Greg Kroah-Hartman | b244131 | 2017-11-01 15:07:57 +0100 | [diff] [blame] | 1 | # SPDX-License-Identifier: GPL-2.0 |
Chris Zankel | 8e1a6dd | 2005-06-23 22:01:10 -0700 | [diff] [blame] | 2 | config XTENSA |
Johannes Weiner | 35f9cd0 | 2009-03-04 16:21:28 +0100 | [diff] [blame] | 3 | def_bool y |
Yury Norov | 942fa98 | 2018-05-16 11:18:49 +0300 | [diff] [blame] | 4 | select ARCH_32BIT_OFF_T |
Christoph Hellwig | aef0f78 | 2019-06-13 09:08:57 +0200 | [diff] [blame] | 5 | select ARCH_HAS_BINFMT_FLAT if !MMU |
Christoph Hellwig | 0f665b9 | 2019-10-29 10:53:30 +0100 | [diff] [blame] | 6 | select ARCH_HAS_DMA_PREP_COHERENT if MMU |
| 7 | select ARCH_HAS_SYNC_DMA_FOR_CPU if MMU |
| 8 | select ARCH_HAS_SYNC_DMA_FOR_DEVICE if MMU |
Christoph Hellwig | fa7e224 | 2020-02-21 15:55:43 -0800 | [diff] [blame] | 9 | select ARCH_HAS_DMA_SET_UNCACHED if MMU |
Anshuman Khandual | dce4456 | 2021-04-29 22:55:15 -0700 | [diff] [blame] | 10 | select ARCH_USE_MEMTEST |
Max Filippov | 579afe86 | 2019-01-01 14:08:32 -0800 | [diff] [blame] | 11 | select ARCH_USE_QUEUED_RWLOCKS |
| 12 | select ARCH_USE_QUEUED_SPINLOCKS |
Max Filippov | 8f371c7 | 2013-04-15 09:21:35 +0400 | [diff] [blame] | 13 | select ARCH_WANT_FRAME_POINTERS |
Max Filippov | e969161 | 2013-01-06 16:17:21 +0400 | [diff] [blame] | 14 | select ARCH_WANT_IPC_PARSE_VERSION |
Shile Zhang | 1091670 | 2019-12-04 08:46:31 +0800 | [diff] [blame] | 15 | select BUILDTIME_TABLE_SORT |
Al Viro | 3e41f9b | 2012-10-26 23:41:40 -0400 | [diff] [blame] | 16 | select CLONE_BACKWARDS |
Max Filippov | bda8932 | 2014-01-29 06:20:46 +0400 | [diff] [blame] | 17 | select COMMON_CLK |
Christoph Hellwig | f0edfea | 2018-08-24 10:31:08 +0200 | [diff] [blame] | 18 | select DMA_REMAP if MMU |
Max Filippov | 920f8a39 | 2014-06-16 08:20:17 +0400 | [diff] [blame] | 19 | select GENERIC_ATOMIC64 |
Max Filippov | 920f8a39 | 2014-06-16 08:20:17 +0400 | [diff] [blame] | 20 | select GENERIC_IRQ_SHOW |
| 21 | select GENERIC_PCI_IOMAP |
| 22 | select GENERIC_SCHED_CLOCK |
Max Filippov | 57358ba | 2017-12-17 14:43:15 -0800 | [diff] [blame] | 23 | select GENERIC_STRNCPY_FROM_USER if KASAN |
Max Filippov | ef1a935 | 2017-05-01 06:17:47 -0700 | [diff] [blame] | 24 | select HAVE_ARCH_AUDITSYSCALL |
Max Filippov | 7af710d | 2017-01-03 17:57:51 -0800 | [diff] [blame] | 25 | select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL |
| 26 | select HAVE_ARCH_KASAN if MMU && !XIP_KERNEL |
Max Filippov | da94a40 | 2019-11-13 20:47:17 -0800 | [diff] [blame] | 27 | select HAVE_ARCH_SECCOMP_FILTER |
Max Filippov | 9f24f3c | 2018-11-09 15:45:53 -0800 | [diff] [blame] | 28 | select HAVE_ARCH_TRACEHOOK |
Max Filippov | 0e46c11 | 2016-04-25 22:08:20 +0300 | [diff] [blame] | 29 | select HAVE_DEBUG_KMEMLEAK |
Max Filippov | 9d2ffe5 | 2016-04-25 22:08:52 +0300 | [diff] [blame] | 30 | select HAVE_DMA_CONTIGUOUS |
Jiri Slaby | 5f56a5d | 2016-05-20 17:00:16 -0700 | [diff] [blame] | 31 | select HAVE_EXIT_THREAD |
Max Filippov | 920f8a39 | 2014-06-16 08:20:17 +0400 | [diff] [blame] | 32 | select HAVE_FUNCTION_TRACER |
Max Filippov | d951ba2 | 2015-09-30 15:17:35 +0300 | [diff] [blame] | 33 | select HAVE_FUTEX_CMPXCHG if !MMU |
Max Filippov | c91e02b | 2016-01-24 10:32:10 +0300 | [diff] [blame] | 34 | select HAVE_HW_BREAKPOINT if PERF_EVENTS |
Max Filippov | 920f8a39 | 2014-06-16 08:20:17 +0400 | [diff] [blame] | 35 | select HAVE_IRQ_TIME_ACCOUNTING |
Christoph Hellwig | eb01d42 | 2018-11-15 20:05:32 +0100 | [diff] [blame] | 36 | select HAVE_PCI |
Max Filippov | 920f8a39 | 2014-06-16 08:20:17 +0400 | [diff] [blame] | 37 | select HAVE_PERF_EVENTS |
Masahiro Yamada | d148eac | 2018-06-14 19:36:45 +0900 | [diff] [blame] | 38 | select HAVE_STACKPROTECTOR |
Max Filippov | af5395c | 2018-11-11 21:51:49 -0800 | [diff] [blame] | 39 | select HAVE_SYSCALL_TRACEPOINTS |
Max Filippov | 920f8a39 | 2014-06-16 08:20:17 +0400 | [diff] [blame] | 40 | select IRQ_DOMAIN |
| 41 | select MODULES_USE_ELF_RELA |
Max Filippov | db8165f | 2015-06-04 13:41:27 +0300 | [diff] [blame] | 42 | select PERF_USE_VMALLOC |
Christoph Hellwig | 5e6e985 | 2020-09-03 16:22:35 +0200 | [diff] [blame] | 43 | select SET_FS |
Masahiro Yamada | 4aae683 | 2021-07-31 14:22:32 +0900 | [diff] [blame^] | 44 | select TRACE_IRQFLAGS_SUPPORT |
Max Filippov | 920f8a39 | 2014-06-16 08:20:17 +0400 | [diff] [blame] | 45 | select VIRT_TO_BUS |
Chris Zankel | 8e1a6dd | 2005-06-23 22:01:10 -0700 | [diff] [blame] | 46 | help |
| 47 | Xtensa processors are 32-bit RISC machines designed by Tensilica |
| 48 | primarily for embedded systems. These processors are both |
| 49 | configurable and extensible. The Linux port to the Xtensa |
| 50 | architecture supports all processor configurations and extensions, |
| 51 | with reasonable minimum requirements. The Xtensa Linux project has |
Masanari Iida | 0ada449 | 2013-01-04 17:29:18 +0900 | [diff] [blame] | 52 | a home page at <http://www.linux-xtensa.org/>. |
