54478b7635ded10f5e6432e89502f11a21612dce
[deliverable/linux.git] / arch / x86 / Kconfig
1 # Select 32 or 64 bit
2 config 64BIT
3 bool "64-bit kernel" if ARCH = "x86"
4 default ARCH != "i386"
5 ---help---
6 Say yes to build a 64-bit kernel - formerly known as x86_64
7 Say no to build a 32-bit kernel - formerly known as i386
8
9 config X86_32
10 def_bool y
11 depends on !64BIT
12
13 config X86_64
14 def_bool y
15 depends on 64BIT
16
17 ### Arch settings
18 config X86
19 def_bool y
20 select ACPI_LEGACY_TABLES_LOOKUP if ACPI
21 select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI
22 select ANON_INODES
23 select ARCH_CLOCKSOURCE_DATA
24 select ARCH_DISCARD_MEMBLOCK
25 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
26 select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
27 select ARCH_HAS_DEVMEM_IS_ALLOWED
28 select ARCH_HAS_ELF_RANDOMIZE
29 select ARCH_HAS_FAST_MULTIPLIER
30 select ARCH_HAS_GCOV_PROFILE_ALL
31 select ARCH_HAS_KCOV if X86_64
32 select ARCH_HAS_PMEM_API if X86_64
33 select ARCH_HAS_MMIO_FLUSH
34 select ARCH_HAS_SG_CHAIN
35 select ARCH_HAS_UBSAN_SANITIZE_ALL
36 select ARCH_HAVE_NMI_SAFE_CMPXCHG
37 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
38 select ARCH_MIGHT_HAVE_PC_PARPORT
39 select ARCH_MIGHT_HAVE_PC_SERIO
40 select ARCH_SUPPORTS_ATOMIC_RMW
41 select ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT
42 select ARCH_SUPPORTS_INT128 if X86_64
43 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
44 select ARCH_USE_BUILTIN_BSWAP
45 select ARCH_USE_CMPXCHG_LOCKREF if X86_64
46 select ARCH_USE_QUEUED_RWLOCKS
47 select ARCH_USE_QUEUED_SPINLOCKS
48 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH if SMP
49 select ARCH_WANTS_DYNAMIC_TASK_STRUCT
50 select ARCH_WANT_FRAME_POINTERS
51 select ARCH_WANT_IPC_PARSE_VERSION if X86_32
52 select ARCH_WANT_OPTIONAL_GPIOLIB
53 select BUILDTIME_EXTABLE_SORT
54 select CLKEVT_I8253
55 select CLKSRC_I8253 if X86_32
56 select CLOCKSOURCE_VALIDATE_LAST_CYCLE
57 select CLOCKSOURCE_WATCHDOG
58 select CLONE_BACKWARDS if X86_32
59 select COMPAT_OLD_SIGACTION if IA32_EMULATION
60 select DCACHE_WORD_ACCESS
61 select EDAC_ATOMIC_SCRUB
62 select EDAC_SUPPORT
63 select GENERIC_CLOCKEVENTS
64 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
65 select GENERIC_CLOCKEVENTS_MIN_ADJUST
66 select GENERIC_CMOS_UPDATE
67 select GENERIC_CPU_AUTOPROBE
68 select GENERIC_EARLY_IOREMAP
69 select GENERIC_FIND_FIRST_BIT
70 select GENERIC_IOMAP
71 select GENERIC_IRQ_PROBE
72 select GENERIC_IRQ_SHOW
73 select GENERIC_PENDING_IRQ if SMP
74 select GENERIC_SMP_IDLE_THREAD
75 select GENERIC_STRNCPY_FROM_USER
76 select GENERIC_STRNLEN_USER
77 select GENERIC_TIME_VSYSCALL
78 select HAVE_ACPI_APEI if ACPI
79 select HAVE_ACPI_APEI_NMI if ACPI
80 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
81 select HAVE_AOUT if X86_32
82 select HAVE_ARCH_AUDITSYSCALL
83 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE
84 select HAVE_ARCH_JUMP_LABEL
85 select HAVE_ARCH_KASAN if X86_64 && SPARSEMEM_VMEMMAP
86 select HAVE_ARCH_KGDB
87 select HAVE_ARCH_KMEMCHECK
88 select HAVE_ARCH_MMAP_RND_BITS if MMU
89 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if MMU && COMPAT
90 select HAVE_ARCH_SECCOMP_FILTER
91 select HAVE_ARCH_SOFT_DIRTY if X86_64
92 select HAVE_ARCH_TRACEHOOK
93 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
94 select HAVE_BPF_JIT if X86_64
95 select HAVE_CC_STACKPROTECTOR
96 select HAVE_CMPXCHG_DOUBLE
97 select HAVE_CMPXCHG_LOCAL
98 select HAVE_CONTEXT_TRACKING if X86_64
99 select HAVE_COPY_THREAD_TLS
100 select HAVE_C_RECORDMCOUNT
101 select HAVE_DEBUG_KMEMLEAK
102 select HAVE_DEBUG_STACKOVERFLOW
103 select HAVE_DMA_API_DEBUG
104 select HAVE_DMA_CONTIGUOUS
105 select HAVE_DYNAMIC_FTRACE
106 select HAVE_DYNAMIC_FTRACE_WITH_REGS
107 select HAVE_EFFICIENT_UNALIGNED_ACCESS
108 select HAVE_FENTRY if X86_64
109 select HAVE_FTRACE_MCOUNT_RECORD
110 select HAVE_FUNCTION_GRAPH_FP_TEST
111 select HAVE_FUNCTION_GRAPH_TRACER
112 select HAVE_FUNCTION_TRACER
113 select HAVE_GENERIC_DMA_COHERENT if X86_32
114 select HAVE_HW_BREAKPOINT
115 select HAVE_IDE
116 select HAVE_IOREMAP_PROT
117 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
118 select HAVE_IRQ_TIME_ACCOUNTING
119 select HAVE_KERNEL_BZIP2
120 select HAVE_KERNEL_GZIP
121 select HAVE_KERNEL_LZ4
122 select HAVE_KERNEL_LZMA
123 select HAVE_KERNEL_LZO
124 select HAVE_KERNEL_XZ
125 select HAVE_KPROBES
126 select HAVE_KPROBES_ON_FTRACE
127 select HAVE_KRETPROBES
128 select HAVE_KVM
129 select HAVE_LIVEPATCH if X86_64
130 select HAVE_MEMBLOCK
131 select HAVE_MEMBLOCK_NODE_MAP
132 select HAVE_MIXED_BREAKPOINTS_REGS
133 select HAVE_OPROFILE
134 select HAVE_OPTPROBES
135 select HAVE_PCSPKR_PLATFORM
136 select HAVE_PERF_EVENTS
137 select HAVE_PERF_EVENTS_NMI
138 select HAVE_PERF_REGS
139 select HAVE_PERF_USER_STACK_DUMP
140 select HAVE_REGS_AND_STACK_ACCESS_API
141 select HAVE_SYSCALL_TRACEPOINTS
142 select HAVE_UID16 if X86_32 || IA32_EMULATION
143 select HAVE_UNSTABLE_SCHED_CLOCK
144 select HAVE_USER_RETURN_NOTIFIER
145 select IRQ_FORCED_THREADING
146 select MODULES_USE_ELF_RELA if X86_64
147 select MODULES_USE_ELF_REL if X86_32
148 select OLD_SIGACTION if X86_32
149 select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION
150 select PERF_EVENTS
151 select RTC_LIB
152 select SPARSE_IRQ
153 select SRCU
154 select SYSCTL_EXCEPTION_TRACE
155 select USER_STACKTRACE_SUPPORT
156 select VIRT_TO_BUS
157 select X86_DEV_DMA_OPS if X86_64
158 select X86_FEATURE_NAMES if PROC_FS
159 select HAVE_STACK_VALIDATION if X86_64
160 select ARCH_USES_HIGH_VMA_FLAGS if X86_INTEL_MEMORY_PROTECTION_KEYS
161 select ARCH_HAS_PKEYS if X86_INTEL_MEMORY_PROTECTION_KEYS
162
163 config INSTRUCTION_DECODER
164 def_bool y
165 depends on KPROBES || PERF_EVENTS || UPROBES
166
167 config PERF_EVENTS_INTEL_UNCORE
168 def_bool y
169 depends on PERF_EVENTS && CPU_SUP_INTEL && PCI
170
171 config OUTPUT_FORMAT
172 string
173 default "elf32-i386" if X86_32
174 default "elf64-x86-64" if X86_64
175
176 config ARCH_DEFCONFIG
177 string
178 default "arch/x86/configs/i386_defconfig" if X86_32
179 default "arch/x86/configs/x86_64_defconfig" if X86_64
180
181 config LOCKDEP_SUPPORT
182 def_bool y
183
184 config STACKTRACE_SUPPORT
185 def_bool y
186
187 config MMU
188 def_bool y
189
190 config ARCH_MMAP_RND_BITS_MIN
191 default 28 if 64BIT
192 default 8
193
194 config ARCH_MMAP_RND_BITS_MAX
195 default 32 if 64BIT
196 default 16
197
198 config ARCH_MMAP_RND_COMPAT_BITS_MIN
199 default 8
200
201 config ARCH_MMAP_RND_COMPAT_BITS_MAX
202 default 16
203
204 config SBUS
205 bool
206
207 config NEED_DMA_MAP_STATE
208 def_bool y
209 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB
210
211 config NEED_SG_DMA_LENGTH
212 def_bool y
213
214 config GENERIC_ISA_DMA
215 def_bool y
216 depends on ISA_DMA_API
217
218 config GENERIC_BUG
219 def_bool y
220 depends on BUG
221 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
222
223 config GENERIC_BUG_RELATIVE_POINTERS
224 bool
225
226 config GENERIC_HWEIGHT
227 def_bool y
228
229 config ARCH_MAY_HAVE_PC_FDC
230 def_bool y
231 depends on ISA_DMA_API
232
233 config RWSEM_XCHGADD_ALGORITHM
234 def_bool y
235
236 config GENERIC_CALIBRATE_DELAY
237 def_bool y
238
239 config ARCH_HAS_CPU_RELAX
240 def_bool y
241
242 config ARCH_HAS_CACHE_LINE_SIZE
243 def_bool y
244
245 config HAVE_SETUP_PER_CPU_AREA
246 def_bool y
247
248 config NEED_PER_CPU_EMBED_FIRST_CHUNK
249 def_bool y
250
251 config NEED_PER_CPU_PAGE_FIRST_CHUNK
252 def_bool y
253
254 config ARCH_HIBERNATION_POSSIBLE
255 def_bool y
256
257 config ARCH_SUSPEND_POSSIBLE
258 def_bool y
259
260 config ARCH_WANT_HUGE_PMD_SHARE
261 def_bool y
262
263 config ARCH_WANT_GENERAL_HUGETLB
264 def_bool y
265
266 config ZONE_DMA32
267 def_bool y if X86_64
268
269 config AUDIT_ARCH
270 def_bool y if X86_64
271
272 config ARCH_SUPPORTS_OPTIMIZED_INLINING
273 def_bool y
274
275 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
276 def_bool y
277
278 config KASAN_SHADOW_OFFSET
279 hex
280 depends on KASAN
281 default 0xdffffc0000000000
282
283 config HAVE_INTEL_TXT
284 def_bool y
285 depends on INTEL_IOMMU && ACPI
286
287 config X86_32_SMP
288 def_bool y
289 depends on X86_32 && SMP
290
291 config X86_64_SMP
292 def_bool y
293 depends on X86_64 && SMP
294
295 config X86_32_LAZY_GS
296 def_bool y
297 depends on X86_32 && !CC_STACKPROTECTOR
298
299 config ARCH_HWEIGHT_CFLAGS
300 string
301 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
302 default "-fcall-saved-rdi -fcall-saved-rsi -fcall-saved-rdx -fcall-saved-rcx -fcall-saved-r8 -fcall-saved-r9 -fcall-saved-r10 -fcall-saved-r11" if X86_64
303
304 config ARCH_SUPPORTS_UPROBES
305 def_bool y
306
307 config FIX_EARLYCON_MEM
308 def_bool y
309
310 config DEBUG_RODATA
311 def_bool y
312
313 config PGTABLE_LEVELS
314 int
315 default 4 if X86_64
316 default 3 if X86_PAE
317 default 2
318
319 source "init/Kconfig"
320 source "kernel/Kconfig.freezer"
321
322 menu "Processor type and features"
323
324 config ZONE_DMA
325 bool "DMA memory allocation support" if EXPERT
326 default y
327 help
328 DMA memory allocation support allows devices with less than 32-bit
329 addressing to allocate within the first 16MB of address space.
