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daa93fab
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1# Select 32 or 64 bit
2config 64BIT
6840999b 3 bool "64-bit kernel" if ARCH = "x86"
ffee0de4 4 default ARCH != "i386"
8f9ca475 5 ---help---
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SR
6 Say yes to build a 64-bit kernel - formerly known as x86_64
7 Say no to build a 32-bit kernel - formerly known as i386
8
9config X86_32
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10 def_bool y
11 depends on !64BIT
341c787e
IM
12 # Options that are inherently 32-bit kernel only:
13 select ARCH_WANT_IPC_PARSE_VERSION
14 select CLKSRC_I8253
15 select CLONE_BACKWARDS
16 select HAVE_AOUT
17 select HAVE_GENERIC_DMA_COHERENT
18 select MODULES_USE_ELF_REL
19 select OLD_SIGACTION
daa93fab
SR
20
21config X86_64
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JB
22 def_bool y
23 depends on 64BIT
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24 # Options that are inherently 64-bit kernel only:
25 select ARCH_HAS_GIGANTIC_PAGE
26 select ARCH_SUPPORTS_INT128
27 select ARCH_USE_CMPXCHG_LOCKREF
28 select HAVE_ARCH_SOFT_DIRTY
29 select MODULES_USE_ELF_RELA
30 select X86_DEV_DMA_OPS
1032c0ba 31
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IM
32#
33# Arch settings
34#
35# ( Note that options that are marked 'if X86_64' could in principle be
36# ported to 32-bit as well. )
37#
8d5fffb9 38config X86
3c2362e6 39 def_bool y
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IM
40 #
41 # Note: keep this list sorted alphabetically
42 #
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43 select ACPI_LEGACY_TABLES_LOOKUP if ACPI
44 select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI
45 select ANON_INODES
46 select ARCH_CLOCKSOURCE_DATA
47 select ARCH_DISCARD_MEMBLOCK
c763ea26 48 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
21266be9 49 select ARCH_HAS_DEVMEM_IS_ALLOWED
6471b825 50 select ARCH_HAS_ELF_RANDOMIZE
72d93104 51 select ARCH_HAS_FAST_MULTIPLIER
957e3fac 52 select ARCH_HAS_GCOV_PROFILE_ALL
5c9a8750 53 select ARCH_HAS_KCOV if X86_64
67a3e8fe 54 select ARCH_HAS_MMIO_FLUSH
c763ea26 55 select ARCH_HAS_PMEM_API if X86_64
6471b825 56 select ARCH_HAS_SG_CHAIN
c6d30853 57 select ARCH_HAS_UBSAN_SANITIZE_ALL
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IM
58 select ARCH_HAVE_NMI_SAFE_CMPXCHG
59 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
77fbbc81 60 select ARCH_MIGHT_HAVE_PC_PARPORT
5e2c18c0 61 select ARCH_MIGHT_HAVE_PC_SERIO
6471b825 62 select ARCH_SUPPORTS_ATOMIC_RMW
3b242c66 63 select ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT
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64 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
65 select ARCH_USE_BUILTIN_BSWAP
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66 select ARCH_USE_QUEUED_RWLOCKS
67 select ARCH_USE_QUEUED_SPINLOCKS
72b252ae 68 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH if SMP
da4276b8 69 select ARCH_WANT_FRAME_POINTERS
c763ea26 70 select ARCH_WANTS_DYNAMIC_TASK_STRUCT
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71 select BUILDTIME_EXTABLE_SORT
72 select CLKEVT_I8253
6471b825
IM
73 select CLOCKSOURCE_VALIDATE_LAST_CYCLE
74 select CLOCKSOURCE_WATCHDOG
6471b825 75 select DCACHE_WORD_ACCESS
45471cd9
LT
76 select EDAC_ATOMIC_SCRUB
77 select EDAC_SUPPORT
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IM
78 select GENERIC_CLOCKEVENTS
79 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
80 select GENERIC_CLOCKEVENTS_MIN_ADJUST
81 select GENERIC_CMOS_UPDATE
82 select GENERIC_CPU_AUTOPROBE
5b7c73e0 83 select GENERIC_EARLY_IOREMAP
6471b825
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84 select GENERIC_FIND_FIRST_BIT
85 select GENERIC_IOMAP
86 select GENERIC_IRQ_PROBE
87 select GENERIC_IRQ_SHOW
88 select GENERIC_PENDING_IRQ if SMP
89 select GENERIC_SMP_IDLE_THREAD
90 select GENERIC_STRNCPY_FROM_USER
91 select GENERIC_STRNLEN_USER
92 select GENERIC_TIME_VSYSCALL
93 select HAVE_ACPI_APEI if ACPI
94 select HAVE_ACPI_APEI_NMI if ACPI
95 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
6471b825 96 select HAVE_ARCH_AUDITSYSCALL
5b710f34 97 select HAVE_ARCH_HARDENED_USERCOPY
6471b825
IM
98 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE
99 select HAVE_ARCH_JUMP_LABEL
100 select HAVE_ARCH_KASAN if X86_64 && SPARSEMEM_VMEMMAP
101 select HAVE_ARCH_KGDB
102 select HAVE_ARCH_KMEMCHECK
9e08f57d
DC
103 select HAVE_ARCH_MMAP_RND_BITS if MMU
104 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT
6471b825 105 select HAVE_ARCH_SECCOMP_FILTER
6471b825
IM
106 select HAVE_ARCH_TRACEHOOK
107 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
e37e43a4 108 select HAVE_ARCH_VMAP_STACK if X86_64
c763ea26 109 select HAVE_ARCH_WITHIN_STACK_FRAMES
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IM
110 select HAVE_CC_STACKPROTECTOR
111 select HAVE_CMPXCHG_DOUBLE
112 select HAVE_CMPXCHG_LOCAL
113 select HAVE_CONTEXT_TRACKING if X86_64
c1bd55f9 114 select HAVE_COPY_THREAD_TLS
cf4db259 115 select HAVE_C_RECORDMCOUNT
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IM
116 select HAVE_DEBUG_KMEMLEAK
117 select HAVE_DEBUG_STACKOVERFLOW
118 select HAVE_DMA_API_DEBUG
6471b825 119 select HAVE_DMA_CONTIGUOUS
677aa9f7 120 select HAVE_DYNAMIC_FTRACE
06aeaaea 121 select HAVE_DYNAMIC_FTRACE_WITH_REGS
c763ea26 122 select HAVE_EBPF_JIT if X86_64
58340a07 123 select HAVE_EFFICIENT_UNALIGNED_ACCESS
5f56a5df 124 select HAVE_EXIT_THREAD
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125 select HAVE_FENTRY if X86_64
126 select HAVE_FTRACE_MCOUNT_RECORD
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127 select HAVE_FUNCTION_GRAPH_TRACER
128 select HAVE_FUNCTION_TRACER
6b90bd4b 129 select HAVE_GCC_PLUGINS
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130 select HAVE_HW_BREAKPOINT
131 select HAVE_IDE
132 select HAVE_IOREMAP_PROT
133 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
134 select HAVE_IRQ_TIME_ACCOUNTING
2e9f3bdd 135 select HAVE_KERNEL_BZIP2
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136 select HAVE_KERNEL_GZIP
137 select HAVE_KERNEL_LZ4
2e9f3bdd 138 select HAVE_KERNEL_LZMA
13510997 139 select HAVE_KERNEL_LZO
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140 select HAVE_KERNEL_XZ
141 select HAVE_KPROBES
142 select HAVE_KPROBES_ON_FTRACE
143 select HAVE_KRETPROBES
144 select HAVE_KVM
145 select HAVE_LIVEPATCH if X86_64
146 select HAVE_MEMBLOCK
147 select HAVE_MEMBLOCK_NODE_MAP
0102752e 148 select HAVE_MIXED_BREAKPOINTS_REGS
42a0bb3f 149 select HAVE_NMI
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IM
150 select HAVE_OPROFILE
151 select HAVE_OPTPROBES
152 select HAVE_PCSPKR_PLATFORM
153 select HAVE_PERF_EVENTS
c01d4323 154 select HAVE_PERF_EVENTS_NMI
c5e63197 155 select HAVE_PERF_REGS
c5ebcedb 156 select HAVE_PERF_USER_STACK_DUMP
6471b825 157 select HAVE_REGS_AND_STACK_ACCESS_API
c763ea26 158 select HAVE_STACK_VALIDATION if X86_64
6471b825 159 select HAVE_SYSCALL_TRACEPOINTS
6471b825 160 select HAVE_UNSTABLE_SCHED_CLOCK
7c68af6e 161 select HAVE_USER_RETURN_NOTIFIER
c0185808 162 select IRQ_FORCED_THREADING
6471b825 163 select PERF_EVENTS
3195ef59 164 select RTC_LIB
d6faca40 165 select RTC_MC146818_LIB
6471b825 166 select SPARSE_IRQ
83fe27ea 167 select SRCU
6471b825 168 select SYSCTL_EXCEPTION_TRACE
15f4eae7 169 select THREAD_INFO_IN_TASK
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IM
170 select USER_STACKTRACE_SUPPORT
171 select VIRT_TO_BUS
6471b825 172 select X86_FEATURE_NAMES if PROC_FS
7d8330a5 173
ba7e4d13 174config INSTRUCTION_DECODER
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175 def_bool y
176 depends on KPROBES || PERF_EVENTS || UPROBES
ba7e4d13 177
51b26ada
LT
178config OUTPUT_FORMAT
179 string
180 default "elf32-i386" if X86_32
181 default "elf64-x86-64" if X86_64
182
73531905 183config ARCH_DEFCONFIG
b9b39bfb 184 string
73531905
SR
185 default "arch/x86/configs/i386_defconfig" if X86_32
186 default "arch/x86/configs/x86_64_defconfig" if X86_64
b9b39bfb 187
8d5fffb9 188config LOCKDEP_SUPPORT
3c2362e6 189 def_bool y
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SR
190
191config STACKTRACE_SUPPORT
3c2362e6 192 def_bool y
8d5fffb9 193
8d5fffb9 194config MMU
3c2362e6 195 def_bool y
8d5fffb9 196
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DC
197config ARCH_MMAP_RND_BITS_MIN
198 default 28 if 64BIT
199 default 8
200
201config ARCH_MMAP_RND_BITS_MAX
202 default 32 if 64BIT
203 default 16
204
205config ARCH_MMAP_RND_COMPAT_BITS_MIN
206 default 8
207
208config ARCH_MMAP_RND_COMPAT_BITS_MAX
209 default 16
210
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SR
211config SBUS
212 bool
213
3bc4e459 214config NEED_DMA_MAP_STATE
3120e25e 215 def_bool y
a6dfa128 216 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB
3bc4e459 217
18e98307 218config NEED_SG_DMA_LENGTH
4a14d84e 219 def_bool y
18e98307 220
8d5fffb9 221config GENERIC_ISA_DMA
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JB
222 def_bool y
223 depends on ISA_DMA_API
8d5fffb9 224
8d5fffb9 225config GENERIC_BUG
3c2362e6 226 def_bool y
8d5fffb9 227 depends on BUG
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JB
228 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
229
230config GENERIC_BUG_RELATIVE_POINTERS
231 bool
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SR
232
233config GENERIC_HWEIGHT
3c2362e6 234 def_bool y
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235
236config ARCH_MAY_HAVE_PC_FDC
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JB
237 def_bool y
238 depends on ISA_DMA_API
8d5fffb9 239
1032c0ba 240config RWSEM_XCHGADD_ALGORITHM
3120e25e 241 def_bool y
1032c0ba 242
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SR
243config GENERIC_CALIBRATE_DELAY
244 def_bool y
245
9a0b8415 246config ARCH_HAS_CPU_RELAX
247 def_bool y
248
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PE
249config ARCH_HAS_CACHE_LINE_SIZE
250 def_bool y
251
dd5af90a 252config HAVE_SETUP_PER_CPU_AREA
89c9c4c5 253 def_bool y
b32ef636 254
08fc4580
TH
255config NEED_PER_CPU_EMBED_FIRST_CHUNK
256 def_bool y
257
258config NEED_PER_CPU_PAGE_FIRST_CHUNK
11124411
TH
259 def_bool y
260
801e4062
JB
261config ARCH_HIBERNATION_POSSIBLE
262 def_bool y
801e4062 263
f4cb5700
JB
264config ARCH_SUSPEND_POSSIBLE
265 def_bool y
f4cb5700 266
cfe28c5d
SC
267config ARCH_WANT_HUGE_PMD_SHARE
268 def_bool y
269
53313b2c
SC
270config ARCH_WANT_GENERAL_HUGETLB
271 def_bool y
272
8d5fffb9 273config ZONE_DMA32
e0fd24a3 274 def_bool y if X86_64
8d5fffb9 275
8d5fffb9 276config AUDIT_ARCH
e0fd24a3 277 def_bool y if X86_64
8d5fffb9 278
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IM
279config ARCH_SUPPORTS_OPTIMIZED_INLINING
280 def_bool y
281
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AM
282config ARCH_SUPPORTS_DEBUG_PAGEALLOC
283 def_bool y
284
d6f2d75a
AR
285config KASAN_SHADOW_OFFSET
286 hex
287 depends on KASAN
288 default 0xdffffc0000000000
289
69575d38
SW
290config HAVE_INTEL_TXT
291 def_bool y
6ea30386 292 depends on INTEL_IOMMU && ACPI
69575d38 293
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SR
294config X86_32_SMP
295 def_bool y
296 depends on X86_32 && SMP
297
298config X86_64_SMP
299 def_bool y
300 depends on X86_64 && SMP
301
ccbeed3a
TH
302config X86_32_LAZY_GS
303 def_bool y
60a5317f 304 depends on X86_32 && !CC_STACKPROTECTOR
ccbeed3a 305
2b144498
SD
306config ARCH_SUPPORTS_UPROBES
307 def_bool y
308
d20642f0
RH
309config FIX_EARLYCON_MEM
310 def_bool y
311
9ccaf77c
KC
312config DEBUG_RODATA
313 def_bool y
314
98233368
KS
315config PGTABLE_LEVELS
316 int
317 default 4 if X86_64
318 default 3 if X86_PAE
319 default 2
320
506f1d07 321source "init/Kconfig"
dc52ddc0 322source "kernel/Kconfig.freezer"
8d5fffb9 323
506f1d07
SR
324menu "Processor type and features"
325
5ee71535
RD
326config ZONE_DMA
327 bool "DMA memory allocation support" if EXPERT
328 default y
329 help
330 DMA memory allocation support allows devices with less than 32-bit
331 addressing to allocate within the first 16MB of address space.
332 Disable if no such devices will be used.
333
334 If unsure, say Y.
335
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SR
336config SMP
337 bool "Symmetric multi-processing support"
338 ---help---
339 This enables support for systems with more than one CPU. If you have
4a474157
RG
340 a system with only one CPU, say N. If you have a system with more
341 than one CPU, say Y.