Chris Zankel | 8e1a6dd | 2005-06-23 22:01:10 -0700 | [diff] [blame] | 53 | |
Akinobu Mita | d4337aa | 2006-03-26 01:39:43 -0800 | [diff] [blame] | 54 | config GENERIC_HWEIGHT |
Johannes Weiner | 35f9cd0 | 2009-03-04 16:21:28 +0100 | [diff] [blame] | 55 | def_bool y |
Akinobu Mita | d4337aa | 2006-03-26 01:39:43 -0800 | [diff] [blame] | 56 | |
David Howells | f0d1b0b | 2006-12-08 02:37:49 -0800 | [diff] [blame] | 57 | config ARCH_HAS_ILOG2_U32 |
Johannes Weiner | 35f9cd0 | 2009-03-04 16:21:28 +0100 | [diff] [blame] | 58 | def_bool n |
David Howells | f0d1b0b | 2006-12-08 02:37:49 -0800 | [diff] [blame] | 59 | |
| 60 | config ARCH_HAS_ILOG2_U64 |
Johannes Weiner | 35f9cd0 | 2009-03-04 16:21:28 +0100 | [diff] [blame] | 61 | def_bool n |
David Howells | f0d1b0b | 2006-12-08 02:37:49 -0800 | [diff] [blame] | 62 | |
Uwe Kleine-König | ce816fa | 2014-04-07 15:39:19 -0700 | [diff] [blame] | 63 | config NO_IOPORT_MAP |
Max Filippov | d046f77 | 2012-09-17 05:44:41 +0400 | [diff] [blame] | 64 | def_bool n |
Al Viro | 5ea8176 | 2007-02-11 15:41:31 +0000 | [diff] [blame] | 65 | |
H. Peter Anvin | bdc8078 | 2008-02-08 04:21:26 -0800 | [diff] [blame] | 66 | config HZ |
| 67 | int |
| 68 | default 100 |
| 69 | |
Max Filippov | 8f371c7 | 2013-04-15 09:21:35 +0400 | [diff] [blame] | 70 | config LOCKDEP_SUPPORT |
| 71 | def_bool y |
| 72 | |
Max Filippov | 3e4196a | 2013-04-15 09:20:48 +0400 | [diff] [blame] | 73 | config STACKTRACE_SUPPORT |
| 74 | def_bool y |
| 75 | |
Johannes Weiner | 35f9cd0 | 2009-03-04 16:21:28 +0100 | [diff] [blame] | 76 | config MMU |
Max Filippov | de7c1c7 | 2015-06-27 07:31:12 +0300 | [diff] [blame] | 77 | def_bool n |
Johannes Weiner | 35f9cd0 | 2009-03-04 16:21:28 +0100 | [diff] [blame] | 78 | |
Baruch Siach | a1a2bde | 2013-12-18 09:10:29 +0200 | [diff] [blame] | 79 | config HAVE_XTENSA_GPIO32 |
| 80 | def_bool n |
| 81 | |
Max Filippov | c633544 | 2017-12-03 13:28:52 -0800 | [diff] [blame] | 82 | config KASAN_SHADOW_OFFSET |
| 83 | hex |
| 84 | default 0x6e400000 |
| 85 | |
Masahiro Yamada | c425c54 | 2021-03-13 21:23:41 +0900 | [diff] [blame] | 86 | config CPU_BIG_ENDIAN |
| 87 | def_bool $(success,test "$(shell,echo __XTENSA_EB__ | $(CC) -E -P -)" = 1) |
| 88 | |
| 89 | config CPU_LITTLE_ENDIAN |
| 90 | def_bool !CPU_BIG_ENDIAN |
| 91 | |
Chris Zankel | 8e1a6dd | 2005-06-23 22:01:10 -0700 | [diff] [blame] | 92 | menu "Processor type and features" |
| 93 | |
| 94 | choice |
| 95 | prompt "Xtensa Processor Configuration" |
Chris Zankel | 173d668 | 2006-12-10 02:18:48 -0800 | [diff] [blame] | 96 | default XTENSA_VARIANT_FSF |
Chris Zankel | 8e1a6dd | 2005-06-23 22:01:10 -0700 | [diff] [blame] | 97 | |
Chris Zankel | 173d668 | 2006-12-10 02:18:48 -0800 | [diff] [blame] | 98 | config XTENSA_VARIANT_FSF |
Chris Zankel | 0025427 | 2008-10-21 09:11:43 -0700 | [diff] [blame] | 99 | bool "fsf - default (not generic) configuration" |
Johannes Weiner | 35f9cd0 | 2009-03-04 16:21:28 +0100 | [diff] [blame] | 100 | select MMU |
Chris Zankel | 0025427 | 2008-10-21 09:11:43 -0700 | [diff] [blame] | 101 | |
| 102 | config XTENSA_VARIANT_DC232B |
| 103 | bool "dc232b - Diamond 232L Standard Core Rev.B (LE)" |
Johannes Weiner | 35f9cd0 | 2009-03-04 16:21:28 +0100 | [diff] [blame] | 104 | select MMU |
Baruch Siach | a1a2bde | 2013-12-18 09:10:29 +0200 | [diff] [blame] | 105 | select HAVE_XTENSA_GPIO32 |
Chris Zankel | 0025427 | 2008-10-21 09:11:43 -0700 | [diff] [blame] | 106 | help |
Johannes Weiner | 35f9cd0 | 2009-03-04 16:21:28 +0100 | [diff] [blame] | 107 | This variant refers to Tensilica's Diamond 232L Standard core Rev.B (LE). |
Johannes Weiner | 000af2c | 2009-03-04 16:21:32 +0100 | [diff] [blame] | 108 | |
Pete Delaney | d0b73b4 | 2013-01-05 04:57:16 +0400 | [diff] [blame] | 109 | config XTENSA_VARIANT_DC233C |
| 110 | bool "dc233c - Diamond 233L Standard Core Rev.C (LE)" |
| 111 | select MMU |
Baruch Siach | a1a2bde | 2013-12-18 09:10:29 +0200 | [diff] [blame] | 112 | select HAVE_XTENSA_GPIO32 |
Pete Delaney | d0b73b4 | 2013-01-05 04:57:16 +0400 | [diff] [blame] | 113 | help |
| 114 | This variant refers to Tensilica's Diamond 233L Standard core Rev.C (LE). |
| 115 | |
Max Filippov | 420ae95 | 2014-06-16 07:25:06 +0400 | [diff] [blame] | 116 | config XTENSA_VARIANT_CUSTOM |
| 117 | bool "Custom Xtensa processor configuration" |
Max Filippov | 420ae95 | 2014-06-16 07:25:06 +0400 | [diff] [blame] | 118 | select HAVE_XTENSA_GPIO32 |
| 119 | help |
| 120 | Select this variant to use a custom Xtensa processor configuration. |
| 121 | You will be prompted for a processor variant CORENAME. |
Chris Zankel | 8e1a6dd | 2005-06-23 22:01:10 -0700 | [diff] [blame] | 122 | endchoice |
| 123 | |
Max Filippov | 420ae95 | 2014-06-16 07:25:06 +0400 | [diff] [blame] | 124 | config XTENSA_VARIANT_CUSTOM_NAME |
| 125 | string "Xtensa Processor Custom Core Variant Name" |
| 126 | depends on XTENSA_VARIANT_CUSTOM |
| 127 | help |