330 Disable if no such devices will be used.
331
332 If unsure, say Y.
333
334 config SMP
335 bool "Symmetric multi-processing support"
336 ---help---
337 This enables support for systems with more than one CPU. If you have
338 a system with only one CPU, say N. If you have a system with more
339 than one CPU, say Y.
340
341 If you say N here, the kernel will run on uni- and multiprocessor
342 machines, but will use only one CPU of a multiprocessor machine. If
343 you say Y here, the kernel will run on many, but not all,
344 uniprocessor machines. On a uniprocessor machine, the kernel
345 will run faster if you say N here.
346
347 Note that if you say Y here and choose architecture "586" or
348 "Pentium" under "Processor family", the kernel will not work on 486
349 architectures. Similarly, multiprocessor kernels for the "PPro"
350 architecture may not work on all Pentium based boards.
351
352 People using multiprocessor machines who say Y here should also say
353 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
354 Management" code will be disabled if you say Y here.
355
356 See also <file:Documentation/x86/i386/IO-APIC.txt>,
357 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
358 <http://www.tldp.org/docs.html#howto>.
359
360 If you don't know what to do here, say N.
361
362 config X86_FEATURE_NAMES
363 bool "Processor feature human-readable names" if EMBEDDED
364 default y
365 ---help---
366 This option compiles in a table of x86 feature bits and corresponding
367 names. This is required to support /proc/cpuinfo and a few kernel
368 messages. You can disable this to save space, at the expense of
369 making those few kernel messages show numeric feature bits instead.
370
371 If in doubt, say Y.
372
373 config X86_FAST_FEATURE_TESTS
374 bool "Fast CPU feature tests" if EMBEDDED
375 default y
376 ---help---
377 Some fast-paths in the kernel depend on the capabilities of the CPU.
378 Say Y here for the kernel to patch in the appropriate code at runtime
379 based on the capabilities of the CPU. The infrastructure for patching
380 code at runtime takes up some additional space; space-constrained
381 embedded systems may wish to say N here to produce smaller, slightly
382 slower code.
383
384 config X86_X2APIC
385 bool "Support x2apic"
386 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
387 ---help---
388 This enables x2apic support on CPUs that have this feature.
389
390 This allows 32-bit apic IDs (so it can support very large systems),
391 and accesses the local apic via MSRs not via mmio.
392
393 If you don't know what to do here, say N.
394
395 config X86_MPPARSE
396 bool "Enable MPS table" if ACPI || SFI
397 default y
398 depends on X86_LOCAL_APIC
399 ---help---
400 For old smp systems that do not have proper acpi support. Newer systems
401 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
402
403 config X86_BIGSMP
404 bool "Support for big SMP systems with more than 8 CPUs"
405 depends on X86_32 && SMP
406 ---help---
407 This option is needed for the systems that have more than 8 CPUs
408
409 config GOLDFISH
410 def_bool y
411 depends on X86_GOLDFISH
412
413 if X86_32
414 config X86_EXTENDED_PLATFORM
415 bool "Support for extended (non-PC) x86 platforms"
416 default y
417 ---help---
418 If you disable this option then the kernel will only support
419 standard PC platforms. (which covers the vast majority of
420 systems out there.)
421
422 If you enable this option then you'll be able to select support
423 for the following (non-PC) 32 bit x86 platforms:
424 Goldfish (Android emulator)
425 AMD Elan
426 RDC R-321x SoC
427 SGI 320/540 (Visual Workstation)
428 STA2X11-based (e.g. Northville)
429 Moorestown MID devices
430
431 If you have one of these systems, or if you want to build a
432 generic distribution kernel, say Y here - otherwise say N.
433 endif
434
435 if X86_64
436 config X86_EXTENDED_PLATFORM
437 bool "Support for extended (non-PC) x86 platforms"
438 default y
439 ---help---
440 If you disable this option then the kernel will only support
441 standard PC platforms. (which covers the vast majority of
442 systems out there.)
443
444 If you enable this option then you'll be able to select support
445 for the following (non-PC) 64 bit x86 platforms:
446 Numascale NumaChip
447 ScaleMP vSMP
448 SGI Ultraviolet
449
450 If you have one of these systems, or if you want to build a
451 generic distribution kernel, say Y here - otherwise say N.
452 endif
453 # This is an alphabetically sorted list of 64 bit extended platforms
454 # Please maintain the alphabetic order if and when there are additions
455 config X86_NUMACHIP
456 bool "Numascale NumaChip"
457 depends on X86_64
458 depends on X86_EXTENDED_PLATFORM
459 depends on NUMA
460 depends on SMP
461 depends on X86_X2APIC
462 depends on PCI_MMCONFIG
463 ---help---
464 Adds support for Numascale NumaChip large-SMP systems. Needed to
465 enable more than ~168 cores.
466 If you don't have one of these, you should say N here.
467
468 config X86_VSMP
469 bool "ScaleMP vSMP"
470 select HYPERVISOR_GUEST
471 select PARAVIRT
472 depends on X86_64 && PCI
473 depends on X86_EXTENDED_PLATFORM
474 depends on SMP
475 ---help---
476 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
477 supposed to run on these EM64T-based machines. Only choose this option
478 if you have one of these machines.
479
480 config X86_UV
481 bool "SGI Ultraviolet"
482 depends on X86_64
483 depends on X86_EXTENDED_PLATFORM
484 depends on NUMA
485 depends on EFI
486 depends on X86_X2APIC
487 depends on PCI
488 ---help---
489 This option is needed in order to support SGI Ultraviolet systems.
490 If you don't have one of these, you should say N here.
491
492 # Following is an alphabetically sorted list of 32 bit extended platforms
493 # Please maintain the alphabetic order if and when there are additions
494
495 config X86_GOLDFISH
496 bool "Goldfish (Virtual Platform)"
497 depends on X86_EXTENDED_PLATFORM
498 ---help---
499 Enable support for the Goldfish virtual platform used primarily
500 for Android development. Unless you are building for the Android
501 Goldfish emulator say N here.
502
503 config X86_INTEL_CE
504 bool "CE4100 TV platform"
505 depends on PCI
506 depends on PCI_GODIRECT
507 depends on X86_IO_APIC
508 depends on X86_32
509 depends on X86_EXTENDED_PLATFORM
510 select X86_REBOOTFIXUPS
511 select OF
512 select OF_EARLY_FLATTREE
513 ---help---
514 Select for the Intel CE media processor (CE4100) SOC.
515 This option compiles in support for the CE4100 SOC for settop
516 boxes and media devices.
517
518 config X86_INTEL_MID
519 bool "Intel MID platform support"
520 depends on X86_EXTENDED_PLATFORM
521 depends on X86_PLATFORM_DEVICES
522 depends on PCI
523 depends on X86_64 || (PCI_GOANY && X86_32)
524 depends on X86_IO_APIC
525 select SFI
526 select I2C
527 select DW_APB_TIMER
528 select APB_TIMER
529 select INTEL_SCU_IPC
530 select MFD_INTEL_MSIC
531 ---help---
532 Select to build a kernel capable of supporting Intel MID (Mobile
533 Internet Device) platform systems which do not have the PCI legacy
534 interfaces. If you are building for a PC class system say N here.
535
536 Intel MID platforms are based on an Intel processor and chipset which
537 consume less power than most of the x86 derivatives.
538
539 config X86_INTEL_QUARK
540 bool "Intel Quark platform support"
541 depends on X86_32
542 depends on X86_EXTENDED_PLATFORM
543 depends on X86_PLATFORM_DEVICES
544 depends on X86_TSC
545 depends on PCI
546 depends on PCI_GOANY
547 depends on X86_IO_APIC
548 select IOSF_MBI
549 select INTEL_IMR
550 select COMMON_CLK
551 ---help---
552 Select to include support for Quark X1000 SoC.
553 Say Y here if you have a Quark based system such as the Arduino
554 compatible Intel Galileo.
555
556 config X86_INTEL_LPSS
557 bool "Intel Low Power Subsystem Support"
558 depends on X86 && ACPI
559 select COMMON_CLK
560 select PINCTRL
561 select IOSF_MBI
562 ---help---
563 Select to build support for Intel Low Power Subsystem such as
564 found on Intel Lynxpoint PCH. Selecting this option enables
565 things like clock tree (common clock framework) and pincontrol
566 which are needed by the LPSS peripheral drivers.
567
568 config X86_AMD_PLATFORM_DEVICE
569 bool "AMD ACPI2Platform devices support"
570 depends on ACPI
571 select COMMON_CLK
572 select PINCTRL
573 ---help---
574 Select to interpret AMD specific ACPI device to platform device
575 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
576 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
577 implemented under PINCTRL subsystem.
578
579 config IOSF_MBI
580 tristate "Intel SoC IOSF Sideband support for SoC platforms"
581 depends on PCI
582 ---help---
583 This option enables sideband register access support for Intel SoC
584 platforms. On these platforms the IOSF sideband is used in lieu of
585 MSR's for some register accesses, mostly but not limited to thermal
586 and power. Drivers may query the availability of this device to
587 determine if they need the sideband in order to work on these
588 platforms. The sideband is available on the following SoC products.
589 This list is not meant to be exclusive.
590 - BayTrail
591 - Braswell
592 - Quark
593
594 You should say Y if you are running a kernel on one of these SoC's.
595
596 config IOSF_MBI_DEBUG
597 bool "Enable IOSF sideband access through debugfs"
598 depends on IOSF_MBI && DEBUG_FS
599 ---help---
600 Select this option to expose the IOSF sideband access registers (MCR,
601 MDR, MCRX) through debugfs to write and read register information from
602 different units on the SoC. This is most useful for obtaining device
603 state information for debug and analysis. As this is a general access
604 mechanism, users of this option would have specific knowledge of the
605 device they want to access.
606
607 If you don't require the option or are in doubt, say N.
608
609 config X86_RDC321X
610 bool "RDC R-321x SoC"
611 depends on X86_32
612 depends on X86_EXTENDED_PLATFORM
613 select M486
614 select X86_REBOOTFIXUPS
615 ---help---
616 This option is needed for RDC R-321x system-on-chip, also known
617 as R-8610-(G).
618 If you don't have one of these chips, you should say N here.
619
620 config X86_32_NON_STANDARD
621 bool "Support non-standard 32-bit SMP architectures"
622 depends on X86_32 && SMP
623 depends on X86_EXTENDED_PLATFORM
624 ---help---
625 This option compiles in the bigsmp and STA2X11 default
626 subarchitectures. It is intended for a generic binary
627 kernel. If you select them all, kernel will probe it one by
628 one and will fallback to default.
629
630 # Alphabetically sorted list of Non standard 32 bit platforms
631
632 config X86_SUPPORTS_MEMORY_FAILURE
633 def_bool y
634 # MCE code calls memory_failure():
635 depends on X86_MCE
636 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
637 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
638 depends on X86_64 || !SPARSEMEM
639 select ARCH_SUPPORTS_MEMORY_FAILURE
640
641 config STA2X11
642 bool "STA2X11 Companion Chip Support"
643 depends on X86_32_NON_STANDARD && PCI
644 select X86_DEV_DMA_OPS
645 select X86_DMA_REMAP
646 select SWIOTLB
647 select MFD_STA2X11
648 select ARCH_REQUIRE_GPIOLIB
649 default n
650 ---help---
651 This adds support for boards based on the STA2X11 IO-Hub,
652 a.k.a. "ConneXt". The chip is used in place of the standard
653 PC chipset, so all "standard" peripherals are missing. If this
654 option is selected the kernel will still be able to boot on
655 standard PC machines.
656
657 config X86_32_IRIS
658 tristate "Eurobraille/Iris poweroff module"
659 depends on X86_32
660 ---help---
661 The Iris machines from EuroBraille do not have APM or ACPI support
662 to shut themselves down properly. A special I/O sequence is
663 needed to do so, which is what this module does at
664 kernel shutdown.
665
666 This is only for Iris machines from EuroBraille.
667
668 If unused, say N.
669
670 config SCHED_OMIT_FRAME_POINTER
671 def_bool y
672 prompt "Single-depth WCHAN output"
673 depends on X86
674 ---help---
675 Calculate simpler /proc/<PID>/wchan values. If this option
676 is disabled then wchan values will recurse back to the
677 caller function. This provides more accurate wchan values,
678 at the expense of slightly more scheduling overhead.
679
680 If in doubt, say "Y".
681
682 menuconfig HYPERVISOR_GUEST
683 bool "Linux guest support"
684 ---help---
685 Say Y here to enable options for running Linux under various hyper-
686 visors. This option enables basic hypervisor detection and platform
687 setup.
