Commit | Line | Data |
---|---|---|
b2441318 | 1 | # SPDX-License-Identifier: GPL-2.0 |
daa93fab SR |
2 | # Select 32 or 64 bit |
3 | config 64BIT | |
104daea1 MY |
4 | bool "64-bit kernel" if "$(ARCH)" = "x86" |
5 | default "$(ARCH)" != "i386" | |
a7f7f624 | 6 | help |
daa93fab SR |
7 | 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 | ||
10 | config X86_32 | |
3120e25e JB |
11 | def_bool y |
12 | depends on !64BIT | |
341c787e IM |
13 | # Options that are inherently 32-bit kernel only: |
14 | select ARCH_WANT_IPC_PARSE_VERSION | |
15 | select CLKSRC_I8253 | |
16 | select CLONE_BACKWARDS | |
157e118b | 17 | select GENERIC_VDSO_32 |
117ed454 | 18 | select HAVE_DEBUG_STACKOVERFLOW |
157e118b | 19 | select KMAP_LOCAL |
341c787e IM |
20 | select MODULES_USE_ELF_REL |
21 | select OLD_SIGACTION | |
2ca408d9 | 22 | select ARCH_SPLIT_ARG64 |
daa93fab SR |
23 | |
24 | config X86_64 | |
3120e25e JB |
25 | def_bool y |
26 | depends on 64BIT | |
d94e0685 | 27 | # Options that are inherently 64-bit kernel only: |
4eb0716e | 28 | select ARCH_HAS_GIGANTIC_PAGE |
c12d3362 | 29 | select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 |
d94e0685 IM |
30 | select ARCH_USE_CMPXCHG_LOCKREF |
31 | select HAVE_ARCH_SOFT_DIRTY | |
32 | select MODULES_USE_ELF_RELA | |
f616ab59 | 33 | select NEED_DMA_MAP_STATE |
09230cbc | 34 | select SWIOTLB |
7facdc42 | 35 | select ARCH_HAS_ELFCORE_COMPAT |
63703f37 | 36 | select ZONE_DMA32 |
1032c0ba | 37 | |
518049d9 SRV |
38 | config FORCE_DYNAMIC_FTRACE |
39 | def_bool y | |
40 | depends on X86_32 | |
41 | depends on FUNCTION_TRACER | |
42 | select DYNAMIC_FTRACE | |
43 | help | |
758cd94a JH |
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. | |
d94e0685 IM |
49 | # |
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 | # | |
8d5fffb9 | 55 | config X86 |
3c2362e6 | 56 | def_bool y |
c763ea26 IM |
57 | # |
58 | # Note: keep this list sorted alphabetically | |
59 | # | |
6471b825 IM |
60 | select ACPI_LEGACY_TABLES_LOOKUP if ACPI |
61 | select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI | |
942fa985 | 62 | select ARCH_32BIT_OFF_T if X86_32 |
2a21ad57 | 63 | select ARCH_CLOCKSOURCE_INIT |
1f6d3a8f | 64 | select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE |
1e866974 | 65 | select ARCH_ENABLE_HUGEPAGE_MIGRATION if X86_64 && HUGETLB_PAGE && MIGRATION |
5c11f00b | 66 | select ARCH_ENABLE_MEMORY_HOTPLUG if X86_64 |
91024b3c | 67 | select ARCH_ENABLE_MEMORY_HOTREMOVE if MEMORY_HOTPLUG |
cebc774f | 68 | select ARCH_ENABLE_SPLIT_PMD_PTLOCK if (PGTABLE_LEVELS > 2) && (X86_64 || X86_PAE) |
1e866974 | 69 | select ARCH_ENABLE_THP_MIGRATION if X86_64 && TRANSPARENT_HUGEPAGE |
c763ea26 | 70 | select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI |
c2280be8 | 71 | select ARCH_HAS_CACHE_LINE_SIZE |
2792d84e | 72 | select ARCH_HAS_CURRENT_STACK_POINTER |
fa5b6ec9 | 73 | select ARCH_HAS_DEBUG_VIRTUAL |
399145f9 | 74 | select ARCH_HAS_DEBUG_VM_PGTABLE if !X86_PAE |
21266be9 | 75 | select ARCH_HAS_DEVMEM_IS_ALLOWED |
b1a57bbf | 76 | select ARCH_HAS_EARLY_DEBUG if KGDB |
6471b825 | 77 | select ARCH_HAS_ELF_RANDOMIZE |
72d93104 | 78 | select ARCH_HAS_FAST_MULTIPLIER |
6974f0c4 | 79 | select ARCH_HAS_FORTIFY_SOURCE |
957e3fac | 80 | select ARCH_HAS_GCOV_PROFILE_ALL |
bece04b5 | 81 | select ARCH_HAS_KCOV if X86_64 |
0c9c1d56 | 82 | select ARCH_HAS_MEM_ENCRYPT |
10bcc80e | 83 | select ARCH_HAS_MEMBARRIER_SYNC_CORE |
0ebeea8c | 84 | select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE |
c763ea26 | 85 | select ARCH_HAS_PMEM_API if X86_64 |
17596731 | 86 | select ARCH_HAS_PTE_DEVMAP if X86_64 |
3010a5ea | 87 | select ARCH_HAS_PTE_SPECIAL |
0aed55af | 88 | select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64 |
ec6347bb | 89 | select ARCH_HAS_COPY_MC if X86_64 |
d2852a22 | 90 | select ARCH_HAS_SET_MEMORY |
d253ca0c | 91 | select ARCH_HAS_SET_DIRECT_MAP |
ad21fc4f LA |
92 | select ARCH_HAS_STRICT_KERNEL_RWX |
93 | select ARCH_HAS_STRICT_MODULE_RWX | |
ac1ab12a | 94 | select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE |
25c619e5 | 95 | select ARCH_HAS_SYSCALL_WRAPPER |
c6d30853 | 96 | select ARCH_HAS_UBSAN_SANITIZE_ALL |
7e01ccb4 | 97 | select ARCH_HAS_DEBUG_WX |
63703f37 | 98 | select ARCH_HAS_ZONE_DMA_SET if EXPERT |
6471b825 IM |
99 | select ARCH_HAVE_NMI_SAFE_CMPXCHG |
100 | select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI | |
77fbbc81 | 101 | select ARCH_MIGHT_HAVE_PC_PARPORT |
5e2c18c0 | 102 | select ARCH_MIGHT_HAVE_PC_SERIO |
3599fe12 | 103 | select ARCH_STACKWALK |
2c870e61 | 104 | select ARCH_SUPPORTS_ACPI |
6471b825 | 105 | select ARCH_SUPPORTS_ATOMIC_RMW |
5d6ad668 | 106 | select ARCH_SUPPORTS_DEBUG_PAGEALLOC |
d283d422 | 107 | select ARCH_SUPPORTS_PAGE_TABLE_CHECK if X86_64 |
6471b825 | 108 | select ARCH_SUPPORTS_NUMA_BALANCING if X86_64 |
14df3267 | 109 | select ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP if NR_CPUS <= 4096 |
583bfd48 NC |
110 | select ARCH_SUPPORTS_LTO_CLANG |
111 | select ARCH_SUPPORTS_LTO_CLANG_THIN | |
6471b825 | 112 | select ARCH_USE_BUILTIN_BSWAP |
dce44566 | 113 | select ARCH_USE_MEMTEST |
6471b825 IM |
114 | select ARCH_USE_QUEUED_RWLOCKS |
115 | select ARCH_USE_QUEUED_SPINLOCKS | |
2ce0d7f9 | 116 | select ARCH_USE_SYM_ANNOTATIONS |
ce4a4e56 | 117 | select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH |
81c22041 | 118 | select ARCH_WANT_DEFAULT_BPF_JIT if X86_64 |
c763ea26 | 119 | select ARCH_WANTS_DYNAMIC_TASK_STRUCT |
51c2ee6d | 120 | select ARCH_WANTS_NO_INSTR |
07431506 | 121 | select ARCH_WANT_GENERAL_HUGETLB |
3876d4a3 | 122 | select ARCH_WANT_HUGE_PMD_SHARE |
47010c04 | 123 | select ARCH_WANT_HUGETLB_PAGE_OPTIMIZE_VMEMMAP if X86_64 |
59612b24 | 124 | select ARCH_WANT_LD_ORPHAN_WARN |
38d8b4e6 | 125 | select ARCH_WANTS_THP_SWAP if X86_64 |
b5f06f64 | 126 | select ARCH_HAS_PARANOID_L1D_FLUSH |
10916706 | 127 | select BUILDTIME_TABLE_SORT |
6471b825 | 128 | select CLKEVT_I8253 |
6471b825 IM |
129 | select CLOCKSOURCE_VALIDATE_LAST_CYCLE |
130 | select CLOCKSOURCE_WATCHDOG | |
6471b825 | 131 | select DCACHE_WORD_ACCESS |
3aac3ebe | 132 | select DYNAMIC_SIGFRAME |
45471cd9 LT |
133 | select EDAC_ATOMIC_SCRUB |
134 | select EDAC_SUPPORT | |
6471b825 IM |
135 | select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC) |
136 | select GENERIC_CLOCKEVENTS_MIN_ADJUST | |
137 | select GENERIC_CMOS_UPDATE | |
138 | select GENERIC_CPU_AUTOPROBE | |
61dc0f55 | 139 | select GENERIC_CPU_VULNERABILITIES |
5b7c73e0 | 140 | select GENERIC_EARLY_IOREMAP |
27d6b4d1 | 141 | select GENERIC_ENTRY |
6471b825 | 142 | select GENERIC_IOMAP |
c7d6c9dd | 143 | select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP |
0fa115da | 144 | select GENERIC_IRQ_MATRIX_ALLOCATOR if X86_LOCAL_APIC |
ad7a929f | 145 | select GENERIC_IRQ_MIGRATION if SMP |
6471b825 | 146 | select GENERIC_IRQ_PROBE |
c201c917 | 147 | select GENERIC_IRQ_RESERVATION_MODE |
6471b825 IM |
148 | select GENERIC_IRQ_SHOW |
149 | select GENERIC_PENDING_IRQ if SMP | |
2ae27137 | 150 | select GENERIC_PTDUMP |
6471b825 | 151 | select GENERIC_SMP_IDLE_THREAD |
6471b825 | 152 | select GENERIC_TIME_VSYSCALL |
7ac87074 | 153 | select GENERIC_GETTIMEOFDAY |
550a77a7 | 154 | select GENERIC_VDSO_TIME_NS |
39656e83 | 155 | select GUP_GET_PTE_LOW_HIGH if X86_PAE |
17e5888e | 156 | select HARDIRQS_SW_RESEND |
7edaeb68 | 157 | select HARDLOCKUP_CHECK_TIMESTAMP if X86_64 |
6471b825 IM |
158 | select HAVE_ACPI_APEI if ACPI |
159 | select HAVE_ACPI_APEI_NMI if ACPI | |
160 | select HAVE_ALIGNED_STRUCT_PAGE if SLUB | |
6471b825 IM |
161 | select HAVE_ARCH_AUDITSYSCALL |
162 | select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE | |
eed1fcee | 163 | select HAVE_ARCH_HUGE_VMALLOC if X86_64 |
6471b825 | 164 | select HAVE_ARCH_JUMP_LABEL |
b34006c4 | 165 | select HAVE_ARCH_JUMP_LABEL_RELATIVE |
d17a1d97 | 166 | select HAVE_ARCH_KASAN if X86_64 |
0609ae01 | 167 | select HAVE_ARCH_KASAN_VMALLOC if X86_64 |
1dc0da6e | 168 | select HAVE_ARCH_KFENCE |
6471b825 | 169 | select HAVE_ARCH_KGDB |
9e08f57d DC |
170 | select HAVE_ARCH_MMAP_RND_BITS if MMU |
171 | select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT | |
1b028f78 | 172 | select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT |
271ca788 | 173 | select HAVE_ARCH_PREL32_RELOCATIONS |
6471b825 | 174 | select HAVE_ARCH_SECCOMP_FILTER |
f7d83c1c | 175 | select HAVE_ARCH_THREAD_STRUCT_WHITELIST |
afaef01c | 176 | select HAVE_ARCH_STACKLEAK |
6471b825 IM |
177 | select HAVE_ARCH_TRACEHOOK |
178 | select HAVE_ARCH_TRANSPARENT_HUGEPAGE | |
a00cc7d9 | 179 | select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64 |
b64d8d1e | 180 | select HAVE_ARCH_USERFAULTFD_WP if X86_64 && USERFAULTFD |
7677f7fd | 181 | select HAVE_ARCH_USERFAULTFD_MINOR if X86_64 && USERFAULTFD |
e37e43a4 | 182 | select HAVE_ARCH_VMAP_STACK if X86_64 |
fe950f60 | 183 | select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET |
c763ea26 | 184 | select HAVE_ARCH_WITHIN_STACK_FRAMES |
2ff2b7ec | 185 | select HAVE_ASM_MODVERSIONS |
6471b825 IM |
186 | select HAVE_CMPXCHG_DOUBLE |
187 | select HAVE_CMPXCHG_LOCAL | |
24a9c541 FW |
188 | select HAVE_CONTEXT_TRACKING_USER if X86_64 |
189 | select HAVE_CONTEXT_TRACKING_USER_OFFSTACK if HAVE_CONTEXT_TRACKING_USER | |
cf4db259 | 190 | select HAVE_C_RECORDMCOUNT |
03f16cd0 | 191 | select HAVE_OBJTOOL_MCOUNT if HAVE_OBJTOOL |
4ed308c4 | 192 | select HAVE_BUILDTIME_MCOUNT_SORT |
6471b825 | 193 | select HAVE_DEBUG_KMEMLEAK |
6471b825 | 194 | select HAVE_DMA_CONTIGUOUS |
677aa9f7 | 195 | select HAVE_DYNAMIC_FTRACE |
06aeaaea | 196 | select HAVE_DYNAMIC_FTRACE_WITH_REGS |
02a474ca | 197 | select HAVE_DYNAMIC_FTRACE_WITH_ARGS if X86_64 |
562955fe | 198 | select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS |
c316eb44 | 199 | select HAVE_SAMPLE_FTRACE_DIRECT if X86_64 |
503e4510 | 200 | select HAVE_SAMPLE_FTRACE_DIRECT_MULTI if X86_64 |
03f5781b | 201 | select HAVE_EBPF_JIT |
58340a07 | 202 | select HAVE_EFFICIENT_UNALIGNED_ACCESS |
6630a8e5 | 203 | select HAVE_EISA |
5f56a5df | 204 | select HAVE_EXIT_THREAD |
67a929e0 | 205 | select HAVE_FAST_GUP |
644e0e8d | 206 | select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE |
6471b825 | 207 | select HAVE_FTRACE_MCOUNT_RECORD |
4a30e4c9 | 208 | select HAVE_FUNCTION_GRAPH_TRACER if X86_32 || (X86_64 && DYNAMIC_FTRACE) |
6471b825 | 209 | select HAVE_FUNCTION_TRACER |
6b90bd4b | 210 | select HAVE_GCC_PLUGINS |
6471b825 | 211 | select HAVE_HW_BREAKPOINT |
6471b825 | 212 | select HAVE_IOREMAP_PROT |
624db9ea | 213 | select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64 |
6471b825 | 214 | select HAVE_IRQ_TIME_ACCOUNTING |
4ab7674f | 215 | select HAVE_JUMP_LABEL_HACK if HAVE_OBJTOOL |
2e9f3bdd | 216 | select HAVE_KERNEL_BZIP2 |
6471b825 IM |
217 | select HAVE_KERNEL_GZIP |
218 | select HAVE_KERNEL_LZ4 | |
2e9f3bdd | 219 | select HAVE_KERNEL_LZMA |
13510997 | 220 | select HAVE_KERNEL_LZO |
6471b825 | 221 | select HAVE_KERNEL_XZ |
fb46d057 | 222 | select HAVE_KERNEL_ZSTD |
6471b825 IM |
223 | select HAVE_KPROBES |
224 | select HAVE_KPROBES_ON_FTRACE | |
540adea3 | 225 | select HAVE_FUNCTION_ERROR_INJECTION |
6471b825 | 226 | select HAVE_KRETPROBES |
f3a112c0 | 227 | select HAVE_RETHOOK |
6471b825 IM |
228 | select HAVE_KVM |
229 | select HAVE_LIVEPATCH if X86_64 | |
0102752e | 230 | select HAVE_MIXED_BREAKPOINTS_REGS |
ee9f8fce | 231 | select HAVE_MOD_ARCH_SPECIFIC |
9f132f7e | 232 | select HAVE_MOVE_PMD |
be37c98d | 233 | select HAVE_MOVE_PUD |
22102f45 | 234 | select HAVE_NOINSTR_HACK if HAVE_OBJTOOL |
42a0bb3f | 235 | select HAVE_NMI |
489e355b | 236 | select HAVE_NOINSTR_VALIDATION if HAVE_OBJTOOL |
03f16cd0 | 237 | select HAVE_OBJTOOL if X86_64 |
6471b825 IM |
238 | select HAVE_OPTPROBES |
239 | select HAVE_PCSPKR_PLATFORM | |
240 | select HAVE_PERF_EVENTS | |
c01d4323 | 241 | select HAVE_PERF_EVENTS_NMI |
92e5aae4 | 242 | select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI |
eb01d42a | 243 | select HAVE_PCI |
c5e63197 | 244 | select HAVE_PERF_REGS |
c5ebcedb | 245 | select HAVE_PERF_USER_STACK_DUMP |
03f16cd0 | 246 | select MMU_GATHER_RCU_TABLE_FREE if PARAVIRT |
1e9fdf21 | 247 | select MMU_GATHER_MERGE_VMAS |
00998085 | 248 | select HAVE_POSIX_CPU_TIMERS_TASK_WORK |
6471b825 | 249 | select HAVE_REGS_AND_STACK_ACCESS_API |
03f16cd0 | 250 | select HAVE_RELIABLE_STACKTRACE if UNWINDER_ORC || STACK_VALIDATION |
3c88ee19 | 251 | select HAVE_FUNCTION_ARG_ACCESS_API |
7ecd19cf | 252 | select HAVE_SETUP_PER_CPU_AREA |
cd1a41ce | 253 | select HAVE_SOFTIRQ_ON_OWN_STACK |
d148eac0 | 254 | select HAVE_STACKPROTECTOR if CC_HAS_SANE_STACKPROTECTOR |
03f16cd0 | 255 | select HAVE_STACK_VALIDATION if HAVE_OBJTOOL |
e6d6c071 | 256 | select HAVE_STATIC_CALL |
03f16cd0 | 257 | select HAVE_STATIC_CALL_INLINE if HAVE_OBJTOOL |
99cf983c | 258 | select HAVE_PREEMPT_DYNAMIC_CALL |
d6761b8f | 259 | select HAVE_RSEQ |
6471b825 | 260 | select HAVE_SYSCALL_TRACEPOINTS |
5f3da8c0 | 261 | select HAVE_UACCESS_VALIDATION if HAVE_OBJTOOL |
6471b825 | 262 | select HAVE_UNSTABLE_SCHED_CLOCK |
7c68af6e | 263 | select HAVE_USER_RETURN_NOTIFIER |
7ac87074 | 264 | select HAVE_GENERIC_VDSO |
05736e4a | 265 | select HOTPLUG_SMT if SMP |
c0185808 | 266 | select IRQ_FORCED_THREADING |
7ecd19cf KW |
267 | select NEED_PER_CPU_EMBED_FIRST_CHUNK |
268 | select NEED_PER_CPU_PAGE_FIRST_CHUNK | |
86596f0a | 269 | select NEED_SG_DMA_LENGTH |
2eac9c2d | 270 | select PCI_DOMAINS if PCI |
625210cf | 271 | select PCI_LOCKLESS_CONFIG if PCI |
6471b825 | 272 | select PERF_EVENTS |
3195ef59 | 273 | select RTC_LIB |
d6faca40 | 274 | select RTC_MC146818_LIB |
6471b825 | 275 | select SPARSE_IRQ |
83fe27ea | 276 | select SRCU |
6471b825 | 277 | select SYSCTL_EXCEPTION_TRACE |
15f4eae7 | 278 | select THREAD_INFO_IN_TASK |
4aae683f | 279 | select TRACE_IRQFLAGS_SUPPORT |
4510bffb | 280 | select TRACE_IRQFLAGS_NMI_SUPPORT |
6471b825 | 281 | select USER_STACKTRACE_SUPPORT |
3b02a051 | 282 | select HAVE_ARCH_KCSAN if X86_64 |
6471b825 | 283 | select X86_FEATURE_NAMES if PROC_FS |
0c608dad | 284 | select PROC_PID_ARCH_STATUS if PROC_FS |
50468e43 | 285 | select HAVE_ARCH_NODE_DEV_GROUP if X86_SGX |
9e2b4be3 | 286 | imply IMA_SECURE_AND_OR_TRUSTED_BOOT if EFI |
7d8330a5 | 287 | |
ba7e4d13 | 288 | config INSTRUCTION_DECODER |
3120e25e JB |
289 | def_bool y |
290 | depends on KPROBES || PERF_EVENTS || UPROBES | |
ba7e4d13 | 291 | |
51b26ada LT |
292 | config OUTPUT_FORMAT |
293 | string | |
294 | default "elf32-i386" if X86_32 | |
295 | default "elf64-x86-64" if X86_64 | |
296 | ||
8d5fffb9 | 297 | config LOCKDEP_SUPPORT |
3c2362e6 | 298 | def_bool y |
8d5fffb9 SR |
299 | |
300 | config STACKTRACE_SUPPORT | |
3c2362e6 | 301 | def_bool y |
8d5fffb9 | 302 | |
8d5fffb9 | 303 | config MMU |
3c2362e6 | 304 | def_bool y |
8d5fffb9 | 305 | |
9e08f57d DC |
306 | config ARCH_MMAP_RND_BITS_MIN |
307 | default 28 if 64BIT | |
308 | default 8 | |
309 | ||
310 | config ARCH_MMAP_RND_BITS_MAX | |
311 | default 32 if 64BIT | |
312 | default 16 | |
313 | ||
314 | config ARCH_MMAP_RND_COMPAT_BITS_MIN | |
315 | default 8 | |
316 | ||
317 | config ARCH_MMAP_RND_COMPAT_BITS_MAX | |
318 | default 16 | |
319 | ||
8d5fffb9 SR |
320 | config SBUS |
321 | bool | |
322 | ||
323 | config GENERIC_ISA_DMA | |
3120e25e JB |
324 | def_bool y |
325 | depends on ISA_DMA_API | |
8d5fffb9 | 326 | |
8d5fffb9 | 327 | config GENERIC_BUG |
3c2362e6 | 328 | def_bool y |
8d5fffb9 | 329 | depends on BUG |
b93a531e JB |
330 | select GENERIC_BUG_RELATIVE_POINTERS if X86_64 |
331 | ||
332 | config GENERIC_BUG_RELATIVE_POINTERS | |
333 | bool | |
8d5fffb9 | 334 | |
8d5fffb9 | 335 | config ARCH_MAY_HAVE_PC_FDC |
3120e25e JB |
336 | def_bool y |
337 | depends on ISA_DMA_API | |
8d5fffb9 | 338 | |
1032c0ba SR |
339 | config GENERIC_CALIBRATE_DELAY |
340 | def_bool y | |
341 | ||
9a0b8415 | 342 | config ARCH_HAS_CPU_RELAX |
343 | def_bool y | |
344 | ||
801e4062 JB |
345 | config ARCH_HIBERNATION_POSSIBLE |
346 | def_bool y | |
801e4062 | 347 | |
d7109fe3 AS |
348 | config ARCH_NR_GPIO |
349 | int | |
350 | default 1024 if X86_64 | |
351 | default 512 | |
352 | ||
f4cb5700 JB |
353 | config ARCH_SUSPEND_POSSIBLE |
354 | def_bool y | |
f4cb5700 | 355 | |
8d5fffb9 | 356 | config AUDIT_ARCH |
e0fd24a3 | 357 | def_bool y if X86_64 |
8d5fffb9 | 358 | |
d6f2d75a AR |
359 | config KASAN_SHADOW_OFFSET |
360 | hex | |
361 | depends on KASAN | |
362 | default 0xdffffc0000000000 | |
363 | ||
69575d38 SW |
364 | config HAVE_INTEL_TXT |
365 | def_bool y | |
6ea30386 | 366 | depends on INTEL_IOMMU && ACPI |
69575d38 | 367 | |
6b0c3d44 SR |
368 | config X86_32_SMP |
369 | def_bool y | |
370 | depends on X86_32 && SMP | |
371 | ||
372 | config X86_64_SMP | |
373 | def_bool y | |
374 | depends on X86_64 && SMP | |
375 | ||
2b144498 SD |
376 | config ARCH_SUPPORTS_UPROBES |
377 | def_bool y | |
378 | ||
d20642f0 RH |
379 | config FIX_EARLYCON_MEM |
380 | def_bool y | |
381 | ||
94d49eb3 KS |
382 | config DYNAMIC_PHYSICAL_MASK |
383 | bool | |
384 | ||
98233368 KS |
385 | config PGTABLE_LEVELS |
386 | int | |
77ef56e4 | 387 | default 5 if X86_5LEVEL |
98233368 KS |
388 | default 4 if X86_64 |
389 | default 3 if X86_PAE | |