| 128 | Provide the name of a custom Xtensa processor variant. |
| 129 | This CORENAME selects arch/xtensa/variant/CORENAME. |
Hu Haowen | 70cbddb | 2020-03-30 12:54:36 +0800 | [diff] [blame] | 130 | Don't forget you have to select MMU if you have one. |
Max Filippov | 420ae95 | 2014-06-16 07:25:06 +0400 | [diff] [blame] | 131 | |
| 132 | config XTENSA_VARIANT_NAME |
| 133 | string |
| 134 | default "dc232b" if XTENSA_VARIANT_DC232B |
| 135 | default "dc233c" if XTENSA_VARIANT_DC233C |
| 136 | default "fsf" if XTENSA_VARIANT_FSF |
Max Filippov | 420ae95 | 2014-06-16 07:25:06 +0400 | [diff] [blame] | 137 | default XTENSA_VARIANT_CUSTOM_NAME if XTENSA_VARIANT_CUSTOM |
| 138 | |
| 139 | config XTENSA_VARIANT_MMU |
| 140 | bool "Core variant has a Full MMU (TLB, Pages, Protection, etc)" |
| 141 | depends on XTENSA_VARIANT_CUSTOM |
| 142 | default y |
Max Filippov | de7c1c7 | 2015-06-27 07:31:12 +0300 | [diff] [blame] | 143 | select MMU |
Max Filippov | 420ae95 | 2014-06-16 07:25:06 +0400 | [diff] [blame] | 144 | help |
| 145 | Build a Conventional Kernel with full MMU support, |
| 146 | ie: it supports a TLB with auto-loading, page protection. |
| 147 | |
Max Filippov | 9bd46da | 2015-06-14 01:41:25 +0300 | [diff] [blame] | 148 | config XTENSA_VARIANT_HAVE_PERF_EVENTS |
| 149 | bool "Core variant has Performance Monitor Module" |
| 150 | depends on XTENSA_VARIANT_CUSTOM |
| 151 | default n |
| 152 | help |
| 153 | Enable if core variant has Performance Monitor Module with |
| 154 | External Registers Interface. |
| 155 | |
| 156 | If unsure, say N. |
| 157 | |
Max Filippov | e462919 | 2015-11-27 16:26:41 +0300 | [diff] [blame] | 158 | config XTENSA_FAKE_NMI |
| 159 | bool "Treat PMM IRQ as NMI" |
| 160 | depends on XTENSA_VARIANT_HAVE_PERF_EVENTS |
| 161 | default n |
| 162 | help |
| 163 | If PMM IRQ is the only IRQ at EXCM level it is safe to |
| 164 | treat it as NMI, which improves accuracy of profiling. |
| 165 | |
| 166 | If there are other interrupts at or above PMM IRQ priority level |
| 167 | but not above the EXCM level, PMM IRQ still may be treated as NMI, |
| 168 | but only if these IRQs are not used. There will be a build warning |
| 169 | saying that this is not safe, and a bugcheck if one of these IRQs |
| 170 | actually fire. |
| 171 | |
| 172 | If unsure, say N. |
| 173 | |
Chris Zankel | 8e1a6dd | 2005-06-23 22:01:10 -0700 | [diff] [blame] | 174 | config XTENSA_UNALIGNED_USER |
Corentin Labbe | ad33cc8 | 2019-01-18 13:45:27 +0000 | [diff] [blame] | 175 | bool "Unaligned memory access in user space" |
Johannes Weiner | 35f9cd0 | 2009-03-04 16:21:28 +0100 | [diff] [blame] | 176 | help |
| 177 | The Xtensa architecture currently does not handle unaligned |
| 178 | memory accesses in hardware but through an exception handler. |
| 179 | Per default, unaligned memory accesses are disabled in user space. |
Chris Zankel | 8e1a6dd | 2005-06-23 22:01:10 -0700 | [diff] [blame] | 180 | |
Johannes Weiner | 35f9cd0 | 2009-03-04 16:21:28 +0100 | [diff] [blame] | 181 | Say Y here to enable unaligned memory access in user space. |
Chris Zankel | 8e1a6dd | 2005-06-23 22:01:10 -0700 | [diff] [blame] | 182 | |
Max Filippov | f615136 | 2013-10-17 02:42:26 +0400 | [diff] [blame] | 183 | config HAVE_SMP |
| 184 | bool "System Supports SMP (MX)" |
Max Filippov | de7c1c7 | 2015-06-27 07:31:12 +0300 | [diff] [blame] | 185 | depends on XTENSA_VARIANT_CUSTOM |
Max Filippov | f615136 | 2013-10-17 02:42:26 +0400 | [diff] [blame] | 186 | select XTENSA_MX |
| 187 | help |
Randy Dunlap | 58bc6c6 | 2020-01-31 17:59:26 -0800 | [diff] [blame] | 188 | This option is used to indicate that the system-on-a-chip (SOC) |
Max Filippov | f615136 | 2013-10-17 02:42:26 +0400 | [diff] [blame] | 189 | supports Multiprocessing. Multiprocessor support implemented above |
| 190 | the CPU core definition and currently needs to be selected manually. |
| 191 | |
Randy Dunlap | 58bc6c6 | 2020-01-31 17:59:26 -0800 | [diff] [blame] | 192 | Multiprocessor support is implemented with external cache and |
Masanari Iida | 769a12a | 2015-04-27 22:52:07 +0900 | [diff] [blame] | 193 | interrupt controllers. |
Max Filippov | f615136 | 2013-10-17 02:42:26 +0400 | [diff] [blame] | 194 | |
| 195 | The MX interrupt distributer adds Interprocessor Interrupts |
| 196 | and causes the IRQ numbers to be increased by 4 for devices |
| 197 | like the open cores ethernet driver and the serial interface. |
| 198 | |
| 199 | You still have to select "Enable SMP" to enable SMP on this SOC. |
| 200 | |
| 201 | config SMP |
| 202 | bool "Enable Symmetric multi-processing support" |
| 203 | depends on HAVE_SMP |
Max Filippov | f615136 | 2013-10-17 02:42:26 +0400 | [diff] [blame] | 204 | select GENERIC_SMP_IDLE_THREAD |
| 205 | help |
| 206 | Enabled SMP Software; allows more than one CPU/CORE |
| 207 | to be activated during startup. |
| 208 | |
| 209 | config NR_CPUS |
| 210 | depends on SMP |
| 211 | int "Maximum number of CPUs (2-32)" |
