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" | |
8f9ca475 | 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 | |
117ed454 | 17 | select HAVE_DEBUG_STACKOVERFLOW |
341c787e IM |
18 | select MODULES_USE_ELF_REL |
19 | select OLD_SIGACTION | |
7ac87074 | 20 | select GENERIC_VDSO_32 |
daa93fab SR |
21 | |
22 | config X86_64 | |
3120e25e JB |
23 | def_bool y |
24 | depends on 64BIT | |
d94e0685 | 25 | # Options that are inherently 64-bit kernel only: |
4eb0716e | 26 | select ARCH_HAS_GIGANTIC_PAGE |
c12d3362 | 27 | select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 |
d94e0685 IM |
28 | select ARCH_USE_CMPXCHG_LOCKREF |
29 | select HAVE_ARCH_SOFT_DIRTY | |
30 | select MODULES_USE_ELF_RELA | |
f616ab59 | 31 | select NEED_DMA_MAP_STATE |
09230cbc | 32 | select SWIOTLB |
1032c0ba | 33 | |
518049d9 SRV |
34 | config FORCE_DYNAMIC_FTRACE |
35 | def_bool y | |
36 | depends on X86_32 | |
37 | depends on FUNCTION_TRACER | |
38 | select DYNAMIC_FTRACE | |
39 | help | |
40 | We keep the static function tracing (!DYNAMIC_FTRACE) around | |
41 | in order to test the non static function tracing in the | |
42 | generic code, as other architectures still use it. But we | |
43 | only need to keep it around for x86_64. No need to keep it | |
44 | for x86_32. For x86_32, force DYNAMIC_FTRACE. | |
d94e0685 IM |
45 | # |
46 | # Arch settings | |
47 | # | |
48 | # ( Note that options that are marked 'if X86_64' could in principle be | |
49 | # ported to 32-bit as well. ) | |
50 | # | |
8d5fffb9 | 51 | config X86 |
3c2362e6 | 52 | def_bool y |
c763ea26 IM |
53 | # |
54 | # Note: keep this list sorted alphabetically | |
55 | # | |
6471b825 IM |
56 | select ACPI_LEGACY_TABLES_LOOKUP if ACPI |
57 | select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI | |
942fa985 | 58 | select ARCH_32BIT_OFF_T if X86_32 |
2a21ad57 | 59 | select ARCH_CLOCKSOURCE_INIT |
c763ea26 | 60 | select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI |
fa5b6ec9 | 61 | select ARCH_HAS_DEBUG_VIRTUAL |
21266be9 | 62 | select ARCH_HAS_DEVMEM_IS_ALLOWED |
6471b825 | 63 | select ARCH_HAS_ELF_RANDOMIZE |
72d93104 | 64 | select ARCH_HAS_FAST_MULTIPLIER |
316d097c | 65 | select ARCH_HAS_FILTER_PGPROT |
6974f0c4 | 66 | select ARCH_HAS_FORTIFY_SOURCE |
957e3fac | 67 | select ARCH_HAS_GCOV_PROFILE_ALL |
5c9a8750 | 68 | select ARCH_HAS_KCOV if X86_64 |
0c9c1d56 | 69 | select ARCH_HAS_MEM_ENCRYPT |
10bcc80e | 70 | select ARCH_HAS_MEMBARRIER_SYNC_CORE |
0ebeea8c | 71 | select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE |
c763ea26 | 72 | select ARCH_HAS_PMEM_API if X86_64 |
17596731 | 73 | select ARCH_HAS_PTE_DEVMAP if X86_64 |
3010a5ea | 74 | select ARCH_HAS_PTE_SPECIAL |
0aed55af | 75 | select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64 |
092b31aa | 76 | select ARCH_HAS_UACCESS_MCSAFE if X86_64 && X86_MCE |
d2852a22 | 77 | select ARCH_HAS_SET_MEMORY |
d253ca0c | 78 | select ARCH_HAS_SET_DIRECT_MAP |
ad21fc4f LA |
79 | select ARCH_HAS_STRICT_KERNEL_RWX |
80 | select ARCH_HAS_STRICT_MODULE_RWX | |
ac1ab12a | 81 | select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE |
25c619e5 | 82 | select ARCH_HAS_SYSCALL_WRAPPER |
c6d30853 | 83 | select ARCH_HAS_UBSAN_SANITIZE_ALL |
6471b825 IM |
84 | select ARCH_HAVE_NMI_SAFE_CMPXCHG |
85 | select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI | |
77fbbc81 | 86 | select ARCH_MIGHT_HAVE_PC_PARPORT |
5e2c18c0 | 87 | select ARCH_MIGHT_HAVE_PC_SERIO |
3599fe12 | 88 | select ARCH_STACKWALK |
2c870e61 | 89 | select ARCH_SUPPORTS_ACPI |
6471b825 | 90 | select ARCH_SUPPORTS_ATOMIC_RMW |
6471b825 IM |
91 | select ARCH_SUPPORTS_NUMA_BALANCING if X86_64 |
92 | select ARCH_USE_BUILTIN_BSWAP | |
6471b825 IM |
93 | select ARCH_USE_QUEUED_RWLOCKS |
94 | select ARCH_USE_QUEUED_SPINLOCKS | |
2ce0d7f9 | 95 | select ARCH_USE_SYM_ANNOTATIONS |
ce4a4e56 | 96 | select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH |
81c22041 | 97 | select ARCH_WANT_DEFAULT_BPF_JIT if X86_64 |
c763ea26 | 98 | select ARCH_WANTS_DYNAMIC_TASK_STRUCT |
3876d4a3 | 99 | select ARCH_WANT_HUGE_PMD_SHARE |
38d8b4e6 | 100 | select ARCH_WANTS_THP_SWAP if X86_64 |
10916706 | 101 | select BUILDTIME_TABLE_SORT |
6471b825 | 102 | select CLKEVT_I8253 |
6471b825 IM |
103 | select CLOCKSOURCE_VALIDATE_LAST_CYCLE |
104 | select CLOCKSOURCE_WATCHDOG | |
6471b825 | 105 | select DCACHE_WORD_ACCESS |
45471cd9 LT |
106 | select EDAC_ATOMIC_SCRUB |
107 | select EDAC_SUPPORT | |
6471b825 IM |
108 | select GENERIC_CLOCKEVENTS |
109 | select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC) | |
110 | select GENERIC_CLOCKEVENTS_MIN_ADJUST | |
111 | select GENERIC_CMOS_UPDATE | |
112 | select GENERIC_CPU_AUTOPROBE | |
61dc0f55 | 113 | select GENERIC_CPU_VULNERABILITIES |
5b7c73e0 | 114 | select GENERIC_EARLY_IOREMAP |
6471b825 IM |
115 | select GENERIC_FIND_FIRST_BIT |
116 | select GENERIC_IOMAP | |
c7d6c9dd | 117 | select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP |
0fa115da | 118 | select GENERIC_IRQ_MATRIX_ALLOCATOR if X86_LOCAL_APIC |
ad7a929f | 119 | select GENERIC_IRQ_MIGRATION if SMP |
6471b825 | 120 | select GENERIC_IRQ_PROBE |
c201c917 | 121 | select GENERIC_IRQ_RESERVATION_MODE |
6471b825 IM |
122 | select GENERIC_IRQ_SHOW |
123 | select GENERIC_PENDING_IRQ if SMP | |
2ae27137 | 124 | select GENERIC_PTDUMP |
6471b825 IM |
125 | select GENERIC_SMP_IDLE_THREAD |
126 | select GENERIC_STRNCPY_FROM_USER | |
127 | select GENERIC_STRNLEN_USER | |
128 | select GENERIC_TIME_VSYSCALL | |
7ac87074 | 129 | select GENERIC_GETTIMEOFDAY |
550a77a7 | 130 | select GENERIC_VDSO_TIME_NS |
39656e83 | 131 | select GUP_GET_PTE_LOW_HIGH if X86_PAE |
17e5888e | 132 | select HARDIRQS_SW_RESEND |
7edaeb68 | 133 | select HARDLOCKUP_CHECK_TIMESTAMP if X86_64 |
6471b825 IM |
134 | select HAVE_ACPI_APEI if ACPI |
135 | select HAVE_ACPI_APEI_NMI if ACPI | |
136 | select HAVE_ALIGNED_STRUCT_PAGE if SLUB | |
6471b825 IM |
137 | select HAVE_ARCH_AUDITSYSCALL |
138 | select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE | |
139 | select HAVE_ARCH_JUMP_LABEL | |
b34006c4 | 140 | select HAVE_ARCH_JUMP_LABEL_RELATIVE |
d17a1d97 | 141 | select HAVE_ARCH_KASAN if X86_64 |
0609ae01 | 142 | select HAVE_ARCH_KASAN_VMALLOC if X86_64 |
6471b825 | 143 | select HAVE_ARCH_KGDB |
9e08f57d DC |
144 | select HAVE_ARCH_MMAP_RND_BITS if MMU |
145 | select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT | |
1b028f78 | 146 | select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT |
271ca788 | 147 | select HAVE_ARCH_PREL32_RELOCATIONS |
6471b825 | 148 | select HAVE_ARCH_SECCOMP_FILTER |
f7d83c1c | 149 | select HAVE_ARCH_THREAD_STRUCT_WHITELIST |
afaef01c | 150 | select HAVE_ARCH_STACKLEAK |
6471b825 IM |
151 | select HAVE_ARCH_TRACEHOOK |
152 | select HAVE_ARCH_TRANSPARENT_HUGEPAGE | |
a00cc7d9 | 153 | select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64 |
b64d8d1e | 154 | select HAVE_ARCH_USERFAULTFD_WP if X86_64 && USERFAULTFD |
e37e43a4 | 155 | select HAVE_ARCH_VMAP_STACK if X86_64 |
c763ea26 | 156 | select HAVE_ARCH_WITHIN_STACK_FRAMES |
2ff2b7ec | 157 | select HAVE_ASM_MODVERSIONS |
6471b825 IM |
158 | select HAVE_CMPXCHG_DOUBLE |
159 | select HAVE_CMPXCHG_LOCAL | |
160 | select HAVE_CONTEXT_TRACKING if X86_64 | |
c1bd55f9 | 161 | select HAVE_COPY_THREAD_TLS |
cf4db259 | 162 | select HAVE_C_RECORDMCOUNT |
6471b825 | 163 | select HAVE_DEBUG_KMEMLEAK |
6471b825 | 164 | select HAVE_DMA_CONTIGUOUS |
677aa9f7 | 165 | select HAVE_DYNAMIC_FTRACE |
06aeaaea | 166 | select HAVE_DYNAMIC_FTRACE_WITH_REGS |
562955fe | 167 | select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS |
03f5781b | 168 | select HAVE_EBPF_JIT |
58340a07 | 169 | select HAVE_EFFICIENT_UNALIGNED_ACCESS |
6630a8e5 | 170 | select HAVE_EISA |
5f56a5df | 171 | select HAVE_EXIT_THREAD |
67a929e0 | 172 | select HAVE_FAST_GUP |
644e0e8d | 173 | select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE |
6471b825 | 174 | select HAVE_FTRACE_MCOUNT_RECORD |
6471b825 IM |
175 | select HAVE_FUNCTION_GRAPH_TRACER |
176 | select HAVE_FUNCTION_TRACER | |
6b90bd4b | 177 | select HAVE_GCC_PLUGINS |
6471b825 IM |
178 | select HAVE_HW_BREAKPOINT |
179 | select HAVE_IDE | |
180 | select HAVE_IOREMAP_PROT | |
181 | select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64 | |
182 | select HAVE_IRQ_TIME_ACCOUNTING | |
2e9f3bdd | 183 | select HAVE_KERNEL_BZIP2 |
6471b825 IM |
184 | select HAVE_KERNEL_GZIP |
185 | select HAVE_KERNEL_LZ4 | |
2e9f3bdd | 186 | select HAVE_KERNEL_LZMA |
13510997 | 187 | select HAVE_KERNEL_LZO |
6471b825 IM |
188 | select HAVE_KERNEL_XZ |
189 | select HAVE_KPROBES | |
190 | select HAVE_KPROBES_ON_FTRACE | |
540adea3 | 191 | select HAVE_FUNCTION_ERROR_INJECTION |
6471b825 IM |
192 | select HAVE_KRETPROBES |
193 | select HAVE_KVM | |
194 | select HAVE_LIVEPATCH if X86_64 | |
0102752e | 195 | select HAVE_MIXED_BREAKPOINTS_REGS |
ee9f8fce | 196 | select HAVE_MOD_ARCH_SPECIFIC |
9f132f7e | 197 | select HAVE_MOVE_PMD |
42a0bb3f | 198 | select HAVE_NMI |
6471b825 IM |
199 | select HAVE_OPROFILE |
200 | select HAVE_OPTPROBES | |
201 | select HAVE_PCSPKR_PLATFORM | |
202 | select HAVE_PERF_EVENTS | |
c01d4323 | 203 | select HAVE_PERF_EVENTS_NMI |
92e5aae4 | 204 | select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI |
eb01d42a | 205 | select HAVE_PCI |
c5e63197 | 206 | select HAVE_PERF_REGS |
c5ebcedb | 207 | select HAVE_PERF_USER_STACK_DUMP |
ff2e6d72 | 208 | select MMU_GATHER_RCU_TABLE_FREE if PARAVIRT |
6471b825 | 209 | select HAVE_REGS_AND_STACK_ACCESS_API |
6415b38b | 210 | select HAVE_RELIABLE_STACKTRACE if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION |
3c88ee19 | 211 | select HAVE_FUNCTION_ARG_ACCESS_API |
d148eac0 | 212 | select HAVE_STACKPROTECTOR if CC_HAS_SANE_STACKPROTECTOR |
c763ea26 | 213 | select HAVE_STACK_VALIDATION if X86_64 |
d6761b8f | 214 | select HAVE_RSEQ |
6471b825 | 215 | select HAVE_SYSCALL_TRACEPOINTS |
6471b825 | 216 | select HAVE_UNSTABLE_SCHED_CLOCK |
7c68af6e | 217 | select HAVE_USER_RETURN_NOTIFIER |
7ac87074 | 218 | select HAVE_GENERIC_VDSO |
05736e4a | 219 | select HOTPLUG_SMT if SMP |
c0185808 | 220 | select IRQ_FORCED_THREADING |
86596f0a | 221 | select NEED_SG_DMA_LENGTH |
2eac9c2d | 222 | select PCI_DOMAINS if PCI |
625210cf | 223 | select PCI_LOCKLESS_CONFIG if PCI |
6471b825 | 224 | select PERF_EVENTS |
3195ef59 | 225 | select RTC_LIB |
d6faca40 | 226 | select RTC_MC146818_LIB |
6471b825 | 227 | select SPARSE_IRQ |
83fe27ea | 228 | select SRCU |
6471b825 | 229 | select SYSCTL_EXCEPTION_TRACE |
15f4eae7 | 230 | select THREAD_INFO_IN_TASK |
6471b825 IM |
231 | select USER_STACKTRACE_SUPPORT |
232 | select VIRT_TO_BUS | |
6471b825 | 233 | select X86_FEATURE_NAMES if PROC_FS |
0c608dad | 234 | select PROC_PID_ARCH_STATUS if PROC_FS |
9e2b4be3 | 235 | imply IMA_SECURE_AND_OR_TRUSTED_BOOT if EFI |
7d8330a5 | 236 | |
ba7e4d13 | 237 | config INSTRUCTION_DECODER |
3120e25e JB |
238 | def_bool y |
239 | depends on KPROBES || PERF_EVENTS || UPROBES | |
ba7e4d13 | 240 | |
51b26ada LT |
241 | config OUTPUT_FORMAT |
242 | string | |
243 | default "elf32-i386" if X86_32 | |
244 | default "elf64-x86-64" if X86_64 | |
245 | ||
8d5fffb9 | 246 | config LOCKDEP_SUPPORT |
3c2362e6 | 247 | def_bool y |
8d5fffb9 SR |
248 | |
249 | config STACKTRACE_SUPPORT | |
3c2362e6 | 250 | def_bool y |
8d5fffb9 | 251 | |
8d5fffb9 | 252 | config MMU |
3c2362e6 | 253 | def_bool y |
8d5fffb9 | 254 | |
9e08f57d DC |
255 | config ARCH_MMAP_RND_BITS_MIN |
256 | default 28 if 64BIT | |
257 | default 8 | |
258 | ||
259 | config ARCH_MMAP_RND_BITS_MAX | |
260 | default 32 if 64BIT | |
261 | default 16 | |
262 | ||
263 | config ARCH_MMAP_RND_COMPAT_BITS_MIN | |
264 | default 8 | |
265 | ||
266 | config ARCH_MMAP_RND_COMPAT_BITS_MAX | |
267 | default 16 | |
268 | ||
8d5fffb9 SR |
269 | config SBUS |
270 | bool | |
271 | ||
272 | config GENERIC_ISA_DMA | |
3120e25e JB |
273 | def_bool y |
274 | depends on ISA_DMA_API | |
8d5fffb9 | 275 | |
8d5fffb9 | 276 | config GENERIC_BUG |
3c2362e6 | 277 | def_bool y |
8d5fffb9 | 278 | depends on BUG |
b93a531e JB |
279 | select GENERIC_BUG_RELATIVE_POINTERS if X86_64 |
280 | ||
281 | config GENERIC_BUG_RELATIVE_POINTERS | |
282 | bool | |
8d5fffb9 | 283 | |
8d5fffb9 | 284 | config ARCH_MAY_HAVE_PC_FDC |
3120e25e JB |
285 | def_bool y |
286 | depends on ISA_DMA_API | |
8d5fffb9 | 287 | |
1032c0ba SR |
288 | config GENERIC_CALIBRATE_DELAY |
289 | def_bool y | |
290 | ||
9a0b8415 | 291 | config ARCH_HAS_CPU_RELAX |
292 | def_bool y | |
293 | ||
1b27d05b PE |
294 | config ARCH_HAS_CACHE_LINE_SIZE |
295 | def_bool y | |
296 | ||
316d097c DH |
297 | config ARCH_HAS_FILTER_PGPROT |
298 | def_bool y | |
299 | ||
dd5af90a | 300 | config HAVE_SETUP_PER_CPU_AREA |
89c9c4c5 | 301 | def_bool y |
b32ef636 | 302 | |
08fc4580 TH |
303 | config NEED_PER_CPU_EMBED_FIRST_CHUNK |
304 | def_bool y | |
305 | ||
306 | config NEED_PER_CPU_PAGE_FIRST_CHUNK | |
11124411 TH |
307 | def_bool y |
308 | ||
801e4062 JB |
309 | config ARCH_HIBERNATION_POSSIBLE |
310 | def_bool y | |
801e4062 | 311 | |
f4cb5700 JB |
312 | config ARCH_SUSPEND_POSSIBLE |
313 | def_bool y | |
f4cb5700 | 314 | |
53313b2c SC |
315 | config ARCH_WANT_GENERAL_HUGETLB |
316 | def_bool y | |
317 | ||
8d5fffb9 | 318 | config ZONE_DMA32 |
e0fd24a3 | 319 | def_bool y if X86_64 |
8d5fffb9 | 320 | |
8d5fffb9 | 321 | config AUDIT_ARCH |
e0fd24a3 | 322 | def_bool y if X86_64 |
8d5fffb9 | 323 | |
6a11f75b AM |
324 | config ARCH_SUPPORTS_DEBUG_PAGEALLOC |
325 | def_bool y | |
326 | ||
d6f2d75a AR |
327 | config KASAN_SHADOW_OFFSET |
328 | hex | |
329 | depends on KASAN | |
330 | default 0xdffffc0000000000 | |
331 | ||
69575d38 SW |
332 | config HAVE_INTEL_TXT |
333 | def_bool y | |
6ea30386 | 334 | depends on INTEL_IOMMU && ACPI |
69575d38 | 335 | |
6b0c3d44 SR |
336 | config X86_32_SMP |
337 | def_bool y | |
338 | depends on X86_32 && SMP | |
339 | ||
340 | config X86_64_SMP | |
341 | def_bool y | |
342 | depends on X86_64 && SMP | |
343 | ||
ccbeed3a TH |
344 | config X86_32_LAZY_GS |
345 | def_bool y | |
8458f8c2 | 346 | depends on X86_32 && !STACKPROTECTOR |
ccbeed3a | 347 | |
2b144498 SD |
348 | config ARCH_SUPPORTS_UPROBES |
349 | def_bool y | |
350 | ||
d20642f0 RH |
351 | config FIX_EARLYCON_MEM |
352 | def_bool y | |
353 | ||
94d49eb3 KS |
354 | config DYNAMIC_PHYSICAL_MASK |
355 | bool | |
356 | ||
98233368 KS |
357 | config PGTABLE_LEVELS |
358 | int | |
77ef56e4 | 359 | default 5 if X86_5LEVEL |
98233368 KS |
360 | default 4 if X86_64 |
361 | default 3 if X86_PAE | |
362 | default 2 | |
363 | ||
2a61f474 MY |
364 | config CC_HAS_SANE_STACKPROTECTOR |
365 | bool | |
366 | default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT | |
367 | default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC)) | |
368 | help | |
369 | We have to make sure stack protector is unconditionally disabled if | |
370 | the compiler produces broken code. | |
371 | ||
506f1d07 SR |
372 | menu "Processor type and features" |
373 | ||
5ee71535 RD |
374 | config ZONE_DMA |
375 | bool "DMA memory allocation support" if EXPERT | |
376 | default y | |
377 | help | |
378 | DMA memory allocation support allows devices with less than 32-bit | |
379 | addressing to allocate within the first 16MB of address space. | |
380 | Disable if no such devices will be used. | |
381 | ||
382 | If unsure, say Y. | |
383 | ||
506f1d07 SR |
384 | config SMP |
385 | bool "Symmetric multi-processing support" | |
386 | ---help--- | |
387 | This enables support for systems with more than one CPU. If you have | |
4a474157 RG |
388 | a system with only one CPU, say N. If you have a system with more |
389 | than one CPU, say Y. | |
506f1d07 | 390 | |
4a474157 | 391 | If you say N here, the kernel will run on uni- and multiprocessor |
506f1d07 SR |
392 | machines, but will use only one CPU of a multiprocessor machine. If |
393 | you say Y here, the kernel will run on many, but not all, | |
4a474157 | 394 | uniprocessor machines. On a uniprocessor machine, the kernel |
506f1d07 SR |
395 | will run faster if you say N here. |
396 | ||
397 | Note that if you say Y here and choose architecture "586" or | |
398 | "Pentium" under "Processor family", the kernel will not work on 486 | |
399 | architectures. Similarly, multiprocessor kernels for the "PPro" | |
400 | architecture may not work on all Pentium based boards. | |
401 | ||
402 | People using multiprocessor machines who say Y here should also say | |
403 | Y to "Enhanced Real Time Clock Support", below. The "Advanced Power | |
404 | Management" code will be disabled if you say Y here. | |
405 | ||
cb1aaebe | 406 | See also <file:Documentation/x86/i386/IO-APIC.rst>, |
4f4cfa6c | 407 | <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at |
506f1d07 SR |
408 | <http://www.tldp.org/docs.html#howto>. |
