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b2441318 1# SPDX-License-Identifier: GPL-2.0
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2# Select 32 or 64 bit
3config 64BIT
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MY
4 bool "64-bit kernel" if "$(ARCH)" = "x86"
5 default "$(ARCH)" != "i386"
a7f7f624 6 help
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7 Say yes to build a 64-bit kernel - formerly known as x86_64
8 Say no to build a 32-bit kernel - formerly known as i386
9
10config X86_32
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11 def_bool y
12 depends on !64BIT
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13 # Options that are inherently 32-bit kernel only:
14 select ARCH_WANT_IPC_PARSE_VERSION
15 select CLKSRC_I8253
16 select CLONE_BACKWARDS
157e118b 17 select GENERIC_VDSO_32
117ed454 18 select HAVE_DEBUG_STACKOVERFLOW
157e118b 19 select KMAP_LOCAL
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IM
20 select MODULES_USE_ELF_REL
21 select OLD_SIGACTION
2ca408d9 22 select ARCH_SPLIT_ARG64
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SR
23
24config X86_64
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25 def_bool y
26 depends on 64BIT
d94e0685 27 # Options that are inherently 64-bit kernel only:
4eb0716e 28 select ARCH_HAS_GIGANTIC_PAGE
c12d3362 29 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
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IM
30 select ARCH_USE_CMPXCHG_LOCKREF
31 select HAVE_ARCH_SOFT_DIRTY
32 select MODULES_USE_ELF_RELA
f616ab59 33 select NEED_DMA_MAP_STATE
09230cbc 34 select SWIOTLB
1032c0ba 35
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SRV
36config FORCE_DYNAMIC_FTRACE
37 def_bool y
38 depends on X86_32
39 depends on FUNCTION_TRACER
40 select DYNAMIC_FTRACE
41 help
42 We keep the static function tracing (!DYNAMIC_FTRACE) around
43 in order to test the non static function tracing in the
44 generic code, as other architectures still use it. But we
45 only need to keep it around for x86_64. No need to keep it
46 for x86_32. For x86_32, force DYNAMIC_FTRACE.
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47#
48# Arch settings
49#
50# ( Note that options that are marked 'if X86_64' could in principle be
51# ported to 32-bit as well. )
52#
8d5fffb9 53config X86
3c2362e6 54 def_bool y
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55 #
56 # Note: keep this list sorted alphabetically
57 #
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58 select ACPI_LEGACY_TABLES_LOOKUP if ACPI
59 select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI
942fa985 60 select ARCH_32BIT_OFF_T if X86_32
2a21ad57 61 select ARCH_CLOCKSOURCE_INIT
c763ea26 62 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
fa5b6ec9 63 select ARCH_HAS_DEBUG_VIRTUAL
399145f9 64 select ARCH_HAS_DEBUG_VM_PGTABLE if !X86_PAE
21266be9 65 select ARCH_HAS_DEVMEM_IS_ALLOWED
b1a57bbf 66 select ARCH_HAS_EARLY_DEBUG if KGDB
6471b825 67 select ARCH_HAS_ELF_RANDOMIZE
72d93104 68 select ARCH_HAS_FAST_MULTIPLIER
316d097c 69 select ARCH_HAS_FILTER_PGPROT
6974f0c4 70 select ARCH_HAS_FORTIFY_SOURCE
957e3fac 71 select ARCH_HAS_GCOV_PROFILE_ALL
0f1441b4 72 select ARCH_HAS_KCOV if X86_64 && STACK_VALIDATION
0c9c1d56 73 select ARCH_HAS_MEM_ENCRYPT
10bcc80e 74 select ARCH_HAS_MEMBARRIER_SYNC_CORE
0ebeea8c 75 select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
c763ea26 76 select ARCH_HAS_PMEM_API if X86_64
17596731 77 select ARCH_HAS_PTE_DEVMAP if X86_64
3010a5ea 78 select ARCH_HAS_PTE_SPECIAL
0aed55af 79 select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64
ec6347bb 80 select ARCH_HAS_COPY_MC if X86_64
d2852a22 81 select ARCH_HAS_SET_MEMORY
d253ca0c 82 select ARCH_HAS_SET_DIRECT_MAP
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LA
83 select ARCH_HAS_STRICT_KERNEL_RWX
84 select ARCH_HAS_STRICT_MODULE_RWX
ac1ab12a 85 select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
25c619e5 86 select ARCH_HAS_SYSCALL_WRAPPER
c6d30853 87 select ARCH_HAS_UBSAN_SANITIZE_ALL
7e01ccb4 88 select ARCH_HAS_DEBUG_WX
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89 select ARCH_HAVE_NMI_SAFE_CMPXCHG
90 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
77fbbc81 91 select ARCH_MIGHT_HAVE_PC_PARPORT
5e2c18c0 92 select ARCH_MIGHT_HAVE_PC_SERIO
3599fe12 93 select ARCH_STACKWALK
2c870e61 94 select ARCH_SUPPORTS_ACPI
6471b825 95 select ARCH_SUPPORTS_ATOMIC_RMW
5d6ad668 96 select ARCH_SUPPORTS_DEBUG_PAGEALLOC
6471b825 97 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
14df3267 98 select ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP if NR_CPUS <= 4096
6471b825 99 select ARCH_USE_BUILTIN_BSWAP
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100 select ARCH_USE_QUEUED_RWLOCKS
101 select ARCH_USE_QUEUED_SPINLOCKS
2ce0d7f9 102 select ARCH_USE_SYM_ANNOTATIONS
ce4a4e56 103 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
81c22041 104 select ARCH_WANT_DEFAULT_BPF_JIT if X86_64
c763ea26 105 select ARCH_WANTS_DYNAMIC_TASK_STRUCT
3876d4a3 106 select ARCH_WANT_HUGE_PMD_SHARE
59612b24 107 select ARCH_WANT_LD_ORPHAN_WARN
38d8b4e6 108 select ARCH_WANTS_THP_SWAP if X86_64
10916706 109 select BUILDTIME_TABLE_SORT
6471b825 110 select CLKEVT_I8253
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111 select CLOCKSOURCE_VALIDATE_LAST_CYCLE
112 select CLOCKSOURCE_WATCHDOG
6471b825 113 select DCACHE_WORD_ACCESS
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LT
114 select EDAC_ATOMIC_SCRUB
115 select EDAC_SUPPORT
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116 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
117 select GENERIC_CLOCKEVENTS_MIN_ADJUST
118 select GENERIC_CMOS_UPDATE
119 select GENERIC_CPU_AUTOPROBE
61dc0f55 120 select GENERIC_CPU_VULNERABILITIES
5b7c73e0 121 select GENERIC_EARLY_IOREMAP
27d6b4d1 122 select GENERIC_ENTRY
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123 select GENERIC_FIND_FIRST_BIT
124 select GENERIC_IOMAP
c7d6c9dd 125 select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP
0fa115da 126 select GENERIC_IRQ_MATRIX_ALLOCATOR if X86_LOCAL_APIC
ad7a929f 127 select GENERIC_IRQ_MIGRATION if SMP
6471b825 128 select GENERIC_IRQ_PROBE
c201c917 129 select GENERIC_IRQ_RESERVATION_MODE
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130 select GENERIC_IRQ_SHOW
131 select GENERIC_PENDING_IRQ if SMP
2ae27137 132 select GENERIC_PTDUMP
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133 select GENERIC_SMP_IDLE_THREAD
134 select GENERIC_STRNCPY_FROM_USER
135 select GENERIC_STRNLEN_USER
136 select GENERIC_TIME_VSYSCALL
7ac87074 137 select GENERIC_GETTIMEOFDAY
550a77a7 138 select GENERIC_VDSO_TIME_NS
39656e83 139 select GUP_GET_PTE_LOW_HIGH if X86_PAE
17e5888e 140 select HARDIRQS_SW_RESEND
7edaeb68 141 select HARDLOCKUP_CHECK_TIMESTAMP if X86_64
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142 select HAVE_ACPI_APEI if ACPI
143 select HAVE_ACPI_APEI_NMI if ACPI
144 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
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145 select HAVE_ARCH_AUDITSYSCALL
146 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE
147 select HAVE_ARCH_JUMP_LABEL
b34006c4 148 select HAVE_ARCH_JUMP_LABEL_RELATIVE
d17a1d97 149 select HAVE_ARCH_KASAN if X86_64
0609ae01 150 select HAVE_ARCH_KASAN_VMALLOC if X86_64
6471b825 151 select HAVE_ARCH_KGDB
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152 select HAVE_ARCH_MMAP_RND_BITS if MMU
153 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT
1b028f78 154 select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT
271ca788 155 select HAVE_ARCH_PREL32_RELOCATIONS
6471b825 156 select HAVE_ARCH_SECCOMP_FILTER
f7d83c1c 157 select HAVE_ARCH_THREAD_STRUCT_WHITELIST
afaef01c 158 select HAVE_ARCH_STACKLEAK
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159 select HAVE_ARCH_TRACEHOOK
160 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
a00cc7d9 161 select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
b64d8d1e 162 select HAVE_ARCH_USERFAULTFD_WP if X86_64 && USERFAULTFD
e37e43a4 163 select HAVE_ARCH_VMAP_STACK if X86_64
c763ea26 164 select HAVE_ARCH_WITHIN_STACK_FRAMES
2ff2b7ec 165 select HAVE_ASM_MODVERSIONS
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166 select HAVE_CMPXCHG_DOUBLE
167 select HAVE_CMPXCHG_LOCAL
168 select HAVE_CONTEXT_TRACKING if X86_64
d1f250e2 169 select HAVE_CONTEXT_TRACKING_OFFSTACK if HAVE_CONTEXT_TRACKING
cf4db259 170 select HAVE_C_RECORDMCOUNT
6471b825 171 select HAVE_DEBUG_KMEMLEAK
6471b825 172 select HAVE_DMA_CONTIGUOUS
677aa9f7 173 select HAVE_DYNAMIC_FTRACE
06aeaaea 174 select HAVE_DYNAMIC_FTRACE_WITH_REGS
02a474ca 175 select HAVE_DYNAMIC_FTRACE_WITH_ARGS if X86_64
562955fe 176 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
03f5781b 177 select HAVE_EBPF_JIT
58340a07 178 select HAVE_EFFICIENT_UNALIGNED_ACCESS
6630a8e5 179 select HAVE_EISA
5f56a5df 180 select HAVE_EXIT_THREAD
67a929e0 181 select HAVE_FAST_GUP
644e0e8d 182 select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE
6471b825 183 select HAVE_FTRACE_MCOUNT_RECORD
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184 select HAVE_FUNCTION_GRAPH_TRACER
185 select HAVE_FUNCTION_TRACER
6b90bd4b 186 select HAVE_GCC_PLUGINS
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187 select HAVE_HW_BREAKPOINT
188 select HAVE_IDE
189 select HAVE_IOREMAP_PROT
624db9ea 190 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
6471b825 191 select HAVE_IRQ_TIME_ACCOUNTING
2e9f3bdd 192 select HAVE_KERNEL_BZIP2
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193 select HAVE_KERNEL_GZIP
194 select HAVE_KERNEL_LZ4
2e9f3bdd 195 select HAVE_KERNEL_LZMA
13510997 196 select HAVE_KERNEL_LZO
6471b825 197 select HAVE_KERNEL_XZ
fb46d057 198 select HAVE_KERNEL_ZSTD
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199 select HAVE_KPROBES
200 select HAVE_KPROBES_ON_FTRACE
540adea3 201 select HAVE_FUNCTION_ERROR_INJECTION
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202 select HAVE_KRETPROBES
203 select HAVE_KVM
204 select HAVE_LIVEPATCH if X86_64
0102752e 205 select HAVE_MIXED_BREAKPOINTS_REGS
ee9f8fce 206 select HAVE_MOD_ARCH_SPECIFIC
9f132f7e 207 select HAVE_MOVE_PMD
be37c98d 208 select HAVE_MOVE_PUD
42a0bb3f 209 select HAVE_NMI
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210 select HAVE_OPROFILE
211 select HAVE_OPTPROBES
212 select HAVE_PCSPKR_PLATFORM
213 select HAVE_PERF_EVENTS
c01d4323 214 select HAVE_PERF_EVENTS_NMI
92e5aae4 215 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
eb01d42a 216 select HAVE_PCI
c5e63197 217 select HAVE_PERF_REGS
c5ebcedb 218 select HAVE_PERF_USER_STACK_DUMP
ff2e6d72 219 select MMU_GATHER_RCU_TABLE_FREE if PARAVIRT
00998085 220 select HAVE_POSIX_CPU_TIMERS_TASK_WORK
6471b825 221 select HAVE_REGS_AND_STACK_ACCESS_API
6415b38b 222 select HAVE_RELIABLE_STACKTRACE if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION
3c88ee19 223 select HAVE_FUNCTION_ARG_ACCESS_API
d148eac0 224 select HAVE_STACKPROTECTOR if CC_HAS_SANE_STACKPROTECTOR
c763ea26 225 select HAVE_STACK_VALIDATION if X86_64
e6d6c071 226 select HAVE_STATIC_CALL
1e7e4788 227 select HAVE_STATIC_CALL_INLINE if HAVE_STACK_VALIDATION
d6761b8f 228 select HAVE_RSEQ
6471b825 229 select HAVE_SYSCALL_TRACEPOINTS
6471b825 230 select HAVE_UNSTABLE_SCHED_CLOCK
7c68af6e 231 select HAVE_USER_RETURN_NOTIFIER
7ac87074 232 select HAVE_GENERIC_VDSO
05736e4a 233 select HOTPLUG_SMT if SMP
c0185808 234 select IRQ_FORCED_THREADING
86596f0a 235 select NEED_SG_DMA_LENGTH
2eac9c2d 236 select PCI_DOMAINS if PCI
625210cf 237 select PCI_LOCKLESS_CONFIG if PCI
6471b825 238 select PERF_EVENTS
3195ef59 239 select RTC_LIB
d6faca40 240 select RTC_MC146818_LIB
6471b825 241 select SPARSE_IRQ
83fe27ea 242 select SRCU
1e7e4788 243 select STACK_VALIDATION if HAVE_STACK_VALIDATION && (HAVE_STATIC_CALL_INLINE || RETPOLINE)
6471b825 244 select SYSCTL_EXCEPTION_TRACE
15f4eae7 245 select THREAD_INFO_IN_TASK
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246 select USER_STACKTRACE_SUPPORT
247 select VIRT_TO_BUS
3b02a051 248 select HAVE_ARCH_KCSAN if X86_64
6471b825 249 select X86_FEATURE_NAMES if PROC_FS
0c608dad 250 select PROC_PID_ARCH_STATUS if PROC_FS
9e2b4be3 251 imply IMA_SECURE_AND_OR_TRUSTED_BOOT if EFI
7d8330a5 252
ba7e4d13 253config INSTRUCTION_DECODER
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254 def_bool y
255 depends on KPROBES || PERF_EVENTS || UPROBES
ba7e4d13 256
51b26ada
LT
257config OUTPUT_FORMAT
258 string
259 default "elf32-i386" if X86_32
260 default "elf64-x86-64" if X86_64
261
8d5fffb9 262config LOCKDEP_SUPPORT
3c2362e6 263 def_bool y
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SR
264
265config STACKTRACE_SUPPORT
3c2362e6 266 def_bool y
8d5fffb9 267
8d5fffb9 268config MMU
3c2362e6 269 def_bool y
8d5fffb9 270
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DC
271config ARCH_MMAP_RND_BITS_MIN
272 default 28 if 64BIT
273 default 8
274
275config ARCH_MMAP_RND_BITS_MAX
276 default 32 if 64BIT
277 default 16
278
279config ARCH_MMAP_RND_COMPAT_BITS_MIN
280 default 8
281
282config ARCH_MMAP_RND_COMPAT_BITS_MAX
283 default 16
284
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SR
285config SBUS
286 bool
287
288config GENERIC_ISA_DMA
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JB
289 def_bool y
290 depends on ISA_DMA_API
8d5fffb9 291
8d5fffb9 292config GENERIC_BUG
3c2362e6 293 def_bool y
8d5fffb9 294 depends on BUG
b93a531e
JB
295 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
296
297config GENERIC_BUG_RELATIVE_POINTERS
298 bool
8d5fffb9 299
8d5fffb9 300config ARCH_MAY_HAVE_PC_FDC
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301 def_bool y
302 depends on ISA_DMA_API
8d5fffb9 303
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SR
304config GENERIC_CALIBRATE_DELAY
305 def_bool y
306
9a0b8415 307config ARCH_HAS_CPU_RELAX
308 def_bool y
309
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310config ARCH_HAS_CACHE_LINE_SIZE
311 def_bool y
312
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DH
313config ARCH_HAS_FILTER_PGPROT
314 def_bool y
315
dd5af90a 316config HAVE_SETUP_PER_CPU_AREA
89c9c4c5 317 def_bool y
b32ef636 318
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TH
319config NEED_PER_CPU_EMBED_FIRST_CHUNK
320 def_bool y
321
322config NEED_PER_CPU_PAGE_FIRST_CHUNK
11124411
TH
323 def_bool y
324
801e4062
JB
325config ARCH_HIBERNATION_POSSIBLE
326 def_bool y
801e4062 327
f4cb5700
JB
328config ARCH_SUSPEND_POSSIBLE
329 def_bool y
f4cb5700 330
53313b2c
SC
331config ARCH_WANT_GENERAL_HUGETLB
332 def_bool y
333
8d5fffb9 334config ZONE_DMA32
e0fd24a3 335 def_bool y if X86_64
8d5fffb9 336
8d5fffb9 337config AUDIT_ARCH
e0fd24a3 338 def_bool y if X86_64
8d5fffb9 339
d6f2d75a
AR
340config KASAN_SHADOW_OFFSET
341 hex
342 depends on KASAN
343 default 0xdffffc0000000000
344
69575d38
SW
345config HAVE_INTEL_TXT
346 def_bool y
6ea30386 347 depends on INTEL_IOMMU && ACPI
69575d38 348
6b0c3d44
SR
349config X86_32_SMP
350 def_bool y
351 depends on X86_32 && SMP
352
353config X86_64_SMP
354 def_bool y
355 depends on X86_64 && SMP
356
ccbeed3a
TH
357config X86_32_LAZY_GS
358 def_bool y
8458f8c2 359 depends on X86_32 && !STACKPROTECTOR
ccbeed3a 360
2b144498
SD
361config ARCH_SUPPORTS_UPROBES
362 def_bool y
363
d20642f0
RH
364config FIX_EARLYCON_MEM
365 def_bool y
366
94d49eb3
KS
367config DYNAMIC_PHYSICAL_MASK
368 bool
369
98233368
KS
370config PGTABLE_LEVELS
371 int
77ef56e4 372 default 5 if X86_5LEVEL
98233368
KS
373 default 4 if X86_64
374 default 3 if X86_PAE
375 default 2
376
2a61f474
MY
377config CC_HAS_SANE_STACKPROTECTOR
378 bool
379 default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT
380 default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC))
381 help
382 We have to make sure stack protector is unconditionally disabled if
383 the compiler produces broken code.