688
689 If you say N, all options in this submenu will be skipped and
690 disabled, and Linux guest support won't be built in.
691
692 if HYPERVISOR_GUEST
693
694 config PARAVIRT
695 bool "Enable paravirtualization code"
696 ---help---
697 This changes the kernel so it can modify itself when it is run
698 under a hypervisor, potentially improving performance significantly
699 over full virtualization. However, when run without a hypervisor
700 the kernel is theoretically slower and slightly larger.
701
702 config PARAVIRT_DEBUG
703 bool "paravirt-ops debugging"
704 depends on PARAVIRT && DEBUG_KERNEL
705 ---help---
706 Enable to debug paravirt_ops internals. Specifically, BUG if
707 a paravirt_op is missing when it is called.
708
709 config PARAVIRT_SPINLOCKS
710 bool "Paravirtualization layer for spinlocks"
711 depends on PARAVIRT && SMP
712 select UNINLINE_SPIN_UNLOCK if !QUEUED_SPINLOCKS
713 ---help---
714 Paravirtualized spinlocks allow a pvops backend to replace the
715 spinlock implementation with something virtualization-friendly
716 (for example, block the virtual CPU rather than spinning).
717
718 It has a minimal impact on native kernels and gives a nice performance
719 benefit on paravirtualized KVM / Xen kernels.
720
721 If you are unsure how to answer this question, answer Y.
722
723 config QUEUED_LOCK_STAT
724 bool "Paravirt queued spinlock statistics"
725 depends on PARAVIRT_SPINLOCKS && DEBUG_FS && QUEUED_SPINLOCKS
726 ---help---
727 Enable the collection of statistical data on the slowpath
728 behavior of paravirtualized queued spinlocks and report
729 them on debugfs.
730
731 source "arch/x86/xen/Kconfig"
732
733 config KVM_GUEST
734 bool "KVM Guest support (including kvmclock)"
735 depends on PARAVIRT
736 select PARAVIRT_CLOCK
737 default y
738 ---help---
739 This option enables various optimizations for running under the KVM
740 hypervisor. It includes a paravirtualized clock, so that instead
741 of relying on a PIT (or probably other) emulation by the
742 underlying device model, the host provides the guest with
743 timing infrastructure such as time of day, and system time
744
745 config KVM_DEBUG_FS
746 bool "Enable debug information for KVM Guests in debugfs"
747 depends on KVM_GUEST && DEBUG_FS
748 default n
749 ---help---
750 This option enables collection of various statistics for KVM guest.
751 Statistics are displayed in debugfs filesystem. Enabling this option
752 may incur significant overhead.
753
754 source "arch/x86/lguest/Kconfig"
755
756 config PARAVIRT_TIME_ACCOUNTING
757 bool "Paravirtual steal time accounting"
758 depends on PARAVIRT
759 default n
760 ---help---
761 Select this option to enable fine granularity task steal time
762 accounting. Time spent executing other tasks in parallel with
763 the current vCPU is discounted from the vCPU power. To account for
764 that, there can be a small performance impact.
765
766 If in doubt, say N here.
767
768 config PARAVIRT_CLOCK
769 bool
770
771 endif #HYPERVISOR_GUEST
772
773 config NO_BOOTMEM
774 def_bool y
775
776 source "arch/x86/Kconfig.cpu"
777
778 config HPET_TIMER
779 def_bool X86_64
780 prompt "HPET Timer Support" if X86_32
781 ---help---
782 Use the IA-PC HPET (High Precision Event Timer) to manage
783 time in preference to the PIT and RTC, if a HPET is
784 present.
785 HPET is the next generation timer replacing legacy 8254s.
786 The HPET provides a stable time base on SMP
787 systems, unlike the TSC, but it is more expensive to access,
788 as it is off-chip. The interface used is documented
789 in the HPET spec, revision 1.
790
791 You can safely choose Y here. However, HPET will only be
792 activated if the platform and the BIOS support this feature.
793 Otherwise the 8254 will be used for timing services.
794
795 Choose N to continue using the legacy 8254 timer.
796
797 config HPET_EMULATE_RTC
798 def_bool y
799 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
800
801 config APB_TIMER
802 def_bool y if X86_INTEL_MID
803 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
804 select DW_APB_TIMER
805 depends on X86_INTEL_MID && SFI
806 help
807 APB timer is the replacement for 8254, HPET on X86 MID platforms.
808 The APBT provides a stable time base on SMP
809 systems, unlike the TSC, but it is more expensive to access,
810 as it is off-chip. APB timers are always running regardless of CPU
811 C states, they are used as per CPU clockevent device when possible.
812
813 # Mark as expert because too many people got it wrong.
814 # The code disables itself when not needed.
815 config DMI
816 default y
817 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
818 bool "Enable DMI scanning" if EXPERT
819 ---help---
820 Enabled scanning of DMI to identify machine quirks. Say Y
821 here unless you have verified that your setup is not
822 affected by entries in the DMI blacklist. Required by PNP
823 BIOS code.
824
825 config GART_IOMMU
826 bool "Old AMD GART IOMMU support"
827 select SWIOTLB
828 depends on X86_64 && PCI && AMD_NB
829 ---help---
830 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
831 GART based hardware IOMMUs.
832
833 The GART supports full DMA access for devices with 32-bit access
834 limitations, on systems with more than 3 GB. This is usually needed
835 for USB, sound, many IDE/SATA chipsets and some other devices.
836
837 Newer systems typically have a modern AMD IOMMU, supported via
838 the CONFIG_AMD_IOMMU=y config option.
839
840 In normal configurations this driver is only active when needed:
841 there's more than 3 GB of memory and the system contains a
842 32-bit limited device.
843
844 If unsure, say Y.
845
846 config CALGARY_IOMMU
847 bool "IBM Calgary IOMMU support"
848 select SWIOTLB
849 depends on X86_64 && PCI
850 ---help---
851 Support for hardware IOMMUs in IBM's xSeries x366 and x460
852 systems. Needed to run systems with more than 3GB of memory
853 properly with 32-bit PCI devices that do not support DAC
854 (Double Address Cycle). Calgary also supports bus level
855 isolation, where all DMAs pass through the IOMMU. This
856 prevents them from going anywhere except their intended
857 destination. This catches hard-to-find kernel bugs and
858 mis-behaving drivers and devices that do not use the DMA-API
859 properly to set up their DMA buffers. The IOMMU can be
860 turned off at boot time with the iommu=off parameter.
861 Normally the kernel will make the right choice by itself.
862 If unsure, say Y.
863
864 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
865 def_bool y
866 prompt "Should Calgary be enabled by default?"
867 depends on CALGARY_IOMMU
868 ---help---
869 Should Calgary be enabled by default? if you choose 'y', Calgary
870 will be used (if it exists). If you choose 'n', Calgary will not be
871 used even if it exists. If you choose 'n' and would like to use
872 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
873 If unsure, say Y.
874
875 # need this always selected by IOMMU for the VIA workaround
876 config SWIOTLB
877 def_bool y if X86_64
878 ---help---
879 Support for software bounce buffers used on x86-64 systems
880 which don't have a hardware IOMMU. Using this PCI devices
881 which can only access 32-bits of memory can be used on systems
882 with more than 3 GB of memory.
883 If unsure, say Y.
884
885 config IOMMU_HELPER
886 def_bool y
887 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
888
889 config MAXSMP
890 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
891 depends on X86_64 && SMP && DEBUG_KERNEL
892 select CPUMASK_OFFSTACK
893 ---help---
894 Enable maximum number of CPUS and NUMA Nodes for this architecture.
895 If unsure, say N.
896
897 config NR_CPUS
898 int "Maximum number of CPUs" if SMP && !MAXSMP
899 range 2 8 if SMP && X86_32 && !X86_BIGSMP
900 range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK
901 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
902 default "1" if !SMP
903 default "8192" if MAXSMP
904 default "32" if SMP && X86_BIGSMP
905 default "8" if SMP && X86_32
906 default "64" if SMP
907 ---help---
908 This allows you to specify the maximum number of CPUs which this
909 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
910 supported value is 8192, otherwise the maximum value is 512. The
911 minimum value which makes sense is 2.
912
913 This is purely to save memory - each supported CPU adds
914 approximately eight kilobytes to the kernel image.
915
916 config SCHED_SMT
917 bool "SMT (Hyperthreading) scheduler support"
918 depends on SMP
919 ---help---
920 SMT scheduler support improves the CPU scheduler's decision making
921 when dealing with Intel Pentium 4 chips with HyperThreading at a
922 cost of slightly increased overhead in some places. If unsure say
923 N here.
924
925 config SCHED_MC
926 def_bool y
927 prompt "Multi-core scheduler support"
928 depends on SMP
929 ---help---
930 Multi-core scheduler support improves the CPU scheduler's decision
931 making when dealing with multi-core CPU chips at a cost of slightly
932 increased overhead in some places. If unsure say N here.
933
934 source "kernel/Kconfig.preempt"
935
936 config UP_LATE_INIT
937 def_bool y
938 depends on !SMP && X86_LOCAL_APIC
939
940 config X86_UP_APIC
941 bool "Local APIC support on uniprocessors" if !PCI_MSI
942 default PCI_MSI
943 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
944 ---help---
945 A local APIC (Advanced Programmable Interrupt Controller) is an
946 integrated interrupt controller in the CPU. If you have a single-CPU
947 system which has a processor with a local APIC, you can say Y here to
948 enable and use it. If you say Y here even though your machine doesn't
949 have a local APIC, then the kernel will still run with no slowdown at
950 all. The local APIC supports CPU-generated self-interrupts (timer,
951 performance counters), and the NMI watchdog which detects hard
952 lockups.
953
954 config X86_UP_IOAPIC
955 bool "IO-APIC support on uniprocessors"
956 depends on X86_UP_APIC
957 ---help---
958 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
959 SMP-capable replacement for PC-style interrupt controllers. Most
960 SMP systems and many recent uniprocessor systems have one.
961
962 If you have a single-CPU system with an IO-APIC, you can say Y here
963 to use it. If you say Y here even though your machine doesn't have
964 an IO-APIC, then the kernel will still run with no slowdown at all.
965
966 config X86_LOCAL_APIC
967 def_bool y
968 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
969 select IRQ_DOMAIN_HIERARCHY
970 select PCI_MSI_IRQ_DOMAIN if PCI_MSI
971
972 config X86_IO_APIC
973 def_bool y
974 depends on X86_LOCAL_APIC || X86_UP_IOAPIC
975
976 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
977 bool "Reroute for broken boot IRQs"
978 depends on X86_IO_APIC
979 ---help---
980 This option enables a workaround that fixes a source of
981 spurious interrupts. This is recommended when threaded
982 interrupt handling is used on systems where the generation of
983 superfluous "boot interrupts" cannot be disabled.
984
985 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
986 entry in the chipset's IO-APIC is masked (as, e.g. the RT
987 kernel does during interrupt handling). On chipsets where this
988 boot IRQ generation cannot be disabled, this workaround keeps
989 the original IRQ line masked so that only the equivalent "boot
990 IRQ" is delivered to the CPUs. The workaround also tells the
991 kernel to set up the IRQ handler on the boot IRQ line. In this
992 way only one interrupt is delivered to the kernel. Otherwise
993 the spurious second interrupt may cause the kernel to bring
994 down (vital) interrupt lines.
995
996 Only affects "broken" chipsets. Interrupt sharing may be
997 increased on these systems.
998
999 config X86_MCE
1000 bool "Machine Check / overheating reporting"
1001 select GENERIC_ALLOCATOR
1002 default y
1003 ---help---
1004 Machine Check support allows the processor to notify the
1005 kernel if it detects a problem (e.g. overheating, data corruption).
1006 The action the kernel takes depends on the severity of the problem,
1007 ranging from warning messages to halting the machine.
1008
1009 config X86_MCE_INTEL
1010 def_bool y
1011 prompt "Intel MCE features"
1012 depends on X86_MCE && X86_LOCAL_APIC
1013 ---help---
1014 Additional support for intel specific MCE features such as
1015 the thermal monitor.
1016
1017 config X86_MCE_AMD
1018 def_bool y
1019 prompt "AMD MCE features"
1020 depends on X86_MCE && X86_LOCAL_APIC
1021 ---help---
1022 Additional support for AMD specific MCE features such as
1023 the DRAM Error Threshold.
1024
1025 config X86_ANCIENT_MCE
1026 bool "Support for old Pentium 5 / WinChip machine checks"
1027 depends on X86_32 && X86_MCE
1028 ---help---
1029 Include support for machine check handling on old Pentium 5 or WinChip
1030 systems. These typically need to be enabled explicitly on the command
1031 line.