| 212 | range 2 32 |
| 213 | default "4" |
| 214 | |
Max Filippov | 49b424f | 2013-10-17 02:42:28 +0400 | [diff] [blame] | 215 | config HOTPLUG_CPU |
| 216 | bool "Enable CPU hotplug support" |
| 217 | depends on SMP |
| 218 | help |
| 219 | Say Y here to allow turning CPUs off and on. CPUs can be |
| 220 | controlled through /sys/devices/system/cpu. |
| 221 | |
| 222 | Say N if you want to disable CPU hotplug. |
| 223 | |
Max Filippov | 9184289 | 2014-08-07 03:32:30 +0400 | [diff] [blame] | 224 | config FAST_SYSCALL_XTENSA |
| 225 | bool "Enable fast atomic syscalls" |
| 226 | default n |
| 227 | help |
| 228 | fast_syscall_xtensa is a syscall that can make atomic operations |
| 229 | on UP kernel when processor has no s32c1i support. |
| 230 | |
| 231 | This syscall is deprecated. It may have issues when called with |
| 232 | invalid arguments. It is provided only for backwards compatibility. |
| 233 | Only enable it if your userspace software requires it. |
| 234 | |
| 235 | If unsure, say N. |
| 236 | |
| 237 | config FAST_SYSCALL_SPILL_REGISTERS |
| 238 | bool "Enable spill registers syscall" |
| 239 | default n |
| 240 | help |
| 241 | fast_syscall_spill_registers is a syscall that spills all active |
| 242 | register windows of a calling userspace task onto its stack. |
| 243 | |
| 244 | This syscall is deprecated. It may have issues when called with |
| 245 | invalid arguments. It is provided only for backwards compatibility. |
| 246 | Only enable it if your userspace software requires it. |
| 247 | |
| 248 | If unsure, say N. |
| 249 | |
Max Filippov | 09f8a6d | 2015-01-12 09:44:44 +0300 | [diff] [blame] | 250 | config USER_ABI_CALL0 |
| 251 | bool |
| 252 | |
| 253 | choice |
| 254 | prompt "Userspace ABI" |
| 255 | default USER_ABI_DEFAULT |
| 256 | help |
| 257 | Select supported userspace ABI. |
| 258 | |
| 259 | If unsure, choose the default ABI. |
| 260 | |
| 261 | config USER_ABI_DEFAULT |
| 262 | bool "Default ABI only" |
| 263 | help |
| 264 | Assume default userspace ABI. For XEA2 cores it is windowed ABI. |
| 265 | call0 ABI binaries may be run on such kernel, but signal delivery |
| 266 | will not work correctly for them. |
| 267 | |
| 268 | config USER_ABI_CALL0_ONLY |
| 269 | bool "Call0 ABI only" |
| 270 | select USER_ABI_CALL0 |
| 271 | help |
| 272 | Select this option to support only call0 ABI in userspace. |
| 273 | Windowed ABI binaries will crash with a segfault caused by |
| 274 | an illegal instruction exception on the first 'entry' opcode. |
| 275 | |
| 276 | Choose this option if you're planning to run only user code |
| 277 | built with call0 ABI. |
| 278 | |
| 279 | config USER_ABI_CALL0_PROBE |
| 280 | bool "Support both windowed and call0 ABI by probing" |
| 281 | select USER_ABI_CALL0 |
| 282 | help |
| 283 | Select this option to support both windowed and call0 userspace |
| 284 | ABIs. When enabled all processes are started with PS.WOE disabled |
| 285 | and a fast user exception handler for an illegal instruction is |
| 286 | used to turn on PS.WOE bit on the first 'entry' opcode executed by |
| 287 | the userspace. |
| 288 | |
| 289 | This option should be enabled for the kernel that must support |
| 290 | both call0 and windowed ABIs in userspace at the same time. |
| 291 | |
| 292 | Note that Xtensa ISA does not guarantee that entry opcode will |
| 293 | raise an illegal instruction exception on cores with XEA2 when |
| 294 | PS.WOE is disabled, check whether the target core supports it. |
| 295 | |
| 296 | endchoice |
| 297 | |
Chris Zankel | 8e1a6dd | 2005-06-23 22:01:10 -0700 | [diff] [blame] | 298 | endmenu |
| 299 | |
Johannes Weiner | 35f9cd0 | 2009-03-04 16:21:28 +0100 | [diff] [blame] | 300 | config XTENSA_CALIBRATE_CCOUNT |
| 301 | def_bool n |
| 302 | help |
| 303 | On some platforms (XT2000, for example), the CPU clock rate can |
| 304 | vary. The frequency can be determined, however, by measuring |
| 305 | against a well known, fixed frequency, such as an UART oscillator. |
| 306 | |
| 307 | config SERIAL_CONSOLE |
| 308 | def_bool n |
| 309 | |
Max Filippov | 7af710d | 2017-01-03 17:57:51 -0800 | [diff] [blame] | 310 | config PLATFORM_HAVE_XIP |
| 311 | def_bool n |
| 312 | |
Chris Zankel | 8e1a6dd | 2005-06-23 22:01:10 -0700 | [diff] [blame] | 313 | menu "Platform options" |
| 314 | |
| 315 | choice |
| 316 | prompt "Xtensa System Type" |
| 317 | default XTENSA_PLATFORM_ISS |
| 318 | |
| 319 | config XTENSA_PLATFORM_ISS |
| 320 | bool "ISS" |
Johannes Weiner | 35f9cd0 | 2009-03-04 16:21:28 +0100 | [diff] [blame] | 321 | select XTENSA_CALIBRATE_CCOUNT |
| 322 | select SERIAL_CONSOLE |
Chris Zankel | 8e1a6dd | 2005-06-23 22:01:10 -0700 | [diff] [blame] | 323 | help |
| 324 | ISS is an acronym for Tensilica's Instruction Set Simulator. |
| 325 | |
| 326 | config XTENSA_PLATFORM_XT2000 |
| 327 | bool "XT2000" |