506f1d07 342
4a474157 343 If you say N here, the kernel will run on uni- and multiprocessor
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SR
344 machines, but will use only one CPU of a multiprocessor machine. If
345 you say Y here, the kernel will run on many, but not all,
4a474157 346 uniprocessor machines. On a uniprocessor machine, the kernel
506f1d07
SR
347 will run faster if you say N here.
348
349 Note that if you say Y here and choose architecture "586" or
350 "Pentium" under "Processor family", the kernel will not work on 486
351 architectures. Similarly, multiprocessor kernels for the "PPro"
352 architecture may not work on all Pentium based boards.
353
354 People using multiprocessor machines who say Y here should also say
355 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
356 Management" code will be disabled if you say Y here.
357
395cf969 358 See also <file:Documentation/x86/i386/IO-APIC.txt>,
506f1d07
SR
359 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
360 <http://www.tldp.org/docs.html#howto>.
361
362 If you don't know what to do here, say N.
363
9def39be
JT
364config X86_FEATURE_NAMES
365 bool "Processor feature human-readable names" if EMBEDDED
366 default y
367 ---help---
368 This option compiles in a table of x86 feature bits and corresponding
369 names. This is required to support /proc/cpuinfo and a few kernel
370 messages. You can disable this to save space, at the expense of
371 making those few kernel messages show numeric feature bits instead.
372
373 If in doubt, say Y.
374
6e1315fe
BP
375config X86_FAST_FEATURE_TESTS
376 bool "Fast CPU feature tests" if EMBEDDED
377 default y
378 ---help---
379 Some fast-paths in the kernel depend on the capabilities of the CPU.
380 Say Y here for the kernel to patch in the appropriate code at runtime
381 based on the capabilities of the CPU. The infrastructure for patching
382 code at runtime takes up some additional space; space-constrained
383 embedded systems may wish to say N here to produce smaller, slightly
384 slower code.
385
06cd9a7d
YL
386config X86_X2APIC
387 bool "Support x2apic"
19e3d60d 388 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
06cd9a7d
YL
389 ---help---
390 This enables x2apic support on CPUs that have this feature.
391
392 This allows 32-bit apic IDs (so it can support very large systems),
393 and accesses the local apic via MSRs not via mmio.
394
06cd9a7d
YL
395 If you don't know what to do here, say N.
396
6695c85b 397config X86_MPPARSE
6e87f9b7 398 bool "Enable MPS table" if ACPI || SFI
7a527688 399 default y
5ab74722 400 depends on X86_LOCAL_APIC
8f9ca475 401 ---help---
6695c85b
YL
402 For old smp systems that do not have proper acpi support. Newer systems
403 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
6695c85b 404
26f7ef14
YL
405config X86_BIGSMP
406 bool "Support for big SMP systems with more than 8 CPUs"
407 depends on X86_32 && SMP
8f9ca475 408 ---help---
26f7ef14 409 This option is needed for the systems that have more than 8 CPUs
506f1d07 410
ddd70cf9
JN
411config GOLDFISH
412 def_bool y
413 depends on X86_GOLDFISH
414
78e99b4a
FY
415config INTEL_RDT_A
416 bool "Intel Resource Director Technology Allocation support"
417 default n
418 depends on X86 && CPU_SUP_INTEL
59fe5a77 419 select KERNFS
78e99b4a
FY
420 help
421 Select to enable resource allocation which is a sub-feature of
422 Intel Resource Director Technology(RDT). More information about
423 RDT can be found in the Intel x86 Architecture Software
424 Developer Manual.
425
426 Say N if unsure.
427
8425091f 428if X86_32
c5c606d9
RT
429config X86_EXTENDED_PLATFORM
430 bool "Support for extended (non-PC) x86 platforms"
431 default y
8f9ca475 432 ---help---
06ac8346
IM
433 If you disable this option then the kernel will only support
434 standard PC platforms. (which covers the vast majority of
435 systems out there.)
436
8425091f
RT
437 If you enable this option then you'll be able to select support
438 for the following (non-PC) 32 bit x86 platforms:
cb7b8023 439 Goldfish (Android emulator)
8425091f 440 AMD Elan
8425091f
RT
441 RDC R-321x SoC
442 SGI 320/540 (Visual Workstation)
83125a3a 443 STA2X11-based (e.g. Northville)
3f4110a4 444 Moorestown MID devices
06ac8346
IM
445
446 If you have one of these systems, or if you want to build a
447 generic distribution kernel, say Y here - otherwise say N.
8425091f 448endif
06ac8346 449
8425091f
RT
450if X86_64
451config X86_EXTENDED_PLATFORM
452 bool "Support for extended (non-PC) x86 platforms"
453 default y
454 ---help---
455 If you disable this option then the kernel will only support
456 standard PC platforms. (which covers the vast majority of
457 systems out there.)
458
459 If you enable this option then you'll be able to select support
460 for the following (non-PC) 64 bit x86 platforms:
44b111b5 461 Numascale NumaChip
8425091f
RT
462 ScaleMP vSMP
463 SGI Ultraviolet
464
465 If you have one of these systems, or if you want to build a
466 generic distribution kernel, say Y here - otherwise say N.
467endif
c5c606d9
RT
468# This is an alphabetically sorted list of 64 bit extended platforms
469# Please maintain the alphabetic order if and when there are additions
44b111b5
SP
470config X86_NUMACHIP
471 bool "Numascale NumaChip"
472 depends on X86_64
473 depends on X86_EXTENDED_PLATFORM
474 depends on NUMA
475 depends on SMP
476 depends on X86_X2APIC
f9726bfd 477 depends on PCI_MMCONFIG
44b111b5
SP
478 ---help---
479 Adds support for Numascale NumaChip large-SMP systems. Needed to
480 enable more than ~168 cores.
481 If you don't have one of these, you should say N here.
506f1d07 482
c5c606d9
RT
483config X86_VSMP
484 bool "ScaleMP vSMP"
6276a074 485 select HYPERVISOR_GUEST
c5c606d9
RT
486 select PARAVIRT
487 depends on X86_64 && PCI
488 depends on X86_EXTENDED_PLATFORM
ead91d4b 489 depends on SMP
8f9ca475 490 ---help---
c5c606d9
RT
491 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
492 supposed to run on these EM64T-based machines. Only choose this option
493 if you have one of these machines.
5e3a77e9 494
03b48632
NP
495config X86_UV
496 bool "SGI Ultraviolet"
497 depends on X86_64
c5c606d9 498 depends on X86_EXTENDED_PLATFORM
54c28d29 499 depends on NUMA
1ecb4ae5 500 depends on EFI
9d6c26e7 501 depends on X86_X2APIC
1222e564 502 depends on PCI
8f9ca475 503 ---help---
03b48632
NP
504 This option is needed in order to support SGI Ultraviolet systems.
505 If you don't have one of these, you should say N here.
506
c5c606d9
RT
507# Following is an alphabetically sorted list of 32 bit extended platforms
508# Please maintain the alphabetic order if and when there are additions
506f1d07 509
ddd70cf9
JN
510config X86_GOLDFISH
511 bool "Goldfish (Virtual Platform)"
cb7b8023 512 depends on X86_EXTENDED_PLATFORM
ddd70cf9
JN
513 ---help---
514 Enable support for the Goldfish virtual platform used primarily
515 for Android development. Unless you are building for the Android
516 Goldfish emulator say N here.
517
c751e17b
TG
518config X86_INTEL_CE
519 bool "CE4100 TV platform"
520 depends on PCI
521 depends on PCI_GODIRECT
6084a6e2 522 depends on X86_IO_APIC
c751e17b
TG
523 depends on X86_32
524 depends on X86_EXTENDED_PLATFORM
37bc9f50 525 select X86_REBOOTFIXUPS
da6b737b
SAS
526 select OF
527 select OF_EARLY_FLATTREE
c751e17b
TG
528 ---help---
529 Select for the Intel CE media processor (CE4100) SOC.
530 This option compiles in support for the CE4100 SOC for settop
531 boxes and media devices.
532
4cb9b00f 533config X86_INTEL_MID
43605ef1 534 bool "Intel MID platform support"
43605ef1 535 depends on X86_EXTENDED_PLATFORM
edc6bc78 536 depends on X86_PLATFORM_DEVICES
1ea7c673 537 depends on PCI
3fda5bb4 538 depends on X86_64 || (PCI_GOANY && X86_32)
1ea7c673 539 depends on X86_IO_APIC
7c9c3a1e 540 select SFI
4cb9b00f 541 select I2C
7c9c3a1e 542 select DW_APB_TIMER
1ea7c673 543 select APB_TIMER
1ea7c673 544 select INTEL_SCU_IPC
15a713df 545 select MFD_INTEL_MSIC
1ea7c673 546 ---help---
4cb9b00f
DC
547 Select to build a kernel capable of supporting Intel MID (Mobile
548 Internet Device) platform systems which do not have the PCI legacy
549 interfaces. If you are building for a PC class system say N here.
1ea7c673 550
4cb9b00f
DC
551 Intel MID platforms are based on an Intel processor and chipset which
552 consume less power than most of the x86 derivatives.
43605ef1 553
8bbc2a13
BD
554config X86_INTEL_QUARK
555 bool "Intel Quark platform support"
556 depends on X86_32
557 depends on X86_EXTENDED_PLATFORM
558 depends on X86_PLATFORM_DEVICES
559 depends on X86_TSC
560 depends on PCI
561 depends on PCI_GOANY
562 depends on X86_IO_APIC
563 select IOSF_MBI
564 select INTEL_IMR
9ab6eb51 565 select COMMON_CLK
8bbc2a13
BD
566 ---help---
567 Select to include support for Quark X1000 SoC.
568 Say Y here if you have a Quark based system such as the Arduino
569 compatible Intel Galileo.
570
3d48aab1
MW
571config X86_INTEL_LPSS
572 bool "Intel Low Power Subsystem Support"
eebb3e8d 573 depends on X86 && ACPI
3d48aab1 574 select COMMON_CLK
0f531431 575 select PINCTRL
eebb3e8d 576 select IOSF_MBI
3d48aab1
MW
577 ---help---
578 Select to build support for Intel Low Power Subsystem such as
579 found on Intel Lynxpoint PCH. Selecting this option enables
0f531431
MN
580 things like clock tree (common clock framework) and pincontrol
581 which are needed by the LPSS peripheral drivers.
3d48aab1 582
92082a88
KX
583config X86_AMD_PLATFORM_DEVICE
584 bool "AMD ACPI2Platform devices support"
585 depends on ACPI
586 select COMMON_CLK
587 select PINCTRL
588 ---help---
589 Select to interpret AMD specific ACPI device to platform device
590 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
591 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
592 implemented under PINCTRL subsystem.
593
ced3ce76
DB
594config IOSF_MBI
595 tristate "Intel SoC IOSF Sideband support for SoC platforms"
596 depends on PCI
597 ---help---
598 This option enables sideband register access support for Intel SoC
599 platforms. On these platforms the IOSF sideband is used in lieu of
600 MSR's for some register accesses, mostly but not limited to thermal
601 and power. Drivers may query the availability of this device to
602 determine if they need the sideband in order to work on these
603 platforms. The sideband is available on the following SoC products.
604 This list is not meant to be exclusive.
605 - BayTrail
606 - Braswell
607 - Quark
608
609 You should say Y if you are running a kernel on one of these SoC's.
610
ed2226bd
DB
611config IOSF_MBI_DEBUG
612 bool "Enable IOSF sideband access through debugfs"
613 depends on IOSF_MBI && DEBUG_FS
614 ---help---
615 Select this option to expose the IOSF sideband access registers (MCR,
616 MDR, MCRX) through debugfs to write and read register information from
617 different units on the SoC. This is most useful for obtaining device
618 state information for debug and analysis. As this is a general access
619 mechanism, users of this option would have specific knowledge of the
620 device they want to access.
621
622 If you don't require the option or are in doubt, say N.
623
c5c606d9
RT
624config X86_RDC321X
625 bool "RDC R-321x SoC"
506f1d07 626 depends on X86_32
c5c606d9
RT
627 depends on X86_EXTENDED_PLATFORM
628 select M486
629 select X86_REBOOTFIXUPS
630 ---help---
631 This option is needed for RDC R-321x system-on-chip, also known
632 as R-8610-(G).
633 If you don't have one of these chips, you should say N here.
634
e0c7ae37 635config X86_32_NON_STANDARD
9c398017
IM
636 bool "Support non-standard 32-bit SMP architectures"
637 depends on X86_32 && SMP
c5c606d9 638 depends on X86_EXTENDED_PLATFORM
8f9ca475 639 ---help---
b5660ba7
PA
640 This option compiles in the bigsmp and STA2X11 default
641 subarchitectures. It is intended for a generic binary
642 kernel. If you select them all, kernel will probe it one by
643 one and will fallback to default.
d49c4288 644
c5c606d9 645# Alphabetically sorted list of Non standard 32 bit platforms
d49c4288 646
d949f36f 647config X86_SUPPORTS_MEMORY_FAILURE
6fc108a0 648 def_bool y
d949f36f
LT
649 # MCE code calls memory_failure():
650 depends on X86_MCE
651 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
d949f36f
LT
652 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
653 depends on X86_64 || !SPARSEMEM
654 select ARCH_SUPPORTS_MEMORY_FAILURE
d949f36f 655
83125a3a
AR
656config STA2X11
657 bool "STA2X11 Companion Chip Support"
658 depends on X86_32_NON_STANDARD && PCI
659 select X86_DEV_DMA_OPS
660 select X86_DMA_REMAP
661 select SWIOTLB
662 select MFD_STA2X11
0145071b 663 select GPIOLIB
83125a3a
AR
664 default n
665 ---help---
666 This adds support for boards based on the STA2X11 IO-Hub,
667 a.k.a. "ConneXt". The chip is used in place of the standard
668 PC chipset, so all "standard" peripherals are missing. If this
669 option is selected the kernel will still be able to boot on
670 standard PC machines.
671
82148d1d
S
672config X86_32_IRIS
673 tristate "Eurobraille/Iris poweroff module"
674 depends on X86_32
675 ---help---
676 The Iris machines from EuroBraille do not have APM or ACPI support
677 to shut themselves down properly. A special I/O sequence is
678 needed to do so, which is what this module does at
679 kernel shutdown.
680
681 This is only for Iris machines from EuroBraille.
682
683 If unused, say N.
684
ae1e9130 685config SCHED_OMIT_FRAME_POINTER
3c2362e6
HH
686 def_bool y
687 prompt "Single-depth WCHAN output"
a87d0914 688 depends on X86
8f9ca475 689 ---help---
506f1d07
SR
690 Calculate simpler /proc/<PID>/wchan values. If this option
691 is disabled then wchan values will recurse back to the
692 caller function. This provides more accurate wchan values,
693 at the expense of slightly more scheduling overhead.
694
695 If in doubt, say "Y".
696
6276a074
BP
697menuconfig HYPERVISOR_GUEST
698 bool "Linux guest support"
8f9ca475 699 ---help---
6276a074
BP
700 Say Y here to enable options for running Linux under various hyper-
701 visors. This option enables basic hypervisor detection and platform
702 setup.
506f1d07 703
6276a074
BP
704 If you say N, all options in this submenu will be skipped and
705 disabled, and Linux guest support won't be built in.