1032
1033 config X86_MCE_THRESHOLD
1034 depends on X86_MCE_AMD || X86_MCE_INTEL
1035 def_bool y
1036
1037 config X86_MCE_INJECT
1038 depends on X86_MCE
1039 tristate "Machine check injector support"
1040 ---help---
1041 Provide support for injecting machine checks for testing purposes.
1042 If you don't know what a machine check is and you don't do kernel
1043 QA it is safe to say n.
1044
1045 config X86_THERMAL_VECTOR
1046 def_bool y
1047 depends on X86_MCE_INTEL
1048
1049 config X86_LEGACY_VM86
1050 bool "Legacy VM86 support"
1051 default n
1052 depends on X86_32
1053 ---help---
1054 This option allows user programs to put the CPU into V8086
1055 mode, which is an 80286-era approximation of 16-bit real mode.
1056
1057 Some very old versions of X and/or vbetool require this option
1058 for user mode setting. Similarly, DOSEMU will use it if
1059 available to accelerate real mode DOS programs. However, any
1060 recent version of DOSEMU, X, or vbetool should be fully
1061 functional even without kernel VM86 support, as they will all
1062 fall back to software emulation. Nevertheless, if you are using
1063 a 16-bit DOS program where 16-bit performance matters, vm86
1064 mode might be faster than emulation and you might want to
1065 enable this option.
1066
1067 Note that any app that works on a 64-bit kernel is unlikely to
1068 need this option, as 64-bit kernels don't, and can't, support
1069 V8086 mode. This option is also unrelated to 16-bit protected
1070 mode and is not needed to run most 16-bit programs under Wine.
1071
1072 Enabling this option increases the complexity of the kernel
1073 and slows down exception handling a tiny bit.
1074
1075 If unsure, say N here.
1076
1077 config VM86
1078 bool
1079 default X86_LEGACY_VM86
1080
1081 config X86_16BIT
1082 bool "Enable support for 16-bit segments" if EXPERT
1083 default y
1084 depends on MODIFY_LDT_SYSCALL
1085 ---help---
1086 This option is required by programs like Wine to run 16-bit
1087 protected mode legacy code on x86 processors. Disabling
1088 this option saves about 300 bytes on i386, or around 6K text
1089 plus 16K runtime memory on x86-64,
1090
1091 config X86_ESPFIX32
1092 def_bool y
1093 depends on X86_16BIT && X86_32
1094
1095 config X86_ESPFIX64
1096 def_bool y
1097 depends on X86_16BIT && X86_64
1098
1099 config X86_VSYSCALL_EMULATION
1100 bool "Enable vsyscall emulation" if EXPERT
1101 default y
1102 depends on X86_64
1103 ---help---
1104 This enables emulation of the legacy vsyscall page. Disabling
1105 it is roughly equivalent to booting with vsyscall=none, except
1106 that it will also disable the helpful warning if a program
1107 tries to use a vsyscall. With this option set to N, offending
1108 programs will just segfault, citing addresses of the form
1109 0xffffffffff600?00.
1110
1111 This option is required by many programs built before 2013, and
1112 care should be used even with newer programs if set to N.
1113
1114 Disabling this option saves about 7K of kernel size and
1115 possibly 4K of additional runtime pagetable memory.
1116
1117 config TOSHIBA
1118 tristate "Toshiba Laptop support"
1119 depends on X86_32
1120 ---help---
1121 This adds a driver to safely access the System Management Mode of
1122 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1123 not work on models with a Phoenix BIOS. The System Management Mode
1124 is used to set the BIOS and power saving options on Toshiba portables.
1125
1126 For information on utilities to make use of this driver see the
1127 Toshiba Linux utilities web site at:
1128 <http://www.buzzard.org.uk/toshiba/>.
1129
1130 Say Y if you intend to run this kernel on a Toshiba portable.
1131 Say N otherwise.
1132
1133 config I8K
1134 tristate "Dell i8k legacy laptop support"
1135 select HWMON
1136 select SENSORS_DELL_SMM
1137 ---help---
1138 This option enables legacy /proc/i8k userspace interface in hwmon
1139 dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1140 temperature and allows controlling fan speeds of Dell laptops via
1141 System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1142 it reports also power and hotkey status. For fan speed control is
1143 needed userspace package i8kutils.
1144
1145 Say Y if you intend to run this kernel on old Dell laptops or want to
1146 use userspace package i8kutils.
1147 Say N otherwise.
1148
1149 config X86_REBOOTFIXUPS
1150 bool "Enable X86 board specific fixups for reboot"
1151 depends on X86_32
1152 ---help---
1153 This enables chipset and/or board specific fixups to be done
1154 in order to get reboot to work correctly. This is only needed on
1155 some combinations of hardware and BIOS. The symptom, for which
1156 this config is intended, is when reboot ends with a stalled/hung
1157 system.
1158
1159 Currently, the only fixup is for the Geode machines using
1160 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1161
1162 Say Y if you want to enable the fixup. Currently, it's safe to
1163 enable this option even if you don't need it.
1164 Say N otherwise.
1165
1166 config MICROCODE
1167 bool "CPU microcode loading support"
1168 default y
1169 depends on CPU_SUP_AMD || CPU_SUP_INTEL
1170 select FW_LOADER
1171 ---help---
1172 If you say Y here, you will be able to update the microcode on
1173 Intel and AMD processors. The Intel support is for the IA32 family,
1174 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
1175 AMD support is for families 0x10 and later. You will obviously need
1176 the actual microcode binary data itself which is not shipped with
1177 the Linux kernel.
1178
1179 The preferred method to load microcode from a detached initrd is described
1180 in Documentation/x86/early-microcode.txt. For that you need to enable
1181 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
1182 initrd for microcode blobs.
1183
1184 In addition, you can build-in the microcode into the kernel. For that you
1185 need to enable FIRMWARE_IN_KERNEL and add the vendor-supplied microcode
1186 to the CONFIG_EXTRA_FIRMWARE config option.
1187
1188 config MICROCODE_INTEL
1189 bool "Intel microcode loading support"
1190 depends on MICROCODE
1191 default MICROCODE
1192 select FW_LOADER
1193 ---help---
1194 This options enables microcode patch loading support for Intel
1195 processors.
1196
1197 For the current Intel microcode data package go to
1198 <https://downloadcenter.intel.com> and search for
1199 'Linux Processor Microcode Data File'.
1200
1201 config MICROCODE_AMD
1202 bool "AMD microcode loading support"
1203 depends on MICROCODE
1204 select FW_LOADER
1205 ---help---
1206 If you select this option, microcode patch loading support for AMD
1207 processors will be enabled.
1208
1209 config MICROCODE_OLD_INTERFACE
1210 def_bool y
1211 depends on MICROCODE
1212
1213 config X86_MSR
1214 tristate "/dev/cpu/*/msr - Model-specific register support"
1215 ---help---
1216 This device gives privileged processes access to the x86
1217 Model-Specific Registers (MSRs). It is a character device with
1218 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1219 MSR accesses are directed to a specific CPU on multi-processor
1220 systems.
1221
1222 config X86_CPUID
1223 tristate "/dev/cpu/*/cpuid - CPU information support"
1224 ---help---
1225 This device gives processes access to the x86 CPUID instruction to
1226 be executed on a specific processor. It is a character device
1227 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1228 /dev/cpu/31/cpuid.
1229
1230 choice
1231 prompt "High Memory Support"
1232 default HIGHMEM4G
1233 depends on X86_32
1234
1235 config NOHIGHMEM
1236 bool "off"
1237 ---help---
1238 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1239 However, the address space of 32-bit x86 processors is only 4
1240 Gigabytes large. That means that, if you have a large amount of
1241 physical memory, not all of it can be "permanently mapped" by the
1242 kernel. The physical memory that's not permanently mapped is called
1243 "high memory".
1244
1245 If you are compiling a kernel which will never run on a machine with
1246 more than 1 Gigabyte total physical RAM, answer "off" here (default
1247 choice and suitable for most users). This will result in a "3GB/1GB"
1248 split: 3GB are mapped so that each process sees a 3GB virtual memory
1249 space and the remaining part of the 4GB virtual memory space is used
1250 by the kernel to permanently map as much physical memory as
1251 possible.
1252
1253 If the machine has between 1 and 4 Gigabytes physical RAM, then
1254 answer "4GB" here.
1255
1256 If more than 4 Gigabytes is used then answer "64GB" here. This
1257 selection turns Intel PAE (Physical Address Extension) mode on.
1258 PAE implements 3-level paging on IA32 processors. PAE is fully
1259 supported by Linux, PAE mode is implemented on all recent Intel
1260 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1261 then the kernel will not boot on CPUs that don't support PAE!
1262
1263 The actual amount of total physical memory will either be
1264 auto detected or can be forced by using a kernel command line option
1265 such as "mem=256M". (Try "man bootparam" or see the documentation of
1266 your boot loader (lilo or loadlin) about how to pass options to the
1267 kernel at boot time.)
1268
1269 If unsure, say "off".
1270
1271 config HIGHMEM4G
1272 bool "4GB"
1273 ---help---
1274 Select this if you have a 32-bit processor and between 1 and 4
1275 gigabytes of physical RAM.
1276
1277 config HIGHMEM64G
1278 bool "64GB"
1279 depends on !M486
1280 select X86_PAE
1281 ---help---
1282 Select this if you have a 32-bit processor and more than 4
1283 gigabytes of physical RAM.
1284
1285 endchoice
1286
1287 choice
1288 prompt "Memory split" if EXPERT
1289 default VMSPLIT_3G
1290 depends on X86_32
1291 ---help---
1292 Select the desired split between kernel and user memory.
1293
1294 If the address range available to the kernel is less than the
1295 physical memory installed, the remaining memory will be available
1296 as "high memory". Accessing high memory is a little more costly
1297 than low memory, as it needs to be mapped into the kernel first.
1298 Note that increasing the kernel address space limits the range
1299 available to user programs, making the address space there
1300 tighter. Selecting anything other than the default 3G/1G split
1301 will also likely make your kernel incompatible with binary-only
1302 kernel modules.
1303
1304 If you are not absolutely sure what you are doing, leave this
1305 option alone!
1306
1307 config VMSPLIT_3G
1308 bool "3G/1G user/kernel split"
1309 config VMSPLIT_3G_OPT
1310 depends on !X86_PAE
1311 bool "3G/1G user/kernel split (for full 1G low memory)"
1312 config VMSPLIT_2G
1313 bool "2G/2G user/kernel split"
1314 config VMSPLIT_2G_OPT
1315 depends on !X86_PAE
1316 bool "2G/2G user/kernel split (for full 2G low memory)"
1317 config VMSPLIT_1G
1318 bool "1G/3G user/kernel split"
1319 endchoice
1320
1321 config PAGE_OFFSET
1322 hex
1323 default 0xB0000000 if VMSPLIT_3G_OPT
1324 default 0x80000000 if VMSPLIT_2G
1325 default 0x78000000 if VMSPLIT_2G_OPT
1326 default 0x40000000 if VMSPLIT_1G
1327 default 0xC0000000
1328 depends on X86_32
1329
1330 config HIGHMEM
1331 def_bool y
1332 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1333
1334 config X86_PAE
1335 bool "PAE (Physical Address Extension) Support"
1336 depends on X86_32 && !HIGHMEM4G
1337 select SWIOTLB
1338 ---help---
1339 PAE is required for NX support, and furthermore enables
1340 larger swapspace support for non-overcommit purposes. It
1341 has the cost of more pagetable lookup overhead, and also
1342 consumes more pagetable space per process.
1343
1344 config ARCH_PHYS_ADDR_T_64BIT
1345 def_bool y
1346 depends on X86_64 || X86_PAE
1347
1348 config ARCH_DMA_ADDR_T_64BIT
1349 def_bool y
1350 depends on X86_64 || HIGHMEM64G
1351
1352 config X86_DIRECT_GBPAGES
1353 def_bool y
1354 depends on X86_64 && !DEBUG_PAGEALLOC && !KMEMCHECK
1355 ---help---
1356 Certain kernel features effectively disable kernel
1357 linear 1 GB mappings (even if the CPU otherwise
1358 supports them), so don't confuse the user by printing
1359 that we have them enabled.
1360
1361 # Common NUMA Features
1362 config NUMA
1363 bool "Numa Memory Allocation and Scheduler Support"
1364 depends on SMP
1365 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1366 default y if X86_BIGSMP
1367 ---help---
1368 Enable NUMA (Non Uniform Memory Access) support.
1369
1370 The kernel will try to allocate memory used by a CPU on the
1371 local memory controller of the CPU and add some more
1372 NUMA awareness to the kernel.
1373
1374 For 64-bit this is recommended if the system is Intel Core i7
1375 (or later), AMD Opteron, or EM64T NUMA.