409 | ||
410 | If you don't know what to do here, say N. | |
411 | ||
9def39be JT |
412 | config X86_FEATURE_NAMES |
413 | bool "Processor feature human-readable names" if EMBEDDED | |
414 | default y | |
415 | ---help--- | |
416 | This option compiles in a table of x86 feature bits and corresponding | |
417 | names. This is required to support /proc/cpuinfo and a few kernel | |
418 | messages. You can disable this to save space, at the expense of | |
419 | making those few kernel messages show numeric feature bits instead. | |
420 | ||
421 | If in doubt, say Y. | |
422 | ||
06cd9a7d YL |
423 | config X86_X2APIC |
424 | bool "Support x2apic" | |
19e3d60d | 425 | depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST) |
06cd9a7d YL |
426 | ---help--- |
427 | This enables x2apic support on CPUs that have this feature. | |
428 | ||
429 | This allows 32-bit apic IDs (so it can support very large systems), | |
430 | and accesses the local apic via MSRs not via mmio. | |
431 | ||
06cd9a7d YL |
432 | If you don't know what to do here, say N. |
433 | ||
6695c85b | 434 | config X86_MPPARSE |
6e87f9b7 | 435 | bool "Enable MPS table" if ACPI || SFI |
7a527688 | 436 | default y |
5ab74722 | 437 | depends on X86_LOCAL_APIC |
8f9ca475 | 438 | ---help--- |
6695c85b YL |
439 | For old smp systems that do not have proper acpi support. Newer systems |
440 | (esp with 64bit cpus) with acpi support, MADT and DSDT will override it | |
6695c85b | 441 | |
ddd70cf9 | 442 | config GOLDFISH |
b03b016f KK |
443 | def_bool y |
444 | depends on X86_GOLDFISH | |
ddd70cf9 | 445 | |
76b04384 DW |
446 | config RETPOLINE |
447 | bool "Avoid speculative indirect branches in kernel" | |
448 | default y | |
d5028ba8 | 449 | select STACK_VALIDATION if HAVE_STACK_VALIDATION |
76b04384 DW |
450 | help |
451 | Compile kernel with the retpoline compiler options to guard against | |
452 | kernel-to-user data leaks by avoiding speculative indirect | |
453 | branches. Requires a compiler with -mindirect-branch=thunk-extern | |
454 | support for full protection. The kernel may run slower. | |
455 | ||
e6d42931 JW |
456 | config X86_CPU_RESCTRL |
457 | bool "x86 CPU resource control support" | |
6fe07ce3 | 458 | depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD) |
59fe5a77 | 459 | select KERNFS |
e79f15a4 | 460 | select PROC_CPU_RESCTRL if PROC_FS |
78e99b4a | 461 | help |
e6d42931 | 462 | Enable x86 CPU resource control support. |
6fe07ce3 BM |
463 | |
464 | Provide support for the allocation and monitoring of system resources | |
465 | usage by the CPU. | |
466 | ||
467 | Intel calls this Intel Resource Director Technology | |
468 | (Intel(R) RDT). More information about RDT can be found in the | |
469 | Intel x86 Architecture Software Developer Manual. | |
470 | ||
471 | AMD calls this AMD Platform Quality of Service (AMD QoS). | |
472 | More information about AMD QoS can be found in the AMD64 Technology | |
473 | Platform Quality of Service Extensions manual. | |
78e99b4a FY |
474 | |
475 | Say N if unsure. | |
476 | ||
8425091f | 477 | if X86_32 |
a0d0bb4d RD |
478 | config X86_BIGSMP |
479 | bool "Support for big SMP systems with more than 8 CPUs" | |
480 | depends on SMP | |
481 | ---help--- | |
e133f6ea | 482 | This option is needed for the systems that have more than 8 CPUs. |
a0d0bb4d | 483 | |
c5c606d9 RT |
484 | config X86_EXTENDED_PLATFORM |
485 | bool "Support for extended (non-PC) x86 platforms" | |
486 | default y | |
8f9ca475 | 487 | ---help--- |
06ac8346 IM |
488 | If you disable this option then the kernel will only support |
489 | standard PC platforms. (which covers the vast majority of | |
490 | systems out there.) | |
491 | ||
8425091f RT |
492 | If you enable this option then you'll be able to select support |
493 | for the following (non-PC) 32 bit x86 platforms: | |
cb7b8023 | 494 | Goldfish (Android emulator) |
8425091f | 495 | AMD Elan |
8425091f RT |
496 | RDC R-321x SoC |
497 | SGI 320/540 (Visual Workstation) | |
83125a3a | 498 | STA2X11-based (e.g. Northville) |
3f4110a4 | 499 | Moorestown MID devices |
06ac8346 IM |
500 | |
501 | If you have one of these systems, or if you want to build a | |
502 | generic distribution kernel, say Y here - otherwise say N. | |
8425091f | 503 | endif |
06ac8346 | 504 | |
8425091f RT |
505 | if X86_64 |
506 | config X86_EXTENDED_PLATFORM | |
507 | bool "Support for extended (non-PC) x86 platforms" | |
508 | default y | |
509 | ---help--- | |
510 | If you disable this option then the kernel will only support | |
511 | standard PC platforms. (which covers the vast majority of | |
512 | systems out there.) | |
513 | ||
514 | If you enable this option then you'll be able to select support | |
515 | for the following (non-PC) 64 bit x86 platforms: | |
44b111b5 | 516 | Numascale NumaChip |
8425091f RT |
517 | ScaleMP vSMP |
518 | SGI Ultraviolet | |
519 | ||
520 | If you have one of these systems, or if you want to build a | |
521 | generic distribution kernel, say Y here - otherwise say N. | |
522 | endif | |
c5c606d9 RT |
523 | # This is an alphabetically sorted list of 64 bit extended platforms |
524 | # Please maintain the alphabetic order if and when there are additions | |
44b111b5 SP |
525 | config X86_NUMACHIP |
526 | bool "Numascale NumaChip" | |
527 | depends on X86_64 | |
528 | depends on X86_EXTENDED_PLATFORM | |
529 | depends on NUMA | |
530 | depends on SMP | |
531 | depends on X86_X2APIC | |
f9726bfd | 532 | depends on PCI_MMCONFIG |
44b111b5 SP |
533 | ---help--- |
534 | Adds support for Numascale NumaChip large-SMP systems. Needed to | |
535 | enable more than ~168 cores. | |
536 | If you don't have one of these, you should say N here. | |
506f1d07 | 537 | |
c5c606d9 RT |
538 | config X86_VSMP |
539 | bool "ScaleMP vSMP" | |
6276a074 | 540 | select HYPERVISOR_GUEST |
c5c606d9 RT |
541 | select PARAVIRT |
542 | depends on X86_64 && PCI | |
543 | depends on X86_EXTENDED_PLATFORM | |
ead91d4b | 544 | depends on SMP |
8f9ca475 | 545 | ---help--- |
c5c606d9 RT |
546 | Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is |
547 | supposed to run on these EM64T-based machines. Only choose this option | |
548 | if you have one of these machines. | |
5e3a77e9 | 549 | |
03b48632 NP |
550 | config X86_UV |
551 | bool "SGI Ultraviolet" | |
552 | depends on X86_64 | |
c5c606d9 | 553 | depends on X86_EXTENDED_PLATFORM |
54c28d29 | 554 | depends on NUMA |
1ecb4ae5 | 555 | depends on EFI |
9d6c26e7 | 556 | depends on X86_X2APIC |
1222e564 | 557 | depends on PCI |
8f9ca475 | 558 | ---help--- |
03b48632 NP |
559 | This option is needed in order to support SGI Ultraviolet systems. |
560 | If you don't have one of these, you should say N here. | |
561 | ||
c5c606d9 RT |
562 | # Following is an alphabetically sorted list of 32 bit extended platforms |
563 | # Please maintain the alphabetic order if and when there are additions | |
506f1d07 | 564 | |
ddd70cf9 | 565 | config X86_GOLDFISH |
b03b016f KK |
566 | bool "Goldfish (Virtual Platform)" |
567 | depends on X86_EXTENDED_PLATFORM | |
568 | ---help--- | |
ddd70cf9 JN |
569 | Enable support for the Goldfish virtual platform used primarily |
570 | for Android development. Unless you are building for the Android | |
571 | Goldfish emulator say N here. | |
572 | ||
c751e17b TG |
573 | config X86_INTEL_CE |
574 | bool "CE4100 TV platform" | |
575 | depends on PCI | |
576 | depends on PCI_GODIRECT | |
6084a6e2 | 577 | depends on X86_IO_APIC |
c751e17b TG |
578 | depends on X86_32 |
579 | depends on X86_EXTENDED_PLATFORM | |
37bc9f50 | 580 | select X86_REBOOTFIXUPS |
da6b737b SAS |
581 | select OF |
582 | select OF_EARLY_FLATTREE | |
c751e17b TG |
583 | ---help--- |
584 | Select for the Intel CE media processor (CE4100) SOC. | |
585 | This option compiles in support for the CE4100 SOC for settop | |
586 | boxes and media devices. | |
587 | ||
4cb9b00f | 588 | config X86_INTEL_MID |
43605ef1 | 589 | bool "Intel MID platform support" |
43605ef1 | 590 | depends on X86_EXTENDED_PLATFORM |
edc6bc78 | 591 | depends on X86_PLATFORM_DEVICES |
1ea7c673 | 592 | depends on PCI |
3fda5bb4 | 593 | depends on X86_64 || (PCI_GOANY && X86_32) |
1ea7c673 | 594 | depends on X86_IO_APIC |
7c9c3a1e | 595 | select SFI |
4cb9b00f | 596 | select I2C |
7c9c3a1e | 597 | select DW_APB_TIMER |
1ea7c673 | 598 | select APB_TIMER |
54b34aa0 | 599 | select INTEL_SCU_PCI |
15a713df | 600 | select MFD_INTEL_MSIC |
1ea7c673 | 601 | ---help--- |
4cb9b00f DC |
602 | Select to build a kernel capable of supporting Intel MID (Mobile |
603 | Internet Device) platform systems which do not have the PCI legacy | |
604 | interfaces. If you are building for a PC class system say N here. | |
1ea7c673 | 605 | |
4cb9b00f DC |
606 | Intel MID platforms are based on an Intel processor and chipset which |
607 | consume less power than most of the x86 derivatives. | |
43605ef1 | 608 | |
8bbc2a13 BD |
609 | config X86_INTEL_QUARK |
610 | bool "Intel Quark platform support" | |
611 | depends on X86_32 | |
612 | depends on X86_EXTENDED_PLATFORM | |
613 | depends on X86_PLATFORM_DEVICES | |
614 | depends on X86_TSC | |
615 | depends on PCI | |
616 | depends on PCI_GOANY | |
617 | depends on X86_IO_APIC | |
618 | select IOSF_MBI | |
619 | select INTEL_IMR | |
9ab6eb51 | 620 | select COMMON_CLK |
8bbc2a13 BD |
621 | ---help--- |
622 | Select to include support for Quark X1000 SoC. | |
623 | Say Y here if you have a Quark based system such as the Arduino | |
624 | compatible Intel Galileo. | |
625 | ||
3d48aab1 MW |
626 | config X86_INTEL_LPSS |
627 | bool "Intel Low Power Subsystem Support" | |
5962dd22 | 628 | depends on X86 && ACPI && PCI |
3d48aab1 | 629 | select COMMON_CLK |
0f531431 | 630 | select PINCTRL |
eebb3e8d | 631 | select IOSF_MBI |
3d48aab1 MW |
632 | ---help--- |
633 | Select to build support for Intel Low Power Subsystem such as | |
634 | found on Intel Lynxpoint PCH. Selecting this option enables | |
0f531431 MN |
635 | things like clock tree (common clock framework) and pincontrol |
636 | which are needed by the LPSS peripheral drivers. | |
3d48aab1 | 637 | |
92082a88 KX |
638 | config X86_AMD_PLATFORM_DEVICE |
639 | bool "AMD ACPI2Platform devices support" | |
640 | depends on ACPI | |
641 | select COMMON_CLK | |
642 | select PINCTRL | |
643 | ---help--- | |
644 | Select to interpret AMD specific ACPI device to platform device | |
645 | such as I2C, UART, GPIO found on AMD Carrizo and later chipsets. | |
646 | I2C and UART depend on COMMON_CLK to set clock. GPIO driver is | |
647 | implemented under PINCTRL subsystem. | |
648 | ||
ced3ce76 DB |
649 | config IOSF_MBI |
650 | tristate "Intel SoC IOSF Sideband support for SoC platforms" | |
651 | depends on PCI | |
652 | ---help--- | |
653 | This option enables sideband register access support for Intel SoC | |
654 | platforms. On these platforms the IOSF sideband is used in lieu of | |
655 | MSR's for some register accesses, mostly but not limited to thermal | |
656 | and power. Drivers may query the availability of this device to | |
657 | determine if they need the sideband in order to work on these | |
658 | platforms. The sideband is available on the following SoC products. | |
659 | This list is not meant to be exclusive. | |
660 | - BayTrail | |
661 | - Braswell | |
662 | - Quark | |
663 | ||
664 | You should say Y if you are running a kernel on one of these SoC's. | |
665 | ||
ed2226bd DB |
666 | config IOSF_MBI_DEBUG |
667 | bool "Enable IOSF sideband access through debugfs" | |
668 | depends on IOSF_MBI && DEBUG_FS | |
669 | ---help--- | |
670 | Select this option to expose the IOSF sideband access registers (MCR, | |
671 | MDR, MCRX) through debugfs to write and read register information from | |
672 | different units on the SoC. This is most useful for obtaining device | |
673 | state information for debug and analysis. As this is a general access | |
674 | mechanism, users of this option would have specific knowledge of the | |
675 | device they want to access. | |
676 | ||
677 | If you don't require the option or are in doubt, say N. | |
678 | ||
c5c606d9 RT |
679 | config X86_RDC321X |
680 | bool "RDC R-321x SoC" | |
506f1d07 | 681 | depends on X86_32 |
c5c606d9 RT |
682 | depends on X86_EXTENDED_PLATFORM |
683 | select M486 | |
684 | select X86_REBOOTFIXUPS | |
685 | ---help--- | |
686 | This option is needed for RDC R-321x system-on-chip, also known | |
687 | as R-8610-(G). | |
688 | If you don't have one of these chips, you should say N here. | |
689 | ||
e0c7ae37 | 690 | config X86_32_NON_STANDARD |
9c398017 IM |
691 | bool "Support non-standard 32-bit SMP architectures" |
692 | depends on X86_32 && SMP | |
c5c606d9 | 693 | depends on X86_EXTENDED_PLATFORM |
8f9ca475 | 694 | ---help--- |
b5660ba7 PA |
695 | This option compiles in the bigsmp and STA2X11 default |
696 | subarchitectures. It is intended for a generic binary | |
697 | kernel. If you select them all, kernel will probe it one by | |
698 | one and will fallback to default. | |
d49c4288 | 699 | |
c5c606d9 | 700 | # Alphabetically sorted list of Non standard 32 bit platforms |
d49c4288 | 701 | |
d949f36f | 702 | config X86_SUPPORTS_MEMORY_FAILURE |
6fc108a0 | 703 | def_bool y |
d949f36f LT |
704 | # MCE code calls memory_failure(): |
705 | depends on X86_MCE | |
706 | # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: | |
d949f36f LT |
707 | # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: |
708 | depends on X86_64 || !SPARSEMEM | |
709 | select ARCH_SUPPORTS_MEMORY_FAILURE | |
d949f36f | 710 | |
83125a3a AR |
711 | config STA2X11 |
712 | bool "STA2X11 Companion Chip Support" | |
713 | depends on X86_32_NON_STANDARD && PCI | |
83125a3a AR |
714 | select SWIOTLB |
715 | select MFD_STA2X11 | |
0145071b | 716 | select GPIOLIB |
83125a3a AR |
717 | ---help--- |
718 | This adds support for boards based on the STA2X11 IO-Hub, | |
719 | a.k.a. "ConneXt". The chip is used in place of the standard | |
720 | PC chipset, so all "standard" peripherals are missing. If this | |
721 | option is selected the kernel will still be able to boot on | |
722 | standard PC machines. | |
723 | ||
82148d1d S |
724 | config X86_32_IRIS |
725 | tristate "Eurobraille/Iris poweroff module" | |
726 | depends on X86_32 | |
727 | ---help--- | |
728 | The Iris machines from EuroBraille do not have APM or ACPI support | |
729 | to shut themselves down properly. A special I/O sequence is | |
730 | needed to do so, which is what this module does at | |
731 | kernel shutdown. | |
732 | ||
733 | This is only for Iris machines from EuroBraille. | |
734 | ||
735 | If unused, say N. | |
736 | ||
ae1e9130 | 737 | config SCHED_OMIT_FRAME_POINTER |
3c2362e6 HH |
738 | def_bool y |
739 | prompt "Single-depth WCHAN output" | |
a87d0914 | 740 | depends on X86 |
8f9ca475 | 741 | ---help--- |
506f1d07 SR |
742 | Calculate simpler /proc/<PID>/wchan values. If this option |
743 | is disabled then wchan values will recurse back to the | |
744 | caller function. This provides more accurate wchan values, | |
745 | at the expense of slightly more scheduling overhead. | |
746 | ||
747 | If in doubt, say "Y". | |
748 | ||
6276a074 BP |
749 | menuconfig HYPERVISOR_GUEST |
750 | bool "Linux guest support" | |
8f9ca475 | 751 | ---help--- |
6276a074 BP |
752 | Say Y here to enable options for running Linux under various hyper- |
753 | visors. This option enables basic hypervisor detection and platform | |
754 | setup. | |
506f1d07 | 755 | |
6276a074 BP |
756 | If you say N, all options in this submenu will be skipped and |
757 | disabled, and Linux guest support won't be built in. | |
506f1d07 | 758 | |
6276a074 | 759 | if HYPERVISOR_GUEST |
506f1d07 | 760 | |
e61bd94a EPH |
761 | config PARAVIRT |
762 | bool "Enable paravirtualization code" | |
8f9ca475 | 763 | ---help--- |
e61bd94a EPH |
764 | This changes the kernel so it can modify itself when it is run |
765 | under a hypervisor, potentially improving performance significantly | |
766 | over full virtualization. However, when run without a hypervisor | |
767 | the kernel is theoretically slower and slightly larger. | |
768 | ||
c00a280a JG |
769 | config PARAVIRT_XXL |
770 | bool | |
771 | ||
6276a074 BP |
772 | config PARAVIRT_DEBUG |
773 | bool "paravirt-ops debugging" | |
774 | depends on PARAVIRT && DEBUG_KERNEL | |
775 | ---help--- | |
776 | Enable to debug paravirt_ops internals. Specifically, BUG if | |
777 | a paravirt_op is missing when it is called. | |
778 | ||
b4ecc126 JF |
779 | config PARAVIRT_SPINLOCKS |
780 | bool "Paravirtualization layer for spinlocks" | |
6ea30386 | 781 | depends on PARAVIRT && SMP |
b4ecc126 JF |
782 | ---help--- |
783 | Paravirtualized spinlocks allow a pvops backend to replace the | |