506f1d07 706
6276a074 707if HYPERVISOR_GUEST
506f1d07 708
e61bd94a
EPH
709config PARAVIRT
710 bool "Enable paravirtualization code"
8f9ca475 711 ---help---
e61bd94a
EPH
712 This changes the kernel so it can modify itself when it is run
713 under a hypervisor, potentially improving performance significantly
714 over full virtualization. However, when run without a hypervisor
715 the kernel is theoretically slower and slightly larger.
716
6276a074
BP
717config PARAVIRT_DEBUG
718 bool "paravirt-ops debugging"
719 depends on PARAVIRT && DEBUG_KERNEL
720 ---help---
721 Enable to debug paravirt_ops internals. Specifically, BUG if
722 a paravirt_op is missing when it is called.
723
b4ecc126
JF
724config PARAVIRT_SPINLOCKS
725 bool "Paravirtualization layer for spinlocks"
6ea30386 726 depends on PARAVIRT && SMP
b4ecc126
JF
727 ---help---
728 Paravirtualized spinlocks allow a pvops backend to replace the
729 spinlock implementation with something virtualization-friendly
730 (for example, block the virtual CPU rather than spinning).
731
4c4e4f61
R
732 It has a minimal impact on native kernels and gives a nice performance
733 benefit on paravirtualized KVM / Xen kernels.
b4ecc126 734
4c4e4f61 735 If you are unsure how to answer this question, answer Y.
b4ecc126 736
45e898b7
WL
737config QUEUED_LOCK_STAT
738 bool "Paravirt queued spinlock statistics"
cfd8983f 739 depends on PARAVIRT_SPINLOCKS && DEBUG_FS
45e898b7
WL
740 ---help---
741 Enable the collection of statistical data on the slowpath
742 behavior of paravirtualized queued spinlocks and report
743 them on debugfs.
744
6276a074 745source "arch/x86/xen/Kconfig"
7af192c9 746
6276a074
BP
747config KVM_GUEST
748 bool "KVM Guest support (including kvmclock)"
749 depends on PARAVIRT
750 select PARAVIRT_CLOCK
751 default y
8f9ca475 752 ---help---
6276a074
BP
753 This option enables various optimizations for running under the KVM
754 hypervisor. It includes a paravirtualized clock, so that instead
755 of relying on a PIT (or probably other) emulation by the
756 underlying device model, the host provides the guest with
757 timing infrastructure such as time of day, and system time
506f1d07 758
1e20eb85
SV
759config KVM_DEBUG_FS
760 bool "Enable debug information for KVM Guests in debugfs"
761 depends on KVM_GUEST && DEBUG_FS
762 default n
763 ---help---
764 This option enables collection of various statistics for KVM guest.
765 Statistics are displayed in debugfs filesystem. Enabling this option
766 may incur significant overhead.
767
6276a074
BP
768source "arch/x86/lguest/Kconfig"
769
770config PARAVIRT_TIME_ACCOUNTING
771 bool "Paravirtual steal time accounting"
772 depends on PARAVIRT
773 default n
8f9ca475 774 ---help---
6276a074
BP
775 Select this option to enable fine granularity task steal time
776 accounting. Time spent executing other tasks in parallel with
777 the current vCPU is discounted from the vCPU power. To account for
778 that, there can be a small performance impact.
779
780 If in doubt, say N here.
781
782config PARAVIRT_CLOCK
783 bool
97349135 784
6276a074 785endif #HYPERVISOR_GUEST
97349135 786
08677214 787config NO_BOOTMEM
774ea0bc 788 def_bool y
08677214 789
506f1d07
SR
790source "arch/x86/Kconfig.cpu"
791
792config HPET_TIMER
3c2362e6 793 def_bool X86_64
506f1d07 794 prompt "HPET Timer Support" if X86_32
8f9ca475
IM
795 ---help---
796 Use the IA-PC HPET (High Precision Event Timer) to manage
797 time in preference to the PIT and RTC, if a HPET is
798 present.
799 HPET is the next generation timer replacing legacy 8254s.
800 The HPET provides a stable time base on SMP
801 systems, unlike the TSC, but it is more expensive to access,
4e7f9df2
MT
802 as it is off-chip. The interface used is documented
803 in the HPET spec, revision 1.
506f1d07 804
8f9ca475
IM
805 You can safely choose Y here. However, HPET will only be
806 activated if the platform and the BIOS support this feature.
807 Otherwise the 8254 will be used for timing services.
506f1d07 808
8f9ca475 809 Choose N to continue using the legacy 8254 timer.
506f1d07
SR
810
811config HPET_EMULATE_RTC
3c2362e6 812 def_bool y
9d8af78b 813 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
506f1d07 814
bb24c471 815config APB_TIMER
933b9463
AC
816 def_bool y if X86_INTEL_MID
817 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
06c3df49 818 select DW_APB_TIMER
a0c3832a 819 depends on X86_INTEL_MID && SFI
bb24c471
JP
820 help
821 APB timer is the replacement for 8254, HPET on X86 MID platforms.
822 The APBT provides a stable time base on SMP
823 systems, unlike the TSC, but it is more expensive to access,
824 as it is off-chip. APB timers are always running regardless of CPU
825 C states, they are used as per CPU clockevent device when possible.
826
6a108a14 827# Mark as expert because too many people got it wrong.
506f1d07 828# The code disables itself when not needed.
7ae9392c
TP
829config DMI
830 default y
cf074402 831 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
6a108a14 832 bool "Enable DMI scanning" if EXPERT
8f9ca475 833 ---help---
7ae9392c
TP
834 Enabled scanning of DMI to identify machine quirks. Say Y
835 here unless you have verified that your setup is not
836 affected by entries in the DMI blacklist. Required by PNP
837 BIOS code.
838
506f1d07 839config GART_IOMMU
38901f1c 840 bool "Old AMD GART IOMMU support"
506f1d07 841 select SWIOTLB
23ac4ae8 842 depends on X86_64 && PCI && AMD_NB
8f9ca475 843 ---help---
ced3c42c
IM
844 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
845 GART based hardware IOMMUs.
846
847 The GART supports full DMA access for devices with 32-bit access
848 limitations, on systems with more than 3 GB. This is usually needed
849 for USB, sound, many IDE/SATA chipsets and some other devices.
850
851 Newer systems typically have a modern AMD IOMMU, supported via
852 the CONFIG_AMD_IOMMU=y config option.
853
854 In normal configurations this driver is only active when needed:
855 there's more than 3 GB of memory and the system contains a
856 32-bit limited device.
857
858 If unsure, say Y.
506f1d07
SR
859
860config CALGARY_IOMMU
861 bool "IBM Calgary IOMMU support"
862 select SWIOTLB
6ea30386 863 depends on X86_64 && PCI
8f9ca475 864 ---help---
506f1d07
SR
865 Support for hardware IOMMUs in IBM's xSeries x366 and x460
866 systems. Needed to run systems with more than 3GB of memory
867 properly with 32-bit PCI devices that do not support DAC
868 (Double Address Cycle). Calgary also supports bus level
869 isolation, where all DMAs pass through the IOMMU. This
870 prevents them from going anywhere except their intended
871 destination. This catches hard-to-find kernel bugs and
872 mis-behaving drivers and devices that do not use the DMA-API
873 properly to set up their DMA buffers. The IOMMU can be
874 turned off at boot time with the iommu=off parameter.
875 Normally the kernel will make the right choice by itself.
876 If unsure, say Y.
877
878config CALGARY_IOMMU_ENABLED_BY_DEFAULT
3c2362e6
HH
879 def_bool y
880 prompt "Should Calgary be enabled by default?"
506f1d07 881 depends on CALGARY_IOMMU
8f9ca475 882 ---help---
506f1d07
SR
883 Should Calgary be enabled by default? if you choose 'y', Calgary
884 will be used (if it exists). If you choose 'n', Calgary will not be
885 used even if it exists. If you choose 'n' and would like to use
886 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
887 If unsure, say Y.
888
889# need this always selected by IOMMU for the VIA workaround
890config SWIOTLB
a1afd01c 891 def_bool y if X86_64
8f9ca475 892 ---help---
506f1d07 893 Support for software bounce buffers used on x86-64 systems
4454d327
JM
894 which don't have a hardware IOMMU. Using this PCI devices
895 which can only access 32-bits of memory can be used on systems
896 with more than 3 GB of memory.
897 If unsure, say Y.
506f1d07 898
a8522509 899config IOMMU_HELPER
3120e25e
JB
900 def_bool y
901 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
d25e26b6 902
1184dc2f 903config MAXSMP
ddb0c5a6 904 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
6ea30386 905 depends on X86_64 && SMP && DEBUG_KERNEL
36f5101a 906 select CPUMASK_OFFSTACK
8f9ca475 907 ---help---
ddb0c5a6 908 Enable maximum number of CPUS and NUMA Nodes for this architecture.
1184dc2f 909 If unsure, say N.
506f1d07
SR
910
911config NR_CPUS
36f5101a 912 int "Maximum number of CPUs" if SMP && !MAXSMP
2a3313f4 913 range 2 8 if SMP && X86_32 && !X86_BIGSMP
bb61ccc7 914 range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK
b53b5eda 915 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
78637a97 916 default "1" if !SMP
b53b5eda 917 default "8192" if MAXSMP
b5660ba7 918 default "32" if SMP && X86_BIGSMP
c5c19941
KS
919 default "8" if SMP && X86_32
920 default "64" if SMP
8f9ca475 921 ---help---
506f1d07 922 This allows you to specify the maximum number of CPUs which this
bb61ccc7 923 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
cad14bb9 924 supported value is 8192, otherwise the maximum value is 512. The
506f1d07
SR
925 minimum value which makes sense is 2.
926
927 This is purely to save memory - each supported CPU adds
928 approximately eight kilobytes to the kernel image.
929
930config SCHED_SMT
931 bool "SMT (Hyperthreading) scheduler support"
c8e56d20 932 depends on SMP
8f9ca475 933 ---help---
506f1d07
SR
934 SMT scheduler support improves the CPU scheduler's decision making
935 when dealing with Intel Pentium 4 chips with HyperThreading at a
936 cost of slightly increased overhead in some places. If unsure say
937 N here.
938
939config SCHED_MC
3c2362e6
HH
940 def_bool y
941 prompt "Multi-core scheduler support"
c8e56d20 942 depends on SMP
8f9ca475 943 ---help---
506f1d07
SR
944 Multi-core scheduler support improves the CPU scheduler's decision
945 making when dealing with multi-core CPU chips at a cost of slightly
946 increased overhead in some places. If unsure say N here.
947
de966cf4
TC
948config SCHED_MC_PRIO
949 bool "CPU core priorities scheduler support"
0a21fc12
IM
950 depends on SCHED_MC && CPU_SUP_INTEL
951 select X86_INTEL_PSTATE
952 select CPU_FREQ
de966cf4 953 default y
5e76b2ab 954 ---help---
0a21fc12
IM
955 Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
956 core ordering determined at manufacturing time, which allows
957 certain cores to reach higher turbo frequencies (when running
958 single threaded workloads) than others.
de966cf4 959
0a21fc12
IM
960 Enabling this kernel feature teaches the scheduler about
961 the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
962 scheduler's CPU selection logic accordingly, so that higher
963 overall system performance can be achieved.
de966cf4 964
0a21fc12 965 This feature will have no effect on CPUs without this feature.
de966cf4 966
0a21fc12 967 If unsure say Y here.
5e76b2ab 968
506f1d07
SR
969source "kernel/Kconfig.preempt"
970
30b8b006
TG
971config UP_LATE_INIT
972 def_bool y
ba360f88 973 depends on !SMP && X86_LOCAL_APIC
30b8b006 974
506f1d07 975config X86_UP_APIC
50849eef
JB
976 bool "Local APIC support on uniprocessors" if !PCI_MSI
977 default PCI_MSI
38a1dfda 978 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
8f9ca475 979 ---help---
506f1d07
SR
980 A local APIC (Advanced Programmable Interrupt Controller) is an
981 integrated interrupt controller in the CPU. If you have a single-CPU
982 system which has a processor with a local APIC, you can say Y here to
983 enable and use it. If you say Y here even though your machine doesn't
984 have a local APIC, then the kernel will still run with no slowdown at
985 all. The local APIC supports CPU-generated self-interrupts (timer,
986 performance counters), and the NMI watchdog which detects hard
987 lockups.
988
989config X86_UP_IOAPIC
990 bool "IO-APIC support on uniprocessors"
991 depends on X86_UP_APIC
8f9ca475 992 ---help---
506f1d07
SR
993 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
994 SMP-capable replacement for PC-style interrupt controllers. Most
995 SMP systems and many recent uniprocessor systems have one.
996
997 If you have a single-CPU system with an IO-APIC, you can say Y here
998 to use it. If you say Y here even though your machine doesn't have
999 an IO-APIC, then the kernel will still run with no slowdown at all.
1000
1001config X86_LOCAL_APIC
3c2362e6 1002 def_bool y
0dbc6078 1003 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
b5dc8e6c 1004 select IRQ_DOMAIN_HIERARCHY
52f518a3 1005 select PCI_MSI_IRQ_DOMAIN if PCI_MSI
506f1d07
SR
1006
1007config X86_IO_APIC
b1da1e71
JB
1008 def_bool y
1009 depends on X86_LOCAL_APIC || X86_UP_IOAPIC
506f1d07 1010
41b9eb26
SA
1011config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
1012 bool "Reroute for broken boot IRQs"
41b9eb26 1013 depends on X86_IO_APIC
8f9ca475 1014 ---help---
41b9eb26
SA
1015 This option enables a workaround that fixes a source of
1016 spurious interrupts. This is recommended when threaded
1017 interrupt handling is used on systems where the generation of
1018 superfluous "boot interrupts" cannot be disabled.
1019
1020 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
1021 entry in the chipset's IO-APIC is masked (as, e.g. the RT
1022 kernel does during interrupt handling). On chipsets where this
1023 boot IRQ generation cannot be disabled, this workaround keeps
1024 the original IRQ line masked so that only the equivalent "boot
1025 IRQ" is delivered to the CPUs. The workaround also tells the
1026 kernel to set up the IRQ handler on the boot IRQ line. In this
1027 way only one interrupt is delivered to the kernel. Otherwise
1028 the spurious second interrupt may cause the kernel to bring
1029 down (vital) interrupt lines.
1030
1031 Only affects "broken" chipsets. Interrupt sharing may be
1032 increased on these systems.
1033
506f1d07 1034config X86_MCE
bab9bc65 1035 bool "Machine Check / overheating reporting"
648ed940 1036 select GENERIC_ALLOCATOR
e57dbaf7 1037 default y
506f1d07 1038 ---help---
bab9bc65
AK
1039 Machine Check support allows the processor to notify the
1040 kernel if it detects a problem (e.g. overheating, data corruption).
506f1d07 1041 The action the kernel takes depends on the severity of the problem,
bab9bc65 1042 ranging from warning messages to halting the machine.
