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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
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12
13config X86_64
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14 def_bool y
15 depends on 64BIT
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16
17### Arch settings
8d5fffb9 18config X86
3c2362e6 19 def_bool y
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20 select ACPI_LEGACY_TABLES_LOOKUP if ACPI
21 select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI
22 select ANON_INODES
23 select ARCH_CLOCKSOURCE_DATA
24 select ARCH_DISCARD_MEMBLOCK
25 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
446f24d1 26 select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
6471b825 27 select ARCH_HAS_ELF_RANDOMIZE
72d93104 28 select ARCH_HAS_FAST_MULTIPLIER
957e3fac 29 select ARCH_HAS_GCOV_PROFILE_ALL
96601adb 30 select ARCH_HAS_PMEM_API if X86_64
67a3e8fe 31 select ARCH_HAS_MMIO_FLUSH
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IM
32 select ARCH_HAS_SG_CHAIN
33 select ARCH_HAVE_NMI_SAFE_CMPXCHG
34 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
77fbbc81 35 select ARCH_MIGHT_HAVE_PC_PARPORT
5e2c18c0 36 select ARCH_MIGHT_HAVE_PC_SERIO
6471b825 37 select ARCH_SUPPORTS_ATOMIC_RMW
3b242c66 38 select ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT
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IM
39 select ARCH_SUPPORTS_INT128 if X86_64
40 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
41 select ARCH_USE_BUILTIN_BSWAP
42 select ARCH_USE_CMPXCHG_LOCKREF if X86_64
43 select ARCH_USE_QUEUED_RWLOCKS
44 select ARCH_USE_QUEUED_SPINLOCKS
72b252ae 45 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH if SMP
5aaeb5c0 46 select ARCH_WANTS_DYNAMIC_TASK_STRUCT
da4276b8 47 select ARCH_WANT_FRAME_POINTERS
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48 select ARCH_WANT_IPC_PARSE_VERSION if X86_32
49 select ARCH_WANT_OPTIONAL_GPIOLIB
50 select BUILDTIME_EXTABLE_SORT
51 select CLKEVT_I8253
52 select CLKSRC_I8253 if X86_32
53 select CLOCKSOURCE_VALIDATE_LAST_CYCLE
54 select CLOCKSOURCE_WATCHDOG
55 select CLONE_BACKWARDS if X86_32
56 select COMPAT_OLD_SIGACTION if IA32_EMULATION
57 select DCACHE_WORD_ACCESS
45471cd9
LT
58 select EDAC_ATOMIC_SCRUB
59 select EDAC_SUPPORT
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60 select GENERIC_CLOCKEVENTS
61 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
62 select GENERIC_CLOCKEVENTS_MIN_ADJUST
63 select GENERIC_CMOS_UPDATE
64 select GENERIC_CPU_AUTOPROBE
5b7c73e0 65 select GENERIC_EARLY_IOREMAP
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66 select GENERIC_FIND_FIRST_BIT
67 select GENERIC_IOMAP
68 select GENERIC_IRQ_PROBE
69 select GENERIC_IRQ_SHOW
70 select GENERIC_PENDING_IRQ if SMP
71 select GENERIC_SMP_IDLE_THREAD
72 select GENERIC_STRNCPY_FROM_USER
73 select GENERIC_STRNLEN_USER
74 select GENERIC_TIME_VSYSCALL
75 select HAVE_ACPI_APEI if ACPI
76 select HAVE_ACPI_APEI_NMI if ACPI
77 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
78 select HAVE_AOUT if X86_32
79 select HAVE_ARCH_AUDITSYSCALL
80 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE
81 select HAVE_ARCH_JUMP_LABEL
82 select HAVE_ARCH_KASAN if X86_64 && SPARSEMEM_VMEMMAP
83 select HAVE_ARCH_KGDB
84 select HAVE_ARCH_KMEMCHECK
85 select HAVE_ARCH_SECCOMP_FILTER
86 select HAVE_ARCH_SOFT_DIRTY if X86_64
87 select HAVE_ARCH_TRACEHOOK
88 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
89 select HAVE_BPF_JIT if X86_64
90 select HAVE_CC_STACKPROTECTOR
91 select HAVE_CMPXCHG_DOUBLE
92 select HAVE_CMPXCHG_LOCAL
93 select HAVE_CONTEXT_TRACKING if X86_64
c1bd55f9 94 select HAVE_COPY_THREAD_TLS
cf4db259 95 select HAVE_C_RECORDMCOUNT
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96 select HAVE_DEBUG_KMEMLEAK
97 select HAVE_DEBUG_STACKOVERFLOW
98 select HAVE_DMA_API_DEBUG
99 select HAVE_DMA_ATTRS
100 select HAVE_DMA_CONTIGUOUS
677aa9f7 101 select HAVE_DYNAMIC_FTRACE
06aeaaea 102 select HAVE_DYNAMIC_FTRACE_WITH_REGS
58340a07 103 select HAVE_EFFICIENT_UNALIGNED_ACCESS
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IM
104 select HAVE_FENTRY if X86_64
105 select HAVE_FTRACE_MCOUNT_RECORD
106 select HAVE_FUNCTION_GRAPH_FP_TEST
107 select HAVE_FUNCTION_GRAPH_TRACER
108 select HAVE_FUNCTION_TRACER
109 select HAVE_GENERIC_DMA_COHERENT if X86_32
110 select HAVE_HW_BREAKPOINT
111 select HAVE_IDE
112 select HAVE_IOREMAP_PROT
113 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
114 select HAVE_IRQ_TIME_ACCOUNTING
2e9f3bdd 115 select HAVE_KERNEL_BZIP2
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116 select HAVE_KERNEL_GZIP
117 select HAVE_KERNEL_LZ4
2e9f3bdd 118 select HAVE_KERNEL_LZMA
13510997 119 select HAVE_KERNEL_LZO
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120 select HAVE_KERNEL_XZ
121 select HAVE_KPROBES
122 select HAVE_KPROBES_ON_FTRACE
123 select HAVE_KRETPROBES
124 select HAVE_KVM
125 select HAVE_LIVEPATCH if X86_64
126 select HAVE_MEMBLOCK
127 select HAVE_MEMBLOCK_NODE_MAP
0102752e 128 select HAVE_MIXED_BREAKPOINTS_REGS
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IM
129 select HAVE_OPROFILE
130 select HAVE_OPTPROBES
131 select HAVE_PCSPKR_PLATFORM
132 select HAVE_PERF_EVENTS
c01d4323 133 select HAVE_PERF_EVENTS_NMI
c5e63197 134 select HAVE_PERF_REGS
c5ebcedb 135 select HAVE_PERF_USER_STACK_DUMP
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IM
136 select HAVE_REGS_AND_STACK_ACCESS_API
137 select HAVE_SYSCALL_TRACEPOINTS
0c3619ea 138 select HAVE_UID16 if X86_32 || IA32_EMULATION
6471b825 139 select HAVE_UNSTABLE_SCHED_CLOCK
7c68af6e 140 select HAVE_USER_RETURN_NOTIFIER
c0185808 141 select IRQ_FORCED_THREADING
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IM
142 select MODULES_USE_ELF_RELA if X86_64
143 select MODULES_USE_ELF_REL if X86_32
144 select OLD_SIGACTION if X86_32
145 select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION
146 select PERF_EVENTS
3195ef59 147 select RTC_LIB
6471b825 148 select SPARSE_IRQ
83fe27ea 149 select SRCU
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IM
150 select SYSCTL_EXCEPTION_TRACE
151 select USER_STACKTRACE_SUPPORT
152 select VIRT_TO_BUS
153 select X86_DEV_DMA_OPS if X86_64
154 select X86_FEATURE_NAMES if PROC_FS
7d8330a5 155
ba7e4d13 156config INSTRUCTION_DECODER
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157 def_bool y
158 depends on KPROBES || PERF_EVENTS || UPROBES
ba7e4d13 159
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160config PERF_EVENTS_INTEL_UNCORE
161 def_bool y
ce5686d4 162 depends on PERF_EVENTS && CPU_SUP_INTEL && PCI
7fb0f1de 163
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LT
164config OUTPUT_FORMAT
165 string
166 default "elf32-i386" if X86_32
167 default "elf64-x86-64" if X86_64
168
73531905 169config ARCH_DEFCONFIG
b9b39bfb 170 string
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SR
171 default "arch/x86/configs/i386_defconfig" if X86_32
172 default "arch/x86/configs/x86_64_defconfig" if X86_64
b9b39bfb 173
8d5fffb9 174config LOCKDEP_SUPPORT
3c2362e6 175 def_bool y
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SR
176
177config STACKTRACE_SUPPORT
3c2362e6 178 def_bool y
8d5fffb9 179
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HC
180config HAVE_LATENCYTOP_SUPPORT
181 def_bool y
182
8d5fffb9 183config MMU
3c2362e6 184 def_bool y
8d5fffb9 185
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SR
186config SBUS
187 bool
188
3bc4e459 189config NEED_DMA_MAP_STATE
3120e25e 190 def_bool y
a6dfa128 191 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB
3bc4e459 192
18e98307 193config NEED_SG_DMA_LENGTH
4a14d84e 194 def_bool y
18e98307 195
8d5fffb9 196config GENERIC_ISA_DMA
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197 def_bool y
198 depends on ISA_DMA_API
8d5fffb9 199
8d5fffb9 200config GENERIC_BUG
3c2362e6 201 def_bool y
8d5fffb9 202 depends on BUG
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203 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
204
205config GENERIC_BUG_RELATIVE_POINTERS
206 bool
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207
208config GENERIC_HWEIGHT
3c2362e6 209 def_bool y
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210
211config ARCH_MAY_HAVE_PC_FDC
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212 def_bool y
213 depends on ISA_DMA_API
8d5fffb9 214
1032c0ba 215config RWSEM_XCHGADD_ALGORITHM
3120e25e 216 def_bool y
1032c0ba 217
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SR
218config GENERIC_CALIBRATE_DELAY
219 def_bool y
220
9a0b8415 221config ARCH_HAS_CPU_RELAX
222 def_bool y
223
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PE
224config ARCH_HAS_CACHE_LINE_SIZE
225 def_bool y
226
dd5af90a 227config HAVE_SETUP_PER_CPU_AREA
89c9c4c5 228 def_bool y
b32ef636 229
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TH
230config NEED_PER_CPU_EMBED_FIRST_CHUNK
231 def_bool y
232
233config NEED_PER_CPU_PAGE_FIRST_CHUNK
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TH
234 def_bool y
235
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236config ARCH_HIBERNATION_POSSIBLE
237 def_bool y
801e4062 238
f4cb5700
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239config ARCH_SUSPEND_POSSIBLE
240 def_bool y
f4cb5700 241
cfe28c5d
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242config ARCH_WANT_HUGE_PMD_SHARE
243 def_bool y
244
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245config ARCH_WANT_GENERAL_HUGETLB
246 def_bool y
247
8d5fffb9 248config ZONE_DMA32
e0fd24a3 249 def_bool y if X86_64
8d5fffb9 250
8d5fffb9 251config AUDIT_ARCH
e0fd24a3 252 def_bool y if X86_64
8d5fffb9 253
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254config ARCH_SUPPORTS_OPTIMIZED_INLINING
255 def_bool y
256
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AM
257config ARCH_SUPPORTS_DEBUG_PAGEALLOC
258 def_bool y
259
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260config KASAN_SHADOW_OFFSET
261 hex
262 depends on KASAN
263 default 0xdffffc0000000000
264
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265config HAVE_INTEL_TXT
266 def_bool y
6ea30386 267 depends on INTEL_IOMMU && ACPI
69575d38 268
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SR
269config X86_32_SMP
270 def_bool y
271 depends on X86_32 && SMP
272
273config X86_64_SMP
274 def_bool y
275 depends on X86_64 && SMP
276
ccbeed3a
TH
277config X86_32_LAZY_GS
278 def_bool y
60a5317f 279 depends on X86_32 && !CC_STACKPROTECTOR
ccbeed3a 280
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281config ARCH_HWEIGHT_CFLAGS
282 string
283 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
284 default "-fcall-saved-rdi -fcall-saved-rsi -fcall-saved-rdx -fcall-saved-rcx -fcall-saved-r8 -fcall-saved-r9 -fcall-saved-r10 -fcall-saved-r11" if X86_64
285
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SD
286config ARCH_SUPPORTS_UPROBES
287 def_bool y
288
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289config FIX_EARLYCON_MEM
290 def_bool y
291
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KS
292config PGTABLE_LEVELS
293 int
294 default 4 if X86_64
295 default 3 if X86_PAE
296 default 2
297
506f1d07 298source "init/Kconfig"
dc52ddc0 299source "kernel/Kconfig.freezer"
8d5fffb9 300
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SR
301menu "Processor type and features"
302
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RD
303config ZONE_DMA
304 bool "DMA memory allocation support" if EXPERT
305 default y
306 help
307 DMA memory allocation support allows devices with less than 32-bit
308 addressing to allocate within the first 16MB of address space.
309 Disable if no such devices will be used.
310
311 If unsure, say Y.
312
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SR
313config SMP
314 bool "Symmetric multi-processing support"
315 ---help---
316 This enables support for systems with more than one CPU. If you have
4a474157
RG
317 a system with only one CPU, say N. If you have a system with more
318 than one CPU, say Y.
506f1d07 319
4a474157 320 If you say N here, the kernel will run on uni- and multiprocessor
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SR
321 machines, but will use only one CPU of a multiprocessor machine. If
322 you say Y here, the kernel will run on many, but not all,
4a474157 323 uniprocessor machines. On a uniprocessor machine, the kernel
506f1d07
SR
324 will run faster if you say N here.
325
326 Note that if you say Y here and choose architecture "586" or
327 "Pentium" under "Processor family", the kernel will not work on 486
328 architectures. Similarly, multiprocessor kernels for the "PPro"
329 architecture may not work on all Pentium based boards.
330
331 People using multiprocessor machines who say Y here should also say
332 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
333 Management" code will be disabled if you say Y here.
334
395cf969 335 See also <file:Documentation/x86/i386/IO-APIC.txt>,
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SR
336 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
337 <http://www.tldp.org/docs.html#howto>.