384
506f1d07
SR
385menu "Processor type and features"
386
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RD
387config ZONE_DMA
388 bool "DMA memory allocation support" if EXPERT
389 default y
390 help
391 DMA memory allocation support allows devices with less than 32-bit
392 addressing to allocate within the first 16MB of address space.
393 Disable if no such devices will be used.
394
395 If unsure, say Y.
396
506f1d07
SR
397config SMP
398 bool "Symmetric multi-processing support"
a7f7f624 399 help
506f1d07 400 This enables support for systems with more than one CPU. If you have
4a474157
RG
401 a system with only one CPU, say N. If you have a system with more
402 than one CPU, say Y.
506f1d07 403
4a474157 404 If you say N here, the kernel will run on uni- and multiprocessor
506f1d07
SR
405 machines, but will use only one CPU of a multiprocessor machine. If
406 you say Y here, the kernel will run on many, but not all,
4a474157 407 uniprocessor machines. On a uniprocessor machine, the kernel
506f1d07
SR
408 will run faster if you say N here.
409
410 Note that if you say Y here and choose architecture "586" or
411 "Pentium" under "Processor family", the kernel will not work on 486
412 architectures. Similarly, multiprocessor kernels for the "PPro"
413 architecture may not work on all Pentium based boards.
414
415 People using multiprocessor machines who say Y here should also say
416 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
417 Management" code will be disabled if you say Y here.
418
cb1aaebe 419 See also <file:Documentation/x86/i386/IO-APIC.rst>,
4f4cfa6c 420 <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
506f1d07
SR
421 <http://www.tldp.org/docs.html#howto>.
422
423 If you don't know what to do here, say N.
424
9def39be
JT
425config X86_FEATURE_NAMES
426 bool "Processor feature human-readable names" if EMBEDDED
427 default y
a7f7f624 428 help
9def39be
JT
429 This option compiles in a table of x86 feature bits and corresponding
430 names. This is required to support /proc/cpuinfo and a few kernel
431 messages. You can disable this to save space, at the expense of
432 making those few kernel messages show numeric feature bits instead.
433
434 If in doubt, say Y.
435
06cd9a7d
YL
436config X86_X2APIC
437 bool "Support x2apic"
19e3d60d 438 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
a7f7f624 439 help
06cd9a7d
YL
440 This enables x2apic support on CPUs that have this feature.
441
442 This allows 32-bit apic IDs (so it can support very large systems),
443 and accesses the local apic via MSRs not via mmio.
444
06cd9a7d
YL
445 If you don't know what to do here, say N.
446
6695c85b 447config X86_MPPARSE
6e87f9b7 448 bool "Enable MPS table" if ACPI || SFI
7a527688 449 default y
5ab74722 450 depends on X86_LOCAL_APIC
a7f7f624 451 help
6695c85b
YL
452 For old smp systems that do not have proper acpi support. Newer systems
453 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
6695c85b 454
ddd70cf9 455config GOLDFISH
b03b016f
KK
456 def_bool y
457 depends on X86_GOLDFISH
ddd70cf9 458
76b04384
DW
459config RETPOLINE
460 bool "Avoid speculative indirect branches in kernel"
461 default y
462 help
463 Compile kernel with the retpoline compiler options to guard against
464 kernel-to-user data leaks by avoiding speculative indirect
465 branches. Requires a compiler with -mindirect-branch=thunk-extern
466 support for full protection. The kernel may run slower.
467
e6d42931
JW
468config X86_CPU_RESCTRL
469 bool "x86 CPU resource control support"
6fe07ce3 470 depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
59fe5a77 471 select KERNFS
e79f15a4 472 select PROC_CPU_RESCTRL if PROC_FS
78e99b4a 473 help
e6d42931 474 Enable x86 CPU resource control support.
6fe07ce3
BM
475
476 Provide support for the allocation and monitoring of system resources
477 usage by the CPU.
478
479 Intel calls this Intel Resource Director Technology
480 (Intel(R) RDT). More information about RDT can be found in the
481 Intel x86 Architecture Software Developer Manual.
482
483 AMD calls this AMD Platform Quality of Service (AMD QoS).
484 More information about AMD QoS can be found in the AMD64 Technology
485 Platform Quality of Service Extensions manual.
78e99b4a
FY
486
487 Say N if unsure.
488
8425091f 489if X86_32
a0d0bb4d
RD
490config X86_BIGSMP
491 bool "Support for big SMP systems with more than 8 CPUs"
492 depends on SMP
a7f7f624 493 help
e133f6ea 494 This option is needed for the systems that have more than 8 CPUs.
a0d0bb4d 495
c5c606d9
RT
496config X86_EXTENDED_PLATFORM
497 bool "Support for extended (non-PC) x86 platforms"
498 default y
a7f7f624 499 help
06ac8346
IM
500 If you disable this option then the kernel will only support
501 standard PC platforms. (which covers the vast majority of
502 systems out there.)
503
8425091f
RT
504 If you enable this option then you'll be able to select support
505 for the following (non-PC) 32 bit x86 platforms:
cb7b8023 506 Goldfish (Android emulator)
8425091f 507 AMD Elan
8425091f
RT
508 RDC R-321x SoC
509 SGI 320/540 (Visual Workstation)
83125a3a 510 STA2X11-based (e.g. Northville)
3f4110a4 511 Moorestown MID devices
06ac8346
IM
512
513 If you have one of these systems, or if you want to build a
514 generic distribution kernel, say Y here - otherwise say N.
8425091f 515endif
06ac8346 516
8425091f
RT
517if X86_64
518config X86_EXTENDED_PLATFORM
519 bool "Support for extended (non-PC) x86 platforms"
520 default y
a7f7f624 521 help
8425091f
RT
522 If you disable this option then the kernel will only support
523 standard PC platforms. (which covers the vast majority of
524 systems out there.)
525
526 If you enable this option then you'll be able to select support
527 for the following (non-PC) 64 bit x86 platforms:
44b111b5 528 Numascale NumaChip
8425091f
RT
529 ScaleMP vSMP
530 SGI Ultraviolet
531
532 If you have one of these systems, or if you want to build a
533 generic distribution kernel, say Y here - otherwise say N.
534endif
c5c606d9
RT
535# This is an alphabetically sorted list of 64 bit extended platforms
536# Please maintain the alphabetic order if and when there are additions
44b111b5
SP
537config X86_NUMACHIP
538 bool "Numascale NumaChip"
539 depends on X86_64
540 depends on X86_EXTENDED_PLATFORM
541 depends on NUMA
542 depends on SMP
543 depends on X86_X2APIC
f9726bfd 544 depends on PCI_MMCONFIG
a7f7f624 545 help
44b111b5
SP
546 Adds support for Numascale NumaChip large-SMP systems. Needed to
547 enable more than ~168 cores.
548 If you don't have one of these, you should say N here.
506f1d07 549
c5c606d9
RT
550config X86_VSMP
551 bool "ScaleMP vSMP"
6276a074 552 select HYPERVISOR_GUEST
c5c606d9
RT
553 select PARAVIRT
554 depends on X86_64 && PCI
555 depends on X86_EXTENDED_PLATFORM
ead91d4b 556 depends on SMP
a7f7f624 557 help
c5c606d9
RT
558 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
559 supposed to run on these EM64T-based machines. Only choose this option
560 if you have one of these machines.
5e3a77e9 561
03b48632
NP
562config X86_UV
563 bool "SGI Ultraviolet"
564 depends on X86_64
c5c606d9 565 depends on X86_EXTENDED_PLATFORM
54c28d29 566 depends on NUMA
1ecb4ae5 567 depends on EFI
9d6c26e7 568 depends on X86_X2APIC
1222e564 569 depends on PCI
a7f7f624 570 help
03b48632
NP
571 This option is needed in order to support SGI Ultraviolet systems.
572 If you don't have one of these, you should say N here.
573
c5c606d9
RT
574# Following is an alphabetically sorted list of 32 bit extended platforms
575# Please maintain the alphabetic order if and when there are additions
506f1d07 576
ddd70cf9 577config X86_GOLDFISH
b03b016f
KK
578 bool "Goldfish (Virtual Platform)"
579 depends on X86_EXTENDED_PLATFORM
a7f7f624 580 help
ddd70cf9
JN
581 Enable support for the Goldfish virtual platform used primarily
582 for Android development. Unless you are building for the Android
583 Goldfish emulator say N here.
584
c751e17b
TG
585config X86_INTEL_CE
586 bool "CE4100 TV platform"
587 depends on PCI
588 depends on PCI_GODIRECT
6084a6e2 589 depends on X86_IO_APIC
c751e17b
TG
590 depends on X86_32
591 depends on X86_EXTENDED_PLATFORM
37bc9f50 592 select X86_REBOOTFIXUPS
da6b737b
SAS
593 select OF
594 select OF_EARLY_FLATTREE
a7f7f624 595 help
c751e17b
TG
596 Select for the Intel CE media processor (CE4100) SOC.
597 This option compiles in support for the CE4100 SOC for settop
598 boxes and media devices.
599
4cb9b00f 600config X86_INTEL_MID
43605ef1 601 bool "Intel MID platform support"
43605ef1 602 depends on X86_EXTENDED_PLATFORM
edc6bc78 603 depends on X86_PLATFORM_DEVICES
1ea7c673 604 depends on PCI
3fda5bb4 605 depends on X86_64 || (PCI_GOANY && X86_32)
1ea7c673 606 depends on X86_IO_APIC
7c9c3a1e 607 select SFI
4cb9b00f 608 select I2C
7c9c3a1e 609 select DW_APB_TIMER
1ea7c673 610 select APB_TIMER
54b34aa0 611 select INTEL_SCU_PCI
15a713df 612 select MFD_INTEL_MSIC
a7f7f624 613 help
4cb9b00f
DC
614 Select to build a kernel capable of supporting Intel MID (Mobile
615 Internet Device) platform systems which do not have the PCI legacy
616 interfaces. If you are building for a PC class system say N here.
1ea7c673 617
4cb9b00f
DC
618 Intel MID platforms are based on an Intel processor and chipset which
619 consume less power than most of the x86 derivatives.
43605ef1 620
8bbc2a13
BD
621config X86_INTEL_QUARK
622 bool "Intel Quark platform support"
623 depends on X86_32
624 depends on X86_EXTENDED_PLATFORM
625 depends on X86_PLATFORM_DEVICES
626 depends on X86_TSC
627 depends on PCI
628 depends on PCI_GOANY
629 depends on X86_IO_APIC
630 select IOSF_MBI
631 select INTEL_IMR
9ab6eb51 632 select COMMON_CLK
a7f7f624 633 help
8bbc2a13
BD
634 Select to include support for Quark X1000 SoC.
635 Say Y here if you have a Quark based system such as the Arduino
636 compatible Intel Galileo.
637
3d48aab1
MW
638config X86_INTEL_LPSS
639 bool "Intel Low Power Subsystem Support"
5962dd22 640 depends on X86 && ACPI && PCI
3d48aab1 641 select COMMON_CLK
0f531431 642 select PINCTRL
eebb3e8d 643 select IOSF_MBI
a7f7f624 644 help
3d48aab1
MW
645 Select to build support for Intel Low Power Subsystem such as
646 found on Intel Lynxpoint PCH. Selecting this option enables
0f531431
MN
647 things like clock tree (common clock framework) and pincontrol
648 which are needed by the LPSS peripheral drivers.
3d48aab1 649
92082a88
KX
650config X86_AMD_PLATFORM_DEVICE
651 bool "AMD ACPI2Platform devices support"
652 depends on ACPI
653 select COMMON_CLK
654 select PINCTRL
a7f7f624 655 help
92082a88
KX
656 Select to interpret AMD specific ACPI device to platform device
657 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
658 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
659 implemented under PINCTRL subsystem.
660
ced3ce76
DB
661config IOSF_MBI
662 tristate "Intel SoC IOSF Sideband support for SoC platforms"
663 depends on PCI
a7f7f624 664 help
ced3ce76
DB
665 This option enables sideband register access support for Intel SoC
666 platforms. On these platforms the IOSF sideband is used in lieu of
667 MSR's for some register accesses, mostly but not limited to thermal
668 and power. Drivers may query the availability of this device to
669 determine if they need the sideband in order to work on these
670 platforms. The sideband is available on the following SoC products.
671 This list is not meant to be exclusive.
672 - BayTrail
673 - Braswell
674 - Quark
675
676 You should say Y if you are running a kernel on one of these SoC's.
677
ed2226bd
DB
678config IOSF_MBI_DEBUG
679 bool "Enable IOSF sideband access through debugfs"
680 depends on IOSF_MBI && DEBUG_FS
a7f7f624 681 help
ed2226bd
DB
682 Select this option to expose the IOSF sideband access registers (MCR,
683 MDR, MCRX) through debugfs to write and read register information from
684 different units on the SoC. This is most useful for obtaining device
685 state information for debug and analysis. As this is a general access
686 mechanism, users of this option would have specific knowledge of the
687 device they want to access.
688
689 If you don't require the option or are in doubt, say N.
690
c5c606d9
RT
691config X86_RDC321X
692 bool "RDC R-321x SoC"
506f1d07 693 depends on X86_32
c5c606d9
RT
694 depends on X86_EXTENDED_PLATFORM
695 select M486
696 select X86_REBOOTFIXUPS
a7f7f624 697 help
c5c606d9
RT
698 This option is needed for RDC R-321x system-on-chip, also known
699 as R-8610-(G).