784 | spinlock implementation with something virtualization-friendly | |
785 | (for example, block the virtual CPU rather than spinning). | |
786 | ||
4c4e4f61 R |
787 | It has a minimal impact on native kernels and gives a nice performance |
788 | benefit on paravirtualized KVM / Xen kernels. | |
b4ecc126 | 789 | |
4c4e4f61 | 790 | If you are unsure how to answer this question, answer Y. |
b4ecc126 | 791 | |
ecca2502 ZY |
792 | config X86_HV_CALLBACK_VECTOR |
793 | def_bool n | |
794 | ||
6276a074 | 795 | source "arch/x86/xen/Kconfig" |
7af192c9 | 796 | |
6276a074 BP |
797 | config KVM_GUEST |
798 | bool "KVM Guest support (including kvmclock)" | |
799 | depends on PARAVIRT | |
800 | select PARAVIRT_CLOCK | |
a1c4423b | 801 | select ARCH_CPUIDLE_HALTPOLL |
6276a074 | 802 | default y |
8f9ca475 | 803 | ---help--- |
6276a074 BP |
804 | This option enables various optimizations for running under the KVM |
805 | hypervisor. It includes a paravirtualized clock, so that instead | |
806 | of relying on a PIT (or probably other) emulation by the | |
807 | underlying device model, the host provides the guest with | |
808 | timing infrastructure such as time of day, and system time | |
506f1d07 | 809 | |
a1c4423b | 810 | config ARCH_CPUIDLE_HALTPOLL |
b03b016f KK |
811 | def_bool n |
812 | prompt "Disable host haltpoll when loading haltpoll driver" | |
813 | help | |
a1c4423b MT |
814 | If virtualized under KVM, disable host haltpoll. |
815 | ||
7733607f MW |
816 | config PVH |
817 | bool "Support for running PVH guests" | |
818 | ---help--- | |
819 | This option enables the PVH entry point for guest virtual machines | |
820 | as specified in the x86/HVM direct boot ABI. | |
821 | ||
1e20eb85 SV |
822 | config KVM_DEBUG_FS |
823 | bool "Enable debug information for KVM Guests in debugfs" | |
824 | depends on KVM_GUEST && DEBUG_FS | |
1e20eb85 SV |
825 | ---help--- |
826 | This option enables collection of various statistics for KVM guest. | |
827 | Statistics are displayed in debugfs filesystem. Enabling this option | |
828 | may incur significant overhead. | |
829 | ||
6276a074 BP |
830 | config PARAVIRT_TIME_ACCOUNTING |
831 | bool "Paravirtual steal time accounting" | |
832 | depends on PARAVIRT | |
8f9ca475 | 833 | ---help--- |
6276a074 BP |
834 | Select this option to enable fine granularity task steal time |
835 | accounting. Time spent executing other tasks in parallel with | |
836 | the current vCPU is discounted from the vCPU power. To account for | |
837 | that, there can be a small performance impact. | |
838 | ||
839 | If in doubt, say N here. | |
840 | ||
841 | config PARAVIRT_CLOCK | |
842 | bool | |
97349135 | 843 | |
4a362601 JK |
844 | config JAILHOUSE_GUEST |
845 | bool "Jailhouse non-root cell support" | |
abde587b | 846 | depends on X86_64 && PCI |
87e65d05 | 847 | select X86_PM_TIMER |
4a362601 JK |
848 | ---help--- |
849 | This option allows to run Linux as guest in a Jailhouse non-root | |
850 | cell. You can leave this option disabled if you only want to start | |
851 | Jailhouse and run Linux afterwards in the root cell. | |
852 | ||
ec7972c9 ZY |
853 | config ACRN_GUEST |
854 | bool "ACRN Guest support" | |
855 | depends on X86_64 | |
498ad393 | 856 | select X86_HV_CALLBACK_VECTOR |
ec7972c9 ZY |
857 | help |
858 | This option allows to run Linux as guest in the ACRN hypervisor. ACRN is | |
859 | a flexible, lightweight reference open-source hypervisor, built with | |
860 | real-time and safety-criticality in mind. It is built for embedded | |
861 | IOT with small footprint and real-time features. More details can be | |
862 | found in https://projectacrn.org/. | |
863 | ||
6276a074 | 864 | endif #HYPERVISOR_GUEST |
97349135 | 865 | |
506f1d07 SR |
866 | source "arch/x86/Kconfig.cpu" |
867 | ||
868 | config HPET_TIMER | |
3c2362e6 | 869 | def_bool X86_64 |
506f1d07 | 870 | prompt "HPET Timer Support" if X86_32 |
8f9ca475 IM |
871 | ---help--- |
872 | Use the IA-PC HPET (High Precision Event Timer) to manage | |
873 | time in preference to the PIT and RTC, if a HPET is | |
874 | present. | |
875 | HPET is the next generation timer replacing legacy 8254s. | |
876 | The HPET provides a stable time base on SMP | |
877 | systems, unlike the TSC, but it is more expensive to access, | |
4e7f9df2 MT |
878 | as it is off-chip. The interface used is documented |
879 | in the HPET spec, revision 1. | |
506f1d07 | 880 | |
8f9ca475 IM |
881 | You can safely choose Y here. However, HPET will only be |
882 | activated if the platform and the BIOS support this feature. | |
883 | Otherwise the 8254 will be used for timing services. | |
506f1d07 | 884 | |
8f9ca475 | 885 | Choose N to continue using the legacy 8254 timer. |
506f1d07 SR |
886 | |
887 | config HPET_EMULATE_RTC | |
3c2362e6 | 888 | def_bool y |
9d8af78b | 889 | depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) |
506f1d07 | 890 | |
bb24c471 | 891 | config APB_TIMER |
b03b016f KK |
892 | def_bool y if X86_INTEL_MID |
893 | prompt "Intel MID APB Timer Support" if X86_INTEL_MID | |
894 | select DW_APB_TIMER | |
895 | depends on X86_INTEL_MID && SFI | |
896 | help | |
897 | APB timer is the replacement for 8254, HPET on X86 MID platforms. | |
898 | The APBT provides a stable time base on SMP | |
899 | systems, unlike the TSC, but it is more expensive to access, | |
900 | as it is off-chip. APB timers are always running regardless of CPU | |
901 | C states, they are used as per CPU clockevent device when possible. | |
bb24c471 | 902 | |
6a108a14 | 903 | # Mark as expert because too many people got it wrong. |
506f1d07 | 904 | # The code disables itself when not needed. |
7ae9392c TP |
905 | config DMI |
906 | default y | |
cf074402 | 907 | select DMI_SCAN_MACHINE_NON_EFI_FALLBACK |
6a108a14 | 908 | bool "Enable DMI scanning" if EXPERT |
8f9ca475 | 909 | ---help--- |
7ae9392c TP |
910 | Enabled scanning of DMI to identify machine quirks. Say Y |
911 | here unless you have verified that your setup is not | |
912 | affected by entries in the DMI blacklist. Required by PNP | |
913 | BIOS code. | |
914 | ||
506f1d07 | 915 | config GART_IOMMU |
38901f1c | 916 | bool "Old AMD GART IOMMU support" |
a4ce5a48 | 917 | select IOMMU_HELPER |
506f1d07 | 918 | select SWIOTLB |
23ac4ae8 | 919 | depends on X86_64 && PCI && AMD_NB |
8f9ca475 | 920 | ---help--- |
ced3c42c IM |
921 | Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron |
922 | GART based hardware IOMMUs. | |
923 | ||
924 | The GART supports full DMA access for devices with 32-bit access | |
925 | limitations, on systems with more than 3 GB. This is usually needed | |
926 | for USB, sound, many IDE/SATA chipsets and some other devices. | |
927 | ||
928 | Newer systems typically have a modern AMD IOMMU, supported via | |
929 | the CONFIG_AMD_IOMMU=y config option. | |
930 | ||
931 | In normal configurations this driver is only active when needed: | |
932 | there's more than 3 GB of memory and the system contains a | |
933 | 32-bit limited device. | |
934 | ||
935 | If unsure, say Y. | |
506f1d07 | 936 | |
1184dc2f | 937 | config MAXSMP |
ddb0c5a6 | 938 | bool "Enable Maximum number of SMP Processors and NUMA Nodes" |
6ea30386 | 939 | depends on X86_64 && SMP && DEBUG_KERNEL |
36f5101a | 940 | select CPUMASK_OFFSTACK |
8f9ca475 | 941 | ---help--- |
ddb0c5a6 | 942 | Enable maximum number of CPUS and NUMA Nodes for this architecture. |
1184dc2f | 943 | If unsure, say N. |
506f1d07 | 944 | |
aec6487e IM |
945 | # |
946 | # The maximum number of CPUs supported: | |
947 | # | |
948 | # The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT, | |
949 | # and which can be configured interactively in the | |
950 | # [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range. | |
951 | # | |
952 | # The ranges are different on 32-bit and 64-bit kernels, depending on | |
953 | # hardware capabilities and scalability features of the kernel. | |
954 | # | |
955 | # ( If MAXSMP is enabled we just use the highest possible value and disable | |
956 | # interactive configuration. ) | |
957 | # | |
958 | ||
959 | config NR_CPUS_RANGE_BEGIN | |
a0d0bb4d | 960 | int |
aec6487e IM |
961 | default NR_CPUS_RANGE_END if MAXSMP |
962 | default 1 if !SMP | |
963 | default 2 | |
a0d0bb4d | 964 | |
aec6487e | 965 | config NR_CPUS_RANGE_END |
a0d0bb4d | 966 | int |
aec6487e IM |
967 | depends on X86_32 |
968 | default 64 if SMP && X86_BIGSMP | |
969 | default 8 if SMP && !X86_BIGSMP | |
970 | default 1 if !SMP | |
a0d0bb4d | 971 | |
aec6487e | 972 | config NR_CPUS_RANGE_END |
a0d0bb4d | 973 | int |
aec6487e | 974 | depends on X86_64 |
1edae1ae SW |
975 | default 8192 if SMP && CPUMASK_OFFSTACK |
976 | default 512 if SMP && !CPUMASK_OFFSTACK | |
aec6487e | 977 | default 1 if !SMP |
a0d0bb4d | 978 | |
aec6487e | 979 | config NR_CPUS_DEFAULT |
a0d0bb4d RD |
980 | int |
981 | depends on X86_32 | |
aec6487e IM |
982 | default 32 if X86_BIGSMP |
983 | default 8 if SMP | |
984 | default 1 if !SMP | |
a0d0bb4d | 985 | |
aec6487e | 986 | config NR_CPUS_DEFAULT |
a0d0bb4d RD |
987 | int |
988 | depends on X86_64 | |
aec6487e IM |
989 | default 8192 if MAXSMP |
990 | default 64 if SMP | |
991 | default 1 if !SMP | |
a0d0bb4d | 992 | |
506f1d07 | 993 | config NR_CPUS |
36f5101a | 994 | int "Maximum number of CPUs" if SMP && !MAXSMP |
aec6487e IM |
995 | range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END |
996 | default NR_CPUS_DEFAULT | |
8f9ca475 | 997 | ---help--- |
506f1d07 | 998 | This allows you to specify the maximum number of CPUs which this |
bb61ccc7 | 999 | kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum |
cad14bb9 | 1000 | supported value is 8192, otherwise the maximum value is 512. The |
506f1d07 SR |
1001 | minimum value which makes sense is 2. |
1002 | ||
aec6487e IM |
1003 | This is purely to save memory: each supported CPU adds about 8KB |
1004 | to the kernel image. | |
506f1d07 SR |
1005 | |
1006 | config SCHED_SMT | |
dbe73364 | 1007 | def_bool y if SMP |
506f1d07 SR |
1008 | |
1009 | config SCHED_MC | |
3c2362e6 HH |
1010 | def_bool y |
1011 | prompt "Multi-core scheduler support" | |
c8e56d20 | 1012 | depends on SMP |
8f9ca475 | 1013 | ---help--- |
506f1d07 SR |
1014 | Multi-core scheduler support improves the CPU scheduler's decision |
1015 | making when dealing with multi-core CPU chips at a cost of slightly | |
1016 | increased overhead in some places. If unsure say N here. | |
1017 | ||
de966cf4 TC |
1018 | config SCHED_MC_PRIO |
1019 | bool "CPU core priorities scheduler support" | |
0a21fc12 IM |
1020 | depends on SCHED_MC && CPU_SUP_INTEL |
1021 | select X86_INTEL_PSTATE | |
1022 | select CPU_FREQ | |
de966cf4 | 1023 | default y |
5e76b2ab | 1024 | ---help--- |
0a21fc12 IM |
1025 | Intel Turbo Boost Max Technology 3.0 enabled CPUs have a |
1026 | core ordering determined at manufacturing time, which allows | |
1027 | certain cores to reach higher turbo frequencies (when running | |
1028 | single threaded workloads) than others. | |
de966cf4 | 1029 | |
0a21fc12 IM |
1030 | Enabling this kernel feature teaches the scheduler about |
1031 | the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the | |
1032 | scheduler's CPU selection logic accordingly, so that higher | |
1033 | overall system performance can be achieved. | |
de966cf4 | 1034 | |
0a21fc12 | 1035 | This feature will have no effect on CPUs without this feature. |
de966cf4 | 1036 | |
0a21fc12 | 1037 | If unsure say Y here. |
5e76b2ab | 1038 | |
30b8b006 | 1039 | config UP_LATE_INIT |
b03b016f KK |
1040 | def_bool y |
1041 | depends on !SMP && X86_LOCAL_APIC | |
30b8b006 | 1042 | |
506f1d07 | 1043 | config X86_UP_APIC |
50849eef JB |
1044 | bool "Local APIC support on uniprocessors" if !PCI_MSI |
1045 | default PCI_MSI | |
38a1dfda | 1046 | depends on X86_32 && !SMP && !X86_32_NON_STANDARD |
8f9ca475 | 1047 | ---help--- |
506f1d07 SR |
1048 | A local APIC (Advanced Programmable Interrupt Controller) is an |
1049 | integrated interrupt controller in the CPU. If you have a single-CPU | |
1050 | system which has a processor with a local APIC, you can say Y here to | |
1051 | enable and use it. If you say Y here even though your machine doesn't | |
1052 | have a local APIC, then the kernel will still run with no slowdown at | |
1053 | all. The local APIC supports CPU-generated self-interrupts (timer, | |
1054 | performance counters), and the NMI watchdog which detects hard | |
1055 | lockups. | |
1056 | ||
1057 | config X86_UP_IOAPIC | |
1058 | bool "IO-APIC support on uniprocessors" | |
1059 | depends on X86_UP_APIC | |
8f9ca475 | 1060 | ---help--- |
506f1d07 SR |
1061 | An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an |
1062 | SMP-capable replacement for PC-style interrupt controllers. Most | |
1063 | SMP systems and many recent uniprocessor systems have one. | |
1064 | ||
1065 | If you have a single-CPU system with an IO-APIC, you can say Y here | |
1066 | to use it. If you say Y here even though your machine doesn't have | |
1067 | an IO-APIC, then the kernel will still run with no slowdown at all. | |
1068 | ||
1069 | config X86_LOCAL_APIC | |
3c2362e6 | 1070 | def_bool y |
0dbc6078 | 1071 | depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI |
b5dc8e6c | 1072 | select IRQ_DOMAIN_HIERARCHY |
52f518a3 | 1073 | select PCI_MSI_IRQ_DOMAIN if PCI_MSI |
506f1d07 SR |
1074 | |
1075 | config X86_IO_APIC | |
b1da1e71 JB |
1076 | def_bool y |
1077 | depends on X86_LOCAL_APIC || X86_UP_IOAPIC | |
506f1d07 | 1078 | |
41b9eb26 SA |
1079 | config X86_REROUTE_FOR_BROKEN_BOOT_IRQS |
1080 | bool "Reroute for broken boot IRQs" | |
41b9eb26 | 1081 | depends on X86_IO_APIC |
8f9ca475 | 1082 | ---help--- |
41b9eb26 SA |
1083 | This option enables a workaround that fixes a source of |
1084 | spurious interrupts. This is recommended when threaded | |
1085 | interrupt handling is used on systems where the generation of | |
1086 | superfluous "boot interrupts" cannot be disabled. | |
1087 | ||
1088 | Some chipsets generate a legacy INTx "boot IRQ" when the IRQ | |
1089 | entry in the chipset's IO-APIC is masked (as, e.g. the RT | |
1090 | kernel does during interrupt handling). On chipsets where this | |
1091 | boot IRQ generation cannot be disabled, this workaround keeps | |
1092 | the original IRQ line masked so that only the equivalent "boot | |
1093 | IRQ" is delivered to the CPUs. The workaround also tells the | |
1094 | kernel to set up the IRQ handler on the boot IRQ line. In this | |
1095 | way only one interrupt is delivered to the kernel. Otherwise | |
1096 | the spurious second interrupt may cause the kernel to bring | |
1097 | down (vital) interrupt lines. | |
1098 | ||
1099 | Only affects "broken" chipsets. Interrupt sharing may be | |
1100 | increased on these systems. | |
1101 | ||
506f1d07 | 1102 | config X86_MCE |
bab9bc65 | 1103 | bool "Machine Check / overheating reporting" |
648ed940 | 1104 | select GENERIC_ALLOCATOR |
e57dbaf7 | 1105 | default y |
506f1d07 | 1106 | ---help--- |
bab9bc65 AK |
1107 | Machine Check support allows the processor to notify the |
1108 | kernel if it detects a problem (e.g. overheating, data corruption). | |
506f1d07 | 1109 | The action the kernel takes depends on the severity of the problem, |
bab9bc65 | 1110 | ranging from warning messages to halting the machine. |
4efc0670 | 1111 | |
5de97c9f TL |
1112 | config X86_MCELOG_LEGACY |
1113 | bool "Support for deprecated /dev/mcelog character device" | |
1114 | depends on X86_MCE | |
1115 | ---help--- | |
1116 | Enable support for /dev/mcelog which is needed by the old mcelog | |
1117 | userspace logging daemon. Consider switching to the new generation | |
1118 | rasdaemon solution. | |
1119 | ||
506f1d07 | 1120 | config X86_MCE_INTEL |
3c2362e6 HH |
1121 | def_bool y |
1122 | prompt "Intel MCE features" | |
c1ebf835 | 1123 | depends on X86_MCE && X86_LOCAL_APIC |
8f9ca475 | 1124 | ---help--- |
506f1d07 SR |
1125 | Additional support for intel specific MCE features such as |
1126 | the thermal monitor. | |
1127 | ||
1128 | config X86_MCE_AMD | |
3c2362e6 HH |
1129 | def_bool y |
1130 | prompt "AMD MCE features" | |
f5382de9 | 1131 | depends on X86_MCE && X86_LOCAL_APIC && AMD_NB |
8f9ca475 | 1132 | ---help--- |
506f1d07 SR |
1133 | Additional support for AMD specific MCE features such as |
1134 | the DRAM Error Threshold. | |
1135 | ||
4efc0670 | 1136 | config X86_ANCIENT_MCE |
6fc108a0 | 1137 | bool "Support for old Pentium 5 / WinChip machine checks" |
c31d9633 | 1138 | depends on X86_32 && X86_MCE |
cd13adcc HS |
1139 | ---help--- |
1140 | Include support for machine check handling on old Pentium 5 or WinChip | |
5065a706 | 1141 | systems. These typically need to be enabled explicitly on the command |
cd13adcc | 1142 | line. |
4efc0670 | 1143 | |
b2762686 AK |
1144 | config X86_MCE_THRESHOLD |
