selftests/x86, x86/ldt: Add a selftest for modify_ldt()
[deliverable/linux.git] / arch / x86 / Kconfig
CommitLineData
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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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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
61031952 30 select ARCH_HAS_PMEM_API
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IM
31 select ARCH_HAS_SG_CHAIN
32 select ARCH_HAVE_NMI_SAFE_CMPXCHG
33 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
77fbbc81 34 select ARCH_MIGHT_HAVE_PC_PARPORT
5e2c18c0 35 select ARCH_MIGHT_HAVE_PC_SERIO
6471b825 36 select ARCH_SUPPORTS_ATOMIC_RMW
3b242c66 37 select ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT
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IM
38 select ARCH_SUPPORTS_INT128 if X86_64
39 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
40 select ARCH_USE_BUILTIN_BSWAP
41 select ARCH_USE_CMPXCHG_LOCKREF if X86_64
42 select ARCH_USE_QUEUED_RWLOCKS
43 select ARCH_USE_QUEUED_SPINLOCKS
5aaeb5c0 44 select ARCH_WANTS_DYNAMIC_TASK_STRUCT
da4276b8 45 select ARCH_WANT_FRAME_POINTERS
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46 select ARCH_WANT_IPC_PARSE_VERSION if X86_32
47 select ARCH_WANT_OPTIONAL_GPIOLIB
48 select BUILDTIME_EXTABLE_SORT
49 select CLKEVT_I8253
50 select CLKSRC_I8253 if X86_32
51 select CLOCKSOURCE_VALIDATE_LAST_CYCLE
52 select CLOCKSOURCE_WATCHDOG
53 select CLONE_BACKWARDS if X86_32
54 select COMPAT_OLD_SIGACTION if IA32_EMULATION
55 select DCACHE_WORD_ACCESS
45471cd9
LT
56 select EDAC_ATOMIC_SCRUB
57 select EDAC_SUPPORT
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58 select GENERIC_CLOCKEVENTS
59 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
60 select GENERIC_CLOCKEVENTS_MIN_ADJUST
61 select GENERIC_CMOS_UPDATE
62 select GENERIC_CPU_AUTOPROBE
5b7c73e0 63 select GENERIC_EARLY_IOREMAP
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64 select GENERIC_FIND_FIRST_BIT
65 select GENERIC_IOMAP
66 select GENERIC_IRQ_PROBE
67 select GENERIC_IRQ_SHOW
68 select GENERIC_PENDING_IRQ if SMP
69 select GENERIC_SMP_IDLE_THREAD
70 select GENERIC_STRNCPY_FROM_USER
71 select GENERIC_STRNLEN_USER
72 select GENERIC_TIME_VSYSCALL
73 select HAVE_ACPI_APEI if ACPI
74 select HAVE_ACPI_APEI_NMI if ACPI
75 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
76 select HAVE_AOUT if X86_32
77 select HAVE_ARCH_AUDITSYSCALL
78 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE
79 select HAVE_ARCH_JUMP_LABEL
80 select HAVE_ARCH_KASAN if X86_64 && SPARSEMEM_VMEMMAP
81 select HAVE_ARCH_KGDB
82 select HAVE_ARCH_KMEMCHECK
83 select HAVE_ARCH_SECCOMP_FILTER
84 select HAVE_ARCH_SOFT_DIRTY if X86_64
85 select HAVE_ARCH_TRACEHOOK
86 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
87 select HAVE_BPF_JIT if X86_64
88 select HAVE_CC_STACKPROTECTOR
89 select HAVE_CMPXCHG_DOUBLE
90 select HAVE_CMPXCHG_LOCAL
91 select HAVE_CONTEXT_TRACKING if X86_64
c1bd55f9 92 select HAVE_COPY_THREAD_TLS
cf4db259 93 select HAVE_C_RECORDMCOUNT
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94 select HAVE_DEBUG_KMEMLEAK
95 select HAVE_DEBUG_STACKOVERFLOW
96 select HAVE_DMA_API_DEBUG
97 select HAVE_DMA_ATTRS
98 select HAVE_DMA_CONTIGUOUS
677aa9f7 99 select HAVE_DYNAMIC_FTRACE
06aeaaea 100 select HAVE_DYNAMIC_FTRACE_WITH_REGS
58340a07 101 select HAVE_EFFICIENT_UNALIGNED_ACCESS
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102 select HAVE_FENTRY if X86_64
103 select HAVE_FTRACE_MCOUNT_RECORD
104 select HAVE_FUNCTION_GRAPH_FP_TEST
105 select HAVE_FUNCTION_GRAPH_TRACER
106 select HAVE_FUNCTION_TRACER
107 select HAVE_GENERIC_DMA_COHERENT if X86_32
108 select HAVE_HW_BREAKPOINT
109 select HAVE_IDE
110 select HAVE_IOREMAP_PROT
111 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
112 select HAVE_IRQ_TIME_ACCOUNTING
2e9f3bdd 113 select HAVE_KERNEL_BZIP2
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114 select HAVE_KERNEL_GZIP
115 select HAVE_KERNEL_LZ4
2e9f3bdd 116 select HAVE_KERNEL_LZMA
13510997 117 select HAVE_KERNEL_LZO
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118 select HAVE_KERNEL_XZ
119 select HAVE_KPROBES
120 select HAVE_KPROBES_ON_FTRACE
121 select HAVE_KRETPROBES
122 select HAVE_KVM
123 select HAVE_LIVEPATCH if X86_64
124 select HAVE_MEMBLOCK
125 select HAVE_MEMBLOCK_NODE_MAP
0102752e 126 select HAVE_MIXED_BREAKPOINTS_REGS
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127 select HAVE_OPROFILE
128 select HAVE_OPTPROBES
129 select HAVE_PCSPKR_PLATFORM
130 select HAVE_PERF_EVENTS
c01d4323 131 select HAVE_PERF_EVENTS_NMI
c5e63197 132 select HAVE_PERF_REGS
c5ebcedb 133 select HAVE_PERF_USER_STACK_DUMP
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134 select HAVE_REGS_AND_STACK_ACCESS_API
135 select HAVE_SYSCALL_TRACEPOINTS
0c3619ea 136 select HAVE_UID16 if X86_32 || IA32_EMULATION
6471b825 137 select HAVE_UNSTABLE_SCHED_CLOCK
7c68af6e 138 select HAVE_USER_RETURN_NOTIFIER
c0185808 139 select IRQ_FORCED_THREADING
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140 select MODULES_USE_ELF_RELA if X86_64
141 select MODULES_USE_ELF_REL if X86_32
142 select OLD_SIGACTION if X86_32
143 select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION
144 select PERF_EVENTS
3195ef59 145 select RTC_LIB
6471b825 146 select SPARSE_IRQ
83fe27ea 147 select SRCU
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148 select SYSCTL_EXCEPTION_TRACE
149 select USER_STACKTRACE_SUPPORT
150 select VIRT_TO_BUS
151 select X86_DEV_DMA_OPS if X86_64
152 select X86_FEATURE_NAMES if PROC_FS
7d8330a5 153
ba7e4d13 154config INSTRUCTION_DECODER
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155 def_bool y
156 depends on KPROBES || PERF_EVENTS || UPROBES
ba7e4d13 157
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158config PERF_EVENTS_INTEL_UNCORE
159 def_bool y
ce5686d4 160 depends on PERF_EVENTS && CPU_SUP_INTEL && PCI
7fb0f1de 161
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162config OUTPUT_FORMAT
163 string
164 default "elf32-i386" if X86_32
165 default "elf64-x86-64" if X86_64
166
73531905 167config ARCH_DEFCONFIG
b9b39bfb 168 string
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SR
169 default "arch/x86/configs/i386_defconfig" if X86_32
170 default "arch/x86/configs/x86_64_defconfig" if X86_64
b9b39bfb 171
8d5fffb9 172config LOCKDEP_SUPPORT
3c2362e6 173 def_bool y
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SR
174
175config STACKTRACE_SUPPORT
3c2362e6 176 def_bool y
8d5fffb9 177
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178config HAVE_LATENCYTOP_SUPPORT
179 def_bool y
180
8d5fffb9 181config MMU
3c2362e6 182 def_bool y
8d5fffb9 183
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SR
184config SBUS
185 bool
186
3bc4e459 187config NEED_DMA_MAP_STATE
3120e25e 188 def_bool y
a6dfa128 189 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB
3bc4e459 190
18e98307 191config NEED_SG_DMA_LENGTH
4a14d84e 192 def_bool y
18e98307 193
8d5fffb9 194config GENERIC_ISA_DMA
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195 def_bool y
196 depends on ISA_DMA_API
8d5fffb9 197
8d5fffb9 198config GENERIC_BUG
3c2362e6 199 def_bool y
8d5fffb9 200 depends on BUG
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201 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
202
203config GENERIC_BUG_RELATIVE_POINTERS
204 bool
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205
206config GENERIC_HWEIGHT
3c2362e6 207 def_bool y
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208
209config ARCH_MAY_HAVE_PC_FDC
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210 def_bool y
211 depends on ISA_DMA_API
8d5fffb9 212
1032c0ba 213config RWSEM_XCHGADD_ALGORITHM
3120e25e 214 def_bool y
1032c0ba 215
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216config GENERIC_CALIBRATE_DELAY
217 def_bool y
218
9a0b8415 219config ARCH_HAS_CPU_RELAX
220 def_bool y
221
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222config ARCH_HAS_CACHE_LINE_SIZE
223 def_bool y
224
dd5af90a 225config HAVE_SETUP_PER_CPU_AREA
89c9c4c5 226 def_bool y
b32ef636 227
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228config NEED_PER_CPU_EMBED_FIRST_CHUNK
229 def_bool y
230
231config NEED_PER_CPU_PAGE_FIRST_CHUNK
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232 def_bool y
233
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234config ARCH_HIBERNATION_POSSIBLE
235 def_bool y
801e4062 236
f4cb5700
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237config ARCH_SUSPEND_POSSIBLE
238 def_bool y
f4cb5700 239
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240config ARCH_WANT_HUGE_PMD_SHARE
241 def_bool y
242
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243config ARCH_WANT_GENERAL_HUGETLB
244 def_bool y
245
8d5fffb9 246config ZONE_DMA32
e0fd24a3 247 def_bool y if X86_64
8d5fffb9 248
8d5fffb9 249config AUDIT_ARCH
e0fd24a3 250 def_bool y if X86_64
8d5fffb9 251
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252config ARCH_SUPPORTS_OPTIMIZED_INLINING
253 def_bool y
254
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255config ARCH_SUPPORTS_DEBUG_PAGEALLOC
256 def_bool y
257
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258config KASAN_SHADOW_OFFSET
259 hex
260 depends on KASAN
261 default 0xdffffc0000000000
262
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263config HAVE_INTEL_TXT
264 def_bool y
6ea30386 265 depends on INTEL_IOMMU && ACPI
69575d38 266
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SR
267config X86_32_SMP
268 def_bool y
269 depends on X86_32 && SMP
270
271config X86_64_SMP
272 def_bool y
273 depends on X86_64 && SMP
274
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275config X86_32_LAZY_GS
276 def_bool y
60a5317f 277 depends on X86_32 && !CC_STACKPROTECTOR
ccbeed3a 278
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279config ARCH_HWEIGHT_CFLAGS
280 string
281 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
282 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
283
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284config ARCH_SUPPORTS_UPROBES
285 def_bool y
286
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287config FIX_EARLYCON_MEM
288 def_bool y
289
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290config PGTABLE_LEVELS
291 int
292 default 4 if X86_64
293 default 3 if X86_PAE
294 default 2
295
506f1d07 296source "init/Kconfig"
dc52ddc0 297source "kernel/Kconfig.freezer"
8d5fffb9 298
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299menu "Processor type and features"
300
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301config ZONE_DMA
302 bool "DMA memory allocation support" if EXPERT
303 default y
304 help
305 DMA memory allocation support allows devices with less than 32-bit
306 addressing to allocate within the first 16MB of address space.
307 Disable if no such devices will be used.
308
309 If unsure, say Y.
310
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311config SMP
312 bool "Symmetric multi-processing support"
313 ---help---
314 This enables support for systems with more than one CPU. If you have
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315 a system with only one CPU, say N. If you have a system with more
316 than one CPU, say Y.
506f1d07 317
4a474157 318 If you say N here, the kernel will run on uni- and multiprocessor
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SR
319 machines, but will use only one CPU of a multiprocessor machine. If
320 you say Y here, the kernel will run on many, but not all,
4a474157 321 uniprocessor machines. On a uniprocessor machine, the kernel
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SR
322 will run faster if you say N here.
323
324 Note that if you say Y here and choose architecture "586" or
325 "Pentium" under "Processor family", the kernel will not work on 486
326 architectures. Similarly, multiprocessor kernels for the "PPro"
327 architecture may not work on all Pentium based boards.
328
329 People using multiprocessor machines who say Y here should also say
330 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
331 Management" code will be disabled if you say Y here.
332
395cf969 333 See also <file:Documentation/x86/i386/IO-APIC.txt>,
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SR
334 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
335 <http://www.tldp.org/docs.html#howto>.
336
337 If you don't know what to do here, say N.
338
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339config X86_FEATURE_NAMES
340 bool "Processor feature human-readable names" if EMBEDDED
341 default y
342 ---help---
343 This option compiles in a table of x86 feature bits and corresponding
344 names. This is required to support /proc/cpuinfo and a few kernel
345 messages. You can disable this to save space, at the expense of
346 making those few kernel messages show numeric feature bits instead.
347
348 If in doubt, say Y.
349
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YL
350config X86_X2APIC
351 bool "Support x2apic"
19e3d60d 352 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
06cd9a7d
YL
353 ---help---
354 This enables x2apic support on CPUs that have this feature.
355
356 This allows 32-bit apic IDs (so it can support very large systems),
357 and accesses the local apic via MSRs not via mmio.