700 If you don't have one of these chips, you should say N here.
701
e0c7ae37 702config X86_32_NON_STANDARD
9c398017
IM
703 bool "Support non-standard 32-bit SMP architectures"
704 depends on X86_32 && SMP
c5c606d9 705 depends on X86_EXTENDED_PLATFORM
a7f7f624 706 help
b5660ba7
PA
707 This option compiles in the bigsmp and STA2X11 default
708 subarchitectures. It is intended for a generic binary
709 kernel. If you select them all, kernel will probe it one by
710 one and will fallback to default.
d49c4288 711
c5c606d9 712# Alphabetically sorted list of Non standard 32 bit platforms
d49c4288 713
d949f36f 714config X86_SUPPORTS_MEMORY_FAILURE
6fc108a0 715 def_bool y
d949f36f
LT
716 # MCE code calls memory_failure():
717 depends on X86_MCE
718 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
d949f36f
LT
719 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
720 depends on X86_64 || !SPARSEMEM
721 select ARCH_SUPPORTS_MEMORY_FAILURE
d949f36f 722
83125a3a
AR
723config STA2X11
724 bool "STA2X11 Companion Chip Support"
725 depends on X86_32_NON_STANDARD && PCI
83125a3a
AR
726 select SWIOTLB
727 select MFD_STA2X11
0145071b 728 select GPIOLIB
a7f7f624 729 help
83125a3a
AR
730 This adds support for boards based on the STA2X11 IO-Hub,
731 a.k.a. "ConneXt". The chip is used in place of the standard
732 PC chipset, so all "standard" peripherals are missing. If this
733 option is selected the kernel will still be able to boot on
734 standard PC machines.
735
82148d1d
S
736config X86_32_IRIS
737 tristate "Eurobraille/Iris poweroff module"
738 depends on X86_32
a7f7f624 739 help
82148d1d
S
740 The Iris machines from EuroBraille do not have APM or ACPI support
741 to shut themselves down properly. A special I/O sequence is
742 needed to do so, which is what this module does at
743 kernel shutdown.
744
745 This is only for Iris machines from EuroBraille.
746
747 If unused, say N.
748
ae1e9130 749config SCHED_OMIT_FRAME_POINTER
3c2362e6
HH
750 def_bool y
751 prompt "Single-depth WCHAN output"
a87d0914 752 depends on X86
a7f7f624 753 help
506f1d07
SR
754 Calculate simpler /proc/<PID>/wchan values. If this option
755 is disabled then wchan values will recurse back to the
756 caller function. This provides more accurate wchan values,
757 at the expense of slightly more scheduling overhead.
758
759 If in doubt, say "Y".
760
6276a074
BP
761menuconfig HYPERVISOR_GUEST
762 bool "Linux guest support"
a7f7f624 763 help
6276a074
BP
764 Say Y here to enable options for running Linux under various hyper-
765 visors. This option enables basic hypervisor detection and platform
766 setup.
506f1d07 767
6276a074
BP
768 If you say N, all options in this submenu will be skipped and
769 disabled, and Linux guest support won't be built in.
506f1d07 770
6276a074 771if HYPERVISOR_GUEST
506f1d07 772
e61bd94a
EPH
773config PARAVIRT
774 bool "Enable paravirtualization code"
a7f7f624 775 help
e61bd94a
EPH
776 This changes the kernel so it can modify itself when it is run
777 under a hypervisor, potentially improving performance significantly
778 over full virtualization. However, when run without a hypervisor
779 the kernel is theoretically slower and slightly larger.
780
c00a280a
JG
781config PARAVIRT_XXL
782 bool
783
6276a074
BP
784config PARAVIRT_DEBUG
785 bool "paravirt-ops debugging"
786 depends on PARAVIRT && DEBUG_KERNEL
a7f7f624 787 help
6276a074
BP
788 Enable to debug paravirt_ops internals. Specifically, BUG if
789 a paravirt_op is missing when it is called.
790
b4ecc126
JF
791config PARAVIRT_SPINLOCKS
792 bool "Paravirtualization layer for spinlocks"
6ea30386 793 depends on PARAVIRT && SMP
a7f7f624 794 help
b4ecc126
JF
795 Paravirtualized spinlocks allow a pvops backend to replace the
796 spinlock implementation with something virtualization-friendly
797 (for example, block the virtual CPU rather than spinning).
798
4c4e4f61
R
799 It has a minimal impact on native kernels and gives a nice performance
800 benefit on paravirtualized KVM / Xen kernels.
b4ecc126 801
4c4e4f61 802 If you are unsure how to answer this question, answer Y.
b4ecc126 803
ecca2502
ZY
804config X86_HV_CALLBACK_VECTOR
805 def_bool n
806
6276a074 807source "arch/x86/xen/Kconfig"
7af192c9 808
6276a074
BP
809config KVM_GUEST
810 bool "KVM Guest support (including kvmclock)"
811 depends on PARAVIRT
812 select PARAVIRT_CLOCK
a1c4423b 813 select ARCH_CPUIDLE_HALTPOLL
b1d40575 814 select X86_HV_CALLBACK_VECTOR
6276a074 815 default y
a7f7f624 816 help
6276a074
BP
817 This option enables various optimizations for running under the KVM
818 hypervisor. It includes a paravirtualized clock, so that instead
819 of relying on a PIT (or probably other) emulation by the
820 underlying device model, the host provides the guest with
821 timing infrastructure such as time of day, and system time
506f1d07 822
a1c4423b 823config ARCH_CPUIDLE_HALTPOLL
b03b016f
KK
824 def_bool n
825 prompt "Disable host haltpoll when loading haltpoll driver"
826 help
a1c4423b
MT
827 If virtualized under KVM, disable host haltpoll.
828
7733607f
MW
829config PVH
830 bool "Support for running PVH guests"
a7f7f624 831 help
7733607f
MW
832 This option enables the PVH entry point for guest virtual machines
833 as specified in the x86/HVM direct boot ABI.
834
6276a074
BP
835config PARAVIRT_TIME_ACCOUNTING
836 bool "Paravirtual steal time accounting"
837 depends on PARAVIRT
a7f7f624 838 help
6276a074
BP
839 Select this option to enable fine granularity task steal time
840 accounting. Time spent executing other tasks in parallel with
841 the current vCPU is discounted from the vCPU power. To account for
842 that, there can be a small performance impact.
843
844 If in doubt, say N here.
845
846config PARAVIRT_CLOCK
847 bool
97349135 848
4a362601
JK
849config JAILHOUSE_GUEST
850 bool "Jailhouse non-root cell support"
abde587b 851 depends on X86_64 && PCI
87e65d05 852 select X86_PM_TIMER
a7f7f624 853 help
4a362601
JK
854 This option allows to run Linux as guest in a Jailhouse non-root
855 cell. You can leave this option disabled if you only want to start
856 Jailhouse and run Linux afterwards in the root cell.
857
ec7972c9
ZY
858config ACRN_GUEST
859 bool "ACRN Guest support"
860 depends on X86_64
498ad393 861 select X86_HV_CALLBACK_VECTOR
ec7972c9
ZY
862 help
863 This option allows to run Linux as guest in the ACRN hypervisor. ACRN is
864 a flexible, lightweight reference open-source hypervisor, built with
865 real-time and safety-criticality in mind. It is built for embedded
866 IOT with small footprint and real-time features. More details can be
867 found in https://projectacrn.org/.
868
6276a074 869endif #HYPERVISOR_GUEST
97349135 870
506f1d07
SR
871source "arch/x86/Kconfig.cpu"
872
873config HPET_TIMER
3c2362e6 874 def_bool X86_64
506f1d07 875 prompt "HPET Timer Support" if X86_32
a7f7f624 876 help
8f9ca475
IM
877 Use the IA-PC HPET (High Precision Event Timer) to manage
878 time in preference to the PIT and RTC, if a HPET is
879 present.
880 HPET is the next generation timer replacing legacy 8254s.
881 The HPET provides a stable time base on SMP
882 systems, unlike the TSC, but it is more expensive to access,
4e7f9df2
MT
883 as it is off-chip. The interface used is documented
884 in the HPET spec, revision 1.
506f1d07 885
8f9ca475
IM
886 You can safely choose Y here. However, HPET will only be
887 activated if the platform and the BIOS support this feature.
888 Otherwise the 8254 will be used for timing services.
506f1d07 889
8f9ca475 890 Choose N to continue using the legacy 8254 timer.
506f1d07
SR
891
892config HPET_EMULATE_RTC
3c2362e6 893 def_bool y
9d8af78b 894 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
506f1d07 895
bb24c471 896config APB_TIMER
b03b016f
KK
897 def_bool y if X86_INTEL_MID
898 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
899 select DW_APB_TIMER
900 depends on X86_INTEL_MID && SFI
901 help
902 APB timer is the replacement for 8254, HPET on X86 MID platforms.
903 The APBT provides a stable time base on SMP
904 systems, unlike the TSC, but it is more expensive to access,
905 as it is off-chip. APB timers are always running regardless of CPU
906 C states, they are used as per CPU clockevent device when possible.
bb24c471 907
6a108a14 908# Mark as expert because too many people got it wrong.
506f1d07 909# The code disables itself when not needed.
7ae9392c
TP
910config DMI
911 default y
cf074402 912 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
6a108a14 913 bool "Enable DMI scanning" if EXPERT
a7f7f624 914 help
7ae9392c
TP
915 Enabled scanning of DMI to identify machine quirks. Say Y
916 here unless you have verified that your setup is not
917 affected by entries in the DMI blacklist. Required by PNP
918 BIOS code.
919
506f1d07 920config GART_IOMMU
38901f1c 921 bool "Old AMD GART IOMMU support"
2f9237d4 922 select DMA_OPS
a4ce5a48 923 select IOMMU_HELPER
506f1d07 924 select SWIOTLB
23ac4ae8 925 depends on X86_64 && PCI && AMD_NB
a7f7f624 926 help
ced3c42c
IM
927 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
928 GART based hardware IOMMUs.
929
930 The GART supports full DMA access for devices with 32-bit access
931 limitations, on systems with more than 3 GB. This is usually needed
932 for USB, sound, many IDE/SATA chipsets and some other devices.
933
934 Newer systems typically have a modern AMD IOMMU, supported via
935 the CONFIG_AMD_IOMMU=y config option.
936
937 In normal configurations this driver is only active when needed:
938 there's more than 3 GB of memory and the system contains a
939 32-bit limited device.
940
941 If unsure, say Y.
506f1d07 942
1184dc2f 943config MAXSMP
ddb0c5a6 944 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
6ea30386 945 depends on X86_64 && SMP && DEBUG_KERNEL
36f5101a 946 select CPUMASK_OFFSTACK
a7f7f624 947 help
ddb0c5a6 948 Enable maximum number of CPUS and NUMA Nodes for this architecture.
1184dc2f 949 If unsure, say N.
506f1d07 950
aec6487e
IM
951#
952# The maximum number of CPUs supported:
953#
954# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
955# and which can be configured interactively in the
956# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
957#
958# The ranges are different on 32-bit and 64-bit kernels, depending on
959# hardware capabilities and scalability features of the kernel.
960#
961# ( If MAXSMP is enabled we just use the highest possible value and disable
962# interactive configuration. )
963#
964
965config NR_CPUS_RANGE_BEGIN
a0d0bb4d 966 int
aec6487e
IM
967 default NR_CPUS_RANGE_END if MAXSMP
968 default 1 if !SMP
969 default 2
a0d0bb4d 970
aec6487e 971config NR_CPUS_RANGE_END
a0d0bb4d 972 int
aec6487e
IM
973 depends on X86_32
974 default 64 if SMP && X86_BIGSMP
975 default 8 if SMP && !X86_BIGSMP
976 default 1 if !SMP
a0d0bb4d 977
aec6487e 978config NR_CPUS_RANGE_END
a0d0bb4d 979 int
aec6487e 980 depends on X86_64
1edae1ae
SW
981 default 8192 if SMP && CPUMASK_OFFSTACK
982 default 512 if SMP && !CPUMASK_OFFSTACK
aec6487e 983 default 1 if !SMP
a0d0bb4d 984
aec6487e 985config NR_CPUS_DEFAULT
a0d0bb4d
RD
986 int
987 depends on X86_32
aec6487e
IM
988 default 32 if X86_BIGSMP
989 default 8 if SMP
990 default 1 if !SMP
a0d0bb4d 991
aec6487e 992config NR_CPUS_DEFAULT
a0d0bb4d
RD
993 int
994 depends on X86_64
aec6487e
IM
995 default 8192 if MAXSMP
996 default 64 if SMP
997 default 1 if !SMP
a0d0bb4d 998
506f1d07 999config NR_CPUS
36f5101a 1000 int "Maximum number of CPUs" if SMP && !MAXSMP
aec6487e
IM
1001 range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
1002 default NR_CPUS_DEFAULT
a7f7f624 1003 help
506f1d07 1004 This allows you to specify the maximum number of CPUs which this
bb61ccc7 1005 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
cad14bb9 1006 supported value is 8192, otherwise the maximum value is 512. The
506f1d07
SR
1007 minimum value which makes sense is 2.
1008
aec6487e
IM
1009 This is purely to save memory: each supported CPU adds about 8KB
1010 to the kernel image.
506f1d07
SR
1011
1012config SCHED_SMT
dbe73364 1013 def_bool y if SMP
506f1d07
SR
1014
1015config SCHED_MC
3c2362e6
HH
1016 def_bool y
1017 prompt "Multi-core scheduler support"
c8e56d20 1018 depends on SMP
a7f7f624 1019 help
506f1d07
SR
1020 Multi-core scheduler support improves the CPU scheduler's decision
1021 making when dealing with multi-core CPU chips at a cost of slightly
1022 increased overhead in some places. If unsure say N here.
1023
de966cf4
TC
1024config SCHED_MC_PRIO
1025 bool "CPU core priorities scheduler support"
0a21fc12
IM
1026 depends on SCHED_MC && CPU_SUP_INTEL
1027 select X86_INTEL_PSTATE
1028 select CPU_FREQ
de966cf4 1029 default y
a7f7f624 1030 help
0a21fc12
IM
1031 Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1032 core ordering determined at manufacturing time, which allows
1033 certain cores to reach higher turbo frequencies (when running
1034 single threaded workloads) than others.
de966cf4 1035
0a21fc12
IM
1036 Enabling this kernel feature teaches the scheduler about
1037 the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1038 scheduler's CPU selection logic accordingly, so that higher
1039 overall system performance can be achieved.
de966cf4 1040
0a21fc12 1041 This feature will have no effect on CPUs without this feature.
de966cf4 1042
0a21fc12 1043 If unsure say Y here.
5e76b2ab 1044
30b8b006 1045config UP_LATE_INIT
b03b016f
KK
1046 def_bool y
1047 depends on !SMP && X86_LOCAL_APIC
30b8b006 1048
506f1d07 1049config X86_UP_APIC
50849eef
JB
1050 bool "Local APIC support on uniprocessors" if !PCI_MSI
1051 default PCI_MSI
38a1dfda 1052 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
a7f7f624 1053 help
506f1d07
SR
1054 A local APIC (Advanced Programmable Interrupt Controller) is an
1055 integrated interrupt controller in the CPU. If you have a single-CPU
1056 system which has a processor with a local APIC, you can say Y here to
1057 enable and use it. If you say Y here even though your machine doesn't
1058 have a local APIC, then the kernel will still run with no slowdown at
1059 all. The local APIC supports CPU-generated self-interrupts (timer,
1060 performance counters), and the NMI watchdog which detects hard
1061 lockups.
1062
1063config X86_UP_IOAPIC
1064 bool "IO-APIC support on uniprocessors"
1065 depends on X86_UP_APIC
a7f7f624 1066 help
506f1d07
SR
1067 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1068 SMP-capable replacement for PC-style interrupt controllers. Most
1069 SMP systems and many recent uniprocessor systems have one.
1070
1071 If you have a single-CPU system with an IO-APIC, you can say Y here
1072 to use it. If you say Y here even though your machine doesn't have
1073 an IO-APIC, then the kernel will still run with no slowdown at all.