338
339 If you don't know what to do here, say N.
340
9def39be
JT
341config X86_FEATURE_NAMES
342 bool "Processor feature human-readable names" if EMBEDDED
343 default y
344 ---help---
345 This option compiles in a table of x86 feature bits and corresponding
346 names. This is required to support /proc/cpuinfo and a few kernel
347 messages. You can disable this to save space, at the expense of
348 making those few kernel messages show numeric feature bits instead.
349
350 If in doubt, say Y.
351
06cd9a7d
YL
352config X86_X2APIC
353 bool "Support x2apic"
19e3d60d 354 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
06cd9a7d
YL
355 ---help---
356 This enables x2apic support on CPUs that have this feature.
357
358 This allows 32-bit apic IDs (so it can support very large systems),
359 and accesses the local apic via MSRs not via mmio.
360
06cd9a7d
YL
361 If you don't know what to do here, say N.
362
6695c85b 363config X86_MPPARSE
6e87f9b7 364 bool "Enable MPS table" if ACPI || SFI
7a527688 365 default y
5ab74722 366 depends on X86_LOCAL_APIC
8f9ca475 367 ---help---
6695c85b
YL
368 For old smp systems that do not have proper acpi support. Newer systems
369 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
6695c85b 370
26f7ef14
YL
371config X86_BIGSMP
372 bool "Support for big SMP systems with more than 8 CPUs"
373 depends on X86_32 && SMP
8f9ca475 374 ---help---
26f7ef14 375 This option is needed for the systems that have more than 8 CPUs
506f1d07 376
ddd70cf9
JN
377config GOLDFISH
378 def_bool y
379 depends on X86_GOLDFISH
380
8425091f 381if X86_32
c5c606d9
RT
382config X86_EXTENDED_PLATFORM
383 bool "Support for extended (non-PC) x86 platforms"
384 default y
8f9ca475 385 ---help---
06ac8346
IM
386 If you disable this option then the kernel will only support
387 standard PC platforms. (which covers the vast majority of
388 systems out there.)
389
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RT
390 If you enable this option then you'll be able to select support
391 for the following (non-PC) 32 bit x86 platforms:
cb7b8023 392 Goldfish (Android emulator)
8425091f 393 AMD Elan
8425091f
RT
394 RDC R-321x SoC
395 SGI 320/540 (Visual Workstation)
83125a3a 396 STA2X11-based (e.g. Northville)
3f4110a4 397 Moorestown MID devices
06ac8346
IM
398
399 If you have one of these systems, or if you want to build a
400 generic distribution kernel, say Y here - otherwise say N.
8425091f 401endif
06ac8346 402
8425091f
RT
403if X86_64
404config X86_EXTENDED_PLATFORM
405 bool "Support for extended (non-PC) x86 platforms"
406 default y
407 ---help---
408 If you disable this option then the kernel will only support
409 standard PC platforms. (which covers the vast majority of
410 systems out there.)
411
412 If you enable this option then you'll be able to select support
413 for the following (non-PC) 64 bit x86 platforms:
44b111b5 414 Numascale NumaChip
8425091f
RT
415 ScaleMP vSMP
416 SGI Ultraviolet
417
418 If you have one of these systems, or if you want to build a
419 generic distribution kernel, say Y here - otherwise say N.
420endif
c5c606d9
RT
421# This is an alphabetically sorted list of 64 bit extended platforms
422# Please maintain the alphabetic order if and when there are additions
44b111b5
SP
423config X86_NUMACHIP
424 bool "Numascale NumaChip"
425 depends on X86_64
426 depends on X86_EXTENDED_PLATFORM
427 depends on NUMA
428 depends on SMP
429 depends on X86_X2APIC
f9726bfd 430 depends on PCI_MMCONFIG
44b111b5
SP
431 ---help---
432 Adds support for Numascale NumaChip large-SMP systems. Needed to
433 enable more than ~168 cores.
434 If you don't have one of these, you should say N here.
506f1d07 435
c5c606d9
RT
436config X86_VSMP
437 bool "ScaleMP vSMP"
6276a074 438 select HYPERVISOR_GUEST
c5c606d9
RT
439 select PARAVIRT
440 depends on X86_64 && PCI
441 depends on X86_EXTENDED_PLATFORM
ead91d4b 442 depends on SMP
8f9ca475 443 ---help---
c5c606d9
RT
444 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
445 supposed to run on these EM64T-based machines. Only choose this option
446 if you have one of these machines.
5e3a77e9 447
03b48632
NP
448config X86_UV
449 bool "SGI Ultraviolet"
450 depends on X86_64
c5c606d9 451 depends on X86_EXTENDED_PLATFORM
54c28d29 452 depends on NUMA
9d6c26e7 453 depends on X86_X2APIC
1222e564 454 depends on PCI
8f9ca475 455 ---help---
03b48632
NP
456 This option is needed in order to support SGI Ultraviolet systems.
457 If you don't have one of these, you should say N here.
458
c5c606d9
RT
459# Following is an alphabetically sorted list of 32 bit extended platforms
460# Please maintain the alphabetic order if and when there are additions
506f1d07 461
ddd70cf9
JN
462config X86_GOLDFISH
463 bool "Goldfish (Virtual Platform)"
cb7b8023 464 depends on X86_EXTENDED_PLATFORM
ddd70cf9
JN
465 ---help---
466 Enable support for the Goldfish virtual platform used primarily
467 for Android development. Unless you are building for the Android
468 Goldfish emulator say N here.
469
c751e17b
TG
470config X86_INTEL_CE
471 bool "CE4100 TV platform"
472 depends on PCI
473 depends on PCI_GODIRECT
6084a6e2 474 depends on X86_IO_APIC
c751e17b
TG
475 depends on X86_32
476 depends on X86_EXTENDED_PLATFORM
37bc9f50 477 select X86_REBOOTFIXUPS
da6b737b
SAS
478 select OF
479 select OF_EARLY_FLATTREE
c751e17b
TG
480 ---help---
481 Select for the Intel CE media processor (CE4100) SOC.
482 This option compiles in support for the CE4100 SOC for settop
483 boxes and media devices.
484
4cb9b00f 485config X86_INTEL_MID
43605ef1
AC
486 bool "Intel MID platform support"
487 depends on X86_32
488 depends on X86_EXTENDED_PLATFORM
edc6bc78 489 depends on X86_PLATFORM_DEVICES
1ea7c673
AC
490 depends on PCI
491 depends on PCI_GOANY
492 depends on X86_IO_APIC
7c9c3a1e 493 select SFI
4cb9b00f 494 select I2C
7c9c3a1e 495 select DW_APB_TIMER
1ea7c673 496 select APB_TIMER
1ea7c673 497 select INTEL_SCU_IPC
15a713df 498 select MFD_INTEL_MSIC
1ea7c673 499 ---help---
4cb9b00f
DC
500 Select to build a kernel capable of supporting Intel MID (Mobile
501 Internet Device) platform systems which do not have the PCI legacy
502 interfaces. If you are building for a PC class system say N here.
1ea7c673 503
4cb9b00f
DC
504 Intel MID platforms are based on an Intel processor and chipset which
505 consume less power than most of the x86 derivatives.
43605ef1 506
8bbc2a13
BD
507config X86_INTEL_QUARK
508 bool "Intel Quark platform support"
509 depends on X86_32
510 depends on X86_EXTENDED_PLATFORM
511 depends on X86_PLATFORM_DEVICES
512 depends on X86_TSC
513 depends on PCI
514 depends on PCI_GOANY
515 depends on X86_IO_APIC
516 select IOSF_MBI
517 select INTEL_IMR
9ab6eb51 518 select COMMON_CLK
8bbc2a13
BD
519 ---help---
520 Select to include support for Quark X1000 SoC.
521 Say Y here if you have a Quark based system such as the Arduino
522 compatible Intel Galileo.
523
3d48aab1
MW
524config X86_INTEL_LPSS
525 bool "Intel Low Power Subsystem Support"
526 depends on ACPI
527 select COMMON_CLK
0f531431 528 select PINCTRL
3d48aab1
MW
529 ---help---
530 Select to build support for Intel Low Power Subsystem such as
531 found on Intel Lynxpoint PCH. Selecting this option enables
0f531431
MN
532 things like clock tree (common clock framework) and pincontrol
533 which are needed by the LPSS peripheral drivers.
3d48aab1 534
92082a88
KX
535config X86_AMD_PLATFORM_DEVICE
536 bool "AMD ACPI2Platform devices support"
537 depends on ACPI
538 select COMMON_CLK
539 select PINCTRL
540 ---help---
541 Select to interpret AMD specific ACPI device to platform device
542 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
543 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
544 implemented under PINCTRL subsystem.
545
ced3ce76
DB
546config IOSF_MBI
547 tristate "Intel SoC IOSF Sideband support for SoC platforms"
548 depends on PCI
549 ---help---
550 This option enables sideband register access support for Intel SoC
551 platforms. On these platforms the IOSF sideband is used in lieu of
552 MSR's for some register accesses, mostly but not limited to thermal
553 and power. Drivers may query the availability of this device to
554 determine if they need the sideband in order to work on these
555 platforms. The sideband is available on the following SoC products.
556 This list is not meant to be exclusive.
557 - BayTrail
558 - Braswell
559 - Quark
560
561 You should say Y if you are running a kernel on one of these SoC's.
562
ed2226bd
DB
563config IOSF_MBI_DEBUG
564 bool "Enable IOSF sideband access through debugfs"
565 depends on IOSF_MBI && DEBUG_FS
566 ---help---
567 Select this option to expose the IOSF sideband access registers (MCR,
568 MDR, MCRX) through debugfs to write and read register information from
569 different units on the SoC. This is most useful for obtaining device
570 state information for debug and analysis. As this is a general access
571 mechanism, users of this option would have specific knowledge of the
572 device they want to access.
573
574 If you don't require the option or are in doubt, say N.
575
c5c606d9
RT
576config X86_RDC321X
577 bool "RDC R-321x SoC"
506f1d07 578 depends on X86_32
c5c606d9
RT
579 depends on X86_EXTENDED_PLATFORM
580 select M486
581 select X86_REBOOTFIXUPS
582 ---help---
583 This option is needed for RDC R-321x system-on-chip, also known
584 as R-8610-(G).
585 If you don't have one of these chips, you should say N here.
586
e0c7ae37 587config X86_32_NON_STANDARD
9c398017
IM
588 bool "Support non-standard 32-bit SMP architectures"
589 depends on X86_32 && SMP
c5c606d9 590 depends on X86_EXTENDED_PLATFORM
8f9ca475 591 ---help---
b5660ba7
PA
592 This option compiles in the bigsmp and STA2X11 default
593 subarchitectures. It is intended for a generic binary
594 kernel. If you select them all, kernel will probe it one by
595 one and will fallback to default.
d49c4288 596
c5c606d9 597# Alphabetically sorted list of Non standard 32 bit platforms
d49c4288 598
d949f36f 599config X86_SUPPORTS_MEMORY_FAILURE
6fc108a0 600 def_bool y
d949f36f
LT
601 # MCE code calls memory_failure():
602 depends on X86_MCE
603 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
d949f36f
LT
604 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
605 depends on X86_64 || !SPARSEMEM
606 select ARCH_SUPPORTS_MEMORY_FAILURE
d949f36f 607
83125a3a
AR
608config STA2X11
609 bool "STA2X11 Companion Chip Support"
610 depends on X86_32_NON_STANDARD && PCI
611 select X86_DEV_DMA_OPS
612 select X86_DMA_REMAP
613 select SWIOTLB
614 select MFD_STA2X11
615 select ARCH_REQUIRE_GPIOLIB
616 default n
617 ---help---
618 This adds support for boards based on the STA2X11 IO-Hub,
619 a.k.a. "ConneXt". The chip is used in place of the standard
620 PC chipset, so all "standard" peripherals are missing. If this
621 option is selected the kernel will still be able to boot on
622 standard PC machines.
623
82148d1d
S
624config X86_32_IRIS
625 tristate "Eurobraille/Iris poweroff module"
626 depends on X86_32
627 ---help---
628 The Iris machines from EuroBraille do not have APM or ACPI support
629 to shut themselves down properly. A special I/O sequence is
630 needed to do so, which is what this module does at
631 kernel shutdown.
632
633 This is only for Iris machines from EuroBraille.
634
635 If unused, say N.
636
ae1e9130 637config SCHED_OMIT_FRAME_POINTER
3c2362e6
HH
638 def_bool y
639 prompt "Single-depth WCHAN output"
a87d0914 640 depends on X86
8f9ca475 641 ---help---
506f1d07
SR
642 Calculate simpler /proc/<PID>/wchan values. If this option
643 is disabled then wchan values will recurse back to the
644 caller function. This provides more accurate wchan values,
645 at the expense of slightly more scheduling overhead.
646
647 If in doubt, say "Y".
648
6276a074
BP
649menuconfig HYPERVISOR_GUEST
650 bool "Linux guest support"
8f9ca475 651 ---help---
6276a074
BP
652 Say Y here to enable options for running Linux under various hyper-
653 visors. This option enables basic hypervisor detection and platform
654 setup.
506f1d07 655
6276a074
BP
656 If you say N, all options in this submenu will be skipped and
657 disabled, and Linux guest support won't be built in.
506f1d07 658
6276a074 659if HYPERVISOR_GUEST
506f1d07 660
e61bd94a
EPH
661config PARAVIRT
662 bool "Enable paravirtualization code"
8f9ca475 663 ---help---
e61bd94a
EPH
664 This changes the kernel so it can modify itself when it is run
665 under a hypervisor, potentially improving performance significantly
666 over full virtualization. However, when run without a hypervisor
667 the kernel is theoretically slower and slightly larger.
668
6276a074
BP
669config PARAVIRT_DEBUG
670 bool "paravirt-ops debugging"
671 depends on PARAVIRT && DEBUG_KERNEL
672 ---help---
673 Enable to debug paravirt_ops internals. Specifically, BUG if
674 a paravirt_op is missing when it is called.
675
b4ecc126
JF
676config PARAVIRT_SPINLOCKS
677 bool "Paravirtualization layer for spinlocks"
6ea30386 678 depends on PARAVIRT && SMP
62c7a1e9 679 select UNINLINE_SPIN_UNLOCK if !QUEUED_SPINLOCKS
b4ecc126
JF
680 ---help---
681 Paravirtualized spinlocks allow a pvops backend to replace the
682 spinlock implementation with something virtualization-friendly
683 (for example, block the virtual CPU rather than spinning).
