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b2441318 1# SPDX-License-Identifier: GPL-2.0
daa93fab
SR
2# Select 32 or 64 bit
3config 64BIT
6840999b 4 bool "64-bit kernel" if ARCH = "x86"
ffee0de4 5 default ARCH != "i386"
8f9ca475 6 ---help---
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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
10config X86_32
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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
17 select HAVE_AOUT
18 select HAVE_GENERIC_DMA_COHERENT
19 select MODULES_USE_ELF_REL
20 select OLD_SIGACTION
daa93fab
SR
21
22config X86_64
3120e25e
JB
23 def_bool y
24 depends on 64BIT
d94e0685 25 # Options that are inherently 64-bit kernel only:
e1073d1e 26 select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA
d94e0685
IM
27 select ARCH_SUPPORTS_INT128
28 select ARCH_USE_CMPXCHG_LOCKREF
29 select HAVE_ARCH_SOFT_DIRTY
30 select MODULES_USE_ELF_RELA
31 select X86_DEV_DMA_OPS
1032c0ba 32
d94e0685
IM
33#
34# Arch settings
35#
36# ( Note that options that are marked 'if X86_64' could in principle be
37# ported to 32-bit as well. )
38#
8d5fffb9 39config X86
3c2362e6 40 def_bool y
c763ea26
IM
41 #
42 # Note: keep this list sorted alphabetically
43 #
6471b825
IM
44 select ACPI_LEGACY_TABLES_LOOKUP if ACPI
45 select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI
46 select ANON_INODES
47 select ARCH_CLOCKSOURCE_DATA
48 select ARCH_DISCARD_MEMBLOCK
c763ea26 49 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
fa5b6ec9 50 select ARCH_HAS_DEBUG_VIRTUAL
21266be9 51 select ARCH_HAS_DEVMEM_IS_ALLOWED
6471b825 52 select ARCH_HAS_ELF_RANDOMIZE
72d93104 53 select ARCH_HAS_FAST_MULTIPLIER
59cf57f4 54 select ARCH_HAS_FILTER_PGPROT
6974f0c4 55 select ARCH_HAS_FORTIFY_SOURCE
957e3fac 56 select ARCH_HAS_GCOV_PROFILE_ALL
5c9a8750 57 select ARCH_HAS_KCOV if X86_64
c763ea26 58 select ARCH_HAS_PMEM_API if X86_64
39208aa7 59 select ARCH_HAS_REFCOUNT
0aed55af 60 select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64
d2852a22 61 select ARCH_HAS_SET_MEMORY
6471b825 62 select ARCH_HAS_SG_CHAIN
ad21fc4f
LA
63 select ARCH_HAS_STRICT_KERNEL_RWX
64 select ARCH_HAS_STRICT_MODULE_RWX
c6d30853 65 select ARCH_HAS_UBSAN_SANITIZE_ALL
65f7d049 66 select ARCH_HAS_ZONE_DEVICE if X86_64
6471b825
IM
67 select ARCH_HAVE_NMI_SAFE_CMPXCHG
68 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
77fbbc81 69 select ARCH_MIGHT_HAVE_PC_PARPORT
5e2c18c0 70 select ARCH_MIGHT_HAVE_PC_SERIO
6471b825 71 select ARCH_SUPPORTS_ATOMIC_RMW
3b242c66 72 select ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT
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IM
73 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
74 select ARCH_USE_BUILTIN_BSWAP
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IM
75 select ARCH_USE_QUEUED_RWLOCKS
76 select ARCH_USE_QUEUED_SPINLOCKS
ce4a4e56 77 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
c763ea26 78 select ARCH_WANTS_DYNAMIC_TASK_STRUCT
38d8b4e6 79 select ARCH_WANTS_THP_SWAP if X86_64
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IM
80 select BUILDTIME_EXTABLE_SORT
81 select CLKEVT_I8253
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IM
82 select CLOCKSOURCE_VALIDATE_LAST_CYCLE
83 select CLOCKSOURCE_WATCHDOG
6471b825 84 select DCACHE_WORD_ACCESS
45471cd9
LT
85 select EDAC_ATOMIC_SCRUB
86 select EDAC_SUPPORT
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IM
87 select GENERIC_CLOCKEVENTS
88 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
89 select GENERIC_CLOCKEVENTS_MIN_ADJUST
90 select GENERIC_CMOS_UPDATE
91 select GENERIC_CPU_AUTOPROBE
61dc0f55 92 select GENERIC_CPU_VULNERABILITIES
5b7c73e0 93 select GENERIC_EARLY_IOREMAP
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IM
94 select GENERIC_FIND_FIRST_BIT
95 select GENERIC_IOMAP
c7d6c9dd 96 select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP
0fa115da 97 select GENERIC_IRQ_MATRIX_ALLOCATOR if X86_LOCAL_APIC
ad7a929f 98 select GENERIC_IRQ_MIGRATION if SMP
6471b825 99 select GENERIC_IRQ_PROBE
c201c917 100 select GENERIC_IRQ_RESERVATION_MODE
6471b825
IM
101 select GENERIC_IRQ_SHOW
102 select GENERIC_PENDING_IRQ if SMP
103 select GENERIC_SMP_IDLE_THREAD
104 select GENERIC_STRNCPY_FROM_USER
105 select GENERIC_STRNLEN_USER
106 select GENERIC_TIME_VSYSCALL
7edaeb68 107 select HARDLOCKUP_CHECK_TIMESTAMP if X86_64
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IM
108 select HAVE_ACPI_APEI if ACPI
109 select HAVE_ACPI_APEI_NMI if ACPI
110 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
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IM
111 select HAVE_ARCH_AUDITSYSCALL
112 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE
113 select HAVE_ARCH_JUMP_LABEL
d17a1d97 114 select HAVE_ARCH_KASAN if X86_64
6471b825 115 select HAVE_ARCH_KGDB
9e08f57d
DC
116 select HAVE_ARCH_MMAP_RND_BITS if MMU
117 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT
1b028f78 118 select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT
6471b825 119 select HAVE_ARCH_SECCOMP_FILTER
6471b825
IM
120 select HAVE_ARCH_TRACEHOOK
121 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
a00cc7d9 122 select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
e37e43a4 123 select HAVE_ARCH_VMAP_STACK if X86_64
c763ea26 124 select HAVE_ARCH_WITHIN_STACK_FRAMES
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IM
125 select HAVE_CC_STACKPROTECTOR
126 select HAVE_CMPXCHG_DOUBLE
127 select HAVE_CMPXCHG_LOCAL
128 select HAVE_CONTEXT_TRACKING if X86_64
c1bd55f9 129 select HAVE_COPY_THREAD_TLS
cf4db259 130 select HAVE_C_RECORDMCOUNT
6471b825
IM
131 select HAVE_DEBUG_KMEMLEAK
132 select HAVE_DEBUG_STACKOVERFLOW
133 select HAVE_DMA_API_DEBUG
6471b825 134 select HAVE_DMA_CONTIGUOUS
677aa9f7 135 select HAVE_DYNAMIC_FTRACE
06aeaaea 136 select HAVE_DYNAMIC_FTRACE_WITH_REGS
c763ea26 137 select HAVE_EBPF_JIT if X86_64
58340a07 138 select HAVE_EFFICIENT_UNALIGNED_ACCESS
5f56a5df 139 select HAVE_EXIT_THREAD
644e0e8d 140 select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE
6471b825 141 select HAVE_FTRACE_MCOUNT_RECORD
6471b825
IM
142 select HAVE_FUNCTION_GRAPH_TRACER
143 select HAVE_FUNCTION_TRACER
6b90bd4b 144 select HAVE_GCC_PLUGINS
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IM
145 select HAVE_HW_BREAKPOINT
146 select HAVE_IDE
147 select HAVE_IOREMAP_PROT
148 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
149 select HAVE_IRQ_TIME_ACCOUNTING
2e9f3bdd 150 select HAVE_KERNEL_BZIP2
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IM
151 select HAVE_KERNEL_GZIP
152 select HAVE_KERNEL_LZ4
2e9f3bdd 153 select HAVE_KERNEL_LZMA
13510997 154 select HAVE_KERNEL_LZO
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IM
155 select HAVE_KERNEL_XZ
156 select HAVE_KPROBES
157 select HAVE_KPROBES_ON_FTRACE
158 select HAVE_KRETPROBES
159 select HAVE_KVM
160 select HAVE_LIVEPATCH if X86_64
161 select HAVE_MEMBLOCK
162 select HAVE_MEMBLOCK_NODE_MAP
0102752e 163 select HAVE_MIXED_BREAKPOINTS_REGS
ee9f8fce 164 select HAVE_MOD_ARCH_SPECIFIC
42a0bb3f 165 select HAVE_NMI
6471b825
IM
166 select HAVE_OPROFILE
167 select HAVE_OPTPROBES
168 select HAVE_PCSPKR_PLATFORM
169 select HAVE_PERF_EVENTS
c01d4323 170 select HAVE_PERF_EVENTS_NMI
92e5aae4 171 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
c5e63197 172 select HAVE_PERF_REGS
c5ebcedb 173 select HAVE_PERF_USER_STACK_DUMP
9e52fc2b 174 select HAVE_RCU_TABLE_FREE
6471b825 175 select HAVE_REGS_AND_STACK_ACCESS_API
11af8474 176 select HAVE_RELIABLE_STACKTRACE if X86_64 && UNWINDER_FRAME_POINTER && STACK_VALIDATION
c763ea26 177 select HAVE_STACK_VALIDATION if X86_64
6471b825 178 select HAVE_SYSCALL_TRACEPOINTS
6471b825 179 select HAVE_UNSTABLE_SCHED_CLOCK
7c68af6e 180 select HAVE_USER_RETURN_NOTIFIER
47b4c679 181 select HOTPLUG_SMT if SMP
c0185808 182 select IRQ_FORCED_THREADING
df65c1bc 183 select PCI_LOCKLESS_CONFIG
6471b825 184 select PERF_EVENTS
3195ef59 185 select RTC_LIB
d6faca40 186 select RTC_MC146818_LIB
6471b825 187 select SPARSE_IRQ
83fe27ea 188 select SRCU
6471b825 189 select SYSCTL_EXCEPTION_TRACE
15f4eae7 190 select THREAD_INFO_IN_TASK
6471b825
IM
191 select USER_STACKTRACE_SUPPORT
192 select VIRT_TO_BUS
6471b825 193 select X86_FEATURE_NAMES if PROC_FS
7d8330a5 194
ba7e4d13 195config INSTRUCTION_DECODER
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JB
196 def_bool y
197 depends on KPROBES || PERF_EVENTS || UPROBES
ba7e4d13 198
51b26ada
LT
199config OUTPUT_FORMAT
200 string
201 default "elf32-i386" if X86_32
202 default "elf64-x86-64" if X86_64
203
73531905 204config ARCH_DEFCONFIG
b9b39bfb 205 string
73531905
SR
206 default "arch/x86/configs/i386_defconfig" if X86_32
207 default "arch/x86/configs/x86_64_defconfig" if X86_64
b9b39bfb 208
8d5fffb9 209config LOCKDEP_SUPPORT
3c2362e6 210 def_bool y
8d5fffb9
SR
211
212config STACKTRACE_SUPPORT
3c2362e6 213 def_bool y
8d5fffb9 214
8d5fffb9 215config MMU
3c2362e6 216 def_bool y
8d5fffb9 217
9e08f57d
DC
218config ARCH_MMAP_RND_BITS_MIN
219 default 28 if 64BIT
220 default 8
221
222config ARCH_MMAP_RND_BITS_MAX
223 default 32 if 64BIT
224 default 16
225
226config ARCH_MMAP_RND_COMPAT_BITS_MIN
227 default 8
228
229config ARCH_MMAP_RND_COMPAT_BITS_MAX
230 default 16
231
8d5fffb9
SR
232config SBUS
233 bool
234
3bc4e459 235config NEED_DMA_MAP_STATE
3120e25e 236 def_bool y
a6dfa128 237 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB
3bc4e459 238
18e98307 239config NEED_SG_DMA_LENGTH
4a14d84e 240 def_bool y
18e98307 241
8d5fffb9 242config GENERIC_ISA_DMA
3120e25e
JB
243 def_bool y
244 depends on ISA_DMA_API
8d5fffb9 245
8d5fffb9 246config GENERIC_BUG
3c2362e6 247 def_bool y
8d5fffb9 248 depends on BUG
b93a531e
JB
249 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
250
251config GENERIC_BUG_RELATIVE_POINTERS
252 bool
8d5fffb9
SR
253
254config GENERIC_HWEIGHT
3c2362e6 255 def_bool y
8d5fffb9
SR
256
257config ARCH_MAY_HAVE_PC_FDC
3120e25e
JB
258 def_bool y
259 depends on ISA_DMA_API
8d5fffb9 260
1032c0ba 261config RWSEM_XCHGADD_ALGORITHM
3120e25e 262 def_bool y
1032c0ba 263
1032c0ba
SR
264config GENERIC_CALIBRATE_DELAY
265 def_bool y
266
9a0b8415 267config ARCH_HAS_CPU_RELAX
268 def_bool y
269
1b27d05b
PE
270config ARCH_HAS_CACHE_LINE_SIZE
271 def_bool y
272
59cf57f4
DH
273config ARCH_HAS_FILTER_PGPROT
274 def_bool y
275
dd5af90a 276config HAVE_SETUP_PER_CPU_AREA
89c9c4c5 277 def_bool y
b32ef636 278
08fc4580
TH
279config NEED_PER_CPU_EMBED_FIRST_CHUNK
280 def_bool y
281
282config NEED_PER_CPU_PAGE_FIRST_CHUNK
11124411
TH
283 def_bool y
284
801e4062
JB
285config ARCH_HIBERNATION_POSSIBLE
286 def_bool y
801e4062 287
f4cb5700
JB
288config ARCH_SUSPEND_POSSIBLE
289 def_bool y
f4cb5700 290
cfe28c5d
SC
291config ARCH_WANT_HUGE_PMD_SHARE
292 def_bool y
293
53313b2c
SC
294config ARCH_WANT_GENERAL_HUGETLB
295 def_bool y
296
8d5fffb9 297config ZONE_DMA32
e0fd24a3 298 def_bool y if X86_64
8d5fffb9 299
8d5fffb9 300config AUDIT_ARCH
e0fd24a3 301 def_bool y if X86_64
8d5fffb9 302
765c68bd
IM
303config ARCH_SUPPORTS_OPTIMIZED_INLINING
304 def_bool y
305
6a11f75b
AM
306config ARCH_SUPPORTS_DEBUG_PAGEALLOC
307 def_bool y
308
d6f2d75a
AR
309config KASAN_SHADOW_OFFSET
310 hex
311 depends on KASAN
312 default 0xdffffc0000000000
313
69575d38
SW
314config HAVE_INTEL_TXT
315 def_bool y
6ea30386 316 depends on INTEL_IOMMU && ACPI
69575d38 317
6b0c3d44
SR
318config X86_32_SMP
319 def_bool y
320 depends on X86_32 && SMP
321
322config X86_64_SMP
323 def_bool y
324 depends on X86_64 && SMP
325
ccbeed3a
TH
326config X86_32_LAZY_GS
327 def_bool y
60a5317f 328 depends on X86_32 && !CC_STACKPROTECTOR
ccbeed3a 329
2b144498
SD
330config ARCH_SUPPORTS_UPROBES
331 def_bool y
332
d20642f0
RH
333config FIX_EARLYCON_MEM
334 def_bool y
335
98233368
KS
336config PGTABLE_LEVELS
337 int
77ef56e4 338 default 5 if X86_5LEVEL
98233368
KS
339 default 4 if X86_64
340 default 3 if X86_PAE
341 default 2
342
506f1d07 343source "init/Kconfig"
dc52ddc0 344source "kernel/Kconfig.freezer"
8d5fffb9 345
506f1d07
SR
346menu "Processor type and features"
347
5ee71535
RD
348config ZONE_DMA
349 bool "DMA memory allocation support" if EXPERT
350 default y
351 help
352 DMA memory allocation support allows devices with less than 32-bit
353 addressing to allocate within the first 16MB of address space.
