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 |
399145f9 | 62 | select ARCH_HAS_DEBUG_VM_PGTABLE if !X86_PAE |
21266be9 | 63 | select ARCH_HAS_DEVMEM_IS_ALLOWED |
b1a57bbf | 64 | select ARCH_HAS_EARLY_DEBUG if KGDB |
6471b825 | 65 | select ARCH_HAS_ELF_RANDOMIZE |
72d93104 | 66 | select ARCH_HAS_FAST_MULTIPLIER |
316d097c | 67 | select ARCH_HAS_FILTER_PGPROT |
6974f0c4 | 68 | select ARCH_HAS_FORTIFY_SOURCE |
957e3fac | 69 | select ARCH_HAS_GCOV_PROFILE_ALL |
5c9a8750 | 70 | select ARCH_HAS_KCOV if X86_64 |
0c9c1d56 | 71 | select ARCH_HAS_MEM_ENCRYPT |
10bcc80e | 72 | select ARCH_HAS_MEMBARRIER_SYNC_CORE |
0ebeea8c | 73 | select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE |
c763ea26 | 74 | select ARCH_HAS_PMEM_API if X86_64 |
17596731 | 75 | select ARCH_HAS_PTE_DEVMAP if X86_64 |
3010a5ea | 76 | select ARCH_HAS_PTE_SPECIAL |
0aed55af | 77 | select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64 |
092b31aa | 78 | select ARCH_HAS_UACCESS_MCSAFE if X86_64 && X86_MCE |
d2852a22 | 79 | select ARCH_HAS_SET_MEMORY |
d253ca0c | 80 | select ARCH_HAS_SET_DIRECT_MAP |
ad21fc4f LA |
81 | select ARCH_HAS_STRICT_KERNEL_RWX |
82 | select ARCH_HAS_STRICT_MODULE_RWX | |
ac1ab12a | 83 | select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE |
25c619e5 | 84 | select ARCH_HAS_SYSCALL_WRAPPER |
c6d30853 | 85 | select ARCH_HAS_UBSAN_SANITIZE_ALL |
7e01ccb4 | 86 | select ARCH_HAS_DEBUG_WX |
6471b825 IM |
87 | select ARCH_HAVE_NMI_SAFE_CMPXCHG |
88 | select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI | |
77fbbc81 | 89 | select ARCH_MIGHT_HAVE_PC_PARPORT |
5e2c18c0 | 90 | select ARCH_MIGHT_HAVE_PC_SERIO |
3599fe12 | 91 | select ARCH_STACKWALK |
2c870e61 | 92 | select ARCH_SUPPORTS_ACPI |
6471b825 | 93 | select ARCH_SUPPORTS_ATOMIC_RMW |
6471b825 IM |
94 | select ARCH_SUPPORTS_NUMA_BALANCING if X86_64 |
95 | select ARCH_USE_BUILTIN_BSWAP | |
6471b825 IM |
96 | select ARCH_USE_QUEUED_RWLOCKS |
97 | select ARCH_USE_QUEUED_SPINLOCKS | |
2ce0d7f9 | 98 | select ARCH_USE_SYM_ANNOTATIONS |
ce4a4e56 | 99 | select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH |
81c22041 | 100 | select ARCH_WANT_DEFAULT_BPF_JIT if X86_64 |
c763ea26 | 101 | select ARCH_WANTS_DYNAMIC_TASK_STRUCT |
3876d4a3 | 102 | select ARCH_WANT_HUGE_PMD_SHARE |
38d8b4e6 | 103 | select ARCH_WANTS_THP_SWAP if X86_64 |
10916706 | 104 | select BUILDTIME_TABLE_SORT |
6471b825 | 105 | select CLKEVT_I8253 |
6471b825 IM |
106 | select CLOCKSOURCE_VALIDATE_LAST_CYCLE |
107 | select CLOCKSOURCE_WATCHDOG | |
6471b825 | 108 | select DCACHE_WORD_ACCESS |
45471cd9 LT |
109 | select EDAC_ATOMIC_SCRUB |
110 | select EDAC_SUPPORT | |
6471b825 IM |
111 | select GENERIC_CLOCKEVENTS |
112 | select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC) | |
113 | select GENERIC_CLOCKEVENTS_MIN_ADJUST | |
114 | select GENERIC_CMOS_UPDATE | |
115 | select GENERIC_CPU_AUTOPROBE | |
61dc0f55 | 116 | select GENERIC_CPU_VULNERABILITIES |
5b7c73e0 | 117 | select GENERIC_EARLY_IOREMAP |
6471b825 IM |
118 | select GENERIC_FIND_FIRST_BIT |
119 | select GENERIC_IOMAP | |
c7d6c9dd | 120 | select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP |
0fa115da | 121 | select GENERIC_IRQ_MATRIX_ALLOCATOR if X86_LOCAL_APIC |
ad7a929f | 122 | select GENERIC_IRQ_MIGRATION if SMP |
6471b825 | 123 | select GENERIC_IRQ_PROBE |
c201c917 | 124 | select GENERIC_IRQ_RESERVATION_MODE |
6471b825 IM |
125 | select GENERIC_IRQ_SHOW |
126 | select GENERIC_PENDING_IRQ if SMP | |
2ae27137 | 127 | select GENERIC_PTDUMP |
6471b825 IM |
128 | select GENERIC_SMP_IDLE_THREAD |
129 | select GENERIC_STRNCPY_FROM_USER | |
130 | select GENERIC_STRNLEN_USER | |
131 | select GENERIC_TIME_VSYSCALL | |
7ac87074 | 132 | select GENERIC_GETTIMEOFDAY |
550a77a7 | 133 | select GENERIC_VDSO_TIME_NS |
39656e83 | 134 | select GUP_GET_PTE_LOW_HIGH if X86_PAE |
17e5888e | 135 | select HARDIRQS_SW_RESEND |
7edaeb68 | 136 | select HARDLOCKUP_CHECK_TIMESTAMP if X86_64 |
6471b825 IM |
137 | select HAVE_ACPI_APEI if ACPI |
138 | select HAVE_ACPI_APEI_NMI if ACPI | |
139 | select HAVE_ALIGNED_STRUCT_PAGE if SLUB | |
6471b825 IM |
140 | select HAVE_ARCH_AUDITSYSCALL |
141 | select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE | |
142 | select HAVE_ARCH_JUMP_LABEL | |
b34006c4 | 143 | select HAVE_ARCH_JUMP_LABEL_RELATIVE |
d17a1d97 | 144 | select HAVE_ARCH_KASAN if X86_64 |
0609ae01 | 145 | select HAVE_ARCH_KASAN_VMALLOC if X86_64 |
6471b825 | 146 | select HAVE_ARCH_KGDB |
9e08f57d DC |
147 | select HAVE_ARCH_MMAP_RND_BITS if MMU |
148 | select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT | |
1b028f78 | 149 | select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT |
271ca788 | 150 | select HAVE_ARCH_PREL32_RELOCATIONS |
6471b825 | 151 | select HAVE_ARCH_SECCOMP_FILTER |
f7d83c1c | 152 | select HAVE_ARCH_THREAD_STRUCT_WHITELIST |
afaef01c | 153 | select HAVE_ARCH_STACKLEAK |
6471b825 IM |
154 | select HAVE_ARCH_TRACEHOOK |
155 | select HAVE_ARCH_TRANSPARENT_HUGEPAGE | |
a00cc7d9 | 156 | select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64 |
b64d8d1e | 157 | select HAVE_ARCH_USERFAULTFD_WP if X86_64 && USERFAULTFD |
e37e43a4 | 158 | select HAVE_ARCH_VMAP_STACK if X86_64 |
c763ea26 | 159 | select HAVE_ARCH_WITHIN_STACK_FRAMES |
2ff2b7ec | 160 | select HAVE_ASM_MODVERSIONS |
6471b825 IM |
161 | select HAVE_CMPXCHG_DOUBLE |
162 | select HAVE_CMPXCHG_LOCAL | |
163 | select HAVE_CONTEXT_TRACKING if X86_64 | |
c1bd55f9 | 164 | select HAVE_COPY_THREAD_TLS |
cf4db259 | 165 | select HAVE_C_RECORDMCOUNT |
6471b825 | 166 | select HAVE_DEBUG_KMEMLEAK |
6471b825 | 167 | select HAVE_DMA_CONTIGUOUS |
677aa9f7 | 168 | select HAVE_DYNAMIC_FTRACE |
06aeaaea | 169 | select HAVE_DYNAMIC_FTRACE_WITH_REGS |
562955fe | 170 | select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS |
03f5781b | 171 | select HAVE_EBPF_JIT |
58340a07 | 172 | select HAVE_EFFICIENT_UNALIGNED_ACCESS |
6630a8e5 | 173 | select HAVE_EISA |
5f56a5df | 174 | select HAVE_EXIT_THREAD |
67a929e0 | 175 | select HAVE_FAST_GUP |
644e0e8d | 176 | select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE |
6471b825 | 177 | select HAVE_FTRACE_MCOUNT_RECORD |
6471b825 IM |
178 | select HAVE_FUNCTION_GRAPH_TRACER |
179 | select HAVE_FUNCTION_TRACER | |
6b90bd4b | 180 | select HAVE_GCC_PLUGINS |
6471b825 IM |
181 | select HAVE_HW_BREAKPOINT |
182 | select HAVE_IDE | |
183 | select HAVE_IOREMAP_PROT | |
184 | select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64 | |
185 | select HAVE_IRQ_TIME_ACCOUNTING | |
2e9f3bdd | 186 | select HAVE_KERNEL_BZIP2 |
6471b825 IM |
187 | select HAVE_KERNEL_GZIP |
188 | select HAVE_KERNEL_LZ4 | |
2e9f3bdd | 189 | select HAVE_KERNEL_LZMA |
13510997 | 190 | select HAVE_KERNEL_LZO |
6471b825 IM |
191 | select HAVE_KERNEL_XZ |
192 | select HAVE_KPROBES | |
193 | select HAVE_KPROBES_ON_FTRACE | |
540adea3 | 194 | select HAVE_FUNCTION_ERROR_INJECTION |
6471b825 IM |
195 | select HAVE_KRETPROBES |
196 | select HAVE_KVM | |
197 | select HAVE_LIVEPATCH if X86_64 | |
0102752e | 198 | select HAVE_MIXED_BREAKPOINTS_REGS |
ee9f8fce | 199 | select HAVE_MOD_ARCH_SPECIFIC |
9f132f7e | 200 | select HAVE_MOVE_PMD |
42a0bb3f | 201 | select HAVE_NMI |
6471b825 IM |
202 | select HAVE_OPROFILE |
203 | select HAVE_OPTPROBES | |
204 | select HAVE_PCSPKR_PLATFORM | |
205 | select HAVE_PERF_EVENTS | |
c01d4323 | 206 | select HAVE_PERF_EVENTS_NMI |
92e5aae4 | 207 | select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI |
eb01d42a | 208 | select HAVE_PCI |
c5e63197 | 209 | select HAVE_PERF_REGS |
c5ebcedb | 210 | select HAVE_PERF_USER_STACK_DUMP |
ff2e6d72 | 211 | select MMU_GATHER_RCU_TABLE_FREE if PARAVIRT |
6471b825 | 212 | select HAVE_REGS_AND_STACK_ACCESS_API |
6415b38b | 213 | select HAVE_RELIABLE_STACKTRACE if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION |
3c88ee19 | 214 | select HAVE_FUNCTION_ARG_ACCESS_API |
d148eac0 | 215 | select HAVE_STACKPROTECTOR if CC_HAS_SANE_STACKPROTECTOR |
c763ea26 | 216 | select HAVE_STACK_VALIDATION if X86_64 |
d6761b8f | 217 | select HAVE_RSEQ |
6471b825 | 218 | select HAVE_SYSCALL_TRACEPOINTS |
6471b825 | 219 | select HAVE_UNSTABLE_SCHED_CLOCK |
7c68af6e | 220 | select HAVE_USER_RETURN_NOTIFIER |
7ac87074 | 221 | select HAVE_GENERIC_VDSO |
05736e4a | 222 | select HOTPLUG_SMT if SMP |
c0185808 | 223 | select IRQ_FORCED_THREADING |
86596f0a | 224 | select NEED_SG_DMA_LENGTH |
2eac9c2d | 225 | select PCI_DOMAINS if PCI |
625210cf | 226 | select PCI_LOCKLESS_CONFIG if PCI |
6471b825 | 227 | select PERF_EVENTS |
3195ef59 | 228 | select RTC_LIB |
d6faca40 | 229 | select RTC_MC146818_LIB |
6471b825 | 230 | select SPARSE_IRQ |
83fe27ea | 231 | select SRCU |
6471b825 | 232 | select SYSCTL_EXCEPTION_TRACE |
15f4eae7 | 233 | select THREAD_INFO_IN_TASK |
6471b825 IM |
234 | select USER_STACKTRACE_SUPPORT |
235 | select VIRT_TO_BUS | |
6471b825 | 236 | select X86_FEATURE_NAMES if PROC_FS |
0c608dad | 237 | select PROC_PID_ARCH_STATUS if PROC_FS |
9e2b4be3 | 238 | imply IMA_SECURE_AND_OR_TRUSTED_BOOT if EFI |
7d8330a5 | 239 | |
ba7e4d13 | 240 | config INSTRUCTION_DECODER |
3120e25e JB |
241 | def_bool y |
242 | depends on KPROBES || PERF_EVENTS || UPROBES | |
ba7e4d13 | 243 | |
51b26ada LT |
244 | config OUTPUT_FORMAT |
245 | string | |
246 | default "elf32-i386" if X86_32 | |
247 | default "elf64-x86-64" if X86_64 | |
248 | ||
8d5fffb9 | 249 | config LOCKDEP_SUPPORT |
3c2362e6 | 250 | def_bool y |
8d5fffb9 SR |
251 | |
252 | config STACKTRACE_SUPPORT | |
3c2362e6 | 253 | def_bool y |
8d5fffb9 | 254 | |
8d5fffb9 | 255 | config MMU |
3c2362e6 | 256 | def_bool y |
8d5fffb9 | 257 | |
9e08f57d DC |
258 | config ARCH_MMAP_RND_BITS_MIN |
259 | default 28 if 64BIT | |
260 | default 8 | |
261 | ||
262 | config ARCH_MMAP_RND_BITS_MAX | |
263 | default 32 if 64BIT | |
264 | default 16 | |
265 | ||
266 | config ARCH_MMAP_RND_COMPAT_BITS_MIN | |
267 | default 8 | |
268 | ||
269 | config ARCH_MMAP_RND_COMPAT_BITS_MAX | |
270 | default 16 | |
271 | ||
8d5fffb9 SR |
272 | config SBUS |
273 | bool | |
274 | ||
275 | config GENERIC_ISA_DMA | |
3120e25e JB |
276 | def_bool y |
277 | depends on ISA_DMA_API | |
8d5fffb9 | 278 | |
8d5fffb9 | 279 | config GENERIC_BUG |
3c2362e6 | 280 | def_bool y |
8d5fffb9 | 281 | depends on BUG |
b93a531e JB |
282 | select GENERIC_BUG_RELATIVE_POINTERS if X86_64 |
283 | ||
284 | config GENERIC_BUG_RELATIVE_POINTERS | |
285 | bool | |
8d5fffb9 | 286 | |
8d5fffb9 | 287 | config ARCH_MAY_HAVE_PC_FDC |
3120e25e JB |
288 | def_bool y |
289 | depends on ISA_DMA_API | |
8d5fffb9 | 290 | |
1032c0ba SR |
291 | config GENERIC_CALIBRATE_DELAY |
292 | def_bool y | |
293 | ||
9a0b8415 | 294 | config ARCH_HAS_CPU_RELAX |
295 | def_bool y | |
296 | ||
1b27d05b PE |
297 | config ARCH_HAS_CACHE_LINE_SIZE |
298 | def_bool y | |
299 | ||
316d097c DH |
300 | config ARCH_HAS_FILTER_PGPROT |
301 | def_bool y | |
302 | ||
dd5af90a | 303 | config HAVE_SETUP_PER_CPU_AREA |
89c9c4c5 | 304 | def_bool y |
b32ef636 | 305 | |
08fc4580 TH |
306 | config NEED_PER_CPU_EMBED_FIRST_CHUNK |
307 | def_bool y | |
308 | ||
309 | config NEED_PER_CPU_PAGE_FIRST_CHUNK | |
11124411 TH |
310 | def_bool y |
311 | ||
801e4062 JB |
312 | config ARCH_HIBERNATION_POSSIBLE |
313 | def_bool y | |
801e4062 | 314 | |
f4cb5700 JB |
315 | config ARCH_SUSPEND_POSSIBLE |
316 | def_bool y | |
f4cb5700 | 317 | |
53313b2c SC |
318 | config ARCH_WANT_GENERAL_HUGETLB |
319 | def_bool y | |
320 | ||
8d5fffb9 | 321 | config ZONE_DMA32 |
e0fd24a3 | 322 | def_bool y if X86_64 |
8d5fffb9 | 323 | |
8d5fffb9 | 324 | config AUDIT_ARCH |
e0fd24a3 | 325 | def_bool y if X86_64 |
8d5fffb9 | 326 | |
6a11f75b AM |
327 | config ARCH_SUPPORTS_DEBUG_PAGEALLOC |
328 | def_bool y | |
329 | ||
d6f2d75a AR |
330 | config KASAN_SHADOW_OFFSET |
331 | hex | |
332 | depends on KASAN | |
333 | default 0xdffffc0000000000 | |
334 | ||
69575d38 SW |
335 | config HAVE_INTEL_TXT |
336 | def_bool y | |
6ea30386 | 337 | depends on INTEL_IOMMU && ACPI |
69575d38 | 338 | |
6b0c3d44 SR |
339 | config X86_32_SMP |
340 | def_bool y | |
341 | depends on X86_32 && SMP | |
342 | ||
343 | config X86_64_SMP | |
344 | def_bool y | |
345 | depends on X86_64 && SMP | |
346 | ||
ccbeed3a TH |
347 | config X86_32_LAZY_GS |
348 | def_bool y | |
8458f8c2 | 349 | depends on X86_32 && !STACKPROTECTOR |
ccbeed3a | 350 | |
2b144498 SD |
351 | config ARCH_SUPPORTS_UPROBES |
352 | def_bool y | |
353 | ||
d20642f0 RH |
354 | config FIX_EARLYCON_MEM |
355 | def_bool y | |
356 | ||
94d49eb3 KS |
357 | config DYNAMIC_PHYSICAL_MASK |
358 | bool | |
359 | ||
98233368 KS |
360 | config PGTABLE_LEVELS |
361 | int | |
77ef56e4 | 362 | default 5 if X86_5LEVEL |
98233368 KS |
363 | default 4 if X86_64 |
364 | default 3 if X86_PAE | |
365 | default 2 | |
366 | ||
2a61f474 MY |
367 | config CC_HAS_SANE_STACKPROTECTOR |
368 | bool | |
369 | default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT | |
370 | default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC)) | |
371 | help | |
372 | We have to make sure stack protector is unconditionally disabled if | |
373 | the compiler produces broken code. | |
374 | ||
506f1d07 SR |
375 | menu "Processor type and features" |
376 | ||
5ee71535 RD |
377 | config ZONE_DMA |
378 | bool "DMA memory allocation support" if EXPERT | |
379 | default y | |
380 | help | |
381 | DMA memory allocation support allows devices with less than 32-bit | |
382 | addressing to allocate within the first 16MB of address space. | |
383 | Disable if no such devices will be used. | |
384 | ||
385 | If unsure, say Y. | |
386 | ||
506f1d07 SR |
387 | config SMP |
388 | bool "Symmetric multi-processing support" | |
389 | ---help--- | |
390 | This enables support for systems with more than one CPU. If you have | |
4a474157 RG |
391 | a system with only one CPU, say N. If you have a system with more |
392 | than one CPU, say Y. | |
506f1d07 | 393 | |
4a474157 | 394 | If you say N here, the kernel will run on uni- and multiprocessor |
506f1d07 SR |
395 | machines, but will use only one CPU of a multiprocessor machine. If |
396 | you say Y here, the kernel will run on many, but not all, | |
4a474157 | 397 | uniprocessor machines. On a uniprocessor machine, the kernel |
506f1d07 SR |
398 | will run faster if you say N here. |
399 | ||
400 | Note that if you say Y here and choose architecture "586" or | |
401 | "Pentium" under "Processor family", the kernel will not work on 486 | |
402 | architectures. Similarly, multiprocessor kernels for the "PPro" | |
403 | architecture may not work on all Pentium based boards. | |
404 | ||
405 | People using multiprocessor machines who say Y here should also say | |
406 | Y to "Enhanced Real Time Clock Support", below. The "Advanced Power | |
407 | Management" code will be disabled if you say Y here. | |
408 | ||
cb1aaebe | 409 | See also <file:Documentation/x86/i386/IO-APIC.rst>, |
4f4cfa6c | 410 | <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at |
506f1d07 SR |
411 | <http://www.tldp.org/docs.html#howto>. |
412 | ||
413 | If you don't know what to do here, say N. | |
414 | ||
9def39be JT |
415 | config X86_FEATURE_NAMES |
416 | bool "Processor feature human-readable names" if EMBEDDED | |
417 | default y | |
418 | ---help--- | |
419 | This option compiles in a table of x86 feature bits and corresponding | |
420 | names. This is required to support /proc/cpuinfo and a few kernel | |
421 | messages. You can disable this to save space, at the expense of | |
422 | making those few kernel messages show numeric feature bits instead. | |
423 | ||
424 | If in doubt, say Y. | |
425 | ||
06cd9a7d YL |
426 | config X86_X2APIC |
427 | bool "Support x2apic" | |
19e3d60d | 428 | depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST) |
06cd9a7d YL |
429 | ---help--- |
430 | This enables x2apic support on CPUs that have this feature. | |
431 | ||
432 | This allows 32-bit apic IDs (so it can support very large systems), | |
433 | and accesses the local apic via MSRs not via mmio. | |
434 | ||
06cd9a7d YL |
435 | If you don't know what to do here, say N. |
436 | ||
6695c85b | 437 | config X86_MPPARSE |
6e87f9b7 | 438 | bool "Enable MPS table" if ACPI || SFI |
7a527688 | 439 | default y |
5ab74722 | 440 | depends on X86_LOCAL_APIC |
8f9ca475 | 441 | ---help--- |
6695c85b YL |
442 | For old smp systems that do not have proper acpi support. Newer systems |
443 | (esp with 64bit cpus) with acpi support, MADT and DSDT will override it | |
6695c85b | 444 | |
ddd70cf9 | 445 | config GOLDFISH |
b03b016f KK |
446 | def_bool y |
447 | depends on X86_GOLDFISH | |
ddd70cf9 | 448 | |
76b04384 DW |