684
4c4e4f61
R
685 It has a minimal impact on native kernels and gives a nice performance
686 benefit on paravirtualized KVM / Xen kernels.
b4ecc126 687
4c4e4f61 688 If you are unsure how to answer this question, answer Y.
b4ecc126 689
6276a074 690source "arch/x86/xen/Kconfig"
7af192c9 691
6276a074
BP
692config KVM_GUEST
693 bool "KVM Guest support (including kvmclock)"
694 depends on PARAVIRT
695 select PARAVIRT_CLOCK
696 default y
8f9ca475 697 ---help---
6276a074
BP
698 This option enables various optimizations for running under the KVM
699 hypervisor. It includes a paravirtualized clock, so that instead
700 of relying on a PIT (or probably other) emulation by the
701 underlying device model, the host provides the guest with
702 timing infrastructure such as time of day, and system time
506f1d07 703
1e20eb85
SV
704config KVM_DEBUG_FS
705 bool "Enable debug information for KVM Guests in debugfs"
706 depends on KVM_GUEST && DEBUG_FS
707 default n
708 ---help---
709 This option enables collection of various statistics for KVM guest.
710 Statistics are displayed in debugfs filesystem. Enabling this option
711 may incur significant overhead.
712
6276a074
BP
713source "arch/x86/lguest/Kconfig"
714
715config PARAVIRT_TIME_ACCOUNTING
716 bool "Paravirtual steal time accounting"
717 depends on PARAVIRT
718 default n
8f9ca475 719 ---help---
6276a074
BP
720 Select this option to enable fine granularity task steal time
721 accounting. Time spent executing other tasks in parallel with
722 the current vCPU is discounted from the vCPU power. To account for
723 that, there can be a small performance impact.
724
725 If in doubt, say N here.
726
727config PARAVIRT_CLOCK
728 bool
97349135 729
6276a074 730endif #HYPERVISOR_GUEST
97349135 731
08677214 732config NO_BOOTMEM
774ea0bc 733 def_bool y
08677214 734
506f1d07
SR
735source "arch/x86/Kconfig.cpu"
736
737config HPET_TIMER
3c2362e6 738 def_bool X86_64
506f1d07 739 prompt "HPET Timer Support" if X86_32
8f9ca475
IM
740 ---help---
741 Use the IA-PC HPET (High Precision Event Timer) to manage
742 time in preference to the PIT and RTC, if a HPET is
743 present.
744 HPET is the next generation timer replacing legacy 8254s.
745 The HPET provides a stable time base on SMP
746 systems, unlike the TSC, but it is more expensive to access,
747 as it is off-chip. You can find the HPET spec at
748 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
506f1d07 749
8f9ca475
IM
750 You can safely choose Y here. However, HPET will only be
751 activated if the platform and the BIOS support this feature.
752 Otherwise the 8254 will be used for timing services.
506f1d07 753
8f9ca475 754 Choose N to continue using the legacy 8254 timer.
506f1d07
SR
755
756config HPET_EMULATE_RTC
3c2362e6 757 def_bool y
9d8af78b 758 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
506f1d07 759
bb24c471 760config APB_TIMER
933b9463
AC
761 def_bool y if X86_INTEL_MID
762 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
06c3df49 763 select DW_APB_TIMER
a0c3832a 764 depends on X86_INTEL_MID && SFI
bb24c471
JP
765 help
766 APB timer is the replacement for 8254, HPET on X86 MID platforms.
767 The APBT provides a stable time base on SMP
768 systems, unlike the TSC, but it is more expensive to access,
769 as it is off-chip. APB timers are always running regardless of CPU
770 C states, they are used as per CPU clockevent device when possible.
771
6a108a14 772# Mark as expert because too many people got it wrong.
506f1d07 773# The code disables itself when not needed.
7ae9392c
TP
774config DMI
775 default y
cf074402 776 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
6a108a14 777 bool "Enable DMI scanning" if EXPERT
8f9ca475 778 ---help---
7ae9392c
TP
779 Enabled scanning of DMI to identify machine quirks. Say Y
780 here unless you have verified that your setup is not
781 affected by entries in the DMI blacklist. Required by PNP
782 BIOS code.
783
506f1d07 784config GART_IOMMU
38901f1c 785 bool "Old AMD GART IOMMU support"
506f1d07 786 select SWIOTLB
23ac4ae8 787 depends on X86_64 && PCI && AMD_NB
8f9ca475 788 ---help---
ced3c42c
IM
789 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
790 GART based hardware IOMMUs.
791
792 The GART supports full DMA access for devices with 32-bit access
793 limitations, on systems with more than 3 GB. This is usually needed
794 for USB, sound, many IDE/SATA chipsets and some other devices.
795
796 Newer systems typically have a modern AMD IOMMU, supported via
797 the CONFIG_AMD_IOMMU=y config option.
798
799 In normal configurations this driver is only active when needed:
800 there's more than 3 GB of memory and the system contains a
801 32-bit limited device.
802
803 If unsure, say Y.
506f1d07
SR
804
805config CALGARY_IOMMU
806 bool "IBM Calgary IOMMU support"
807 select SWIOTLB
6ea30386 808 depends on X86_64 && PCI
8f9ca475 809 ---help---
506f1d07
SR
810 Support for hardware IOMMUs in IBM's xSeries x366 and x460
811 systems. Needed to run systems with more than 3GB of memory
812 properly with 32-bit PCI devices that do not support DAC
813 (Double Address Cycle). Calgary also supports bus level
814 isolation, where all DMAs pass through the IOMMU. This
815 prevents them from going anywhere except their intended
816 destination. This catches hard-to-find kernel bugs and
817 mis-behaving drivers and devices that do not use the DMA-API
818 properly to set up their DMA buffers. The IOMMU can be
819 turned off at boot time with the iommu=off parameter.
820 Normally the kernel will make the right choice by itself.
821 If unsure, say Y.
822
823config CALGARY_IOMMU_ENABLED_BY_DEFAULT
3c2362e6
HH
824 def_bool y
825 prompt "Should Calgary be enabled by default?"
506f1d07 826 depends on CALGARY_IOMMU
8f9ca475 827 ---help---
506f1d07
SR
828 Should Calgary be enabled by default? if you choose 'y', Calgary
829 will be used (if it exists). If you choose 'n', Calgary will not be
830 used even if it exists. If you choose 'n' and would like to use
831 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
832 If unsure, say Y.
833
834# need this always selected by IOMMU for the VIA workaround
835config SWIOTLB
a1afd01c 836 def_bool y if X86_64
8f9ca475 837 ---help---
506f1d07 838 Support for software bounce buffers used on x86-64 systems
4454d327
JM
839 which don't have a hardware IOMMU. Using this PCI devices
840 which can only access 32-bits of memory can be used on systems
841 with more than 3 GB of memory.
842 If unsure, say Y.
506f1d07 843
a8522509 844config IOMMU_HELPER
3120e25e
JB
845 def_bool y
846 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
d25e26b6 847
1184dc2f 848config MAXSMP
ddb0c5a6 849 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
6ea30386 850 depends on X86_64 && SMP && DEBUG_KERNEL
36f5101a 851 select CPUMASK_OFFSTACK
8f9ca475 852 ---help---
ddb0c5a6 853 Enable maximum number of CPUS and NUMA Nodes for this architecture.
1184dc2f 854 If unsure, say N.
506f1d07
SR
855
856config NR_CPUS
36f5101a 857 int "Maximum number of CPUs" if SMP && !MAXSMP
2a3313f4 858 range 2 8 if SMP && X86_32 && !X86_BIGSMP
bb61ccc7 859 range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK
b53b5eda 860 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
78637a97 861 default "1" if !SMP
b53b5eda 862 default "8192" if MAXSMP
b5660ba7 863 default "32" if SMP && X86_BIGSMP
c5c19941
KS
864 default "8" if SMP && X86_32
865 default "64" if SMP
8f9ca475 866 ---help---
506f1d07 867 This allows you to specify the maximum number of CPUs which this
bb61ccc7 868 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
cad14bb9 869 supported value is 8192, otherwise the maximum value is 512. The
506f1d07
SR
870 minimum value which makes sense is 2.
871
872 This is purely to save memory - each supported CPU adds
873 approximately eight kilobytes to the kernel image.
874
875config SCHED_SMT
876 bool "SMT (Hyperthreading) scheduler support"
c8e56d20 877 depends on SMP
8f9ca475 878 ---help---
506f1d07
SR
879 SMT scheduler support improves the CPU scheduler's decision making
880 when dealing with Intel Pentium 4 chips with HyperThreading at a
881 cost of slightly increased overhead in some places. If unsure say
882 N here.
883
884config SCHED_MC
3c2362e6
HH
885 def_bool y
886 prompt "Multi-core scheduler support"
c8e56d20 887 depends on SMP
8f9ca475 888 ---help---
506f1d07
SR
889 Multi-core scheduler support improves the CPU scheduler's decision
890 making when dealing with multi-core CPU chips at a cost of slightly
891 increased overhead in some places. If unsure say N here.
892
893source "kernel/Kconfig.preempt"
894
30b8b006
TG
895config UP_LATE_INIT
896 def_bool y
ba360f88 897 depends on !SMP && X86_LOCAL_APIC
30b8b006 898
506f1d07 899config X86_UP_APIC
50849eef
JB
900 bool "Local APIC support on uniprocessors" if !PCI_MSI
901 default PCI_MSI
38a1dfda 902 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
8f9ca475 903 ---help---
506f1d07
SR
904 A local APIC (Advanced Programmable Interrupt Controller) is an
905 integrated interrupt controller in the CPU. If you have a single-CPU
906 system which has a processor with a local APIC, you can say Y here to
907 enable and use it. If you say Y here even though your machine doesn't
908 have a local APIC, then the kernel will still run with no slowdown at
909 all. The local APIC supports CPU-generated self-interrupts (timer,
910 performance counters), and the NMI watchdog which detects hard
911 lockups.
912
913config X86_UP_IOAPIC
914 bool "IO-APIC support on uniprocessors"
915 depends on X86_UP_APIC
8f9ca475 916 ---help---
506f1d07
SR
917 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
918 SMP-capable replacement for PC-style interrupt controllers. Most
919 SMP systems and many recent uniprocessor systems have one.
920
921 If you have a single-CPU system with an IO-APIC, you can say Y here
922 to use it. If you say Y here even though your machine doesn't have
923 an IO-APIC, then the kernel will still run with no slowdown at all.
924
925config X86_LOCAL_APIC
3c2362e6 926 def_bool y
0dbc6078 927 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
b5dc8e6c 928 select IRQ_DOMAIN_HIERARCHY
52f518a3 929 select PCI_MSI_IRQ_DOMAIN if PCI_MSI
506f1d07
SR
930
931config X86_IO_APIC
b1da1e71
JB
932 def_bool y
933 depends on X86_LOCAL_APIC || X86_UP_IOAPIC
506f1d07 934
41b9eb26
SA
935config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
936 bool "Reroute for broken boot IRQs"
41b9eb26 937 depends on X86_IO_APIC
8f9ca475 938 ---help---
41b9eb26
SA
939 This option enables a workaround that fixes a source of
940 spurious interrupts. This is recommended when threaded
941 interrupt handling is used on systems where the generation of
942 superfluous "boot interrupts" cannot be disabled.
943
944 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
945 entry in the chipset's IO-APIC is masked (as, e.g. the RT
946 kernel does during interrupt handling). On chipsets where this
947 boot IRQ generation cannot be disabled, this workaround keeps
948 the original IRQ line masked so that only the equivalent "boot
949 IRQ" is delivered to the CPUs. The workaround also tells the
950 kernel to set up the IRQ handler on the boot IRQ line. In this
951 way only one interrupt is delivered to the kernel. Otherwise
952 the spurious second interrupt may cause the kernel to bring
953 down (vital) interrupt lines.
954
955 Only affects "broken" chipsets. Interrupt sharing may be
956 increased on these systems.
957
506f1d07 958config X86_MCE
bab9bc65 959 bool "Machine Check / overheating reporting"
648ed940 960 select GENERIC_ALLOCATOR
e57dbaf7 961 default y
506f1d07 962 ---help---
bab9bc65
AK
963 Machine Check support allows the processor to notify the
964 kernel if it detects a problem (e.g. overheating, data corruption).
506f1d07 965 The action the kernel takes depends on the severity of the problem,
bab9bc65 966 ranging from warning messages to halting the machine.
4efc0670 967
506f1d07 968config X86_MCE_INTEL
3c2362e6
HH
969 def_bool y
970 prompt "Intel MCE features"
c1ebf835 971 depends on X86_MCE && X86_LOCAL_APIC
8f9ca475 972 ---help---
506f1d07
SR
973 Additional support for intel specific MCE features such as
974 the thermal monitor.
975
976config X86_MCE_AMD
3c2362e6
HH
977 def_bool y
978 prompt "AMD MCE features"
c1ebf835 979 depends on X86_MCE && X86_LOCAL_APIC
8f9ca475 980 ---help---
506f1d07
SR
981 Additional support for AMD specific MCE features such as
982 the DRAM Error Threshold.
983
4efc0670 984config X86_ANCIENT_MCE
6fc108a0 985 bool "Support for old Pentium 5 / WinChip machine checks"
c31d9633 986 depends on X86_32 && X86_MCE
cd13adcc
HS
987 ---help---
988 Include support for machine check handling on old Pentium 5 or WinChip
5065a706 989 systems. These typically need to be enabled explicitly on the command
cd13adcc 990 line.
4efc0670 991
b2762686
AK
992config X86_MCE_THRESHOLD
993 depends on X86_MCE_AMD || X86_MCE_INTEL
6fc108a0 994 def_bool y
b2762686 995
ea149b36 996config X86_MCE_INJECT
c1ebf835 997 depends on X86_MCE
ea149b36
AK
998 tristate "Machine check injector support"
999 ---help---
1000 Provide support for injecting machine checks for testing purposes.
1001 If you don't know what a machine check is and you don't do kernel
1002 QA it is safe to say n.
1003
4efc0670
AK
1004config X86_THERMAL_VECTOR
1005 def_bool y
5bb38adc 1006 depends on X86_MCE_INTEL
4efc0670 1007
5aef51c3 1008config X86_LEGACY_VM86
1e642812 1009 bool "Legacy VM86 support"
5aef51c3 1010 default n
506f1d07 1011 depends on X86_32
8f9ca475 1012 ---help---
5aef51c3
AL
1013 This option allows user programs to put the CPU into V8086
1014 mode, which is an 80286-era approximation of 16-bit real mode.