354 Disable if no such devices will be used.
355
356 If unsure, say Y.
357
506f1d07
SR
358config SMP
359 bool "Symmetric multi-processing support"
360 ---help---
361 This enables support for systems with more than one CPU. If you have
4a474157
RG
362 a system with only one CPU, say N. If you have a system with more
363 than one CPU, say Y.
506f1d07 364
4a474157 365 If you say N here, the kernel will run on uni- and multiprocessor
506f1d07
SR
366 machines, but will use only one CPU of a multiprocessor machine. If
367 you say Y here, the kernel will run on many, but not all,
4a474157 368 uniprocessor machines. On a uniprocessor machine, the kernel
506f1d07
SR
369 will run faster if you say N here.
370
371 Note that if you say Y here and choose architecture "586" or
372 "Pentium" under "Processor family", the kernel will not work on 486
373 architectures. Similarly, multiprocessor kernels for the "PPro"
374 architecture may not work on all Pentium based boards.
375
376 People using multiprocessor machines who say Y here should also say
377 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
378 Management" code will be disabled if you say Y here.
379
395cf969 380 See also <file:Documentation/x86/i386/IO-APIC.txt>,
c9525a3f 381 <file:Documentation/lockup-watchdogs.txt> and the SMP-HOWTO available at
506f1d07
SR
382 <http://www.tldp.org/docs.html#howto>.
383
384 If you don't know what to do here, say N.
385
9def39be
JT
386config X86_FEATURE_NAMES
387 bool "Processor feature human-readable names" if EMBEDDED
388 default y
389 ---help---
390 This option compiles in a table of x86 feature bits and corresponding
391 names. This is required to support /proc/cpuinfo and a few kernel
392 messages. You can disable this to save space, at the expense of
393 making those few kernel messages show numeric feature bits instead.
394
395 If in doubt, say Y.
396
6e1315fe
BP
397config X86_FAST_FEATURE_TESTS
398 bool "Fast CPU feature tests" if EMBEDDED
399 default y
400 ---help---
401 Some fast-paths in the kernel depend on the capabilities of the CPU.
402 Say Y here for the kernel to patch in the appropriate code at runtime
403 based on the capabilities of the CPU. The infrastructure for patching
404 code at runtime takes up some additional space; space-constrained
405 embedded systems may wish to say N here to produce smaller, slightly
406 slower code.
407
06cd9a7d
YL
408config X86_X2APIC
409 bool "Support x2apic"
19e3d60d 410 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
06cd9a7d
YL
411 ---help---
412 This enables x2apic support on CPUs that have this feature.
413
414 This allows 32-bit apic IDs (so it can support very large systems),
415 and accesses the local apic via MSRs not via mmio.
416
06cd9a7d
YL
417 If you don't know what to do here, say N.
418
6695c85b 419config X86_MPPARSE
6e87f9b7 420 bool "Enable MPS table" if ACPI || SFI
7a527688 421 default y
5ab74722 422 depends on X86_LOCAL_APIC
8f9ca475 423 ---help---
6695c85b
YL
424 For old smp systems that do not have proper acpi support. Newer systems
425 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
6695c85b 426
26f7ef14
YL
427config X86_BIGSMP
428 bool "Support for big SMP systems with more than 8 CPUs"
429 depends on X86_32 && SMP
8f9ca475 430 ---help---
26f7ef14 431 This option is needed for the systems that have more than 8 CPUs
506f1d07 432
ddd70cf9
JN
433config GOLDFISH
434 def_bool y
435 depends on X86_GOLDFISH
436
76b04384
DW
437config RETPOLINE
438 bool "Avoid speculative indirect branches in kernel"
439 default y
f1ef2f11 440 select STACK_VALIDATION if HAVE_STACK_VALIDATION
76b04384
DW
441 help
442 Compile kernel with the retpoline compiler options to guard against
443 kernel-to-user data leaks by avoiding speculative indirect
444 branches. Requires a compiler with -mindirect-branch=thunk-extern
445 support for full protection. The kernel may run slower.
446
447 Without compiler support, at least indirect branches in assembler
448 code are eliminated. Since this includes the syscall entry path,
449 it is not entirely pointless.
450
f01d7d51
VS
451config INTEL_RDT
452 bool "Intel Resource Director Technology support"
78e99b4a
FY
453 default n
454 depends on X86 && CPU_SUP_INTEL
59fe5a77 455 select KERNFS
78e99b4a 456 help
f01d7d51
VS
457 Select to enable resource allocation and monitoring which are
458 sub-features of Intel Resource Director Technology(RDT). More
459 information about RDT can be found in the Intel x86
460 Architecture Software Developer Manual.
78e99b4a
FY
461
462 Say N if unsure.
463
8425091f 464if X86_32
c5c606d9
RT
465config X86_EXTENDED_PLATFORM
466 bool "Support for extended (non-PC) x86 platforms"
467 default y
8f9ca475 468 ---help---
06ac8346
IM
469 If you disable this option then the kernel will only support
470 standard PC platforms. (which covers the vast majority of
471 systems out there.)
472
8425091f
RT
473 If you enable this option then you'll be able to select support
474 for the following (non-PC) 32 bit x86 platforms:
cb7b8023 475 Goldfish (Android emulator)
8425091f 476 AMD Elan
8425091f
RT
477 RDC R-321x SoC
478 SGI 320/540 (Visual Workstation)
83125a3a 479 STA2X11-based (e.g. Northville)
3f4110a4 480 Moorestown MID devices
06ac8346
IM
481
482 If you have one of these systems, or if you want to build a
483 generic distribution kernel, say Y here - otherwise say N.
8425091f 484endif
06ac8346 485
8425091f
RT
486if X86_64
487config X86_EXTENDED_PLATFORM
488 bool "Support for extended (non-PC) x86 platforms"
489 default y
490 ---help---
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
495 If you enable this option then you'll be able to select support
496 for the following (non-PC) 64 bit x86 platforms:
44b111b5 497 Numascale NumaChip
8425091f
RT
498 ScaleMP vSMP
499 SGI Ultraviolet
500
501 If you have one of these systems, or if you want to build a
502 generic distribution kernel, say Y here - otherwise say N.
503endif
c5c606d9
RT
504# This is an alphabetically sorted list of 64 bit extended platforms
505# Please maintain the alphabetic order if and when there are additions
44b111b5
SP
506config X86_NUMACHIP
507 bool "Numascale NumaChip"
508 depends on X86_64
509 depends on X86_EXTENDED_PLATFORM
510 depends on NUMA
511 depends on SMP
512 depends on X86_X2APIC
f9726bfd 513 depends on PCI_MMCONFIG
44b111b5
SP
514 ---help---
515 Adds support for Numascale NumaChip large-SMP systems. Needed to
516 enable more than ~168 cores.
517 If you don't have one of these, you should say N here.
506f1d07 518
c5c606d9
RT
519config X86_VSMP
520 bool "ScaleMP vSMP"
6276a074 521 select HYPERVISOR_GUEST
c5c606d9
RT
522 select PARAVIRT
523 depends on X86_64 && PCI
524 depends on X86_EXTENDED_PLATFORM
ead91d4b 525 depends on SMP
8f9ca475 526 ---help---
c5c606d9
RT
527 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
528 supposed to run on these EM64T-based machines. Only choose this option
529 if you have one of these machines.
5e3a77e9 530
03b48632
NP
531config X86_UV
532 bool "SGI Ultraviolet"
533 depends on X86_64
c5c606d9 534 depends on X86_EXTENDED_PLATFORM
54c28d29 535 depends on NUMA
1ecb4ae5 536 depends on EFI
9d6c26e7 537 depends on X86_X2APIC
1222e564 538 depends on PCI
8f9ca475 539 ---help---
03b48632
NP
540 This option is needed in order to support SGI Ultraviolet systems.
541 If you don't have one of these, you should say N here.
542
c5c606d9
RT
543# Following is an alphabetically sorted list of 32 bit extended platforms
544# Please maintain the alphabetic order if and when there are additions
506f1d07 545
ddd70cf9
JN
546config X86_GOLDFISH
547 bool "Goldfish (Virtual Platform)"
cb7b8023 548 depends on X86_EXTENDED_PLATFORM
ddd70cf9
JN
549 ---help---
550 Enable support for the Goldfish virtual platform used primarily
551 for Android development. Unless you are building for the Android
552 Goldfish emulator say N here.
553
c751e17b
TG
554config X86_INTEL_CE
555 bool "CE4100 TV platform"
556 depends on PCI
557 depends on PCI_GODIRECT
6084a6e2 558 depends on X86_IO_APIC
c751e17b
TG
559 depends on X86_32
560 depends on X86_EXTENDED_PLATFORM
37bc9f50 561 select X86_REBOOTFIXUPS
da6b737b
SAS
562 select OF
563 select OF_EARLY_FLATTREE
c751e17b
TG
564 ---help---
565 Select for the Intel CE media processor (CE4100) SOC.
566 This option compiles in support for the CE4100 SOC for settop
567 boxes and media devices.
568
4cb9b00f 569config X86_INTEL_MID
43605ef1 570 bool "Intel MID platform support"
43605ef1 571 depends on X86_EXTENDED_PLATFORM
edc6bc78 572 depends on X86_PLATFORM_DEVICES
1ea7c673 573 depends on PCI
3fda5bb4 574 depends on X86_64 || (PCI_GOANY && X86_32)
1ea7c673 575 depends on X86_IO_APIC
7c9c3a1e 576 select SFI
4cb9b00f 577 select I2C
7c9c3a1e 578 select DW_APB_TIMER
1ea7c673 579 select APB_TIMER
1ea7c673 580 select INTEL_SCU_IPC
15a713df 581 select MFD_INTEL_MSIC
1ea7c673 582 ---help---
4cb9b00f
DC
583 Select to build a kernel capable of supporting Intel MID (Mobile
584 Internet Device) platform systems which do not have the PCI legacy
585 interfaces. If you are building for a PC class system say N here.
1ea7c673 586
4cb9b00f
DC
587 Intel MID platforms are based on an Intel processor and chipset which
588 consume less power than most of the x86 derivatives.
43605ef1 589
8bbc2a13
BD
590config X86_INTEL_QUARK
591 bool "Intel Quark platform support"
592 depends on X86_32
593 depends on X86_EXTENDED_PLATFORM
594 depends on X86_PLATFORM_DEVICES
595 depends on X86_TSC
596 depends on PCI
597 depends on PCI_GOANY
598 depends on X86_IO_APIC
599 select IOSF_MBI
600 select INTEL_IMR
9ab6eb51 601 select COMMON_CLK
8bbc2a13
BD
602 ---help---
603 Select to include support for Quark X1000 SoC.
604 Say Y here if you have a Quark based system such as the Arduino
605 compatible Intel Galileo.
606
3d48aab1
MW
607config X86_INTEL_LPSS
608 bool "Intel Low Power Subsystem Support"
eebb3e8d 609 depends on X86 && ACPI
3d48aab1 610 select COMMON_CLK
0f531431 611 select PINCTRL
eebb3e8d 612 select IOSF_MBI
3d48aab1
MW
613 ---help---
614 Select to build support for Intel Low Power Subsystem such as
615 found on Intel Lynxpoint PCH. Selecting this option enables
0f531431
MN
616 things like clock tree (common clock framework) and pincontrol
617 which are needed by the LPSS peripheral drivers.
3d48aab1 618
92082a88
KX
619config X86_AMD_PLATFORM_DEVICE
620 bool "AMD ACPI2Platform devices support"
621 depends on ACPI
622 select COMMON_CLK
623 select PINCTRL
624 ---help---
625 Select to interpret AMD specific ACPI device to platform device
626 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
627 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
628 implemented under PINCTRL subsystem.
629
ced3ce76
DB
630config IOSF_MBI
631 tristate "Intel SoC IOSF Sideband support for SoC platforms"
632 depends on PCI
633 ---help---
634 This option enables sideband register access support for Intel SoC
635 platforms. On these platforms the IOSF sideband is used in lieu of
636 MSR's for some register accesses, mostly but not limited to thermal
637 and power. Drivers may query the availability of this device to
638 determine if they need the sideband in order to work on these
639 platforms. The sideband is available on the following SoC products.
640 This list is not meant to be exclusive.
641 - BayTrail
642 - Braswell
643 - Quark
644
645 You should say Y if you are running a kernel on one of these SoC's.
646
ed2226bd
DB
647config IOSF_MBI_DEBUG
648 bool "Enable IOSF sideband access through debugfs"
649 depends on IOSF_MBI && DEBUG_FS
650 ---help---
651 Select this option to expose the IOSF sideband access registers (MCR,
652 MDR, MCRX) through debugfs to write and read register information from
653 different units on the SoC. This is most useful for obtaining device
654 state information for debug and analysis. As this is a general access
655 mechanism, users of this option would have specific knowledge of the
656 device they want to access.
657
658 If you don't require the option or are in doubt, say N.
659
c5c606d9
RT
660config X86_RDC321X
661 bool "RDC R-321x SoC"
506f1d07 662 depends on X86_32
c5c606d9
RT
663 depends on X86_EXTENDED_PLATFORM
664 select M486
665 select X86_REBOOTFIXUPS
666 ---help---
667 This option is needed for RDC R-321x system-on-chip, also known
668 as R-8610-(G).
669 If you don't have one of these chips, you should say N here.
670
e0c7ae37 671config X86_32_NON_STANDARD
9c398017
IM
672 bool "Support non-standard 32-bit SMP architectures"
673 depends on X86_32 && SMP
c5c606d9 674 depends on X86_EXTENDED_PLATFORM
8f9ca475 675 ---help---
b5660ba7
PA
676 This option compiles in the bigsmp and STA2X11 default
677 subarchitectures. It is intended for a generic binary
678 kernel. If you select them all, kernel will probe it one by
679 one and will fallback to default.
d49c4288 680
c5c606d9 681# Alphabetically sorted list of Non standard 32 bit platforms
d49c4288 682
d949f36f 683config X86_SUPPORTS_MEMORY_FAILURE
6fc108a0 684 def_bool y
d949f36f
LT
685 # MCE code calls memory_failure():
686 depends on X86_MCE
687 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
d949f36f
LT
688 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
689 depends on X86_64 || !SPARSEMEM
690 select ARCH_SUPPORTS_MEMORY_FAILURE
d949f36f 691
83125a3a
AR
692config STA2X11
693 bool "STA2X11 Companion Chip Support"
694 depends on X86_32_NON_STANDARD && PCI
695 select X86_DEV_DMA_OPS
696 select X86_DMA_REMAP
697 select SWIOTLB
698 select MFD_STA2X11
0145071b 699 select GPIOLIB
83125a3a
AR
700 default n
701 ---help---
702 This adds support for boards based on the STA2X11 IO-Hub,
703 a.k.a. "ConneXt". The chip is used in place of the standard
704 PC chipset, so all "standard" peripherals are missing. If this
705 option is selected the kernel will still be able to boot on
706 standard PC machines.
707
82148d1d
S
708config X86_32_IRIS
709 tristate "Eurobraille/Iris poweroff module"
710 depends on X86_32
711 ---help---
712 The Iris machines from EuroBraille do not have APM or ACPI support
713 to shut themselves down properly. A special I/O sequence is
714 needed to do so, which is what this module does at
715 kernel shutdown.
