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xjb04a4022021-11-25 15:01:52 +08001# SPDX-License-Identifier: GPL-2.0
2# Select 32 or 64 bit
3config 64BIT
4 bool "64-bit kernel" if "$(ARCH)" = "x86"
5 default "$(ARCH)" != "i386"
6 ---help---
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
11 def_bool y
12 depends on !64BIT
13 # Options that are inherently 32-bit kernel only:
14 select ARCH_WANT_IPC_PARSE_VERSION
15 select CLKSRC_I8253
16 select CLONE_BACKWARDS
17 select HAVE_AOUT
18 select HAVE_GENERIC_DMA_COHERENT
19 select MODULES_USE_ELF_REL
20 select OLD_SIGACTION
21
22config X86_64
23 def_bool y
24 depends on 64BIT
25 # Options that are inherently 64-bit kernel only:
26 select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA
27 select ARCH_SUPPORTS_INT128
28 select ARCH_USE_CMPXCHG_LOCKREF
29 select HAVE_ARCH_SOFT_DIRTY
30 select MODULES_USE_ELF_RELA
31 select NEED_DMA_MAP_STATE
32 select SWIOTLB
33 select X86_DEV_DMA_OPS
34 select ARCH_HAS_SYSCALL_WRAPPER
35
36#
37# Arch settings
38#
39# ( Note that options that are marked 'if X86_64' could in principle be
40# ported to 32-bit as well. )
41#
42config X86
43 def_bool y
44 #
45 # Note: keep this list sorted alphabetically
46 #
47 select ACPI_LEGACY_TABLES_LOOKUP if ACPI
48 select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI
49 select ARCH_CLOCKSOURCE_DATA
50 select ARCH_DISCARD_MEMBLOCK
51 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
52 select ARCH_HAS_DEBUG_VIRTUAL
53 select ARCH_HAS_DEVMEM_IS_ALLOWED
54 select ARCH_HAS_ELF_RANDOMIZE
55 select ARCH_HAS_FAST_MULTIPLIER
56 select ARCH_HAS_FILTER_PGPROT
57 select ARCH_HAS_FORTIFY_SOURCE
58 select ARCH_HAS_GCOV_PROFILE_ALL
59 select ARCH_HAS_KCOV if X86_64
60 select ARCH_HAS_MEMBARRIER_SYNC_CORE
61 select ARCH_HAS_PMEM_API if X86_64
62 select ARCH_HAS_PTE_SPECIAL
63 select ARCH_HAS_REFCOUNT
64 select ARCH_HAS_UACCESS_FLUSHCACHE if X86_64
65 select ARCH_HAS_UACCESS_MCSAFE if X86_64 && X86_MCE
66 select ARCH_HAS_SET_MEMORY
67 select ARCH_HAS_SG_CHAIN
68 select ARCH_HAS_STRICT_KERNEL_RWX
69 select ARCH_HAS_STRICT_MODULE_RWX
70 select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
71 select ARCH_HAS_UBSAN_SANITIZE_ALL
72 select ARCH_HAS_ZONE_DEVICE if X86_64
73 select ARCH_HAVE_NMI_SAFE_CMPXCHG
74 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
75 select ARCH_MIGHT_HAVE_PC_PARPORT
76 select ARCH_MIGHT_HAVE_PC_SERIO
77 select ARCH_SUPPORTS_ACPI
78 select ARCH_SUPPORTS_ATOMIC_RMW
79 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
80 select ARCH_SUPPORTS_LTO_CLANG if X86_64
81 select ARCH_USE_BUILTIN_BSWAP
82 select ARCH_USE_QUEUED_RWLOCKS
83 select ARCH_USE_QUEUED_SPINLOCKS
84 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
85 select ARCH_WANTS_DYNAMIC_TASK_STRUCT
86 select ARCH_WANTS_THP_SWAP if X86_64
87 select BUILDTIME_EXTABLE_SORT
88 select CLKEVT_I8253
89 select CLOCKSOURCE_VALIDATE_LAST_CYCLE
90 select CLOCKSOURCE_WATCHDOG
91 select DCACHE_WORD_ACCESS
92 select DMA_DIRECT_OPS
93 select EDAC_ATOMIC_SCRUB
94 select EDAC_SUPPORT
95 select GENERIC_CLOCKEVENTS
96 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
97 select GENERIC_CLOCKEVENTS_MIN_ADJUST
98 select GENERIC_CMOS_UPDATE
99 select GENERIC_CPU_AUTOPROBE
100 select GENERIC_CPU_VULNERABILITIES
101 select GENERIC_EARLY_IOREMAP
102 select GENERIC_FIND_FIRST_BIT
103 select GENERIC_IOMAP
104 select GENERIC_IRQ_EFFECTIVE_AFF_MASK if SMP
105 select GENERIC_IRQ_MATRIX_ALLOCATOR if X86_LOCAL_APIC
106 select GENERIC_IRQ_MIGRATION if SMP
107 select GENERIC_IRQ_PROBE
108 select GENERIC_IRQ_RESERVATION_MODE
109 select GENERIC_IRQ_SHOW
110 select GENERIC_PENDING_IRQ if SMP
111 select GENERIC_SMP_IDLE_THREAD
112 select GENERIC_STRNCPY_FROM_USER
113 select GENERIC_STRNLEN_USER
114 select GENERIC_TIME_VSYSCALL
115 select HARDLOCKUP_CHECK_TIMESTAMP if X86_64
116 select HAVE_ACPI_APEI if ACPI
117 select HAVE_ACPI_APEI_NMI if ACPI
118 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
119 select HAVE_ARCH_AUDITSYSCALL
120 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE
121 select HAVE_ARCH_JUMP_LABEL
122 select HAVE_ARCH_KASAN if X86_64
123 select HAVE_ARCH_KGDB
124 select HAVE_ARCH_MMAP_RND_BITS if MMU
125 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT
126 select HAVE_ARCH_COMPAT_MMAP_BASES if MMU && COMPAT
127 select HAVE_ARCH_PREL32_RELOCATIONS if !LTO_CLANG
128 select HAVE_ARCH_SECCOMP_FILTER
129 select HAVE_ARCH_THREAD_STRUCT_WHITELIST
130 select HAVE_ARCH_TRACEHOOK
131 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
132 select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if X86_64
133 select HAVE_ARCH_VMAP_STACK if X86_64
134 select HAVE_ARCH_WITHIN_STACK_FRAMES
135 select HAVE_CMPXCHG_DOUBLE
136 select HAVE_CMPXCHG_LOCAL
137 select HAVE_CONTEXT_TRACKING if X86_64
138 select HAVE_COPY_THREAD_TLS
139 select HAVE_C_RECORDMCOUNT
140 select HAVE_DEBUG_KMEMLEAK
141 select HAVE_DEBUG_STACKOVERFLOW
142 select HAVE_DMA_CONTIGUOUS
143 select HAVE_DYNAMIC_FTRACE
144 select HAVE_DYNAMIC_FTRACE_WITH_REGS
145 select HAVE_EBPF_JIT
146 select HAVE_EFFICIENT_UNALIGNED_ACCESS
147 select HAVE_EXIT_THREAD
148 select HAVE_FENTRY if X86_64 || DYNAMIC_FTRACE
149 select HAVE_FTRACE_MCOUNT_RECORD
150 select HAVE_FUNCTION_GRAPH_TRACER
151 select HAVE_FUNCTION_TRACER
152 select HAVE_GCC_PLUGINS
153 select HAVE_HW_BREAKPOINT
154 select HAVE_IDE
155 select HAVE_IOREMAP_PROT
156 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
157 select HAVE_IRQ_TIME_ACCOUNTING
158 select HAVE_KERNEL_BZIP2
159 select HAVE_KERNEL_GZIP
160 select HAVE_KERNEL_LZ4
161 select HAVE_KERNEL_LZMA
162 select HAVE_KERNEL_LZO
163 select HAVE_KERNEL_XZ
164 select HAVE_KPROBES
165 select HAVE_KPROBES_ON_FTRACE
166 select HAVE_FUNCTION_ERROR_INJECTION
167 select HAVE_KRETPROBES
168 select HAVE_KVM
169 select HAVE_LIVEPATCH if X86_64
170 select HAVE_MEMBLOCK
171 select HAVE_MEMBLOCK_NODE_MAP
172 select HAVE_MIXED_BREAKPOINTS_REGS
173 select HAVE_MOD_ARCH_SPECIFIC
174 select HAVE_NMI
175 select HAVE_OPROFILE
176 select HAVE_OPTPROBES
177 select HAVE_PCSPKR_PLATFORM
178 select HAVE_PERF_EVENTS
179 select HAVE_PERF_EVENTS_NMI
180 select HAVE_HARDLOCKUP_DETECTOR_PERF if PERF_EVENTS && HAVE_PERF_EVENTS_NMI
181 select HAVE_PERF_REGS
182 select HAVE_PERF_USER_STACK_DUMP
183 select HAVE_RCU_TABLE_FREE if PARAVIRT
184 select HAVE_RCU_TABLE_INVALIDATE if HAVE_RCU_TABLE_FREE
185 select HAVE_REGS_AND_STACK_ACCESS_API
186 select HAVE_RELIABLE_STACKTRACE if X86_64 && (UNWINDER_FRAME_POINTER || UNWINDER_ORC) && STACK_VALIDATION
187 select HAVE_STACKPROTECTOR if CC_HAS_SANE_STACKPROTECTOR
188 select HAVE_STACK_VALIDATION if X86_64 && !LTO_CLANG
189 select HAVE_RSEQ
190 select HAVE_SYSCALL_TRACEPOINTS
191 select HAVE_UNSTABLE_SCHED_CLOCK
192 select HAVE_USER_RETURN_NOTIFIER
193 select HOTPLUG_SMT if SMP
194 select IRQ_FORCED_THREADING
195 select NEED_SG_DMA_LENGTH
196 select PCI_LOCKLESS_CONFIG
197 select PERF_EVENTS
198 select RTC_LIB
199 select RTC_MC146818_LIB
200 select SPARSE_IRQ
201 select SRCU
202 select SYSCTL_EXCEPTION_TRACE
203 select THREAD_INFO_IN_TASK
204 select USER_STACKTRACE_SUPPORT
205 select VIRT_TO_BUS
206 select X86_FEATURE_NAMES if PROC_FS
207
208config INSTRUCTION_DECODER
209 def_bool y
210 depends on KPROBES || PERF_EVENTS || UPROBES
211
212config OUTPUT_FORMAT
213 string
214 default "elf32-i386" if X86_32
215 default "elf64-x86-64" if X86_64
216
217config ARCH_DEFCONFIG
218 string
219 default "arch/x86/configs/i386_defconfig" if X86_32
220 default "arch/x86/configs/x86_64_defconfig" if X86_64
221
222config LOCKDEP_SUPPORT
223 def_bool y
224
225config STACKTRACE_SUPPORT
226 def_bool y
227
228config MMU
229 def_bool y
230
231config ARCH_MMAP_RND_BITS_MIN
232 default 28 if 64BIT
233 default 8
234
235config ARCH_MMAP_RND_BITS_MAX
236 default 32 if 64BIT
237 default 16
238
239config ARCH_MMAP_RND_COMPAT_BITS_MIN
240 default 8
241
242config ARCH_MMAP_RND_COMPAT_BITS_MAX
243 default 16
244
245config SBUS
246 bool
247
248config GENERIC_ISA_DMA
249 def_bool y
250 depends on ISA_DMA_API
251
252config GENERIC_BUG
253 def_bool y
254 depends on BUG
255 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
256
257config GENERIC_BUG_RELATIVE_POINTERS
258 bool
259
260config GENERIC_HWEIGHT
261 def_bool y
262
263config ARCH_MAY_HAVE_PC_FDC
264 def_bool y
265 depends on ISA_DMA_API
266
267config RWSEM_XCHGADD_ALGORITHM
268 def_bool y
269
270config GENERIC_CALIBRATE_DELAY
271 def_bool y
272
273config ARCH_HAS_CPU_RELAX
274 def_bool y
275
276config ARCH_HAS_CACHE_LINE_SIZE
277 def_bool y
278
279config ARCH_HAS_FILTER_PGPROT
280 def_bool y
281
282config HAVE_SETUP_PER_CPU_AREA
283 def_bool y
284
285config NEED_PER_CPU_EMBED_FIRST_CHUNK
286 def_bool y
287
288config NEED_PER_CPU_PAGE_FIRST_CHUNK
289 def_bool y
290
291config ARCH_HIBERNATION_POSSIBLE
292 def_bool y
293
294config ARCH_SUSPEND_POSSIBLE
295 def_bool y
296
297config ARCH_WANT_HUGE_PMD_SHARE
298 def_bool y
299
300config ARCH_WANT_GENERAL_HUGETLB
301 def_bool y
302
303config ZONE_DMA32
304 def_bool y if X86_64
305
306config AUDIT_ARCH
307 def_bool y if X86_64
308
309config ARCH_SUPPORTS_DEBUG_PAGEALLOC
310 def_bool y
311
312config KASAN_SHADOW_OFFSET
313 hex
314 depends on KASAN
315 default 0xdffffc0000000000
316
317config HAVE_INTEL_TXT
318 def_bool y
319 depends on INTEL_IOMMU && ACPI
320
321config X86_32_SMP
322 def_bool y
323 depends on X86_32 && SMP
324
325config X86_64_SMP
326 def_bool y
327 depends on X86_64 && SMP
328
329config X86_32_LAZY_GS
330 def_bool y
331 depends on X86_32 && !STACKPROTECTOR
332
333config ARCH_SUPPORTS_UPROBES
334 def_bool y
335
336config FIX_EARLYCON_MEM
337 def_bool y
338
339config DYNAMIC_PHYSICAL_MASK
340 bool
341
342config PGTABLE_LEVELS
343 int
344 default 5 if X86_5LEVEL
345 default 4 if X86_64
346 default 3 if X86_PAE
347 default 2
348
349config CC_HAS_SANE_STACKPROTECTOR
350 bool
351 default $(success,$(srctree)/scripts/gcc-x86_64-has-stack-protector.sh $(CC)) if 64BIT
352 default $(success,$(srctree)/scripts/gcc-x86_32-has-stack-protector.sh $(CC))
353 help
354 We have to make sure stack protector is unconditionally disabled if
355 the compiler produces broken code.