1376
1377 For 32-bit this is only needed if you boot a 32-bit
1378 kernel on a 64-bit NUMA platform.
1379
1380 Otherwise, you should say N.
1381
1382 config AMD_NUMA
1383 def_bool y
1384 prompt "Old style AMD Opteron NUMA detection"
1385 depends on X86_64 && NUMA && PCI
1386 ---help---
1387 Enable AMD NUMA node topology detection. You should say Y here if
1388 you have a multi processor AMD system. This uses an old method to
1389 read the NUMA configuration directly from the builtin Northbridge
1390 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1391 which also takes priority if both are compiled in.
1392
1393 config X86_64_ACPI_NUMA
1394 def_bool y
1395 prompt "ACPI NUMA detection"
1396 depends on X86_64 && NUMA && ACPI && PCI
1397 select ACPI_NUMA
1398 ---help---
1399 Enable ACPI SRAT based node topology detection.
1400
1401 # Some NUMA nodes have memory ranges that span
1402 # other nodes. Even though a pfn is valid and
1403 # between a node's start and end pfns, it may not
1404 # reside on that node. See memmap_init_zone()
1405 # for details.
1406 config NODES_SPAN_OTHER_NODES
1407 def_bool y
1408 depends on X86_64_ACPI_NUMA
1409
1410 config NUMA_EMU
1411 bool "NUMA emulation"
1412 depends on NUMA
1413 ---help---
1414 Enable NUMA emulation. A flat machine will be split
1415 into virtual nodes when booted with "numa=fake=N", where N is the
1416 number of nodes. This is only useful for debugging.
1417
1418 config NODES_SHIFT
1419 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1420 range 1 10
1421 default "10" if MAXSMP
1422 default "6" if X86_64
1423 default "3"
1424 depends on NEED_MULTIPLE_NODES
1425 ---help---
1426 Specify the maximum number of NUMA Nodes available on the target
1427 system. Increases memory reserved to accommodate various tables.
1428
1429 config ARCH_HAVE_MEMORY_PRESENT
1430 def_bool y
1431 depends on X86_32 && DISCONTIGMEM
1432
1433 config NEED_NODE_MEMMAP_SIZE
1434 def_bool y
1435 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1436
1437 config ARCH_FLATMEM_ENABLE
1438 def_bool y
1439 depends on X86_32 && !NUMA
1440
1441 config ARCH_DISCONTIGMEM_ENABLE
1442 def_bool y
1443 depends on NUMA && X86_32
1444
1445 config ARCH_DISCONTIGMEM_DEFAULT
1446 def_bool y
1447 depends on NUMA && X86_32
1448
1449 config ARCH_SPARSEMEM_ENABLE
1450 def_bool y
1451 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1452 select SPARSEMEM_STATIC if X86_32
1453 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1454
1455 config ARCH_SPARSEMEM_DEFAULT
1456 def_bool y
1457 depends on X86_64
1458
1459 config ARCH_SELECT_MEMORY_MODEL
1460 def_bool y
1461 depends on ARCH_SPARSEMEM_ENABLE
1462
1463 config ARCH_MEMORY_PROBE
1464 bool "Enable sysfs memory/probe interface"
1465 depends on X86_64 && MEMORY_HOTPLUG
1466 help
1467 This option enables a sysfs memory/probe interface for testing.
1468 See Documentation/memory-hotplug.txt for more information.
1469 If you are unsure how to answer this question, answer N.
1470
1471 config ARCH_PROC_KCORE_TEXT
1472 def_bool y
1473 depends on X86_64 && PROC_KCORE
1474
1475 config ILLEGAL_POINTER_VALUE
1476 hex
1477 default 0 if X86_32
1478 default 0xdead000000000000 if X86_64
1479
1480 source "mm/Kconfig"
1481
1482 config X86_PMEM_LEGACY_DEVICE
1483 bool
1484
1485 config X86_PMEM_LEGACY
1486 tristate "Support non-standard NVDIMMs and ADR protected memory"
1487 depends on PHYS_ADDR_T_64BIT
1488 depends on BLK_DEV
1489 select X86_PMEM_LEGACY_DEVICE
1490 select LIBNVDIMM
1491 help
1492 Treat memory marked using the non-standard e820 type of 12 as used
1493 by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1494 The kernel will offer these regions to the 'pmem' driver so
1495 they can be used for persistent storage.
1496
1497 Say Y if unsure.
1498
1499 config HIGHPTE
1500 bool "Allocate 3rd-level pagetables from highmem"
1501 depends on HIGHMEM
1502 ---help---
1503 The VM uses one page table entry for each page of physical memory.
1504 For systems with a lot of RAM, this can be wasteful of precious
1505 low memory. Setting this option will put user-space page table
1506 entries in high memory.
1507
1508 config X86_CHECK_BIOS_CORRUPTION
1509 bool "Check for low memory corruption"
1510 ---help---
1511 Periodically check for memory corruption in low memory, which
1512 is suspected to be caused by BIOS. Even when enabled in the
1513 configuration, it is disabled at runtime. Enable it by
1514 setting "memory_corruption_check=1" on the kernel command
1515 line. By default it scans the low 64k of memory every 60
1516 seconds; see the memory_corruption_check_size and
1517 memory_corruption_check_period parameters in
1518 Documentation/kernel-parameters.txt to adjust this.
1519
1520 When enabled with the default parameters, this option has
1521 almost no overhead, as it reserves a relatively small amount
1522 of memory and scans it infrequently. It both detects corruption
1523 and prevents it from affecting the running system.
1524
1525 It is, however, intended as a diagnostic tool; if repeatable
1526 BIOS-originated corruption always affects the same memory,
1527 you can use memmap= to prevent the kernel from using that
1528 memory.
1529
1530 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1531 bool "Set the default setting of memory_corruption_check"
1532 depends on X86_CHECK_BIOS_CORRUPTION
1533 default y
1534 ---help---
1535 Set whether the default state of memory_corruption_check is
1536 on or off.
1537
1538 config X86_RESERVE_LOW
1539 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1540 default 64
1541 range 4 640
1542 ---help---
1543 Specify the amount of low memory to reserve for the BIOS.
1544
1545 The first page contains BIOS data structures that the kernel
1546 must not use, so that page must always be reserved.
1547
1548 By default we reserve the first 64K of physical RAM, as a
1549 number of BIOSes are known to corrupt that memory range
1550 during events such as suspend/resume or monitor cable
1551 insertion, so it must not be used by the kernel.
1552
1553 You can set this to 4 if you are absolutely sure that you
1554 trust the BIOS to get all its memory reservations and usages
1555 right. If you know your BIOS have problems beyond the
1556 default 64K area, you can set this to 640 to avoid using the
1557 entire low memory range.
1558
1559 If you have doubts about the BIOS (e.g. suspend/resume does
1560 not work or there's kernel crashes after certain hardware
1561 hotplug events) then you might want to enable
1562 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1563 typical corruption patterns.
1564
1565 Leave this to the default value of 64 if you are unsure.
1566
1567 config MATH_EMULATION
1568 bool
1569 depends on MODIFY_LDT_SYSCALL
1570 prompt "Math emulation" if X86_32
1571 ---help---
1572 Linux can emulate a math coprocessor (used for floating point
1573 operations) if you don't have one. 486DX and Pentium processors have
1574 a math coprocessor built in, 486SX and 386 do not, unless you added
1575 a 487DX or 387, respectively. (The messages during boot time can
1576 give you some hints here ["man dmesg"].) Everyone needs either a
1577 coprocessor or this emulation.
1578
1579 If you don't have a math coprocessor, you need to say Y here; if you
1580 say Y here even though you have a coprocessor, the coprocessor will
1581 be used nevertheless. (This behavior can be changed with the kernel
1582 command line option "no387", which comes handy if your coprocessor
1583 is broken. Try "man bootparam" or see the documentation of your boot
1584 loader (lilo or loadlin) about how to pass options to the kernel at
1585 boot time.) This means that it is a good idea to say Y here if you
1586 intend to use this kernel on different machines.
1587
1588 More information about the internals of the Linux math coprocessor
1589 emulation can be found in <file:arch/x86/math-emu/README>.
1590
1591 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1592 kernel, it won't hurt.
1593
1594 config MTRR
1595 def_bool y
1596 prompt "MTRR (Memory Type Range Register) support" if EXPERT
1597 ---help---
1598 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1599 the Memory Type Range Registers (MTRRs) may be used to control
1600 processor access to memory ranges. This is most useful if you have
1601 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1602 allows bus write transfers to be combined into a larger transfer
1603 before bursting over the PCI/AGP bus. This can increase performance
1604 of image write operations 2.5 times or more. Saying Y here creates a
1605 /proc/mtrr file which may be used to manipulate your processor's
1606 MTRRs. Typically the X server should use this.
1607
1608 This code has a reasonably generic interface so that similar
1609 control registers on other processors can be easily supported
1610 as well:
1611
1612 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1613 Registers (ARRs) which provide a similar functionality to MTRRs. For
1614 these, the ARRs are used to emulate the MTRRs.
1615 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1616 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1617 write-combining. All of these processors are supported by this code
1618 and it makes sense to say Y here if you have one of them.
1619
1620 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1621 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1622 can lead to all sorts of problems, so it's good to say Y here.
1623
1624 You can safely say Y even if your machine doesn't have MTRRs, you'll
1625 just add about 9 KB to your kernel.
1626
1627 See <file:Documentation/x86/mtrr.txt> for more information.
1628
1629 config MTRR_SANITIZER
1630 def_bool y
1631 prompt "MTRR cleanup support"
1632 depends on MTRR
1633 ---help---
1634 Convert MTRR layout from continuous to discrete, so X drivers can
1635 add writeback entries.
1636
1637 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1638 The largest mtrr entry size for a continuous block can be set with
1639 mtrr_chunk_size.
1640
1641 If unsure, say Y.
1642
1643 config MTRR_SANITIZER_ENABLE_DEFAULT
1644 int "MTRR cleanup enable value (0-1)"
1645 range 0 1
1646 default "0"
1647 depends on MTRR_SANITIZER
1648 ---help---
1649 Enable mtrr cleanup default value
1650
1651 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1652 int "MTRR cleanup spare reg num (0-7)"
1653 range 0 7
1654 default "1"
1655 depends on MTRR_SANITIZER
1656 ---help---
1657 mtrr cleanup spare entries default, it can be changed via
1658 mtrr_spare_reg_nr=N on the kernel command line.
1659
1660 config X86_PAT
1661 def_bool y
1662 prompt "x86 PAT support" if EXPERT
1663 depends on MTRR
1664 ---help---
1665 Use PAT attributes to setup page level cache control.
1666
1667 PATs are the modern equivalents of MTRRs and are much more
1668 flexible than MTRRs.
1669
1670 Say N here if you see bootup problems (boot crash, boot hang,
1671 spontaneous reboots) or a non-working video driver.
1672
1673 If unsure, say Y.
1674
1675 config ARCH_USES_PG_UNCACHED
1676 def_bool y
1677 depends on X86_PAT
1678
1679 config ARCH_RANDOM
1680 def_bool y
1681 prompt "x86 architectural random number generator" if EXPERT
1682 ---help---
1683 Enable the x86 architectural RDRAND instruction
1684 (Intel Bull Mountain technology) to generate random numbers.
1685 If supported, this is a high bandwidth, cryptographically
1686 secure hardware random number generator.
1687
1688 config X86_SMAP
1689 def_bool y
1690 prompt "Supervisor Mode Access Prevention" if EXPERT
1691 ---help---
1692 Supervisor Mode Access Prevention (SMAP) is a security
1693 feature in newer Intel processors. There is a small
1694 performance cost if this enabled and turned on; there is
1695 also a small increase in the kernel size if this is enabled.
1696
1697 If unsure, say Y.
1698
1699 config X86_INTEL_MPX
1700 prompt "Intel MPX (Memory Protection Extensions)"
1701 def_bool n
1702 depends on CPU_SUP_INTEL
1703 ---help---
1704 MPX provides hardware features that can be used in
1705 conjunction with compiler-instrumented code to check
1706 memory references. It is designed to detect buffer
1707 overflow or underflow bugs.
1708
1709 This option enables running applications which are
1710 instrumented or otherwise use MPX. It does not use MPX
1711 itself inside the kernel or to protect the kernel
1712 against bad memory references.