1145 | depends on X86_MCE_AMD || X86_MCE_INTEL | |
6fc108a0 | 1146 | def_bool y |
b2762686 | 1147 | |
ea149b36 | 1148 | config X86_MCE_INJECT |
bc8e80d5 | 1149 | depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS |
ea149b36 AK |
1150 | tristate "Machine check injector support" |
1151 | ---help--- | |
1152 | Provide support for injecting machine checks for testing purposes. | |
1153 | If you don't know what a machine check is and you don't do kernel | |
1154 | QA it is safe to say n. | |
1155 | ||
4efc0670 AK |
1156 | config X86_THERMAL_VECTOR |
1157 | def_bool y | |
5bb38adc | 1158 | depends on X86_MCE_INTEL |
4efc0670 | 1159 | |
07dc900e | 1160 | source "arch/x86/events/Kconfig" |
e633c65a | 1161 | |
5aef51c3 | 1162 | config X86_LEGACY_VM86 |
1e642812 | 1163 | bool "Legacy VM86 support" |
506f1d07 | 1164 | depends on X86_32 |
8f9ca475 | 1165 | ---help--- |
5aef51c3 AL |
1166 | This option allows user programs to put the CPU into V8086 |
1167 | mode, which is an 80286-era approximation of 16-bit real mode. | |
1168 | ||
1169 | Some very old versions of X and/or vbetool require this option | |
1170 | for user mode setting. Similarly, DOSEMU will use it if | |
1171 | available to accelerate real mode DOS programs. However, any | |
1172 | recent version of DOSEMU, X, or vbetool should be fully | |
1173 | functional even without kernel VM86 support, as they will all | |
1e642812 IM |
1174 | fall back to software emulation. Nevertheless, if you are using |
1175 | a 16-bit DOS program where 16-bit performance matters, vm86 | |
1176 | mode might be faster than emulation and you might want to | |
1177 | enable this option. | |
5aef51c3 | 1178 | |
1e642812 IM |
1179 | Note that any app that works on a 64-bit kernel is unlikely to |
1180 | need this option, as 64-bit kernels don't, and can't, support | |
1181 | V8086 mode. This option is also unrelated to 16-bit protected | |
1182 | mode and is not needed to run most 16-bit programs under Wine. | |
5aef51c3 | 1183 | |
1e642812 IM |
1184 | Enabling this option increases the complexity of the kernel |
1185 | and slows down exception handling a tiny bit. | |
5aef51c3 | 1186 | |
1e642812 | 1187 | If unsure, say N here. |
5aef51c3 AL |
1188 | |
1189 | config VM86 | |
b03b016f KK |
1190 | bool |
1191 | default X86_LEGACY_VM86 | |
34273f41 PA |
1192 | |
1193 | config X86_16BIT | |
1194 | bool "Enable support for 16-bit segments" if EXPERT | |
1195 | default y | |
a5b9e5a2 | 1196 | depends on MODIFY_LDT_SYSCALL |
34273f41 PA |
1197 | ---help--- |
1198 | This option is required by programs like Wine to run 16-bit | |
1199 | protected mode legacy code on x86 processors. Disabling | |
1200 | this option saves about 300 bytes on i386, or around 6K text | |
1201 | plus 16K runtime memory on x86-64, | |
1202 | ||
1203 | config X86_ESPFIX32 | |
1204 | def_bool y | |
1205 | depends on X86_16BIT && X86_32 | |
506f1d07 | 1206 | |
197725de PA |
1207 | config X86_ESPFIX64 |
1208 | def_bool y | |
34273f41 | 1209 | depends on X86_16BIT && X86_64 |
506f1d07 | 1210 | |
1ad83c85 | 1211 | config X86_VSYSCALL_EMULATION |
b03b016f KK |
1212 | bool "Enable vsyscall emulation" if EXPERT |
1213 | default y | |
1214 | depends on X86_64 | |
1215 | ---help--- | |
1ad83c85 AL |
1216 | This enables emulation of the legacy vsyscall page. Disabling |
1217 | it is roughly equivalent to booting with vsyscall=none, except | |
1218 | that it will also disable the helpful warning if a program | |
1219 | tries to use a vsyscall. With this option set to N, offending | |
1220 | programs will just segfault, citing addresses of the form | |
1221 | 0xffffffffff600?00. | |
1222 | ||
1223 | This option is required by many programs built before 2013, and | |
1224 | care should be used even with newer programs if set to N. | |
1225 | ||
1226 | Disabling this option saves about 7K of kernel size and | |
1227 | possibly 4K of additional runtime pagetable memory. | |
1228 | ||
111e7b15 TG |
1229 | config X86_IOPL_IOPERM |
1230 | bool "IOPERM and IOPL Emulation" | |
a24ca997 | 1231 | default y |
c8137ace | 1232 | ---help--- |
111e7b15 TG |
1233 | This enables the ioperm() and iopl() syscalls which are necessary |
1234 | for legacy applications. | |
1235 | ||
c8137ace TG |
1236 | Legacy IOPL support is an overbroad mechanism which allows user |
1237 | space aside of accessing all 65536 I/O ports also to disable | |
1238 | interrupts. To gain this access the caller needs CAP_SYS_RAWIO | |
1239 | capabilities and permission from potentially active security | |
1240 | modules. | |
1241 | ||
1242 | The emulation restricts the functionality of the syscall to | |
1243 | only allowing the full range I/O port access, but prevents the | |
a24ca997 TG |
1244 | ability to disable interrupts from user space which would be |
1245 | granted if the hardware IOPL mechanism would be used. | |
c8137ace | 1246 | |
506f1d07 SR |
1247 | config TOSHIBA |
1248 | tristate "Toshiba Laptop support" | |
1249 | depends on X86_32 | |
1250 | ---help--- | |
1251 | This adds a driver to safely access the System Management Mode of | |
1252 | the CPU on Toshiba portables with a genuine Toshiba BIOS. It does | |
1253 | not work on models with a Phoenix BIOS. The System Management Mode | |
1254 | is used to set the BIOS and power saving options on Toshiba portables. | |
1255 | ||
1256 | For information on utilities to make use of this driver see the | |
1257 | Toshiba Linux utilities web site at: | |
1258 | <http://www.buzzard.org.uk/toshiba/>. | |
1259 | ||
1260 | Say Y if you intend to run this kernel on a Toshiba portable. | |
1261 | Say N otherwise. | |
1262 | ||
1263 | config I8K | |
039ae585 | 1264 | tristate "Dell i8k legacy laptop support" |
949a9d70 | 1265 | select HWMON |
039ae585 | 1266 | select SENSORS_DELL_SMM |
506f1d07 | 1267 | ---help--- |
039ae585 PR |
1268 | This option enables legacy /proc/i8k userspace interface in hwmon |
1269 | dell-smm-hwmon driver. Character file /proc/i8k reports bios version, | |
1270 | temperature and allows controlling fan speeds of Dell laptops via | |
1271 | System Management Mode. For old Dell laptops (like Dell Inspiron 8000) | |
1272 | it reports also power and hotkey status. For fan speed control is | |
1273 | needed userspace package i8kutils. | |
1274 | ||
1275 | Say Y if you intend to run this kernel on old Dell laptops or want to | |
1276 | use userspace package i8kutils. | |
506f1d07 SR |
1277 | Say N otherwise. |
1278 | ||
1279 | config X86_REBOOTFIXUPS | |
9ba16087 JB |
1280 | bool "Enable X86 board specific fixups for reboot" |
1281 | depends on X86_32 | |
506f1d07 SR |
1282 | ---help--- |
1283 | This enables chipset and/or board specific fixups to be done | |
1284 | in order to get reboot to work correctly. This is only needed on | |
1285 | some combinations of hardware and BIOS. The symptom, for which | |
1286 | this config is intended, is when reboot ends with a stalled/hung | |
1287 | system. | |
1288 | ||
1289 | Currently, the only fixup is for the Geode machines using | |
5e3a77e9 | 1290 | CS5530A and CS5536 chipsets and the RDC R-321x SoC. |
506f1d07 SR |
1291 | |
1292 | Say Y if you want to enable the fixup. Currently, it's safe to | |
1293 | enable this option even if you don't need it. | |
1294 | Say N otherwise. | |
1295 | ||
1296 | config MICROCODE | |
9a2bc335 BP |
1297 | bool "CPU microcode loading support" |
1298 | default y | |
80030e3d | 1299 | depends on CPU_SUP_AMD || CPU_SUP_INTEL |
506f1d07 SR |
1300 | select FW_LOADER |
1301 | ---help--- | |
1302 | If you say Y here, you will be able to update the microcode on | |
5f9c01aa BP |
1303 | Intel and AMD processors. The Intel support is for the IA32 family, |
1304 | e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The | |
1305 | AMD support is for families 0x10 and later. You will obviously need | |
1306 | the actual microcode binary data itself which is not shipped with | |
1307 | the Linux kernel. | |
1308 | ||
1309 | The preferred method to load microcode from a detached initrd is described | |
cb1aaebe | 1310 | in Documentation/x86/microcode.rst. For that you need to enable |
5f9c01aa BP |
1311 | CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the |
1312 | initrd for microcode blobs. | |
1313 | ||
c508c46e BG |
1314 | In addition, you can build the microcode into the kernel. For that you |
1315 | need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE | |
1316 | config option. | |
506f1d07 | 1317 | |
8d86f390 | 1318 | config MICROCODE_INTEL |
e43f6e67 | 1319 | bool "Intel microcode loading support" |
8f9ca475 IM |
1320 | depends on MICROCODE |
1321 | default MICROCODE | |
1322 | select FW_LOADER | |
1323 | ---help--- | |
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" |
8f9ca475 IM |
1333 | depends on MICROCODE |
1334 | select FW_LOADER | |
1335 | ---help--- | |
1336 | If you select this option, microcode patch loading support for AMD | |
1337 | processors will be enabled. | |
80cc9f10 | 1338 | |
8f9ca475 | 1339 | config MICROCODE_OLD_INTERFACE |
c02f48e0 BP |
1340 | bool "Ancient loading interface (DEPRECATED)" |
1341 | default n | |
506f1d07 | 1342 | depends on MICROCODE |
c02f48e0 BP |
1343 | ---help--- |
1344 | DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface | |
1345 | which was used by userspace tools like iucode_tool and microcode.ctl. | |
1346 | It is inadequate because it runs too late to be able to properly | |
1347 | load microcode on a machine and it needs special tools. Instead, you | |
1348 | should've switched to the early loading method with the initrd or | |
cb1aaebe | 1349 | builtin microcode by now: Documentation/x86/microcode.rst |
506f1d07 SR |
1350 | |
1351 | config X86_MSR | |
1352 | tristate "/dev/cpu/*/msr - Model-specific register support" | |
8f9ca475 | 1353 | ---help--- |
506f1d07 SR |
1354 | This device gives privileged processes access to the x86 |
1355 | Model-Specific Registers (MSRs). It is a character device with | |
1356 | major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. | |
1357 | MSR accesses are directed to a specific CPU on multi-processor | |
1358 | systems. | |
1359 | ||
1360 | config X86_CPUID | |
1361 | tristate "/dev/cpu/*/cpuid - CPU information support" | |
8f9ca475 | 1362 | ---help--- |
506f1d07 SR |
1363 | This device gives processes access to the x86 CPUID instruction to |
1364 | be executed on a specific processor. It is a character device | |
1365 | with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to | |
1366 | /dev/cpu/31/cpuid. | |
1367 | ||
1368 | choice | |
1369 | prompt "High Memory Support" | |
6fc108a0 | 1370 | default HIGHMEM4G |
506f1d07 SR |
1371 | depends on X86_32 |
1372 | ||
1373 | config NOHIGHMEM | |
1374 | bool "off" | |
506f1d07 SR |
1375 | ---help--- |
1376 | Linux can use up to 64 Gigabytes of physical memory on x86 systems. | |
1377 | However, the address space of 32-bit x86 processors is only 4 | |
1378 | Gigabytes large. That means that, if you have a large amount of | |
1379 | physical memory, not all of it can be "permanently mapped" by the | |
1380 | kernel. The physical memory that's not permanently mapped is called | |
1381 | "high memory". | |
1382 | ||
1383 | If you are compiling a kernel which will never run on a machine with | |
1384 | more than 1 Gigabyte total physical RAM, answer "off" here (default | |
1385 | choice and suitable for most users). This will result in a "3GB/1GB" | |
1386 | split: 3GB are mapped so that each process sees a 3GB virtual memory | |
1387 | space and the remaining part of the 4GB virtual memory space is used | |
1388 | by the kernel to permanently map as much physical memory as | |
1389 | possible. | |
1390 | ||
1391 | If the machine has between 1 and 4 Gigabytes physical RAM, then | |
1392 | answer "4GB" here. | |
1393 | ||
1394 | If more than 4 Gigabytes is used then answer "64GB" here. This | |
1395 | selection turns Intel PAE (Physical Address Extension) mode on. | |
1396 | PAE implements 3-level paging on IA32 processors. PAE is fully | |
1397 | supported by Linux, PAE mode is implemented on all recent Intel | |
1398 | processors (Pentium Pro and better). NOTE: If you say "64GB" here, | |
1399 | then the kernel will not boot on CPUs that don't support PAE! | |
1400 | ||
1401 | The actual amount of total physical memory will either be | |
1402 | auto detected or can be forced by using a kernel command line option | |
1403 | such as "mem=256M". (Try "man bootparam" or see the documentation of | |
1404 | your boot loader (lilo or loadlin) about how to pass options to the | |
1405 | kernel at boot time.) | |
1406 | ||
1407 | If unsure, say "off". | |
1408 | ||
1409 | config HIGHMEM4G | |
1410 | bool "4GB" | |
8f9ca475 | 1411 | ---help--- |
506f1d07 SR |
1412 | Select this if you have a 32-bit processor and between 1 and 4 |
1413 | gigabytes of physical RAM. | |
1414 | ||
1415 | config HIGHMEM64G | |
1416 | bool "64GB" | |
69b8d3fc | 1417 | depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6 |
506f1d07 | 1418 | select X86_PAE |
8f9ca475 | 1419 | ---help--- |
506f1d07 SR |
1420 | Select this if you have a 32-bit processor and more than 4 |
1421 | gigabytes of physical RAM. | |
1422 | ||
1423 | endchoice | |
1424 | ||
1425 | choice | |
6a108a14 | 1426 | prompt "Memory split" if EXPERT |
506f1d07 SR |
1427 | default VMSPLIT_3G |
1428 | depends on X86_32 | |
8f9ca475 | 1429 | ---help--- |
506f1d07 SR |
1430 | Select the desired split between kernel and user memory. |
1431 | ||
1432 | If the address range available to the kernel is less than the | |
1433 | physical memory installed, the remaining memory will be available | |
1434 | as "high memory". Accessing high memory is a little more costly | |
1435 | than low memory, as it needs to be mapped into the kernel first. | |
1436 | Note that increasing the kernel address space limits the range | |
1437 | available to user programs, making the address space there | |
1438 | tighter. Selecting anything other than the default 3G/1G split | |
1439 | will also likely make your kernel incompatible with binary-only | |
1440 | kernel modules. | |
1441 | ||
1442 | If you are not absolutely sure what you are doing, leave this | |
1443 | option alone! | |
1444 | ||
1445 | config VMSPLIT_3G | |
1446 | bool "3G/1G user/kernel split" | |
1447 | config VMSPLIT_3G_OPT | |
1448 | depends on !X86_PAE | |
1449 | bool "3G/1G user/kernel split (for full 1G low memory)" | |
1450 | config VMSPLIT_2G | |
1451 | bool "2G/2G user/kernel split" | |
1452 | config VMSPLIT_2G_OPT | |
1453 | depends on !X86_PAE | |
1454 | bool "2G/2G user/kernel split (for full 2G low memory)" | |
1455 | config VMSPLIT_1G | |
1456 | bool "1G/3G user/kernel split" | |
1457 | endchoice | |
1458 | ||
1459 | config PAGE_OFFSET | |
1460 | hex | |
1461 | default 0xB0000000 if VMSPLIT_3G_OPT | |
1462 | default 0x80000000 if VMSPLIT_2G | |
1463 | default 0x78000000 if VMSPLIT_2G_OPT | |
1464 | default 0x40000000 if VMSPLIT_1G | |
1465 | default 0xC0000000 | |
1466 | depends on X86_32 | |
1467 | ||
1468 | config HIGHMEM | |
3c2362e6 | 1469 | def_bool y |
506f1d07 | 1470 | depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) |
506f1d07 SR |
1471 | |
1472 | config X86_PAE | |
9ba16087 | 1473 | bool "PAE (Physical Address Extension) Support" |
506f1d07 | 1474 | depends on X86_32 && !HIGHMEM4G |
d4a451d5 | 1475 | select PHYS_ADDR_T_64BIT |
9d99c712 | 1476 | select SWIOTLB |
8f9ca475 | 1477 | ---help--- |
506f1d07 SR |
1478 | PAE is required for NX support, and furthermore enables |
1479 | larger swapspace support for non-overcommit purposes. It | |
1480 | has the cost of more pagetable lookup overhead, and also | |
1481 | consumes more pagetable space per process. | |
1482 | ||
77ef56e4 KS |
1483 | config X86_5LEVEL |
1484 | bool "Enable 5-level page tables support" | |
18ec1eaf | 1485 | default y |
eedb92ab | 1486 | select DYNAMIC_MEMORY_LAYOUT |
162434e7 | 1487 | select SPARSEMEM_VMEMMAP |
77ef56e4 KS |
1488 | depends on X86_64 |
1489 | ---help--- | |
1490 | 5-level paging enables access to larger address space: | |
1491 | upto 128 PiB of virtual address space and 4 PiB of | |
1492 | physical address space. | |
1493 | ||
1494 | It will be supported by future Intel CPUs. | |
1495 | ||
6657fca0 KS |
1496 | A kernel with the option enabled can be booted on machines that |
1497 | support 4- or 5-level paging. | |
77ef56e4 | 1498 | |
cb1aaebe | 1499 | See Documentation/x86/x86_64/5level-paging.rst for more |
77ef56e4 KS |
1500 | information. |
1501 | ||
1502 | Say N if unsure. | |
1503 | ||
10971ab2 | 1504 | config X86_DIRECT_GBPAGES |
e5008abe | 1505 | def_bool y |
2e1da13f | 1506 | depends on X86_64 |
8f9ca475 | 1507 | ---help--- |
10971ab2 IM |
1508 | Certain kernel features effectively disable kernel |