356
357menu "Processor type and features"
358
359config ZONE_DMA
360 bool "DMA memory allocation support" if EXPERT
361 default y
362 help
363 DMA memory allocation support allows devices with less than 32-bit
364 addressing to allocate within the first 16MB of address space.
365 Disable if no such devices will be used.
366
367 If unsure, say Y.
368
369config SMP
370 bool "Symmetric multi-processing support"
371 ---help---
372 This enables support for systems with more than one CPU. If you have
373 a system with only one CPU, say N. If you have a system with more
374 than one CPU, say Y.
375
376 If you say N here, the kernel will run on uni- and multiprocessor
377 machines, but will use only one CPU of a multiprocessor machine. If
378 you say Y here, the kernel will run on many, but not all,
379 uniprocessor machines. On a uniprocessor machine, the kernel
380 will run faster if you say N here.
381
382 Note that if you say Y here and choose architecture "586" or
383 "Pentium" under "Processor family", the kernel will not work on 486
384 architectures. Similarly, multiprocessor kernels for the "PPro"
385 architecture may not work on all Pentium based boards.
386
387 People using multiprocessor machines who say Y here should also say
388 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
389 Management" code will be disabled if you say Y here.
390
391 See also <file:Documentation/x86/i386/IO-APIC.txt>,
392 <file:Documentation/lockup-watchdogs.txt> and the SMP-HOWTO available at
393 <http://www.tldp.org/docs.html#howto>.
394
395 If you don't know what to do here, say N.
396
397config X86_FEATURE_NAMES
398 bool "Processor feature human-readable names" if EMBEDDED
399 default y
400 ---help---
401 This option compiles in a table of x86 feature bits and corresponding
402 names. This is required to support /proc/cpuinfo and a few kernel
403 messages. You can disable this to save space, at the expense of
404 making those few kernel messages show numeric feature bits instead.
405
406 If in doubt, say Y.
407
408config X86_X2APIC
409 bool "Support x2apic"
410 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
411 ---help---
412 This enables x2apic support on CPUs that have this feature.
413
414 This allows 32-bit apic IDs (so it can support very large systems),
415 and accesses the local apic via MSRs not via mmio.
416
417 If you don't know what to do here, say N.
418
419config X86_MPPARSE
420 bool "Enable MPS table" if ACPI || SFI
421 default y
422 depends on X86_LOCAL_APIC
423 ---help---
424 For old smp systems that do not have proper acpi support. Newer systems
425 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
426
427config GOLDFISH
428 def_bool y
429 depends on X86_GOLDFISH
430
431config RETPOLINE
432 bool "Avoid speculative indirect branches in kernel"
433 default y
434 select STACK_VALIDATION if HAVE_STACK_VALIDATION
435 help
436 Compile kernel with the retpoline compiler options to guard against
437 kernel-to-user data leaks by avoiding speculative indirect
438 branches. Requires a compiler with -mindirect-branch=thunk-extern
439 support for full protection. The kernel may run slower.
440
441config INTEL_RDT
442 bool "Intel Resource Director Technology support"
443 default n
444 depends on X86 && CPU_SUP_INTEL
445 select KERNFS
446 help
447 Select to enable resource allocation and monitoring which are
448 sub-features of Intel Resource Director Technology(RDT). More
449 information about RDT can be found in the Intel x86
450 Architecture Software Developer Manual.
451
452 Say N if unsure.
453
454if X86_32
455config X86_BIGSMP
456 bool "Support for big SMP systems with more than 8 CPUs"
457 depends on SMP
458 ---help---
459 This option is needed for the systems that have more than 8 CPUs
460
461config X86_EXTENDED_PLATFORM
462 bool "Support for extended (non-PC) x86 platforms"
463 default y
464 ---help---
465 If you disable this option then the kernel will only support
466 standard PC platforms. (which covers the vast majority of
467 systems out there.)
468
469 If you enable this option then you'll be able to select support
470 for the following (non-PC) 32 bit x86 platforms:
471 Goldfish (Android emulator)
472 AMD Elan
473 RDC R-321x SoC
474 SGI 320/540 (Visual Workstation)
475 STA2X11-based (e.g. Northville)
476 Moorestown MID devices
477
478 If you have one of these systems, or if you want to build a
479 generic distribution kernel, say Y here - otherwise say N.
480endif
481
482if X86_64
483config X86_EXTENDED_PLATFORM
484 bool "Support for extended (non-PC) x86 platforms"
485 default y
486 ---help---
487 If you disable this option then the kernel will only support
488 standard PC platforms. (which covers the vast majority of
489 systems out there.)
490
491 If you enable this option then you'll be able to select support
492 for the following (non-PC) 64 bit x86 platforms:
493 Numascale NumaChip
494 ScaleMP vSMP
495 SGI Ultraviolet
496
497 If you have one of these systems, or if you want to build a
498 generic distribution kernel, say Y here - otherwise say N.
499endif
500# This is an alphabetically sorted list of 64 bit extended platforms
501# Please maintain the alphabetic order if and when there are additions
502config X86_NUMACHIP
503 bool "Numascale NumaChip"
504 depends on X86_64
505 depends on X86_EXTENDED_PLATFORM
506 depends on NUMA
507 depends on SMP
508 depends on X86_X2APIC
509 depends on PCI_MMCONFIG
510 ---help---
511 Adds support for Numascale NumaChip large-SMP systems. Needed to
512 enable more than ~168 cores.
513 If you don't have one of these, you should say N here.
514
515config X86_VSMP
516 bool "ScaleMP vSMP"
517 select HYPERVISOR_GUEST
518 select PARAVIRT
519 depends on X86_64 && PCI
520 depends on X86_EXTENDED_PLATFORM
521 depends on SMP
522 ---help---
523 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
524 supposed to run on these EM64T-based machines. Only choose this option
525 if you have one of these machines.
526
527config X86_UV
528 bool "SGI Ultraviolet"
529 depends on X86_64
530 depends on X86_EXTENDED_PLATFORM
531 depends on NUMA
532 depends on EFI
533 depends on X86_X2APIC
534 depends on PCI
535 ---help---
536 This option is needed in order to support SGI Ultraviolet systems.
537 If you don't have one of these, you should say N here.
538
539# Following is an alphabetically sorted list of 32 bit extended platforms
540# Please maintain the alphabetic order if and when there are additions
541
542config X86_GOLDFISH
543 bool "Goldfish (Virtual Platform)"
544 depends on X86_EXTENDED_PLATFORM
545 ---help---
546 Enable support for the Goldfish virtual platform used primarily
547 for Android development. Unless you are building for the Android
548 Goldfish emulator say N here.
549
550config X86_INTEL_CE
551 bool "CE4100 TV platform"
552 depends on PCI
553 depends on PCI_GODIRECT
554 depends on X86_IO_APIC
555 depends on X86_32
556 depends on X86_EXTENDED_PLATFORM
557 select X86_REBOOTFIXUPS
558 select OF
559 select OF_EARLY_FLATTREE
560 ---help---
561 Select for the Intel CE media processor (CE4100) SOC.
562 This option compiles in support for the CE4100 SOC for settop
563 boxes and media devices.
564
565config X86_INTEL_MID
566 bool "Intel MID platform support"
567 depends on X86_EXTENDED_PLATFORM
568 depends on X86_PLATFORM_DEVICES
569 depends on PCI
570 depends on X86_64 || (PCI_GOANY && X86_32)
571 depends on X86_IO_APIC
572 select SFI
573 select I2C
574 select DW_APB_TIMER
575 select APB_TIMER
576 select INTEL_SCU_IPC
577 select MFD_INTEL_MSIC
578 ---help---
579 Select to build a kernel capable of supporting Intel MID (Mobile
580 Internet Device) platform systems which do not have the PCI legacy
581 interfaces. If you are building for a PC class system say N here.
582
583 Intel MID platforms are based on an Intel processor and chipset which
584 consume less power than most of the x86 derivatives.
585
586config X86_INTEL_QUARK
587 bool "Intel Quark platform support"
588 depends on X86_32
589 depends on X86_EXTENDED_PLATFORM
590 depends on X86_PLATFORM_DEVICES
591 depends on X86_TSC
592 depends on PCI
593 depends on PCI_GOANY
594 depends on X86_IO_APIC
595 select IOSF_MBI
596 select INTEL_IMR
597 select COMMON_CLK
598 ---help---
599 Select to include support for Quark X1000 SoC.
600 Say Y here if you have a Quark based system such as the Arduino
601 compatible Intel Galileo.
602
603config X86_INTEL_LPSS
604 bool "Intel Low Power Subsystem Support"
605 depends on X86 && ACPI
606 select COMMON_CLK
607 select PINCTRL
608 select IOSF_MBI
609 ---help---
610 Select to build support for Intel Low Power Subsystem such as
611 found on Intel Lynxpoint PCH. Selecting this option enables
612 things like clock tree (common clock framework) and pincontrol
613 which are needed by the LPSS peripheral drivers.
614
615config X86_AMD_PLATFORM_DEVICE
616 bool "AMD ACPI2Platform devices support"
617 depends on ACPI
618 select COMMON_CLK
619 select PINCTRL
620 ---help---
621 Select to interpret AMD specific ACPI device to platform device
622 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
623 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
624 implemented under PINCTRL subsystem.
625
626config IOSF_MBI
627 tristate "Intel SoC IOSF Sideband support for SoC platforms"
628 depends on PCI
629 ---help---
630 This option enables sideband register access support for Intel SoC
631 platforms. On these platforms the IOSF sideband is used in lieu of
632 MSR's for some register accesses, mostly but not limited to thermal
633 and power. Drivers may query the availability of this device to
634 determine if they need the sideband in order to work on these
635 platforms. The sideband is available on the following SoC products.
636 This list is not meant to be exclusive.
637 - BayTrail
638 - Braswell
639 - Quark
640
641 You should say Y if you are running a kernel on one of these SoC's.
642
643config IOSF_MBI_DEBUG
644 bool "Enable IOSF sideband access through debugfs"
645 depends on IOSF_MBI && DEBUG_FS
646 ---help---
647 Select this option to expose the IOSF sideband access registers (MCR,
648 MDR, MCRX) through debugfs to write and read register information from
649 different units on the SoC. This is most useful for obtaining device
650 state information for debug and analysis. As this is a general access
651 mechanism, users of this option would have specific knowledge of the
652 device they want to access.
653
654 If you don't require the option or are in doubt, say N.
655
656config X86_RDC321X
657 bool "RDC R-321x SoC"
658 depends on X86_32
659 depends on X86_EXTENDED_PLATFORM
660 select M486
661 select X86_REBOOTFIXUPS
662 ---help---
663 This option is needed for RDC R-321x system-on-chip, also known
664 as R-8610-(G).
665 If you don't have one of these chips, you should say N here.
666
667config X86_32_NON_STANDARD
668 bool "Support non-standard 32-bit SMP architectures"
669 depends on X86_32 && SMP
670 depends on X86_EXTENDED_PLATFORM
671 ---help---
672 This option compiles in the bigsmp and STA2X11 default
673 subarchitectures. It is intended for a generic binary
674 kernel. If you select them all, kernel will probe it one by
675 one and will fallback to default.
676
677# Alphabetically sorted list of Non standard 32 bit platforms
678
679config X86_SUPPORTS_MEMORY_FAILURE
680 def_bool y
681 # MCE code calls memory_failure():
682 depends on X86_MCE
683 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
684 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
685 depends on X86_64 || !SPARSEMEM
686 select ARCH_SUPPORTS_MEMORY_FAILURE
687
688config STA2X11
689 bool "STA2X11 Companion Chip Support"
690 depends on X86_32_NON_STANDARD && PCI
691 select ARCH_HAS_PHYS_TO_DMA
692 select X86_DEV_DMA_OPS
693 select X86_DMA_REMAP
694 select SWIOTLB
695 select MFD_STA2X11
696 select GPIOLIB
697 default n
698 ---help---
699 This adds support for boards based on the STA2X11 IO-Hub,
700 a.k.a. "ConneXt". The chip is used in place of the standard
701 PC chipset, so all "standard" peripherals are missing. If this
702 option is selected the kernel will still be able to boot on
703 standard PC machines.
704
705config X86_32_IRIS
706 tristate "Eurobraille/Iris poweroff module"
707 depends on X86_32
708 ---help---
709 The Iris machines from EuroBraille do not have APM or ACPI support
710 to shut themselves down properly. A special I/O sequence is
711 needed to do so, which is what this module does at
712 kernel shutdown.
713
714 This is only for Iris machines from EuroBraille.
715
716 If unused, say N.
717
718config SCHED_OMIT_FRAME_POINTER
719 def_bool y
720 prompt "Single-depth WCHAN output"
721 depends on X86
722 ---help---
723 Calculate simpler /proc/<PID>/wchan values. If this option
724 is disabled then wchan values will recurse back to the
725 caller function. This provides more accurate wchan values,
726 at the expense of slightly more scheduling overhead.
727
728 If in doubt, say "Y".
729
730menuconfig HYPERVISOR_GUEST
731 bool "Linux guest support"
732 ---help---
733 Say Y here to enable options for running Linux under various hyper-
734 visors. This option enables basic hypervisor detection and platform
735 setup.