4efc0670 1043
506f1d07 1044config X86_MCE_INTEL
3c2362e6
HH
1045 def_bool y
1046 prompt "Intel MCE features"
c1ebf835 1047 depends on X86_MCE && X86_LOCAL_APIC
8f9ca475 1048 ---help---
506f1d07
SR
1049 Additional support for intel specific MCE features such as
1050 the thermal monitor.
1051
1052config X86_MCE_AMD
3c2362e6
HH
1053 def_bool y
1054 prompt "AMD MCE features"
f5382de9 1055 depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
8f9ca475 1056 ---help---
506f1d07
SR
1057 Additional support for AMD specific MCE features such as
1058 the DRAM Error Threshold.
1059
4efc0670 1060config X86_ANCIENT_MCE
6fc108a0 1061 bool "Support for old Pentium 5 / WinChip machine checks"
c31d9633 1062 depends on X86_32 && X86_MCE
cd13adcc
HS
1063 ---help---
1064 Include support for machine check handling on old Pentium 5 or WinChip
5065a706 1065 systems. These typically need to be enabled explicitly on the command
cd13adcc 1066 line.
4efc0670 1067
b2762686
AK
1068config X86_MCE_THRESHOLD
1069 depends on X86_MCE_AMD || X86_MCE_INTEL
6fc108a0 1070 def_bool y
b2762686 1071
ea149b36 1072config X86_MCE_INJECT
c1ebf835 1073 depends on X86_MCE
ea149b36
AK
1074 tristate "Machine check injector support"
1075 ---help---
1076 Provide support for injecting machine checks for testing purposes.
1077 If you don't know what a machine check is and you don't do kernel
1078 QA it is safe to say n.
1079
4efc0670
AK
1080config X86_THERMAL_VECTOR
1081 def_bool y
5bb38adc 1082 depends on X86_MCE_INTEL
4efc0670 1083
07dc900e 1084source "arch/x86/events/Kconfig"
e633c65a 1085
5aef51c3 1086config X86_LEGACY_VM86
1e642812 1087 bool "Legacy VM86 support"
5aef51c3 1088 default n
506f1d07 1089 depends on X86_32
8f9ca475 1090 ---help---
5aef51c3
AL
1091 This option allows user programs to put the CPU into V8086
1092 mode, which is an 80286-era approximation of 16-bit real mode.
1093
1094 Some very old versions of X and/or vbetool require this option
1095 for user mode setting. Similarly, DOSEMU will use it if
1096 available to accelerate real mode DOS programs. However, any
1097 recent version of DOSEMU, X, or vbetool should be fully
1098 functional even without kernel VM86 support, as they will all
1e642812
IM
1099 fall back to software emulation. Nevertheless, if you are using
1100 a 16-bit DOS program where 16-bit performance matters, vm86
1101 mode might be faster than emulation and you might want to
1102 enable this option.
5aef51c3 1103
1e642812
IM
1104 Note that any app that works on a 64-bit kernel is unlikely to
1105 need this option, as 64-bit kernels don't, and can't, support
1106 V8086 mode. This option is also unrelated to 16-bit protected
1107 mode and is not needed to run most 16-bit programs under Wine.
5aef51c3 1108
1e642812
IM
1109 Enabling this option increases the complexity of the kernel
1110 and slows down exception handling a tiny bit.
5aef51c3 1111
1e642812 1112 If unsure, say N here.
5aef51c3
AL
1113
1114config VM86
1115 bool
1116 default X86_LEGACY_VM86
34273f41
PA
1117
1118config X86_16BIT
1119 bool "Enable support for 16-bit segments" if EXPERT
1120 default y
a5b9e5a2 1121 depends on MODIFY_LDT_SYSCALL
34273f41
PA
1122 ---help---
1123 This option is required by programs like Wine to run 16-bit
1124 protected mode legacy code on x86 processors. Disabling
1125 this option saves about 300 bytes on i386, or around 6K text
1126 plus 16K runtime memory on x86-64,
1127
1128config X86_ESPFIX32
1129 def_bool y
1130 depends on X86_16BIT && X86_32
506f1d07 1131
197725de
PA
1132config X86_ESPFIX64
1133 def_bool y
34273f41 1134 depends on X86_16BIT && X86_64
506f1d07 1135
1ad83c85
AL
1136config X86_VSYSCALL_EMULATION
1137 bool "Enable vsyscall emulation" if EXPERT
1138 default y
1139 depends on X86_64
1140 ---help---
1141 This enables emulation of the legacy vsyscall page. Disabling
1142 it is roughly equivalent to booting with vsyscall=none, except
1143 that it will also disable the helpful warning if a program
1144 tries to use a vsyscall. With this option set to N, offending
1145 programs will just segfault, citing addresses of the form
1146 0xffffffffff600?00.
1147
1148 This option is required by many programs built before 2013, and
1149 care should be used even with newer programs if set to N.
1150
1151 Disabling this option saves about 7K of kernel size and
1152 possibly 4K of additional runtime pagetable memory.
1153
506f1d07
SR
1154config TOSHIBA
1155 tristate "Toshiba Laptop support"
1156 depends on X86_32
1157 ---help---
1158 This adds a driver to safely access the System Management Mode of
1159 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1160 not work on models with a Phoenix BIOS. The System Management Mode
1161 is used to set the BIOS and power saving options on Toshiba portables.
1162
1163 For information on utilities to make use of this driver see the
1164 Toshiba Linux utilities web site at:
1165 <http://www.buzzard.org.uk/toshiba/>.
1166
1167 Say Y if you intend to run this kernel on a Toshiba portable.
1168 Say N otherwise.
1169
1170config I8K
039ae585 1171 tristate "Dell i8k legacy laptop support"
949a9d70 1172 select HWMON
039ae585 1173 select SENSORS_DELL_SMM
506f1d07 1174 ---help---
039ae585
PR
1175 This option enables legacy /proc/i8k userspace interface in hwmon
1176 dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1177 temperature and allows controlling fan speeds of Dell laptops via
1178 System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1179 it reports also power and hotkey status. For fan speed control is
1180 needed userspace package i8kutils.
1181
1182 Say Y if you intend to run this kernel on old Dell laptops or want to
1183 use userspace package i8kutils.
506f1d07
SR
1184 Say N otherwise.
1185
1186config X86_REBOOTFIXUPS
9ba16087
JB
1187 bool "Enable X86 board specific fixups for reboot"
1188 depends on X86_32
506f1d07
SR
1189 ---help---
1190 This enables chipset and/or board specific fixups to be done
1191 in order to get reboot to work correctly. This is only needed on
1192 some combinations of hardware and BIOS. The symptom, for which
1193 this config is intended, is when reboot ends with a stalled/hung
1194 system.
1195
1196 Currently, the only fixup is for the Geode machines using
5e3a77e9 1197 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
506f1d07
SR
1198
1199 Say Y if you want to enable the fixup. Currently, it's safe to
1200 enable this option even if you don't need it.
1201 Say N otherwise.
1202
1203config MICROCODE
9a2bc335
BP
1204 bool "CPU microcode loading support"
1205 default y
80030e3d 1206 depends on CPU_SUP_AMD || CPU_SUP_INTEL
506f1d07
SR
1207 select FW_LOADER
1208 ---help---
1209 If you say Y here, you will be able to update the microcode on
5f9c01aa
BP
1210 Intel and AMD processors. The Intel support is for the IA32 family,
1211 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
1212 AMD support is for families 0x10 and later. You will obviously need
1213 the actual microcode binary data itself which is not shipped with
1214 the Linux kernel.
1215
1216 The preferred method to load microcode from a detached initrd is described
1217 in Documentation/x86/early-microcode.txt. For that you need to enable
1218 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
1219 initrd for microcode blobs.
1220
1221 In addition, you can build-in the microcode into the kernel. For that you
1222 need to enable FIRMWARE_IN_KERNEL and add the vendor-supplied microcode
1223 to the CONFIG_EXTRA_FIRMWARE config option.
506f1d07 1224
8d86f390 1225config MICROCODE_INTEL
e43f6e67 1226 bool "Intel microcode loading support"
8f9ca475
IM
1227 depends on MICROCODE
1228 default MICROCODE
1229 select FW_LOADER
1230 ---help---
1231 This options enables microcode patch loading support for Intel
1232 processors.
1233
b8989db9
A
1234 For the current Intel microcode data package go to
1235 <https://downloadcenter.intel.com> and search for
1236 'Linux Processor Microcode Data File'.
8d86f390 1237
80cc9f10 1238config MICROCODE_AMD
e43f6e67 1239 bool "AMD microcode loading support"
8f9ca475
IM
1240 depends on MICROCODE
1241 select FW_LOADER
1242 ---help---
1243 If you select this option, microcode patch loading support for AMD
1244 processors will be enabled.
80cc9f10 1245
8f9ca475 1246config MICROCODE_OLD_INTERFACE
3c2362e6 1247 def_bool y
506f1d07 1248 depends on MICROCODE
506f1d07
SR
1249
1250config X86_MSR
1251 tristate "/dev/cpu/*/msr - Model-specific register support"
8f9ca475 1252 ---help---
506f1d07
SR
1253 This device gives privileged processes access to the x86
1254 Model-Specific Registers (MSRs). It is a character device with
1255 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1256 MSR accesses are directed to a specific CPU on multi-processor
1257 systems.
1258
1259config X86_CPUID
1260 tristate "/dev/cpu/*/cpuid - CPU information support"
8f9ca475 1261 ---help---
506f1d07
SR
1262 This device gives processes access to the x86 CPUID instruction to
1263 be executed on a specific processor. It is a character device
1264 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1265 /dev/cpu/31/cpuid.
1266
1267choice
1268 prompt "High Memory Support"
6fc108a0 1269 default HIGHMEM4G
506f1d07
SR
1270 depends on X86_32
1271
1272config NOHIGHMEM
1273 bool "off"
506f1d07
SR
1274 ---help---
1275 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1276 However, the address space of 32-bit x86 processors is only 4
1277 Gigabytes large. That means that, if you have a large amount of
1278 physical memory, not all of it can be "permanently mapped" by the
1279 kernel. The physical memory that's not permanently mapped is called
1280 "high memory".
1281
1282 If you are compiling a kernel which will never run on a machine with
1283 more than 1 Gigabyte total physical RAM, answer "off" here (default
1284 choice and suitable for most users). This will result in a "3GB/1GB"
1285 split: 3GB are mapped so that each process sees a 3GB virtual memory
1286 space and the remaining part of the 4GB virtual memory space is used
1287 by the kernel to permanently map as much physical memory as
1288 possible.
1289
1290 If the machine has between 1 and 4 Gigabytes physical RAM, then
1291 answer "4GB" here.
1292
1293 If more than 4 Gigabytes is used then answer "64GB" here. This
1294 selection turns Intel PAE (Physical Address Extension) mode on.
1295 PAE implements 3-level paging on IA32 processors. PAE is fully
1296 supported by Linux, PAE mode is implemented on all recent Intel
1297 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1298 then the kernel will not boot on CPUs that don't support PAE!
1299
1300 The actual amount of total physical memory will either be
1301 auto detected or can be forced by using a kernel command line option
1302 such as "mem=256M". (Try "man bootparam" or see the documentation of
1303 your boot loader (lilo or loadlin) about how to pass options to the
1304 kernel at boot time.)
1305
1306 If unsure, say "off".
1307
1308config HIGHMEM4G
1309 bool "4GB"
8f9ca475 1310 ---help---
506f1d07
SR
1311 Select this if you have a 32-bit processor and between 1 and 4
1312 gigabytes of physical RAM.
1313
1314config HIGHMEM64G
1315 bool "64GB"
eb068e78 1316 depends on !M486
506f1d07 1317 select X86_PAE
8f9ca475 1318 ---help---
506f1d07
SR
1319 Select this if you have a 32-bit processor and more than 4
1320 gigabytes of physical RAM.
1321
1322endchoice
1323
1324choice
6a108a14 1325 prompt "Memory split" if EXPERT
506f1d07
SR
1326 default VMSPLIT_3G
1327 depends on X86_32
8f9ca475 1328 ---help---
506f1d07
SR
1329 Select the desired split between kernel and user memory.
1330
1331 If the address range available to the kernel is less than the
1332 physical memory installed, the remaining memory will be available
1333 as "high memory". Accessing high memory is a little more costly
1334 than low memory, as it needs to be mapped into the kernel first.
1335 Note that increasing the kernel address space limits the range
1336 available to user programs, making the address space there
1337 tighter. Selecting anything other than the default 3G/1G split
1338 will also likely make your kernel incompatible with binary-only
1339 kernel modules.
1340
1341 If you are not absolutely sure what you are doing, leave this
1342 option alone!
1343
1344 config VMSPLIT_3G
1345 bool "3G/1G user/kernel split"
1346 config VMSPLIT_3G_OPT
1347 depends on !X86_PAE
1348 bool "3G/1G user/kernel split (for full 1G low memory)"
1349 config VMSPLIT_2G
1350 bool "2G/2G user/kernel split"
1351 config VMSPLIT_2G_OPT
1352 depends on !X86_PAE
1353 bool "2G/2G user/kernel split (for full 2G low memory)"
1354 config VMSPLIT_1G
1355 bool "1G/3G user/kernel split"
1356endchoice
1357
1358config PAGE_OFFSET
1359 hex
1360 default 0xB0000000 if VMSPLIT_3G_OPT
1361 default 0x80000000 if VMSPLIT_2G
1362 default 0x78000000 if VMSPLIT_2G_OPT
1363 default 0x40000000 if VMSPLIT_1G
1364 default 0xC0000000
1365 depends on X86_32
1366
1367config HIGHMEM
3c2362e6 1368 def_bool y
506f1d07 1369 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
506f1d07
SR
1370
1371config X86_PAE
9ba16087 1372 bool "PAE (Physical Address Extension) Support"
506f1d07 1373 depends on X86_32 && !HIGHMEM4G
9d99c712 1374 select SWIOTLB
8f9ca475 1375 ---help---
506f1d07
SR
1376 PAE is required for NX support, and furthermore enables
1377 larger swapspace support for non-overcommit purposes. It
1378 has the cost of more pagetable lookup overhead, and also
1379 consumes more pagetable space per process.
1380
600715dc 1381config ARCH_PHYS_ADDR_T_64BIT
3120e25e
JB
1382 def_bool y
1383 depends on X86_64 || X86_PAE
600715dc 1384
66f2b061 1385config ARCH_DMA_ADDR_T_64BIT
3120e25e
JB
1386 def_bool y
1387 depends on X86_64 || HIGHMEM64G
66f2b061 1388
10971ab2 1389config X86_DIRECT_GBPAGES
e5008abe
LR
1390 def_bool y
1391 depends on X86_64 && !DEBUG_PAGEALLOC && !KMEMCHECK
8f9ca475 1392 ---help---
10971ab2
IM
1393 Certain kernel features effectively disable kernel
1394 linear 1 GB mappings (even if the CPU otherwise
1395 supports them), so don't confuse the user by printing
1396 that we have them enabled.