1509 | linear 1 GB mappings (even if the CPU otherwise | |
1510 | supports them), so don't confuse the user by printing | |
1511 | that we have them enabled. | |
9e899816 | 1512 | |
5c280cf6 TG |
1513 | config X86_CPA_STATISTICS |
1514 | bool "Enable statistic for Change Page Attribute" | |
1515 | depends on DEBUG_FS | |
1516 | ---help--- | |
b75baaf3 | 1517 | Expose statistics about the Change Page Attribute mechanism, which |
a943245a | 1518 | helps to determine the effectiveness of preserving large and huge |
5c280cf6 TG |
1519 | page mappings when mapping protections are changed. |
1520 | ||
7744ccdb TL |
1521 | config AMD_MEM_ENCRYPT |
1522 | bool "AMD Secure Memory Encryption (SME) support" | |
1523 | depends on X86_64 && CPU_SUP_AMD | |
94d49eb3 | 1524 | select DYNAMIC_PHYSICAL_MASK |
ce9084ba | 1525 | select ARCH_USE_MEMREMAP_PROT |
9087c375 | 1526 | select ARCH_HAS_FORCE_DMA_UNENCRYPTED |
7744ccdb TL |
1527 | ---help--- |
1528 | Say yes to enable support for the encryption of system memory. | |
1529 | This requires an AMD processor that supports Secure Memory | |
1530 | Encryption (SME). | |
1531 | ||
1532 | config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT | |
1533 | bool "Activate AMD Secure Memory Encryption (SME) by default" | |
1534 | default y | |
1535 | depends on AMD_MEM_ENCRYPT | |
1536 | ---help--- | |
1537 | Say yes to have system memory encrypted by default if running on | |
1538 | an AMD processor that supports Secure Memory Encryption (SME). | |
1539 | ||
1540 | If set to Y, then the encryption of system memory can be | |
1541 | deactivated with the mem_encrypt=off command line option. | |
1542 | ||
1543 | If set to N, then the encryption of system memory can be | |
1544 | activated with the mem_encrypt=on command line option. | |
1545 | ||
506f1d07 SR |
1546 | # Common NUMA Features |
1547 | config NUMA | |
e133f6ea | 1548 | bool "NUMA Memory Allocation and Scheduler Support" |
506f1d07 | 1549 | depends on SMP |
b5660ba7 PA |
1550 | depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP) |
1551 | default y if X86_BIGSMP | |
8f9ca475 | 1552 | ---help--- |
e133f6ea | 1553 | Enable NUMA (Non-Uniform Memory Access) support. |
fd51b2d7 | 1554 | |
506f1d07 SR |
1555 | The kernel will try to allocate memory used by a CPU on the |
1556 | local memory controller of the CPU and add some more | |
1557 | NUMA awareness to the kernel. | |
1558 | ||
c280ea5e | 1559 | For 64-bit this is recommended if the system is Intel Core i7 |
fd51b2d7 KM |
1560 | (or later), AMD Opteron, or EM64T NUMA. |
1561 | ||
b5660ba7 | 1562 | For 32-bit this is only needed if you boot a 32-bit |
7cf6c945 | 1563 | kernel on a 64-bit NUMA platform. |
fd51b2d7 KM |
1564 | |
1565 | Otherwise, you should say N. | |
506f1d07 | 1566 | |
eec1d4fa | 1567 | config AMD_NUMA |
3c2362e6 HH |
1568 | def_bool y |
1569 | prompt "Old style AMD Opteron NUMA detection" | |
5da0ef9a | 1570 | depends on X86_64 && NUMA && PCI |
8f9ca475 | 1571 | ---help--- |
eec1d4fa HR |
1572 | Enable AMD NUMA node topology detection. You should say Y here if |
1573 | you have a multi processor AMD system. This uses an old method to | |
1574 | read the NUMA configuration directly from the builtin Northbridge | |
1575 | of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, | |
1576 | which also takes priority if both are compiled in. | |
506f1d07 SR |
1577 | |
1578 | config X86_64_ACPI_NUMA | |
3c2362e6 HH |
1579 | def_bool y |
1580 | prompt "ACPI NUMA detection" | |
506f1d07 SR |
1581 | depends on X86_64 && NUMA && ACPI && PCI |
1582 | select ACPI_NUMA | |
8f9ca475 | 1583 | ---help--- |
506f1d07 SR |
1584 | Enable ACPI SRAT based node topology detection. |
1585 | ||
1586 | config NUMA_EMU | |
1587 | bool "NUMA emulation" | |
1b7e03ef | 1588 | depends on NUMA |
8f9ca475 | 1589 | ---help--- |
506f1d07 SR |
1590 | Enable NUMA emulation. A flat machine will be split |
1591 | into virtual nodes when booted with "numa=fake=N", where N is the | |
1592 | number of nodes. This is only useful for debugging. | |
1593 | ||
1594 | config NODES_SHIFT | |
d25e26b6 | 1595 | int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP |
51591e31 DR |
1596 | range 1 10 |
1597 | default "10" if MAXSMP | |
506f1d07 | 1598 | default "6" if X86_64 |
506f1d07 SR |
1599 | default "3" |
1600 | depends on NEED_MULTIPLE_NODES | |
8f9ca475 | 1601 | ---help--- |
1184dc2f | 1602 | Specify the maximum number of NUMA Nodes available on the target |
692105b8 | 1603 | system. Increases memory reserved to accommodate various tables. |
506f1d07 | 1604 | |
506f1d07 SR |
1605 | config ARCH_FLATMEM_ENABLE |
1606 | def_bool y | |
3b16651f | 1607 | depends on X86_32 && !NUMA |
506f1d07 | 1608 | |
506f1d07 SR |
1609 | config ARCH_SPARSEMEM_ENABLE |
1610 | def_bool y | |
6ea30386 | 1611 | depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD |
506f1d07 SR |
1612 | select SPARSEMEM_STATIC if X86_32 |
1613 | select SPARSEMEM_VMEMMAP_ENABLE if X86_64 | |
1614 | ||
3b16651f | 1615 | config ARCH_SPARSEMEM_DEFAULT |
6ad57f7f | 1616 | def_bool X86_64 || (NUMA && X86_32) |
3b16651f | 1617 | |
506f1d07 SR |
1618 | config ARCH_SELECT_MEMORY_MODEL |
1619 | def_bool y | |
b263295d | 1620 | depends on ARCH_SPARSEMEM_ENABLE |
506f1d07 SR |
1621 | |
1622 | config ARCH_MEMORY_PROBE | |
a0842b70 | 1623 | bool "Enable sysfs memory/probe interface" |
3120e25e | 1624 | depends on X86_64 && MEMORY_HOTPLUG |
a0842b70 TK |
1625 | help |
1626 | This option enables a sysfs memory/probe interface for testing. | |
cb1aaebe | 1627 | See Documentation/admin-guide/mm/memory-hotplug.rst for more information. |
a0842b70 | 1628 | If you are unsure how to answer this question, answer N. |
506f1d07 | 1629 | |
3b16651f TH |
1630 | config ARCH_PROC_KCORE_TEXT |
1631 | def_bool y | |
1632 | depends on X86_64 && PROC_KCORE | |
1633 | ||
a29815a3 | 1634 | config ILLEGAL_POINTER_VALUE |
b03b016f KK |
1635 | hex |
1636 | default 0 if X86_32 | |
1637 | default 0xdead000000000000 if X86_64 | |
a29815a3 | 1638 | |
7a67832c DW |
1639 | config X86_PMEM_LEGACY_DEVICE |
1640 | bool | |
1641 | ||
ec776ef6 | 1642 | config X86_PMEM_LEGACY |
7a67832c | 1643 | tristate "Support non-standard NVDIMMs and ADR protected memory" |
9f53f9fa DW |
1644 | depends on PHYS_ADDR_T_64BIT |
1645 | depends on BLK_DEV | |
7a67832c | 1646 | select X86_PMEM_LEGACY_DEVICE |
7b27a862 | 1647 | select NUMA_KEEP_MEMINFO if NUMA |
9f53f9fa | 1648 | select LIBNVDIMM |
ec776ef6 CH |
1649 | help |
1650 | Treat memory marked using the non-standard e820 type of 12 as used | |
1651 | by the Intel Sandy Bridge-EP reference BIOS as protected memory. | |
1652 | The kernel will offer these regions to the 'pmem' driver so | |
1653 | they can be used for persistent storage. | |
1654 | ||
1655 | Say Y if unsure. | |
1656 | ||
506f1d07 SR |
1657 | config HIGHPTE |
1658 | bool "Allocate 3rd-level pagetables from highmem" | |
6fc108a0 | 1659 | depends on HIGHMEM |
8f9ca475 | 1660 | ---help--- |
506f1d07 SR |
1661 | The VM uses one page table entry for each page of physical memory. |
1662 | For systems with a lot of RAM, this can be wasteful of precious | |
1663 | low memory. Setting this option will put user-space page table | |
1664 | entries in high memory. | |
1665 | ||
9f077871 | 1666 | config X86_CHECK_BIOS_CORRUPTION |
8f9ca475 IM |
1667 | bool "Check for low memory corruption" |
1668 | ---help--- | |
1669 | Periodically check for memory corruption in low memory, which | |
1670 | is suspected to be caused by BIOS. Even when enabled in the | |
1671 | configuration, it is disabled at runtime. Enable it by | |
1672 | setting "memory_corruption_check=1" on the kernel command | |
1673 | line. By default it scans the low 64k of memory every 60 | |
1674 | seconds; see the memory_corruption_check_size and | |
1675 | memory_corruption_check_period parameters in | |
8c27ceff | 1676 | Documentation/admin-guide/kernel-parameters.rst to adjust this. |
8f9ca475 IM |
1677 | |
1678 | When enabled with the default parameters, this option has | |
1679 | almost no overhead, as it reserves a relatively small amount | |
1680 | of memory and scans it infrequently. It both detects corruption | |
1681 | and prevents it from affecting the running system. | |
1682 | ||
1683 | It is, however, intended as a diagnostic tool; if repeatable | |
1684 | BIOS-originated corruption always affects the same memory, | |
1685 | you can use memmap= to prevent the kernel from using that | |
1686 | memory. | |
9f077871 | 1687 | |
c885df50 | 1688 | config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK |
8f9ca475 | 1689 | bool "Set the default setting of memory_corruption_check" |
c885df50 JF |
1690 | depends on X86_CHECK_BIOS_CORRUPTION |
1691 | default y | |
8f9ca475 IM |
1692 | ---help--- |
1693 | Set whether the default state of memory_corruption_check is | |
1694 | on or off. | |
c885df50 | 1695 | |
9ea77bdb | 1696 | config X86_RESERVE_LOW |
d0cd7425 PA |
1697 | int "Amount of low memory, in kilobytes, to reserve for the BIOS" |
1698 | default 64 | |
1699 | range 4 640 | |
8f9ca475 | 1700 | ---help--- |
d0cd7425 PA |
1701 | Specify the amount of low memory to reserve for the BIOS. |
1702 | ||
1703 | The first page contains BIOS data structures that the kernel | |
1704 | must not use, so that page must always be reserved. | |
1705 | ||
1706 | By default we reserve the first 64K of physical RAM, as a | |
1707 | number of BIOSes are known to corrupt that memory range | |
1708 | during events such as suspend/resume or monitor cable | |
1709 | insertion, so it must not be used by the kernel. | |
fc381519 | 1710 | |
d0cd7425 PA |
1711 | You can set this to 4 if you are absolutely sure that you |
1712 | trust the BIOS to get all its memory reservations and usages | |
1713 | right. If you know your BIOS have problems beyond the | |
1714 | default 64K area, you can set this to 640 to avoid using the | |
1715 | entire low memory range. | |
fc381519 | 1716 | |
d0cd7425 PA |
1717 | If you have doubts about the BIOS (e.g. suspend/resume does |
1718 | not work or there's kernel crashes after certain hardware | |
1719 | hotplug events) then you might want to enable | |
1720 | X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check | |
1721 | typical corruption patterns. | |
fc381519 | 1722 | |
d0cd7425 | 1723 | Leave this to the default value of 64 if you are unsure. |
fc381519 | 1724 | |
506f1d07 SR |
1725 | config MATH_EMULATION |
1726 | bool | |
a5b9e5a2 | 1727 | depends on MODIFY_LDT_SYSCALL |
87d6021b | 1728 | prompt "Math emulation" if X86_32 && (M486SX || MELAN) |
506f1d07 SR |
1729 | ---help--- |
1730 | Linux can emulate a math coprocessor (used for floating point | |
1731 | operations) if you don't have one. 486DX and Pentium processors have | |
1732 | a math coprocessor built in, 486SX and 386 do not, unless you added | |
1733 | a 487DX or 387, respectively. (The messages during boot time can | |
1734 | give you some hints here ["man dmesg"].) Everyone needs either a | |
1735 | coprocessor or this emulation. | |
1736 | ||
1737 | If you don't have a math coprocessor, you need to say Y here; if you | |
1738 | say Y here even though you have a coprocessor, the coprocessor will | |
1739 | be used nevertheless. (This behavior can be changed with the kernel | |
1740 | command line option "no387", which comes handy if your coprocessor | |
1741 | is broken. Try "man bootparam" or see the documentation of your boot | |
1742 | loader (lilo or loadlin) about how to pass options to the kernel at | |
1743 | boot time.) This means that it is a good idea to say Y here if you | |
1744 | intend to use this kernel on different machines. | |
1745 | ||
1746 | More information about the internals of the Linux math coprocessor | |
1747 | emulation can be found in <file:arch/x86/math-emu/README>. | |
1748 | ||
1749 | If you are not sure, say Y; apart from resulting in a 66 KB bigger | |
1750 | kernel, it won't hurt. | |
1751 | ||
1752 | config MTRR | |
6fc108a0 | 1753 | def_bool y |
6a108a14 | 1754 | prompt "MTRR (Memory Type Range Register) support" if EXPERT |
506f1d07 SR |
1755 | ---help--- |
1756 | On Intel P6 family processors (Pentium Pro, Pentium II and later) | |
1757 | the Memory Type Range Registers (MTRRs) may be used to control | |
1758 | processor access to memory ranges. This is most useful if you have | |
1759 | a video (VGA) card on a PCI or AGP bus. Enabling write-combining | |
1760 | allows bus write transfers to be combined into a larger transfer | |
1761 | before bursting over the PCI/AGP bus. This can increase performance | |
1762 | of image write operations 2.5 times or more. Saying Y here creates a | |
1763 | /proc/mtrr file which may be used to manipulate your processor's | |
1764 | MTRRs. Typically the X server should use this. | |
1765 | ||
1766 | This code has a reasonably generic interface so that similar | |
1767 | control registers on other processors can be easily supported | |
1768 | as well: | |
1769 | ||
1770 | The Cyrix 6x86, 6x86MX and M II processors have Address Range | |
1771 | Registers (ARRs) which provide a similar functionality to MTRRs. For | |
1772 | these, the ARRs are used to emulate the MTRRs. | |
1773 | The AMD K6-2 (stepping 8 and above) and K6-3 processors have two | |
1774 | MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing | |
1775 | write-combining. All of these processors are supported by this code | |
1776 | and it makes sense to say Y here if you have one of them. | |
1777 | ||
1778 | Saying Y here also fixes a problem with buggy SMP BIOSes which only | |
1779 | set the MTRRs for the boot CPU and not for the secondary CPUs. This | |
1780 | can lead to all sorts of problems, so it's good to say Y here. | |
1781 | ||
1782 | You can safely say Y even if your machine doesn't have MTRRs, you'll | |
1783 | just add about 9 KB to your kernel. | |
1784 | ||
cb1aaebe | 1785 | See <file:Documentation/x86/mtrr.rst> for more information. |
506f1d07 | 1786 | |
95ffa243 | 1787 | config MTRR_SANITIZER |
2ffb3501 | 1788 | def_bool y |
95ffa243 YL |
1789 | prompt "MTRR cleanup support" |
1790 | depends on MTRR | |
8f9ca475 | 1791 | ---help--- |
aba3728c TG |
1792 | Convert MTRR layout from continuous to discrete, so X drivers can |
1793 | add writeback entries. | |
95ffa243 | 1794 | |
aba3728c | 1795 | Can be disabled with disable_mtrr_cleanup on the kernel command line. |
692105b8 | 1796 | The largest mtrr entry size for a continuous block can be set with |
aba3728c | 1797 | mtrr_chunk_size. |
95ffa243 | 1798 | |
2ffb3501 | 1799 | If unsure, say Y. |
95ffa243 YL |
1800 | |
1801 | config MTRR_SANITIZER_ENABLE_DEFAULT | |
f5098d62 YL |
1802 | int "MTRR cleanup enable value (0-1)" |
1803 | range 0 1 | |
1804 | default "0" | |
95ffa243 | 1805 | depends on MTRR_SANITIZER |
8f9ca475 | 1806 | ---help--- |
f5098d62 | 1807 | Enable mtrr cleanup default value |
95ffa243 | 1808 | |
12031a62 YL |
1809 | config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT |
1810 | int "MTRR cleanup spare reg num (0-7)" | |
1811 | range 0 7 | |
1812 | default "1" | |
1813 | depends on MTRR_SANITIZER | |
8f9ca475 | 1814 | ---help--- |
12031a62 | 1815 | mtrr cleanup spare entries default, it can be changed via |
aba3728c | 1816 | mtrr_spare_reg_nr=N on the kernel command line. |
12031a62 | 1817 | |
2e5d9c85 | 1818 | config X86_PAT |
6fc108a0 | 1819 | def_bool y |
6a108a14 | 1820 | prompt "x86 PAT support" if EXPERT |
2a8a2719 | 1821 | depends on MTRR |
8f9ca475 | 1822 | ---help--- |
2e5d9c85 | 1823 | Use PAT attributes to setup page level cache control. |
042b78e4 | 1824 | |
2e5d9c85 | 1825 | PATs are the modern equivalents of MTRRs and are much more |
1826 | flexible than MTRRs. | |
1827 | ||
1828 | Say N here if you see bootup problems (boot crash, boot hang, | |
042b78e4 | 1829 | spontaneous reboots) or a non-working video driver. |
2e5d9c85 | 1830 | |
1831 | If unsure, say Y. | |
1832 | ||
46cf98cd VP |
1833 | config ARCH_USES_PG_UNCACHED |
1834 | def_bool y | |
1835 | depends on X86_PAT | |
1836 | ||
628c6246 PA |
1837 | config ARCH_RANDOM |
1838 | def_bool y | |
1839 | prompt "x86 architectural random number generator" if EXPERT | |
1840 | ---help--- | |
1841 | Enable the x86 architectural RDRAND instruction | |
1842 | (Intel Bull Mountain technology) to generate random numbers. | |
1843 | If supported, this is a high bandwidth, cryptographically | |
1844 | secure hardware random number generator. | |
1845 | ||
51ae4a2d PA |
1846 | config X86_SMAP |
1847 | def_bool y | |
1848 | prompt "Supervisor Mode Access Prevention" if EXPERT | |
1849 | ---help--- | |
1850 | Supervisor Mode Access Prevention (SMAP) is a security | |
1851 | feature in newer Intel processors. There is a small | |