736
737 If you say N, all options in this submenu will be skipped and
738 disabled, and Linux guest support won't be built in.
739
740if HYPERVISOR_GUEST
741
742config PARAVIRT
743 bool "Enable paravirtualization code"
744 ---help---
745 This changes the kernel so it can modify itself when it is run
746 under a hypervisor, potentially improving performance significantly
747 over full virtualization. However, when run without a hypervisor
748 the kernel is theoretically slower and slightly larger.
749
750config PARAVIRT_DEBUG
751 bool "paravirt-ops debugging"
752 depends on PARAVIRT && DEBUG_KERNEL
753 ---help---
754 Enable to debug paravirt_ops internals. Specifically, BUG if
755 a paravirt_op is missing when it is called.
756
757config PARAVIRT_SPINLOCKS
758 bool "Paravirtualization layer for spinlocks"
759 depends on PARAVIRT && SMP
760 ---help---
761 Paravirtualized spinlocks allow a pvops backend to replace the
762 spinlock implementation with something virtualization-friendly
763 (for example, block the virtual CPU rather than spinning).
764
765 It has a minimal impact on native kernels and gives a nice performance
766 benefit on paravirtualized KVM / Xen kernels.
767
768 If you are unsure how to answer this question, answer Y.
769
770config QUEUED_LOCK_STAT
771 bool "Paravirt queued spinlock statistics"
772 depends on PARAVIRT_SPINLOCKS && DEBUG_FS
773 ---help---
774 Enable the collection of statistical data on the slowpath
775 behavior of paravirtualized queued spinlocks and report
776 them on debugfs.
777
778source "arch/x86/xen/Kconfig"
779
780config KVM_GUEST
781 bool "KVM Guest support (including kvmclock)"
782 depends on PARAVIRT
783 select PARAVIRT_CLOCK
784 default y
785 ---help---
786 This option enables various optimizations for running under the KVM
787 hypervisor. It includes a paravirtualized clock, so that instead
788 of relying on a PIT (or probably other) emulation by the
789 underlying device model, the host provides the guest with
790 timing infrastructure such as time of day, and system time
791
792config KVM_DEBUG_FS
793 bool "Enable debug information for KVM Guests in debugfs"
794 depends on KVM_GUEST && DEBUG_FS
795 default n
796 ---help---
797 This option enables collection of various statistics for KVM guest.
798 Statistics are displayed in debugfs filesystem. Enabling this option
799 may incur significant overhead.
800
801config PARAVIRT_TIME_ACCOUNTING
802 bool "Paravirtual steal time accounting"
803 depends on PARAVIRT
804 default n
805 ---help---
806 Select this option to enable fine granularity task steal time
807 accounting. Time spent executing other tasks in parallel with
808 the current vCPU is discounted from the vCPU power. To account for
809 that, there can be a small performance impact.
810
811 If in doubt, say N here.
812
813config PARAVIRT_CLOCK
814 bool
815
816config JAILHOUSE_GUEST
817 bool "Jailhouse non-root cell support"
818 depends on X86_64 && PCI
819 select X86_PM_TIMER
820 ---help---
821 This option allows to run Linux as guest in a Jailhouse non-root
822 cell. You can leave this option disabled if you only want to start
823 Jailhouse and run Linux afterwards in the root cell.
824
825endif #HYPERVISOR_GUEST
826
827config NO_BOOTMEM
828 def_bool y
829
830source "arch/x86/Kconfig.cpu"
831
832config HPET_TIMER
833 def_bool X86_64
834 prompt "HPET Timer Support" if X86_32
835 ---help---
836 Use the IA-PC HPET (High Precision Event Timer) to manage
837 time in preference to the PIT and RTC, if a HPET is
838 present.
839 HPET is the next generation timer replacing legacy 8254s.
840 The HPET provides a stable time base on SMP
841 systems, unlike the TSC, but it is more expensive to access,
842 as it is off-chip. The interface used is documented
843 in the HPET spec, revision 1.
844
845 You can safely choose Y here. However, HPET will only be
846 activated if the platform and the BIOS support this feature.
847 Otherwise the 8254 will be used for timing services.
848
849 Choose N to continue using the legacy 8254 timer.
850
851config HPET_EMULATE_RTC
852 def_bool y
853 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
854
855config APB_TIMER
856 def_bool y if X86_INTEL_MID
857 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
858 select DW_APB_TIMER
859 depends on X86_INTEL_MID && SFI
860 help
861 APB timer is the replacement for 8254, HPET on X86 MID platforms.
862 The APBT provides a stable time base on SMP
863 systems, unlike the TSC, but it is more expensive to access,
864 as it is off-chip. APB timers are always running regardless of CPU
865 C states, they are used as per CPU clockevent device when possible.
866
867# Mark as expert because too many people got it wrong.
868# The code disables itself when not needed.
869config DMI
870 default y
871 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
872 bool "Enable DMI scanning" if EXPERT
873 ---help---
874 Enabled scanning of DMI to identify machine quirks. Say Y
875 here unless you have verified that your setup is not
876 affected by entries in the DMI blacklist. Required by PNP
877 BIOS code.
878
879config GART_IOMMU
880 bool "Old AMD GART IOMMU support"
881 select IOMMU_HELPER
882 select SWIOTLB
883 depends on X86_64 && PCI && AMD_NB
884 ---help---
885 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
886 GART based hardware IOMMUs.
887
888 The GART supports full DMA access for devices with 32-bit access
889 limitations, on systems with more than 3 GB. This is usually needed
890 for USB, sound, many IDE/SATA chipsets and some other devices.
891
892 Newer systems typically have a modern AMD IOMMU, supported via
893 the CONFIG_AMD_IOMMU=y config option.
894
895 In normal configurations this driver is only active when needed:
896 there's more than 3 GB of memory and the system contains a
897 32-bit limited device.
898
899 If unsure, say Y.
900
901config CALGARY_IOMMU
902 bool "IBM Calgary IOMMU support"
903 select IOMMU_HELPER
904 select SWIOTLB
905 depends on X86_64 && PCI
906 ---help---
907 Support for hardware IOMMUs in IBM's xSeries x366 and x460
908 systems. Needed to run systems with more than 3GB of memory
909 properly with 32-bit PCI devices that do not support DAC
910 (Double Address Cycle). Calgary also supports bus level
911 isolation, where all DMAs pass through the IOMMU. This
912 prevents them from going anywhere except their intended
913 destination. This catches hard-to-find kernel bugs and
914 mis-behaving drivers and devices that do not use the DMA-API
915 properly to set up their DMA buffers. The IOMMU can be
916 turned off at boot time with the iommu=off parameter.
917 Normally the kernel will make the right choice by itself.
918 If unsure, say Y.
919
920config CALGARY_IOMMU_ENABLED_BY_DEFAULT
921 def_bool y
922 prompt "Should Calgary be enabled by default?"
923 depends on CALGARY_IOMMU
924 ---help---
925 Should Calgary be enabled by default? if you choose 'y', Calgary
926 will be used (if it exists). If you choose 'n', Calgary will not be
927 used even if it exists. If you choose 'n' and would like to use
928 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
929 If unsure, say Y.
930
931config MAXSMP
932 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
933 depends on X86_64 && SMP && DEBUG_KERNEL
934 select CPUMASK_OFFSTACK
935 ---help---
936 Enable maximum number of CPUS and NUMA Nodes for this architecture.
937 If unsure, say N.
938
939#
940# The maximum number of CPUs supported:
941#
942# The main config value is NR_CPUS, which defaults to NR_CPUS_DEFAULT,
943# and which can be configured interactively in the
944# [NR_CPUS_RANGE_BEGIN ... NR_CPUS_RANGE_END] range.
945#
946# The ranges are different on 32-bit and 64-bit kernels, depending on
947# hardware capabilities and scalability features of the kernel.
948#
949# ( If MAXSMP is enabled we just use the highest possible value and disable
950# interactive configuration. )
951#
952
953config NR_CPUS_RANGE_BEGIN
954 int
955 default NR_CPUS_RANGE_END if MAXSMP
956 default 1 if !SMP
957 default 2
958
959config NR_CPUS_RANGE_END
960 int
961 depends on X86_32
962 default 64 if SMP && X86_BIGSMP
963 default 8 if SMP && !X86_BIGSMP
964 default 1 if !SMP
965
966config NR_CPUS_RANGE_END
967 int
968 depends on X86_64
969 default 8192 if SMP && ( MAXSMP || CPUMASK_OFFSTACK)
970 default 512 if SMP && (!MAXSMP && !CPUMASK_OFFSTACK)
971 default 1 if !SMP
972
973config NR_CPUS_DEFAULT
974 int
975 depends on X86_32
976 default 32 if X86_BIGSMP
977 default 8 if SMP
978 default 1 if !SMP
979
980config NR_CPUS_DEFAULT
981 int
982 depends on X86_64
983 default 8192 if MAXSMP
984 default 64 if SMP
985 default 1 if !SMP
986
987config NR_CPUS
988 int "Maximum number of CPUs" if SMP && !MAXSMP
989 range NR_CPUS_RANGE_BEGIN NR_CPUS_RANGE_END
990 default NR_CPUS_DEFAULT
991 ---help---
992 This allows you to specify the maximum number of CPUs which this
993 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
994 supported value is 8192, otherwise the maximum value is 512. The
995 minimum value which makes sense is 2.
996
997 This is purely to save memory: each supported CPU adds about 8KB
998 to the kernel image.
999
1000config SCHED_SMT
1001 def_bool y if SMP
1002
1003config SCHED_MC
1004 def_bool y
1005 prompt "Multi-core scheduler support"
1006 depends on SMP
1007 ---help---
1008 Multi-core scheduler support improves the CPU scheduler's decision
1009 making when dealing with multi-core CPU chips at a cost of slightly
1010 increased overhead in some places. If unsure say N here.
1011
1012config SCHED_MC_PRIO
1013 bool "CPU core priorities scheduler support"
1014 depends on SCHED_MC && CPU_SUP_INTEL
1015 select X86_INTEL_PSTATE
1016 select CPU_FREQ
1017 default y
1018 ---help---
1019 Intel Turbo Boost Max Technology 3.0 enabled CPUs have a
1020 core ordering determined at manufacturing time, which allows
1021 certain cores to reach higher turbo frequencies (when running
1022 single threaded workloads) than others.
1023
1024 Enabling this kernel feature teaches the scheduler about
1025 the TBM3 (aka ITMT) priority order of the CPU cores and adjusts the
1026 scheduler's CPU selection logic accordingly, so that higher
1027 overall system performance can be achieved.
1028
1029 This feature will have no effect on CPUs without this feature.
1030
1031 If unsure say Y here.
1032
1033config UP_LATE_INIT
1034 def_bool y
1035 depends on !SMP && X86_LOCAL_APIC
1036
1037config X86_UP_APIC
1038 bool "Local APIC support on uniprocessors" if !PCI_MSI
1039 default PCI_MSI
1040 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
1041 ---help---
1042 A local APIC (Advanced Programmable Interrupt Controller) is an
1043 integrated interrupt controller in the CPU. If you have a single-CPU
1044 system which has a processor with a local APIC, you can say Y here to
1045 enable and use it. If you say Y here even though your machine doesn't
1046 have a local APIC, then the kernel will still run with no slowdown at
1047 all. The local APIC supports CPU-generated self-interrupts (timer,
1048 performance counters), and the NMI watchdog which detects hard
1049 lockups.
1050
1051config X86_UP_IOAPIC
1052 bool "IO-APIC support on uniprocessors"
1053 depends on X86_UP_APIC
1054 ---help---
1055 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
1056 SMP-capable replacement for PC-style interrupt controllers. Most
1057 SMP systems and many recent uniprocessor systems have one.
1058
1059 If you have a single-CPU system with an IO-APIC, you can say Y here
1060 to use it. If you say Y here even though your machine doesn't have
1061 an IO-APIC, then the kernel will still run with no slowdown at all.
1062
1063config X86_LOCAL_APIC
1064 def_bool y
1065 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
1066 select IRQ_DOMAIN_HIERARCHY
1067 select PCI_MSI_IRQ_DOMAIN if PCI_MSI
1068
1069config X86_IO_APIC
1070 def_bool y
1071 depends on X86_LOCAL_APIC || X86_UP_IOAPIC
1072
1073config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
1074 bool "Reroute for broken boot IRQs"
1075 depends on X86_IO_APIC
1076 ---help---
1077 This option enables a workaround that fixes a source of
1078 spurious interrupts. This is recommended when threaded
1079 interrupt handling is used on systems where the generation of
1080 superfluous "boot interrupts" cannot be disabled.
1081
1082 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
1083 entry in the chipset's IO-APIC is masked (as, e.g. the RT
1084 kernel does during interrupt handling). On chipsets where this
1085 boot IRQ generation cannot be disabled, this workaround keeps
1086 the original IRQ line masked so that only the equivalent "boot
1087 IRQ" is delivered to the CPUs. The workaround also tells the
1088 kernel to set up the IRQ handler on the boot IRQ line. In this
1089 way only one interrupt is delivered to the kernel. Otherwise
1090 the spurious second interrupt may cause the kernel to bring
1091 down (vital) interrupt lines.
1092
1093 Only affects "broken" chipsets. Interrupt sharing may be
1094 increased on these systems.
1095
1096config X86_MCE
1097 bool "Machine Check / overheating reporting"
1098 select GENERIC_ALLOCATOR
1099 default y
1100 ---help---
1101 Machine Check support allows the processor to notify the
1102 kernel if it detects a problem (e.g. overheating, data corruption).
1103 The action the kernel takes depends on the severity of the problem,
1104 ranging from warning messages to halting the machine.