390 | default 2 | |
391 | ||
2a61f474 MY |
392 | config CC_HAS_SANE_STACKPROTECTOR |
393 | bool | |
1b866781 NC |
394 | default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC) $(CLANG_FLAGS)) if 64BIT |
395 | default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC) $(CLANG_FLAGS)) | |
2a61f474 | 396 | help |
758cd94a JH |
397 | We have to make sure stack protector is unconditionally disabled if |
398 | the compiler produces broken code or if it does not let us control | |
399 | the segment on 32-bit kernels. | |
2a61f474 | 400 | |
506f1d07 SR |
401 | menu "Processor type and features" |
402 | ||
506f1d07 SR |
403 | config SMP |
404 | bool "Symmetric multi-processing support" | |
a7f7f624 | 405 | help |
506f1d07 | 406 | This enables support for systems with more than one CPU. If you have |
4a474157 RG |
407 | a system with only one CPU, say N. If you have a system with more |
408 | than one CPU, say Y. | |
506f1d07 | 409 | |
4a474157 | 410 | If you say N here, the kernel will run on uni- and multiprocessor |
506f1d07 SR |
411 | machines, but will use only one CPU of a multiprocessor machine. If |
412 | you say Y here, the kernel will run on many, but not all, | |
4a474157 | 413 | uniprocessor machines. On a uniprocessor machine, the kernel |
506f1d07 SR |
414 | will run faster if you say N here. |
415 | ||
416 | Note that if you say Y here and choose architecture "586" or | |
417 | "Pentium" under "Processor family", the kernel will not work on 486 | |
418 | architectures. Similarly, multiprocessor kernels for the "PPro" | |
419 | architecture may not work on all Pentium based boards. | |
420 | ||
421 | People using multiprocessor machines who say Y here should also say | |
422 | Y to "Enhanced Real Time Clock Support", below. The "Advanced Power | |
423 | Management" code will be disabled if you say Y here. | |
424 | ||
cb1aaebe | 425 | See also <file:Documentation/x86/i386/IO-APIC.rst>, |
4f4cfa6c | 426 | <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at |
506f1d07 SR |
427 | <http://www.tldp.org/docs.html#howto>. |
428 | ||
429 | If you don't know what to do here, say N. | |
430 | ||
9def39be JT |
431 | config X86_FEATURE_NAMES |
432 | bool "Processor feature human-readable names" if EMBEDDED | |
433 | default y | |
a7f7f624 | 434 | help |
9def39be JT |
435 | This option compiles in a table of x86 feature bits and corresponding |
436 | names. This is required to support /proc/cpuinfo and a few kernel | |
437 | messages. You can disable this to save space, at the expense of | |
438 | making those few kernel messages show numeric feature bits instead. | |
439 | ||
440 | If in doubt, say Y. | |
441 | ||
06cd9a7d YL |
442 | config X86_X2APIC |
443 | bool "Support x2apic" | |
19e3d60d | 444 | depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST) |
a7f7f624 | 445 | help |
06cd9a7d YL |
446 | This enables x2apic support on CPUs that have this feature. |
447 | ||
448 | This allows 32-bit apic IDs (so it can support very large systems), | |
449 | and accesses the local apic via MSRs not via mmio. | |
450 | ||
06cd9a7d YL |
451 | If you don't know what to do here, say N. |
452 | ||
6695c85b | 453 | config X86_MPPARSE |
4590d98f | 454 | bool "Enable MPS table" if ACPI |
7a527688 | 455 | default y |
5ab74722 | 456 | depends on X86_LOCAL_APIC |
a7f7f624 | 457 | help |
6695c85b YL |
458 | For old smp systems that do not have proper acpi support. Newer systems |
459 | (esp with 64bit cpus) with acpi support, MADT and DSDT will override it | |
6695c85b | 460 | |
ddd70cf9 | 461 | config GOLDFISH |
b03b016f KK |
462 | def_bool y |
463 | depends on X86_GOLDFISH | |
ddd70cf9 | 464 | |
e6d42931 JW |
465 | config X86_CPU_RESCTRL |
466 | bool "x86 CPU resource control support" | |
6fe07ce3 | 467 | depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD) |
59fe5a77 | 468 | select KERNFS |
e79f15a4 | 469 | select PROC_CPU_RESCTRL if PROC_FS |
78e99b4a | 470 | help |
e6d42931 | 471 | Enable x86 CPU resource control support. |
6fe07ce3 BM |
472 | |
473 | Provide support for the allocation and monitoring of system resources | |
474 | usage by the CPU. | |
475 | ||
476 | Intel calls this Intel Resource Director Technology | |
477 | (Intel(R) RDT). More information about RDT can be found in the | |
478 | Intel x86 Architecture Software Developer Manual. | |
479 | ||
480 | AMD calls this AMD Platform Quality of Service (AMD QoS). | |
481 | More information about AMD QoS can be found in the AMD64 Technology | |
482 | Platform Quality of Service Extensions manual. | |
78e99b4a FY |
483 | |
484 | Say N if unsure. | |
485 | ||
8425091f | 486 | if X86_32 |
a0d0bb4d RD |
487 | config X86_BIGSMP |
488 | bool "Support for big SMP systems with more than 8 CPUs" | |
489 | depends on SMP | |
a7f7f624 | 490 | help |
e133f6ea | 491 | This option is needed for the systems that have more than 8 CPUs. |
a0d0bb4d | 492 | |
c5c606d9 RT |
493 | config X86_EXTENDED_PLATFORM |
494 | bool "Support for extended (non-PC) x86 platforms" | |
495 | default y | |
a7f7f624 | 496 | help |
06ac8346 IM |
497 | If you disable this option then the kernel will only support |
498 | standard PC platforms. (which covers the vast majority of | |
499 | systems out there.) | |
500 | ||
8425091f RT |
501 | If you enable this option then you'll be able to select support |
502 | for the following (non-PC) 32 bit x86 platforms: | |
cb7b8023 | 503 | Goldfish (Android emulator) |
8425091f | 504 | AMD Elan |
8425091f RT |
505 | RDC R-321x SoC |
506 | SGI 320/540 (Visual Workstation) | |
83125a3a | 507 | STA2X11-based (e.g. Northville) |
3f4110a4 | 508 | Moorestown MID devices |
06ac8346 IM |
509 | |
510 | If you have one of these systems, or if you want to build a | |
511 | generic distribution kernel, say Y here - otherwise say N. | |
758cd94a | 512 | endif # X86_32 |
06ac8346 | 513 | |
8425091f RT |
514 | if X86_64 |
515 | config X86_EXTENDED_PLATFORM | |
516 | bool "Support for extended (non-PC) x86 platforms" | |
517 | default y | |
a7f7f624 | 518 | help |
8425091f RT |
519 | If you disable this option then the kernel will only support |
520 | standard PC platforms. (which covers the vast majority of | |
521 | systems out there.) | |
522 | ||
523 | If you enable this option then you'll be able to select support | |
524 | for the following (non-PC) 64 bit x86 platforms: | |
44b111b5 | 525 | Numascale NumaChip |
8425091f RT |
526 | ScaleMP vSMP |
527 | SGI Ultraviolet | |
528 | ||
529 | If you have one of these systems, or if you want to build a | |
530 | generic distribution kernel, say Y here - otherwise say N. | |
758cd94a | 531 | endif # X86_64 |
c5c606d9 RT |
532 | # This is an alphabetically sorted list of 64 bit extended platforms |
533 | # Please maintain the alphabetic order if and when there are additions | |
44b111b5 SP |
534 | config X86_NUMACHIP |
535 | bool "Numascale NumaChip" | |
536 | depends on X86_64 | |
537 | depends on X86_EXTENDED_PLATFORM | |
538 | depends on NUMA | |
539 | depends on SMP | |
540 | depends on X86_X2APIC | |
f9726bfd | 541 | depends on PCI_MMCONFIG |
a7f7f624 | 542 | help |
44b111b5 SP |
543 | Adds support for Numascale NumaChip large-SMP systems. Needed to |
544 | enable more than ~168 cores. | |
545 | If you don't have one of these, you should say N here. | |
506f1d07 | 546 | |
c5c606d9 RT |
547 | config X86_VSMP |
548 | bool "ScaleMP vSMP" | |
6276a074 | 549 | select HYPERVISOR_GUEST |
c5c606d9 RT |
550 | select PARAVIRT |
551 | depends on X86_64 && PCI | |
552 | depends on X86_EXTENDED_PLATFORM | |
ead91d4b | 553 | depends on SMP |
a7f7f624 | 554 | help |
c5c606d9 RT |
555 | Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is |
556 | supposed to run on these EM64T-based machines. Only choose this option | |
557 | if you have one of these machines. | |
5e3a77e9 | 558 | |
03b48632 NP |
559 | config X86_UV |
560 | bool "SGI Ultraviolet" | |
561 | depends on X86_64 | |
c5c606d9 | 562 | depends on X86_EXTENDED_PLATFORM |
54c28d29 | 563 | depends on NUMA |
1ecb4ae5 | 564 | depends on EFI |
c2209ea5 | 565 | depends on KEXEC_CORE |
9d6c26e7 | 566 | depends on X86_X2APIC |
1222e564 | 567 | depends on PCI |
a7f7f624 | 568 | help |
03b48632 NP |
569 | This option is needed in order to support SGI Ultraviolet systems. |
570 | If you don't have one of these, you should say N here. | |
571 | ||
c5c606d9 RT |
572 | # Following is an alphabetically sorted list of 32 bit extended platforms |
573 | # Please maintain the alphabetic order if and when there are additions | |
506f1d07 | 574 | |
ddd70cf9 | 575 | config X86_GOLDFISH |
b03b016f KK |
576 | bool "Goldfish (Virtual Platform)" |
577 | depends on X86_EXTENDED_PLATFORM | |
a7f7f624 | 578 | help |
758cd94a JH |
579 | Enable support for the Goldfish virtual platform used primarily |
580 | for Android development. Unless you are building for the Android | |
581 | Goldfish emulator say N here. | |
ddd70cf9 | 582 | |
c751e17b TG |
583 | config X86_INTEL_CE |
584 | bool "CE4100 TV platform" | |
585 | depends on PCI | |
586 | depends on PCI_GODIRECT | |
6084a6e2 | 587 | depends on X86_IO_APIC |
c751e17b TG |
588 | depends on X86_32 |
589 | depends on X86_EXTENDED_PLATFORM | |
37bc9f50 | 590 | select X86_REBOOTFIXUPS |
da6b737b SAS |
591 | select OF |
592 | select OF_EARLY_FLATTREE | |
a7f7f624 | 593 | help |
c751e17b TG |
594 | Select for the Intel CE media processor (CE4100) SOC. |
595 | This option compiles in support for the CE4100 SOC for settop | |
596 | boxes and media devices. | |
597 | ||
4cb9b00f | 598 | config X86_INTEL_MID |
43605ef1 | 599 | bool "Intel MID platform support" |
43605ef1 | 600 | depends on X86_EXTENDED_PLATFORM |
edc6bc78 | 601 | depends on X86_PLATFORM_DEVICES |
1ea7c673 | 602 | depends on PCI |
3fda5bb4 | 603 | depends on X86_64 || (PCI_GOANY && X86_32) |
1ea7c673 | 604 | depends on X86_IO_APIC |
4cb9b00f | 605 | select I2C |
7c9c3a1e | 606 | select DW_APB_TIMER |
54b34aa0 | 607 | select INTEL_SCU_PCI |
a7f7f624 | 608 | help |
4cb9b00f DC |
609 | Select to build a kernel capable of supporting Intel MID (Mobile |
610 | Internet Device) platform systems which do not have the PCI legacy | |
611 | interfaces. If you are building for a PC class system say N here. | |
1ea7c673 | 612 | |
4cb9b00f DC |
613 | Intel MID platforms are based on an Intel processor and chipset which |
614 | consume less power than most of the x86 derivatives. | |
43605ef1 | 615 | |
8bbc2a13 BD |
616 | config X86_INTEL_QUARK |
617 | bool "Intel Quark platform support" | |
618 | depends on X86_32 | |
619 | depends on X86_EXTENDED_PLATFORM | |
620 | depends on X86_PLATFORM_DEVICES | |
621 | depends on X86_TSC | |
622 | depends on PCI | |
623 | depends on PCI_GOANY | |
624 | depends on X86_IO_APIC | |
625 | select IOSF_MBI | |
626 | select INTEL_IMR | |
9ab6eb51 | 627 | select COMMON_CLK |
a7f7f624 | 628 | help |
8bbc2a13 BD |
629 | Select to include support for Quark X1000 SoC. |
630 | Say Y here if you have a Quark based system such as the Arduino | |
631 | compatible Intel Galileo. | |
632 | ||
3d48aab1 MW |
633 | config X86_INTEL_LPSS |
634 | bool "Intel Low Power Subsystem Support" | |
5962dd22 | 635 | depends on X86 && ACPI && PCI |
3d48aab1 | 636 | select COMMON_CLK |
0f531431 | 637 | select PINCTRL |
eebb3e8d | 638 | select IOSF_MBI |
a7f7f624 | 639 | help |
3d48aab1 MW |
640 | Select to build support for Intel Low Power Subsystem such as |
641 | found on Intel Lynxpoint PCH. Selecting this option enables | |
0f531431 MN |
642 | things like clock tree (common clock framework) and pincontrol |
643 | which are needed by the LPSS peripheral drivers. | |
3d48aab1 | 644 | |
92082a88 KX |
645 | config X86_AMD_PLATFORM_DEVICE |
646 | bool "AMD ACPI2Platform devices support" | |
647 | depends on ACPI | |
648 | select COMMON_CLK | |
649 | select PINCTRL | |
a7f7f624 | 650 | help |
92082a88 KX |
651 | Select to interpret AMD specific ACPI device to platform device |
652 | such as I2C, UART, GPIO found on AMD Carrizo and later chipsets. | |
653 | I2C and UART depend on COMMON_CLK to set clock. GPIO driver is | |
654 | implemented under PINCTRL subsystem. | |
655 | ||
ced3ce76 DB |
656 | config IOSF_MBI |
657 | tristate "Intel SoC IOSF Sideband support for SoC platforms" | |
658 | depends on PCI | |
a7f7f624 | 659 | help |
ced3ce76 DB |
660 | This option enables sideband register access support for Intel SoC |
661 | platforms. On these platforms the IOSF sideband is used in lieu of | |
662 | MSR's for some register accesses, mostly but not limited to thermal | |
663 | and power. Drivers may query the availability of this device to | |
664 | determine if they need the sideband in order to work on these | |
665 | platforms. The sideband is available on the following SoC products. | |
666 | This list is not meant to be exclusive. | |
667 | - BayTrail | |
668 | - Braswell | |
669 | - Quark | |
670 | ||
671 | You should say Y if you are running a kernel on one of these SoC's. | |
672 | ||
ed2226bd DB |
673 | config IOSF_MBI_DEBUG |
674 | bool "Enable IOSF sideband access through debugfs" | |
675 | depends on IOSF_MBI && DEBUG_FS | |
a7f7f624 | 676 | help |
ed2226bd DB |
677 | Select this option to expose the IOSF sideband access registers (MCR, |
678 | MDR, MCRX) through debugfs to write and read register information from | |
679 | different units on the SoC. This is most useful for obtaining device | |
680 | state information for debug and analysis. As this is a general access | |
681 | mechanism, users of this option would have specific knowledge of the | |
682 | device they want to access. | |
683 | ||
684 | If you don't require the option or are in doubt, say N. | |
685 | ||
c5c606d9 RT |
686 | config X86_RDC321X |
687 | bool "RDC R-321x SoC" | |
506f1d07 | 688 | depends on X86_32 |
c5c606d9 RT |
689 | depends on X86_EXTENDED_PLATFORM |
690 | select M486 | |
691 | select X86_REBOOTFIXUPS | |
a7f7f624 | 692 | help |
c5c606d9 RT |
693 | This option is needed for RDC R-321x system-on-chip, also known |
694 | as R-8610-(G). | |
695 | If you don't have one of these chips, you should say N here. | |
696 | ||
e0c7ae37 | 697 | config X86_32_NON_STANDARD |
9c398017 IM |
698 | bool "Support non-standard 32-bit SMP architectures" |
699 | depends on X86_32 && SMP | |
c5c606d9 | 700 | depends on X86_EXTENDED_PLATFORM |
a7f7f624 | 701 | help |
b5660ba7 PA |
702 | This option compiles in the bigsmp and STA2X11 default |
703 | subarchitectures. It is intended for a generic binary | |
704 | kernel. If you select them all, kernel will probe it one by | |
705 | one and will fallback to default. | |
d49c4288 | 706 | |
c5c606d9 | 707 | # Alphabetically sorted list of Non standard 32 bit platforms |
d49c4288 | 708 | |
d949f36f | 709 | config X86_SUPPORTS_MEMORY_FAILURE |
6fc108a0 | 710 | def_bool y |
d949f36f LT |
711 | # MCE code calls memory_failure(): |
712 | depends on X86_MCE | |
713 | # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: | |
d949f36f LT |
714 | # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: |
715 | depends on X86_64 || !SPARSEMEM | |
716 | select ARCH_SUPPORTS_MEMORY_FAILURE | |
d949f36f | 717 | |
83125a3a AR |
718 | config STA2X11 |
719 | bool "STA2X11 Companion Chip Support" | |
720 | depends on X86_32_NON_STANDARD && PCI | |
83125a3a AR |
721 | select SWIOTLB |
722 | select MFD_STA2X11 | |
0145071b | 723 | select GPIOLIB |
a7f7f624 | 724 | help |
83125a3a AR |
725 | This adds support for boards based on the STA2X11 IO-Hub, |
726 | a.k.a. "ConneXt". The chip is used in place of the standard | |
727 | PC chipset, so all "standard" peripherals are missing. If this | |
728 | option is selected the kernel will still be able to boot on | |
729 | standard PC machines. | |
730 | ||
82148d1d S |
731 | config X86_32_IRIS |
732 | tristate "Eurobraille/Iris poweroff module" | |
733 | depends on X86_32 | |
a7f7f624 | 734 | help |
82148d1d S |
735 | The Iris machines from EuroBraille do not have APM or ACPI support |
736 | to shut themselves down properly. A special I/O sequence is | |
737 | needed to do so, which is what this module does at | |
738 | kernel shutdown. | |
739 | ||
740 | This is only for Iris machines from EuroBraille. | |
741 | ||
742 | If unused, say N. | |
743 | ||
ae1e9130 | 744 | config SCHED_OMIT_FRAME_POINTER |
3c2362e6 HH |
745 | def_bool y |
746 | prompt "Single-depth WCHAN output" | |
a87d0914 | 747 | depends on X86 |
a7f7f624 | 748 | help |
506f1d07 SR |
749 | Calculate simpler /proc/<PID>/wchan values. If this option |
750 | is disabled then wchan values will recurse back to the | |
751 | caller function. This provides more accurate wchan values, | |
752 | at the expense of slightly more scheduling overhead. | |
753 | ||
754 | If in doubt, say "Y". | |
755 | ||
6276a074 BP |
756 | menuconfig HYPERVISOR_GUEST |
757 | bool "Linux guest support" | |
a7f7f624 | 758 | help |
6276a074 BP |
759 | Say Y here to enable options for running Linux under various hyper- |
760 | visors. This option enables basic hypervisor detection and platform | |
761 | setup. | |
506f1d07 | 762 | |
6276a074 BP |
763 | If you say N, all options in this submenu will be skipped and |