1852 | performance cost if this enabled and turned on; there is | |
1853 | also a small increase in the kernel size if this is enabled. | |
1854 | ||
1855 | If unsure, say Y. | |
1856 | ||
b971880f | 1857 | config X86_UMIP |
796ebc81 | 1858 | def_bool y |
b971880f BM |
1859 | prompt "User Mode Instruction Prevention" if EXPERT |
1860 | ---help--- | |
1861 | User Mode Instruction Prevention (UMIP) is a security feature in | |
1862 | some x86 processors. If enabled, a general protection fault is | |
1863 | issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are | |
1864 | executed in user mode. These instructions unnecessarily expose | |
1865 | information about the hardware state. | |
796ebc81 RN |
1866 | |
1867 | The vast majority of applications do not use these instructions. | |
1868 | For the very few that do, software emulation is provided in | |
1869 | specific cases in protected and virtual-8086 modes. Emulated | |
1870 | results are dummy. | |
aa35f896 | 1871 | |
35e97790 | 1872 | config X86_INTEL_MEMORY_PROTECTION_KEYS |
38f3e775 | 1873 | prompt "Memory Protection Keys" |
35e97790 | 1874 | def_bool y |
284244a9 | 1875 | # Note: only available in 64-bit mode |
38f3e775 | 1876 | depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD) |
52c8e601 IM |
1877 | select ARCH_USES_HIGH_VMA_FLAGS |
1878 | select ARCH_HAS_PKEYS | |
284244a9 DH |
1879 | ---help--- |
1880 | Memory Protection Keys provides a mechanism for enforcing | |
1881 | page-based protections, but without requiring modification of the | |
1882 | page tables when an application changes protection domains. | |
1883 | ||
1eecbcdc | 1884 | For details, see Documentation/core-api/protection-keys.rst |
284244a9 DH |
1885 | |
1886 | If unsure, say y. | |
35e97790 | 1887 | |
db616173 MH |
1888 | choice |
1889 | prompt "TSX enable mode" | |
1890 | depends on CPU_SUP_INTEL | |
1891 | default X86_INTEL_TSX_MODE_OFF | |
1892 | help | |
1893 | Intel's TSX (Transactional Synchronization Extensions) feature | |
1894 | allows to optimize locking protocols through lock elision which | |
1895 | can lead to a noticeable performance boost. | |
1896 | ||
1897 | On the other hand it has been shown that TSX can be exploited | |
1898 | to form side channel attacks (e.g. TAA) and chances are there | |
1899 | will be more of those attacks discovered in the future. | |
1900 | ||
1901 | Therefore TSX is not enabled by default (aka tsx=off). An admin | |
1902 | might override this decision by tsx=on the command line parameter. | |
1903 | Even with TSX enabled, the kernel will attempt to enable the best | |
1904 | possible TAA mitigation setting depending on the microcode available | |
1905 | for the particular machine. | |
1906 | ||
1907 | This option allows to set the default tsx mode between tsx=on, =off | |
1908 | and =auto. See Documentation/admin-guide/kernel-parameters.txt for more | |
1909 | details. | |
1910 | ||
1911 | Say off if not sure, auto if TSX is in use but it should be used on safe | |
1912 | platforms or on if TSX is in use and the security aspect of tsx is not | |
1913 | relevant. | |
1914 | ||
1915 | config X86_INTEL_TSX_MODE_OFF | |
1916 | bool "off" | |
1917 | help | |
1918 | TSX is disabled if possible - equals to tsx=off command line parameter. | |
1919 | ||
1920 | config X86_INTEL_TSX_MODE_ON | |
1921 | bool "on" | |
1922 | help | |
1923 | TSX is always enabled on TSX capable HW - equals the tsx=on command | |
1924 | line parameter. | |
1925 | ||
1926 | config X86_INTEL_TSX_MODE_AUTO | |
1927 | bool "auto" | |
1928 | help | |
1929 | TSX is enabled on TSX capable HW that is believed to be safe against | |
1930 | side channel attacks- equals the tsx=auto command line parameter. | |
1931 | endchoice | |
1932 | ||
506f1d07 | 1933 | config EFI |
9ba16087 | 1934 | bool "EFI runtime service support" |
5b83683f | 1935 | depends on ACPI |
f6ce5002 | 1936 | select UCS2_STRING |
022ee6c5 | 1937 | select EFI_RUNTIME_WRAPPERS |
506f1d07 | 1938 | ---help--- |
8f9ca475 IM |
1939 | This enables the kernel to use EFI runtime services that are |
1940 | available (such as the EFI variable services). | |
506f1d07 | 1941 | |
8f9ca475 IM |
1942 | This option is only useful on systems that have EFI firmware. |
1943 | In addition, you should use the latest ELILO loader available | |
1944 | at <http://elilo.sourceforge.net> in order to take advantage | |
1945 | of EFI runtime services. However, even with this option, the | |
1946 | resultant kernel should continue to boot on existing non-EFI | |
1947 | platforms. | |
506f1d07 | 1948 | |
291f3632 | 1949 | config EFI_STUB |
8f24f8c2 AB |
1950 | bool "EFI stub support" |
1951 | depends on EFI && !X86_USE_3DNOW | |
1952 | depends on $(cc-option,-mabi=ms) || X86_32 | |
1953 | select RELOCATABLE | |
1954 | ---help--- | |
1955 | This kernel feature allows a bzImage to be loaded directly | |
291f3632 MF |
1956 | by EFI firmware without the use of a bootloader. |
1957 | ||
4f4cfa6c | 1958 | See Documentation/admin-guide/efi-stub.rst for more information. |
0c759662 | 1959 | |
7d453eee MF |
1960 | config EFI_MIXED |
1961 | bool "EFI mixed-mode support" | |
1962 | depends on EFI_STUB && X86_64 | |
1963 | ---help--- | |
1964 | Enabling this feature allows a 64-bit kernel to be booted | |
1965 | on a 32-bit firmware, provided that your CPU supports 64-bit | |
1966 | mode. | |
1967 | ||
1968 | Note that it is not possible to boot a mixed-mode enabled | |
1969 | kernel via the EFI boot stub - a bootloader that supports | |
1970 | the EFI handover protocol must be used. | |
1971 | ||
1972 | If unsure, say N. | |
1973 | ||
506f1d07 | 1974 | config SECCOMP |
3c2362e6 HH |
1975 | def_bool y |
1976 | prompt "Enable seccomp to safely compute untrusted bytecode" | |
8f9ca475 | 1977 | ---help--- |
506f1d07 SR |
1978 | This kernel feature is useful for number crunching applications |
1979 | that may need to compute untrusted bytecode during their | |
1980 | execution. By using pipes or other transports made available to | |
1981 | the process as file descriptors supporting the read/write | |
1982 | syscalls, it's possible to isolate those applications in | |
1983 | their own address space using seccomp. Once seccomp is | |
9c0bbee8 | 1984 | enabled via prctl(PR_SET_SECCOMP), it cannot be disabled |
506f1d07 SR |
1985 | and the task is only allowed to execute a few safe syscalls |
1986 | defined by each seccomp mode. | |
1987 | ||
1988 | If unsure, say Y. Only embedded should say N here. | |
1989 | ||
8636a1f9 | 1990 | source "kernel/Kconfig.hz" |
506f1d07 SR |
1991 | |
1992 | config KEXEC | |
1993 | bool "kexec system call" | |
2965faa5 | 1994 | select KEXEC_CORE |
8f9ca475 | 1995 | ---help--- |
506f1d07 SR |
1996 | kexec is a system call that implements the ability to shutdown your |
1997 | current kernel, and to start another kernel. It is like a reboot | |
1998 | but it is independent of the system firmware. And like a reboot | |
1999 | you can start any kernel with it, not just Linux. | |
2000 | ||
2001 | The name comes from the similarity to the exec system call. | |
2002 | ||
2003 | It is an ongoing process to be certain the hardware in a machine | |
2004 | is properly shutdown, so do not be surprised if this code does not | |
bf220695 GU |
2005 | initially work for you. As of this writing the exact hardware |
2006 | interface is strongly in flux, so no good recommendation can be | |
2007 | made. | |
506f1d07 | 2008 | |
74ca317c VG |
2009 | config KEXEC_FILE |
2010 | bool "kexec file based system call" | |
2965faa5 | 2011 | select KEXEC_CORE |
74ca317c | 2012 | select BUILD_BIN2C |
74ca317c VG |
2013 | depends on X86_64 |
2014 | depends on CRYPTO=y | |
2015 | depends on CRYPTO_SHA256=y | |
2016 | ---help--- | |
2017 | This is new version of kexec system call. This system call is | |
2018 | file based and takes file descriptors as system call argument | |
2019 | for kernel and initramfs as opposed to list of segments as | |
2020 | accepted by previous system call. | |
2021 | ||
b799a09f AT |
2022 | config ARCH_HAS_KEXEC_PURGATORY |
2023 | def_bool KEXEC_FILE | |
2024 | ||
99d5cadf | 2025 | config KEXEC_SIG |
8e7d8381 | 2026 | bool "Verify kernel signature during kexec_file_load() syscall" |
74ca317c | 2027 | depends on KEXEC_FILE |
8e7d8381 | 2028 | ---help--- |
d8eb8940 | 2029 | |
99d5cadf JB |
2030 | This option makes the kexec_file_load() syscall check for a valid |
2031 | signature of the kernel image. The image can still be loaded without | |
2032 | a valid signature unless you also enable KEXEC_SIG_FORCE, though if | |
2033 | there's a signature that we can check, then it must be valid. | |
2034 | ||
2035 | In addition to this option, you need to enable signature | |
d8eb8940 BP |
2036 | verification for the corresponding kernel image type being |
2037 | loaded in order for this to work. | |
8e7d8381 | 2038 | |
99d5cadf JB |
2039 | config KEXEC_SIG_FORCE |
2040 | bool "Require a valid signature in kexec_file_load() syscall" | |
2041 | depends on KEXEC_SIG | |
2042 | ---help--- | |
2043 | This option makes kernel signature verification mandatory for | |
2044 | the kexec_file_load() syscall. | |
2045 | ||
8e7d8381 VG |
2046 | config KEXEC_BZIMAGE_VERIFY_SIG |
2047 | bool "Enable bzImage signature verification support" | |
99d5cadf | 2048 | depends on KEXEC_SIG |
8e7d8381 VG |
2049 | depends on SIGNED_PE_FILE_VERIFICATION |
2050 | select SYSTEM_TRUSTED_KEYRING | |
2051 | ---help--- | |
2052 | Enable bzImage signature verification support. | |
2053 | ||
506f1d07 | 2054 | config CRASH_DUMP |
04b69447 | 2055 | bool "kernel crash dumps" |
506f1d07 | 2056 | depends on X86_64 || (X86_32 && HIGHMEM) |
8f9ca475 | 2057 | ---help--- |
506f1d07 SR |
2058 | Generate crash dump after being started by kexec. |
2059 | This should be normally only set in special crash dump kernels | |
2060 | which are loaded in the main kernel with kexec-tools into | |
2061 | a specially reserved region and then later executed after | |
2062 | a crash by kdump/kexec. The crash dump kernel must be compiled | |
2063 | to a memory address not used by the main kernel or BIOS using | |
2064 | PHYSICAL_START, or it must be built as a relocatable image | |
2065 | (CONFIG_RELOCATABLE=y). | |
330d4810 | 2066 | For more details see Documentation/admin-guide/kdump/kdump.rst |
506f1d07 | 2067 | |
3ab83521 | 2068 | config KEXEC_JUMP |
6ea30386 | 2069 | bool "kexec jump" |
fee7b0d8 | 2070 | depends on KEXEC && HIBERNATION |
8f9ca475 | 2071 | ---help--- |
89081d17 HY |
2072 | Jump between original kernel and kexeced kernel and invoke |
2073 | code in physical address mode via KEXEC | |
3ab83521 | 2074 | |
506f1d07 | 2075 | config PHYSICAL_START |
6a108a14 | 2076 | hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) |
ceefccc9 | 2077 | default "0x1000000" |
8f9ca475 | 2078 | ---help--- |
506f1d07 SR |
2079 | This gives the physical address where the kernel is loaded. |
2080 | ||
2081 | If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then | |
2082 | bzImage will decompress itself to above physical address and | |
2083 | run from there. Otherwise, bzImage will run from the address where | |
2084 | it has been loaded by the boot loader and will ignore above physical | |
2085 | address. | |
2086 | ||
2087 | In normal kdump cases one does not have to set/change this option | |
2088 | as now bzImage can be compiled as a completely relocatable image | |
2089 | (CONFIG_RELOCATABLE=y) and be used to load and run from a different | |
2090 | address. This option is mainly useful for the folks who don't want | |
2091 | to use a bzImage for capturing the crash dump and want to use a | |
2092 | vmlinux instead. vmlinux is not relocatable hence a kernel needs | |
2093 | to be specifically compiled to run from a specific memory area | |
2094 | (normally a reserved region) and this option comes handy. | |
2095 | ||
ceefccc9 PA |
2096 | So if you are using bzImage for capturing the crash dump, |
2097 | leave the value here unchanged to 0x1000000 and set | |
2098 | CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux | |
2099 | for capturing the crash dump change this value to start of | |
2100 | the reserved region. In other words, it can be set based on | |
2101 | the "X" value as specified in the "crashkernel=YM@XM" | |
2102 | command line boot parameter passed to the panic-ed | |
330d4810 | 2103 | kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst |
ceefccc9 | 2104 | for more details about crash dumps. |
506f1d07 SR |
2105 | |
2106 | Usage of bzImage for capturing the crash dump is recommended as | |
2107 | one does not have to build two kernels. Same kernel can be used | |
2108 | as production kernel and capture kernel. Above option should have | |
2109 | gone away after relocatable bzImage support is introduced. But it | |
2110 | is present because there are users out there who continue to use | |
2111 | vmlinux for dump capture. This option should go away down the | |
2112 | line. | |
2113 | ||
2114 | Don't change this unless you know what you are doing. | |
2115 | ||
2116 | config RELOCATABLE | |
26717808 PA |
2117 | bool "Build a relocatable kernel" |
2118 | default y | |
8f9ca475 | 2119 | ---help--- |
506f1d07 SR |
2120 | This builds a kernel image that retains relocation information |
2121 | so it can be loaded someplace besides the default 1MB. | |
2122 | The relocations tend to make the kernel binary about 10% larger, | |
2123 | but are discarded at runtime. | |
2124 | ||
2125 | One use is for the kexec on panic case where the recovery kernel | |
2126 | must live at a different physical address than the primary | |
2127 | kernel. | |
2128 | ||
2129 | Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address | |
2130 | it has been loaded at and the compile time physical address | |
8ab3820f | 2131 | (CONFIG_PHYSICAL_START) is used as the minimum location. |
506f1d07 | 2132 | |
8ab3820f | 2133 | config RANDOMIZE_BASE |
e8581e3d | 2134 | bool "Randomize the address of the kernel image (KASLR)" |
8ab3820f | 2135 | depends on RELOCATABLE |
6807c846 | 2136 | default y |
8ab3820f | 2137 | ---help--- |
e8581e3d BH |
2138 | In support of Kernel Address Space Layout Randomization (KASLR), |
2139 | this randomizes the physical address at which the kernel image | |
2140 | is decompressed and the virtual address where the kernel | |
2141 | image is mapped, as a security feature that deters exploit | |
2142 | attempts relying on knowledge of the location of kernel | |
2143 | code internals. | |
2144 | ||
ed9f007e KC |
2145 | On 64-bit, the kernel physical and virtual addresses are |
2146 | randomized separately. The physical address will be anywhere | |
2147 | between 16MB and the top of physical memory (up to 64TB). The | |
2148 | virtual address will be randomized from 16MB up to 1GB (9 bits | |
2149 | of entropy). Note that this also reduces the memory space | |
2150 | available to kernel modules from 1.5GB to 1GB. | |
2151 | ||
2152 | On 32-bit, the kernel physical and virtual addresses are | |
2153 | randomized together. They will be randomized from 16MB up to | |
2154 | 512MB (8 bits of entropy). | |
e8581e3d BH |
2155 | |
2156 | Entropy is generated using the RDRAND instruction if it is | |
2157 | supported. If RDTSC is supported, its value is mixed into | |
2158 | the entropy pool as well. If neither RDRAND nor RDTSC are | |
ed9f007e KC |
2159 | supported, then entropy is read from the i8254 timer. The |
2160 | usable entropy is limited by the kernel being built using | |
2161 | 2GB addressing, and that PHYSICAL_ALIGN must be at a | |
2162 | minimum of 2MB. As a result, only 10 bits of entropy are | |
2163 | theoretically possible, but the implementations are further | |
2164 | limited due to memory layouts. | |
e8581e3d | 2165 | |
6807c846 | 2166 | If unsure, say Y. |
8ab3820f KC |
2167 | |
2168 | # Relocation on x86 needs some additional build support | |
845adf72 PA |
2169 | config X86_NEED_RELOCS |
2170 | def_bool y | |
8ab3820f | 2171 | depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) |
845adf72 | 2172 | |
506f1d07 | 2173 | config PHYSICAL_ALIGN |
a0215061 | 2174 | hex "Alignment value to which kernel should be aligned" |
8ab3820f | 2175 | default "0x200000" |
a0215061 KC |
2176 | range 0x2000 0x1000000 if X86_32 |
2177 | range 0x200000 0x1000000 if X86_64 | |
8f9ca475 | 2178 | ---help--- |
506f1d07 SR |
2179 | This value puts the alignment restrictions on physical address |
2180 | where kernel is loaded and run from. Kernel is compiled for an | |
2181 | address which meets above alignment restriction. | |
2182 | ||
2183 | If bootloader loads the kernel at a non-aligned address and | |
2184 | CONFIG_RELOCATABLE is set, kernel will move itself to nearest | |