358
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YL
359 If you don't know what to do here, say N.
360
6695c85b 361config X86_MPPARSE
6e87f9b7 362 bool "Enable MPS table" if ACPI || SFI
7a527688 363 default y
5ab74722 364 depends on X86_LOCAL_APIC
8f9ca475 365 ---help---
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YL
366 For old smp systems that do not have proper acpi support. Newer systems
367 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
6695c85b 368
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369config X86_BIGSMP
370 bool "Support for big SMP systems with more than 8 CPUs"
371 depends on X86_32 && SMP
8f9ca475 372 ---help---
26f7ef14 373 This option is needed for the systems that have more than 8 CPUs
506f1d07 374
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375config GOLDFISH
376 def_bool y
377 depends on X86_GOLDFISH
378
8425091f 379if X86_32
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RT
380config X86_EXTENDED_PLATFORM
381 bool "Support for extended (non-PC) x86 platforms"
382 default y
8f9ca475 383 ---help---
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384 If you disable this option then the kernel will only support
385 standard PC platforms. (which covers the vast majority of
386 systems out there.)
387
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388 If you enable this option then you'll be able to select support
389 for the following (non-PC) 32 bit x86 platforms:
cb7b8023 390 Goldfish (Android emulator)
8425091f 391 AMD Elan
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392 RDC R-321x SoC
393 SGI 320/540 (Visual Workstation)
83125a3a 394 STA2X11-based (e.g. Northville)
3f4110a4 395 Moorestown MID devices
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IM
396
397 If you have one of these systems, or if you want to build a
398 generic distribution kernel, say Y here - otherwise say N.
8425091f 399endif
06ac8346 400
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RT
401if X86_64
402config X86_EXTENDED_PLATFORM
403 bool "Support for extended (non-PC) x86 platforms"
404 default y
405 ---help---
406 If you disable this option then the kernel will only support
407 standard PC platforms. (which covers the vast majority of
408 systems out there.)
409
410 If you enable this option then you'll be able to select support
411 for the following (non-PC) 64 bit x86 platforms:
44b111b5 412 Numascale NumaChip
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RT
413 ScaleMP vSMP
414 SGI Ultraviolet
415
416 If you have one of these systems, or if you want to build a
417 generic distribution kernel, say Y here - otherwise say N.
418endif
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RT
419# This is an alphabetically sorted list of 64 bit extended platforms
420# Please maintain the alphabetic order if and when there are additions
44b111b5
SP
421config X86_NUMACHIP
422 bool "Numascale NumaChip"
423 depends on X86_64
424 depends on X86_EXTENDED_PLATFORM
425 depends on NUMA
426 depends on SMP
427 depends on X86_X2APIC
f9726bfd 428 depends on PCI_MMCONFIG
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SP
429 ---help---
430 Adds support for Numascale NumaChip large-SMP systems. Needed to
431 enable more than ~168 cores.
432 If you don't have one of these, you should say N here.
506f1d07 433
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RT
434config X86_VSMP
435 bool "ScaleMP vSMP"
6276a074 436 select HYPERVISOR_GUEST
c5c606d9
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437 select PARAVIRT
438 depends on X86_64 && PCI
439 depends on X86_EXTENDED_PLATFORM
ead91d4b 440 depends on SMP
8f9ca475 441 ---help---
c5c606d9
RT
442 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
443 supposed to run on these EM64T-based machines. Only choose this option
444 if you have one of these machines.
5e3a77e9 445
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NP
446config X86_UV
447 bool "SGI Ultraviolet"
448 depends on X86_64
c5c606d9 449 depends on X86_EXTENDED_PLATFORM
54c28d29 450 depends on NUMA
9d6c26e7 451 depends on X86_X2APIC
1222e564 452 depends on PCI
8f9ca475 453 ---help---
03b48632
NP
454 This option is needed in order to support SGI Ultraviolet systems.
455 If you don't have one of these, you should say N here.
456
c5c606d9
RT
457# Following is an alphabetically sorted list of 32 bit extended platforms
458# Please maintain the alphabetic order if and when there are additions
506f1d07 459
ddd70cf9
JN
460config X86_GOLDFISH
461 bool "Goldfish (Virtual Platform)"
cb7b8023 462 depends on X86_EXTENDED_PLATFORM
ddd70cf9
JN
463 ---help---
464 Enable support for the Goldfish virtual platform used primarily
465 for Android development. Unless you are building for the Android
466 Goldfish emulator say N here.
467
c751e17b
TG
468config X86_INTEL_CE
469 bool "CE4100 TV platform"
470 depends on PCI
471 depends on PCI_GODIRECT
6084a6e2 472 depends on X86_IO_APIC
c751e17b
TG
473 depends on X86_32
474 depends on X86_EXTENDED_PLATFORM
37bc9f50 475 select X86_REBOOTFIXUPS
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476 select OF
477 select OF_EARLY_FLATTREE
c751e17b
TG
478 ---help---
479 Select for the Intel CE media processor (CE4100) SOC.
480 This option compiles in support for the CE4100 SOC for settop
481 boxes and media devices.
482
4cb9b00f 483config X86_INTEL_MID
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AC
484 bool "Intel MID platform support"
485 depends on X86_32
486 depends on X86_EXTENDED_PLATFORM
edc6bc78 487 depends on X86_PLATFORM_DEVICES
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488 depends on PCI
489 depends on PCI_GOANY
490 depends on X86_IO_APIC
7c9c3a1e 491 select SFI
4cb9b00f 492 select I2C
7c9c3a1e 493 select DW_APB_TIMER
1ea7c673 494 select APB_TIMER
1ea7c673 495 select INTEL_SCU_IPC
15a713df 496 select MFD_INTEL_MSIC
1ea7c673 497 ---help---
4cb9b00f
DC
498 Select to build a kernel capable of supporting Intel MID (Mobile
499 Internet Device) platform systems which do not have the PCI legacy
500 interfaces. If you are building for a PC class system say N here.
1ea7c673 501
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DC
502 Intel MID platforms are based on an Intel processor and chipset which
503 consume less power than most of the x86 derivatives.
43605ef1 504
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BD
505config X86_INTEL_QUARK
506 bool "Intel Quark platform support"
507 depends on X86_32
508 depends on X86_EXTENDED_PLATFORM
509 depends on X86_PLATFORM_DEVICES
510 depends on X86_TSC
511 depends on PCI
512 depends on PCI_GOANY
513 depends on X86_IO_APIC
514 select IOSF_MBI
515 select INTEL_IMR
9ab6eb51 516 select COMMON_CLK
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BD
517 ---help---
518 Select to include support for Quark X1000 SoC.
519 Say Y here if you have a Quark based system such as the Arduino
520 compatible Intel Galileo.
521
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MW
522config X86_INTEL_LPSS
523 bool "Intel Low Power Subsystem Support"
524 depends on ACPI
525 select COMMON_CLK
0f531431 526 select PINCTRL
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MW
527 ---help---
528 Select to build support for Intel Low Power Subsystem such as
529 found on Intel Lynxpoint PCH. Selecting this option enables
0f531431
MN
530 things like clock tree (common clock framework) and pincontrol
531 which are needed by the LPSS peripheral drivers.
3d48aab1 532
92082a88
KX
533config X86_AMD_PLATFORM_DEVICE
534 bool "AMD ACPI2Platform devices support"
535 depends on ACPI
536 select COMMON_CLK
537 select PINCTRL
538 ---help---
539 Select to interpret AMD specific ACPI device to platform device
540 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
541 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
542 implemented under PINCTRL subsystem.
543
ced3ce76
DB
544config IOSF_MBI
545 tristate "Intel SoC IOSF Sideband support for SoC platforms"
546 depends on PCI
547 ---help---
548 This option enables sideband register access support for Intel SoC
549 platforms. On these platforms the IOSF sideband is used in lieu of
550 MSR's for some register accesses, mostly but not limited to thermal
551 and power. Drivers may query the availability of this device to
552 determine if they need the sideband in order to work on these
553 platforms. The sideband is available on the following SoC products.
554 This list is not meant to be exclusive.
555 - BayTrail
556 - Braswell
557 - Quark
558
559 You should say Y if you are running a kernel on one of these SoC's.
560
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DB
561config IOSF_MBI_DEBUG
562 bool "Enable IOSF sideband access through debugfs"
563 depends on IOSF_MBI && DEBUG_FS
564 ---help---
565 Select this option to expose the IOSF sideband access registers (MCR,
566 MDR, MCRX) through debugfs to write and read register information from
567 different units on the SoC. This is most useful for obtaining device
568 state information for debug and analysis. As this is a general access
569 mechanism, users of this option would have specific knowledge of the
570 device they want to access.
571
572 If you don't require the option or are in doubt, say N.
573
c5c606d9
RT
574config X86_RDC321X
575 bool "RDC R-321x SoC"
506f1d07 576 depends on X86_32
c5c606d9
RT
577 depends on X86_EXTENDED_PLATFORM
578 select M486
579 select X86_REBOOTFIXUPS
580 ---help---
581 This option is needed for RDC R-321x system-on-chip, also known
582 as R-8610-(G).
583 If you don't have one of these chips, you should say N here.
584
e0c7ae37 585config X86_32_NON_STANDARD
9c398017
IM
586 bool "Support non-standard 32-bit SMP architectures"
587 depends on X86_32 && SMP
c5c606d9 588 depends on X86_EXTENDED_PLATFORM
8f9ca475 589 ---help---
b5660ba7
PA
590 This option compiles in the bigsmp and STA2X11 default
591 subarchitectures. It is intended for a generic binary
592 kernel. If you select them all, kernel will probe it one by
593 one and will fallback to default.
d49c4288 594
c5c606d9 595# Alphabetically sorted list of Non standard 32 bit platforms
d49c4288 596
d949f36f 597config X86_SUPPORTS_MEMORY_FAILURE
6fc108a0 598 def_bool y
d949f36f
LT
599 # MCE code calls memory_failure():
600 depends on X86_MCE
601 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
d949f36f
LT
602 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
603 depends on X86_64 || !SPARSEMEM
604 select ARCH_SUPPORTS_MEMORY_FAILURE
d949f36f 605
83125a3a
AR
606config STA2X11
607 bool "STA2X11 Companion Chip Support"
608 depends on X86_32_NON_STANDARD && PCI
609 select X86_DEV_DMA_OPS
610 select X86_DMA_REMAP
611 select SWIOTLB
612 select MFD_STA2X11
613 select ARCH_REQUIRE_GPIOLIB
614 default n
615 ---help---
616 This adds support for boards based on the STA2X11 IO-Hub,
617 a.k.a. "ConneXt". The chip is used in place of the standard
618 PC chipset, so all "standard" peripherals are missing. If this
619 option is selected the kernel will still be able to boot on
620 standard PC machines.
621
82148d1d
S
622config X86_32_IRIS
623 tristate "Eurobraille/Iris poweroff module"
624 depends on X86_32
625 ---help---
626 The Iris machines from EuroBraille do not have APM or ACPI support
627 to shut themselves down properly. A special I/O sequence is
628 needed to do so, which is what this module does at
629 kernel shutdown.
630
631 This is only for Iris machines from EuroBraille.
632
633 If unused, say N.
634
ae1e9130 635config SCHED_OMIT_FRAME_POINTER
3c2362e6
HH
636 def_bool y
637 prompt "Single-depth WCHAN output"
a87d0914 638 depends on X86
8f9ca475 639 ---help---
506f1d07
SR
640 Calculate simpler /proc/<PID>/wchan values. If this option
641 is disabled then wchan values will recurse back to the
642 caller function. This provides more accurate wchan values,
643 at the expense of slightly more scheduling overhead.
644
645 If in doubt, say "Y".
646
6276a074
BP
647menuconfig HYPERVISOR_GUEST
648 bool "Linux guest support"
8f9ca475 649 ---help---
6276a074
BP
650 Say Y here to enable options for running Linux under various hyper-
651 visors. This option enables basic hypervisor detection and platform
652 setup.
506f1d07 653
6276a074
BP
654 If you say N, all options in this submenu will be skipped and
655 disabled, and Linux guest support won't be built in.
506f1d07 656
6276a074 657if HYPERVISOR_GUEST
506f1d07 658
e61bd94a
EPH
659config PARAVIRT
660 bool "Enable paravirtualization code"
8f9ca475 661 ---help---
e61bd94a
EPH
662 This changes the kernel so it can modify itself when it is run
663 under a hypervisor, potentially improving performance significantly
664 over full virtualization. However, when run without a hypervisor
665 the kernel is theoretically slower and slightly larger.
666
6276a074
BP
667config PARAVIRT_DEBUG
668 bool "paravirt-ops debugging"
669 depends on PARAVIRT && DEBUG_KERNEL
670 ---help---
671 Enable to debug paravirt_ops internals. Specifically, BUG if
672 a paravirt_op is missing when it is called.
673
b4ecc126
JF
674config PARAVIRT_SPINLOCKS
675 bool "Paravirtualization layer for spinlocks"
6ea30386 676 depends on PARAVIRT && SMP
62c7a1e9 677 select UNINLINE_SPIN_UNLOCK if !QUEUED_SPINLOCKS
b4ecc126
JF
678 ---help---
679 Paravirtualized spinlocks allow a pvops backend to replace the
680 spinlock implementation with something virtualization-friendly
681 (for example, block the virtual CPU rather than spinning).