1015
1016 Some very old versions of X and/or vbetool require this option
1017 for user mode setting. Similarly, DOSEMU will use it if
1018 available to accelerate real mode DOS programs. However, any
1019 recent version of DOSEMU, X, or vbetool should be fully
1020 functional even without kernel VM86 support, as they will all
1e642812
IM
1021 fall back to software emulation. Nevertheless, if you are using
1022 a 16-bit DOS program where 16-bit performance matters, vm86
1023 mode might be faster than emulation and you might want to
1024 enable this option.
5aef51c3 1025
1e642812
IM
1026 Note that any app that works on a 64-bit kernel is unlikely to
1027 need this option, as 64-bit kernels don't, and can't, support
1028 V8086 mode. This option is also unrelated to 16-bit protected
1029 mode and is not needed to run most 16-bit programs under Wine.
5aef51c3 1030
1e642812
IM
1031 Enabling this option increases the complexity of the kernel
1032 and slows down exception handling a tiny bit.
5aef51c3 1033
1e642812 1034 If unsure, say N here.
5aef51c3
AL
1035
1036config VM86
1037 bool
1038 default X86_LEGACY_VM86
34273f41
PA
1039
1040config X86_16BIT
1041 bool "Enable support for 16-bit segments" if EXPERT
1042 default y
a5b9e5a2 1043 depends on MODIFY_LDT_SYSCALL
34273f41
PA
1044 ---help---
1045 This option is required by programs like Wine to run 16-bit
1046 protected mode legacy code on x86 processors. Disabling
1047 this option saves about 300 bytes on i386, or around 6K text
1048 plus 16K runtime memory on x86-64,
1049
1050config X86_ESPFIX32
1051 def_bool y
1052 depends on X86_16BIT && X86_32
506f1d07 1053
197725de
PA
1054config X86_ESPFIX64
1055 def_bool y
34273f41 1056 depends on X86_16BIT && X86_64
506f1d07 1057
1ad83c85
AL
1058config X86_VSYSCALL_EMULATION
1059 bool "Enable vsyscall emulation" if EXPERT
1060 default y
1061 depends on X86_64
1062 ---help---
1063 This enables emulation of the legacy vsyscall page. Disabling
1064 it is roughly equivalent to booting with vsyscall=none, except
1065 that it will also disable the helpful warning if a program
1066 tries to use a vsyscall. With this option set to N, offending
1067 programs will just segfault, citing addresses of the form
1068 0xffffffffff600?00.
1069
1070 This option is required by many programs built before 2013, and
1071 care should be used even with newer programs if set to N.
1072
1073 Disabling this option saves about 7K of kernel size and
1074 possibly 4K of additional runtime pagetable memory.
1075
506f1d07
SR
1076config TOSHIBA
1077 tristate "Toshiba Laptop support"
1078 depends on X86_32
1079 ---help---
1080 This adds a driver to safely access the System Management Mode of
1081 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1082 not work on models with a Phoenix BIOS. The System Management Mode
1083 is used to set the BIOS and power saving options on Toshiba portables.
1084
1085 For information on utilities to make use of this driver see the
1086 Toshiba Linux utilities web site at:
1087 <http://www.buzzard.org.uk/toshiba/>.
1088
1089 Say Y if you intend to run this kernel on a Toshiba portable.
1090 Say N otherwise.
1091
1092config I8K
039ae585 1093 tristate "Dell i8k legacy laptop support"
949a9d70 1094 select HWMON
039ae585 1095 select SENSORS_DELL_SMM
506f1d07 1096 ---help---
039ae585
PR
1097 This option enables legacy /proc/i8k userspace interface in hwmon
1098 dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1099 temperature and allows controlling fan speeds of Dell laptops via
1100 System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1101 it reports also power and hotkey status. For fan speed control is
1102 needed userspace package i8kutils.
1103
1104 Say Y if you intend to run this kernel on old Dell laptops or want to
1105 use userspace package i8kutils.
506f1d07
SR
1106 Say N otherwise.
1107
1108config X86_REBOOTFIXUPS
9ba16087
JB
1109 bool "Enable X86 board specific fixups for reboot"
1110 depends on X86_32
506f1d07
SR
1111 ---help---
1112 This enables chipset and/or board specific fixups to be done
1113 in order to get reboot to work correctly. This is only needed on
1114 some combinations of hardware and BIOS. The symptom, for which
1115 this config is intended, is when reboot ends with a stalled/hung
1116 system.
1117
1118 Currently, the only fixup is for the Geode machines using
5e3a77e9 1119 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
506f1d07
SR
1120
1121 Say Y if you want to enable the fixup. Currently, it's safe to
1122 enable this option even if you don't need it.
1123 Say N otherwise.
1124
1125config MICROCODE
9a2bc335
BP
1126 bool "CPU microcode loading support"
1127 default y
80030e3d 1128 depends on CPU_SUP_AMD || CPU_SUP_INTEL
fe055896 1129 depends on BLK_DEV_INITRD
506f1d07
SR
1130 select FW_LOADER
1131 ---help---
e43f6e67 1132
506f1d07 1133 If you say Y here, you will be able to update the microcode on
80cc9f10 1134 certain Intel and AMD processors. The Intel support is for the
e43f6e67
BP
1135 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4,
1136 Xeon etc. The AMD support is for families 0x10 and later. You will
1137 obviously need the actual microcode binary data itself which is not
1138 shipped with the Linux kernel.
506f1d07 1139
8d86f390
PO
1140 This option selects the general module only, you need to select
1141 at least one vendor specific module as well.
506f1d07 1142
e43f6e67
BP
1143 To compile this driver as a module, choose M here: the module
1144 will be called microcode.
506f1d07 1145
8d86f390 1146config MICROCODE_INTEL
e43f6e67 1147 bool "Intel microcode loading support"
8f9ca475
IM
1148 depends on MICROCODE
1149 default MICROCODE
1150 select FW_LOADER
1151 ---help---
1152 This options enables microcode patch loading support for Intel
1153 processors.
1154
b8989db9
A
1155 For the current Intel microcode data package go to
1156 <https://downloadcenter.intel.com> and search for
1157 'Linux Processor Microcode Data File'.
8d86f390 1158
80cc9f10 1159config MICROCODE_AMD
e43f6e67 1160 bool "AMD microcode loading support"
8f9ca475
IM
1161 depends on MICROCODE
1162 select FW_LOADER
1163 ---help---
1164 If you select this option, microcode patch loading support for AMD
1165 processors will be enabled.
80cc9f10 1166
8f9ca475 1167config MICROCODE_OLD_INTERFACE
3c2362e6 1168 def_bool y
506f1d07 1169 depends on MICROCODE
506f1d07
SR
1170
1171config X86_MSR
1172 tristate "/dev/cpu/*/msr - Model-specific register support"
8f9ca475 1173 ---help---
506f1d07
SR
1174 This device gives privileged processes access to the x86
1175 Model-Specific Registers (MSRs). It is a character device with
1176 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1177 MSR accesses are directed to a specific CPU on multi-processor
1178 systems.
1179
1180config X86_CPUID
1181 tristate "/dev/cpu/*/cpuid - CPU information support"
8f9ca475 1182 ---help---
506f1d07
SR
1183 This device gives processes access to the x86 CPUID instruction to
1184 be executed on a specific processor. It is a character device
1185 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1186 /dev/cpu/31/cpuid.
1187
1188choice
1189 prompt "High Memory Support"
6fc108a0 1190 default HIGHMEM4G
506f1d07
SR
1191 depends on X86_32
1192
1193config NOHIGHMEM
1194 bool "off"
506f1d07
SR
1195 ---help---
1196 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1197 However, the address space of 32-bit x86 processors is only 4
1198 Gigabytes large. That means that, if you have a large amount of
1199 physical memory, not all of it can be "permanently mapped" by the
1200 kernel. The physical memory that's not permanently mapped is called
1201 "high memory".
1202
1203 If you are compiling a kernel which will never run on a machine with
1204 more than 1 Gigabyte total physical RAM, answer "off" here (default
1205 choice and suitable for most users). This will result in a "3GB/1GB"
1206 split: 3GB are mapped so that each process sees a 3GB virtual memory
1207 space and the remaining part of the 4GB virtual memory space is used
1208 by the kernel to permanently map as much physical memory as
1209 possible.
1210
1211 If the machine has between 1 and 4 Gigabytes physical RAM, then
1212 answer "4GB" here.
1213
1214 If more than 4 Gigabytes is used then answer "64GB" here. This
1215 selection turns Intel PAE (Physical Address Extension) mode on.
1216 PAE implements 3-level paging on IA32 processors. PAE is fully
1217 supported by Linux, PAE mode is implemented on all recent Intel
1218 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1219 then the kernel will not boot on CPUs that don't support PAE!
1220
1221 The actual amount of total physical memory will either be
1222 auto detected or can be forced by using a kernel command line option
1223 such as "mem=256M". (Try "man bootparam" or see the documentation of
1224 your boot loader (lilo or loadlin) about how to pass options to the
1225 kernel at boot time.)
1226
1227 If unsure, say "off".
1228
1229config HIGHMEM4G
1230 bool "4GB"
8f9ca475 1231 ---help---
506f1d07
SR
1232 Select this if you have a 32-bit processor and between 1 and 4
1233 gigabytes of physical RAM.
1234
1235config HIGHMEM64G
1236 bool "64GB"
eb068e78 1237 depends on !M486
506f1d07 1238 select X86_PAE
8f9ca475 1239 ---help---
506f1d07
SR
1240 Select this if you have a 32-bit processor and more than 4
1241 gigabytes of physical RAM.
1242
1243endchoice
1244
1245choice
6a108a14 1246 prompt "Memory split" if EXPERT
506f1d07
SR
1247 default VMSPLIT_3G
1248 depends on X86_32
8f9ca475 1249 ---help---
506f1d07
SR
1250 Select the desired split between kernel and user memory.
1251
1252 If the address range available to the kernel is less than the
1253 physical memory installed, the remaining memory will be available
1254 as "high memory". Accessing high memory is a little more costly
1255 than low memory, as it needs to be mapped into the kernel first.
1256 Note that increasing the kernel address space limits the range
1257 available to user programs, making the address space there
1258 tighter. Selecting anything other than the default 3G/1G split
1259 will also likely make your kernel incompatible with binary-only
1260 kernel modules.
1261
1262 If you are not absolutely sure what you are doing, leave this
1263 option alone!
1264
1265 config VMSPLIT_3G
1266 bool "3G/1G user/kernel split"
1267 config VMSPLIT_3G_OPT
1268 depends on !X86_PAE
1269 bool "3G/1G user/kernel split (for full 1G low memory)"
1270 config VMSPLIT_2G
1271 bool "2G/2G user/kernel split"
1272 config VMSPLIT_2G_OPT
1273 depends on !X86_PAE
1274 bool "2G/2G user/kernel split (for full 2G low memory)"
1275 config VMSPLIT_1G
1276 bool "1G/3G user/kernel split"
1277endchoice
1278
1279config PAGE_OFFSET
1280 hex
1281 default 0xB0000000 if VMSPLIT_3G_OPT
1282 default 0x80000000 if VMSPLIT_2G
1283 default 0x78000000 if VMSPLIT_2G_OPT
1284 default 0x40000000 if VMSPLIT_1G
1285 default 0xC0000000
1286 depends on X86_32
1287
1288config HIGHMEM
3c2362e6 1289 def_bool y
506f1d07 1290 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
506f1d07
SR
1291
1292config X86_PAE
9ba16087 1293 bool "PAE (Physical Address Extension) Support"
506f1d07 1294 depends on X86_32 && !HIGHMEM4G
9d99c712 1295 select SWIOTLB
8f9ca475 1296 ---help---
506f1d07
SR
1297 PAE is required for NX support, and furthermore enables
1298 larger swapspace support for non-overcommit purposes. It
1299 has the cost of more pagetable lookup overhead, and also
1300 consumes more pagetable space per process.
1301
600715dc 1302config ARCH_PHYS_ADDR_T_64BIT
3120e25e
JB
1303 def_bool y
1304 depends on X86_64 || X86_PAE
600715dc 1305
66f2b061 1306config ARCH_DMA_ADDR_T_64BIT
3120e25e
JB
1307 def_bool y
1308 depends on X86_64 || HIGHMEM64G
66f2b061 1309
10971ab2 1310config X86_DIRECT_GBPAGES
e5008abe
LR
1311 def_bool y
1312 depends on X86_64 && !DEBUG_PAGEALLOC && !KMEMCHECK
8f9ca475 1313 ---help---
10971ab2
IM
1314 Certain kernel features effectively disable kernel
1315 linear 1 GB mappings (even if the CPU otherwise
1316 supports them), so don't confuse the user by printing
1317 that we have them enabled.
9e899816 1318
506f1d07
SR
1319# Common NUMA Features
1320config NUMA
fd51b2d7 1321 bool "Numa Memory Allocation and Scheduler Support"
506f1d07 1322 depends on SMP
b5660ba7
PA
1323 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1324 default y if X86_BIGSMP
8f9ca475 1325 ---help---
506f1d07 1326 Enable NUMA (Non Uniform Memory Access) support.
fd51b2d7 1327
506f1d07
SR
1328 The kernel will try to allocate memory used by a CPU on the
1329 local memory controller of the CPU and add some more
1330 NUMA awareness to the kernel.
1331
c280ea5e 1332 For 64-bit this is recommended if the system is Intel Core i7
fd51b2d7
KM
1333 (or later), AMD Opteron, or EM64T NUMA.