Max Filippov | 4964527 | 2014-06-16 08:25:43 +0400 | [diff] [blame] | 328 | select HAVE_IDE |
Chris Zankel | 8e1a6dd | 2005-06-23 22:01:10 -0700 | [diff] [blame] | 329 | help |
| 330 | XT2000 is the name of Tensilica's feature-rich emulation platform. |
| 331 | This hardware is capable of running a full Linux distribution. |
| 332 | |
Max Filippov | 0d456ba | 2012-11-05 07:37:14 +0400 | [diff] [blame] | 333 | config XTENSA_PLATFORM_XTFPGA |
| 334 | bool "XTFPGA" |
Max Filippov | 61e47e9 | 2014-10-04 04:44:04 +0400 | [diff] [blame] | 335 | select ETHOC if ETHERNET |
Max Filippov | 3de0048 | 2016-07-23 02:47:58 +0300 | [diff] [blame] | 336 | select PLATFORM_WANT_DEFAULT_MEM if !MMU |
Max Filippov | 0d456ba | 2012-11-05 07:37:14 +0400 | [diff] [blame] | 337 | select SERIAL_CONSOLE |
Max Filippov | 0d456ba | 2012-11-05 07:37:14 +0400 | [diff] [blame] | 338 | select XTENSA_CALIBRATE_CCOUNT |
Max Filippov | 7af710d | 2017-01-03 17:57:51 -0800 | [diff] [blame] | 339 | select PLATFORM_HAVE_XIP |
Max Filippov | 0d456ba | 2012-11-05 07:37:14 +0400 | [diff] [blame] | 340 | help |
| 341 | XTFPGA is the name of Tensilica board family (LX60, LX110, LX200, ML605). |
| 342 | This hardware is capable of running a full Linux distribution. |
| 343 | |
Chris Zankel | 8e1a6dd | 2005-06-23 22:01:10 -0700 | [diff] [blame] | 344 | endchoice |
| 345 | |
Max Filippov | 994fa1c | 2018-08-13 18:11:38 -0700 | [diff] [blame] | 346 | config PLATFORM_NR_IRQS |
| 347 | int |
| 348 | default 3 if XTENSA_PLATFORM_XT2000 |
| 349 | default 0 |
Chris Zankel | 8e1a6dd | 2005-06-23 22:01:10 -0700 | [diff] [blame] | 350 | |
Chris Zankel | 8e1a6dd | 2005-06-23 22:01:10 -0700 | [diff] [blame] | 351 | config XTENSA_CPU_CLOCK |
| 352 | int "CPU clock rate [MHz]" |
| 353 | depends on !XTENSA_CALIBRATE_CCOUNT |
Johannes Weiner | 35f9cd0 | 2009-03-04 16:21:28 +0100 | [diff] [blame] | 354 | default 16 |
Chris Zankel | 8e1a6dd | 2005-06-23 22:01:10 -0700 | [diff] [blame] | 355 | |
| 356 | config GENERIC_CALIBRATE_DELAY |
| 357 | bool "Auto calibration of the BogoMIPS value" |
Johannes Weiner | 35f9cd0 | 2009-03-04 16:21:28 +0100 | [diff] [blame] | 358 | help |
Chris Zankel | 82300bf | 2005-06-30 02:58:58 -0700 | [diff] [blame] | 359 | The BogoMIPS value can easily be derived from the CPU frequency. |
Chris Zankel | 8e1a6dd | 2005-06-23 22:01:10 -0700 | [diff] [blame] | 360 | |
| 361 | config CMDLINE_BOOL |
| 362 | bool "Default bootloader kernel arguments" |
| 363 | |
| 364 | config CMDLINE |
| 365 | string "Initial kernel command string" |
| 366 | depends on CMDLINE_BOOL |
| 367 | default "console=ttyS0,38400 root=/dev/ram" |
| 368 | help |
| 369 | On some architectures (EBSA110 and CATS), there is currently no way |
| 370 | for the boot loader to pass arguments to the kernel. For these |
| 371 | architectures, you should supply some command-line options at build |
| 372 | time by entering them here. As a minimum, you should specify the |
| 373 | memory size and the root device (e.g., mem=64M root=/dev/nfs). |
| 374 | |
Max Filippov | da844a8 | 2012-11-04 00:30:13 +0400 | [diff] [blame] | 375 | config USE_OF |
| 376 | bool "Flattened Device Tree support" |
| 377 | select OF |
| 378 | select OF_EARLY_FLATTREE |
| 379 | help |
| 380 | Include support for flattened device tree machine descriptions. |
| 381 | |
Corentin Labbe | 687cffd | 2019-01-23 09:49:18 +0000 | [diff] [blame] | 382 | config BUILTIN_DTB_SOURCE |
Max Filippov | da844a8 | 2012-11-04 00:30:13 +0400 | [diff] [blame] | 383 | string "DTB to build into the kernel image" |
| 384 | depends on OF |
| 385 | |
Max Filippov | baac1d3 | 2018-08-13 18:56:37 -0700 | [diff] [blame] | 386 | config PARSE_BOOTPARAM |
| 387 | bool "Parse bootparam block" |
| 388 | default y |
| 389 | help |
| 390 | Parse parameters passed to the kernel from the bootloader. It may |
| 391 | be disabled if the kernel is known to run without the bootloader. |
| 392 | |
| 393 | If unsure, say Y. |
| 394 | |
Max Filippov | 6a8eb99 | 2021-02-18 10:18:00 -0800 | [diff] [blame] | 395 | choice |
| 396 | prompt "Semihosting interface" |
| 397 | default XTENSA_SIMCALL_ISS |
| 398 | depends on XTENSA_PLATFORM_ISS |
| 399 | help |
| 400 | Choose semihosting interface that will be used for serial port, |
| 401 | block device and networking. |
| 402 | |
| 403 | config XTENSA_SIMCALL_ISS |
| 404 | bool "simcall" |
| 405 | help |
| 406 | Use simcall instruction. simcall is only available on simulators, |
| 407 | it does nothing on hardware. |
| 408 | |
| 409 | config XTENSA_SIMCALL_GDBIO |
| 410 | bool "GDBIO" |
| 411 | help |
| 412 | Use break instruction. It is available on real hardware when GDB |
| 413 | is attached to it via JTAG. |
| 414 | |
| 415 | endchoice |
| 416 | |
Victor Prupis | b6c7e87 | 2008-05-19 14:50:38 -0700 | [diff] [blame] | 417 | config BLK_DEV_SIMDISK |
| 418 | tristate "Host file-based simulated block device support" |
| 419 | default n |