449 | config RETPOLINE |
450 | bool "Avoid speculative indirect branches in kernel" | |
451 | default y | |
d5028ba8 | 452 | select STACK_VALIDATION if HAVE_STACK_VALIDATION |
76b04384 DW |
453 | help |
454 | Compile kernel with the retpoline compiler options to guard against | |
455 | kernel-to-user data leaks by avoiding speculative indirect | |
456 | branches. Requires a compiler with -mindirect-branch=thunk-extern | |
457 | support for full protection. The kernel may run slower. | |
458 | ||
e6d42931 JW |
459 | config X86_CPU_RESCTRL |
460 | bool "x86 CPU resource control support" | |
6fe07ce3 | 461 | depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD) |
59fe5a77 | 462 | select KERNFS |
e79f15a4 | 463 | select PROC_CPU_RESCTRL if PROC_FS |
78e99b4a | 464 | help |
e6d42931 | 465 | Enable x86 CPU resource control support. |
6fe07ce3 BM |
466 | |
467 | Provide support for the allocation and monitoring of system resources | |
468 | usage by the CPU. | |
469 | ||
470 | Intel calls this Intel Resource Director Technology | |
471 | (Intel(R) RDT). More information about RDT can be found in the | |
472 | Intel x86 Architecture Software Developer Manual. | |
473 | ||
474 | AMD calls this AMD Platform Quality of Service (AMD QoS). | |
475 | More information about AMD QoS can be found in the AMD64 Technology | |
476 | Platform Quality of Service Extensions manual. | |
78e99b4a FY |
477 | |
478 | Say N if unsure. | |
479 | ||
8425091f | 480 | if X86_32 |
a0d0bb4d RD |
481 | config X86_BIGSMP |
482 | bool "Support for big SMP systems with more than 8 CPUs" | |
483 | depends on SMP | |
484 | ---help--- | |
e133f6ea | 485 | This option is needed for the systems that have more than 8 CPUs. |
a0d0bb4d | 486 | |
c5c606d9 RT |
487 | config X86_EXTENDED_PLATFORM |
488 | bool "Support for extended (non-PC) x86 platforms" | |
489 | default y | |
8f9ca475 | 490 | ---help--- |
06ac8346 IM |
491 | If you disable this option then the kernel will only support |
492 | standard PC platforms. (which covers the vast majority of | |
493 | systems out there.) | |
494 | ||
8425091f RT |
495 | If you enable this option then you'll be able to select support |
496 | for the following (non-PC) 32 bit x86 platforms: | |
cb7b8023 | 497 | Goldfish (Android emulator) |
8425091f | 498 | AMD Elan |
8425091f RT |
499 | RDC R-321x SoC |
500 | SGI 320/540 (Visual Workstation) | |
83125a3a | 501 | STA2X11-based (e.g. Northville) |
3f4110a4 | 502 | Moorestown MID devices |
06ac8346 IM |
503 | |
504 | If you have one of these systems, or if you want to build a | |
505 | generic distribution kernel, say Y here - otherwise say N. | |
8425091f | 506 | endif |
06ac8346 | 507 | |
8425091f RT |
508 | if X86_64 |
509 | config X86_EXTENDED_PLATFORM | |
510 | bool "Support for extended (non-PC) x86 platforms" | |
511 | default y | |
512 | ---help--- | |
513 | If you disable this option then the kernel will only support | |
514 | standard PC platforms. (which covers the vast majority of | |
515 | systems out there.) | |
516 | ||
517 | If you enable this option then you'll be able to select support | |
518 | for the following (non-PC) 64 bit x86 platforms: | |
44b111b5 | 519 | Numascale NumaChip |
8425091f RT |
520 | ScaleMP vSMP |
521 | SGI Ultraviolet | |
522 | ||
523 | If you have one of these systems, or if you want to build a | |
524 | generic distribution kernel, say Y here - otherwise say N. | |
525 | endif | |
c5c606d9 RT |
526 | # This is an alphabetically sorted list of 64 bit extended platforms |
527 | # Please maintain the alphabetic order if and when there are additions | |
44b111b5 SP |
528 | config X86_NUMACHIP |
529 | bool "Numascale NumaChip" | |
530 | depends on X86_64 | |
531 | depends on X86_EXTENDED_PLATFORM | |
532 | depends on NUMA | |
533 | depends on SMP | |
534 | depends on X86_X2APIC | |
f9726bfd | 535 | depends on PCI_MMCONFIG |
44b111b5 SP |
536 | ---help--- |
537 | Adds support for Numascale NumaChip large-SMP systems. Needed to | |
538 | enable more than ~168 cores. | |
539 | If you don't have one of these, you should say N here. | |
506f1d07 | 540 | |
c5c606d9 RT |
541 | config X86_VSMP |
542 | bool "ScaleMP vSMP" | |
6276a074 | 543 | select HYPERVISOR_GUEST |
c5c606d9 RT |
544 | select PARAVIRT |
545 | depends on X86_64 && PCI | |
546 | depends on X86_EXTENDED_PLATFORM | |
ead91d4b | 547 | depends on SMP |
8f9ca475 | 548 | ---help--- |
c5c606d9 RT |
549 | Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is |
550 | supposed to run on these EM64T-based machines. Only choose this option | |
551 | if you have one of these machines. | |
5e3a77e9 | 552 | |
03b48632 NP |
553 | config X86_UV |
554 | bool "SGI Ultraviolet" | |
555 | depends on X86_64 | |
c5c606d9 | 556 | depends on X86_EXTENDED_PLATFORM |
54c28d29 | 557 | depends on NUMA |
1ecb4ae5 | 558 | depends on EFI |
9d6c26e7 | 559 | depends on X86_X2APIC |
1222e564 | 560 | depends on PCI |
8f9ca475 | 561 | ---help--- |
03b48632 NP |
562 | This option is needed in order to support SGI Ultraviolet systems. |
563 | If you don't have one of these, you should say N here. | |
564 | ||
c5c606d9 RT |
565 | # Following is an alphabetically sorted list of 32 bit extended platforms |
566 | # Please maintain the alphabetic order if and when there are additions | |
506f1d07 | 567 | |
ddd70cf9 | 568 | config X86_GOLDFISH |
b03b016f KK |
569 | bool "Goldfish (Virtual Platform)" |
570 | depends on X86_EXTENDED_PLATFORM | |
571 | ---help--- | |
ddd70cf9 JN |
572 | Enable support for the Goldfish virtual platform used primarily |
573 | for Android development. Unless you are building for the Android | |
574 | Goldfish emulator say N here. | |
575 | ||
c751e17b TG |
576 | config X86_INTEL_CE |
577 | bool "CE4100 TV platform" | |
578 | depends on PCI | |
579 | depends on PCI_GODIRECT | |
6084a6e2 | 580 | depends on X86_IO_APIC |
c751e17b TG |
581 | depends on X86_32 |
582 | depends on X86_EXTENDED_PLATFORM | |
37bc9f50 | 583 | select X86_REBOOTFIXUPS |
da6b737b SAS |
584 | select OF |
585 | select OF_EARLY_FLATTREE | |
c751e17b TG |
586 | ---help--- |
587 | Select for the Intel CE media processor (CE4100) SOC. | |
588 | This option compiles in support for the CE4100 SOC for settop | |
589 | boxes and media devices. | |
590 | ||
4cb9b00f | 591 | config X86_INTEL_MID |
43605ef1 | 592 | bool "Intel MID platform support" |
43605ef1 | 593 | depends on X86_EXTENDED_PLATFORM |
edc6bc78 | 594 | depends on X86_PLATFORM_DEVICES |
1ea7c673 | 595 | depends on PCI |
3fda5bb4 | 596 | depends on X86_64 || (PCI_GOANY && X86_32) |
1ea7c673 | 597 | depends on X86_IO_APIC |
7c9c3a1e | 598 | select SFI |
4cb9b00f | 599 | select I2C |
7c9c3a1e | 600 | select DW_APB_TIMER |
1ea7c673 | 601 | select APB_TIMER |
54b34aa0 | 602 | select INTEL_SCU_PCI |
15a713df | 603 | select MFD_INTEL_MSIC |
1ea7c673 | 604 | ---help--- |
4cb9b00f DC |
605 | Select to build a kernel capable of supporting Intel MID (Mobile |
606 | Internet Device) platform systems which do not have the PCI legacy | |
607 | interfaces. If you are building for a PC class system say N here. | |
1ea7c673 | 608 | |
4cb9b00f DC |
609 | Intel MID platforms are based on an Intel processor and chipset which |
610 | consume less power than most of the x86 derivatives. | |
43605ef1 | 611 | |
8bbc2a13 BD |
612 | config X86_INTEL_QUARK |
613 | bool "Intel Quark platform support" | |
614 | depends on X86_32 | |
615 | depends on X86_EXTENDED_PLATFORM | |
616 | depends on X86_PLATFORM_DEVICES | |
617 | depends on X86_TSC | |
618 | depends on PCI | |
619 | depends on PCI_GOANY | |
620 | depends on X86_IO_APIC | |
621 | select IOSF_MBI | |
622 | select INTEL_IMR | |
9ab6eb51 | 623 | select COMMON_CLK |
8bbc2a13 BD |
624 | ---help--- |
625 | Select to include support for Quark X1000 SoC. | |
626 | Say Y here if you have a Quark based system such as the Arduino | |
627 | compatible Intel Galileo. | |
628 | ||
3d48aab1 MW |
629 | config X86_INTEL_LPSS |
630 | bool "Intel Low Power Subsystem Support" | |
5962dd22 | 631 | depends on X86 && ACPI && PCI |
3d48aab1 | 632 | select COMMON_CLK |
0f531431 | 633 | select PINCTRL |
eebb3e8d | 634 | select IOSF_MBI |
3d48aab1 MW |
635 | ---help--- |
636 | Select to build support for Intel Low Power Subsystem such as | |
637 | found on Intel Lynxpoint PCH. Selecting this option enables | |
0f531431 MN |
638 | things like clock tree (common clock framework) and pincontrol |
639 | which are needed by the LPSS peripheral drivers. | |
3d48aab1 | 640 | |
92082a88 KX |
641 | config X86_AMD_PLATFORM_DEVICE |
642 | bool "AMD ACPI2Platform devices support" | |
643 | depends on ACPI | |
644 | select COMMON_CLK | |
645 | select PINCTRL | |
646 | ---help--- | |
647 | Select to interpret AMD specific ACPI device to platform device | |
648 | such as I2C, UART, GPIO found on AMD Carrizo and later chipsets. | |
649 | I2C and UART depend on COMMON_CLK to set clock. GPIO driver is | |
650 | implemented under PINCTRL subsystem. | |
651 | ||
ced3ce76 DB |
652 | config IOSF_MBI |
653 | tristate "Intel SoC IOSF Sideband support for SoC platforms" | |
654 | depends on PCI | |
655 | ---help--- | |
656 | This option enables sideband register access support for Intel SoC | |
657 | platforms. On these platforms the IOSF sideband is used in lieu of | |
658 | MSR's for some register accesses, mostly but not limited to thermal | |
659 | and power. Drivers may query the availability of this device to | |
660 | determine if they need the sideband in order to work on these | |
661 | platforms. The sideband is available on the following SoC products. | |
662 | This list is not meant to be exclusive. | |
663 | - BayTrail | |
664 | - Braswell | |
665 | - Quark | |
666 | ||
667 | You should say Y if you are running a kernel on one of these SoC's. | |
668 | ||
ed2226bd DB |
669 | config IOSF_MBI_DEBUG |
670 | bool "Enable IOSF sideband access through debugfs" | |
671 | depends on IOSF_MBI && DEBUG_FS | |
672 | ---help--- | |
673 | Select this option to expose the IOSF sideband access registers (MCR, | |
674 | MDR, MCRX) through debugfs to write and read register information from | |
675 | different units on the SoC. This is most useful for obtaining device | |
676 | state information for debug and analysis. As this is a general access | |
677 | mechanism, users of this option would have specific knowledge of the | |
678 | device they want to access. | |
679 | ||
680 | If you don't require the option or are in doubt, say N. | |
681 | ||
c5c606d9 RT |
682 | config X86_RDC321X |
683 | bool "RDC R-321x SoC" | |
506f1d07 | 684 | depends on X86_32 |
c5c606d9 RT |
685 | depends on X86_EXTENDED_PLATFORM |
686 | select M486 | |
687 | select X86_REBOOTFIXUPS | |
688 | ---help--- | |
689 | This option is needed for RDC R-321x system-on-chip, also known | |
690 | as R-8610-(G). | |
691 | If you don't have one of these chips, you should say N here. | |
692 | ||
e0c7ae37 | 693 | config X86_32_NON_STANDARD |
9c398017 IM |
694 | bool "Support non-standard 32-bit SMP architectures" |
695 | depends on X86_32 && SMP | |
c5c606d9 | 696 | depends on X86_EXTENDED_PLATFORM |
8f9ca475 | 697 | ---help--- |
b5660ba7 PA |
698 | This option compiles in the bigsmp and STA2X11 default |
699 | subarchitectures. It is intended for a generic binary | |
700 | kernel. If you select them all, kernel will probe it one by | |
701 | one and will fallback to default. | |
d49c4288 | 702 | |
c5c606d9 | 703 | # Alphabetically sorted list of Non standard 32 bit platforms |
d49c4288 | 704 | |
d949f36f | 705 | config X86_SUPPORTS_MEMORY_FAILURE |
6fc108a0 | 706 | def_bool y |
d949f36f LT |
707 | # MCE code calls memory_failure(): |
708 | depends on X86_MCE | |
709 | # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags: | |
d949f36f LT |
710 | # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH: |
711 | depends on X86_64 || !SPARSEMEM | |
712 | select ARCH_SUPPORTS_MEMORY_FAILURE | |
d949f36f | 713 | |
83125a3a AR |
714 | config STA2X11 |
715 | bool "STA2X11 Companion Chip Support" | |
716 | depends on X86_32_NON_STANDARD && PCI | |
83125a3a AR |
717 | select SWIOTLB |
718 | select MFD_STA2X11 | |
0145071b | 719 | select GPIOLIB |
83125a3a AR |
720 | ---help--- |
721 | This adds support for boards based on the STA2X11 IO-Hub, | |
722 | a.k.a. "ConneXt". The chip is used in place of the standard | |
723 | PC chipset, so all "standard" peripherals are missing. If this | |
724 | option is selected the kernel will still be able to boot on | |
725 | standard PC machines. | |
726 | ||
82148d1d S |
727 | config X86_32_IRIS |
728 | tristate "Eurobraille/Iris poweroff module" | |
729 | depends on X86_32 | |
730 | ---help--- | |
731 | The Iris machines from EuroBraille do not have APM or ACPI support | |
732 | to shut themselves down properly. A special I/O sequence is | |
733 | needed to do so, which is what this module does at | |
734 | kernel shutdown. | |
735 | ||
736 | This is only for Iris machines from EuroBraille. | |
737 | ||
738 | If unused, say N. | |
739 | ||
ae1e9130 | 740 | config SCHED_OMIT_FRAME_POINTER |
3c2362e6 HH |
741 | def_bool y |
742 | prompt "Single-depth WCHAN output" | |
a87d0914 | 743 | depends on X86 |
8f9ca475 | 744 | ---help--- |
506f1d07 SR |
745 | Calculate simpler /proc/<PID>/wchan values. If this option |
746 | is disabled then wchan values will recurse back to the | |
747 | caller function. This provides more accurate wchan values, | |
748 | at the expense of slightly more scheduling overhead. | |
749 | ||
750 | If in doubt, say "Y". | |
751 | ||
6276a074 BP |
752 | menuconfig HYPERVISOR_GUEST |
753 | bool "Linux guest support" | |
8f9ca475 | 754 | ---help--- |
6276a074 BP |
755 | Say Y here to enable options for running Linux under various hyper- |
756 | visors. This option enables basic hypervisor detection and platform | |
757 | setup. | |
506f1d07 | 758 | |
6276a074 BP |
759 | If you say N, all options in this submenu will be skipped and |
760 | disabled, and Linux guest support won't be built in. | |
506f1d07 | 761 | |
6276a074 | 762 | if HYPERVISOR_GUEST |
506f1d07 | 763 | |
e61bd94a EPH |
764 | config PARAVIRT |
765 | bool "Enable paravirtualization code" | |
8f9ca475 | 766 | ---help--- |
e61bd94a EPH |
767 | This changes the kernel so it can modify itself when it is run |
768 | under a hypervisor, potentially improving performance significantly | |
769 | over full virtualization. However, when run without a hypervisor | |
770 | the kernel is theoretically slower and slightly larger. | |
771 | ||
c00a280a JG |
772 | config PARAVIRT_XXL |
773 | bool | |
774 | ||
6276a074 BP |
775 | config PARAVIRT_DEBUG |
776 | bool "paravirt-ops debugging" | |
777 | depends on PARAVIRT && DEBUG_KERNEL | |
778 | ---help--- | |
779 | Enable to debug paravirt_ops internals. Specifically, BUG if | |
780 | a paravirt_op is missing when it is called. | |
781 | ||
b4ecc126 JF |
782 | config PARAVIRT_SPINLOCKS |
783 | bool "Paravirtualization layer for spinlocks" | |
6ea30386 | 784 | depends on PARAVIRT && SMP |
b4ecc126 JF |
785 | ---help--- |
786 | Paravirtualized spinlocks allow a pvops backend to replace the | |
787 | spinlock implementation with something virtualization-friendly | |
788 | (for example, block the virtual CPU rather than spinning). | |
789 | ||
4c4e4f61 R |
790 | It has a minimal impact on native kernels and gives a nice performance |
791 | benefit on paravirtualized KVM / Xen kernels. | |
b4ecc126 | 792 | |
4c4e4f61 | 793 | If you are unsure how to answer this question, answer Y. |
b4ecc126 | 794 | |
ecca2502 ZY |
795 | config X86_HV_CALLBACK_VECTOR |
796 | def_bool n | |
797 | ||
6276a074 | 798 | source "arch/x86/xen/Kconfig" |
7af192c9 | 799 | |
6276a074 BP |
800 | config KVM_GUEST |
801 | bool "KVM Guest support (including kvmclock)" | |
802 | depends on PARAVIRT | |
803 | select PARAVIRT_CLOCK | |
a1c4423b | 804 | select ARCH_CPUIDLE_HALTPOLL |
6276a074 | 805 | default y |
8f9ca475 | 806 | ---help--- |
6276a074 BP |
807 | This option enables various optimizations for running under the KVM |
808 | hypervisor. It includes a paravirtualized clock, so that instead | |
809 | of relying on a PIT (or probably other) emulation by the | |
810 | underlying device model, the host provides the guest with | |
811 | timing infrastructure such as time of day, and system time | |
506f1d07 | 812 | |
a1c4423b | 813 | config ARCH_CPUIDLE_HALTPOLL |
b03b016f KK |
814 | def_bool n |
815 | prompt "Disable host haltpoll when loading haltpoll driver" | |
816 | help | |
a1c4423b MT |
817 | If virtualized under KVM, disable host haltpoll. |
818 | ||
7733607f MW |