1105
1106config X86_MCELOG_LEGACY
1107 bool "Support for deprecated /dev/mcelog character device"
1108 depends on X86_MCE
1109 ---help---
1110 Enable support for /dev/mcelog which is needed by the old mcelog
1111 userspace logging daemon. Consider switching to the new generation
1112 rasdaemon solution.
1113
1114config X86_MCE_INTEL
1115 def_bool y
1116 prompt "Intel MCE features"
1117 depends on X86_MCE && X86_LOCAL_APIC
1118 ---help---
1119 Additional support for intel specific MCE features such as
1120 the thermal monitor.
1121
1122config X86_MCE_AMD
1123 def_bool y
1124 prompt "AMD MCE features"
1125 depends on X86_MCE && X86_LOCAL_APIC && AMD_NB
1126 ---help---
1127 Additional support for AMD specific MCE features such as
1128 the DRAM Error Threshold.
1129
1130config X86_ANCIENT_MCE
1131 bool "Support for old Pentium 5 / WinChip machine checks"
1132 depends on X86_32 && X86_MCE
1133 ---help---
1134 Include support for machine check handling on old Pentium 5 or WinChip
1135 systems. These typically need to be enabled explicitly on the command
1136 line.
1137
1138config X86_MCE_THRESHOLD
1139 depends on X86_MCE_AMD || X86_MCE_INTEL
1140 def_bool y
1141
1142config X86_MCE_INJECT
1143 depends on X86_MCE && X86_LOCAL_APIC && DEBUG_FS
1144 tristate "Machine check injector support"
1145 ---help---
1146 Provide support for injecting machine checks for testing purposes.
1147 If you don't know what a machine check is and you don't do kernel
1148 QA it is safe to say n.
1149
1150config X86_THERMAL_VECTOR
1151 def_bool y
1152 depends on X86_MCE_INTEL
1153
1154source "arch/x86/events/Kconfig"
1155
1156config X86_LEGACY_VM86
1157 bool "Legacy VM86 support"
1158 default n
1159 depends on X86_32
1160 ---help---
1161 This option allows user programs to put the CPU into V8086
1162 mode, which is an 80286-era approximation of 16-bit real mode.
1163
1164 Some very old versions of X and/or vbetool require this option
1165 for user mode setting. Similarly, DOSEMU will use it if
1166 available to accelerate real mode DOS programs. However, any
1167 recent version of DOSEMU, X, or vbetool should be fully
1168 functional even without kernel VM86 support, as they will all
1169 fall back to software emulation. Nevertheless, if you are using
1170 a 16-bit DOS program where 16-bit performance matters, vm86
1171 mode might be faster than emulation and you might want to
1172 enable this option.
1173
1174 Note that any app that works on a 64-bit kernel is unlikely to
1175 need this option, as 64-bit kernels don't, and can't, support
1176 V8086 mode. This option is also unrelated to 16-bit protected
1177 mode and is not needed to run most 16-bit programs under Wine.
1178
1179 Enabling this option increases the complexity of the kernel
1180 and slows down exception handling a tiny bit.
1181
1182 If unsure, say N here.
1183
1184config VM86
1185 bool
1186 default X86_LEGACY_VM86
1187
1188config X86_16BIT
1189 bool "Enable support for 16-bit segments" if EXPERT
1190 default y
1191 depends on MODIFY_LDT_SYSCALL
1192 ---help---
1193 This option is required by programs like Wine to run 16-bit
1194 protected mode legacy code on x86 processors. Disabling
1195 this option saves about 300 bytes on i386, or around 6K text
1196 plus 16K runtime memory on x86-64,
1197
1198config X86_ESPFIX32
1199 def_bool y
1200 depends on X86_16BIT && X86_32
1201
1202config X86_ESPFIX64
1203 def_bool y
1204 depends on X86_16BIT && X86_64
1205
1206config X86_VSYSCALL_EMULATION
1207 bool "Enable vsyscall emulation" if EXPERT
1208 default y
1209 depends on X86_64
1210 ---help---
1211 This enables emulation of the legacy vsyscall page. Disabling
1212 it is roughly equivalent to booting with vsyscall=none, except
1213 that it will also disable the helpful warning if a program
1214 tries to use a vsyscall. With this option set to N, offending
1215 programs will just segfault, citing addresses of the form
1216 0xffffffffff600?00.
1217
1218 This option is required by many programs built before 2013, and
1219 care should be used even with newer programs if set to N.
1220
1221 Disabling this option saves about 7K of kernel size and
1222 possibly 4K of additional runtime pagetable memory.
1223
1224config TOSHIBA
1225 tristate "Toshiba Laptop support"
1226 depends on X86_32
1227 ---help---
1228 This adds a driver to safely access the System Management Mode of
1229 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1230 not work on models with a Phoenix BIOS. The System Management Mode
1231 is used to set the BIOS and power saving options on Toshiba portables.
1232
1233 For information on utilities to make use of this driver see the
1234 Toshiba Linux utilities web site at:
1235 <http://www.buzzard.org.uk/toshiba/>.
1236
1237 Say Y if you intend to run this kernel on a Toshiba portable.
1238 Say N otherwise.
1239
1240config I8K
1241 tristate "Dell i8k legacy laptop support"
1242 select HWMON
1243 select SENSORS_DELL_SMM
1244 ---help---
1245 This option enables legacy /proc/i8k userspace interface in hwmon
1246 dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1247 temperature and allows controlling fan speeds of Dell laptops via
1248 System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1249 it reports also power and hotkey status. For fan speed control is
1250 needed userspace package i8kutils.
1251
1252 Say Y if you intend to run this kernel on old Dell laptops or want to
1253 use userspace package i8kutils.
1254 Say N otherwise.
1255
1256config X86_REBOOTFIXUPS
1257 bool "Enable X86 board specific fixups for reboot"
1258 depends on X86_32
1259 ---help---
1260 This enables chipset and/or board specific fixups to be done
1261 in order to get reboot to work correctly. This is only needed on
1262 some combinations of hardware and BIOS. The symptom, for which
1263 this config is intended, is when reboot ends with a stalled/hung
1264 system.
1265
1266 Currently, the only fixup is for the Geode machines using
1267 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1268
1269 Say Y if you want to enable the fixup. Currently, it's safe to
1270 enable this option even if you don't need it.
1271 Say N otherwise.
1272
1273config MICROCODE
1274 bool "CPU microcode loading support"
1275 default y
1276 depends on CPU_SUP_AMD || CPU_SUP_INTEL
1277 select FW_LOADER
1278 ---help---
1279 If you say Y here, you will be able to update the microcode on
1280 Intel and AMD processors. The Intel support is for the IA32 family,
1281 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
1282 AMD support is for families 0x10 and later. You will obviously need
1283 the actual microcode binary data itself which is not shipped with
1284 the Linux kernel.
1285
1286 The preferred method to load microcode from a detached initrd is described
1287 in Documentation/x86/microcode.txt. For that you need to enable
1288 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
1289 initrd for microcode blobs.
1290
1291 In addition, you can build the microcode into the kernel. For that you
1292 need to add the vendor-supplied microcode to the CONFIG_EXTRA_FIRMWARE
1293 config option.
1294
1295config MICROCODE_INTEL
1296 bool "Intel microcode loading support"
1297 depends on MICROCODE
1298 default MICROCODE
1299 select FW_LOADER
1300 ---help---
1301 This options enables microcode patch loading support for Intel
1302 processors.
1303
1304 For the current Intel microcode data package go to
1305 <https://downloadcenter.intel.com> and search for
1306 'Linux Processor Microcode Data File'.
1307
1308config MICROCODE_AMD
1309 bool "AMD microcode loading support"
1310 depends on MICROCODE
1311 select FW_LOADER
1312 ---help---
1313 If you select this option, microcode patch loading support for AMD
1314 processors will be enabled.
1315
1316config MICROCODE_OLD_INTERFACE
1317 def_bool y
1318 depends on MICROCODE
1319
1320config X86_MSR
1321 tristate "/dev/cpu/*/msr - Model-specific register support"
1322 ---help---
1323 This device gives privileged processes access to the x86
1324 Model-Specific Registers (MSRs). It is a character device with
1325 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1326 MSR accesses are directed to a specific CPU on multi-processor
1327 systems.
1328
1329config X86_CPUID
1330 tristate "/dev/cpu/*/cpuid - CPU information support"
1331 ---help---
1332 This device gives processes access to the x86 CPUID instruction to
1333 be executed on a specific processor. It is a character device
1334 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1335 /dev/cpu/31/cpuid.
1336
1337choice
1338 prompt "High Memory Support"
1339 default HIGHMEM4G
1340 depends on X86_32
1341
1342config NOHIGHMEM
1343 bool "off"
1344 ---help---
1345 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1346 However, the address space of 32-bit x86 processors is only 4
1347 Gigabytes large. That means that, if you have a large amount of
1348 physical memory, not all of it can be "permanently mapped" by the
1349 kernel. The physical memory that's not permanently mapped is called
1350 "high memory".
1351
1352 If you are compiling a kernel which will never run on a machine with
1353 more than 1 Gigabyte total physical RAM, answer "off" here (default
1354 choice and suitable for most users). This will result in a "3GB/1GB"
1355 split: 3GB are mapped so that each process sees a 3GB virtual memory
1356 space and the remaining part of the 4GB virtual memory space is used
1357 by the kernel to permanently map as much physical memory as
1358 possible.
1359
1360 If the machine has between 1 and 4 Gigabytes physical RAM, then
1361 answer "4GB" here.
1362
1363 If more than 4 Gigabytes is used then answer "64GB" here. This
1364 selection turns Intel PAE (Physical Address Extension) mode on.
1365 PAE implements 3-level paging on IA32 processors. PAE is fully
1366 supported by Linux, PAE mode is implemented on all recent Intel
1367 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1368 then the kernel will not boot on CPUs that don't support PAE!
1369
1370 The actual amount of total physical memory will either be
1371 auto detected or can be forced by using a kernel command line option
1372 such as "mem=256M". (Try "man bootparam" or see the documentation of
1373 your boot loader (lilo or loadlin) about how to pass options to the
1374 kernel at boot time.)
1375
1376 If unsure, say "off".
1377
1378config HIGHMEM4G
1379 bool "4GB"
1380 ---help---
1381 Select this if you have a 32-bit processor and between 1 and 4
1382 gigabytes of physical RAM.
1383
1384config HIGHMEM64G
1385 bool "64GB"
1386 depends on !M486 && !M586 && !M586TSC && !M586MMX && !MGEODE_LX && !MGEODEGX1 && !MCYRIXIII && !MELAN && !MWINCHIPC6 && !WINCHIP3D && !MK6
1387 select X86_PAE
1388 ---help---
1389 Select this if you have a 32-bit processor and more than 4
1390 gigabytes of physical RAM.
1391
1392endchoice
1393
1394choice
1395 prompt "Memory split" if EXPERT
1396 default VMSPLIT_3G
1397 depends on X86_32
1398 ---help---
1399 Select the desired split between kernel and user memory.
1400
1401 If the address range available to the kernel is less than the
1402 physical memory installed, the remaining memory will be available
1403 as "high memory". Accessing high memory is a little more costly
1404 than low memory, as it needs to be mapped into the kernel first.
1405 Note that increasing the kernel address space limits the range
1406 available to user programs, making the address space there
1407 tighter. Selecting anything other than the default 3G/1G split
1408 will also likely make your kernel incompatible with binary-only
1409 kernel modules.
1410
1411 If you are not absolutely sure what you are doing, leave this
1412 option alone!
1413
1414 config VMSPLIT_3G
1415 bool "3G/1G user/kernel split"
1416 config VMSPLIT_3G_OPT
1417 depends on !X86_PAE
1418 bool "3G/1G user/kernel split (for full 1G low memory)"
1419 config VMSPLIT_2G
1420 bool "2G/2G user/kernel split"
1421 config VMSPLIT_2G_OPT
1422 depends on !X86_PAE
1423 bool "2G/2G user/kernel split (for full 2G low memory)"
1424 config VMSPLIT_1G
1425 bool "1G/3G user/kernel split"
1426endchoice
1427
1428config PAGE_OFFSET
1429 hex
1430 default 0xB0000000 if VMSPLIT_3G_OPT
1431 default 0x80000000 if VMSPLIT_2G
1432 default 0x78000000 if VMSPLIT_2G_OPT
1433 default 0x40000000 if VMSPLIT_1G
1434 default 0xC0000000
1435 depends on X86_32
1436
1437config HIGHMEM
1438 def_bool y
1439 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1440
1441config X86_PAE
1442 bool "PAE (Physical Address Extension) Support"
1443 depends on X86_32 && !HIGHMEM4G
1444 select PHYS_ADDR_T_64BIT
1445 select SWIOTLB
1446 ---help---
1447 PAE is required for NX support, and furthermore enables
1448 larger swapspace support for non-overcommit purposes. It
1449 has the cost of more pagetable lookup overhead, and also
1450 consumes more pagetable space per process.
1451
1452config X86_5LEVEL
1453 bool "Enable 5-level page tables support"
1454 select DYNAMIC_MEMORY_LAYOUT
1455 select SPARSEMEM_VMEMMAP
1456 depends on X86_64
1457 ---help---
1458 5-level paging enables access to larger address space:
1459 upto 128 PiB of virtual address space and 4 PiB of
1460 physical address space.
1461
1462 It will be supported by future Intel CPUs.
1463
1464 A kernel with the option enabled can be booted on machines that
1465 support 4- or 5-level paging.
1466
1467 See Documentation/x86/x86_64/5level-paging.txt for more
1468 information.