1074
1075config X86_LOCAL_APIC
3c2362e6 1076 def_bool y
0dbc6078 1077 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
b5dc8e6c 1078 select IRQ_DOMAIN_HIERARCHY
52f518a3 1079 select PCI_MSI_IRQ_DOMAIN if PCI_MSI
506f1d07
SR
1080
1081config X86_IO_APIC
b1da1e71
JB
1082 def_bool y
1083 depends on X86_LOCAL_APIC || X86_UP_IOAPIC
506f1d07 1084
41b9eb26
SA
1085config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
1086 bool "Reroute for broken boot IRQs"
41b9eb26 1087 depends on X86_IO_APIC
a7f7f624 1088 help
41b9eb26
SA
1089 This option enables a workaround that fixes a source of
1090 spurious interrupts. This is recommended when threaded
1091 interrupt handling is used on systems where the generation of
1092 superfluous "boot interrupts" cannot be disabled.
1093
1094 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
1095 entry in the chipset's IO-APIC is masked (as, e.g. the RT
1096 kernel does during interrupt handling). On chipsets where this
1097 boot IRQ generation cannot be disabled, this workaround keeps
1098 the original IRQ line masked so that only the equivalent "boot
1099 IRQ" is delivered to the CPUs. The workaround also tells the
1100 kernel to set up the IRQ handler on the boot IRQ line. In this
1101 way only one interrupt is delivered to the kernel. Otherwise
1102 the spurious second interrupt may cause the kernel to bring
1103 down (vital) interrupt lines.
1104
1105 Only affects "broken" chipsets. Interrupt sharing may be
1106 increased on these systems.
1107
506f1d07 1108config X86_MCE
bab9bc65 1109 bool "Machine Check / overheating reporting"
648ed940 1110 select GENERIC_ALLOCATOR
e57dbaf7 1111 default y
a7f7f624 1112 help
bab9bc65
AK
1113 Machine Check support allows the processor to notify the
1114 kernel if it detects a problem (e.g. overheating, data corruption).
506f1d07 1115 The action the kernel takes depends on the severity of the problem,
bab9bc65 1116 ranging from warning messages to halting the machine.
4efc0670 1117
5de97c9f
TL
1118config X86_MCELOG_LEGACY
1119 bool "Support for deprecated /dev/mcelog character device"
1120 depends on X86_MCE
a7f7f624 1121 help
5de97c9f
TL
1122 Enable support for /dev/mcelog which is needed by the old mcelog
1123 userspace logging daemon. Consider switching to the new generation
1124 rasdaemon solution.
1125
506f1d07 1126config X86_MCE_INTEL
3c2362e6
HH
1127 def_bool y
1128 prompt "Intel MCE features"
c1ebf835 1129 depends on X86_MCE && X86_LOCAL_APIC
a7f7f624 1130 help
506f1d07
SR
1131 Additional support for intel specific MCE features such as
1132 the thermal monitor.
1133
1134config X86_MCE_AMD
3c2362e6
HH
1135 def_bool y
1136 prompt "AMD MCE features"
f5382de9 1137 depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
a7f7f624 1138 help
506f1d07
SR
1139 Additional support for AMD specific MCE features such as
1140 the DRAM Error Threshold.
1141
4efc0670 1142config X86_ANCIENT_MCE
6fc108a0 1143 bool "Support for old Pentium 5 / WinChip machine checks"
c31d9633 1144 depends on X86_32 && X86_MCE
a7f7f624 1145 help
cd13adcc 1146 Include support for machine check handling on old Pentium 5 or WinChip
5065a706 1147 systems. These typically need to be enabled explicitly on the command
cd13adcc 1148 line.
4efc0670 1149
b2762686
AK
1150config X86_MCE_THRESHOLD
1151 depends on X86_MCE_AMD || X86_MCE_INTEL
6fc108a0 1152 def_bool y
b2762686 1153
ea149b36 1154config X86_MCE_INJECT
bc8e80d5 1155 depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
ea149b36 1156 tristate "Machine check injector support"
a7f7f624 1157 help
ea149b36
AK
1158 Provide support for injecting machine checks for testing purposes.
1159 If you don't know what a machine check is and you don't do kernel
1160 QA it is safe to say n.
1161
4efc0670
AK
1162config X86_THERMAL_VECTOR
1163 def_bool y
5bb38adc 1164 depends on X86_MCE_INTEL
4efc0670 1165
07dc900e 1166source "arch/x86/events/Kconfig"
e633c65a 1167
5aef51c3 1168config X86_LEGACY_VM86
1e642812 1169 bool "Legacy VM86 support"
506f1d07 1170 depends on X86_32
a7f7f624 1171 help
5aef51c3
AL
1172 This option allows user programs to put the CPU into V8086
1173 mode, which is an 80286-era approximation of 16-bit real mode.
1174
1175 Some very old versions of X and/or vbetool require this option
1176 for user mode setting. Similarly, DOSEMU will use it if
1177 available to accelerate real mode DOS programs. However, any
1178 recent version of DOSEMU, X, or vbetool should be fully
1179 functional even without kernel VM86 support, as they will all
1e642812
IM
1180 fall back to software emulation. Nevertheless, if you are using
1181 a 16-bit DOS program where 16-bit performance matters, vm86
1182 mode might be faster than emulation and you might want to
1183 enable this option.
5aef51c3 1184
1e642812
IM
1185 Note that any app that works on a 64-bit kernel is unlikely to
1186 need this option, as 64-bit kernels don't, and can't, support
1187 V8086 mode. This option is also unrelated to 16-bit protected
1188 mode and is not needed to run most 16-bit programs under Wine.
5aef51c3 1189
1e642812
IM
1190 Enabling this option increases the complexity of the kernel
1191 and slows down exception handling a tiny bit.
5aef51c3 1192
1e642812 1193 If unsure, say N here.
5aef51c3
AL
1194
1195config VM86
b03b016f
KK
1196 bool
1197 default X86_LEGACY_VM86
34273f41
PA
1198
1199config X86_16BIT
1200 bool "Enable support for 16-bit segments" if EXPERT
1201 default y
a5b9e5a2 1202 depends on MODIFY_LDT_SYSCALL
a7f7f624 1203 help
34273f41
PA
1204 This option is required by programs like Wine to run 16-bit
1205 protected mode legacy code on x86 processors. Disabling
1206 this option saves about 300 bytes on i386, or around 6K text
1207 plus 16K runtime memory on x86-64,
1208
1209config X86_ESPFIX32
1210 def_bool y
1211 depends on X86_16BIT && X86_32
506f1d07 1212
197725de
PA
1213config X86_ESPFIX64
1214 def_bool y
34273f41 1215 depends on X86_16BIT && X86_64
506f1d07 1216
1ad83c85 1217config X86_VSYSCALL_EMULATION
b03b016f
KK
1218 bool "Enable vsyscall emulation" if EXPERT
1219 default y
1220 depends on X86_64
a7f7f624 1221 help
1ad83c85
AL
1222 This enables emulation of the legacy vsyscall page. Disabling
1223 it is roughly equivalent to booting with vsyscall=none, except
1224 that it will also disable the helpful warning if a program
1225 tries to use a vsyscall. With this option set to N, offending
1226 programs will just segfault, citing addresses of the form
1227 0xffffffffff600?00.
1228
1229 This option is required by many programs built before 2013, and
1230 care should be used even with newer programs if set to N.
1231
1232 Disabling this option saves about 7K of kernel size and
1233 possibly 4K of additional runtime pagetable memory.
1234
111e7b15
TG
1235config X86_IOPL_IOPERM
1236 bool "IOPERM and IOPL Emulation"
a24ca997 1237 default y
a7f7f624 1238 help
111e7b15
TG
1239 This enables the ioperm() and iopl() syscalls which are necessary
1240 for legacy applications.
1241
c8137ace
TG
1242 Legacy IOPL support is an overbroad mechanism which allows user
1243 space aside of accessing all 65536 I/O ports also to disable
1244 interrupts. To gain this access the caller needs CAP_SYS_RAWIO
1245 capabilities and permission from potentially active security
1246 modules.
1247
1248 The emulation restricts the functionality of the syscall to
1249 only allowing the full range I/O port access, but prevents the
a24ca997
TG
1250 ability to disable interrupts from user space which would be
1251 granted if the hardware IOPL mechanism would be used.
c8137ace 1252
506f1d07
SR
1253config TOSHIBA
1254 tristate "Toshiba Laptop support"
1255 depends on X86_32
a7f7f624 1256 help
506f1d07
SR
1257 This adds a driver to safely access the System Management Mode of
1258 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1259 not work on models with a Phoenix BIOS. The System Management Mode
1260 is used to set the BIOS and power saving options on Toshiba portables.
1261
1262 For information on utilities to make use of this driver see the
1263 Toshiba Linux utilities web site at:
1264 <http://www.buzzard.org.uk/toshiba/>.
1265
1266 Say Y if you intend to run this kernel on a Toshiba portable.
1267 Say N otherwise.
1268
1269config I8K
039ae585 1270 tristate "Dell i8k legacy laptop support"
949a9d70 1271 select HWMON
039ae585 1272 select SENSORS_DELL_SMM
a7f7f624 1273 help
039ae585
PR
1274 This option enables legacy /proc/i8k userspace interface in hwmon
1275 dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1276 temperature and allows controlling fan speeds of Dell laptops via
1277 System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1278 it reports also power and hotkey status. For fan speed control is
1279 needed userspace package i8kutils.
1280
1281 Say Y if you intend to run this kernel on old Dell laptops or want to
1282 use userspace package i8kutils.
506f1d07
SR
1283 Say N otherwise.
1284
1285config X86_REBOOTFIXUPS
9ba16087
JB
1286 bool "Enable X86 board specific fixups for reboot"
1287 depends on X86_32
a7f7f624 1288 help
506f1d07
SR
1289 This enables chipset and/or board specific fixups to be done
1290 in order to get reboot to work correctly. This is only needed on
1291 some combinations of hardware and BIOS. The symptom, for which
1292 this config is intended, is when reboot ends with a stalled/hung
1293 system.
1294
1295 Currently, the only fixup is for the Geode machines using
5e3a77e9 1296 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
506f1d07
SR
1297
1298 Say Y if you want to enable the fixup. Currently, it's safe to
1299 enable this option even if you don't need it.
1300 Say N otherwise.
1301
1302config MICROCODE
9a2bc335
BP
1303 bool "CPU microcode loading support"
1304 default y
80030e3d 1305 depends on CPU_SUP_AMD || CPU_SUP_INTEL
a7f7f624 1306 help
506f1d07 1307 If you say Y here, you will be able to update the microcode on
5f9c01aa
BP
1308 Intel and AMD processors. The Intel support is for the IA32 family,
1309 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
1310 AMD support is for families 0x10 and later. You will obviously need
1311 the actual microcode binary data itself which is not shipped with
1312 the Linux kernel.
1313
1314 The preferred method to load microcode from a detached initrd is described
cb1aaebe 1315 in Documentation/x86/microcode.rst. For that you need to enable
5f9c01aa
BP
1316 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
1317 initrd for microcode blobs.
1318
c508c46e
BG
1319 In addition, you can build the microcode into the kernel. For that you
1320 need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1321 config option.
506f1d07 1322
8d86f390 1323config MICROCODE_INTEL
e43f6e67 1324 bool "Intel microcode loading support"
8f9ca475
IM
1325 depends on MICROCODE
1326 default MICROCODE
a7f7f624 1327 help
8f9ca475
IM
1328 This options enables microcode patch loading support for Intel
1329 processors.
1330
b8989db9
A
1331 For the current Intel microcode data package go to
1332 <https://downloadcenter.intel.com> and search for
1333 'Linux Processor Microcode Data File'.
8d86f390 1334
80cc9f10 1335config MICROCODE_AMD
e43f6e67 1336 bool "AMD microcode loading support"
8f9ca475 1337 depends on MICROCODE
a7f7f624 1338 help
8f9ca475
IM
1339 If you select this option, microcode patch loading support for AMD
1340 processors will be enabled.
80cc9f10 1341
8f9ca475 1342config MICROCODE_OLD_INTERFACE
c02f48e0
BP
1343 bool "Ancient loading interface (DEPRECATED)"
1344 default n
506f1d07 1345 depends on MICROCODE
a7f7f624 1346 help
c02f48e0
BP
1347 DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface
1348 which was used by userspace tools like iucode_tool and microcode.ctl.
1349 It is inadequate because it runs too late to be able to properly
1350 load microcode on a machine and it needs special tools. Instead, you
1351 should've switched to the early loading method with the initrd or
cb1aaebe 1352 builtin microcode by now: Documentation/x86/microcode.rst
506f1d07
SR
1353
1354config X86_MSR
1355 tristate "/dev/cpu/*/msr - Model-specific register support"
a7f7f624 1356 help
506f1d07
SR
1357 This device gives privileged processes access to the x86
1358 Model-Specific Registers (MSRs). It is a character device with
1359 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1360 MSR accesses are directed to a specific CPU on multi-processor
1361 systems.
1362
1363config X86_CPUID
1364 tristate "/dev/cpu/*/cpuid - CPU information support"
a7f7f624 1365 help
506f1d07
SR
1366 This device gives processes access to the x86 CPUID instruction to
1367 be executed on a specific processor. It is a character device
1368 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1369 /dev/cpu/31/cpuid.
1370
1371choice
1372 prompt "High Memory Support"
6fc108a0 1373 default HIGHMEM4G
506f1d07
SR
1374 depends on X86_32
1375
1376config NOHIGHMEM
1377 bool "off"
a7f7f624 1378 help
506f1d07
SR
1379 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1380 However, the address space of 32-bit x86 processors is only 4
1381 Gigabytes large. That means that, if you have a large amount of
1382 physical memory, not all of it can be "permanently mapped" by the
1383 kernel. The physical memory that's not permanently mapped is called
1384 "high memory".
1385
1386 If you are compiling a kernel which will never run on a machine with
1387 more than 1 Gigabyte total physical RAM, answer "off" here (default
1388 choice and suitable for most users). This will result in a "3GB/1GB"
1389 split: 3GB are mapped so that each process sees a 3GB virtual memory
1390 space and the remaining part of the 4GB virtual memory space is used
1391 by the kernel to permanently map as much physical memory as
1392 possible.
1393
1394 If the machine has between 1 and 4 Gigabytes physical RAM, then
1395 answer "4GB" here.
1396
1397 If more than 4 Gigabytes is used then answer "64GB" here. This
1398 selection turns Intel PAE (Physical Address Extension) mode on.
1399 PAE implements 3-level paging on IA32 processors. PAE is fully
1400 supported by Linux, PAE mode is implemented on all recent Intel
1401 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1402 then the kernel will not boot on CPUs that don't support PAE!
1403
1404 The actual amount of total physical memory will either be
1405 auto detected or can be forced by using a kernel command line option
1406 such as "mem=256M". (Try "man bootparam" or see the documentation of
1407 your boot loader (lilo or loadlin) about how to pass options to the
1408 kernel at boot time.)
1409
1410 If unsure, say "off".
1411
1412config HIGHMEM4G
1413 bool "4GB"
a7f7f624 1414 help
506f1d07
SR
1415 Select this if you have a 32-bit processor and between 1 and 4
1416 gigabytes of physical RAM.
1417
1418config HIGHMEM64G
1419 bool "64GB"
69b8d3fc 1420 depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6
506f1d07 1421 select X86_PAE
a7f7f624 1422 help
506f1d07
SR
1423 Select this if you have a 32-bit processor and more than 4
1424 gigabytes of physical RAM.
1425
1426endchoice
1427
1428choice
6a108a14 1429 prompt "Memory split" if EXPERT
506f1d07
SR
1430 default VMSPLIT_3G
1431 depends on X86_32
a7f7f624 1432 help
506f1d07
SR
1433 Select the desired split between kernel and user memory.
1434
1435 If the address range available to the kernel is less than the
1436 physical memory installed, the remaining memory will be available
1437 as "high memory". Accessing high memory is a little more costly
1438 than low memory, as it needs to be mapped into the kernel first.
1439 Note that increasing the kernel address space limits the range
1440 available to user programs, making the address space there
1441 tighter. Selecting anything other than the default 3G/1G split
1442 will also likely make your kernel incompatible with binary-only
1443 kernel modules.