682
4c4e4f61
R
683 It has a minimal impact on native kernels and gives a nice performance
684 benefit on paravirtualized KVM / Xen kernels.
b4ecc126 685
4c4e4f61 686 If you are unsure how to answer this question, answer Y.
b4ecc126 687
6276a074 688source "arch/x86/xen/Kconfig"
7af192c9 689
6276a074
BP
690config KVM_GUEST
691 bool "KVM Guest support (including kvmclock)"
692 depends on PARAVIRT
693 select PARAVIRT_CLOCK
694 default y
8f9ca475 695 ---help---
6276a074
BP
696 This option enables various optimizations for running under the KVM
697 hypervisor. It includes a paravirtualized clock, so that instead
698 of relying on a PIT (or probably other) emulation by the
699 underlying device model, the host provides the guest with
700 timing infrastructure such as time of day, and system time
506f1d07 701
1e20eb85
SV
702config KVM_DEBUG_FS
703 bool "Enable debug information for KVM Guests in debugfs"
704 depends on KVM_GUEST && DEBUG_FS
705 default n
706 ---help---
707 This option enables collection of various statistics for KVM guest.
708 Statistics are displayed in debugfs filesystem. Enabling this option
709 may incur significant overhead.
710
6276a074
BP
711source "arch/x86/lguest/Kconfig"
712
713config PARAVIRT_TIME_ACCOUNTING
714 bool "Paravirtual steal time accounting"
715 depends on PARAVIRT
716 default n
8f9ca475 717 ---help---
6276a074
BP
718 Select this option to enable fine granularity task steal time
719 accounting. Time spent executing other tasks in parallel with
720 the current vCPU is discounted from the vCPU power. To account for
721 that, there can be a small performance impact.
722
723 If in doubt, say N here.
724
725config PARAVIRT_CLOCK
726 bool
97349135 727
6276a074 728endif #HYPERVISOR_GUEST
97349135 729
08677214 730config NO_BOOTMEM
774ea0bc 731 def_bool y
08677214 732
506f1d07
SR
733source "arch/x86/Kconfig.cpu"
734
735config HPET_TIMER
3c2362e6 736 def_bool X86_64
506f1d07 737 prompt "HPET Timer Support" if X86_32
8f9ca475
IM
738 ---help---
739 Use the IA-PC HPET (High Precision Event Timer) to manage
740 time in preference to the PIT and RTC, if a HPET is
741 present.
742 HPET is the next generation timer replacing legacy 8254s.
743 The HPET provides a stable time base on SMP
744 systems, unlike the TSC, but it is more expensive to access,
745 as it is off-chip. You can find the HPET spec at
746 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
506f1d07 747
8f9ca475
IM
748 You can safely choose Y here. However, HPET will only be
749 activated if the platform and the BIOS support this feature.
750 Otherwise the 8254 will be used for timing services.
506f1d07 751
8f9ca475 752 Choose N to continue using the legacy 8254 timer.
506f1d07
SR
753
754config HPET_EMULATE_RTC
3c2362e6 755 def_bool y
9d8af78b 756 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
506f1d07 757
bb24c471 758config APB_TIMER
933b9463
AC
759 def_bool y if X86_INTEL_MID
760 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
06c3df49 761 select DW_APB_TIMER
a0c3832a 762 depends on X86_INTEL_MID && SFI
bb24c471
JP
763 help
764 APB timer is the replacement for 8254, HPET on X86 MID platforms.
765 The APBT provides a stable time base on SMP
766 systems, unlike the TSC, but it is more expensive to access,
767 as it is off-chip. APB timers are always running regardless of CPU
768 C states, they are used as per CPU clockevent device when possible.
769
6a108a14 770# Mark as expert because too many people got it wrong.
506f1d07 771# The code disables itself when not needed.
7ae9392c
TP
772config DMI
773 default y
cf074402 774 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
6a108a14 775 bool "Enable DMI scanning" if EXPERT
8f9ca475 776 ---help---
7ae9392c
TP
777 Enabled scanning of DMI to identify machine quirks. Say Y
778 here unless you have verified that your setup is not
779 affected by entries in the DMI blacklist. Required by PNP
780 BIOS code.
781
506f1d07 782config GART_IOMMU
38901f1c 783 bool "Old AMD GART IOMMU support"
506f1d07 784 select SWIOTLB
23ac4ae8 785 depends on X86_64 && PCI && AMD_NB
8f9ca475 786 ---help---
ced3c42c
IM
787 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
788 GART based hardware IOMMUs.
789
790 The GART supports full DMA access for devices with 32-bit access
791 limitations, on systems with more than 3 GB. This is usually needed
792 for USB, sound, many IDE/SATA chipsets and some other devices.
793
794 Newer systems typically have a modern AMD IOMMU, supported via
795 the CONFIG_AMD_IOMMU=y config option.
796
797 In normal configurations this driver is only active when needed:
798 there's more than 3 GB of memory and the system contains a
799 32-bit limited device.
800
801 If unsure, say Y.
506f1d07
SR
802
803config CALGARY_IOMMU
804 bool "IBM Calgary IOMMU support"
805 select SWIOTLB
6ea30386 806 depends on X86_64 && PCI
8f9ca475 807 ---help---
506f1d07
SR
808 Support for hardware IOMMUs in IBM's xSeries x366 and x460
809 systems. Needed to run systems with more than 3GB of memory
810 properly with 32-bit PCI devices that do not support DAC
811 (Double Address Cycle). Calgary also supports bus level
812 isolation, where all DMAs pass through the IOMMU. This
813 prevents them from going anywhere except their intended
814 destination. This catches hard-to-find kernel bugs and
815 mis-behaving drivers and devices that do not use the DMA-API
816 properly to set up their DMA buffers. The IOMMU can be
817 turned off at boot time with the iommu=off parameter.
818 Normally the kernel will make the right choice by itself.
819 If unsure, say Y.
820
821config CALGARY_IOMMU_ENABLED_BY_DEFAULT
3c2362e6
HH
822 def_bool y
823 prompt "Should Calgary be enabled by default?"
506f1d07 824 depends on CALGARY_IOMMU
8f9ca475 825 ---help---
506f1d07
SR
826 Should Calgary be enabled by default? if you choose 'y', Calgary
827 will be used (if it exists). If you choose 'n', Calgary will not be
828 used even if it exists. If you choose 'n' and would like to use
829 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
830 If unsure, say Y.
831
832# need this always selected by IOMMU for the VIA workaround
833config SWIOTLB
a1afd01c 834 def_bool y if X86_64
8f9ca475 835 ---help---
506f1d07 836 Support for software bounce buffers used on x86-64 systems
4454d327
JM
837 which don't have a hardware IOMMU. Using this PCI devices
838 which can only access 32-bits of memory can be used on systems
839 with more than 3 GB of memory.
840 If unsure, say Y.
506f1d07 841
a8522509 842config IOMMU_HELPER
3120e25e
JB
843 def_bool y
844 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
d25e26b6 845
1184dc2f 846config MAXSMP
ddb0c5a6 847 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
6ea30386 848 depends on X86_64 && SMP && DEBUG_KERNEL
36f5101a 849 select CPUMASK_OFFSTACK
8f9ca475 850 ---help---
ddb0c5a6 851 Enable maximum number of CPUS and NUMA Nodes for this architecture.
1184dc2f 852 If unsure, say N.
506f1d07
SR
853
854config NR_CPUS
36f5101a 855 int "Maximum number of CPUs" if SMP && !MAXSMP
2a3313f4 856 range 2 8 if SMP && X86_32 && !X86_BIGSMP
bb61ccc7 857 range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK
b53b5eda 858 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
78637a97 859 default "1" if !SMP
b53b5eda 860 default "8192" if MAXSMP
b5660ba7 861 default "32" if SMP && X86_BIGSMP
c5c19941
KS
862 default "8" if SMP && X86_32
863 default "64" if SMP
8f9ca475 864 ---help---
506f1d07 865 This allows you to specify the maximum number of CPUs which this
bb61ccc7 866 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
cad14bb9 867 supported value is 8192, otherwise the maximum value is 512. The
506f1d07
SR
868 minimum value which makes sense is 2.
869
870 This is purely to save memory - each supported CPU adds
871 approximately eight kilobytes to the kernel image.
872
873config SCHED_SMT
874 bool "SMT (Hyperthreading) scheduler support"
c8e56d20 875 depends on SMP
8f9ca475 876 ---help---
506f1d07
SR
877 SMT scheduler support improves the CPU scheduler's decision making
878 when dealing with Intel Pentium 4 chips with HyperThreading at a
879 cost of slightly increased overhead in some places. If unsure say
880 N here.
881
882config SCHED_MC
3c2362e6
HH
883 def_bool y
884 prompt "Multi-core scheduler support"
c8e56d20 885 depends on SMP
8f9ca475 886 ---help---
506f1d07
SR
887 Multi-core scheduler support improves the CPU scheduler's decision
888 making when dealing with multi-core CPU chips at a cost of slightly
889 increased overhead in some places. If unsure say N here.
890
891source "kernel/Kconfig.preempt"
892
30b8b006
TG
893config UP_LATE_INIT
894 def_bool y
ba360f88 895 depends on !SMP && X86_LOCAL_APIC
30b8b006 896
506f1d07 897config X86_UP_APIC
50849eef
JB
898 bool "Local APIC support on uniprocessors" if !PCI_MSI
899 default PCI_MSI
38a1dfda 900 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
8f9ca475 901 ---help---
506f1d07
SR
902 A local APIC (Advanced Programmable Interrupt Controller) is an
903 integrated interrupt controller in the CPU. If you have a single-CPU
904 system which has a processor with a local APIC, you can say Y here to
905 enable and use it. If you say Y here even though your machine doesn't
906 have a local APIC, then the kernel will still run with no slowdown at
907 all. The local APIC supports CPU-generated self-interrupts (timer,
908 performance counters), and the NMI watchdog which detects hard
909 lockups.
910
911config X86_UP_IOAPIC
912 bool "IO-APIC support on uniprocessors"
913 depends on X86_UP_APIC
8f9ca475 914 ---help---
506f1d07
SR
915 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
916 SMP-capable replacement for PC-style interrupt controllers. Most
917 SMP systems and many recent uniprocessor systems have one.
918
919 If you have a single-CPU system with an IO-APIC, you can say Y here
920 to use it. If you say Y here even though your machine doesn't have
921 an IO-APIC, then the kernel will still run with no slowdown at all.
922
923config X86_LOCAL_APIC
3c2362e6 924 def_bool y
0dbc6078 925 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
b5dc8e6c 926 select IRQ_DOMAIN_HIERARCHY
52f518a3 927 select PCI_MSI_IRQ_DOMAIN if PCI_MSI
506f1d07
SR
928
929config X86_IO_APIC
b1da1e71
JB
930 def_bool y
931 depends on X86_LOCAL_APIC || X86_UP_IOAPIC
506f1d07 932
41b9eb26
SA
933config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
934 bool "Reroute for broken boot IRQs"
41b9eb26 935 depends on X86_IO_APIC
8f9ca475 936 ---help---
41b9eb26
SA
937 This option enables a workaround that fixes a source of
938 spurious interrupts. This is recommended when threaded
939 interrupt handling is used on systems where the generation of
940 superfluous "boot interrupts" cannot be disabled.
941
942 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
943 entry in the chipset's IO-APIC is masked (as, e.g. the RT
944 kernel does during interrupt handling). On chipsets where this
945 boot IRQ generation cannot be disabled, this workaround keeps
946 the original IRQ line masked so that only the equivalent "boot
947 IRQ" is delivered to the CPUs. The workaround also tells the
948 kernel to set up the IRQ handler on the boot IRQ line. In this
949 way only one interrupt is delivered to the kernel. Otherwise
950 the spurious second interrupt may cause the kernel to bring
951 down (vital) interrupt lines.
952
953 Only affects "broken" chipsets. Interrupt sharing may be
954 increased on these systems.
955
506f1d07 956config X86_MCE
bab9bc65 957 bool "Machine Check / overheating reporting"
e57dbaf7 958 default y
506f1d07 959 ---help---
bab9bc65
AK
960 Machine Check support allows the processor to notify the
961 kernel if it detects a problem (e.g. overheating, data corruption).
506f1d07 962 The action the kernel takes depends on the severity of the problem,
bab9bc65 963 ranging from warning messages to halting the machine.
4efc0670 964
506f1d07 965config X86_MCE_INTEL
3c2362e6
HH
966 def_bool y
967 prompt "Intel MCE features"
c1ebf835 968 depends on X86_MCE && X86_LOCAL_APIC
8f9ca475 969 ---help---
506f1d07
SR
970 Additional support for intel specific MCE features such as
971 the thermal monitor.
972
973config X86_MCE_AMD
3c2362e6
HH
974 def_bool y
975 prompt "AMD MCE features"
c1ebf835 976 depends on X86_MCE && X86_LOCAL_APIC
8f9ca475 977 ---help---
506f1d07
SR
978 Additional support for AMD specific MCE features such as
979 the DRAM Error Threshold.
980
4efc0670 981config X86_ANCIENT_MCE
6fc108a0 982 bool "Support for old Pentium 5 / WinChip machine checks"
c31d9633 983 depends on X86_32 && X86_MCE
cd13adcc
HS
984 ---help---
985 Include support for machine check handling on old Pentium 5 or WinChip
5065a706 986 systems. These typically need to be enabled explicitly on the command
cd13adcc 987 line.
4efc0670 988
b2762686
AK
989config X86_MCE_THRESHOLD
990 depends on X86_MCE_AMD || X86_MCE_INTEL
6fc108a0 991 def_bool y
b2762686 992
ea149b36 993config X86_MCE_INJECT
c1ebf835 994 depends on X86_MCE
ea149b36
AK
995 tristate "Machine check injector support"
996 ---help---
997 Provide support for injecting machine checks for testing purposes.
998 If you don't know what a machine check is and you don't do kernel
999 QA it is safe to say n.
1000
4efc0670
AK
1001config X86_THERMAL_VECTOR
1002 def_bool y
5bb38adc 1003 depends on X86_MCE_INTEL
4efc0670 1004
5aef51c3
AL
1005config X86_LEGACY_VM86
1006 bool "Legacy VM86 support (obsolete)"
1007 default n
506f1d07 1008 depends on X86_32
8f9ca475 1009 ---help---
5aef51c3
AL
1010 This option allows user programs to put the CPU into V8086
1011 mode, which is an 80286-era approximation of 16-bit real mode.