1713
1714 Enabling this option will make the kernel larger:
1715 ~8k of kernel text and 36 bytes of data on a 64-bit
1716 defconfig. It adds a long to the 'mm_struct' which
1717 will increase the kernel memory overhead of each
1718 process and adds some branches to paths used during
1719 exec() and munmap().
1720
1721 For details, see Documentation/x86/intel_mpx.txt
1722
1723 If unsure, say N.
1724
1725 config X86_INTEL_MEMORY_PROTECTION_KEYS
1726 prompt "Intel Memory Protection Keys"
1727 def_bool y
1728 # Note: only available in 64-bit mode
1729 depends on CPU_SUP_INTEL && X86_64
1730 ---help---
1731 Memory Protection Keys provides a mechanism for enforcing
1732 page-based protections, but without requiring modification of the
1733 page tables when an application changes protection domains.
1734
1735 For details, see Documentation/x86/protection-keys.txt
1736
1737 If unsure, say y.
1738
1739 config EFI
1740 bool "EFI runtime service support"
1741 depends on ACPI
1742 select UCS2_STRING
1743 select EFI_RUNTIME_WRAPPERS
1744 ---help---
1745 This enables the kernel to use EFI runtime services that are
1746 available (such as the EFI variable services).
1747
1748 This option is only useful on systems that have EFI firmware.
1749 In addition, you should use the latest ELILO loader available
1750 at <http://elilo.sourceforge.net> in order to take advantage
1751 of EFI runtime services. However, even with this option, the
1752 resultant kernel should continue to boot on existing non-EFI
1753 platforms.
1754
1755 config EFI_STUB
1756 bool "EFI stub support"
1757 depends on EFI && !X86_USE_3DNOW
1758 select RELOCATABLE
1759 ---help---
1760 This kernel feature allows a bzImage to be loaded directly
1761 by EFI firmware without the use of a bootloader.
1762
1763 See Documentation/efi-stub.txt for more information.
1764
1765 config EFI_MIXED
1766 bool "EFI mixed-mode support"
1767 depends on EFI_STUB && X86_64
1768 ---help---
1769 Enabling this feature allows a 64-bit kernel to be booted
1770 on a 32-bit firmware, provided that your CPU supports 64-bit
1771 mode.
1772
1773 Note that it is not possible to boot a mixed-mode enabled
1774 kernel via the EFI boot stub - a bootloader that supports
1775 the EFI handover protocol must be used.
1776
1777 If unsure, say N.
1778
1779 config SECCOMP
1780 def_bool y
1781 prompt "Enable seccomp to safely compute untrusted bytecode"
1782 ---help---
1783 This kernel feature is useful for number crunching applications
1784 that may need to compute untrusted bytecode during their
1785 execution. By using pipes or other transports made available to
1786 the process as file descriptors supporting the read/write
1787 syscalls, it's possible to isolate those applications in
1788 their own address space using seccomp. Once seccomp is
1789 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1790 and the task is only allowed to execute a few safe syscalls
1791 defined by each seccomp mode.
1792
1793 If unsure, say Y. Only embedded should say N here.
1794
1795 source kernel/Kconfig.hz
1796
1797 config KEXEC
1798 bool "kexec system call"
1799 select KEXEC_CORE
1800 ---help---
1801 kexec is a system call that implements the ability to shutdown your
1802 current kernel, and to start another kernel. It is like a reboot
1803 but it is independent of the system firmware. And like a reboot
1804 you can start any kernel with it, not just Linux.
1805
1806 The name comes from the similarity to the exec system call.
1807
1808 It is an ongoing process to be certain the hardware in a machine
1809 is properly shutdown, so do not be surprised if this code does not
1810 initially work for you. As of this writing the exact hardware
1811 interface is strongly in flux, so no good recommendation can be
1812 made.
1813
1814 config KEXEC_FILE
1815 bool "kexec file based system call"
1816 select KEXEC_CORE
1817 select BUILD_BIN2C
1818 depends on X86_64
1819 depends on CRYPTO=y
1820 depends on CRYPTO_SHA256=y
1821 ---help---
1822 This is new version of kexec system call. This system call is
1823 file based and takes file descriptors as system call argument
1824 for kernel and initramfs as opposed to list of segments as
1825 accepted by previous system call.
1826
1827 config KEXEC_VERIFY_SIG
1828 bool "Verify kernel signature during kexec_file_load() syscall"
1829 depends on KEXEC_FILE
1830 ---help---
1831 This option makes kernel signature verification mandatory for
1832 the kexec_file_load() syscall.
1833
1834 In addition to that option, you need to enable signature
1835 verification for the corresponding kernel image type being
1836 loaded in order for this to work.
1837
1838 config KEXEC_BZIMAGE_VERIFY_SIG
1839 bool "Enable bzImage signature verification support"
1840 depends on KEXEC_VERIFY_SIG
1841 depends on SIGNED_PE_FILE_VERIFICATION
1842 select SYSTEM_TRUSTED_KEYRING
1843 ---help---
1844 Enable bzImage signature verification support.
1845
1846 config CRASH_DUMP
1847 bool "kernel crash dumps"
1848 depends on X86_64 || (X86_32 && HIGHMEM)
1849 ---help---
1850 Generate crash dump after being started by kexec.
1851 This should be normally only set in special crash dump kernels
1852 which are loaded in the main kernel with kexec-tools into
1853 a specially reserved region and then later executed after
1854 a crash by kdump/kexec. The crash dump kernel must be compiled
1855 to a memory address not used by the main kernel or BIOS using
1856 PHYSICAL_START, or it must be built as a relocatable image
1857 (CONFIG_RELOCATABLE=y).
1858 For more details see Documentation/kdump/kdump.txt
1859
1860 config KEXEC_JUMP
1861 bool "kexec jump"
1862 depends on KEXEC && HIBERNATION
1863 ---help---
1864 Jump between original kernel and kexeced kernel and invoke
1865 code in physical address mode via KEXEC
1866
1867 config PHYSICAL_START
1868 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1869 default "0x1000000"
1870 ---help---
1871 This gives the physical address where the kernel is loaded.
1872
1873 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1874 bzImage will decompress itself to above physical address and
1875 run from there. Otherwise, bzImage will run from the address where
1876 it has been loaded by the boot loader and will ignore above physical
1877 address.
1878
1879 In normal kdump cases one does not have to set/change this option
1880 as now bzImage can be compiled as a completely relocatable image
1881 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1882 address. This option is mainly useful for the folks who don't want
1883 to use a bzImage for capturing the crash dump and want to use a
1884 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1885 to be specifically compiled to run from a specific memory area
1886 (normally a reserved region) and this option comes handy.
1887
1888 So if you are using bzImage for capturing the crash dump,
1889 leave the value here unchanged to 0x1000000 and set
1890 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1891 for capturing the crash dump change this value to start of
1892 the reserved region. In other words, it can be set based on
1893 the "X" value as specified in the "crashkernel=YM@XM"
1894 command line boot parameter passed to the panic-ed
1895 kernel. Please take a look at Documentation/kdump/kdump.txt
1896 for more details about crash dumps.
1897
1898 Usage of bzImage for capturing the crash dump is recommended as
1899 one does not have to build two kernels. Same kernel can be used
1900 as production kernel and capture kernel. Above option should have
1901 gone away after relocatable bzImage support is introduced. But it
1902 is present because there are users out there who continue to use
1903 vmlinux for dump capture. This option should go away down the
1904 line.
1905
1906 Don't change this unless you know what you are doing.
1907
1908 config RELOCATABLE
1909 bool "Build a relocatable kernel"
1910 default y
1911 ---help---
1912 This builds a kernel image that retains relocation information
1913 so it can be loaded someplace besides the default 1MB.
1914 The relocations tend to make the kernel binary about 10% larger,
1915 but are discarded at runtime.
1916
1917 One use is for the kexec on panic case where the recovery kernel
1918 must live at a different physical address than the primary
1919 kernel.
1920
1921 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1922 it has been loaded at and the compile time physical address
1923 (CONFIG_PHYSICAL_START) is used as the minimum location.
1924
1925 config RANDOMIZE_BASE
1926 bool "Randomize the address of the kernel image"
1927 depends on RELOCATABLE
1928 default n
1929 ---help---
1930 Randomizes the physical and virtual address at which the
1931 kernel image is decompressed, as a security feature that
1932 deters exploit attempts relying on knowledge of the location
1933 of kernel internals.
1934
1935 Entropy is generated using the RDRAND instruction if it is
1936 supported. If RDTSC is supported, it is used as well. If
1937 neither RDRAND nor RDTSC are supported, then randomness is
1938 read from the i8254 timer.
1939
1940 The kernel will be offset by up to RANDOMIZE_BASE_MAX_OFFSET,
1941 and aligned according to PHYSICAL_ALIGN. Since the kernel is
1942 built using 2GiB addressing, and PHYSICAL_ALGIN must be at a
1943 minimum of 2MiB, only 10 bits of entropy is theoretically
1944 possible. At best, due to page table layouts, 64-bit can use
1945 9 bits of entropy and 32-bit uses 8 bits.
1946
1947 If unsure, say N.
1948
1949 config RANDOMIZE_BASE_MAX_OFFSET
1950 hex "Maximum kASLR offset allowed" if EXPERT
1951 depends on RANDOMIZE_BASE
1952 range 0x0 0x20000000 if X86_32
1953 default "0x20000000" if X86_32
1954 range 0x0 0x40000000 if X86_64
1955 default "0x40000000" if X86_64
1956 ---help---
1957 The lesser of RANDOMIZE_BASE_MAX_OFFSET and available physical
1958 memory is used to determine the maximal offset in bytes that will
1959 be applied to the kernel when kernel Address Space Layout
1960 Randomization (kASLR) is active. This must be a multiple of
1961 PHYSICAL_ALIGN.
1962
1963 On 32-bit this is limited to 512MiB by page table layouts. The
1964 default is 512MiB.
1965
1966 On 64-bit this is limited by how the kernel fixmap page table is
1967 positioned, so this cannot be larger than 1GiB currently. Without
1968 RANDOMIZE_BASE, there is a 512MiB to 1.5GiB split between kernel
1969 and modules. When RANDOMIZE_BASE_MAX_OFFSET is above 512MiB, the
1970 modules area will shrink to compensate, up to the current maximum
1971 1GiB to 1GiB split. The default is 1GiB.
1972
1973 If unsure, leave at the default value.
1974
1975 # Relocation on x86 needs some additional build support
1976 config X86_NEED_RELOCS
1977 def_bool y
1978 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
1979
1980 config PHYSICAL_ALIGN
1981 hex "Alignment value to which kernel should be aligned"
1982 default "0x200000"
1983 range 0x2000 0x1000000 if X86_32
1984 range 0x200000 0x1000000 if X86_64
1985 ---help---
1986 This value puts the alignment restrictions on physical address
1987 where kernel is loaded and run from. Kernel is compiled for an
1988 address which meets above alignment restriction.
1989
1990 If bootloader loads the kernel at a non-aligned address and
1991 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1992 address aligned to above value and run from there.
1993
1994 If bootloader loads the kernel at a non-aligned address and
1995 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1996 load address and decompress itself to the address it has been
1997 compiled for and run from there. The address for which kernel is
1998 compiled already meets above alignment restrictions. Hence the
1999 end result is that kernel runs from a physical address meeting
2000 above alignment restrictions.
2001
2002 On 32-bit this value must be a multiple of 0x2000. On 64-bit
2003 this value must be a multiple of 0x200000.
2004
2005 Don't change this unless you know what you are doing.
2006
2007 config HOTPLUG_CPU
2008 bool "Support for hot-pluggable CPUs"
2009 depends on SMP
2010 ---help---
2011 Say Y here to allow turning CPUs off and on. CPUs can be
2012 controlled through /sys/devices/system/cpu.
2013 ( Note: power management support will enable this option
2014 automatically on SMP systems. )
2015 Say N if you want to disable CPU hotplug.
2016
2017 config BOOTPARAM_HOTPLUG_CPU0
2018 bool "Set default setting of cpu0_hotpluggable"
2019 default n
2020 depends on HOTPLUG_CPU
2021 ---help---
2022 Set whether default state of cpu0_hotpluggable is on or off.
2023
2024 Say Y here to enable CPU0 hotplug by default. If this switch
2025 is turned on, there is no need to give cpu0_hotplug kernel
2026 parameter and the CPU0 hotplug feature is enabled by default.
2027
2028 Please note: there are two known CPU0 dependencies if you want
2029 to enable the CPU0 hotplug feature either by this switch or by
2030 cpu0_hotplug kernel parameter.
2031
2032 First, resume from hibernate or suspend always starts from CPU0.
2033 So hibernate and suspend are prevented if CPU0 is offline.
2034
2035 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2036 offline if any interrupt can not migrate out of CPU0. There may
2037 be other CPU0 dependencies.
