEL
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001295 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001296 If you say Y here, you will be able to update the microcode on
Borislav Petkov5f9c01a2016-02-03 12:33:29 +01001297 Intel and AMD processors. The Intel support is for the IA32 family,
1298 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
1299 AMD support is for families 0x10 and later. You will obviously need
1300 the actual microcode binary data itself which is not shipped with
1301 the Linux kernel.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001302
Borislav Petkov5f9c01a2016-02-03 12:33:29 +01001303 The preferred method to load microcode from a detached initrd is described
Mauro Carvalho Chehabcb1aaeb2019-06-07 15:54:32 -03001304 in Documentation/x86/microcode.rst. For that you need to enable
Borislav Petkov5f9c01a2016-02-03 12:33:29 +01001305 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
1306 initrd for microcode blobs.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001307
Benjamin Gilbertc508c462018-01-23 18:06:32 -08001308 In addition, you can build the microcode into the kernel. For that you
1309 need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1310 config option.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001311
Peter Oruba8d86f392008-07-28 18:44:21 +02001312config MICROCODE_INTEL
Borislav Petkove43f6e62012-08-01 19:17:01 +02001313 bool "Intel microcode loading support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001314 depends on MICROCODE
1315 default MICROCODE
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001316 help
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001317 This options enables microcode patch loading support for Intel
1318 processors.
Peter Oruba8d86f392008-07-28 18:44:21 +02001319
Alanb8989db2014-01-20 18:01:56 +00001320 For the current Intel microcode data package go to
1321 <https://downloadcenter.intel.com> and search for
1322 'Linux Processor Microcode Data File'.
Peter Oruba8d86f392008-07-28 18:44:21 +02001323
Peter Oruba80cc9f12008-07-28 18:44:22 +02001324config MICROCODE_AMD
Borislav Petkove43f6e62012-08-01 19:17:01 +02001325 bool "AMD microcode loading support"
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001326 depends on MICROCODE
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001327 help
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001328 If you select this option, microcode patch loading support for AMD
1329 processors will be enabled.
Peter Oruba80cc9f12008-07-28 18:44:22 +02001330
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001331config MICROCODE_OLD_INTERFACE
Borislav Petkovc02f48e2019-04-05 06:28:11 +02001332 bool "Ancient loading interface (DEPRECATED)"
1333 default n
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001334 depends on MICROCODE
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001335 help
Borislav Petkovc02f48e2019-04-05 06:28:11 +02001336 DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface
1337 which was used by userspace tools like iucode_tool and microcode.ctl.
1338 It is inadequate because it runs too late to be able to properly
1339 load microcode on a machine and it needs special tools. Instead, you
1340 should've switched to the early loading method with the initrd or
Mauro Carvalho Chehabcb1aaeb2019-06-07 15:54:32 -03001341 builtin microcode by now: Documentation/x86/microcode.rst
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001342
1343config X86_MSR
1344 tristate "/dev/cpu/*/msr - Model-specific register support"
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001345 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001346 This device gives privileged processes access to the x86
1347 Model-Specific Registers (MSRs). It is a character device with
1348 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1349 MSR accesses are directed to a specific CPU on multi-processor
1350 systems.
1351
1352config X86_CPUID
1353 tristate "/dev/cpu/*/cpuid - CPU information support"
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001354 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001355 This device gives processes access to the x86 CPUID instruction to
1356 be executed on a specific processor. It is a character device
1357 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1358 /dev/cpu/31/cpuid.
1359
1360choice
1361 prompt "High Memory Support"
Jan Beulich6fc108a2010-04-21 15:23:44 +01001362 default HIGHMEM4G
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001363 depends on X86_32
1364
1365config NOHIGHMEM
1366 bool "off"
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001367 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001368 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1369 However, the address space of 32-bit x86 processors is only 4
1370 Gigabytes large. That means that, if you have a large amount of
1371 physical memory, not all of it can be "permanently mapped" by the
1372 kernel. The physical memory that's not permanently mapped is called
1373 "high memory".
1374
1375 If you are compiling a kernel which will never run on a machine with
1376 more than 1 Gigabyte total physical RAM, answer "off" here (default
1377 choice and suitable for most users). This will result in a "3GB/1GB"
1378 split: 3GB are mapped so that each process sees a 3GB virtual memory
1379 space and the remaining part of the 4GB virtual memory space is used
1380 by the kernel to permanently map as much physical memory as
1381 possible.
1382
1383 If the machine has between 1 and 4 Gigabytes physical RAM, then
1384 answer "4GB" here.
1385
1386 If more than 4 Gigabytes is used then answer "64GB" here. This
1387 selection turns Intel PAE (Physical Address Extension) mode on.
1388 PAE implements 3-level paging on IA32 processors. PAE is fully
1389 supported by Linux, PAE mode is implemented on all recent Intel
1390 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1391 then the kernel will not boot on CPUs that don't support PAE!
1392
1393 The actual amount of total physical memory will either be
1394 auto detected or can be forced by using a kernel command line option
1395 such as "mem=256M". (Try "man bootparam" or see the documentation of
1396 your boot loader (lilo or loadlin) about how to pass options to the
1397 kernel at boot time.)
1398
1399 If unsure, say "off".
1400
1401config HIGHMEM4G
1402 bool "4GB"
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001403 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001404 Select this if you have a 32-bit processor and between 1 and 4
1405 gigabytes of physical RAM.
1406
1407config HIGHMEM64G
1408 bool "64GB"
Maciej W. Rozycki0ef34392021-04-14 12:38:28 +02001409 depends on !M486SX && !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001410 select X86_PAE
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001411 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001412 Select this if you have a 32-bit processor and more than 4
1413 gigabytes of physical RAM.
1414
1415endchoice
1416
1417choice
David Rientjes6a108a12011-01-20 14:44:16 -08001418 prompt "Memory split" if EXPERT
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001419 default VMSPLIT_3G
1420 depends on X86_32
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001421 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001422 Select the desired split between kernel and user memory.
1423
1424 If the address range available to the kernel is less than the
1425 physical memory installed, the remaining memory will be available
1426 as "high memory". Accessing high memory is a little more costly
1427 than low memory, as it needs to be mapped into the kernel first.
1428 Note that increasing the kernel address space limits the range
1429 available to user programs, making the address space there
1430 tighter. Selecting anything other than the default 3G/1G split
1431 will also likely make your kernel incompatible with binary-only
1432 kernel modules.
1433
1434 If you are not absolutely sure what you are doing, leave this
1435 option alone!
1436
1437 config VMSPLIT_3G
1438 bool "3G/1G user/kernel split"
1439 config VMSPLIT_3G_OPT
1440 depends on !X86_PAE
1441 bool "3G/1G user/kernel split (for full 1G low memory)"
1442 config VMSPLIT_2G
1443 bool "2G/2G user/kernel split"
1444 config VMSPLIT_2G_OPT
1445 depends on !X86_PAE
1446 bool "2G/2G user/kernel split (for full 2G low memory)"
1447 config VMSPLIT_1G
1448 bool "1G/3G user/kernel split"
1449endchoice
1450
1451config PAGE_OFFSET
1452 hex
1453 default 0xB0000000 if VMSPLIT_3G_OPT
1454 default 0x80000000 if VMSPLIT_2G
1455 default 0x78000000 if VMSPLIT_2G_OPT
1456 default 0x40000000 if VMSPLIT_1G
1457 default 0xC0000000
1458 depends on X86_32
1459
1460config HIGHMEM
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001461 def_bool y
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001462 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001463
1464config X86_PAE
Jan Beulich9ba16082008-10-15 22:01:38 -07001465 bool "PAE (Physical Address Extension) Support"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001466 depends on X86_32 && !HIGHMEM4G
Christoph Hellwigd4a451d2018-04-03 16:24:20 +02001467 select PHYS_ADDR_T_64BIT
Christian Melki9d99c712015-10-05 17:31:33 +02001468 select SWIOTLB
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001469 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001470 PAE is required for NX support, and furthermore enables
1471 larger swapspace support for non-overcommit purposes. It
1472 has the cost of more pagetable lookup overhead, and also
1473 consumes more pagetable space per process.
1474
Kirill A. Shutemov77ef56e2017-07-17 01:59:54 +03001475config X86_5LEVEL
1476 bool "Enable 5-level page tables support"
Kirill A. Shutemov18ec1ea2019-09-13 12:54:52 +03001477 default y
Kirill A. Shutemoveedb92a2018-02-14 14:16:50 +03001478 select DYNAMIC_MEMORY_LAYOUT
Kirill A. Shutemov162434e2018-02-14 14:16:54 +03001479 select SPARSEMEM_VMEMMAP
Kirill A. Shutemov77ef56e2017-07-17 01:59:54 +03001480 depends on X86_64
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001481 help
Kirill A. Shutemov77ef56e2017-07-17 01:59:54 +03001482 5-level paging enables access to larger address space:
1483 upto 128 PiB of virtual address space and 4 PiB of
1484 physical address space.
1485
1486 It will be supported by future Intel CPUs.
1487
Kirill A. Shutemov6657fca2018-02-14 21:25:42 +03001488 A kernel with the option enabled can be booted on machines that
1489 support 4- or 5-level paging.
Kirill A. Shutemov77ef56e2017-07-17 01:59:54 +03001490
Mauro Carvalho Chehabcb1aaeb2019-06-07 15:54:32 -03001491 See Documentation/x86/x86_64/5level-paging.rst for more
Kirill A. Shutemov77ef56e2017-07-17 01:59:54 +03001492 information.
1493
1494 Say N if unsure.
1495
Ingo Molnar10971ab2015-03-05 08:18:23 +01001496config X86_DIRECT_GBPAGES
Luis R. Rodrigueze5008ab2015-03-04 17:24:12 -08001497 def_bool y
Vlastimil Babka2e1da132019-08-07 15:02:58 +02001498 depends on X86_64
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001499 help
Ingo Molnar10971ab2015-03-05 08:18:23 +01001500 Certain kernel features effectively disable kernel
1501 linear 1 GB mappings (even if the CPU otherwise
1502 supports them), so don't confuse the user by printing
1503 that we have them enabled.