819 | config PVH |
820 | bool "Support for running PVH guests" | |
821 | ---help--- | |
822 | This option enables the PVH entry point for guest virtual machines | |
823 | as specified in the x86/HVM direct boot ABI. | |
824 | ||
1e20eb85 SV |
825 | config KVM_DEBUG_FS |
826 | bool "Enable debug information for KVM Guests in debugfs" | |
827 | depends on KVM_GUEST && DEBUG_FS | |
1e20eb85 SV |
828 | ---help--- |
829 | This option enables collection of various statistics for KVM guest. | |
830 | Statistics are displayed in debugfs filesystem. Enabling this option | |
831 | may incur significant overhead. | |
832 | ||
6276a074 BP |
833 | config PARAVIRT_TIME_ACCOUNTING |
834 | bool "Paravirtual steal time accounting" | |
835 | depends on PARAVIRT | |
8f9ca475 | 836 | ---help--- |
6276a074 BP |
837 | Select this option to enable fine granularity task steal time |
838 | accounting. Time spent executing other tasks in parallel with | |
839 | the current vCPU is discounted from the vCPU power. To account for | |
840 | that, there can be a small performance impact. | |
841 | ||
842 | If in doubt, say N here. | |
843 | ||
844 | config PARAVIRT_CLOCK | |
845 | bool | |
97349135 | 846 | |
4a362601 JK |
847 | config JAILHOUSE_GUEST |
848 | bool "Jailhouse non-root cell support" | |
abde587b | 849 | depends on X86_64 && PCI |
87e65d05 | 850 | select X86_PM_TIMER |
4a362601 JK |
851 | ---help--- |
852 | This option allows to run Linux as guest in a Jailhouse non-root | |
853 | cell. You can leave this option disabled if you only want to start | |
854 | Jailhouse and run Linux afterwards in the root cell. | |
855 | ||
ec7972c9 ZY |
856 | config ACRN_GUEST |
857 | bool "ACRN Guest support" | |
858 | depends on X86_64 | |
498ad393 | 859 | select X86_HV_CALLBACK_VECTOR |
ec7972c9 ZY |
860 | help |
861 | This option allows to run Linux as guest in the ACRN hypervisor. ACRN is | |
862 | a flexible, lightweight reference open-source hypervisor, built with | |
863 | real-time and safety-criticality in mind. It is built for embedded | |
864 | IOT with small footprint and real-time features. More details can be | |
865 | found in https://projectacrn.org/. | |
866 | ||
6276a074 | 867 | endif #HYPERVISOR_GUEST |
97349135 | 868 | |
506f1d07 SR |
869 | source "arch/x86/Kconfig.cpu" |
870 | ||
871 | config HPET_TIMER | |
3c2362e6 | 872 | def_bool X86_64 |
506f1d07 | 873 | prompt "HPET Timer Support" if X86_32 |
8f9ca475 IM |
874 | ---help--- |
875 | Use the IA-PC HPET (High Precision Event Timer) to manage | |
876 | time in preference to the PIT and RTC, if a HPET is | |
877 | present. | |
878 | HPET is the next generation timer replacing legacy 8254s. | |
879 | The HPET provides a stable time base on SMP | |
880 | systems, unlike the TSC, but it is more expensive to access, | |
4e7f9df2 MT |
881 | as it is off-chip. The interface used is documented |
882 | in the HPET spec, revision 1. | |
506f1d07 | 883 | |
8f9ca475 IM |
884 | You can safely choose Y here. However, HPET will only be |
885 | activated if the platform and the BIOS support this feature. | |
886 | Otherwise the 8254 will be used for timing services. | |
506f1d07 | 887 | |
8f9ca475 | 888 | Choose N to continue using the legacy 8254 timer. |
506f1d07 SR |
889 | |
890 | config HPET_EMULATE_RTC | |
3c2362e6 | 891 | def_bool y |
9d8af78b | 892 | depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y) |
506f1d07 | 893 | |
bb24c471 | 894 | config APB_TIMER |
b03b016f KK |
895 | def_bool y if X86_INTEL_MID |
896 | prompt "Intel MID APB Timer Support" if X86_INTEL_MID | |
897 | select DW_APB_TIMER | |
898 | depends on X86_INTEL_MID && SFI | |
899 | help | |
900 | APB timer is the replacement for 8254, HPET on X86 MID platforms. | |
901 | The APBT provides a stable time base on SMP | |
902 | systems, unlike the TSC, but it is more expensive to access, | |
903 | as it is off-chip. APB timers are always running regardless of CPU | |
904 | C states, they are used as per CPU clockevent device when possible. | |
bb24c471 | 905 | |
6a108a14 | 906 | # Mark as expert because too many people got it wrong. |
506f1d07 | 907 | # The code disables itself when not needed. |
7ae9392c TP |
908 | config DMI |
909 | default y | |
cf074402 | 910 | select DMI_SCAN_MACHINE_NON_EFI_FALLBACK |
6a108a14 | 911 | bool "Enable DMI scanning" if EXPERT |
8f9ca475 | 912 | ---help--- |
7ae9392c TP |
913 | Enabled scanning of DMI to identify machine quirks. Say Y |
914 | here unless you have verified that your setup is not | |
915 | affected by entries in the DMI blacklist. Required by PNP | |
916 | BIOS code. | |
917 | ||
506f1d07 | 918 | config GART_IOMMU |
38901f1c | 919 | bool "Old AMD GART IOMMU support" |
a4ce5a48 | 920 | select IOMMU_HELPER |
506f1d07 | 921 | select SWIOTLB |
23ac4ae8 | 922 | depends on X86_64 && PCI && AMD_NB |
8f9ca475 | 923 | ---help--- |
ced3c42c IM |
924 | Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron |
925 | GART based hardware IOMMUs. | |
926 | ||
927 | The GART supports full DMA access for devices with 32-bit access | |
928 | limitations, on systems with more than 3 GB. This is usually needed | |
929 | for USB, sound, many IDE/SATA chipsets and some other devices. | |
930 | ||
931 | Newer systems typically have a modern AMD IOMMU, supported via | |
932 | the CONFIG_AMD_IOMMU=y config option. | |
933 | ||
934 | In normal configurations this driver is only active when needed: | |
935 | there's more than 3 GB of memory and the system contains a | |
936 | 32-bit limited device. | |
937 | ||
938 | If unsure, say Y. | |
506f1d07 | 939 | |
1184dc2f | 940 | config MAXSMP |
ddb0c5a6 | 941 | bool "Enable Maximum number of SMP Processors and NUMA Nodes" |
6ea30386 | 942 | depends on X86_64 && SMP && DEBUG_KERNEL |
36f5101a | 943 | select CPUMASK_OFFSTACK |
8f9ca475 | 944 | ---help--- |
ddb0c5a6 | 945 | Enable maximum number of CPUS and NUMA Nodes for this architecture. |
1184dc2f | 946 | If unsure, say N. |
506f1d07 | 947 | |
aec6487e IM |
948 | # |
949 | # The maximum number of CPUs supported: | |
950 | # | |
951 | # The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT, | |
952 | # and which can be configured interactively in the | |
953 | # [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range. | |
954 | # | |
955 | # The ranges are different on 32-bit and 64-bit kernels, depending on | |
956 | # hardware capabilities and scalability features of the kernel. | |
957 | # | |
958 | # ( If MAXSMP is enabled we just use the highest possible value and disable | |
959 | # interactive configuration. ) | |
960 | # | |
961 | ||
962 | config NR_CPUS_RANGE_BEGIN | |
a0d0bb4d | 963 | int |
aec6487e IM |
964 | default NR_CPUS_RANGE_END if MAXSMP |
965 | default 1 if !SMP | |
966 | default 2 | |
a0d0bb4d | 967 | |
aec6487e | 968 | config NR_CPUS_RANGE_END |
a0d0bb4d | 969 | int |
aec6487e IM |
970 | depends on X86_32 |
971 | default 64 if SMP && X86_BIGSMP | |
972 | default 8 if SMP && !X86_BIGSMP | |
973 | default 1 if !SMP | |
a0d0bb4d | 974 | |
aec6487e | 975 | config NR_CPUS_RANGE_END |
a0d0bb4d | 976 | int |
aec6487e | 977 | depends on X86_64 |
1edae1ae SW |
978 | default 8192 if SMP && CPUMASK_OFFSTACK |
979 | default 512 if SMP && !CPUMASK_OFFSTACK | |
aec6487e | 980 | default 1 if !SMP |
a0d0bb4d | 981 | |
aec6487e | 982 | config NR_CPUS_DEFAULT |
a0d0bb4d RD |
983 | int |
984 | depends on X86_32 | |
aec6487e IM |
985 | default 32 if X86_BIGSMP |
986 | default 8 if SMP | |
987 | default 1 if !SMP | |
a0d0bb4d | 988 | |
aec6487e | 989 | config NR_CPUS_DEFAULT |
a0d0bb4d RD |
990 | int |
991 | depends on X86_64 | |
aec6487e IM |
992 | default 8192 if MAXSMP |
993 | default 64 if SMP | |
994 | default 1 if !SMP | |
a0d0bb4d | 995 | |
506f1d07 | 996 | config NR_CPUS |
36f5101a | 997 | int "Maximum number of CPUs" if SMP && !MAXSMP |
aec6487e IM |
998 | range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END |
999 | default NR_CPUS_DEFAULT | |
8f9ca475 | 1000 | ---help--- |
506f1d07 | 1001 | This allows you to specify the maximum number of CPUs which this |
bb61ccc7 | 1002 | kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum |
cad14bb9 | 1003 | supported value is 8192, otherwise the maximum value is 512. The |
506f1d07 SR |
1004 | minimum value which makes sense is 2. |
1005 | ||
aec6487e IM |
1006 | This is purely to save memory: each supported CPU adds about 8KB |
1007 | to the kernel image. | |
506f1d07 SR |
1008 | |
1009 | config SCHED_SMT | |
dbe73364 | 1010 | def_bool y if SMP |
506f1d07 SR |
1011 | |
1012 | config SCHED_MC | |
3c2362e6 HH |
1013 | def_bool y |
1014 | prompt "Multi-core scheduler support" | |
c8e56d20 | 1015 | depends on SMP |
8f9ca475 | 1016 | ---help--- |
506f1d07 SR |
1017 | Multi-core scheduler support improves the CPU scheduler's decision |
1018 | making when dealing with multi-core CPU chips at a cost of slightly | |
1019 | increased overhead in some places. If unsure say N here. | |
1020 | ||
de966cf4 TC |
1021 | config SCHED_MC_PRIO |
1022 | bool "CPU core priorities scheduler support" | |
0a21fc12 IM |
1023 | depends on SCHED_MC && CPU_SUP_INTEL |
1024 | select X86_INTEL_PSTATE | |
1025 | select CPU_FREQ | |
de966cf4 | 1026 | default y |
5e76b2ab | 1027 | ---help--- |
0a21fc12 IM |
1028 | Intel Turbo Boost Max Technology 3.0 enabled CPUs have a |
1029 | core ordering determined at manufacturing time, which allows | |
1030 | certain cores to reach higher turbo frequencies (when running | |
1031 | single threaded workloads) than others. | |
de966cf4 | 1032 | |
0a21fc12 IM |
1033 | Enabling this kernel feature teaches the scheduler about |
1034 | the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the | |
1035 | scheduler's CPU selection logic accordingly, so that higher | |
1036 | overall system performance can be achieved. | |
de966cf4 | 1037 | |
0a21fc12 | 1038 | This feature will have no effect on CPUs without this feature. |
de966cf4 | 1039 | |
0a21fc12 | 1040 | If unsure say Y here. |
5e76b2ab | 1041 | |
30b8b006 | 1042 | config UP_LATE_INIT |
b03b016f KK |
1043 | def_bool y |
1044 | depends on !SMP && X86_LOCAL_APIC | |
30b8b006 | 1045 | |
506f1d07 | 1046 | config X86_UP_APIC |
50849eef JB |
1047 | bool "Local APIC support on uniprocessors" if !PCI_MSI |
1048 | default PCI_MSI | |
38a1dfda | 1049 | depends on X86_32 && !SMP && !X86_32_NON_STANDARD |
8f9ca475 | 1050 | ---help--- |
506f1d07 SR |
1051 | A local APIC (Advanced Programmable Interrupt Controller) is an |
1052 | integrated interrupt controller in the CPU. If you have a single-CPU | |
1053 | system which has a processor with a local APIC, you can say Y here to | |
1054 | enable and use it. If you say Y here even though your machine doesn't | |
1055 | have a local APIC, then the kernel will still run with no slowdown at | |
1056 | all. The local APIC supports CPU-generated self-interrupts (timer, | |
1057 | performance counters), and the NMI watchdog which detects hard | |
1058 | lockups. | |
1059 | ||
1060 | config X86_UP_IOAPIC | |
1061 | bool "IO-APIC support on uniprocessors" | |
1062 | depends on X86_UP_APIC | |
8f9ca475 | 1063 | ---help--- |
506f1d07 SR |
1064 | An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an |
1065 | SMP-capable replacement for PC-style interrupt controllers. Most | |
1066 | SMP systems and many recent uniprocessor systems have one. | |
1067 | ||
1068 | If you have a single-CPU system with an IO-APIC, you can say Y here | |
1069 | to use it. If you say Y here even though your machine doesn't have | |
1070 | an IO-APIC, then the kernel will still run with no slowdown at all. | |
1071 | ||
1072 | config X86_LOCAL_APIC | |
3c2362e6 | 1073 | def_bool y |
0dbc6078 | 1074 | depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI |
b5dc8e6c | 1075 | select IRQ_DOMAIN_HIERARCHY |
52f518a3 | 1076 | select PCI_MSI_IRQ_DOMAIN if PCI_MSI |
506f1d07 SR |
1077 | |
1078 | config X86_IO_APIC | |
b1da1e71 JB |
1079 | def_bool y |
1080 | depends on X86_LOCAL_APIC || X86_UP_IOAPIC | |
506f1d07 | 1081 | |
41b9eb26 SA |
1082 | config X86_REROUTE_FOR_BROKEN_BOOT_IRQS |
1083 | bool "Reroute for broken boot IRQs" | |
41b9eb26 | 1084 | depends on X86_IO_APIC |
8f9ca475 | 1085 | ---help--- |
41b9eb26 SA |
1086 | This option enables a workaround that fixes a source of |
1087 | spurious interrupts. This is recommended when threaded | |
1088 | interrupt handling is used on systems where the generation of | |
1089 | superfluous "boot interrupts" cannot be disabled. | |
1090 | ||
1091 | Some chipsets generate a legacy INTx "boot IRQ" when the IRQ | |
1092 | entry in the chipset's IO-APIC is masked (as, e.g. the RT | |
1093 | kernel does during interrupt handling). On chipsets where this | |
1094 | boot IRQ generation cannot be disabled, this workaround keeps | |
1095 | the original IRQ line masked so that only the equivalent "boot | |
1096 | IRQ" is delivered to the CPUs. The workaround also tells the | |
1097 | kernel to set up the IRQ handler on the boot IRQ line. In this | |
1098 | way only one interrupt is delivered to the kernel. Otherwise | |
1099 | the spurious second interrupt may cause the kernel to bring | |
1100 | down (vital) interrupt lines. | |
1101 | ||
1102 | Only affects "broken" chipsets. Interrupt sharing may be | |
1103 | increased on these systems. | |
1104 | ||
506f1d07 | 1105 | config X86_MCE |
bab9bc65 | 1106 | bool "Machine Check / overheating reporting" |
648ed940 | 1107 | select GENERIC_ALLOCATOR |
e57dbaf7 | 1108 | default y |
506f1d07 | 1109 | ---help--- |
bab9bc65 AK |
1110 | Machine Check support allows the processor to notify the |
1111 | kernel if it detects a problem (e.g. overheating, data corruption). | |
506f1d07 | 1112 | The action the kernel takes depends on the severity of the problem, |
bab9bc65 | 1113 | ranging from warning messages to halting the machine. |
4efc0670 | 1114 | |
5de97c9f TL |
1115 | config X86_MCELOG_LEGACY |
1116 | bool "Support for deprecated /dev/mcelog character device" | |
1117 | depends on X86_MCE | |
1118 | ---help--- | |
1119 | Enable support for /dev/mcelog which is needed by the old mcelog | |
1120 | userspace logging daemon. Consider switching to the new generation | |
1121 | rasdaemon solution. | |
1122 | ||
506f1d07 | 1123 | config X86_MCE_INTEL |
3c2362e6 HH |
1124 | def_bool y |
1125 | prompt "Intel MCE features" | |
c1ebf835 | 1126 | depends on X86_MCE && X86_LOCAL_APIC |
8f9ca475 | 1127 | ---help--- |
506f1d07 SR |
1128 | Additional support for intel specific MCE features such as |
1129 | the thermal monitor. | |
1130 | ||
1131 | config X86_MCE_AMD | |
3c2362e6 HH |
1132 | def_bool y |
1133 | prompt "AMD MCE features" | |
f5382de9 | 1134 | depends on X86_MCE && X86_LOCAL_APIC && AMD_NB |
8f9ca475 | 1135 | ---help--- |
506f1d07 SR |
1136 | Additional support for AMD specific MCE features such as |
1137 | the DRAM Error Threshold. | |
1138 | ||
4efc0670 | 1139 | config X86_ANCIENT_MCE |
6fc108a0 | 1140 | bool "Support for old Pentium 5 / WinChip machine checks" |
c31d9633 | 1141 | depends on X86_32 && X86_MCE |
cd13adcc HS |
1142 | ---help--- |
1143 | Include support for machine check handling on old Pentium 5 or WinChip | |
5065a706 | 1144 | systems. These typically need to be enabled explicitly on the command |
cd13adcc | 1145 | line. |
4efc0670 | 1146 | |
b2762686 AK |
1147 | config X86_MCE_THRESHOLD |
1148 | depends on X86_MCE_AMD || X86_MCE_INTEL | |
6fc108a0 | 1149 | def_bool y |
b2762686 | 1150 | |
ea149b36 | 1151 | config X86_MCE_INJECT |
bc8e80d5 | 1152 | depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS |
ea149b36 AK |
1153 | tristate "Machine check injector support" |
1154 | ---help--- | |
1155 | Provide support for injecting machine checks for testing purposes. | |
1156 | If you don't know what a machine check is and you don't do kernel | |
1157 | QA it is safe to say n. | |
1158 | ||
4efc0670 AK |
1159 | config X86_THERMAL_VECTOR |
1160 | def_bool y | |
5bb38adc | 1161 | depends on X86_MCE_INTEL |
4efc0670 | 1162 | |
07dc900e | 1163 | source "arch/x86/events/Kconfig" |
e633c65a | 1164 | |
5aef51c3 | 1165 | config X86_LEGACY_VM86 |
1e642812 | 1166 | bool "Legacy VM86 support" |
506f1d07 | 1167 | depends on X86_32 |
8f9ca475 | 1168 | ---help--- |
5aef51c3 AL |
1169 | This option allows user programs to put the CPU into V8086 |
1170 | mode, which is an 80286-era approximation of 16-bit real mode. | |
1171 | ||
1172 | Some very old versions of X and/or vbetool require this option | |
1173 | for user mode setting. Similarly, DOSEMU will use it if | |
1174 | available to accelerate real mode DOS programs. However, any | |