1469
1470 Say N if unsure.
1471
1472config X86_DIRECT_GBPAGES
1473 def_bool y
1474 depends on X86_64 && !DEBUG_PAGEALLOC
1475 ---help---
1476 Certain kernel features effectively disable kernel
1477 linear 1 GB mappings (even if the CPU otherwise
1478 supports them), so don't confuse the user by printing
1479 that we have them enabled.
1480
1481config ARCH_HAS_MEM_ENCRYPT
1482 def_bool y
1483
1484config AMD_MEM_ENCRYPT
1485 bool "AMD Secure Memory Encryption (SME) support"
1486 depends on X86_64 && CPU_SUP_AMD
1487 select DYNAMIC_PHYSICAL_MASK
1488 ---help---
1489 Say yes to enable support for the encryption of system memory.
1490 This requires an AMD processor that supports Secure Memory
1491 Encryption (SME).
1492
1493config AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT
1494 bool "Activate AMD Secure Memory Encryption (SME) by default"
1495 default y
1496 depends on AMD_MEM_ENCRYPT
1497 ---help---
1498 Say yes to have system memory encrypted by default if running on
1499 an AMD processor that supports Secure Memory Encryption (SME).
1500
1501 If set to Y, then the encryption of system memory can be
1502 deactivated with the mem_encrypt=off command line option.
1503
1504 If set to N, then the encryption of system memory can be
1505 activated with the mem_encrypt=on command line option.
1506
1507config ARCH_USE_MEMREMAP_PROT
1508 def_bool y
1509 depends on AMD_MEM_ENCRYPT
1510
1511# Common NUMA Features
1512config NUMA
1513 bool "Numa Memory Allocation and Scheduler Support"
1514 depends on SMP
1515 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1516 default y if X86_BIGSMP
1517 ---help---
1518 Enable NUMA (Non Uniform Memory Access) support.
1519
1520 The kernel will try to allocate memory used by a CPU on the
1521 local memory controller of the CPU and add some more
1522 NUMA awareness to the kernel.
1523
1524 For 64-bit this is recommended if the system is Intel Core i7
1525 (or later), AMD Opteron, or EM64T NUMA.
1526
1527 For 32-bit this is only needed if you boot a 32-bit
1528 kernel on a 64-bit NUMA platform.
1529
1530 Otherwise, you should say N.
1531
1532config AMD_NUMA
1533 def_bool y
1534 prompt "Old style AMD Opteron NUMA detection"
1535 depends on X86_64 && NUMA && PCI
1536 ---help---
1537 Enable AMD NUMA node topology detection. You should say Y here if
1538 you have a multi processor AMD system. This uses an old method to
1539 read the NUMA configuration directly from the builtin Northbridge
1540 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1541 which also takes priority if both are compiled in.
1542
1543config X86_64_ACPI_NUMA
1544 def_bool y
1545 prompt "ACPI NUMA detection"
1546 depends on X86_64 && NUMA && ACPI && PCI
1547 select ACPI_NUMA
1548 ---help---
1549 Enable ACPI SRAT based node topology detection.
1550
1551# Some NUMA nodes have memory ranges that span
1552# other nodes. Even though a pfn is valid and
1553# between a node's start and end pfns, it may not
1554# reside on that node. See memmap_init_zone()
1555# for details.
1556config NODES_SPAN_OTHER_NODES
1557 def_bool y
1558 depends on X86_64_ACPI_NUMA
1559
1560config NUMA_EMU
1561 bool "NUMA emulation"
1562 depends on NUMA
1563 ---help---
1564 Enable NUMA emulation. A flat machine will be split
1565 into virtual nodes when booted with "numa=fake=N", where N is the
1566 number of nodes. This is only useful for debugging.
1567
1568config NODES_SHIFT
1569 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1570 range 1 10
1571 default "10" if MAXSMP
1572 default "6" if X86_64
1573 default "3"
1574 depends on NEED_MULTIPLE_NODES
1575 ---help---
1576 Specify the maximum number of NUMA Nodes available on the target
1577 system. Increases memory reserved to accommodate various tables.
1578
1579config ARCH_HAVE_MEMORY_PRESENT
1580 def_bool y
1581 depends on X86_32 && DISCONTIGMEM
1582
1583config ARCH_FLATMEM_ENABLE
1584 def_bool y
1585 depends on X86_32 && !NUMA
1586
1587config ARCH_DISCONTIGMEM_ENABLE
1588 def_bool y
1589 depends on NUMA && X86_32
1590
1591config ARCH_DISCONTIGMEM_DEFAULT
1592 def_bool y
1593 depends on NUMA && X86_32
1594
1595config ARCH_SPARSEMEM_ENABLE
1596 def_bool y
1597 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1598 select SPARSEMEM_STATIC if X86_32
1599 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1600
1601config ARCH_SPARSEMEM_DEFAULT
1602 def_bool y
1603 depends on X86_64
1604
1605config ARCH_SELECT_MEMORY_MODEL
1606 def_bool y
1607 depends on ARCH_SPARSEMEM_ENABLE
1608
1609config ARCH_MEMORY_PROBE
1610 bool "Enable sysfs memory/probe interface"
1611 depends on X86_64 && MEMORY_HOTPLUG
1612 help
1613 This option enables a sysfs memory/probe interface for testing.
1614 See Documentation/memory-hotplug.txt for more information.
1615 If you are unsure how to answer this question, answer N.
1616
1617config ARCH_PROC_KCORE_TEXT
1618 def_bool y
1619 depends on X86_64 && PROC_KCORE
1620
1621config ILLEGAL_POINTER_VALUE
1622 hex
1623 default 0 if X86_32
1624 default 0xdead000000000000 if X86_64
1625
1626config X86_PMEM_LEGACY_DEVICE
1627 bool
1628
1629config X86_PMEM_LEGACY
1630 tristate "Support non-standard NVDIMMs and ADR protected memory"
1631 depends on PHYS_ADDR_T_64BIT
1632 depends on BLK_DEV
1633 select X86_PMEM_LEGACY_DEVICE
1634 select LIBNVDIMM
1635 help
1636 Treat memory marked using the non-standard e820 type of 12 as used
1637 by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1638 The kernel will offer these regions to the 'pmem' driver so
1639 they can be used for persistent storage.
1640
1641 Say Y if unsure.
1642
1643config HIGHPTE
1644 bool "Allocate 3rd-level pagetables from highmem"
1645 depends on HIGHMEM
1646 ---help---
1647 The VM uses one page table entry for each page of physical memory.
1648 For systems with a lot of RAM, this can be wasteful of precious
1649 low memory. Setting this option will put user-space page table
1650 entries in high memory.
1651
1652config X86_CHECK_BIOS_CORRUPTION
1653 bool "Check for low memory corruption"
1654 ---help---
1655 Periodically check for memory corruption in low memory, which
1656 is suspected to be caused by BIOS. Even when enabled in the
1657 configuration, it is disabled at runtime. Enable it by
1658 setting "memory_corruption_check=1" on the kernel command
1659 line. By default it scans the low 64k of memory every 60
1660 seconds; see the memory_corruption_check_size and
1661 memory_corruption_check_period parameters in
1662 Documentation/admin-guide/kernel-parameters.rst to adjust this.
1663
1664 When enabled with the default parameters, this option has
1665 almost no overhead, as it reserves a relatively small amount
1666 of memory and scans it infrequently. It both detects corruption
1667 and prevents it from affecting the running system.
1668
1669 It is, however, intended as a diagnostic tool; if repeatable
1670 BIOS-originated corruption always affects the same memory,
1671 you can use memmap= to prevent the kernel from using that
1672 memory.
1673
1674config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1675 bool "Set the default setting of memory_corruption_check"
1676 depends on X86_CHECK_BIOS_CORRUPTION
1677 default y
1678 ---help---
1679 Set whether the default state of memory_corruption_check is
1680 on or off.
1681
1682config X86_RESERVE_LOW
1683 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1684 default 64
1685 range 4 640
1686 ---help---
1687 Specify the amount of low memory to reserve for the BIOS.
1688
1689 The first page contains BIOS data structures that the kernel
1690 must not use, so that page must always be reserved.
1691
1692 By default we reserve the first 64K of physical RAM, as a
1693 number of BIOSes are known to corrupt that memory range
1694 during events such as suspend/resume or monitor cable
1695 insertion, so it must not be used by the kernel.
1696
1697 You can set this to 4 if you are absolutely sure that you
1698 trust the BIOS to get all its memory reservations and usages
1699 right. If you know your BIOS have problems beyond the
1700 default 64K area, you can set this to 640 to avoid using the
1701 entire low memory range.
1702
1703 If you have doubts about the BIOS (e.g. suspend/resume does
1704 not work or there's kernel crashes after certain hardware
1705 hotplug events) then you might want to enable
1706 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1707 typical corruption patterns.
1708
1709 Leave this to the default value of 64 if you are unsure.
1710
1711config MATH_EMULATION
1712 bool
1713 depends on MODIFY_LDT_SYSCALL
1714 prompt "Math emulation" if X86_32
1715 ---help---
1716 Linux can emulate a math coprocessor (used for floating point
1717 operations) if you don't have one. 486DX and Pentium processors have
1718 a math coprocessor built in, 486SX and 386 do not, unless you added
1719 a 487DX or 387, respectively. (The messages during boot time can
1720 give you some hints here ["man dmesg"].) Everyone needs either a
1721 coprocessor or this emulation.
1722
1723 If you don't have a math coprocessor, you need to say Y here; if you
1724 say Y here even though you have a coprocessor, the coprocessor will
1725 be used nevertheless. (This behavior can be changed with the kernel
1726 command line option "no387", which comes handy if your coprocessor
1727 is broken. Try "man bootparam" or see the documentation of your boot
1728 loader (lilo or loadlin) about how to pass options to the kernel at
1729 boot time.) This means that it is a good idea to say Y here if you
1730 intend to use this kernel on different machines.
1731
1732 More information about the internals of the Linux math coprocessor
1733 emulation can be found in <file:arch/x86/math-emu/README>.
1734
1735 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1736 kernel, it won't hurt.
1737
1738config MTRR
1739 def_bool y
1740 prompt "MTRR (Memory Type Range Register) support" if EXPERT
1741 ---help---
1742 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1743 the Memory Type Range Registers (MTRRs) may be used to control
1744 processor access to memory ranges. This is most useful if you have
1745 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1746 allows bus write transfers to be combined into a larger transfer
1747 before bursting over the PCI/AGP bus. This can increase performance
1748 of image write operations 2.5 times or more. Saying Y here creates a
1749 /proc/mtrr file which may be used to manipulate your processor's
1750 MTRRs. Typically the X server should use this.
1751
1752 This code has a reasonably generic interface so that similar
1753 control registers on other processors can be easily supported
1754 as well:
1755
1756 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1757 Registers (ARRs) which provide a similar functionality to MTRRs. For
1758 these, the ARRs are used to emulate the MTRRs.
1759 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1760 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1761 write-combining. All of these processors are supported by this code
1762 and it makes sense to say Y here if you have one of them.
1763
1764 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1765 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1766 can lead to all sorts of problems, so it's good to say Y here.
1767
1768 You can safely say Y even if your machine doesn't have MTRRs, you'll
1769 just add about 9 KB to your kernel.
1770
1771 See <file:Documentation/x86/mtrr.txt> for more information.
1772
1773config MTRR_SANITIZER
1774 def_bool y
1775 prompt "MTRR cleanup support"
1776 depends on MTRR
1777 ---help---
1778 Convert MTRR layout from continuous to discrete, so X drivers can
1779 add writeback entries.
1780
1781 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1782 The largest mtrr entry size for a continuous block can be set with
1783 mtrr_chunk_size.
1784
1785 If unsure, say Y.
1786
1787config MTRR_SANITIZER_ENABLE_DEFAULT
1788 int "MTRR cleanup enable value (0-1)"
1789 range 0 1
1790 default "0"
1791 depends on MTRR_SANITIZER
1792 ---help---
1793 Enable mtrr cleanup default value
1794
1795config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1796 int "MTRR cleanup spare reg num (0-7)"
1797 range 0 7
1798 default "1"
1799 depends on MTRR_SANITIZER
1800 ---help---
1801 mtrr cleanup spare entries default, it can be changed via
1802 mtrr_spare_reg_nr=N on the kernel command line.
1803
1804config X86_PAT
1805 def_bool y
1806 prompt "x86 PAT support" if EXPERT
1807 depends on MTRR
1808 ---help---
1809 Use PAT attributes to setup page level cache control.
1810
1811 PATs are the modern equivalents of MTRRs and are much more
1812 flexible than MTRRs.
1813
1814 Say N here if you see bootup problems (boot crash, boot hang,
1815 spontaneous reboots) or a non-working video driver.
1816
1817 If unsure, say Y.
1818
1819config ARCH_USES_PG_UNCACHED
1820 def_bool y
1821 depends on X86_PAT
1822
1823config ARCH_RANDOM
1824 def_bool y
1825 prompt "x86 architectural random number generator" if EXPERT
1826 ---help---
1827 Enable the x86 architectural RDRAND instruction
1828 (Intel Bull Mountain technology) to generate random numbers.
1829 If supported, this is a high bandwidth, cryptographically
1830 secure hardware random number generator.
1831
1832config X86_SMAP
1833 def_bool y
1834 prompt "Supervisor Mode Access Prevention" if EXPERT
1835 ---help---
1836 Supervisor Mode Access Prevention (SMAP) is a security
1837 feature in newer Intel processors. There is a small
1838 performance cost if this enabled and turned on; there is
1839 also a small increase in the kernel size if this is enabled.