Nick Piggin9e899812008-10-22 12:33:16 +02001504
Thomas Gleixner5c280cf2018-09-17 16:29:12 +02001505config X86_CPA_STATISTICS
1506 bool "Enable statistic for Change Page Attribute"
1507 depends on DEBUG_FS
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001508 help
Ingo Molnarb75baaf2019-11-20 15:57:04 +01001509 Expose statistics about the Change Page Attribute mechanism, which
Colin Ian Kinga9432452019-04-16 11:57:51 +01001510 helps to determine the effectiveness of preserving large and huge
Thomas Gleixner5c280cf2018-09-17 16:29:12 +02001511 page mappings when mapping protections are changed.
1512
Tom Lendacky7744ccd2017-07-17 16:10:03 -05001513config AMD_MEM_ENCRYPT
1514 bool "AMD Secure Memory Encryption (SME) support"
1515 depends on X86_64 && CPU_SUP_AMD
David Rientjes82fef0a2020-04-14 17:05:01 -07001516 select DMA_COHERENT_POOL
Kirill A. Shutemov94d49eb2018-05-18 14:30:28 +03001517 select DYNAMIC_PHYSICAL_MASK
Ard Biesheuvelce9084b2019-02-02 10:41:17 +01001518 select ARCH_USE_MEMREMAP_PROT
Tom Lendacky9087c372019-07-10 19:01:19 +00001519 select ARCH_HAS_FORCE_DMA_UNENCRYPTED
Joerg Roedel597cfe482020-09-07 15:15:24 +02001520 select INSTRUCTION_DECODER
Tom Lendacky22916412021-03-04 16:40:11 -06001521 select ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001522 help
Tom Lendacky7744ccd2017-07-17 16:10:03 -05001523 Say yes to enable support for the encryption of system memory.
1524 This requires an AMD processor that supports Secure Memory
1525 Encryption (SME).
1526
1527config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
1528 bool "Activate AMD Secure Memory Encryption (SME) by default"
1529 default y
1530 depends on AMD_MEM_ENCRYPT
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001531 help
Tom Lendacky7744ccd2017-07-17 16:10:03 -05001532 Say yes to have system memory encrypted by default if running on
1533 an AMD processor that supports Secure Memory Encryption (SME).
1534
1535 If set to Y, then the encryption of system memory can be
1536 deactivated with the mem_encrypt=off command line option.
1537
1538 If set to N, then the encryption of system memory can be
1539 activated with the mem_encrypt=on command line option.
1540
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001541# Common NUMA Features
1542config NUMA
Randy Dunlape133f6e2019-12-03 16:06:47 -08001543 bool "NUMA Memory Allocation and Scheduler Support"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001544 depends on SMP
H. Peter Anvinb5660ba2014-02-25 12:14:06 -08001545 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1546 default y if X86_BIGSMP
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001547 help
Randy Dunlape133f6e2019-12-03 16:06:47 -08001548 Enable NUMA (Non-Uniform Memory Access) support.
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001549
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001550 The kernel will try to allocate memory used by a CPU on the
1551 local memory controller of the CPU and add some more
1552 NUMA awareness to the kernel.
1553
Ingo Molnarc280ea52008-11-08 13:29:45 +01001554 For 64-bit this is recommended if the system is Intel Core i7
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001555 (or later), AMD Opteron, or EM64T NUMA.
1556
H. Peter Anvinb5660ba2014-02-25 12:14:06 -08001557 For 32-bit this is only needed if you boot a 32-bit
David Rientjes7cf6c942014-02-11 18:11:13 -08001558 kernel on a 64-bit NUMA platform.
KOSAKI Motohirofd51b2d2008-11-05 02:27:19 +09001559
1560 Otherwise, you should say N.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001561
Hans Rosenfeldeec1d4f2010-10-29 17:14:30 +02001562config AMD_NUMA
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001563 def_bool y
1564 prompt "Old style AMD Opteron NUMA detection"
Tejun Heo5da0ef92011-07-11 10:34:32 +02001565 depends on X86_64 && NUMA && PCI
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001566 help
Hans Rosenfeldeec1d4f2010-10-29 17:14:30 +02001567 Enable AMD NUMA node topology detection. You should say Y here if
1568 you have a multi processor AMD system. This uses an old method to
1569 read the NUMA configuration directly from the builtin Northbridge
1570 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1571 which also takes priority if both are compiled in.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001572
1573config X86_64_ACPI_NUMA
Harvey Harrison3c2362e2008-01-30 13:31:03 +01001574 def_bool y
1575 prompt "ACPI NUMA detection"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001576 depends on X86_64 && NUMA && ACPI && PCI
1577 select ACPI_NUMA
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001578 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001579 Enable ACPI SRAT based node topology detection.
1580
1581config NUMA_EMU
1582 bool "NUMA emulation"
Tejun Heo1b7e03e2011-05-02 17:24:48 +02001583 depends on NUMA
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001584 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001585 Enable NUMA emulation. A flat machine will be split
1586 into virtual nodes when booted with "numa=fake=N", where N is the
1587 number of nodes. This is only useful for debugging.
1588
1589config NODES_SHIFT
Linus Torvaldsd25e26b2008-08-25 14:15:38 -07001590 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
David Rientjes51591e32010-03-25 15:39:27 -07001591 range 1 10
1592 default "10" if MAXSMP
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001593 default "6" if X86_64
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001594 default "3"
Mike Rapoporta9ee6cf2021-06-28 19:43:01 -07001595 depends on NUMA
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001596 help
Mike Travis1184dc22008-05-12 21:21:12 +02001597 Specify the maximum number of NUMA Nodes available on the target
Matt LaPlante692105b2009-01-26 11:12:25 +01001598 system. Increases memory reserved to accommodate various tables.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001599
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001600config ARCH_FLATMEM_ENABLE
1601 def_bool y
Tejun Heo3b166512011-04-01 11:15:12 +02001602 depends on X86_32 && !NUMA
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001603
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001604config ARCH_SPARSEMEM_ENABLE
1605 def_bool y
Kees Cook6ea30382012-10-02 11:16:47 -07001606 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001607 select SPARSEMEM_STATIC if X86_32
1608 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1609
Tejun Heo3b166512011-04-01 11:15:12 +02001610config ARCH_SPARSEMEM_DEFAULT
Mike Rapoport6ad57f72019-04-24 16:24:11 +03001611 def_bool X86_64 || (NUMA && X86_32)
Tejun Heo3b166512011-04-01 11:15:12 +02001612
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001613config ARCH_SELECT_MEMORY_MODEL
1614 def_bool y
Christoph Lameterb2632952008-01-30 13:30:47 +01001615 depends on ARCH_SPARSEMEM_ENABLE
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001616
1617config ARCH_MEMORY_PROBE
Toshi Kania0842b72013-07-19 11:47:48 -06001618 bool "Enable sysfs memory/probe interface"
Jan Beulich3120e252012-09-10 12:41:45 +01001619 depends on X86_64 && MEMORY_HOTPLUG
Toshi Kania0842b72013-07-19 11:47:48 -06001620 help
1621 This option enables a sysfs memory/probe interface for testing.
Mauro Carvalho Chehabcb1aaeb2019-06-07 15:54:32 -03001622 See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
Toshi Kania0842b72013-07-19 11:47:48 -06001623 If you are unsure how to answer this question, answer N.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001624
Tejun Heo3b166512011-04-01 11:15:12 +02001625config ARCH_PROC_KCORE_TEXT
1626 def_bool y
1627 depends on X86_64 && PROC_KCORE
1628
Avi Kivitya29815a2010-01-10 16:28:09 +02001629config ILLEGAL_POINTER_VALUE
Krzysztof Kozlowskib03b0162019-11-21 04:21:09 +01001630 hex
1631 default 0 if X86_32
1632 default 0xdead000000000000 if X86_64
Avi Kivitya29815a2010-01-10 16:28:09 +02001633
Dan Williams7a678322015-08-19 00:34:34 -04001634config X86_PMEM_LEGACY_DEVICE
1635 bool
1636
Christoph Hellwigec776ef2015-04-01 09:12:18 +02001637config X86_PMEM_LEGACY
Dan Williams7a678322015-08-19 00:34:34 -04001638 tristate "Support non-standard NVDIMMs and ADR protected memory"
Dan Williams9f53f9f2015-06-09 15:33:45 -04001639 depends on PHYS_ADDR_T_64BIT
1640 depends on BLK_DEV
Dan Williams7a678322015-08-19 00:34:34 -04001641 select X86_PMEM_LEGACY_DEVICE
Dan Williams7b27a862020-02-16 12:01:16 -08001642 select NUMA_KEEP_MEMINFO if NUMA
Dan Williams9f53f9f2015-06-09 15:33:45 -04001643 select LIBNVDIMM
Christoph Hellwigec776ef2015-04-01 09:12:18 +02001644 help
1645 Treat memory marked using the non-standard e820 type of 12 as used
1646 by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1647 The kernel will offer these regions to the 'pmem' driver so
1648 they can be used for persistent storage.
1649
1650 Say Y if unsure.
1651
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001652config HIGHPTE
1653 bool "Allocate 3rd-level pagetables from highmem"
Jan Beulich6fc108a2010-04-21 15:23:44 +01001654 depends on HIGHMEM
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001655 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001656 The VM uses one page table entry for each page of physical memory.
1657 For systems with a lot of RAM, this can be wasteful of precious
1658 low memory. Setting this option will put user-space page table
1659 entries in high memory.
1660
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001661config X86_CHECK_BIOS_CORRUPTION
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001662 bool "Check for low memory corruption"
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001663 help
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001664 Periodically check for memory corruption in low memory, which
1665 is suspected to be caused by BIOS. Even when enabled in the
1666 configuration, it is disabled at runtime. Enable it by
1667 setting "memory_corruption_check=1" on the kernel command
1668 line. By default it scans the low 64k of memory every 60
1669 seconds; see the memory_corruption_check_size and
1670 memory_corruption_check_period parameters in
Mauro Carvalho Chehab8c27ceff32016-10-18 10:12:27 -02001671 Documentation/admin-guide/kernel-parameters.rst to adjust this.
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001672
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001673 When enabled with the default parameters, this option has
1674 almost no overhead, as it reserves a relatively small amount
1675 of memory and scans it infrequently. It both detects corruption
1676 and prevents it from affecting the running system.
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001677
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001678 It is, however, intended as a diagnostic tool; if repeatable
1679 BIOS-originated corruption always affects the same memory,
1680 you can use memmap= to prevent the kernel from using that
1681 memory.