1012
1013 Some very old versions of X and/or vbetool require this option
1014 for user mode setting. Similarly, DOSEMU will use it if
1015 available to accelerate real mode DOS programs. However, any
1016 recent version of DOSEMU, X, or vbetool should be fully
1017 functional even without kernel VM86 support, as they will all
1018 fall back to (pretty well performing) software emulation.
1019
1020 Anything that works on a 64-bit kernel is unlikely to need
1021 this option, as 64-bit kernels don't, and can't, support V8086
1022 mode. This option is also unrelated to 16-bit protected mode
1023 and is not needed to run most 16-bit programs under Wine.
1024
1025 Enabling this option adds considerable attack surface to the
1026 kernel and slows down system calls and exception handling.
1027
1028 Unless you use very old userspace or need the last drop of
1029 performance in your real mode DOS games and can't use KVM,
1030 say N here.
1031
1032config VM86
1033 bool
1034 default X86_LEGACY_VM86
34273f41
PA
1035
1036config X86_16BIT
1037 bool "Enable support for 16-bit segments" if EXPERT
1038 default y
1039 ---help---
1040 This option is required by programs like Wine to run 16-bit
1041 protected mode legacy code on x86 processors. Disabling
1042 this option saves about 300 bytes on i386, or around 6K text
1043 plus 16K runtime memory on x86-64,
1044
1045config X86_ESPFIX32
1046 def_bool y
1047 depends on X86_16BIT && X86_32
506f1d07 1048
197725de
PA
1049config X86_ESPFIX64
1050 def_bool y
34273f41 1051 depends on X86_16BIT && X86_64
506f1d07 1052
1ad83c85
AL
1053config X86_VSYSCALL_EMULATION
1054 bool "Enable vsyscall emulation" if EXPERT
1055 default y
1056 depends on X86_64
1057 ---help---
1058 This enables emulation of the legacy vsyscall page. Disabling
1059 it is roughly equivalent to booting with vsyscall=none, except
1060 that it will also disable the helpful warning if a program
1061 tries to use a vsyscall. With this option set to N, offending
1062 programs will just segfault, citing addresses of the form
1063 0xffffffffff600?00.
1064
1065 This option is required by many programs built before 2013, and
1066 care should be used even with newer programs if set to N.
1067
1068 Disabling this option saves about 7K of kernel size and
1069 possibly 4K of additional runtime pagetable memory.
1070
506f1d07
SR
1071config TOSHIBA
1072 tristate "Toshiba Laptop support"
1073 depends on X86_32
1074 ---help---
1075 This adds a driver to safely access the System Management Mode of
1076 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1077 not work on models with a Phoenix BIOS. The System Management Mode
1078 is used to set the BIOS and power saving options on Toshiba portables.
1079
1080 For information on utilities to make use of this driver see the
1081 Toshiba Linux utilities web site at:
1082 <http://www.buzzard.org.uk/toshiba/>.
1083
1084 Say Y if you intend to run this kernel on a Toshiba portable.
1085 Say N otherwise.
1086
1087config I8K
039ae585 1088 tristate "Dell i8k legacy laptop support"
949a9d70 1089 select HWMON
039ae585 1090 select SENSORS_DELL_SMM
506f1d07 1091 ---help---
039ae585
PR
1092 This option enables legacy /proc/i8k userspace interface in hwmon
1093 dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1094 temperature and allows controlling fan speeds of Dell laptops via
1095 System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1096 it reports also power and hotkey status. For fan speed control is
1097 needed userspace package i8kutils.
1098
1099 Say Y if you intend to run this kernel on old Dell laptops or want to
1100 use userspace package i8kutils.
506f1d07
SR
1101 Say N otherwise.
1102
1103config X86_REBOOTFIXUPS
9ba16087
JB
1104 bool "Enable X86 board specific fixups for reboot"
1105 depends on X86_32
506f1d07
SR
1106 ---help---
1107 This enables chipset and/or board specific fixups to be done
1108 in order to get reboot to work correctly. This is only needed on
1109 some combinations of hardware and BIOS. The symptom, for which
1110 this config is intended, is when reboot ends with a stalled/hung
1111 system.
1112
1113 Currently, the only fixup is for the Geode machines using
5e3a77e9 1114 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
506f1d07
SR
1115
1116 Say Y if you want to enable the fixup. Currently, it's safe to
1117 enable this option even if you don't need it.
1118 Say N otherwise.
1119
1120config MICROCODE
e43f6e67 1121 tristate "CPU microcode loading support"
80030e3d 1122 depends on CPU_SUP_AMD || CPU_SUP_INTEL
506f1d07
SR
1123 select FW_LOADER
1124 ---help---
e43f6e67 1125
506f1d07 1126 If you say Y here, you will be able to update the microcode on
80cc9f10 1127 certain Intel and AMD processors. The Intel support is for the
e43f6e67
BP
1128 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4,
1129 Xeon etc. The AMD support is for families 0x10 and later. You will
1130 obviously need the actual microcode binary data itself which is not
1131 shipped with the Linux kernel.
506f1d07 1132
8d86f390
PO
1133 This option selects the general module only, you need to select
1134 at least one vendor specific module as well.
506f1d07 1135
e43f6e67
BP
1136 To compile this driver as a module, choose M here: the module
1137 will be called microcode.
506f1d07 1138
8d86f390 1139config MICROCODE_INTEL
e43f6e67 1140 bool "Intel microcode loading support"
8f9ca475
IM
1141 depends on MICROCODE
1142 default MICROCODE
1143 select FW_LOADER
1144 ---help---
1145 This options enables microcode patch loading support for Intel
1146 processors.
1147
b8989db9
A
1148 For the current Intel microcode data package go to
1149 <https://downloadcenter.intel.com> and search for
1150 'Linux Processor Microcode Data File'.
8d86f390 1151
80cc9f10 1152config MICROCODE_AMD
e43f6e67 1153 bool "AMD microcode loading support"
8f9ca475
IM
1154 depends on MICROCODE
1155 select FW_LOADER
1156 ---help---
1157 If you select this option, microcode patch loading support for AMD
1158 processors will be enabled.
80cc9f10 1159
8f9ca475 1160config MICROCODE_OLD_INTERFACE
3c2362e6 1161 def_bool y
506f1d07 1162 depends on MICROCODE
506f1d07 1163
da76f64e 1164config MICROCODE_INTEL_EARLY
e0fd24a3 1165 bool
757885e9
JS
1166
1167config MICROCODE_AMD_EARLY
e0fd24a3 1168 bool
757885e9
JS
1169
1170config MICROCODE_EARLY
da76f64e 1171 bool "Early load microcode"
6b3389ac 1172 depends on MICROCODE=y && BLK_DEV_INITRD
757885e9
JS
1173 select MICROCODE_INTEL_EARLY if MICROCODE_INTEL
1174 select MICROCODE_AMD_EARLY if MICROCODE_AMD
da76f64e
FY
1175 default y
1176 help
1177 This option provides functionality to read additional microcode data
1178 at the beginning of initrd image. The data tells kernel to load
1179 microcode to CPU's as early as possible. No functional change if no
1180 microcode data is glued to the initrd, therefore it's safe to say Y.
1181
506f1d07
SR
1182config X86_MSR
1183 tristate "/dev/cpu/*/msr - Model-specific register support"
8f9ca475 1184 ---help---
506f1d07
SR
1185 This device gives privileged processes access to the x86
1186 Model-Specific Registers (MSRs). It is a character device with
1187 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1188 MSR accesses are directed to a specific CPU on multi-processor
1189 systems.
1190
1191config X86_CPUID
1192 tristate "/dev/cpu/*/cpuid - CPU information support"
8f9ca475 1193 ---help---
506f1d07
SR
1194 This device gives processes access to the x86 CPUID instruction to
1195 be executed on a specific processor. It is a character device
1196 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1197 /dev/cpu/31/cpuid.
1198
1199choice
1200 prompt "High Memory Support"
6fc108a0 1201 default HIGHMEM4G
506f1d07
SR
1202 depends on X86_32
1203
1204config NOHIGHMEM
1205 bool "off"
506f1d07
SR
1206 ---help---
1207 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1208 However, the address space of 32-bit x86 processors is only 4
1209 Gigabytes large. That means that, if you have a large amount of
1210 physical memory, not all of it can be "permanently mapped" by the
1211 kernel. The physical memory that's not permanently mapped is called
1212 "high memory".
1213
1214 If you are compiling a kernel which will never run on a machine with
1215 more than 1 Gigabyte total physical RAM, answer "off" here (default
1216 choice and suitable for most users). This will result in a "3GB/1GB"
1217 split: 3GB are mapped so that each process sees a 3GB virtual memory
1218 space and the remaining part of the 4GB virtual memory space is used
1219 by the kernel to permanently map as much physical memory as
1220 possible.
1221
1222 If the machine has between 1 and 4 Gigabytes physical RAM, then
1223 answer "4GB" here.
1224
1225 If more than 4 Gigabytes is used then answer "64GB" here. This
1226 selection turns Intel PAE (Physical Address Extension) mode on.
1227 PAE implements 3-level paging on IA32 processors. PAE is fully
1228 supported by Linux, PAE mode is implemented on all recent Intel
1229 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1230 then the kernel will not boot on CPUs that don't support PAE!
1231
1232 The actual amount of total physical memory will either be
1233 auto detected or can be forced by using a kernel command line option
1234 such as "mem=256M". (Try "man bootparam" or see the documentation of
1235 your boot loader (lilo or loadlin) about how to pass options to the
1236 kernel at boot time.)
1237
1238 If unsure, say "off".
1239
1240config HIGHMEM4G
1241 bool "4GB"
8f9ca475 1242 ---help---
506f1d07
SR
1243 Select this if you have a 32-bit processor and between 1 and 4
1244 gigabytes of physical RAM.
1245
1246config HIGHMEM64G
1247 bool "64GB"
eb068e78 1248 depends on !M486
506f1d07 1249 select X86_PAE
8f9ca475 1250 ---help---
506f1d07
SR
1251 Select this if you have a 32-bit processor and more than 4
1252 gigabytes of physical RAM.
1253
1254endchoice
1255
1256choice
6a108a14 1257 prompt "Memory split" if EXPERT
506f1d07
SR
1258 default VMSPLIT_3G
1259 depends on X86_32
8f9ca475 1260 ---help---
506f1d07
SR
1261 Select the desired split between kernel and user memory.
1262
1263 If the address range available to the kernel is less than the
1264 physical memory installed, the remaining memory will be available
1265 as "high memory". Accessing high memory is a little more costly
1266 than low memory, as it needs to be mapped into the kernel first.
1267 Note that increasing the kernel address space limits the range
1268 available to user programs, making the address space there
1269 tighter. Selecting anything other than the default 3G/1G split
1270 will also likely make your kernel incompatible with binary-only
1271 kernel modules.
1272
1273 If you are not absolutely sure what you are doing, leave this
1274 option alone!
1275
1276 config VMSPLIT_3G
1277 bool "3G/1G user/kernel split"
1278 config VMSPLIT_3G_OPT
1279 depends on !X86_PAE
1280 bool "3G/1G user/kernel split (for full 1G low memory)"
1281 config VMSPLIT_2G
1282 bool "2G/2G user/kernel split"
1283 config VMSPLIT_2G_OPT
1284 depends on !X86_PAE
1285 bool "2G/2G user/kernel split (for full 2G low memory)"
1286 config VMSPLIT_1G
1287 bool "1G/3G user/kernel split"
1288endchoice
1289
1290config PAGE_OFFSET
1291 hex
1292 default 0xB0000000 if VMSPLIT_3G_OPT
1293 default 0x80000000 if VMSPLIT_2G
1294 default 0x78000000 if VMSPLIT_2G_OPT
1295 default 0x40000000 if VMSPLIT_1G
1296 default 0xC0000000
1297 depends on X86_32
1298
1299config HIGHMEM
3c2362e6 1300 def_bool y
506f1d07 1301 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
506f1d07
SR
1302
1303config X86_PAE
9ba16087 1304 bool "PAE (Physical Address Extension) Support"
506f1d07 1305 depends on X86_32 && !HIGHMEM4G
8f9ca475 1306 ---help---
506f1d07
SR
1307 PAE is required for NX support, and furthermore enables
1308 larger swapspace support for non-overcommit purposes. It
1309 has the cost of more pagetable lookup overhead, and also
1310 consumes more pagetable space per process.
1311
600715dc 1312config ARCH_PHYS_ADDR_T_64BIT
3120e25e
JB
1313 def_bool y
1314 depends on X86_64 || X86_PAE
600715dc 1315
66f2b061 1316config ARCH_DMA_ADDR_T_64BIT
3120e25e
JB
1317 def_bool y
1318 depends on X86_64 || HIGHMEM64G
66f2b061 1319
10971ab2 1320config X86_DIRECT_GBPAGES
e5008abe
LR
1321 def_bool y
1322 depends on X86_64 && !DEBUG_PAGEALLOC && !KMEMCHECK
8f9ca475 1323 ---help---
10971ab2
IM
1324 Certain kernel features effectively disable kernel
1325 linear 1 GB mappings (even if the CPU otherwise
1326 supports them), so don't confuse the user by printing
1327 that we have them enabled.