9e899816 1397
506f1d07
SR
1398# Common NUMA Features
1399config NUMA
fd51b2d7 1400 bool "Numa Memory Allocation and Scheduler Support"
506f1d07 1401 depends on SMP
b5660ba7
PA
1402 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1403 default y if X86_BIGSMP
8f9ca475 1404 ---help---
506f1d07 1405 Enable NUMA (Non Uniform Memory Access) support.
fd51b2d7 1406
506f1d07
SR
1407 The kernel will try to allocate memory used by a CPU on the
1408 local memory controller of the CPU and add some more
1409 NUMA awareness to the kernel.
1410
c280ea5e 1411 For 64-bit this is recommended if the system is Intel Core i7
fd51b2d7
KM
1412 (or later), AMD Opteron, or EM64T NUMA.
1413
b5660ba7 1414 For 32-bit this is only needed if you boot a 32-bit
7cf6c945 1415 kernel on a 64-bit NUMA platform.
fd51b2d7
KM
1416
1417 Otherwise, you should say N.
506f1d07 1418
eec1d4fa 1419config AMD_NUMA
3c2362e6
HH
1420 def_bool y
1421 prompt "Old style AMD Opteron NUMA detection"
5da0ef9a 1422 depends on X86_64 && NUMA && PCI
8f9ca475 1423 ---help---
eec1d4fa
HR
1424 Enable AMD NUMA node topology detection. You should say Y here if
1425 you have a multi processor AMD system. This uses an old method to
1426 read the NUMA configuration directly from the builtin Northbridge
1427 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1428 which also takes priority if both are compiled in.
506f1d07
SR
1429
1430config X86_64_ACPI_NUMA
3c2362e6
HH
1431 def_bool y
1432 prompt "ACPI NUMA detection"
506f1d07
SR
1433 depends on X86_64 && NUMA && ACPI && PCI
1434 select ACPI_NUMA
8f9ca475 1435 ---help---
506f1d07
SR
1436 Enable ACPI SRAT based node topology detection.
1437
6ec6e0d9
SS
1438# Some NUMA nodes have memory ranges that span
1439# other nodes. Even though a pfn is valid and
1440# between a node's start and end pfns, it may not
1441# reside on that node. See memmap_init_zone()
1442# for details.
1443config NODES_SPAN_OTHER_NODES
1444 def_bool y
1445 depends on X86_64_ACPI_NUMA
1446
506f1d07
SR
1447config NUMA_EMU
1448 bool "NUMA emulation"
1b7e03ef 1449 depends on NUMA
8f9ca475 1450 ---help---
506f1d07
SR
1451 Enable NUMA emulation. A flat machine will be split
1452 into virtual nodes when booted with "numa=fake=N", where N is the
1453 number of nodes. This is only useful for debugging.
1454
1455config NODES_SHIFT
d25e26b6 1456 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
51591e31
DR
1457 range 1 10
1458 default "10" if MAXSMP
506f1d07 1459 default "6" if X86_64
506f1d07
SR
1460 default "3"
1461 depends on NEED_MULTIPLE_NODES
8f9ca475 1462 ---help---
1184dc2f 1463 Specify the maximum number of NUMA Nodes available on the target
692105b8 1464 system. Increases memory reserved to accommodate various tables.
506f1d07 1465
506f1d07 1466config ARCH_HAVE_MEMORY_PRESENT
3c2362e6 1467 def_bool y
506f1d07 1468 depends on X86_32 && DISCONTIGMEM
506f1d07
SR
1469
1470config NEED_NODE_MEMMAP_SIZE
3c2362e6 1471 def_bool y
506f1d07 1472 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
506f1d07 1473
506f1d07
SR
1474config ARCH_FLATMEM_ENABLE
1475 def_bool y
3b16651f 1476 depends on X86_32 && !NUMA
506f1d07
SR
1477
1478config ARCH_DISCONTIGMEM_ENABLE
1479 def_bool y
b263295d 1480 depends on NUMA && X86_32
506f1d07
SR
1481
1482config ARCH_DISCONTIGMEM_DEFAULT
1483 def_bool y
b263295d
CL
1484 depends on NUMA && X86_32
1485
506f1d07
SR
1486config ARCH_SPARSEMEM_ENABLE
1487 def_bool y
6ea30386 1488 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
506f1d07
SR
1489 select SPARSEMEM_STATIC if X86_32
1490 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1491
3b16651f
TH
1492config ARCH_SPARSEMEM_DEFAULT
1493 def_bool y
1494 depends on X86_64
1495
506f1d07
SR
1496config ARCH_SELECT_MEMORY_MODEL
1497 def_bool y
b263295d 1498 depends on ARCH_SPARSEMEM_ENABLE
506f1d07
SR
1499
1500config ARCH_MEMORY_PROBE
a0842b70 1501 bool "Enable sysfs memory/probe interface"
3120e25e 1502 depends on X86_64 && MEMORY_HOTPLUG
a0842b70
TK
1503 help
1504 This option enables a sysfs memory/probe interface for testing.
1505 See Documentation/memory-hotplug.txt for more information.
1506 If you are unsure how to answer this question, answer N.
506f1d07 1507
3b16651f
TH
1508config ARCH_PROC_KCORE_TEXT
1509 def_bool y
1510 depends on X86_64 && PROC_KCORE
1511
a29815a3
AK
1512config ILLEGAL_POINTER_VALUE
1513 hex
1514 default 0 if X86_32
1515 default 0xdead000000000000 if X86_64
1516
506f1d07
SR
1517source "mm/Kconfig"
1518
7a67832c
DW
1519config X86_PMEM_LEGACY_DEVICE
1520 bool
1521
ec776ef6 1522config X86_PMEM_LEGACY
7a67832c 1523 tristate "Support non-standard NVDIMMs and ADR protected memory"
9f53f9fa
DW
1524 depends on PHYS_ADDR_T_64BIT
1525 depends on BLK_DEV
7a67832c 1526 select X86_PMEM_LEGACY_DEVICE
9f53f9fa 1527 select LIBNVDIMM
ec776ef6
CH
1528 help
1529 Treat memory marked using the non-standard e820 type of 12 as used
1530 by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1531 The kernel will offer these regions to the 'pmem' driver so
1532 they can be used for persistent storage.
1533
1534 Say Y if unsure.
1535
506f1d07
SR
1536config HIGHPTE
1537 bool "Allocate 3rd-level pagetables from highmem"
6fc108a0 1538 depends on HIGHMEM
8f9ca475 1539 ---help---
506f1d07
SR
1540 The VM uses one page table entry for each page of physical memory.
1541 For systems with a lot of RAM, this can be wasteful of precious
1542 low memory. Setting this option will put user-space page table
1543 entries in high memory.
1544
9f077871 1545config X86_CHECK_BIOS_CORRUPTION
8f9ca475
IM
1546 bool "Check for low memory corruption"
1547 ---help---
1548 Periodically check for memory corruption in low memory, which
1549 is suspected to be caused by BIOS. Even when enabled in the
1550 configuration, it is disabled at runtime. Enable it by
1551 setting "memory_corruption_check=1" on the kernel command
1552 line. By default it scans the low 64k of memory every 60
1553 seconds; see the memory_corruption_check_size and
1554 memory_corruption_check_period parameters in
8c27ceff 1555 Documentation/admin-guide/kernel-parameters.rst to adjust this.
8f9ca475
IM
1556
1557 When enabled with the default parameters, this option has
1558 almost no overhead, as it reserves a relatively small amount
1559 of memory and scans it infrequently. It both detects corruption
1560 and prevents it from affecting the running system.
1561
1562 It is, however, intended as a diagnostic tool; if repeatable
1563 BIOS-originated corruption always affects the same memory,
1564 you can use memmap= to prevent the kernel from using that
1565 memory.
9f077871 1566
c885df50 1567config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
8f9ca475 1568 bool "Set the default setting of memory_corruption_check"
c885df50
JF
1569 depends on X86_CHECK_BIOS_CORRUPTION
1570 default y
8f9ca475
IM
1571 ---help---
1572 Set whether the default state of memory_corruption_check is
1573 on or off.
c885df50 1574
9ea77bdb 1575config X86_RESERVE_LOW
d0cd7425
PA
1576 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1577 default 64
1578 range 4 640
8f9ca475 1579 ---help---
d0cd7425
PA
1580 Specify the amount of low memory to reserve for the BIOS.
1581
1582 The first page contains BIOS data structures that the kernel
1583 must not use, so that page must always be reserved.
1584
1585 By default we reserve the first 64K of physical RAM, as a
1586 number of BIOSes are known to corrupt that memory range
1587 during events such as suspend/resume or monitor cable
1588 insertion, so it must not be used by the kernel.
fc381519 1589
d0cd7425
PA
1590 You can set this to 4 if you are absolutely sure that you
1591 trust the BIOS to get all its memory reservations and usages
1592 right. If you know your BIOS have problems beyond the
1593 default 64K area, you can set this to 640 to avoid using the
1594 entire low memory range.
fc381519 1595
d0cd7425
PA
1596 If you have doubts about the BIOS (e.g. suspend/resume does
1597 not work or there's kernel crashes after certain hardware
1598 hotplug events) then you might want to enable
1599 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1600 typical corruption patterns.
fc381519 1601
d0cd7425 1602 Leave this to the default value of 64 if you are unsure.
fc381519 1603
506f1d07
SR
1604config MATH_EMULATION
1605 bool
a5b9e5a2 1606 depends on MODIFY_LDT_SYSCALL
506f1d07
SR
1607 prompt "Math emulation" if X86_32
1608 ---help---
1609 Linux can emulate a math coprocessor (used for floating point
1610 operations) if you don't have one. 486DX and Pentium processors have
1611 a math coprocessor built in, 486SX and 386 do not, unless you added
1612 a 487DX or 387, respectively. (The messages during boot time can
1613 give you some hints here ["man dmesg"].) Everyone needs either a
1614 coprocessor or this emulation.
1615
1616 If you don't have a math coprocessor, you need to say Y here; if you
1617 say Y here even though you have a coprocessor, the coprocessor will
1618 be used nevertheless. (This behavior can be changed with the kernel
1619 command line option "no387", which comes handy if your coprocessor
1620 is broken. Try "man bootparam" or see the documentation of your boot
1621 loader (lilo or loadlin) about how to pass options to the kernel at
1622 boot time.) This means that it is a good idea to say Y here if you
1623 intend to use this kernel on different machines.
1624
1625 More information about the internals of the Linux math coprocessor
1626 emulation can be found in <file:arch/x86/math-emu/README>.
1627
1628 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1629 kernel, it won't hurt.
1630
1631config MTRR
6fc108a0 1632 def_bool y
6a108a14 1633 prompt "MTRR (Memory Type Range Register) support" if EXPERT
506f1d07
SR
1634 ---help---
1635 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1636 the Memory Type Range Registers (MTRRs) may be used to control
1637 processor access to memory ranges. This is most useful if you have
1638 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1639 allows bus write transfers to be combined into a larger transfer
1640 before bursting over the PCI/AGP bus. This can increase performance
1641 of image write operations 2.5 times or more. Saying Y here creates a
1642 /proc/mtrr file which may be used to manipulate your processor's
1643 MTRRs. Typically the X server should use this.
1644
1645 This code has a reasonably generic interface so that similar
1646 control registers on other processors can be easily supported
1647 as well:
1648
1649 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1650 Registers (ARRs) which provide a similar functionality to MTRRs. For
1651 these, the ARRs are used to emulate the MTRRs.
1652 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1653 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1654 write-combining. All of these processors are supported by this code
1655 and it makes sense to say Y here if you have one of them.
1656
1657 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1658 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1659 can lead to all sorts of problems, so it's good to say Y here.
1660
1661 You can safely say Y even if your machine doesn't have MTRRs, you'll
1662 just add about 9 KB to your kernel.
1663
7225e751 1664 See <file:Documentation/x86/mtrr.txt> for more information.
506f1d07 1665
95ffa243 1666config MTRR_SANITIZER
2ffb3501 1667 def_bool y
95ffa243
YL
1668 prompt "MTRR cleanup support"
1669 depends on MTRR
8f9ca475 1670 ---help---
aba3728c
TG
1671 Convert MTRR layout from continuous to discrete, so X drivers can
1672 add writeback entries.
95ffa243 1673
aba3728c 1674 Can be disabled with disable_mtrr_cleanup on the kernel command line.
692105b8 1675 The largest mtrr entry size for a continuous block can be set with
aba3728c 1676 mtrr_chunk_size.
95ffa243 1677
2ffb3501 1678 If unsure, say Y.
95ffa243
YL
1679
1680config MTRR_SANITIZER_ENABLE_DEFAULT
f5098d62
YL
1681 int "MTRR cleanup enable value (0-1)"
1682 range 0 1
1683 default "0"
95ffa243 1684 depends on MTRR_SANITIZER
8f9ca475 1685 ---help---
f5098d62 1686 Enable mtrr cleanup default value
95ffa243 1687
12031a62
YL
1688config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1689 int "MTRR cleanup spare reg num (0-7)"
1690 range 0 7
1691 default "1"
1692 depends on MTRR_SANITIZER
8f9ca475 1693 ---help---
12031a62 1694 mtrr cleanup spare entries default, it can be changed via
aba3728c 1695 mtrr_spare_reg_nr=N on the kernel command line.
12031a62 1696
2e5d9c85 1697config X86_PAT
6fc108a0 1698 def_bool y
6a108a14 1699 prompt "x86 PAT support" if EXPERT
2a8a2719 1700 depends on MTRR
8f9ca475 1701 ---help---
2e5d9c85 1702 Use PAT attributes to setup page level cache control.
042b78e4 1703
2e5d9c85 1704 PATs are the modern equivalents of MTRRs and are much more
1705 flexible than MTRRs.
1706
1707 Say N here if you see bootup problems (boot crash, boot hang,
042b78e4 1708 spontaneous reboots) or a non-working video driver.
2e5d9c85 1709
1710 If unsure, say Y.
1711
46cf98cd
VP
1712config ARCH_USES_PG_UNCACHED
1713 def_bool y
1714 depends on X86_PAT
1715
628c6246
PA
1716config ARCH_RANDOM
1717 def_bool y
1718 prompt "x86 architectural random number generator" if EXPERT
1719 ---help---
1720 Enable the x86 architectural RDRAND instruction
1721 (Intel Bull Mountain technology) to generate random numbers.
1722 If supported, this is a high bandwidth, cryptographically
1723 secure hardware random number generator.
1724
51ae4a2d
PA
1725config X86_SMAP
1726 def_bool y
1727 prompt "Supervisor Mode Access Prevention" if EXPERT
1728 ---help---
1729 Supervisor Mode Access Prevention (SMAP) is a security
1730 feature in newer Intel processors. There is a small
1731 performance cost if this enabled and turned on; there is
1732 also a small increase in the kernel size if this is enabled.
1733
1734 If unsure, say Y.
1735
72e9b5fe
DH
1736config X86_INTEL_MPX
1737 prompt "Intel MPX (Memory Protection Extensions)"
1738 def_bool n
1739 depends on CPU_SUP_INTEL
1740 ---help---
1741 MPX provides hardware features that can be used in
1742 conjunction with compiler-instrumented code to check
1743 memory references. It is designed to detect buffer
1744 overflow or underflow bugs.