Jeremy Fitzhardinge9f077872008-09-07 01:51:34 -07001682
Jeremy Fitzhardingec885df52008-09-07 02:37:32 -07001683config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001684 bool "Set the default setting of memory_corruption_check"
Jeremy Fitzhardingec885df52008-09-07 02:37:32 -07001685 depends on X86_CHECK_BIOS_CORRUPTION
1686 default y
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001687 help
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001688 Set whether the default state of memory_corruption_check is
1689 on or off.
Jeremy Fitzhardingec885df52008-09-07 02:37:32 -07001690
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001691config MATH_EMULATION
1692 bool
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07001693 depends on MODIFY_LDT_SYSCALL
Arnd Bergmann87d60212019-10-01 16:23:35 +02001694 prompt "Math emulation" if X86_32 && (M486SX || MELAN)
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001695 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001696 Linux can emulate a math coprocessor (used for floating point
1697 operations) if you don't have one. 486DX and Pentium processors have
1698 a math coprocessor built in, 486SX and 386 do not, unless you added
1699 a 487DX or 387, respectively. (The messages during boot time can
1700 give you some hints here ["man dmesg"].) Everyone needs either a
1701 coprocessor or this emulation.
1702
1703 If you don't have a math coprocessor, you need to say Y here; if you
1704 say Y here even though you have a coprocessor, the coprocessor will
1705 be used nevertheless. (This behavior can be changed with the kernel
1706 command line option "no387", which comes handy if your coprocessor
1707 is broken. Try "man bootparam" or see the documentation of your boot
1708 loader (lilo or loadlin) about how to pass options to the kernel at
1709 boot time.) This means that it is a good idea to say Y here if you
1710 intend to use this kernel on different machines.
1711
1712 More information about the internals of the Linux math coprocessor
1713 emulation can be found in <file:arch/x86/math-emu/README>.
1714
1715 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1716 kernel, it won't hurt.
1717
1718config MTRR
Jan Beulich6fc108a2010-04-21 15:23:44 +01001719 def_bool y
David Rientjes6a108a12011-01-20 14:44:16 -08001720 prompt "MTRR (Memory Type Range Register) support" if EXPERT
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001721 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001722 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1723 the Memory Type Range Registers (MTRRs) may be used to control
1724 processor access to memory ranges. This is most useful if you have
1725 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1726 allows bus write transfers to be combined into a larger transfer
1727 before bursting over the PCI/AGP bus. This can increase performance
1728 of image write operations 2.5 times or more. Saying Y here creates a
1729 /proc/mtrr file which may be used to manipulate your processor's
1730 MTRRs. Typically the X server should use this.
1731
1732 This code has a reasonably generic interface so that similar
1733 control registers on other processors can be easily supported
1734 as well:
1735
1736 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1737 Registers (ARRs) which provide a similar functionality to MTRRs. For
1738 these, the ARRs are used to emulate the MTRRs.
1739 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1740 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1741 write-combining. All of these processors are supported by this code
1742 and it makes sense to say Y here if you have one of them.
1743
1744 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1745 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1746 can lead to all sorts of problems, so it's good to say Y here.
1747
1748 You can safely say Y even if your machine doesn't have MTRRs, you'll
1749 just add about 9 KB to your kernel.
1750
Mauro Carvalho Chehabcb1aaeb2019-06-07 15:54:32 -03001751 See <file:Documentation/x86/mtrr.rst> for more information.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001752
Yinghai Lu95ffa242008-04-29 03:52:33 -07001753config MTRR_SANITIZER
Yinghai Lu2ffb3502008-09-30 16:29:40 -07001754 def_bool y
Yinghai Lu95ffa242008-04-29 03:52:33 -07001755 prompt "MTRR cleanup support"
1756 depends on MTRR
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001757 help
Thomas Gleixneraba37282008-07-15 14:48:48 +02001758 Convert MTRR layout from continuous to discrete, so X drivers can
1759 add writeback entries.
Yinghai Lu95ffa242008-04-29 03:52:33 -07001760
Thomas Gleixneraba37282008-07-15 14:48:48 +02001761 Can be disabled with disable_mtrr_cleanup on the kernel command line.
Matt LaPlante692105b2009-01-26 11:12:25 +01001762 The largest mtrr entry size for a continuous block can be set with
Thomas Gleixneraba37282008-07-15 14:48:48 +02001763 mtrr_chunk_size.
Yinghai Lu95ffa242008-04-29 03:52:33 -07001764
Yinghai Lu2ffb3502008-09-30 16:29:40 -07001765 If unsure, say Y.
Yinghai Lu95ffa242008-04-29 03:52:33 -07001766
1767config MTRR_SANITIZER_ENABLE_DEFAULT
Yinghai Luf5098d62008-04-29 20:25:58 -07001768 int "MTRR cleanup enable value (0-1)"
1769 range 0 1
1770 default "0"
Yinghai Lu95ffa242008-04-29 03:52:33 -07001771 depends on MTRR_SANITIZER
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001772 help
Yinghai Luf5098d62008-04-29 20:25:58 -07001773 Enable mtrr cleanup default value
Yinghai Lu95ffa242008-04-29 03:52:33 -07001774
Yinghai Lu12031a62008-05-02 02:40:22 -07001775config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1776 int "MTRR cleanup spare reg num (0-7)"
1777 range 0 7
1778 default "1"
1779 depends on MTRR_SANITIZER
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001780 help
Yinghai Lu12031a62008-05-02 02:40:22 -07001781 mtrr cleanup spare entries default, it can be changed via
Thomas Gleixneraba37282008-07-15 14:48:48 +02001782 mtrr_spare_reg_nr=N on the kernel command line.
Yinghai Lu12031a62008-05-02 02:40:22 -07001783
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001784config X86_PAT
Jan Beulich6fc108a2010-04-21 15:23:44 +01001785 def_bool y
David Rientjes6a108a12011-01-20 14:44:16 -08001786 prompt "x86 PAT support" if EXPERT
Ingo Molnar2a8a2712008-04-26 10:26:52 +02001787 depends on MTRR
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001788 help
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001789 Use PAT attributes to setup page level cache control.
Venki Pallipadi042b78e2008-03-24 14:22:35 -07001790
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001791 PATs are the modern equivalents of MTRRs and are much more
1792 flexible than MTRRs.
1793
1794 Say N here if you see bootup problems (boot crash, boot hang,
Venki Pallipadi042b78e2008-03-24 14:22:35 -07001795 spontaneous reboots) or a non-working video driver.
venkatesh.pallipadi@intel.com2e5d9c82008-03-18 17:00:14 -07001796
1797 If unsure, say Y.
1798
Venkatesh Pallipadi46cf98c2009-07-10 09:57:37 -07001799config ARCH_USES_PG_UNCACHED
1800 def_bool y
1801 depends on X86_PAT
1802
H. Peter Anvin628c6242011-07-31 13:59:29 -07001803config ARCH_RANDOM
1804 def_bool y
1805 prompt "x86 architectural random number generator" if EXPERT
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001806 help
H. Peter Anvin628c6242011-07-31 13:59:29 -07001807 Enable the x86 architectural RDRAND instruction
1808 (Intel Bull Mountain technology) to generate random numbers.
1809 If supported, this is a high bandwidth, cryptographically
1810 secure hardware random number generator.
1811
H. Peter Anvin51ae4a22012-09-21 12:43:10 -07001812config X86_SMAP
1813 def_bool y
1814 prompt "Supervisor Mode Access Prevention" if EXPERT
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001815 help
H. Peter Anvin51ae4a22012-09-21 12:43:10 -07001816 Supervisor Mode Access Prevention (SMAP) is a security
1817 feature in newer Intel processors. There is a small
1818 performance cost if this enabled and turned on; there is
1819 also a small increase in the kernel size if this is enabled.
1820
1821 If unsure, say Y.
1822
Babu Mogerb9718802019-11-05 21:25:32 +00001823config X86_UMIP
Ricardo Neri796ebc82017-11-13 22:29:42 -08001824 def_bool y
Babu Mogerb9718802019-11-05 21:25:32 +00001825 prompt "User Mode Instruction Prevention" if EXPERT
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001826 help
Babu Mogerb9718802019-11-05 21:25:32 +00001827 User Mode Instruction Prevention (UMIP) is a security feature in
1828 some x86 processors. If enabled, a general protection fault is
1829 issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are
1830 executed in user mode. These instructions unnecessarily expose
1831 information about the hardware state.
Ricardo Neri796ebc82017-11-13 22:29:42 -08001832
1833 The vast majority of applications do not use these instructions.
1834 For the very few that do, software emulation is provided in
1835 specific cases in protected and virtual-8086 modes. Emulated
1836 results are dummy.
Ricardo Neriaa35f892017-11-05 18:27:54 -08001837
Dave Hansen35e97792016-02-12 13:02:00 -08001838config X86_INTEL_MEMORY_PROTECTION_KEYS
Babu Moger38f3e772020-05-28 11:08:23 -05001839 prompt "Memory Protection Keys"
Dave Hansen35e97792016-02-12 13:02:00 -08001840 def_bool y
Dave Hansen284244a2016-02-12 13:02:28 -08001841 # Note: only available in 64-bit mode
Babu Moger38f3e772020-05-28 11:08:23 -05001842 depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD)
Ingo Molnar52c8e602016-11-15 10:15:03 +01001843 select ARCH_USES_HIGH_VMA_FLAGS
1844 select ARCH_HAS_PKEYS
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001845 help
Dave Hansen284244a2016-02-12 13:02:28 -08001846 Memory Protection Keys provides a mechanism for enforcing
1847 page-based protections, but without requiring modification of the
1848 page tables when an application changes protection domains.
1849
Mauro Carvalho Chehab1eecbcd2019-06-07 15:54:31 -03001850 For details, see Documentation/core-api/protection-keys.rst
Dave Hansen284244a2016-02-12 13:02:28 -08001851
1852 If unsure, say y.
Dave Hansen35e97792016-02-12 13:02:00 -08001853
Michal Hockodb616172019-10-23 12:35:50 +02001854choice
1855 prompt "TSX enable mode"
1856 depends on CPU_SUP_INTEL
1857 default X86_INTEL_TSX_MODE_OFF
1858 help
1859 Intel's TSX (Transactional Synchronization Extensions) feature
1860 allows to optimize locking protocols through lock elision which
1861 can lead to a noticeable performance boost.
