Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
[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_ACPI_TABLE_UPGRADE if ACPI
26 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
27 select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
28 select ARCH_HAS_DEVMEM_IS_ALLOWED
29 select ARCH_HAS_ELF_RANDOMIZE
30 select ARCH_HAS_FAST_MULTIPLIER
31 select ARCH_HAS_GCOV_PROFILE_ALL
32 select ARCH_HAS_KCOV if X86_64
33 select ARCH_HAS_PMEM_API if X86_64
34 select ARCH_HAS_MMIO_FLUSH
35 select ARCH_HAS_SG_CHAIN
36 select ARCH_HAS_UBSAN_SANITIZE_ALL
37 select ARCH_HAVE_NMI_SAFE_CMPXCHG
38 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
39 select ARCH_MIGHT_HAVE_PC_PARPORT
40 select ARCH_MIGHT_HAVE_PC_SERIO
41 select ARCH_SUPPORTS_ATOMIC_RMW
42 select ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT
43 select ARCH_SUPPORTS_INT128 if X86_64
44 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
45 select ARCH_USE_BUILTIN_BSWAP
46 select ARCH_USE_CMPXCHG_LOCKREF if X86_64
47 select ARCH_USE_QUEUED_RWLOCKS
48 select ARCH_USE_QUEUED_SPINLOCKS
49 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH if SMP
50 select ARCH_WANTS_DYNAMIC_TASK_STRUCT
51 select ARCH_WANT_FRAME_POINTERS
52 select ARCH_WANT_IPC_PARSE_VERSION if X86_32
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_EBPF_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_EXIT_THREAD
109 select HAVE_FENTRY if X86_64
110 select HAVE_FTRACE_MCOUNT_RECORD
111 select HAVE_FUNCTION_GRAPH_FP_TEST
112 select HAVE_FUNCTION_GRAPH_TRACER
113 select HAVE_FUNCTION_TRACER
114 select HAVE_GCC_PLUGINS
115 select HAVE_GENERIC_DMA_COHERENT if X86_32
116 select HAVE_HW_BREAKPOINT
117 select HAVE_IDE
118 select HAVE_IOREMAP_PROT
119 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
120 select HAVE_IRQ_TIME_ACCOUNTING
121 select HAVE_KERNEL_BZIP2
122 select HAVE_KERNEL_GZIP
123 select HAVE_KERNEL_LZ4
124 select HAVE_KERNEL_LZMA
125 select HAVE_KERNEL_LZO
126 select HAVE_KERNEL_XZ
127 select HAVE_KPROBES
128 select HAVE_KPROBES_ON_FTRACE
129 select HAVE_KRETPROBES
130 select HAVE_KVM
131 select HAVE_LIVEPATCH if X86_64
132 select HAVE_MEMBLOCK
133 select HAVE_MEMBLOCK_NODE_MAP
134 select HAVE_MIXED_BREAKPOINTS_REGS
135 select HAVE_NMI
136 select HAVE_OPROFILE
137 select HAVE_OPTPROBES
138 select HAVE_PCSPKR_PLATFORM
139 select HAVE_PERF_EVENTS
140 select HAVE_PERF_EVENTS_NMI
141 select HAVE_PERF_REGS
142 select HAVE_PERF_USER_STACK_DUMP
143 select HAVE_REGS_AND_STACK_ACCESS_API
144 select HAVE_SYSCALL_TRACEPOINTS
145 select HAVE_UID16 if X86_32 || IA32_EMULATION
146 select HAVE_UNSTABLE_SCHED_CLOCK
147 select HAVE_USER_RETURN_NOTIFIER
148 select IRQ_FORCED_THREADING
149 select MODULES_USE_ELF_RELA if X86_64
150 select MODULES_USE_ELF_REL if X86_32
151 select OLD_SIGACTION if X86_32
152 select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION
153 select PERF_EVENTS
154 select RTC_LIB
155 select RTC_MC146818_LIB
156 select SPARSE_IRQ
157 select SRCU
158 select SYSCTL_EXCEPTION_TRACE
159 select USER_STACKTRACE_SUPPORT
160 select VIRT_TO_BUS
161 select X86_DEV_DMA_OPS if X86_64
162 select X86_FEATURE_NAMES if PROC_FS
163 select HAVE_STACK_VALIDATION if X86_64
164 select ARCH_USES_HIGH_VMA_FLAGS if X86_INTEL_MEMORY_PROTECTION_KEYS
165 select ARCH_HAS_PKEYS if X86_INTEL_MEMORY_PROTECTION_KEYS
166
167 config INSTRUCTION_DECODER
168 def_bool y
169 depends on KPROBES || PERF_EVENTS || UPROBES
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_SUPPORTS_UPROBES
300 def_bool y
301
302 config FIX_EARLYCON_MEM
303 def_bool y
304
305 config DEBUG_RODATA
306 def_bool y
307
308 config PGTABLE_LEVELS
309 int
310 default 4 if X86_64
311 default 3 if X86_PAE
312 default 2
313
314 source "init/Kconfig"
315 source "kernel/Kconfig.freezer"
316
317 menu "Processor type and features"
318
319 config ZONE_DMA
320 bool "DMA memory allocation support" if EXPERT
321 default y
322 help
323 DMA memory allocation support allows devices with less than 32-bit
324 addressing to allocate within the first 16MB of address space.
325 Disable if no such devices will be used.
326
327 If unsure, say Y.
328
329 config SMP
330 bool "Symmetric multi-processing support"
331 ---help---
332 This enables support for systems with more than one CPU. If you have
333 a system with only one CPU, say N. If you have a system with more
334 than one CPU, say Y.
335
336 If you say N here, the kernel will run on uni- and multiprocessor
337 machines, but will use only one CPU of a multiprocessor machine. If
338 you say Y here, the kernel will run on many, but not all,
339 uniprocessor machines. On a uniprocessor machine, the kernel
340 will run faster if you say N here.
341
342 Note that if you say Y here and choose architecture "586" or
343 "Pentium" under "Processor family", the kernel will not work on 486
344 architectures. Similarly, multiprocessor kernels for the "PPro"
345 architecture may not work on all Pentium based boards.
346
347 People using multiprocessor machines who say Y here should also say
348 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
349 Management" code will be disabled if you say Y here.
350
351 See also <file:Documentation/x86/i386/IO-APIC.txt>,
352 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
353 <http://www.tldp.org/docs.html#howto>.
354
355 If you don't know what to do here, say N.
356
357 config X86_FEATURE_NAMES
358 bool "Processor feature human-readable names" if EMBEDDED
359 default y
360 ---help---
361 This option compiles in a table of x86 feature bits and corresponding
362 names. This is required to support /proc/cpuinfo and a few kernel
363 messages. You can disable this to save space, at the expense of
364 making those few kernel messages show numeric feature bits instead.
365
366 If in doubt, say Y.
367
368 config X86_FAST_FEATURE_TESTS
369 bool "Fast CPU feature tests" if EMBEDDED
370 default y
371 ---help---
372 Some fast-paths in the kernel depend on the capabilities of the CPU.
373 Say Y here for the kernel to patch in the appropriate code at runtime
374 based on the capabilities of the CPU. The infrastructure for patching
375 code at runtime takes up some additional space; space-constrained
376 embedded systems may wish to say N here to produce smaller, slightly
377 slower code.
378
379 config X86_X2APIC
380 bool "Support x2apic"
381 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
382 ---help---
383 This enables x2apic support on CPUs that have this feature.
384
385 This allows 32-bit apic IDs (so it can support very large systems),
386 and accesses the local apic via MSRs not via mmio.
387
388 If you don't know what to do here, say N.
389
390 config X86_MPPARSE
391 bool "Enable MPS table" if ACPI || SFI
392 default y
393 depends on X86_LOCAL_APIC
394 ---help---
395 For old smp systems that do not have proper acpi support. Newer systems
396 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
397
398 config X86_BIGSMP
399 bool "Support for big SMP systems with more than 8 CPUs"
400 depends on X86_32 && SMP
401 ---help---
402 This option is needed for the systems that have more than 8 CPUs
403
404 config GOLDFISH
405 def_bool y
406 depends on X86_GOLDFISH
407
408 if X86_32
409 config X86_EXTENDED_PLATFORM
410 bool "Support for extended (non-PC) x86 platforms"
411 default y
412 ---help---
413 If you disable this option then the kernel will only support
414 standard PC platforms. (which covers the vast majority of
415 systems out there.)
416
417 If you enable this option then you'll be able to select support
418 for the following (non-PC) 32 bit x86 platforms:
419 Goldfish (Android emulator)
420 AMD Elan
421 RDC R-321x SoC
422 SGI 320/540 (Visual Workstation)
423 STA2X11-based (e.g. Northville)
424 Moorestown MID devices
425
426 If you have one of these systems, or if you want to build a
427 generic distribution kernel, say Y here - otherwise say N.
428 endif
429
430 if X86_64
431 config X86_EXTENDED_PLATFORM
432 bool "Support for extended (non-PC) x86 platforms"
433 default y
434 ---help---
435 If you disable this option then the kernel will only support
436 standard PC platforms. (which covers the vast majority of
437 systems out there.)
438
439 If you enable this option then you'll be able to select support
440 for the following (non-PC) 64 bit x86 platforms:
441 Numascale NumaChip
442 ScaleMP vSMP
443 SGI Ultraviolet
444
445 If you have one of these systems, or if you want to build a
446 generic distribution kernel, say Y here - otherwise say N.
447 endif
448 # This is an alphabetically sorted list of 64 bit extended platforms
449 # Please maintain the alphabetic order if and when there are additions
450 config X86_NUMACHIP
451 bool "Numascale NumaChip"
452 depends on X86_64
453 depends on X86_EXTENDED_PLATFORM
454 depends on NUMA
455 depends on SMP
456 depends on X86_X2APIC
457 depends on PCI_MMCONFIG
458 ---help---
459 Adds support for Numascale NumaChip large-SMP systems. Needed to
460 enable more than ~168 cores.
461 If you don't have one of these, you should say N here.
462
463 config X86_VSMP
464 bool "ScaleMP vSMP"
465 select HYPERVISOR_GUEST
466 select PARAVIRT
467 depends on X86_64 && PCI
468 depends on X86_EXTENDED_PLATFORM
469 depends on SMP
470 ---help---
471 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
472 supposed to run on these EM64T-based machines. Only choose this option
473 if you have one of these machines.
474
475 config X86_UV
476 bool "SGI Ultraviolet"
477 depends on X86_64
478 depends on X86_EXTENDED_PLATFORM
479 depends on NUMA
480 depends on EFI
481 depends on X86_X2APIC
482 depends on PCI
483 ---help---
484 This option is needed in order to support SGI Ultraviolet systems.
485 If you don't have one of these, you should say N here.
486
487 # Following is an alphabetically sorted list of 32 bit extended platforms
488 # Please maintain the alphabetic order if and when there are additions
489
490 config X86_GOLDFISH
491 bool "Goldfish (Virtual Platform)"
492 depends on X86_EXTENDED_PLATFORM
493 ---help---
494 Enable support for the Goldfish virtual platform used primarily
495 for Android development. Unless you are building for the Android
496 Goldfish emulator say N here.
497
498 config X86_INTEL_CE
499 bool "CE4100 TV platform"
500 depends on PCI
501 depends on PCI_GODIRECT
502 depends on X86_IO_APIC
503 depends on X86_32
504 depends on X86_EXTENDED_PLATFORM
505 select X86_REBOOTFIXUPS
506 select OF
507 select OF_EARLY_FLATTREE
508 ---help---
509 Select for the Intel CE media processor (CE4100) SOC.
510 This option compiles in support for the CE4100 SOC for settop
511 boxes and media devices.