Max Filippov | 7a0684c | 2014-08-27 14:54:48 +0400 | [diff] [blame] | 420 | depends on XTENSA_PLATFORM_ISS && BLOCK |
Victor Prupis | b6c7e87 | 2008-05-19 14:50:38 -0700 | [diff] [blame] | 421 | help |
| 422 | Create block devices that map to files in the host file system. |
| 423 | Device binding to host file may be changed at runtime via proc |
| 424 | interface provided the device is not in use. |
| 425 | |
| 426 | config BLK_DEV_SIMDISK_COUNT |
| 427 | int "Number of host file-based simulated block devices" |
| 428 | range 1 10 |
| 429 | depends on BLK_DEV_SIMDISK |
| 430 | default 2 |
| 431 | help |
| 432 | This is the default minimal number of created block devices. |
| 433 | Kernel/module parameter 'simdisk_count' may be used to change this |
| 434 | value at runtime. More file names (but no more than 10) may be |
| 435 | specified as parameters, simdisk_count grows accordingly. |
| 436 | |
| 437 | config SIMDISK0_FILENAME |
| 438 | string "Host filename for the first simulated device" |
| 439 | depends on BLK_DEV_SIMDISK = y |
| 440 | default "" |
| 441 | help |
| 442 | Attach a first simdisk to a host file. Conventionally, this file |
| 443 | contains a root file system. |
| 444 | |
| 445 | config SIMDISK1_FILENAME |
| 446 | string "Host filename for the second simulated device" |
| 447 | depends on BLK_DEV_SIMDISK = y && BLK_DEV_SIMDISK_COUNT != 1 |
| 448 | default "" |
| 449 | help |
| 450 | Another simulated disk in a host file for a buildroot-independent |
| 451 | storage. |
| 452 | |
Max Filippov | 4949009 | 2015-02-27 06:28:00 +0300 | [diff] [blame] | 453 | config XTFPGA_LCD |
| 454 | bool "Enable XTFPGA LCD driver" |
| 455 | depends on XTENSA_PLATFORM_XTFPGA |
| 456 | default n |
| 457 | help |
| 458 | There's a 2x16 LCD on most of XTFPGA boards, kernel may output |
| 459 | progress messages there during bootup/shutdown. It may be useful |
| 460 | during board bringup. |
| 461 | |
| 462 | If unsure, say N. |
| 463 | |
| 464 | config XTFPGA_LCD_BASE_ADDR |
| 465 | hex "XTFPGA LCD base address" |
| 466 | depends on XTFPGA_LCD |
| 467 | default "0x0d0c0000" |
| 468 | help |
| 469 | Base address of the LCD controller inside KIO region. |
| 470 | Different boards from XTFPGA family have LCD controller at different |
| 471 | addresses. Please consult prototyping user guide for your board for |
| 472 | the correct address. Wrong address here may lead to hardware lockup. |
| 473 | |
| 474 | config XTFPGA_LCD_8BIT_ACCESS |
| 475 | bool "Use 8-bit access to XTFPGA LCD" |
| 476 | depends on XTFPGA_LCD |
| 477 | default n |
| 478 | help |
| 479 | LCD may be connected with 4- or 8-bit interface, 8-bit access may |
| 480 | only be used with 8-bit interface. Please consult prototyping user |
| 481 | guide for your board for the correct interface width. |
| 482 | |
Max Filippov | 76743c0 | 2019-10-01 00:25:30 -0700 | [diff] [blame] | 483 | comment "Kernel memory layout" |
| 484 | |
| 485 | config INITIALIZE_XTENSA_MMU_INSIDE_VMLINUX |
| 486 | bool "Initialize Xtensa MMU inside the Linux kernel code" |
| 487 | depends on !XTENSA_VARIANT_FSF && !XTENSA_VARIANT_DC232B |
| 488 | default y if XTENSA_VARIANT_DC233C || XTENSA_VARIANT_CUSTOM |
| 489 | help |
| 490 | Earlier version initialized the MMU in the exception vector |
| 491 | before jumping to _startup in head.S and had an advantage that |
| 492 | it was possible to place a software breakpoint at 'reset' and |
| 493 | then enter your normal kernel breakpoints once the MMU was mapped |
| 494 | to the kernel mappings (0XC0000000). |
| 495 | |
Colin Ian King | 8a128bc | 2020-12-17 17:24:27 +0000 | [diff] [blame] | 496 | This unfortunately won't work for U-Boot and likely also won't |
Max Filippov | 76743c0 | 2019-10-01 00:25:30 -0700 | [diff] [blame] | 497 | work for using KEXEC to have a hot kernel ready for doing a |
| 498 | KDUMP. |
| 499 | |
| 500 | So now the MMU is initialized in head.S but it's necessary to |
| 501 | use hardware breakpoints (gdb 'hbreak' cmd) to break at _startup. |
| 502 | xt-gdb can't place a Software Breakpoint in the 0XD region prior |
| 503 | to mapping the MMU and after mapping even if the area of low memory |
| 504 | was mapped gdb wouldn't remove the breakpoint on hitting it as the |
| 505 | PC wouldn't match. Since Hardware Breakpoints are recommended for |
| 506 | Linux configurations it seems reasonable to just assume they exist |
| 507 | and leave this older mechanism for unfortunate souls that choose |
| 508 | not to follow Tensilica's recommendation. |
| 509 | |
| 510 | Selecting this will cause U-Boot to set the KERNEL Load and Entry |
| 511 | address at 0x00003000 instead of the mapped std of 0xD0003000. |
| 512 | |
| 513 | If in doubt, say Y. |
| 514 | |
Max Filippov | 7af710d | 2017-01-03 17:57:51 -0800 | [diff] [blame] | 515 | config XIP_KERNEL |
| 516 | bool "Kernel Execute-In-Place from ROM" |
| 517 | depends on PLATFORM_HAVE_XIP |
| 518 | help |