1444
1445 If you are not absolutely sure what you are doing, leave this
1446 option alone!
1447
1448 config VMSPLIT_3G
1449 bool "3G/1G user/kernel split"
1450 config VMSPLIT_3G_OPT
1451 depends on !X86_PAE
1452 bool "3G/1G user/kernel split (for full 1G low memory)"
1453 config VMSPLIT_2G
1454 bool "2G/2G user/kernel split"
1455 config VMSPLIT_2G_OPT
1456 depends on !X86_PAE
1457 bool "2G/2G user/kernel split (for full 2G low memory)"
1458 config VMSPLIT_1G
1459 bool "1G/3G user/kernel split"
1460endchoice
1461
1462config PAGE_OFFSET
1463 hex
1464 default 0xB0000000 if VMSPLIT_3G_OPT
1465 default 0x80000000 if VMSPLIT_2G
1466 default 0x78000000 if VMSPLIT_2G_OPT
1467 default 0x40000000 if VMSPLIT_1G
1468 default 0xC0000000
1469 depends on X86_32
1470
1471config HIGHMEM
3c2362e6 1472 def_bool y
506f1d07 1473 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
506f1d07
SR
1474
1475config X86_PAE
9ba16087 1476 bool "PAE (Physical Address Extension) Support"
506f1d07 1477 depends on X86_32 && !HIGHMEM4G
d4a451d5 1478 select PHYS_ADDR_T_64BIT
9d99c712 1479 select SWIOTLB
a7f7f624 1480 help
506f1d07
SR
1481 PAE is required for NX support, and furthermore enables
1482 larger swapspace support for non-overcommit purposes. It
1483 has the cost of more pagetable lookup overhead, and also
1484 consumes more pagetable space per process.
1485
77ef56e4
KS
1486config X86_5LEVEL
1487 bool "Enable 5-level page tables support"
18ec1eaf 1488 default y
eedb92ab 1489 select DYNAMIC_MEMORY_LAYOUT
162434e7 1490 select SPARSEMEM_VMEMMAP
77ef56e4 1491 depends on X86_64
a7f7f624 1492 help
77ef56e4
KS
1493 5-level paging enables access to larger address space:
1494 upto 128 PiB of virtual address space and 4 PiB of
1495 physical address space.
1496
1497 It will be supported by future Intel CPUs.
1498
6657fca0
KS
1499 A kernel with the option enabled can be booted on machines that
1500 support 4- or 5-level paging.
77ef56e4 1501
cb1aaebe 1502 See Documentation/x86/x86_64/5level-paging.rst for more
77ef56e4
KS
1503 information.
1504
1505 Say N if unsure.
1506
10971ab2 1507config X86_DIRECT_GBPAGES
e5008abe 1508 def_bool y
2e1da13f 1509 depends on X86_64
a7f7f624 1510 help
10971ab2
IM
1511 Certain kernel features effectively disable kernel
1512 linear 1 GB mappings (even if the CPU otherwise
1513 supports them), so don't confuse the user by printing
1514 that we have them enabled.
9e899816 1515
5c280cf6
TG
1516config X86_CPA_STATISTICS
1517 bool "Enable statistic for Change Page Attribute"
1518 depends on DEBUG_FS
a7f7f624 1519 help
b75baaf3 1520 Expose statistics about the Change Page Attribute mechanism, which
a943245a 1521 helps to determine the effectiveness of preserving large and huge
5c280cf6
TG
1522 page mappings when mapping protections are changed.
1523
7744ccdb
TL
1524config AMD_MEM_ENCRYPT
1525 bool "AMD Secure Memory Encryption (SME) support"
1526 depends on X86_64 && CPU_SUP_AMD
82fef0ad 1527 select DMA_COHERENT_POOL
94d49eb3 1528 select DYNAMIC_PHYSICAL_MASK
ce9084ba 1529 select ARCH_USE_MEMREMAP_PROT
9087c375 1530 select ARCH_HAS_FORCE_DMA_UNENCRYPTED
597cfe48 1531 select INSTRUCTION_DECODER
a7f7f624 1532 help
7744ccdb
TL
1533 Say yes to enable support for the encryption of system memory.
1534 This requires an AMD processor that supports Secure Memory
1535 Encryption (SME).
1536
1537config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
1538 bool "Activate AMD Secure Memory Encryption (SME) by default"
1539 default y
1540 depends on AMD_MEM_ENCRYPT
a7f7f624 1541 help
7744ccdb
TL
1542 Say yes to have system memory encrypted by default if running on
1543 an AMD processor that supports Secure Memory Encryption (SME).
1544
1545 If set to Y, then the encryption of system memory can be
1546 deactivated with the mem_encrypt=off command line option.
1547
1548 If set to N, then the encryption of system memory can be
1549 activated with the mem_encrypt=on command line option.
1550
506f1d07
SR
1551# Common NUMA Features
1552config NUMA
e133f6ea 1553 bool "NUMA Memory Allocation and Scheduler Support"
506f1d07 1554 depends on SMP
b5660ba7
PA
1555 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1556 default y if X86_BIGSMP
a7f7f624 1557 help
e133f6ea 1558 Enable NUMA (Non-Uniform Memory Access) support.
fd51b2d7 1559
506f1d07
SR
1560 The kernel will try to allocate memory used by a CPU on the
1561 local memory controller of the CPU and add some more
1562 NUMA awareness to the kernel.
1563
c280ea5e 1564 For 64-bit this is recommended if the system is Intel Core i7
fd51b2d7
KM
1565 (or later), AMD Opteron, or EM64T NUMA.
1566
b5660ba7 1567 For 32-bit this is only needed if you boot a 32-bit
7cf6c945 1568 kernel on a 64-bit NUMA platform.
fd51b2d7
KM
1569
1570 Otherwise, you should say N.
506f1d07 1571
eec1d4fa 1572config AMD_NUMA
3c2362e6
HH
1573 def_bool y
1574 prompt "Old style AMD Opteron NUMA detection"
5da0ef9a 1575 depends on X86_64 && NUMA && PCI
a7f7f624 1576 help
eec1d4fa
HR
1577 Enable AMD NUMA node topology detection. You should say Y here if
1578 you have a multi processor AMD system. This uses an old method to
1579 read the NUMA configuration directly from the builtin Northbridge
1580 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1581 which also takes priority if both are compiled in.
506f1d07
SR
1582
1583config X86_64_ACPI_NUMA
3c2362e6
HH
1584 def_bool y
1585 prompt "ACPI NUMA detection"
506f1d07
SR
1586 depends on X86_64 && NUMA && ACPI && PCI
1587 select ACPI_NUMA
a7f7f624 1588 help
506f1d07
SR
1589 Enable ACPI SRAT based node topology detection.
1590
1591config NUMA_EMU
1592 bool "NUMA emulation"
1b7e03ef 1593 depends on NUMA
a7f7f624 1594 help
506f1d07
SR
1595 Enable NUMA emulation. A flat machine will be split
1596 into virtual nodes when booted with "numa=fake=N", where N is the
1597 number of nodes. This is only useful for debugging.
1598
1599config NODES_SHIFT
d25e26b6 1600 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
51591e31
DR
1601 range 1 10
1602 default "10" if MAXSMP
506f1d07 1603 default "6" if X86_64
506f1d07
SR
1604 default "3"
1605 depends on NEED_MULTIPLE_NODES
a7f7f624 1606 help
1184dc2f 1607 Specify the maximum number of NUMA Nodes available on the target
692105b8 1608 system. Increases memory reserved to accommodate various tables.
506f1d07 1609
506f1d07
SR
1610config ARCH_FLATMEM_ENABLE
1611 def_bool y
3b16651f 1612 depends on X86_32 && !NUMA
506f1d07 1613
506f1d07
SR
1614config ARCH_SPARSEMEM_ENABLE
1615 def_bool y
6ea30386 1616 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
506f1d07
SR
1617 select SPARSEMEM_STATIC if X86_32
1618 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1619
3b16651f 1620config ARCH_SPARSEMEM_DEFAULT
6ad57f7f 1621 def_bool X86_64 || (NUMA && X86_32)
3b16651f 1622
506f1d07
SR
1623config ARCH_SELECT_MEMORY_MODEL
1624 def_bool y
b263295d 1625 depends on ARCH_SPARSEMEM_ENABLE
506f1d07
SR
1626
1627config ARCH_MEMORY_PROBE
a0842b70 1628 bool "Enable sysfs memory/probe interface"
3120e25e 1629 depends on X86_64 && MEMORY_HOTPLUG
a0842b70
TK
1630 help
1631 This option enables a sysfs memory/probe interface for testing.
cb1aaebe 1632 See Documentation/admin-guide/mm/memory-hotplug.rst for more information.
a0842b70 1633 If you are unsure how to answer this question, answer N.
506f1d07 1634
3b16651f
TH
1635config ARCH_PROC_KCORE_TEXT
1636 def_bool y
1637 depends on X86_64 && PROC_KCORE
1638
a29815a3 1639config ILLEGAL_POINTER_VALUE
b03b016f
KK
1640 hex
1641 default 0 if X86_32
1642 default 0xdead000000000000 if X86_64
a29815a3 1643
7a67832c
DW
1644config X86_PMEM_LEGACY_DEVICE
1645 bool
1646
ec776ef6 1647config X86_PMEM_LEGACY
7a67832c 1648 tristate "Support non-standard NVDIMMs and ADR protected memory"
9f53f9fa
DW
1649 depends on PHYS_ADDR_T_64BIT
1650 depends on BLK_DEV
7a67832c 1651 select X86_PMEM_LEGACY_DEVICE
7b27a862 1652 select NUMA_KEEP_MEMINFO if NUMA
9f53f9fa 1653 select LIBNVDIMM
ec776ef6
CH
1654 help
1655 Treat memory marked using the non-standard e820 type of 12 as used
1656 by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1657 The kernel will offer these regions to the 'pmem' driver so
1658 they can be used for persistent storage.
1659
1660 Say Y if unsure.
1661
506f1d07
SR
1662config HIGHPTE
1663 bool "Allocate 3rd-level pagetables from highmem"
6fc108a0 1664 depends on HIGHMEM
a7f7f624 1665 help
506f1d07
SR
1666 The VM uses one page table entry for each page of physical memory.
1667 For systems with a lot of RAM, this can be wasteful of precious
1668 low memory. Setting this option will put user-space page table
1669 entries in high memory.
1670
9f077871 1671config X86_CHECK_BIOS_CORRUPTION
8f9ca475 1672 bool "Check for low memory corruption"
a7f7f624 1673 help
8f9ca475
IM
1674 Periodically check for memory corruption in low memory, which
1675 is suspected to be caused by BIOS. Even when enabled in the
1676 configuration, it is disabled at runtime. Enable it by
1677 setting "memory_corruption_check=1" on the kernel command
1678 line. By default it scans the low 64k of memory every 60
1679 seconds; see the memory_corruption_check_size and
1680 memory_corruption_check_period parameters in
8c27ceff 1681 Documentation/admin-guide/kernel-parameters.rst to adjust this.
8f9ca475
IM
1682
1683 When enabled with the default parameters, this option has
1684 almost no overhead, as it reserves a relatively small amount
1685 of memory and scans it infrequently. It both detects corruption
1686 and prevents it from affecting the running system.
1687
1688 It is, however, intended as a diagnostic tool; if repeatable
1689 BIOS-originated corruption always affects the same memory,
1690 you can use memmap= to prevent the kernel from using that
1691 memory.
9f077871 1692
c885df50 1693config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
8f9ca475 1694 bool "Set the default setting of memory_corruption_check"
c885df50
JF
1695 depends on X86_CHECK_BIOS_CORRUPTION
1696 default y
a7f7f624 1697 help
8f9ca475
IM
1698 Set whether the default state of memory_corruption_check is
1699 on or off.
c885df50 1700
9ea77bdb 1701config X86_RESERVE_LOW
d0cd7425
PA
1702 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1703 default 64
1704 range 4 640
a7f7f624 1705 help
d0cd7425
PA
1706 Specify the amount of low memory to reserve for the BIOS.
1707
1708 The first page contains BIOS data structures that the kernel
1709 must not use, so that page must always be reserved.
1710
1711 By default we reserve the first 64K of physical RAM, as a
1712 number of BIOSes are known to corrupt that memory range
1713 during events such as suspend/resume or monitor cable
1714 insertion, so it must not be used by the kernel.
fc381519 1715
d0cd7425
PA
1716 You can set this to 4 if you are absolutely sure that you
1717 trust the BIOS to get all its memory reservations and usages
1718 right. If you know your BIOS have problems beyond the
1719 default 64K area, you can set this to 640 to avoid using the
1720 entire low memory range.
fc381519 1721
d0cd7425
PA
1722 If you have doubts about the BIOS (e.g. suspend/resume does
1723 not work or there's kernel crashes after certain hardware
1724 hotplug events) then you might want to enable
1725 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1726 typical corruption patterns.
fc381519 1727
d0cd7425 1728 Leave this to the default value of 64 if you are unsure.
fc381519 1729
506f1d07
SR
1730config MATH_EMULATION
1731 bool
a5b9e5a2 1732 depends on MODIFY_LDT_SYSCALL
87d6021b 1733 prompt "Math emulation" if X86_32 && (M486SX || MELAN)
a7f7f624 1734 help
506f1d07
SR
1735 Linux can emulate a math coprocessor (used for floating point
1736 operations) if you don't have one. 486DX and Pentium processors have
1737 a math coprocessor built in, 486SX and 386 do not, unless you added
1738 a 487DX or 387, respectively. (The messages during boot time can
1739 give you some hints here ["man dmesg"].) Everyone needs either a
1740 coprocessor or this emulation.
1741
1742 If you don't have a math coprocessor, you need to say Y here; if you
1743 say Y here even though you have a coprocessor, the coprocessor will
1744 be used nevertheless. (This behavior can be changed with the kernel
1745 command line option "no387", which comes handy if your coprocessor
1746 is broken. Try "man bootparam" or see the documentation of your boot
1747 loader (lilo or loadlin) about how to pass options to the kernel at
1748 boot time.) This means that it is a good idea to say Y here if you
1749 intend to use this kernel on different machines.
1750
1751 More information about the internals of the Linux math coprocessor
1752 emulation can be found in <file:arch/x86/math-emu/README>.
1753
1754 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1755 kernel, it won't hurt.
1756
1757config MTRR
6fc108a0 1758 def_bool y
6a108a14 1759 prompt "MTRR (Memory Type Range Register) support" if EXPERT
a7f7f624 1760 help
506f1d07
SR
1761 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1762 the Memory Type Range Registers (MTRRs) may be used to control
1763 processor access to memory ranges. This is most useful if you have
1764 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1765 allows bus write transfers to be combined into a larger transfer
1766 before bursting over the PCI/AGP bus. This can increase performance
1767 of image write operations 2.5 times or more. Saying Y here creates a
1768 /proc/mtrr file which may be used to manipulate your processor's
1769 MTRRs. Typically the X server should use this.
1770
1771 This code has a reasonably generic interface so that similar
1772 control registers on other processors can be easily supported
1773 as well:
1774
1775 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1776 Registers (ARRs) which provide a similar functionality to MTRRs. For
1777 these, the ARRs are used to emulate the MTRRs.
1778 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1779 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1780 write-combining. All of these processors are supported by this code
1781 and it makes sense to say Y here if you have one of them.
1782
1783 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1784 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1785 can lead to all sorts of problems, so it's good to say Y here.
1786
1787 You can safely say Y even if your machine doesn't have MTRRs, you'll
1788 just add about 9 KB to your kernel.
1789
cb1aaebe 1790 See <file:Documentation/x86/mtrr.rst> for more information.
506f1d07 1791
95ffa243 1792config MTRR_SANITIZER
2ffb3501 1793 def_bool y
95ffa243
YL
1794 prompt "MTRR cleanup support"
1795 depends on MTRR
a7f7f624 1796 help
aba3728c
TG
1797 Convert MTRR layout from continuous to discrete, so X drivers can
1798 add writeback entries.
95ffa243 1799
aba3728c 1800 Can be disabled with disable_mtrr_cleanup on the kernel command line.
692105b8 1801 The largest mtrr entry size for a continuous block can be set with
aba3728c 1802 mtrr_chunk_size.