1334
b5660ba7 1335 For 32-bit this is only needed if you boot a 32-bit
7cf6c945 1336 kernel on a 64-bit NUMA platform.
fd51b2d7
KM
1337
1338 Otherwise, you should say N.
506f1d07 1339
eec1d4fa 1340config AMD_NUMA
3c2362e6
HH
1341 def_bool y
1342 prompt "Old style AMD Opteron NUMA detection"
5da0ef9a 1343 depends on X86_64 && NUMA && PCI
8f9ca475 1344 ---help---
eec1d4fa
HR
1345 Enable AMD NUMA node topology detection. You should say Y here if
1346 you have a multi processor AMD system. This uses an old method to
1347 read the NUMA configuration directly from the builtin Northbridge
1348 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1349 which also takes priority if both are compiled in.
506f1d07
SR
1350
1351config X86_64_ACPI_NUMA
3c2362e6
HH
1352 def_bool y
1353 prompt "ACPI NUMA detection"
506f1d07
SR
1354 depends on X86_64 && NUMA && ACPI && PCI
1355 select ACPI_NUMA
8f9ca475 1356 ---help---
506f1d07
SR
1357 Enable ACPI SRAT based node topology detection.
1358
6ec6e0d9
SS
1359# Some NUMA nodes have memory ranges that span
1360# other nodes. Even though a pfn is valid and
1361# between a node's start and end pfns, it may not
1362# reside on that node. See memmap_init_zone()
1363# for details.
1364config NODES_SPAN_OTHER_NODES
1365 def_bool y
1366 depends on X86_64_ACPI_NUMA
1367
506f1d07
SR
1368config NUMA_EMU
1369 bool "NUMA emulation"
1b7e03ef 1370 depends on NUMA
8f9ca475 1371 ---help---
506f1d07
SR
1372 Enable NUMA emulation. A flat machine will be split
1373 into virtual nodes when booted with "numa=fake=N", where N is the
1374 number of nodes. This is only useful for debugging.
1375
1376config NODES_SHIFT
d25e26b6 1377 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
51591e31
DR
1378 range 1 10
1379 default "10" if MAXSMP
506f1d07 1380 default "6" if X86_64
506f1d07
SR
1381 default "3"
1382 depends on NEED_MULTIPLE_NODES
8f9ca475 1383 ---help---
1184dc2f 1384 Specify the maximum number of NUMA Nodes available on the target
692105b8 1385 system. Increases memory reserved to accommodate various tables.
506f1d07 1386
506f1d07 1387config ARCH_HAVE_MEMORY_PRESENT
3c2362e6 1388 def_bool y
506f1d07 1389 depends on X86_32 && DISCONTIGMEM
506f1d07
SR
1390
1391config NEED_NODE_MEMMAP_SIZE
3c2362e6 1392 def_bool y
506f1d07 1393 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
506f1d07 1394
506f1d07
SR
1395config ARCH_FLATMEM_ENABLE
1396 def_bool y
3b16651f 1397 depends on X86_32 && !NUMA
506f1d07
SR
1398
1399config ARCH_DISCONTIGMEM_ENABLE
1400 def_bool y
b263295d 1401 depends on NUMA && X86_32
506f1d07
SR
1402
1403config ARCH_DISCONTIGMEM_DEFAULT
1404 def_bool y
b263295d
CL
1405 depends on NUMA && X86_32
1406
506f1d07
SR
1407config ARCH_SPARSEMEM_ENABLE
1408 def_bool y
6ea30386 1409 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
506f1d07
SR
1410 select SPARSEMEM_STATIC if X86_32
1411 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1412
3b16651f
TH
1413config ARCH_SPARSEMEM_DEFAULT
1414 def_bool y
1415 depends on X86_64
1416
506f1d07
SR
1417config ARCH_SELECT_MEMORY_MODEL
1418 def_bool y
b263295d 1419 depends on ARCH_SPARSEMEM_ENABLE
506f1d07
SR
1420
1421config ARCH_MEMORY_PROBE
a0842b70 1422 bool "Enable sysfs memory/probe interface"
3120e25e 1423 depends on X86_64 && MEMORY_HOTPLUG
a0842b70
TK
1424 help
1425 This option enables a sysfs memory/probe interface for testing.
1426 See Documentation/memory-hotplug.txt for more information.
1427 If you are unsure how to answer this question, answer N.
506f1d07 1428
3b16651f
TH
1429config ARCH_PROC_KCORE_TEXT
1430 def_bool y
1431 depends on X86_64 && PROC_KCORE
1432
a29815a3
AK
1433config ILLEGAL_POINTER_VALUE
1434 hex
1435 default 0 if X86_32
1436 default 0xdead000000000000 if X86_64
1437
506f1d07
SR
1438source "mm/Kconfig"
1439
7a67832c
DW
1440config X86_PMEM_LEGACY_DEVICE
1441 bool
1442
ec776ef6 1443config X86_PMEM_LEGACY
7a67832c 1444 tristate "Support non-standard NVDIMMs and ADR protected memory"
9f53f9fa
DW
1445 depends on PHYS_ADDR_T_64BIT
1446 depends on BLK_DEV
7a67832c 1447 select X86_PMEM_LEGACY_DEVICE
9f53f9fa 1448 select LIBNVDIMM
ec776ef6
CH
1449 help
1450 Treat memory marked using the non-standard e820 type of 12 as used
1451 by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1452 The kernel will offer these regions to the 'pmem' driver so
1453 they can be used for persistent storage.
1454
1455 Say Y if unsure.
1456
506f1d07
SR
1457config HIGHPTE
1458 bool "Allocate 3rd-level pagetables from highmem"
6fc108a0 1459 depends on HIGHMEM
8f9ca475 1460 ---help---
506f1d07
SR
1461 The VM uses one page table entry for each page of physical memory.
1462 For systems with a lot of RAM, this can be wasteful of precious
1463 low memory. Setting this option will put user-space page table
1464 entries in high memory.
1465
9f077871 1466config X86_CHECK_BIOS_CORRUPTION
8f9ca475
IM
1467 bool "Check for low memory corruption"
1468 ---help---
1469 Periodically check for memory corruption in low memory, which
1470 is suspected to be caused by BIOS. Even when enabled in the
1471 configuration, it is disabled at runtime. Enable it by
1472 setting "memory_corruption_check=1" on the kernel command
1473 line. By default it scans the low 64k of memory every 60
1474 seconds; see the memory_corruption_check_size and
1475 memory_corruption_check_period parameters in
1476 Documentation/kernel-parameters.txt to adjust this.
1477
1478 When enabled with the default parameters, this option has
1479 almost no overhead, as it reserves a relatively small amount
1480 of memory and scans it infrequently. It both detects corruption
1481 and prevents it from affecting the running system.
1482
1483 It is, however, intended as a diagnostic tool; if repeatable
1484 BIOS-originated corruption always affects the same memory,
1485 you can use memmap= to prevent the kernel from using that
1486 memory.
9f077871 1487
c885df50 1488config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
8f9ca475 1489 bool "Set the default setting of memory_corruption_check"
c885df50
JF
1490 depends on X86_CHECK_BIOS_CORRUPTION
1491 default y
8f9ca475
IM
1492 ---help---
1493 Set whether the default state of memory_corruption_check is
1494 on or off.
c885df50 1495
9ea77bdb 1496config X86_RESERVE_LOW
d0cd7425
PA
1497 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1498 default 64
1499 range 4 640
8f9ca475 1500 ---help---
d0cd7425
PA
1501 Specify the amount of low memory to reserve for the BIOS.
1502
1503 The first page contains BIOS data structures that the kernel
1504 must not use, so that page must always be reserved.
1505
1506 By default we reserve the first 64K of physical RAM, as a
1507 number of BIOSes are known to corrupt that memory range
1508 during events such as suspend/resume or monitor cable
1509 insertion, so it must not be used by the kernel.
fc381519 1510
d0cd7425
PA
1511 You can set this to 4 if you are absolutely sure that you
1512 trust the BIOS to get all its memory reservations and usages
1513 right. If you know your BIOS have problems beyond the
1514 default 64K area, you can set this to 640 to avoid using the
1515 entire low memory range.
fc381519 1516
d0cd7425
PA
1517 If you have doubts about the BIOS (e.g. suspend/resume does
1518 not work or there's kernel crashes after certain hardware
1519 hotplug events) then you might want to enable
1520 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1521 typical corruption patterns.
fc381519 1522
d0cd7425 1523 Leave this to the default value of 64 if you are unsure.
fc381519 1524
506f1d07
SR
1525config MATH_EMULATION
1526 bool
a5b9e5a2 1527 depends on MODIFY_LDT_SYSCALL
506f1d07
SR
1528 prompt "Math emulation" if X86_32
1529 ---help---
1530 Linux can emulate a math coprocessor (used for floating point
1531 operations) if you don't have one. 486DX and Pentium processors have
1532 a math coprocessor built in, 486SX and 386 do not, unless you added
1533 a 487DX or 387, respectively. (The messages during boot time can
1534 give you some hints here ["man dmesg"].) Everyone needs either a
1535 coprocessor or this emulation.
1536
1537 If you don't have a math coprocessor, you need to say Y here; if you
1538 say Y here even though you have a coprocessor, the coprocessor will
1539 be used nevertheless. (This behavior can be changed with the kernel
1540 command line option "no387", which comes handy if your coprocessor
1541 is broken. Try "man bootparam" or see the documentation of your boot
1542 loader (lilo or loadlin) about how to pass options to the kernel at
1543 boot time.) This means that it is a good idea to say Y here if you
1544 intend to use this kernel on different machines.
1545
1546 More information about the internals of the Linux math coprocessor
1547 emulation can be found in <file:arch/x86/math-emu/README>.
1548
1549 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1550 kernel, it won't hurt.
1551
1552config MTRR
6fc108a0 1553 def_bool y
6a108a14 1554 prompt "MTRR (Memory Type Range Register) support" if EXPERT
506f1d07
SR
1555 ---help---
1556 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1557 the Memory Type Range Registers (MTRRs) may be used to control
1558 processor access to memory ranges. This is most useful if you have
1559 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1560 allows bus write transfers to be combined into a larger transfer
1561 before bursting over the PCI/AGP bus. This can increase performance
1562 of image write operations 2.5 times or more. Saying Y here creates a
1563 /proc/mtrr file which may be used to manipulate your processor's
1564 MTRRs. Typically the X server should use this.
1565
1566 This code has a reasonably generic interface so that similar
1567 control registers on other processors can be easily supported
1568 as well:
1569
1570 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1571 Registers (ARRs) which provide a similar functionality to MTRRs. For
1572 these, the ARRs are used to emulate the MTRRs.
1573 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1574 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1575 write-combining. All of these processors are supported by this code
1576 and it makes sense to say Y here if you have one of them.
1577
1578 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1579 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1580 can lead to all sorts of problems, so it's good to say Y here.
1581
1582 You can safely say Y even if your machine doesn't have MTRRs, you'll
1583 just add about 9 KB to your kernel.
1584
7225e751 1585 See <file:Documentation/x86/mtrr.txt> for more information.
506f1d07 1586
95ffa243 1587config MTRR_SANITIZER
2ffb3501 1588 def_bool y
95ffa243
YL
1589 prompt "MTRR cleanup support"
1590 depends on MTRR
8f9ca475 1591 ---help---
aba3728c
TG
1592 Convert MTRR layout from continuous to discrete, so X drivers can
1593 add writeback entries.
95ffa243 1594
aba3728c 1595 Can be disabled with disable_mtrr_cleanup on the kernel command line.
692105b8 1596 The largest mtrr entry size for a continuous block can be set with
aba3728c 1597 mtrr_chunk_size.
95ffa243 1598
2ffb3501 1599 If unsure, say Y.
95ffa243
YL
1600
1601config MTRR_SANITIZER_ENABLE_DEFAULT
f5098d62
YL
1602 int "MTRR cleanup enable value (0-1)"
1603 range 0 1
1604 default "0"
95ffa243 1605 depends on MTRR_SANITIZER
8f9ca475 1606 ---help---
f5098d62 1607 Enable mtrr cleanup default value
95ffa243 1608
12031a62
YL
1609config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1610 int "MTRR cleanup spare reg num (0-7)"
1611 range 0 7
1612 default "1"
1613 depends on MTRR_SANITIZER
8f9ca475 1614 ---help---
12031a62 1615 mtrr cleanup spare entries default, it can be changed via
aba3728c 1616 mtrr_spare_reg_nr=N on the kernel command line.
12031a62 1617
2e5d9c85 1618config X86_PAT
6fc108a0 1619 def_bool y
6a108a14 1620 prompt "x86 PAT support" if EXPERT
2a8a2719 1621 depends on MTRR
8f9ca475 1622 ---help---
2e5d9c85 1623 Use PAT attributes to setup page level cache control.
042b78e4 1624
2e5d9c85 1625 PATs are the modern equivalents of MTRRs and are much more
1626 flexible than MTRRs.
1627
1628 Say N here if you see bootup problems (boot crash, boot hang,
042b78e4 1629 spontaneous reboots) or a non-working video driver.
2e5d9c85 1630
1631 If unsure, say Y.
1632
46cf98cd
VP
1633config ARCH_USES_PG_UNCACHED
1634 def_bool y
1635 depends on X86_PAT
1636
628c6246
PA
1637config ARCH_RANDOM
1638 def_bool y
1639 prompt "x86 architectural random number generator" if EXPERT
1640 ---help---
1641 Enable the x86 architectural RDRAND instruction
1642 (Intel Bull Mountain technology) to generate random numbers.
1643 If supported, this is a high bandwidth, cryptographically
1644 secure hardware random number generator.
1645
51ae4a2d
PA
1646config X86_SMAP
1647 def_bool y
1648 prompt "Supervisor Mode Access Prevention" if EXPERT
1649 ---help---
1650 Supervisor Mode Access Prevention (SMAP) is a security
1651 feature in newer Intel processors. There is a small
1652 performance cost if this enabled and turned on; there is
1653 also a small increase in the kernel size if this is enabled.
1654
1655 If unsure, say Y.
1656
72e9b5fe
DH
1657config X86_INTEL_MPX
1658 prompt "Intel MPX (Memory Protection Extensions)"
1659 def_bool n
1660 depends on CPU_SUP_INTEL
1661 ---help---
1662 MPX provides hardware features that can be used in
1663 conjunction with compiler-instrumented code to check
1664 memory references. It is designed to detect buffer
1665 overflow or underflow bugs.