1745
1746 This option enables running applications which are
1747 instrumented or otherwise use MPX. It does not use MPX
1748 itself inside the kernel or to protect the kernel
1749 against bad memory references.
1750
1751 Enabling this option will make the kernel larger:
1752 ~8k of kernel text and 36 bytes of data on a 64-bit
1753 defconfig. It adds a long to the 'mm_struct' which
1754 will increase the kernel memory overhead of each
1755 process and adds some branches to paths used during
1756 exec() and munmap().
1757
1758 For details, see Documentation/x86/intel_mpx.txt
1759
1760 If unsure, say N.
1761
35e97790 1762config X86_INTEL_MEMORY_PROTECTION_KEYS
284244a9 1763 prompt "Intel Memory Protection Keys"
35e97790 1764 def_bool y
284244a9 1765 # Note: only available in 64-bit mode
35e97790 1766 depends on CPU_SUP_INTEL && X86_64
52c8e601
IM
1767 select ARCH_USES_HIGH_VMA_FLAGS
1768 select ARCH_HAS_PKEYS
284244a9
DH
1769 ---help---
1770 Memory Protection Keys provides a mechanism for enforcing
1771 page-based protections, but without requiring modification of the
1772 page tables when an application changes protection domains.
1773
1774 For details, see Documentation/x86/protection-keys.txt
1775
1776 If unsure, say y.
35e97790 1777
506f1d07 1778config EFI
9ba16087 1779 bool "EFI runtime service support"
5b83683f 1780 depends on ACPI
f6ce5002 1781 select UCS2_STRING
022ee6c5 1782 select EFI_RUNTIME_WRAPPERS
506f1d07 1783 ---help---
8f9ca475
IM
1784 This enables the kernel to use EFI runtime services that are
1785 available (such as the EFI variable services).
506f1d07 1786
8f9ca475
IM
1787 This option is only useful on systems that have EFI firmware.
1788 In addition, you should use the latest ELILO loader available
1789 at <http://elilo.sourceforge.net> in order to take advantage
1790 of EFI runtime services. However, even with this option, the
1791 resultant kernel should continue to boot on existing non-EFI
1792 platforms.
506f1d07 1793
291f3632
MF
1794config EFI_STUB
1795 bool "EFI stub support"
b16d8c23 1796 depends on EFI && !X86_USE_3DNOW
7b2a583a 1797 select RELOCATABLE
291f3632
MF
1798 ---help---
1799 This kernel feature allows a bzImage to be loaded directly
1800 by EFI firmware without the use of a bootloader.
1801
4172fe2f 1802 See Documentation/efi-stub.txt for more information.
0c759662 1803
7d453eee
MF
1804config EFI_MIXED
1805 bool "EFI mixed-mode support"
1806 depends on EFI_STUB && X86_64
1807 ---help---
1808 Enabling this feature allows a 64-bit kernel to be booted
1809 on a 32-bit firmware, provided that your CPU supports 64-bit
1810 mode.
1811
1812 Note that it is not possible to boot a mixed-mode enabled
1813 kernel via the EFI boot stub - a bootloader that supports
1814 the EFI handover protocol must be used.
1815
1816 If unsure, say N.
1817
8c26f36d
MG
1818config EFI_SECURE_BOOT_SIG_ENFORCE
1819 def_bool n
1820 depends on EFI
1821 prompt "Force module signing when UEFI Secure Boot is enabled"
1822 ---help---
1823 UEFI Secure Boot provides a mechanism for ensuring that the
1824 firmware will only load signed bootloaders and kernels. Certain
1825 use cases may also require that all kernel modules also be signed.
1826 Say Y here to automatically enable module signature enforcement
1827 when a system boots with UEFI Secure Boot enabled.
1828
506f1d07 1829config SECCOMP
3c2362e6
HH
1830 def_bool y
1831 prompt "Enable seccomp to safely compute untrusted bytecode"
8f9ca475 1832 ---help---
506f1d07
SR
1833 This kernel feature is useful for number crunching applications
1834 that may need to compute untrusted bytecode during their
1835 execution. By using pipes or other transports made available to
1836 the process as file descriptors supporting the read/write
1837 syscalls, it's possible to isolate those applications in
1838 their own address space using seccomp. Once seccomp is
9c0bbee8 1839 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
506f1d07
SR
1840 and the task is only allowed to execute a few safe syscalls
1841 defined by each seccomp mode.
1842
1843 If unsure, say Y. Only embedded should say N here.
1844
506f1d07
SR
1845source kernel/Kconfig.hz
1846
1847config KEXEC
1848 bool "kexec system call"
2965faa5 1849 select KEXEC_CORE
8f9ca475 1850 ---help---
506f1d07
SR
1851 kexec is a system call that implements the ability to shutdown your
1852 current kernel, and to start another kernel. It is like a reboot
1853 but it is independent of the system firmware. And like a reboot
1854 you can start any kernel with it, not just Linux.
1855
1856 The name comes from the similarity to the exec system call.
1857
1858 It is an ongoing process to be certain the hardware in a machine
1859 is properly shutdown, so do not be surprised if this code does not
bf220695
GU
1860 initially work for you. As of this writing the exact hardware
1861 interface is strongly in flux, so no good recommendation can be
1862 made.
506f1d07 1863
74ca317c
VG
1864config KEXEC_FILE
1865 bool "kexec file based system call"
2965faa5 1866 select KEXEC_CORE
74ca317c 1867 select BUILD_BIN2C
74ca317c
VG
1868 depends on X86_64
1869 depends on CRYPTO=y
1870 depends on CRYPTO_SHA256=y
1871 ---help---
1872 This is new version of kexec system call. This system call is
1873 file based and takes file descriptors as system call argument
1874 for kernel and initramfs as opposed to list of segments as
1875 accepted by previous system call.
1876
8e7d8381
VG
1877config KEXEC_VERIFY_SIG
1878 bool "Verify kernel signature during kexec_file_load() syscall"
74ca317c 1879 depends on KEXEC_FILE
8e7d8381
VG
1880 ---help---
1881 This option makes kernel signature verification mandatory for
d8eb8940
BP
1882 the kexec_file_load() syscall.
1883
1884 In addition to that option, you need to enable signature
1885 verification for the corresponding kernel image type being
1886 loaded in order for this to work.
8e7d8381
VG
1887
1888config KEXEC_BZIMAGE_VERIFY_SIG
1889 bool "Enable bzImage signature verification support"
1890 depends on KEXEC_VERIFY_SIG
1891 depends on SIGNED_PE_FILE_VERIFICATION
1892 select SYSTEM_TRUSTED_KEYRING
1893 ---help---
1894 Enable bzImage signature verification support.
1895
506f1d07 1896config CRASH_DUMP
04b69447 1897 bool "kernel crash dumps"
506f1d07 1898 depends on X86_64 || (X86_32 && HIGHMEM)
8f9ca475 1899 ---help---
506f1d07
SR
1900 Generate crash dump after being started by kexec.
1901 This should be normally only set in special crash dump kernels
1902 which are loaded in the main kernel with kexec-tools into
1903 a specially reserved region and then later executed after
1904 a crash by kdump/kexec. The crash dump kernel must be compiled
1905 to a memory address not used by the main kernel or BIOS using
1906 PHYSICAL_START, or it must be built as a relocatable image
1907 (CONFIG_RELOCATABLE=y).
1908 For more details see Documentation/kdump/kdump.txt
1909
3ab83521 1910config KEXEC_JUMP
6ea30386 1911 bool "kexec jump"
fee7b0d8 1912 depends on KEXEC && HIBERNATION
8f9ca475 1913 ---help---
89081d17
HY
1914 Jump between original kernel and kexeced kernel and invoke
1915 code in physical address mode via KEXEC
3ab83521 1916
506f1d07 1917config PHYSICAL_START
6a108a14 1918 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
ceefccc9 1919 default "0x1000000"
8f9ca475 1920 ---help---
506f1d07
SR
1921 This gives the physical address where the kernel is loaded.
1922
1923 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1924 bzImage will decompress itself to above physical address and
1925 run from there. Otherwise, bzImage will run from the address where
1926 it has been loaded by the boot loader and will ignore above physical
1927 address.
1928
1929 In normal kdump cases one does not have to set/change this option
1930 as now bzImage can be compiled as a completely relocatable image
1931 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1932 address. This option is mainly useful for the folks who don't want
1933 to use a bzImage for capturing the crash dump and want to use a
1934 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1935 to be specifically compiled to run from a specific memory area
1936 (normally a reserved region) and this option comes handy.
1937
ceefccc9
PA
1938 So if you are using bzImage for capturing the crash dump,
1939 leave the value here unchanged to 0x1000000 and set
1940 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1941 for capturing the crash dump change this value to start of
1942 the reserved region. In other words, it can be set based on
1943 the "X" value as specified in the "crashkernel=YM@XM"
1944 command line boot parameter passed to the panic-ed
1945 kernel. Please take a look at Documentation/kdump/kdump.txt
1946 for more details about crash dumps.
506f1d07
SR
1947
1948 Usage of bzImage for capturing the crash dump is recommended as
1949 one does not have to build two kernels. Same kernel can be used
1950 as production kernel and capture kernel. Above option should have
1951 gone away after relocatable bzImage support is introduced. But it
1952 is present because there are users out there who continue to use
1953 vmlinux for dump capture. This option should go away down the
1954 line.
1955
1956 Don't change this unless you know what you are doing.
1957
1958config RELOCATABLE
26717808
PA
1959 bool "Build a relocatable kernel"
1960 default y
8f9ca475 1961 ---help---
506f1d07
SR
1962 This builds a kernel image that retains relocation information
1963 so it can be loaded someplace besides the default 1MB.
1964 The relocations tend to make the kernel binary about 10% larger,
1965 but are discarded at runtime.
1966
1967 One use is for the kexec on panic case where the recovery kernel
1968 must live at a different physical address than the primary
1969 kernel.
1970
1971 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1972 it has been loaded at and the compile time physical address
8ab3820f 1973 (CONFIG_PHYSICAL_START) is used as the minimum location.
506f1d07 1974
8ab3820f 1975config RANDOMIZE_BASE
e8581e3d 1976 bool "Randomize the address of the kernel image (KASLR)"
8ab3820f 1977 depends on RELOCATABLE
8ab3820f
KC
1978 default n
1979 ---help---
e8581e3d
BH
1980 In support of Kernel Address Space Layout Randomization (KASLR),
1981 this randomizes the physical address at which the kernel image
1982 is decompressed and the virtual address where the kernel
1983 image is mapped, as a security feature that deters exploit
1984 attempts relying on knowledge of the location of kernel
1985 code internals.
1986
ed9f007e
KC
1987 On 64-bit, the kernel physical and virtual addresses are
1988 randomized separately. The physical address will be anywhere
1989 between 16MB and the top of physical memory (up to 64TB). The
1990 virtual address will be randomized from 16MB up to 1GB (9 bits
1991 of entropy). Note that this also reduces the memory space
1992 available to kernel modules from 1.5GB to 1GB.
1993
1994 On 32-bit, the kernel physical and virtual addresses are
1995 randomized together. They will be randomized from 16MB up to
1996 512MB (8 bits of entropy).
e8581e3d
BH
1997
1998 Entropy is generated using the RDRAND instruction if it is
1999 supported. If RDTSC is supported, its value is mixed into
2000 the entropy pool as well. If neither RDRAND nor RDTSC are
ed9f007e
KC
2001 supported, then entropy is read from the i8254 timer. The
2002 usable entropy is limited by the kernel being built using
2003 2GB addressing, and that PHYSICAL_ALIGN must be at a
2004 minimum of 2MB. As a result, only 10 bits of entropy are
2005 theoretically possible, but the implementations are further
2006 limited due to memory layouts.
e8581e3d
BH
2007
2008 If CONFIG_HIBERNATE is also enabled, KASLR is disabled at boot
2009 time. To enable it, boot with "kaslr" on the kernel command
2010 line (which will also disable hibernation).
8ab3820f 2011
e8581e3d 2012 If unsure, say N.
8ab3820f
KC
2013
2014# Relocation on x86 needs some additional build support
845adf72
PA
2015config X86_NEED_RELOCS
2016 def_bool y
8ab3820f 2017 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
845adf72 2018
506f1d07 2019config PHYSICAL_ALIGN
a0215061 2020 hex "Alignment value to which kernel should be aligned"
8ab3820f 2021 default "0x200000"
a0215061
KC
2022 range 0x2000 0x1000000 if X86_32
2023 range 0x200000 0x1000000 if X86_64
8f9ca475 2024 ---help---
506f1d07
SR
2025 This value puts the alignment restrictions on physical address
2026 where kernel is loaded and run from. Kernel is compiled for an
2027 address which meets above alignment restriction.
2028
2029 If bootloader loads the kernel at a non-aligned address and
2030 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2031 address aligned to above value and run from there.
2032
2033 If bootloader loads the kernel at a non-aligned address and
2034 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2035 load address and decompress itself to the address it has been
2036 compiled for and run from there. The address for which kernel is
2037 compiled already meets above alignment restrictions. Hence the
2038 end result is that kernel runs from a physical address meeting
2039 above alignment restrictions.
2040
a0215061
KC
2041 On 32-bit this value must be a multiple of 0x2000. On 64-bit
2042 this value must be a multiple of 0x200000.
2043
506f1d07
SR
2044 Don't change this unless you know what you are doing.
2045
0483e1fa
TG
2046config RANDOMIZE_MEMORY
2047 bool "Randomize the kernel memory sections"
2048 depends on X86_64
2049 depends on RANDOMIZE_BASE
2050 default RANDOMIZE_BASE
2051 ---help---
2052 Randomizes the base virtual address of kernel memory sections
2053 (physical memory mapping, vmalloc & vmemmap). This security feature
2054 makes exploits relying on predictable memory locations less reliable.
2055
2056 The order of allocations remains unchanged. Entropy is generated in
2057 the same way as RANDOMIZE_BASE. Current implementation in the optimal
2058 configuration have in average 30,000 different possible virtual
2059 addresses for each memory section.
2060
2061 If unsure, say N.
2062
90397a41
TG
2063config RANDOMIZE_MEMORY_PHYSICAL_PADDING
2064 hex "Physical memory mapping padding" if EXPERT
2065 depends on RANDOMIZE_MEMORY
2066 default "0xa" if MEMORY_HOTPLUG
2067 default "0x0"
2068 range 0x1 0x40 if MEMORY_HOTPLUG
2069 range 0x0 0x40
2070 ---help---
2071 Define the padding in terabytes added to the existing physical
2072 memory size during kernel memory randomization. It is useful
2073 for memory hotplug support but reduces the entropy available for
2074 address randomization.
2075
2076 If unsure, leave at the default value.
2077
506f1d07 2078config HOTPLUG_CPU
7c13e6a3 2079 bool "Support for hot-pluggable CPUs"
40b31360 2080 depends on SMP
506f1d07 2081 ---help---
7c13e6a3
DS
2082 Say Y here to allow turning CPUs off and on. CPUs can be
2083 controlled through /sys/devices/system/cpu.