1862
1863 On the other hand it has been shown that TSX can be exploited
1864 to form side channel attacks (e.g. TAA) and chances are there
1865 will be more of those attacks discovered in the future.
1866
1867 Therefore TSX is not enabled by default (aka tsx=off). An admin
1868 might override this decision by tsx=on the command line parameter.
1869 Even with TSX enabled, the kernel will attempt to enable the best
1870 possible TAA mitigation setting depending on the microcode available
1871 for the particular machine.
1872
1873 This option allows to set the default tsx mode between tsx=on, =off
1874 and =auto. See Documentation/admin-guide/kernel-parameters.txt for more
1875 details.
1876
1877 Say off if not sure, auto if TSX is in use but it should be used on safe
1878 platforms or on if TSX is in use and the security aspect of tsx is not
1879 relevant.
1880
1881config X86_INTEL_TSX_MODE_OFF
1882 bool "off"
1883 help
1884 TSX is disabled if possible - equals to tsx=off command line parameter.
1885
1886config X86_INTEL_TSX_MODE_ON
1887 bool "on"
1888 help
1889 TSX is always enabled on TSX capable HW - equals the tsx=on command
1890 line parameter.
1891
1892config X86_INTEL_TSX_MODE_AUTO
1893 bool "auto"
1894 help
1895 TSX is enabled on TSX capable HW that is believed to be safe against
1896 side channel attacks- equals the tsx=auto command line parameter.
1897endchoice
1898
Sean Christophersone7e05452020-11-13 00:01:16 +02001899config X86_SGX
1900 bool "Software Guard eXtensions (SGX)"
1901 depends on X86_64 && CPU_SUP_INTEL
1902 depends on CRYPTO=y
1903 depends on CRYPTO_SHA256=y
1904 select SRCU
1905 select MMU_NOTIFIER
Jarkko Sakkinen901ddbb2021-03-18 01:53:31 +02001906 select NUMA_KEEP_MEMINFO if NUMA
Sean Christophersone7e05452020-11-13 00:01:16 +02001907 help
1908 Intel(R) Software Guard eXtensions (SGX) is a set of CPU instructions
1909 that can be used by applications to set aside private regions of code
1910 and data, referred to as enclaves. An enclave's private memory can
1911 only be accessed by code running within the enclave. Accesses from
1912 outside the enclave, including other enclaves, are disallowed by
1913 hardware.
1914
1915 If unsure, say N.
1916
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001917config EFI
Jan Beulich9ba16082008-10-15 22:01:38 -07001918 bool "EFI runtime service support"
Huang, Ying5b836832008-01-30 13:31:19 +01001919 depends on ACPI
Sergey Vlasovf6ce5002013-04-16 18:31:08 +04001920 select UCS2_STRING
Ard Biesheuvel022ee6c2014-06-26 12:09:05 +02001921 select EFI_RUNTIME_WRAPPERS
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001922 help
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001923 This enables the kernel to use EFI runtime services that are
1924 available (such as the EFI variable services).
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001925
Ingo Molnar8f9ca472009-02-05 16:21:53 +01001926 This option is only useful on systems that have EFI firmware.
1927 In addition, you should use the latest ELILO loader available
1928 at <http://elilo.sourceforge.net> in order to take advantage
1929 of EFI runtime services. However, even with this option, the
1930 resultant kernel should continue to boot on existing non-EFI
1931 platforms.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001932
Matt Fleming291f3632011-12-12 21:27:52 +00001933config EFI_STUB
Ard Biesheuvel8f24f8c2019-12-24 16:10:12 +01001934 bool "EFI stub support"
1935 depends on EFI && !X86_USE_3DNOW
1936 depends on $(cc-option,-mabi=ms) || X86_32
1937 select RELOCATABLE
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001938 help
Ard Biesheuvel8f24f8c2019-12-24 16:10:12 +01001939 This kernel feature allows a bzImage to be loaded directly
Matt Fleming291f3632011-12-12 21:27:52 +00001940 by EFI firmware without the use of a bootloader.
1941
Mauro Carvalho Chehab4f4cfa62019-06-27 14:56:51 -03001942 See Documentation/admin-guide/efi-stub.rst for more information.
Matt Fleming0c759662012-03-16 12:03:13 +00001943
Matt Fleming7d453ee2014-01-10 18:52:06 +00001944config EFI_MIXED
1945 bool "EFI mixed-mode support"
1946 depends on EFI_STUB && X86_64
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001947 help
Matt Fleming7d453ee2014-01-10 18:52:06 +00001948 Enabling this feature allows a 64-bit kernel to be booted
1949 on a 32-bit firmware, provided that your CPU supports 64-bit
1950 mode.
1951
1952 Note that it is not possible to boot a mixed-mode enabled
1953 kernel via the EFI boot stub - a bootloader that supports
1954 the EFI handover protocol must be used.
1955
1956 If unsure, say N.
1957
Masahiro Yamada8636a1f2018-12-11 20:01:04 +09001958source "kernel/Kconfig.hz"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001959
1960config KEXEC
1961 bool "kexec system call"
Dave Young2965faa2015-09-09 15:38:55 -07001962 select KEXEC_CORE
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001963 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001964 kexec is a system call that implements the ability to shutdown your
1965 current kernel, and to start another kernel. It is like a reboot
1966 but it is independent of the system firmware. And like a reboot
1967 you can start any kernel with it, not just Linux.
1968
1969 The name comes from the similarity to the exec system call.
1970
1971 It is an ongoing process to be certain the hardware in a machine
1972 is properly shutdown, so do not be surprised if this code does not
Geert Uytterhoevenbf220692013-08-20 21:38:03 +02001973 initially work for you. As of this writing the exact hardware
1974 interface is strongly in flux, so no good recommendation can be
1975 made.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01001976
Vivek Goyal74ca3172014-08-29 15:18:46 -07001977config KEXEC_FILE
1978 bool "kexec file based system call"
Dave Young2965faa2015-09-09 15:38:55 -07001979 select KEXEC_CORE
Vivek Goyal74ca3172014-08-29 15:18:46 -07001980 select BUILD_BIN2C
Vivek Goyal74ca3172014-08-29 15:18:46 -07001981 depends on X86_64
1982 depends on CRYPTO=y
1983 depends on CRYPTO_SHA256=y
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001984 help
Vivek Goyal74ca3172014-08-29 15:18:46 -07001985 This is new version of kexec system call. This system call is
1986 file based and takes file descriptors as system call argument
1987 for kernel and initramfs as opposed to list of segments as
1988 accepted by previous system call.
1989
AKASHI Takahirob799a092018-04-13 15:35:45 -07001990config ARCH_HAS_KEXEC_PURGATORY
1991 def_bool KEXEC_FILE
1992
Jiri Bohac99d5cadf2019-08-19 17:17:44 -07001993config KEXEC_SIG
Vivek Goyal8e7d8382014-08-08 14:26:13 -07001994 bool "Verify kernel signature during kexec_file_load() syscall"
Vivek Goyal74ca3172014-08-29 15:18:46 -07001995 depends on KEXEC_FILE
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001996 help
Jiri Bohac99d5cadf2019-08-19 17:17:44 -07001997
1998 This option makes the kexec_file_load() syscall check for a valid
1999 signature of the kernel image. The image can still be loaded without
2000 a valid signature unless you also enable KEXEC_SIG_FORCE, though if
2001 there's a signature that we can check, then it must be valid.
2002
2003 In addition to this option, you need to enable signature
2004 verification for the corresponding kernel image type being
2005 loaded in order for this to work.
2006
2007config KEXEC_SIG_FORCE
2008 bool "Require a valid signature in kexec_file_load() syscall"
2009 depends on KEXEC_SIG
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002010 help
Vivek Goyal8e7d8382014-08-08 14:26:13 -07002011 This option makes kernel signature verification mandatory for
Borislav Petkovd8eb8942015-03-13 14:04:37 +01002012 the kexec_file_load() syscall.
Vivek Goyal8e7d8382014-08-08 14:26:13 -07002013
Vivek Goyal8e7d8382014-08-08 14:26:13 -07002014config KEXEC_BZIMAGE_VERIFY_SIG
2015 bool "Enable bzImage signature verification support"
Jiri Bohac99d5cadf2019-08-19 17:17:44 -07002016 depends on KEXEC_SIG
Vivek Goyal8e7d8382014-08-08 14:26:13 -07002017 depends on SIGNED_PE_FILE_VERIFICATION
2018 select SYSTEM_TRUSTED_KEYRING
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002019 help
Vivek Goyal8e7d8382014-08-08 14:26:13 -07002020 Enable bzImage signature verification support.
2021
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002022config CRASH_DUMP
Pavel Machek04b69442008-08-14 17:16:50 +02002023 bool "kernel crash dumps"
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002024 depends on X86_64 || (X86_32 && HIGHMEM)
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002025 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002026 Generate crash dump after being started by kexec.
2027 This should be normally only set in special crash dump kernels
2028 which are loaded in the main kernel with kexec-tools into
2029 a specially reserved region and then later executed after
2030 a crash by kdump/kexec. The crash dump kernel must be compiled
2031 to a memory address not used by the main kernel or BIOS using
2032 PHYSICAL_START, or it must be built as a relocatable image
2033 (CONFIG_RELOCATABLE=y).
Mauro Carvalho Chehab330d4812019-06-13 15:21:39 -03002034 For more details see Documentation/admin-guide/kdump/kdump.rst
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002035
Huang Ying3ab83522008-07-25 19:45:07 -07002036config KEXEC_JUMP
Kees Cook6ea30382012-10-02 11:16:47 -07002037 bool "kexec jump"
Huang Yingfee7b0d2009-03-10 10:57:16 +08002038 depends on KEXEC && HIBERNATION
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002039 help
Huang Ying89081d12008-07-25 19:45:10 -07002040 Jump between original kernel and kexeced kernel and invoke
2041 code in physical address mode via KEXEC
Huang Ying3ab83522008-07-25 19:45:07 -07002042
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002043config PHYSICAL_START
David Rientjes6a108a12011-01-20 14:44:16 -08002044 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
H. Peter Anvinceefccc2009-05-11 16:12:16 -07002045 default "0x1000000"
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002046 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002047 This gives the physical address where the kernel is loaded.
2048
2049 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2050 bzImage will decompress itself to above physical address and
2051 run from there. Otherwise, bzImage will run from the address where
2052 it has been loaded by the boot loader and will ignore above physical
2053 address.