716
717 This is only for Iris machines from EuroBraille.
718
719 If unused, say N.
720
ae1e9130 721config SCHED_OMIT_FRAME_POINTER
3c2362e6
HH
722 def_bool y
723 prompt "Single-depth WCHAN output"
a87d0914 724 depends on X86
8f9ca475 725 ---help---
506f1d07
SR
726 Calculate simpler /proc/<PID>/wchan values. If this option
727 is disabled then wchan values will recurse back to the
728 caller function. This provides more accurate wchan values,
729 at the expense of slightly more scheduling overhead.
730
731 If in doubt, say "Y".
732
6276a074
BP
733menuconfig HYPERVISOR_GUEST
734 bool "Linux guest support"
8f9ca475 735 ---help---
6276a074
BP
736 Say Y here to enable options for running Linux under various hyper-
737 visors. This option enables basic hypervisor detection and platform
738 setup.
506f1d07 739
6276a074
BP
740 If you say N, all options in this submenu will be skipped and
741 disabled, and Linux guest support won't be built in.
506f1d07 742
6276a074 743if HYPERVISOR_GUEST
506f1d07 744
e61bd94a
EPH
745config PARAVIRT
746 bool "Enable paravirtualization code"
8f9ca475 747 ---help---
e61bd94a
EPH
748 This changes the kernel so it can modify itself when it is run
749 under a hypervisor, potentially improving performance significantly
750 over full virtualization. However, when run without a hypervisor
751 the kernel is theoretically slower and slightly larger.
752
6276a074
BP
753config PARAVIRT_DEBUG
754 bool "paravirt-ops debugging"
755 depends on PARAVIRT && DEBUG_KERNEL
756 ---help---
757 Enable to debug paravirt_ops internals. Specifically, BUG if
758 a paravirt_op is missing when it is called.
759
b4ecc126
JF
760config PARAVIRT_SPINLOCKS
761 bool "Paravirtualization layer for spinlocks"
6ea30386 762 depends on PARAVIRT && SMP
b4ecc126
JF
763 ---help---
764 Paravirtualized spinlocks allow a pvops backend to replace the
765 spinlock implementation with something virtualization-friendly
766 (for example, block the virtual CPU rather than spinning).
767
4c4e4f61
R
768 It has a minimal impact on native kernels and gives a nice performance
769 benefit on paravirtualized KVM / Xen kernels.
b4ecc126 770
4c4e4f61 771 If you are unsure how to answer this question, answer Y.
b4ecc126 772
45e898b7
WL
773config QUEUED_LOCK_STAT
774 bool "Paravirt queued spinlock statistics"
cfd8983f 775 depends on PARAVIRT_SPINLOCKS && DEBUG_FS
45e898b7
WL
776 ---help---
777 Enable the collection of statistical data on the slowpath
778 behavior of paravirtualized queued spinlocks and report
779 them on debugfs.
780
6276a074 781source "arch/x86/xen/Kconfig"
7af192c9 782
6276a074
BP
783config KVM_GUEST
784 bool "KVM Guest support (including kvmclock)"
785 depends on PARAVIRT
786 select PARAVIRT_CLOCK
787 default y
8f9ca475 788 ---help---
6276a074
BP
789 This option enables various optimizations for running under the KVM
790 hypervisor. It includes a paravirtualized clock, so that instead
791 of relying on a PIT (or probably other) emulation by the
792 underlying device model, the host provides the guest with
793 timing infrastructure such as time of day, and system time
506f1d07 794
1e20eb85
SV
795config KVM_DEBUG_FS
796 bool "Enable debug information for KVM Guests in debugfs"
797 depends on KVM_GUEST && DEBUG_FS
798 default n
799 ---help---
800 This option enables collection of various statistics for KVM guest.
801 Statistics are displayed in debugfs filesystem. Enabling this option
802 may incur significant overhead.
803
6276a074
BP
804config PARAVIRT_TIME_ACCOUNTING
805 bool "Paravirtual steal time accounting"
806 depends on PARAVIRT
807 default n
8f9ca475 808 ---help---
6276a074
BP
809 Select this option to enable fine granularity task steal time
810 accounting. Time spent executing other tasks in parallel with
811 the current vCPU is discounted from the vCPU power. To account for
812 that, there can be a small performance impact.
813
814 If in doubt, say N here.
815
816config PARAVIRT_CLOCK
817 bool
97349135 818
6276a074 819endif #HYPERVISOR_GUEST
97349135 820
08677214 821config NO_BOOTMEM
774ea0bc 822 def_bool y
08677214 823
506f1d07
SR
824source "arch/x86/Kconfig.cpu"
825
826config HPET_TIMER
3c2362e6 827 def_bool X86_64
506f1d07 828 prompt "HPET Timer Support" if X86_32
8f9ca475
IM
829 ---help---
830 Use the IA-PC HPET (High Precision Event Timer) to manage
831 time in preference to the PIT and RTC, if a HPET is
832 present.
833 HPET is the next generation timer replacing legacy 8254s.
834 The HPET provides a stable time base on SMP
835 systems, unlike the TSC, but it is more expensive to access,
4e7f9df2
MT
836 as it is off-chip. The interface used is documented
837 in the HPET spec, revision 1.
506f1d07 838
8f9ca475
IM
839 You can safely choose Y here. However, HPET will only be
840 activated if the platform and the BIOS support this feature.
841 Otherwise the 8254 will be used for timing services.
506f1d07 842
8f9ca475 843 Choose N to continue using the legacy 8254 timer.
506f1d07
SR
844
845config HPET_EMULATE_RTC
3c2362e6 846 def_bool y
9d8af78b 847 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
506f1d07 848
bb24c471 849config APB_TIMER
933b9463
AC
850 def_bool y if X86_INTEL_MID
851 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
06c3df49 852 select DW_APB_TIMER
a0c3832a 853 depends on X86_INTEL_MID && SFI
bb24c471
JP
854 help
855 APB timer is the replacement for 8254, HPET on X86 MID platforms.
856 The APBT provides a stable time base on SMP
857 systems, unlike the TSC, but it is more expensive to access,
858 as it is off-chip. APB timers are always running regardless of CPU
859 C states, they are used as per CPU clockevent device when possible.
860
6a108a14 861# Mark as expert because too many people got it wrong.
506f1d07 862# The code disables itself when not needed.
7ae9392c
TP
863config DMI
864 default y
cf074402 865 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
6a108a14 866 bool "Enable DMI scanning" if EXPERT
8f9ca475 867 ---help---
7ae9392c
TP
868 Enabled scanning of DMI to identify machine quirks. Say Y
869 here unless you have verified that your setup is not
870 affected by entries in the DMI blacklist. Required by PNP
871 BIOS code.
872
506f1d07 873config GART_IOMMU
38901f1c 874 bool "Old AMD GART IOMMU support"
506f1d07 875 select SWIOTLB
23ac4ae8 876 depends on X86_64 && PCI && AMD_NB
8f9ca475 877 ---help---
ced3c42c
IM
878 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
879 GART based hardware IOMMUs.
880
881 The GART supports full DMA access for devices with 32-bit access
882 limitations, on systems with more than 3 GB. This is usually needed
883 for USB, sound, many IDE/SATA chipsets and some other devices.
884
885 Newer systems typically have a modern AMD IOMMU, supported via
886 the CONFIG_AMD_IOMMU=y config option.
887
888 In normal configurations this driver is only active when needed:
889 there's more than 3 GB of memory and the system contains a
890 32-bit limited device.
891
892 If unsure, say Y.
506f1d07
SR
893
894config CALGARY_IOMMU
895 bool "IBM Calgary IOMMU support"
896 select SWIOTLB
6ea30386 897 depends on X86_64 && PCI
8f9ca475 898 ---help---
506f1d07
SR
899 Support for hardware IOMMUs in IBM's xSeries x366 and x460
900 systems. Needed to run systems with more than 3GB of memory
901 properly with 32-bit PCI devices that do not support DAC
902 (Double Address Cycle). Calgary also supports bus level
903 isolation, where all DMAs pass through the IOMMU. This
904 prevents them from going anywhere except their intended
905 destination. This catches hard-to-find kernel bugs and
906 mis-behaving drivers and devices that do not use the DMA-API
907 properly to set up their DMA buffers. The IOMMU can be
908 turned off at boot time with the iommu=off parameter.
909 Normally the kernel will make the right choice by itself.
910 If unsure, say Y.
911
912config CALGARY_IOMMU_ENABLED_BY_DEFAULT
3c2362e6
HH
913 def_bool y
914 prompt "Should Calgary be enabled by default?"
506f1d07 915 depends on CALGARY_IOMMU
8f9ca475 916 ---help---
506f1d07
SR
917 Should Calgary be enabled by default? if you choose 'y', Calgary
918 will be used (if it exists). If you choose 'n', Calgary will not be
919 used even if it exists. If you choose 'n' and would like to use
920 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
921 If unsure, say Y.
922
923# need this always selected by IOMMU for the VIA workaround
924config SWIOTLB
a1afd01c 925 def_bool y if X86_64
8f9ca475 926 ---help---
506f1d07 927 Support for software bounce buffers used on x86-64 systems
4454d327
JM
928 which don't have a hardware IOMMU. Using this PCI devices
929 which can only access 32-bits of memory can be used on systems
930 with more than 3 GB of memory.
931 If unsure, say Y.
506f1d07 932
a8522509 933config IOMMU_HELPER
3120e25e
JB
934 def_bool y
935 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
d25e26b6 936
1184dc2f 937config MAXSMP
ddb0c5a6 938 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
6ea30386 939 depends on X86_64 && SMP && DEBUG_KERNEL
36f5101a 940 select CPUMASK_OFFSTACK
8f9ca475 941 ---help---
ddb0c5a6 942 Enable maximum number of CPUS and NUMA Nodes for this architecture.
1184dc2f 943 If unsure, say N.
506f1d07
SR
944
945config NR_CPUS
36f5101a 946 int "Maximum number of CPUs" if SMP && !MAXSMP
2a3313f4 947 range 2 8 if SMP && X86_32 && !X86_BIGSMP
7bbcbd3d
TG
948 range 2 64 if SMP && X86_32 && X86_BIGSMP
949 range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK && X86_64
b53b5eda 950 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
78637a97 951 default "1" if !SMP
b53b5eda 952 default "8192" if MAXSMP
b5660ba7 953 default "32" if SMP && X86_BIGSMP
c5c19941
KS
954 default "8" if SMP && X86_32
955 default "64" if SMP
8f9ca475 956 ---help---
506f1d07 957 This allows you to specify the maximum number of CPUs which this
bb61ccc7 958 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
cad14bb9 959 supported value is 8192, otherwise the maximum value is 512. The
506f1d07
SR
960 minimum value which makes sense is 2.
961
962 This is purely to save memory - each supported CPU adds
963 approximately eight kilobytes to the kernel image.
964
965config SCHED_SMT
966 bool "SMT (Hyperthreading) scheduler support"
c8e56d20 967 depends on SMP
8f9ca475 968 ---help---
506f1d07
SR
969 SMT scheduler support improves the CPU scheduler's decision making
970 when dealing with Intel Pentium 4 chips with HyperThreading at a
971 cost of slightly increased overhead in some places. If unsure say
972 N here.
973
974config SCHED_MC
3c2362e6
HH
975 def_bool y
976 prompt "Multi-core scheduler support"
c8e56d20 977 depends on SMP
8f9ca475 978 ---help---
506f1d07
SR
979 Multi-core scheduler support improves the CPU scheduler's decision
980 making when dealing with multi-core CPU chips at a cost of slightly
981 increased overhead in some places. If unsure say N here.
982
de966cf4
TC
983config SCHED_MC_PRIO
984 bool "CPU core priorities scheduler support"
0a21fc12
IM
985 depends on SCHED_MC && CPU_SUP_INTEL
986 select X86_INTEL_PSTATE
987 select CPU_FREQ
de966cf4 988 default y
5e76b2ab 989 ---help---
0a21fc12
IM
990 Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
991 core ordering determined at manufacturing time, which allows
992 certain cores to reach higher turbo frequencies (when running
993 single threaded workloads) than others.
de966cf4 994
0a21fc12
IM
995 Enabling this kernel feature teaches the scheduler about
996 the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
997 scheduler's CPU selection logic accordingly, so that higher
998 overall system performance can be achieved.
de966cf4 999
0a21fc12 1000 This feature will have no effect on CPUs without this feature.
de966cf4 1001
0a21fc12 1002 If unsure say Y here.
5e76b2ab 1003
506f1d07
SR
1004source "kernel/Kconfig.preempt"
1005
30b8b006
TG
1006config UP_LATE_INIT
1007 def_bool y
ba360f88 1008 depends on !SMP && X86_LOCAL_APIC
30b8b006 1009
506f1d07 1010config X86_UP_APIC
50849eef
JB
1011 bool "Local APIC support on uniprocessors" if !PCI_MSI
1012 default PCI_MSI
38a1dfda 1013 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
8f9ca475 1014 ---help---
506f1d07
SR
1015 A local APIC (Advanced Programmable Interrupt Controller) is an
1016 integrated interrupt controller in the CPU. If you have a single-CPU
1017 system which has a processor with a local APIC, you can say Y here to
1018 enable and use it. If you say Y here even though your machine doesn't
1019 have a local APIC, then the kernel will still run with no slowdown at
1020 all. The local APIC supports CPU-generated self-interrupts (timer,
1021 performance counters), and the NMI watchdog which detects hard
1022 lockups.
1023
1024config X86_UP_IOAPIC
1025 bool "IO-APIC support on uniprocessors"
1026 depends on X86_UP_APIC
8f9ca475 1027 ---help---
506f1d07
SR
1028 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1029 SMP-capable replacement for PC-style interrupt controllers. Most
1030 SMP systems and many recent uniprocessor systems have one.
1031
1032 If you have a single-CPU system with an IO-APIC, you can say Y here
1033 to use it. If you say Y here even though your machine doesn't have
1034 an IO-APIC, then the kernel will still run with no slowdown at all.
1035
1036config X86_LOCAL_APIC
3c2362e6 1037 def_bool y
0dbc6078 1038 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
b5dc8e6c 1039 select IRQ_DOMAIN_HIERARCHY
52f518a3 1040 select PCI_MSI_IRQ_DOMAIN if PCI_MSI
506f1d07
SR
1041
1042config X86_IO_APIC
b1da1e71
JB
1043 def_bool y
1044 depends on X86_LOCAL_APIC || X86_UP_IOAPIC
506f1d07 1045
41b9eb26
SA
1046config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
1047 bool "Reroute for broken boot IRQs"
41b9eb26 1048 depends on X86_IO_APIC
8f9ca475 1049 ---help---
41b9eb26
SA
1050 This option enables a workaround that fixes a source of
1051 spurious interrupts. This is recommended when threaded
1052 interrupt handling is used on systems where the generation of
1053 superfluous "boot interrupts" cannot be disabled.
1054
1055 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
1056 entry in the chipset's IO-APIC is masked (as, e.g. the RT
1057 kernel does during interrupt handling). On chipsets where this
1058 boot IRQ generation cannot be disabled, this workaround keeps
1059 the original IRQ line masked so that only the equivalent "boot
1060 IRQ" is delivered to the CPUs. The workaround also tells the
1061 kernel to set up the IRQ handler on the boot IRQ line. In this
1062 way only one interrupt is delivered to the kernel. Otherwise
1063 the spurious second interrupt may cause the kernel to bring
1064 down (vital) interrupt lines.
1065
1066 Only affects "broken" chipsets. Interrupt sharing may be
1067 increased on these systems.