2084 ( Note: power management support will enable this option
2085 automatically on SMP systems. )
2086 Say N if you want to disable CPU hotplug.
506f1d07 2087
80aa1dff
FY
2088config BOOTPARAM_HOTPLUG_CPU0
2089 bool "Set default setting of cpu0_hotpluggable"
2090 default n
2c922cd0 2091 depends on HOTPLUG_CPU
80aa1dff
FY
2092 ---help---
2093 Set whether default state of cpu0_hotpluggable is on or off.
2094
2095 Say Y here to enable CPU0 hotplug by default. If this switch
2096 is turned on, there is no need to give cpu0_hotplug kernel
2097 parameter and the CPU0 hotplug feature is enabled by default.
2098
2099 Please note: there are two known CPU0 dependencies if you want
2100 to enable the CPU0 hotplug feature either by this switch or by
2101 cpu0_hotplug kernel parameter.
2102
2103 First, resume from hibernate or suspend always starts from CPU0.
2104 So hibernate and suspend are prevented if CPU0 is offline.
2105
2106 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2107 offline if any interrupt can not migrate out of CPU0. There may
2108 be other CPU0 dependencies.
2109
2110 Please make sure the dependencies are under your control before
2111 you enable this feature.
2112
2113 Say N if you don't want to enable CPU0 hotplug feature by default.
2114 You still can enable the CPU0 hotplug feature at boot by kernel
2115 parameter cpu0_hotplug.
2116
a71c8bc5
FY
2117config DEBUG_HOTPLUG_CPU0
2118 def_bool n
2119 prompt "Debug CPU0 hotplug"
2c922cd0 2120 depends on HOTPLUG_CPU
a71c8bc5
FY
2121 ---help---
2122 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2123 soon as possible and boots up userspace with CPU0 offlined. User
2124 can online CPU0 back after boot time.
2125
2126 To debug CPU0 hotplug, you need to enable CPU0 offline/online
2127 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2128 compilation or giving cpu0_hotplug kernel parameter at boot.
2129
2130 If unsure, say N.
2131
506f1d07 2132config COMPAT_VDSO
b0b49f26
AL
2133 def_bool n
2134 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
953fee1d 2135 depends on COMPAT_32
8f9ca475 2136 ---help---
b0b49f26
AL
2137 Certain buggy versions of glibc will crash if they are
2138 presented with a 32-bit vDSO that is not mapped at the address
2139 indicated in its segment table.
e84446de 2140
b0b49f26
AL
2141 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2142 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2143 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
2144 the only released version with the bug, but OpenSUSE 9
2145 contains a buggy "glibc 2.3.2".
506f1d07 2146
b0b49f26
AL
2147 The symptom of the bug is that everything crashes on startup, saying:
2148 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2149
2150 Saying Y here changes the default value of the vdso32 boot
2151 option from 1 to 0, which turns off the 32-bit vDSO entirely.
2152 This works around the glibc bug but hurts performance.
2153
2154 If unsure, say N: if you are compiling your own kernel, you
2155 are unlikely to be using a buggy version of glibc.
506f1d07 2156
3dc33bd3
KC
2157choice
2158 prompt "vsyscall table for legacy applications"
2159 depends on X86_64
2160 default LEGACY_VSYSCALL_EMULATE
2161 help
2162 Legacy user code that does not know how to find the vDSO expects
2163 to be able to issue three syscalls by calling fixed addresses in
2164 kernel space. Since this location is not randomized with ASLR,
2165 it can be used to assist security vulnerability exploitation.
2166
2167 This setting can be changed at boot time via the kernel command
2168 line parameter vsyscall=[native|emulate|none].
2169
2170 On a system with recent enough glibc (2.14 or newer) and no
2171 static binaries, you can say None without a performance penalty
2172 to improve security.
2173
2174 If unsure, select "Emulate".
2175
2176 config LEGACY_VSYSCALL_NATIVE
2177 bool "Native"
2178 help
2179 Actual executable code is located in the fixed vsyscall
2180 address mapping, implementing time() efficiently. Since
2181 this makes the mapping executable, it can be used during
2182 security vulnerability exploitation (traditionally as
2183 ROP gadgets). This configuration is not recommended.
2184
2185 config LEGACY_VSYSCALL_EMULATE
2186 bool "Emulate"
2187 help
2188 The kernel traps and emulates calls into the fixed
2189 vsyscall address mapping. This makes the mapping
2190 non-executable, but it still contains known contents,
2191 which could be used in certain rare security vulnerability
2192 exploits. This configuration is recommended when userspace
2193 still uses the vsyscall area.
2194
2195 config LEGACY_VSYSCALL_NONE
2196 bool "None"
2197 help
2198 There will be no vsyscall mapping at all. This will
2199 eliminate any risk of ASLR bypass due to the vsyscall
2200 fixed address mapping. Attempts to use the vsyscalls
2201 will be reported to dmesg, so that either old or
2202 malicious userspace programs can be identified.
2203
2204endchoice
2205
516cbf37
TB
2206config CMDLINE_BOOL
2207 bool "Built-in kernel command line"
8f9ca475 2208 ---help---
516cbf37
TB
2209 Allow for specifying boot arguments to the kernel at
2210 build time. On some systems (e.g. embedded ones), it is
2211 necessary or convenient to provide some or all of the
2212 kernel boot arguments with the kernel itself (that is,
2213 to not rely on the boot loader to provide them.)
2214
2215 To compile command line arguments into the kernel,
2216 set this option to 'Y', then fill in the
69711ca1 2217 boot arguments in CONFIG_CMDLINE.
516cbf37
TB
2218
2219 Systems with fully functional boot loaders (i.e. non-embedded)
2220 should leave this option set to 'N'.
2221
2222config CMDLINE
2223 string "Built-in kernel command string"
2224 depends on CMDLINE_BOOL
2225 default ""
8f9ca475 2226 ---help---
516cbf37
TB
2227 Enter arguments here that should be compiled into the kernel
2228 image and used at boot time. If the boot loader provides a
2229 command line at boot time, it is appended to this string to
2230 form the full kernel command line, when the system boots.
2231
2232 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2233 change this behavior.
2234
2235 In most cases, the command line (whether built-in or provided
2236 by the boot loader) should specify the device for the root
2237 file system.
2238
2239config CMDLINE_OVERRIDE
2240 bool "Built-in command line overrides boot loader arguments"
516cbf37 2241 depends on CMDLINE_BOOL
8f9ca475 2242 ---help---
516cbf37
TB
2243 Set this option to 'Y' to have the kernel ignore the boot loader
2244 command line, and use ONLY the built-in command line.
2245
2246 This is used to work around broken boot loaders. This should
2247 be set to 'N' under normal conditions.
2248
a5b9e5a2
AL
2249config MODIFY_LDT_SYSCALL
2250 bool "Enable the LDT (local descriptor table)" if EXPERT
2251 default y
2252 ---help---
2253 Linux can allow user programs to install a per-process x86
2254 Local Descriptor Table (LDT) using the modify_ldt(2) system
2255 call. This is required to run 16-bit or segmented code such as
2256 DOSEMU or some Wine programs. It is also used by some very old
2257 threading libraries.
2258
2259 Enabling this feature adds a small amount of overhead to
2260 context switches and increases the low-level kernel attack
2261 surface. Disabling it removes the modify_ldt(2) system call.
2262
2263 Saying 'N' here may make sense for embedded or server kernels.
2264
b700e7f0
SJ
2265source "kernel/livepatch/Kconfig"
2266
506f1d07
SR
2267endmenu
2268
2269config ARCH_ENABLE_MEMORY_HOTPLUG
2270 def_bool y
2271 depends on X86_64 || (X86_32 && HIGHMEM)
2272
35551053
GH
2273config ARCH_ENABLE_MEMORY_HOTREMOVE
2274 def_bool y
2275 depends on MEMORY_HOTPLUG
2276
e534c7c5 2277config USE_PERCPU_NUMA_NODE_ID
645a7919 2278 def_bool y
e534c7c5
LS
2279 depends on NUMA
2280
9491846f
KS
2281config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2282 def_bool y
2283 depends on X86_64 || X86_PAE
2284
c177c81e
NH
2285config ARCH_ENABLE_HUGEPAGE_MIGRATION
2286 def_bool y
2287 depends on X86_64 && HUGETLB_PAGE && MIGRATION
2288
da85f865 2289menu "Power management and ACPI options"
e279b6c1
SR
2290
2291config ARCH_HIBERNATION_HEADER
3c2362e6 2292 def_bool y
e279b6c1 2293 depends on X86_64 && HIBERNATION
e279b6c1
SR
2294
2295source "kernel/power/Kconfig"
2296
2297source "drivers/acpi/Kconfig"
2298
efafc8b2
FT
2299source "drivers/sfi/Kconfig"
2300
a6b68076 2301config X86_APM_BOOT
6fc108a0 2302 def_bool y
282e5aab 2303 depends on APM
a6b68076 2304
e279b6c1
SR
2305menuconfig APM
2306 tristate "APM (Advanced Power Management) BIOS support"
efefa6f6 2307 depends on X86_32 && PM_SLEEP
e279b6c1
SR
2308 ---help---
2309 APM is a BIOS specification for saving power using several different
2310 techniques. This is mostly useful for battery powered laptops with
2311 APM compliant BIOSes. If you say Y here, the system time will be
2312 reset after a RESUME operation, the /proc/apm device will provide
2313 battery status information, and user-space programs will receive
2314 notification of APM "events" (e.g. battery status change).
2315
2316 If you select "Y" here, you can disable actual use of the APM
2317 BIOS by passing the "apm=off" option to the kernel at boot time.
2318
2319 Note that the APM support is almost completely disabled for
2320 machines with more than one CPU.
2321
2322 In order to use APM, you will need supporting software. For location
2dc98fd3
MW
2323 and more information, read <file:Documentation/power/apm-acpi.txt>
2324 and the Battery Powered Linux mini-HOWTO, available from
e279b6c1
SR
2325 <http://www.tldp.org/docs.html#howto>.
2326
2327 This driver does not spin down disk drives (see the hdparm(8)
2328 manpage ("man 8 hdparm") for that), and it doesn't turn off
2329 VESA-compliant "green" monitors.
2330
2331 This driver does not support the TI 4000M TravelMate and the ACER
2332 486/DX4/75 because they don't have compliant BIOSes. Many "green"
2333 desktop machines also don't have compliant BIOSes, and this driver
2334 may cause those machines to panic during the boot phase.
2335
2336 Generally, if you don't have a battery in your machine, there isn't
2337 much point in using this driver and you should say N. If you get
2338 random kernel OOPSes or reboots that don't seem to be related to
2339 anything, try disabling/enabling this option (or disabling/enabling
2340 APM in your BIOS).
2341
2342 Some other things you should try when experiencing seemingly random,
2343 "weird" problems:
2344
2345 1) make sure that you have enough swap space and that it is
2346 enabled.
2347 2) pass the "no-hlt" option to the kernel
2348 3) switch on floating point emulation in the kernel and pass
2349 the "no387" option to the kernel
2350 4) pass the "floppy=nodma" option to the kernel
2351 5) pass the "mem=4M" option to the kernel (thereby disabling
2352 all but the first 4 MB of RAM)
2353 6) make sure that the CPU is not over clocked.
2354 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2355 8) disable the cache from your BIOS settings
2356 9) install a fan for the video card or exchange video RAM
2357 10) install a better fan for the CPU
2358 11) exchange RAM chips
2359 12) exchange the motherboard.
2360
2361 To compile this driver as a module, choose M here: the
2362 module will be called apm.
2363
2364if APM
2365
2366config APM_IGNORE_USER_SUSPEND
2367 bool "Ignore USER SUSPEND"
8f9ca475 2368 ---help---
e279b6c1
SR
2369 This option will ignore USER SUSPEND requests. On machines with a
2370 compliant APM BIOS, you want to say N. However, on the NEC Versa M
2371 series notebooks, it is necessary to say Y because of a BIOS bug.
2372
2373config APM_DO_ENABLE
2374 bool "Enable PM at boot time"
2375 ---help---
2376 Enable APM features at boot time. From page 36 of the APM BIOS
2377 specification: "When disabled, the APM BIOS does not automatically
2378 power manage devices, enter the Standby State, enter the Suspend
2379 State, or take power saving steps in response to CPU Idle calls."
2380 This driver will make CPU Idle calls when Linux is idle (unless this
2381 feature is turned off -- see "Do CPU IDLE calls", below). This
2382 should always save battery power, but more complicated APM features
2383 will be dependent on your BIOS implementation. You may need to turn
2384 this option off if your computer hangs at boot time when using APM
2385 support, or if it beeps continuously instead of suspending. Turn
2386 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2387 T400CDT. This is off by default since most machines do fine without
2388 this feature.
2389
2390config APM_CPU_IDLE
dd8af076 2391 depends on CPU_IDLE
e279b6c1 2392 bool "Make CPU Idle calls when idle"
8f9ca475 2393 ---help---
e279b6c1
SR
2394 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2395 On some machines, this can activate improved power savings, such as
2396 a slowed CPU clock rate, when the machine is idle. These idle calls
2397 are made after the idle loop has run for some length of time (e.g.,
2398 333 mS). On some machines, this will cause a hang at boot time or
2399 whenever the CPU becomes idle. (On machines with more than one CPU,
2400 this option does nothing.)
2401
2402config APM_DISPLAY_BLANK
2403 bool "Enable console blanking using APM"
8f9ca475 2404 ---help---
e279b6c1
SR
2405 Enable console blanking using the APM. Some laptops can use this to
2406 turn off the LCD backlight when the screen blanker of the Linux
2407 virtual console blanks the screen. Note that this is only used by
2408 the virtual console screen blanker, and won't turn off the backlight
2409 when using the X Window system. This also doesn't have anything to
2410 do with your VESA-compliant power-saving monitor. Further, this
2411 option doesn't work for all laptops -- it might not turn off your
2412 backlight at all, or it might print a lot of errors to the console,
2413 especially if you are using gpm.
2414
2415config APM_ALLOW_INTS
2416 bool "Allow interrupts during APM BIOS calls"
8f9ca475 2417 ---help---
e279b6c1
SR
2418 Normally we disable external interrupts while we are making calls to
2419 the APM BIOS as a measure to lessen the effects of a badly behaving
2420 BIOS implementation. The BIOS should reenable interrupts if it
2421 needs to. Unfortunately, some BIOSes do not -- especially those in
2422 many of the newer IBM Thinkpads. If you experience hangs when you
2423 suspend, try setting this to Y. Otherwise, say N.
2424
e279b6c1
SR
2425endif # APM
2426
bb0a56ec 2427source "drivers/cpufreq/Kconfig"
e279b6c1
SR
2428
2429source "drivers/cpuidle/Kconfig"
2430
27471fdb
AH
2431source "drivers/idle/Kconfig"
2432
e279b6c1
SR
2433endmenu
2434
2435
2436menu "Bus options (PCI etc.)"