764 | disabled, and Linux guest support won't be built in. | |
506f1d07 | 765 | |
6276a074 | 766 | if HYPERVISOR_GUEST |
506f1d07 | 767 | |
e61bd94a EPH |
768 | config PARAVIRT |
769 | bool "Enable paravirtualization code" | |
a0e2bf7c | 770 | depends on HAVE_STATIC_CALL |
a7f7f624 | 771 | help |
e61bd94a EPH |
772 | This changes the kernel so it can modify itself when it is run |
773 | under a hypervisor, potentially improving performance significantly | |
774 | over full virtualization. However, when run without a hypervisor | |
775 | the kernel is theoretically slower and slightly larger. | |
776 | ||
c00a280a JG |
777 | config PARAVIRT_XXL |
778 | bool | |
779 | ||
6276a074 BP |
780 | config PARAVIRT_DEBUG |
781 | bool "paravirt-ops debugging" | |
782 | depends on PARAVIRT && DEBUG_KERNEL | |
a7f7f624 | 783 | help |
6276a074 BP |
784 | Enable to debug paravirt_ops internals. Specifically, BUG if |
785 | a paravirt_op is missing when it is called. | |
786 | ||
b4ecc126 JF |
787 | config PARAVIRT_SPINLOCKS |
788 | bool "Paravirtualization layer for spinlocks" | |
6ea30386 | 789 | depends on PARAVIRT && SMP |
a7f7f624 | 790 | help |
b4ecc126 JF |
791 | Paravirtualized spinlocks allow a pvops backend to replace the |
792 | spinlock implementation with something virtualization-friendly | |
793 | (for example, block the virtual CPU rather than spinning). | |
794 | ||
4c4e4f61 R |
795 | It has a minimal impact on native kernels and gives a nice performance |
796 | benefit on paravirtualized KVM / Xen kernels. | |
b4ecc126 | 797 | |
4c4e4f61 | 798 | If you are unsure how to answer this question, answer Y. |
b4ecc126 | 799 | |
ecca2502 ZY |
800 | config X86_HV_CALLBACK_VECTOR |
801 | def_bool n | |
802 | ||
6276a074 | 803 | source "arch/x86/xen/Kconfig" |
7af192c9 | 804 | |
6276a074 BP |
805 | config KVM_GUEST |
806 | bool "KVM Guest support (including kvmclock)" | |
807 | depends on PARAVIRT | |
808 | select PARAVIRT_CLOCK | |
a1c4423b | 809 | select ARCH_CPUIDLE_HALTPOLL |
b1d40575 | 810 | select X86_HV_CALLBACK_VECTOR |
6276a074 | 811 | default y |
a7f7f624 | 812 | help |
6276a074 BP |
813 | This option enables various optimizations for running under the KVM |
814 | hypervisor. It includes a paravirtualized clock, so that instead | |
815 | of relying on a PIT (or probably other) emulation by the | |
816 | underlying device model, the host provides the guest with | |
817 | timing infrastructure such as time of day, and system time | |
506f1d07 | 818 | |
a1c4423b | 819 | config ARCH_CPUIDLE_HALTPOLL |
b03b016f KK |
820 | def_bool n |
821 | prompt "Disable host haltpoll when loading haltpoll driver" | |
822 | help | |
a1c4423b MT |
823 | If virtualized under KVM, disable host haltpoll. |
824 | ||
7733607f MW |
825 | config PVH |
826 | bool "Support for running PVH guests" | |
a7f7f624 | 827 | help |
7733607f MW |
828 | This option enables the PVH entry point for guest virtual machines |
829 | as specified in the x86/HVM direct boot ABI. | |
830 | ||
6276a074 BP |
831 | config PARAVIRT_TIME_ACCOUNTING |
832 | bool "Paravirtual steal time accounting" | |
833 | depends on PARAVIRT | |
a7f7f624 | 834 | help |
6276a074 BP |
835 | Select this option to enable fine granularity task steal time |
836 | accounting. Time spent executing other tasks in parallel with | |
837 | the current vCPU is discounted from the vCPU power. To account for | |
838 | that, there can be a small performance impact. | |
839 | ||
840 | If in doubt, say N here. | |
841 | ||
842 | config PARAVIRT_CLOCK | |
843 | bool | |
97349135 | 844 | |
4a362601 JK |
845 | config JAILHOUSE_GUEST |
846 | bool "Jailhouse non-root cell support" | |
abde587b | 847 | depends on X86_64 && PCI |
87e65d05 | 848 | select X86_PM_TIMER |
a7f7f624 | 849 | help |
4a362601 JK |
850 | This option allows to run Linux as guest in a Jailhouse non-root |
851 | cell. You can leave this option disabled if you only want to start | |
852 | Jailhouse and run Linux afterwards in the root cell. | |
853 | ||
ec7972c9 ZY |
854 | config ACRN_GUEST |
855 | bool "ACRN Guest support" | |
856 | depends on X86_64 | |
498ad393 | 857 | select X86_HV_CALLBACK_VECTOR |
ec7972c9 ZY |
858 | help |
859 | This option allows to run Linux as guest in the ACRN hypervisor. ACRN is | |
860 | a flexible, lightweight reference open-source hypervisor, built with | |
861 | real-time and safety-criticality in mind. It is built for embedded | |
862 | IOT with small footprint and real-time features. More details can be | |
863 | found in https://projectacrn.org/. | |
864 | ||
59bd54a8 KS |
865 | config INTEL_TDX_GUEST |
866 | bool "Intel TDX (Trust Domain Extensions) - Guest Support" | |
867 | depends on X86_64 && CPU_SUP_INTEL | |
868 | depends on X86_X2APIC | |
41394e33 | 869 | select ARCH_HAS_CC_PLATFORM |
968b4931 | 870 | select X86_MEM_ENCRYPT |
77a512e3 | 871 | select X86_MCE |
59bd54a8 KS |
872 | help |
873 | Support running as a guest under Intel TDX. Without this support, | |
874 | the guest kernel can not boot or run under TDX. | |
875 | TDX includes memory encryption and integrity capabilities | |
876 | which protect the confidentiality and integrity of guest | |
877 | memory contents and CPU state. TDX guests are protected from | |
878 | some attacks from the VMM. | |
879 | ||
758cd94a | 880 | endif # HYPERVISOR_GUEST |
97349135 | 881 | |
506f1d07 SR |
882 | source "arch/x86/Kconfig.cpu" |
883 | ||
884 | config HPET_TIMER | |
3c2362e6 | 885 | def_bool X86_64 |
506f1d07 | 886 | prompt "HPET Timer Support" if X86_32 |
a7f7f624 | 887 | help |
8f9ca475 IM |
888 | Use the IA-PC HPET (High Precision Event Timer) to manage |
889 | time in preference to the PIT and RTC, if a HPET is | |
890 | present. | |
891 | HPET is the next generation timer replacing legacy 8254s. | |
892 | The HPET provides a stable time base on SMP | |
893 | systems, unlike the TSC, but it is more expensive to access, | |
4e7f9df2 MT |
894 | as it is off-chip. The interface used is documented |
895 | in the HPET spec, revision 1. | |
506f1d07 | 896 | |
8f9ca475 IM |
897 | You can safely choose Y here. However, HPET will only be |
898 | activated if the platform and the BIOS support this feature. | |
899 | Otherwise the 8254 will be used for timing services. | |
506f1d07 | 900 | |
8f9ca475 | 901 | Choose N to continue using the legacy 8254 timer. |
506f1d07 SR |
902 | |
903 | config HPET_EMULATE_RTC | |
3c2362e6 | 904 | def_bool y |
3228e1dc | 905 | depends on HPET_TIMER && (RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) |
506f1d07 | 906 | |
6a108a14 | 907 | # Mark as expert because too many people got it wrong. |
506f1d07 | 908 | # The code disables itself when not needed. |
7ae9392c TP |
909 | config DMI |
910 | default y | |
cf074402 | 911 | select DMI_SCAN_MACHINE_NON_EFI_FALLBACK |
6a108a14 | 912 | bool "Enable DMI scanning" if EXPERT |
a7f7f624 | 913 | help |
7ae9392c TP |
914 | Enabled scanning of DMI to identify machine quirks. Say Y |
915 | here unless you have verified that your setup is not | |
916 | affected by entries in the DMI blacklist. Required by PNP | |
917 | BIOS code. | |
918 | ||
506f1d07 | 919 | config GART_IOMMU |
38901f1c | 920 | bool "Old AMD GART IOMMU support" |
2f9237d4 | 921 | select DMA_OPS |
a4ce5a48 | 922 | select IOMMU_HELPER |
506f1d07 | 923 | select SWIOTLB |
23ac4ae8 | 924 | depends on X86_64 && PCI && AMD_NB |
a7f7f624 | 925 | help |
ced3c42c IM |
926 | Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron |
927 | GART based hardware IOMMUs. | |
928 | ||
929 | The GART supports full DMA access for devices with 32-bit access | |
930 | limitations, on systems with more than 3 GB. This is usually needed | |
931 | for USB, sound, many IDE/SATA chipsets and some other devices. | |
932 | ||
933 | Newer systems typically have a modern AMD IOMMU, supported via | |
934 | the CONFIG_AMD_IOMMU=y config option. | |
935 | ||
936 | In normal configurations this driver is only active when needed: | |
937 | there's more than 3 GB of memory and the system contains a | |
938 | 32-bit limited device. | |
939 | ||
940 | If unsure, say Y. | |
506f1d07 | 941 | |
8b766b0f MS |
942 | config BOOT_VESA_SUPPORT |
943 | bool | |
944 | help | |
945 | If true, at least one selected framebuffer driver can take advantage | |
946 | of VESA video modes set at an early boot stage via the vga= parameter. | |
506f1d07 | 947 | |
1184dc2f | 948 | config MAXSMP |
ddb0c5a6 | 949 | bool "Enable Maximum number of SMP Processors and NUMA Nodes" |
6ea30386 | 950 | depends on X86_64 && SMP && DEBUG_KERNEL |
36f5101a | 951 | select CPUMASK_OFFSTACK |
a7f7f624 | 952 | help |
ddb0c5a6 | 953 | Enable maximum number of CPUS and NUMA Nodes for this architecture. |
1184dc2f | 954 | If unsure, say N. |
506f1d07 | 955 | |
aec6487e IM |
956 | # |
957 | # The maximum number of CPUs supported: | |
958 | # | |
959 | # The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT, | |
960 | # and which can be configured interactively in the | |
961 | # [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range. | |
962 | # | |
963 | # The ranges are different on 32-bit and 64-bit kernels, depending on | |
964 | # hardware capabilities and scalability features of the kernel. | |
965 | # | |
966 | # ( If MAXSMP is enabled we just use the highest possible value and disable | |
967 | # interactive configuration. ) | |
968 | # | |
969 | ||
970 | config NR_CPUS_RANGE_BEGIN | |
a0d0bb4d | 971 | int |
aec6487e IM |
972 | default NR_CPUS_RANGE_END if MAXSMP |
973 | default 1 if !SMP | |
974 | default 2 | |
a0d0bb4d | 975 | |
aec6487e | 976 | config NR_CPUS_RANGE_END |
a0d0bb4d | 977 | int |
aec6487e IM |
978 | depends on X86_32 |
979 | default 64 if SMP && X86_BIGSMP | |
980 | default 8 if SMP && !X86_BIGSMP | |
981 | default 1 if !SMP | |
a0d0bb4d | 982 | |
aec6487e | 983 | config NR_CPUS_RANGE_END |
a0d0bb4d | 984 | int |
aec6487e | 985 | depends on X86_64 |
1edae1ae SW |
986 | default 8192 if SMP && CPUMASK_OFFSTACK |
987 | default 512 if SMP && !CPUMASK_OFFSTACK | |
aec6487e | 988 | default 1 if !SMP |
a0d0bb4d | 989 | |
aec6487e | 990 | config NR_CPUS_DEFAULT |
a0d0bb4d RD |
991 | int |
992 | depends on X86_32 | |
aec6487e IM |
993 | default 32 if X86_BIGSMP |
994 | default 8 if SMP | |
995 | default 1 if !SMP | |
a0d0bb4d | 996 | |
aec6487e | 997 | config NR_CPUS_DEFAULT |
a0d0bb4d RD |
998 | int |
999 | depends on X86_64 | |
aec6487e IM |
1000 | default 8192 if MAXSMP |
1001 | default 64 if SMP | |
1002 | default 1 if !SMP | |
a0d0bb4d | 1003 | |
506f1d07 | 1004 | config NR_CPUS |
36f5101a | 1005 | int "Maximum number of CPUs" if SMP && !MAXSMP |
aec6487e IM |
1006 | range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END |
1007 | default NR_CPUS_DEFAULT | |
a7f7f624 | 1008 | help |
506f1d07 | 1009 | This allows you to specify the maximum number of CPUs which this |
bb61ccc7 | 1010 | kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum |
cad14bb9 | 1011 | supported value is 8192, otherwise the maximum value is 512. The |
506f1d07 SR |
1012 | minimum value which makes sense is 2. |
1013 | ||
aec6487e IM |
1014 | This is purely to save memory: each supported CPU adds about 8KB |
1015 | to the kernel image. | |
506f1d07 | 1016 | |
66558b73 TC |
1017 | config SCHED_CLUSTER |
1018 | bool "Cluster scheduler support" | |
1019 | depends on SMP | |
1020 | default y | |
1021 | help | |
1022 | Cluster scheduler support improves the CPU scheduler's decision | |
1023 | making when dealing with machines that have clusters of CPUs. | |
1024 | Cluster usually means a couple of CPUs which are placed closely | |
1025 | by sharing mid-level caches, last-level cache tags or internal | |
1026 | busses. | |
1027 | ||
506f1d07 | 1028 | config SCHED_SMT |
dbe73364 | 1029 | def_bool y if SMP |
506f1d07 SR |
1030 | |
1031 | config SCHED_MC | |
3c2362e6 HH |
1032 | def_bool y |
1033 | prompt "Multi-core scheduler support" | |
c8e56d20 | 1034 | depends on SMP |
a7f7f624 | 1035 | help |
506f1d07 SR |
1036 | Multi-core scheduler support improves the CPU scheduler's decision |
1037 | making when dealing with multi-core CPU chips at a cost of slightly | |
1038 | increased overhead in some places. If unsure say N here. | |
1039 | ||
de966cf4 TC |
1040 | config SCHED_MC_PRIO |
1041 | bool "CPU core priorities scheduler support" | |
0a21fc12 IM |
1042 | depends on SCHED_MC && CPU_SUP_INTEL |
1043 | select X86_INTEL_PSTATE | |
1044 | select CPU_FREQ | |
de966cf4 | 1045 | default y |
a7f7f624 | 1046 | help |
0a21fc12 IM |
1047 | Intel Turbo Boost Max Technology 3.0 enabled CPUs have a |
1048 | core ordering determined at manufacturing time, which allows | |
1049 | certain cores to reach higher turbo frequencies (when running | |
1050 | single threaded workloads) than others. | |
de966cf4 | 1051 | |
0a21fc12 IM |
1052 | Enabling this kernel feature teaches the scheduler about |
1053 | the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the | |
1054 | scheduler's CPU selection logic accordingly, so that higher | |
1055 | overall system performance can be achieved. | |
de966cf4 | 1056 | |
0a21fc12 | 1057 | This feature will have no effect on CPUs without this feature. |
de966cf4 | 1058 | |
0a21fc12 | 1059 | If unsure say Y here. |
5e76b2ab | 1060 | |
30b8b006 | 1061 | config UP_LATE_INIT |
b03b016f KK |
1062 | def_bool y |
1063 | depends on !SMP && X86_LOCAL_APIC | |
30b8b006 | 1064 | |
506f1d07 | 1065 | config X86_UP_APIC |
50849eef JB |
1066 | bool "Local APIC support on uniprocessors" if !PCI_MSI |
1067 | default PCI_MSI | |
38a1dfda | 1068 | depends on X86_32 && !SMP && !X86_32_NON_STANDARD |
a7f7f624 | 1069 | help |
506f1d07 SR |
1070 | A local APIC (Advanced Programmable Interrupt Controller) is an |
1071 | integrated interrupt controller in the CPU. If you have a single-CPU | |
1072 | system which has a processor with a local APIC, you can say Y here to | |
1073 | enable and use it. If you say Y here even though your machine doesn't | |
1074 | have a local APIC, then the kernel will still run with no slowdown at | |
1075 | all. The local APIC supports CPU-generated self-interrupts (timer, | |
1076 | performance counters), and the NMI watchdog which detects hard | |
1077 | lockups. | |
1078 | ||
1079 | config X86_UP_IOAPIC | |
1080 | bool "IO-APIC support on uniprocessors" | |
1081 | depends on X86_UP_APIC | |
a7f7f624 | 1082 | help |
506f1d07 SR |
1083 | An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an |
1084 | SMP-capable replacement for PC-style interrupt controllers. Most | |
1085 | SMP systems and many recent uniprocessor systems have one. | |
1086 | ||
1087 | If you have a single-CPU system with an IO-APIC, you can say Y here | |
1088 | to use it. If you say Y here even though your machine doesn't have | |
1089 | an IO-APIC, then the kernel will still run with no slowdown at all. | |
1090 | ||
1091 | config X86_LOCAL_APIC | |
3c2362e6 | 1092 | def_bool y |
0dbc6078 | 1093 | depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI |
b5dc8e6c | 1094 | select IRQ_DOMAIN_HIERARCHY |
52f518a3 | 1095 | select PCI_MSI_IRQ_DOMAIN if PCI_MSI |
506f1d07 SR |
1096 | |
1097 | config X86_IO_APIC | |
b1da1e71 JB |
1098 | def_bool y |
1099 | depends on X86_LOCAL_APIC || X86_UP_IOAPIC | |
506f1d07 | 1100 | |
41b9eb26 SA |
1101 | config X86_REROUTE_FOR_BROKEN_BOOT_IRQS |
1102 | bool "Reroute for broken boot IRQs" | |
41b9eb26 | 1103 | depends on X86_IO_APIC |
a7f7f624 | 1104 | help |
41b9eb26 SA |
1105 | This option enables a workaround that fixes a source of |
1106 | spurious interrupts. This is recommended when threaded | |
1107 | interrupt handling is used on systems where the generation of | |
1108 | superfluous "boot interrupts" cannot be disabled. | |
1109 | ||
1110 | Some chipsets generate a legacy INTx "boot IRQ" when the IRQ | |
1111 | entry in the chipset's IO-APIC is masked (as, e.g. the RT | |
1112 | kernel does during interrupt handling). On chipsets where this | |
1113 | boot IRQ generation cannot be disabled, this workaround keeps | |
1114 | the original IRQ line masked so that only the equivalent "boot | |
1115 | IRQ" is delivered to the CPUs. The workaround also tells the | |
1116 | kernel to set up the IRQ handler on the boot IRQ line. In this | |
1117 | way only one interrupt is delivered to the kernel. Otherwise | |
1118 | the spurious second interrupt may cause the kernel to bring | |
1119 | down (vital) interrupt lines. | |
1120 | ||
1121 | Only affects "broken" chipsets. Interrupt sharing may be | |
1122 | increased on these systems. | |
1123 | ||
506f1d07 | 1124 | config X86_MCE |
bab9bc65 | 1125 | bool "Machine Check / overheating reporting" |
648ed940 | 1126 | select GENERIC_ALLOCATOR |
e57dbaf7 | 1127 | default y |
a7f7f624 | 1128 | help |
bab9bc65 AK |
1129 | Machine Check support allows the processor to notify the |
1130 | kernel if it detects a problem (e.g. overheating, data corruption). | |
506f1d07 | 1131 | The action the kernel takes depends on the severity of the problem, |
bab9bc65 | 1132 | ranging from warning messages to halting the machine. |
4efc0670 | 1133 | |
5de97c9f TL |