512
513 config X86_INTEL_MID
514 bool "Intel MID platform support"
515 depends on X86_EXTENDED_PLATFORM
516 depends on X86_PLATFORM_DEVICES
517 depends on PCI
518 depends on X86_64 || (PCI_GOANY && X86_32)
519 depends on X86_IO_APIC
520 select SFI
521 select I2C
522 select DW_APB_TIMER
523 select APB_TIMER
524 select INTEL_SCU_IPC
525 select MFD_INTEL_MSIC
526 ---help---
527 Select to build a kernel capable of supporting Intel MID (Mobile
528 Internet Device) platform systems which do not have the PCI legacy
529 interfaces. If you are building for a PC class system say N here.
530
531 Intel MID platforms are based on an Intel processor and chipset which
532 consume less power than most of the x86 derivatives.
533
534 config X86_INTEL_QUARK
535 bool "Intel Quark platform support"
536 depends on X86_32
537 depends on X86_EXTENDED_PLATFORM
538 depends on X86_PLATFORM_DEVICES
539 depends on X86_TSC
540 depends on PCI
541 depends on PCI_GOANY
542 depends on X86_IO_APIC
543 select IOSF_MBI
544 select INTEL_IMR
545 select COMMON_CLK
546 ---help---
547 Select to include support for Quark X1000 SoC.
548 Say Y here if you have a Quark based system such as the Arduino
549 compatible Intel Galileo.
550
551 config X86_INTEL_LPSS
552 bool "Intel Low Power Subsystem Support"
553 depends on X86 && ACPI
554 select COMMON_CLK
555 select PINCTRL
556 select IOSF_MBI
557 ---help---
558 Select to build support for Intel Low Power Subsystem such as
559 found on Intel Lynxpoint PCH. Selecting this option enables
560 things like clock tree (common clock framework) and pincontrol
561 which are needed by the LPSS peripheral drivers.
562
563 config X86_AMD_PLATFORM_DEVICE
564 bool "AMD ACPI2Platform devices support"
565 depends on ACPI
566 select COMMON_CLK
567 select PINCTRL
568 ---help---
569 Select to interpret AMD specific ACPI device to platform device
570 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
571 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
572 implemented under PINCTRL subsystem.
573
574 config IOSF_MBI
575 tristate "Intel SoC IOSF Sideband support for SoC platforms"
576 depends on PCI
577 ---help---
578 This option enables sideband register access support for Intel SoC
579 platforms. On these platforms the IOSF sideband is used in lieu of
580 MSR's for some register accesses, mostly but not limited to thermal
581 and power. Drivers may query the availability of this device to
582 determine if they need the sideband in order to work on these
583 platforms. The sideband is available on the following SoC products.
584 This list is not meant to be exclusive.
585 - BayTrail
586 - Braswell
587 - Quark
588
589 You should say Y if you are running a kernel on one of these SoC's.
590
591 config IOSF_MBI_DEBUG
592 bool "Enable IOSF sideband access through debugfs"
593 depends on IOSF_MBI && DEBUG_FS
594 ---help---
595 Select this option to expose the IOSF sideband access registers (MCR,
596 MDR, MCRX) through debugfs to write and read register information from
597 different units on the SoC. This is most useful for obtaining device
598 state information for debug and analysis. As this is a general access
599 mechanism, users of this option would have specific knowledge of the
600 device they want to access.
601
602 If you don't require the option or are in doubt, say N.
603
604 config X86_RDC321X
605 bool "RDC R-321x SoC"
606 depends on X86_32
607 depends on X86_EXTENDED_PLATFORM
608 select M486
609 select X86_REBOOTFIXUPS
610 ---help---
611 This option is needed for RDC R-321x system-on-chip, also known
612 as R-8610-(G).
613 If you don't have one of these chips, you should say N here.
614
615 config X86_32_NON_STANDARD
616 bool "Support non-standard 32-bit SMP architectures"
617 depends on X86_32 && SMP
618 depends on X86_EXTENDED_PLATFORM
619 ---help---
620 This option compiles in the bigsmp and STA2X11 default
621 subarchitectures. It is intended for a generic binary
622 kernel. If you select them all, kernel will probe it one by
623 one and will fallback to default.
624
625 # Alphabetically sorted list of Non standard 32 bit platforms
626
627 config X86_SUPPORTS_MEMORY_FAILURE
628 def_bool y
629 # MCE code calls memory_failure():
630 depends on X86_MCE
631 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
632 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
633 depends on X86_64 || !SPARSEMEM
634 select ARCH_SUPPORTS_MEMORY_FAILURE
635
636 config STA2X11
637 bool "STA2X11 Companion Chip Support"
638 depends on X86_32_NON_STANDARD && PCI
639 select X86_DEV_DMA_OPS
640 select X86_DMA_REMAP
641 select SWIOTLB
642 select MFD_STA2X11
643 select GPIOLIB
644 default n
645 ---help---
646 This adds support for boards based on the STA2X11 IO-Hub,
647 a.k.a. "ConneXt". The chip is used in place of the standard
648 PC chipset, so all "standard" peripherals are missing. If this
649 option is selected the kernel will still be able to boot on
650 standard PC machines.
651
652 config X86_32_IRIS
653 tristate "Eurobraille/Iris poweroff module"
654 depends on X86_32
655 ---help---
656 The Iris machines from EuroBraille do not have APM or ACPI support
657 to shut themselves down properly. A special I/O sequence is
658 needed to do so, which is what this module does at
659 kernel shutdown.
660
661 This is only for Iris machines from EuroBraille.
662
663 If unused, say N.
664
665 config SCHED_OMIT_FRAME_POINTER
666 def_bool y
667 prompt "Single-depth WCHAN output"
668 depends on X86
669 ---help---
670 Calculate simpler /proc/<PID>/wchan values. If this option
671 is disabled then wchan values will recurse back to the
672 caller function. This provides more accurate wchan values,
673 at the expense of slightly more scheduling overhead.
674
675 If in doubt, say "Y".
676
677 menuconfig HYPERVISOR_GUEST
678 bool "Linux guest support"
679 ---help---
680 Say Y here to enable options for running Linux under various hyper-
681 visors. This option enables basic hypervisor detection and platform
682 setup.
683
684 If you say N, all options in this submenu will be skipped and
685 disabled, and Linux guest support won't be built in.
686
687 if HYPERVISOR_GUEST
688
689 config PARAVIRT
690 bool "Enable paravirtualization code"
691 ---help---
692 This changes the kernel so it can modify itself when it is run
693 under a hypervisor, potentially improving performance significantly
694 over full virtualization. However, when run without a hypervisor
695 the kernel is theoretically slower and slightly larger.
696
697 config PARAVIRT_DEBUG
698 bool "paravirt-ops debugging"
699 depends on PARAVIRT && DEBUG_KERNEL
700 ---help---
701 Enable to debug paravirt_ops internals. Specifically, BUG if
702 a paravirt_op is missing when it is called.
703
704 config PARAVIRT_SPINLOCKS
705 bool "Paravirtualization layer for spinlocks"
706 depends on PARAVIRT && SMP
707 select UNINLINE_SPIN_UNLOCK if !QUEUED_SPINLOCKS
708 ---help---
709 Paravirtualized spinlocks allow a pvops backend to replace the
710 spinlock implementation with something virtualization-friendly
711 (for example, block the virtual CPU rather than spinning).
712
713 It has a minimal impact on native kernels and gives a nice performance
714 benefit on paravirtualized KVM / Xen kernels.
715
716 If you are unsure how to answer this question, answer Y.
717
718 config QUEUED_LOCK_STAT
719 bool "Paravirt queued spinlock statistics"
720 depends on PARAVIRT_SPINLOCKS && DEBUG_FS && QUEUED_SPINLOCKS
721 ---help---
722 Enable the collection of statistical data on the slowpath
723 behavior of paravirtualized queued spinlocks and report
724 them on debugfs.
725
726 source "arch/x86/xen/Kconfig"
727
728 config KVM_GUEST
729 bool "KVM Guest support (including kvmclock)"
730 depends on PARAVIRT
731 select PARAVIRT_CLOCK
732 default y
733 ---help---
734 This option enables various optimizations for running under the KVM
735 hypervisor. It includes a paravirtualized clock, so that instead
736 of relying on a PIT (or probably other) emulation by the
737 underlying device model, the host provides the guest with
738 timing infrastructure such as time of day, and system time
739
740 config KVM_DEBUG_FS
741 bool "Enable debug information for KVM Guests in debugfs"
742 depends on KVM_GUEST && DEBUG_FS
743 default n
744 ---help---
745 This option enables collection of various statistics for KVM guest.
746 Statistics are displayed in debugfs filesystem. Enabling this option
747 may incur significant overhead.
748
749 source "arch/x86/lguest/Kconfig"
750
751 config PARAVIRT_TIME_ACCOUNTING
752 bool "Paravirtual steal time accounting"
753 depends on PARAVIRT
754 default n
755 ---help---
756 Select this option to enable fine granularity task steal time
757 accounting. Time spent executing other tasks in parallel with
758 the current vCPU is discounted from the vCPU power. To account for
759 that, there can be a small performance impact.
760
761 If in doubt, say N here.
762
763 config PARAVIRT_CLOCK
764 bool
765
766 endif #HYPERVISOR_GUEST
767
768 config NO_BOOTMEM
769 def_bool y
770
771 source "arch/x86/Kconfig.cpu"
772
773 config HPET_TIMER
774 def_bool X86_64
775 prompt "HPET Timer Support" if X86_32
776 ---help---
777 Use the IA-PC HPET (High Precision Event Timer) to manage
778 time in preference to the PIT and RTC, if a HPET is
779 present.
780 HPET is the next generation timer replacing legacy 8254s.
781 The HPET provides a stable time base on SMP
782 systems, unlike the TSC, but it is more expensive to access,
783 as it is off-chip. The interface used is documented
784 in the HPET spec, revision 1.
785
786 You can safely choose Y here. However, HPET will only be
787 activated if the platform and the BIOS support this feature.
788 Otherwise the 8254 will be used for timing services.
789
790 Choose N to continue using the legacy 8254 timer.
791
792 config HPET_EMULATE_RTC
793 def_bool y
794 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
795
796 config APB_TIMER
797 def_bool y if X86_INTEL_MID
798 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
799 select DW_APB_TIMER
800 depends on X86_INTEL_MID && SFI
801 help
802 APB timer is the replacement for 8254, HPET on X86 MID platforms.
803 The APBT provides a stable time base on SMP
804 systems, unlike the TSC, but it is more expensive to access,
805 as it is off-chip. APB timers are always running regardless of CPU
806 C states, they are used as per CPU clockevent device when possible.
807
808 # Mark as expert because too many people got it wrong.
809 # The code disables itself when not needed.
810 config DMI
811 default y
812 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
813 bool "Enable DMI scanning" if EXPERT
814 ---help---
815 Enabled scanning of DMI to identify machine quirks. Say Y
816 here unless you have verified that your setup is not
817 affected by entries in the DMI blacklist. Required by PNP
818 BIOS code.
819
820 config GART_IOMMU
821 bool "Old AMD GART IOMMU support"
822 select SWIOTLB
823 depends on X86_64 && PCI && AMD_NB
824 ---help---
825 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
826 GART based hardware IOMMUs.
827
828 The GART supports full DMA access for devices with 32-bit access
829 limitations, on systems with more than 3 GB. This is usually needed
830 for USB, sound, many IDE/SATA chipsets and some other devices.
831
832 Newer systems typically have a modern AMD IOMMU, supported via
833 the CONFIG_AMD_IOMMU=y config option.
834
835 In normal configurations this driver is only active when needed:
836 there's more than 3 GB of memory and the system contains a
837 32-bit limited device.