2038
2039 Please make sure the dependencies are under your control before
2040 you enable this feature.
2041
2042 Say N if you don't want to enable CPU0 hotplug feature by default.
2043 You still can enable the CPU0 hotplug feature at boot by kernel
2044 parameter cpu0_hotplug.
2045
2046 config DEBUG_HOTPLUG_CPU0
2047 def_bool n
2048 prompt "Debug CPU0 hotplug"
2049 depends on HOTPLUG_CPU
2050 ---help---
2051 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2052 soon as possible and boots up userspace with CPU0 offlined. User
2053 can online CPU0 back after boot time.
2054
2055 To debug CPU0 hotplug, you need to enable CPU0 offline/online
2056 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2057 compilation or giving cpu0_hotplug kernel parameter at boot.
2058
2059 If unsure, say N.
2060
2061 config COMPAT_VDSO
2062 def_bool n
2063 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2064 depends on X86_32 || IA32_EMULATION
2065 ---help---
2066 Certain buggy versions of glibc will crash if they are
2067 presented with a 32-bit vDSO that is not mapped at the address
2068 indicated in its segment table.
2069
2070 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2071 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2072 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
2073 the only released version with the bug, but OpenSUSE 9
2074 contains a buggy "glibc 2.3.2".
2075
2076 The symptom of the bug is that everything crashes on startup, saying:
2077 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2078
2079 Saying Y here changes the default value of the vdso32 boot
2080 option from 1 to 0, which turns off the 32-bit vDSO entirely.
2081 This works around the glibc bug but hurts performance.
2082
2083 If unsure, say N: if you are compiling your own kernel, you
2084 are unlikely to be using a buggy version of glibc.
2085
2086 choice
2087 prompt "vsyscall table for legacy applications"
2088 depends on X86_64
2089 default LEGACY_VSYSCALL_EMULATE
2090 help
2091 Legacy user code that does not know how to find the vDSO expects
2092 to be able to issue three syscalls by calling fixed addresses in
2093 kernel space. Since this location is not randomized with ASLR,
2094 it can be used to assist security vulnerability exploitation.
2095
2096 This setting can be changed at boot time via the kernel command
2097 line parameter vsyscall=[native|emulate|none].
2098
2099 On a system with recent enough glibc (2.14 or newer) and no
2100 static binaries, you can say None without a performance penalty
2101 to improve security.
2102
2103 If unsure, select "Emulate".
2104
2105 config LEGACY_VSYSCALL_NATIVE
2106 bool "Native"
2107 help
2108 Actual executable code is located in the fixed vsyscall
2109 address mapping, implementing time() efficiently. Since
2110 this makes the mapping executable, it can be used during
2111 security vulnerability exploitation (traditionally as
2112 ROP gadgets). This configuration is not recommended.
2113
2114 config LEGACY_VSYSCALL_EMULATE
2115 bool "Emulate"
2116 help
2117 The kernel traps and emulates calls into the fixed
2118 vsyscall address mapping. This makes the mapping
2119 non-executable, but it still contains known contents,
2120 which could be used in certain rare security vulnerability
2121 exploits. This configuration is recommended when userspace
2122 still uses the vsyscall area.
2123
2124 config LEGACY_VSYSCALL_NONE
2125 bool "None"
2126 help
2127 There will be no vsyscall mapping at all. This will
2128 eliminate any risk of ASLR bypass due to the vsyscall
2129 fixed address mapping. Attempts to use the vsyscalls
2130 will be reported to dmesg, so that either old or
2131 malicious userspace programs can be identified.
2132
2133 endchoice
2134
2135 config CMDLINE_BOOL
2136 bool "Built-in kernel command line"
2137 ---help---
2138 Allow for specifying boot arguments to the kernel at
2139 build time. On some systems (e.g. embedded ones), it is
2140 necessary or convenient to provide some or all of the
2141 kernel boot arguments with the kernel itself (that is,
2142 to not rely on the boot loader to provide them.)
2143
2144 To compile command line arguments into the kernel,
2145 set this option to 'Y', then fill in the
2146 boot arguments in CONFIG_CMDLINE.
2147
2148 Systems with fully functional boot loaders (i.e. non-embedded)
2149 should leave this option set to 'N'.
2150
2151 config CMDLINE
2152 string "Built-in kernel command string"
2153 depends on CMDLINE_BOOL
2154 default ""
2155 ---help---
2156 Enter arguments here that should be compiled into the kernel
2157 image and used at boot time. If the boot loader provides a
2158 command line at boot time, it is appended to this string to
2159 form the full kernel command line, when the system boots.
2160
2161 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2162 change this behavior.
2163
2164 In most cases, the command line (whether built-in or provided
2165 by the boot loader) should specify the device for the root
2166 file system.
2167
2168 config CMDLINE_OVERRIDE
2169 bool "Built-in command line overrides boot loader arguments"
2170 depends on CMDLINE_BOOL
2171 ---help---
2172 Set this option to 'Y' to have the kernel ignore the boot loader
2173 command line, and use ONLY the built-in command line.
2174
2175 This is used to work around broken boot loaders. This should
2176 be set to 'N' under normal conditions.
2177
2178 config MODIFY_LDT_SYSCALL
2179 bool "Enable the LDT (local descriptor table)" if EXPERT
2180 default y
2181 ---help---
2182 Linux can allow user programs to install a per-process x86
2183 Local Descriptor Table (LDT) using the modify_ldt(2) system
2184 call. This is required to run 16-bit or segmented code such as
2185 DOSEMU or some Wine programs. It is also used by some very old
2186 threading libraries.
2187
2188 Enabling this feature adds a small amount of overhead to
2189 context switches and increases the low-level kernel attack
2190 surface. Disabling it removes the modify_ldt(2) system call.
2191
2192 Saying 'N' here may make sense for embedded or server kernels.
2193
2194 source "kernel/livepatch/Kconfig"
2195
2196 endmenu
2197
2198 config ARCH_ENABLE_MEMORY_HOTPLUG
2199 def_bool y
2200 depends on X86_64 || (X86_32 && HIGHMEM)
2201
2202 config ARCH_ENABLE_MEMORY_HOTREMOVE
2203 def_bool y
2204 depends on MEMORY_HOTPLUG
2205
2206 config USE_PERCPU_NUMA_NODE_ID
2207 def_bool y
2208 depends on NUMA
2209
2210 config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2211 def_bool y
2212 depends on X86_64 || X86_PAE
2213
2214 config ARCH_ENABLE_HUGEPAGE_MIGRATION
2215 def_bool y
2216 depends on X86_64 && HUGETLB_PAGE && MIGRATION
2217
2218 menu "Power management and ACPI options"
2219
2220 config ARCH_HIBERNATION_HEADER
2221 def_bool y
2222 depends on X86_64 && HIBERNATION
2223
2224 source "kernel/power/Kconfig"
2225
2226 source "drivers/acpi/Kconfig"
2227
2228 source "drivers/sfi/Kconfig"
2229
2230 config X86_APM_BOOT
2231 def_bool y
2232 depends on APM
2233
2234 menuconfig APM
2235 tristate "APM (Advanced Power Management) BIOS support"
2236 depends on X86_32 && PM_SLEEP
2237 ---help---
2238 APM is a BIOS specification for saving power using several different
2239 techniques. This is mostly useful for battery powered laptops with
2240 APM compliant BIOSes. If you say Y here, the system time will be
2241 reset after a RESUME operation, the /proc/apm device will provide
2242 battery status information, and user-space programs will receive
2243 notification of APM "events" (e.g. battery status change).
2244
2245 If you select "Y" here, you can disable actual use of the APM
2246 BIOS by passing the "apm=off" option to the kernel at boot time.
2247
2248 Note that the APM support is almost completely disabled for
2249 machines with more than one CPU.
2250
2251 In order to use APM, you will need supporting software. For location
2252 and more information, read <file:Documentation/power/apm-acpi.txt>
2253 and the Battery Powered Linux mini-HOWTO, available from
2254 <http://www.tldp.org/docs.html#howto>.
2255
2256 This driver does not spin down disk drives (see the hdparm(8)
2257 manpage ("man 8 hdparm") for that), and it doesn't turn off
2258 VESA-compliant "green" monitors.
2259
2260 This driver does not support the TI 4000M TravelMate and the ACER
2261 486/DX4/75 because they don't have compliant BIOSes. Many "green"
2262 desktop machines also don't have compliant BIOSes, and this driver
2263 may cause those machines to panic during the boot phase.
2264
2265 Generally, if you don't have a battery in your machine, there isn't
2266 much point in using this driver and you should say N. If you get
2267 random kernel OOPSes or reboots that don't seem to be related to
2268 anything, try disabling/enabling this option (or disabling/enabling
2269 APM in your BIOS).
2270
2271 Some other things you should try when experiencing seemingly random,
2272 "weird" problems:
2273
2274 1) make sure that you have enough swap space and that it is
2275 enabled.
2276 2) pass the "no-hlt" option to the kernel
2277 3) switch on floating point emulation in the kernel and pass
2278 the "no387" option to the kernel
2279 4) pass the "floppy=nodma" option to the kernel
2280 5) pass the "mem=4M" option to the kernel (thereby disabling
2281 all but the first 4 MB of RAM)
2282 6) make sure that the CPU is not over clocked.
2283 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2284 8) disable the cache from your BIOS settings
2285 9) install a fan for the video card or exchange video RAM
2286 10) install a better fan for the CPU
2287 11) exchange RAM chips
2288 12) exchange the motherboard.
2289
2290 To compile this driver as a module, choose M here: the
2291 module will be called apm.
2292
2293 if APM
2294
2295 config APM_IGNORE_USER_SUSPEND
2296 bool "Ignore USER SUSPEND"
2297 ---help---
2298 This option will ignore USER SUSPEND requests. On machines with a
2299 compliant APM BIOS, you want to say N. However, on the NEC Versa M
2300 series notebooks, it is necessary to say Y because of a BIOS bug.
2301
2302 config APM_DO_ENABLE
2303 bool "Enable PM at boot time"
2304 ---help---
2305 Enable APM features at boot time. From page 36 of the APM BIOS
2306 specification: "When disabled, the APM BIOS does not automatically
2307 power manage devices, enter the Standby State, enter the Suspend
2308 State, or take power saving steps in response to CPU Idle calls."
2309 This driver will make CPU Idle calls when Linux is idle (unless this
2310 feature is turned off -- see "Do CPU IDLE calls", below). This
2311 should always save battery power, but more complicated APM features
2312 will be dependent on your BIOS implementation. You may need to turn
2313 this option off if your computer hangs at boot time when using APM
2314 support, or if it beeps continuously instead of suspending. Turn
2315 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2316 T400CDT. This is off by default since most machines do fine without
2317 this feature.
2318
2319 config APM_CPU_IDLE
2320 depends on CPU_IDLE
2321 bool "Make CPU Idle calls when idle"
2322 ---help---
2323 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2324 On some machines, this can activate improved power savings, such as
2325 a slowed CPU clock rate, when the machine is idle. These idle calls
2326 are made after the idle loop has run for some length of time (e.g.,
2327 333 mS). On some machines, this will cause a hang at boot time or
2328 whenever the CPU becomes idle. (On machines with more than one CPU,
2329 this option does nothing.)
2330
2331 config APM_DISPLAY_BLANK
2332 bool "Enable console blanking using APM"
2333 ---help---
2334 Enable console blanking using the APM. Some laptops can use this to
2335 turn off the LCD backlight when the screen blanker of the Linux
2336 virtual console blanks the screen. Note that this is only used by
2337 the virtual console screen blanker, and won't turn off the backlight
2338 when using the X Window system. This also doesn't have anything to
2339 do with your VESA-compliant power-saving monitor. Further, this
2340 option doesn't work for all laptops -- it might not turn off your
2341 backlight at all, or it might print a lot of errors to the console,
2342 especially if you are using gpm.
2343
2344 config APM_ALLOW_INTS
2345 bool "Allow interrupts during APM BIOS calls"
2346 ---help---
2347 Normally we disable external interrupts while we are making calls to
2348 the APM BIOS as a measure to lessen the effects of a badly behaving
2349 BIOS implementation. The BIOS should reenable interrupts if it
2350 needs to. Unfortunately, some BIOSes do not -- especially those in
2351 many of the newer IBM Thinkpads. If you experience hangs when you
2352 suspend, try setting this to Y. Otherwise, say N.
2353
2354 endif # APM
2355
2356 source "drivers/cpufreq/Kconfig"
2357
2358 source "drivers/cpuidle/Kconfig"
2359
2360 source "drivers/idle/Kconfig"
2361
2362 endmenu
2363
2364
2365 menu "Bus options (PCI etc.)"