1068
506f1d07 1069config X86_MCE
bab9bc65 1070 bool "Machine Check / overheating reporting"
648ed940 1071 select GENERIC_ALLOCATOR
e57dbaf7 1072 default y
506f1d07 1073 ---help---
bab9bc65
AK
1074 Machine Check support allows the processor to notify the
1075 kernel if it detects a problem (e.g. overheating, data corruption).
506f1d07 1076 The action the kernel takes depends on the severity of the problem,
bab9bc65 1077 ranging from warning messages to halting the machine.
4efc0670 1078
5de97c9f
TL
1079config X86_MCELOG_LEGACY
1080 bool "Support for deprecated /dev/mcelog character device"
1081 depends on X86_MCE
1082 ---help---
1083 Enable support for /dev/mcelog which is needed by the old mcelog
1084 userspace logging daemon. Consider switching to the new generation
1085 rasdaemon solution.
1086
506f1d07 1087config X86_MCE_INTEL
3c2362e6
HH
1088 def_bool y
1089 prompt "Intel MCE features"
c1ebf835 1090 depends on X86_MCE && X86_LOCAL_APIC
8f9ca475 1091 ---help---
506f1d07
SR
1092 Additional support for intel specific MCE features such as
1093 the thermal monitor.
1094
1095config X86_MCE_AMD
3c2362e6
HH
1096 def_bool y
1097 prompt "AMD MCE features"
f5382de9 1098 depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
8f9ca475 1099 ---help---
506f1d07
SR
1100 Additional support for AMD specific MCE features such as
1101 the DRAM Error Threshold.
1102
4efc0670 1103config X86_ANCIENT_MCE
6fc108a0 1104 bool "Support for old Pentium 5 / WinChip machine checks"
c31d9633 1105 depends on X86_32 && X86_MCE
cd13adcc
HS
1106 ---help---
1107 Include support for machine check handling on old Pentium 5 or WinChip
5065a706 1108 systems. These typically need to be enabled explicitly on the command
cd13adcc 1109 line.
4efc0670 1110
b2762686
AK
1111config X86_MCE_THRESHOLD
1112 depends on X86_MCE_AMD || X86_MCE_INTEL
6fc108a0 1113 def_bool y
b2762686 1114
ea149b36 1115config X86_MCE_INJECT
bc8e80d5 1116 depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
ea149b36
AK
1117 tristate "Machine check injector support"
1118 ---help---
1119 Provide support for injecting machine checks for testing purposes.
1120 If you don't know what a machine check is and you don't do kernel
1121 QA it is safe to say n.
1122
4efc0670
AK
1123config X86_THERMAL_VECTOR
1124 def_bool y
5bb38adc 1125 depends on X86_MCE_INTEL
4efc0670 1126
07dc900e 1127source "arch/x86/events/Kconfig"
e633c65a 1128
5aef51c3 1129config X86_LEGACY_VM86
1e642812 1130 bool "Legacy VM86 support"
5aef51c3 1131 default n
506f1d07 1132 depends on X86_32
8f9ca475 1133 ---help---
5aef51c3
AL
1134 This option allows user programs to put the CPU into V8086
1135 mode, which is an 80286-era approximation of 16-bit real mode.
1136
1137 Some very old versions of X and/or vbetool require this option
1138 for user mode setting. Similarly, DOSEMU will use it if
1139 available to accelerate real mode DOS programs. However, any
1140 recent version of DOSEMU, X, or vbetool should be fully
1141 functional even without kernel VM86 support, as they will all
1e642812
IM
1142 fall back to software emulation. Nevertheless, if you are using
1143 a 16-bit DOS program where 16-bit performance matters, vm86
1144 mode might be faster than emulation and you might want to
1145 enable this option.
5aef51c3 1146
1e642812
IM
1147 Note that any app that works on a 64-bit kernel is unlikely to
1148 need this option, as 64-bit kernels don't, and can't, support
1149 V8086 mode. This option is also unrelated to 16-bit protected
1150 mode and is not needed to run most 16-bit programs under Wine.
5aef51c3 1151
1e642812
IM
1152 Enabling this option increases the complexity of the kernel
1153 and slows down exception handling a tiny bit.
5aef51c3 1154
1e642812 1155 If unsure, say N here.
5aef51c3
AL
1156
1157config VM86
1158 bool
1159 default X86_LEGACY_VM86
34273f41
PA
1160
1161config X86_16BIT
1162 bool "Enable support for 16-bit segments" if EXPERT
1163 default y
a5b9e5a2 1164 depends on MODIFY_LDT_SYSCALL
34273f41
PA
1165 ---help---
1166 This option is required by programs like Wine to run 16-bit
1167 protected mode legacy code on x86 processors. Disabling
1168 this option saves about 300 bytes on i386, or around 6K text
1169 plus 16K runtime memory on x86-64,
1170
1171config X86_ESPFIX32
1172 def_bool y
1173 depends on X86_16BIT && X86_32
506f1d07 1174
197725de
PA
1175config X86_ESPFIX64
1176 def_bool y
34273f41 1177 depends on X86_16BIT && X86_64
506f1d07 1178
1ad83c85
AL
1179config X86_VSYSCALL_EMULATION
1180 bool "Enable vsyscall emulation" if EXPERT
1181 default y
1182 depends on X86_64
1183 ---help---
1184 This enables emulation of the legacy vsyscall page. Disabling
1185 it is roughly equivalent to booting with vsyscall=none, except
1186 that it will also disable the helpful warning if a program
1187 tries to use a vsyscall. With this option set to N, offending
1188 programs will just segfault, citing addresses of the form
1189 0xffffffffff600?00.
1190
1191 This option is required by many programs built before 2013, and
1192 care should be used even with newer programs if set to N.
1193
1194 Disabling this option saves about 7K of kernel size and
1195 possibly 4K of additional runtime pagetable memory.
1196
506f1d07
SR
1197config TOSHIBA
1198 tristate "Toshiba Laptop support"
1199 depends on X86_32
1200 ---help---
1201 This adds a driver to safely access the System Management Mode of
1202 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1203 not work on models with a Phoenix BIOS. The System Management Mode
1204 is used to set the BIOS and power saving options on Toshiba portables.
1205
1206 For information on utilities to make use of this driver see the
1207 Toshiba Linux utilities web site at:
1208 <http://www.buzzard.org.uk/toshiba/>.
1209
1210 Say Y if you intend to run this kernel on a Toshiba portable.
1211 Say N otherwise.
1212
1213config I8K
039ae585 1214 tristate "Dell i8k legacy laptop support"
949a9d70 1215 select HWMON
039ae585 1216 select SENSORS_DELL_SMM
506f1d07 1217 ---help---
039ae585
PR
1218 This option enables legacy /proc/i8k userspace interface in hwmon
1219 dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1220 temperature and allows controlling fan speeds of Dell laptops via
1221 System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1222 it reports also power and hotkey status. For fan speed control is
1223 needed userspace package i8kutils.
1224
1225 Say Y if you intend to run this kernel on old Dell laptops or want to
1226 use userspace package i8kutils.
506f1d07
SR
1227 Say N otherwise.
1228
1229config X86_REBOOTFIXUPS
9ba16087
JB
1230 bool "Enable X86 board specific fixups for reboot"
1231 depends on X86_32
506f1d07
SR
1232 ---help---
1233 This enables chipset and/or board specific fixups to be done
1234 in order to get reboot to work correctly. This is only needed on
1235 some combinations of hardware and BIOS. The symptom, for which
1236 this config is intended, is when reboot ends with a stalled/hung
1237 system.
1238
1239 Currently, the only fixup is for the Geode machines using
5e3a77e9 1240 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
506f1d07
SR
1241
1242 Say Y if you want to enable the fixup. Currently, it's safe to
1243 enable this option even if you don't need it.
1244 Say N otherwise.
1245
1246config MICROCODE
9a2bc335
BP
1247 bool "CPU microcode loading support"
1248 default y
80030e3d 1249 depends on CPU_SUP_AMD || CPU_SUP_INTEL
506f1d07
SR
1250 select FW_LOADER
1251 ---help---
1252 If you say Y here, you will be able to update the microcode on
5f9c01aa
BP
1253 Intel and AMD processors. The Intel support is for the IA32 family,
1254 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
1255 AMD support is for families 0x10 and later. You will obviously need
1256 the actual microcode binary data itself which is not shipped with
1257 the Linux kernel.
1258
1259 The preferred method to load microcode from a detached initrd is described
1260 in Documentation/x86/early-microcode.txt. For that you need to enable
1261 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
1262 initrd for microcode blobs.
1263
1264 In addition, you can build-in the microcode into the kernel. For that you
1265 need to enable FIRMWARE_IN_KERNEL and add the vendor-supplied microcode
1266 to the CONFIG_EXTRA_FIRMWARE config option.
506f1d07 1267
8d86f390 1268config MICROCODE_INTEL
e43f6e67 1269 bool "Intel microcode loading support"
8f9ca475
IM
1270 depends on MICROCODE
1271 default MICROCODE
1272 select FW_LOADER
1273 ---help---
1274 This options enables microcode patch loading support for Intel
1275 processors.
1276
b8989db9
A
1277 For the current Intel microcode data package go to
1278 <https://downloadcenter.intel.com> and search for
1279 'Linux Processor Microcode Data File'.
8d86f390 1280
80cc9f10 1281config MICROCODE_AMD
e43f6e67 1282 bool "AMD microcode loading support"
8f9ca475
IM
1283 depends on MICROCODE
1284 select FW_LOADER
1285 ---help---
1286 If you select this option, microcode patch loading support for AMD
1287 processors will be enabled.
80cc9f10 1288
8f9ca475 1289config MICROCODE_OLD_INTERFACE
3c2362e6 1290 def_bool y
506f1d07 1291 depends on MICROCODE
506f1d07
SR
1292
1293config X86_MSR
1294 tristate "/dev/cpu/*/msr - Model-specific register support"
8f9ca475 1295 ---help---
506f1d07
SR
1296 This device gives privileged processes access to the x86
1297 Model-Specific Registers (MSRs). It is a character device with
1298 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1299 MSR accesses are directed to a specific CPU on multi-processor
1300 systems.
1301
1302config X86_CPUID
1303 tristate "/dev/cpu/*/cpuid - CPU information support"
8f9ca475 1304 ---help---
506f1d07
SR
1305 This device gives processes access to the x86 CPUID instruction to
1306 be executed on a specific processor. It is a character device
1307 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1308 /dev/cpu/31/cpuid.
1309
1310choice
1311 prompt "High Memory Support"
6fc108a0 1312 default HIGHMEM4G
506f1d07
SR
1313 depends on X86_32
1314
1315config NOHIGHMEM
1316 bool "off"
506f1d07
SR
1317 ---help---
1318 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1319 However, the address space of 32-bit x86 processors is only 4
1320 Gigabytes large. That means that, if you have a large amount of
1321 physical memory, not all of it can be "permanently mapped" by the
1322 kernel. The physical memory that's not permanently mapped is called
1323 "high memory".
1324
1325 If you are compiling a kernel which will never run on a machine with
1326 more than 1 Gigabyte total physical RAM, answer "off" here (default
1327 choice and suitable for most users). This will result in a "3GB/1GB"
1328 split: 3GB are mapped so that each process sees a 3GB virtual memory
1329 space and the remaining part of the 4GB virtual memory space is used
1330 by the kernel to permanently map as much physical memory as
1331 possible.
1332
1333 If the machine has between 1 and 4 Gigabytes physical RAM, then
1334 answer "4GB" here.
1335
1336 If more than 4 Gigabytes is used then answer "64GB" here. This
1337 selection turns Intel PAE (Physical Address Extension) mode on.
1338 PAE implements 3-level paging on IA32 processors. PAE is fully
1339 supported by Linux, PAE mode is implemented on all recent Intel
1340 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1341 then the kernel will not boot on CPUs that don't support PAE!
1342
1343 The actual amount of total physical memory will either be
1344 auto detected or can be forced by using a kernel command line option
1345 such as "mem=256M". (Try "man bootparam" or see the documentation of
1346 your boot loader (lilo or loadlin) about how to pass options to the
1347 kernel at boot time.)
1348
1349 If unsure, say "off".
1350
1351config HIGHMEM4G
1352 bool "4GB"
8f9ca475 1353 ---help---
506f1d07
SR
1354 Select this if you have a 32-bit processor and between 1 and 4
1355 gigabytes of physical RAM.
1356
1357config HIGHMEM64G
1358 bool "64GB"
eb068e78 1359 depends on !M486
506f1d07 1360 select X86_PAE
8f9ca475 1361 ---help---
506f1d07
SR
1362 Select this if you have a 32-bit processor and more than 4
1363 gigabytes of physical RAM.
1364
1365endchoice
1366
1367choice
6a108a14 1368 prompt "Memory split" if EXPERT
506f1d07
SR
1369 default VMSPLIT_3G
1370 depends on X86_32
8f9ca475 1371 ---help---
506f1d07
SR
1372 Select the desired split between kernel and user memory.
1373
1374 If the address range available to the kernel is less than the
1375 physical memory installed, the remaining memory will be available
1376 as "high memory". Accessing high memory is a little more costly
1377 than low memory, as it needs to be mapped into the kernel first.
1378 Note that increasing the kernel address space limits the range
1379 available to user programs, making the address space there
1380 tighter. Selecting anything other than the default 3G/1G split
1381 will also likely make your kernel incompatible with binary-only
1382 kernel modules.
1383
1384 If you are not absolutely sure what you are doing, leave this
1385 option alone!
1386
1387 config VMSPLIT_3G
1388 bool "3G/1G user/kernel split"
1389 config VMSPLIT_3G_OPT
1390 depends on !X86_PAE
1391 bool "3G/1G user/kernel split (for full 1G low memory)"
1392 config VMSPLIT_2G
1393 bool "2G/2G user/kernel split"
1394 config VMSPLIT_2G_OPT
1395 depends on !X86_PAE
1396 bool "2G/2G user/kernel split (for full 2G low memory)"
1397 config VMSPLIT_1G
1398 bool "1G/3G user/kernel split"
1399endchoice
1400
1401config PAGE_OFFSET
1402 hex
1403 default 0xB0000000 if VMSPLIT_3G_OPT
1404 default 0x80000000 if VMSPLIT_2G
1405 default 0x78000000 if VMSPLIT_2G_OPT
1406 default 0x40000000 if VMSPLIT_1G
1407 default 0xC0000000
1408 depends on X86_32
1409
1410config HIGHMEM
3c2362e6 1411 def_bool y
506f1d07 1412 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
506f1d07
SR
1413
1414config X86_PAE
9ba16087 1415 bool "PAE (Physical Address Extension) Support"
506f1d07 1416 depends on X86_32 && !HIGHMEM4G
9d99c712 1417 select SWIOTLB
8f9ca475 1418 ---help---
506f1d07
SR
1419 PAE is required for NX support, and furthermore enables
1420 larger swapspace support for non-overcommit purposes. It
1421 has the cost of more pagetable lookup overhead, and also
1422 consumes more pagetable space per process.
1423
77ef56e4
KS
1424config X86_5LEVEL
1425 bool "Enable 5-level page tables support"
1426 depends on X86_64
1427 ---help---
1428 5-level paging enables access to larger address space:
1429 upto 128 PiB of virtual address space and 4 PiB of
1430 physical address space.
1431
1432 It will be supported by future Intel CPUs.
1433
1434 Note: a kernel with this option enabled can only be booted
1435 on machines that support the feature.
1436
1437 See Documentation/x86/x86_64/5level-paging.txt for more
1438 information.