838
839 If unsure, say Y.
840
841 config CALGARY_IOMMU
842 bool "IBM Calgary IOMMU support"
843 select SWIOTLB
844 depends on X86_64 && PCI
845 ---help---
846 Support for hardware IOMMUs in IBM's xSeries x366 and x460
847 systems. Needed to run systems with more than 3GB of memory
848 properly with 32-bit PCI devices that do not support DAC
849 (Double Address Cycle). Calgary also supports bus level
850 isolation, where all DMAs pass through the IOMMU. This
851 prevents them from going anywhere except their intended
852 destination. This catches hard-to-find kernel bugs and
853 mis-behaving drivers and devices that do not use the DMA-API
854 properly to set up their DMA buffers. The IOMMU can be
855 turned off at boot time with the iommu=off parameter.
856 Normally the kernel will make the right choice by itself.
857 If unsure, say Y.
858
859 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
860 def_bool y
861 prompt "Should Calgary be enabled by default?"
862 depends on CALGARY_IOMMU
863 ---help---
864 Should Calgary be enabled by default? if you choose 'y', Calgary
865 will be used (if it exists). If you choose 'n', Calgary will not be
866 used even if it exists. If you choose 'n' and would like to use
867 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
868 If unsure, say Y.
869
870 # need this always selected by IOMMU for the VIA workaround
871 config SWIOTLB
872 def_bool y if X86_64
873 ---help---
874 Support for software bounce buffers used on x86-64 systems
875 which don't have a hardware IOMMU. Using this PCI devices
876 which can only access 32-bits of memory can be used on systems
877 with more than 3 GB of memory.
878 If unsure, say Y.
879
880 config IOMMU_HELPER
881 def_bool y
882 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
883
884 config MAXSMP
885 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
886 depends on X86_64 && SMP && DEBUG_KERNEL
887 select CPUMASK_OFFSTACK
888 ---help---
889 Enable maximum number of CPUS and NUMA Nodes for this architecture.
890 If unsure, say N.
891
892 config NR_CPUS
893 int "Maximum number of CPUs" if SMP && !MAXSMP
894 range 2 8 if SMP && X86_32 && !X86_BIGSMP
895 range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK
896 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
897 default "1" if !SMP
898 default "8192" if MAXSMP
899 default "32" if SMP && X86_BIGSMP
900 default "8" if SMP && X86_32
901 default "64" if SMP
902 ---help---
903 This allows you to specify the maximum number of CPUs which this
904 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
905 supported value is 8192, otherwise the maximum value is 512. The
906 minimum value which makes sense is 2.
907
908 This is purely to save memory - each supported CPU adds
909 approximately eight kilobytes to the kernel image.
910
911 config SCHED_SMT
912 bool "SMT (Hyperthreading) scheduler support"
913 depends on SMP
914 ---help---
915 SMT scheduler support improves the CPU scheduler's decision making
916 when dealing with Intel Pentium 4 chips with HyperThreading at a
917 cost of slightly increased overhead in some places. If unsure say
918 N here.
919
920 config SCHED_MC
921 def_bool y
922 prompt "Multi-core scheduler support"
923 depends on SMP
924 ---help---
925 Multi-core scheduler support improves the CPU scheduler's decision
926 making when dealing with multi-core CPU chips at a cost of slightly
927 increased overhead in some places. If unsure say N here.
928
929 source "kernel/Kconfig.preempt"
930
931 config UP_LATE_INIT
932 def_bool y
933 depends on !SMP && X86_LOCAL_APIC
934
935 config X86_UP_APIC
936 bool "Local APIC support on uniprocessors" if !PCI_MSI
937 default PCI_MSI
938 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
939 ---help---
940 A local APIC (Advanced Programmable Interrupt Controller) is an
941 integrated interrupt controller in the CPU. If you have a single-CPU
942 system which has a processor with a local APIC, you can say Y here to
943 enable and use it. If you say Y here even though your machine doesn't
944 have a local APIC, then the kernel will still run with no slowdown at
945 all. The local APIC supports CPU-generated self-interrupts (timer,
946 performance counters), and the NMI watchdog which detects hard
947 lockups.
948
949 config X86_UP_IOAPIC
950 bool "IO-APIC support on uniprocessors"
951 depends on X86_UP_APIC
952 ---help---
953 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
954 SMP-capable replacement for PC-style interrupt controllers. Most
955 SMP systems and many recent uniprocessor systems have one.
956
957 If you have a single-CPU system with an IO-APIC, you can say Y here
958 to use it. If you say Y here even though your machine doesn't have
959 an IO-APIC, then the kernel will still run with no slowdown at all.
960
961 config X86_LOCAL_APIC
962 def_bool y
963 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
964 select IRQ_DOMAIN_HIERARCHY
965 select PCI_MSI_IRQ_DOMAIN if PCI_MSI
966
967 config X86_IO_APIC
968 def_bool y
969 depends on X86_LOCAL_APIC || X86_UP_IOAPIC
970
971 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
972 bool "Reroute for broken boot IRQs"
973 depends on X86_IO_APIC
974 ---help---
975 This option enables a workaround that fixes a source of
976 spurious interrupts. This is recommended when threaded
977 interrupt handling is used on systems where the generation of
978 superfluous "boot interrupts" cannot be disabled.
979
980 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
981 entry in the chipset's IO-APIC is masked (as, e.g. the RT
982 kernel does during interrupt handling). On chipsets where this
983 boot IRQ generation cannot be disabled, this workaround keeps
984 the original IRQ line masked so that only the equivalent "boot
985 IRQ" is delivered to the CPUs. The workaround also tells the
986 kernel to set up the IRQ handler on the boot IRQ line. In this
987 way only one interrupt is delivered to the kernel. Otherwise
988 the spurious second interrupt may cause the kernel to bring
989 down (vital) interrupt lines.
990
991 Only affects "broken" chipsets. Interrupt sharing may be
992 increased on these systems.
993
994 config X86_MCE
995 bool "Machine Check / overheating reporting"
996 select GENERIC_ALLOCATOR
997 default y
998 ---help---
999 Machine Check support allows the processor to notify the
1000 kernel if it detects a problem (e.g. overheating, data corruption).
1001 The action the kernel takes depends on the severity of the problem,
1002 ranging from warning messages to halting the machine.
1003
1004 config X86_MCE_INTEL
1005 def_bool y
1006 prompt "Intel MCE features"
1007 depends on X86_MCE && X86_LOCAL_APIC
1008 ---help---
1009 Additional support for intel specific MCE features such as
1010 the thermal monitor.
1011
1012 config X86_MCE_AMD
1013 def_bool y
1014 prompt "AMD MCE features"
1015 depends on X86_MCE && X86_LOCAL_APIC
1016 ---help---
1017 Additional support for AMD specific MCE features such as
1018 the DRAM Error Threshold.
1019
1020 config X86_ANCIENT_MCE
1021 bool "Support for old Pentium 5 / WinChip machine checks"
1022 depends on X86_32 && X86_MCE
1023 ---help---
1024 Include support for machine check handling on old Pentium 5 or WinChip
1025 systems. These typically need to be enabled explicitly on the command
1026 line.
1027
1028 config X86_MCE_THRESHOLD
1029 depends on X86_MCE_AMD || X86_MCE_INTEL
1030 def_bool y
1031
1032 config X86_MCE_INJECT
1033 depends on X86_MCE
1034 tristate "Machine check injector support"
1035 ---help---
1036 Provide support for injecting machine checks for testing purposes.
1037 If you don't know what a machine check is and you don't do kernel
1038 QA it is safe to say n.
1039
1040 config X86_THERMAL_VECTOR
1041 def_bool y
1042 depends on X86_MCE_INTEL
1043
1044 source "arch/x86/events/Kconfig"
1045
1046 config X86_LEGACY_VM86
1047 bool "Legacy VM86 support"
1048 default n
1049 depends on X86_32
1050 ---help---
1051 This option allows user programs to put the CPU into V8086
1052 mode, which is an 80286-era approximation of 16-bit real mode.
1053
1054 Some very old versions of X and/or vbetool require this option
1055 for user mode setting. Similarly, DOSEMU will use it if
1056 available to accelerate real mode DOS programs. However, any
1057 recent version of DOSEMU, X, or vbetool should be fully
1058 functional even without kernel VM86 support, as they will all
1059 fall back to software emulation. Nevertheless, if you are using
1060 a 16-bit DOS program where 16-bit performance matters, vm86
1061 mode might be faster than emulation and you might want to
1062 enable this option.
1063
1064 Note that any app that works on a 64-bit kernel is unlikely to
1065 need this option, as 64-bit kernels don't, and can't, support
1066 V8086 mode. This option is also unrelated to 16-bit protected
1067 mode and is not needed to run most 16-bit programs under Wine.
1068
1069 Enabling this option increases the complexity of the kernel
1070 and slows down exception handling a tiny bit.
1071
1072 If unsure, say N here.
1073
1074 config VM86
1075 bool
1076 default X86_LEGACY_VM86
1077
1078 config X86_16BIT
1079 bool "Enable support for 16-bit segments" if EXPERT
1080 default y
1081 depends on MODIFY_LDT_SYSCALL
1082 ---help---
1083 This option is required by programs like Wine to run 16-bit
1084 protected mode legacy code on x86 processors. Disabling
1085 this option saves about 300 bytes on i386, or around 6K text
1086 plus 16K runtime memory on x86-64,
1087
1088 config X86_ESPFIX32
1089 def_bool y
1090 depends on X86_16BIT && X86_32
1091
1092 config X86_ESPFIX64
1093 def_bool y
1094 depends on X86_16BIT && X86_64
1095
1096 config X86_VSYSCALL_EMULATION
1097 bool "Enable vsyscall emulation" if EXPERT
1098 default y
1099 depends on X86_64
1100 ---help---
1101 This enables emulation of the legacy vsyscall page. Disabling
1102 it is roughly equivalent to booting with vsyscall=none, except
1103 that it will also disable the helpful warning if a program
1104 tries to use a vsyscall. With this option set to N, offending
1105 programs will just segfault, citing addresses of the form
1106 0xffffffffff600?00.
1107
1108 This option is required by many programs built before 2013, and
1109 care should be used even with newer programs if set to N.
1110
1111 Disabling this option saves about 7K of kernel size and
1112 possibly 4K of additional runtime pagetable memory.
1113
1114 config TOSHIBA
1115 tristate "Toshiba Laptop support"
1116 depends on X86_32
1117 ---help---
1118 This adds a driver to safely access the System Management Mode of
1119 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1120 not work on models with a Phoenix BIOS. The System Management Mode
1121 is used to set the BIOS and power saving options on Toshiba portables.
1122
1123 For information on utilities to make use of this driver see the
1124 Toshiba Linux utilities web site at:
1125 <http://www.buzzard.org.uk/toshiba/>.
1126
1127 Say Y if you intend to run this kernel on a Toshiba portable.
1128 Say N otherwise.
1129
1130 config I8K
1131 tristate "Dell i8k legacy laptop support"
1132 select HWMON
1133 select SENSORS_DELL_SMM
1134 ---help---
1135 This option enables legacy /proc/i8k userspace interface in hwmon
1136 dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1137 temperature and allows controlling fan speeds of Dell laptops via
1138 System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1139 it reports also power and hotkey status. For fan speed control is
1140 needed userspace package i8kutils.
1141
1142 Say Y if you intend to run this kernel on old Dell laptops or want to
1143 use userspace package i8kutils.
1144 Say N otherwise.
1145
1146 config X86_REBOOTFIXUPS
1147 bool "Enable X86 board specific fixups for reboot"
1148 depends on X86_32
1149 ---help---
1150 This enables chipset and/or board specific fixups to be done
1151 in order to get reboot to work correctly. This is only needed on
1152 some combinations of hardware and BIOS. The symptom, for which
1153 this config is intended, is when reboot ends with a stalled/hung
1154 system.
1155
1156 Currently, the only fixup is for the Geode machines using
1157 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1158
1159 Say Y if you want to enable the fixup. Currently, it's safe to
1160 enable this option even if you don't need it.