2185 | address aligned to above value and run from there. | |
2186 | ||
2187 | If bootloader loads the kernel at a non-aligned address and | |
2188 | CONFIG_RELOCATABLE is not set, kernel will ignore the run time | |
2189 | load address and decompress itself to the address it has been | |
2190 | compiled for and run from there. The address for which kernel is | |
2191 | compiled already meets above alignment restrictions. Hence the | |
2192 | end result is that kernel runs from a physical address meeting | |
2193 | above alignment restrictions. | |
2194 | ||
a0215061 KC |
2195 | On 32-bit this value must be a multiple of 0x2000. On 64-bit |
2196 | this value must be a multiple of 0x200000. | |
2197 | ||
506f1d07 SR |
2198 | Don't change this unless you know what you are doing. |
2199 | ||
eedb92ab KS |
2200 | config DYNAMIC_MEMORY_LAYOUT |
2201 | bool | |
2202 | ---help--- | |
2203 | This option makes base addresses of vmalloc and vmemmap as well as | |
2204 | __PAGE_OFFSET movable during boot. | |
2205 | ||
0483e1fa TG |
2206 | config RANDOMIZE_MEMORY |
2207 | bool "Randomize the kernel memory sections" | |
2208 | depends on X86_64 | |
2209 | depends on RANDOMIZE_BASE | |
eedb92ab | 2210 | select DYNAMIC_MEMORY_LAYOUT |
0483e1fa TG |
2211 | default RANDOMIZE_BASE |
2212 | ---help--- | |
2213 | Randomizes the base virtual address of kernel memory sections | |
2214 | (physical memory mapping, vmalloc & vmemmap). This security feature | |
2215 | makes exploits relying on predictable memory locations less reliable. | |
2216 | ||
2217 | The order of allocations remains unchanged. Entropy is generated in | |
2218 | the same way as RANDOMIZE_BASE. Current implementation in the optimal | |
2219 | configuration have in average 30,000 different possible virtual | |
2220 | addresses for each memory section. | |
2221 | ||
6807c846 | 2222 | If unsure, say Y. |
0483e1fa | 2223 | |
90397a41 TG |
2224 | config RANDOMIZE_MEMORY_PHYSICAL_PADDING |
2225 | hex "Physical memory mapping padding" if EXPERT | |
2226 | depends on RANDOMIZE_MEMORY | |
2227 | default "0xa" if MEMORY_HOTPLUG | |
2228 | default "0x0" | |
2229 | range 0x1 0x40 if MEMORY_HOTPLUG | |
2230 | range 0x0 0x40 | |
2231 | ---help--- | |
2232 | Define the padding in terabytes added to the existing physical | |
2233 | memory size during kernel memory randomization. It is useful | |
2234 | for memory hotplug support but reduces the entropy available for | |
2235 | address randomization. | |
2236 | ||
2237 | If unsure, leave at the default value. | |
2238 | ||
506f1d07 | 2239 | config HOTPLUG_CPU |
bebd024e | 2240 | def_bool y |
40b31360 | 2241 | depends on SMP |
506f1d07 | 2242 | |
80aa1dff FY |
2243 | config BOOTPARAM_HOTPLUG_CPU0 |
2244 | bool "Set default setting of cpu0_hotpluggable" | |
2c922cd0 | 2245 | depends on HOTPLUG_CPU |
80aa1dff FY |
2246 | ---help--- |
2247 | Set whether default state of cpu0_hotpluggable is on or off. | |
2248 | ||
2249 | Say Y here to enable CPU0 hotplug by default. If this switch | |
2250 | is turned on, there is no need to give cpu0_hotplug kernel | |
2251 | parameter and the CPU0 hotplug feature is enabled by default. | |
2252 | ||
2253 | Please note: there are two known CPU0 dependencies if you want | |
2254 | to enable the CPU0 hotplug feature either by this switch or by | |
2255 | cpu0_hotplug kernel parameter. | |
2256 | ||
2257 | First, resume from hibernate or suspend always starts from CPU0. | |
2258 | So hibernate and suspend are prevented if CPU0 is offline. | |
2259 | ||
2260 | Second dependency is PIC interrupts always go to CPU0. CPU0 can not | |
2261 | offline if any interrupt can not migrate out of CPU0. There may | |
2262 | be other CPU0 dependencies. | |
2263 | ||
2264 | Please make sure the dependencies are under your control before | |
2265 | you enable this feature. | |
2266 | ||
2267 | Say N if you don't want to enable CPU0 hotplug feature by default. | |
2268 | You still can enable the CPU0 hotplug feature at boot by kernel | |
2269 | parameter cpu0_hotplug. | |
2270 | ||
a71c8bc5 FY |
2271 | config DEBUG_HOTPLUG_CPU0 |
2272 | def_bool n | |
2273 | prompt "Debug CPU0 hotplug" | |
2c922cd0 | 2274 | depends on HOTPLUG_CPU |
a71c8bc5 FY |
2275 | ---help--- |
2276 | Enabling this option offlines CPU0 (if CPU0 can be offlined) as | |
2277 | soon as possible and boots up userspace with CPU0 offlined. User | |
2278 | can online CPU0 back after boot time. | |
2279 | ||
2280 | To debug CPU0 hotplug, you need to enable CPU0 offline/online | |
2281 | feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during | |
2282 | compilation or giving cpu0_hotplug kernel parameter at boot. | |
2283 | ||
2284 | If unsure, say N. | |
2285 | ||
506f1d07 | 2286 | config COMPAT_VDSO |
b0b49f26 AL |
2287 | def_bool n |
2288 | prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)" | |
953fee1d | 2289 | depends on COMPAT_32 |
8f9ca475 | 2290 | ---help--- |
b0b49f26 AL |
2291 | Certain buggy versions of glibc will crash if they are |
2292 | presented with a 32-bit vDSO that is not mapped at the address | |
2293 | indicated in its segment table. | |
e84446de | 2294 | |
b0b49f26 AL |
2295 | The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a |
2296 | and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and | |
2297 | 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is | |
2298 | the only released version with the bug, but OpenSUSE 9 | |
2299 | contains a buggy "glibc 2.3.2". | |
506f1d07 | 2300 | |
b0b49f26 AL |
2301 | The symptom of the bug is that everything crashes on startup, saying: |
2302 | dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! | |
2303 | ||
2304 | Saying Y here changes the default value of the vdso32 boot | |
2305 | option from 1 to 0, which turns off the 32-bit vDSO entirely. | |
2306 | This works around the glibc bug but hurts performance. | |
2307 | ||
2308 | If unsure, say N: if you are compiling your own kernel, you | |
2309 | are unlikely to be using a buggy version of glibc. | |
506f1d07 | 2310 | |
3dc33bd3 KC |
2311 | choice |
2312 | prompt "vsyscall table for legacy applications" | |
2313 | depends on X86_64 | |
625b7b7f | 2314 | default LEGACY_VSYSCALL_XONLY |
3dc33bd3 KC |
2315 | help |
2316 | Legacy user code that does not know how to find the vDSO expects | |
2317 | to be able to issue three syscalls by calling fixed addresses in | |
2318 | kernel space. Since this location is not randomized with ASLR, | |
2319 | it can be used to assist security vulnerability exploitation. | |
2320 | ||
2321 | This setting can be changed at boot time via the kernel command | |
bd49e16e | 2322 | line parameter vsyscall=[emulate|xonly|none]. |
3dc33bd3 KC |
2323 | |
2324 | On a system with recent enough glibc (2.14 or newer) and no | |
2325 | static binaries, you can say None without a performance penalty | |
2326 | to improve security. | |
2327 | ||
bd49e16e | 2328 | If unsure, select "Emulate execution only". |
3dc33bd3 | 2329 | |
3dc33bd3 | 2330 | config LEGACY_VSYSCALL_EMULATE |
bd49e16e | 2331 | bool "Full emulation" |
3dc33bd3 | 2332 | help |
bd49e16e AL |
2333 | The kernel traps and emulates calls into the fixed vsyscall |
2334 | address mapping. This makes the mapping non-executable, but | |
2335 | it still contains readable known contents, which could be | |
2336 | used in certain rare security vulnerability exploits. This | |
2337 | configuration is recommended when using legacy userspace | |
2338 | that still uses vsyscalls along with legacy binary | |
2339 | instrumentation tools that require code to be readable. | |
2340 | ||
2341 | An example of this type of legacy userspace is running | |
2342 | Pin on an old binary that still uses vsyscalls. | |
2343 | ||
2344 | config LEGACY_VSYSCALL_XONLY | |
2345 | bool "Emulate execution only" | |
2346 | help | |
2347 | The kernel traps and emulates calls into the fixed vsyscall | |
2348 | address mapping and does not allow reads. This | |
2349 | configuration is recommended when userspace might use the | |
2350 | legacy vsyscall area but support for legacy binary | |
2351 | instrumentation of legacy code is not needed. It mitigates | |
2352 | certain uses of the vsyscall area as an ASLR-bypassing | |
2353 | buffer. | |
3dc33bd3 KC |
2354 | |
2355 | config LEGACY_VSYSCALL_NONE | |
2356 | bool "None" | |
2357 | help | |
2358 | There will be no vsyscall mapping at all. This will | |
2359 | eliminate any risk of ASLR bypass due to the vsyscall | |
2360 | fixed address mapping. Attempts to use the vsyscalls | |
2361 | will be reported to dmesg, so that either old or | |
2362 | malicious userspace programs can be identified. | |
2363 | ||
2364 | endchoice | |
2365 | ||
516cbf37 TB |
2366 | config CMDLINE_BOOL |
2367 | bool "Built-in kernel command line" | |
8f9ca475 | 2368 | ---help--- |
516cbf37 TB |
2369 | Allow for specifying boot arguments to the kernel at |
2370 | build time. On some systems (e.g. embedded ones), it is | |
2371 | necessary or convenient to provide some or all of the | |
2372 | kernel boot arguments with the kernel itself (that is, | |
2373 | to not rely on the boot loader to provide them.) | |
2374 | ||
2375 | To compile command line arguments into the kernel, | |
2376 | set this option to 'Y', then fill in the | |
69711ca1 | 2377 | boot arguments in CONFIG_CMDLINE. |
516cbf37 TB |
2378 | |
2379 | Systems with fully functional boot loaders (i.e. non-embedded) | |
2380 | should leave this option set to 'N'. | |
2381 | ||
2382 | config CMDLINE | |
2383 | string "Built-in kernel command string" | |
2384 | depends on CMDLINE_BOOL | |
2385 | default "" | |
8f9ca475 | 2386 | ---help--- |
516cbf37 TB |
2387 | Enter arguments here that should be compiled into the kernel |
2388 | image and used at boot time. If the boot loader provides a | |
2389 | command line at boot time, it is appended to this string to | |
2390 | form the full kernel command line, when the system boots. | |
2391 | ||
2392 | However, you can use the CONFIG_CMDLINE_OVERRIDE option to | |
2393 | change this behavior. | |
2394 | ||
2395 | In most cases, the command line (whether built-in or provided | |
2396 | by the boot loader) should specify the device for the root | |
2397 | file system. | |
2398 | ||
2399 | config CMDLINE_OVERRIDE | |
2400 | bool "Built-in command line overrides boot loader arguments" | |
645e6466 | 2401 | depends on CMDLINE_BOOL && CMDLINE != "" |
8f9ca475 | 2402 | ---help--- |
516cbf37 TB |
2403 | Set this option to 'Y' to have the kernel ignore the boot loader |
2404 | command line, and use ONLY the built-in command line. | |
2405 | ||
2406 | This is used to work around broken boot loaders. This should | |
2407 | be set to 'N' under normal conditions. | |
2408 | ||
a5b9e5a2 AL |
2409 | config MODIFY_LDT_SYSCALL |
2410 | bool "Enable the LDT (local descriptor table)" if EXPERT | |
2411 | default y | |
2412 | ---help--- | |
2413 | Linux can allow user programs to install a per-process x86 | |
2414 | Local Descriptor Table (LDT) using the modify_ldt(2) system | |
2415 | call. This is required to run 16-bit or segmented code such as | |
2416 | DOSEMU or some Wine programs. It is also used by some very old | |
2417 | threading libraries. | |
2418 | ||
2419 | Enabling this feature adds a small amount of overhead to | |
2420 | context switches and increases the low-level kernel attack | |
2421 | surface. Disabling it removes the modify_ldt(2) system call. | |
2422 | ||
2423 | Saying 'N' here may make sense for embedded or server kernels. | |
2424 | ||
b700e7f0 SJ |
2425 | source "kernel/livepatch/Kconfig" |
2426 | ||
506f1d07 SR |
2427 | endmenu |
2428 | ||
3072e413 MH |
2429 | config ARCH_HAS_ADD_PAGES |
2430 | def_bool y | |
2431 | depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG | |
2432 | ||
506f1d07 SR |
2433 | config ARCH_ENABLE_MEMORY_HOTPLUG |
2434 | def_bool y | |
2435 | depends on X86_64 || (X86_32 && HIGHMEM) | |
2436 | ||
35551053 GH |
2437 | config ARCH_ENABLE_MEMORY_HOTREMOVE |
2438 | def_bool y | |
2439 | depends on MEMORY_HOTPLUG | |
2440 | ||
e534c7c5 | 2441 | config USE_PERCPU_NUMA_NODE_ID |
645a7919 | 2442 | def_bool y |
e534c7c5 LS |
2443 | depends on NUMA |
2444 | ||
9491846f KS |
2445 | config ARCH_ENABLE_SPLIT_PMD_PTLOCK |
2446 | def_bool y | |
2447 | depends on X86_64 || X86_PAE | |
2448 | ||
c177c81e NH |
2449 | config ARCH_ENABLE_HUGEPAGE_MIGRATION |
2450 | def_bool y | |
2451 | depends on X86_64 && HUGETLB_PAGE && MIGRATION | |
2452 | ||
9c670ea3 NH |
2453 | config ARCH_ENABLE_THP_MIGRATION |
2454 | def_bool y | |
2455 | depends on X86_64 && TRANSPARENT_HUGEPAGE | |
2456 | ||
da85f865 | 2457 | menu "Power management and ACPI options" |
e279b6c1 SR |
2458 | |
2459 | config ARCH_HIBERNATION_HEADER | |
3c2362e6 | 2460 | def_bool y |
44556530 | 2461 | depends on HIBERNATION |
e279b6c1 SR |
2462 | |
2463 | source "kernel/power/Kconfig" | |
2464 | ||
2465 | source "drivers/acpi/Kconfig" | |
2466 | ||
efafc8b2 FT |
2467 | source "drivers/sfi/Kconfig" |
2468 | ||
a6b68076 | 2469 | config X86_APM_BOOT |
6fc108a0 | 2470 | def_bool y |
282e5aab | 2471 | depends on APM |
a6b68076 | 2472 | |
e279b6c1 SR |
2473 | menuconfig APM |
2474 | tristate "APM (Advanced Power Management) BIOS support" | |
efefa6f6 | 2475 | depends on X86_32 && PM_SLEEP |
e279b6c1 SR |
2476 | ---help--- |
2477 | APM is a BIOS specification for saving power using several different | |
2478 | techniques. This is mostly useful for battery powered laptops with | |
2479 | APM compliant BIOSes. If you say Y here, the system time will be | |
2480 | reset after a RESUME operation, the /proc/apm device will provide | |
2481 | battery status information, and user-space programs will receive | |
2482 | notification of APM "events" (e.g. battery status change). | |
2483 | ||
2484 | If you select "Y" here, you can disable actual use of the APM | |
2485 | BIOS by passing the "apm=off" option to the kernel at boot time. | |
2486 | ||
2487 | Note that the APM support is almost completely disabled for | |
2488 | machines with more than one CPU. | |
2489 | ||
2490 | In order to use APM, you will need supporting software. For location | |
151f4e2b | 2491 | and more information, read <file:Documentation/power/apm-acpi.rst> |
2dc98fd3 | 2492 | and the Battery Powered Linux mini-HOWTO, available from |
e279b6c1 SR |
2493 | <http://www.tldp.org/docs.html#howto>. |
2494 | ||
2495 | This driver does not spin down disk drives (see the hdparm(8) | |
2496 | manpage ("man 8 hdparm") for that), and it doesn't turn off | |
2497 | VESA-compliant "green" monitors. | |
2498 | ||
2499 | This driver does not support the TI 4000M TravelMate and the ACER | |
2500 | 486/DX4/75 because they don't have compliant BIOSes. Many "green" | |
2501 | desktop machines also don't have compliant BIOSes, and this driver | |
2502 | may cause those machines to panic during the boot phase. | |
2503 | ||
2504 | Generally, if you don't have a battery in your machine, there isn't | |
2505 | much point in using this driver and you should say N. If you get | |
2506 | random kernel OOPSes or reboots that don't seem to be related to | |
2507 | anything, try disabling/enabling this option (or disabling/enabling | |
2508 | APM in your BIOS). | |
2509 | ||
2510 | Some other things you should try when experiencing seemingly random, | |
2511 | "weird" problems: | |
2512 | ||
2513 | 1) make sure that you have enough swap space and that it is | |
2514 | enabled. | |
2515 | 2) pass the "no-hlt" option to the kernel | |
2516 | 3) switch on floating point emulation in the kernel and pass | |
2517 | the "no387" option to the kernel | |
2518 | 4) pass the "floppy=nodma" option to the kernel | |
2519 | 5) pass the "mem=4M" option to the kernel (thereby disabling | |
2520 | all but the first 4 MB of RAM) | |
2521 | 6) make sure that the CPU is not over clocked. | |
2522 | 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> | |
2523 | 8) disable the cache from your BIOS settings | |
2524 | 9) install a fan for the video card or exchange video RAM | |
2525 | 10) install a better fan for the CPU | |
2526 | 11) exchange RAM chips | |
2527 | 12) exchange the motherboard. | |
2528 | ||
2529 | To compile this driver as a module, choose M here: the | |
2530 | module will be called apm. | |
2531 | ||
2532 | if APM | |
2533 | ||
2534 | config APM_IGNORE_USER_SUSPEND | |
2535 | bool "Ignore USER SUSPEND" | |
8f9ca475 | 2536 | ---help--- |
e279b6c1 SR |
2537 | This option will ignore USER SUSPEND requests. On machines with a |
2538 | compliant APM BIOS, you want to say N. However, on the NEC Versa M | |
2539 | series notebooks, it is necessary to say Y because of a BIOS bug. | |
2540 | ||
2541 | config APM_DO_ENABLE | |
2542 | bool "Enable PM at boot time" | |
2543 | ---help--- | |