1439
1440 Say N if unsure.
1441
600715dc 1442config ARCH_PHYS_ADDR_T_64BIT
3120e25e
JB
1443 def_bool y
1444 depends on X86_64 || X86_PAE
600715dc 1445
66f2b061 1446config ARCH_DMA_ADDR_T_64BIT
3120e25e
JB
1447 def_bool y
1448 depends on X86_64 || HIGHMEM64G
66f2b061 1449
10971ab2 1450config X86_DIRECT_GBPAGES
e5008abe 1451 def_bool y
4675ff05 1452 depends on X86_64 && !DEBUG_PAGEALLOC
8f9ca475 1453 ---help---
10971ab2
IM
1454 Certain kernel features effectively disable kernel
1455 linear 1 GB mappings (even if the CPU otherwise
1456 supports them), so don't confuse the user by printing
1457 that we have them enabled.
9e899816 1458
7744ccdb
TL
1459config ARCH_HAS_MEM_ENCRYPT
1460 def_bool y
1461
1462config AMD_MEM_ENCRYPT
1463 bool "AMD Secure Memory Encryption (SME) support"
1464 depends on X86_64 && CPU_SUP_AMD
1465 ---help---
1466 Say yes to enable support for the encryption of system memory.
1467 This requires an AMD processor that supports Secure Memory
1468 Encryption (SME).
1469
1470config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
1471 bool "Activate AMD Secure Memory Encryption (SME) by default"
1472 default y
1473 depends on AMD_MEM_ENCRYPT
1474 ---help---
1475 Say yes to have system memory encrypted by default if running on
1476 an AMD processor that supports Secure Memory Encryption (SME).
1477
1478 If set to Y, then the encryption of system memory can be
1479 deactivated with the mem_encrypt=off command line option.
1480
1481 If set to N, then the encryption of system memory can be
1482 activated with the mem_encrypt=on command line option.
1483
f88a68fa
TL
1484config ARCH_USE_MEMREMAP_PROT
1485 def_bool y
1486 depends on AMD_MEM_ENCRYPT
1487
506f1d07
SR
1488# Common NUMA Features
1489config NUMA
fd51b2d7 1490 bool "Numa Memory Allocation and Scheduler Support"
506f1d07 1491 depends on SMP
b5660ba7
PA
1492 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1493 default y if X86_BIGSMP
8f9ca475 1494 ---help---
506f1d07 1495 Enable NUMA (Non Uniform Memory Access) support.
fd51b2d7 1496
506f1d07
SR
1497 The kernel will try to allocate memory used by a CPU on the
1498 local memory controller of the CPU and add some more
1499 NUMA awareness to the kernel.
1500
c280ea5e 1501 For 64-bit this is recommended if the system is Intel Core i7
fd51b2d7
KM
1502 (or later), AMD Opteron, or EM64T NUMA.
1503
b5660ba7 1504 For 32-bit this is only needed if you boot a 32-bit
7cf6c945 1505 kernel on a 64-bit NUMA platform.
fd51b2d7
KM
1506
1507 Otherwise, you should say N.
506f1d07 1508
eec1d4fa 1509config AMD_NUMA
3c2362e6
HH
1510 def_bool y
1511 prompt "Old style AMD Opteron NUMA detection"
5da0ef9a 1512 depends on X86_64 && NUMA && PCI
8f9ca475 1513 ---help---
eec1d4fa
HR
1514 Enable AMD NUMA node topology detection. You should say Y here if
1515 you have a multi processor AMD system. This uses an old method to
1516 read the NUMA configuration directly from the builtin Northbridge
1517 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1518 which also takes priority if both are compiled in.
506f1d07
SR
1519
1520config X86_64_ACPI_NUMA
3c2362e6
HH
1521 def_bool y
1522 prompt "ACPI NUMA detection"
506f1d07
SR
1523 depends on X86_64 && NUMA && ACPI && PCI
1524 select ACPI_NUMA
8f9ca475 1525 ---help---
506f1d07
SR
1526 Enable ACPI SRAT based node topology detection.
1527
6ec6e0d9
SS
1528# Some NUMA nodes have memory ranges that span
1529# other nodes. Even though a pfn is valid and
1530# between a node's start and end pfns, it may not
1531# reside on that node. See memmap_init_zone()
1532# for details.
1533config NODES_SPAN_OTHER_NODES
1534 def_bool y
1535 depends on X86_64_ACPI_NUMA
1536
506f1d07
SR
1537config NUMA_EMU
1538 bool "NUMA emulation"
1b7e03ef 1539 depends on NUMA
8f9ca475 1540 ---help---
506f1d07
SR
1541 Enable NUMA emulation. A flat machine will be split
1542 into virtual nodes when booted with "numa=fake=N", where N is the
1543 number of nodes. This is only useful for debugging.
1544
1545config NODES_SHIFT
d25e26b6 1546 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
51591e31
DR
1547 range 1 10
1548 default "10" if MAXSMP
506f1d07 1549 default "6" if X86_64
506f1d07
SR
1550 default "3"
1551 depends on NEED_MULTIPLE_NODES
8f9ca475 1552 ---help---
1184dc2f 1553 Specify the maximum number of NUMA Nodes available on the target
692105b8 1554 system. Increases memory reserved to accommodate various tables.
506f1d07 1555
506f1d07 1556config ARCH_HAVE_MEMORY_PRESENT
3c2362e6 1557 def_bool y
506f1d07 1558 depends on X86_32 && DISCONTIGMEM
506f1d07
SR
1559
1560config NEED_NODE_MEMMAP_SIZE
3c2362e6 1561 def_bool y
506f1d07 1562 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
506f1d07 1563
506f1d07
SR
1564config ARCH_FLATMEM_ENABLE
1565 def_bool y
3b16651f 1566 depends on X86_32 && !NUMA
506f1d07
SR
1567
1568config ARCH_DISCONTIGMEM_ENABLE
1569 def_bool y
b263295d 1570 depends on NUMA && X86_32
506f1d07
SR
1571
1572config ARCH_DISCONTIGMEM_DEFAULT
1573 def_bool y
b263295d
CL
1574 depends on NUMA && X86_32
1575
506f1d07
SR
1576config ARCH_SPARSEMEM_ENABLE
1577 def_bool y
6ea30386 1578 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
506f1d07
SR
1579 select SPARSEMEM_STATIC if X86_32
1580 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1581
3b16651f
TH
1582config ARCH_SPARSEMEM_DEFAULT
1583 def_bool y
1584 depends on X86_64
1585
506f1d07
SR
1586config ARCH_SELECT_MEMORY_MODEL
1587 def_bool y
b263295d 1588 depends on ARCH_SPARSEMEM_ENABLE
506f1d07
SR
1589
1590config ARCH_MEMORY_PROBE
a0842b70 1591 bool "Enable sysfs memory/probe interface"
3120e25e 1592 depends on X86_64 && MEMORY_HOTPLUG
a0842b70
TK
1593 help
1594 This option enables a sysfs memory/probe interface for testing.
1595 See Documentation/memory-hotplug.txt for more information.
1596 If you are unsure how to answer this question, answer N.
506f1d07 1597
3b16651f
TH
1598config ARCH_PROC_KCORE_TEXT
1599 def_bool y
1600 depends on X86_64 && PROC_KCORE
1601
a29815a3
AK
1602config ILLEGAL_POINTER_VALUE
1603 hex
1604 default 0 if X86_32
1605 default 0xdead000000000000 if X86_64
1606
506f1d07
SR
1607source "mm/Kconfig"
1608
7a67832c
DW
1609config X86_PMEM_LEGACY_DEVICE
1610 bool
1611
ec776ef6 1612config X86_PMEM_LEGACY
7a67832c 1613 tristate "Support non-standard NVDIMMs and ADR protected memory"
9f53f9fa
DW
1614 depends on PHYS_ADDR_T_64BIT
1615 depends on BLK_DEV
7a67832c 1616 select X86_PMEM_LEGACY_DEVICE
9f53f9fa 1617 select LIBNVDIMM
ec776ef6
CH
1618 help
1619 Treat memory marked using the non-standard e820 type of 12 as used
1620 by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1621 The kernel will offer these regions to the 'pmem' driver so
1622 they can be used for persistent storage.
1623
1624 Say Y if unsure.
1625
506f1d07
SR
1626config HIGHPTE
1627 bool "Allocate 3rd-level pagetables from highmem"
6fc108a0 1628 depends on HIGHMEM
8f9ca475 1629 ---help---
506f1d07
SR
1630 The VM uses one page table entry for each page of physical memory.
1631 For systems with a lot of RAM, this can be wasteful of precious
1632 low memory. Setting this option will put user-space page table
1633 entries in high memory.
1634
9f077871 1635config X86_CHECK_BIOS_CORRUPTION
8f9ca475
IM
1636 bool "Check for low memory corruption"
1637 ---help---
1638 Periodically check for memory corruption in low memory, which
1639 is suspected to be caused by BIOS. Even when enabled in the
1640 configuration, it is disabled at runtime. Enable it by
1641 setting "memory_corruption_check=1" on the kernel command
1642 line. By default it scans the low 64k of memory every 60
1643 seconds; see the memory_corruption_check_size and
1644 memory_corruption_check_period parameters in
8c27ceff 1645 Documentation/admin-guide/kernel-parameters.rst to adjust this.
8f9ca475
IM
1646
1647 When enabled with the default parameters, this option has
1648 almost no overhead, as it reserves a relatively small amount
1649 of memory and scans it infrequently. It both detects corruption
1650 and prevents it from affecting the running system.
1651
1652 It is, however, intended as a diagnostic tool; if repeatable
1653 BIOS-originated corruption always affects the same memory,
1654 you can use memmap= to prevent the kernel from using that
1655 memory.
9f077871 1656
c885df50 1657config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
8f9ca475 1658 bool "Set the default setting of memory_corruption_check"
c885df50
JF
1659 depends on X86_CHECK_BIOS_CORRUPTION
1660 default y
8f9ca475
IM
1661 ---help---
1662 Set whether the default state of memory_corruption_check is
1663 on or off.
c885df50 1664
9ea77bdb 1665config X86_RESERVE_LOW
d0cd7425
PA
1666 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1667 default 64
1668 range 4 640
8f9ca475 1669 ---help---
d0cd7425
PA
1670 Specify the amount of low memory to reserve for the BIOS.
1671
1672 The first page contains BIOS data structures that the kernel
1673 must not use, so that page must always be reserved.
1674
1675 By default we reserve the first 64K of physical RAM, as a
1676 number of BIOSes are known to corrupt that memory range
1677 during events such as suspend/resume or monitor cable
1678 insertion, so it must not be used by the kernel.
fc381519 1679
d0cd7425
PA
1680 You can set this to 4 if you are absolutely sure that you
1681 trust the BIOS to get all its memory reservations and usages
1682 right. If you know your BIOS have problems beyond the
1683 default 64K area, you can set this to 640 to avoid using the
1684 entire low memory range.
fc381519 1685
d0cd7425
PA
1686 If you have doubts about the BIOS (e.g. suspend/resume does
1687 not work or there's kernel crashes after certain hardware
1688 hotplug events) then you might want to enable
1689 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1690 typical corruption patterns.
fc381519 1691
d0cd7425 1692 Leave this to the default value of 64 if you are unsure.
fc381519 1693
506f1d07
SR
1694config MATH_EMULATION
1695 bool
a5b9e5a2 1696 depends on MODIFY_LDT_SYSCALL
506f1d07
SR
1697 prompt "Math emulation" if X86_32
1698 ---help---
1699 Linux can emulate a math coprocessor (used for floating point
1700 operations) if you don't have one. 486DX and Pentium processors have
1701 a math coprocessor built in, 486SX and 386 do not, unless you added
1702 a 487DX or 387, respectively. (The messages during boot time can
1703 give you some hints here ["man dmesg"].) Everyone needs either a
1704 coprocessor or this emulation.
1705
1706 If you don't have a math coprocessor, you need to say Y here; if you
1707 say Y here even though you have a coprocessor, the coprocessor will
1708 be used nevertheless. (This behavior can be changed with the kernel
1709 command line option "no387", which comes handy if your coprocessor
1710 is broken. Try "man bootparam" or see the documentation of your boot
1711 loader (lilo or loadlin) about how to pass options to the kernel at
1712 boot time.) This means that it is a good idea to say Y here if you
1713 intend to use this kernel on different machines.
1714
1715 More information about the internals of the Linux math coprocessor
1716 emulation can be found in <file:arch/x86/math-emu/README>.
1717
1718 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1719 kernel, it won't hurt.
1720
1721config MTRR
6fc108a0 1722 def_bool y
6a108a14 1723 prompt "MTRR (Memory Type Range Register) support" if EXPERT
506f1d07
SR
1724 ---help---
1725 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1726 the Memory Type Range Registers (MTRRs) may be used to control
1727 processor access to memory ranges. This is most useful if you have
1728 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1729 allows bus write transfers to be combined into a larger transfer
1730 before bursting over the PCI/AGP bus. This can increase performance
1731 of image write operations 2.5 times or more. Saying Y here creates a
1732 /proc/mtrr file which may be used to manipulate your processor's
1733 MTRRs. Typically the X server should use this.
1734
1735 This code has a reasonably generic interface so that similar
1736 control registers on other processors can be easily supported
1737 as well:
1738
1739 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1740 Registers (ARRs) which provide a similar functionality to MTRRs. For
1741 these, the ARRs are used to emulate the MTRRs.
1742 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1743 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1744 write-combining. All of these processors are supported by this code
1745 and it makes sense to say Y here if you have one of them.
1746
1747 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1748 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1749 can lead to all sorts of problems, so it's good to say Y here.
1750
1751 You can safely say Y even if your machine doesn't have MTRRs, you'll
1752 just add about 9 KB to your kernel.
1753
7225e751 1754 See <file:Documentation/x86/mtrr.txt> for more information.
506f1d07 1755
95ffa243 1756config MTRR_SANITIZER
2ffb3501 1757 def_bool y
95ffa243
YL
1758 prompt "MTRR cleanup support"
1759 depends on MTRR
8f9ca475 1760 ---help---
aba3728c
TG
1761 Convert MTRR layout from continuous to discrete, so X drivers can
1762 add writeback entries.
95ffa243 1763
aba3728c 1764 Can be disabled with disable_mtrr_cleanup on the kernel command line.
692105b8 1765 The largest mtrr entry size for a continuous block can be set with
aba3728c 1766 mtrr_chunk_size.
95ffa243 1767
2ffb3501 1768 If unsure, say Y.
95ffa243
YL
1769
1770config MTRR_SANITIZER_ENABLE_DEFAULT
f5098d62
YL
1771 int "MTRR cleanup enable value (0-1)"
1772 range 0 1
1773 default "0"
95ffa243 1774 depends on MTRR_SANITIZER
8f9ca475 1775 ---help---
f5098d62 1776 Enable mtrr cleanup default value
95ffa243 1777
12031a62
YL
1778config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1779 int "MTRR cleanup spare reg num (0-7)"
1780 range 0 7
1781 default "1"
1782 depends on MTRR_SANITIZER
8f9ca475 1783 ---help---
12031a62 1784 mtrr cleanup spare entries default, it can be changed via
aba3728c 1785 mtrr_spare_reg_nr=N on the kernel command line.
12031a62 1786
2e5d9c85 1787config X86_PAT
6fc108a0 1788 def_bool y
6a108a14 1789 prompt "x86 PAT support" if EXPERT
2a8a2719 1790 depends on MTRR
8f9ca475 1791 ---help---
2e5d9c85 1792 Use PAT attributes to setup page level cache control.
042b78e4 1793
2e5d9c85 1794 PATs are the modern equivalents of MTRRs and are much more
1795 flexible than MTRRs.
1796
1797 Say N here if you see bootup problems (boot crash, boot hang,
042b78e4 1798 spontaneous reboots) or a non-working video driver.