1840
1841 If unsure, say Y.
1842
1843config X86_INTEL_UMIP
1844 def_bool y
1845 depends on CPU_SUP_INTEL
1846 prompt "Intel User Mode Instruction Prevention" if EXPERT
1847 ---help---
1848 The User Mode Instruction Prevention (UMIP) is a security
1849 feature in newer Intel processors. If enabled, a general
1850 protection fault is issued if the SGDT, SLDT, SIDT, SMSW
1851 or STR instructions are executed in user mode. These instructions
1852 unnecessarily expose information about the hardware state.
1853
1854 The vast majority of applications do not use these instructions.
1855 For the very few that do, software emulation is provided in
1856 specific cases in protected and virtual-8086 modes. Emulated
1857 results are dummy.
1858
1859config X86_INTEL_MPX
1860 prompt "Intel MPX (Memory Protection Extensions)"
1861 def_bool n
1862 # Note: only available in 64-bit mode due to VMA flags shortage
1863 depends on CPU_SUP_INTEL && X86_64
1864 select ARCH_USES_HIGH_VMA_FLAGS
1865 ---help---
1866 MPX provides hardware features that can be used in
1867 conjunction with compiler-instrumented code to check
1868 memory references. It is designed to detect buffer
1869 overflow or underflow bugs.
1870
1871 This option enables running applications which are
1872 instrumented or otherwise use MPX. It does not use MPX
1873 itself inside the kernel or to protect the kernel
1874 against bad memory references.
1875
1876 Enabling this option will make the kernel larger:
1877 ~8k of kernel text and 36 bytes of data on a 64-bit
1878 defconfig. It adds a long to the 'mm_struct' which
1879 will increase the kernel memory overhead of each
1880 process and adds some branches to paths used during
1881 exec() and munmap().
1882
1883 For details, see Documentation/x86/intel_mpx.txt
1884
1885 If unsure, say N.
1886
1887config X86_INTEL_MEMORY_PROTECTION_KEYS
1888 prompt "Intel Memory Protection Keys"
1889 def_bool y
1890 # Note: only available in 64-bit mode
1891 depends on CPU_SUP_INTEL && X86_64
1892 select ARCH_USES_HIGH_VMA_FLAGS
1893 select ARCH_HAS_PKEYS
1894 ---help---
1895 Memory Protection Keys provides a mechanism for enforcing
1896 page-based protections, but without requiring modification of the
1897 page tables when an application changes protection domains.
1898
1899 For details, see Documentation/x86/protection-keys.txt
1900
1901 If unsure, say y.
1902
1903choice
1904 prompt "TSX enable mode"
1905 depends on CPU_SUP_INTEL
1906 default X86_INTEL_TSX_MODE_OFF
1907 help
1908 Intel's TSX (Transactional Synchronization Extensions) feature
1909 allows to optimize locking protocols through lock elision which
1910 can lead to a noticeable performance boost.
1911
1912 On the other hand it has been shown that TSX can be exploited
1913 to form side channel attacks (e.g. TAA) and chances are there
1914 will be more of those attacks discovered in the future.
1915
1916 Therefore TSX is not enabled by default (aka tsx=off). An admin
1917 might override this decision by tsx=on the command line parameter.
1918 Even with TSX enabled, the kernel will attempt to enable the best
1919 possible TAA mitigation setting depending on the microcode available
1920 for the particular machine.
1921
1922 This option allows to set the default tsx mode between tsx=on, =off
1923 and =auto. See Documentation/admin-guide/kernel-parameters.txt for more
1924 details.
1925
1926 Say off if not sure, auto if TSX is in use but it should be used on safe
1927 platforms or on if TSX is in use and the security aspect of tsx is not
1928 relevant.
1929
1930config X86_INTEL_TSX_MODE_OFF
1931 bool "off"
1932 help
1933 TSX is disabled if possible - equals to tsx=off command line parameter.
1934
1935config X86_INTEL_TSX_MODE_ON
1936 bool "on"
1937 help
1938 TSX is always enabled on TSX capable HW - equals the tsx=on command
1939 line parameter.
1940
1941config X86_INTEL_TSX_MODE_AUTO
1942 bool "auto"
1943 help
1944 TSX is enabled on TSX capable HW that is believed to be safe against
1945 side channel attacks- equals the tsx=auto command line parameter.
1946endchoice
1947
1948config EFI
1949 bool "EFI runtime service support"
1950 depends on ACPI
1951 select UCS2_STRING
1952 select EFI_RUNTIME_WRAPPERS
1953 ---help---
1954 This enables the kernel to use EFI runtime services that are
1955 available (such as the EFI variable services).
1956
1957 This option is only useful on systems that have EFI firmware.
1958 In addition, you should use the latest ELILO loader available
1959 at <http://elilo.sourceforge.net> in order to take advantage
1960 of EFI runtime services. However, even with this option, the
1961 resultant kernel should continue to boot on existing non-EFI
1962 platforms.
1963
1964config EFI_STUB
1965 bool "EFI stub support"
1966 depends on EFI && !X86_USE_3DNOW
1967 select RELOCATABLE
1968 ---help---
1969 This kernel feature allows a bzImage to be loaded directly
1970 by EFI firmware without the use of a bootloader.
1971
1972 See Documentation/efi-stub.txt for more information.
1973
1974config EFI_MIXED
1975 bool "EFI mixed-mode support"
1976 depends on EFI_STUB && X86_64
1977 ---help---
1978 Enabling this feature allows a 64-bit kernel to be booted
1979 on a 32-bit firmware, provided that your CPU supports 64-bit
1980 mode.
1981
1982 Note that it is not possible to boot a mixed-mode enabled
1983 kernel via the EFI boot stub - a bootloader that supports
1984 the EFI handover protocol must be used.
1985
1986 If unsure, say N.
1987
1988config SECCOMP
1989 def_bool y
1990 prompt "Enable seccomp to safely compute untrusted bytecode"
1991 ---help---
1992 This kernel feature is useful for number crunching applications
1993 that may need to compute untrusted bytecode during their
1994 execution. By using pipes or other transports made available to
1995 the process as file descriptors supporting the read/write
1996 syscalls, it's possible to isolate those applications in
1997 their own address space using seccomp. Once seccomp is
1998 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1999 and the task is only allowed to execute a few safe syscalls
2000 defined by each seccomp mode.
2001
2002 If unsure, say Y. Only embedded should say N here.
2003
2004source kernel/Kconfig.hz
2005
2006config KEXEC
2007 bool "kexec system call"
2008 select KEXEC_CORE
2009 ---help---
2010 kexec is a system call that implements the ability to shutdown your
2011 current kernel, and to start another kernel. It is like a reboot
2012 but it is independent of the system firmware. And like a reboot
2013 you can start any kernel with it, not just Linux.
2014
2015 The name comes from the similarity to the exec system call.
2016
2017 It is an ongoing process to be certain the hardware in a machine
2018 is properly shutdown, so do not be surprised if this code does not
2019 initially work for you. As of this writing the exact hardware
2020 interface is strongly in flux, so no good recommendation can be
2021 made.
2022
2023config KEXEC_FILE
2024 bool "kexec file based system call"
2025 select KEXEC_CORE
2026 select BUILD_BIN2C
2027 depends on X86_64
2028 depends on CRYPTO=y
2029 depends on CRYPTO_SHA256=y
2030 ---help---
2031 This is new version of kexec system call. This system call is
2032 file based and takes file descriptors as system call argument
2033 for kernel and initramfs as opposed to list of segments as
2034 accepted by previous system call.
2035
2036config ARCH_HAS_KEXEC_PURGATORY
2037 def_bool KEXEC_FILE
2038
2039config KEXEC_VERIFY_SIG
2040 bool "Verify kernel signature during kexec_file_load() syscall"
2041 depends on KEXEC_FILE
2042 ---help---
2043 This option makes kernel signature verification mandatory for
2044 the kexec_file_load() syscall.
2045
2046 In addition to that option, you need to enable signature
2047 verification for the corresponding kernel image type being
2048 loaded in order for this to work.
2049
2050config KEXEC_BZIMAGE_VERIFY_SIG
2051 bool "Enable bzImage signature verification support"
2052 depends on KEXEC_VERIFY_SIG
2053 depends on SIGNED_PE_FILE_VERIFICATION
2054 select SYSTEM_TRUSTED_KEYRING
2055 ---help---
2056 Enable bzImage signature verification support.
2057
2058config CRASH_DUMP
2059 bool "kernel crash dumps"
2060 depends on X86_64 || (X86_32 && HIGHMEM)
2061 ---help---
2062 Generate crash dump after being started by kexec.
2063 This should be normally only set in special crash dump kernels
2064 which are loaded in the main kernel with kexec-tools into
2065 a specially reserved region and then later executed after
2066 a crash by kdump/kexec. The crash dump kernel must be compiled
2067 to a memory address not used by the main kernel or BIOS using
2068 PHYSICAL_START, or it must be built as a relocatable image
2069 (CONFIG_RELOCATABLE=y).
2070 For more details see Documentation/kdump/kdump.txt
2071
2072config KEXEC_JUMP
2073 bool "kexec jump"
2074 depends on KEXEC && HIBERNATION
2075 ---help---
2076 Jump between original kernel and kexeced kernel and invoke
2077 code in physical address mode via KEXEC
2078
2079config PHYSICAL_START
2080 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
2081 default "0x1000000"
2082 ---help---
2083 This gives the physical address where the kernel is loaded.
2084
2085 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
2086 bzImage will decompress itself to above physical address and
2087 run from there. Otherwise, bzImage will run from the address where
2088 it has been loaded by the boot loader and will ignore above physical
2089 address.
2090
2091 In normal kdump cases one does not have to set/change this option
2092 as now bzImage can be compiled as a completely relocatable image
2093 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
2094 address. This option is mainly useful for the folks who don't want
2095 to use a bzImage for capturing the crash dump and want to use a
2096 vmlinux instead. vmlinux is not relocatable hence a kernel needs
2097 to be specifically compiled to run from a specific memory area
2098 (normally a reserved region) and this option comes handy.
2099
2100 So if you are using bzImage for capturing the crash dump,
2101 leave the value here unchanged to 0x1000000 and set
2102 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
2103 for capturing the crash dump change this value to start of
2104 the reserved region. In other words, it can be set based on
2105 the "X" value as specified in the "crashkernel=YM@XM"
2106 command line boot parameter passed to the panic-ed
2107 kernel. Please take a look at Documentation/kdump/kdump.txt
2108 for more details about crash dumps.
2109
2110 Usage of bzImage for capturing the crash dump is recommended as
2111 one does not have to build two kernels. Same kernel can be used
2112 as production kernel and capture kernel. Above option should have
2113 gone away after relocatable bzImage support is introduced. But it
2114 is present because there are users out there who continue to use
2115 vmlinux for dump capture. This option should go away down the
2116 line.
2117
2118 Don't change this unless you know what you are doing.
2119
2120config RELOCATABLE
2121 bool "Build a relocatable kernel"
2122 default y
2123 ---help---
2124 This builds a kernel image that retains relocation information
2125 so it can be loaded someplace besides the default 1MB.
2126 The relocations tend to make the kernel binary about 10% larger,
2127 but are discarded at runtime.
2128
2129 One use is for the kexec on panic case where the recovery kernel
2130 must live at a different physical address than the primary
2131 kernel.
2132
2133 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
2134 it has been loaded at and the compile time physical address
2135 (CONFIG_PHYSICAL_START) is used as the minimum location.
2136
2137config RANDOMIZE_BASE
2138 bool "Randomize the address of the kernel image (KASLR)"
2139 depends on RELOCATABLE
2140 default y
2141 ---help---
2142 In support of Kernel Address Space Layout Randomization (KASLR),
2143 this randomizes the physical address at which the kernel image
2144 is decompressed and the virtual address where the kernel
2145 image is mapped, as a security feature that deters exploit
2146 attempts relying on knowledge of the location of kernel
2147 code internals.
2148
2149 On 64-bit, the kernel physical and virtual addresses are
2150 randomized separately. The physical address will be anywhere
2151 between 16MB and the top of physical memory (up to 64TB). The
2152 virtual address will be randomized from 16MB up to 1GB (9 bits
2153 of entropy). Note that this also reduces the memory space
2154 available to kernel modules from 1.5GB to 1GB.
2155
2156 On 32-bit, the kernel physical and virtual addresses are
2157 randomized together. They will be randomized from 16MB up to
2158 512MB (8 bits of entropy).
2159
2160 Entropy is generated using the RDRAND instruction if it is
2161 supported. If RDTSC is supported, its value is mixed into
2162 the entropy pool as well. If neither RDRAND nor RDTSC are
2163 supported, then entropy is read from the i8254 timer. The
2164 usable entropy is limited by the kernel being built using
2165 2GB addressing, and that PHYSICAL_ALIGN must be at a
2166 minimum of 2MB. As a result, only 10 bits of entropy are
2167 theoretically possible, but the implementations are further
2168 limited due to memory layouts.
2169
2170 If unsure, say Y.
2171
2172# Relocation on x86 needs some additional build support
2173config X86_NEED_RELOCS
2174 def_bool y
2175 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
2176
2177config PHYSICAL_ALIGN
2178 hex "Alignment value to which kernel should be aligned"
2179 default "0x200000"
2180 range 0x2000 0x1000000 if X86_32
2181 range 0x200000 0x1000000 if X86_64
2182 ---help---
2183 This value puts the alignment restrictions on physical address
2184 where kernel is loaded and run from. Kernel is compiled for an
2185 address which meets above alignment restriction.
2186
2187 If bootloader loads the kernel at a non-aligned address and
2188 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
2189 address aligned to above value and run from there.
2190
2191 If bootloader loads the kernel at a non-aligned address and
2192 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
2193 load address and decompress itself to the address it has been
2194 compiled for and run from there. The address for which kernel is
2195 compiled already meets above alignment restrictions. Hence the
2196 end result is that kernel runs from a physical address meeting
2197 above alignment restrictions.