1161 Say N otherwise.
1162
1163 config MICROCODE
1164 bool "CPU microcode loading support"
1165 default y
1166 depends on CPU_SUP_AMD || CPU_SUP_INTEL
1167 select FW_LOADER
1168 ---help---
1169 If you say Y here, you will be able to update the microcode on
1170 Intel and AMD processors. The Intel support is for the IA32 family,
1171 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
1172 AMD support is for families 0x10 and later. You will obviously need
1173 the actual microcode binary data itself which is not shipped with
1174 the Linux kernel.
1175
1176 The preferred method to load microcode from a detached initrd is described
1177 in Documentation/x86/early-microcode.txt. For that you need to enable
1178 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
1179 initrd for microcode blobs.
1180
1181 In addition, you can build-in the microcode into the kernel. For that you
1182 need to enable FIRMWARE_IN_KERNEL and add the vendor-supplied microcode
1183 to the CONFIG_EXTRA_FIRMWARE config option.
1184
1185 config MICROCODE_INTEL
1186 bool "Intel microcode loading support"
1187 depends on MICROCODE
1188 default MICROCODE
1189 select FW_LOADER
1190 ---help---
1191 This options enables microcode patch loading support for Intel
1192 processors.
1193
1194 For the current Intel microcode data package go to
1195 <https://downloadcenter.intel.com> and search for
1196 'Linux Processor Microcode Data File'.
1197
1198 config MICROCODE_AMD
1199 bool "AMD microcode loading support"
1200 depends on MICROCODE
1201 select FW_LOADER
1202 ---help---
1203 If you select this option, microcode patch loading support for AMD
1204 processors will be enabled.
1205
1206 config MICROCODE_OLD_INTERFACE
1207 def_bool y
1208 depends on MICROCODE
1209
1210 config X86_MSR
1211 tristate "/dev/cpu/*/msr - Model-specific register support"
1212 ---help---
1213 This device gives privileged processes access to the x86
1214 Model-Specific Registers (MSRs). It is a character device with
1215 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1216 MSR accesses are directed to a specific CPU on multi-processor
1217 systems.
1218
1219 config X86_CPUID
1220 tristate "/dev/cpu/*/cpuid - CPU information support"
1221 ---help---
1222 This device gives processes access to the x86 CPUID instruction to
1223 be executed on a specific processor. It is a character device
1224 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1225 /dev/cpu/31/cpuid.
1226
1227 choice
1228 prompt "High Memory Support"
1229 default HIGHMEM4G
1230 depends on X86_32
1231
1232 config NOHIGHMEM
1233 bool "off"
1234 ---help---
1235 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1236 However, the address space of 32-bit x86 processors is only 4
1237 Gigabytes large. That means that, if you have a large amount of
1238 physical memory, not all of it can be "permanently mapped" by the
1239 kernel. The physical memory that's not permanently mapped is called
1240 "high memory".
1241
1242 If you are compiling a kernel which will never run on a machine with
1243 more than 1 Gigabyte total physical RAM, answer "off" here (default
1244 choice and suitable for most users). This will result in a "3GB/1GB"
1245 split: 3GB are mapped so that each process sees a 3GB virtual memory
1246 space and the remaining part of the 4GB virtual memory space is used
1247 by the kernel to permanently map as much physical memory as
1248 possible.
1249
1250 If the machine has between 1 and 4 Gigabytes physical RAM, then
1251 answer "4GB" here.
1252
1253 If more than 4 Gigabytes is used then answer "64GB" here. This
1254 selection turns Intel PAE (Physical Address Extension) mode on.
1255 PAE implements 3-level paging on IA32 processors. PAE is fully
1256 supported by Linux, PAE mode is implemented on all recent Intel
1257 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1258 then the kernel will not boot on CPUs that don't support PAE!
1259
1260 The actual amount of total physical memory will either be
1261 auto detected or can be forced by using a kernel command line option
1262 such as "mem=256M". (Try "man bootparam" or see the documentation of
1263 your boot loader (lilo or loadlin) about how to pass options to the
1264 kernel at boot time.)
1265
1266 If unsure, say "off".
1267
1268 config HIGHMEM4G
1269 bool "4GB"
1270 ---help---
1271 Select this if you have a 32-bit processor and between 1 and 4
1272 gigabytes of physical RAM.
1273
1274 config HIGHMEM64G
1275 bool "64GB"
1276 depends on !M486
1277 select X86_PAE
1278 ---help---
1279 Select this if you have a 32-bit processor and more than 4
1280 gigabytes of physical RAM.
1281
1282 endchoice
1283
1284 choice
1285 prompt "Memory split" if EXPERT
1286 default VMSPLIT_3G
1287 depends on X86_32
1288 ---help---
1289 Select the desired split between kernel and user memory.
1290
1291 If the address range available to the kernel is less than the
1292 physical memory installed, the remaining memory will be available
1293 as "high memory". Accessing high memory is a little more costly
1294 than low memory, as it needs to be mapped into the kernel first.
1295 Note that increasing the kernel address space limits the range
1296 available to user programs, making the address space there
1297 tighter. Selecting anything other than the default 3G/1G split
1298 will also likely make your kernel incompatible with binary-only
1299 kernel modules.
1300
1301 If you are not absolutely sure what you are doing, leave this
1302 option alone!
1303
1304 config VMSPLIT_3G
1305 bool "3G/1G user/kernel split"
1306 config VMSPLIT_3G_OPT
1307 depends on !X86_PAE
1308 bool "3G/1G user/kernel split (for full 1G low memory)"
1309 config VMSPLIT_2G
1310 bool "2G/2G user/kernel split"
1311 config VMSPLIT_2G_OPT
1312 depends on !X86_PAE
1313 bool "2G/2G user/kernel split (for full 2G low memory)"
1314 config VMSPLIT_1G
1315 bool "1G/3G user/kernel split"
1316 endchoice
1317
1318 config PAGE_OFFSET
1319 hex
1320 default 0xB0000000 if VMSPLIT_3G_OPT
1321 default 0x80000000 if VMSPLIT_2G
1322 default 0x78000000 if VMSPLIT_2G_OPT
1323 default 0x40000000 if VMSPLIT_1G
1324 default 0xC0000000
1325 depends on X86_32
1326
1327 config HIGHMEM
1328 def_bool y
1329 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1330
1331 config X86_PAE
1332 bool "PAE (Physical Address Extension) Support"
1333 depends on X86_32 && !HIGHMEM4G
1334 select SWIOTLB
1335 ---help---
1336 PAE is required for NX support, and furthermore enables
1337 larger swapspace support for non-overcommit purposes. It
1338 has the cost of more pagetable lookup overhead, and also
1339 consumes more pagetable space per process.
1340
1341 config ARCH_PHYS_ADDR_T_64BIT
1342 def_bool y
1343 depends on X86_64 || X86_PAE
1344
1345 config ARCH_DMA_ADDR_T_64BIT
1346 def_bool y
1347 depends on X86_64 || HIGHMEM64G
1348
1349 config X86_DIRECT_GBPAGES
1350 def_bool y
1351 depends on X86_64 && !DEBUG_PAGEALLOC && !KMEMCHECK
1352 ---help---
1353 Certain kernel features effectively disable kernel
1354 linear 1 GB mappings (even if the CPU otherwise
1355 supports them), so don't confuse the user by printing
1356 that we have them enabled.
1357
1358 # Common NUMA Features
1359 config NUMA
1360 bool "Numa Memory Allocation and Scheduler Support"
1361 depends on SMP
1362 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1363 default y if X86_BIGSMP
1364 ---help---
1365 Enable NUMA (Non Uniform Memory Access) support.
1366
1367 The kernel will try to allocate memory used by a CPU on the
1368 local memory controller of the CPU and add some more
1369 NUMA awareness to the kernel.
1370
1371 For 64-bit this is recommended if the system is Intel Core i7
1372 (or later), AMD Opteron, or EM64T NUMA.
1373
1374 For 32-bit this is only needed if you boot a 32-bit
1375 kernel on a 64-bit NUMA platform.
1376
1377 Otherwise, you should say N.
1378
1379 config AMD_NUMA
1380 def_bool y
1381 prompt "Old style AMD Opteron NUMA detection"
1382 depends on X86_64 && NUMA && PCI
1383 ---help---
1384 Enable AMD NUMA node topology detection. You should say Y here if
1385 you have a multi processor AMD system. This uses an old method to
1386 read the NUMA configuration directly from the builtin Northbridge
1387 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1388 which also takes priority if both are compiled in.
1389
1390 config X86_64_ACPI_NUMA
1391 def_bool y
1392 prompt "ACPI NUMA detection"
1393 depends on X86_64 && NUMA && ACPI && PCI
1394 select ACPI_NUMA
1395 ---help---
1396 Enable ACPI SRAT based node topology detection.
1397
1398 # Some NUMA nodes have memory ranges that span
1399 # other nodes. Even though a pfn is valid and
1400 # between a node's start and end pfns, it may not
1401 # reside on that node. See memmap_init_zone()
1402 # for details.
1403 config NODES_SPAN_OTHER_NODES
1404 def_bool y
1405 depends on X86_64_ACPI_NUMA
1406
1407 config NUMA_EMU
1408 bool "NUMA emulation"
1409 depends on NUMA
1410 ---help---
1411 Enable NUMA emulation. A flat machine will be split
1412 into virtual nodes when booted with "numa=fake=N", where N is the
1413 number of nodes. This is only useful for debugging.
1414
1415 config NODES_SHIFT
1416 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1417 range 1 10
1418 default "10" if MAXSMP
1419 default "6" if X86_64
1420 default "3"
1421 depends on NEED_MULTIPLE_NODES
1422 ---help---
1423 Specify the maximum number of NUMA Nodes available on the target
1424 system. Increases memory reserved to accommodate various tables.
1425
1426 config ARCH_HAVE_MEMORY_PRESENT
1427 def_bool y
1428 depends on X86_32 && DISCONTIGMEM
1429
1430 config NEED_NODE_MEMMAP_SIZE
1431 def_bool y
1432 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1433
1434 config ARCH_FLATMEM_ENABLE
1435 def_bool y
1436 depends on X86_32 && !NUMA
1437
1438 config ARCH_DISCONTIGMEM_ENABLE
1439 def_bool y
1440 depends on NUMA && X86_32
1441
1442 config ARCH_DISCONTIGMEM_DEFAULT
1443 def_bool y
1444 depends on NUMA && X86_32
1445
1446 config ARCH_SPARSEMEM_ENABLE
1447 def_bool y
1448 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1449 select SPARSEMEM_STATIC if X86_32
1450 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1451
1452 config ARCH_SPARSEMEM_DEFAULT
1453 def_bool y
1454 depends on X86_64
1455
1456 config ARCH_SELECT_MEMORY_MODEL
1457 def_bool y
1458 depends on ARCH_SPARSEMEM_ENABLE
1459
1460 config ARCH_MEMORY_PROBE
1461 bool "Enable sysfs memory/probe interface"
1462 depends on X86_64 && MEMORY_HOTPLUG
1463 help
1464 This option enables a sysfs memory/probe interface for testing.
1465 See Documentation/memory-hotplug.txt for more information.
1466 If you are unsure how to answer this question, answer N.
1467
1468 config ARCH_PROC_KCORE_TEXT
1469 def_bool y
1470 depends on X86_64 && PROC_KCORE
1471
1472 config ILLEGAL_POINTER_VALUE
1473 hex
1474 default 0 if X86_32
1475 default 0xdead000000000000 if X86_64
1476
1477 source "mm/Kconfig"
1478
1479 config X86_PMEM_LEGACY_DEVICE
1480 bool
1481
1482 config X86_PMEM_LEGACY
1483 tristate "Support non-standard NVDIMMs and ADR protected memory"
1484 depends on PHYS_ADDR_T_64BIT
1485 depends on BLK_DEV
1486 select X86_PMEM_LEGACY_DEVICE
1487 select LIBNVDIMM
1488 help
1489 Treat memory marked using the non-standard e820 type of 12 as used
1490 by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1491 The kernel will offer these regions to the 'pmem' driver so
1492 they can be used for persistent storage.