2437
2438config PCI
1ac97018 2439 bool "PCI support"
1c858087 2440 default y
8f9ca475 2441 ---help---
e279b6c1
SR
2442 Find out whether you have a PCI motherboard. PCI is the name of a
2443 bus system, i.e. the way the CPU talks to the other stuff inside
2444 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2445 VESA. If you have PCI, say Y, otherwise N.
2446
e279b6c1
SR
2447choice
2448 prompt "PCI access mode"
efefa6f6 2449 depends on X86_32 && PCI
e279b6c1
SR
2450 default PCI_GOANY
2451 ---help---
2452 On PCI systems, the BIOS can be used to detect the PCI devices and
2453 determine their configuration. However, some old PCI motherboards
2454 have BIOS bugs and may crash if this is done. Also, some embedded
2455 PCI-based systems don't have any BIOS at all. Linux can also try to
2456 detect the PCI hardware directly without using the BIOS.
2457
2458 With this option, you can specify how Linux should detect the
2459 PCI devices. If you choose "BIOS", the BIOS will be used,
2460 if you choose "Direct", the BIOS won't be used, and if you
2461 choose "MMConfig", then PCI Express MMCONFIG will be used.
2462 If you choose "Any", the kernel will try MMCONFIG, then the
2463 direct access method and falls back to the BIOS if that doesn't
2464 work. If unsure, go with the default, which is "Any".
2465
2466config PCI_GOBIOS
2467 bool "BIOS"
2468
2469config PCI_GOMMCONFIG
2470 bool "MMConfig"
2471
2472config PCI_GODIRECT
2473 bool "Direct"
2474
3ef0e1f8 2475config PCI_GOOLPC
76fb6570 2476 bool "OLPC XO-1"
3ef0e1f8
AS
2477 depends on OLPC
2478
2bdd1b03
AS
2479config PCI_GOANY
2480 bool "Any"
2481
e279b6c1
SR
2482endchoice
2483
2484config PCI_BIOS
3c2362e6 2485 def_bool y
efefa6f6 2486 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
e279b6c1
SR
2487
2488# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2489config PCI_DIRECT
3c2362e6 2490 def_bool y
0aba496f 2491 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
e279b6c1
SR
2492
2493config PCI_MMCONFIG
3c2362e6 2494 def_bool y
5f0db7a2 2495 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
e279b6c1 2496
3ef0e1f8 2497config PCI_OLPC
2bdd1b03
AS
2498 def_bool y
2499 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
3ef0e1f8 2500
b5401a96
AN
2501config PCI_XEN
2502 def_bool y
2503 depends on PCI && XEN
2504 select SWIOTLB_XEN
2505
e279b6c1 2506config PCI_DOMAINS
3c2362e6 2507 def_bool y
e279b6c1 2508 depends on PCI
e279b6c1
SR
2509
2510config PCI_MMCONFIG
2511 bool "Support mmconfig PCI config space access"
2512 depends on X86_64 && PCI && ACPI
2513
3f6ea84a 2514config PCI_CNB20LE_QUIRK
6a108a14 2515 bool "Read CNB20LE Host Bridge Windows" if EXPERT
6ea30386 2516 depends on PCI
3f6ea84a
IS
2517 help
2518 Read the PCI windows out of the CNB20LE host bridge. This allows
2519 PCI hotplug to work on systems with the CNB20LE chipset which do
2520 not have ACPI.
2521
64a5fed6
BH
2522 There's no public spec for this chipset, and this functionality
2523 is known to be incomplete.
2524
2525 You should say N unless you know you need this.
2526
e279b6c1
SR
2527source "drivers/pci/Kconfig"
2528
3a495511
WBG
2529config ISA_BUS
2530 bool "ISA-style bus support on modern systems" if EXPERT
2531 select ISA_BUS_API
2532 help
2533 Enables ISA-style drivers on modern systems. This is necessary to
2534 support PC/104 devices on X86_64 platforms.
2535
2536 If unsure, say N.
2537
1c00f016 2538# x86_64 have no ISA slots, but can have ISA-style DMA.
e279b6c1 2539config ISA_DMA_API
1c00f016
DR
2540 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2541 default y
2542 help
2543 Enables ISA-style DMA support for devices requiring such controllers.
2544 If unsure, say Y.
e279b6c1 2545
51e68d05
LT
2546if X86_32
2547
e279b6c1
SR
2548config ISA
2549 bool "ISA support"
8f9ca475 2550 ---help---
e279b6c1
SR
2551 Find out whether you have ISA slots on your motherboard. ISA is the
2552 name of a bus system, i.e. the way the CPU talks to the other stuff
2553 inside your box. Other bus systems are PCI, EISA, MicroChannel
2554 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2555 newer boards don't support it. If you have ISA, say Y, otherwise N.
2556
2557config EISA
2558 bool "EISA support"
2559 depends on ISA
2560 ---help---
2561 The Extended Industry Standard Architecture (EISA) bus was
2562 developed as an open alternative to the IBM MicroChannel bus.
2563
2564 The EISA bus provided some of the features of the IBM MicroChannel
2565 bus while maintaining backward compatibility with cards made for
2566 the older ISA bus. The EISA bus saw limited use between 1988 and
2567 1995 when it was made obsolete by the PCI bus.
2568
2569 Say Y here if you are building a kernel for an EISA-based machine.
2570
2571 Otherwise, say N.
2572
2573source "drivers/eisa/Kconfig"
2574
e279b6c1
SR
2575config SCx200
2576 tristate "NatSemi SCx200 support"
8f9ca475 2577 ---help---
e279b6c1
SR
2578 This provides basic support for National Semiconductor's
2579 (now AMD's) Geode processors. The driver probes for the
2580 PCI-IDs of several on-chip devices, so its a good dependency
2581 for other scx200_* drivers.
2582
2583 If compiled as a module, the driver is named scx200.
2584
2585config SCx200HR_TIMER
2586 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
592913ec 2587 depends on SCx200
e279b6c1 2588 default y
8f9ca475 2589 ---help---
e279b6c1
SR
2590 This driver provides a clocksource built upon the on-chip
2591 27MHz high-resolution timer. Its also a workaround for
2592 NSC Geode SC-1100's buggy TSC, which loses time when the
2593 processor goes idle (as is done by the scheduler). The
2594 other workaround is idle=poll boot option.
2595
3ef0e1f8
AS
2596config OLPC
2597 bool "One Laptop Per Child support"
54008979 2598 depends on !X86_PAE
3c554946 2599 select GPIOLIB
dc3119e7 2600 select OF
45bb1674 2601 select OF_PROMTREE
b4e51854 2602 select IRQ_DOMAIN
8f9ca475 2603 ---help---
3ef0e1f8
AS
2604 Add support for detecting the unique features of the OLPC
2605 XO hardware.
2606
a3128588
DD
2607config OLPC_XO1_PM
2608 bool "OLPC XO-1 Power Management"
97c4cb71 2609 depends on OLPC && MFD_CS5535 && PM_SLEEP
a3128588 2610 select MFD_CORE
bf1ebf00 2611 ---help---
97c4cb71 2612 Add support for poweroff and suspend of the OLPC XO-1 laptop.
bf1ebf00 2613
cfee9597
DD
2614config OLPC_XO1_RTC
2615 bool "OLPC XO-1 Real Time Clock"
2616 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2617 ---help---
2618 Add support for the XO-1 real time clock, which can be used as a
2619 programmable wakeup source.
2620
7feda8e9
DD
2621config OLPC_XO1_SCI
2622 bool "OLPC XO-1 SCI extras"
d8d01a63 2623 depends on OLPC && OLPC_XO1_PM
ed8e47fe 2624 depends on INPUT=y
d8d01a63 2625 select POWER_SUPPLY
7feda8e9
DD
2626 select GPIO_CS5535
2627 select MFD_CORE
2628 ---help---
2629 Add support for SCI-based features of the OLPC XO-1 laptop:
7bc74b3d 2630 - EC-driven system wakeups
7feda8e9 2631 - Power button
7bc74b3d 2632 - Ebook switch
2cf2baea 2633 - Lid switch
e1040ac6
DD
2634 - AC adapter status updates
2635 - Battery status updates
7feda8e9 2636
a0f30f59
DD
2637config OLPC_XO15_SCI
2638 bool "OLPC XO-1.5 SCI extras"
d8d01a63
DD
2639 depends on OLPC && ACPI
2640 select POWER_SUPPLY
a0f30f59
DD
2641 ---help---
2642 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2643 - EC-driven system wakeups
2644 - AC adapter status updates
2645 - Battery status updates
bf1ebf00 2646
d4f3e350
EW
2647config ALIX
2648 bool "PCEngines ALIX System Support (LED setup)"
2649 select GPIOLIB
2650 ---help---
2651 This option enables system support for the PCEngines ALIX.
2652 At present this just sets up LEDs for GPIO control on
2653 ALIX2/3/6 boards. However, other system specific setup should
2654 get added here.
2655
2656 Note: You must still enable the drivers for GPIO and LED support
2657 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2658
2659 Note: You have to set alix.force=1 for boards with Award BIOS.
2660
da4e3302
PP
2661config NET5501
2662 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2663 select GPIOLIB
2664 ---help---
2665 This option enables system support for the Soekris Engineering net5501.
2666
3197059a
PP
2667config GEOS
2668 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2669 select GPIOLIB
2670 depends on DMI
2671 ---help---
2672 This option enables system support for the Traverse Technologies GEOS.
2673
7d029125
VD
2674config TS5500
2675 bool "Technologic Systems TS-5500 platform support"
2676 depends on MELAN
2677 select CHECK_SIGNATURE
2678 select NEW_LEDS
2679 select LEDS_CLASS
2680 ---help---
2681 This option enables system support for the Technologic Systems TS-5500.
2682
bc0120fd
SR
2683endif # X86_32
2684
23ac4ae8 2685config AMD_NB
e279b6c1 2686 def_bool y
0e152cd7 2687 depends on CPU_SUP_AMD && PCI
e279b6c1
SR
2688
2689source "drivers/pcmcia/Kconfig"
2690
388b78ad 2691config RAPIDIO
fdf90abc 2692 tristate "RapidIO support"
388b78ad
AB
2693 depends on PCI
2694 default n
2695 help
fdf90abc 2696 If enabled this option will include drivers and the core
388b78ad
AB
2697 infrastructure code to support RapidIO interconnect devices.
2698
2699source "drivers/rapidio/Kconfig"
2700
e3263ab3
DH
2701config X86_SYSFB
2702 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2703 help
2704 Firmwares often provide initial graphics framebuffers so the BIOS,
2705 bootloader or kernel can show basic video-output during boot for
2706 user-guidance and debugging. Historically, x86 used the VESA BIOS
2707 Extensions and EFI-framebuffers for this, which are mostly limited
2708 to x86.
2709 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2710 framebuffers so the new generic system-framebuffer drivers can be
2711 used on x86. If the framebuffer is not compatible with the generic
2712 modes, it is adverticed as fallback platform framebuffer so legacy
2713 drivers like efifb, vesafb and uvesafb can pick it up.
2714 If this option is not selected, all system framebuffers are always
2715 marked as fallback platform framebuffers as usual.
2716
2717 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2718 not be able to pick up generic system framebuffers if this option
2719 is selected. You are highly encouraged to enable simplefb as
2720 replacement if you select this option. simplefb can correctly deal
2721 with generic system framebuffers. But you should still keep vesafb
2722 and others enabled as fallback if a system framebuffer is
2723 incompatible with simplefb.
2724
2725 If unsure, say Y.
2726
e279b6c1
SR
2727endmenu
2728
2729
2730menu "Executable file formats / Emulations"
2731
2732source "fs/Kconfig.binfmt"
2733
2734config IA32_EMULATION
2735 bool "IA32 Emulation"
2736 depends on X86_64
39f88911 2737 select ARCH_WANT_OLD_COMPAT_IPC
d1603990 2738 select BINFMT_ELF
a97f52e6 2739 select COMPAT_BINFMT_ELF
39f88911 2740 select COMPAT_OLD_SIGACTION
8f9ca475 2741 ---help---
5fd92e65
L
2742 Include code to run legacy 32-bit programs under a
2743 64-bit kernel. You should likely turn this on, unless you're
2744 100% sure that you don't have any 32-bit programs left.
e279b6c1
SR
2745
2746config IA32_AOUT
8f9ca475
IM
2747 tristate "IA32 a.out support"
2748 depends on IA32_EMULATION
2749 ---help---
2750 Support old a.out binaries in the 32bit emulation.
e279b6c1 2751
0bf62763 2752config X86_X32
6ea30386 2753 bool "x32 ABI for 64-bit mode"
9b54050b 2754 depends on X86_64
5fd92e65
L
2755 ---help---
2756 Include code to run binaries for the x32 native 32-bit ABI
2757 for 64-bit processors. An x32 process gets access to the
2758 full 64-bit register file and wide data path while leaving
2759 pointers at 32 bits for smaller memory footprint.
2760
2761 You will need a recent binutils (2.22 or later) with
2762 elf32_x86_64 support enabled to compile a kernel with this
2763 option set.
2764
953fee1d
IM
2765config COMPAT_32
2766 def_bool y
2767 depends on IA32_EMULATION || X86_32
2768 select HAVE_UID16
2769 select OLD_SIGSUSPEND3
2770
e279b6c1 2771config COMPAT
3c2362e6 2772 def_bool y
0bf62763 2773 depends on IA32_EMULATION || X86_X32
e279b6c1 2774
3120e25e 2775if COMPAT
e279b6c1 2776config COMPAT_FOR_U64_ALIGNMENT
3120e25e 2777 def_bool y
e279b6c1
SR
2778
2779config SYSVIPC_COMPAT
3c2362e6 2780 def_bool y
3120e25e 2781 depends on SYSVIPC
e279b6c1 2782
ee009e4a 2783config KEYS_COMPAT
3120e25e
JB
2784 def_bool y
2785 depends on KEYS
2786endif
ee009e4a 2787
e279b6c1
SR
2788endmenu
2789
2790
e5beae16
KP
2791config HAVE_ATOMIC_IOMAP
2792 def_bool y
2793 depends on X86_32
2794
4692d77f
AR
2795config X86_DEV_DMA_OPS
2796 bool
83125a3a 2797 depends on X86_64 || STA2X11
4692d77f 2798
f7219a53
AR
2799config X86_DMA_REMAP
2800 bool
83125a3a 2801 depends on STA2X11
f7219a53 2802
93e5eadd
LA
2803config PMC_ATOM
2804 def_bool y
2805 depends on PCI
2806
e279b6c1
SR
2807source "net/Kconfig"
2808
2809source "drivers/Kconfig"
2810
dabd3fda
LO
2811source "ubuntu/Kconfig"
2812
e279b6c1
SR
2813source "drivers/firmware/Kconfig"
2814
2815source "fs/Kconfig"
2816
e279b6c1
SR
2817source "arch/x86/Kconfig.debug"
2818
2819source "security/Kconfig"
2820
2821source "crypto/Kconfig"
2822
edf88417
AK
2823source "arch/x86/kvm/Kconfig"
2824
e279b6c1 2825source "lib/Kconfig"