95ffa243 1803
2ffb3501 1804 If unsure, say Y.
95ffa243
YL
1805
1806config MTRR_SANITIZER_ENABLE_DEFAULT
f5098d62
YL
1807 int "MTRR cleanup enable value (0-1)"
1808 range 0 1
1809 default "0"
95ffa243 1810 depends on MTRR_SANITIZER
a7f7f624 1811 help
f5098d62 1812 Enable mtrr cleanup default value
95ffa243 1813
12031a62
YL
1814config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1815 int "MTRR cleanup spare reg num (0-7)"
1816 range 0 7
1817 default "1"
1818 depends on MTRR_SANITIZER
a7f7f624 1819 help
12031a62 1820 mtrr cleanup spare entries default, it can be changed via
aba3728c 1821 mtrr_spare_reg_nr=N on the kernel command line.
12031a62 1822
2e5d9c85 1823config X86_PAT
6fc108a0 1824 def_bool y
6a108a14 1825 prompt "x86 PAT support" if EXPERT
2a8a2719 1826 depends on MTRR
a7f7f624 1827 help
2e5d9c85 1828 Use PAT attributes to setup page level cache control.
042b78e4 1829
2e5d9c85 1830 PATs are the modern equivalents of MTRRs and are much more
1831 flexible than MTRRs.
1832
1833 Say N here if you see bootup problems (boot crash, boot hang,
042b78e4 1834 spontaneous reboots) or a non-working video driver.
2e5d9c85 1835
1836 If unsure, say Y.
1837
46cf98cd
VP
1838config ARCH_USES_PG_UNCACHED
1839 def_bool y
1840 depends on X86_PAT
1841
628c6246
PA
1842config ARCH_RANDOM
1843 def_bool y
1844 prompt "x86 architectural random number generator" if EXPERT
a7f7f624 1845 help
628c6246
PA
1846 Enable the x86 architectural RDRAND instruction
1847 (Intel Bull Mountain technology) to generate random numbers.
1848 If supported, this is a high bandwidth, cryptographically
1849 secure hardware random number generator.
1850
51ae4a2d
PA
1851config X86_SMAP
1852 def_bool y
1853 prompt "Supervisor Mode Access Prevention" if EXPERT
a7f7f624 1854 help
51ae4a2d
PA
1855 Supervisor Mode Access Prevention (SMAP) is a security
1856 feature in newer Intel processors. There is a small
1857 performance cost if this enabled and turned on; there is
1858 also a small increase in the kernel size if this is enabled.
1859
1860 If unsure, say Y.
1861
b971880f 1862config X86_UMIP
796ebc81 1863 def_bool y
b971880f 1864 prompt "User Mode Instruction Prevention" if EXPERT
a7f7f624 1865 help
b971880f
BM
1866 User Mode Instruction Prevention (UMIP) is a security feature in
1867 some x86 processors. If enabled, a general protection fault is
1868 issued if the SGDT, SLDT, SIDT, SMSW or STR instructions are
1869 executed in user mode. These instructions unnecessarily expose
1870 information about the hardware state.
796ebc81
RN
1871
1872 The vast majority of applications do not use these instructions.
1873 For the very few that do, software emulation is provided in
1874 specific cases in protected and virtual-8086 modes. Emulated
1875 results are dummy.
aa35f896 1876
35e97790 1877config X86_INTEL_MEMORY_PROTECTION_KEYS
38f3e775 1878 prompt "Memory Protection Keys"
35e97790 1879 def_bool y
284244a9 1880 # Note: only available in 64-bit mode
38f3e775 1881 depends on X86_64 && (CPU_SUP_INTEL || CPU_SUP_AMD)
52c8e601
IM
1882 select ARCH_USES_HIGH_VMA_FLAGS
1883 select ARCH_HAS_PKEYS
a7f7f624 1884 help
284244a9
DH
1885 Memory Protection Keys provides a mechanism for enforcing
1886 page-based protections, but without requiring modification of the
1887 page tables when an application changes protection domains.
1888
1eecbcdc 1889 For details, see Documentation/core-api/protection-keys.rst
284244a9
DH
1890
1891 If unsure, say y.
35e97790 1892
db616173
MH
1893choice
1894 prompt "TSX enable mode"
1895 depends on CPU_SUP_INTEL
1896 default X86_INTEL_TSX_MODE_OFF
1897 help
1898 Intel's TSX (Transactional Synchronization Extensions) feature
1899 allows to optimize locking protocols through lock elision which
1900 can lead to a noticeable performance boost.
1901
1902 On the other hand it has been shown that TSX can be exploited
1903 to form side channel attacks (e.g. TAA) and chances are there
1904 will be more of those attacks discovered in the future.
1905
1906 Therefore TSX is not enabled by default (aka tsx=off). An admin
1907 might override this decision by tsx=on the command line parameter.
1908 Even with TSX enabled, the kernel will attempt to enable the best
1909 possible TAA mitigation setting depending on the microcode available
1910 for the particular machine.
1911
1912 This option allows to set the default tsx mode between tsx=on, =off
1913 and =auto. See Documentation/admin-guide/kernel-parameters.txt for more
1914 details.
1915
1916 Say off if not sure, auto if TSX is in use but it should be used on safe
1917 platforms or on if TSX is in use and the security aspect of tsx is not
1918 relevant.
1919
1920config X86_INTEL_TSX_MODE_OFF
1921 bool "off"
1922 help
1923 TSX is disabled if possible - equals to tsx=off command line parameter.
1924
1925config X86_INTEL_TSX_MODE_ON
1926 bool "on"
1927 help
1928 TSX is always enabled on TSX capable HW - equals the tsx=on command
1929 line parameter.
1930
1931config X86_INTEL_TSX_MODE_AUTO
1932 bool "auto"
1933 help
1934 TSX is enabled on TSX capable HW that is believed to be safe against
1935 side channel attacks- equals the tsx=auto command line parameter.
1936endchoice
1937
e7e05452
SC
1938config X86_SGX
1939 bool "Software Guard eXtensions (SGX)"
1940 depends on X86_64 && CPU_SUP_INTEL
1941 depends on CRYPTO=y
1942 depends on CRYPTO_SHA256=y
1943 select SRCU
1944 select MMU_NOTIFIER
1945 help
1946 Intel(R) Software Guard eXtensions (SGX) is a set of CPU instructions
1947 that can be used by applications to set aside private regions of code
1948 and data, referred to as enclaves. An enclave's private memory can
1949 only be accessed by code running within the enclave. Accesses from
1950 outside the enclave, including other enclaves, are disallowed by
1951 hardware.
1952
1953 If unsure, say N.
1954
506f1d07 1955config EFI
9ba16087 1956 bool "EFI runtime service support"
5b83683f 1957 depends on ACPI
f6ce5002 1958 select UCS2_STRING
022ee6c5 1959 select EFI_RUNTIME_WRAPPERS
a7f7f624 1960 help
8f9ca475
IM
1961 This enables the kernel to use EFI runtime services that are
1962 available (such as the EFI variable services).
506f1d07 1963
8f9ca475
IM
1964 This option is only useful on systems that have EFI firmware.
1965 In addition, you should use the latest ELILO loader available
1966 at <http://elilo.sourceforge.net> in order to take advantage
1967 of EFI runtime services. However, even with this option, the
1968 resultant kernel should continue to boot on existing non-EFI
1969 platforms.
506f1d07 1970
291f3632 1971config EFI_STUB
8f24f8c2
AB
1972 bool "EFI stub support"
1973 depends on EFI && !X86_USE_3DNOW
1974 depends on $(cc-option,-mabi=ms) || X86_32
1975 select RELOCATABLE
a7f7f624 1976 help
8f24f8c2 1977 This kernel feature allows a bzImage to be loaded directly
291f3632
MF
1978 by EFI firmware without the use of a bootloader.
1979
4f4cfa6c 1980 See Documentation/admin-guide/efi-stub.rst for more information.
0c759662 1981
7d453eee
MF
1982config EFI_MIXED
1983 bool "EFI mixed-mode support"
1984 depends on EFI_STUB && X86_64
a7f7f624 1985 help
7d453eee
MF
1986 Enabling this feature allows a 64-bit kernel to be booted
1987 on a 32-bit firmware, provided that your CPU supports 64-bit
1988 mode.
1989
1990 Note that it is not possible to boot a mixed-mode enabled
1991 kernel via the EFI boot stub - a bootloader that supports
1992 the EFI handover protocol must be used.
1993
1994 If unsure, say N.
1995
8636a1f9 1996source "kernel/Kconfig.hz"
506f1d07
SR
1997
1998config KEXEC
1999 bool "kexec system call"
2965faa5 2000 select KEXEC_CORE
a7f7f624 2001 help
506f1d07
SR
2002 kexec is a system call that implements the ability to shutdown your
2003 current kernel, and to start another kernel. It is like a reboot
2004 but it is independent of the system firmware. And like a reboot
2005 you can start any kernel with it, not just Linux.
2006
2007 The name comes from the similarity to the exec system call.
2008
2009 It is an ongoing process to be certain the hardware in a machine
2010 is properly shutdown, so do not be surprised if this code does not
bf220695
GU
2011 initially work for you. As of this writing the exact hardware
2012 interface is strongly in flux, so no good recommendation can be
2013 made.
506f1d07 2014
74ca317c
VG
2015config KEXEC_FILE
2016 bool "kexec file based system call"
2965faa5 2017 select KEXEC_CORE
74ca317c 2018 select BUILD_BIN2C
74ca317c
VG
2019 depends on X86_64
2020 depends on CRYPTO=y
2021 depends on CRYPTO_SHA256=y
a7f7f624 2022 help
74ca317c
VG
2023 This is new version of kexec system call. This system call is
2024 file based and takes file descriptors as system call argument
2025 for kernel and initramfs as opposed to list of segments as
2026 accepted by previous system call.
2027
b799a09f
AT
2028config ARCH_HAS_KEXEC_PURGATORY
2029 def_bool KEXEC_FILE
2030
99d5cadf 2031config KEXEC_SIG
8e7d8381 2032 bool "Verify kernel signature during kexec_file_load() syscall"
74ca317c 2033 depends on KEXEC_FILE
a7f7f624 2034 help
d8eb8940 2035
99d5cadf
JB
2036 This option makes the kexec_file_load() syscall check for a valid
2037 signature of the kernel image. The image can still be loaded without
2038 a valid signature unless you also enable KEXEC_SIG_FORCE, though if
2039 there's a signature that we can check, then it must be valid.
2040
2041 In addition to this option, you need to enable signature
d8eb8940
BP
2042 verification for the corresponding kernel image type being
2043 loaded in order for this to work.
8e7d8381 2044
99d5cadf
JB
2045config KEXEC_SIG_FORCE
2046 bool "Require a valid signature in kexec_file_load() syscall"
2047 depends on KEXEC_SIG
a7f7f624 2048 help
99d5cadf
JB
2049 This option makes kernel signature verification mandatory for
2050 the kexec_file_load() syscall.
2051
8e7d8381
VG
2052config KEXEC_BZIMAGE_VERIFY_SIG
2053 bool "Enable bzImage signature verification support"
99d5cadf 2054 depends on KEXEC_SIG
8e7d8381
VG
2055 depends on SIGNED_PE_FILE_VERIFICATION
2056 select SYSTEM_TRUSTED_KEYRING
a7f7f624 2057 help
8e7d8381
VG
2058 Enable bzImage signature verification support.
2059
506f1d07 2060config CRASH_DUMP
04b69447 2061 bool "kernel crash dumps"
506f1d07 2062 depends on X86_64 || (X86_32 && HIGHMEM)
a7f7f624 2063 help
506f1d07
SR
2064 Generate crash dump after being started by kexec.
2065 This should be normally only set in special crash dump kernels
2066 which are loaded in the main kernel with kexec-tools into
2067 a specially reserved region and then later executed after
2068 a crash by kdump/kexec. The crash dump kernel must be compiled
2069 to a memory address not used by the main kernel or BIOS using
2070 PHYSICAL_START, or it must be built as a relocatable image
2071 (CONFIG_RELOCATABLE=y).
330d4810 2072 For more details see Documentation/admin-guide/kdump/kdump.rst
506f1d07 2073
3ab83521 2074config KEXEC_JUMP
6ea30386 2075 bool "kexec jump"
fee7b0d8 2076 depends on KEXEC && HIBERNATION
a7f7f624 2077 help
89081d17
HY
2078 Jump between original kernel and kexeced kernel and invoke
2079 code in physical address mode via KEXEC
3ab83521 2080
506f1d07 2081config PHYSICAL_START
6a108a14 2082 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
ceefccc9 2083 default "0x1000000"
a7f7f624 2084 help
506f1d07
SR
2085 This gives the physical address where the kernel is loaded.
2086
2087 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2088 bzImage will decompress itself to above physical address and
2089 run from there. Otherwise, bzImage will run from the address where
2090 it has been loaded by the boot loader and will ignore above physical
2091 address.
2092
2093 In normal kdump cases one does not have to set/change this option
2094 as now bzImage can be compiled as a completely relocatable image
2095 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2096 address. This option is mainly useful for the folks who don't want
2097 to use a bzImage for capturing the crash dump and want to use a
2098 vmlinux instead. vmlinux is not relocatable hence a kernel needs
2099 to be specifically compiled to run from a specific memory area
2100 (normally a reserved region) and this option comes handy.
2101
ceefccc9
PA
2102 So if you are using bzImage for capturing the crash dump,
2103 leave the value here unchanged to 0x1000000 and set
2104 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
2105 for capturing the crash dump change this value to start of
2106 the reserved region. In other words, it can be set based on
2107 the "X" value as specified in the "crashkernel=YM@XM"
2108 command line boot parameter passed to the panic-ed
330d4810 2109 kernel. Please take a look at Documentation/admin-guide/kdump/kdump.rst
ceefccc9 2110 for more details about crash dumps.
506f1d07
SR
2111
2112 Usage of bzImage for capturing the crash dump is recommended as
2113 one does not have to build two kernels. Same kernel can be used
2114 as production kernel and capture kernel. Above option should have
2115 gone away after relocatable bzImage support is introduced. But it
2116 is present because there are users out there who continue to use
2117 vmlinux for dump capture. This option should go away down the
2118 line.
2119
2120 Don't change this unless you know what you are doing.
2121
2122config RELOCATABLE
26717808
PA
2123 bool "Build a relocatable kernel"
2124 default y
a7f7f624 2125 help
506f1d07
SR
2126 This builds a kernel image that retains relocation information
2127 so it can be loaded someplace besides the default 1MB.
2128 The relocations tend to make the kernel binary about 10% larger,
2129 but are discarded at runtime.
2130
2131 One use is for the kexec on panic case where the recovery kernel
2132 must live at a different physical address than the primary
2133 kernel.
2134
2135 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2136 it has been loaded at and the compile time physical address
8ab3820f 2137 (CONFIG_PHYSICAL_START) is used as the minimum location.
506f1d07 2138
8ab3820f 2139config RANDOMIZE_BASE
e8581e3d 2140 bool "Randomize the address of the kernel image (KASLR)"
8ab3820f 2141 depends on RELOCATABLE
6807c846 2142 default y
a7f7f624 2143 help
e8581e3d
BH
2144 In support of Kernel Address Space Layout Randomization (KASLR),
2145 this randomizes the physical address at which the kernel image
2146 is decompressed and the virtual address where the kernel
2147 image is mapped, as a security feature that deters exploit
2148 attempts relying on knowledge of the location of kernel
2149 code internals.
2150
ed9f007e
KC
2151 On 64-bit, the kernel physical and virtual addresses are
2152 randomized separately. The physical address will be anywhere
2153 between 16MB and the top of physical memory (up to 64TB). The
2154 virtual address will be randomized from 16MB up to 1GB (9 bits
2155 of entropy). Note that this also reduces the memory space
2156 available to kernel modules from 1.5GB to 1GB.