9e899816 1328
506f1d07
SR
1329# Common NUMA Features
1330config NUMA
fd51b2d7 1331 bool "Numa Memory Allocation and Scheduler Support"
506f1d07 1332 depends on SMP
b5660ba7
PA
1333 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1334 default y if X86_BIGSMP
8f9ca475 1335 ---help---
506f1d07 1336 Enable NUMA (Non Uniform Memory Access) support.
fd51b2d7 1337
506f1d07
SR
1338 The kernel will try to allocate memory used by a CPU on the
1339 local memory controller of the CPU and add some more
1340 NUMA awareness to the kernel.
1341
c280ea5e 1342 For 64-bit this is recommended if the system is Intel Core i7
fd51b2d7
KM
1343 (or later), AMD Opteron, or EM64T NUMA.
1344
b5660ba7 1345 For 32-bit this is only needed if you boot a 32-bit
7cf6c945 1346 kernel on a 64-bit NUMA platform.
fd51b2d7
KM
1347
1348 Otherwise, you should say N.
506f1d07 1349
eec1d4fa 1350config AMD_NUMA
3c2362e6
HH
1351 def_bool y
1352 prompt "Old style AMD Opteron NUMA detection"
5da0ef9a 1353 depends on X86_64 && NUMA && PCI
8f9ca475 1354 ---help---
eec1d4fa
HR
1355 Enable AMD NUMA node topology detection. You should say Y here if
1356 you have a multi processor AMD system. This uses an old method to
1357 read the NUMA configuration directly from the builtin Northbridge
1358 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1359 which also takes priority if both are compiled in.
506f1d07
SR
1360
1361config X86_64_ACPI_NUMA
3c2362e6
HH
1362 def_bool y
1363 prompt "ACPI NUMA detection"
506f1d07
SR
1364 depends on X86_64 && NUMA && ACPI && PCI
1365 select ACPI_NUMA
8f9ca475 1366 ---help---
506f1d07
SR
1367 Enable ACPI SRAT based node topology detection.
1368
6ec6e0d9
SS
1369# Some NUMA nodes have memory ranges that span
1370# other nodes. Even though a pfn is valid and
1371# between a node's start and end pfns, it may not
1372# reside on that node. See memmap_init_zone()
1373# for details.
1374config NODES_SPAN_OTHER_NODES
1375 def_bool y
1376 depends on X86_64_ACPI_NUMA
1377
506f1d07
SR
1378config NUMA_EMU
1379 bool "NUMA emulation"
1b7e03ef 1380 depends on NUMA
8f9ca475 1381 ---help---
506f1d07
SR
1382 Enable NUMA emulation. A flat machine will be split
1383 into virtual nodes when booted with "numa=fake=N", where N is the
1384 number of nodes. This is only useful for debugging.
1385
1386config NODES_SHIFT
d25e26b6 1387 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
51591e31
DR
1388 range 1 10
1389 default "10" if MAXSMP
506f1d07 1390 default "6" if X86_64
506f1d07
SR
1391 default "3"
1392 depends on NEED_MULTIPLE_NODES
8f9ca475 1393 ---help---
1184dc2f 1394 Specify the maximum number of NUMA Nodes available on the target
692105b8 1395 system. Increases memory reserved to accommodate various tables.
506f1d07 1396
506f1d07 1397config ARCH_HAVE_MEMORY_PRESENT
3c2362e6 1398 def_bool y
506f1d07 1399 depends on X86_32 && DISCONTIGMEM
506f1d07
SR
1400
1401config NEED_NODE_MEMMAP_SIZE
3c2362e6 1402 def_bool y
506f1d07 1403 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
506f1d07 1404
506f1d07
SR
1405config ARCH_FLATMEM_ENABLE
1406 def_bool y
3b16651f 1407 depends on X86_32 && !NUMA
506f1d07
SR
1408
1409config ARCH_DISCONTIGMEM_ENABLE
1410 def_bool y
b263295d 1411 depends on NUMA && X86_32
506f1d07
SR
1412
1413config ARCH_DISCONTIGMEM_DEFAULT
1414 def_bool y
b263295d
CL
1415 depends on NUMA && X86_32
1416
506f1d07
SR
1417config ARCH_SPARSEMEM_ENABLE
1418 def_bool y
6ea30386 1419 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
506f1d07
SR
1420 select SPARSEMEM_STATIC if X86_32
1421 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1422
3b16651f
TH
1423config ARCH_SPARSEMEM_DEFAULT
1424 def_bool y
1425 depends on X86_64
1426
506f1d07
SR
1427config ARCH_SELECT_MEMORY_MODEL
1428 def_bool y
b263295d 1429 depends on ARCH_SPARSEMEM_ENABLE
506f1d07
SR
1430
1431config ARCH_MEMORY_PROBE
a0842b70 1432 bool "Enable sysfs memory/probe interface"
3120e25e 1433 depends on X86_64 && MEMORY_HOTPLUG
a0842b70
TK
1434 help
1435 This option enables a sysfs memory/probe interface for testing.
1436 See Documentation/memory-hotplug.txt for more information.
1437 If you are unsure how to answer this question, answer N.
506f1d07 1438
3b16651f
TH
1439config ARCH_PROC_KCORE_TEXT
1440 def_bool y
1441 depends on X86_64 && PROC_KCORE
1442
a29815a3
AK
1443config ILLEGAL_POINTER_VALUE
1444 hex
1445 default 0 if X86_32
1446 default 0xdead000000000000 if X86_64
1447
506f1d07
SR
1448source "mm/Kconfig"
1449
ec776ef6
CH
1450config X86_PMEM_LEGACY
1451 bool "Support non-standard NVDIMMs and ADR protected memory"
9f53f9fa
DW
1452 depends on PHYS_ADDR_T_64BIT
1453 depends on BLK_DEV
1454 select LIBNVDIMM
ec776ef6
CH
1455 help
1456 Treat memory marked using the non-standard e820 type of 12 as used
1457 by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1458 The kernel will offer these regions to the 'pmem' driver so
1459 they can be used for persistent storage.
1460
1461 Say Y if unsure.
1462
506f1d07
SR
1463config HIGHPTE
1464 bool "Allocate 3rd-level pagetables from highmem"
6fc108a0 1465 depends on HIGHMEM
8f9ca475 1466 ---help---
506f1d07
SR
1467 The VM uses one page table entry for each page of physical memory.
1468 For systems with a lot of RAM, this can be wasteful of precious
1469 low memory. Setting this option will put user-space page table
1470 entries in high memory.
1471
9f077871 1472config X86_CHECK_BIOS_CORRUPTION
8f9ca475
IM
1473 bool "Check for low memory corruption"
1474 ---help---
1475 Periodically check for memory corruption in low memory, which
1476 is suspected to be caused by BIOS. Even when enabled in the
1477 configuration, it is disabled at runtime. Enable it by
1478 setting "memory_corruption_check=1" on the kernel command
1479 line. By default it scans the low 64k of memory every 60
1480 seconds; see the memory_corruption_check_size and
1481 memory_corruption_check_period parameters in
1482 Documentation/kernel-parameters.txt to adjust this.
1483
1484 When enabled with the default parameters, this option has
1485 almost no overhead, as it reserves a relatively small amount
1486 of memory and scans it infrequently. It both detects corruption
1487 and prevents it from affecting the running system.
1488
1489 It is, however, intended as a diagnostic tool; if repeatable
1490 BIOS-originated corruption always affects the same memory,
1491 you can use memmap= to prevent the kernel from using that
1492 memory.
9f077871 1493
c885df50 1494config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
8f9ca475 1495 bool "Set the default setting of memory_corruption_check"
c885df50
JF
1496 depends on X86_CHECK_BIOS_CORRUPTION
1497 default y
8f9ca475
IM
1498 ---help---
1499 Set whether the default state of memory_corruption_check is
1500 on or off.
c885df50 1501
9ea77bdb 1502config X86_RESERVE_LOW
d0cd7425
PA
1503 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1504 default 64
1505 range 4 640
8f9ca475 1506 ---help---
d0cd7425
PA
1507 Specify the amount of low memory to reserve for the BIOS.
1508
1509 The first page contains BIOS data structures that the kernel
1510 must not use, so that page must always be reserved.
1511
1512 By default we reserve the first 64K of physical RAM, as a
1513 number of BIOSes are known to corrupt that memory range
1514 during events such as suspend/resume or monitor cable
1515 insertion, so it must not be used by the kernel.
fc381519 1516
d0cd7425
PA
1517 You can set this to 4 if you are absolutely sure that you
1518 trust the BIOS to get all its memory reservations and usages
1519 right. If you know your BIOS have problems beyond the
1520 default 64K area, you can set this to 640 to avoid using the
1521 entire low memory range.
fc381519 1522
d0cd7425
PA
1523 If you have doubts about the BIOS (e.g. suspend/resume does
1524 not work or there's kernel crashes after certain hardware
1525 hotplug events) then you might want to enable
1526 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1527 typical corruption patterns.
fc381519 1528
d0cd7425 1529 Leave this to the default value of 64 if you are unsure.
fc381519 1530
506f1d07
SR
1531config MATH_EMULATION
1532 bool
1533 prompt "Math emulation" if X86_32
1534 ---help---
1535 Linux can emulate a math coprocessor (used for floating point
1536 operations) if you don't have one. 486DX and Pentium processors have
1537 a math coprocessor built in, 486SX and 386 do not, unless you added
1538 a 487DX or 387, respectively. (The messages during boot time can
1539 give you some hints here ["man dmesg"].) Everyone needs either a
1540 coprocessor or this emulation.
1541
1542 If you don't have a math coprocessor, you need to say Y here; if you
1543 say Y here even though you have a coprocessor, the coprocessor will
1544 be used nevertheless. (This behavior can be changed with the kernel
1545 command line option "no387", which comes handy if your coprocessor
1546 is broken. Try "man bootparam" or see the documentation of your boot
1547 loader (lilo or loadlin) about how to pass options to the kernel at
1548 boot time.) This means that it is a good idea to say Y here if you
1549 intend to use this kernel on different machines.
1550
1551 More information about the internals of the Linux math coprocessor
1552 emulation can be found in <file:arch/x86/math-emu/README>.
1553
1554 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1555 kernel, it won't hurt.
1556
1557config MTRR
6fc108a0 1558 def_bool y
6a108a14 1559 prompt "MTRR (Memory Type Range Register) support" if EXPERT
506f1d07
SR
1560 ---help---
1561 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1562 the Memory Type Range Registers (MTRRs) may be used to control
1563 processor access to memory ranges. This is most useful if you have
1564 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1565 allows bus write transfers to be combined into a larger transfer
1566 before bursting over the PCI/AGP bus. This can increase performance
1567 of image write operations 2.5 times or more. Saying Y here creates a
1568 /proc/mtrr file which may be used to manipulate your processor's
1569 MTRRs. Typically the X server should use this.
1570
1571 This code has a reasonably generic interface so that similar
1572 control registers on other processors can be easily supported
1573 as well:
1574
1575 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1576 Registers (ARRs) which provide a similar functionality to MTRRs. For
1577 these, the ARRs are used to emulate the MTRRs.
1578 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1579 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1580 write-combining. All of these processors are supported by this code
1581 and it makes sense to say Y here if you have one of them.
1582
1583 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1584 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1585 can lead to all sorts of problems, so it's good to say Y here.
1586
1587 You can safely say Y even if your machine doesn't have MTRRs, you'll
1588 just add about 9 KB to your kernel.
1589
7225e751 1590 See <file:Documentation/x86/mtrr.txt> for more information.
506f1d07 1591
95ffa243 1592config MTRR_SANITIZER
2ffb3501 1593 def_bool y
95ffa243
YL
1594 prompt "MTRR cleanup support"
1595 depends on MTRR
8f9ca475 1596 ---help---
aba3728c
TG
1597 Convert MTRR layout from continuous to discrete, so X drivers can
1598 add writeback entries.
95ffa243 1599
aba3728c 1600 Can be disabled with disable_mtrr_cleanup on the kernel command line.
692105b8 1601 The largest mtrr entry size for a continuous block can be set with
aba3728c 1602 mtrr_chunk_size.
95ffa243 1603
2ffb3501 1604 If unsure, say Y.
95ffa243
YL
1605
1606config MTRR_SANITIZER_ENABLE_DEFAULT
f5098d62
YL
1607 int "MTRR cleanup enable value (0-1)"
1608 range 0 1
1609 default "0"
95ffa243 1610 depends on MTRR_SANITIZER
8f9ca475 1611 ---help---
f5098d62 1612 Enable mtrr cleanup default value
95ffa243 1613
12031a62
YL
1614config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1615 int "MTRR cleanup spare reg num (0-7)"
1616 range 0 7
1617 default "1"
1618 depends on MTRR_SANITIZER
8f9ca475 1619 ---help---
12031a62 1620 mtrr cleanup spare entries default, it can be changed via
aba3728c 1621 mtrr_spare_reg_nr=N on the kernel command line.
12031a62 1622
2e5d9c85 1623config X86_PAT
6fc108a0 1624 def_bool y
6a108a14 1625 prompt "x86 PAT support" if EXPERT
2a8a2719 1626 depends on MTRR
8f9ca475 1627 ---help---
2e5d9c85 1628 Use PAT attributes to setup page level cache control.
042b78e4 1629
2e5d9c85 1630 PATs are the modern equivalents of MTRRs and are much more
1631 flexible than MTRRs.
1632
1633 Say N here if you see bootup problems (boot crash, boot hang,
042b78e4 1634 spontaneous reboots) or a non-working video driver.