1666
1667 This option enables running applications which are
1668 instrumented or otherwise use MPX. It does not use MPX
1669 itself inside the kernel or to protect the kernel
1670 against bad memory references.
1671
1672 Enabling this option will make the kernel larger:
1673 ~8k of kernel text and 36 bytes of data on a 64-bit
1674 defconfig. It adds a long to the 'mm_struct' which
1675 will increase the kernel memory overhead of each
1676 process and adds some branches to paths used during
1677 exec() and munmap().
1678
1679 For details, see Documentation/x86/intel_mpx.txt
1680
1681 If unsure, say N.
1682
506f1d07 1683config EFI
9ba16087 1684 bool "EFI runtime service support"
5b83683f 1685 depends on ACPI
f6ce5002 1686 select UCS2_STRING
022ee6c5 1687 select EFI_RUNTIME_WRAPPERS
506f1d07 1688 ---help---
8f9ca475
IM
1689 This enables the kernel to use EFI runtime services that are
1690 available (such as the EFI variable services).
506f1d07 1691
8f9ca475
IM
1692 This option is only useful on systems that have EFI firmware.
1693 In addition, you should use the latest ELILO loader available
1694 at <http://elilo.sourceforge.net> in order to take advantage
1695 of EFI runtime services. However, even with this option, the
1696 resultant kernel should continue to boot on existing non-EFI
1697 platforms.
506f1d07 1698
291f3632
MF
1699config EFI_STUB
1700 bool "EFI stub support"
b16d8c23 1701 depends on EFI && !X86_USE_3DNOW
7b2a583a 1702 select RELOCATABLE
291f3632
MF
1703 ---help---
1704 This kernel feature allows a bzImage to be loaded directly
1705 by EFI firmware without the use of a bootloader.
1706
4172fe2f 1707 See Documentation/efi-stub.txt for more information.
0c759662 1708
7d453eee
MF
1709config EFI_MIXED
1710 bool "EFI mixed-mode support"
1711 depends on EFI_STUB && X86_64
1712 ---help---
1713 Enabling this feature allows a 64-bit kernel to be booted
1714 on a 32-bit firmware, provided that your CPU supports 64-bit
1715 mode.
1716
1717 Note that it is not possible to boot a mixed-mode enabled
1718 kernel via the EFI boot stub - a bootloader that supports
1719 the EFI handover protocol must be used.
1720
1721 If unsure, say N.
1722
506f1d07 1723config SECCOMP
3c2362e6
HH
1724 def_bool y
1725 prompt "Enable seccomp to safely compute untrusted bytecode"
8f9ca475 1726 ---help---
506f1d07
SR
1727 This kernel feature is useful for number crunching applications
1728 that may need to compute untrusted bytecode during their
1729 execution. By using pipes or other transports made available to
1730 the process as file descriptors supporting the read/write
1731 syscalls, it's possible to isolate those applications in
1732 their own address space using seccomp. Once seccomp is
9c0bbee8 1733 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
506f1d07
SR
1734 and the task is only allowed to execute a few safe syscalls
1735 defined by each seccomp mode.
1736
1737 If unsure, say Y. Only embedded should say N here.
1738
506f1d07
SR
1739source kernel/Kconfig.hz
1740
1741config KEXEC
1742 bool "kexec system call"
2965faa5 1743 select KEXEC_CORE
8f9ca475 1744 ---help---
506f1d07
SR
1745 kexec is a system call that implements the ability to shutdown your
1746 current kernel, and to start another kernel. It is like a reboot
1747 but it is independent of the system firmware. And like a reboot
1748 you can start any kernel with it, not just Linux.
1749
1750 The name comes from the similarity to the exec system call.
1751
1752 It is an ongoing process to be certain the hardware in a machine
1753 is properly shutdown, so do not be surprised if this code does not
bf220695
GU
1754 initially work for you. As of this writing the exact hardware
1755 interface is strongly in flux, so no good recommendation can be
1756 made.
506f1d07 1757
74ca317c
VG
1758config KEXEC_FILE
1759 bool "kexec file based system call"
2965faa5 1760 select KEXEC_CORE
74ca317c 1761 select BUILD_BIN2C
74ca317c
VG
1762 depends on X86_64
1763 depends on CRYPTO=y
1764 depends on CRYPTO_SHA256=y
1765 ---help---
1766 This is new version of kexec system call. This system call is
1767 file based and takes file descriptors as system call argument
1768 for kernel and initramfs as opposed to list of segments as
1769 accepted by previous system call.
1770
8e7d8381
VG
1771config KEXEC_VERIFY_SIG
1772 bool "Verify kernel signature during kexec_file_load() syscall"
74ca317c 1773 depends on KEXEC_FILE
8e7d8381
VG
1774 ---help---
1775 This option makes kernel signature verification mandatory for
d8eb8940
BP
1776 the kexec_file_load() syscall.
1777
1778 In addition to that option, you need to enable signature
1779 verification for the corresponding kernel image type being
1780 loaded in order for this to work.
8e7d8381
VG
1781
1782config KEXEC_BZIMAGE_VERIFY_SIG
1783 bool "Enable bzImage signature verification support"
1784 depends on KEXEC_VERIFY_SIG
1785 depends on SIGNED_PE_FILE_VERIFICATION
1786 select SYSTEM_TRUSTED_KEYRING
1787 ---help---
1788 Enable bzImage signature verification support.
1789
506f1d07 1790config CRASH_DUMP
04b69447 1791 bool "kernel crash dumps"
506f1d07 1792 depends on X86_64 || (X86_32 && HIGHMEM)
8f9ca475 1793 ---help---
506f1d07
SR
1794 Generate crash dump after being started by kexec.
1795 This should be normally only set in special crash dump kernels
1796 which are loaded in the main kernel with kexec-tools into
1797 a specially reserved region and then later executed after
1798 a crash by kdump/kexec. The crash dump kernel must be compiled
1799 to a memory address not used by the main kernel or BIOS using
1800 PHYSICAL_START, or it must be built as a relocatable image
1801 (CONFIG_RELOCATABLE=y).
1802 For more details see Documentation/kdump/kdump.txt
1803
3ab83521 1804config KEXEC_JUMP
6ea30386 1805 bool "kexec jump"
fee7b0d8 1806 depends on KEXEC && HIBERNATION
8f9ca475 1807 ---help---
89081d17
HY
1808 Jump between original kernel and kexeced kernel and invoke
1809 code in physical address mode via KEXEC
3ab83521 1810
506f1d07 1811config PHYSICAL_START
6a108a14 1812 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
ceefccc9 1813 default "0x1000000"
8f9ca475 1814 ---help---
506f1d07
SR
1815 This gives the physical address where the kernel is loaded.
1816
1817 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1818 bzImage will decompress itself to above physical address and
1819 run from there. Otherwise, bzImage will run from the address where
1820 it has been loaded by the boot loader and will ignore above physical
1821 address.
1822
1823 In normal kdump cases one does not have to set/change this option
1824 as now bzImage can be compiled as a completely relocatable image
1825 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1826 address. This option is mainly useful for the folks who don't want
1827 to use a bzImage for capturing the crash dump and want to use a
1828 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1829 to be specifically compiled to run from a specific memory area
1830 (normally a reserved region) and this option comes handy.
1831
ceefccc9
PA
1832 So if you are using bzImage for capturing the crash dump,
1833 leave the value here unchanged to 0x1000000 and set
1834 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1835 for capturing the crash dump change this value to start of
1836 the reserved region. In other words, it can be set based on
1837 the "X" value as specified in the "crashkernel=YM@XM"
1838 command line boot parameter passed to the panic-ed
1839 kernel. Please take a look at Documentation/kdump/kdump.txt
1840 for more details about crash dumps.
506f1d07
SR
1841
1842 Usage of bzImage for capturing the crash dump is recommended as
1843 one does not have to build two kernels. Same kernel can be used
1844 as production kernel and capture kernel. Above option should have
1845 gone away after relocatable bzImage support is introduced. But it
1846 is present because there are users out there who continue to use
1847 vmlinux for dump capture. This option should go away down the
1848 line.
1849
1850 Don't change this unless you know what you are doing.
1851
1852config RELOCATABLE
26717808
PA
1853 bool "Build a relocatable kernel"
1854 default y
8f9ca475 1855 ---help---
506f1d07
SR
1856 This builds a kernel image that retains relocation information
1857 so it can be loaded someplace besides the default 1MB.
1858 The relocations tend to make the kernel binary about 10% larger,
1859 but are discarded at runtime.
1860
1861 One use is for the kexec on panic case where the recovery kernel
1862 must live at a different physical address than the primary
1863 kernel.
1864
1865 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1866 it has been loaded at and the compile time physical address
8ab3820f 1867 (CONFIG_PHYSICAL_START) is used as the minimum location.
506f1d07 1868
8ab3820f
KC
1869config RANDOMIZE_BASE
1870 bool "Randomize the address of the kernel image"
1871 depends on RELOCATABLE
8ab3820f
KC
1872 default n
1873 ---help---
1874 Randomizes the physical and virtual address at which the
1875 kernel image is decompressed, as a security feature that
1876 deters exploit attempts relying on knowledge of the location
1877 of kernel internals.
1878
a653f356
KC
1879 Entropy is generated using the RDRAND instruction if it is
1880 supported. If RDTSC is supported, it is used as well. If
1881 neither RDRAND nor RDTSC are supported, then randomness is
1882 read from the i8254 timer.
8ab3820f
KC
1883
1884 The kernel will be offset by up to RANDOMIZE_BASE_MAX_OFFSET,
a653f356
KC
1885 and aligned according to PHYSICAL_ALIGN. Since the kernel is
1886 built using 2GiB addressing, and PHYSICAL_ALGIN must be at a
1887 minimum of 2MiB, only 10 bits of entropy is theoretically
1888 possible. At best, due to page table layouts, 64-bit can use
1889 9 bits of entropy and 32-bit uses 8 bits.
8ab3820f 1890
da2b6fb9
KC
1891 If unsure, say N.
1892
8ab3820f 1893config RANDOMIZE_BASE_MAX_OFFSET
da2b6fb9 1894 hex "Maximum kASLR offset allowed" if EXPERT
8ab3820f 1895 depends on RANDOMIZE_BASE
6145cfe3
KC
1896 range 0x0 0x20000000 if X86_32
1897 default "0x20000000" if X86_32
1898 range 0x0 0x40000000 if X86_64
1899 default "0x40000000" if X86_64
8ab3820f 1900 ---help---
da2b6fb9
KC
1901 The lesser of RANDOMIZE_BASE_MAX_OFFSET and available physical
1902 memory is used to determine the maximal offset in bytes that will
1903 be applied to the kernel when kernel Address Space Layout
1904 Randomization (kASLR) is active. This must be a multiple of
1905 PHYSICAL_ALIGN.
1906
1907 On 32-bit this is limited to 512MiB by page table layouts. The
1908 default is 512MiB.
6145cfe3 1909
da2b6fb9
KC
1910 On 64-bit this is limited by how the kernel fixmap page table is
1911 positioned, so this cannot be larger than 1GiB currently. Without
1912 RANDOMIZE_BASE, there is a 512MiB to 1.5GiB split between kernel
1913 and modules. When RANDOMIZE_BASE_MAX_OFFSET is above 512MiB, the
1914 modules area will shrink to compensate, up to the current maximum
1915 1GiB to 1GiB split. The default is 1GiB.
6145cfe3 1916
da2b6fb9 1917 If unsure, leave at the default value.
8ab3820f
KC
1918
1919# Relocation on x86 needs some additional build support
845adf72
PA
1920config X86_NEED_RELOCS
1921 def_bool y
8ab3820f 1922 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
845adf72 1923
506f1d07 1924config PHYSICAL_ALIGN
a0215061 1925 hex "Alignment value to which kernel should be aligned"
8ab3820f 1926 default "0x200000"
a0215061
KC
1927 range 0x2000 0x1000000 if X86_32
1928 range 0x200000 0x1000000 if X86_64
8f9ca475 1929 ---help---
506f1d07
SR
1930 This value puts the alignment restrictions on physical address
1931 where kernel is loaded and run from. Kernel is compiled for an
1932 address which meets above alignment restriction.
1933
1934 If bootloader loads the kernel at a non-aligned address and
1935 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1936 address aligned to above value and run from there.
1937
1938 If bootloader loads the kernel at a non-aligned address and
1939 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1940 load address and decompress itself to the address it has been
1941 compiled for and run from there. The address for which kernel is
1942 compiled already meets above alignment restrictions. Hence the
1943 end result is that kernel runs from a physical address meeting
1944 above alignment restrictions.
1945
a0215061
KC
1946 On 32-bit this value must be a multiple of 0x2000. On 64-bit
1947 this value must be a multiple of 0x200000.
1948
506f1d07
SR
1949 Don't change this unless you know what you are doing.
1950
1951config HOTPLUG_CPU
7c13e6a3 1952 bool "Support for hot-pluggable CPUs"
40b31360 1953 depends on SMP
506f1d07 1954 ---help---
7c13e6a3
DS
1955 Say Y here to allow turning CPUs off and on. CPUs can be
1956 controlled through /sys/devices/system/cpu.
1957 ( Note: power management support will enable this option
1958 automatically on SMP systems. )
1959 Say N if you want to disable CPU hotplug.
506f1d07 1960
80aa1dff
FY
1961config BOOTPARAM_HOTPLUG_CPU0
1962 bool "Set default setting of cpu0_hotpluggable"
1963 default n
2c922cd0 1964 depends on HOTPLUG_CPU
80aa1dff
FY
1965 ---help---
1966 Set whether default state of cpu0_hotpluggable is on or off.
1967
1968 Say Y here to enable CPU0 hotplug by default. If this switch
1969 is turned on, there is no need to give cpu0_hotplug kernel
1970 parameter and the CPU0 hotplug feature is enabled by default.
1971
1972 Please note: there are two known CPU0 dependencies if you want
1973 to enable the CPU0 hotplug feature either by this switch or by
1974 cpu0_hotplug kernel parameter.
1975
1976 First, resume from hibernate or suspend always starts from CPU0.
1977 So hibernate and suspend are prevented if CPU0 is offline.
1978
1979 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
1980 offline if any interrupt can not migrate out of CPU0. There may
1981 be other CPU0 dependencies.