1175 | recent version of DOSEMU, X, or vbetool should be fully | |
1176 | functional even without kernel VM86 support, as they will all | |
1e642812 IM |
1177 | fall back to software emulation. Nevertheless, if you are using |
1178 | a 16-bit DOS program where 16-bit performance matters, vm86 | |
1179 | mode might be faster than emulation and you might want to | |
1180 | enable this option. | |
5aef51c3 | 1181 | |
1e642812 IM |
1182 | Note that any app that works on a 64-bit kernel is unlikely to |
1183 | need this option, as 64-bit kernels don't, and can't, support | |
1184 | V8086 mode. This option is also unrelated to 16-bit protected | |
1185 | mode and is not needed to run most 16-bit programs under Wine. | |
5aef51c3 | 1186 | |
1e642812 IM |
1187 | Enabling this option increases the complexity of the kernel |
1188 | and slows down exception handling a tiny bit. | |
5aef51c3 | 1189 | |
1e642812 | 1190 | If unsure, say N here. |
5aef51c3 AL |
1191 | |
1192 | config VM86 | |
b03b016f KK |
1193 | bool |
1194 | default X86_LEGACY_VM86 | |
34273f41 PA |
1195 | |
1196 | config X86_16BIT | |
1197 | bool "Enable support for 16-bit segments" if EXPERT | |
1198 | default y | |
a5b9e5a2 | 1199 | depends on MODIFY_LDT_SYSCALL |
34273f41 PA |
1200 | ---help--- |
1201 | This option is required by programs like Wine to run 16-bit | |
1202 | protected mode legacy code on x86 processors. Disabling | |
1203 | this option saves about 300 bytes on i386, or around 6K text | |
1204 | plus 16K runtime memory on x86-64, | |
1205 | ||
1206 | config X86_ESPFIX32 | |
1207 | def_bool y | |
1208 | depends on X86_16BIT && X86_32 | |
506f1d07 | 1209 | |
197725de PA |
1210 | config X86_ESPFIX64 |
1211 | def_bool y | |
34273f41 | 1212 | depends on X86_16BIT && X86_64 |
506f1d07 | 1213 | |
1ad83c85 | 1214 | config X86_VSYSCALL_EMULATION |
b03b016f KK |
1215 | bool "Enable vsyscall emulation" if EXPERT |
1216 | default y | |
1217 | depends on X86_64 | |
1218 | ---help--- | |
1ad83c85 AL |
1219 | This enables emulation of the legacy vsyscall page. Disabling |
1220 | it is roughly equivalent to booting with vsyscall=none, except | |
1221 | that it will also disable the helpful warning if a program | |
1222 | tries to use a vsyscall. With this option set to N, offending | |
1223 | programs will just segfault, citing addresses of the form | |
1224 | 0xffffffffff600?00. | |
1225 | ||
1226 | This option is required by many programs built before 2013, and | |
1227 | care should be used even with newer programs if set to N. | |
1228 | ||
1229 | Disabling this option saves about 7K of kernel size and | |
1230 | possibly 4K of additional runtime pagetable memory. | |
1231 | ||
111e7b15 TG |
1232 | config X86_IOPL_IOPERM |
1233 | bool "IOPERM and IOPL Emulation" | |
a24ca997 | 1234 | default y |
c8137ace | 1235 | ---help--- |
111e7b15 TG |
1236 | This enables the ioperm() and iopl() syscalls which are necessary |
1237 | for legacy applications. | |
1238 | ||
c8137ace TG |
1239 | Legacy IOPL support is an overbroad mechanism which allows user |
1240 | space aside of accessing all 65536 I/O ports also to disable | |
1241 | interrupts. To gain this access the caller needs CAP_SYS_RAWIO | |
1242 | capabilities and permission from potentially active security | |
1243 | modules. | |
1244 | ||
1245 | The emulation restricts the functionality of the syscall to | |
1246 | only allowing the full range I/O port access, but prevents the | |
a24ca997 TG |
1247 | ability to disable interrupts from user space which would be |
1248 | granted if the hardware IOPL mechanism would be used. | |
c8137ace | 1249 | |
506f1d07 SR |
1250 | config TOSHIBA |
1251 | tristate "Toshiba Laptop support" | |
1252 | depends on X86_32 | |
1253 | ---help--- | |
1254 | This adds a driver to safely access the System Management Mode of | |
1255 | the CPU on Toshiba portables with a genuine Toshiba BIOS. It does | |
1256 | not work on models with a Phoenix BIOS. The System Management Mode | |
1257 | is used to set the BIOS and power saving options on Toshiba portables. | |
1258 | ||
1259 | For information on utilities to make use of this driver see the | |
1260 | Toshiba Linux utilities web site at: | |
1261 | <http://www.buzzard.org.uk/toshiba/>. | |
1262 | ||
1263 | Say Y if you intend to run this kernel on a Toshiba portable. | |
1264 | Say N otherwise. | |
1265 | ||
1266 | config I8K | |
039ae585 | 1267 | tristate "Dell i8k legacy laptop support" |
949a9d70 | 1268 | select HWMON |
039ae585 | 1269 | select SENSORS_DELL_SMM |
506f1d07 | 1270 | ---help--- |
039ae585 PR |
1271 | This option enables legacy /proc/i8k userspace interface in hwmon |
1272 | dell-smm-hwmon driver. Character file /proc/i8k reports bios version, | |
1273 | temperature and allows controlling fan speeds of Dell laptops via | |
1274 | System Management Mode. For old Dell laptops (like Dell Inspiron 8000) | |
1275 | it reports also power and hotkey status. For fan speed control is | |
1276 | needed userspace package i8kutils. | |
1277 | ||
1278 | Say Y if you intend to run this kernel on old Dell laptops or want to | |
1279 | use userspace package i8kutils. | |
506f1d07 SR |
1280 | Say N otherwise. |
1281 | ||
1282 | config X86_REBOOTFIXUPS | |
9ba16087 JB |
1283 | bool "Enable X86 board specific fixups for reboot" |
1284 | depends on X86_32 | |
506f1d07 SR |
1285 | ---help--- |
1286 | This enables chipset and/or board specific fixups to be done | |
1287 | in order to get reboot to work correctly. This is only needed on | |
1288 | some combinations of hardware and BIOS. The symptom, for which | |
1289 | this config is intended, is when reboot ends with a stalled/hung | |
1290 | system. | |
1291 | ||
1292 | Currently, the only fixup is for the Geode machines using | |
5e3a77e9 | 1293 | CS5530A and CS5536 chipsets and the RDC R-321x SoC. |
506f1d07 SR |
1294 | |
1295 | Say Y if you want to enable the fixup. Currently, it's safe to | |
1296 | enable this option even if you don't need it. | |
1297 | Say N otherwise. | |
1298 | ||
1299 | config MICROCODE | |
9a2bc335 BP |
1300 | bool "CPU microcode loading support" |
1301 | default y | |
80030e3d | 1302 | depends on CPU_SUP_AMD || CPU_SUP_INTEL |
506f1d07 SR |
1303 | select FW_LOADER |
1304 | ---help--- | |
1305 | If you say Y here, you will be able to update the microcode on | |
5f9c01aa BP |
1306 | Intel and AMD processors. The Intel support is for the IA32 family, |
1307 | e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The | |
1308 | AMD support is for families 0x10 and later. You will obviously need | |
1309 | the actual microcode binary data itself which is not shipped with | |
1310 | the Linux kernel. | |
1311 | ||
1312 | The preferred method to load microcode from a detached initrd is described | |
cb1aaebe | 1313 | in Documentation/x86/microcode.rst. For that you need to enable |
5f9c01aa BP |
1314 | CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the |
1315 | initrd for microcode blobs. | |
1316 | ||
c508c46e BG |
1317 | In addition, you can build the microcode into the kernel. For that you |
1318 | need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE | |
1319 | config option. | |
506f1d07 | 1320 | |
8d86f390 | 1321 | config MICROCODE_INTEL |
e43f6e67 | 1322 | bool "Intel microcode loading support" |
8f9ca475 IM |
1323 | depends on MICROCODE |
1324 | default MICROCODE | |
1325 | select FW_LOADER | |
1326 | ---help--- | |
1327 | This options enables microcode patch loading support for Intel | |
1328 | processors. | |
1329 | ||
b8989db9 A |
1330 | For the current Intel microcode data package go to |
1331 | <https://downloadcenter.intel.com> and search for | |
1332 | 'Linux Processor Microcode Data File'. | |
8d86f390 | 1333 | |
80cc9f10 | 1334 | config MICROCODE_AMD |
e43f6e67 | 1335 | bool "AMD microcode loading support" |
8f9ca475 IM |
1336 | depends on MICROCODE |
1337 | select FW_LOADER | |
1338 | ---help--- | |
1339 | If you select this option, microcode patch loading support for AMD | |
1340 | processors will be enabled. | |
80cc9f10 | 1341 | |
8f9ca475 | 1342 | config MICROCODE_OLD_INTERFACE |
c02f48e0 BP |
1343 | bool "Ancient loading interface (DEPRECATED)" |
1344 | default n | |
506f1d07 | 1345 | depends on MICROCODE |
c02f48e0 BP |
1346 | ---help--- |
1347 | DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface | |
1348 | which was used by userspace tools like iucode_tool and microcode.ctl. | |
1349 | It is inadequate because it runs too late to be able to properly | |
1350 | load microcode on a machine and it needs special tools. Instead, you | |
1351 | should've switched to the early loading method with the initrd or | |
cb1aaebe | 1352 | builtin microcode by now: Documentation/x86/microcode.rst |
506f1d07 SR |
1353 | |
1354 | config X86_MSR | |
1355 | tristate "/dev/cpu/*/msr - Model-specific register support" | |
8f9ca475 | 1356 | ---help--- |
506f1d07 SR |
1357 | This device gives privileged processes access to the x86 |
1358 | Model-Specific Registers (MSRs). It is a character device with | |
1359 | major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr. | |
1360 | MSR accesses are directed to a specific CPU on multi-processor | |
1361 | systems. | |
1362 | ||
1363 | config X86_CPUID | |
1364 | tristate "/dev/cpu/*/cpuid - CPU information support" | |
8f9ca475 | 1365 | ---help--- |
506f1d07 SR |
1366 | This device gives processes access to the x86 CPUID instruction to |
1367 | be executed on a specific processor. It is a character device | |
1368 | with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to | |
1369 | /dev/cpu/31/cpuid. | |
1370 | ||
1371 | choice | |
1372 | prompt "High Memory Support" | |
6fc108a0 | 1373 | default HIGHMEM4G |
506f1d07 SR |
1374 | depends on X86_32 |
1375 | ||
1376 | config NOHIGHMEM | |
1377 | bool "off" | |
506f1d07 SR |
1378 | ---help--- |
1379 | Linux can use up to 64 Gigabytes of physical memory on x86 systems. | |
1380 | However, the address space of 32-bit x86 processors is only 4 | |
1381 | Gigabytes large. That means that, if you have a large amount of | |
1382 | physical memory, not all of it can be "permanently mapped" by the | |
1383 | kernel. The physical memory that's not permanently mapped is called | |
1384 | "high memory". | |
1385 | ||
1386 | If you are compiling a kernel which will never run on a machine with | |
1387 | more than 1 Gigabyte total physical RAM, answer "off" here (default | |
1388 | choice and suitable for most users). This will result in a "3GB/1GB" | |
1389 | split: 3GB are mapped so that each process sees a 3GB virtual memory | |
1390 | space and the remaining part of the 4GB virtual memory space is used | |
1391 | by the kernel to permanently map as much physical memory as | |
1392 | possible. | |
1393 | ||
1394 | If the machine has between 1 and 4 Gigabytes physical RAM, then | |
1395 | answer "4GB" here. | |
1396 | ||
1397 | If more than 4 Gigabytes is used then answer "64GB" here. This | |
1398 | selection turns Intel PAE (Physical Address Extension) mode on. | |
1399 | PAE implements 3-level paging on IA32 processors. PAE is fully | |
1400 | supported by Linux, PAE mode is implemented on all recent Intel | |
1401 | processors (Pentium Pro and better). NOTE: If you say "64GB" here, | |
1402 | then the kernel will not boot on CPUs that don't support PAE! | |
1403 | ||
1404 | The actual amount of total physical memory will either be | |
1405 | auto detected or can be forced by using a kernel command line option | |
1406 | such as "mem=256M". (Try "man bootparam" or see the documentation of | |
1407 | your boot loader (lilo or loadlin) about how to pass options to the | |
1408 | kernel at boot time.) | |
1409 | ||
1410 | If unsure, say "off". | |
1411 | ||
1412 | config HIGHMEM4G | |
1413 | bool "4GB" | |
8f9ca475 | 1414 | ---help--- |
506f1d07 SR |
1415 | Select this if you have a 32-bit processor and between 1 and 4 |
1416 | gigabytes of physical RAM. | |
1417 | ||
1418 | config HIGHMEM64G | |
1419 | bool "64GB" | |
69b8d3fc | 1420 | depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6 |
506f1d07 | 1421 | select X86_PAE |
8f9ca475 | 1422 | ---help--- |
506f1d07 SR |
1423 | Select this if you have a 32-bit processor and more than 4 |
1424 | gigabytes of physical RAM. | |
1425 | ||
1426 | endchoice | |
1427 | ||
1428 | choice | |
6a108a14 | 1429 | prompt "Memory split" if EXPERT |
506f1d07 SR |
1430 | default VMSPLIT_3G |
1431 | depends on X86_32 | |
8f9ca475 | 1432 | ---help--- |
506f1d07 SR |
1433 | Select the desired split between kernel and user memory. |
1434 | ||
1435 | If the address range available to the kernel is less than the | |
1436 | physical memory installed, the remaining memory will be available | |
1437 | as "high memory". Accessing high memory is a little more costly | |
1438 | than low memory, as it needs to be mapped into the kernel first. | |
1439 | Note that increasing the kernel address space limits the range | |
1440 | available to user programs, making the address space there | |
1441 | tighter. Selecting anything other than the default 3G/1G split | |
1442 | will also likely make your kernel incompatible with binary-only | |
1443 | kernel modules. | |
1444 | ||
1445 | If you are not absolutely sure what you are doing, leave this | |
1446 | option alone! | |
1447 | ||
1448 | config VMSPLIT_3G | |
1449 | bool "3G/1G user/kernel split" | |
1450 | config VMSPLIT_3G_OPT | |
1451 | depends on !X86_PAE | |
1452 | bool "3G/1G user/kernel split (for full 1G low memory)" | |
1453 | config VMSPLIT_2G | |
1454 | bool "2G/2G user/kernel split" | |
1455 | config VMSPLIT_2G_OPT | |
1456 | depends on !X86_PAE | |
1457 | bool "2G/2G user/kernel split (for full 2G low memory)" | |
1458 | config VMSPLIT_1G | |
1459 | bool "1G/3G user/kernel split" | |
1460 | endchoice | |
1461 | ||
1462 | config PAGE_OFFSET | |
1463 | hex | |
1464 | default 0xB0000000 if VMSPLIT_3G_OPT | |
1465 | default 0x80000000 if VMSPLIT_2G | |
1466 | default 0x78000000 if VMSPLIT_2G_OPT | |
1467 | default 0x40000000 if VMSPLIT_1G | |
1468 | default 0xC0000000 | |
1469 | depends on X86_32 | |
1470 | ||
1471 | config HIGHMEM | |
3c2362e6 | 1472 | def_bool y |
506f1d07 | 1473 | depends on X86_32 && (HIGHMEM64G || HIGHMEM4G) |
506f1d07 SR |
1474 | |
1475 | config X86_PAE | |
9ba16087 | 1476 | bool "PAE (Physical Address Extension) Support" |
506f1d07 | 1477 | depends on X86_32 && !HIGHMEM4G |
d4a451d5 | 1478 | select PHYS_ADDR_T_64BIT |
9d99c712 | 1479 | select SWIOTLB |
8f9ca475 | 1480 | ---help--- |
506f1d07 SR |
1481 | PAE is required for NX support, and furthermore enables |
1482 | larger swapspace support for non-overcommit purposes. It | |
1483 | has the cost of more pagetable lookup overhead, and also | |
1484 | consumes more pagetable space per process. | |
1485 | ||
77ef56e4 KS |
1486 | config X86_5LEVEL |
1487 | bool "Enable 5-level page tables support" | |
18ec1eaf | 1488 | default y |
eedb92ab | 1489 | select DYNAMIC_MEMORY_LAYOUT |
162434e7 | 1490 | select SPARSEMEM_VMEMMAP |
77ef56e4 KS |
1491 | depends on X86_64 |
1492 | ---help--- | |
1493 | 5-level paging enables access to larger address space: | |
1494 | upto 128 PiB of virtual address space and 4 PiB of | |
1495 | physical address space. | |
1496 | ||
1497 | It will be supported by future Intel CPUs. | |
1498 | ||
6657fca0 KS |
1499 | A kernel with the option enabled can be booted on machines that |
1500 | support 4- or 5-level paging. | |
77ef56e4 | 1501 | |
cb1aaebe | 1502 | See Documentation/x86/x86_64/5level-paging.rst for more |
77ef56e4 KS |
1503 | information. |
1504 | ||
1505 | Say N if unsure. | |
1506 | ||
10971ab2 | 1507 | config X86_DIRECT_GBPAGES |
e5008abe | 1508 | def_bool y |
2e1da13f | 1509 | depends on X86_64 |
8f9ca475 | 1510 | ---help--- |
10971ab2 IM |
1511 | Certain kernel features effectively disable kernel |
1512 | linear 1 GB mappings (even if the CPU otherwise | |
1513 | supports them), so don't confuse the user by printing | |
1514 | that we have them enabled. | |
9e899816 | 1515 | |
5c280cf6 TG |
1516 | config X86_CPA_STATISTICS |
1517 | bool "Enable statistic for Change Page Attribute" | |
1518 | depends on DEBUG_FS | |
1519 | ---help--- | |
b75baaf3 | 1520 | Expose statistics about the Change Page Attribute mechanism, which |
a943245a | 1521 | helps to determine the effectiveness of preserving large and huge |
5c280cf6 TG |
1522 | page mappings when mapping protections are changed. |
1523 | ||
7744ccdb TL |
1524 | config AMD_MEM_ENCRYPT |
1525 | bool "AMD Secure Memory Encryption (SME) support" | |