2e5d9c85 1635
1636 If unsure, say Y.
1637
46cf98cd
VP
1638config ARCH_USES_PG_UNCACHED
1639 def_bool y
1640 depends on X86_PAT
1641
628c6246
PA
1642config ARCH_RANDOM
1643 def_bool y
1644 prompt "x86 architectural random number generator" if EXPERT
1645 ---help---
1646 Enable the x86 architectural RDRAND instruction
1647 (Intel Bull Mountain technology) to generate random numbers.
1648 If supported, this is a high bandwidth, cryptographically
1649 secure hardware random number generator.
1650
51ae4a2d
PA
1651config X86_SMAP
1652 def_bool y
1653 prompt "Supervisor Mode Access Prevention" if EXPERT
1654 ---help---
1655 Supervisor Mode Access Prevention (SMAP) is a security
1656 feature in newer Intel processors. There is a small
1657 performance cost if this enabled and turned on; there is
1658 also a small increase in the kernel size if this is enabled.
1659
1660 If unsure, say Y.
1661
72e9b5fe
DH
1662config X86_INTEL_MPX
1663 prompt "Intel MPX (Memory Protection Extensions)"
1664 def_bool n
1665 depends on CPU_SUP_INTEL
1666 ---help---
1667 MPX provides hardware features that can be used in
1668 conjunction with compiler-instrumented code to check
1669 memory references. It is designed to detect buffer
1670 overflow or underflow bugs.
1671
1672 This option enables running applications which are
1673 instrumented or otherwise use MPX. It does not use MPX
1674 itself inside the kernel or to protect the kernel
1675 against bad memory references.
1676
1677 Enabling this option will make the kernel larger:
1678 ~8k of kernel text and 36 bytes of data on a 64-bit
1679 defconfig. It adds a long to the 'mm_struct' which
1680 will increase the kernel memory overhead of each
1681 process and adds some branches to paths used during
1682 exec() and munmap().
1683
1684 For details, see Documentation/x86/intel_mpx.txt
1685
1686 If unsure, say N.
1687
506f1d07 1688config EFI
9ba16087 1689 bool "EFI runtime service support"
5b83683f 1690 depends on ACPI
f6ce5002 1691 select UCS2_STRING
022ee6c5 1692 select EFI_RUNTIME_WRAPPERS
506f1d07 1693 ---help---
8f9ca475
IM
1694 This enables the kernel to use EFI runtime services that are
1695 available (such as the EFI variable services).
506f1d07 1696
8f9ca475
IM
1697 This option is only useful on systems that have EFI firmware.
1698 In addition, you should use the latest ELILO loader available
1699 at <http://elilo.sourceforge.net> in order to take advantage
1700 of EFI runtime services. However, even with this option, the
1701 resultant kernel should continue to boot on existing non-EFI
1702 platforms.
506f1d07 1703
291f3632
MF
1704config EFI_STUB
1705 bool "EFI stub support"
b16d8c23 1706 depends on EFI && !X86_USE_3DNOW
7b2a583a 1707 select RELOCATABLE
291f3632
MF
1708 ---help---
1709 This kernel feature allows a bzImage to be loaded directly
1710 by EFI firmware without the use of a bootloader.
1711
4172fe2f 1712 See Documentation/efi-stub.txt for more information.
0c759662 1713
7d453eee
MF
1714config EFI_MIXED
1715 bool "EFI mixed-mode support"
1716 depends on EFI_STUB && X86_64
1717 ---help---
1718 Enabling this feature allows a 64-bit kernel to be booted
1719 on a 32-bit firmware, provided that your CPU supports 64-bit
1720 mode.
1721
1722 Note that it is not possible to boot a mixed-mode enabled
1723 kernel via the EFI boot stub - a bootloader that supports
1724 the EFI handover protocol must be used.
1725
1726 If unsure, say N.
1727
506f1d07 1728config SECCOMP
3c2362e6
HH
1729 def_bool y
1730 prompt "Enable seccomp to safely compute untrusted bytecode"
8f9ca475 1731 ---help---
506f1d07
SR
1732 This kernel feature is useful for number crunching applications
1733 that may need to compute untrusted bytecode during their
1734 execution. By using pipes or other transports made available to
1735 the process as file descriptors supporting the read/write
1736 syscalls, it's possible to isolate those applications in
1737 their own address space using seccomp. Once seccomp is
9c0bbee8 1738 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
506f1d07
SR
1739 and the task is only allowed to execute a few safe syscalls
1740 defined by each seccomp mode.
1741
1742 If unsure, say Y. Only embedded should say N here.
1743
506f1d07
SR
1744source kernel/Kconfig.hz
1745
1746config KEXEC
1747 bool "kexec system call"
8f9ca475 1748 ---help---
506f1d07
SR
1749 kexec is a system call that implements the ability to shutdown your
1750 current kernel, and to start another kernel. It is like a reboot
1751 but it is independent of the system firmware. And like a reboot
1752 you can start any kernel with it, not just Linux.
1753
1754 The name comes from the similarity to the exec system call.
1755
1756 It is an ongoing process to be certain the hardware in a machine
1757 is properly shutdown, so do not be surprised if this code does not
bf220695
GU
1758 initially work for you. As of this writing the exact hardware
1759 interface is strongly in flux, so no good recommendation can be
1760 made.
506f1d07 1761
74ca317c
VG
1762config KEXEC_FILE
1763 bool "kexec file based system call"
1764 select BUILD_BIN2C
1765 depends on KEXEC
1766 depends on X86_64
1767 depends on CRYPTO=y
1768 depends on CRYPTO_SHA256=y
1769 ---help---
1770 This is new version of kexec system call. This system call is
1771 file based and takes file descriptors as system call argument
1772 for kernel and initramfs as opposed to list of segments as
1773 accepted by previous system call.
1774
8e7d8381
VG
1775config KEXEC_VERIFY_SIG
1776 bool "Verify kernel signature during kexec_file_load() syscall"
74ca317c 1777 depends on KEXEC_FILE
8e7d8381
VG
1778 ---help---
1779 This option makes kernel signature verification mandatory for
d8eb8940
BP
1780 the kexec_file_load() syscall.
1781
1782 In addition to that option, you need to enable signature
1783 verification for the corresponding kernel image type being
1784 loaded in order for this to work.
8e7d8381
VG
1785
1786config KEXEC_BZIMAGE_VERIFY_SIG
1787 bool "Enable bzImage signature verification support"
1788 depends on KEXEC_VERIFY_SIG
1789 depends on SIGNED_PE_FILE_VERIFICATION
1790 select SYSTEM_TRUSTED_KEYRING
1791 ---help---
1792 Enable bzImage signature verification support.
1793
506f1d07 1794config CRASH_DUMP
04b69447 1795 bool "kernel crash dumps"
506f1d07 1796 depends on X86_64 || (X86_32 && HIGHMEM)
8f9ca475 1797 ---help---
506f1d07
SR
1798 Generate crash dump after being started by kexec.
1799 This should be normally only set in special crash dump kernels
1800 which are loaded in the main kernel with kexec-tools into
1801 a specially reserved region and then later executed after
1802 a crash by kdump/kexec. The crash dump kernel must be compiled
1803 to a memory address not used by the main kernel or BIOS using
1804 PHYSICAL_START, or it must be built as a relocatable image
1805 (CONFIG_RELOCATABLE=y).
1806 For more details see Documentation/kdump/kdump.txt
1807
3ab83521 1808config KEXEC_JUMP
6ea30386 1809 bool "kexec jump"
fee7b0d8 1810 depends on KEXEC && HIBERNATION
8f9ca475 1811 ---help---
89081d17
HY
1812 Jump between original kernel and kexeced kernel and invoke
1813 code in physical address mode via KEXEC
3ab83521 1814
506f1d07 1815config PHYSICAL_START
6a108a14 1816 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
ceefccc9 1817 default "0x1000000"
8f9ca475 1818 ---help---
506f1d07
SR
1819 This gives the physical address where the kernel is loaded.
1820
1821 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1822 bzImage will decompress itself to above physical address and
1823 run from there. Otherwise, bzImage will run from the address where
1824 it has been loaded by the boot loader and will ignore above physical
1825 address.
1826
1827 In normal kdump cases one does not have to set/change this option
1828 as now bzImage can be compiled as a completely relocatable image
1829 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1830 address. This option is mainly useful for the folks who don't want
1831 to use a bzImage for capturing the crash dump and want to use a
1832 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1833 to be specifically compiled to run from a specific memory area
1834 (normally a reserved region) and this option comes handy.
1835
ceefccc9
PA
1836 So if you are using bzImage for capturing the crash dump,
1837 leave the value here unchanged to 0x1000000 and set
1838 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1839 for capturing the crash dump change this value to start of
1840 the reserved region. In other words, it can be set based on
1841 the "X" value as specified in the "crashkernel=YM@XM"
1842 command line boot parameter passed to the panic-ed
1843 kernel. Please take a look at Documentation/kdump/kdump.txt
1844 for more details about crash dumps.
506f1d07
SR
1845
1846 Usage of bzImage for capturing the crash dump is recommended as
1847 one does not have to build two kernels. Same kernel can be used
1848 as production kernel and capture kernel. Above option should have
1849 gone away after relocatable bzImage support is introduced. But it
1850 is present because there are users out there who continue to use
1851 vmlinux for dump capture. This option should go away down the
1852 line.
1853
1854 Don't change this unless you know what you are doing.
1855
1856config RELOCATABLE
26717808
PA
1857 bool "Build a relocatable kernel"
1858 default y
8f9ca475 1859 ---help---
506f1d07
SR
1860 This builds a kernel image that retains relocation information
1861 so it can be loaded someplace besides the default 1MB.
1862 The relocations tend to make the kernel binary about 10% larger,
1863 but are discarded at runtime.
1864
1865 One use is for the kexec on panic case where the recovery kernel
1866 must live at a different physical address than the primary
1867 kernel.
1868
1869 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1870 it has been loaded at and the compile time physical address
8ab3820f 1871 (CONFIG_PHYSICAL_START) is used as the minimum location.
506f1d07 1872
8ab3820f
KC
1873config RANDOMIZE_BASE
1874 bool "Randomize the address of the kernel image"
1875 depends on RELOCATABLE
8ab3820f
KC
1876 default n
1877 ---help---
1878 Randomizes the physical and virtual address at which the
1879 kernel image is decompressed, as a security feature that
1880 deters exploit attempts relying on knowledge of the location
1881 of kernel internals.
1882
a653f356
KC
1883 Entropy is generated using the RDRAND instruction if it is
1884 supported. If RDTSC is supported, it is used as well. If
1885 neither RDRAND nor RDTSC are supported, then randomness is
1886 read from the i8254 timer.
8ab3820f
KC
1887
1888 The kernel will be offset by up to RANDOMIZE_BASE_MAX_OFFSET,
a653f356
KC
1889 and aligned according to PHYSICAL_ALIGN. Since the kernel is
1890 built using 2GiB addressing, and PHYSICAL_ALGIN must be at a
1891 minimum of 2MiB, only 10 bits of entropy is theoretically
1892 possible. At best, due to page table layouts, 64-bit can use
1893 9 bits of entropy and 32-bit uses 8 bits.
8ab3820f 1894
da2b6fb9
KC
1895 If unsure, say N.
1896
8ab3820f 1897config RANDOMIZE_BASE_MAX_OFFSET
da2b6fb9 1898 hex "Maximum kASLR offset allowed" if EXPERT
8ab3820f 1899 depends on RANDOMIZE_BASE
6145cfe3
KC
1900 range 0x0 0x20000000 if X86_32
1901 default "0x20000000" if X86_32
1902 range 0x0 0x40000000 if X86_64
1903 default "0x40000000" if X86_64
8ab3820f 1904 ---help---
da2b6fb9
KC
1905 The lesser of RANDOMIZE_BASE_MAX_OFFSET and available physical
1906 memory is used to determine the maximal offset in bytes that will
1907 be applied to the kernel when kernel Address Space Layout
1908 Randomization (kASLR) is active. This must be a multiple of
1909 PHYSICAL_ALIGN.
1910
1911 On 32-bit this is limited to 512MiB by page table layouts. The
1912 default is 512MiB.
6145cfe3 1913
da2b6fb9
KC
1914 On 64-bit this is limited by how the kernel fixmap page table is
1915 positioned, so this cannot be larger than 1GiB currently. Without
1916 RANDOMIZE_BASE, there is a 512MiB to 1.5GiB split between kernel
1917 and modules. When RANDOMIZE_BASE_MAX_OFFSET is above 512MiB, the
1918 modules area will shrink to compensate, up to the current maximum
1919 1GiB to 1GiB split. The default is 1GiB.
6145cfe3 1920
da2b6fb9 1921 If unsure, leave at the default value.
8ab3820f
KC
1922
1923# Relocation on x86 needs some additional build support
845adf72
PA
1924config X86_NEED_RELOCS
1925 def_bool y
8ab3820f 1926 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
845adf72 1927
506f1d07 1928config PHYSICAL_ALIGN
a0215061 1929 hex "Alignment value to which kernel should be aligned"
8ab3820f 1930 default "0x200000"
a0215061
KC
1931 range 0x2000 0x1000000 if X86_32
1932 range 0x200000 0x1000000 if X86_64
8f9ca475 1933 ---help---
506f1d07
SR
1934 This value puts the alignment restrictions on physical address
1935 where kernel is loaded and run from. Kernel is compiled for an
1936 address which meets above alignment restriction.
1937
1938 If bootloader loads the kernel at a non-aligned address and
1939 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1940 address aligned to above value and run from there.
1941
1942 If bootloader loads the kernel at a non-aligned address and
1943 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1944 load address and decompress itself to the address it has been
1945 compiled for and run from there. The address for which kernel is
1946 compiled already meets above alignment restrictions. Hence the
1947 end result is that kernel runs from a physical address meeting
1948 above alignment restrictions.