1982
1983 Please make sure the dependencies are under your control before
1984 you enable this feature.
1985
1986 Say N if you don't want to enable CPU0 hotplug feature by default.
1987 You still can enable the CPU0 hotplug feature at boot by kernel
1988 parameter cpu0_hotplug.
1989
a71c8bc5
FY
1990config DEBUG_HOTPLUG_CPU0
1991 def_bool n
1992 prompt "Debug CPU0 hotplug"
2c922cd0 1993 depends on HOTPLUG_CPU
a71c8bc5
FY
1994 ---help---
1995 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
1996 soon as possible and boots up userspace with CPU0 offlined. User
1997 can online CPU0 back after boot time.
1998
1999 To debug CPU0 hotplug, you need to enable CPU0 offline/online
2000 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2001 compilation or giving cpu0_hotplug kernel parameter at boot.
2002
2003 If unsure, say N.
2004
506f1d07 2005config COMPAT_VDSO
b0b49f26
AL
2006 def_bool n
2007 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
af65d648 2008 depends on X86_32 || IA32_EMULATION
8f9ca475 2009 ---help---
b0b49f26
AL
2010 Certain buggy versions of glibc will crash if they are
2011 presented with a 32-bit vDSO that is not mapped at the address
2012 indicated in its segment table.
e84446de 2013
b0b49f26
AL
2014 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2015 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2016 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
2017 the only released version with the bug, but OpenSUSE 9
2018 contains a buggy "glibc 2.3.2".
506f1d07 2019
b0b49f26
AL
2020 The symptom of the bug is that everything crashes on startup, saying:
2021 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2022
2023 Saying Y here changes the default value of the vdso32 boot
2024 option from 1 to 0, which turns off the 32-bit vDSO entirely.
2025 This works around the glibc bug but hurts performance.
2026
2027 If unsure, say N: if you are compiling your own kernel, you
2028 are unlikely to be using a buggy version of glibc.
506f1d07 2029
3dc33bd3
KC
2030choice
2031 prompt "vsyscall table for legacy applications"
2032 depends on X86_64
2033 default LEGACY_VSYSCALL_EMULATE
2034 help
2035 Legacy user code that does not know how to find the vDSO expects
2036 to be able to issue three syscalls by calling fixed addresses in
2037 kernel space. Since this location is not randomized with ASLR,
2038 it can be used to assist security vulnerability exploitation.
2039
2040 This setting can be changed at boot time via the kernel command
2041 line parameter vsyscall=[native|emulate|none].
2042
2043 On a system with recent enough glibc (2.14 or newer) and no
2044 static binaries, you can say None without a performance penalty
2045 to improve security.
2046
2047 If unsure, select "Emulate".
2048
2049 config LEGACY_VSYSCALL_NATIVE
2050 bool "Native"
2051 help
2052 Actual executable code is located in the fixed vsyscall
2053 address mapping, implementing time() efficiently. Since
2054 this makes the mapping executable, it can be used during
2055 security vulnerability exploitation (traditionally as
2056 ROP gadgets). This configuration is not recommended.
2057
2058 config LEGACY_VSYSCALL_EMULATE
2059 bool "Emulate"
2060 help
2061 The kernel traps and emulates calls into the fixed
2062 vsyscall address mapping. This makes the mapping
2063 non-executable, but it still contains known contents,
2064 which could be used in certain rare security vulnerability
2065 exploits. This configuration is recommended when userspace
2066 still uses the vsyscall area.
2067
2068 config LEGACY_VSYSCALL_NONE
2069 bool "None"
2070 help
2071 There will be no vsyscall mapping at all. This will
2072 eliminate any risk of ASLR bypass due to the vsyscall
2073 fixed address mapping. Attempts to use the vsyscalls
2074 will be reported to dmesg, so that either old or
2075 malicious userspace programs can be identified.
2076
2077endchoice
2078
516cbf37
TB
2079config CMDLINE_BOOL
2080 bool "Built-in kernel command line"
8f9ca475 2081 ---help---
516cbf37
TB
2082 Allow for specifying boot arguments to the kernel at
2083 build time. On some systems (e.g. embedded ones), it is
2084 necessary or convenient to provide some or all of the
2085 kernel boot arguments with the kernel itself (that is,
2086 to not rely on the boot loader to provide them.)
2087
2088 To compile command line arguments into the kernel,
2089 set this option to 'Y', then fill in the
69711ca1 2090 boot arguments in CONFIG_CMDLINE.
516cbf37
TB
2091
2092 Systems with fully functional boot loaders (i.e. non-embedded)
2093 should leave this option set to 'N'.
2094
2095config CMDLINE
2096 string "Built-in kernel command string"
2097 depends on CMDLINE_BOOL
2098 default ""
8f9ca475 2099 ---help---
516cbf37
TB
2100 Enter arguments here that should be compiled into the kernel
2101 image and used at boot time. If the boot loader provides a
2102 command line at boot time, it is appended to this string to
2103 form the full kernel command line, when the system boots.
2104
2105 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2106 change this behavior.
2107
2108 In most cases, the command line (whether built-in or provided
2109 by the boot loader) should specify the device for the root
2110 file system.
2111
2112config CMDLINE_OVERRIDE
2113 bool "Built-in command line overrides boot loader arguments"
516cbf37 2114 depends on CMDLINE_BOOL
8f9ca475 2115 ---help---
516cbf37
TB
2116 Set this option to 'Y' to have the kernel ignore the boot loader
2117 command line, and use ONLY the built-in command line.
2118
2119 This is used to work around broken boot loaders. This should
2120 be set to 'N' under normal conditions.
2121
a5b9e5a2
AL
2122config MODIFY_LDT_SYSCALL
2123 bool "Enable the LDT (local descriptor table)" if EXPERT
2124 default y
2125 ---help---
2126 Linux can allow user programs to install a per-process x86
2127 Local Descriptor Table (LDT) using the modify_ldt(2) system
2128 call. This is required to run 16-bit or segmented code such as
2129 DOSEMU or some Wine programs. It is also used by some very old
2130 threading libraries.
2131
2132 Enabling this feature adds a small amount of overhead to
2133 context switches and increases the low-level kernel attack
2134 surface. Disabling it removes the modify_ldt(2) system call.
2135
2136 Saying 'N' here may make sense for embedded or server kernels.
2137
b700e7f0
SJ
2138source "kernel/livepatch/Kconfig"
2139
506f1d07
SR
2140endmenu
2141
2142config ARCH_ENABLE_MEMORY_HOTPLUG
2143 def_bool y
2144 depends on X86_64 || (X86_32 && HIGHMEM)
2145
35551053
GH
2146config ARCH_ENABLE_MEMORY_HOTREMOVE
2147 def_bool y
2148 depends on MEMORY_HOTPLUG
2149
e534c7c5 2150config USE_PERCPU_NUMA_NODE_ID
645a7919 2151 def_bool y
e534c7c5
LS
2152 depends on NUMA
2153
9491846f
KS
2154config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2155 def_bool y
2156 depends on X86_64 || X86_PAE
2157
c177c81e
NH
2158config ARCH_ENABLE_HUGEPAGE_MIGRATION
2159 def_bool y
2160 depends on X86_64 && HUGETLB_PAGE && MIGRATION
2161
da85f865 2162menu "Power management and ACPI options"
e279b6c1
SR
2163
2164config ARCH_HIBERNATION_HEADER
3c2362e6 2165 def_bool y
e279b6c1 2166 depends on X86_64 && HIBERNATION
e279b6c1
SR
2167
2168source "kernel/power/Kconfig"
2169
2170source "drivers/acpi/Kconfig"
2171
efafc8b2
FT
2172source "drivers/sfi/Kconfig"
2173
a6b68076 2174config X86_APM_BOOT
6fc108a0 2175 def_bool y
282e5aab 2176 depends on APM
a6b68076 2177
e279b6c1
SR
2178menuconfig APM
2179 tristate "APM (Advanced Power Management) BIOS support"
efefa6f6 2180 depends on X86_32 && PM_SLEEP
e279b6c1
SR
2181 ---help---
2182 APM is a BIOS specification for saving power using several different
2183 techniques. This is mostly useful for battery powered laptops with
2184 APM compliant BIOSes. If you say Y here, the system time will be
2185 reset after a RESUME operation, the /proc/apm device will provide
2186 battery status information, and user-space programs will receive
2187 notification of APM "events" (e.g. battery status change).
2188
2189 If you select "Y" here, you can disable actual use of the APM
2190 BIOS by passing the "apm=off" option to the kernel at boot time.
2191
2192 Note that the APM support is almost completely disabled for
2193 machines with more than one CPU.
2194
2195 In order to use APM, you will need supporting software. For location
2dc98fd3
MW
2196 and more information, read <file:Documentation/power/apm-acpi.txt>
2197 and the Battery Powered Linux mini-HOWTO, available from
e279b6c1
SR
2198 <http://www.tldp.org/docs.html#howto>.
2199
2200 This driver does not spin down disk drives (see the hdparm(8)
2201 manpage ("man 8 hdparm") for that), and it doesn't turn off
2202 VESA-compliant "green" monitors.
2203
2204 This driver does not support the TI 4000M TravelMate and the ACER
2205 486/DX4/75 because they don't have compliant BIOSes. Many "green"
2206 desktop machines also don't have compliant BIOSes, and this driver
2207 may cause those machines to panic during the boot phase.
2208
2209 Generally, if you don't have a battery in your machine, there isn't
2210 much point in using this driver and you should say N. If you get
2211 random kernel OOPSes or reboots that don't seem to be related to
2212 anything, try disabling/enabling this option (or disabling/enabling
2213 APM in your BIOS).
2214
2215 Some other things you should try when experiencing seemingly random,
2216 "weird" problems:
2217
2218 1) make sure that you have enough swap space and that it is
2219 enabled.
2220 2) pass the "no-hlt" option to the kernel
2221 3) switch on floating point emulation in the kernel and pass
2222 the "no387" option to the kernel
2223 4) pass the "floppy=nodma" option to the kernel
2224 5) pass the "mem=4M" option to the kernel (thereby disabling
2225 all but the first 4 MB of RAM)
2226 6) make sure that the CPU is not over clocked.
2227 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2228 8) disable the cache from your BIOS settings
2229 9) install a fan for the video card or exchange video RAM
2230 10) install a better fan for the CPU
2231 11) exchange RAM chips
2232 12) exchange the motherboard.
2233
2234 To compile this driver as a module, choose M here: the
2235 module will be called apm.
2236
2237if APM
2238
2239config APM_IGNORE_USER_SUSPEND
2240 bool "Ignore USER SUSPEND"
8f9ca475 2241 ---help---
e279b6c1
SR
2242 This option will ignore USER SUSPEND requests. On machines with a
2243 compliant APM BIOS, you want to say N. However, on the NEC Versa M
2244 series notebooks, it is necessary to say Y because of a BIOS bug.
2245
2246config APM_DO_ENABLE
2247 bool "Enable PM at boot time"
2248 ---help---
2249 Enable APM features at boot time. From page 36 of the APM BIOS
2250 specification: "When disabled, the APM BIOS does not automatically
2251 power manage devices, enter the Standby State, enter the Suspend
2252 State, or take power saving steps in response to CPU Idle calls."
2253 This driver will make CPU Idle calls when Linux is idle (unless this
2254 feature is turned off -- see "Do CPU IDLE calls", below). This
2255 should always save battery power, but more complicated APM features
2256 will be dependent on your BIOS implementation. You may need to turn
2257 this option off if your computer hangs at boot time when using APM
2258 support, or if it beeps continuously instead of suspending. Turn
2259 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2260 T400CDT. This is off by default since most machines do fine without
2261 this feature.
2262
2263config APM_CPU_IDLE
dd8af076 2264 depends on CPU_IDLE
e279b6c1 2265 bool "Make CPU Idle calls when idle"
8f9ca475 2266 ---help---
e279b6c1
SR
2267 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2268 On some machines, this can activate improved power savings, such as
2269 a slowed CPU clock rate, when the machine is idle. These idle calls
2270 are made after the idle loop has run for some length of time (e.g.,
2271 333 mS). On some machines, this will cause a hang at boot time or
2272 whenever the CPU becomes idle. (On machines with more than one CPU,
2273 this option does nothing.)
2274
2275config APM_DISPLAY_BLANK
2276 bool "Enable console blanking using APM"
8f9ca475 2277 ---help---
e279b6c1
SR
2278 Enable console blanking using the APM. Some laptops can use this to
2279 turn off the LCD backlight when the screen blanker of the Linux
2280 virtual console blanks the screen. Note that this is only used by
2281 the virtual console screen blanker, and won't turn off the backlight
2282 when using the X Window system. This also doesn't have anything to
2283 do with your VESA-compliant power-saving monitor. Further, this
2284 option doesn't work for all laptops -- it might not turn off your
2285 backlight at all, or it might print a lot of errors to the console,
2286 especially if you are using gpm.
2287
2288config APM_ALLOW_INTS
2289 bool "Allow interrupts during APM BIOS calls"
8f9ca475 2290 ---help---
e279b6c1
SR
2291 Normally we disable external interrupts while we are making calls to
2292 the APM BIOS as a measure to lessen the effects of a badly behaving
2293 BIOS implementation. The BIOS should reenable interrupts if it
2294 needs to. Unfortunately, some BIOSes do not -- especially those in
2295 many of the newer IBM Thinkpads. If you experience hangs when you
2296 suspend, try setting this to Y. Otherwise, say N.
2297
e279b6c1
SR
2298endif # APM
2299
bb0a56ec 2300source "drivers/cpufreq/Kconfig"
e279b6c1
SR
2301
2302source "drivers/cpuidle/Kconfig"
2303
27471fdb
AH
2304source "drivers/idle/Kconfig"
2305
e279b6c1
SR
2306endmenu
2307
2308
2309menu "Bus options (PCI etc.)"
2310
2311config PCI
1ac97018 2312 bool "PCI support"
1c858087 2313 default y
8f9ca475 2314 ---help---
e279b6c1
SR
2315 Find out whether you have a PCI motherboard. PCI is the name of a
2316 bus system, i.e. the way the CPU talks to the other stuff inside
2317 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2318 VESA. If you have PCI, say Y, otherwise N.