1493
1494 Say Y if unsure.
1495
1496 config HIGHPTE
1497 bool "Allocate 3rd-level pagetables from highmem"
1498 depends on HIGHMEM
1499 ---help---
1500 The VM uses one page table entry for each page of physical memory.
1501 For systems with a lot of RAM, this can be wasteful of precious
1502 low memory. Setting this option will put user-space page table
1503 entries in high memory.
1504
1505 config X86_CHECK_BIOS_CORRUPTION
1506 bool "Check for low memory corruption"
1507 ---help---
1508 Periodically check for memory corruption in low memory, which
1509 is suspected to be caused by BIOS. Even when enabled in the
1510 configuration, it is disabled at runtime. Enable it by
1511 setting "memory_corruption_check=1" on the kernel command
1512 line. By default it scans the low 64k of memory every 60
1513 seconds; see the memory_corruption_check_size and
1514 memory_corruption_check_period parameters in
1515 Documentation/kernel-parameters.txt to adjust this.
1516
1517 When enabled with the default parameters, this option has
1518 almost no overhead, as it reserves a relatively small amount
1519 of memory and scans it infrequently. It both detects corruption
1520 and prevents it from affecting the running system.
1521
1522 It is, however, intended as a diagnostic tool; if repeatable
1523 BIOS-originated corruption always affects the same memory,
1524 you can use memmap= to prevent the kernel from using that
1525 memory.
1526
1527 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1528 bool "Set the default setting of memory_corruption_check"
1529 depends on X86_CHECK_BIOS_CORRUPTION
1530 default y
1531 ---help---
1532 Set whether the default state of memory_corruption_check is
1533 on or off.
1534
1535 config X86_RESERVE_LOW
1536 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1537 default 64
1538 range 4 640
1539 ---help---
1540 Specify the amount of low memory to reserve for the BIOS.
1541
1542 The first page contains BIOS data structures that the kernel
1543 must not use, so that page must always be reserved.
1544
1545 By default we reserve the first 64K of physical RAM, as a
1546 number of BIOSes are known to corrupt that memory range
1547 during events such as suspend/resume or monitor cable
1548 insertion, so it must not be used by the kernel.
1549
1550 You can set this to 4 if you are absolutely sure that you
1551 trust the BIOS to get all its memory reservations and usages
1552 right. If you know your BIOS have problems beyond the
1553 default 64K area, you can set this to 640 to avoid using the
1554 entire low memory range.
1555
1556 If you have doubts about the BIOS (e.g. suspend/resume does
1557 not work or there's kernel crashes after certain hardware
1558 hotplug events) then you might want to enable
1559 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1560 typical corruption patterns.
1561
1562 Leave this to the default value of 64 if you are unsure.
1563
1564 config MATH_EMULATION
1565 bool
1566 depends on MODIFY_LDT_SYSCALL
1567 prompt "Math emulation" if X86_32
1568 ---help---
1569 Linux can emulate a math coprocessor (used for floating point
1570 operations) if you don't have one. 486DX and Pentium processors have
1571 a math coprocessor built in, 486SX and 386 do not, unless you added
1572 a 487DX or 387, respectively. (The messages during boot time can
1573 give you some hints here ["man dmesg"].) Everyone needs either a
1574 coprocessor or this emulation.
1575
1576 If you don't have a math coprocessor, you need to say Y here; if you
1577 say Y here even though you have a coprocessor, the coprocessor will
1578 be used nevertheless. (This behavior can be changed with the kernel
1579 command line option "no387", which comes handy if your coprocessor
1580 is broken. Try "man bootparam" or see the documentation of your boot
1581 loader (lilo or loadlin) about how to pass options to the kernel at
1582 boot time.) This means that it is a good idea to say Y here if you
1583 intend to use this kernel on different machines.
1584
1585 More information about the internals of the Linux math coprocessor
1586 emulation can be found in <file:arch/x86/math-emu/README>.
1587
1588 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1589 kernel, it won't hurt.
1590
1591 config MTRR
1592 def_bool y
1593 prompt "MTRR (Memory Type Range Register) support" if EXPERT
1594 ---help---
1595 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1596 the Memory Type Range Registers (MTRRs) may be used to control
1597 processor access to memory ranges. This is most useful if you have
1598 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1599 allows bus write transfers to be combined into a larger transfer
1600 before bursting over the PCI/AGP bus. This can increase performance
1601 of image write operations 2.5 times or more. Saying Y here creates a
1602 /proc/mtrr file which may be used to manipulate your processor's
1603 MTRRs. Typically the X server should use this.
1604
1605 This code has a reasonably generic interface so that similar
1606 control registers on other processors can be easily supported
1607 as well:
1608
1609 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1610 Registers (ARRs) which provide a similar functionality to MTRRs. For
1611 these, the ARRs are used to emulate the MTRRs.
1612 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1613 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1614 write-combining. All of these processors are supported by this code
1615 and it makes sense to say Y here if you have one of them.
1616
1617 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1618 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1619 can lead to all sorts of problems, so it's good to say Y here.
1620
1621 You can safely say Y even if your machine doesn't have MTRRs, you'll
1622 just add about 9 KB to your kernel.
1623
1624 See <file:Documentation/x86/mtrr.txt> for more information.
1625
1626 config MTRR_SANITIZER
1627 def_bool y
1628 prompt "MTRR cleanup support"
1629 depends on MTRR
1630 ---help---
1631 Convert MTRR layout from continuous to discrete, so X drivers can
1632 add writeback entries.
1633
1634 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1635 The largest mtrr entry size for a continuous block can be set with
1636 mtrr_chunk_size.
1637
1638 If unsure, say Y.
1639
1640 config MTRR_SANITIZER_ENABLE_DEFAULT
1641 int "MTRR cleanup enable value (0-1)"
1642 range 0 1
1643 default "0"
1644 depends on MTRR_SANITIZER
1645 ---help---
1646 Enable mtrr cleanup default value
1647
1648 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1649 int "MTRR cleanup spare reg num (0-7)"
1650 range 0 7
1651 default "1"
1652 depends on MTRR_SANITIZER
1653 ---help---
1654 mtrr cleanup spare entries default, it can be changed via
1655 mtrr_spare_reg_nr=N on the kernel command line.
1656
1657 config X86_PAT
1658 def_bool y
1659 prompt "x86 PAT support" if EXPERT
1660 depends on MTRR
1661 ---help---
1662 Use PAT attributes to setup page level cache control.
1663
1664 PATs are the modern equivalents of MTRRs and are much more
1665 flexible than MTRRs.
1666
1667 Say N here if you see bootup problems (boot crash, boot hang,
1668 spontaneous reboots) or a non-working video driver.
1669
1670 If unsure, say Y.
1671
1672 config ARCH_USES_PG_UNCACHED
1673 def_bool y
1674 depends on X86_PAT
1675
1676 config ARCH_RANDOM
1677 def_bool y
1678 prompt "x86 architectural random number generator" if EXPERT
1679 ---help---
1680 Enable the x86 architectural RDRAND instruction
1681 (Intel Bull Mountain technology) to generate random numbers.
1682 If supported, this is a high bandwidth, cryptographically
1683 secure hardware random number generator.
1684
1685 config X86_SMAP
1686 def_bool y
1687 prompt "Supervisor Mode Access Prevention" if EXPERT
1688 ---help---
1689 Supervisor Mode Access Prevention (SMAP) is a security
1690 feature in newer Intel processors. There is a small
1691 performance cost if this enabled and turned on; there is
1692 also a small increase in the kernel size if this is enabled.
1693
1694 If unsure, say Y.
1695
1696 config X86_INTEL_MPX
1697 prompt "Intel MPX (Memory Protection Extensions)"
1698 def_bool n
1699 depends on CPU_SUP_INTEL
1700 ---help---
1701 MPX provides hardware features that can be used in
1702 conjunction with compiler-instrumented code to check
1703 memory references. It is designed to detect buffer
1704 overflow or underflow bugs.
1705
1706 This option enables running applications which are
1707 instrumented or otherwise use MPX. It does not use MPX
1708 itself inside the kernel or to protect the kernel
1709 against bad memory references.
1710
1711 Enabling this option will make the kernel larger:
1712 ~8k of kernel text and 36 bytes of data on a 64-bit
1713 defconfig. It adds a long to the 'mm_struct' which
1714 will increase the kernel memory overhead of each
1715 process and adds some branches to paths used during
1716 exec() and munmap().
1717
1718 For details, see Documentation/x86/intel_mpx.txt
1719
1720 If unsure, say N.
1721
1722 config X86_INTEL_MEMORY_PROTECTION_KEYS
1723 prompt "Intel Memory Protection Keys"
1724 def_bool y
1725 # Note: only available in 64-bit mode
1726 depends on CPU_SUP_INTEL && X86_64
1727 ---help---
1728 Memory Protection Keys provides a mechanism for enforcing
1729 page-based protections, but without requiring modification of the
1730 page tables when an application changes protection domains.
1731
1732 For details, see Documentation/x86/protection-keys.txt
1733
1734 If unsure, say y.
1735
1736 config EFI
1737 bool "EFI runtime service support"
1738 depends on ACPI
1739 select UCS2_STRING
1740 select EFI_RUNTIME_WRAPPERS
1741 ---help---
1742 This enables the kernel to use EFI runtime services that are
1743 available (such as the EFI variable services).
1744
1745 This option is only useful on systems that have EFI firmware.
1746 In addition, you should use the latest ELILO loader available
1747 at <http://elilo.sourceforge.net> in order to take advantage
1748 of EFI runtime services. However, even with this option, the
1749 resultant kernel should continue to boot on existing non-EFI
1750 platforms.
1751
1752 config EFI_STUB
1753 bool "EFI stub support"
1754 depends on EFI && !X86_USE_3DNOW
1755 select RELOCATABLE
1756 ---help---
1757 This kernel feature allows a bzImage to be loaded directly
1758 by EFI firmware without the use of a bootloader.
1759
1760 See Documentation/efi-stub.txt for more information.
1761
1762 config EFI_MIXED
1763 bool "EFI mixed-mode support"
1764 depends on EFI_STUB && X86_64
1765 ---help---
1766 Enabling this feature allows a 64-bit kernel to be booted
1767 on a 32-bit firmware, provided that your CPU supports 64-bit
1768 mode.
1769
1770 Note that it is not possible to boot a mixed-mode enabled
1771 kernel via the EFI boot stub - a bootloader that supports
1772 the EFI handover protocol must be used.
1773
1774 If unsure, say N.
1775
1776 config SECCOMP
1777 def_bool y
1778 prompt "Enable seccomp to safely compute untrusted bytecode"
1779 ---help---
1780 This kernel feature is useful for number crunching applications
1781 that may need to compute untrusted bytecode during their
1782 execution. By using pipes or other transports made available to
1783 the process as file descriptors supporting the read/write
1784 syscalls, it's possible to isolate those applications in
1785 their own address space using seccomp. Once seccomp is
1786 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1787 and the task is only allowed to execute a few safe syscalls
1788 defined by each seccomp mode.
1789
1790 If unsure, say Y. Only embedded should say N here.
1791
1792 source kernel/Kconfig.hz
1793
1794 config KEXEC
1795 bool "kexec system call"
1796 select KEXEC_CORE
1797 ---help---
1798 kexec is a system call that implements the ability to shutdown your
1799 current kernel, and to start another kernel. It is like a reboot
1800 but it is independent of the system firmware. And like a reboot
1801 you can start any kernel with it, not just Linux.
1802
1803 The name comes from the similarity to the exec system call.
1804
1805 It is an ongoing process to be certain the hardware in a machine
1806 is properly shutdown, so do not be surprised if this code does not
1807 initially work for you. As of this writing the exact hardware
1808 interface is strongly in flux, so no good recommendation can be
1809 made.