1134 | config X86_MCELOG_LEGACY |
1135 | bool "Support for deprecated /dev/mcelog character device" | |
1136 | depends on X86_MCE | |
a7f7f624 | 1137 | help |
5de97c9f TL |
1138 | Enable support for /dev/mcelog which is needed by the old mcelog |
1139 | userspace logging daemon. Consider switching to the new generation | |
1140 | rasdaemon solution. | |
1141 | ||
506f1d07 | 1142 | config X86_MCE_INTEL |
3c2362e6 HH |
1143 | def_bool y |
1144 | prompt "Intel MCE features" | |
c1ebf835 | 1145 | depends on X86_MCE && X86_LOCAL_APIC |
a7f7f624 | 1146 | help |
758cd94a JH |
1147 | Additional support for intel specific MCE features such as |
1148 | the thermal monitor. | |
506f1d07 SR |
1149 | |
1150 | config X86_MCE_AMD | |
3c2362e6 HH |
1151 | def_bool y |
1152 | prompt "AMD MCE features" | |
f5382de9 | 1153 | depends on X86_MCE && X86_LOCAL_APIC && AMD_NB |
a7f7f624 | 1154 | help |
758cd94a JH |
1155 | Additional support for AMD specific MCE features such as |
1156 | the DRAM Error Threshold. | |
506f1d07 | 1157 | |
4efc0670 | 1158 | config X86_ANCIENT_MCE |
6fc108a0 | 1159 | bool "Support for old Pentium 5 / WinChip machine checks" |
c31d9633 | 1160 | depends on X86_32 && X86_MCE |
a7f7f624 | 1161 | help |
cd13adcc | 1162 | Include support for machine check handling on old Pentium 5 or WinChip |
5065a706 | 1163 | systems. These typically need to be enabled explicitly on the command |
cd13adcc | 1164 | line. |
4efc0670 | 1165 | |
b2762686 AK |
1166 | config X86_MCE_THRESHOLD |
1167 | depends on X86_MCE_AMD || X86_MCE_INTEL | |
6fc108a0 | 1168 | def_bool y |
b2762686 | 1169 | |
ea149b36 | 1170 | config X86_MCE_INJECT |
bc8e80d5 | 1171 | depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS |
ea149b36 | 1172 | tristate "Machine check injector support" |
a7f7f624 | 1173 | help |
ea149b36 AK |
1174 | Provide support for injecting machine checks for testing purposes. |
1175 | If you don't know what a machine check is and you don't do kernel | |
1176 | QA it is safe to say n. | |
1177 | ||
07dc900e | 1178 | source "arch/x86/events/Kconfig" |
e633c65a | 1179 | |
5aef51c3 | 1180 | config X86_LEGACY_VM86 |
1e642812 | 1181 | bool "Legacy VM86 support" |
506f1d07 | 1182 | depends on X86_32 |
a7f7f624 | 1183 | help |
5aef51c3 AL |
1184 | This option allows user programs to put the CPU into V8086 |
1185 | mode, which is an 80286-era approximation of 16-bit real mode. | |
1186 | ||
1187 | Some very old versions of X and/or vbetool require this option | |
1188 | for user mode setting. Similarly, DOSEMU will use it if | |
1189 | available to accelerate real mode DOS programs. However, any | |
1190 | recent version of DOSEMU, X, or vbetool should be fully | |
1191 | functional even without kernel VM86 support, as they will all | |
1e642812 IM |
1192 | fall back to software emulation. Nevertheless, if you are using |
1193 | a 16-bit DOS program where 16-bit performance matters, vm86 | |
1194 | mode might be faster than emulation and you might want to | |
1195 | enable this option. | |
5aef51c3 | 1196 | |
1e642812 IM |
1197 | Note that any app that works on a 64-bit kernel is unlikely to |
1198 | need this option, as 64-bit kernels don't, and can't, support | |
1199 | V8086 mode. This option is also unrelated to 16-bit protected | |
1200 | mode and is not needed to run most 16-bit programs under Wine. | |
5aef51c3 | 1201 | |
1e642812 IM |
1202 | Enabling this option increases the complexity of the kernel |
1203 | and slows down exception handling a tiny bit. | |
5aef51c3 | 1204 | |
1e642812 | 1205 | If unsure, say N here. |
5aef51c3 AL |
1206 | |
1207 | config VM86 | |
b03b016f KK |
1208 | bool |
1209 | default X86_LEGACY_VM86 | |
34273f41 PA |
1210 | |
1211 | config X86_16BIT | |
1212 | bool "Enable support for 16-bit segments" if EXPERT | |
1213 | default y | |
a5b9e5a2 | 1214 | depends on MODIFY_LDT_SYSCALL |
a7f7f624 | 1215 | help |
34273f41 PA |
1216 | This option is required by programs like Wine to run 16-bit |
1217 | protected mode legacy code on x86 processors. Disabling | |
1218 | this option saves about 300 bytes on i386, or around 6K text | |
1219 | plus 16K runtime memory on x86-64, | |
1220 | ||
1221 | config X86_ESPFIX32 | |
1222 | def_bool y | |
1223 | depends on X86_16BIT && X86_32 | |
506f1d07 | 1224 | |
197725de PA |
1225 | config X86_ESPFIX64 |
1226 | def_bool y | |
34273f41 | 1227 | depends on X86_16BIT && X86_64 |
506f1d07 | 1228 | |
1ad83c85 | 1229 | config X86_VSYSCALL_EMULATION |
b03b016f KK |
1230 | bool "Enable vsyscall emulation" if EXPERT |
1231 | default y | |
1232 | depends on X86_64 | |
a7f7f624 | 1233 | help |
758cd94a JH |
1234 | This enables emulation of the legacy vsyscall page. Disabling |
1235 | it is roughly equivalent to booting with vsyscall=none, except | |
1236 | that it will also disable the helpful warning if a program | |
1237 | tries to use a vsyscall. With this option set to N, offending | |
1238 | programs will just segfault, citing addresses of the form | |
1239 | 0xffffffffff600?00. | |
1ad83c85 | 1240 | |
758cd94a JH |
1241 | This option is required by many programs built before 2013, and |
1242 | care should be used even with newer programs if set to N. | |
1ad83c85 | 1243 | |
758cd94a JH |
1244 | Disabling this option saves about 7K of kernel size and |
1245 | possibly 4K of additional runtime pagetable memory. | |
1ad83c85 | 1246 | |
111e7b15 TG |
1247 | config X86_IOPL_IOPERM |
1248 | bool "IOPERM and IOPL Emulation" | |
a24ca997 | 1249 | default y |
a7f7f624 | 1250 | help |
111e7b15 TG |
1251 | This enables the ioperm() and iopl() syscalls which are necessary |
1252 | for legacy applications. | |
1253 | ||
c8137ace TG |
1254 | Legacy IOPL support is an overbroad mechanism which allows user |
1255 | space aside of accessing all 65536 I/O ports also to disable | |
1256 | interrupts. To gain this access the caller needs CAP_SYS_RAWIO | |
1257 | capabilities and permission from potentially active security | |
1258 | modules. | |
1259 | ||
1260 | The emulation restricts the functionality of the syscall to | |
1261 | only allowing the full range I/O port access, but prevents the | |
a24ca997 TG |
1262 | ability to disable interrupts from user space which would be |
1263 | granted if the hardware IOPL mechanism would be used. | |
c8137ace | 1264 | |
506f1d07 SR |
1265 | config TOSHIBA |
1266 | tristate "Toshiba Laptop support" | |
1267 | depends on X86_32 | |
a7f7f624 | 1268 | help |
506f1d07 SR |
1269 | This adds a driver to safely access the System Management Mode of |
1270 | the CPU on Toshiba portables with a genuine Toshiba BIOS. It does | |
1271 | not work on models with a Phoenix BIOS. The System Management Mode | |
1272 | is used to set the BIOS and power saving options on Toshiba portables. | |
1273 | ||
1274 | For information on utilities to make use of this driver see the | |
1275 | Toshiba Linux utilities web site at: | |
1276 | <http://www.buzzard.org.uk/toshiba/>. | |
1277 | ||
1278 | Say Y if you intend to run this kernel on a Toshiba portable. | |
1279 | Say N otherwise. | |
1280 | ||
506f1d07 | 1281 | config X86_REBOOTFIXUPS |
9ba16087 JB |
1282 | bool "Enable X86 board specific fixups for reboot" |
1283 | depends on X86_32 | |
a7f7f624 | 1284 | help |
506f1d07 SR |
1285 | This enables chipset and/or board specific fixups to be done |
1286 | in order to get reboot to work correctly. This is only needed on | |
1287 | some combinations of hardware and BIOS. The symptom, for which | |
1288 | this config is intended, is when reboot ends with a stalled/hung | |
1289 | system. | |
1290 | ||
1291 | Currently, the only fixup is for the Geode machines using | |
5e3a77e9 | 1292 | CS5530A and CS5536 chipsets and the RDC R-321x SoC. |
506f1d07 SR |
1293 | |
1294 | Say Y if you want to enable the fixup. Currently, it's safe to | |
1295 | enable this option even if you don't need it. | |
1296 | Say N otherwise. | |
1297 | ||
1298 | config MICROCODE | |
9a2bc335 BP |
1299 | bool "CPU microcode loading support" |
1300 | default y | |
80030e3d | 1301 | depends on CPU_SUP_AMD || CPU_SUP_INTEL |
a7f7f624 | 1302 | help |
506f1d07 | 1303 | If you say Y here, you will be able to update the microcode on |
5f9c01aa BP |
1304 | Intel and AMD processors. The Intel support is for the IA32 family, |
1305 | e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The | |
1306 | AMD support is for families 0x10 and later. You will obviously need | |
1307 | the actual microcode binary data itself which is not shipped with | |
1308 | the Linux kernel. | |
1309 | ||
1310 | The preferred method to load microcode from a detached initrd is described | |
cb1aaebe | 1311 | in Documentation/x86/microcode.rst. For that you need to enable |
5f9c01aa BP |
1312 | CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the |
1313 | initrd for microcode blobs. | |
1314 | ||
c508c46e BG |
1315 | In addition, you can build the microcode into the kernel. For that you |
1316 | need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE | |
1317 | config option. | |
506f1d07 | 1318 | |
8d86f390 | 1319 | config MICROCODE_INTEL |
e43f6e67 | 1320 | bool "Intel microcode loading support" |
9c55d99e | 1321 | depends on CPU_SUP_INTEL && MICROCODE |
8f9ca475 | 1322 | default MICROCODE |
a7f7f624 | 1323 | help |
8f9ca475 IM |
1324 | This options enables microcode patch loading support for Intel |
1325 | processors. | |
1326 | ||
b8989db9 A |
1327 | For the current Intel microcode data package go to |
1328 | <https://downloadcenter.intel.com> and search for | |
1329 | 'Linux Processor Microcode Data File'. | |
8d86f390 | 1330 | |
80cc9f10 | 1331 | config MICROCODE_AMD |
e43f6e67 | 1332 | bool "AMD microcode loading support" |
9c55d99e | 1333 | depends on CPU_SUP_AMD && MICROCODE |
a7f7f624 | 1334 | help |
8f9ca475 IM |
1335 | If you select this option, microcode patch loading support for AMD |
1336 | processors will be enabled. | |
80cc9f10 | 1337 | |
a77a94f8 BP |
1338 | config MICROCODE_LATE_LOADING |
1339 | bool "Late microcode loading (DANGEROUS)" | |
c02f48e0 | 1340 | default n |
506f1d07 | 1341 | depends on MICROCODE |
a7f7f624 | 1342 | help |
a77a94f8 BP |
1343 | Loading microcode late, when the system is up and executing instructions |
1344 | is a tricky business and should be avoided if possible. Just the sequence | |
1345 | of synchronizing all cores and SMT threads is one fragile dance which does | |
1346 | not guarantee that cores might not softlock after the loading. Therefore, | |
1347 | use this at your own risk. Late loading taints the kernel too. | |
506f1d07 SR |
1348 | |
1349 | config X86_MSR | |
1350 | tristate "/dev/cpu/*/msr - Model-specific register support" | |
a7f7f624 | 1351 | help |
506f1d07 SR |
1352 | This device gives privileged processes access to the x86 |
1353 | Model-Specific Registers (MSRs). It is a character device with | |
1354 | major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. | |
1355 | MSR accesses are directed to a specific CPU on multi-processor | |
1356 | systems. | |
1357 | ||
1358 | config X86_CPUID | |
1359 | tristate "/dev/cpu/*/cpuid - CPU information support" | |
a7f7f624 | 1360 | help |
506f1d07 SR |
1361 | This device gives processes access to the x86 CPUID instruction to |
1362 | be executed on a specific processor. It is a character device | |
1363 | with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to | |
1364 | /dev/cpu/31/cpuid. | |
1365 | ||
1366 | choice | |
1367 | prompt "High Memory Support" | |
6fc108a0 | 1368 | default HIGHMEM4G |
506f1d07 SR |
1369 | depends on X86_32 |
1370 | ||
1371 | config NOHIGHMEM | |
1372 | bool "off" | |
a7f7f624 | 1373 | help |
506f1d07 SR |
1374 | Linux can use up to 64 Gigabytes of physical memory on x86 systems. |
1375 | However, the address space of 32-bit x86 processors is only 4 | |
1376 | Gigabytes large. That means that, if you have a large amount of | |
1377 | physical memory, not all of it can be "permanently mapped" by the | |
1378 | kernel. The physical memory that's not permanently mapped is called | |
1379 | "high memory". | |
1380 | ||
1381 | If you are compiling a kernel which will never run on a machine with | |
1382 | more than 1 Gigabyte total physical RAM, answer "off" here (default | |
1383 | choice and suitable for most users). This will result in a "3GB/1GB" | |
1384 | split: 3GB are mapped so that each process sees a 3GB virtual memory | |
1385 | space and the remaining part of the 4GB virtual memory space is used | |
1386 | by the kernel to permanently map as much physical memory as | |
1387 | possible. | |
1388 | ||
1389 | If the machine has between 1 and 4 Gigabytes physical RAM, then | |
1390 | answer "4GB" here. | |
1391 | ||
1392 | If more than 4 Gigabytes is used then answer "64GB" here. This | |
1393 | selection turns Intel PAE (Physical Address Extension) mode on. | |
1394 | PAE implements 3-level paging on IA32 processors. PAE is fully | |
1395 | supported by Linux, PAE mode is implemented on all recent Intel | |
1396 | processors (Pentium Pro and better). NOTE: If you say "64GB" here, | |
1397 | then the kernel will not boot on CPUs that don't support PAE! | |
1398 | ||
1399 | The actual amount of total physical memory will either be | |
1400 | auto detected or can be forced by using a kernel command line option | |
1401 | such as "mem=256M". (Try "man bootparam" or see the documentation of | |
1402 | your boot loader (lilo or loadlin) about how to pass options to the | |
1403 | kernel at boot time.) | |
1404 | ||
1405 | If unsure, say "off". | |
1406 | ||
1407 | config HIGHMEM4G | |
1408 | bool "4GB" | |
a7f7f624 | 1409 | help |
506f1d07 SR |
1410 | Select this if you have a 32-bit processor and between 1 and 4 |
1411 | gigabytes of physical RAM. | |
1412 | ||
1413 | config HIGHMEM64G | |
1414 | bool "64GB" | |
225bac2d | 1415 | depends on !M486SX && !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !MWINCHIP3D && !MK6 |
506f1d07 | 1416 | select X86_PAE |
a7f7f624 | 1417 | help |
506f1d07 SR |
1418 | Select this if you have a 32-bit processor and more than 4 |
1419 | gigabytes of physical RAM. | |
1420 | ||
1421 | endchoice | |
1422 | ||
1423 | choice | |
6a108a14 | 1424 | prompt "Memory split" if EXPERT |
506f1d07 SR |
1425 | default VMSPLIT_3G |
1426 | depends on X86_32 | |
a7f7f624 | 1427 | help |
506f1d07 SR |
1428 | Select the desired split between kernel and user memory. |
1429 | ||
1430 | If the address range available to the kernel is less than the | |
1431 | physical memory installed, the remaining memory will be available | |
1432 | as "high memory". Accessing high memory is a little more costly | |
1433 | than low memory, as it needs to be mapped into the kernel first. | |
1434 | Note that increasing the kernel address space limits the range | |
1435 | available to user programs, making the address space there | |
1436 | tighter. Selecting anything other than the default 3G/1G split | |
1437 | will also likely make your kernel incompatible with binary-only | |
1438 | kernel modules. | |
1439 | ||
1440 | If you are not absolutely sure what you are doing, leave this | |
1441 | option alone! | |
1442 | ||
1443 | config VMSPLIT_3G | |
1444 | bool "3G/1G user/kernel split" | |
1445 | config VMSPLIT_3G_OPT | |
1446 | depends on !X86_PAE | |
1447 | bool "3G/1G user/kernel split (for full 1G low memory)" | |
1448 | config VMSPLIT_2G | |
1449 | bool "2G/2G user/kernel split" | |
1450 | config VMSPLIT_2G_OPT | |
1451 | depends on !X86_PAE | |
1452 | bool "2G/2G user/kernel split (for full 2G low memory)" | |
1453 | config VMSPLIT_1G | |
1454 | bool "1G/3G user/kernel split" | |
1455 | endchoice | |
1456 | ||
1457 | config PAGE_OFFSET | |
1458 | hex | |
1459 | default 0xB0000000 if VMSPLIT_3G_OPT | |
1460 | default 0x80000000 if VMSPLIT_2G | |
1461 | default 0x78000000 if VMSPLIT_2G_OPT | |
1462 | default 0x40000000 if VMSPLIT_1G | |
1463 | default 0xC0000000 | |
1464 | depends on X86_32 | |
1465 | ||
1466 | config HIGHMEM | |
3c2362e6 | 1467 | def_bool y |
506f1d07 | 1468 | depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) |
506f1d07 SR |
1469 | |
1470 | config X86_PAE | |
9ba16087 | 1471 | bool "PAE (Physical Address Extension) Support" |
506f1d07 | 1472 | depends on X86_32 && !HIGHMEM4G |
d4a451d5 | 1473 | select PHYS_ADDR_T_64BIT |
9d99c712 | 1474 | select SWIOTLB |
a7f7f624 | 1475 | help |
506f1d07 SR |
1476 | PAE is required for NX support, and furthermore enables |
1477 | larger swapspace support for non-overcommit purposes. It | |
1478 | has the cost of more pagetable lookup overhead, and also | |
1479 | consumes more pagetable space per process. | |
1480 | ||
77ef56e4 KS |
1481 | config X86_5LEVEL |
1482 | bool "Enable 5-level page tables support" | |
18ec1eaf | 1483 | default y |
eedb92ab | 1484 | select DYNAMIC_MEMORY_LAYOUT |
162434e7 | 1485 | select SPARSEMEM_VMEMMAP |
77ef56e4 | 1486 | depends on X86_64 |
a7f7f624 | 1487 | help |
77ef56e4 KS |
1488 | 5-level paging enables access to larger address space: |
1489 | upto 128 PiB of virtual address space and 4 PiB of | |
1490 | physical address space. | |
1491 | ||