2319
e279b6c1
SR
2320choice
2321 prompt "PCI access mode"
efefa6f6 2322 depends on X86_32 && PCI
e279b6c1
SR
2323 default PCI_GOANY
2324 ---help---
2325 On PCI systems, the BIOS can be used to detect the PCI devices and
2326 determine their configuration. However, some old PCI motherboards
2327 have BIOS bugs and may crash if this is done. Also, some embedded
2328 PCI-based systems don't have any BIOS at all. Linux can also try to
2329 detect the PCI hardware directly without using the BIOS.
2330
2331 With this option, you can specify how Linux should detect the
2332 PCI devices. If you choose "BIOS", the BIOS will be used,
2333 if you choose "Direct", the BIOS won't be used, and if you
2334 choose "MMConfig", then PCI Express MMCONFIG will be used.
2335 If you choose "Any", the kernel will try MMCONFIG, then the
2336 direct access method and falls back to the BIOS if that doesn't
2337 work. If unsure, go with the default, which is "Any".
2338
2339config PCI_GOBIOS
2340 bool "BIOS"
2341
2342config PCI_GOMMCONFIG
2343 bool "MMConfig"
2344
2345config PCI_GODIRECT
2346 bool "Direct"
2347
3ef0e1f8 2348config PCI_GOOLPC
76fb6570 2349 bool "OLPC XO-1"
3ef0e1f8
AS
2350 depends on OLPC
2351
2bdd1b03
AS
2352config PCI_GOANY
2353 bool "Any"
2354
e279b6c1
SR
2355endchoice
2356
2357config PCI_BIOS
3c2362e6 2358 def_bool y
efefa6f6 2359 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
e279b6c1
SR
2360
2361# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2362config PCI_DIRECT
3c2362e6 2363 def_bool y
0aba496f 2364 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
e279b6c1
SR
2365
2366config PCI_MMCONFIG
3c2362e6 2367 def_bool y
5f0db7a2 2368 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
e279b6c1 2369
3ef0e1f8 2370config PCI_OLPC
2bdd1b03
AS
2371 def_bool y
2372 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
3ef0e1f8 2373
b5401a96
AN
2374config PCI_XEN
2375 def_bool y
2376 depends on PCI && XEN
2377 select SWIOTLB_XEN
2378
e279b6c1 2379config PCI_DOMAINS
3c2362e6 2380 def_bool y
e279b6c1 2381 depends on PCI
e279b6c1
SR
2382
2383config PCI_MMCONFIG
2384 bool "Support mmconfig PCI config space access"
2385 depends on X86_64 && PCI && ACPI
2386
3f6ea84a 2387config PCI_CNB20LE_QUIRK
6a108a14 2388 bool "Read CNB20LE Host Bridge Windows" if EXPERT
6ea30386 2389 depends on PCI
3f6ea84a
IS
2390 help
2391 Read the PCI windows out of the CNB20LE host bridge. This allows
2392 PCI hotplug to work on systems with the CNB20LE chipset which do
2393 not have ACPI.
2394
64a5fed6
BH
2395 There's no public spec for this chipset, and this functionality
2396 is known to be incomplete.
2397
2398 You should say N unless you know you need this.
2399
e279b6c1
SR
2400source "drivers/pci/pcie/Kconfig"
2401
2402source "drivers/pci/Kconfig"
2403
1c00f016 2404# x86_64 have no ISA slots, but can have ISA-style DMA.
e279b6c1 2405config ISA_DMA_API
1c00f016
DR
2406 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2407 default y
2408 help
2409 Enables ISA-style DMA support for devices requiring such controllers.
2410 If unsure, say Y.
e279b6c1
SR
2411
2412if X86_32
2413
2414config ISA
2415 bool "ISA support"
8f9ca475 2416 ---help---
e279b6c1
SR
2417 Find out whether you have ISA slots on your motherboard. ISA is the
2418 name of a bus system, i.e. the way the CPU talks to the other stuff
2419 inside your box. Other bus systems are PCI, EISA, MicroChannel
2420 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2421 newer boards don't support it. If you have ISA, say Y, otherwise N.
2422
2423config EISA
2424 bool "EISA support"
2425 depends on ISA
2426 ---help---
2427 The Extended Industry Standard Architecture (EISA) bus was
2428 developed as an open alternative to the IBM MicroChannel bus.
2429
2430 The EISA bus provided some of the features of the IBM MicroChannel
2431 bus while maintaining backward compatibility with cards made for
2432 the older ISA bus. The EISA bus saw limited use between 1988 and
2433 1995 when it was made obsolete by the PCI bus.
2434
2435 Say Y here if you are building a kernel for an EISA-based machine.
2436
2437 Otherwise, say N.
2438
2439source "drivers/eisa/Kconfig"
2440
e279b6c1
SR
2441config SCx200
2442 tristate "NatSemi SCx200 support"
8f9ca475 2443 ---help---
e279b6c1
SR
2444 This provides basic support for National Semiconductor's
2445 (now AMD's) Geode processors. The driver probes for the
2446 PCI-IDs of several on-chip devices, so its a good dependency
2447 for other scx200_* drivers.
2448
2449 If compiled as a module, the driver is named scx200.
2450
2451config SCx200HR_TIMER
2452 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
592913ec 2453 depends on SCx200
e279b6c1 2454 default y
8f9ca475 2455 ---help---
e279b6c1
SR
2456 This driver provides a clocksource built upon the on-chip
2457 27MHz high-resolution timer. Its also a workaround for
2458 NSC Geode SC-1100's buggy TSC, which loses time when the
2459 processor goes idle (as is done by the scheduler). The
2460 other workaround is idle=poll boot option.
2461
3ef0e1f8
AS
2462config OLPC
2463 bool "One Laptop Per Child support"
54008979 2464 depends on !X86_PAE
3c554946 2465 select GPIOLIB
dc3119e7 2466 select OF
45bb1674 2467 select OF_PROMTREE
b4e51854 2468 select IRQ_DOMAIN
8f9ca475 2469 ---help---
3ef0e1f8
AS
2470 Add support for detecting the unique features of the OLPC
2471 XO hardware.
2472
a3128588
DD
2473config OLPC_XO1_PM
2474 bool "OLPC XO-1 Power Management"
97c4cb71 2475 depends on OLPC && MFD_CS5535 && PM_SLEEP
a3128588 2476 select MFD_CORE
bf1ebf00 2477 ---help---
97c4cb71 2478 Add support for poweroff and suspend of the OLPC XO-1 laptop.
bf1ebf00 2479
cfee9597
DD
2480config OLPC_XO1_RTC
2481 bool "OLPC XO-1 Real Time Clock"
2482 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2483 ---help---
2484 Add support for the XO-1 real time clock, which can be used as a
2485 programmable wakeup source.
2486
7feda8e9
DD
2487config OLPC_XO1_SCI
2488 bool "OLPC XO-1 SCI extras"
d8d01a63 2489 depends on OLPC && OLPC_XO1_PM
ed8e47fe 2490 depends on INPUT=y
d8d01a63 2491 select POWER_SUPPLY
7feda8e9
DD
2492 select GPIO_CS5535
2493 select MFD_CORE
2494 ---help---
2495 Add support for SCI-based features of the OLPC XO-1 laptop:
7bc74b3d 2496 - EC-driven system wakeups
7feda8e9 2497 - Power button
7bc74b3d 2498 - Ebook switch
2cf2baea 2499 - Lid switch
e1040ac6
DD
2500 - AC adapter status updates
2501 - Battery status updates
7feda8e9 2502
a0f30f59
DD
2503config OLPC_XO15_SCI
2504 bool "OLPC XO-1.5 SCI extras"
d8d01a63
DD
2505 depends on OLPC && ACPI
2506 select POWER_SUPPLY
a0f30f59
DD
2507 ---help---
2508 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2509 - EC-driven system wakeups
2510 - AC adapter status updates
2511 - Battery status updates
bf1ebf00 2512
d4f3e350
EW
2513config ALIX
2514 bool "PCEngines ALIX System Support (LED setup)"
2515 select GPIOLIB
2516 ---help---
2517 This option enables system support for the PCEngines ALIX.
2518 At present this just sets up LEDs for GPIO control on
2519 ALIX2/3/6 boards. However, other system specific setup should
2520 get added here.
2521
2522 Note: You must still enable the drivers for GPIO and LED support
2523 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2524
2525 Note: You have to set alix.force=1 for boards with Award BIOS.
2526
da4e3302
PP
2527config NET5501
2528 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2529 select GPIOLIB
2530 ---help---
2531 This option enables system support for the Soekris Engineering net5501.
2532
3197059a
PP
2533config GEOS
2534 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2535 select GPIOLIB
2536 depends on DMI
2537 ---help---
2538 This option enables system support for the Traverse Technologies GEOS.
2539
7d029125
VD
2540config TS5500
2541 bool "Technologic Systems TS-5500 platform support"
2542 depends on MELAN
2543 select CHECK_SIGNATURE
2544 select NEW_LEDS
2545 select LEDS_CLASS
2546 ---help---
2547 This option enables system support for the Technologic Systems TS-5500.
2548
bc0120fd
SR
2549endif # X86_32
2550
23ac4ae8 2551config AMD_NB
e279b6c1 2552 def_bool y
0e152cd7 2553 depends on CPU_SUP_AMD && PCI
e279b6c1
SR
2554
2555source "drivers/pcmcia/Kconfig"
2556
2557source "drivers/pci/hotplug/Kconfig"
2558
388b78ad 2559config RAPIDIO
fdf90abc 2560 tristate "RapidIO support"
388b78ad
AB
2561 depends on PCI
2562 default n
2563 help
fdf90abc 2564 If enabled this option will include drivers and the core
388b78ad
AB
2565 infrastructure code to support RapidIO interconnect devices.
2566
2567source "drivers/rapidio/Kconfig"
2568
e3263ab3
DH
2569config X86_SYSFB
2570 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2571 help
2572 Firmwares often provide initial graphics framebuffers so the BIOS,
2573 bootloader or kernel can show basic video-output during boot for
2574 user-guidance and debugging. Historically, x86 used the VESA BIOS
2575 Extensions and EFI-framebuffers for this, which are mostly limited
2576 to x86.
2577 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2578 framebuffers so the new generic system-framebuffer drivers can be
2579 used on x86. If the framebuffer is not compatible with the generic
2580 modes, it is adverticed as fallback platform framebuffer so legacy
2581 drivers like efifb, vesafb and uvesafb can pick it up.
2582 If this option is not selected, all system framebuffers are always
2583 marked as fallback platform framebuffers as usual.
2584
2585 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2586 not be able to pick up generic system framebuffers if this option
2587 is selected. You are highly encouraged to enable simplefb as
2588 replacement if you select this option. simplefb can correctly deal
2589 with generic system framebuffers. But you should still keep vesafb
2590 and others enabled as fallback if a system framebuffer is
2591 incompatible with simplefb.
2592
2593 If unsure, say Y.
2594
e279b6c1
SR
2595endmenu
2596
2597
2598menu "Executable file formats / Emulations"
2599
2600source "fs/Kconfig.binfmt"
2601
2602config IA32_EMULATION
2603 bool "IA32 Emulation"
2604 depends on X86_64
d1603990 2605 select BINFMT_ELF
a97f52e6 2606 select COMPAT_BINFMT_ELF
3bead553 2607 select ARCH_WANT_OLD_COMPAT_IPC
8f9ca475 2608 ---help---
5fd92e65
L
2609 Include code to run legacy 32-bit programs under a
2610 64-bit kernel. You should likely turn this on, unless you're
2611 100% sure that you don't have any 32-bit programs left.
e279b6c1
SR
2612
2613config IA32_AOUT
8f9ca475
IM
2614 tristate "IA32 a.out support"
2615 depends on IA32_EMULATION
2616 ---help---
2617 Support old a.out binaries in the 32bit emulation.
e279b6c1 2618
0bf62763 2619config X86_X32
6ea30386 2620 bool "x32 ABI for 64-bit mode"
9b54050b 2621 depends on X86_64
5fd92e65
L
2622 ---help---
2623 Include code to run binaries for the x32 native 32-bit ABI
2624 for 64-bit processors. An x32 process gets access to the
2625 full 64-bit register file and wide data path while leaving
2626 pointers at 32 bits for smaller memory footprint.
2627
2628 You will need a recent binutils (2.22 or later) with
2629 elf32_x86_64 support enabled to compile a kernel with this
2630 option set.
2631
e279b6c1 2632config COMPAT
3c2362e6 2633 def_bool y
0bf62763 2634 depends on IA32_EMULATION || X86_X32
e279b6c1 2635
3120e25e 2636if COMPAT
e279b6c1 2637config COMPAT_FOR_U64_ALIGNMENT
3120e25e 2638 def_bool y
e279b6c1
SR
2639
2640config SYSVIPC_COMPAT
3c2362e6 2641 def_bool y
3120e25e 2642 depends on SYSVIPC
e279b6c1 2643
ee009e4a 2644config KEYS_COMPAT
3120e25e
JB
2645 def_bool y
2646 depends on KEYS
2647endif
ee009e4a 2648
e279b6c1
SR
2649endmenu
2650
2651
e5beae16
KP
2652config HAVE_ATOMIC_IOMAP
2653 def_bool y
2654 depends on X86_32
2655
4692d77f
AR
2656config X86_DEV_DMA_OPS
2657 bool
83125a3a 2658 depends on X86_64 || STA2X11
4692d77f 2659
f7219a53
AR
2660config X86_DMA_REMAP
2661 bool
83125a3a 2662 depends on STA2X11
f7219a53 2663
93e5eadd
LA
2664config PMC_ATOM
2665 def_bool y
2666 depends on PCI
2667
e279b6c1
SR
2668source "net/Kconfig"
2669
2670source "drivers/Kconfig"
2671
2672source "drivers/firmware/Kconfig"
2673
2674source "fs/Kconfig"
2675
e279b6c1
SR
2676source "arch/x86/Kconfig.debug"
2677
2678source "security/Kconfig"
2679
2680source "crypto/Kconfig"
2681
edf88417
AK
2682source "arch/x86/kvm/Kconfig"
2683
e279b6c1 2684source "lib/Kconfig"