2198
2199 On 32-bit this value must be a multiple of 0x2000. On 64-bit
2200 this value must be a multiple of 0x200000.
2201
2202 Don't change this unless you know what you are doing.
2203
2204config DYNAMIC_MEMORY_LAYOUT
2205 bool
2206 ---help---
2207 This option makes base addresses of vmalloc and vmemmap as well as
2208 __PAGE_OFFSET movable during boot.
2209
2210config RANDOMIZE_MEMORY
2211 bool "Randomize the kernel memory sections"
2212 depends on X86_64
2213 depends on RANDOMIZE_BASE
2214 select DYNAMIC_MEMORY_LAYOUT
2215 default RANDOMIZE_BASE
2216 ---help---
2217 Randomizes the base virtual address of kernel memory sections
2218 (physical memory mapping, vmalloc & vmemmap). This security feature
2219 makes exploits relying on predictable memory locations less reliable.
2220
2221 The order of allocations remains unchanged. Entropy is generated in
2222 the same way as RANDOMIZE_BASE. Current implementation in the optimal
2223 configuration have in average 30,000 different possible virtual
2224 addresses for each memory section.
2225
2226 If unsure, say Y.
2227
2228config RANDOMIZE_MEMORY_PHYSICAL_PADDING
2229 hex "Physical memory mapping padding" if EXPERT
2230 depends on RANDOMIZE_MEMORY
2231 default "0xa" if MEMORY_HOTPLUG
2232 default "0x0"
2233 range 0x1 0x40 if MEMORY_HOTPLUG
2234 range 0x0 0x40
2235 ---help---
2236 Define the padding in terabytes added to the existing physical
2237 memory size during kernel memory randomization. It is useful
2238 for memory hotplug support but reduces the entropy available for
2239 address randomization.
2240
2241 If unsure, leave at the default value.
2242
2243config HOTPLUG_CPU
2244 def_bool y
2245 depends on SMP
2246
2247config BOOTPARAM_HOTPLUG_CPU0
2248 bool "Set default setting of cpu0_hotpluggable"
2249 default n
2250 depends on HOTPLUG_CPU
2251 ---help---
2252 Set whether default state of cpu0_hotpluggable is on or off.
2253
2254 Say Y here to enable CPU0 hotplug by default. If this switch
2255 is turned on, there is no need to give cpu0_hotplug kernel
2256 parameter and the CPU0 hotplug feature is enabled by default.
2257
2258 Please note: there are two known CPU0 dependencies if you want
2259 to enable the CPU0 hotplug feature either by this switch or by
2260 cpu0_hotplug kernel parameter.
2261
2262 First, resume from hibernate or suspend always starts from CPU0.
2263 So hibernate and suspend are prevented if CPU0 is offline.
2264
2265 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2266 offline if any interrupt can not migrate out of CPU0. There may
2267 be other CPU0 dependencies.
2268
2269 Please make sure the dependencies are under your control before
2270 you enable this feature.
2271
2272 Say N if you don't want to enable CPU0 hotplug feature by default.
2273 You still can enable the CPU0 hotplug feature at boot by kernel
2274 parameter cpu0_hotplug.
2275
2276config DEBUG_HOTPLUG_CPU0
2277 def_bool n
2278 prompt "Debug CPU0 hotplug"
2279 depends on HOTPLUG_CPU
2280 ---help---
2281 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2282 soon as possible and boots up userspace with CPU0 offlined. User
2283 can online CPU0 back after boot time.
2284
2285 To debug CPU0 hotplug, you need to enable CPU0 offline/online
2286 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2287 compilation or giving cpu0_hotplug kernel parameter at boot.
2288
2289 If unsure, say N.
2290
2291config COMPAT_VDSO
2292 def_bool n
2293 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2294 depends on COMPAT_32
2295 ---help---
2296 Certain buggy versions of glibc will crash if they are
2297 presented with a 32-bit vDSO that is not mapped at the address
2298 indicated in its segment table.
2299
2300 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2301 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2302 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
2303 the only released version with the bug, but OpenSUSE 9
2304 contains a buggy "glibc 2.3.2".
2305
2306 The symptom of the bug is that everything crashes on startup, saying:
2307 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2308
2309 Saying Y here changes the default value of the vdso32 boot
2310 option from 1 to 0, which turns off the 32-bit vDSO entirely.
2311 This works around the glibc bug but hurts performance.
2312
2313 If unsure, say N: if you are compiling your own kernel, you
2314 are unlikely to be using a buggy version of glibc.
2315
2316choice
2317 prompt "vsyscall table for legacy applications"
2318 depends on X86_64
2319 default LEGACY_VSYSCALL_EMULATE
2320 help
2321 Legacy user code that does not know how to find the vDSO expects
2322 to be able to issue three syscalls by calling fixed addresses in
2323 kernel space. Since this location is not randomized with ASLR,
2324 it can be used to assist security vulnerability exploitation.
2325
2326 This setting can be changed at boot time via the kernel command
2327 line parameter vsyscall=[emulate|none].
2328
2329 On a system with recent enough glibc (2.14 or newer) and no
2330 static binaries, you can say None without a performance penalty
2331 to improve security.
2332
2333 If unsure, select "Emulate".
2334
2335 config LEGACY_VSYSCALL_EMULATE
2336 bool "Emulate"
2337 help
2338 The kernel traps and emulates calls into the fixed
2339 vsyscall address mapping. This makes the mapping
2340 non-executable, but it still contains known contents,
2341 which could be used in certain rare security vulnerability
2342 exploits. This configuration is recommended when userspace
2343 still uses the vsyscall area.
2344
2345 config LEGACY_VSYSCALL_NONE
2346 bool "None"
2347 help
2348 There will be no vsyscall mapping at all. This will
2349 eliminate any risk of ASLR bypass due to the vsyscall
2350 fixed address mapping. Attempts to use the vsyscalls
2351 will be reported to dmesg, so that either old or
2352 malicious userspace programs can be identified.
2353
2354endchoice
2355
2356config CMDLINE_BOOL
2357 bool "Built-in kernel command line"
2358 ---help---
2359 Allow for specifying boot arguments to the kernel at
2360 build time. On some systems (e.g. embedded ones), it is
2361 necessary or convenient to provide some or all of the
2362 kernel boot arguments with the kernel itself (that is,
2363 to not rely on the boot loader to provide them.)
2364
2365 To compile command line arguments into the kernel,
2366 set this option to 'Y', then fill in the
2367 boot arguments in CONFIG_CMDLINE.
2368
2369 Systems with fully functional boot loaders (i.e. non-embedded)
2370 should leave this option set to 'N'.
2371
2372config CMDLINE
2373 string "Built-in kernel command string"
2374 depends on CMDLINE_BOOL
2375 default ""
2376 ---help---
2377 Enter arguments here that should be compiled into the kernel
2378 image and used at boot time. If the boot loader provides a
2379 command line at boot time, it is appended to this string to
2380 form the full kernel command line, when the system boots.
2381
2382 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2383 change this behavior.
2384
2385 In most cases, the command line (whether built-in or provided
2386 by the boot loader) should specify the device for the root
2387 file system.
2388
2389config CMDLINE_OVERRIDE
2390 bool "Built-in command line overrides boot loader arguments"
2391 depends on CMDLINE_BOOL
2392 ---help---
2393 Set this option to 'Y' to have the kernel ignore the boot loader
2394 command line, and use ONLY the built-in command line.
2395
2396 This is used to work around broken boot loaders. This should
2397 be set to 'N' under normal conditions.
2398
2399config MODIFY_LDT_SYSCALL
2400 bool "Enable the LDT (local descriptor table)" if EXPERT
2401 default y
2402 ---help---
2403 Linux can allow user programs to install a per-process x86
2404 Local Descriptor Table (LDT) using the modify_ldt(2) system
2405 call. This is required to run 16-bit or segmented code such as
2406 DOSEMU or some Wine programs. It is also used by some very old
2407 threading libraries.
2408
2409 Enabling this feature adds a small amount of overhead to
2410 context switches and increases the low-level kernel attack
2411 surface. Disabling it removes the modify_ldt(2) system call.
2412
2413 Saying 'N' here may make sense for embedded or server kernels.
2414
2415source "kernel/livepatch/Kconfig"
2416
2417endmenu
2418
2419config ARCH_HAS_ADD_PAGES
2420 def_bool y
2421 depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG
2422
2423config ARCH_ENABLE_MEMORY_HOTPLUG
2424 def_bool y
2425 depends on X86_64 || (X86_32 && HIGHMEM)
2426
2427config ARCH_ENABLE_MEMORY_HOTREMOVE
2428 def_bool y
2429 depends on MEMORY_HOTPLUG
2430
2431config USE_PERCPU_NUMA_NODE_ID
2432 def_bool y
2433 depends on NUMA
2434
2435config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2436 def_bool y
2437 depends on X86_64 || X86_PAE
2438
2439config ARCH_ENABLE_HUGEPAGE_MIGRATION
2440 def_bool y
2441 depends on X86_64 && HUGETLB_PAGE && MIGRATION
2442
2443config ARCH_ENABLE_THP_MIGRATION
2444 def_bool y
2445 depends on X86_64 && TRANSPARENT_HUGEPAGE
2446
2447menu "Power management and ACPI options"
2448
2449config ARCH_HIBERNATION_HEADER
2450 def_bool y
2451 depends on X86_64 && HIBERNATION
2452
2453source "kernel/power/Kconfig"
2454
2455source "drivers/acpi/Kconfig"
2456
2457source "drivers/sfi/Kconfig"
2458
2459config X86_APM_BOOT
2460 def_bool y
2461 depends on APM
2462
2463menuconfig APM
2464 tristate "APM (Advanced Power Management) BIOS support"
2465 depends on X86_32 && PM_SLEEP
2466 ---help---
2467 APM is a BIOS specification for saving power using several different
2468 techniques. This is mostly useful for battery powered laptops with
2469 APM compliant BIOSes. If you say Y here, the system time will be
2470 reset after a RESUME operation, the /proc/apm device will provide
2471 battery status information, and user-space programs will receive
2472 notification of APM "events" (e.g. battery status change).
2473
2474 If you select "Y" here, you can disable actual use of the APM
2475 BIOS by passing the "apm=off" option to the kernel at boot time.
2476
2477 Note that the APM support is almost completely disabled for
2478 machines with more than one CPU.
2479
2480 In order to use APM, you will need supporting software. For location
2481 and more information, read <file:Documentation/power/apm-acpi.txt>
2482 and the Battery Powered Linux mini-HOWTO, available from
2483 <http://www.tldp.org/docs.html#howto>.
2484
2485 This driver does not spin down disk drives (see the hdparm(8)
2486 manpage ("man 8 hdparm") for that), and it doesn't turn off
2487 VESA-compliant "green" monitors.
2488
2489 This driver does not support the TI 4000M TravelMate and the ACER
2490 486/DX4/75 because they don't have compliant BIOSes. Many "green"
2491 desktop machines also don't have compliant BIOSes, and this driver
2492 may cause those machines to panic during the boot phase.
2493
2494 Generally, if you don't have a battery in your machine, there isn't
2495 much point in using this driver and you should say N. If you get
2496 random kernel OOPSes or reboots that don't seem to be related to
2497 anything, try disabling/enabling this option (or disabling/enabling
2498 APM in your BIOS).
2499
2500 Some other things you should try when experiencing seemingly random,
2501 "weird" problems:
2502
2503 1) make sure that you have enough swap space and that it is
2504 enabled.
2505 2) pass the "no-hlt" option to the kernel
2506 3) switch on floating point emulation in the kernel and pass
2507 the "no387" option to the kernel
2508 4) pass the "floppy=nodma" option to the kernel
2509 5) pass the "mem=4M" option to the kernel (thereby disabling
2510 all but the first 4 MB of RAM)
2511 6) make sure that the CPU is not over clocked.
2512 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2513 8) disable the cache from your BIOS settings
2514 9) install a fan for the video card or exchange video RAM
2515 10) install a better fan for the CPU
2516 11) exchange RAM chips
2517 12) exchange the motherboard.
2518
2519 To compile this driver as a module, choose M here: the
2520 module will be called apm.
2521
2522if APM
2523
2524config APM_IGNORE_USER_SUSPEND
2525 bool "Ignore USER SUSPEND"
2526 ---help---
2527 This option will ignore USER SUSPEND requests. On machines with a
2528 compliant APM BIOS, you want to say N. However, on the NEC Versa M
2529 series notebooks, it is necessary to say Y because of a BIOS bug.
2530
2531config APM_DO_ENABLE
2532 bool "Enable PM at boot time"
2533 ---help---
2534 Enable APM features at boot time. From page 36 of the APM BIOS
2535 specification: "When disabled, the APM BIOS does not automatically
2536 power manage devices, enter the Standby State, enter the Suspend
2537 State, or take power saving steps in response to CPU Idle calls."
2538 This driver will make CPU Idle calls when Linux is idle (unless this
2539 feature is turned off -- see "Do CPU IDLE calls", below). This
2540 should always save battery power, but more complicated APM features
2541 will be dependent on your BIOS implementation. You may need to turn
2542 this option off if your computer hangs at boot time when using APM
2543 support, or if it beeps continuously instead of suspending. Turn
2544 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2545 T400CDT. This is off by default since most machines do fine without
2546 this feature.
2547
2548config APM_CPU_IDLE
2549 depends on CPU_IDLE
2550 bool "Make CPU Idle calls when idle"
2551 ---help---
2552 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2553 On some machines, this can activate improved power savings, such as
2554 a slowed CPU clock rate, when the machine is idle. These idle calls
2555 are made after the idle loop has run for some length of time (e.g.,
2556 333 mS). On some machines, this will cause a hang at boot time or
2557 whenever the CPU becomes idle. (On machines with more than one CPU,
2558 this option does nothing.)