2054
2055 In normal kdump cases one does not have to set/change this option
2056 as now bzImage can be compiled as a completely relocatable image
2057 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2058 address. This option is mainly useful for the folks who don't want
2059 to use a bzImage for capturing the crash dump and want to use a
2060 vmlinux instead. vmlinux is not relocatable hence a kernel needs
2061 to be specifically compiled to run from a specific memory area
2062 (normally a reserved region) and this option comes handy.
2063
H. Peter Anvinceefccc2009-05-11 16:12:16 -07002064 So if you are using bzImage for capturing the crash dump,
2065 leave the value here unchanged to 0x1000000 and set
2066 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
2067 for capturing the crash dump change this value to start of
2068 the reserved region. In other words, it can be set based on
2069 the "X" value as specified in the "crashkernel=YM@XM"
2070 command line boot parameter passed to the panic-ed
Mauro Carvalho Chehab330d4812019-06-13 15:21:39 -03002071 kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst
H. Peter Anvinceefccc2009-05-11 16:12:16 -07002072 for more details about crash dumps.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002073
2074 Usage of bzImage for capturing the crash dump is recommended as
2075 one does not have to build two kernels. Same kernel can be used
2076 as production kernel and capture kernel. Above option should have
2077 gone away after relocatable bzImage support is introduced. But it
2078 is present because there are users out there who continue to use
2079 vmlinux for dump capture. This option should go away down the
2080 line.
2081
2082 Don't change this unless you know what you are doing.
2083
2084config RELOCATABLE
H. Peter Anvin26717802009-05-07 14:19:34 -07002085 bool "Build a relocatable kernel"
2086 default y
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002087 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002088 This builds a kernel image that retains relocation information
2089 so it can be loaded someplace besides the default 1MB.
2090 The relocations tend to make the kernel binary about 10% larger,
2091 but are discarded at runtime.
2092
2093 One use is for the kexec on panic case where the recovery kernel
2094 must live at a different physical address than the primary
2095 kernel.
2096
2097 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2098 it has been loaded at and the compile time physical address
Kees Cook8ab38202013-10-10 17:18:14 -07002099 (CONFIG_PHYSICAL_START) is used as the minimum location.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002100
Kees Cook8ab38202013-10-10 17:18:14 -07002101config RANDOMIZE_BASE
Baoquan Hee8581e32016-04-20 13:55:43 -07002102 bool "Randomize the address of the kernel image (KASLR)"
Kees Cook8ab38202013-10-10 17:18:14 -07002103 depends on RELOCATABLE
Ingo Molnar6807c842017-04-18 11:08:12 +02002104 default y
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002105 help
Baoquan Hee8581e32016-04-20 13:55:43 -07002106 In support of Kernel Address Space Layout Randomization (KASLR),
2107 this randomizes the physical address at which the kernel image
2108 is decompressed and the virtual address where the kernel
2109 image is mapped, as a security feature that deters exploit
2110 attempts relying on knowledge of the location of kernel
2111 code internals.
Kees Cook8ab38202013-10-10 17:18:14 -07002112
Kees Cooked9f0072016-05-25 15:45:33 -07002113 On 64-bit, the kernel physical and virtual addresses are
2114 randomized separately. The physical address will be anywhere
2115 between 16MB and the top of physical memory (up to 64TB). The
2116 virtual address will be randomized from 16MB up to 1GB (9 bits
2117 of entropy). Note that this also reduces the memory space
2118 available to kernel modules from 1.5GB to 1GB.
2119
2120 On 32-bit, the kernel physical and virtual addresses are
2121 randomized together. They will be randomized from 16MB up to
2122 512MB (8 bits of entropy).
Kees Cook8ab38202013-10-10 17:18:14 -07002123
Baoquan Hee8581e32016-04-20 13:55:43 -07002124 Entropy is generated using the RDRAND instruction if it is
2125 supported. If RDTSC is supported, its value is mixed into
2126 the entropy pool as well. If neither RDRAND nor RDTSC are
Kees Cooked9f0072016-05-25 15:45:33 -07002127 supported, then entropy is read from the i8254 timer. The
2128 usable entropy is limited by the kernel being built using
2129 2GB addressing, and that PHYSICAL_ALIGN must be at a
2130 minimum of 2MB. As a result, only 10 bits of entropy are
2131 theoretically possible, but the implementations are further
2132 limited due to memory layouts.
Kees Cookda2b6fb2013-12-10 12:27:45 -08002133
Ingo Molnar6807c842017-04-18 11:08:12 +02002134 If unsure, say Y.
Kees Cook8ab38202013-10-10 17:18:14 -07002135
2136# Relocation on x86 needs some additional build support
H. Peter Anvin845adf72009-05-05 21:20:51 -07002137config X86_NEED_RELOCS
2138 def_bool y
Kees Cook8ab38202013-10-10 17:18:14 -07002139 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
H. Peter Anvin845adf72009-05-05 21:20:51 -07002140
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002141config PHYSICAL_ALIGN
Kees Cooka0215062013-07-08 09:15:17 -07002142 hex "Alignment value to which kernel should be aligned"
Kees Cook8ab38202013-10-10 17:18:14 -07002143 default "0x200000"
Kees Cooka0215062013-07-08 09:15:17 -07002144 range 0x2000 0x1000000 if X86_32
2145 range 0x200000 0x1000000 if X86_64
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002146 help
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002147 This value puts the alignment restrictions on physical address
2148 where kernel is loaded and run from. Kernel is compiled for an
2149 address which meets above alignment restriction.
2150
2151 If bootloader loads the kernel at a non-aligned address and
2152 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2153 address aligned to above value and run from there.
2154
2155 If bootloader loads the kernel at a non-aligned address and
2156 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2157 load address and decompress itself to the address it has been
2158 compiled for and run from there. The address for which kernel is
2159 compiled already meets above alignment restrictions. Hence the
2160 end result is that kernel runs from a physical address meeting
2161 above alignment restrictions.
2162
Kees Cooka0215062013-07-08 09:15:17 -07002163 On 32-bit this value must be a multiple of 0x2000. On 64-bit
2164 this value must be a multiple of 0x200000.
2165
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002166 Don't change this unless you know what you are doing.
2167
Kirill A. Shutemoveedb92a2018-02-14 14:16:50 +03002168config DYNAMIC_MEMORY_LAYOUT
2169 bool
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002170 help
Kirill A. Shutemoveedb92a2018-02-14 14:16:50 +03002171 This option makes base addresses of vmalloc and vmemmap as well as
2172 __PAGE_OFFSET movable during boot.
2173
Thomas Garnier0483e1f2016-06-21 17:47:02 -07002174config RANDOMIZE_MEMORY
2175 bool "Randomize the kernel memory sections"
2176 depends on X86_64
2177 depends on RANDOMIZE_BASE
Kirill A. Shutemoveedb92a2018-02-14 14:16:50 +03002178 select DYNAMIC_MEMORY_LAYOUT
Thomas Garnier0483e1f2016-06-21 17:47:02 -07002179 default RANDOMIZE_BASE
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002180 help
Thomas Garnier0483e1f2016-06-21 17:47:02 -07002181 Randomizes the base virtual address of kernel memory sections
2182 (physical memory mapping, vmalloc & vmemmap). This security feature
2183 makes exploits relying on predictable memory locations less reliable.
2184
2185 The order of allocations remains unchanged. Entropy is generated in
2186 the same way as RANDOMIZE_BASE. Current implementation in the optimal
2187 configuration have in average 30,000 different possible virtual
2188 addresses for each memory section.
2189
Ingo Molnar6807c842017-04-18 11:08:12 +02002190 If unsure, say Y.
Thomas Garnier0483e1f2016-06-21 17:47:02 -07002191
Thomas Garnier90397a42016-06-21 17:47:06 -07002192config RANDOMIZE_MEMORY_PHYSICAL_PADDING
2193 hex "Physical memory mapping padding" if EXPERT
2194 depends on RANDOMIZE_MEMORY
2195 default "0xa" if MEMORY_HOTPLUG
2196 default "0x0"
2197 range 0x1 0x40 if MEMORY_HOTPLUG
2198 range 0x0 0x40
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002199 help
Thomas Garnier90397a42016-06-21 17:47:06 -07002200 Define the padding in terabytes added to the existing physical
2201 memory size during kernel memory randomization. It is useful
2202 for memory hotplug support but reduces the entropy available for
2203 address randomization.
2204
2205 If unsure, leave at the default value.
2206
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002207config HOTPLUG_CPU
Thomas Gleixnerbebd0242019-03-26 17:36:06 +01002208 def_bool y
Stephen Rothwell40b31362013-05-21 13:49:35 +10002209 depends on SMP
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002210
Fenghua Yu80aa1df2012-11-13 11:32:39 -08002211config BOOTPARAM_HOTPLUG_CPU0
2212 bool "Set default setting of cpu0_hotpluggable"
Kees Cook2c922cd2013-01-22 13:01:19 -08002213 depends on HOTPLUG_CPU
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002214 help
Fenghua Yu80aa1df2012-11-13 11:32:39 -08002215 Set whether default state of cpu0_hotpluggable is on or off.
2216
2217 Say Y here to enable CPU0 hotplug by default. If this switch
2218 is turned on, there is no need to give cpu0_hotplug kernel
2219 parameter and the CPU0 hotplug feature is enabled by default.
2220
2221 Please note: there are two known CPU0 dependencies if you want
2222 to enable the CPU0 hotplug feature either by this switch or by
2223 cpu0_hotplug kernel parameter.
2224
2225 First, resume from hibernate or suspend always starts from CPU0.
2226 So hibernate and suspend are prevented if CPU0 is offline.
2227
2228 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2229 offline if any interrupt can not migrate out of CPU0. There may
2230 be other CPU0 dependencies.
2231
2232 Please make sure the dependencies are under your control before
2233 you enable this feature.
2234
2235 Say N if you don't want to enable CPU0 hotplug feature by default.
2236 You still can enable the CPU0 hotplug feature at boot by kernel
2237 parameter cpu0_hotplug.
2238
Fenghua Yua71c8bc2012-11-13 11:32:51 -08002239config DEBUG_HOTPLUG_CPU0
2240 def_bool n
2241 prompt "Debug CPU0 hotplug"
Kees Cook2c922cd2013-01-22 13:01:19 -08002242 depends on HOTPLUG_CPU
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002243 help
Fenghua Yua71c8bc2012-11-13 11:32:51 -08002244 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2245 soon as possible and boots up userspace with CPU0 offlined. User
2246 can online CPU0 back after boot time.