2e5d9c85 1799
1800 If unsure, say Y.
1801
46cf98cd
VP
1802config ARCH_USES_PG_UNCACHED
1803 def_bool y
1804 depends on X86_PAT
1805
628c6246
PA
1806config ARCH_RANDOM
1807 def_bool y
1808 prompt "x86 architectural random number generator" if EXPERT
1809 ---help---
1810 Enable the x86 architectural RDRAND instruction
1811 (Intel Bull Mountain technology) to generate random numbers.
1812 If supported, this is a high bandwidth, cryptographically
1813 secure hardware random number generator.
1814
51ae4a2d
PA
1815config X86_SMAP
1816 def_bool y
1817 prompt "Supervisor Mode Access Prevention" if EXPERT
1818 ---help---
1819 Supervisor Mode Access Prevention (SMAP) is a security
1820 feature in newer Intel processors. There is a small
1821 performance cost if this enabled and turned on; there is
1822 also a small increase in the kernel size if this is enabled.
1823
1824 If unsure, say Y.
1825
aa35f896 1826config X86_INTEL_UMIP
796ebc81 1827 def_bool y
aa35f896
RN
1828 depends on CPU_SUP_INTEL
1829 prompt "Intel User Mode Instruction Prevention" if EXPERT
1830 ---help---
1831 The User Mode Instruction Prevention (UMIP) is a security
1832 feature in newer Intel processors. If enabled, a general
796ebc81
RN
1833 protection fault is issued if the SGDT, SLDT, SIDT, SMSW
1834 or STR instructions are executed in user mode. These instructions
1835 unnecessarily expose information about the hardware state.
1836
1837 The vast majority of applications do not use these instructions.
1838 For the very few that do, software emulation is provided in
1839 specific cases in protected and virtual-8086 modes. Emulated
1840 results are dummy.
aa35f896 1841
72e9b5fe
DH
1842config X86_INTEL_MPX
1843 prompt "Intel MPX (Memory Protection Extensions)"
1844 def_bool n
df3735c5
RR
1845 # Note: only available in 64-bit mode due to VMA flags shortage
1846 depends on CPU_SUP_INTEL && X86_64
1847 select ARCH_USES_HIGH_VMA_FLAGS
72e9b5fe
DH
1848 ---help---
1849 MPX provides hardware features that can be used in
1850 conjunction with compiler-instrumented code to check
1851 memory references. It is designed to detect buffer
1852 overflow or underflow bugs.
1853
1854 This option enables running applications which are
1855 instrumented or otherwise use MPX. It does not use MPX
1856 itself inside the kernel or to protect the kernel
1857 against bad memory references.
1858
1859 Enabling this option will make the kernel larger:
1860 ~8k of kernel text and 36 bytes of data on a 64-bit
1861 defconfig. It adds a long to the 'mm_struct' which
1862 will increase the kernel memory overhead of each
1863 process and adds some branches to paths used during
1864 exec() and munmap().
1865
1866 For details, see Documentation/x86/intel_mpx.txt
1867
1868 If unsure, say N.
1869
35e97790 1870config X86_INTEL_MEMORY_PROTECTION_KEYS
284244a9 1871 prompt "Intel Memory Protection Keys"
35e97790 1872 def_bool y
284244a9 1873 # Note: only available in 64-bit mode
35e97790 1874 depends on CPU_SUP_INTEL && X86_64
52c8e601
IM
1875 select ARCH_USES_HIGH_VMA_FLAGS
1876 select ARCH_HAS_PKEYS
284244a9
DH
1877 ---help---
1878 Memory Protection Keys provides a mechanism for enforcing
1879 page-based protections, but without requiring modification of the
1880 page tables when an application changes protection domains.
1881
1882 For details, see Documentation/x86/protection-keys.txt
1883
1884 If unsure, say y.
35e97790 1885
506f1d07 1886config EFI
9ba16087 1887 bool "EFI runtime service support"
5b83683f 1888 depends on ACPI
f6ce5002 1889 select UCS2_STRING
022ee6c5 1890 select EFI_RUNTIME_WRAPPERS
506f1d07 1891 ---help---
8f9ca475
IM
1892 This enables the kernel to use EFI runtime services that are
1893 available (such as the EFI variable services).
506f1d07 1894
8f9ca475
IM
1895 This option is only useful on systems that have EFI firmware.
1896 In addition, you should use the latest ELILO loader available
1897 at <http://elilo.sourceforge.net> in order to take advantage
1898 of EFI runtime services. However, even with this option, the
1899 resultant kernel should continue to boot on existing non-EFI
1900 platforms.
506f1d07 1901
291f3632
MF
1902config EFI_STUB
1903 bool "EFI stub support"
b16d8c23 1904 depends on EFI && !X86_USE_3DNOW
7b2a583a 1905 select RELOCATABLE
291f3632
MF
1906 ---help---
1907 This kernel feature allows a bzImage to be loaded directly
1908 by EFI firmware without the use of a bootloader.
1909
4172fe2f 1910 See Documentation/efi-stub.txt for more information.
0c759662 1911
7d453eee
MF
1912config EFI_MIXED
1913 bool "EFI mixed-mode support"
1914 depends on EFI_STUB && X86_64
1915 ---help---
1916 Enabling this feature allows a 64-bit kernel to be booted
1917 on a 32-bit firmware, provided that your CPU supports 64-bit
1918 mode.
1919
1920 Note that it is not possible to boot a mixed-mode enabled
1921 kernel via the EFI boot stub - a bootloader that supports
1922 the EFI handover protocol must be used.
1923
1924 If unsure, say N.
1925
506f1d07 1926config SECCOMP
3c2362e6
HH
1927 def_bool y
1928 prompt "Enable seccomp to safely compute untrusted bytecode"
8f9ca475 1929 ---help---
506f1d07
SR
1930 This kernel feature is useful for number crunching applications
1931 that may need to compute untrusted bytecode during their
1932 execution. By using pipes or other transports made available to
1933 the process as file descriptors supporting the read/write
1934 syscalls, it's possible to isolate those applications in
1935 their own address space using seccomp. Once seccomp is
9c0bbee8 1936 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
506f1d07
SR
1937 and the task is only allowed to execute a few safe syscalls
1938 defined by each seccomp mode.
1939
1940 If unsure, say Y. Only embedded should say N here.
1941
506f1d07
SR
1942source kernel/Kconfig.hz
1943
1944config KEXEC
1945 bool "kexec system call"
2965faa5 1946 select KEXEC_CORE
8f9ca475 1947 ---help---
506f1d07
SR
1948 kexec is a system call that implements the ability to shutdown your
1949 current kernel, and to start another kernel. It is like a reboot
1950 but it is independent of the system firmware. And like a reboot
1951 you can start any kernel with it, not just Linux.
1952
1953 The name comes from the similarity to the exec system call.
1954
1955 It is an ongoing process to be certain the hardware in a machine
1956 is properly shutdown, so do not be surprised if this code does not
bf220695
GU
1957 initially work for you. As of this writing the exact hardware
1958 interface is strongly in flux, so no good recommendation can be
1959 made.
506f1d07 1960
74ca317c
VG
1961config KEXEC_FILE
1962 bool "kexec file based system call"
2965faa5 1963 select KEXEC_CORE
74ca317c 1964 select BUILD_BIN2C
74ca317c
VG
1965 depends on X86_64
1966 depends on CRYPTO=y
1967 depends on CRYPTO_SHA256=y
1968 ---help---
1969 This is new version of kexec system call. This system call is
1970 file based and takes file descriptors as system call argument
1971 for kernel and initramfs as opposed to list of segments as
1972 accepted by previous system call.
1973
8e7d8381
VG
1974config KEXEC_VERIFY_SIG
1975 bool "Verify kernel signature during kexec_file_load() syscall"
74ca317c 1976 depends on KEXEC_FILE
8e7d8381
VG
1977 ---help---
1978 This option makes kernel signature verification mandatory for
d8eb8940
BP
1979 the kexec_file_load() syscall.
1980
1981 In addition to that option, you need to enable signature
1982 verification for the corresponding kernel image type being
1983 loaded in order for this to work.
8e7d8381
VG
1984
1985config KEXEC_BZIMAGE_VERIFY_SIG
1986 bool "Enable bzImage signature verification support"
1987 depends on KEXEC_VERIFY_SIG
1988 depends on SIGNED_PE_FILE_VERIFICATION
1989 select SYSTEM_TRUSTED_KEYRING
1990 ---help---
1991 Enable bzImage signature verification support.
1992
506f1d07 1993config CRASH_DUMP
04b69447 1994 bool "kernel crash dumps"
506f1d07 1995 depends on X86_64 || (X86_32 && HIGHMEM)
8f9ca475 1996 ---help---
506f1d07
SR
1997 Generate crash dump after being started by kexec.
1998 This should be normally only set in special crash dump kernels
1999 which are loaded in the main kernel with kexec-tools into
2000 a specially reserved region and then later executed after
2001 a crash by kdump/kexec. The crash dump kernel must be compiled
2002 to a memory address not used by the main kernel or BIOS using
2003 PHYSICAL_START, or it must be built as a relocatable image
2004 (CONFIG_RELOCATABLE=y).
2005 For more details see Documentation/kdump/kdump.txt
2006
3ab83521 2007config KEXEC_JUMP
6ea30386 2008 bool "kexec jump"
fee7b0d8 2009 depends on KEXEC && HIBERNATION
8f9ca475 2010 ---help---
89081d17
HY
2011 Jump between original kernel and kexeced kernel and invoke
2012 code in physical address mode via KEXEC
3ab83521 2013
506f1d07 2014config PHYSICAL_START
6a108a14 2015 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
ceefccc9 2016 default "0x1000000"
8f9ca475 2017 ---help---
506f1d07
SR
2018 This gives the physical address where the kernel is loaded.
2019
2020 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2021 bzImage will decompress itself to above physical address and
2022 run from there. Otherwise, bzImage will run from the address where
2023 it has been loaded by the boot loader and will ignore above physical
2024 address.
2025
2026 In normal kdump cases one does not have to set/change this option
2027 as now bzImage can be compiled as a completely relocatable image
2028 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2029 address. This option is mainly useful for the folks who don't want
2030 to use a bzImage for capturing the crash dump and want to use a
2031 vmlinux instead. vmlinux is not relocatable hence a kernel needs
2032 to be specifically compiled to run from a specific memory area
2033 (normally a reserved region) and this option comes handy.
2034
ceefccc9
PA
2035 So if you are using bzImage for capturing the crash dump,
2036 leave the value here unchanged to 0x1000000 and set
2037 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
2038 for capturing the crash dump change this value to start of
2039 the reserved region. In other words, it can be set based on
2040 the "X" value as specified in the "crashkernel=YM@XM"
2041 command line boot parameter passed to the panic-ed
2042 kernel. Please take a look at Documentation/kdump/kdump.txt
2043 for more details about crash dumps.
506f1d07
SR
2044
2045 Usage of bzImage for capturing the crash dump is recommended as
2046 one does not have to build two kernels. Same kernel can be used
2047 as production kernel and capture kernel. Above option should have
2048 gone away after relocatable bzImage support is introduced. But it
2049 is present because there are users out there who continue to use
2050 vmlinux for dump capture. This option should go away down the
2051 line.
2052
2053 Don't change this unless you know what you are doing.
2054
2055config RELOCATABLE
26717808
PA
2056 bool "Build a relocatable kernel"
2057 default y
8f9ca475 2058 ---help---
506f1d07
SR
2059 This builds a kernel image that retains relocation information
2060 so it can be loaded someplace besides the default 1MB.
2061 The relocations tend to make the kernel binary about 10% larger,
2062 but are discarded at runtime.
2063
2064 One use is for the kexec on panic case where the recovery kernel
2065 must live at a different physical address than the primary
2066 kernel.
2067
2068 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2069 it has been loaded at and the compile time physical address
8ab3820f 2070 (CONFIG_PHYSICAL_START) is used as the minimum location.
506f1d07 2071
8ab3820f 2072config RANDOMIZE_BASE
e8581e3d 2073 bool "Randomize the address of the kernel image (KASLR)"
8ab3820f 2074 depends on RELOCATABLE
6807c846 2075 default y
8ab3820f 2076 ---help---
e8581e3d
BH
2077 In support of Kernel Address Space Layout Randomization (KASLR),
2078 this randomizes the physical address at which the kernel image
2079 is decompressed and the virtual address where the kernel
2080 image is mapped, as a security feature that deters exploit
2081 attempts relying on knowledge of the location of kernel
2082 code internals.
2083
ed9f007e
KC
2084 On 64-bit, the kernel physical and virtual addresses are
2085 randomized separately. The physical address will be anywhere
2086 between 16MB and the top of physical memory (up to 64TB). The
2087 virtual address will be randomized from 16MB up to 1GB (9 bits
2088 of entropy). Note that this also reduces the memory space
2089 available to kernel modules from 1.5GB to 1GB.
2090
2091 On 32-bit, the kernel physical and virtual addresses are
2092 randomized together. They will be randomized from 16MB up to
2093 512MB (8 bits of entropy).
e8581e3d
BH
2094
2095 Entropy is generated using the RDRAND instruction if it is
2096 supported. If RDTSC is supported, its value is mixed into
2097 the entropy pool as well. If neither RDRAND nor RDTSC are
ed9f007e
KC
2098 supported, then entropy is read from the i8254 timer. The
2099 usable entropy is limited by the kernel being built using
2100 2GB addressing, and that PHYSICAL_ALIGN must be at a
2101 minimum of 2MB. As a result, only 10 bits of entropy are
2102 theoretically possible, but the implementations are further
2103 limited due to memory layouts.
e8581e3d 2104
6807c846 2105 If unsure, say Y.
8ab3820f
KC
2106
2107# Relocation on x86 needs some additional build support
845adf72
PA
2108config X86_NEED_RELOCS
2109 def_bool y
8ab3820f 2110 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
845adf72 2111
506f1d07 2112config PHYSICAL_ALIGN
a0215061 2113 hex "Alignment value to which kernel should be aligned"
8ab3820f 2114 default "0x200000"
a0215061
KC
2115 range 0x2000 0x1000000 if X86_32
2116 range 0x200000 0x1000000 if X86_64
8f9ca475 2117 ---help---
506f1d07
SR
2118 This value puts the alignment restrictions on physical address
2119 where kernel is loaded and run from. Kernel is compiled for an
2120 address which meets above alignment restriction.
2121
2122 If bootloader loads the kernel at a non-aligned address and
2123 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2124 address aligned to above value and run from there.
2125
2126 If bootloader loads the kernel at a non-aligned address and
2127 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2128 load address and decompress itself to the address it has been
2129 compiled for and run from there. The address for which kernel is
2130 compiled already meets above alignment restrictions. Hence the
2131 end result is that kernel runs from a physical address meeting
2132 above alignment restrictions.
2133
a0215061
KC
2134 On 32-bit this value must be a multiple of 0x2000. On 64-bit
2135 this value must be a multiple of 0x200000.
2136
506f1d07
SR
2137 Don't change this unless you know what you are doing.
2138
0483e1fa
TG
2139config RANDOMIZE_MEMORY
2140 bool "Randomize the kernel memory sections"
2141 depends on X86_64
2142 depends on RANDOMIZE_BASE
2143 default RANDOMIZE_BASE
2144 ---help---
2145 Randomizes the base virtual address of kernel memory sections
2146 (physical memory mapping, vmalloc & vmemmap). This security feature
2147 makes exploits relying on predictable memory locations less reliable.
2148
2149 The order of allocations remains unchanged. Entropy is generated in
2150 the same way as RANDOMIZE_BASE. Current implementation in the optimal
2151 configuration have in average 30,000 different possible virtual
2152 addresses for each memory section.