2544 | Enable APM features at boot time. From page 36 of the APM BIOS | |
2545 | specification: "When disabled, the APM BIOS does not automatically | |
2546 | power manage devices, enter the Standby State, enter the Suspend | |
2547 | State, or take power saving steps in response to CPU Idle calls." | |
2548 | This driver will make CPU Idle calls when Linux is idle (unless this | |
2549 | feature is turned off -- see "Do CPU IDLE calls", below). This | |
2550 | should always save battery power, but more complicated APM features | |
2551 | will be dependent on your BIOS implementation. You may need to turn | |
2552 | this option off if your computer hangs at boot time when using APM | |
2553 | support, or if it beeps continuously instead of suspending. Turn | |
2554 | this off if you have a NEC UltraLite Versa 33/C or a Toshiba | |
2555 | T400CDT. This is off by default since most machines do fine without | |
2556 | this feature. | |
2557 | ||
2558 | config APM_CPU_IDLE | |
dd8af076 | 2559 | depends on CPU_IDLE |
e279b6c1 | 2560 | bool "Make CPU Idle calls when idle" |
8f9ca475 | 2561 | ---help--- |
e279b6c1 SR |
2562 | Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. |
2563 | On some machines, this can activate improved power savings, such as | |
2564 | a slowed CPU clock rate, when the machine is idle. These idle calls | |
2565 | are made after the idle loop has run for some length of time (e.g., | |
2566 | 333 mS). On some machines, this will cause a hang at boot time or | |
2567 | whenever the CPU becomes idle. (On machines with more than one CPU, | |
2568 | this option does nothing.) | |
2569 | ||
2570 | config APM_DISPLAY_BLANK | |
2571 | bool "Enable console blanking using APM" | |
8f9ca475 | 2572 | ---help--- |
e279b6c1 SR |
2573 | Enable console blanking using the APM. Some laptops can use this to |
2574 | turn off the LCD backlight when the screen blanker of the Linux | |
2575 | virtual console blanks the screen. Note that this is only used by | |
2576 | the virtual console screen blanker, and won't turn off the backlight | |
2577 | when using the X Window system. This also doesn't have anything to | |
2578 | do with your VESA-compliant power-saving monitor. Further, this | |
2579 | option doesn't work for all laptops -- it might not turn off your | |
2580 | backlight at all, or it might print a lot of errors to the console, | |
2581 | especially if you are using gpm. | |
2582 | ||
2583 | config APM_ALLOW_INTS | |
2584 | bool "Allow interrupts during APM BIOS calls" | |
8f9ca475 | 2585 | ---help--- |
e279b6c1 SR |
2586 | Normally we disable external interrupts while we are making calls to |
2587 | the APM BIOS as a measure to lessen the effects of a badly behaving | |
2588 | BIOS implementation. The BIOS should reenable interrupts if it | |
2589 | needs to. Unfortunately, some BIOSes do not -- especially those in | |
2590 | many of the newer IBM Thinkpads. If you experience hangs when you | |
2591 | suspend, try setting this to Y. Otherwise, say N. | |
2592 | ||
e279b6c1 SR |
2593 | endif # APM |
2594 | ||
bb0a56ec | 2595 | source "drivers/cpufreq/Kconfig" |
e279b6c1 SR |
2596 | |
2597 | source "drivers/cpuidle/Kconfig" | |
2598 | ||
27471fdb AH |
2599 | source "drivers/idle/Kconfig" |
2600 | ||
e279b6c1 SR |
2601 | endmenu |
2602 | ||
2603 | ||
2604 | menu "Bus options (PCI etc.)" | |
2605 | ||
e279b6c1 SR |
2606 | choice |
2607 | prompt "PCI access mode" | |
efefa6f6 | 2608 | depends on X86_32 && PCI |
e279b6c1 SR |
2609 | default PCI_GOANY |
2610 | ---help--- | |
2611 | On PCI systems, the BIOS can be used to detect the PCI devices and | |
2612 | determine their configuration. However, some old PCI motherboards | |
2613 | have BIOS bugs and may crash if this is done. Also, some embedded | |
2614 | PCI-based systems don't have any BIOS at all. Linux can also try to | |
2615 | detect the PCI hardware directly without using the BIOS. | |
2616 | ||
2617 | With this option, you can specify how Linux should detect the | |
2618 | PCI devices. If you choose "BIOS", the BIOS will be used, | |
2619 | if you choose "Direct", the BIOS won't be used, and if you | |
2620 | choose "MMConfig", then PCI Express MMCONFIG will be used. | |
2621 | If you choose "Any", the kernel will try MMCONFIG, then the | |
2622 | direct access method and falls back to the BIOS if that doesn't | |
2623 | work. If unsure, go with the default, which is "Any". | |
2624 | ||
2625 | config PCI_GOBIOS | |
2626 | bool "BIOS" | |
2627 | ||
2628 | config PCI_GOMMCONFIG | |
2629 | bool "MMConfig" | |
2630 | ||
2631 | config PCI_GODIRECT | |
2632 | bool "Direct" | |
2633 | ||
3ef0e1f8 | 2634 | config PCI_GOOLPC |
76fb6570 | 2635 | bool "OLPC XO-1" |
3ef0e1f8 AS |
2636 | depends on OLPC |
2637 | ||
2bdd1b03 AS |
2638 | config PCI_GOANY |
2639 | bool "Any" | |
2640 | ||
e279b6c1 SR |
2641 | endchoice |
2642 | ||
2643 | config PCI_BIOS | |
3c2362e6 | 2644 | def_bool y |
efefa6f6 | 2645 | depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) |
e279b6c1 SR |
2646 | |
2647 | # x86-64 doesn't support PCI BIOS access from long mode so always go direct. | |
2648 | config PCI_DIRECT | |
3c2362e6 | 2649 | def_bool y |
0aba496f | 2650 | depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) |
e279b6c1 SR |
2651 | |
2652 | config PCI_MMCONFIG | |
b45c9f36 JK |
2653 | bool "Support mmconfig PCI config space access" if X86_64 |
2654 | default y | |
8364e1f8 | 2655 | depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST) |
b45c9f36 | 2656 | depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG) |
e279b6c1 | 2657 | |
3ef0e1f8 | 2658 | config PCI_OLPC |
2bdd1b03 AS |
2659 | def_bool y |
2660 | depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) | |
3ef0e1f8 | 2661 | |
b5401a96 AN |
2662 | config PCI_XEN |
2663 | def_bool y | |
2664 | depends on PCI && XEN | |
2665 | select SWIOTLB_XEN | |
2666 | ||
8364e1f8 JK |
2667 | config MMCONF_FAM10H |
2668 | def_bool y | |
2669 | depends on X86_64 && PCI_MMCONFIG && ACPI | |
e279b6c1 | 2670 | |
3f6ea84a | 2671 | config PCI_CNB20LE_QUIRK |
6a108a14 | 2672 | bool "Read CNB20LE Host Bridge Windows" if EXPERT |
6ea30386 | 2673 | depends on PCI |
3f6ea84a IS |
2674 | help |
2675 | Read the PCI windows out of the CNB20LE host bridge. This allows | |
2676 | PCI hotplug to work on systems with the CNB20LE chipset which do | |
2677 | not have ACPI. | |
2678 | ||
64a5fed6 BH |
2679 | There's no public spec for this chipset, and this functionality |
2680 | is known to be incomplete. | |
2681 | ||
2682 | You should say N unless you know you need this. | |
2683 | ||
3a495511 | 2684 | config ISA_BUS |
17a2a129 | 2685 | bool "ISA bus support on modern systems" if EXPERT |
3a495511 | 2686 | help |
17a2a129 WBG |
2687 | Expose ISA bus device drivers and options available for selection and |
2688 | configuration. Enable this option if your target machine has an ISA | |
2689 | bus. ISA is an older system, displaced by PCI and newer bus | |
2690 | architectures -- if your target machine is modern, it probably does | |
2691 | not have an ISA bus. | |
3a495511 WBG |
2692 | |
2693 | If unsure, say N. | |
2694 | ||
1c00f016 | 2695 | # x86_64 have no ISA slots, but can have ISA-style DMA. |
e279b6c1 | 2696 | config ISA_DMA_API |
1c00f016 DR |
2697 | bool "ISA-style DMA support" if (X86_64 && EXPERT) |
2698 | default y | |
2699 | help | |
2700 | Enables ISA-style DMA support for devices requiring such controllers. | |
2701 | If unsure, say Y. | |
e279b6c1 | 2702 | |
51e68d05 LT |
2703 | if X86_32 |
2704 | ||
e279b6c1 SR |
2705 | config ISA |
2706 | bool "ISA support" | |
8f9ca475 | 2707 | ---help--- |
e279b6c1 SR |
2708 | Find out whether you have ISA slots on your motherboard. ISA is the |
2709 | name of a bus system, i.e. the way the CPU talks to the other stuff | |
2710 | inside your box. Other bus systems are PCI, EISA, MicroChannel | |
2711 | (MCA) or VESA. ISA is an older system, now being displaced by PCI; | |
2712 | newer boards don't support it. If you have ISA, say Y, otherwise N. | |
2713 | ||
e279b6c1 SR |
2714 | config SCx200 |
2715 | tristate "NatSemi SCx200 support" | |
8f9ca475 | 2716 | ---help--- |
e279b6c1 SR |
2717 | This provides basic support for National Semiconductor's |
2718 | (now AMD's) Geode processors. The driver probes for the | |
2719 | PCI-IDs of several on-chip devices, so its a good dependency | |
2720 | for other scx200_* drivers. | |
2721 | ||
2722 | If compiled as a module, the driver is named scx200. | |
2723 | ||
2724 | config SCx200HR_TIMER | |
2725 | tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" | |
592913ec | 2726 | depends on SCx200 |
e279b6c1 | 2727 | default y |
8f9ca475 | 2728 | ---help--- |
e279b6c1 SR |
2729 | This driver provides a clocksource built upon the on-chip |
2730 | 27MHz high-resolution timer. Its also a workaround for | |
2731 | NSC Geode SC-1100's buggy TSC, which loses time when the | |
2732 | processor goes idle (as is done by the scheduler). The | |
2733 | other workaround is idle=poll boot option. | |
2734 | ||
3ef0e1f8 AS |
2735 | config OLPC |
2736 | bool "One Laptop Per Child support" | |
54008979 | 2737 | depends on !X86_PAE |
3c554946 | 2738 | select GPIOLIB |
dc3119e7 | 2739 | select OF |
45bb1674 | 2740 | select OF_PROMTREE |
b4e51854 | 2741 | select IRQ_DOMAIN |
0c3d931b | 2742 | select OLPC_EC |
8f9ca475 | 2743 | ---help--- |
3ef0e1f8 AS |
2744 | Add support for detecting the unique features of the OLPC |
2745 | XO hardware. | |
2746 | ||
a3128588 DD |
2747 | config OLPC_XO1_PM |
2748 | bool "OLPC XO-1 Power Management" | |
fa112cf1 | 2749 | depends on OLPC && MFD_CS5535=y && PM_SLEEP |
bf1ebf00 | 2750 | ---help--- |
97c4cb71 | 2751 | Add support for poweroff and suspend of the OLPC XO-1 laptop. |
bf1ebf00 | 2752 | |
cfee9597 DD |
2753 | config OLPC_XO1_RTC |
2754 | bool "OLPC XO-1 Real Time Clock" | |
2755 | depends on OLPC_XO1_PM && RTC_DRV_CMOS | |
2756 | ---help--- | |
2757 | Add support for the XO-1 real time clock, which can be used as a | |
2758 | programmable wakeup source. | |
2759 | ||
7feda8e9 DD |
2760 | config OLPC_XO1_SCI |
2761 | bool "OLPC XO-1 SCI extras" | |
92e830f2 | 2762 | depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y |
ed8e47fe | 2763 | depends on INPUT=y |
d8d01a63 | 2764 | select POWER_SUPPLY |
7feda8e9 DD |
2765 | ---help--- |
2766 | Add support for SCI-based features of the OLPC XO-1 laptop: | |
7bc74b3d | 2767 | - EC-driven system wakeups |
7feda8e9 | 2768 | - Power button |
7bc74b3d | 2769 | - Ebook switch |
2cf2baea | 2770 | - Lid switch |
e1040ac6 DD |
2771 | - AC adapter status updates |
2772 | - Battery status updates | |
7feda8e9 | 2773 | |
a0f30f59 DD |
2774 | config OLPC_XO15_SCI |
2775 | bool "OLPC XO-1.5 SCI extras" | |
d8d01a63 DD |
2776 | depends on OLPC && ACPI |
2777 | select POWER_SUPPLY | |
a0f30f59 DD |
2778 | ---help--- |
2779 | Add support for SCI-based features of the OLPC XO-1.5 laptop: | |
2780 | - EC-driven system wakeups | |
2781 | - AC adapter status updates | |
2782 | - Battery status updates | |
bf1ebf00 | 2783 | |
d4f3e350 EW |
2784 | config ALIX |
2785 | bool "PCEngines ALIX System Support (LED setup)" | |
2786 | select GPIOLIB | |
2787 | ---help--- | |
2788 | This option enables system support for the PCEngines ALIX. | |
2789 | At present this just sets up LEDs for GPIO control on | |
2790 | ALIX2/3/6 boards. However, other system specific setup should | |
2791 | get added here. | |
2792 | ||
2793 | Note: You must still enable the drivers for GPIO and LED support | |
2794 | (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs | |
2795 | ||
2796 | Note: You have to set alix.force=1 for boards with Award BIOS. | |
2797 | ||
da4e3302 PP |
2798 | config NET5501 |
2799 | bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" | |
2800 | select GPIOLIB | |
2801 | ---help--- | |
2802 | This option enables system support for the Soekris Engineering net5501. | |
2803 | ||
3197059a PP |
2804 | config GEOS |
2805 | bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" | |
2806 | select GPIOLIB | |
2807 | depends on DMI | |
2808 | ---help--- | |
2809 | This option enables system support for the Traverse Technologies GEOS. | |
2810 | ||
7d029125 VD |
2811 | config TS5500 |
2812 | bool "Technologic Systems TS-5500 platform support" | |
2813 | depends on MELAN | |
2814 | select CHECK_SIGNATURE | |
2815 | select NEW_LEDS | |
2816 | select LEDS_CLASS | |
2817 | ---help--- | |
2818 | This option enables system support for the Technologic Systems TS-5500. | |
2819 | ||
bc0120fd SR |
2820 | endif # X86_32 |
2821 | ||
23ac4ae8 | 2822 | config AMD_NB |
e279b6c1 | 2823 | def_bool y |
0e152cd7 | 2824 | depends on CPU_SUP_AMD && PCI |
e279b6c1 | 2825 | |
e3263ab3 DH |
2826 | config X86_SYSFB |
2827 | bool "Mark VGA/VBE/EFI FB as generic system framebuffer" | |
2828 | help | |
2829 | Firmwares often provide initial graphics framebuffers so the BIOS, | |
2830 | bootloader or kernel can show basic video-output during boot for | |
2831 | user-guidance and debugging. Historically, x86 used the VESA BIOS | |
2832 | Extensions and EFI-framebuffers for this, which are mostly limited | |
2833 | to x86. | |
2834 | This option, if enabled, marks VGA/VBE/EFI framebuffers as generic | |
2835 | framebuffers so the new generic system-framebuffer drivers can be | |
2836 | used on x86. If the framebuffer is not compatible with the generic | |
e3a5dc08 | 2837 | modes, it is advertised as fallback platform framebuffer so legacy |
e3263ab3 DH |
2838 | drivers like efifb, vesafb and uvesafb can pick it up. |
2839 | If this option is not selected, all system framebuffers are always | |
2840 | marked as fallback platform framebuffers as usual. | |
2841 | ||
2842 | Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will | |
2843 | not be able to pick up generic system framebuffers if this option | |
2844 | is selected. You are highly encouraged to enable simplefb as | |
2845 | replacement if you select this option. simplefb can correctly deal | |
2846 | with generic system framebuffers. But you should still keep vesafb | |
2847 | and others enabled as fallback if a system framebuffer is | |
2848 | incompatible with simplefb. | |
2849 | ||
2850 | If unsure, say Y. | |
2851 | ||
e279b6c1 SR |
2852 | endmenu |
2853 | ||
2854 | ||
1572497c | 2855 | menu "Binary Emulations" |
e279b6c1 SR |
2856 | |
2857 | config IA32_EMULATION | |
2858 | bool "IA32 Emulation" | |
2859 | depends on X86_64 | |
39f88911 | 2860 | select ARCH_WANT_OLD_COMPAT_IPC |
d1603990 | 2861 | select BINFMT_ELF |
a97f52e6 | 2862 | select COMPAT_BINFMT_ELF |
39f88911 | 2863 | select COMPAT_OLD_SIGACTION |
8f9ca475 | 2864 | ---help--- |
5fd92e65 L |
2865 | Include code to run legacy 32-bit programs under a |
2866 | 64-bit kernel. You should likely turn this on, unless you're | |
2867 | 100% sure that you don't have any 32-bit programs left. | |
e279b6c1 SR |
2868 | |
2869 | config IA32_AOUT | |
8f9ca475 IM |
2870 | tristate "IA32 a.out support" |
2871 | depends on IA32_EMULATION | |
eac61655 | 2872 | depends on BROKEN |
8f9ca475 IM |
2873 | ---help--- |
2874 | Support old a.out binaries in the 32bit emulation. | |
e279b6c1 | 2875 | |
0bf62763 | 2876 | config X86_X32 |
6ea30386 | 2877 | bool "x32 ABI for 64-bit mode" |
9b54050b | 2878 | depends on X86_64 |
5fd92e65 L |
2879 | ---help--- |
2880 | Include code to run binaries for the x32 native 32-bit ABI | |
2881 | for 64-bit processors. An x32 process gets access to the | |
2882 | full 64-bit register file and wide data path while leaving | |
2883 | pointers at 32 bits for smaller memory footprint. | |
2884 | ||
2885 | You will need a recent binutils (2.22 or later) with | |
2886 | elf32_x86_64 support enabled to compile a kernel with this | |
2887 | option set. | |
2888 | ||
953fee1d IM |
2889 | config COMPAT_32 |
2890 | def_bool y | |
2891 | depends on IA32_EMULATION || X86_32 | |
2892 | select HAVE_UID16 | |
2893 | select OLD_SIGSUSPEND3 | |
2894 | ||
e279b6c1 | 2895 | config COMPAT |
3c2362e6 | 2896 | def_bool y |
0bf62763 | 2897 | depends on IA32_EMULATION || X86_X32 |
e279b6c1 | 2898 | |
3120e25e | 2899 | if COMPAT |
e279b6c1 | 2900 | config COMPAT_FOR_U64_ALIGNMENT |
3120e25e | 2901 | def_bool y |
e279b6c1 SR |
2902 | |
2903 | config SYSVIPC_COMPAT | |
3c2362e6 | 2904 | def_bool y |
3120e25e | 2905 | depends on SYSVIPC |
3120e25e | 2906 | endif |
ee009e4a | 2907 | |
e279b6c1 SR |
2908 | endmenu |
2909 | ||
2910 | ||
e5beae16 KP |
2911 | config HAVE_ATOMIC_IOMAP |
2912 | def_bool y | |
2913 | depends on X86_32 | |
2914 | ||
e279b6c1 SR |
2915 | source "drivers/firmware/Kconfig" |
2916 | ||
edf88417 | 2917 | source "arch/x86/kvm/Kconfig" |
5e8ebd84 JD |
2918 | |
2919 | source "arch/x86/Kconfig.assembler" |