2247
2248 To debug CPU0 hotplug, you need to enable CPU0 offline/online
2249 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2250 compilation or giving cpu0_hotplug kernel parameter at boot.
2251
2252 If unsure, say N.
2253
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002254config COMPAT_VDSO
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002255 def_bool n
2256 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
Ingo Molnar953fee12016-11-15 10:22:52 +01002257 depends on COMPAT_32
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002258 help
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002259 Certain buggy versions of glibc will crash if they are
2260 presented with a 32-bit vDSO that is not mapped at the address
2261 indicated in its segment table.
Randy Dunlape84446d2009-11-10 15:46:52 -08002262
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002263 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2264 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2265 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
2266 the only released version with the bug, but OpenSUSE 9
2267 contains a buggy "glibc 2.3.2".
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002268
Andy Lutomirskib0b49f22014-03-13 16:01:26 -07002269 The symptom of the bug is that everything crashes on startup, saying:
2270 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2271
2272 Saying Y here changes the default value of the vdso32 boot
2273 option from 1 to 0, which turns off the 32-bit vDSO entirely.
2274 This works around the glibc bug but hurts performance.
2275
2276 If unsure, say N: if you are compiling your own kernel, you
2277 are unlikely to be using a buggy version of glibc.
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002278
Kees Cook3dc33bd2015-08-12 17:55:19 -07002279choice
2280 prompt "vsyscall table for legacy applications"
2281 depends on X86_64
Andy Lutomirski625b7b72019-06-26 21:45:07 -07002282 default LEGACY_VSYSCALL_XONLY
Kees Cook3dc33bd2015-08-12 17:55:19 -07002283 help
2284 Legacy user code that does not know how to find the vDSO expects
2285 to be able to issue three syscalls by calling fixed addresses in
2286 kernel space. Since this location is not randomized with ASLR,
2287 it can be used to assist security vulnerability exploitation.
2288
2289 This setting can be changed at boot time via the kernel command
Andy Lutomirskibd49e162019-06-26 21:45:03 -07002290 line parameter vsyscall=[emulate|xonly|none].
Kees Cook3dc33bd2015-08-12 17:55:19 -07002291
2292 On a system with recent enough glibc (2.14 or newer) and no
2293 static binaries, you can say None without a performance penalty
2294 to improve security.
2295
Andy Lutomirskibd49e162019-06-26 21:45:03 -07002296 If unsure, select "Emulate execution only".
Kees Cook3dc33bd2015-08-12 17:55:19 -07002297
Kees Cook3dc33bd2015-08-12 17:55:19 -07002298 config LEGACY_VSYSCALL_EMULATE
Andy Lutomirskibd49e162019-06-26 21:45:03 -07002299 bool "Full emulation"
Kees Cook3dc33bd2015-08-12 17:55:19 -07002300 help
Andy Lutomirskibd49e162019-06-26 21:45:03 -07002301 The kernel traps and emulates calls into the fixed vsyscall
2302 address mapping. This makes the mapping non-executable, but
2303 it still contains readable known contents, which could be
2304 used in certain rare security vulnerability exploits. This
2305 configuration is recommended when using legacy userspace
2306 that still uses vsyscalls along with legacy binary
2307 instrumentation tools that require code to be readable.
2308
2309 An example of this type of legacy userspace is running
2310 Pin on an old binary that still uses vsyscalls.
2311
2312 config LEGACY_VSYSCALL_XONLY
2313 bool "Emulate execution only"
2314 help
2315 The kernel traps and emulates calls into the fixed vsyscall
2316 address mapping and does not allow reads. This
2317 configuration is recommended when userspace might use the
2318 legacy vsyscall area but support for legacy binary
2319 instrumentation of legacy code is not needed. It mitigates
2320 certain uses of the vsyscall area as an ASLR-bypassing
2321 buffer.
Kees Cook3dc33bd2015-08-12 17:55:19 -07002322
2323 config LEGACY_VSYSCALL_NONE
2324 bool "None"
2325 help
2326 There will be no vsyscall mapping at all. This will
2327 eliminate any risk of ASLR bypass due to the vsyscall
2328 fixed address mapping. Attempts to use the vsyscalls
2329 will be reported to dmesg, so that either old or
2330 malicious userspace programs can be identified.
2331
2332endchoice
2333
Tim Bird516cbf32008-08-12 12:52:36 -07002334config CMDLINE_BOOL
2335 bool "Built-in kernel command line"
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002336 help
Tim Bird516cbf32008-08-12 12:52:36 -07002337 Allow for specifying boot arguments to the kernel at
2338 build time. On some systems (e.g. embedded ones), it is
2339 necessary or convenient to provide some or all of the
2340 kernel boot arguments with the kernel itself (that is,
2341 to not rely on the boot loader to provide them.)
2342
2343 To compile command line arguments into the kernel,
2344 set this option to 'Y', then fill in the
Sébastien Hinderer69711ca2015-07-08 00:02:01 +02002345 boot arguments in CONFIG_CMDLINE.
Tim Bird516cbf32008-08-12 12:52:36 -07002346
2347 Systems with fully functional boot loaders (i.e. non-embedded)
2348 should leave this option set to 'N'.
2349
2350config CMDLINE
2351 string "Built-in kernel command string"
2352 depends on CMDLINE_BOOL
2353 default ""
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002354 help
Tim Bird516cbf32008-08-12 12:52:36 -07002355 Enter arguments here that should be compiled into the kernel
2356 image and used at boot time. If the boot loader provides a
2357 command line at boot time, it is appended to this string to
2358 form the full kernel command line, when the system boots.
2359
2360 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2361 change this behavior.
2362
2363 In most cases, the command line (whether built-in or provided
2364 by the boot loader) should specify the device for the root
2365 file system.
2366
2367config CMDLINE_OVERRIDE
2368 bool "Built-in command line overrides boot loader arguments"
Anders Roxell645e6462020-01-24 12:46:15 +01002369 depends on CMDLINE_BOOL && CMDLINE != ""
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002370 help
Tim Bird516cbf32008-08-12 12:52:36 -07002371 Set this option to 'Y' to have the kernel ignore the boot loader
2372 command line, and use ONLY the built-in command line.
2373
2374 This is used to work around broken boot loaders. This should
2375 be set to 'N' under normal conditions.
2376
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07002377config MODIFY_LDT_SYSCALL
2378 bool "Enable the LDT (local descriptor table)" if EXPERT
2379 default y
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002380 help
Andy Lutomirskia5b9e5a2015-07-30 14:31:34 -07002381 Linux can allow user programs to install a per-process x86
2382 Local Descriptor Table (LDT) using the modify_ldt(2) system
2383 call. This is required to run 16-bit or segmented code such as
2384 DOSEMU or some Wine programs. It is also used by some very old
2385 threading libraries.
2386
2387 Enabling this feature adds a small amount of overhead to
2388 context switches and increases the low-level kernel attack
2389 surface. Disabling it removes the modify_ldt(2) system call.
2390
2391 Saying 'N' here may make sense for embedded or server kernels.
2392
Seth Jenningsb700e7f2014-12-16 11:58:19 -06002393source "kernel/livepatch/Kconfig"
2394
Sam Ravnborg506f1d072007-11-09 21:56:54 +01002395endmenu
2396
Michal Hocko3072e412017-09-08 16:11:39 -07002397config ARCH_HAS_ADD_PAGES
2398 def_bool y
2399 depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
2400
Oscar Salvadorf91ef222021-05-04 18:39:51 -07002401config ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE
2402 def_bool y
2403
Lee Schermerhorne534c7c2010-05-26 14:44:58 -07002404config USE_PERCPU_NUMA_NODE_ID
Tejun Heo645a7912011-01-23 14:37:40 +01002405 def_bool y
Lee Schermerhorne534c7c2010-05-26 14:44:58 -07002406 depends on NUMA
2407
Bjorn Helgaasda85f862008-11-05 13:37:27 -06002408menu "Power management and ACPI options"
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002409
2410config ARCH_HIBERNATION_HEADER
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002411 def_bool y
Zhimin Gu44556532018-09-21 14:27:29 +08002412 depends on HIBERNATION
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002413
2414source "kernel/power/Kconfig"
2415
2416source "drivers/acpi/Kconfig"
2417
Andi Kleena6b68072008-01-30 13:32:49 +01002418config X86_APM_BOOT
Jan Beulich6fc108a2010-04-21 15:23:44 +01002419 def_bool y
Paul Bolle282e5aa2011-11-17 11:41:31 +01002420 depends on APM
Andi Kleena6b68072008-01-30 13:32:49 +01002421
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002422menuconfig APM
2423 tristate "APM (Advanced Power Management) BIOS support"
Ingo Molnarefefa6f2008-07-10 16:09:50 +02002424 depends on X86_32 && PM_SLEEP
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002425 help
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002426 APM is a BIOS specification for saving power using several different
2427 techniques. This is mostly useful for battery powered laptops with
2428 APM compliant BIOSes. If you say Y here, the system time will be
2429 reset after a RESUME operation, the /proc/apm device will provide
2430 battery status information, and user-space programs will receive
2431 notification of APM "events" (e.g. battery status change).
2432
2433 If you select "Y" here, you can disable actual use of the APM
2434 BIOS by passing the "apm=off" option to the kernel at boot time.
2435
2436 Note that the APM support is almost completely disabled for
2437 machines with more than one CPU.
2438
2439 In order to use APM, you will need supporting software. For location
Mauro Carvalho Chehab151f4e22019-06-13 07:10:36 -03002440 and more information, read <file:Documentation/power/apm-acpi.rst>
Michael Witten2dc98fd2011-07-08 21:11:16 +00002441 and the Battery Powered Linux mini-HOWTO, available from
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002442 <http://www.tldp.org/docs.html#howto>.
2443
2444 This driver does not spin down disk drives (see the hdparm(8)
2445 manpage ("man 8 hdparm") for that), and it doesn't turn off
2446 VESA-compliant "green" monitors.
2447
2448 This driver does not support the TI 4000M TravelMate and the ACER
2449 486/DX4/75 because they don't have compliant BIOSes. Many "green"
2450 desktop machines also don't have compliant BIOSes, and this driver
2451 may cause those machines to panic during the boot phase.