1810
1811 config KEXEC_FILE
1812 bool "kexec file based system call"
1813 select KEXEC_CORE
1814 select BUILD_BIN2C
1815 depends on X86_64
1816 depends on CRYPTO=y
1817 depends on CRYPTO_SHA256=y
1818 ---help---
1819 This is new version of kexec system call. This system call is
1820 file based and takes file descriptors as system call argument
1821 for kernel and initramfs as opposed to list of segments as
1822 accepted by previous system call.
1823
1824 config KEXEC_VERIFY_SIG
1825 bool "Verify kernel signature during kexec_file_load() syscall"
1826 depends on KEXEC_FILE
1827 ---help---
1828 This option makes kernel signature verification mandatory for
1829 the kexec_file_load() syscall.
1830
1831 In addition to that option, you need to enable signature
1832 verification for the corresponding kernel image type being
1833 loaded in order for this to work.
1834
1835 config KEXEC_BZIMAGE_VERIFY_SIG
1836 bool "Enable bzImage signature verification support"
1837 depends on KEXEC_VERIFY_SIG
1838 depends on SIGNED_PE_FILE_VERIFICATION
1839 select SYSTEM_TRUSTED_KEYRING
1840 ---help---
1841 Enable bzImage signature verification support.
1842
1843 config CRASH_DUMP
1844 bool "kernel crash dumps"
1845 depends on X86_64 || (X86_32 && HIGHMEM)
1846 ---help---
1847 Generate crash dump after being started by kexec.
1848 This should be normally only set in special crash dump kernels
1849 which are loaded in the main kernel with kexec-tools into
1850 a specially reserved region and then later executed after
1851 a crash by kdump/kexec. The crash dump kernel must be compiled
1852 to a memory address not used by the main kernel or BIOS using
1853 PHYSICAL_START, or it must be built as a relocatable image
1854 (CONFIG_RELOCATABLE=y).
1855 For more details see Documentation/kdump/kdump.txt
1856
1857 config KEXEC_JUMP
1858 bool "kexec jump"
1859 depends on KEXEC && HIBERNATION
1860 ---help---
1861 Jump between original kernel and kexeced kernel and invoke
1862 code in physical address mode via KEXEC
1863
1864 config PHYSICAL_START
1865 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1866 default "0x1000000"
1867 ---help---
1868 This gives the physical address where the kernel is loaded.
1869
1870 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1871 bzImage will decompress itself to above physical address and
1872 run from there. Otherwise, bzImage will run from the address where
1873 it has been loaded by the boot loader and will ignore above physical
1874 address.
1875
1876 In normal kdump cases one does not have to set/change this option
1877 as now bzImage can be compiled as a completely relocatable image
1878 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1879 address. This option is mainly useful for the folks who don't want
1880 to use a bzImage for capturing the crash dump and want to use a
1881 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1882 to be specifically compiled to run from a specific memory area
1883 (normally a reserved region) and this option comes handy.
1884
1885 So if you are using bzImage for capturing the crash dump,
1886 leave the value here unchanged to 0x1000000 and set
1887 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1888 for capturing the crash dump change this value to start of
1889 the reserved region. In other words, it can be set based on
1890 the "X" value as specified in the "crashkernel=YM@XM"
1891 command line boot parameter passed to the panic-ed
1892 kernel. Please take a look at Documentation/kdump/kdump.txt
1893 for more details about crash dumps.
1894
1895 Usage of bzImage for capturing the crash dump is recommended as
1896 one does not have to build two kernels. Same kernel can be used
1897 as production kernel and capture kernel. Above option should have
1898 gone away after relocatable bzImage support is introduced. But it
1899 is present because there are users out there who continue to use
1900 vmlinux for dump capture. This option should go away down the
1901 line.
1902
1903 Don't change this unless you know what you are doing.
1904
1905 config RELOCATABLE
1906 bool "Build a relocatable kernel"
1907 default y
1908 ---help---
1909 This builds a kernel image that retains relocation information
1910 so it can be loaded someplace besides the default 1MB.
1911 The relocations tend to make the kernel binary about 10% larger,
1912 but are discarded at runtime.
1913
1914 One use is for the kexec on panic case where the recovery kernel
1915 must live at a different physical address than the primary
1916 kernel.
1917
1918 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1919 it has been loaded at and the compile time physical address
1920 (CONFIG_PHYSICAL_START) is used as the minimum location.
1921
1922 config RANDOMIZE_BASE
1923 bool "Randomize the address of the kernel image (KASLR)"
1924 depends on RELOCATABLE
1925 default n
1926 ---help---
1927 In support of Kernel Address Space Layout Randomization (KASLR),
1928 this randomizes the physical address at which the kernel image
1929 is decompressed and the virtual address where the kernel
1930 image is mapped, as a security feature that deters exploit
1931 attempts relying on knowledge of the location of kernel
1932 code internals.
1933
1934 On 64-bit, the kernel physical and virtual addresses are
1935 randomized separately. The physical address will be anywhere
1936 between 16MB and the top of physical memory (up to 64TB). The
1937 virtual address will be randomized from 16MB up to 1GB (9 bits
1938 of entropy). Note that this also reduces the memory space
1939 available to kernel modules from 1.5GB to 1GB.
1940
1941 On 32-bit, the kernel physical and virtual addresses are
1942 randomized together. They will be randomized from 16MB up to
1943 512MB (8 bits of entropy).
1944
1945 Entropy is generated using the RDRAND instruction if it is
1946 supported. If RDTSC is supported, its value is mixed into
1947 the entropy pool as well. If neither RDRAND nor RDTSC are
1948 supported, then entropy is read from the i8254 timer. The
1949 usable entropy is limited by the kernel being built using
1950 2GB addressing, and that PHYSICAL_ALIGN must be at a
1951 minimum of 2MB. As a result, only 10 bits of entropy are
1952 theoretically possible, but the implementations are further
1953 limited due to memory layouts.
1954
1955 If CONFIG_HIBERNATE is also enabled, KASLR is disabled at boot
1956 time. To enable it, boot with "kaslr" on the kernel command
1957 line (which will also disable hibernation).
1958
1959 If unsure, say N.
1960
1961 # Relocation on x86 needs some additional build support
1962 config X86_NEED_RELOCS
1963 def_bool y
1964 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
1965
1966 config PHYSICAL_ALIGN
1967 hex "Alignment value to which kernel should be aligned"
1968 default "0x200000"
1969 range 0x2000 0x1000000 if X86_32
1970 range 0x200000 0x1000000 if X86_64
1971 ---help---
1972 This value puts the alignment restrictions on physical address
1973 where kernel is loaded and run from. Kernel is compiled for an
1974 address which meets above alignment restriction.
1975
1976 If bootloader loads the kernel at a non-aligned address and
1977 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1978 address aligned to above value and run from there.
1979
1980 If bootloader loads the kernel at a non-aligned address and
1981 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1982 load address and decompress itself to the address it has been
1983 compiled for and run from there. The address for which kernel is
1984 compiled already meets above alignment restrictions. Hence the
1985 end result is that kernel runs from a physical address meeting
1986 above alignment restrictions.
1987
1988 On 32-bit this value must be a multiple of 0x2000. On 64-bit
1989 this value must be a multiple of 0x200000.
1990
1991 Don't change this unless you know what you are doing.
1992
1993 config RANDOMIZE_MEMORY
1994 bool "Randomize the kernel memory sections"
1995 depends on X86_64
1996 depends on RANDOMIZE_BASE
1997 default RANDOMIZE_BASE
1998 ---help---
1999 Randomizes the base virtual address of kernel memory sections
2000 (physical memory mapping, vmalloc & vmemmap). This security feature
2001 makes exploits relying on predictable memory locations less reliable.
2002
2003 The order of allocations remains unchanged. Entropy is generated in
2004 the same way as RANDOMIZE_BASE. Current implementation in the optimal
2005 configuration have in average 30,000 different possible virtual
2006 addresses for each memory section.
2007
2008 If unsure, say N.
2009
2010 config RANDOMIZE_MEMORY_PHYSICAL_PADDING
2011 hex "Physical memory mapping padding" if EXPERT
2012 depends on RANDOMIZE_MEMORY
2013 default "0xa" if MEMORY_HOTPLUG
2014 default "0x0"
2015 range 0x1 0x40 if MEMORY_HOTPLUG
2016 range 0x0 0x40
2017 ---help---
2018 Define the padding in terabytes added to the existing physical
2019 memory size during kernel memory randomization. It is useful
2020 for memory hotplug support but reduces the entropy available for
2021 address randomization.
2022
2023 If unsure, leave at the default value.
2024
2025 config HOTPLUG_CPU
2026 bool "Support for hot-pluggable CPUs"
2027 depends on SMP
2028 ---help---
2029 Say Y here to allow turning CPUs off and on. CPUs can be
2030 controlled through /sys/devices/system/cpu.
2031 ( Note: power management support will enable this option
2032 automatically on SMP systems. )
2033 Say N if you want to disable CPU hotplug.
2034
2035 config BOOTPARAM_HOTPLUG_CPU0
2036 bool "Set default setting of cpu0_hotpluggable"
2037 default n
2038 depends on HOTPLUG_CPU
2039 ---help---
2040 Set whether default state of cpu0_hotpluggable is on or off.
2041
2042 Say Y here to enable CPU0 hotplug by default. If this switch
2043 is turned on, there is no need to give cpu0_hotplug kernel
2044 parameter and the CPU0 hotplug feature is enabled by default.
2045
2046 Please note: there are two known CPU0 dependencies if you want
2047 to enable the CPU0 hotplug feature either by this switch or by
2048 cpu0_hotplug kernel parameter.
2049
2050 First, resume from hibernate or suspend always starts from CPU0.
2051 So hibernate and suspend are prevented if CPU0 is offline.
2052
2053 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2054 offline if any interrupt can not migrate out of CPU0. There may
2055 be other CPU0 dependencies.
2056
2057 Please make sure the dependencies are under your control before
2058 you enable this feature.
2059
2060 Say N if you don't want to enable CPU0 hotplug feature by default.
2061 You still can enable the CPU0 hotplug feature at boot by kernel
2062 parameter cpu0_hotplug.
2063
2064 config DEBUG_HOTPLUG_CPU0
2065 def_bool n
2066 prompt "Debug CPU0 hotplug"
2067 depends on HOTPLUG_CPU
2068 ---help---
2069 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2070 soon as possible and boots up userspace with CPU0 offlined. User
2071 can online CPU0 back after boot time.
2072
2073 To debug CPU0 hotplug, you need to enable CPU0 offline/online
2074 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2075 compilation or giving cpu0_hotplug kernel parameter at boot.
2076
2077 If unsure, say N.
2078
2079 config COMPAT_VDSO
2080 def_bool n
2081 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2082 depends on X86_32 || IA32_EMULATION
2083 ---help---
2084 Certain buggy versions of glibc will crash if they are
2085 presented with a 32-bit vDSO that is not mapped at the address
2086 indicated in its segment table.
2087
2088 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2089 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2090 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
2091 the only released version with the bug, but OpenSUSE 9
2092 contains a buggy "glibc 2.3.2".
2093
2094 The symptom of the bug is that everything crashes on startup, saying:
2095 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2096
2097 Saying Y here changes the default value of the vdso32 boot
2098 option from 1 to 0, which turns off the 32-bit vDSO entirely.
2099 This works around the glibc bug but hurts performance.
2100
2101 If unsure, say N: if you are compiling your own kernel, you
2102 are unlikely to be using a buggy version of glibc.
2103
2104 choice
2105 prompt "vsyscall table for legacy applications"
2106 depends on X86_64
2107 default LEGACY_VSYSCALL_EMULATE
2108 help
2109 Legacy user code that does not know how to find the vDSO expects
2110 to be able to issue three syscalls by calling fixed addresses in
2111 kernel space. Since this location is not randomized with ASLR,
2112 it can be used to assist security vulnerability exploitation.