2157
2158 On 32-bit, the kernel physical and virtual addresses are
2159 randomized together. They will be randomized from 16MB up to
2160 512MB (8 bits of entropy).
e8581e3d
BH
2161
2162 Entropy is generated using the RDRAND instruction if it is
2163 supported. If RDTSC is supported, its value is mixed into
2164 the entropy pool as well. If neither RDRAND nor RDTSC are
ed9f007e
KC
2165 supported, then entropy is read from the i8254 timer. The
2166 usable entropy is limited by the kernel being built using
2167 2GB addressing, and that PHYSICAL_ALIGN must be at a
2168 minimum of 2MB. As a result, only 10 bits of entropy are
2169 theoretically possible, but the implementations are further
2170 limited due to memory layouts.
e8581e3d 2171
6807c846 2172 If unsure, say Y.
8ab3820f
KC
2173
2174# Relocation on x86 needs some additional build support
845adf72
PA
2175config X86_NEED_RELOCS
2176 def_bool y
8ab3820f 2177 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
845adf72 2178
506f1d07 2179config PHYSICAL_ALIGN
a0215061 2180 hex "Alignment value to which kernel should be aligned"
8ab3820f 2181 default "0x200000"
a0215061
KC
2182 range 0x2000 0x1000000 if X86_32
2183 range 0x200000 0x1000000 if X86_64
a7f7f624 2184 help
506f1d07
SR
2185 This value puts the alignment restrictions on physical address
2186 where kernel is loaded and run from. Kernel is compiled for an
2187 address which meets above alignment restriction.
2188
2189 If bootloader loads the kernel at a non-aligned address and
2190 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2191 address aligned to above value and run from there.
2192
2193 If bootloader loads the kernel at a non-aligned address and
2194 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2195 load address and decompress itself to the address it has been
2196 compiled for and run from there. The address for which kernel is
2197 compiled already meets above alignment restrictions. Hence the
2198 end result is that kernel runs from a physical address meeting
2199 above alignment restrictions.
2200
a0215061
KC
2201 On 32-bit this value must be a multiple of 0x2000. On 64-bit
2202 this value must be a multiple of 0x200000.
2203
506f1d07
SR
2204 Don't change this unless you know what you are doing.
2205
eedb92ab
KS
2206config DYNAMIC_MEMORY_LAYOUT
2207 bool
a7f7f624 2208 help
eedb92ab
KS
2209 This option makes base addresses of vmalloc and vmemmap as well as
2210 __PAGE_OFFSET movable during boot.
2211
0483e1fa
TG
2212config RANDOMIZE_MEMORY
2213 bool "Randomize the kernel memory sections"
2214 depends on X86_64
2215 depends on RANDOMIZE_BASE
eedb92ab 2216 select DYNAMIC_MEMORY_LAYOUT
0483e1fa 2217 default RANDOMIZE_BASE
a7f7f624 2218 help
0483e1fa
TG
2219 Randomizes the base virtual address of kernel memory sections
2220 (physical memory mapping, vmalloc & vmemmap). This security feature
2221 makes exploits relying on predictable memory locations less reliable.
2222
2223 The order of allocations remains unchanged. Entropy is generated in
2224 the same way as RANDOMIZE_BASE. Current implementation in the optimal
2225 configuration have in average 30,000 different possible virtual
2226 addresses for each memory section.
2227
6807c846 2228 If unsure, say Y.
0483e1fa 2229
90397a41
TG
2230config RANDOMIZE_MEMORY_PHYSICAL_PADDING
2231 hex "Physical memory mapping padding" if EXPERT
2232 depends on RANDOMIZE_MEMORY
2233 default "0xa" if MEMORY_HOTPLUG
2234 default "0x0"
2235 range 0x1 0x40 if MEMORY_HOTPLUG
2236 range 0x0 0x40
a7f7f624 2237 help
90397a41
TG
2238 Define the padding in terabytes added to the existing physical
2239 memory size during kernel memory randomization. It is useful
2240 for memory hotplug support but reduces the entropy available for
2241 address randomization.
2242
2243 If unsure, leave at the default value.
2244
506f1d07 2245config HOTPLUG_CPU
bebd024e 2246 def_bool y
40b31360 2247 depends on SMP
506f1d07 2248
80aa1dff
FY
2249config BOOTPARAM_HOTPLUG_CPU0
2250 bool "Set default setting of cpu0_hotpluggable"
2c922cd0 2251 depends on HOTPLUG_CPU
a7f7f624 2252 help
80aa1dff
FY
2253 Set whether default state of cpu0_hotpluggable is on or off.
2254
2255 Say Y here to enable CPU0 hotplug by default. If this switch
2256 is turned on, there is no need to give cpu0_hotplug kernel
2257 parameter and the CPU0 hotplug feature is enabled by default.
2258
2259 Please note: there are two known CPU0 dependencies if you want
2260 to enable the CPU0 hotplug feature either by this switch or by
2261 cpu0_hotplug kernel parameter.
2262
2263 First, resume from hibernate or suspend always starts from CPU0.
2264 So hibernate and suspend are prevented if CPU0 is offline.
2265
2266 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2267 offline if any interrupt can not migrate out of CPU0. There may
2268 be other CPU0 dependencies.
2269
2270 Please make sure the dependencies are under your control before
2271 you enable this feature.
2272
2273 Say N if you don't want to enable CPU0 hotplug feature by default.
2274 You still can enable the CPU0 hotplug feature at boot by kernel
2275 parameter cpu0_hotplug.
2276
a71c8bc5
FY
2277config DEBUG_HOTPLUG_CPU0
2278 def_bool n
2279 prompt "Debug CPU0 hotplug"
2c922cd0 2280 depends on HOTPLUG_CPU
a7f7f624 2281 help
a71c8bc5
FY
2282 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2283 soon as possible and boots up userspace with CPU0 offlined. User
2284 can online CPU0 back after boot time.
2285
2286 To debug CPU0 hotplug, you need to enable CPU0 offline/online
2287 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2288 compilation or giving cpu0_hotplug kernel parameter at boot.
2289
2290 If unsure, say N.
2291
506f1d07 2292config COMPAT_VDSO
b0b49f26
AL
2293 def_bool n
2294 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
953fee1d 2295 depends on COMPAT_32
a7f7f624 2296 help
b0b49f26
AL
2297 Certain buggy versions of glibc will crash if they are
2298 presented with a 32-bit vDSO that is not mapped at the address
2299 indicated in its segment table.
e84446de 2300
b0b49f26
AL
2301 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2302 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2303 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
2304 the only released version with the bug, but OpenSUSE 9
2305 contains a buggy "glibc 2.3.2".
506f1d07 2306
b0b49f26
AL
2307 The symptom of the bug is that everything crashes on startup, saying:
2308 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2309
2310 Saying Y here changes the default value of the vdso32 boot
2311 option from 1 to 0, which turns off the 32-bit vDSO entirely.
2312 This works around the glibc bug but hurts performance.
2313
2314 If unsure, say N: if you are compiling your own kernel, you
2315 are unlikely to be using a buggy version of glibc.
506f1d07 2316
3dc33bd3
KC
2317choice
2318 prompt "vsyscall table for legacy applications"
2319 depends on X86_64
625b7b7f 2320 default LEGACY_VSYSCALL_XONLY
3dc33bd3
KC
2321 help
2322 Legacy user code that does not know how to find the vDSO expects
2323 to be able to issue three syscalls by calling fixed addresses in
2324 kernel space. Since this location is not randomized with ASLR,
2325 it can be used to assist security vulnerability exploitation.
2326
2327 This setting can be changed at boot time via the kernel command
bd49e16e 2328 line parameter vsyscall=[emulate|xonly|none].
3dc33bd3
KC
2329
2330 On a system with recent enough glibc (2.14 or newer) and no
2331 static binaries, you can say None without a performance penalty
2332 to improve security.
2333
bd49e16e 2334 If unsure, select "Emulate execution only".
3dc33bd3 2335
3dc33bd3 2336 config LEGACY_VSYSCALL_EMULATE
bd49e16e 2337 bool "Full emulation"
3dc33bd3 2338 help
bd49e16e
AL
2339 The kernel traps and emulates calls into the fixed vsyscall
2340 address mapping. This makes the mapping non-executable, but
2341 it still contains readable known contents, which could be
2342 used in certain rare security vulnerability exploits. This
2343 configuration is recommended when using legacy userspace
2344 that still uses vsyscalls along with legacy binary
2345 instrumentation tools that require code to be readable.
2346
2347 An example of this type of legacy userspace is running
2348 Pin on an old binary that still uses vsyscalls.
2349
2350 config LEGACY_VSYSCALL_XONLY
2351 bool "Emulate execution only"
2352 help
2353 The kernel traps and emulates calls into the fixed vsyscall
2354 address mapping and does not allow reads. This
2355 configuration is recommended when userspace might use the
2356 legacy vsyscall area but support for legacy binary
2357 instrumentation of legacy code is not needed. It mitigates
2358 certain uses of the vsyscall area as an ASLR-bypassing
2359 buffer.
3dc33bd3
KC
2360
2361 config LEGACY_VSYSCALL_NONE
2362 bool "None"
2363 help
2364 There will be no vsyscall mapping at all. This will
2365 eliminate any risk of ASLR bypass due to the vsyscall
2366 fixed address mapping. Attempts to use the vsyscalls
2367 will be reported to dmesg, so that either old or
2368 malicious userspace programs can be identified.
2369
2370endchoice
2371
516cbf37
TB
2372config CMDLINE_BOOL
2373 bool "Built-in kernel command line"
a7f7f624 2374 help
516cbf37
TB
2375 Allow for specifying boot arguments to the kernel at
2376 build time. On some systems (e.g. embedded ones), it is
2377 necessary or convenient to provide some or all of the
2378 kernel boot arguments with the kernel itself (that is,
2379 to not rely on the boot loader to provide them.)
2380
2381 To compile command line arguments into the kernel,
2382 set this option to 'Y', then fill in the
69711ca1 2383 boot arguments in CONFIG_CMDLINE.
516cbf37
TB
2384
2385 Systems with fully functional boot loaders (i.e. non-embedded)
2386 should leave this option set to 'N'.
2387
2388config CMDLINE
2389 string "Built-in kernel command string"
2390 depends on CMDLINE_BOOL
2391 default ""
a7f7f624 2392 help
516cbf37
TB
2393 Enter arguments here that should be compiled into the kernel
2394 image and used at boot time. If the boot loader provides a
2395 command line at boot time, it is appended to this string to
2396 form the full kernel command line, when the system boots.
2397
2398 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2399 change this behavior.
2400
2401 In most cases, the command line (whether built-in or provided
2402 by the boot loader) should specify the device for the root
2403 file system.
2404
2405config CMDLINE_OVERRIDE
2406 bool "Built-in command line overrides boot loader arguments"
645e6466 2407 depends on CMDLINE_BOOL && CMDLINE != ""
a7f7f624 2408 help
516cbf37
TB
2409 Set this option to 'Y' to have the kernel ignore the boot loader
2410 command line, and use ONLY the built-in command line.
2411
2412 This is used to work around broken boot loaders. This should
2413 be set to 'N' under normal conditions.
2414
a5b9e5a2
AL
2415config MODIFY_LDT_SYSCALL
2416 bool "Enable the LDT (local descriptor table)" if EXPERT
2417 default y
a7f7f624 2418 help
a5b9e5a2
AL
2419 Linux can allow user programs to install a per-process x86
2420 Local Descriptor Table (LDT) using the modify_ldt(2) system
2421 call. This is required to run 16-bit or segmented code such as
2422 DOSEMU or some Wine programs. It is also used by some very old
2423 threading libraries.
2424
2425 Enabling this feature adds a small amount of overhead to
2426 context switches and increases the low-level kernel attack
2427 surface. Disabling it removes the modify_ldt(2) system call.
2428
2429 Saying 'N' here may make sense for embedded or server kernels.
2430
b700e7f0
SJ
2431source "kernel/livepatch/Kconfig"
2432
506f1d07
SR
2433endmenu
2434
3072e413
MH
2435config ARCH_HAS_ADD_PAGES
2436 def_bool y
2437 depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
2438
506f1d07
SR
2439config ARCH_ENABLE_MEMORY_HOTPLUG
2440 def_bool y
2441 depends on X86_64 || (X86_32 && HIGHMEM)
2442
35551053
GH
2443config ARCH_ENABLE_MEMORY_HOTREMOVE
2444 def_bool y
2445 depends on MEMORY_HOTPLUG
2446
e534c7c5 2447config USE_PERCPU_NUMA_NODE_ID
645a7919 2448 def_bool y
e534c7c5
LS
2449 depends on NUMA
2450
9491846f
KS
2451config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2452 def_bool y
2453 depends on X86_64 || X86_PAE
2454
c177c81e
NH
2455config ARCH_ENABLE_HUGEPAGE_MIGRATION
2456 def_bool y
2457 depends on X86_64 && HUGETLB_PAGE && MIGRATION
2458
9c670ea3
NH
2459config ARCH_ENABLE_THP_MIGRATION
2460 def_bool y
2461 depends on X86_64 && TRANSPARENT_HUGEPAGE
2462
da85f865 2463menu "Power management and ACPI options"
e279b6c1
SR
2464
2465config ARCH_HIBERNATION_HEADER
3c2362e6 2466 def_bool y
44556530 2467 depends on HIBERNATION
e279b6c1
SR
2468
2469source "kernel/power/Kconfig"
2470
2471source "drivers/acpi/Kconfig"
2472
efafc8b2
FT
2473source "drivers/sfi/Kconfig"
2474
a6b68076 2475config X86_APM_BOOT
6fc108a0 2476 def_bool y
282e5aab 2477 depends on APM
a6b68076 2478
e279b6c1
SR
2479menuconfig APM
2480 tristate "APM (Advanced Power Management) BIOS support"
efefa6f6 2481 depends on X86_32 && PM_SLEEP
a7f7f624 2482 help
e279b6c1
SR
2483 APM is a BIOS specification for saving power using several different
2484 techniques. This is mostly useful for battery powered laptops with
2485 APM compliant BIOSes. If you say Y here, the system time will be
2486 reset after a RESUME operation, the /proc/apm device will provide
2487 battery status information, and user-space programs will receive
2488 notification of APM "events" (e.g. battery status change).
2489
2490 If you select "Y" here, you can disable actual use of the APM
2491 BIOS by passing the "apm=off" option to the kernel at boot time.
2492
2493 Note that the APM support is almost completely disabled for
2494 machines with more than one CPU.
2495
2496 In order to use APM, you will need supporting software. For location
151f4e2b 2497 and more information, read <file:Documentation/power/apm-acpi.rst>
2dc98fd3 2498 and the Battery Powered Linux mini-HOWTO, available from
e279b6c1
SR
2499 <http://www.tldp.org/docs.html#howto>.
2500
2501 This driver does not spin down disk drives (see the hdparm(8)
2502 manpage ("man 8 hdparm") for that), and it doesn't turn off
2503 VESA-compliant "green" monitors.
2504
2505 This driver does not support the TI 4000M TravelMate and the ACER
2506 486/DX4/75 because they don't have compliant BIOSes. Many "green"
2507 desktop machines also don't have compliant BIOSes, and this driver
2508 may cause those machines to panic during the boot phase.
2509
2510 Generally, if you don't have a battery in your machine, there isn't
2511 much point in using this driver and you should say N. If you get
2512 random kernel OOPSes or reboots that don't seem to be related to
2513 anything, try disabling/enabling this option (or disabling/enabling
2514 APM in your BIOS).
2515
2516 Some other things you should try when experiencing seemingly random,
2517 "weird" problems:
2518
2519 1) make sure that you have enough swap space and that it is
2520 enabled.
2521 2) pass the "no-hlt" option to the kernel
2522 3) switch on floating point emulation in the kernel and pass
2523 the "no387" option to the kernel
2524 4) pass the "floppy=nodma" option to the kernel
2525 5) pass the "mem=4M" option to the kernel (thereby disabling
2526 all but the first 4 MB of RAM)
2527 6) make sure that the CPU is not over clocked.
2528 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2529 8) disable the cache from your BIOS settings
2530 9) install a fan for the video card or exchange video RAM
2531 10) install a better fan for the CPU
2532 11) exchange RAM chips
2533 12) exchange the motherboard.
2534
2535 To compile this driver as a module, choose M here: the
2536 module will be called apm.
2537
2538if APM
2539
2540config APM_IGNORE_USER_SUSPEND
2541 bool "Ignore USER SUSPEND"
a7f7f624 2542 help
e279b6c1
SR
2543 This option will ignore USER SUSPEND requests. On machines with a
2544 compliant APM BIOS, you want to say N. However, on the NEC Versa M
2545 series notebooks, it is necessary to say Y because of a BIOS bug.