| 519 | Execute-In-Place allows the kernel to run from non-volatile storage |
| 520 | directly addressable by the CPU, such as NOR flash. This saves RAM |
| 521 | space since the text section of the kernel is not loaded from flash |
| 522 | to RAM. Read-write sections, such as the data section and stack, |
| 523 | are still copied to RAM. The XIP kernel is not compressed since |
| 524 | it has to run directly from flash, so it will take more space to |
| 525 | store it. The flash address used to link the kernel object files, |
| 526 | and for storing it, is configuration dependent. Therefore, if you |
| 527 | say Y here, you must know the proper physical address where to |
| 528 | store the kernel image depending on your own flash memory usage. |
| 529 | |
| 530 | Also note that the make target becomes "make xipImage" rather than |
| 531 | "make Image" or "make uImage". The final kernel binary to put in |
| 532 | ROM memory will be arch/xtensa/boot/xipImage. |
| 533 | |
| 534 | If unsure, say N. |
| 535 | |
Max Filippov | 76743c0 | 2019-10-01 00:25:30 -0700 | [diff] [blame] | 536 | config MEMMAP_CACHEATTR |
| 537 | hex "Cache attributes for the memory address space" |
| 538 | depends on !MMU |
| 539 | default 0x22222222 |
| 540 | help |
| 541 | These cache attributes are set up for noMMU systems. Each hex digit |
| 542 | specifies cache attributes for the corresponding 512MB memory |
| 543 | region: bits 0..3 -- for addresses 0x00000000..0x1fffffff, |
| 544 | bits 4..7 -- for addresses 0x20000000..0x3fffffff, and so on. |
| 545 | |
| 546 | Cache attribute values are specific for the MMU type. |
| 547 | For region protection MMUs: |
| 548 | 1: WT cached, |
| 549 | 2: cache bypass, |
| 550 | 4: WB cached, |
| 551 | f: illegal. |
Randy Dunlap | 2a9b29b | 2020-08-29 22:57:51 -0700 | [diff] [blame] | 552 | For full MMU: |
Max Filippov | 76743c0 | 2019-10-01 00:25:30 -0700 | [diff] [blame] | 553 | bit 0: executable, |
| 554 | bit 1: writable, |
| 555 | bits 2..3: |
| 556 | 0: cache bypass, |
| 557 | 1: WB cache, |
| 558 | 2: WT cache, |
| 559 | 3: special (c and e are illegal, f is reserved). |
| 560 | For MPU: |
| 561 | 0: illegal, |
| 562 | 1: WB cache, |
| 563 | 2: WB, no-write-allocate cache, |
| 564 | 3: WT cache, |
| 565 | 4: cache bypass. |
| 566 | |
| 567 | config KSEG_PADDR |
| 568 | hex "Physical address of the KSEG mapping" |
| 569 | depends on INITIALIZE_XTENSA_MMU_INSIDE_VMLINUX && MMU |
| 570 | default 0x00000000 |
| 571 | help |
| 572 | This is the physical address where KSEG is mapped. Please refer to |
| 573 | the chosen KSEG layout help for the required address alignment. |
| 574 | Unpacked kernel image (including vectors) must be located completely |
| 575 | within KSEG. |
| 576 | Physical memory below this address is not available to linux. |
| 577 | |
| 578 | If unsure, leave the default value here. |
| 579 | |
Max Filippov | 7af710d | 2017-01-03 17:57:51 -0800 | [diff] [blame] | 580 | config KERNEL_VIRTUAL_ADDRESS |
| 581 | hex "Kernel virtual address" |
| 582 | depends on MMU && XIP_KERNEL |
| 583 | default 0xd0003000 |
| 584 | help |
| 585 | This is the virtual address where the XIP kernel is mapped. |
| 586 | XIP kernel may be mapped into KSEG or KIO region, virtual address |
| 587 | provided here must match kernel load address provided in |
| 588 | KERNEL_LOAD_ADDRESS. |
| 589 | |
Max Filippov | 76743c0 | 2019-10-01 00:25:30 -0700 | [diff] [blame] | 590 | config KERNEL_LOAD_ADDRESS |
| 591 | hex "Kernel load address" |
| 592 | default 0x60003000 if !MMU |
| 593 | default 0x00003000 if MMU && INITIALIZE_XTENSA_MMU_INSIDE_VMLINUX |
| 594 | default 0xd0003000 if MMU && !INITIALIZE_XTENSA_MMU_INSIDE_VMLINUX |
| 595 | help |
| 596 | This is the address where the kernel is loaded. |
| 597 | It is virtual address for MMUv2 configurations and physical address |
| 598 | for all other configurations. |
| 599 | |
| 600 | If unsure, leave the default value here. |
| 601 | |
Max Filippov | 5e4417f | 2020-01-31 20:11:24 -0800 | [diff] [blame] | 602 | choice |
| 603 | prompt "Relocatable vectors location" |
| 604 | default XTENSA_VECTORS_IN_TEXT |
Max Filippov | 76743c0 | 2019-10-01 00:25:30 -0700 | [diff] [blame] | 605 | help |
Max Filippov | 5e4417f | 2020-01-31 20:11:24 -0800 | [diff] [blame] | 606 | Choose whether relocatable vectors are merged into the kernel .text |
| 607 | or placed separately at runtime. This option does not affect |
| 608 | configurations without VECBASE register where vectors are always |
| 609 | placed at their hardware-defined locations. |
Max Filippov | 76743c0 | 2019-10-01 00:25:30 -0700 | [diff] [blame] | 610 | |
Max Filippov | 5e4417f | 2020-01-31 20:11:24 -0800 | [diff] [blame] | 611 | config XTENSA_VECTORS_IN_TEXT |
| 612 | bool "Merge relocatable vectors into kernel text" |
| 613 | depends on !MTD_XIP |
| 614 | help |
| 615 | This option puts relocatable vectors into the kernel .text section |
| 616 | with proper alignment. |