1526 | depends on X86_64 && CPU_SUP_AMD | |
82fef0ad | 1527 | select DMA_COHERENT_POOL |
94d49eb3 | 1528 | select DYNAMIC_PHYSICAL_MASK |
ce9084ba | 1529 | select ARCH_USE_MEMREMAP_PROT |
9087c375 | 1530 | select ARCH_HAS_FORCE_DMA_UNENCRYPTED |
7744ccdb TL |
1531 | ---help--- |
1532 | Say yes to enable support for the encryption of system memory. | |
1533 | This requires an AMD processor that supports Secure Memory | |
1534 | Encryption (SME). | |
1535 | ||
1536 | config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT | |
1537 | bool "Activate AMD Secure Memory Encryption (SME) by default" | |
1538 | default y | |
1539 | depends on AMD_MEM_ENCRYPT | |
1540 | ---help--- | |
1541 | Say yes to have system memory encrypted by default if running on | |
1542 | an AMD processor that supports Secure Memory Encryption (SME). | |
1543 | ||
1544 | If set to Y, then the encryption of system memory can be | |
1545 | deactivated with the mem_encrypt=off command line option. | |
1546 | ||
1547 | If set to N, then the encryption of system memory can be | |
1548 | activated with the mem_encrypt=on command line option. | |
1549 | ||
506f1d07 SR |
1550 | # Common NUMA Features |
1551 | config NUMA | |
e133f6ea | 1552 | bool "NUMA Memory Allocation and Scheduler Support" |
506f1d07 | 1553 | depends on SMP |
b5660ba7 PA |
1554 | depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP) |
1555 | default y if X86_BIGSMP | |
8f9ca475 | 1556 | ---help--- |
e133f6ea | 1557 | Enable NUMA (Non-Uniform Memory Access) support. |
fd51b2d7 | 1558 | |
506f1d07 SR |
1559 | The kernel will try to allocate memory used by a CPU on the |
1560 | local memory controller of the CPU and add some more | |
1561 | NUMA awareness to the kernel. | |
1562 | ||
c280ea5e | 1563 | For 64-bit this is recommended if the system is Intel Core i7 |
fd51b2d7 KM |
1564 | (or later), AMD Opteron, or EM64T NUMA. |
1565 | ||
b5660ba7 | 1566 | For 32-bit this is only needed if you boot a 32-bit |
7cf6c945 | 1567 | kernel on a 64-bit NUMA platform. |
fd51b2d7 KM |
1568 | |
1569 | Otherwise, you should say N. | |
506f1d07 | 1570 | |
eec1d4fa | 1571 | config AMD_NUMA |
3c2362e6 HH |
1572 | def_bool y |
1573 | prompt "Old style AMD Opteron NUMA detection" | |
5da0ef9a | 1574 | depends on X86_64 && NUMA && PCI |
8f9ca475 | 1575 | ---help--- |
eec1d4fa HR |
1576 | Enable AMD NUMA node topology detection. You should say Y here if |
1577 | you have a multi processor AMD system. This uses an old method to | |
1578 | read the NUMA configuration directly from the builtin Northbridge | |
1579 | of Opteron. It is recommended to use X86_64_ACPI_NUMA instead, | |
1580 | which also takes priority if both are compiled in. | |
506f1d07 SR |
1581 | |
1582 | config X86_64_ACPI_NUMA | |
3c2362e6 HH |
1583 | def_bool y |
1584 | prompt "ACPI NUMA detection" | |
506f1d07 SR |
1585 | depends on X86_64 && NUMA && ACPI && PCI |
1586 | select ACPI_NUMA | |
8f9ca475 | 1587 | ---help--- |
506f1d07 SR |
1588 | Enable ACPI SRAT based node topology detection. |
1589 | ||
1590 | config NUMA_EMU | |
1591 | bool "NUMA emulation" | |
1b7e03ef | 1592 | depends on NUMA |
8f9ca475 | 1593 | ---help--- |
506f1d07 SR |
1594 | Enable NUMA emulation. A flat machine will be split |
1595 | into virtual nodes when booted with "numa=fake=N", where N is the | |
1596 | number of nodes. This is only useful for debugging. | |
1597 | ||
1598 | config NODES_SHIFT | |
d25e26b6 | 1599 | int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP |
51591e31 DR |
1600 | range 1 10 |
1601 | default "10" if MAXSMP | |
506f1d07 | 1602 | default "6" if X86_64 |
506f1d07 SR |
1603 | default "3" |
1604 | depends on NEED_MULTIPLE_NODES | |
8f9ca475 | 1605 | ---help--- |
1184dc2f | 1606 | Specify the maximum number of NUMA Nodes available on the target |
692105b8 | 1607 | system. Increases memory reserved to accommodate various tables. |
506f1d07 | 1608 | |
506f1d07 SR |
1609 | config ARCH_FLATMEM_ENABLE |
1610 | def_bool y | |
3b16651f | 1611 | depends on X86_32 && !NUMA |
506f1d07 | 1612 | |
506f1d07 SR |
1613 | config ARCH_SPARSEMEM_ENABLE |
1614 | def_bool y | |
6ea30386 | 1615 | depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD |
506f1d07 SR |
1616 | select SPARSEMEM_STATIC if X86_32 |
1617 | select SPARSEMEM_VMEMMAP_ENABLE if X86_64 | |
1618 | ||
3b16651f | 1619 | config ARCH_SPARSEMEM_DEFAULT |
6ad57f7f | 1620 | def_bool X86_64 || (NUMA && X86_32) |
3b16651f | 1621 | |
506f1d07 SR |
1622 | config ARCH_SELECT_MEMORY_MODEL |
1623 | def_bool y | |
b263295d | 1624 | depends on ARCH_SPARSEMEM_ENABLE |
506f1d07 SR |
1625 | |
1626 | config ARCH_MEMORY_PROBE | |
a0842b70 | 1627 | bool "Enable sysfs memory/probe interface" |
3120e25e | 1628 | depends on X86_64 && MEMORY_HOTPLUG |
a0842b70 TK |
1629 | help |
1630 | This option enables a sysfs memory/probe interface for testing. | |
cb1aaebe | 1631 | See Documentation/admin-guide/mm/memory-hotplug.rst for more information. |
a0842b70 | 1632 | If you are unsure how to answer this question, answer N. |
506f1d07 | 1633 | |
3b16651f TH |
1634 | config ARCH_PROC_KCORE_TEXT |
1635 | def_bool y | |
1636 | depends on X86_64 && PROC_KCORE | |
1637 | ||
a29815a3 | 1638 | config ILLEGAL_POINTER_VALUE |
b03b016f KK |
1639 | hex |
1640 | default 0 if X86_32 | |
1641 | default 0xdead000000000000 if X86_64 | |
a29815a3 | 1642 | |
7a67832c DW |
1643 | config X86_PMEM_LEGACY_DEVICE |
1644 | bool | |
1645 | ||
ec776ef6 | 1646 | config X86_PMEM_LEGACY |
7a67832c | 1647 | tristate "Support non-standard NVDIMMs and ADR protected memory" |
9f53f9fa DW |
1648 | depends on PHYS_ADDR_T_64BIT |
1649 | depends on BLK_DEV | |
7a67832c | 1650 | select X86_PMEM_LEGACY_DEVICE |
7b27a862 | 1651 | select NUMA_KEEP_MEMINFO if NUMA |
9f53f9fa | 1652 | select LIBNVDIMM |
ec776ef6 CH |
1653 | help |
1654 | Treat memory marked using the non-standard e820 type of 12 as used | |
1655 | by the Intel Sandy Bridge-EP reference BIOS as protected memory. | |
1656 | The kernel will offer these regions to the 'pmem' driver so | |
1657 | they can be used for persistent storage. | |
1658 | ||
1659 | Say Y if unsure. | |
1660 | ||
506f1d07 SR |
1661 | config HIGHPTE |
1662 | bool "Allocate 3rd-level pagetables from highmem" | |
6fc108a0 | 1663 | depends on HIGHMEM |
8f9ca475 | 1664 | ---help--- |
506f1d07 SR |
1665 | The VM uses one page table entry for each page of physical memory. |
1666 | For systems with a lot of RAM, this can be wasteful of precious | |
1667 | low memory. Setting this option will put user-space page table | |
1668 | entries in high memory. | |
1669 | ||
9f077871 | 1670 | config X86_CHECK_BIOS_CORRUPTION |
8f9ca475 IM |
1671 | bool "Check for low memory corruption" |
1672 | ---help--- | |
1673 | Periodically check for memory corruption in low memory, which | |
1674 | is suspected to be caused by BIOS. Even when enabled in the | |
1675 | configuration, it is disabled at runtime. Enable it by | |
1676 | setting "memory_corruption_check=1" on the kernel command | |
1677 | line. By default it scans the low 64k of memory every 60 | |
1678 | seconds; see the memory_corruption_check_size and | |
1679 | memory_corruption_check_period parameters in | |
8c27ceff | 1680 | Documentation/admin-guide/kernel-parameters.rst to adjust this. |
8f9ca475 IM |
1681 | |
1682 | When enabled with the default parameters, this option has | |
1683 | almost no overhead, as it reserves a relatively small amount | |
1684 | of memory and scans it infrequently. It both detects corruption | |
1685 | and prevents it from affecting the running system. | |
1686 | ||
1687 | It is, however, intended as a diagnostic tool; if repeatable | |
1688 | BIOS-originated corruption always affects the same memory, | |
1689 | you can use memmap= to prevent the kernel from using that | |
1690 | memory. | |
9f077871 | 1691 | |
c885df50 | 1692 | config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK |
8f9ca475 | 1693 | bool "Set the default setting of memory_corruption_check" |
c885df50 JF |
1694 | depends on X86_CHECK_BIOS_CORRUPTION |
1695 | default y | |
8f9ca475 IM |
1696 | ---help--- |
1697 | Set whether the default state of memory_corruption_check is | |
1698 | on or off. | |
c885df50 | 1699 | |
9ea77bdb | 1700 | config X86_RESERVE_LOW |
d0cd7425 PA |
1701 | int "Amount of low memory, in kilobytes, to reserve for the BIOS" |
1702 | default 64 | |
1703 | range 4 640 | |
8f9ca475 | 1704 | ---help--- |
d0cd7425 PA |
1705 | Specify the amount of low memory to reserve for the BIOS. |
1706 | ||
1707 | The first page contains BIOS data structures that the kernel | |
1708 | must not use, so that page must always be reserved. | |
1709 | ||
1710 | By default we reserve the first 64K of physical RAM, as a | |
1711 | number of BIOSes are known to corrupt that memory range | |
1712 | during events such as suspend/resume or monitor cable | |
1713 | insertion, so it must not be used by the kernel. | |
fc381519 | 1714 | |
d0cd7425 PA |
1715 | You can set this to 4 if you are absolutely sure that you |
1716 | trust the BIOS to get all its memory reservations and usages | |
1717 | right. If you know your BIOS have problems beyond the | |
1718 | default 64K area, you can set this to 640 to avoid using the | |
1719 | entire low memory range. | |
fc381519 | 1720 | |
d0cd7425 PA |
1721 | If you have doubts about the BIOS (e.g. suspend/resume does |
1722 | not work or there's kernel crashes after certain hardware | |
1723 | hotplug events) then you might want to enable | |
1724 | X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check | |
1725 | typical corruption patterns. | |
fc381519 | 1726 | |
d0cd7425 | 1727 | Leave this to the default value of 64 if you are unsure. |
fc381519 | 1728 | |
506f1d07 SR |
1729 | config MATH_EMULATION |
1730 | bool | |
a5b9e5a2 | 1731 | depends on MODIFY_LDT_SYSCALL |
87d6021b | 1732 | prompt "Math emulation" if X86_32 && (M486SX || MELAN) |
506f1d07 SR |
1733 | ---help--- |
1734 | Linux can emulate a math coprocessor (used for floating point | |
1735 | operations) if you don't have one. 486DX and Pentium processors have | |
1736 | a math coprocessor built in, 486SX and 386 do not, unless you added | |
1737 | a 487DX or 387, respectively. (The messages during boot time can | |
1738 | give you some hints here ["man dmesg"].) Everyone needs either a | |
1739 | coprocessor or this emulation. | |
1740 | ||
1741 | If you don't have a math coprocessor, you need to say Y here; if you | |
1742 | say Y here even though you have a coprocessor, the coprocessor will | |
1743 | be used nevertheless. (This behavior can be changed with the kernel | |
1744 | command line option "no387", which comes handy if your coprocessor | |
1745 | is broken. Try "man bootparam" or see the documentation of your boot | |
1746 | loader (lilo or loadlin) about how to pass options to the kernel at | |
1747 | boot time.) This means that it is a good idea to say Y here if you | |
1748 | intend to use this kernel on different machines. | |
1749 | ||
1750 | More information about the internals of the Linux math coprocessor | |
1751 | emulation can be found in <file:arch/x86/math-emu/README>. | |
1752 | ||
1753 | If you are not sure, say Y; apart from resulting in a 66 KB bigger | |
1754 | kernel, it won't hurt. | |
1755 | ||
1756 | config MTRR | |
6fc108a0 | 1757 | def_bool y |
6a108a14 | 1758 | prompt "MTRR (Memory Type Range Register) support" if EXPERT |
506f1d07 SR |
1759 | ---help--- |
1760 | On Intel P6 family processors (Pentium Pro, Pentium II and later) | |
1761 | the Memory Type Range Registers (MTRRs) may be used to control | |
1762 | processor access to memory ranges. This is most useful if you have | |
1763 | a video (VGA) card on a PCI or AGP bus. Enabling write-combining | |
1764 | allows bus write transfers to be combined into a larger transfer | |
1765 | before bursting over the PCI/AGP bus. This can increase performance | |
1766 | of image write operations 2.5 times or more. Saying Y here creates a | |
1767 | /proc/mtrr file which may be used to manipulate your processor's | |
1768 | MTRRs. Typically the X server should use this. | |
1769 | ||
1770 | This code has a reasonably generic interface so that similar | |
1771 | control registers on other processors can be easily supported | |
1772 | as well: | |
1773 | ||
1774 | The Cyrix 6x86, 6x86MX and M II processors have Address Range | |
1775 | Registers (ARRs) which provide a similar functionality to MTRRs. For | |
1776 | these, the ARRs are used to emulate the MTRRs. | |
1777 | The AMD K6-2 (stepping 8 and above) and K6-3 processors have two | |
1778 | MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing | |
1779 | write-combining. All of these processors are supported by this code | |
1780 | and it makes sense to say Y here if you have one of them. | |
1781 | ||
1782 | Saying Y here also fixes a problem with buggy SMP BIOSes which only | |
1783 | set the MTRRs for the boot CPU and not for the secondary CPUs. This | |
1784 | can lead to all sorts of problems, so it's good to say Y here. | |
1785 | ||
1786 | You can safely say Y even if your machine doesn't have MTRRs, you'll | |
1787 | just add about 9 KB to your kernel. | |
1788 | ||
cb1aaebe | 1789 | See <file:Documentation/x86/mtrr.rst> for more information. |
506f1d07 | 1790 | |
95ffa243 | 1791 | config MTRR_SANITIZER |
2ffb3501 | 1792 | def_bool y |
95ffa243 YL |
1793 | prompt "MTRR cleanup support" |
1794 | depends on MTRR | |
8f9ca475 | 1795 | ---help--- |
aba3728c TG |
1796 | Convert MTRR layout from continuous to discrete, so X drivers can |
1797 | add writeback entries. | |
95ffa243 | 1798 | |
aba3728c | 1799 | Can be disabled with disable_mtrr_cleanup on the kernel command line. |
692105b8 | 1800 | The largest mtrr entry size for a continuous block can be set with |
aba3728c | 1801 | mtrr_chunk_size. |
95ffa243 | 1802 | |
2ffb3501 | 1803 | If unsure, say Y. |
95ffa243 YL |
1804 | |
1805 | config MTRR_SANITIZER_ENABLE_DEFAULT | |
f5098d62 YL |
1806 | int "MTRR cleanup enable value (0-1)" |
1807 | range 0 1 | |
1808 | default "0" | |
95ffa243 | 1809 | depends on MTRR_SANITIZER |
8f9ca475 | 1810 | ---help--- |
f5098d62 | 1811 | Enable mtrr cleanup default value |
95ffa243 | 1812 | |
12031a62 YL |
1813 | config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT |
1814 | int "MTRR cleanup spare reg num (0-7)" | |
1815 | range 0 7 | |
1816 | default "1" | |
1817 | depends on MTRR_SANITIZER | |
8f9ca475 | 1818 | ---help--- |
12031a62 | 1819 | mtrr cleanup spare entries default, it can be changed via |
aba3728c | 1820 | mtrr_spare_reg_nr=N on the kernel command line. |
12031a62 | 1821 | |
2e5d9c85 | 1822 | config X86_PAT |
6fc108a0 | 1823 | def_bool y |
6a108a14 | 1824 | prompt "x86 PAT support" if EXPERT |
2a8a2719 | 1825 | depends on MTRR |
8f9ca475 | 1826 | ---help--- |
2e5d9c85 | 1827 | Use PAT attributes to setup page level cache control. |
042b78e4 | 1828 | |
2e5d9c85 | 1829 | PATs are the modern equivalents of MTRRs and are much more |
1830 | flexible than MTRRs. | |
1831 | ||
1832 | Say N here if you see bootup problems (boot crash, boot hang, | |
042b78e4 | 1833 | spontaneous reboots) or a non-working video driver. |
2e5d9c85 | 1834 | |
1835 | If unsure, say Y. | |
1836 | ||
46cf98cd VP |
1837 | config ARCH_USES_PG_UNCACHED |
1838 | def_bool y | |
1839 | depends on X86_PAT | |
1840 | ||
628c6246 PA |
1841 | config ARCH_RANDOM |
1842 | def_bool y | |
1843 | prompt "x86 architectural random number generator" if EXPERT | |
1844 | ---help--- | |
1845 | Enable the x86 architectural RDRAND instruction | |
1846 | (Intel Bull Mountain technology) to generate random numbers. | |
1847 | If supported, this is a high bandwidth, cryptographically | |
1848 | secure hardware random number generator. | |
1849 | ||
51ae4a2d PA |
1850 | config X86_SMAP |
1851 | def_bool y | |
1852 | prompt "Supervisor Mode Access Prevention" if EXPERT | |
1853 | ---help--- | |
1854 | Supervisor Mode Access Prevention (SMAP) is a security | |
1855 | feature in newer Intel processors. There is a small | |
1856 | performance cost if this enabled and turned on; there is | |
1857 | also a small increase in the kernel size if this is enabled. | |
1858 | ||
1859 | If unsure, say Y. | |
1860 | ||
b971880f | 1861 | config X86_UMIP |
796ebc81 | 1862 | def_bool y |
b971880f BM |
1863 | prompt "User Mode Instruction Prevention" if EXPERT |
1864 | ---help--- | |
1865 | User Mode Instruction Prevention (UMIP) is a security feature in | |
1866 | some x86 processors. If enabled, a general protection fault is | |