2153
6807c846 2154 If unsure, say Y.
0483e1fa 2155
90397a41
TG
2156config RANDOMIZE_MEMORY_PHYSICAL_PADDING
2157 hex "Physical memory mapping padding" if EXPERT
2158 depends on RANDOMIZE_MEMORY
2159 default "0xa" if MEMORY_HOTPLUG
2160 default "0x0"
2161 range 0x1 0x40 if MEMORY_HOTPLUG
2162 range 0x0 0x40
2163 ---help---
2164 Define the padding in terabytes added to the existing physical
2165 memory size during kernel memory randomization. It is useful
2166 for memory hotplug support but reduces the entropy available for
2167 address randomization.
2168
2169 If unsure, leave at the default value.
2170
506f1d07 2171config HOTPLUG_CPU
7c13e6a3 2172 bool "Support for hot-pluggable CPUs"
40b31360 2173 depends on SMP
506f1d07 2174 ---help---
7c13e6a3
DS
2175 Say Y here to allow turning CPUs off and on. CPUs can be
2176 controlled through /sys/devices/system/cpu.
2177 ( Note: power management support will enable this option
2178 automatically on SMP systems. )
2179 Say N if you want to disable CPU hotplug.
506f1d07 2180
80aa1dff
FY
2181config BOOTPARAM_HOTPLUG_CPU0
2182 bool "Set default setting of cpu0_hotpluggable"
2183 default n
2c922cd0 2184 depends on HOTPLUG_CPU
80aa1dff
FY
2185 ---help---
2186 Set whether default state of cpu0_hotpluggable is on or off.
2187
2188 Say Y here to enable CPU0 hotplug by default. If this switch
2189 is turned on, there is no need to give cpu0_hotplug kernel
2190 parameter and the CPU0 hotplug feature is enabled by default.
2191
2192 Please note: there are two known CPU0 dependencies if you want
2193 to enable the CPU0 hotplug feature either by this switch or by
2194 cpu0_hotplug kernel parameter.
2195
2196 First, resume from hibernate or suspend always starts from CPU0.
2197 So hibernate and suspend are prevented if CPU0 is offline.
2198
2199 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2200 offline if any interrupt can not migrate out of CPU0. There may
2201 be other CPU0 dependencies.
2202
2203 Please make sure the dependencies are under your control before
2204 you enable this feature.
2205
2206 Say N if you don't want to enable CPU0 hotplug feature by default.
2207 You still can enable the CPU0 hotplug feature at boot by kernel
2208 parameter cpu0_hotplug.
2209
a71c8bc5
FY
2210config DEBUG_HOTPLUG_CPU0
2211 def_bool n
2212 prompt "Debug CPU0 hotplug"
2c922cd0 2213 depends on HOTPLUG_CPU
a71c8bc5
FY
2214 ---help---
2215 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2216 soon as possible and boots up userspace with CPU0 offlined. User
2217 can online CPU0 back after boot time.
2218
2219 To debug CPU0 hotplug, you need to enable CPU0 offline/online
2220 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2221 compilation or giving cpu0_hotplug kernel parameter at boot.
2222
2223 If unsure, say N.
2224
506f1d07 2225config COMPAT_VDSO
b0b49f26
AL
2226 def_bool n
2227 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
953fee1d 2228 depends on COMPAT_32
8f9ca475 2229 ---help---
b0b49f26
AL
2230 Certain buggy versions of glibc will crash if they are
2231 presented with a 32-bit vDSO that is not mapped at the address
2232 indicated in its segment table.
e84446de 2233
b0b49f26
AL
2234 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2235 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2236 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
2237 the only released version with the bug, but OpenSUSE 9
2238 contains a buggy "glibc 2.3.2".
506f1d07 2239
b0b49f26
AL
2240 The symptom of the bug is that everything crashes on startup, saying:
2241 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2242
2243 Saying Y here changes the default value of the vdso32 boot
2244 option from 1 to 0, which turns off the 32-bit vDSO entirely.
2245 This works around the glibc bug but hurts performance.
2246
2247 If unsure, say N: if you are compiling your own kernel, you
2248 are unlikely to be using a buggy version of glibc.
506f1d07 2249
3dc33bd3
KC
2250choice
2251 prompt "vsyscall table for legacy applications"
2252 depends on X86_64
2253 default LEGACY_VSYSCALL_EMULATE
2254 help
2255 Legacy user code that does not know how to find the vDSO expects
2256 to be able to issue three syscalls by calling fixed addresses in
2257 kernel space. Since this location is not randomized with ASLR,
2258 it can be used to assist security vulnerability exploitation.
2259
2260 This setting can be changed at boot time via the kernel command
2261 line parameter vsyscall=[native|emulate|none].
2262
2263 On a system with recent enough glibc (2.14 or newer) and no
2264 static binaries, you can say None without a performance penalty
2265 to improve security.
2266
2267 If unsure, select "Emulate".
2268
2269 config LEGACY_VSYSCALL_NATIVE
2270 bool "Native"
2271 help
2272 Actual executable code is located in the fixed vsyscall
2273 address mapping, implementing time() efficiently. Since
2274 this makes the mapping executable, it can be used during
2275 security vulnerability exploitation (traditionally as
2276 ROP gadgets). This configuration is not recommended.
2277
2278 config LEGACY_VSYSCALL_EMULATE
2279 bool "Emulate"
2280 help
2281 The kernel traps and emulates calls into the fixed
2282 vsyscall address mapping. This makes the mapping
2283 non-executable, but it still contains known contents,
2284 which could be used in certain rare security vulnerability
2285 exploits. This configuration is recommended when userspace
2286 still uses the vsyscall area.
2287
2288 config LEGACY_VSYSCALL_NONE
2289 bool "None"
2290 help
2291 There will be no vsyscall mapping at all. This will
2292 eliminate any risk of ASLR bypass due to the vsyscall
2293 fixed address mapping. Attempts to use the vsyscalls
2294 will be reported to dmesg, so that either old or
2295 malicious userspace programs can be identified.
2296
2297endchoice
2298
516cbf37
TB
2299config CMDLINE_BOOL
2300 bool "Built-in kernel command line"
8f9ca475 2301 ---help---
516cbf37
TB
2302 Allow for specifying boot arguments to the kernel at
2303 build time. On some systems (e.g. embedded ones), it is
2304 necessary or convenient to provide some or all of the
2305 kernel boot arguments with the kernel itself (that is,
2306 to not rely on the boot loader to provide them.)
2307
2308 To compile command line arguments into the kernel,
2309 set this option to 'Y', then fill in the
69711ca1 2310 boot arguments in CONFIG_CMDLINE.
516cbf37
TB
2311
2312 Systems with fully functional boot loaders (i.e. non-embedded)
2313 should leave this option set to 'N'.
2314
2315config CMDLINE
2316 string "Built-in kernel command string"
2317 depends on CMDLINE_BOOL
2318 default ""
8f9ca475 2319 ---help---
516cbf37
TB
2320 Enter arguments here that should be compiled into the kernel
2321 image and used at boot time. If the boot loader provides a
2322 command line at boot time, it is appended to this string to
2323 form the full kernel command line, when the system boots.
2324
2325 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2326 change this behavior.
2327
2328 In most cases, the command line (whether built-in or provided
2329 by the boot loader) should specify the device for the root
2330 file system.
2331
2332config CMDLINE_OVERRIDE
2333 bool "Built-in command line overrides boot loader arguments"
516cbf37 2334 depends on CMDLINE_BOOL
8f9ca475 2335 ---help---
516cbf37
TB
2336 Set this option to 'Y' to have the kernel ignore the boot loader
2337 command line, and use ONLY the built-in command line.
2338
2339 This is used to work around broken boot loaders. This should
2340 be set to 'N' under normal conditions.
2341
a5b9e5a2
AL
2342config MODIFY_LDT_SYSCALL
2343 bool "Enable the LDT (local descriptor table)" if EXPERT
2344 default y
2345 ---help---
2346 Linux can allow user programs to install a per-process x86
2347 Local Descriptor Table (LDT) using the modify_ldt(2) system
2348 call. This is required to run 16-bit or segmented code such as
2349 DOSEMU or some Wine programs. It is also used by some very old
2350 threading libraries.
2351
2352 Enabling this feature adds a small amount of overhead to
2353 context switches and increases the low-level kernel attack
2354 surface. Disabling it removes the modify_ldt(2) system call.
2355
2356 Saying 'N' here may make sense for embedded or server kernels.
2357
b700e7f0
SJ
2358source "kernel/livepatch/Kconfig"
2359
506f1d07
SR
2360endmenu
2361
3072e413
MH
2362config ARCH_HAS_ADD_PAGES
2363 def_bool y
2364 depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
2365
506f1d07
SR
2366config ARCH_ENABLE_MEMORY_HOTPLUG
2367 def_bool y
2368 depends on X86_64 || (X86_32 && HIGHMEM)
2369
35551053
GH
2370config ARCH_ENABLE_MEMORY_HOTREMOVE
2371 def_bool y
2372 depends on MEMORY_HOTPLUG
2373
e534c7c5 2374config USE_PERCPU_NUMA_NODE_ID
645a7919 2375 def_bool y
e534c7c5
LS
2376 depends on NUMA
2377
9491846f
KS
2378config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2379 def_bool y
2380 depends on X86_64 || X86_PAE
2381
c177c81e
NH
2382config ARCH_ENABLE_HUGEPAGE_MIGRATION
2383 def_bool y
2384 depends on X86_64 && HUGETLB_PAGE && MIGRATION
2385
9c670ea3
NH
2386config ARCH_ENABLE_THP_MIGRATION
2387 def_bool y
2388 depends on X86_64 && TRANSPARENT_HUGEPAGE
2389
da85f865 2390menu "Power management and ACPI options"
e279b6c1
SR
2391
2392config ARCH_HIBERNATION_HEADER
3c2362e6 2393 def_bool y
e279b6c1 2394 depends on X86_64 && HIBERNATION
e279b6c1
SR
2395
2396source "kernel/power/Kconfig"
2397
2398source "drivers/acpi/Kconfig"
2399
efafc8b2
FT
2400source "drivers/sfi/Kconfig"
2401
a6b68076 2402config X86_APM_BOOT
6fc108a0 2403 def_bool y
282e5aab 2404 depends on APM
a6b68076 2405
e279b6c1
SR
2406menuconfig APM
2407 tristate "APM (Advanced Power Management) BIOS support"
efefa6f6 2408 depends on X86_32 && PM_SLEEP
e279b6c1
SR
2409 ---help---
2410 APM is a BIOS specification for saving power using several different
2411 techniques. This is mostly useful for battery powered laptops with
2412 APM compliant BIOSes. If you say Y here, the system time will be
2413 reset after a RESUME operation, the /proc/apm device will provide
2414 battery status information, and user-space programs will receive
2415 notification of APM "events" (e.g. battery status change).
2416
2417 If you select "Y" here, you can disable actual use of the APM
2418 BIOS by passing the "apm=off" option to the kernel at boot time.
2419
2420 Note that the APM support is almost completely disabled for
2421 machines with more than one CPU.
2422
2423 In order to use APM, you will need supporting software. For location
2dc98fd3
MW
2424 and more information, read <file:Documentation/power/apm-acpi.txt>
2425 and the Battery Powered Linux mini-HOWTO, available from
e279b6c1
SR
2426 <http://www.tldp.org/docs.html#howto>.
2427
2428 This driver does not spin down disk drives (see the hdparm(8)
2429 manpage ("man 8 hdparm") for that), and it doesn't turn off
2430 VESA-compliant "green" monitors.
2431
2432 This driver does not support the TI 4000M TravelMate and the ACER
2433 486/DX4/75 because they don't have compliant BIOSes. Many "green"
2434 desktop machines also don't have compliant BIOSes, and this driver
2435 may cause those machines to panic during the boot phase.
2436
2437 Generally, if you don't have a battery in your machine, there isn't
2438 much point in using this driver and you should say N. If you get
2439 random kernel OOPSes or reboots that don't seem to be related to
2440 anything, try disabling/enabling this option (or disabling/enabling
2441 APM in your BIOS).
2442
2443 Some other things you should try when experiencing seemingly random,
2444 "weird" problems:
2445
2446 1) make sure that you have enough swap space and that it is
2447 enabled.
2448 2) pass the "no-hlt" option to the kernel
2449 3) switch on floating point emulation in the kernel and pass
2450 the "no387" option to the kernel
2451 4) pass the "floppy=nodma" option to the kernel
2452 5) pass the "mem=4M" option to the kernel (thereby disabling
2453 all but the first 4 MB of RAM)
2454 6) make sure that the CPU is not over clocked.
2455 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2456 8) disable the cache from your BIOS settings
2457 9) install a fan for the video card or exchange video RAM
2458 10) install a better fan for the CPU
2459 11) exchange RAM chips
2460 12) exchange the motherboard.
2461
2462 To compile this driver as a module, choose M here: the
2463 module will be called apm.
2464
2465if APM
2466
2467config APM_IGNORE_USER_SUSPEND
2468 bool "Ignore USER SUSPEND"
8f9ca475 2469 ---help---
e279b6c1
SR
2470 This option will ignore USER SUSPEND requests. On machines with a
2471 compliant APM BIOS, you want to say N. However, on the NEC Versa M
2472 series notebooks, it is necessary to say Y because of a BIOS bug.
2473
2474config APM_DO_ENABLE
2475 bool "Enable PM at boot time"
2476 ---help---
2477 Enable APM features at boot time. From page 36 of the APM BIOS
2478 specification: "When disabled, the APM BIOS does not automatically
2479 power manage devices, enter the Standby State, enter the Suspend
2480 State, or take power saving steps in response to CPU Idle calls."
2481 This driver will make CPU Idle calls when Linux is idle (unless this
2482 feature is turned off -- see "Do CPU IDLE calls", below). This
2483 should always save battery power, but more complicated APM features
2484 will be dependent on your BIOS implementation. You may need to turn
2485 this option off if your computer hangs at boot time when using APM
2486 support, or if it beeps continuously instead of suspending. Turn
2487 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2488 T400CDT. This is off by default since most machines do fine without
2489 this feature.
2490
2491config APM_CPU_IDLE
dd8af076 2492 depends on CPU_IDLE
e279b6c1 2493 bool "Make CPU Idle calls when idle"
8f9ca475 2494 ---help---
e279b6c1
SR
2495 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2496 On some machines, this can activate improved power savings, such as
2497 a slowed CPU clock rate, when the machine is idle. These idle calls
2498 are made after the idle loop has run for some length of time (e.g.,
2499 333 mS). On some machines, this will cause a hang at boot time or
2500 whenever the CPU becomes idle. (On machines with more than one CPU,
2501 this option does nothing.)
2502
2503config APM_DISPLAY_BLANK
2504 bool "Enable console blanking using APM"
8f9ca475 2505 ---help---
e279b6c1
SR
2506 Enable console blanking using the APM. Some laptops can use this to
2507 turn off the LCD backlight when the screen blanker of the Linux
2508 virtual console blanks the screen. Note that this is only used by
2509 the virtual console screen blanker, and won't turn off the backlight
2510 when using the X Window system. This also doesn't have anything to
2511 do with your VESA-compliant power-saving monitor. Further, this
2512 option doesn't work for all laptops -- it might not turn off your
2513 backlight at all, or it might print a lot of errors to the console,
2514 especially if you are using gpm.