2452
2453 Generally, if you don't have a battery in your machine, there isn't
2454 much point in using this driver and you should say N. If you get
2455 random kernel OOPSes or reboots that don't seem to be related to
2456 anything, try disabling/enabling this option (or disabling/enabling
2457 APM in your BIOS).
2458
2459 Some other things you should try when experiencing seemingly random,
2460 "weird" problems:
2461
2462 1) make sure that you have enough swap space and that it is
2463 enabled.
2464 2) pass the "no-hlt" option to the kernel
2465 3) switch on floating point emulation in the kernel and pass
2466 the "no387" option to the kernel
2467 4) pass the "floppy=nodma" option to the kernel
2468 5) pass the "mem=4M" option to the kernel (thereby disabling
2469 all but the first 4 MB of RAM)
2470 6) make sure that the CPU is not over clocked.
2471 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2472 8) disable the cache from your BIOS settings
2473 9) install a fan for the video card or exchange video RAM
2474 10) install a better fan for the CPU
2475 11) exchange RAM chips
2476 12) exchange the motherboard.
2477
2478 To compile this driver as a module, choose M here: the
2479 module will be called apm.
2480
2481if APM
2482
2483config APM_IGNORE_USER_SUSPEND
2484 bool "Ignore USER SUSPEND"
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002485 help
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002486 This option will ignore USER SUSPEND requests. On machines with a
2487 compliant APM BIOS, you want to say N. However, on the NEC Versa M
2488 series notebooks, it is necessary to say Y because of a BIOS bug.
2489
2490config APM_DO_ENABLE
2491 bool "Enable PM at boot time"
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002492 help
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002493 Enable APM features at boot time. From page 36 of the APM BIOS
2494 specification: "When disabled, the APM BIOS does not automatically
2495 power manage devices, enter the Standby State, enter the Suspend
2496 State, or take power saving steps in response to CPU Idle calls."
2497 This driver will make CPU Idle calls when Linux is idle (unless this
2498 feature is turned off -- see "Do CPU IDLE calls", below). This
2499 should always save battery power, but more complicated APM features
2500 will be dependent on your BIOS implementation. You may need to turn
2501 this option off if your computer hangs at boot time when using APM
2502 support, or if it beeps continuously instead of suspending. Turn
2503 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2504 T400CDT. This is off by default since most machines do fine without
2505 this feature.
2506
2507config APM_CPU_IDLE
Len Browndd8af072013-02-09 21:10:04 -05002508 depends on CPU_IDLE
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002509 bool "Make CPU Idle calls when idle"
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002510 help
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002511 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2512 On some machines, this can activate improved power savings, such as
2513 a slowed CPU clock rate, when the machine is idle. These idle calls
2514 are made after the idle loop has run for some length of time (e.g.,
2515 333 mS). On some machines, this will cause a hang at boot time or
2516 whenever the CPU becomes idle. (On machines with more than one CPU,
2517 this option does nothing.)
2518
2519config APM_DISPLAY_BLANK
2520 bool "Enable console blanking using APM"
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002521 help
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002522 Enable console blanking using the APM. Some laptops can use this to
2523 turn off the LCD backlight when the screen blanker of the Linux
2524 virtual console blanks the screen. Note that this is only used by
2525 the virtual console screen blanker, and won't turn off the backlight
2526 when using the X Window system. This also doesn't have anything to
2527 do with your VESA-compliant power-saving monitor. Further, this
2528 option doesn't work for all laptops -- it might not turn off your
2529 backlight at all, or it might print a lot of errors to the console,
2530 especially if you are using gpm.
2531
2532config APM_ALLOW_INTS
2533 bool "Allow interrupts during APM BIOS calls"
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002534 help
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002535 Normally we disable external interrupts while we are making calls to
2536 the APM BIOS as a measure to lessen the effects of a badly behaving
2537 BIOS implementation. The BIOS should reenable interrupts if it
2538 needs to. Unfortunately, some BIOSes do not -- especially those in
2539 many of the newer IBM Thinkpads. If you experience hangs when you
2540 suspend, try setting this to Y. Otherwise, say N.
2541
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002542endif # APM
2543
Dave Jonesbb0a56e2011-05-19 18:51:07 -04002544source "drivers/cpufreq/Kconfig"
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002545
2546source "drivers/cpuidle/Kconfig"
2547
Andy Henroid27471fd2008-10-09 11:45:22 -07002548source "drivers/idle/Kconfig"
2549
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002550endmenu
2551
2552
2553menu "Bus options (PCI etc.)"
2554
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002555choice
2556 prompt "PCI access mode"
Ingo Molnarefefa6f2008-07-10 16:09:50 +02002557 depends on X86_32 && PCI
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002558 default PCI_GOANY
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002559 help
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002560 On PCI systems, the BIOS can be used to detect the PCI devices and
2561 determine their configuration. However, some old PCI motherboards
2562 have BIOS bugs and may crash if this is done. Also, some embedded
2563 PCI-based systems don't have any BIOS at all. Linux can also try to
2564 detect the PCI hardware directly without using the BIOS.
2565
2566 With this option, you can specify how Linux should detect the
2567 PCI devices. If you choose "BIOS", the BIOS will be used,
2568 if you choose "Direct", the BIOS won't be used, and if you
2569 choose "MMConfig", then PCI Express MMCONFIG will be used.
2570 If you choose "Any", the kernel will try MMCONFIG, then the
2571 direct access method and falls back to the BIOS if that doesn't
2572 work. If unsure, go with the default, which is "Any".
2573
2574config PCI_GOBIOS
2575 bool "BIOS"
2576
2577config PCI_GOMMCONFIG
2578 bool "MMConfig"
2579
2580config PCI_GODIRECT
2581 bool "Direct"
2582
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002583config PCI_GOOLPC
Daniel Drake76fb6572010-09-23 17:28:04 +01002584 bool "OLPC XO-1"
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002585 depends on OLPC
2586
Andres Salomon2bdd1b02008-06-05 14:14:41 -07002587config PCI_GOANY
2588 bool "Any"
2589
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002590endchoice
2591
2592config PCI_BIOS
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002593 def_bool y
Ingo Molnarefefa6f2008-07-10 16:09:50 +02002594 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002595
2596# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2597config PCI_DIRECT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002598 def_bool y
Shaohua Li0aba4962011-05-27 14:59:39 +08002599 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002600
2601config PCI_MMCONFIG
Jan Kiszkab45c9f32018-03-07 08:39:16 +01002602 bool "Support mmconfig PCI config space access" if X86_64
2603 default y
Andy Shevchenko4590d982021-02-11 15:40:02 +02002604 depends on PCI && (ACPI || JAILHOUSE_GUEST)
Jan Kiszkab45c9f32018-03-07 08:39:16 +01002605 depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002606
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002607config PCI_OLPC
Andres Salomon2bdd1b02008-06-05 14:14:41 -07002608 def_bool y
2609 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002610
Alex Nixonb5401a92010-03-18 16:31:34 -04002611config PCI_XEN
2612 def_bool y
2613 depends on PCI && XEN
2614 select SWIOTLB_XEN
2615
Jan Kiszka8364e1f2018-03-07 08:39:17 +01002616config MMCONF_FAM10H
2617 def_bool y
2618 depends on X86_64 && PCI_MMCONFIG && ACPI
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002619
Ira W. Snyder3f6ea842010-04-01 11:43:30 -07002620config PCI_CNB20LE_QUIRK
David Rientjes6a108a12011-01-20 14:44:16 -08002621 bool "Read CNB20LE Host Bridge Windows" if EXPERT
Kees Cook6ea30382012-10-02 11:16:47 -07002622 depends on PCI
Ira W. Snyder3f6ea842010-04-01 11:43:30 -07002623 help
2624 Read the PCI windows out of the CNB20LE host bridge. This allows
2625 PCI hotplug to work on systems with the CNB20LE chipset which do
2626 not have ACPI.
2627
Bjorn Helgaas64a5fed2011-01-06 10:12:30 -07002628 There's no public spec for this chipset, and this functionality
2629 is known to be incomplete.
2630
2631 You should say N unless you know you need this.
2632
William Breathitt Gray3a495512016-05-27 18:08:27 -04002633config ISA_BUS
William Breathitt Gray17a2a122017-12-29 15:14:46 -05002634 bool "ISA bus support on modern systems" if EXPERT
William Breathitt Gray3a495512016-05-27 18:08:27 -04002635 help
William Breathitt Gray17a2a122017-12-29 15:14:46 -05002636 Expose ISA bus device drivers and options available for selection and
2637 configuration. Enable this option if your target machine has an ISA
2638 bus. ISA is an older system, displaced by PCI and newer bus
2639 architectures -- if your target machine is modern, it probably does
2640 not have an ISA bus.
William Breathitt Gray3a495512016-05-27 18:08:27 -04002641
2642 If unsure, say N.
2643
David Rientjes1c00f012011-03-22 16:34:59 -07002644# x86_64 have no ISA slots, but can have ISA-style DMA.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002645config ISA_DMA_API
David Rientjes1c00f012011-03-22 16:34:59 -07002646 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2647 default y
2648 help
2649 Enables ISA-style DMA support for devices requiring such controllers.
2650 If unsure, say Y.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002651
Linus Torvalds51e68d02016-05-21 10:25:19 -07002652if X86_32
2653
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002654config ISA
2655 bool "ISA support"
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002656 help
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002657 Find out whether you have ISA slots on your motherboard. ISA is the
2658 name of a bus system, i.e. the way the CPU talks to the other stuff
2659 inside your box. Other bus systems are PCI, EISA, MicroChannel
2660 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2661 newer boards don't support it. If you have ISA, say Y, otherwise N.
2662
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002663config SCx200
2664 tristate "NatSemi SCx200 support"
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002665 help
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002666 This provides basic support for National Semiconductor's
2667 (now AMD's) Geode processors. The driver probes for the
2668 PCI-IDs of several on-chip devices, so its a good dependency
2669 for other scx200_* drivers.
2670
2671 If compiled as a module, the driver is named scx200.
2672
2673config SCx200HR_TIMER
2674 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
John Stultz592913e2010-07-13 17:56:20 -07002675 depends on SCx200
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002676 default y
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002677 help
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002678 This driver provides a clocksource built upon the on-chip
2679 27MHz high-resolution timer. Its also a workaround for
2680 NSC Geode SC-1100's buggy TSC, which loses time when the
2681 processor goes idle (as is done by the scheduler). The
2682 other workaround is idle=poll boot option.