1867 | issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are | |
1868 | executed in user mode. These instructions unnecessarily expose | |
1869 | information about the hardware state. | |
796ebc81 RN |
1870 | |
1871 | The vast majority of applications do not use these instructions. | |
1872 | For the very few that do, software emulation is provided in | |
1873 | specific cases in protected and virtual-8086 modes. Emulated | |
1874 | results are dummy. | |
aa35f896 | 1875 | |
35e97790 | 1876 | config X86_INTEL_MEMORY_PROTECTION_KEYS |
38f3e775 | 1877 | prompt "Memory Protection Keys" |
35e97790 | 1878 | def_bool y |
284244a9 | 1879 | # Note: only available in 64-bit mode |
38f3e775 | 1880 | depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD) |
52c8e601 IM |
1881 | select ARCH_USES_HIGH_VMA_FLAGS |
1882 | select ARCH_HAS_PKEYS | |
284244a9 DH |
1883 | ---help--- |
1884 | Memory Protection Keys provides a mechanism for enforcing | |
1885 | page-based protections, but without requiring modification of the | |
1886 | page tables when an application changes protection domains. | |
1887 | ||
1eecbcdc | 1888 | For details, see Documentation/core-api/protection-keys.rst |
284244a9 DH |
1889 | |
1890 | If unsure, say y. | |
35e97790 | 1891 | |
db616173 MH |
1892 | choice |
1893 | prompt "TSX enable mode" | |
1894 | depends on CPU_SUP_INTEL | |
1895 | default X86_INTEL_TSX_MODE_OFF | |
1896 | help | |
1897 | Intel's TSX (Transactional Synchronization Extensions) feature | |
1898 | allows to optimize locking protocols through lock elision which | |
1899 | can lead to a noticeable performance boost. | |
1900 | ||
1901 | On the other hand it has been shown that TSX can be exploited | |
1902 | to form side channel attacks (e.g. TAA) and chances are there | |
1903 | will be more of those attacks discovered in the future. | |
1904 | ||
1905 | Therefore TSX is not enabled by default (aka tsx=off). An admin | |
1906 | might override this decision by tsx=on the command line parameter. | |
1907 | Even with TSX enabled, the kernel will attempt to enable the best | |
1908 | possible TAA mitigation setting depending on the microcode available | |
1909 | for the particular machine. | |
1910 | ||
1911 | This option allows to set the default tsx mode between tsx=on, =off | |
1912 | and =auto. See Documentation/admin-guide/kernel-parameters.txt for more | |
1913 | details. | |
1914 | ||
1915 | Say off if not sure, auto if TSX is in use but it should be used on safe | |
1916 | platforms or on if TSX is in use and the security aspect of tsx is not | |
1917 | relevant. | |
1918 | ||
1919 | config X86_INTEL_TSX_MODE_OFF | |
1920 | bool "off" | |
1921 | help | |
1922 | TSX is disabled if possible - equals to tsx=off command line parameter. | |
1923 | ||
1924 | config X86_INTEL_TSX_MODE_ON | |
1925 | bool "on" | |
1926 | help | |
1927 | TSX is always enabled on TSX capable HW - equals the tsx=on command | |
1928 | line parameter. | |
1929 | ||
1930 | config X86_INTEL_TSX_MODE_AUTO | |
1931 | bool "auto" | |
1932 | help | |
1933 | TSX is enabled on TSX capable HW that is believed to be safe against | |
1934 | side channel attacks- equals the tsx=auto command line parameter. | |
1935 | endchoice | |
1936 | ||
506f1d07 | 1937 | config EFI |
9ba16087 | 1938 | bool "EFI runtime service support" |
5b83683f | 1939 | depends on ACPI |
f6ce5002 | 1940 | select UCS2_STRING |
022ee6c5 | 1941 | select EFI_RUNTIME_WRAPPERS |
506f1d07 | 1942 | ---help--- |
8f9ca475 IM |
1943 | This enables the kernel to use EFI runtime services that are |
1944 | available (such as the EFI variable services). | |
506f1d07 | 1945 | |
8f9ca475 IM |
1946 | This option is only useful on systems that have EFI firmware. |
1947 | In addition, you should use the latest ELILO loader available | |
1948 | at <http://elilo.sourceforge.net> in order to take advantage | |
1949 | of EFI runtime services. However, even with this option, the | |
1950 | resultant kernel should continue to boot on existing non-EFI | |
1951 | platforms. | |
506f1d07 | 1952 | |
291f3632 | 1953 | config EFI_STUB |
8f24f8c2 AB |
1954 | bool "EFI stub support" |
1955 | depends on EFI && !X86_USE_3DNOW | |
1956 | depends on $(cc-option,-mabi=ms) || X86_32 | |
1957 | select RELOCATABLE | |
1958 | ---help--- | |
1959 | This kernel feature allows a bzImage to be loaded directly | |
291f3632 MF |
1960 | by EFI firmware without the use of a bootloader. |
1961 | ||
4f4cfa6c | 1962 | See Documentation/admin-guide/efi-stub.rst for more information. |
0c759662 | 1963 | |
7d453eee MF |
1964 | config EFI_MIXED |
1965 | bool "EFI mixed-mode support" | |
1966 | depends on EFI_STUB && X86_64 | |
1967 | ---help--- | |
1968 | Enabling this feature allows a 64-bit kernel to be booted | |
1969 | on a 32-bit firmware, provided that your CPU supports 64-bit | |
1970 | mode. | |
1971 | ||
1972 | Note that it is not possible to boot a mixed-mode enabled | |
1973 | kernel via the EFI boot stub - a bootloader that supports | |
1974 | the EFI handover protocol must be used. | |
1975 | ||
1976 | If unsure, say N. | |
1977 | ||
506f1d07 | 1978 | config SECCOMP |
3c2362e6 HH |
1979 | def_bool y |
1980 | prompt "Enable seccomp to safely compute untrusted bytecode" | |
8f9ca475 | 1981 | ---help--- |
506f1d07 SR |
1982 | This kernel feature is useful for number crunching applications |
1983 | that may need to compute untrusted bytecode during their | |
1984 | execution. By using pipes or other transports made available to | |
1985 | the process as file descriptors supporting the read/write | |
1986 | syscalls, it's possible to isolate those applications in | |
1987 | their own address space using seccomp. Once seccomp is | |
9c0bbee8 | 1988 | enabled via prctl(PR_SET_SECCOMP), it cannot be disabled |
506f1d07 SR |
1989 | and the task is only allowed to execute a few safe syscalls |
1990 | defined by each seccomp mode. | |
1991 | ||
1992 | If unsure, say Y. Only embedded should say N here. | |
1993 | ||
8636a1f9 | 1994 | source "kernel/Kconfig.hz" |
506f1d07 SR |
1995 | |
1996 | config KEXEC | |
1997 | bool "kexec system call" | |
2965faa5 | 1998 | select KEXEC_CORE |
8f9ca475 | 1999 | ---help--- |
506f1d07 SR |
2000 | kexec is a system call that implements the ability to shutdown your |
2001 | current kernel, and to start another kernel. It is like a reboot | |
2002 | but it is independent of the system firmware. And like a reboot | |
2003 | you can start any kernel with it, not just Linux. | |
2004 | ||
2005 | The name comes from the similarity to the exec system call. | |
2006 | ||
2007 | It is an ongoing process to be certain the hardware in a machine | |
2008 | is properly shutdown, so do not be surprised if this code does not | |
bf220695 GU |
2009 | initially work for you. As of this writing the exact hardware |
2010 | interface is strongly in flux, so no good recommendation can be | |
2011 | made. | |
506f1d07 | 2012 | |
74ca317c VG |
2013 | config KEXEC_FILE |
2014 | bool "kexec file based system call" | |
2965faa5 | 2015 | select KEXEC_CORE |
74ca317c | 2016 | select BUILD_BIN2C |
74ca317c VG |
2017 | depends on X86_64 |
2018 | depends on CRYPTO=y | |
2019 | depends on CRYPTO_SHA256=y | |
2020 | ---help--- | |
2021 | This is new version of kexec system call. This system call is | |
2022 | file based and takes file descriptors as system call argument | |
2023 | for kernel and initramfs as opposed to list of segments as | |
2024 | accepted by previous system call. | |
2025 | ||
b799a09f AT |
2026 | config ARCH_HAS_KEXEC_PURGATORY |
2027 | def_bool KEXEC_FILE | |
2028 | ||
99d5cadf | 2029 | config KEXEC_SIG |
8e7d8381 | 2030 | bool "Verify kernel signature during kexec_file_load() syscall" |
74ca317c | 2031 | depends on KEXEC_FILE |
8e7d8381 | 2032 | ---help--- |
d8eb8940 | 2033 | |
99d5cadf JB |
2034 | This option makes the kexec_file_load() syscall check for a valid |
2035 | signature of the kernel image. The image can still be loaded without | |
2036 | a valid signature unless you also enable KEXEC_SIG_FORCE, though if | |
2037 | there's a signature that we can check, then it must be valid. | |
2038 | ||
2039 | In addition to this option, you need to enable signature | |
d8eb8940 BP |
2040 | verification for the corresponding kernel image type being |
2041 | loaded in order for this to work. | |
8e7d8381 | 2042 | |
99d5cadf JB |
2043 | config KEXEC_SIG_FORCE |
2044 | bool "Require a valid signature in kexec_file_load() syscall" | |
2045 | depends on KEXEC_SIG | |
2046 | ---help--- | |
2047 | This option makes kernel signature verification mandatory for | |
2048 | the kexec_file_load() syscall. | |
2049 | ||
8e7d8381 VG |
2050 | config KEXEC_BZIMAGE_VERIFY_SIG |
2051 | bool "Enable bzImage signature verification support" | |
99d5cadf | 2052 | depends on KEXEC_SIG |
8e7d8381 VG |
2053 | depends on SIGNED_PE_FILE_VERIFICATION |
2054 | select SYSTEM_TRUSTED_KEYRING | |
2055 | ---help--- | |
2056 | Enable bzImage signature verification support. | |
2057 | ||
506f1d07 | 2058 | config CRASH_DUMP |
04b69447 | 2059 | bool "kernel crash dumps" |
506f1d07 | 2060 | depends on X86_64 || (X86_32 && HIGHMEM) |
8f9ca475 | 2061 | ---help--- |
506f1d07 SR |
2062 | Generate crash dump after being started by kexec. |
2063 | This should be normally only set in special crash dump kernels | |
2064 | which are loaded in the main kernel with kexec-tools into | |
2065 | a specially reserved region and then later executed after | |
2066 | a crash by kdump/kexec. The crash dump kernel must be compiled | |
2067 | to a memory address not used by the main kernel or BIOS using | |
2068 | PHYSICAL_START, or it must be built as a relocatable image | |
2069 | (CONFIG_RELOCATABLE=y). | |
330d4810 | 2070 | For more details see Documentation/admin-guide/kdump/kdump.rst |
506f1d07 | 2071 | |
3ab83521 | 2072 | config KEXEC_JUMP |
6ea30386 | 2073 | bool "kexec jump" |
fee7b0d8 | 2074 | depends on KEXEC && HIBERNATION |
8f9ca475 | 2075 | ---help--- |
89081d17 HY |
2076 | Jump between original kernel and kexeced kernel and invoke |
2077 | code in physical address mode via KEXEC | |
3ab83521 | 2078 | |
506f1d07 | 2079 | config PHYSICAL_START |
6a108a14 | 2080 | hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP) |
ceefccc9 | 2081 | default "0x1000000" |
8f9ca475 | 2082 | ---help--- |
506f1d07 SR |
2083 | This gives the physical address where the kernel is loaded. |
2084 | ||
2085 | If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then | |
2086 | bzImage will decompress itself to above physical address and | |
2087 | run from there. Otherwise, bzImage will run from the address where | |
2088 | it has been loaded by the boot loader and will ignore above physical | |
2089 | address. | |
2090 | ||
2091 | In normal kdump cases one does not have to set/change this option | |
2092 | as now bzImage can be compiled as a completely relocatable image | |
2093 | (CONFIG_RELOCATABLE=y) and be used to load and run from a different | |
2094 | address. This option is mainly useful for the folks who don't want | |
2095 | to use a bzImage for capturing the crash dump and want to use a | |
2096 | vmlinux instead. vmlinux is not relocatable hence a kernel needs | |
2097 | to be specifically compiled to run from a specific memory area | |
2098 | (normally a reserved region) and this option comes handy. | |
2099 | ||
ceefccc9 PA |
2100 | So if you are using bzImage for capturing the crash dump, |
2101 | leave the value here unchanged to 0x1000000 and set | |
2102 | CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux | |
2103 | for capturing the crash dump change this value to start of | |
2104 | the reserved region. In other words, it can be set based on | |
2105 | the "X" value as specified in the "crashkernel=YM@XM" | |
2106 | command line boot parameter passed to the panic-ed | |
330d4810 | 2107 | kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst |
ceefccc9 | 2108 | for more details about crash dumps. |
506f1d07 SR |
2109 | |
2110 | Usage of bzImage for capturing the crash dump is recommended as | |
2111 | one does not have to build two kernels. Same kernel can be used | |
2112 | as production kernel and capture kernel. Above option should have | |
2113 | gone away after relocatable bzImage support is introduced. But it | |
2114 | is present because there are users out there who continue to use | |
2115 | vmlinux for dump capture. This option should go away down the | |
2116 | line. | |
2117 | ||
2118 | Don't change this unless you know what you are doing. | |
2119 | ||
2120 | config RELOCATABLE | |
26717808 PA |
2121 | bool "Build a relocatable kernel" |
2122 | default y | |
8f9ca475 | 2123 | ---help--- |
506f1d07 SR |
2124 | This builds a kernel image that retains relocation information |
2125 | so it can be loaded someplace besides the default 1MB. | |
2126 | The relocations tend to make the kernel binary about 10% larger, | |
2127 | but are discarded at runtime. | |
2128 | ||
2129 | One use is for the kexec on panic case where the recovery kernel | |
2130 | must live at a different physical address than the primary | |
2131 | kernel. | |
2132 | ||
2133 | Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address | |
2134 | it has been loaded at and the compile time physical address | |
8ab3820f | 2135 | (CONFIG_PHYSICAL_START) is used as the minimum location. |
506f1d07 | 2136 | |
8ab3820f | 2137 | config RANDOMIZE_BASE |
e8581e3d | 2138 | bool "Randomize the address of the kernel image (KASLR)" |
8ab3820f | 2139 | depends on RELOCATABLE |
6807c846 | 2140 | default y |
8ab3820f | 2141 | ---help--- |
e8581e3d BH |
2142 | In support of Kernel Address Space Layout Randomization (KASLR), |
2143 | this randomizes the physical address at which the kernel image | |
2144 | is decompressed and the virtual address where the kernel | |
2145 | image is mapped, as a security feature that deters exploit | |
2146 | attempts relying on knowledge of the location of kernel | |
2147 | code internals. | |
2148 | ||
ed9f007e KC |
2149 | On 64-bit, the kernel physical and virtual addresses are |
2150 | randomized separately. The physical address will be anywhere | |
2151 | between 16MB and the top of physical memory (up to 64TB). The | |
2152 | virtual address will be randomized from 16MB up to 1GB (9 bits | |
2153 | of entropy). Note that this also reduces the memory space | |
2154 | available to kernel modules from 1.5GB to 1GB. | |
2155 | ||
2156 | On 32-bit, the kernel physical and virtual addresses are | |
2157 | randomized together. They will be randomized from 16MB up to | |
2158 | 512MB (8 bits of entropy). | |
e8581e3d BH |
2159 | |
2160 | Entropy is generated using the RDRAND instruction if it is | |
2161 | supported. If RDTSC is supported, its value is mixed into | |
2162 | the entropy pool as well. If neither RDRAND nor RDTSC are | |
ed9f007e KC |
2163 | supported, then entropy is read from the i8254 timer. The |
2164 | usable entropy is limited by the kernel being built using | |
2165 | 2GB addressing, and that PHYSICAL_ALIGN must be at a | |
2166 | minimum of 2MB. As a result, only 10 bits of entropy are | |
2167 | theoretically possible, but the implementations are further | |
2168 | limited due to memory layouts. | |
e8581e3d | 2169 | |
6807c846 | 2170 | If unsure, say Y. |
8ab3820f KC |
2171 | |
2172 | # Relocation on x86 needs some additional build support | |
845adf72 PA |
2173 | config X86_NEED_RELOCS |
2174 | def_bool y | |
8ab3820f | 2175 | depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE) |
845adf72 | 2176 | |
506f1d07 | 2177 | config PHYSICAL_ALIGN |
a0215061 | 2178 | hex "Alignment value to which kernel should be aligned" |
8ab3820f | 2179 | default "0x200000" |
a0215061 KC |
2180 | range 0x2000 0x1000000 if X86_32 |
2181 | range 0x200000 0x1000000 if X86_64 | |
8f9ca475 | 2182 | ---help--- |
506f1d07 SR |
2183 | This value puts the alignment restrictions on physical address |
2184 | where kernel is loaded and run from. Kernel is compiled for an | |
2185 | address which meets above alignment restriction. | |
2186 | ||
2187 | If bootloader loads the kernel at a non-aligned address and | |
2188 | CONFIG_RELOCATABLE is set, kernel will move itself to nearest | |
2189 | address aligned to above value and run from there. | |
2190 | ||
2191 | If bootloader loads the kernel at a non-aligned address and | |
2192 | CONFIG_RELOCATABLE is not set, kernel will ignore the run time | |
2193 | load address and decompress itself to the address it has been | |
2194 | compiled for and run from there. The address for which kernel is | |