1492 | It will be supported by future Intel CPUs. | |
1493 | ||
6657fca0 KS |
1494 | A kernel with the option enabled can be booted on machines that |
1495 | support 4- or 5-level paging. | |
77ef56e4 | 1496 | |
cb1aaebe | 1497 | See Documentation/x86/x86_64/5level-paging.rst for more |
77ef56e4 KS |
1498 | information. |
1499 | ||
1500 | Say N if unsure. | |
1501 | ||
10971ab2 | 1502 | config X86_DIRECT_GBPAGES |
e5008abe | 1503 | def_bool y |
2e1da13f | 1504 | depends on X86_64 |
a7f7f624 | 1505 | help |
10971ab2 IM |
1506 | Certain kernel features effectively disable kernel |
1507 | linear 1 GB mappings (even if the CPU otherwise | |
1508 | supports them), so don't confuse the user by printing | |
1509 | that we have them enabled. | |
9e899816 | 1510 | |
5c280cf6 TG |
1511 | config X86_CPA_STATISTICS |
1512 | bool "Enable statistic for Change Page Attribute" | |
1513 | depends on DEBUG_FS | |
a7f7f624 | 1514 | help |
b75baaf3 | 1515 | Expose statistics about the Change Page Attribute mechanism, which |
a943245a | 1516 | helps to determine the effectiveness of preserving large and huge |
5c280cf6 TG |
1517 | page mappings when mapping protections are changed. |
1518 | ||
20f07a04 KS |
1519 | config X86_MEM_ENCRYPT |
1520 | select ARCH_HAS_FORCE_DMA_UNENCRYPTED | |
1521 | select DYNAMIC_PHYSICAL_MASK | |
20f07a04 KS |
1522 | def_bool n |
1523 | ||
7744ccdb TL |
1524 | config AMD_MEM_ENCRYPT |
1525 | bool "AMD Secure Memory Encryption (SME) support" | |
1526 | depends on X86_64 && CPU_SUP_AMD | |
82fef0ad | 1527 | select DMA_COHERENT_POOL |
ce9084ba | 1528 | select ARCH_USE_MEMREMAP_PROT |
597cfe48 | 1529 | select INSTRUCTION_DECODER |
aa5a4611 | 1530 | select ARCH_HAS_CC_PLATFORM |
20f07a04 | 1531 | select X86_MEM_ENCRYPT |
a7f7f624 | 1532 | help |
7744ccdb TL |
1533 | Say yes to enable support for the encryption of system memory. |
1534 | This requires an AMD processor that supports Secure Memory | |
1535 | Encryption (SME). | |
1536 | ||
1537 | config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT | |
1538 | bool "Activate AMD Secure Memory Encryption (SME) by default" | |
7744ccdb | 1539 | depends on AMD_MEM_ENCRYPT |
a7f7f624 | 1540 | help |
7744ccdb TL |
1541 | Say yes to have system memory encrypted by default if running on |
1542 | an AMD processor that supports Secure Memory Encryption (SME). | |
1543 | ||
1544 | If set to Y, then the encryption of system memory can be | |
1545 | deactivated with the mem_encrypt=off command line option. | |
1546 | ||
1547 | If set to N, then the encryption of system memory can be | |
1548 | activated with the mem_encrypt=on command line option. | |
1549 | ||
506f1d07 SR |
1550 | # Common NUMA Features |
1551 | config NUMA | |
e133f6ea | 1552 | bool "NUMA Memory Allocation and Scheduler Support" |
506f1d07 | 1553 | depends on SMP |
b5660ba7 PA |
1554 | depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP) |
1555 | default y if X86_BIGSMP | |
7ecd19cf | 1556 | select USE_PERCPU_NUMA_NODE_ID |
a7f7f624 | 1557 | help |
e133f6ea | 1558 | Enable NUMA (Non-Uniform Memory Access) support. |
fd51b2d7 | 1559 | |
506f1d07 SR |
1560 | The kernel will try to allocate memory used by a CPU on the |
1561 | local memory controller of the CPU and add some more | |
1562 | NUMA awareness to the kernel. | |
1563 | ||
c280ea5e | 1564 | For 64-bit this is recommended if the system is Intel Core i7 |
fd51b2d7 KM |
1565 | (or later), AMD Opteron, or EM64T NUMA. |
1566 | ||
b5660ba7 | 1567 | For 32-bit this is only needed if you boot a 32-bit |
7cf6c945 | 1568 | kernel on a 64-bit NUMA platform. |
fd51b2d7 KM |
1569 | |
1570 | Otherwise, you should say N. | |
506f1d07 | 1571 | |
eec1d4fa | 1572 | config AMD_NUMA |
3c2362e6 HH |
1573 | def_bool y |
1574 | prompt "Old style AMD Opteron NUMA detection" | |
5da0ef9a | 1575 | depends on X86_64 && NUMA && PCI |
a7f7f624 | 1576 | help |
eec1d4fa HR |
1577 | Enable AMD NUMA node topology detection. You should say Y here if |
1578 | you have a multi processor AMD system. This uses an old method to | |
1579 | read the NUMA configuration directly from the builtin Northbridge | |
1580 | of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, | |
1581 | which also takes priority if both are compiled in. | |
506f1d07 SR |
1582 | |
1583 | config X86_64_ACPI_NUMA | |
3c2362e6 HH |
1584 | def_bool y |
1585 | prompt "ACPI NUMA detection" | |
506f1d07 SR |
1586 | depends on X86_64 && NUMA && ACPI && PCI |
1587 | select ACPI_NUMA | |
a7f7f624 | 1588 | help |
506f1d07 SR |
1589 | Enable ACPI SRAT based node topology detection. |
1590 | ||
1591 | config NUMA_EMU | |
1592 | bool "NUMA emulation" | |
1b7e03ef | 1593 | depends on NUMA |
a7f7f624 | 1594 | help |
506f1d07 SR |
1595 | Enable NUMA emulation. A flat machine will be split |
1596 | into virtual nodes when booted with "numa=fake=N", where N is the | |
1597 | number of nodes. This is only useful for debugging. | |
1598 | ||
1599 | config NODES_SHIFT | |
d25e26b6 | 1600 | int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP |
51591e31 DR |
1601 | range 1 10 |
1602 | default "10" if MAXSMP | |
506f1d07 | 1603 | default "6" if X86_64 |
506f1d07 | 1604 | default "3" |
a9ee6cf5 | 1605 | depends on NUMA |
a7f7f624 | 1606 | help |
1184dc2f | 1607 | Specify the maximum number of NUMA Nodes available on the target |
692105b8 | 1608 | system. Increases memory reserved to accommodate various tables. |
506f1d07 | 1609 | |
506f1d07 SR |
1610 | config ARCH_FLATMEM_ENABLE |
1611 | def_bool y | |
3b16651f | 1612 | depends on X86_32 && !NUMA |
506f1d07 | 1613 | |
506f1d07 SR |
1614 | config ARCH_SPARSEMEM_ENABLE |
1615 | def_bool y | |
6ea30386 | 1616 | depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD |
506f1d07 SR |
1617 | select SPARSEMEM_STATIC if X86_32 |
1618 | select SPARSEMEM_VMEMMAP_ENABLE if X86_64 | |
1619 | ||
3b16651f | 1620 | config ARCH_SPARSEMEM_DEFAULT |
6ad57f7f | 1621 | def_bool X86_64 || (NUMA && X86_32) |
3b16651f | 1622 | |
506f1d07 SR |
1623 | config ARCH_SELECT_MEMORY_MODEL |
1624 | def_bool y | |
4eda2bc3 | 1625 | depends on ARCH_SPARSEMEM_ENABLE && ARCH_FLATMEM_ENABLE |
506f1d07 SR |
1626 | |
1627 | config ARCH_MEMORY_PROBE | |
a0842b70 | 1628 | bool "Enable sysfs memory/probe interface" |
5c11f00b | 1629 | depends on MEMORY_HOTPLUG |
a0842b70 TK |
1630 | help |
1631 | This option enables a sysfs memory/probe interface for testing. | |
cb1aaebe | 1632 | See Documentation/admin-guide/mm/memory-hotplug.rst for more information. |
a0842b70 | 1633 | If you are unsure how to answer this question, answer N. |
506f1d07 | 1634 | |
3b16651f TH |
1635 | config ARCH_PROC_KCORE_TEXT |
1636 | def_bool y | |
1637 | depends on X86_64 && PROC_KCORE | |
1638 | ||
a29815a3 | 1639 | config ILLEGAL_POINTER_VALUE |
b03b016f KK |
1640 | hex |
1641 | default 0 if X86_32 | |
1642 | default 0xdead000000000000 if X86_64 | |
a29815a3 | 1643 | |
7a67832c DW |
1644 | config X86_PMEM_LEGACY_DEVICE |
1645 | bool | |
1646 | ||
ec776ef6 | 1647 | config X86_PMEM_LEGACY |
7a67832c | 1648 | tristate "Support non-standard NVDIMMs and ADR protected memory" |
9f53f9fa DW |
1649 | depends on PHYS_ADDR_T_64BIT |
1650 | depends on BLK_DEV | |
7a67832c | 1651 | select X86_PMEM_LEGACY_DEVICE |
7b27a862 | 1652 | select NUMA_KEEP_MEMINFO if NUMA |
9f53f9fa | 1653 | select LIBNVDIMM |
ec776ef6 CH |
1654 | help |
1655 | Treat memory marked using the non-standard e820 type of 12 as used | |
1656 | by the Intel Sandy Bridge-EP reference BIOS as protected memory. | |
1657 | The kernel will offer these regions to the 'pmem' driver so | |
1658 | they can be used for persistent storage. | |
1659 | ||
1660 | Say Y if unsure. | |
1661 | ||
506f1d07 SR |
1662 | config HIGHPTE |
1663 | bool "Allocate 3rd-level pagetables from highmem" | |
6fc108a0 | 1664 | depends on HIGHMEM |
a7f7f624 | 1665 | help |
506f1d07 SR |
1666 | The VM uses one page table entry for each page of physical memory. |
1667 | For systems with a lot of RAM, this can be wasteful of precious | |
1668 | low memory. Setting this option will put user-space page table | |
1669 | entries in high memory. | |
1670 | ||
9f077871 | 1671 | config X86_CHECK_BIOS_CORRUPTION |
8f9ca475 | 1672 | bool "Check for low memory corruption" |
a7f7f624 | 1673 | help |
8f9ca475 IM |
1674 | Periodically check for memory corruption in low memory, which |
1675 | is suspected to be caused by BIOS. Even when enabled in the | |
1676 | configuration, it is disabled at runtime. Enable it by | |
1677 | setting "memory_corruption_check=1" on the kernel command | |
1678 | line. By default it scans the low 64k of memory every 60 | |
1679 | seconds; see the memory_corruption_check_size and | |
1680 | memory_corruption_check_period parameters in | |
8c27ceff | 1681 | Documentation/admin-guide/kernel-parameters.rst to adjust this. |
8f9ca475 IM |
1682 | |
1683 | When enabled with the default parameters, this option has | |
1684 | almost no overhead, as it reserves a relatively small amount | |
1685 | of memory and scans it infrequently. It both detects corruption | |
1686 | and prevents it from affecting the running system. | |
1687 | ||
1688 | It is, however, intended as a diagnostic tool; if repeatable | |
1689 | BIOS-originated corruption always affects the same memory, | |
1690 | you can use memmap= to prevent the kernel from using that | |
1691 | memory. | |
9f077871 | 1692 | |
c885df50 | 1693 | config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK |
8f9ca475 | 1694 | bool "Set the default setting of memory_corruption_check" |
c885df50 JF |
1695 | depends on X86_CHECK_BIOS_CORRUPTION |
1696 | default y | |
a7f7f624 | 1697 | help |
8f9ca475 IM |
1698 | Set whether the default state of memory_corruption_check is |
1699 | on or off. | |
c885df50 | 1700 | |
506f1d07 SR |
1701 | config MATH_EMULATION |
1702 | bool | |
a5b9e5a2 | 1703 | depends on MODIFY_LDT_SYSCALL |
87d6021b | 1704 | prompt "Math emulation" if X86_32 && (M486SX || MELAN) |
a7f7f624 | 1705 | help |
506f1d07 SR |
1706 | Linux can emulate a math coprocessor (used for floating point |
1707 | operations) if you don't have one. 486DX and Pentium processors have | |
1708 | a math coprocessor built in, 486SX and 386 do not, unless you added | |
1709 | a 487DX or 387, respectively. (The messages during boot time can | |
1710 | give you some hints here ["man dmesg"].) Everyone needs either a | |
1711 | coprocessor or this emulation. | |
1712 | ||
1713 | If you don't have a math coprocessor, you need to say Y here; if you | |
1714 | say Y here even though you have a coprocessor, the coprocessor will | |
1715 | be used nevertheless. (This behavior can be changed with the kernel | |
1716 | command line option "no387", which comes handy if your coprocessor | |
1717 | is broken. Try "man bootparam" or see the documentation of your boot | |
1718 | loader (lilo or loadlin) about how to pass options to the kernel at | |
1719 | boot time.) This means that it is a good idea to say Y here if you | |
1720 | intend to use this kernel on different machines. | |
1721 | ||
1722 | More information about the internals of the Linux math coprocessor | |
1723 | emulation can be found in <file:arch/x86/math-emu/README>. | |
1724 | ||
1725 | If you are not sure, say Y; apart from resulting in a 66 KB bigger | |
1726 | kernel, it won't hurt. | |
1727 | ||
1728 | config MTRR | |
6fc108a0 | 1729 | def_bool y |
6a108a14 | 1730 | prompt "MTRR (Memory Type Range Register) support" if EXPERT |
a7f7f624 | 1731 | help |
506f1d07 SR |
1732 | On Intel P6 family processors (Pentium Pro, Pentium II and later) |
1733 | the Memory Type Range Registers (MTRRs) may be used to control | |
1734 | processor access to memory ranges. This is most useful if you have | |
1735 | a video (VGA) card on a PCI or AGP bus. Enabling write-combining | |
1736 | allows bus write transfers to be combined into a larger transfer | |
1737 | before bursting over the PCI/AGP bus. This can increase performance | |
1738 | of image write operations 2.5 times or more. Saying Y here creates a | |
1739 | /proc/mtrr file which may be used to manipulate your processor's | |
1740 | MTRRs. Typically the X server should use this. | |
1741 | ||
1742 | This code has a reasonably generic interface so that similar | |
1743 | control registers on other processors can be easily supported | |
1744 | as well: | |
1745 | ||
1746 | The Cyrix 6x86, 6x86MX and M II processors have Address Range | |
1747 | Registers (ARRs) which provide a similar functionality to MTRRs. For | |
1748 | these, the ARRs are used to emulate the MTRRs. | |
1749 | The AMD K6-2 (stepping 8 and above) and K6-3 processors have two | |
1750 | MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing | |
1751 | write-combining. All of these processors are supported by this code | |
1752 | and it makes sense to say Y here if you have one of them. | |
1753 | ||
1754 | Saying Y here also fixes a problem with buggy SMP BIOSes which only | |
1755 | set the MTRRs for the boot CPU and not for the secondary CPUs. This | |
1756 | can lead to all sorts of problems, so it's good to say Y here. | |
1757 | ||
1758 | You can safely say Y even if your machine doesn't have MTRRs, you'll | |
1759 | just add about 9 KB to your kernel. | |
1760 | ||
cb1aaebe | 1761 | See <file:Documentation/x86/mtrr.rst> for more information. |
506f1d07 | 1762 | |
95ffa243 | 1763 | config MTRR_SANITIZER |
2ffb3501 | 1764 | def_bool y |
95ffa243 YL |
1765 | prompt "MTRR cleanup support" |
1766 | depends on MTRR | |
a7f7f624 | 1767 | help |
aba3728c TG |
1768 | Convert MTRR layout from continuous to discrete, so X drivers can |
1769 | add writeback entries. | |
95ffa243 | 1770 | |
aba3728c | 1771 | Can be disabled with disable_mtrr_cleanup on the kernel command line. |
692105b8 | 1772 | The largest mtrr entry size for a continuous block can be set with |
aba3728c | 1773 | mtrr_chunk_size. |
95ffa243 | 1774 | |
2ffb3501 | 1775 | If unsure, say Y. |
95ffa243 YL |
1776 | |
1777 | config MTRR_SANITIZER_ENABLE_DEFAULT | |
f5098d62 YL |
1778 | int "MTRR cleanup enable value (0-1)" |
1779 | range 0 1 | |
1780 | default "0" | |
95ffa243 | 1781 | depends on MTRR_SANITIZER |
a7f7f624 | 1782 | help |
f5098d62 | 1783 | Enable mtrr cleanup default value |
95ffa243 | 1784 | |
12031a62 YL |
1785 | config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT |
1786 | int "MTRR cleanup spare reg num (0-7)" | |
1787 | range 0 7 | |
1788 | default "1" | |
1789 | depends on MTRR_SANITIZER | |
a7f7f624 | 1790 | help |
12031a62 | 1791 | mtrr cleanup spare entries default, it can be changed via |
aba3728c | 1792 | mtrr_spare_reg_nr=N on the kernel command line. |
12031a62 | 1793 | |
2e5d9c85 | 1794 | config X86_PAT |
6fc108a0 | 1795 | def_bool y |
6a108a14 | 1796 | prompt "x86 PAT support" if EXPERT |
2a8a2719 | 1797 | depends on MTRR |
a7f7f624 | 1798 | help |
2e5d9c85 | 1799 | Use PAT attributes to setup page level cache control. |
042b78e4 | 1800 | |
2e5d9c85 | 1801 | PATs are the modern equivalents of MTRRs and are much more |
1802 | flexible than MTRRs. | |
1803 | ||
1804 | Say N here if you see bootup problems (boot crash, boot hang, | |
042b78e4 | 1805 | spontaneous reboots) or a non-working video driver. |
2e5d9c85 | 1806 | |
1807 | If unsure, say Y. | |
1808 | ||
46cf98cd VP |
1809 | config ARCH_USES_PG_UNCACHED |
1810 | def_bool y | |
1811 | depends on X86_PAT | |
1812 | ||
b971880f | 1813 | config X86_UMIP |
796ebc81 | 1814 | def_bool y |
b971880f | 1815 | prompt "User Mode Instruction Prevention" if EXPERT |
a7f7f624 | 1816 | help |
b971880f BM |
1817 | User Mode Instruction Prevention (UMIP) is a security feature in |
1818 | some x86 processors. If enabled, a general protection fault is | |
1819 | issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are | |
1820 | executed in user mode. These instructions unnecessarily expose | |
1821 | information about the hardware state. | |
796ebc81 RN |
1822 | |
1823 | The vast majority of applications do not use these instructions. | |
1824 | For the very few that do, software emulation is provided in | |
1825 | specific cases in protected and virtual-8086 modes. Emulated | |
1826 | results are dummy. | |
aa35f896 | 1827 | |
156ff4a5 PZ |
1828 | config CC_HAS_IBT |
1829 | # GCC >= 9 and binutils >= 2.29 | |
1830 | # Retpoline check to work around https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93654 | |
1831 | # Clang/LLVM >= 14 | |
262448f3 NC |
1832 | # https://github.com/llvm/llvm-project/commit/e0b89df2e0f0130881bf6c39bf31d7f6aac00e0f |
1833 | # https://github.com/llvm/llvm-project/commit/dfcf69770bc522b9e411c66454934a37c1f35332 | |
156ff4a5 | 1834 | def_bool ((CC_IS_GCC && $(cc-option, -fcf-protection=branch -mindirect-branch-register)) || \ |
262448f3 | 1835 | (CC_IS_CLANG && CLANG_VERSION >= 140000)) && \ |
156ff4a5 PZ |
1836 | $(as-instr,endbr64) |
1837 | ||
1838 | config X86_KERNEL_IBT | |
1839 | prompt "Indirect Branch Tracking" | |
1840 | bool | |
03f16cd0 | 1841 | depends on X86_64 && CC_HAS_IBT && HAVE_OBJTOOL |
f6a2c2b2 NC |
1842 | # https://github.com/llvm/llvm-project/commit/9d7001eba9c4cb311e03cd8cdc231f9e579f2d0f |