2546
2547config APM_DO_ENABLE
2548 bool "Enable PM at boot time"
a7f7f624 2549 help
e279b6c1
SR
2550 Enable APM features at boot time. From page 36 of the APM BIOS
2551 specification: "When disabled, the APM BIOS does not automatically
2552 power manage devices, enter the Standby State, enter the Suspend
2553 State, or take power saving steps in response to CPU Idle calls."
2554 This driver will make CPU Idle calls when Linux is idle (unless this
2555 feature is turned off -- see "Do CPU IDLE calls", below). This
2556 should always save battery power, but more complicated APM features
2557 will be dependent on your BIOS implementation. You may need to turn
2558 this option off if your computer hangs at boot time when using APM
2559 support, or if it beeps continuously instead of suspending. Turn
2560 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2561 T400CDT. This is off by default since most machines do fine without
2562 this feature.
2563
2564config APM_CPU_IDLE
dd8af076 2565 depends on CPU_IDLE
e279b6c1 2566 bool "Make CPU Idle calls when idle"
a7f7f624 2567 help
e279b6c1
SR
2568 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2569 On some machines, this can activate improved power savings, such as
2570 a slowed CPU clock rate, when the machine is idle. These idle calls
2571 are made after the idle loop has run for some length of time (e.g.,
2572 333 mS). On some machines, this will cause a hang at boot time or
2573 whenever the CPU becomes idle. (On machines with more than one CPU,
2574 this option does nothing.)
2575
2576config APM_DISPLAY_BLANK
2577 bool "Enable console blanking using APM"
a7f7f624 2578 help
e279b6c1
SR
2579 Enable console blanking using the APM. Some laptops can use this to
2580 turn off the LCD backlight when the screen blanker of the Linux
2581 virtual console blanks the screen. Note that this is only used by
2582 the virtual console screen blanker, and won't turn off the backlight
2583 when using the X Window system. This also doesn't have anything to
2584 do with your VESA-compliant power-saving monitor. Further, this
2585 option doesn't work for all laptops -- it might not turn off your
2586 backlight at all, or it might print a lot of errors to the console,
2587 especially if you are using gpm.
2588
2589config APM_ALLOW_INTS
2590 bool "Allow interrupts during APM BIOS calls"
a7f7f624 2591 help
e279b6c1
SR
2592 Normally we disable external interrupts while we are making calls to
2593 the APM BIOS as a measure to lessen the effects of a badly behaving
2594 BIOS implementation. The BIOS should reenable interrupts if it
2595 needs to. Unfortunately, some BIOSes do not -- especially those in
2596 many of the newer IBM Thinkpads. If you experience hangs when you
2597 suspend, try setting this to Y. Otherwise, say N.
2598
e279b6c1
SR
2599endif # APM
2600
bb0a56ec 2601source "drivers/cpufreq/Kconfig"
e279b6c1
SR
2602
2603source "drivers/cpuidle/Kconfig"
2604
27471fdb
AH
2605source "drivers/idle/Kconfig"
2606
e279b6c1
SR
2607endmenu
2608
2609
2610menu "Bus options (PCI etc.)"
2611
e279b6c1
SR
2612choice
2613 prompt "PCI access mode"
efefa6f6 2614 depends on X86_32 && PCI
e279b6c1 2615 default PCI_GOANY
a7f7f624 2616 help
e279b6c1
SR
2617 On PCI systems, the BIOS can be used to detect the PCI devices and
2618 determine their configuration. However, some old PCI motherboards
2619 have BIOS bugs and may crash if this is done. Also, some embedded
2620 PCI-based systems don't have any BIOS at all. Linux can also try to
2621 detect the PCI hardware directly without using the BIOS.
2622
2623 With this option, you can specify how Linux should detect the
2624 PCI devices. If you choose "BIOS", the BIOS will be used,
2625 if you choose "Direct", the BIOS won't be used, and if you
2626 choose "MMConfig", then PCI Express MMCONFIG will be used.
2627 If you choose "Any", the kernel will try MMCONFIG, then the
2628 direct access method and falls back to the BIOS if that doesn't
2629 work. If unsure, go with the default, which is "Any".
2630
2631config PCI_GOBIOS
2632 bool "BIOS"
2633
2634config PCI_GOMMCONFIG
2635 bool "MMConfig"
2636
2637config PCI_GODIRECT
2638 bool "Direct"
2639
3ef0e1f8 2640config PCI_GOOLPC
76fb6570 2641 bool "OLPC XO-1"
3ef0e1f8
AS
2642 depends on OLPC
2643
2bdd1b03
AS
2644config PCI_GOANY
2645 bool "Any"
2646
e279b6c1
SR
2647endchoice
2648
2649config PCI_BIOS
3c2362e6 2650 def_bool y
efefa6f6 2651 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
e279b6c1
SR
2652
2653# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2654config PCI_DIRECT
3c2362e6 2655 def_bool y
0aba496f 2656 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
e279b6c1
SR
2657
2658config PCI_MMCONFIG
b45c9f36
JK
2659 bool "Support mmconfig PCI config space access" if X86_64
2660 default y
8364e1f8 2661 depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST)
b45c9f36 2662 depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
e279b6c1 2663
3ef0e1f8 2664config PCI_OLPC
2bdd1b03
AS
2665 def_bool y
2666 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
3ef0e1f8 2667
b5401a96
AN
2668config PCI_XEN
2669 def_bool y
2670 depends on PCI && XEN
2671 select SWIOTLB_XEN
2672
8364e1f8
JK
2673config MMCONF_FAM10H
2674 def_bool y
2675 depends on X86_64 && PCI_MMCONFIG && ACPI
e279b6c1 2676
3f6ea84a 2677config PCI_CNB20LE_QUIRK
6a108a14 2678 bool "Read CNB20LE Host Bridge Windows" if EXPERT
6ea30386 2679 depends on PCI
3f6ea84a
IS
2680 help
2681 Read the PCI windows out of the CNB20LE host bridge. This allows
2682 PCI hotplug to work on systems with the CNB20LE chipset which do
2683 not have ACPI.
2684
64a5fed6
BH
2685 There's no public spec for this chipset, and this functionality
2686 is known to be incomplete.
2687
2688 You should say N unless you know you need this.
2689
3a495511 2690config ISA_BUS
17a2a129 2691 bool "ISA bus support on modern systems" if EXPERT
3a495511 2692 help
17a2a129
WBG
2693 Expose ISA bus device drivers and options available for selection and
2694 configuration. Enable this option if your target machine has an ISA
2695 bus. ISA is an older system, displaced by PCI and newer bus
2696 architectures -- if your target machine is modern, it probably does
2697 not have an ISA bus.
3a495511
WBG
2698
2699 If unsure, say N.
2700
1c00f016 2701# x86_64 have no ISA slots, but can have ISA-style DMA.
e279b6c1 2702config ISA_DMA_API
1c00f016
DR
2703 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2704 default y
2705 help
2706 Enables ISA-style DMA support for devices requiring such controllers.
2707 If unsure, say Y.
e279b6c1 2708
51e68d05
LT
2709if X86_32
2710
e279b6c1
SR
2711config ISA
2712 bool "ISA support"
a7f7f624 2713 help
e279b6c1
SR
2714 Find out whether you have ISA slots on your motherboard. ISA is the
2715 name of a bus system, i.e. the way the CPU talks to the other stuff
2716 inside your box. Other bus systems are PCI, EISA, MicroChannel
2717 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2718 newer boards don't support it. If you have ISA, say Y, otherwise N.
2719
e279b6c1
SR
2720config SCx200
2721 tristate "NatSemi SCx200 support"
a7f7f624 2722 help
e279b6c1
SR
2723 This provides basic support for National Semiconductor's
2724 (now AMD's) Geode processors. The driver probes for the
2725 PCI-IDs of several on-chip devices, so its a good dependency
2726 for other scx200_* drivers.
2727
2728 If compiled as a module, the driver is named scx200.
2729
2730config SCx200HR_TIMER
2731 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
592913ec 2732 depends on SCx200
e279b6c1 2733 default y
a7f7f624 2734 help
e279b6c1
SR
2735 This driver provides a clocksource built upon the on-chip
2736 27MHz high-resolution timer. Its also a workaround for
2737 NSC Geode SC-1100's buggy TSC, which loses time when the
2738 processor goes idle (as is done by the scheduler). The
2739 other workaround is idle=poll boot option.
2740
3ef0e1f8
AS
2741config OLPC
2742 bool "One Laptop Per Child support"
54008979 2743 depends on !X86_PAE
3c554946 2744 select GPIOLIB
dc3119e7 2745 select OF
45bb1674 2746 select OF_PROMTREE
b4e51854 2747 select IRQ_DOMAIN
0c3d931b 2748 select OLPC_EC
a7f7f624 2749 help
3ef0e1f8
AS
2750 Add support for detecting the unique features of the OLPC
2751 XO hardware.
2752
a3128588
DD
2753config OLPC_XO1_PM
2754 bool "OLPC XO-1 Power Management"
fa112cf1 2755 depends on OLPC && MFD_CS5535=y && PM_SLEEP
a7f7f624 2756 help
97c4cb71 2757 Add support for poweroff and suspend of the OLPC XO-1 laptop.
bf1ebf00 2758
cfee9597
DD
2759config OLPC_XO1_RTC
2760 bool "OLPC XO-1 Real Time Clock"
2761 depends on OLPC_XO1_PM && RTC_DRV_CMOS
a7f7f624 2762 help
cfee9597
DD
2763 Add support for the XO-1 real time clock, which can be used as a
2764 programmable wakeup source.
2765
7feda8e9
DD
2766config OLPC_XO1_SCI
2767 bool "OLPC XO-1 SCI extras"
92e830f2 2768 depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
ed8e47fe 2769 depends on INPUT=y
d8d01a63 2770 select POWER_SUPPLY
a7f7f624 2771 help
7feda8e9 2772 Add support for SCI-based features of the OLPC XO-1 laptop:
7bc74b3d 2773 - EC-driven system wakeups
7feda8e9 2774 - Power button
7bc74b3d 2775 - Ebook switch
2cf2baea 2776 - Lid switch
e1040ac6
DD
2777 - AC adapter status updates
2778 - Battery status updates
7feda8e9 2779
a0f30f59
DD
2780config OLPC_XO15_SCI
2781 bool "OLPC XO-1.5 SCI extras"
d8d01a63
DD
2782 depends on OLPC && ACPI
2783 select POWER_SUPPLY
a7f7f624 2784 help
a0f30f59
DD
2785 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2786 - EC-driven system wakeups
2787 - AC adapter status updates
2788 - Battery status updates
bf1ebf00 2789
d4f3e350
EW
2790config ALIX
2791 bool "PCEngines ALIX System Support (LED setup)"
2792 select GPIOLIB
a7f7f624 2793 help
d4f3e350
EW
2794 This option enables system support for the PCEngines ALIX.
2795 At present this just sets up LEDs for GPIO control on
2796 ALIX2/3/6 boards. However, other system specific setup should
2797 get added here.
2798
2799 Note: You must still enable the drivers for GPIO and LED support
2800 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2801
2802 Note: You have to set alix.force=1 for boards with Award BIOS.
2803
da4e3302
PP
2804config NET5501
2805 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2806 select GPIOLIB
a7f7f624 2807 help
da4e3302
PP
2808 This option enables system support for the Soekris Engineering net5501.
2809
3197059a
PP
2810config GEOS
2811 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2812 select GPIOLIB
2813 depends on DMI
a7f7f624 2814 help
3197059a
PP
2815 This option enables system support for the Traverse Technologies GEOS.
2816
7d029125
VD
2817config TS5500
2818 bool "Technologic Systems TS-5500 platform support"
2819 depends on MELAN
2820 select CHECK_SIGNATURE
2821 select NEW_LEDS
2822 select LEDS_CLASS
a7f7f624 2823 help
7d029125
VD
2824 This option enables system support for the Technologic Systems TS-5500.
2825
bc0120fd
SR
2826endif # X86_32
2827
23ac4ae8 2828config AMD_NB
e279b6c1 2829 def_bool y
0e152cd7 2830 depends on CPU_SUP_AMD && PCI
e279b6c1 2831
e3263ab3
DR
2832config X86_SYSFB
2833 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2834 help
2835 Firmwares often provide initial graphics framebuffers so the BIOS,
2836 bootloader or kernel can show basic video-output during boot for
2837 user-guidance and debugging. Historically, x86 used the VESA BIOS
2838 Extensions and EFI-framebuffers for this, which are mostly limited
2839 to x86.
2840 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2841 framebuffers so the new generic system-framebuffer drivers can be
2842 used on x86. If the framebuffer is not compatible with the generic
e3a5dc08 2843 modes, it is advertised as fallback platform framebuffer so legacy
e3263ab3
DR
2844 drivers like efifb, vesafb and uvesafb can pick it up.
2845 If this option is not selected, all system framebuffers are always
2846 marked as fallback platform framebuffers as usual.
2847
2848 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2849 not be able to pick up generic system framebuffers if this option
2850 is selected. You are highly encouraged to enable simplefb as
2851 replacement if you select this option. simplefb can correctly deal
2852 with generic system framebuffers. But you should still keep vesafb
2853 and others enabled as fallback if a system framebuffer is
2854 incompatible with simplefb.
2855
2856 If unsure, say Y.
2857
e279b6c1
SR
2858endmenu
2859
2860
1572497c 2861menu "Binary Emulations"
e279b6c1
SR
2862
2863config IA32_EMULATION
2864 bool "IA32 Emulation"
2865 depends on X86_64
39f88911 2866 select ARCH_WANT_OLD_COMPAT_IPC
d1603990 2867 select BINFMT_ELF
a97f52e6 2868 select COMPAT_BINFMT_ELF
39f88911 2869 select COMPAT_OLD_SIGACTION
a7f7f624 2870 help
5fd92e65
L
2871 Include code to run legacy 32-bit programs under a
2872 64-bit kernel. You should likely turn this on, unless you're
2873 100% sure that you don't have any 32-bit programs left.
e279b6c1
SR
2874
2875config IA32_AOUT
8f9ca475
IM
2876 tristate "IA32 a.out support"
2877 depends on IA32_EMULATION
eac61655 2878 depends on BROKEN
a7f7f624 2879 help
8f9ca475 2880 Support old a.out binaries in the 32bit emulation.
e279b6c1 2881
0bf62763 2882config X86_X32
6ea30386 2883 bool "x32 ABI for 64-bit mode"
9b54050b 2884 depends on X86_64
a7f7f624 2885 help
5fd92e65
L
2886 Include code to run binaries for the x32 native 32-bit ABI
2887 for 64-bit processors. An x32 process gets access to the
2888 full 64-bit register file and wide data path while leaving
2889 pointers at 32 bits for smaller memory footprint.
2890
2891 You will need a recent binutils (2.22 or later) with
2892 elf32_x86_64 support enabled to compile a kernel with this
2893 option set.
2894
953fee1d
IM
2895config COMPAT_32
2896 def_bool y
2897 depends on IA32_EMULATION || X86_32
2898 select HAVE_UID16
2899 select OLD_SIGSUSPEND3
2900
e279b6c1 2901config COMPAT
3c2362e6 2902 def_bool y
0bf62763 2903 depends on IA32_EMULATION || X86_X32
e279b6c1 2904
3120e25e 2905if COMPAT
e279b6c1 2906config COMPAT_FOR_U64_ALIGNMENT
3120e25e 2907 def_bool y
e279b6c1
SR
2908
2909config SYSVIPC_COMPAT
3c2362e6 2910 def_bool y
3120e25e 2911 depends on SYSVIPC
3120e25e 2912endif
ee009e4a 2913
e279b6c1
SR
2914endmenu
2915
2916
e5beae16
KP
2917config HAVE_ATOMIC_IOMAP
2918 def_bool y
2919 depends on X86_32
2920
e279b6c1
SR
2921source "drivers/firmware/Kconfig"
2922
edf88417 2923source "arch/x86/kvm/Kconfig"
5e8ebd84
JD
2924
2925source "arch/x86/Kconfig.assembler"