2195 | compiled already meets above alignment restrictions. Hence the | |
2196 | end result is that kernel runs from a physical address meeting | |
2197 | above alignment restrictions. | |
2198 | ||
a0215061 KC |
2199 | On 32-bit this value must be a multiple of 0x2000. On 64-bit |
2200 | this value must be a multiple of 0x200000. | |
2201 | ||
506f1d07 SR |
2202 | Don't change this unless you know what you are doing. |
2203 | ||
eedb92ab KS |
2204 | config DYNAMIC_MEMORY_LAYOUT |
2205 | bool | |
2206 | ---help--- | |
2207 | This option makes base addresses of vmalloc and vmemmap as well as | |
2208 | __PAGE_OFFSET movable during boot. | |
2209 | ||
0483e1fa TG |
2210 | config RANDOMIZE_MEMORY |
2211 | bool "Randomize the kernel memory sections" | |
2212 | depends on X86_64 | |
2213 | depends on RANDOMIZE_BASE | |
eedb92ab | 2214 | select DYNAMIC_MEMORY_LAYOUT |
0483e1fa TG |
2215 | default RANDOMIZE_BASE |
2216 | ---help--- | |
2217 | Randomizes the base virtual address of kernel memory sections | |
2218 | (physical memory mapping, vmalloc & vmemmap). This security feature | |
2219 | makes exploits relying on predictable memory locations less reliable. | |
2220 | ||
2221 | The order of allocations remains unchanged. Entropy is generated in | |
2222 | the same way as RANDOMIZE_BASE. Current implementation in the optimal | |
2223 | configuration have in average 30,000 different possible virtual | |
2224 | addresses for each memory section. | |
2225 | ||
6807c846 | 2226 | If unsure, say Y. |
0483e1fa | 2227 | |
90397a41 TG |
2228 | config RANDOMIZE_MEMORY_PHYSICAL_PADDING |
2229 | hex "Physical memory mapping padding" if EXPERT | |
2230 | depends on RANDOMIZE_MEMORY | |
2231 | default "0xa" if MEMORY_HOTPLUG | |
2232 | default "0x0" | |
2233 | range 0x1 0x40 if MEMORY_HOTPLUG | |
2234 | range 0x0 0x40 | |
2235 | ---help--- | |
2236 | Define the padding in terabytes added to the existing physical | |
2237 | memory size during kernel memory randomization. It is useful | |
2238 | for memory hotplug support but reduces the entropy available for | |
2239 | address randomization. | |
2240 | ||
2241 | If unsure, leave at the default value. | |
2242 | ||
506f1d07 | 2243 | config HOTPLUG_CPU |
bebd024e | 2244 | def_bool y |
40b31360 | 2245 | depends on SMP |
506f1d07 | 2246 | |
80aa1dff FY |
2247 | config BOOTPARAM_HOTPLUG_CPU0 |
2248 | bool "Set default setting of cpu0_hotpluggable" | |
2c922cd0 | 2249 | depends on HOTPLUG_CPU |
80aa1dff FY |
2250 | ---help--- |
2251 | Set whether default state of cpu0_hotpluggable is on or off. | |
2252 | ||
2253 | Say Y here to enable CPU0 hotplug by default. If this switch | |
2254 | is turned on, there is no need to give cpu0_hotplug kernel | |
2255 | parameter and the CPU0 hotplug feature is enabled by default. | |
2256 | ||
2257 | Please note: there are two known CPU0 dependencies if you want | |
2258 | to enable the CPU0 hotplug feature either by this switch or by | |
2259 | cpu0_hotplug kernel parameter. | |
2260 | ||
2261 | First, resume from hibernate or suspend always starts from CPU0. | |
2262 | So hibernate and suspend are prevented if CPU0 is offline. | |
2263 | ||
2264 | Second dependency is PIC interrupts always go to CPU0. CPU0 can not | |
2265 | offline if any interrupt can not migrate out of CPU0. There may | |
2266 | be other CPU0 dependencies. | |
2267 | ||
2268 | Please make sure the dependencies are under your control before | |
2269 | you enable this feature. | |
2270 | ||
2271 | Say N if you don't want to enable CPU0 hotplug feature by default. | |
2272 | You still can enable the CPU0 hotplug feature at boot by kernel | |
2273 | parameter cpu0_hotplug. | |
2274 | ||
a71c8bc5 FY |
2275 | config DEBUG_HOTPLUG_CPU0 |
2276 | def_bool n | |
2277 | prompt "Debug CPU0 hotplug" | |
2c922cd0 | 2278 | depends on HOTPLUG_CPU |
a71c8bc5 FY |
2279 | ---help--- |
2280 | Enabling this option offlines CPU0 (if CPU0 can be offlined) as | |
2281 | soon as possible and boots up userspace with CPU0 offlined. User | |
2282 | can online CPU0 back after boot time. | |
2283 | ||
2284 | To debug CPU0 hotplug, you need to enable CPU0 offline/online | |
2285 | feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during | |
2286 | compilation or giving cpu0_hotplug kernel parameter at boot. | |
2287 | ||
2288 | If unsure, say N. | |
2289 | ||
506f1d07 | 2290 | config COMPAT_VDSO |
b0b49f26 AL |
2291 | def_bool n |
2292 | prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)" | |
953fee1d | 2293 | depends on COMPAT_32 |
8f9ca475 | 2294 | ---help--- |
b0b49f26 AL |
2295 | Certain buggy versions of glibc will crash if they are |
2296 | presented with a 32-bit vDSO that is not mapped at the address | |
2297 | indicated in its segment table. | |
e84446de | 2298 | |
b0b49f26 AL |
2299 | The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a |
2300 | and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and | |
2301 | 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is | |
2302 | the only released version with the bug, but OpenSUSE 9 | |
2303 | contains a buggy "glibc 2.3.2". | |
506f1d07 | 2304 | |
b0b49f26 AL |
2305 | The symptom of the bug is that everything crashes on startup, saying: |
2306 | dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed! | |
2307 | ||
2308 | Saying Y here changes the default value of the vdso32 boot | |
2309 | option from 1 to 0, which turns off the 32-bit vDSO entirely. | |
2310 | This works around the glibc bug but hurts performance. | |
2311 | ||
2312 | If unsure, say N: if you are compiling your own kernel, you | |
2313 | are unlikely to be using a buggy version of glibc. | |
506f1d07 | 2314 | |
3dc33bd3 KC |
2315 | choice |
2316 | prompt "vsyscall table for legacy applications" | |
2317 | depends on X86_64 | |
625b7b7f | 2318 | default LEGACY_VSYSCALL_XONLY |
3dc33bd3 KC |
2319 | help |
2320 | Legacy user code that does not know how to find the vDSO expects | |
2321 | to be able to issue three syscalls by calling fixed addresses in | |
2322 | kernel space. Since this location is not randomized with ASLR, | |
2323 | it can be used to assist security vulnerability exploitation. | |
2324 | ||
2325 | This setting can be changed at boot time via the kernel command | |
bd49e16e | 2326 | line parameter vsyscall=[emulate|xonly|none]. |
3dc33bd3 KC |
2327 | |
2328 | On a system with recent enough glibc (2.14 or newer) and no | |
2329 | static binaries, you can say None without a performance penalty | |
2330 | to improve security. | |
2331 | ||
bd49e16e | 2332 | If unsure, select "Emulate execution only". |
3dc33bd3 | 2333 | |
3dc33bd3 | 2334 | config LEGACY_VSYSCALL_EMULATE |
bd49e16e | 2335 | bool "Full emulation" |
3dc33bd3 | 2336 | help |
bd49e16e AL |
2337 | The kernel traps and emulates calls into the fixed vsyscall |
2338 | address mapping. This makes the mapping non-executable, but | |
2339 | it still contains readable known contents, which could be | |
2340 | used in certain rare security vulnerability exploits. This | |
2341 | configuration is recommended when using legacy userspace | |
2342 | that still uses vsyscalls along with legacy binary | |
2343 | instrumentation tools that require code to be readable. | |
2344 | ||
2345 | An example of this type of legacy userspace is running | |
2346 | Pin on an old binary that still uses vsyscalls. | |
2347 | ||
2348 | config LEGACY_VSYSCALL_XONLY | |
2349 | bool "Emulate execution only" | |
2350 | help | |
2351 | The kernel traps and emulates calls into the fixed vsyscall | |
2352 | address mapping and does not allow reads. This | |
2353 | configuration is recommended when userspace might use the | |
2354 | legacy vsyscall area but support for legacy binary | |
2355 | instrumentation of legacy code is not needed. It mitigates | |
2356 | certain uses of the vsyscall area as an ASLR-bypassing | |
2357 | buffer. | |
3dc33bd3 KC |
2358 | |
2359 | config LEGACY_VSYSCALL_NONE | |
2360 | bool "None" | |
2361 | help | |
2362 | There will be no vsyscall mapping at all. This will | |
2363 | eliminate any risk of ASLR bypass due to the vsyscall | |
2364 | fixed address mapping. Attempts to use the vsyscalls | |
2365 | will be reported to dmesg, so that either old or | |
2366 | malicious userspace programs can be identified. | |
2367 | ||
2368 | endchoice | |
2369 | ||
516cbf37 TB |
2370 | config CMDLINE_BOOL |
2371 | bool "Built-in kernel command line" | |
8f9ca475 | 2372 | ---help--- |
516cbf37 TB |
2373 | Allow for specifying boot arguments to the kernel at |
2374 | build time. On some systems (e.g. embedded ones), it is | |
2375 | necessary or convenient to provide some or all of the | |
2376 | kernel boot arguments with the kernel itself (that is, | |
2377 | to not rely on the boot loader to provide them.) | |
2378 | ||
2379 | To compile command line arguments into the kernel, | |
2380 | set this option to 'Y', then fill in the | |
69711ca1 | 2381 | boot arguments in CONFIG_CMDLINE. |
516cbf37 TB |
2382 | |
2383 | Systems with fully functional boot loaders (i.e. non-embedded) | |
2384 | should leave this option set to 'N'. | |
2385 | ||
2386 | config CMDLINE | |
2387 | string "Built-in kernel command string" | |
2388 | depends on CMDLINE_BOOL | |
2389 | default "" | |
8f9ca475 | 2390 | ---help--- |
516cbf37 TB |
2391 | Enter arguments here that should be compiled into the kernel |
2392 | image and used at boot time. If the boot loader provides a | |
2393 | command line at boot time, it is appended to this string to | |
2394 | form the full kernel command line, when the system boots. | |
2395 | ||
2396 | However, you can use the CONFIG_CMDLINE_OVERRIDE option to | |
2397 | change this behavior. | |
2398 | ||
2399 | In most cases, the command line (whether built-in or provided | |
2400 | by the boot loader) should specify the device for the root | |
2401 | file system. | |
2402 | ||
2403 | config CMDLINE_OVERRIDE | |
2404 | bool "Built-in command line overrides boot loader arguments" | |
645e6466 | 2405 | depends on CMDLINE_BOOL && CMDLINE != "" |
8f9ca475 | 2406 | ---help--- |
516cbf37 TB |
2407 | Set this option to 'Y' to have the kernel ignore the boot loader |
2408 | command line, and use ONLY the built-in command line. | |
2409 | ||
2410 | This is used to work around broken boot loaders. This should | |
2411 | be set to 'N' under normal conditions. | |
2412 | ||
a5b9e5a2 AL |
2413 | config MODIFY_LDT_SYSCALL |
2414 | bool "Enable the LDT (local descriptor table)" if EXPERT | |
2415 | default y | |
2416 | ---help--- | |
2417 | Linux can allow user programs to install a per-process x86 | |
2418 | Local Descriptor Table (LDT) using the modify_ldt(2) system | |
2419 | call. This is required to run 16-bit or segmented code such as | |
2420 | DOSEMU or some Wine programs. It is also used by some very old | |
2421 | threading libraries. | |
2422 | ||
2423 | Enabling this feature adds a small amount of overhead to | |
2424 | context switches and increases the low-level kernel attack | |
2425 | surface. Disabling it removes the modify_ldt(2) system call. | |
2426 | ||
2427 | Saying 'N' here may make sense for embedded or server kernels. | |
2428 | ||
b700e7f0 SJ |
2429 | source "kernel/livepatch/Kconfig" |
2430 | ||
506f1d07 SR |
2431 | endmenu |
2432 | ||
3072e413 MH |
2433 | config ARCH_HAS_ADD_PAGES |
2434 | def_bool y | |
2435 | depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG | |
2436 | ||
506f1d07 SR |
2437 | config ARCH_ENABLE_MEMORY_HOTPLUG |
2438 | def_bool y | |
2439 | depends on X86_64 || (X86_32 && HIGHMEM) | |
2440 | ||
35551053 GH |
2441 | config ARCH_ENABLE_MEMORY_HOTREMOVE |
2442 | def_bool y | |
2443 | depends on MEMORY_HOTPLUG | |
2444 | ||
e534c7c5 | 2445 | config USE_PERCPU_NUMA_NODE_ID |
645a7919 | 2446 | def_bool y |
e534c7c5 LS |
2447 | depends on NUMA |
2448 | ||
9491846f KS |
2449 | config ARCH_ENABLE_SPLIT_PMD_PTLOCK |
2450 | def_bool y | |
2451 | depends on X86_64 || X86_PAE | |
2452 | ||
c177c81e NH |
2453 | config ARCH_ENABLE_HUGEPAGE_MIGRATION |
2454 | def_bool y | |
2455 | depends on X86_64 && HUGETLB_PAGE && MIGRATION | |
2456 | ||
9c670ea3 NH |
2457 | config ARCH_ENABLE_THP_MIGRATION |
2458 | def_bool y | |
2459 | depends on X86_64 && TRANSPARENT_HUGEPAGE | |
2460 | ||
da85f865 | 2461 | menu "Power management and ACPI options" |
e279b6c1 SR |
2462 | |
2463 | config ARCH_HIBERNATION_HEADER | |
3c2362e6 | 2464 | def_bool y |
44556530 | 2465 | depends on HIBERNATION |
e279b6c1 SR |
2466 | |
2467 | source "kernel/power/Kconfig" | |
2468 | ||
2469 | source "drivers/acpi/Kconfig" | |
2470 | ||
efafc8b2 FT |
2471 | source "drivers/sfi/Kconfig" |
2472 | ||
a6b68076 | 2473 | config X86_APM_BOOT |
6fc108a0 | 2474 | def_bool y |
282e5aab | 2475 | depends on APM |
a6b68076 | 2476 | |
e279b6c1 SR |
2477 | menuconfig APM |
2478 | tristate "APM (Advanced Power Management) BIOS support" | |
efefa6f6 | 2479 | depends on X86_32 && PM_SLEEP |
e279b6c1 SR |
2480 | ---help--- |
2481 | APM is a BIOS specification for saving power using several different | |
2482 | techniques. This is mostly useful for battery powered laptops with | |
2483 | APM compliant BIOSes. If you say Y here, the system time will be | |
2484 | reset after a RESUME operation, the /proc/apm device will provide | |
2485 | battery status information, and user-space programs will receive | |
2486 | notification of APM "events" (e.g. battery status change). | |
2487 | ||
2488 | If you select "Y" here, you can disable actual use of the APM | |
2489 | BIOS by passing the "apm=off" option to the kernel at boot time. | |
2490 | ||
2491 | Note that the APM support is almost completely disabled for | |
2492 | machines with more than one CPU. | |
2493 | ||
2494 | In order to use APM, you will need supporting software. For location | |
151f4e2b | 2495 | and more information, read <file:Documentation/power/apm-acpi.rst> |
2dc98fd3 | 2496 | and the Battery Powered Linux mini-HOWTO, available from |
e279b6c1 SR |
2497 | <http://www.tldp.org/docs.html#howto>. |
2498 | ||
2499 | This driver does not spin down disk drives (see the hdparm(8) | |
2500 | manpage ("man 8 hdparm") for that), and it doesn't turn off | |
2501 | VESA-compliant "green" monitors. | |
2502 | ||
2503 | This driver does not support the TI 4000M TravelMate and the ACER | |
2504 | 486/DX4/75 because they don't have compliant BIOSes. Many "green" | |
2505 | desktop machines also don't have compliant BIOSes, and this driver | |
2506 | may cause those machines to panic during the boot phase. | |
2507 | ||
2508 | Generally, if you don't have a battery in your machine, there isn't | |
2509 | much point in using this driver and you should say N. If you get | |
2510 | random kernel OOPSes or reboots that don't seem to be related to | |
2511 | anything, try disabling/enabling this option (or disabling/enabling | |
2512 | APM in your BIOS). | |
2513 | ||
2514 | Some other things you should try when experiencing seemingly random, | |
2515 | "weird" problems: | |
2516 | ||
2517 | 1) make sure that you have enough swap space and that it is | |
2518 | enabled. | |
2519 | 2) pass the "no-hlt" option to the kernel | |
2520 | 3) switch on floating point emulation in the kernel and pass | |
2521 | the "no387" option to the kernel | |
2522 | 4) pass the "floppy=nodma" option to the kernel | |
2523 | 5) pass the "mem=4M" option to the kernel (thereby disabling | |
2524 | all but the first 4 MB of RAM) | |
2525 | 6) make sure that the CPU is not over clocked. | |
2526 | 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/> | |
2527 | 8) disable the cache from your BIOS settings | |
2528 | 9) install a fan for the video card or exchange video RAM | |
2529 | 10) install a better fan for the CPU | |
2530 | 11) exchange RAM chips | |
2531 | 12) exchange the motherboard. | |
2532 | ||
2533 | To compile this driver as a module, choose M here: the | |
2534 | module will be called apm. | |
2535 | ||
2536 | if APM | |
2537 | ||
2538 | config APM_IGNORE_USER_SUSPEND | |
2539 | bool "Ignore USER SUSPEND" | |
8f9ca475 | 2540 | ---help--- |
e279b6c1 SR |
2541 | This option will ignore USER SUSPEND requests. On machines with a |
2542 | compliant APM BIOS, you want to say N. However, on the NEC Versa M | |
2543 | series notebooks, it is necessary to say Y because of a BIOS bug. | |
2544 | ||
2545 | config APM_DO_ENABLE | |
2546 | bool "Enable PM at boot time" | |
2547 | ---help--- | |
2548 | Enable APM features at boot time. From page 36 of the APM BIOS | |
2549 | specification: "When disabled, the APM BIOS does not automatically | |