1843 | depends on !LD_IS_LLD || LLD_VERSION >= 140000 | |
03f16cd0 | 1844 | select OBJTOOL |
156ff4a5 PZ |
1845 | help |
1846 | Build the kernel with support for Indirect Branch Tracking, a | |
1847 | hardware support course-grain forward-edge Control Flow Integrity | |
1848 | protection. It enforces that all indirect calls must land on | |
1849 | an ENDBR instruction, as such, the compiler will instrument the | |
1850 | code with them to make this happen. | |
1851 | ||
ed53a0d9 | 1852 | In addition to building the kernel with IBT, seal all functions that |
4cdfc11b | 1853 | are not indirect call targets, avoiding them ever becoming one. |
ed53a0d9 PZ |
1854 | |
1855 | This requires LTO like objtool runs and will slow down the build. It | |
1856 | does significantly reduce the number of ENDBR instructions in the | |
1857 | kernel image. | |
1858 | ||
35e97790 | 1859 | config X86_INTEL_MEMORY_PROTECTION_KEYS |
38f3e775 | 1860 | prompt "Memory Protection Keys" |
35e97790 | 1861 | def_bool y |
284244a9 | 1862 | # Note: only available in 64-bit mode |
38f3e775 | 1863 | depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD) |
52c8e601 IM |
1864 | select ARCH_USES_HIGH_VMA_FLAGS |
1865 | select ARCH_HAS_PKEYS | |
a7f7f624 | 1866 | help |
284244a9 DH |
1867 | Memory Protection Keys provides a mechanism for enforcing |
1868 | page-based protections, but without requiring modification of the | |
1869 | page tables when an application changes protection domains. | |
1870 | ||
1eecbcdc | 1871 | For details, see Documentation/core-api/protection-keys.rst |
284244a9 DH |
1872 | |
1873 | If unsure, say y. | |
35e97790 | 1874 | |
db616173 MH |
1875 | choice |
1876 | prompt "TSX enable mode" | |
1877 | depends on CPU_SUP_INTEL | |
1878 | default X86_INTEL_TSX_MODE_OFF | |
1879 | help | |
1880 | Intel's TSX (Transactional Synchronization Extensions) feature | |
1881 | allows to optimize locking protocols through lock elision which | |
1882 | can lead to a noticeable performance boost. | |
1883 | ||
1884 | On the other hand it has been shown that TSX can be exploited | |
1885 | to form side channel attacks (e.g. TAA) and chances are there | |
1886 | will be more of those attacks discovered in the future. | |
1887 | ||
1888 | Therefore TSX is not enabled by default (aka tsx=off). An admin | |
1889 | might override this decision by tsx=on the command line parameter. | |
1890 | Even with TSX enabled, the kernel will attempt to enable the best | |
1891 | possible TAA mitigation setting depending on the microcode available | |
1892 | for the particular machine. | |
1893 | ||
1894 | This option allows to set the default tsx mode between tsx=on, =off | |
1895 | and =auto. See Documentation/admin-guide/kernel-parameters.txt for more | |
1896 | details. | |
1897 | ||
1898 | Say off if not sure, auto if TSX is in use but it should be used on safe | |
1899 | platforms or on if TSX is in use and the security aspect of tsx is not | |
1900 | relevant. | |
1901 | ||
1902 | config X86_INTEL_TSX_MODE_OFF | |
1903 | bool "off" | |
1904 | help | |
1905 | TSX is disabled if possible - equals to tsx=off command line parameter. | |
1906 | ||
1907 | config X86_INTEL_TSX_MODE_ON | |
1908 | bool "on" | |
1909 | help | |
1910 | TSX is always enabled on TSX capable HW - equals the tsx=on command | |
1911 | line parameter. | |
1912 | ||
1913 | config X86_INTEL_TSX_MODE_AUTO | |
1914 | bool "auto" | |
1915 | help | |
1916 | TSX is enabled on TSX capable HW that is believed to be safe against | |
1917 | side channel attacks- equals the tsx=auto command line parameter. | |
1918 | endchoice | |
1919 | ||
e7e05452 SC |
1920 | config X86_SGX |
1921 | bool "Software Guard eXtensions (SGX)" | |
1922 | depends on X86_64 && CPU_SUP_INTEL | |
1923 | depends on CRYPTO=y | |
1924 | depends on CRYPTO_SHA256=y | |
1925 | select SRCU | |
1926 | select MMU_NOTIFIER | |
901ddbb9 | 1927 | select NUMA_KEEP_MEMINFO if NUMA |
40e0e784 | 1928 | select XARRAY_MULTI |
e7e05452 SC |
1929 | help |
1930 | Intel(R) Software Guard eXtensions (SGX) is a set of CPU instructions | |
1931 | that can be used by applications to set aside private regions of code | |
1932 | and data, referred to as enclaves. An enclave's private memory can | |
1933 | only be accessed by code running within the enclave. Accesses from | |
1934 | outside the enclave, including other enclaves, are disallowed by | |
1935 | hardware. | |
1936 | ||
1937 | If unsure, say N. | |
1938 | ||
506f1d07 | 1939 | config EFI |
9ba16087 | 1940 | bool "EFI runtime service support" |
5b83683f | 1941 | depends on ACPI |
f6ce5002 | 1942 | select UCS2_STRING |
022ee6c5 | 1943 | select EFI_RUNTIME_WRAPPERS |
1ff2fc02 | 1944 | select ARCH_USE_MEMREMAP_PROT |
a7f7f624 | 1945 | help |
8f9ca475 IM |
1946 | This enables the kernel to use EFI runtime services that are |
1947 | available (such as the EFI variable services). | |
506f1d07 | 1948 | |
8f9ca475 IM |
1949 | This option is only useful on systems that have EFI firmware. |
1950 | In addition, you should use the latest ELILO loader available | |
1951 | at <http://elilo.sourceforge.net> in order to take advantage | |
1952 | of EFI runtime services. However, even with this option, the | |
1953 | resultant kernel should continue to boot on existing non-EFI | |
1954 | platforms. | |
506f1d07 | 1955 | |
291f3632 | 1956 | config EFI_STUB |
8f24f8c2 | 1957 | bool "EFI stub support" |
c6dbd3e5 | 1958 | depends on EFI |
8f24f8c2 AB |
1959 | depends on $(cc-option,-mabi=ms) || X86_32 |
1960 | select RELOCATABLE | |
a7f7f624 | 1961 | help |
8f24f8c2 | 1962 | This kernel feature allows a bzImage to be loaded directly |
291f3632 MF |
1963 | by EFI firmware without the use of a bootloader. |
1964 | ||
4f4cfa6c | 1965 | See Documentation/admin-guide/efi-stub.rst for more information. |
0c759662 | 1966 | |
7d453eee MF |
1967 | config EFI_MIXED |
1968 | bool "EFI mixed-mode support" | |
1969 | depends on EFI_STUB && X86_64 | |
a7f7f624 | 1970 | help |
758cd94a JH |
1971 | Enabling this feature allows a 64-bit kernel to be booted |
1972 | on a 32-bit firmware, provided that your CPU supports 64-bit | |
1973 | mode. | |
7d453eee | 1974 | |
758cd94a JH |
1975 | Note that it is not possible to boot a mixed-mode enabled |
1976 | kernel via the EFI boot stub - a bootloader that supports | |
1977 | the EFI handover protocol must be used. | |
7d453eee | 1978 | |
758cd94a | 1979 | If unsure, say N. |
7d453eee | 1980 | |
8636a1f9 | 1981 | source "kernel/Kconfig.hz" |
506f1d07 SR |
1982 | |
1983 | config KEXEC | |
1984 | bool "kexec system call" | |
2965faa5 | 1985 | select KEXEC_CORE |
a7f7f624 | 1986 | help |
506f1d07 SR |
1987 | kexec is a system call that implements the ability to shutdown your |
1988 | current kernel, and to start another kernel. It is like a reboot | |
1989 | but it is independent of the system firmware. And like a reboot | |
1990 | you can start any kernel with it, not just Linux. | |
1991 | ||
1992 | The name comes from the similarity to the exec system call. | |
1993 | ||
1994 | It is an ongoing process to be certain the hardware in a machine | |
1995 | is properly shutdown, so do not be surprised if this code does not | |
bf220695 GU |
1996 | initially work for you. As of this writing the exact hardware |
1997 | interface is strongly in flux, so no good recommendation can be | |
1998 | made. | |
506f1d07 | 1999 | |
74ca317c VG |
2000 | config KEXEC_FILE |
2001 | bool "kexec file based system call" | |
2965faa5 | 2002 | select KEXEC_CORE |
b69a2afd | 2003 | select HAVE_IMA_KEXEC if IMA |
74ca317c VG |
2004 | depends on X86_64 |
2005 | depends on CRYPTO=y | |
2006 | depends on CRYPTO_SHA256=y | |
a7f7f624 | 2007 | help |
74ca317c VG |
2008 | This is new version of kexec system call. This system call is |
2009 | file based and takes file descriptors as system call argument | |
2010 | for kernel and initramfs as opposed to list of segments as | |
2011 | accepted by previous system call. | |
2012 | ||
b799a09f AT |
2013 | config ARCH_HAS_KEXEC_PURGATORY |
2014 | def_bool KEXEC_FILE | |
2015 | ||
99d5cadf | 2016 | config KEXEC_SIG |
8e7d8381 | 2017 | bool "Verify kernel signature during kexec_file_load() syscall" |
74ca317c | 2018 | depends on KEXEC_FILE |
a7f7f624 | 2019 | help |
d8eb8940 | 2020 | |
99d5cadf JB |
2021 | This option makes the kexec_file_load() syscall check for a valid |
2022 | signature of the kernel image. The image can still be loaded without | |
2023 | a valid signature unless you also enable KEXEC_SIG_FORCE, though if | |
2024 | there's a signature that we can check, then it must be valid. | |
2025 | ||
2026 | In addition to this option, you need to enable signature | |
d8eb8940 BP |
2027 | verification for the corresponding kernel image type being |
2028 | loaded in order for this to work. | |
8e7d8381 | 2029 | |
99d5cadf JB |
2030 | config KEXEC_SIG_FORCE |
2031 | bool "Require a valid signature in kexec_file_load() syscall" | |
2032 | depends on KEXEC_SIG | |
a7f7f624 | 2033 | help |
99d5cadf JB |
2034 | This option makes kernel signature verification mandatory for |
2035 | the kexec_file_load() syscall. | |
2036 | ||
8e7d8381 VG |
2037 | config KEXEC_BZIMAGE_VERIFY_SIG |
2038 | bool "Enable bzImage signature verification support" | |
99d5cadf | 2039 | depends on KEXEC_SIG |
8e7d8381 VG |
2040 | depends on SIGNED_PE_FILE_VERIFICATION |
2041 | select SYSTEM_TRUSTED_KEYRING | |
a7f7f624 | 2042 | help |
8e7d8381 VG |
2043 | Enable bzImage signature verification support. |
2044 | ||
506f1d07 | 2045 | config CRASH_DUMP |
04b69447 | 2046 | bool "kernel crash dumps" |
506f1d07 | 2047 | depends on X86_64 || (X86_32 && HIGHMEM) |
a7f7f624 | 2048 | help |
506f1d07 SR |
2049 | Generate crash dump after being started by kexec. |
2050 | This should be normally only set in special crash dump kernels | |
2051 | which are loaded in the main kernel with kexec-tools into | |
2052 | a specially reserved region and then later executed after | |
2053 | a crash by kdump/kexec. The crash dump kernel must be compiled | |
2054 | to a memory address not used by the main kernel or BIOS using | |
2055 | PHYSICAL_START, or it must be built as a relocatable image | |
2056 | (CONFIG_RELOCATABLE=y). | |
330d4810 | 2057 | For more details see Documentation/admin-guide/kdump/kdump.rst |
506f1d07 | 2058 | |
3ab83521 | 2059 | config KEXEC_JUMP |
6ea30386 | 2060 | bool "kexec jump" |
fee7b0d8 | 2061 | depends on KEXEC && HIBERNATION |
a7f7f624 | 2062 | help |
89081d17 HY |
2063 | Jump between original kernel and kexeced kernel and invoke |
2064 | code in physical address mode via KEXEC | |
3ab83521 | 2065 | |
506f1d07 | 2066 | config PHYSICAL_START |
6a108a14 | 2067 | hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) |
ceefccc9 | 2068 | default "0x1000000" |
a7f7f624 | 2069 | help |
506f1d07 SR |
2070 | This gives the physical address where the kernel is loaded. |
2071 | ||
2072 | If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then | |
2073 | bzImage will decompress itself to above physical address and | |
2074 | run from there. Otherwise, bzImage will run from the address where | |
2075 | it has been loaded by the boot loader and will ignore above physical | |
2076 | address. | |
2077 | ||
2078 | In normal kdump cases one does not have to set/change this option | |
2079 | as now bzImage can be compiled as a completely relocatable image | |
2080 | (CONFIG_RELOCATABLE=y) and be used to load and run from a different | |
2081 | address. This option is mainly useful for the folks who don't want | |
2082 | to use a bzImage for capturing the crash dump and want to use a | |
2083 | vmlinux instead. vmlinux is not relocatable hence a kernel needs | |
2084 | to be specifically compiled to run from a specific memory area | |
2085 | (normally a reserved region) and this option comes handy. | |
2086 | ||
ceefccc9 PA |
2087 | So if you are using bzImage for capturing the crash dump, |
2088 | leave the value here unchanged to 0x1000000 and set | |
2089 | CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux | |
2090 | for capturing the crash dump change this value to start of | |
2091 | the reserved region. In other words, it can be set based on | |
2092 | the "X" value as specified in the "crashkernel=YM@XM" | |
2093 | command line boot parameter passed to the panic-ed | |
330d4810 | 2094 | kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst |
ceefccc9 | 2095 | for more details about crash dumps. |
506f1d07 SR |
2096 | |
2097 | Usage of bzImage for capturing the crash dump is recommended as | |
2098 | one does not have to build two kernels. Same kernel can be used | |
2099 | as production kernel and capture kernel. Above option should have | |
2100 | gone away after relocatable bzImage support is introduced. But it | |
2101 | is present because there are users out there who continue to use | |
2102 | vmlinux for dump capture. This option should go away down the | |
2103 | line. | |
2104 | ||
2105 | Don't change this unless you know what you are doing. | |
2106 | ||
2107 | config RELOCATABLE | |
26717808 PA |
2108 | bool "Build a relocatable kernel" |
2109 | default y | |
a7f7f624 | 2110 | help |
506f1d07 SR |
2111 | This builds a kernel image that retains relocation information |
2112 | so it can be loaded someplace besides the default 1MB. | |
2113 | The relocations tend to make the kernel binary about 10% larger, | |
2114 | but are discarded at runtime. | |
2115 | ||
2116 | One use is for the kexec on panic case where the recovery kernel | |
2117 | must live at a different physical address than the primary | |
2118 | kernel. | |
2119 | ||
2120 | Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address | |
2121 | it has been loaded at and the compile time physical address | |
8ab3820f | 2122 | (CONFIG_PHYSICAL_START) is used as the minimum location. |
506f1d07 | 2123 | |
8ab3820f | 2124 | config RANDOMIZE_BASE |
e8581e3d | 2125 | bool "Randomize the address of the kernel image (KASLR)" |
8ab3820f | 2126 | depends on RELOCATABLE |
6807c846 | 2127 | default y |
a7f7f624 | 2128 | help |
e8581e3d BH |
2129 | In support of Kernel Address Space Layout Randomization (KASLR), |
2130 | this randomizes the physical address at which the kernel image | |
2131 | is decompressed and the virtual address where the kernel | |
2132 | image is mapped, as a security feature that deters exploit | |
2133 | attempts relying on knowledge of the location of kernel | |
2134 | code internals. | |
2135 | ||
ed9f007e KC |
2136 | On 64-bit, the kernel physical and virtual addresses are |
2137 | randomized separately. The physical address will be anywhere | |
2138 | between 16MB and the top of physical memory (up to 64TB). The | |
2139 | virtual address will be randomized from 16MB up to 1GB (9 bits | |
2140 | of entropy). Note that this also reduces the memory space | |
2141 | available to kernel modules from 1.5GB to 1GB. | |
2142 | ||
2143 | On 32-bit, the kernel physical and virtual addresses are | |
2144 | randomized together. They will be randomized from 16MB up to | |
2145 | 512MB (8 bits of entropy). | |
e8581e3d BH |
2146 | |
2147 | Entropy is generated using the RDRAND instruction if it is | |
2148 | supported. If RDTSC is supported, its value is mixed into | |
2149 | the entropy pool as well. If neither RDRAND nor RDTSC are | |
ed9f007e KC |
2150 | supported, then entropy is read from the i8254 timer. The |
2151 | usable entropy is limited by the kernel being built using | |
2152 | 2GB addressing, and that PHYSICAL_ALIGN must be at a | |
2153 | minimum of 2MB. As a result, only 10 bits of entropy are | |
2154 | theoretically possible, but the implementations are further | |
2155 | limited due to memory layouts. | |
e8581e3d | 2156 | |
6807c846 | 2157 | If unsure, say Y. |
8ab3820f KC |
2158 | |
2159 | # Relocation on x86 needs some additional build support | |
845adf72 PA |
2160 | config X86_NEED_RELOCS |
2161 | def_bool y | |
8ab3820f | 2162 | depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) |
845adf72 | 2163 | |
506f1d07 | 2164 | config PHYSICAL_ALIGN |
a0215061 | 2165 | hex "Alignment value to which kernel should be aligned" |
8ab3820f | 2166 | default "0x200000" |
a0215061 KC |
2167 | range 0x2000 0x1000000 if X86_32 |
2168 | range 0x200000 0x1000000 if X86_64 | |
a7f7f624 | 2169 | help |
506f1d07 SR |
2170 | This value puts the alignment restrictions on physical address |
2171 | where kernel is loaded and run from. Kernel is compiled for an | |
2172 | address which meets above alignment restriction. | |
2173 | ||
2174 | If bootloader loads the kernel at a non-aligned address and | |
2175 | CONFIG_RELOCATABLE is set, kernel will move itself to nearest | |
2176 | address aligned to above value and run from there. | |
2177 | ||
2178 | If bootloader loads the kernel at a non-aligned address and | |
2179 | CONFIG_RELOCATABLE is not set, kernel will ignore the run time | |
2180 | load address and decompress itself to the address it has been | |
2181 | compiled for and run from there. The address for which kernel is | |
2182 | compiled already meets above alignment restrictions. Hence the | |