2113
2114 This setting can be changed at boot time via the kernel command
2115 line parameter vsyscall=[native|emulate|none].
2116
2117 On a system with recent enough glibc (2.14 or newer) and no
2118 static binaries, you can say None without a performance penalty
2119 to improve security.
2120
2121 If unsure, select "Emulate".
2122
2123 config LEGACY_VSYSCALL_NATIVE
2124 bool "Native"
2125 help
2126 Actual executable code is located in the fixed vsyscall
2127 address mapping, implementing time() efficiently. Since
2128 this makes the mapping executable, it can be used during
2129 security vulnerability exploitation (traditionally as
2130 ROP gadgets). This configuration is not recommended.
2131
2132 config LEGACY_VSYSCALL_EMULATE
2133 bool "Emulate"
2134 help
2135 The kernel traps and emulates calls into the fixed
2136 vsyscall address mapping. This makes the mapping
2137 non-executable, but it still contains known contents,
2138 which could be used in certain rare security vulnerability
2139 exploits. This configuration is recommended when userspace
2140 still uses the vsyscall area.
2141
2142 config LEGACY_VSYSCALL_NONE
2143 bool "None"
2144 help
2145 There will be no vsyscall mapping at all. This will
2146 eliminate any risk of ASLR bypass due to the vsyscall
2147 fixed address mapping. Attempts to use the vsyscalls
2148 will be reported to dmesg, so that either old or
2149 malicious userspace programs can be identified.
2150
2151 endchoice
2152
2153 config CMDLINE_BOOL
2154 bool "Built-in kernel command line"
2155 ---help---
2156 Allow for specifying boot arguments to the kernel at
2157 build time. On some systems (e.g. embedded ones), it is
2158 necessary or convenient to provide some or all of the
2159 kernel boot arguments with the kernel itself (that is,
2160 to not rely on the boot loader to provide them.)
2161
2162 To compile command line arguments into the kernel,
2163 set this option to 'Y', then fill in the
2164 boot arguments in CONFIG_CMDLINE.
2165
2166 Systems with fully functional boot loaders (i.e. non-embedded)
2167 should leave this option set to 'N'.
2168
2169 config CMDLINE
2170 string "Built-in kernel command string"
2171 depends on CMDLINE_BOOL
2172 default ""
2173 ---help---
2174 Enter arguments here that should be compiled into the kernel
2175 image and used at boot time. If the boot loader provides a
2176 command line at boot time, it is appended to this string to
2177 form the full kernel command line, when the system boots.
2178
2179 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2180 change this behavior.
2181
2182 In most cases, the command line (whether built-in or provided
2183 by the boot loader) should specify the device for the root
2184 file system.
2185
2186 config CMDLINE_OVERRIDE
2187 bool "Built-in command line overrides boot loader arguments"
2188 depends on CMDLINE_BOOL
2189 ---help---
2190 Set this option to 'Y' to have the kernel ignore the boot loader
2191 command line, and use ONLY the built-in command line.
2192
2193 This is used to work around broken boot loaders. This should
2194 be set to 'N' under normal conditions.
2195
2196 config MODIFY_LDT_SYSCALL
2197 bool "Enable the LDT (local descriptor table)" if EXPERT
2198 default y
2199 ---help---
2200 Linux can allow user programs to install a per-process x86
2201 Local Descriptor Table (LDT) using the modify_ldt(2) system
2202 call. This is required to run 16-bit or segmented code such as
2203 DOSEMU or some Wine programs. It is also used by some very old
2204 threading libraries.
2205
2206 Enabling this feature adds a small amount of overhead to
2207 context switches and increases the low-level kernel attack
2208 surface. Disabling it removes the modify_ldt(2) system call.
2209
2210 Saying 'N' here may make sense for embedded or server kernels.
2211
2212 source "kernel/livepatch/Kconfig"
2213
2214 endmenu
2215
2216 config ARCH_ENABLE_MEMORY_HOTPLUG
2217 def_bool y
2218 depends on X86_64 || (X86_32 && HIGHMEM)
2219
2220 config ARCH_ENABLE_MEMORY_HOTREMOVE
2221 def_bool y
2222 depends on MEMORY_HOTPLUG
2223
2224 config USE_PERCPU_NUMA_NODE_ID
2225 def_bool y
2226 depends on NUMA
2227
2228 config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2229 def_bool y
2230 depends on X86_64 || X86_PAE
2231
2232 config ARCH_ENABLE_HUGEPAGE_MIGRATION
2233 def_bool y
2234 depends on X86_64 && HUGETLB_PAGE && MIGRATION
2235
2236 menu "Power management and ACPI options"
2237
2238 config ARCH_HIBERNATION_HEADER
2239 def_bool y
2240 depends on X86_64 && HIBERNATION
2241
2242 source "kernel/power/Kconfig"
2243
2244 source "drivers/acpi/Kconfig"
2245
2246 source "drivers/sfi/Kconfig"
2247
2248 config X86_APM_BOOT
2249 def_bool y
2250 depends on APM
2251
2252 menuconfig APM
2253 tristate "APM (Advanced Power Management) BIOS support"
2254 depends on X86_32 && PM_SLEEP
2255 ---help---
2256 APM is a BIOS specification for saving power using several different
2257 techniques. This is mostly useful for battery powered laptops with
2258 APM compliant BIOSes. If you say Y here, the system time will be
2259 reset after a RESUME operation, the /proc/apm device will provide
2260 battery status information, and user-space programs will receive
2261 notification of APM "events" (e.g. battery status change).
2262
2263 If you select "Y" here, you can disable actual use of the APM
2264 BIOS by passing the "apm=off" option to the kernel at boot time.
2265
2266 Note that the APM support is almost completely disabled for
2267 machines with more than one CPU.
2268
2269 In order to use APM, you will need supporting software. For location
2270 and more information, read <file:Documentation/power/apm-acpi.txt>
2271 and the Battery Powered Linux mini-HOWTO, available from
2272 <http://www.tldp.org/docs.html#howto>.
2273
2274 This driver does not spin down disk drives (see the hdparm(8)
2275 manpage ("man 8 hdparm") for that), and it doesn't turn off
2276 VESA-compliant "green" monitors.
2277
2278 This driver does not support the TI 4000M TravelMate and the ACER
2279 486/DX4/75 because they don't have compliant BIOSes. Many "green"
2280 desktop machines also don't have compliant BIOSes, and this driver
2281 may cause those machines to panic during the boot phase.
2282
2283 Generally, if you don't have a battery in your machine, there isn't
2284 much point in using this driver and you should say N. If you get
2285 random kernel OOPSes or reboots that don't seem to be related to
2286 anything, try disabling/enabling this option (or disabling/enabling
2287 APM in your BIOS).
2288
2289 Some other things you should try when experiencing seemingly random,
2290 "weird" problems:
2291
2292 1) make sure that you have enough swap space and that it is
2293 enabled.
2294 2) pass the "no-hlt" option to the kernel
2295 3) switch on floating point emulation in the kernel and pass
2296 the "no387" option to the kernel
2297 4) pass the "floppy=nodma" option to the kernel
2298 5) pass the "mem=4M" option to the kernel (thereby disabling
2299 all but the first 4 MB of RAM)
2300 6) make sure that the CPU is not over clocked.
2301 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2302 8) disable the cache from your BIOS settings
2303 9) install a fan for the video card or exchange video RAM
2304 10) install a better fan for the CPU
2305 11) exchange RAM chips
2306 12) exchange the motherboard.
2307
2308 To compile this driver as a module, choose M here: the
2309 module will be called apm.
2310
2311 if APM
2312
2313 config APM_IGNORE_USER_SUSPEND
2314 bool "Ignore USER SUSPEND"
2315 ---help---
2316 This option will ignore USER SUSPEND requests. On machines with a
2317 compliant APM BIOS, you want to say N. However, on the NEC Versa M
2318 series notebooks, it is necessary to say Y because of a BIOS bug.
2319
2320 config APM_DO_ENABLE
2321 bool "Enable PM at boot time"
2322 ---help---
2323 Enable APM features at boot time. From page 36 of the APM BIOS
2324 specification: "When disabled, the APM BIOS does not automatically
2325 power manage devices, enter the Standby State, enter the Suspend
2326 State, or take power saving steps in response to CPU Idle calls."
2327 This driver will make CPU Idle calls when Linux is idle (unless this
2328 feature is turned off -- see "Do CPU IDLE calls", below). This
2329 should always save battery power, but more complicated APM features
2330 will be dependent on your BIOS implementation. You may need to turn
2331 this option off if your computer hangs at boot time when using APM
2332 support, or if it beeps continuously instead of suspending. Turn
2333 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2334 T400CDT. This is off by default since most machines do fine without
2335 this feature.
2336
2337 config APM_CPU_IDLE
2338 depends on CPU_IDLE
2339 bool "Make CPU Idle calls when idle"
2340 ---help---
2341 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2342 On some machines, this can activate improved power savings, such as
2343 a slowed CPU clock rate, when the machine is idle. These idle calls
2344 are made after the idle loop has run for some length of time (e.g.,
2345 333 mS). On some machines, this will cause a hang at boot time or
2346 whenever the CPU becomes idle. (On machines with more than one CPU,
2347 this option does nothing.)
2348
2349 config APM_DISPLAY_BLANK
2350 bool "Enable console blanking using APM"
2351 ---help---
2352 Enable console blanking using the APM. Some laptops can use this to
2353 turn off the LCD backlight when the screen blanker of the Linux
2354 virtual console blanks the screen. Note that this is only used by
2355 the virtual console screen blanker, and won't turn off the backlight
2356 when using the X Window system. This also doesn't have anything to
2357 do with your VESA-compliant power-saving monitor. Further, this
2358 option doesn't work for all laptops -- it might not turn off your
2359 backlight at all, or it might print a lot of errors to the console,
2360 especially if you are using gpm.
2361
2362 config APM_ALLOW_INTS
2363 bool "Allow interrupts during APM BIOS calls"
2364 ---help---
2365 Normally we disable external interrupts while we are making calls to
2366 the APM BIOS as a measure to lessen the effects of a badly behaving
2367 BIOS implementation. The BIOS should reenable interrupts if it
2368 needs to. Unfortunately, some BIOSes do not -- especially those in
2369 many of the newer IBM Thinkpads. If you experience hangs when you
2370 suspend, try setting this to Y. Otherwise, say N.
2371
2372 endif # APM
2373
2374 source "drivers/cpufreq/Kconfig"
2375
2376 source "drivers/cpuidle/Kconfig"
2377
2378 source "drivers/idle/Kconfig"
2379
2380 endmenu
2381
2382
2383 menu "Bus options (PCI etc.)"
2384
2385 config PCI
2386 bool "PCI support"
2387 default y
2388 ---help---
2389 Find out whether you have a PCI motherboard. PCI is the name of a
2390 bus system, i.e. the way the CPU talks to the other stuff inside
2391 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2392 VESA. If you have PCI, say Y, otherwise N.
2393
2394 choice
2395 prompt "PCI access mode"
2396 depends on X86_32 && PCI
2397 default PCI_GOANY
2398 ---help---
2399 On PCI systems, the BIOS can be used to detect the PCI devices and
2400 determine their configuration. However, some old PCI motherboards
2401 have BIOS bugs and may crash if this is done. Also, some embedded
2402 PCI-based systems don't have any BIOS at all. Linux can also try to
2403 detect the PCI hardware directly without using the BIOS.
2404
2405 With this option, you can specify how Linux should detect the
2406 PCI devices. If you choose "BIOS", the BIOS will be used,
2407 if you choose "Direct", the BIOS won't be used, and if you
2408 choose "MMConfig", then PCI Express MMCONFIG will be used.