2366
2367 config PCI
2368 bool "PCI support"
2369 default y
2370 ---help---
2371 Find out whether you have a PCI motherboard. PCI is the name of a
2372 bus system, i.e. the way the CPU talks to the other stuff inside
2373 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2374 VESA. If you have PCI, say Y, otherwise N.
2375
2376 choice
2377 prompt "PCI access mode"
2378 depends on X86_32 && PCI
2379 default PCI_GOANY
2380 ---help---
2381 On PCI systems, the BIOS can be used to detect the PCI devices and
2382 determine their configuration. However, some old PCI motherboards
2383 have BIOS bugs and may crash if this is done. Also, some embedded
2384 PCI-based systems don't have any BIOS at all. Linux can also try to
2385 detect the PCI hardware directly without using the BIOS.
2386
2387 With this option, you can specify how Linux should detect the
2388 PCI devices. If you choose "BIOS", the BIOS will be used,
2389 if you choose "Direct", the BIOS won't be used, and if you
2390 choose "MMConfig", then PCI Express MMCONFIG will be used.
2391 If you choose "Any", the kernel will try MMCONFIG, then the
2392 direct access method and falls back to the BIOS if that doesn't
2393 work. If unsure, go with the default, which is "Any".
2394
2395 config PCI_GOBIOS
2396 bool "BIOS"
2397
2398 config PCI_GOMMCONFIG
2399 bool "MMConfig"
2400
2401 config PCI_GODIRECT
2402 bool "Direct"
2403
2404 config PCI_GOOLPC
2405 bool "OLPC XO-1"
2406 depends on OLPC
2407
2408 config PCI_GOANY
2409 bool "Any"
2410
2411 endchoice
2412
2413 config PCI_BIOS
2414 def_bool y
2415 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2416
2417 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2418 config PCI_DIRECT
2419 def_bool y
2420 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2421
2422 config PCI_MMCONFIG
2423 def_bool y
2424 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
2425
2426 config PCI_OLPC
2427 def_bool y
2428 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2429
2430 config PCI_XEN
2431 def_bool y
2432 depends on PCI && XEN
2433 select SWIOTLB_XEN
2434
2435 config PCI_DOMAINS
2436 def_bool y
2437 depends on PCI
2438
2439 config PCI_MMCONFIG
2440 bool "Support mmconfig PCI config space access"
2441 depends on X86_64 && PCI && ACPI
2442
2443 config PCI_CNB20LE_QUIRK
2444 bool "Read CNB20LE Host Bridge Windows" if EXPERT
2445 depends on PCI
2446 help
2447 Read the PCI windows out of the CNB20LE host bridge. This allows
2448 PCI hotplug to work on systems with the CNB20LE chipset which do
2449 not have ACPI.
2450
2451 There's no public spec for this chipset, and this functionality
2452 is known to be incomplete.
2453
2454 You should say N unless you know you need this.
2455
2456 source "drivers/pci/Kconfig"
2457
2458 # x86_64 have no ISA slots, but can have ISA-style DMA.
2459 config ISA_DMA_API
2460 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2461 default y
2462 help
2463 Enables ISA-style DMA support for devices requiring such controllers.
2464 If unsure, say Y.
2465
2466 if X86_32
2467
2468 config ISA
2469 bool "ISA support"
2470 ---help---
2471 Find out whether you have ISA slots on your motherboard. ISA is the
2472 name of a bus system, i.e. the way the CPU talks to the other stuff
2473 inside your box. Other bus systems are PCI, EISA, MicroChannel
2474 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2475 newer boards don't support it. If you have ISA, say Y, otherwise N.
2476
2477 config EISA
2478 bool "EISA support"
2479 depends on ISA
2480 ---help---
2481 The Extended Industry Standard Architecture (EISA) bus was
2482 developed as an open alternative to the IBM MicroChannel bus.
2483
2484 The EISA bus provided some of the features of the IBM MicroChannel
2485 bus while maintaining backward compatibility with cards made for
2486 the older ISA bus. The EISA bus saw limited use between 1988 and
2487 1995 when it was made obsolete by the PCI bus.
2488
2489 Say Y here if you are building a kernel for an EISA-based machine.
2490
2491 Otherwise, say N.
2492
2493 source "drivers/eisa/Kconfig"
2494
2495 config SCx200
2496 tristate "NatSemi SCx200 support"
2497 ---help---
2498 This provides basic support for National Semiconductor's
2499 (now AMD's) Geode processors. The driver probes for the
2500 PCI-IDs of several on-chip devices, so its a good dependency
2501 for other scx200_* drivers.
2502
2503 If compiled as a module, the driver is named scx200.
2504
2505 config SCx200HR_TIMER
2506 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2507 depends on SCx200
2508 default y
2509 ---help---
2510 This driver provides a clocksource built upon the on-chip
2511 27MHz high-resolution timer. Its also a workaround for
2512 NSC Geode SC-1100's buggy TSC, which loses time when the
2513 processor goes idle (as is done by the scheduler). The
2514 other workaround is idle=poll boot option.
2515
2516 config OLPC
2517 bool "One Laptop Per Child support"
2518 depends on !X86_PAE
2519 select GPIOLIB
2520 select OF
2521 select OF_PROMTREE
2522 select IRQ_DOMAIN
2523 ---help---
2524 Add support for detecting the unique features of the OLPC
2525 XO hardware.
2526
2527 config OLPC_XO1_PM
2528 bool "OLPC XO-1 Power Management"
2529 depends on OLPC && MFD_CS5535 && PM_SLEEP
2530 select MFD_CORE
2531 ---help---
2532 Add support for poweroff and suspend of the OLPC XO-1 laptop.
2533
2534 config OLPC_XO1_RTC
2535 bool "OLPC XO-1 Real Time Clock"
2536 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2537 ---help---
2538 Add support for the XO-1 real time clock, which can be used as a
2539 programmable wakeup source.
2540
2541 config OLPC_XO1_SCI
2542 bool "OLPC XO-1 SCI extras"
2543 depends on OLPC && OLPC_XO1_PM
2544 depends on INPUT=y
2545 select POWER_SUPPLY
2546 select GPIO_CS5535
2547 select MFD_CORE
2548 ---help---
2549 Add support for SCI-based features of the OLPC XO-1 laptop:
2550 - EC-driven system wakeups
2551 - Power button
2552 - Ebook switch
2553 - Lid switch
2554 - AC adapter status updates
2555 - Battery status updates
2556
2557 config OLPC_XO15_SCI
2558 bool "OLPC XO-1.5 SCI extras"
2559 depends on OLPC && ACPI
2560 select POWER_SUPPLY
2561 ---help---
2562 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2563 - EC-driven system wakeups
2564 - AC adapter status updates
2565 - Battery status updates
2566
2567 config ALIX
2568 bool "PCEngines ALIX System Support (LED setup)"
2569 select GPIOLIB
2570 ---help---
2571 This option enables system support for the PCEngines ALIX.
2572 At present this just sets up LEDs for GPIO control on
2573 ALIX2/3/6 boards. However, other system specific setup should
2574 get added here.
2575
2576 Note: You must still enable the drivers for GPIO and LED support
2577 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2578
2579 Note: You have to set alix.force=1 for boards with Award BIOS.
2580
2581 config NET5501
2582 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2583 select GPIOLIB
2584 ---help---
2585 This option enables system support for the Soekris Engineering net5501.
2586
2587 config GEOS
2588 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2589 select GPIOLIB
2590 depends on DMI
2591 ---help---
2592 This option enables system support for the Traverse Technologies GEOS.
2593
2594 config TS5500
2595 bool "Technologic Systems TS-5500 platform support"
2596 depends on MELAN
2597 select CHECK_SIGNATURE
2598 select NEW_LEDS
2599 select LEDS_CLASS
2600 ---help---
2601 This option enables system support for the Technologic Systems TS-5500.
2602
2603 endif # X86_32
2604
2605 config AMD_NB
2606 def_bool y
2607 depends on CPU_SUP_AMD && PCI
2608
2609 source "drivers/pcmcia/Kconfig"
2610
2611 config RAPIDIO
2612 tristate "RapidIO support"
2613 depends on PCI
2614 default n
2615 help
2616 If enabled this option will include drivers and the core
2617 infrastructure code to support RapidIO interconnect devices.
2618
2619 source "drivers/rapidio/Kconfig"
2620
2621 config X86_SYSFB
2622 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2623 help
2624 Firmwares often provide initial graphics framebuffers so the BIOS,
2625 bootloader or kernel can show basic video-output during boot for
2626 user-guidance and debugging. Historically, x86 used the VESA BIOS
2627 Extensions and EFI-framebuffers for this, which are mostly limited
2628 to x86.
2629 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2630 framebuffers so the new generic system-framebuffer drivers can be
2631 used on x86. If the framebuffer is not compatible with the generic
2632 modes, it is adverticed as fallback platform framebuffer so legacy
2633 drivers like efifb, vesafb and uvesafb can pick it up.
2634 If this option is not selected, all system framebuffers are always
2635 marked as fallback platform framebuffers as usual.
2636
2637 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2638 not be able to pick up generic system framebuffers if this option
2639 is selected. You are highly encouraged to enable simplefb as
2640 replacement if you select this option. simplefb can correctly deal
2641 with generic system framebuffers. But you should still keep vesafb
2642 and others enabled as fallback if a system framebuffer is
2643 incompatible with simplefb.
2644
2645 If unsure, say Y.
2646
2647 endmenu
2648
2649
2650 menu "Executable file formats / Emulations"
2651
2652 source "fs/Kconfig.binfmt"
2653
2654 config IA32_EMULATION
2655 bool "IA32 Emulation"
2656 depends on X86_64
2657 select BINFMT_ELF
2658 select COMPAT_BINFMT_ELF
2659 select ARCH_WANT_OLD_COMPAT_IPC
2660 ---help---
2661 Include code to run legacy 32-bit programs under a
2662 64-bit kernel. You should likely turn this on, unless you're
2663 100% sure that you don't have any 32-bit programs left.
2664
2665 config IA32_AOUT
2666 tristate "IA32 a.out support"
2667 depends on IA32_EMULATION
2668 ---help---
2669 Support old a.out binaries in the 32bit emulation.
2670
2671 config X86_X32
2672 bool "x32 ABI for 64-bit mode"
2673 depends on X86_64
2674 ---help---
2675 Include code to run binaries for the x32 native 32-bit ABI
2676 for 64-bit processors. An x32 process gets access to the
2677 full 64-bit register file and wide data path while leaving
2678 pointers at 32 bits for smaller memory footprint.
2679
2680 You will need a recent binutils (2.22 or later) with
2681 elf32_x86_64 support enabled to compile a kernel with this
2682 option set.
2683
2684 config COMPAT
2685 def_bool y
2686 depends on IA32_EMULATION || X86_X32
2687
2688 if COMPAT
2689 config COMPAT_FOR_U64_ALIGNMENT
2690 def_bool y
2691
2692 config SYSVIPC_COMPAT
2693 def_bool y
2694 depends on SYSVIPC
2695
2696 config KEYS_COMPAT
2697 def_bool y
2698 depends on KEYS
2699 endif
2700
2701 endmenu
2702
2703
2704 config HAVE_ATOMIC_IOMAP
2705 def_bool y
2706 depends on X86_32
2707
2708 config X86_DEV_DMA_OPS
2709 bool
2710 depends on X86_64 || STA2X11
2711
2712 config X86_DMA_REMAP
2713 bool
2714 depends on STA2X11
2715
2716 config PMC_ATOM
2717 def_bool y
2718 depends on PCI
2719
2720 config VMD
2721 depends on PCI_MSI
2722 tristate "Volume Management Device Driver"
2723 default N
2724 ---help---
2725 Adds support for the Intel Volume Management Device (VMD). VMD is a
2726 secondary PCI host bridge that allows PCI Express root ports,
2727 and devices attached to them, to be removed from the default
2728 PCI domain and placed within the VMD domain. This provides
2729 more bus resources than are otherwise possible with a
2730 single domain. If you know your system provides one of these and
2731 has devices attached to it, say Y; if you are not sure, say N.
2732
2733 source "net/Kconfig"
2734
2735 source "drivers/Kconfig"
2736
2737 source "drivers/firmware/Kconfig"
2738
2739 source "fs/Kconfig"
2740
2741 source "arch/x86/Kconfig.debug"
2742
2743 source "security/Kconfig"
2744
2745 source "crypto/Kconfig"
2746
2747 source "arch/x86/kvm/Kconfig"
2748
2749 source "lib/Kconfig"
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