2183 | end result is that kernel runs from a physical address meeting | |
2184 | above alignment restrictions. | |
2185 | ||
a0215061 KC |
2186 | On 32-bit this value must be a multiple of 0x2000. On 64-bit |
2187 | this value must be a multiple of 0x200000. | |
2188 | ||
506f1d07 SR |
2189 | Don't change this unless you know what you are doing. |
2190 | ||
eedb92ab KS |
2191 | config DYNAMIC_MEMORY_LAYOUT |
2192 | bool | |
a7f7f624 | 2193 | help |
eedb92ab KS |
2194 | This option makes base addresses of vmalloc and vmemmap as well as |
2195 | __PAGE_OFFSET movable during boot. | |
2196 | ||
0483e1fa TG |
2197 | config RANDOMIZE_MEMORY |
2198 | bool "Randomize the kernel memory sections" | |
2199 | depends on X86_64 | |
2200 | depends on RANDOMIZE_BASE | |
eedb92ab | 2201 | select DYNAMIC_MEMORY_LAYOUT |
0483e1fa | 2202 | default RANDOMIZE_BASE |
a7f7f624 | 2203 | help |
758cd94a JH |
2204 | Randomizes the base virtual address of kernel memory sections |
2205 | (physical memory mapping, vmalloc & vmemmap). This security feature | |
2206 | makes exploits relying on predictable memory locations less reliable. | |
0483e1fa | 2207 | |
758cd94a JH |
2208 | The order of allocations remains unchanged. Entropy is generated in |
2209 | the same way as RANDOMIZE_BASE. Current implementation in the optimal | |
2210 | configuration have in average 30,000 different possible virtual | |
2211 | addresses for each memory section. | |
0483e1fa | 2212 | |
758cd94a | 2213 | If unsure, say Y. |
0483e1fa | 2214 | |
90397a41 TG |
2215 | config RANDOMIZE_MEMORY_PHYSICAL_PADDING |
2216 | hex "Physical memory mapping padding" if EXPERT | |
2217 | depends on RANDOMIZE_MEMORY | |
2218 | default "0xa" if MEMORY_HOTPLUG | |
2219 | default "0x0" | |
2220 | range 0x1 0x40 if MEMORY_HOTPLUG | |
2221 | range 0x0 0x40 | |
a7f7f624 | 2222 | help |
758cd94a JH |
2223 | Define the padding in terabytes added to the existing physical |
2224 | memory size during kernel memory randomization. It is useful | |
2225 | for memory hotplug support but reduces the entropy available for | |
2226 | address randomization. | |
90397a41 | 2227 | |
758cd94a | 2228 | If unsure, leave at the default value. |
90397a41 | 2229 | |
506f1d07 | 2230 | config HOTPLUG_CPU |
bebd024e | 2231 | def_bool y |
40b31360 | 2232 | depends on SMP |
506f1d07 | 2233 | |
80aa1dff FY |
2234 | config BOOTPARAM_HOTPLUG_CPU0 |
2235 | bool "Set default setting of cpu0_hotpluggable" | |
2c922cd0 | 2236 | depends on HOTPLUG_CPU |
a7f7f624 | 2237 | help |
80aa1dff FY |
2238 | Set whether default state of cpu0_hotpluggable is on or off. |
2239 | ||
2240 | Say Y here to enable CPU0 hotplug by default. If this switch | |
2241 | is turned on, there is no need to give cpu0_hotplug kernel | |
2242 | parameter and the CPU0 hotplug feature is enabled by default. | |
2243 | ||
2244 | Please note: there are two known CPU0 dependencies if you want | |
2245 | to enable the CPU0 hotplug feature either by this switch or by | |
2246 | cpu0_hotplug kernel parameter. | |
2247 | ||
2248 | First, resume from hibernate or suspend always starts from CPU0. | |
2249 | So hibernate and suspend are prevented if CPU0 is offline. | |
2250 | ||
2251 | Second dependency is PIC interrupts always go to CPU0. CPU0 can not | |
2252 | offline if any interrupt can not migrate out of CPU0. There may | |
2253 | be other CPU0 dependencies. | |
2254 | ||
2255 | Please make sure the dependencies are under your control before | |
2256 | you enable this feature. | |
2257 | ||
2258 | Say N if you don't want to enable CPU0 hotplug feature by default. | |
2259 | You still can enable the CPU0 hotplug feature at boot by kernel | |
2260 | parameter cpu0_hotplug. | |
2261 | ||
a71c8bc5 FY |
2262 | config DEBUG_HOTPLUG_CPU0 |
2263 | def_bool n | |
2264 | prompt "Debug CPU0 hotplug" | |
2c922cd0 | 2265 | depends on HOTPLUG_CPU |
a7f7f624 | 2266 | help |
a71c8bc5 FY |
2267 | Enabling this option offlines CPU0 (if CPU0 can be offlined) as |
2268 | soon as possible and boots up userspace with CPU0 offlined. User | |
2269 | can online CPU0 back after boot time. | |
2270 | ||
2271 | To debug CPU0 hotplug, you need to enable CPU0 offline/online | |
2272 | feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during | |
2273 | compilation or giving cpu0_hotplug kernel parameter at boot. | |
2274 | ||
2275 | If unsure, say N. | |
2276 | ||
506f1d07 | 2277 | config COMPAT_VDSO |
b0b49f26 AL |
2278 | def_bool n |
2279 | prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)" | |
953fee1d | 2280 | depends on COMPAT_32 |
a7f7f624 | 2281 | help |
b0b49f26 AL |
2282 | Certain buggy versions of glibc will crash if they are |
2283 | presented with a 32-bit vDSO that is not mapped at the address | |
2284 | indicated in its segment table. | |
e84446de | 2285 | |
b0b49f26 AL |
2286 | The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a |
2287 | and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and | |
2288 | 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is | |
2289 | the only released version with the bug, but OpenSUSE 9 | |
2290 | contains a buggy "glibc 2.3.2". | |
506f1d07 | 2291 | |
b0b49f26 AL |
2292 | The symptom of the bug is that everything crashes on startup, saying: |
2293 | dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! | |
2294 | ||
2295 | Saying Y here changes the default value of the vdso32 boot | |
2296 | option from 1 to 0, which turns off the 32-bit vDSO entirely. | |
2297 | This works around the glibc bug but hurts performance. | |
2298 | ||
2299 | If unsure, say N: if you are compiling your own kernel, you | |
2300 | are unlikely to be using a buggy version of glibc. | |
506f1d07 | 2301 | |
3dc33bd3 KC |
2302 | choice |
2303 | prompt "vsyscall table for legacy applications" | |
2304 | depends on X86_64 | |
625b7b7f | 2305 | default LEGACY_VSYSCALL_XONLY |
3dc33bd3 KC |
2306 | help |
2307 | Legacy user code that does not know how to find the vDSO expects | |
2308 | to be able to issue three syscalls by calling fixed addresses in | |
2309 | kernel space. Since this location is not randomized with ASLR, | |
2310 | it can be used to assist security vulnerability exploitation. | |
2311 | ||
2312 | This setting can be changed at boot time via the kernel command | |
bf00745e AL |
2313 | line parameter vsyscall=[emulate|xonly|none]. Emulate mode |
2314 | is deprecated and can only be enabled using the kernel command | |
2315 | line. | |
3dc33bd3 KC |
2316 | |
2317 | On a system with recent enough glibc (2.14 or newer) and no | |
2318 | static binaries, you can say None without a performance penalty | |
2319 | to improve security. | |
2320 | ||
bd49e16e | 2321 | If unsure, select "Emulate execution only". |
3dc33bd3 | 2322 | |
bd49e16e AL |
2323 | config LEGACY_VSYSCALL_XONLY |
2324 | bool "Emulate execution only" | |
2325 | help | |
2326 | The kernel traps and emulates calls into the fixed vsyscall | |
2327 | address mapping and does not allow reads. This | |
2328 | configuration is recommended when userspace might use the | |
2329 | legacy vsyscall area but support for legacy binary | |
2330 | instrumentation of legacy code is not needed. It mitigates | |
2331 | certain uses of the vsyscall area as an ASLR-bypassing | |
2332 | buffer. | |
3dc33bd3 KC |
2333 | |
2334 | config LEGACY_VSYSCALL_NONE | |
2335 | bool "None" | |
2336 | help | |
2337 | There will be no vsyscall mapping at all. This will | |
2338 | eliminate any risk of ASLR bypass due to the vsyscall | |
2339 | fixed address mapping. Attempts to use the vsyscalls | |
2340 | will be reported to dmesg, so that either old or | |
2341 | malicious userspace programs can be identified. | |
2342 | ||
2343 | endchoice | |
2344 | ||
516cbf37 TB |
2345 | config CMDLINE_BOOL |
2346 | bool "Built-in kernel command line" | |
a7f7f624 | 2347 | help |
516cbf37 TB |
2348 | Allow for specifying boot arguments to the kernel at |
2349 | build time. On some systems (e.g. embedded ones), it is | |
2350 | necessary or convenient to provide some or all of the | |
2351 | kernel boot arguments with the kernel itself (that is, | |
2352 | to not rely on the boot loader to provide them.) | |
2353 | ||
2354 | To compile command line arguments into the kernel, | |
2355 | set this option to 'Y', then fill in the | |
69711ca1 | 2356 | boot arguments in CONFIG_CMDLINE. |
516cbf37 TB |
2357 | |
2358 | Systems with fully functional boot loaders (i.e. non-embedded) | |
2359 | should leave this option set to 'N'. | |
2360 | ||
2361 | config CMDLINE | |
2362 | string "Built-in kernel command string" | |
2363 | depends on CMDLINE_BOOL | |
2364 | default "" | |
a7f7f624 | 2365 | help |
516cbf37 TB |
2366 | Enter arguments here that should be compiled into the kernel |
2367 | image and used at boot time. If the boot loader provides a | |
2368 | command line at boot time, it is appended to this string to | |
2369 | form the full kernel command line, when the system boots. | |
2370 | ||
2371 | However, you can use the CONFIG_CMDLINE_OVERRIDE option to | |
2372 | change this behavior. | |
2373 | ||
2374 | In most cases, the command line (whether built-in or provided | |
2375 | by the boot loader) should specify the device for the root | |
2376 | file system. | |
2377 | ||
2378 | config CMDLINE_OVERRIDE | |
2379 | bool "Built-in command line overrides boot loader arguments" | |
645e6466 | 2380 | depends on CMDLINE_BOOL && CMDLINE != "" |
a7f7f624 | 2381 | help |
516cbf37 TB |
2382 | Set this option to 'Y' to have the kernel ignore the boot loader |
2383 | command line, and use ONLY the built-in command line. | |
2384 | ||
2385 | This is used to work around broken boot loaders. This should | |
2386 | be set to 'N' under normal conditions. | |
2387 | ||
a5b9e5a2 AL |
2388 | config MODIFY_LDT_SYSCALL |
2389 | bool "Enable the LDT (local descriptor table)" if EXPERT | |
2390 | default y | |
a7f7f624 | 2391 | help |
a5b9e5a2 AL |
2392 | Linux can allow user programs to install a per-process x86 |
2393 | Local Descriptor Table (LDT) using the modify_ldt(2) system | |
2394 | call. This is required to run 16-bit or segmented code such as | |
2395 | DOSEMU or some Wine programs. It is also used by some very old | |
2396 | threading libraries. | |
2397 | ||
2398 | Enabling this feature adds a small amount of overhead to | |
2399 | context switches and increases the low-level kernel attack | |
2400 | surface. Disabling it removes the modify_ldt(2) system call. | |
2401 | ||
2402 | Saying 'N' here may make sense for embedded or server kernels. | |
2403 | ||
3aac3ebe TG |
2404 | config STRICT_SIGALTSTACK_SIZE |
2405 | bool "Enforce strict size checking for sigaltstack" | |
2406 | depends on DYNAMIC_SIGFRAME | |
2407 | help | |
2408 | For historical reasons MINSIGSTKSZ is a constant which became | |
2409 | already too small with AVX512 support. Add a mechanism to | |
2410 | enforce strict checking of the sigaltstack size against the | |
2411 | real size of the FPU frame. This option enables the check | |
2412 | by default. It can also be controlled via the kernel command | |
2413 | line option 'strict_sas_size' independent of this config | |
2414 | switch. Enabling it might break existing applications which | |
2415 | allocate a too small sigaltstack but 'work' because they | |
2416 | never get a signal delivered. | |
2417 | ||
2418 | Say 'N' unless you want to really enforce this check. | |
2419 | ||
b700e7f0 SJ |
2420 | source "kernel/livepatch/Kconfig" |
2421 | ||
506f1d07 SR |
2422 | endmenu |
2423 | ||
f43b9876 PZ |
2424 | config CC_HAS_SLS |
2425 | def_bool $(cc-option,-mharden-sls=all) | |
2426 | ||
2427 | config CC_HAS_RETURN_THUNK | |
2428 | def_bool $(cc-option,-mfunction-return=thunk-extern) | |
2429 | ||
2430 | menuconfig SPECULATION_MITIGATIONS | |
2431 | bool "Mitigations for speculative execution vulnerabilities" | |
2432 | default y | |
2433 | help | |
2434 | Say Y here to enable options which enable mitigations for | |
2435 | speculative execution hardware vulnerabilities. | |
2436 | ||
2437 | If you say N, all mitigations will be disabled. You really | |
2438 | should know what you are doing to say so. | |
2439 | ||
2440 | if SPECULATION_MITIGATIONS | |
2441 | ||
2442 | config PAGE_TABLE_ISOLATION | |
2443 | bool "Remove the kernel mapping in user mode" | |
2444 | default y | |
2445 | depends on (X86_64 || X86_PAE) | |
2446 | help | |
2447 | This feature reduces the number of hardware side channels by | |
2448 | ensuring that the majority of kernel addresses are not mapped | |
2449 | into userspace. | |
2450 | ||
2451 | See Documentation/x86/pti.rst for more details. | |
2452 | ||
2453 | config RETPOLINE | |
2454 | bool "Avoid speculative indirect branches in kernel" | |
2455 | select OBJTOOL if HAVE_OBJTOOL | |
2456 | default y | |
2457 | help | |
2458 | Compile kernel with the retpoline compiler options to guard against | |
2459 | kernel-to-user data leaks by avoiding speculative indirect | |
2460 | branches. Requires a compiler with -mindirect-branch=thunk-extern | |
2461 | support for full protection. The kernel may run slower. | |
2462 | ||
2463 | config RETHUNK | |
2464 | bool "Enable return-thunks" | |
2465 | depends on RETPOLINE && CC_HAS_RETURN_THUNK | |
2466 | select OBJTOOL if HAVE_OBJTOOL | |
b648ab48 | 2467 | default y if X86_64 |
f43b9876 PZ |
2468 | help |
2469 | Compile the kernel with the return-thunks compiler option to guard | |
2470 | against kernel-to-user data leaks by avoiding return speculation. | |
2471 | Requires a compiler with -mfunction-return=thunk-extern | |
2472 | support for full protection. The kernel may run slower. | |
2473 | ||
2474 | config CPU_UNRET_ENTRY | |
2475 | bool "Enable UNRET on kernel entry" | |
b648ab48 | 2476 | depends on CPU_SUP_AMD && RETHUNK && X86_64 |
f43b9876 PZ |
2477 | default y |
2478 | help | |
2479 | Compile the kernel with support for the retbleed=unret mitigation. | |
2480 | ||
2481 | config CPU_IBPB_ENTRY | |
2482 | bool "Enable IBPB on kernel entry" | |
b648ab48 | 2483 | depends on CPU_SUP_AMD && X86_64 |
f43b9876 PZ |
2484 | default y |
2485 | help | |
2486 | Compile the kernel with support for the retbleed=ibpb mitigation. | |
2487 | ||
2488 | config CPU_IBRS_ENTRY | |
2489 | bool "Enable IBRS on kernel entry" | |
b648ab48 | 2490 | depends on CPU_SUP_INTEL && X86_64 |
f43b9876 PZ |
2491 | default y |
2492 | help | |
2493 | Compile the kernel with support for the spectre_v2=ibrs mitigation. | |
2494 | This mitigates both spectre_v2 and retbleed at great cost to | |
2495 | performance. | |
2496 | ||
2497 | config SLS | |
2498 | bool "Mitigate Straight-Line-Speculation" | |
2499 | depends on CC_HAS_SLS && X86_64 | |
2500 | select OBJTOOL if HAVE_OBJTOOL | |
2501 | default n | |
2502 | help | |
2503 | Compile the kernel with straight-line-speculation options to guard | |
2504 | against straight line speculation. The kernel image might be slightly | |
2505 | larger. | |
2506 | ||
2507 | endif | |
2508 | ||
3072e413 MH |
2509 | config ARCH_HAS_ADD_PAGES |
2510 | def_bool y | |
5c11f00b | 2511 | depends on ARCH_ENABLE_MEMORY_HOTPLUG |
3072e413 | 2512 | |
f91ef222 OS |
2513 | config ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE |
2514 | def_bool y | |
2515 | ||
da85f865 | 2516 | menu "Power management and ACPI options" |
e279b6c1 SR |
2517 | |
2518 | config ARCH_HIBERNATION_HEADER | |
3c2362e6 | 2519 | def_bool y |
44556530 | 2520 | depends on HIBERNATION |
e279b6c1 SR |
2521 | |
2522 | source "kernel/power/Kconfig" | |
2523 | ||
2524 | source "drivers/acpi/Kconfig" | |
2525 | ||
a6b68076 | 2526 | config X86_APM_BOOT |
6fc108a0 | 2527 | def_bool y |
282e5aab | 2528 | depends on APM |
a6b68076 | 2529 | |
e279b6c1 SR |
2530 | menuconfig APM |
2531 | tristate "APM (Advanced Power Management) BIOS support" | |
efefa6f6 | 2532 | depends on X86_32 && PM_SLEEP |
a7f7f624 | 2533 | help |
e279b6c1 SR |
2534 | APM is a BIOS specification for saving power using several different |
2535 | techniques. This is mostly useful for battery powered laptops with | |
2536 | APM compliant BIOSes. If you say Y here, the system time will be | |
2537 | reset after a RESUME operation, the /proc/apm device will provide | |
2538 | battery status information, and user-space programs will receive | |
2539 | notification of APM "events" (e.g. battery status change). | |
2540 | ||
2541 | If you select "Y" here, you can disable actual use of the APM | |
2542 | BIOS by passing the "apm=off" option to the kernel at boot time. | |
2543 | ||
2544 | Note that the APM support is almost completely disabled for | |
2545 | machines with more than one CPU. | |
2546 | ||
2547 | In order to use APM, you will need supporting software. For location | |
151f4e2b | 2548 | and more information, read <file:Documentation/power/apm-acpi.rst> |
2dc98fd3 | 2549 | and the Battery Powered Linux mini-HOWTO, available from |
e279b6c1 SR |
2550 | <http://www.tldp.org/docs.html#howto>. |
2551 | ||
2552 | This driver does not spin down disk drives (see the hdparm(8) | |
2553 | manpage ("man 8 hdparm") for that), and it doesn't turn off | |