2409 If you choose "Any", the kernel will try MMCONFIG, then the
2410 direct access method and falls back to the BIOS if that doesn't
2411 work. If unsure, go with the default, which is "Any".
2412
2413 config PCI_GOBIOS
2414 bool "BIOS"
2415
2416 config PCI_GOMMCONFIG
2417 bool "MMConfig"
2418
2419 config PCI_GODIRECT
2420 bool "Direct"
2421
2422 config PCI_GOOLPC
2423 bool "OLPC XO-1"
2424 depends on OLPC
2425
2426 config PCI_GOANY
2427 bool "Any"
2428
2429 endchoice
2430
2431 config PCI_BIOS
2432 def_bool y
2433 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2434
2435 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2436 config PCI_DIRECT
2437 def_bool y
2438 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2439
2440 config PCI_MMCONFIG
2441 def_bool y
2442 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
2443
2444 config PCI_OLPC
2445 def_bool y
2446 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2447
2448 config PCI_XEN
2449 def_bool y
2450 depends on PCI && XEN
2451 select SWIOTLB_XEN
2452
2453 config PCI_DOMAINS
2454 def_bool y
2455 depends on PCI
2456
2457 config PCI_MMCONFIG
2458 bool "Support mmconfig PCI config space access"
2459 depends on X86_64 && PCI && ACPI
2460
2461 config PCI_CNB20LE_QUIRK
2462 bool "Read CNB20LE Host Bridge Windows" if EXPERT
2463 depends on PCI
2464 help
2465 Read the PCI windows out of the CNB20LE host bridge. This allows
2466 PCI hotplug to work on systems with the CNB20LE chipset which do
2467 not have ACPI.
2468
2469 There's no public spec for this chipset, and this functionality
2470 is known to be incomplete.
2471
2472 You should say N unless you know you need this.
2473
2474 source "drivers/pci/Kconfig"
2475
2476 config ISA_BUS
2477 bool "ISA-style bus support on modern systems" if EXPERT
2478 select ISA_BUS_API
2479 help
2480 Enables ISA-style drivers on modern systems. This is necessary to
2481 support PC/104 devices on X86_64 platforms.
2482
2483 If unsure, say N.
2484
2485 # x86_64 have no ISA slots, but can have ISA-style DMA.
2486 config ISA_DMA_API
2487 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2488 default y
2489 help
2490 Enables ISA-style DMA support for devices requiring such controllers.
2491 If unsure, say Y.
2492
2493 if X86_32
2494
2495 config ISA
2496 bool "ISA support"
2497 ---help---
2498 Find out whether you have ISA slots on your motherboard. ISA is the
2499 name of a bus system, i.e. the way the CPU talks to the other stuff
2500 inside your box. Other bus systems are PCI, EISA, MicroChannel
2501 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2502 newer boards don't support it. If you have ISA, say Y, otherwise N.
2503
2504 config EISA
2505 bool "EISA support"
2506 depends on ISA
2507 ---help---
2508 The Extended Industry Standard Architecture (EISA) bus was
2509 developed as an open alternative to the IBM MicroChannel bus.
2510
2511 The EISA bus provided some of the features of the IBM MicroChannel
2512 bus while maintaining backward compatibility with cards made for
2513 the older ISA bus. The EISA bus saw limited use between 1988 and
2514 1995 when it was made obsolete by the PCI bus.
2515
2516 Say Y here if you are building a kernel for an EISA-based machine.
2517
2518 Otherwise, say N.
2519
2520 source "drivers/eisa/Kconfig"
2521
2522 config SCx200
2523 tristate "NatSemi SCx200 support"
2524 ---help---
2525 This provides basic support for National Semiconductor's
2526 (now AMD's) Geode processors. The driver probes for the
2527 PCI-IDs of several on-chip devices, so its a good dependency
2528 for other scx200_* drivers.
2529
2530 If compiled as a module, the driver is named scx200.
2531
2532 config SCx200HR_TIMER
2533 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2534 depends on SCx200
2535 default y
2536 ---help---
2537 This driver provides a clocksource built upon the on-chip
2538 27MHz high-resolution timer. Its also a workaround for
2539 NSC Geode SC-1100's buggy TSC, which loses time when the
2540 processor goes idle (as is done by the scheduler). The
2541 other workaround is idle=poll boot option.
2542
2543 config OLPC
2544 bool "One Laptop Per Child support"
2545 depends on !X86_PAE
2546 select GPIOLIB
2547 select OF
2548 select OF_PROMTREE
2549 select IRQ_DOMAIN
2550 ---help---
2551 Add support for detecting the unique features of the OLPC
2552 XO hardware.
2553
2554 config OLPC_XO1_PM
2555 bool "OLPC XO-1 Power Management"
2556 depends on OLPC && MFD_CS5535 && PM_SLEEP
2557 select MFD_CORE
2558 ---help---
2559 Add support for poweroff and suspend of the OLPC XO-1 laptop.
2560
2561 config OLPC_XO1_RTC
2562 bool "OLPC XO-1 Real Time Clock"
2563 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2564 ---help---
2565 Add support for the XO-1 real time clock, which can be used as a
2566 programmable wakeup source.
2567
2568 config OLPC_XO1_SCI
2569 bool "OLPC XO-1 SCI extras"
2570 depends on OLPC && OLPC_XO1_PM
2571 depends on INPUT=y
2572 select POWER_SUPPLY
2573 select GPIO_CS5535
2574 select MFD_CORE
2575 ---help---
2576 Add support for SCI-based features of the OLPC XO-1 laptop:
2577 - EC-driven system wakeups
2578 - Power button
2579 - Ebook switch
2580 - Lid switch
2581 - AC adapter status updates
2582 - Battery status updates
2583
2584 config OLPC_XO15_SCI
2585 bool "OLPC XO-1.5 SCI extras"
2586 depends on OLPC && ACPI
2587 select POWER_SUPPLY
2588 ---help---
2589 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2590 - EC-driven system wakeups
2591 - AC adapter status updates
2592 - Battery status updates
2593
2594 config ALIX
2595 bool "PCEngines ALIX System Support (LED setup)"
2596 select GPIOLIB
2597 ---help---
2598 This option enables system support for the PCEngines ALIX.
2599 At present this just sets up LEDs for GPIO control on
2600 ALIX2/3/6 boards. However, other system specific setup should
2601 get added here.
2602
2603 Note: You must still enable the drivers for GPIO and LED support
2604 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2605
2606 Note: You have to set alix.force=1 for boards with Award BIOS.
2607
2608 config NET5501
2609 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2610 select GPIOLIB
2611 ---help---
2612 This option enables system support for the Soekris Engineering net5501.
2613
2614 config GEOS
2615 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2616 select GPIOLIB
2617 depends on DMI
2618 ---help---
2619 This option enables system support for the Traverse Technologies GEOS.
2620
2621 config TS5500
2622 bool "Technologic Systems TS-5500 platform support"
2623 depends on MELAN
2624 select CHECK_SIGNATURE
2625 select NEW_LEDS
2626 select LEDS_CLASS
2627 ---help---
2628 This option enables system support for the Technologic Systems TS-5500.
2629
2630 endif # X86_32
2631
2632 config AMD_NB
2633 def_bool y
2634 depends on CPU_SUP_AMD && PCI
2635
2636 source "drivers/pcmcia/Kconfig"
2637
2638 config RAPIDIO
2639 tristate "RapidIO support"
2640 depends on PCI
2641 default n
2642 help
2643 If enabled this option will include drivers and the core
2644 infrastructure code to support RapidIO interconnect devices.
2645
2646 source "drivers/rapidio/Kconfig"
2647
2648 config X86_SYSFB
2649 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2650 help
2651 Firmwares often provide initial graphics framebuffers so the BIOS,
2652 bootloader or kernel can show basic video-output during boot for
2653 user-guidance and debugging. Historically, x86 used the VESA BIOS
2654 Extensions and EFI-framebuffers for this, which are mostly limited
2655 to x86.
2656 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2657 framebuffers so the new generic system-framebuffer drivers can be
2658 used on x86. If the framebuffer is not compatible with the generic
2659 modes, it is adverticed as fallback platform framebuffer so legacy
2660 drivers like efifb, vesafb and uvesafb can pick it up.
2661 If this option is not selected, all system framebuffers are always
2662 marked as fallback platform framebuffers as usual.
2663
2664 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2665 not be able to pick up generic system framebuffers if this option
2666 is selected. You are highly encouraged to enable simplefb as
2667 replacement if you select this option. simplefb can correctly deal
2668 with generic system framebuffers. But you should still keep vesafb
2669 and others enabled as fallback if a system framebuffer is
2670 incompatible with simplefb.
2671
2672 If unsure, say Y.
2673
2674 endmenu
2675
2676
2677 menu "Executable file formats / Emulations"
2678
2679 source "fs/Kconfig.binfmt"
2680
2681 config IA32_EMULATION
2682 bool "IA32 Emulation"
2683 depends on X86_64
2684 select BINFMT_ELF
2685 select COMPAT_BINFMT_ELF
2686 select ARCH_WANT_OLD_COMPAT_IPC
2687 ---help---
2688 Include code to run legacy 32-bit programs under a
2689 64-bit kernel. You should likely turn this on, unless you're
2690 100% sure that you don't have any 32-bit programs left.
2691
2692 config IA32_AOUT
2693 tristate "IA32 a.out support"
2694 depends on IA32_EMULATION
2695 ---help---
2696 Support old a.out binaries in the 32bit emulation.
2697
2698 config X86_X32
2699 bool "x32 ABI for 64-bit mode"
2700 depends on X86_64
2701 ---help---
2702 Include code to run binaries for the x32 native 32-bit ABI
2703 for 64-bit processors. An x32 process gets access to the
2704 full 64-bit register file and wide data path while leaving
2705 pointers at 32 bits for smaller memory footprint.
2706
2707 You will need a recent binutils (2.22 or later) with
2708 elf32_x86_64 support enabled to compile a kernel with this
2709 option set.
2710
2711 config COMPAT
2712 def_bool y
2713 depends on IA32_EMULATION || X86_X32
2714
2715 if COMPAT
2716 config COMPAT_FOR_U64_ALIGNMENT
2717 def_bool y
2718
2719 config SYSVIPC_COMPAT
2720 def_bool y
2721 depends on SYSVIPC
2722
2723 config KEYS_COMPAT
2724 def_bool y
2725 depends on KEYS
2726 endif
2727
2728 endmenu
2729
2730
2731 config HAVE_ATOMIC_IOMAP
2732 def_bool y
2733 depends on X86_32
2734
2735 config X86_DEV_DMA_OPS
2736 bool
2737 depends on X86_64 || STA2X11
2738
2739 config X86_DMA_REMAP
2740 bool
2741 depends on STA2X11
2742
2743 config PMC_ATOM
2744 def_bool y
2745 depends on PCI
2746
2747 config VMD
2748 depends on PCI_MSI
2749 tristate "Volume Management Device Driver"
2750 default N
2751 ---help---
2752 Adds support for the Intel Volume Management Device (VMD). VMD is a
2753 secondary PCI host bridge that allows PCI Express root ports,
2754 and devices attached to them, to be removed from the default
2755 PCI domain and placed within the VMD domain. This provides
2756 more bus resources than are otherwise possible with a
2757 single domain. If you know your system provides one of these and
2758 has devices attached to it, say Y; if you are not sure, say N.
2759
2760 source "net/Kconfig"
2761
2762 source "drivers/Kconfig"
2763
2764 source "drivers/firmware/Kconfig"
2765
2766 source "fs/Kconfig"
2767
2768 source "arch/x86/Kconfig.debug"
2769
2770 source "security/Kconfig"
2771
2772 source "crypto/Kconfig"
2773
2774 source "arch/x86/kvm/Kconfig"
2775
2776 source "lib/Kconfig"
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