1949
a0215061
KC
1950 On 32-bit this value must be a multiple of 0x2000. On 64-bit
1951 this value must be a multiple of 0x200000.
1952
506f1d07
SR
1953 Don't change this unless you know what you are doing.
1954
1955config HOTPLUG_CPU
7c13e6a3 1956 bool "Support for hot-pluggable CPUs"
40b31360 1957 depends on SMP
506f1d07 1958 ---help---
7c13e6a3
DS
1959 Say Y here to allow turning CPUs off and on. CPUs can be
1960 controlled through /sys/devices/system/cpu.
1961 ( Note: power management support will enable this option
1962 automatically on SMP systems. )
1963 Say N if you want to disable CPU hotplug.
506f1d07 1964
80aa1dff
FY
1965config BOOTPARAM_HOTPLUG_CPU0
1966 bool "Set default setting of cpu0_hotpluggable"
1967 default n
2c922cd0 1968 depends on HOTPLUG_CPU
80aa1dff
FY
1969 ---help---
1970 Set whether default state of cpu0_hotpluggable is on or off.
1971
1972 Say Y here to enable CPU0 hotplug by default. If this switch
1973 is turned on, there is no need to give cpu0_hotplug kernel
1974 parameter and the CPU0 hotplug feature is enabled by default.
1975
1976 Please note: there are two known CPU0 dependencies if you want
1977 to enable the CPU0 hotplug feature either by this switch or by
1978 cpu0_hotplug kernel parameter.
1979
1980 First, resume from hibernate or suspend always starts from CPU0.
1981 So hibernate and suspend are prevented if CPU0 is offline.
1982
1983 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
1984 offline if any interrupt can not migrate out of CPU0. There may
1985 be other CPU0 dependencies.
1986
1987 Please make sure the dependencies are under your control before
1988 you enable this feature.
1989
1990 Say N if you don't want to enable CPU0 hotplug feature by default.
1991 You still can enable the CPU0 hotplug feature at boot by kernel
1992 parameter cpu0_hotplug.
1993
a71c8bc5
FY
1994config DEBUG_HOTPLUG_CPU0
1995 def_bool n
1996 prompt "Debug CPU0 hotplug"
2c922cd0 1997 depends on HOTPLUG_CPU
a71c8bc5
FY
1998 ---help---
1999 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2000 soon as possible and boots up userspace with CPU0 offlined. User
2001 can online CPU0 back after boot time.
2002
2003 To debug CPU0 hotplug, you need to enable CPU0 offline/online
2004 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2005 compilation or giving cpu0_hotplug kernel parameter at boot.
2006
2007 If unsure, say N.
2008
506f1d07 2009config COMPAT_VDSO
b0b49f26
AL
2010 def_bool n
2011 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
af65d648 2012 depends on X86_32 || IA32_EMULATION
8f9ca475 2013 ---help---
b0b49f26
AL
2014 Certain buggy versions of glibc will crash if they are
2015 presented with a 32-bit vDSO that is not mapped at the address
2016 indicated in its segment table.
e84446de 2017
b0b49f26
AL
2018 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2019 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2020 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
2021 the only released version with the bug, but OpenSUSE 9
2022 contains a buggy "glibc 2.3.2".
506f1d07 2023
b0b49f26
AL
2024 The symptom of the bug is that everything crashes on startup, saying:
2025 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2026
2027 Saying Y here changes the default value of the vdso32 boot
2028 option from 1 to 0, which turns off the 32-bit vDSO entirely.
2029 This works around the glibc bug but hurts performance.
2030
2031 If unsure, say N: if you are compiling your own kernel, you
2032 are unlikely to be using a buggy version of glibc.
506f1d07 2033
516cbf37
TB
2034config CMDLINE_BOOL
2035 bool "Built-in kernel command line"
8f9ca475 2036 ---help---
516cbf37
TB
2037 Allow for specifying boot arguments to the kernel at
2038 build time. On some systems (e.g. embedded ones), it is
2039 necessary or convenient to provide some or all of the
2040 kernel boot arguments with the kernel itself (that is,
2041 to not rely on the boot loader to provide them.)
2042
2043 To compile command line arguments into the kernel,
2044 set this option to 'Y', then fill in the
69711ca1 2045 boot arguments in CONFIG_CMDLINE.
516cbf37
TB
2046
2047 Systems with fully functional boot loaders (i.e. non-embedded)
2048 should leave this option set to 'N'.
2049
2050config CMDLINE
2051 string "Built-in kernel command string"
2052 depends on CMDLINE_BOOL
2053 default ""
8f9ca475 2054 ---help---
516cbf37
TB
2055 Enter arguments here that should be compiled into the kernel
2056 image and used at boot time. If the boot loader provides a
2057 command line at boot time, it is appended to this string to
2058 form the full kernel command line, when the system boots.
2059
2060 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2061 change this behavior.
2062
2063 In most cases, the command line (whether built-in or provided
2064 by the boot loader) should specify the device for the root
2065 file system.
2066
2067config CMDLINE_OVERRIDE
2068 bool "Built-in command line overrides boot loader arguments"
516cbf37 2069 depends on CMDLINE_BOOL
8f9ca475 2070 ---help---
516cbf37
TB
2071 Set this option to 'Y' to have the kernel ignore the boot loader
2072 command line, and use ONLY the built-in command line.
2073
2074 This is used to work around broken boot loaders. This should
2075 be set to 'N' under normal conditions.
2076
b700e7f0
SJ
2077source "kernel/livepatch/Kconfig"
2078
506f1d07
SR
2079endmenu
2080
2081config ARCH_ENABLE_MEMORY_HOTPLUG
2082 def_bool y
2083 depends on X86_64 || (X86_32 && HIGHMEM)
2084
35551053
GH
2085config ARCH_ENABLE_MEMORY_HOTREMOVE
2086 def_bool y
2087 depends on MEMORY_HOTPLUG
2088
e534c7c5 2089config USE_PERCPU_NUMA_NODE_ID
645a7919 2090 def_bool y
e534c7c5
LS
2091 depends on NUMA
2092
9491846f
KS
2093config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2094 def_bool y
2095 depends on X86_64 || X86_PAE
2096
c177c81e
NH
2097config ARCH_ENABLE_HUGEPAGE_MIGRATION
2098 def_bool y
2099 depends on X86_64 && HUGETLB_PAGE && MIGRATION
2100
da85f865 2101menu "Power management and ACPI options"
e279b6c1
SR
2102
2103config ARCH_HIBERNATION_HEADER
3c2362e6 2104 def_bool y
e279b6c1 2105 depends on X86_64 && HIBERNATION
e279b6c1
SR
2106
2107source "kernel/power/Kconfig"
2108
2109source "drivers/acpi/Kconfig"
2110
efafc8b2
FT
2111source "drivers/sfi/Kconfig"
2112
a6b68076 2113config X86_APM_BOOT
6fc108a0 2114 def_bool y
282e5aab 2115 depends on APM
a6b68076 2116
e279b6c1
SR
2117menuconfig APM
2118 tristate "APM (Advanced Power Management) BIOS support"
efefa6f6 2119 depends on X86_32 && PM_SLEEP
e279b6c1
SR
2120 ---help---
2121 APM is a BIOS specification for saving power using several different
2122 techniques. This is mostly useful for battery powered laptops with
2123 APM compliant BIOSes. If you say Y here, the system time will be
2124 reset after a RESUME operation, the /proc/apm device will provide
2125 battery status information, and user-space programs will receive
2126 notification of APM "events" (e.g. battery status change).
2127
2128 If you select "Y" here, you can disable actual use of the APM
2129 BIOS by passing the "apm=off" option to the kernel at boot time.
2130
2131 Note that the APM support is almost completely disabled for
2132 machines with more than one CPU.
2133
2134 In order to use APM, you will need supporting software. For location
2dc98fd3
MW
2135 and more information, read <file:Documentation/power/apm-acpi.txt>
2136 and the Battery Powered Linux mini-HOWTO, available from
e279b6c1
SR
2137 <http://www.tldp.org/docs.html#howto>.
2138
2139 This driver does not spin down disk drives (see the hdparm(8)
2140 manpage ("man 8 hdparm") for that), and it doesn't turn off
2141 VESA-compliant "green" monitors.
2142
2143 This driver does not support the TI 4000M TravelMate and the ACER
2144 486/DX4/75 because they don't have compliant BIOSes. Many "green"
2145 desktop machines also don't have compliant BIOSes, and this driver
2146 may cause those machines to panic during the boot phase.
2147
2148 Generally, if you don't have a battery in your machine, there isn't
2149 much point in using this driver and you should say N. If you get
2150 random kernel OOPSes or reboots that don't seem to be related to
2151 anything, try disabling/enabling this option (or disabling/enabling
2152 APM in your BIOS).
2153
2154 Some other things you should try when experiencing seemingly random,
2155 "weird" problems:
2156
2157 1) make sure that you have enough swap space and that it is
2158 enabled.
2159 2) pass the "no-hlt" option to the kernel
2160 3) switch on floating point emulation in the kernel and pass
2161 the "no387" option to the kernel
2162 4) pass the "floppy=nodma" option to the kernel
2163 5) pass the "mem=4M" option to the kernel (thereby disabling
2164 all but the first 4 MB of RAM)
2165 6) make sure that the CPU is not over clocked.
2166 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2167 8) disable the cache from your BIOS settings
2168 9) install a fan for the video card or exchange video RAM
2169 10) install a better fan for the CPU
2170 11) exchange RAM chips
2171 12) exchange the motherboard.
2172
2173 To compile this driver as a module, choose M here: the
2174 module will be called apm.
2175
2176if APM
2177
2178config APM_IGNORE_USER_SUSPEND
2179 bool "Ignore USER SUSPEND"
8f9ca475 2180 ---help---
e279b6c1
SR
2181 This option will ignore USER SUSPEND requests. On machines with a
2182 compliant APM BIOS, you want to say N. However, on the NEC Versa M
2183 series notebooks, it is necessary to say Y because of a BIOS bug.
2184
2185config APM_DO_ENABLE
2186 bool "Enable PM at boot time"
2187 ---help---
2188 Enable APM features at boot time. From page 36 of the APM BIOS
2189 specification: "When disabled, the APM BIOS does not automatically
2190 power manage devices, enter the Standby State, enter the Suspend
2191 State, or take power saving steps in response to CPU Idle calls."
2192 This driver will make CPU Idle calls when Linux is idle (unless this
2193 feature is turned off -- see "Do CPU IDLE calls", below). This
2194 should always save battery power, but more complicated APM features
2195 will be dependent on your BIOS implementation. You may need to turn
2196 this option off if your computer hangs at boot time when using APM
2197 support, or if it beeps continuously instead of suspending. Turn
2198 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2199 T400CDT. This is off by default since most machines do fine without
2200 this feature.
2201
2202config APM_CPU_IDLE
dd8af076 2203 depends on CPU_IDLE
e279b6c1 2204 bool "Make CPU Idle calls when idle"
8f9ca475 2205 ---help---
e279b6c1
SR
2206 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2207 On some machines, this can activate improved power savings, such as
2208 a slowed CPU clock rate, when the machine is idle. These idle calls
2209 are made after the idle loop has run for some length of time (e.g.,
2210 333 mS). On some machines, this will cause a hang at boot time or
2211 whenever the CPU becomes idle. (On machines with more than one CPU,
2212 this option does nothing.)
2213
2214config APM_DISPLAY_BLANK
2215 bool "Enable console blanking using APM"
8f9ca475 2216 ---help---
e279b6c1
SR
2217 Enable console blanking using the APM. Some laptops can use this to
2218 turn off the LCD backlight when the screen blanker of the Linux
2219 virtual console blanks the screen. Note that this is only used by
2220 the virtual console screen blanker, and won't turn off the backlight
2221 when using the X Window system. This also doesn't have anything to
2222 do with your VESA-compliant power-saving monitor. Further, this
2223 option doesn't work for all laptops -- it might not turn off your
2224 backlight at all, or it might print a lot of errors to the console,
2225 especially if you are using gpm.
2226
2227config APM_ALLOW_INTS
2228 bool "Allow interrupts during APM BIOS calls"
8f9ca475 2229 ---help---
e279b6c1
SR
2230 Normally we disable external interrupts while we are making calls to
2231 the APM BIOS as a measure to lessen the effects of a badly behaving
2232 BIOS implementation. The BIOS should reenable interrupts if it
2233 needs to. Unfortunately, some BIOSes do not -- especially those in
2234 many of the newer IBM Thinkpads. If you experience hangs when you
2235 suspend, try setting this to Y. Otherwise, say N.
2236
e279b6c1
SR
2237endif # APM
2238
bb0a56ec 2239source "drivers/cpufreq/Kconfig"
e279b6c1
SR
2240
2241source "drivers/cpuidle/Kconfig"
2242
27471fdb
AH
2243source "drivers/idle/Kconfig"
2244
e279b6c1
SR
2245endmenu
2246
2247
2248menu "Bus options (PCI etc.)"
2249
2250config PCI
1ac97018 2251 bool "PCI support"
1c858087 2252 default y
8f9ca475 2253 ---help---
e279b6c1
SR
2254 Find out whether you have a PCI motherboard. PCI is the name of a
2255 bus system, i.e. the way the CPU talks to the other stuff inside
2256 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2257 VESA. If you have PCI, say Y, otherwise N.
2258
e279b6c1
SR
2259choice
2260 prompt "PCI access mode"
efefa6f6 2261 depends on X86_32 && PCI
e279b6c1
SR
2262 default PCI_GOANY
2263 ---help---
2264 On PCI systems, the BIOS can be used to detect the PCI devices and
2265 determine their configuration. However, some old PCI motherboards
2266 have BIOS bugs and may crash if this is done. Also, some embedded
2267 PCI-based systems don't have any BIOS at all. Linux can also try to
2268 detect the PCI hardware directly without using the BIOS.