2554 | VESA-compliant "green" monitors. | |
2555 | ||
2556 | This driver does not support the TI 4000M TravelMate and the ACER | |
2557 | 486/DX4/75 because they don't have compliant BIOSes. Many "green" | |
2558 | desktop machines also don't have compliant BIOSes, and this driver | |
2559 | may cause those machines to panic during the boot phase. | |
2560 | ||
2561 | Generally, if you don't have a battery in your machine, there isn't | |
2562 | much point in using this driver and you should say N. If you get | |
2563 | random kernel OOPSes or reboots that don't seem to be related to | |
2564 | anything, try disabling/enabling this option (or disabling/enabling | |
2565 | APM in your BIOS). | |
2566 | ||
2567 | Some other things you should try when experiencing seemingly random, | |
2568 | "weird" problems: | |
2569 | ||
2570 | 1) make sure that you have enough swap space and that it is | |
2571 | enabled. | |
2572 | 2) pass the "no-hlt" option to the kernel | |
2573 | 3) switch on floating point emulation in the kernel and pass | |
2574 | the "no387" option to the kernel | |
2575 | 4) pass the "floppy=nodma" option to the kernel | |
2576 | 5) pass the "mem=4M" option to the kernel (thereby disabling | |
2577 | all but the first 4 MB of RAM) | |
2578 | 6) make sure that the CPU is not over clocked. | |
2579 | 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> | |
2580 | 8) disable the cache from your BIOS settings | |
2581 | 9) install a fan for the video card or exchange video RAM | |
2582 | 10) install a better fan for the CPU | |
2583 | 11) exchange RAM chips | |
2584 | 12) exchange the motherboard. | |
2585 | ||
2586 | To compile this driver as a module, choose M here: the | |
2587 | module will be called apm. | |
2588 | ||
2589 | if APM | |
2590 | ||
2591 | config APM_IGNORE_USER_SUSPEND | |
2592 | bool "Ignore USER SUSPEND" | |
a7f7f624 | 2593 | help |
e279b6c1 SR |
2594 | This option will ignore USER SUSPEND requests. On machines with a |
2595 | compliant APM BIOS, you want to say N. However, on the NEC Versa M | |
2596 | series notebooks, it is necessary to say Y because of a BIOS bug. | |
2597 | ||
2598 | config APM_DO_ENABLE | |
2599 | bool "Enable PM at boot time" | |
a7f7f624 | 2600 | help |
e279b6c1 SR |
2601 | Enable APM features at boot time. From page 36 of the APM BIOS |
2602 | specification: "When disabled, the APM BIOS does not automatically | |
2603 | power manage devices, enter the Standby State, enter the Suspend | |
2604 | State, or take power saving steps in response to CPU Idle calls." | |
2605 | This driver will make CPU Idle calls when Linux is idle (unless this | |
2606 | feature is turned off -- see "Do CPU IDLE calls", below). This | |
2607 | should always save battery power, but more complicated APM features | |
2608 | will be dependent on your BIOS implementation. You may need to turn | |
2609 | this option off if your computer hangs at boot time when using APM | |
2610 | support, or if it beeps continuously instead of suspending. Turn | |
2611 | this off if you have a NEC UltraLite Versa 33/C or a Toshiba | |
2612 | T400CDT. This is off by default since most machines do fine without | |
2613 | this feature. | |
2614 | ||
2615 | config APM_CPU_IDLE | |
dd8af076 | 2616 | depends on CPU_IDLE |
e279b6c1 | 2617 | bool "Make CPU Idle calls when idle" |
a7f7f624 | 2618 | help |
e279b6c1 SR |
2619 | Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. |
2620 | On some machines, this can activate improved power savings, such as | |
2621 | a slowed CPU clock rate, when the machine is idle. These idle calls | |
2622 | are made after the idle loop has run for some length of time (e.g., | |
2623 | 333 mS). On some machines, this will cause a hang at boot time or | |
2624 | whenever the CPU becomes idle. (On machines with more than one CPU, | |
2625 | this option does nothing.) | |
2626 | ||
2627 | config APM_DISPLAY_BLANK | |
2628 | bool "Enable console blanking using APM" | |
a7f7f624 | 2629 | help |
e279b6c1 SR |
2630 | Enable console blanking using the APM. Some laptops can use this to |
2631 | turn off the LCD backlight when the screen blanker of the Linux | |
2632 | virtual console blanks the screen. Note that this is only used by | |
2633 | the virtual console screen blanker, and won't turn off the backlight | |
2634 | when using the X Window system. This also doesn't have anything to | |
2635 | do with your VESA-compliant power-saving monitor. Further, this | |
2636 | option doesn't work for all laptops -- it might not turn off your | |
2637 | backlight at all, or it might print a lot of errors to the console, | |
2638 | especially if you are using gpm. | |
2639 | ||
2640 | config APM_ALLOW_INTS | |
2641 | bool "Allow interrupts during APM BIOS calls" | |
a7f7f624 | 2642 | help |
e279b6c1 SR |
2643 | Normally we disable external interrupts while we are making calls to |
2644 | the APM BIOS as a measure to lessen the effects of a badly behaving | |
2645 | BIOS implementation. The BIOS should reenable interrupts if it | |
2646 | needs to. Unfortunately, some BIOSes do not -- especially those in | |
2647 | many of the newer IBM Thinkpads. If you experience hangs when you | |
2648 | suspend, try setting this to Y. Otherwise, say N. | |
2649 | ||
e279b6c1 SR |
2650 | endif # APM |
2651 | ||
bb0a56ec | 2652 | source "drivers/cpufreq/Kconfig" |
e279b6c1 SR |
2653 | |
2654 | source "drivers/cpuidle/Kconfig" | |
2655 | ||
27471fdb AH |
2656 | source "drivers/idle/Kconfig" |
2657 | ||
e279b6c1 SR |
2658 | endmenu |
2659 | ||
e279b6c1 SR |
2660 | menu "Bus options (PCI etc.)" |
2661 | ||
e279b6c1 SR |
2662 | choice |
2663 | prompt "PCI access mode" | |
efefa6f6 | 2664 | depends on X86_32 && PCI |
e279b6c1 | 2665 | default PCI_GOANY |
a7f7f624 | 2666 | help |
e279b6c1 SR |
2667 | On PCI systems, the BIOS can be used to detect the PCI devices and |
2668 | determine their configuration. However, some old PCI motherboards | |
2669 | have BIOS bugs and may crash if this is done. Also, some embedded | |
2670 | PCI-based systems don't have any BIOS at all. Linux can also try to | |
2671 | detect the PCI hardware directly without using the BIOS. | |
2672 | ||
2673 | With this option, you can specify how Linux should detect the | |
2674 | PCI devices. If you choose "BIOS", the BIOS will be used, | |
2675 | if you choose "Direct", the BIOS won't be used, and if you | |
2676 | choose "MMConfig", then PCI Express MMCONFIG will be used. | |
2677 | If you choose "Any", the kernel will try MMCONFIG, then the | |
2678 | direct access method and falls back to the BIOS if that doesn't | |
2679 | work. If unsure, go with the default, which is "Any". | |
2680 | ||
2681 | config PCI_GOBIOS | |
2682 | bool "BIOS" | |
2683 | ||
2684 | config PCI_GOMMCONFIG | |
2685 | bool "MMConfig" | |
2686 | ||
2687 | config PCI_GODIRECT | |
2688 | bool "Direct" | |
2689 | ||
3ef0e1f8 | 2690 | config PCI_GOOLPC |
76fb6570 | 2691 | bool "OLPC XO-1" |
3ef0e1f8 AS |
2692 | depends on OLPC |
2693 | ||
2bdd1b03 AS |
2694 | config PCI_GOANY |
2695 | bool "Any" | |
2696 | ||
e279b6c1 SR |
2697 | endchoice |
2698 | ||
2699 | config PCI_BIOS | |
3c2362e6 | 2700 | def_bool y |
efefa6f6 | 2701 | depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) |
e279b6c1 SR |
2702 | |
2703 | # x86-64 doesn't support PCI BIOS access from long mode so always go direct. | |
2704 | config PCI_DIRECT | |
3c2362e6 | 2705 | def_bool y |
0aba496f | 2706 | depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) |
e279b6c1 SR |
2707 | |
2708 | config PCI_MMCONFIG | |
b45c9f36 JK |
2709 | bool "Support mmconfig PCI config space access" if X86_64 |
2710 | default y | |
4590d98f | 2711 | depends on PCI && (ACPI || JAILHOUSE_GUEST) |
b45c9f36 | 2712 | depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG) |
e279b6c1 | 2713 | |
3ef0e1f8 | 2714 | config PCI_OLPC |
2bdd1b03 AS |
2715 | def_bool y |
2716 | depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) | |
3ef0e1f8 | 2717 | |
b5401a96 AN |
2718 | config PCI_XEN |
2719 | def_bool y | |
2720 | depends on PCI && XEN | |
b5401a96 | 2721 | |
8364e1f8 JK |
2722 | config MMCONF_FAM10H |
2723 | def_bool y | |
2724 | depends on X86_64 && PCI_MMCONFIG && ACPI | |
e279b6c1 | 2725 | |
3f6ea84a | 2726 | config PCI_CNB20LE_QUIRK |
6a108a14 | 2727 | bool "Read CNB20LE Host Bridge Windows" if EXPERT |
6ea30386 | 2728 | depends on PCI |
3f6ea84a IS |
2729 | help |
2730 | Read the PCI windows out of the CNB20LE host bridge. This allows | |
2731 | PCI hotplug to work on systems with the CNB20LE chipset which do | |
2732 | not have ACPI. | |
2733 | ||
64a5fed6 BH |
2734 | There's no public spec for this chipset, and this functionality |
2735 | is known to be incomplete. | |
2736 | ||
2737 | You should say N unless you know you need this. | |
2738 | ||
3a495511 | 2739 | config ISA_BUS |
17a2a129 | 2740 | bool "ISA bus support on modern systems" if EXPERT |
3a495511 | 2741 | help |
17a2a129 WBG |
2742 | Expose ISA bus device drivers and options available for selection and |
2743 | configuration. Enable this option if your target machine has an ISA | |
2744 | bus. ISA is an older system, displaced by PCI and newer bus | |
2745 | architectures -- if your target machine is modern, it probably does | |
2746 | not have an ISA bus. | |
3a495511 WBG |
2747 | |
2748 | If unsure, say N. | |
2749 | ||
1c00f016 | 2750 | # x86_64 have no ISA slots, but can have ISA-style DMA. |
e279b6c1 | 2751 | config ISA_DMA_API |
1c00f016 DR |
2752 | bool "ISA-style DMA support" if (X86_64 && EXPERT) |
2753 | default y | |
2754 | help | |
2755 | Enables ISA-style DMA support for devices requiring such controllers. | |
2756 | If unsure, say Y. | |
e279b6c1 | 2757 | |
51e68d05 LT |
2758 | if X86_32 |
2759 | ||
e279b6c1 SR |
2760 | config ISA |
2761 | bool "ISA support" | |
a7f7f624 | 2762 | help |
e279b6c1 SR |
2763 | Find out whether you have ISA slots on your motherboard. ISA is the |
2764 | name of a bus system, i.e. the way the CPU talks to the other stuff | |
2765 | inside your box. Other bus systems are PCI, EISA, MicroChannel | |
2766 | (MCA) or VESA. ISA is an older system, now being displaced by PCI; | |
2767 | newer boards don't support it. If you have ISA, say Y, otherwise N. | |
2768 | ||
e279b6c1 SR |
2769 | config SCx200 |
2770 | tristate "NatSemi SCx200 support" | |
a7f7f624 | 2771 | help |
e279b6c1 SR |
2772 | This provides basic support for National Semiconductor's |
2773 | (now AMD's) Geode processors. The driver probes for the | |
2774 | PCI-IDs of several on-chip devices, so its a good dependency | |
2775 | for other scx200_* drivers. | |
2776 | ||
2777 | If compiled as a module, the driver is named scx200. | |
2778 | ||
2779 | config SCx200HR_TIMER | |
2780 | tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" | |
592913ec | 2781 | depends on SCx200 |
e279b6c1 | 2782 | default y |
a7f7f624 | 2783 | help |
e279b6c1 SR |
2784 | This driver provides a clocksource built upon the on-chip |
2785 | 27MHz high-resolution timer. Its also a workaround for | |
2786 | NSC Geode SC-1100's buggy TSC, which loses time when the | |
2787 | processor goes idle (as is done by the scheduler). The | |
2788 | other workaround is idle=poll boot option. | |
2789 | ||
3ef0e1f8 AS |
2790 | config OLPC |
2791 | bool "One Laptop Per Child support" | |
54008979 | 2792 | depends on !X86_PAE |
3c554946 | 2793 | select GPIOLIB |
dc3119e7 | 2794 | select OF |
45bb1674 | 2795 | select OF_PROMTREE |
b4e51854 | 2796 | select IRQ_DOMAIN |
0c3d931b | 2797 | select OLPC_EC |
a7f7f624 | 2798 | help |
3ef0e1f8 AS |
2799 | Add support for detecting the unique features of the OLPC |
2800 | XO hardware. | |
2801 | ||
a3128588 DD |
2802 | config OLPC_XO1_PM |
2803 | bool "OLPC XO-1 Power Management" | |
fa112cf1 | 2804 | depends on OLPC && MFD_CS5535=y && PM_SLEEP |
a7f7f624 | 2805 | help |
97c4cb71 | 2806 | Add support for poweroff and suspend of the OLPC XO-1 laptop. |
bf1ebf00 | 2807 | |
cfee9597 DD |
2808 | config OLPC_XO1_RTC |
2809 | bool "OLPC XO-1 Real Time Clock" | |
2810 | depends on OLPC_XO1_PM && RTC_DRV_CMOS | |
a7f7f624 | 2811 | help |
cfee9597 DD |
2812 | Add support for the XO-1 real time clock, which can be used as a |
2813 | programmable wakeup source. | |
2814 | ||
7feda8e9 DD |
2815 | config OLPC_XO1_SCI |
2816 | bool "OLPC XO-1 SCI extras" | |
92e830f2 | 2817 | depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y |
ed8e47fe | 2818 | depends on INPUT=y |
d8d01a63 | 2819 | select POWER_SUPPLY |
a7f7f624 | 2820 | help |
7feda8e9 | 2821 | Add support for SCI-based features of the OLPC XO-1 laptop: |
7bc74b3d | 2822 | - EC-driven system wakeups |
7feda8e9 | 2823 | - Power button |
7bc74b3d | 2824 | - Ebook switch |
2cf2baea | 2825 | - Lid switch |
e1040ac6 DD |
2826 | - AC adapter status updates |
2827 | - Battery status updates | |
7feda8e9 | 2828 | |
a0f30f59 DD |
2829 | config OLPC_XO15_SCI |
2830 | bool "OLPC XO-1.5 SCI extras" | |
d8d01a63 DD |
2831 | depends on OLPC && ACPI |
2832 | select POWER_SUPPLY | |
a7f7f624 | 2833 | help |
a0f30f59 DD |
2834 | Add support for SCI-based features of the OLPC XO-1.5 laptop: |
2835 | - EC-driven system wakeups | |
2836 | - AC adapter status updates | |
2837 | - Battery status updates | |
bf1ebf00 | 2838 | |
d4f3e350 EW |
2839 | config ALIX |
2840 | bool "PCEngines ALIX System Support (LED setup)" | |
2841 | select GPIOLIB | |
a7f7f624 | 2842 | help |
d4f3e350 EW |
2843 | This option enables system support for the PCEngines ALIX. |
2844 | At present this just sets up LEDs for GPIO control on | |
2845 | ALIX2/3/6 boards. However, other system specific setup should | |
2846 | get added here. | |
2847 | ||
2848 | Note: You must still enable the drivers for GPIO and LED support | |
2849 | (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs | |
2850 | ||
2851 | Note: You have to set alix.force=1 for boards with Award BIOS. | |
2852 | ||
da4e3302 PP |
2853 | config NET5501 |
2854 | bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" | |
2855 | select GPIOLIB | |
a7f7f624 | 2856 | help |
da4e3302 PP |
2857 | This option enables system support for the Soekris Engineering net5501. |
2858 | ||
3197059a PP |
2859 | config GEOS |
2860 | bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" | |
2861 | select GPIOLIB | |
2862 | depends on DMI | |
a7f7f624 | 2863 | help |
3197059a PP |
2864 | This option enables system support for the Traverse Technologies GEOS. |
2865 | ||
7d029125 VD |
2866 | config TS5500 |
2867 | bool "Technologic Systems TS-5500 platform support" | |
2868 | depends on MELAN | |
2869 | select CHECK_SIGNATURE | |
2870 | select NEW_LEDS | |
2871 | select LEDS_CLASS | |
a7f7f624 | 2872 | help |
7d029125 VD |
2873 | This option enables system support for the Technologic Systems TS-5500. |
2874 | ||
bc0120fd SR |
2875 | endif # X86_32 |
2876 | ||
23ac4ae8 | 2877 | config AMD_NB |
e279b6c1 | 2878 | def_bool y |
0e152cd7 | 2879 | depends on CPU_SUP_AMD && PCI |
e279b6c1 | 2880 | |
e279b6c1 SR |
2881 | endmenu |
2882 | ||
1572497c | 2883 | menu "Binary Emulations" |
e279b6c1 SR |
2884 | |
2885 | config IA32_EMULATION | |
2886 | bool "IA32 Emulation" | |
2887 | depends on X86_64 | |
39f88911 | 2888 | select ARCH_WANT_OLD_COMPAT_IPC |
d1603990 | 2889 | select BINFMT_ELF |
39f88911 | 2890 | select COMPAT_OLD_SIGACTION |
a7f7f624 | 2891 | help |
5fd92e65 L |
2892 | Include code to run legacy 32-bit programs under a |
2893 | 64-bit kernel. You should likely turn this on, unless you're | |
2894 | 100% sure that you don't have any 32-bit programs left. | |
e279b6c1 | 2895 | |
83a44a4f | 2896 | config X86_X32_ABI |
6ea30386 | 2897 | bool "x32 ABI for 64-bit mode" |
9b54050b | 2898 | depends on X86_64 |
aaeed6ec NC |
2899 | # llvm-objcopy does not convert x86_64 .note.gnu.property or |
2900 | # compressed debug sections to x86_x32 properly: | |
2901 | # https://github.com/ClangBuiltLinux/linux/issues/514 | |
2902 | # https://github.com/ClangBuiltLinux/linux/issues/1141 | |
2903 | depends on $(success,$(OBJCOPY) --version | head -n1 | grep -qv llvm) | |
a7f7f624 | 2904 | help |
5fd92e65 L |
2905 | Include code to run binaries for the x32 native 32-bit ABI |
2906 | for 64-bit processors. An x32 process gets access to the | |
2907 | full 64-bit register file and wide data path while leaving | |
2908 | pointers at 32 bits for smaller memory footprint. | |
2909 | ||
953fee1d IM |
2910 | config COMPAT_32 |
2911 | def_bool y | |
2912 | depends on IA32_EMULATION || X86_32 | |
2913 | select HAVE_UID16 | |
2914 | select OLD_SIGSUSPEND3 | |
2915 | ||
e279b6c1 | 2916 | config COMPAT |
3c2362e6 | 2917 | def_bool y |
83a44a4f | 2918 | depends on IA32_EMULATION || X86_X32_ABI |
e279b6c1 SR |
2919 | |
2920 | config COMPAT_FOR_U64_ALIGNMENT | |
3120e25e | 2921 | def_bool y |
a9251280 | 2922 | depends on COMPAT |
ee009e4a | 2923 | |
e279b6c1 SR |
2924 | endmenu |
2925 | ||
e5beae16 KP |
2926 | config HAVE_ATOMIC_IOMAP |
2927 | def_bool y | |
2928 | depends on X86_32 | |
2929 | ||
edf88417 | 2930 | source "arch/x86/kvm/Kconfig" |
5e8ebd84 JD |
2931 | |
2932 | source "arch/x86/Kconfig.assembler" |