| 617 | This is a safe choice for most configurations. |
| 618 | |
| 619 | config XTENSA_VECTORS_SEPARATE |
| 620 | bool "Put relocatable vectors at fixed address" |
| 621 | help |
| 622 | This option puts relocatable vectors at specific virtual address. |
| 623 | Vectors are merged with the .init data in the kernel image and |
| 624 | are copied into their designated location during kernel startup. |
| 625 | Use it to put vectors into IRAM or out of FLASH on kernels with |
| 626 | XIP-aware MTD support. |
| 627 | |
| 628 | endchoice |
| 629 | |
| 630 | config VECTORS_ADDR |
| 631 | hex "Kernel vectors virtual address" |
| 632 | default 0x00000000 |
| 633 | depends on XTENSA_VECTORS_SEPARATE |
| 634 | help |
| 635 | This is the virtual address of the (relocatable) vectors base. |
| 636 | It must be within KSEG if MMU is used. |
Max Filippov | 76743c0 | 2019-10-01 00:25:30 -0700 | [diff] [blame] | 637 | |
Max Filippov | 7af710d | 2017-01-03 17:57:51 -0800 | [diff] [blame] | 638 | config XIP_DATA_ADDR |
| 639 | hex "XIP kernel data virtual address" |
| 640 | depends on XIP_KERNEL |
| 641 | default 0x00000000 |
| 642 | help |
| 643 | This is the virtual address where XIP kernel data is copied. |
| 644 | It must be within KSEG if MMU is used. |
| 645 | |
Max Filippov | 76743c0 | 2019-10-01 00:25:30 -0700 | [diff] [blame] | 646 | config PLATFORM_WANT_DEFAULT_MEM |
| 647 | def_bool n |
| 648 | |
| 649 | config DEFAULT_MEM_START |
| 650 | hex |
| 651 | prompt "PAGE_OFFSET/PHYS_OFFSET" if !MMU && PLATFORM_WANT_DEFAULT_MEM |
| 652 | default 0x60000000 if PLATFORM_WANT_DEFAULT_MEM |
| 653 | default 0x00000000 |
| 654 | help |
| 655 | This is the base address used for both PAGE_OFFSET and PHYS_OFFSET |
| 656 | in noMMU configurations. |
| 657 | |
| 658 | If unsure, leave the default value here. |
| 659 | |
| 660 | choice |
| 661 | prompt "KSEG layout" |
| 662 | depends on MMU |
| 663 | default XTENSA_KSEG_MMU_V2 |
| 664 | |
| 665 | config XTENSA_KSEG_MMU_V2 |
| 666 | bool "MMUv2: 128MB cached + 128MB uncached" |
| 667 | help |
| 668 | MMUv2 compatible kernel memory map: TLB way 5 maps 128MB starting |
| 669 | at KSEG_PADDR to 0xd0000000 with cache and to 0xd8000000 |
| 670 | without cache. |
| 671 | KSEG_PADDR must be aligned to 128MB. |
| 672 | |
| 673 | config XTENSA_KSEG_256M |
| 674 | bool "256MB cached + 256MB uncached" |
| 675 | depends on INITIALIZE_XTENSA_MMU_INSIDE_VMLINUX |
| 676 | help |
| 677 | TLB way 6 maps 256MB starting at KSEG_PADDR to 0xb0000000 |
| 678 | with cache and to 0xc0000000 without cache. |
| 679 | KSEG_PADDR must be aligned to 256MB. |
| 680 | |
| 681 | config XTENSA_KSEG_512M |
| 682 | bool "512MB cached + 512MB uncached" |
| 683 | depends on INITIALIZE_XTENSA_MMU_INSIDE_VMLINUX |
| 684 | help |
| 685 | TLB way 6 maps 512MB starting at KSEG_PADDR to 0xa0000000 |
| 686 | with cache and to 0xc0000000 without cache. |
| 687 | KSEG_PADDR must be aligned to 256MB. |
| 688 | |
| 689 | endchoice |
| 690 | |
| 691 | config HIGHMEM |
| 692 | bool "High Memory Support" |
| 693 | depends on MMU |
Thomas Gleixner | 629ed3f | 2020-11-03 10:27:29 +0100 | [diff] [blame] | 694 | select KMAP_LOCAL |
Max Filippov | 76743c0 | 2019-10-01 00:25:30 -0700 | [diff] [blame] | 695 | help |
| 696 | Linux can use the full amount of RAM in the system by |
| 697 | default. However, the default MMUv2 setup only maps the |
| 698 | lowermost 128 MB of memory linearly to the areas starting |
| 699 | at 0xd0000000 (cached) and 0xd8000000 (uncached). |
| 700 | When there are more than 128 MB memory in the system not |
| 701 | all of it can be "permanently mapped" by the kernel. |
| 702 | The physical memory that's not permanently mapped is called |
| 703 | "high memory". |
| 704 | |
| 705 | If you are compiling a kernel which will never run on a |
| 706 | machine with more than 128 MB total physical RAM, answer |
| 707 | N here. |
| 708 | |
| 709 | If unsure, say Y. |
| 710 | |
| 711 | config FORCE_MAX_ZONEORDER |
| 712 | int "Maximum zone order" |
| 713 | default "11" |
| 714 | help |
| 715 | The kernel memory allocator divides physically contiguous memory |
| 716 | blocks into "zones", where each zone is a power of two number of |
| 717 | pages. This option selects the largest power of two that the kernel |
| 718 | keeps in the memory allocator. If you need to allocate very large |
| 719 | blocks of physically contiguous memory, then you may need to |
| 720 | increase this value. |
| 721 | |
| 722 | This config option is actually maximum order plus one. For example, |
| 723 | a value of 11 means that the largest free memory block is 2^10 pages. |
| 724 | |
Chris Zankel | 8e1a6dd | 2005-06-23 22:01:10 -0700 | [diff] [blame] | 725 | endmenu |
| 726 | |
Max Filippov | e00d8b2 | 2014-10-29 01:42:01 +0300 | [diff] [blame] | 727 | menu "Power management options" |
| 728 | |
| 729 | source "kernel/power/Kconfig" |
| 730 | |
| 731 | endmenu |