2683
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002684config OLPC
2685 bool "One Laptop Per Child support"
Thomas Gleixner54008972011-02-23 09:50:15 +01002686 depends on !X86_PAE
Andres Salomon3c554942009-12-14 18:00:36 -08002687 select GPIOLIB
Thomas Gleixnerdc3119e702011-02-23 10:08:31 +01002688 select OF
Daniel Drake45bb1672011-03-13 15:10:17 +00002689 select OF_PROMTREE
Grant Likelyb4e51852011-12-16 15:50:17 -07002690 select IRQ_DOMAIN
Lubomir Rintel0c3d9312019-05-13 09:56:37 +02002691 select OLPC_EC
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002692 help
Andres Salomon3ef0e1f2008-04-29 00:59:53 -07002693 Add support for detecting the unique features of the OLPC
2694 XO hardware.
2695
Daniel Drakea3128582011-06-25 17:34:10 +01002696config OLPC_XO1_PM
2697 bool "OLPC XO-1 Power Management"
Borislav Petkovfa112cf2018-10-05 15:13:07 +02002698 depends on OLPC && MFD_CS5535=y && PM_SLEEP
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002699 help
Daniel Drake97c4cb72011-06-25 17:34:11 +01002700 Add support for poweroff and suspend of the OLPC XO-1 laptop.
Daniel Drakebf1ebf02010-10-10 10:40:32 +01002701
Daniel Drakecfee9592011-06-25 17:34:17 +01002702config OLPC_XO1_RTC
2703 bool "OLPC XO-1 Real Time Clock"
2704 depends on OLPC_XO1_PM && RTC_DRV_CMOS
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002705 help
Daniel Drakecfee9592011-06-25 17:34:17 +01002706 Add support for the XO-1 real time clock, which can be used as a
2707 programmable wakeup source.
2708
Daniel Drake7feda8e2011-06-25 17:34:12 +01002709config OLPC_XO1_SCI
2710 bool "OLPC XO-1 SCI extras"
Arnd Bergmann92e830f2018-04-04 14:44:54 +02002711 depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
Randy Dunlaped8e47f2012-12-18 12:22:17 -08002712 depends on INPUT=y
Daniel Draked8d01a62011-07-24 18:33:21 +01002713 select POWER_SUPPLY
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002714 help
Daniel Drake7feda8e2011-06-25 17:34:12 +01002715 Add support for SCI-based features of the OLPC XO-1 laptop:
Daniel Drake7bc74b32011-06-25 17:34:14 +01002716 - EC-driven system wakeups
Daniel Drake7feda8e2011-06-25 17:34:12 +01002717 - Power button
Daniel Drake7bc74b32011-06-25 17:34:14 +01002718 - Ebook switch
Daniel Drake2cf2bae2011-06-25 17:34:15 +01002719 - Lid switch
Daniel Drakee1040ac2011-06-25 17:34:16 +01002720 - AC adapter status updates
2721 - Battery status updates
Daniel Drake7feda8e2011-06-25 17:34:12 +01002722
Daniel Drakea0f30f52011-06-25 17:34:18 +01002723config OLPC_XO15_SCI
2724 bool "OLPC XO-1.5 SCI extras"
Daniel Draked8d01a62011-07-24 18:33:21 +01002725 depends on OLPC && ACPI
2726 select POWER_SUPPLY
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002727 help
Daniel Drakea0f30f52011-06-25 17:34:18 +01002728 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2729 - EC-driven system wakeups
2730 - AC adapter status updates
2731 - Battery status updates
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002732
Ed Wildgoosed4f3e352011-09-20 14:00:12 -07002733config ALIX
2734 bool "PCEngines ALIX System Support (LED setup)"
2735 select GPIOLIB
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002736 help
Ed Wildgoosed4f3e352011-09-20 14:00:12 -07002737 This option enables system support for the PCEngines ALIX.
2738 At present this just sets up LEDs for GPIO control on
2739 ALIX2/3/6 boards. However, other system specific setup should
2740 get added here.
2741
2742 Note: You must still enable the drivers for GPIO and LED support
2743 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2744
2745 Note: You have to set alix.force=1 for boards with Award BIOS.
2746
Philip Prindevilleda4e3302012-03-05 15:05:15 -08002747config NET5501
2748 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2749 select GPIOLIB
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002750 help
Philip Prindevilleda4e3302012-03-05 15:05:15 -08002751 This option enables system support for the Soekris Engineering net5501.
2752
Philip A. Prindeville31970592012-01-14 01:45:39 -07002753config GEOS
2754 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2755 select GPIOLIB
2756 depends on DMI
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002757 help
Philip A. Prindeville31970592012-01-14 01:45:39 -07002758 This option enables system support for the Traverse Technologies GEOS.
2759
Vivien Didelot7d029122013-01-04 16:18:14 -05002760config TS5500
2761 bool "Technologic Systems TS-5500 platform support"
2762 depends on MELAN
2763 select CHECK_SIGNATURE
2764 select NEW_LEDS
2765 select LEDS_CLASS
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002766 help
Vivien Didelot7d029122013-01-04 16:18:14 -05002767 This option enables system support for the Technologic Systems TS-5500.
2768
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002769endif # X86_32
2770
Andreas Herrmann23ac4ae2010-09-17 18:03:43 +02002771config AMD_NB
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002772 def_bool y
Borislav Petkov0e152cd2010-03-12 15:43:03 +01002773 depends on CPU_SUP_AMD && PCI
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002774
David Herrmanne3263ab2013-08-02 14:05:22 +02002775config X86_SYSFB
2776 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2777 help
2778 Firmwares often provide initial graphics framebuffers so the BIOS,
2779 bootloader or kernel can show basic video-output during boot for
2780 user-guidance and debugging. Historically, x86 used the VESA BIOS
2781 Extensions and EFI-framebuffers for this, which are mostly limited
2782 to x86.
2783 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2784 framebuffers so the new generic system-framebuffer drivers can be
2785 used on x86. If the framebuffer is not compatible with the generic
Nikolas Nybye3a5dc02018-08-25 19:10:54 -04002786 modes, it is advertised as fallback platform framebuffer so legacy
David Herrmanne3263ab2013-08-02 14:05:22 +02002787 drivers like efifb, vesafb and uvesafb can pick it up.
2788 If this option is not selected, all system framebuffers are always
2789 marked as fallback platform framebuffers as usual.
2790
2791 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2792 not be able to pick up generic system framebuffers if this option
2793 is selected. You are highly encouraged to enable simplefb as
2794 replacement if you select this option. simplefb can correctly deal
2795 with generic system framebuffers. But you should still keep vesafb
2796 and others enabled as fallback if a system framebuffer is
2797 incompatible with simplefb.
2798
2799 If unsure, say Y.
2800
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002801endmenu
2802
2803
Christoph Hellwig15724972018-07-31 13:39:30 +02002804menu "Binary Emulations"
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002805
2806config IA32_EMULATION
2807 bool "IA32 Emulation"
2808 depends on X86_64
Ingo Molnar39f88912016-11-15 10:22:52 +01002809 select ARCH_WANT_OLD_COMPAT_IPC
Randy Dunlapd1603992013-06-18 12:33:40 -07002810 select BINFMT_ELF
Ingo Molnar39f88912016-11-15 10:22:52 +01002811 select COMPAT_OLD_SIGACTION
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002812 help
H. J. Lu5fd92e62012-02-19 10:40:03 -08002813 Include code to run legacy 32-bit programs under a
2814 64-bit kernel. You should likely turn this on, unless you're
2815 100% sure that you don't have any 32-bit programs left.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002816
2817config IA32_AOUT
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002818 tristate "IA32 a.out support"
2819 depends on IA32_EMULATION
Borislav Petkoveac61652019-03-05 15:47:51 +01002820 depends on BROKEN
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002821 help
Ingo Molnar8f9ca472009-02-05 16:21:53 +01002822 Support old a.out binaries in the 32bit emulation.
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002823
H. Peter Anvin0bf62762012-02-27 14:09:10 -08002824config X86_X32
Kees Cook6ea30382012-10-02 11:16:47 -07002825 bool "x32 ABI for 64-bit mode"
Brian Gerst9b540502015-06-22 07:55:21 -04002826 depends on X86_64
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09002827 help
H. J. Lu5fd92e62012-02-19 10:40:03 -08002828 Include code to run binaries for the x32 native 32-bit ABI
2829 for 64-bit processors. An x32 process gets access to the
2830 full 64-bit register file and wide data path while leaving
2831 pointers at 32 bits for smaller memory footprint.
2832
2833 You will need a recent binutils (2.22 or later) with
2834 elf32_x86_64 support enabled to compile a kernel with this
2835 option set.
2836
Ingo Molnar953fee12016-11-15 10:22:52 +01002837config COMPAT_32
2838 def_bool y
2839 depends on IA32_EMULATION || X86_32
2840 select HAVE_UID16
2841 select OLD_SIGSUSPEND3
2842
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002843config COMPAT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002844 def_bool y
H. Peter Anvin0bf62762012-02-27 14:09:10 -08002845 depends on IA32_EMULATION || X86_X32
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002846
Jan Beulich3120e252012-09-10 12:41:45 +01002847if COMPAT
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002848config COMPAT_FOR_U64_ALIGNMENT
Jan Beulich3120e252012-09-10 12:41:45 +01002849 def_bool y
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002850
2851config SYSVIPC_COMPAT
Harvey Harrison3c2362e2008-01-30 13:31:03 +01002852 def_bool y
Jan Beulich3120e252012-09-10 12:41:45 +01002853 depends on SYSVIPC
Jan Beulich3120e252012-09-10 12:41:45 +01002854endif
David Howellsee009e4a02011-03-07 15:06:20 +00002855
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002856endmenu
2857
2858
Keith Packarde5beae12008-11-03 18:21:45 +01002859config HAVE_ATOMIC_IOMAP
2860 def_bool y
2861 depends on X86_32
2862
Sam Ravnborge279b6c2007-11-06 20:41:05 +01002863source "drivers/firmware/Kconfig"
2864
Avi Kivityedf88412007-12-16 11:02:48 +02002865source "arch/x86/kvm/Kconfig"
Jason A. Donenfeld5e8ebd82020-03-26 17:00:58 +09002866
2867source "arch/x86/Kconfig.assembler"