2515
2516config APM_ALLOW_INTS
2517 bool "Allow interrupts during APM BIOS calls"
8f9ca475 2518 ---help---
e279b6c1
SR
2519 Normally we disable external interrupts while we are making calls to
2520 the APM BIOS as a measure to lessen the effects of a badly behaving
2521 BIOS implementation. The BIOS should reenable interrupts if it
2522 needs to. Unfortunately, some BIOSes do not -- especially those in
2523 many of the newer IBM Thinkpads. If you experience hangs when you
2524 suspend, try setting this to Y. Otherwise, say N.
2525
e279b6c1
SR
2526endif # APM
2527
bb0a56ec 2528source "drivers/cpufreq/Kconfig"
e279b6c1
SR
2529
2530source "drivers/cpuidle/Kconfig"
2531
27471fdb
AH
2532source "drivers/idle/Kconfig"
2533
e279b6c1
SR
2534endmenu
2535
2536
2537menu "Bus options (PCI etc.)"
2538
2539config PCI
1ac97018 2540 bool "PCI support"
1c858087 2541 default y
8f9ca475 2542 ---help---
e279b6c1
SR
2543 Find out whether you have a PCI motherboard. PCI is the name of a
2544 bus system, i.e. the way the CPU talks to the other stuff inside
2545 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2546 VESA. If you have PCI, say Y, otherwise N.
2547
e279b6c1
SR
2548choice
2549 prompt "PCI access mode"
efefa6f6 2550 depends on X86_32 && PCI
e279b6c1
SR
2551 default PCI_GOANY
2552 ---help---
2553 On PCI systems, the BIOS can be used to detect the PCI devices and
2554 determine their configuration. However, some old PCI motherboards
2555 have BIOS bugs and may crash if this is done. Also, some embedded
2556 PCI-based systems don't have any BIOS at all. Linux can also try to
2557 detect the PCI hardware directly without using the BIOS.
2558
2559 With this option, you can specify how Linux should detect the
2560 PCI devices. If you choose "BIOS", the BIOS will be used,
2561 if you choose "Direct", the BIOS won't be used, and if you
2562 choose "MMConfig", then PCI Express MMCONFIG will be used.
2563 If you choose "Any", the kernel will try MMCONFIG, then the
2564 direct access method and falls back to the BIOS if that doesn't
2565 work. If unsure, go with the default, which is "Any".
2566
2567config PCI_GOBIOS
2568 bool "BIOS"
2569
2570config PCI_GOMMCONFIG
2571 bool "MMConfig"
2572
2573config PCI_GODIRECT
2574 bool "Direct"
2575
3ef0e1f8 2576config PCI_GOOLPC
76fb6570 2577 bool "OLPC XO-1"
3ef0e1f8
AS
2578 depends on OLPC
2579
2bdd1b03
AS
2580config PCI_GOANY
2581 bool "Any"
2582
e279b6c1
SR
2583endchoice
2584
2585config PCI_BIOS
3c2362e6 2586 def_bool y
efefa6f6 2587 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
e279b6c1
SR
2588
2589# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2590config PCI_DIRECT
3c2362e6 2591 def_bool y
0aba496f 2592 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
e279b6c1
SR
2593
2594config PCI_MMCONFIG
3c2362e6 2595 def_bool y
5f0db7a2 2596 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
e279b6c1 2597
3ef0e1f8 2598config PCI_OLPC
2bdd1b03
AS
2599 def_bool y
2600 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
3ef0e1f8 2601
b5401a96
AN
2602config PCI_XEN
2603 def_bool y
2604 depends on PCI && XEN
2605 select SWIOTLB_XEN
2606
e279b6c1 2607config PCI_DOMAINS
3c2362e6 2608 def_bool y
e279b6c1 2609 depends on PCI
e279b6c1
SR
2610
2611config PCI_MMCONFIG
2612 bool "Support mmconfig PCI config space access"
2613 depends on X86_64 && PCI && ACPI
2614
3f6ea84a 2615config PCI_CNB20LE_QUIRK
6a108a14 2616 bool "Read CNB20LE Host Bridge Windows" if EXPERT
6ea30386 2617 depends on PCI
3f6ea84a
IS
2618 help
2619 Read the PCI windows out of the CNB20LE host bridge. This allows
2620 PCI hotplug to work on systems with the CNB20LE chipset which do
2621 not have ACPI.
2622
64a5fed6
BH
2623 There's no public spec for this chipset, and this functionality
2624 is known to be incomplete.
2625
2626 You should say N unless you know you need this.
2627
e279b6c1
SR
2628source "drivers/pci/Kconfig"
2629
3a495511
WBG
2630config ISA_BUS
2631 bool "ISA-style bus support on modern systems" if EXPERT
2632 select ISA_BUS_API
2633 help
2634 Enables ISA-style drivers on modern systems. This is necessary to
2635 support PC/104 devices on X86_64 platforms.
2636
2637 If unsure, say N.
2638
1c00f016 2639# x86_64 have no ISA slots, but can have ISA-style DMA.
e279b6c1 2640config ISA_DMA_API
1c00f016
DR
2641 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2642 default y
2643 help
2644 Enables ISA-style DMA support for devices requiring such controllers.
2645 If unsure, say Y.
e279b6c1 2646
51e68d05
LT
2647if X86_32
2648
e279b6c1
SR
2649config ISA
2650 bool "ISA support"
8f9ca475 2651 ---help---
e279b6c1
SR
2652 Find out whether you have ISA slots on your motherboard. ISA is the
2653 name of a bus system, i.e. the way the CPU talks to the other stuff
2654 inside your box. Other bus systems are PCI, EISA, MicroChannel
2655 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2656 newer boards don't support it. If you have ISA, say Y, otherwise N.
2657
2658config EISA
2659 bool "EISA support"
2660 depends on ISA
2661 ---help---
2662 The Extended Industry Standard Architecture (EISA) bus was
2663 developed as an open alternative to the IBM MicroChannel bus.
2664
2665 The EISA bus provided some of the features of the IBM MicroChannel
2666 bus while maintaining backward compatibility with cards made for
2667 the older ISA bus. The EISA bus saw limited use between 1988 and
2668 1995 when it was made obsolete by the PCI bus.
2669
2670 Say Y here if you are building a kernel for an EISA-based machine.
2671
2672 Otherwise, say N.
2673
2674source "drivers/eisa/Kconfig"
2675
e279b6c1
SR
2676config SCx200
2677 tristate "NatSemi SCx200 support"
8f9ca475 2678 ---help---
e279b6c1
SR
2679 This provides basic support for National Semiconductor's
2680 (now AMD's) Geode processors. The driver probes for the
2681 PCI-IDs of several on-chip devices, so its a good dependency
2682 for other scx200_* drivers.
2683
2684 If compiled as a module, the driver is named scx200.
2685
2686config SCx200HR_TIMER
2687 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
592913ec 2688 depends on SCx200
e279b6c1 2689 default y
8f9ca475 2690 ---help---
e279b6c1
SR
2691 This driver provides a clocksource built upon the on-chip
2692 27MHz high-resolution timer. Its also a workaround for
2693 NSC Geode SC-1100's buggy TSC, which loses time when the
2694 processor goes idle (as is done by the scheduler). The
2695 other workaround is idle=poll boot option.
2696
3ef0e1f8
AS
2697config OLPC
2698 bool "One Laptop Per Child support"
54008979 2699 depends on !X86_PAE
3c554946 2700 select GPIOLIB
dc3119e7 2701 select OF
45bb1674 2702 select OF_PROMTREE
b4e51854 2703 select IRQ_DOMAIN
8f9ca475 2704 ---help---
3ef0e1f8
AS
2705 Add support for detecting the unique features of the OLPC
2706 XO hardware.
2707
a3128588
DD
2708config OLPC_XO1_PM
2709 bool "OLPC XO-1 Power Management"
97c4cb71 2710 depends on OLPC && MFD_CS5535 && PM_SLEEP
a3128588 2711 select MFD_CORE
bf1ebf00 2712 ---help---
97c4cb71 2713 Add support for poweroff and suspend of the OLPC XO-1 laptop.
bf1ebf00 2714
cfee9597
DD
2715config OLPC_XO1_RTC
2716 bool "OLPC XO-1 Real Time Clock"
2717 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2718 ---help---
2719 Add support for the XO-1 real time clock, which can be used as a
2720 programmable wakeup source.
2721
7feda8e9
DD
2722config OLPC_XO1_SCI
2723 bool "OLPC XO-1 SCI extras"
d8d01a63 2724 depends on OLPC && OLPC_XO1_PM
ed8e47fe 2725 depends on INPUT=y
d8d01a63 2726 select POWER_SUPPLY
7feda8e9
DD
2727 select GPIO_CS5535
2728 select MFD_CORE
2729 ---help---
2730 Add support for SCI-based features of the OLPC XO-1 laptop:
7bc74b3d 2731 - EC-driven system wakeups
7feda8e9 2732 - Power button
7bc74b3d 2733 - Ebook switch
2cf2baea 2734 - Lid switch
e1040ac6
DD
2735 - AC adapter status updates
2736 - Battery status updates
7feda8e9 2737
a0f30f59
DD
2738config OLPC_XO15_SCI
2739 bool "OLPC XO-1.5 SCI extras"
d8d01a63
DD
2740 depends on OLPC && ACPI
2741 select POWER_SUPPLY
a0f30f59
DD
2742 ---help---
2743 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2744 - EC-driven system wakeups
2745 - AC adapter status updates
2746 - Battery status updates
bf1ebf00 2747
d4f3e350
EW
2748config ALIX
2749 bool "PCEngines ALIX System Support (LED setup)"
2750 select GPIOLIB
2751 ---help---
2752 This option enables system support for the PCEngines ALIX.
2753 At present this just sets up LEDs for GPIO control on
2754 ALIX2/3/6 boards. However, other system specific setup should
2755 get added here.
2756
2757 Note: You must still enable the drivers for GPIO and LED support
2758 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2759
2760 Note: You have to set alix.force=1 for boards with Award BIOS.
2761
da4e3302
PP
2762config NET5501
2763 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2764 select GPIOLIB
2765 ---help---
2766 This option enables system support for the Soekris Engineering net5501.
2767
3197059a
PP
2768config GEOS
2769 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2770 select GPIOLIB
2771 depends on DMI
2772 ---help---
2773 This option enables system support for the Traverse Technologies GEOS.
2774
7d029125
VD
2775config TS5500
2776 bool "Technologic Systems TS-5500 platform support"
2777 depends on MELAN
2778 select CHECK_SIGNATURE
2779 select NEW_LEDS
2780 select LEDS_CLASS
2781 ---help---
2782 This option enables system support for the Technologic Systems TS-5500.
2783
bc0120fd
SR
2784endif # X86_32
2785
23ac4ae8 2786config AMD_NB
e279b6c1 2787 def_bool y
0e152cd7 2788 depends on CPU_SUP_AMD && PCI
e279b6c1
SR
2789
2790source "drivers/pcmcia/Kconfig"
2791
388b78ad 2792config RAPIDIO
fdf90abc 2793 tristate "RapidIO support"
388b78ad
AB
2794 depends on PCI
2795 default n
2796 help
fdf90abc 2797 If enabled this option will include drivers and the core
388b78ad
AB
2798 infrastructure code to support RapidIO interconnect devices.
2799
2800source "drivers/rapidio/Kconfig"
2801
e3263ab3
DH
2802config X86_SYSFB
2803 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2804 help
2805 Firmwares often provide initial graphics framebuffers so the BIOS,
2806 bootloader or kernel can show basic video-output during boot for
2807 user-guidance and debugging. Historically, x86 used the VESA BIOS
2808 Extensions and EFI-framebuffers for this, which are mostly limited
2809 to x86.
2810 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2811 framebuffers so the new generic system-framebuffer drivers can be
2812 used on x86. If the framebuffer is not compatible with the generic
2813 modes, it is adverticed as fallback platform framebuffer so legacy
2814 drivers like efifb, vesafb and uvesafb can pick it up.
2815 If this option is not selected, all system framebuffers are always
2816 marked as fallback platform framebuffers as usual.
2817
2818 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2819 not be able to pick up generic system framebuffers if this option
2820 is selected. You are highly encouraged to enable simplefb as
2821 replacement if you select this option. simplefb can correctly deal
2822 with generic system framebuffers. But you should still keep vesafb
2823 and others enabled as fallback if a system framebuffer is
2824 incompatible with simplefb.
2825
2826 If unsure, say Y.
2827
e279b6c1
SR
2828endmenu
2829
2830
2831menu "Executable file formats / Emulations"
2832
2833source "fs/Kconfig.binfmt"
2834
2835config IA32_EMULATION
2836 bool "IA32 Emulation"
2837 depends on X86_64
39f88911 2838 select ARCH_WANT_OLD_COMPAT_IPC
d1603990 2839 select BINFMT_ELF
a97f52e6 2840 select COMPAT_BINFMT_ELF
39f88911 2841 select COMPAT_OLD_SIGACTION
8f9ca475 2842 ---help---
5fd92e65
L
2843 Include code to run legacy 32-bit programs under a
2844 64-bit kernel. You should likely turn this on, unless you're
2845 100% sure that you don't have any 32-bit programs left.
e279b6c1
SR
2846
2847config IA32_AOUT
8f9ca475
IM
2848 tristate "IA32 a.out support"
2849 depends on IA32_EMULATION
2850 ---help---
2851 Support old a.out binaries in the 32bit emulation.
e279b6c1 2852
0bf62763 2853config X86_X32
6ea30386 2854 bool "x32 ABI for 64-bit mode"
9b54050b 2855 depends on X86_64
5fd92e65
L
2856 ---help---
2857 Include code to run binaries for the x32 native 32-bit ABI
2858 for 64-bit processors. An x32 process gets access to the
2859 full 64-bit register file and wide data path while leaving
2860 pointers at 32 bits for smaller memory footprint.
2861
2862 You will need a recent binutils (2.22 or later) with
2863 elf32_x86_64 support enabled to compile a kernel with this
2864 option set.
2865
953fee1d
IM
2866config COMPAT_32
2867 def_bool y
2868 depends on IA32_EMULATION || X86_32
2869 select HAVE_UID16
2870 select OLD_SIGSUSPEND3
2871
e279b6c1 2872config COMPAT
3c2362e6 2873 def_bool y
0bf62763 2874 depends on IA32_EMULATION || X86_X32
e279b6c1 2875
3120e25e 2876if COMPAT
e279b6c1 2877config COMPAT_FOR_U64_ALIGNMENT
3120e25e 2878 def_bool y
e279b6c1
SR
2879
2880config SYSVIPC_COMPAT
3c2362e6 2881 def_bool y
3120e25e 2882 depends on SYSVIPC
3120e25e 2883endif
ee009e4a 2884
e279b6c1
SR
2885endmenu
2886
2887
e5beae16
KP
2888config HAVE_ATOMIC_IOMAP
2889 def_bool y
2890 depends on X86_32
2891
4692d77f
AR
2892config X86_DEV_DMA_OPS
2893 bool
83125a3a 2894 depends on X86_64 || STA2X11
4692d77f 2895
f7219a53
AR
2896config X86_DMA_REMAP
2897 bool
83125a3a 2898 depends on STA2X11
f7219a53 2899
e585513b
KS
2900config HAVE_GENERIC_GUP
2901 def_bool y
2902
e279b6c1
SR
2903source "net/Kconfig"
2904
2905source "drivers/Kconfig"
2906
0d34a427
LO
2907source "ubuntu/Kconfig"
2908
e279b6c1
SR
2909source "drivers/firmware/Kconfig"
2910
2911source "fs/Kconfig"
2912
e279b6c1
SR
2913source "arch/x86/Kconfig.debug"
2914
2915source "security/Kconfig"
2916
2917source "crypto/Kconfig"
2918
edf88417
AK
2919source "arch/x86/kvm/Kconfig"
2920
e279b6c1 2921source "lib/Kconfig"