2269
2270 With this option, you can specify how Linux should detect the
2271 PCI devices. If you choose "BIOS", the BIOS will be used,
2272 if you choose "Direct", the BIOS won't be used, and if you
2273 choose "MMConfig", then PCI Express MMCONFIG will be used.
2274 If you choose "Any", the kernel will try MMCONFIG, then the
2275 direct access method and falls back to the BIOS if that doesn't
2276 work. If unsure, go with the default, which is "Any".
2277
2278config PCI_GOBIOS
2279 bool "BIOS"
2280
2281config PCI_GOMMCONFIG
2282 bool "MMConfig"
2283
2284config PCI_GODIRECT
2285 bool "Direct"
2286
3ef0e1f8 2287config PCI_GOOLPC
76fb6570 2288 bool "OLPC XO-1"
3ef0e1f8
AS
2289 depends on OLPC
2290
2bdd1b03
AS
2291config PCI_GOANY
2292 bool "Any"
2293
e279b6c1
SR
2294endchoice
2295
2296config PCI_BIOS
3c2362e6 2297 def_bool y
efefa6f6 2298 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
e279b6c1
SR
2299
2300# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2301config PCI_DIRECT
3c2362e6 2302 def_bool y
0aba496f 2303 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
e279b6c1
SR
2304
2305config PCI_MMCONFIG
3c2362e6 2306 def_bool y
5f0db7a2 2307 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
e279b6c1 2308
3ef0e1f8 2309config PCI_OLPC
2bdd1b03
AS
2310 def_bool y
2311 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
3ef0e1f8 2312
b5401a96
AN
2313config PCI_XEN
2314 def_bool y
2315 depends on PCI && XEN
2316 select SWIOTLB_XEN
2317
e279b6c1 2318config PCI_DOMAINS
3c2362e6 2319 def_bool y
e279b6c1 2320 depends on PCI
e279b6c1
SR
2321
2322config PCI_MMCONFIG
2323 bool "Support mmconfig PCI config space access"
2324 depends on X86_64 && PCI && ACPI
2325
3f6ea84a 2326config PCI_CNB20LE_QUIRK
6a108a14 2327 bool "Read CNB20LE Host Bridge Windows" if EXPERT
6ea30386 2328 depends on PCI
3f6ea84a
IS
2329 help
2330 Read the PCI windows out of the CNB20LE host bridge. This allows
2331 PCI hotplug to work on systems with the CNB20LE chipset which do
2332 not have ACPI.
2333
64a5fed6
BH
2334 There's no public spec for this chipset, and this functionality
2335 is known to be incomplete.
2336
2337 You should say N unless you know you need this.
2338
e279b6c1
SR
2339source "drivers/pci/pcie/Kconfig"
2340
2341source "drivers/pci/Kconfig"
2342
1c00f016 2343# x86_64 have no ISA slots, but can have ISA-style DMA.
e279b6c1 2344config ISA_DMA_API
1c00f016
DR
2345 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2346 default y
2347 help
2348 Enables ISA-style DMA support for devices requiring such controllers.
2349 If unsure, say Y.
e279b6c1
SR
2350
2351if X86_32
2352
2353config ISA
2354 bool "ISA support"
8f9ca475 2355 ---help---
e279b6c1
SR
2356 Find out whether you have ISA slots on your motherboard. ISA is the
2357 name of a bus system, i.e. the way the CPU talks to the other stuff
2358 inside your box. Other bus systems are PCI, EISA, MicroChannel
2359 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2360 newer boards don't support it. If you have ISA, say Y, otherwise N.
2361
2362config EISA
2363 bool "EISA support"
2364 depends on ISA
2365 ---help---
2366 The Extended Industry Standard Architecture (EISA) bus was
2367 developed as an open alternative to the IBM MicroChannel bus.
2368
2369 The EISA bus provided some of the features of the IBM MicroChannel
2370 bus while maintaining backward compatibility with cards made for
2371 the older ISA bus. The EISA bus saw limited use between 1988 and
2372 1995 when it was made obsolete by the PCI bus.
2373
2374 Say Y here if you are building a kernel for an EISA-based machine.
2375
2376 Otherwise, say N.
2377
2378source "drivers/eisa/Kconfig"
2379
e279b6c1
SR
2380config SCx200
2381 tristate "NatSemi SCx200 support"
8f9ca475 2382 ---help---
e279b6c1
SR
2383 This provides basic support for National Semiconductor's
2384 (now AMD's) Geode processors. The driver probes for the
2385 PCI-IDs of several on-chip devices, so its a good dependency
2386 for other scx200_* drivers.
2387
2388 If compiled as a module, the driver is named scx200.
2389
2390config SCx200HR_TIMER
2391 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
592913ec 2392 depends on SCx200
e279b6c1 2393 default y
8f9ca475 2394 ---help---
e279b6c1
SR
2395 This driver provides a clocksource built upon the on-chip
2396 27MHz high-resolution timer. Its also a workaround for
2397 NSC Geode SC-1100's buggy TSC, which loses time when the
2398 processor goes idle (as is done by the scheduler). The
2399 other workaround is idle=poll boot option.
2400
3ef0e1f8
AS
2401config OLPC
2402 bool "One Laptop Per Child support"
54008979 2403 depends on !X86_PAE
3c554946 2404 select GPIOLIB
dc3119e7 2405 select OF
45bb1674 2406 select OF_PROMTREE
b4e51854 2407 select IRQ_DOMAIN
8f9ca475 2408 ---help---
3ef0e1f8
AS
2409 Add support for detecting the unique features of the OLPC
2410 XO hardware.
2411
a3128588
DD
2412config OLPC_XO1_PM
2413 bool "OLPC XO-1 Power Management"
97c4cb71 2414 depends on OLPC && MFD_CS5535 && PM_SLEEP
a3128588 2415 select MFD_CORE
bf1ebf00 2416 ---help---
97c4cb71 2417 Add support for poweroff and suspend of the OLPC XO-1 laptop.
bf1ebf00 2418
cfee9597
DD
2419config OLPC_XO1_RTC
2420 bool "OLPC XO-1 Real Time Clock"
2421 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2422 ---help---
2423 Add support for the XO-1 real time clock, which can be used as a
2424 programmable wakeup source.
2425
7feda8e9
DD
2426config OLPC_XO1_SCI
2427 bool "OLPC XO-1 SCI extras"
d8d01a63 2428 depends on OLPC && OLPC_XO1_PM
ed8e47fe 2429 depends on INPUT=y
d8d01a63 2430 select POWER_SUPPLY
7feda8e9
DD
2431 select GPIO_CS5535
2432 select MFD_CORE
2433 ---help---
2434 Add support for SCI-based features of the OLPC XO-1 laptop:
7bc74b3d 2435 - EC-driven system wakeups
7feda8e9 2436 - Power button
7bc74b3d 2437 - Ebook switch
2cf2baea 2438 - Lid switch
e1040ac6
DD
2439 - AC adapter status updates
2440 - Battery status updates
7feda8e9 2441
a0f30f59
DD
2442config OLPC_XO15_SCI
2443 bool "OLPC XO-1.5 SCI extras"
d8d01a63
DD
2444 depends on OLPC && ACPI
2445 select POWER_SUPPLY
a0f30f59
DD
2446 ---help---
2447 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2448 - EC-driven system wakeups
2449 - AC adapter status updates
2450 - Battery status updates
bf1ebf00 2451
d4f3e350
EW
2452config ALIX
2453 bool "PCEngines ALIX System Support (LED setup)"
2454 select GPIOLIB
2455 ---help---
2456 This option enables system support for the PCEngines ALIX.
2457 At present this just sets up LEDs for GPIO control on
2458 ALIX2/3/6 boards. However, other system specific setup should
2459 get added here.
2460
2461 Note: You must still enable the drivers for GPIO and LED support
2462 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2463
2464 Note: You have to set alix.force=1 for boards with Award BIOS.
2465
da4e3302
PP
2466config NET5501
2467 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2468 select GPIOLIB
2469 ---help---
2470 This option enables system support for the Soekris Engineering net5501.
2471
3197059a
PP
2472config GEOS
2473 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2474 select GPIOLIB
2475 depends on DMI
2476 ---help---
2477 This option enables system support for the Traverse Technologies GEOS.
2478
7d029125
VD
2479config TS5500
2480 bool "Technologic Systems TS-5500 platform support"
2481 depends on MELAN
2482 select CHECK_SIGNATURE
2483 select NEW_LEDS
2484 select LEDS_CLASS
2485 ---help---
2486 This option enables system support for the Technologic Systems TS-5500.
2487
bc0120fd
SR
2488endif # X86_32
2489
23ac4ae8 2490config AMD_NB
e279b6c1 2491 def_bool y
0e152cd7 2492 depends on CPU_SUP_AMD && PCI
e279b6c1
SR
2493
2494source "drivers/pcmcia/Kconfig"
2495
2496source "drivers/pci/hotplug/Kconfig"
2497
388b78ad 2498config RAPIDIO
fdf90abc 2499 tristate "RapidIO support"
388b78ad
AB
2500 depends on PCI
2501 default n
2502 help
fdf90abc 2503 If enabled this option will include drivers and the core
388b78ad
AB
2504 infrastructure code to support RapidIO interconnect devices.
2505
2506source "drivers/rapidio/Kconfig"
2507
e3263ab3
DH
2508config X86_SYSFB
2509 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2510 help
2511 Firmwares often provide initial graphics framebuffers so the BIOS,
2512 bootloader or kernel can show basic video-output during boot for
2513 user-guidance and debugging. Historically, x86 used the VESA BIOS
2514 Extensions and EFI-framebuffers for this, which are mostly limited
2515 to x86.
2516 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2517 framebuffers so the new generic system-framebuffer drivers can be
2518 used on x86. If the framebuffer is not compatible with the generic
2519 modes, it is adverticed as fallback platform framebuffer so legacy
2520 drivers like efifb, vesafb and uvesafb can pick it up.
2521 If this option is not selected, all system framebuffers are always
2522 marked as fallback platform framebuffers as usual.
2523
2524 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2525 not be able to pick up generic system framebuffers if this option
2526 is selected. You are highly encouraged to enable simplefb as
2527 replacement if you select this option. simplefb can correctly deal
2528 with generic system framebuffers. But you should still keep vesafb
2529 and others enabled as fallback if a system framebuffer is
2530 incompatible with simplefb.
2531
2532 If unsure, say Y.
2533
e279b6c1
SR
2534endmenu
2535
2536
2537menu "Executable file formats / Emulations"
2538
2539source "fs/Kconfig.binfmt"
2540
2541config IA32_EMULATION
2542 bool "IA32 Emulation"
2543 depends on X86_64
d1603990 2544 select BINFMT_ELF
a97f52e6 2545 select COMPAT_BINFMT_ELF
3bead553 2546 select ARCH_WANT_OLD_COMPAT_IPC
8f9ca475 2547 ---help---
5fd92e65
L
2548 Include code to run legacy 32-bit programs under a
2549 64-bit kernel. You should likely turn this on, unless you're
2550 100% sure that you don't have any 32-bit programs left.
e279b6c1
SR
2551
2552config IA32_AOUT
8f9ca475
IM
2553 tristate "IA32 a.out support"
2554 depends on IA32_EMULATION
2555 ---help---
2556 Support old a.out binaries in the 32bit emulation.
e279b6c1 2557
0bf62763 2558config X86_X32
6ea30386 2559 bool "x32 ABI for 64-bit mode"
9b54050b 2560 depends on X86_64
5fd92e65
L
2561 ---help---
2562 Include code to run binaries for the x32 native 32-bit ABI
2563 for 64-bit processors. An x32 process gets access to the
2564 full 64-bit register file and wide data path while leaving
2565 pointers at 32 bits for smaller memory footprint.
2566
2567 You will need a recent binutils (2.22 or later) with
2568 elf32_x86_64 support enabled to compile a kernel with this
2569 option set.
2570
e279b6c1 2571config COMPAT
3c2362e6 2572 def_bool y
0bf62763 2573 depends on IA32_EMULATION || X86_X32
e279b6c1 2574
3120e25e 2575if COMPAT
e279b6c1 2576config COMPAT_FOR_U64_ALIGNMENT
3120e25e 2577 def_bool y
e279b6c1
SR
2578
2579config SYSVIPC_COMPAT
3c2362e6 2580 def_bool y
3120e25e 2581 depends on SYSVIPC
e279b6c1 2582
ee009e4a 2583config KEYS_COMPAT
3120e25e
JB
2584 def_bool y
2585 depends on KEYS
2586endif
ee009e4a 2587
e279b6c1
SR
2588endmenu
2589
2590
e5beae16
KP
2591config HAVE_ATOMIC_IOMAP
2592 def_bool y
2593 depends on X86_32
2594
4692d77f
AR
2595config X86_DEV_DMA_OPS
2596 bool
83125a3a 2597 depends on X86_64 || STA2X11
4692d77f 2598
f7219a53
AR
2599config X86_DMA_REMAP
2600 bool
83125a3a 2601 depends on STA2X11
f7219a53 2602
93e5eadd
LA
2603config PMC_ATOM
2604 def_bool y
2605 depends on PCI
2606
e279b6c1
SR
2607source "net/Kconfig"
2608
2609source "drivers/Kconfig"
2610
2611source "drivers/firmware/Kconfig"
2612
2613source "fs/Kconfig"
2614
e279b6c1
SR
2615source "arch/x86/Kconfig.debug"
2616
2617source "security/Kconfig"
2618
2619source "crypto/Kconfig"
2620
edf88417
AK
2621source "arch/x86/kvm/Kconfig"
2622
e279b6c1 2623source "lib/Kconfig"
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