2550 | power manage devices, enter the Standby State, enter the Suspend | |
2551 | State, or take power saving steps in response to CPU Idle calls." | |
2552 | This driver will make CPU Idle calls when Linux is idle (unless this | |
2553 | feature is turned off -- see "Do CPU IDLE calls", below). This | |
2554 | should always save battery power, but more complicated APM features | |
2555 | will be dependent on your BIOS implementation. You may need to turn | |
2556 | this option off if your computer hangs at boot time when using APM | |
2557 | support, or if it beeps continuously instead of suspending. Turn | |
2558 | this off if you have a NEC UltraLite Versa 33/C or a Toshiba | |
2559 | T400CDT. This is off by default since most machines do fine without | |
2560 | this feature. | |
2561 | ||
2562 | config APM_CPU_IDLE | |
dd8af076 | 2563 | depends on CPU_IDLE |
e279b6c1 | 2564 | bool "Make CPU Idle calls when idle" |
8f9ca475 | 2565 | ---help--- |
e279b6c1 SR |
2566 | Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop. |
2567 | On some machines, this can activate improved power savings, such as | |
2568 | a slowed CPU clock rate, when the machine is idle. These idle calls | |
2569 | are made after the idle loop has run for some length of time (e.g., | |
2570 | 333 mS). On some machines, this will cause a hang at boot time or | |
2571 | whenever the CPU becomes idle. (On machines with more than one CPU, | |
2572 | this option does nothing.) | |
2573 | ||
2574 | config APM_DISPLAY_BLANK | |
2575 | bool "Enable console blanking using APM" | |
8f9ca475 | 2576 | ---help--- |
e279b6c1 SR |
2577 | Enable console blanking using the APM. Some laptops can use this to |
2578 | turn off the LCD backlight when the screen blanker of the Linux | |
2579 | virtual console blanks the screen. Note that this is only used by | |
2580 | the virtual console screen blanker, and won't turn off the backlight | |
2581 | when using the X Window system. This also doesn't have anything to | |
2582 | do with your VESA-compliant power-saving monitor. Further, this | |
2583 | option doesn't work for all laptops -- it might not turn off your | |
2584 | backlight at all, or it might print a lot of errors to the console, | |
2585 | especially if you are using gpm. | |
2586 | ||
2587 | config APM_ALLOW_INTS | |
2588 | bool "Allow interrupts during APM BIOS calls" | |
8f9ca475 | 2589 | ---help--- |
e279b6c1 SR |
2590 | Normally we disable external interrupts while we are making calls to |
2591 | the APM BIOS as a measure to lessen the effects of a badly behaving | |
2592 | BIOS implementation. The BIOS should reenable interrupts if it | |
2593 | needs to. Unfortunately, some BIOSes do not -- especially those in | |
2594 | many of the newer IBM Thinkpads. If you experience hangs when you | |
2595 | suspend, try setting this to Y. Otherwise, say N. | |
2596 | ||
e279b6c1 SR |
2597 | endif # APM |
2598 | ||
bb0a56ec | 2599 | source "drivers/cpufreq/Kconfig" |
e279b6c1 SR |
2600 | |
2601 | source "drivers/cpuidle/Kconfig" | |
2602 | ||
27471fdb AH |
2603 | source "drivers/idle/Kconfig" |
2604 | ||
e279b6c1 SR |
2605 | endmenu |
2606 | ||
2607 | ||
2608 | menu "Bus options (PCI etc.)" | |
2609 | ||
e279b6c1 SR |
2610 | choice |
2611 | prompt "PCI access mode" | |
efefa6f6 | 2612 | depends on X86_32 && PCI |
e279b6c1 SR |
2613 | default PCI_GOANY |
2614 | ---help--- | |
2615 | On PCI systems, the BIOS can be used to detect the PCI devices and | |
2616 | determine their configuration. However, some old PCI motherboards | |
2617 | have BIOS bugs and may crash if this is done. Also, some embedded | |
2618 | PCI-based systems don't have any BIOS at all. Linux can also try to | |
2619 | detect the PCI hardware directly without using the BIOS. | |
2620 | ||
2621 | With this option, you can specify how Linux should detect the | |
2622 | PCI devices. If you choose "BIOS", the BIOS will be used, | |
2623 | if you choose "Direct", the BIOS won't be used, and if you | |
2624 | choose "MMConfig", then PCI Express MMCONFIG will be used. | |
2625 | If you choose "Any", the kernel will try MMCONFIG, then the | |
2626 | direct access method and falls back to the BIOS if that doesn't | |
2627 | work. If unsure, go with the default, which is "Any". | |
2628 | ||
2629 | config PCI_GOBIOS | |
2630 | bool "BIOS" | |
2631 | ||
2632 | config PCI_GOMMCONFIG | |
2633 | bool "MMConfig" | |
2634 | ||
2635 | config PCI_GODIRECT | |
2636 | bool "Direct" | |
2637 | ||
3ef0e1f8 | 2638 | config PCI_GOOLPC |
76fb6570 | 2639 | bool "OLPC XO-1" |
3ef0e1f8 AS |
2640 | depends on OLPC |
2641 | ||
2bdd1b03 AS |
2642 | config PCI_GOANY |
2643 | bool "Any" | |
2644 | ||
e279b6c1 SR |
2645 | endchoice |
2646 | ||
2647 | config PCI_BIOS | |
3c2362e6 | 2648 | def_bool y |
efefa6f6 | 2649 | depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY) |
e279b6c1 SR |
2650 | |
2651 | # x86-64 doesn't support PCI BIOS access from long mode so always go direct. | |
2652 | config PCI_DIRECT | |
3c2362e6 | 2653 | def_bool y |
0aba496f | 2654 | depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG)) |
e279b6c1 SR |
2655 | |
2656 | config PCI_MMCONFIG | |
b45c9f36 JK |
2657 | bool "Support mmconfig PCI config space access" if X86_64 |
2658 | default y | |
8364e1f8 | 2659 | depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST) |
b45c9f36 | 2660 | depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG) |
e279b6c1 | 2661 | |
3ef0e1f8 | 2662 | config PCI_OLPC |
2bdd1b03 AS |
2663 | def_bool y |
2664 | depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY) | |
3ef0e1f8 | 2665 | |
b5401a96 AN |
2666 | config PCI_XEN |
2667 | def_bool y | |
2668 | depends on PCI && XEN | |
2669 | select SWIOTLB_XEN | |
2670 | ||
8364e1f8 JK |
2671 | config MMCONF_FAM10H |
2672 | def_bool y | |
2673 | depends on X86_64 && PCI_MMCONFIG && ACPI | |
e279b6c1 | 2674 | |
3f6ea84a | 2675 | config PCI_CNB20LE_QUIRK |
6a108a14 | 2676 | bool "Read CNB20LE Host Bridge Windows" if EXPERT |
6ea30386 | 2677 | depends on PCI |
3f6ea84a IS |
2678 | help |
2679 | Read the PCI windows out of the CNB20LE host bridge. This allows | |
2680 | PCI hotplug to work on systems with the CNB20LE chipset which do | |
2681 | not have ACPI. | |
2682 | ||
64a5fed6 BH |
2683 | There's no public spec for this chipset, and this functionality |
2684 | is known to be incomplete. | |
2685 | ||
2686 | You should say N unless you know you need this. | |
2687 | ||
3a495511 | 2688 | config ISA_BUS |
17a2a129 | 2689 | bool "ISA bus support on modern systems" if EXPERT |
3a495511 | 2690 | help |
17a2a129 WBG |
2691 | Expose ISA bus device drivers and options available for selection and |
2692 | configuration. Enable this option if your target machine has an ISA | |
2693 | bus. ISA is an older system, displaced by PCI and newer bus | |
2694 | architectures -- if your target machine is modern, it probably does | |
2695 | not have an ISA bus. | |
3a495511 WBG |
2696 | |
2697 | If unsure, say N. | |
2698 | ||
1c00f016 | 2699 | # x86_64 have no ISA slots, but can have ISA-style DMA. |
e279b6c1 | 2700 | config ISA_DMA_API |
1c00f016 DR |
2701 | bool "ISA-style DMA support" if (X86_64 && EXPERT) |
2702 | default y | |
2703 | help | |
2704 | Enables ISA-style DMA support for devices requiring such controllers. | |
2705 | If unsure, say Y. | |
e279b6c1 | 2706 | |
51e68d05 LT |
2707 | if X86_32 |
2708 | ||
e279b6c1 SR |
2709 | config ISA |
2710 | bool "ISA support" | |
8f9ca475 | 2711 | ---help--- |
e279b6c1 SR |
2712 | Find out whether you have ISA slots on your motherboard. ISA is the |
2713 | name of a bus system, i.e. the way the CPU talks to the other stuff | |
2714 | inside your box. Other bus systems are PCI, EISA, MicroChannel | |
2715 | (MCA) or VESA. ISA is an older system, now being displaced by PCI; | |
2716 | newer boards don't support it. If you have ISA, say Y, otherwise N. | |
2717 | ||
e279b6c1 SR |
2718 | config SCx200 |
2719 | tristate "NatSemi SCx200 support" | |
8f9ca475 | 2720 | ---help--- |
e279b6c1 SR |
2721 | This provides basic support for National Semiconductor's |
2722 | (now AMD's) Geode processors. The driver probes for the | |
2723 | PCI-IDs of several on-chip devices, so its a good dependency | |
2724 | for other scx200_* drivers. | |
2725 | ||
2726 | If compiled as a module, the driver is named scx200. | |
2727 | ||
2728 | config SCx200HR_TIMER | |
2729 | tristate "NatSemi SCx200 27MHz High-Resolution Timer Support" | |
592913ec | 2730 | depends on SCx200 |
e279b6c1 | 2731 | default y |
8f9ca475 | 2732 | ---help--- |
e279b6c1 SR |
2733 | This driver provides a clocksource built upon the on-chip |
2734 | 27MHz high-resolution timer. Its also a workaround for | |
2735 | NSC Geode SC-1100's buggy TSC, which loses time when the | |
2736 | processor goes idle (as is done by the scheduler). The | |
2737 | other workaround is idle=poll boot option. | |
2738 | ||
3ef0e1f8 AS |
2739 | config OLPC |
2740 | bool "One Laptop Per Child support" | |
54008979 | 2741 | depends on !X86_PAE |
3c554946 | 2742 | select GPIOLIB |
dc3119e7 | 2743 | select OF |
45bb1674 | 2744 | select OF_PROMTREE |
b4e51854 | 2745 | select IRQ_DOMAIN |
0c3d931b | 2746 | select OLPC_EC |
8f9ca475 | 2747 | ---help--- |
3ef0e1f8 AS |
2748 | Add support for detecting the unique features of the OLPC |
2749 | XO hardware. | |
2750 | ||
a3128588 DD |
2751 | config OLPC_XO1_PM |
2752 | bool "OLPC XO-1 Power Management" | |
fa112cf1 | 2753 | depends on OLPC && MFD_CS5535=y && PM_SLEEP |
bf1ebf00 | 2754 | ---help--- |
97c4cb71 | 2755 | Add support for poweroff and suspend of the OLPC XO-1 laptop. |
bf1ebf00 | 2756 | |
cfee9597 DD |
2757 | config OLPC_XO1_RTC |
2758 | bool "OLPC XO-1 Real Time Clock" | |
2759 | depends on OLPC_XO1_PM && RTC_DRV_CMOS | |
2760 | ---help--- | |
2761 | Add support for the XO-1 real time clock, which can be used as a | |
2762 | programmable wakeup source. | |
2763 | ||
7feda8e9 DD |
2764 | config OLPC_XO1_SCI |
2765 | bool "OLPC XO-1 SCI extras" | |
92e830f2 | 2766 | depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y |
ed8e47fe | 2767 | depends on INPUT=y |
d8d01a63 | 2768 | select POWER_SUPPLY |
7feda8e9 DD |
2769 | ---help--- |
2770 | Add support for SCI-based features of the OLPC XO-1 laptop: | |
7bc74b3d | 2771 | - EC-driven system wakeups |
7feda8e9 | 2772 | - Power button |
7bc74b3d | 2773 | - Ebook switch |
2cf2baea | 2774 | - Lid switch |
e1040ac6 DD |
2775 | - AC adapter status updates |
2776 | - Battery status updates | |
7feda8e9 | 2777 | |
a0f30f59 DD |
2778 | config OLPC_XO15_SCI |
2779 | bool "OLPC XO-1.5 SCI extras" | |
d8d01a63 DD |
2780 | depends on OLPC && ACPI |
2781 | select POWER_SUPPLY | |
a0f30f59 DD |
2782 | ---help--- |
2783 | Add support for SCI-based features of the OLPC XO-1.5 laptop: | |
2784 | - EC-driven system wakeups | |
2785 | - AC adapter status updates | |
2786 | - Battery status updates | |
bf1ebf00 | 2787 | |
d4f3e350 EW |
2788 | config ALIX |
2789 | bool "PCEngines ALIX System Support (LED setup)" | |
2790 | select GPIOLIB | |
2791 | ---help--- | |
2792 | This option enables system support for the PCEngines ALIX. | |
2793 | At present this just sets up LEDs for GPIO control on | |
2794 | ALIX2/3/6 boards. However, other system specific setup should | |
2795 | get added here. | |
2796 | ||
2797 | Note: You must still enable the drivers for GPIO and LED support | |
2798 | (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs | |
2799 | ||
2800 | Note: You have to set alix.force=1 for boards with Award BIOS. | |
2801 | ||
da4e3302 PP |
2802 | config NET5501 |
2803 | bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)" | |
2804 | select GPIOLIB | |
2805 | ---help--- | |
2806 | This option enables system support for the Soekris Engineering net5501. | |
2807 | ||
3197059a PP |
2808 | config GEOS |
2809 | bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)" | |
2810 | select GPIOLIB | |
2811 | depends on DMI | |
2812 | ---help--- | |
2813 | This option enables system support for the Traverse Technologies GEOS. | |
2814 | ||
7d029125 VD |
2815 | config TS5500 |
2816 | bool "Technologic Systems TS-5500 platform support" | |
2817 | depends on MELAN | |
2818 | select CHECK_SIGNATURE | |
2819 | select NEW_LEDS | |
2820 | select LEDS_CLASS | |
2821 | ---help--- | |
2822 | This option enables system support for the Technologic Systems TS-5500. | |
2823 | ||
bc0120fd SR |
2824 | endif # X86_32 |
2825 | ||
23ac4ae8 | 2826 | config AMD_NB |
e279b6c1 | 2827 | def_bool y |
0e152cd7 | 2828 | depends on CPU_SUP_AMD && PCI |
e279b6c1 | 2829 | |
e3263ab3 DH |
2830 | config X86_SYSFB |
2831 | bool "Mark VGA/VBE/EFI FB as generic system framebuffer" | |
2832 | help | |
2833 | Firmwares often provide initial graphics framebuffers so the BIOS, | |
2834 | bootloader or kernel can show basic video-output during boot for | |
2835 | user-guidance and debugging. Historically, x86 used the VESA BIOS | |
2836 | Extensions and EFI-framebuffers for this, which are mostly limited | |
2837 | to x86. | |
2838 | This option, if enabled, marks VGA/VBE/EFI framebuffers as generic | |
2839 | framebuffers so the new generic system-framebuffer drivers can be | |
2840 | used on x86. If the framebuffer is not compatible with the generic | |
e3a5dc08 | 2841 | modes, it is advertised as fallback platform framebuffer so legacy |
e3263ab3 DH |
2842 | drivers like efifb, vesafb and uvesafb can pick it up. |
2843 | If this option is not selected, all system framebuffers are always | |
2844 | marked as fallback platform framebuffers as usual. | |
2845 | ||
2846 | Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will | |
2847 | not be able to pick up generic system framebuffers if this option | |
2848 | is selected. You are highly encouraged to enable simplefb as | |
2849 | replacement if you select this option. simplefb can correctly deal | |
2850 | with generic system framebuffers. But you should still keep vesafb | |
2851 | and others enabled as fallback if a system framebuffer is | |
2852 | incompatible with simplefb. | |
2853 | ||
2854 | If unsure, say Y. | |
2855 | ||
e279b6c1 SR |
2856 | endmenu |
2857 | ||
2858 | ||
1572497c | 2859 | menu "Binary Emulations" |
e279b6c1 SR |
2860 | |
2861 | config IA32_EMULATION | |
2862 | bool "IA32 Emulation" | |
2863 | depends on X86_64 | |
39f88911 | 2864 | select ARCH_WANT_OLD_COMPAT_IPC |
d1603990 | 2865 | select BINFMT_ELF |
a97f52e6 | 2866 | select COMPAT_BINFMT_ELF |
39f88911 | 2867 | select COMPAT_OLD_SIGACTION |
8f9ca475 | 2868 | ---help--- |
5fd92e65 L |
2869 | Include code to run legacy 32-bit programs under a |
2870 | 64-bit kernel. You should likely turn this on, unless you're | |
2871 | 100% sure that you don't have any 32-bit programs left. | |
e279b6c1 SR |
2872 | |
2873 | config IA32_AOUT | |
8f9ca475 IM |
2874 | tristate "IA32 a.out support" |
2875 | depends on IA32_EMULATION | |
eac61655 | 2876 | depends on BROKEN |
8f9ca475 IM |
2877 | ---help--- |
2878 | Support old a.out binaries in the 32bit emulation. | |
e279b6c1 | 2879 | |
0bf62763 | 2880 | config X86_X32 |
6ea30386 | 2881 | bool "x32 ABI for 64-bit mode" |
9b54050b | 2882 | depends on X86_64 |
5fd92e65 L |
2883 | ---help--- |
2884 | Include code to run binaries for the x32 native 32-bit ABI | |
2885 | for 64-bit processors. An x32 process gets access to the | |
2886 | full 64-bit register file and wide data path while leaving | |
2887 | pointers at 32 bits for smaller memory footprint. | |
2888 | ||
2889 | You will need a recent binutils (2.22 or later) with | |
2890 | elf32_x86_64 support enabled to compile a kernel with this | |
2891 | option set. | |
2892 | ||
953fee1d IM |
2893 | config COMPAT_32 |
2894 | def_bool y | |
2895 | depends on IA32_EMULATION || X86_32 | |
2896 | select HAVE_UID16 | |
2897 | select OLD_SIGSUSPEND3 | |
2898 | ||
e279b6c1 | 2899 | config COMPAT |
3c2362e6 | 2900 | def_bool y |
0bf62763 | 2901 | depends on IA32_EMULATION || X86_X32 |
e279b6c1 | 2902 | |
3120e25e | 2903 | if COMPAT |
e279b6c1 | 2904 | config COMPAT_FOR_U64_ALIGNMENT |
3120e25e | 2905 | def_bool y |
e279b6c1 SR |
2906 | |
2907 | config SYSVIPC_COMPAT | |
3c2362e6 | 2908 | def_bool y |
3120e25e | 2909 | depends on SYSVIPC |
3120e25e | 2910 | endif |
ee009e4a | 2911 | |
e279b6c1 SR |
2912 | endmenu |
2913 | ||
2914 | ||
e5beae16 KP |
2915 | config HAVE_ATOMIC_IOMAP |
2916 | def_bool y | |
2917 | depends on X86_32 | |
2918 | ||
e279b6c1 SR |
2919 | source "drivers/firmware/Kconfig" |
2920 | ||
edf88417 | 2921 | source "arch/x86/kvm/Kconfig" |
5e8ebd84 JD |
2922 | |
2923 | source "arch/x86/Kconfig.assembler" |