2559
2560config APM_DISPLAY_BLANK
2561 bool "Enable console blanking using APM"
2562 ---help---
2563 Enable console blanking using the APM. Some laptops can use this to
2564 turn off the LCD backlight when the screen blanker of the Linux
2565 virtual console blanks the screen. Note that this is only used by
2566 the virtual console screen blanker, and won't turn off the backlight
2567 when using the X Window system. This also doesn't have anything to
2568 do with your VESA-compliant power-saving monitor. Further, this
2569 option doesn't work for all laptops -- it might not turn off your
2570 backlight at all, or it might print a lot of errors to the console,
2571 especially if you are using gpm.
2572
2573config APM_ALLOW_INTS
2574 bool "Allow interrupts during APM BIOS calls"
2575 ---help---
2576 Normally we disable external interrupts while we are making calls to
2577 the APM BIOS as a measure to lessen the effects of a badly behaving
2578 BIOS implementation. The BIOS should reenable interrupts if it
2579 needs to. Unfortunately, some BIOSes do not -- especially those in
2580 many of the newer IBM Thinkpads. If you experience hangs when you
2581 suspend, try setting this to Y. Otherwise, say N.
2582
2583endif # APM
2584
2585source "drivers/cpufreq/Kconfig"
2586
2587source "drivers/cpuidle/Kconfig"
2588
2589source "drivers/idle/Kconfig"
2590
2591endmenu
2592
2593
2594menu "Bus options (PCI etc.)"
2595
2596config PCI
2597 bool "PCI support"
2598 default y
2599 ---help---
2600 Find out whether you have a PCI motherboard. PCI is the name of a
2601 bus system, i.e. the way the CPU talks to the other stuff inside
2602 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2603 VESA. If you have PCI, say Y, otherwise N.
2604
2605choice
2606 prompt "PCI access mode"
2607 depends on X86_32 && PCI
2608 default PCI_GOANY
2609 ---help---
2610 On PCI systems, the BIOS can be used to detect the PCI devices and
2611 determine their configuration. However, some old PCI motherboards
2612 have BIOS bugs and may crash if this is done. Also, some embedded
2613 PCI-based systems don't have any BIOS at all. Linux can also try to
2614 detect the PCI hardware directly without using the BIOS.
2615
2616 With this option, you can specify how Linux should detect the
2617 PCI devices. If you choose "BIOS", the BIOS will be used,
2618 if you choose "Direct", the BIOS won't be used, and if you
2619 choose "MMConfig", then PCI Express MMCONFIG will be used.
2620 If you choose "Any", the kernel will try MMCONFIG, then the
2621 direct access method and falls back to the BIOS if that doesn't
2622 work. If unsure, go with the default, which is "Any".
2623
2624config PCI_GOBIOS
2625 bool "BIOS"
2626
2627config PCI_GOMMCONFIG
2628 bool "MMConfig"
2629
2630config PCI_GODIRECT
2631 bool "Direct"
2632
2633config PCI_GOOLPC
2634 bool "OLPC XO-1"
2635 depends on OLPC
2636
2637config PCI_GOANY
2638 bool "Any"
2639
2640endchoice
2641
2642config PCI_BIOS
2643 def_bool y
2644 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2645
2646# x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2647config PCI_DIRECT
2648 def_bool y
2649 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2650
2651config PCI_MMCONFIG
2652 bool "Support mmconfig PCI config space access" if X86_64
2653 default y
2654 depends on PCI && (ACPI || SFI || JAILHOUSE_GUEST)
2655 depends on X86_64 || (PCI_GOANY || PCI_GOMMCONFIG)
2656
2657config PCI_OLPC
2658 def_bool y
2659 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2660
2661config PCI_XEN
2662 def_bool y
2663 depends on PCI && XEN
2664 select SWIOTLB_XEN
2665
2666config PCI_DOMAINS
2667 def_bool y
2668 depends on PCI
2669
2670config MMCONF_FAM10H
2671 def_bool y
2672 depends on X86_64 && PCI_MMCONFIG && ACPI
2673
2674config PCI_CNB20LE_QUIRK
2675 bool "Read CNB20LE Host Bridge Windows" if EXPERT
2676 depends on PCI
2677 help
2678 Read the PCI windows out of the CNB20LE host bridge. This allows
2679 PCI hotplug to work on systems with the CNB20LE chipset which do
2680 not have ACPI.
2681
2682 There's no public spec for this chipset, and this functionality
2683 is known to be incomplete.
2684
2685 You should say N unless you know you need this.
2686
2687source "drivers/pci/Kconfig"
2688
2689config ISA_BUS
2690 bool "ISA bus support on modern systems" if EXPERT
2691 help
2692 Expose ISA bus device drivers and options available for selection and
2693 configuration. Enable this option if your target machine has an ISA
2694 bus. ISA is an older system, displaced by PCI and newer bus
2695 architectures -- if your target machine is modern, it probably does
2696 not have an ISA bus.
2697
2698 If unsure, say N.
2699
2700# x86_64 have no ISA slots, but can have ISA-style DMA.
2701config ISA_DMA_API
2702 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2703 default y
2704 help
2705 Enables ISA-style DMA support for devices requiring such controllers.
2706 If unsure, say Y.
2707
2708if X86_32
2709
2710config ISA
2711 bool "ISA support"
2712 ---help---
2713 Find out whether you have ISA slots on your motherboard. ISA is the
2714 name of a bus system, i.e. the way the CPU talks to the other stuff
2715 inside your box. Other bus systems are PCI, EISA, MicroChannel
2716 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2717 newer boards don't support it. If you have ISA, say Y, otherwise N.
2718
2719config EISA
2720 bool "EISA support"
2721 depends on ISA
2722 ---help---
2723 The Extended Industry Standard Architecture (EISA) bus was
2724 developed as an open alternative to the IBM MicroChannel bus.
2725
2726 The EISA bus provided some of the features of the IBM MicroChannel
2727 bus while maintaining backward compatibility with cards made for
2728 the older ISA bus. The EISA bus saw limited use between 1988 and
2729 1995 when it was made obsolete by the PCI bus.
2730
2731 Say Y here if you are building a kernel for an EISA-based machine.
2732
2733 Otherwise, say N.
2734
2735source "drivers/eisa/Kconfig"
2736
2737config SCx200
2738 tristate "NatSemi SCx200 support"
2739 ---help---
2740 This provides basic support for National Semiconductor's
2741 (now AMD's) Geode processors. The driver probes for the
2742 PCI-IDs of several on-chip devices, so its a good dependency
2743 for other scx200_* drivers.
2744
2745 If compiled as a module, the driver is named scx200.
2746
2747config SCx200HR_TIMER
2748 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2749 depends on SCx200
2750 default y
2751 ---help---
2752 This driver provides a clocksource built upon the on-chip
2753 27MHz high-resolution timer. Its also a workaround for
2754 NSC Geode SC-1100's buggy TSC, which loses time when the
2755 processor goes idle (as is done by the scheduler). The
2756 other workaround is idle=poll boot option.
2757
2758config OLPC
2759 bool "One Laptop Per Child support"
2760 depends on !X86_PAE
2761 select GPIOLIB
2762 select OF
2763 select OF_PROMTREE
2764 select IRQ_DOMAIN
2765 ---help---
2766 Add support for detecting the unique features of the OLPC
2767 XO hardware.
2768
2769config OLPC_XO1_PM
2770 bool "OLPC XO-1 Power Management"
2771 depends on OLPC && MFD_CS5535=y && PM_SLEEP
2772 ---help---
2773 Add support for poweroff and suspend of the OLPC XO-1 laptop.
2774
2775config OLPC_XO1_RTC
2776 bool "OLPC XO-1 Real Time Clock"
2777 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2778 ---help---
2779 Add support for the XO-1 real time clock, which can be used as a
2780 programmable wakeup source.
2781
2782config OLPC_XO1_SCI
2783 bool "OLPC XO-1 SCI extras"
2784 depends on OLPC && OLPC_XO1_PM && GPIO_CS5535=y
2785 depends on INPUT=y
2786 select POWER_SUPPLY
2787 ---help---
2788 Add support for SCI-based features of the OLPC XO-1 laptop:
2789 - EC-driven system wakeups
2790 - Power button
2791 - Ebook switch
2792 - Lid switch
2793 - AC adapter status updates
2794 - Battery status updates
2795
2796config OLPC_XO15_SCI
2797 bool "OLPC XO-1.5 SCI extras"
2798 depends on OLPC && ACPI
2799 select POWER_SUPPLY
2800 ---help---
2801 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2802 - EC-driven system wakeups
2803 - AC adapter status updates
2804 - Battery status updates
2805
2806config ALIX
2807 bool "PCEngines ALIX System Support (LED setup)"
2808 select GPIOLIB
2809 ---help---
2810 This option enables system support for the PCEngines ALIX.
2811 At present this just sets up LEDs for GPIO control on
2812 ALIX2/3/6 boards. However, other system specific setup should
2813 get added here.
2814
2815 Note: You must still enable the drivers for GPIO and LED support
2816 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2817
2818 Note: You have to set alix.force=1 for boards with Award BIOS.
2819
2820config NET5501
2821 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2822 select GPIOLIB
2823 ---help---
2824 This option enables system support for the Soekris Engineering net5501.
2825
2826config GEOS
2827 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2828 select GPIOLIB
2829 depends on DMI
2830 ---help---
2831 This option enables system support for the Traverse Technologies GEOS.
2832
2833config TS5500
2834 bool "Technologic Systems TS-5500 platform support"
2835 depends on MELAN
2836 select CHECK_SIGNATURE
2837 select NEW_LEDS
2838 select LEDS_CLASS
2839 ---help---
2840 This option enables system support for the Technologic Systems TS-5500.
2841
2842endif # X86_32
2843
2844config AMD_NB
2845 def_bool y
2846 depends on CPU_SUP_AMD && PCI
2847
2848source "drivers/pcmcia/Kconfig"
2849
2850config RAPIDIO
2851 tristate "RapidIO support"
2852 depends on PCI
2853 default n
2854 help
2855 If enabled this option will include drivers and the core
2856 infrastructure code to support RapidIO interconnect devices.
2857
2858source "drivers/rapidio/Kconfig"
2859
2860config X86_SYSFB
2861 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2862 help
2863 Firmwares often provide initial graphics framebuffers so the BIOS,
2864 bootloader or kernel can show basic video-output during boot for
2865 user-guidance and debugging. Historically, x86 used the VESA BIOS
2866 Extensions and EFI-framebuffers for this, which are mostly limited
2867 to x86.
2868 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2869 framebuffers so the new generic system-framebuffer drivers can be
2870 used on x86. If the framebuffer is not compatible with the generic
2871 modes, it is advertised as fallback platform framebuffer so legacy
2872 drivers like efifb, vesafb and uvesafb can pick it up.
2873 If this option is not selected, all system framebuffers are always
2874 marked as fallback platform framebuffers as usual.
2875
2876 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2877 not be able to pick up generic system framebuffers if this option
2878 is selected. You are highly encouraged to enable simplefb as
2879 replacement if you select this option. simplefb can correctly deal
2880 with generic system framebuffers. But you should still keep vesafb
2881 and others enabled as fallback if a system framebuffer is
2882 incompatible with simplefb.
2883
2884 If unsure, say Y.
2885
2886endmenu
2887
2888
2889menu "Binary Emulations"
2890
2891config IA32_EMULATION
2892 bool "IA32 Emulation"
2893 depends on X86_64
2894 select ARCH_WANT_OLD_COMPAT_IPC
2895 select BINFMT_ELF
2896 select COMPAT_BINFMT_ELF
2897 select COMPAT_OLD_SIGACTION
2898 ---help---
2899 Include code to run legacy 32-bit programs under a
2900 64-bit kernel. You should likely turn this on, unless you're
2901 100% sure that you don't have any 32-bit programs left.
2902
2903config IA32_AOUT
2904 tristate "IA32 a.out support"
2905 depends on IA32_EMULATION
2906 ---help---
2907 Support old a.out binaries in the 32bit emulation.
2908
2909config X86_X32
2910 bool "x32 ABI for 64-bit mode"
2911 depends on X86_64
2912 ---help---
2913 Include code to run binaries for the x32 native 32-bit ABI
2914 for 64-bit processors. An x32 process gets access to the
2915 full 64-bit register file and wide data path while leaving
2916 pointers at 32 bits for smaller memory footprint.
2917
2918 You will need a recent binutils (2.22 or later) with
2919 elf32_x86_64 support enabled to compile a kernel with this
2920 option set.
2921
2922config COMPAT_32
2923 def_bool y
2924 depends on IA32_EMULATION || X86_32
2925 select HAVE_UID16
2926 select OLD_SIGSUSPEND3
2927
2928config COMPAT
2929 def_bool y
2930 depends on IA32_EMULATION || X86_X32
2931
2932if COMPAT
2933config COMPAT_FOR_U64_ALIGNMENT
2934 def_bool y
2935
2936config SYSVIPC_COMPAT
2937 def_bool y
2938 depends on SYSVIPC
2939endif
2940
2941endmenu
2942
2943
2944config HAVE_ATOMIC_IOMAP
2945 def_bool y
2946 depends on X86_32
2947
2948config X86_DEV_DMA_OPS
2949 bool
2950 depends on X86_64 || STA2X11
2951
2952config X86_DMA_REMAP
2953 bool
2954 depends on STA2X11
2955
2956config HAVE_GENERIC_GUP
2957 def_bool y
2958
2959source "drivers/firmware/Kconfig"
2960
2961source "arch/x86/kvm/Kconfig"