Merge branch 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild
[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 SPARSE_IRQ
156 select SRCU
157 select SYSCTL_EXCEPTION_TRACE
158 select USER_STACKTRACE_SUPPORT
159 select VIRT_TO_BUS
160 select X86_DEV_DMA_OPS if X86_64
161 select X86_FEATURE_NAMES if PROC_FS
162 select HAVE_STACK_VALIDATION if X86_64
163 select ARCH_USES_HIGH_VMA_FLAGS if X86_INTEL_MEMORY_PROTECTION_KEYS
164 select ARCH_HAS_PKEYS if X86_INTEL_MEMORY_PROTECTION_KEYS
165
166 config INSTRUCTION_DECODER
167 def_bool y
168 depends on KPROBES || PERF_EVENTS || UPROBES
169
170 config OUTPUT_FORMAT
171 string
172 default "elf32-i386" if X86_32
173 default "elf64-x86-64" if X86_64
174
175 config ARCH_DEFCONFIG
176 string
177 default "arch/x86/configs/i386_defconfig" if X86_32
178 default "arch/x86/configs/x86_64_defconfig" if X86_64
179
180 config LOCKDEP_SUPPORT
181 def_bool y
182
183 config STACKTRACE_SUPPORT
184 def_bool y
185
186 config MMU
187 def_bool y
188
189 config ARCH_MMAP_RND_BITS_MIN
190 default 28 if 64BIT
191 default 8
192
193 config ARCH_MMAP_RND_BITS_MAX
194 default 32 if 64BIT
195 default 16
196
197 config ARCH_MMAP_RND_COMPAT_BITS_MIN
198 default 8
199
200 config ARCH_MMAP_RND_COMPAT_BITS_MAX
201 default 16
202
203 config SBUS
204 bool
205
206 config NEED_DMA_MAP_STATE
207 def_bool y
208 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB
209
210 config NEED_SG_DMA_LENGTH
211 def_bool y
212
213 config GENERIC_ISA_DMA
214 def_bool y
215 depends on ISA_DMA_API
216
217 config GENERIC_BUG
218 def_bool y
219 depends on BUG
220 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
221
222 config GENERIC_BUG_RELATIVE_POINTERS
223 bool
224
225 config GENERIC_HWEIGHT
226 def_bool y
227
228 config ARCH_MAY_HAVE_PC_FDC
229 def_bool y
230 depends on ISA_DMA_API
231
232 config RWSEM_XCHGADD_ALGORITHM
233 def_bool y
234
235 config GENERIC_CALIBRATE_DELAY
236 def_bool y
237
238 config ARCH_HAS_CPU_RELAX
239 def_bool y
240
241 config ARCH_HAS_CACHE_LINE_SIZE
242 def_bool y
243
244 config HAVE_SETUP_PER_CPU_AREA
245 def_bool y
246
247 config NEED_PER_CPU_EMBED_FIRST_CHUNK
248 def_bool y
249
250 config NEED_PER_CPU_PAGE_FIRST_CHUNK
251 def_bool y
252
253 config ARCH_HIBERNATION_POSSIBLE
254 def_bool y
255
256 config ARCH_SUSPEND_POSSIBLE
257 def_bool y
258
259 config ARCH_WANT_HUGE_PMD_SHARE
260 def_bool y
261
262 config ARCH_WANT_GENERAL_HUGETLB
263 def_bool y
264
265 config ZONE_DMA32
266 def_bool y if X86_64
267
268 config AUDIT_ARCH
269 def_bool y if X86_64
270
271 config ARCH_SUPPORTS_OPTIMIZED_INLINING
272 def_bool y
273
274 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
275 def_bool y
276
277 config KASAN_SHADOW_OFFSET
278 hex
279 depends on KASAN
280 default 0xdffffc0000000000
281
282 config HAVE_INTEL_TXT
283 def_bool y
284 depends on INTEL_IOMMU && ACPI
285
286 config X86_32_SMP
287 def_bool y
288 depends on X86_32 && SMP
289
290 config X86_64_SMP
291 def_bool y
292 depends on X86_64 && SMP
293
294 config X86_32_LAZY_GS
295 def_bool y
296 depends on X86_32 && !CC_STACKPROTECTOR
297
298 config ARCH_SUPPORTS_UPROBES
299 def_bool y
300
301 config FIX_EARLYCON_MEM
302 def_bool y
303
304 config DEBUG_RODATA
305 def_bool y
306
307 config PGTABLE_LEVELS
308 int
309 default 4 if X86_64
310 default 3 if X86_PAE
311 default 2
312
313 source "init/Kconfig"
314 source "kernel/Kconfig.freezer"
315
316 menu "Processor type and features"
317
318 config ZONE_DMA
319 bool "DMA memory allocation support" if EXPERT
320 default y
321 help
322 DMA memory allocation support allows devices with less than 32-bit
323 addressing to allocate within the first 16MB of address space.
324 Disable if no such devices will be used.
325
326 If unsure, say Y.
327
328 config SMP
329 bool "Symmetric multi-processing support"
330 ---help---
331 This enables support for systems with more than one CPU. If you have
332 a system with only one CPU, say N. If you have a system with more
333 than one CPU, say Y.
334
335 If you say N here, the kernel will run on uni- and multiprocessor
336 machines, but will use only one CPU of a multiprocessor machine. If
337 you say Y here, the kernel will run on many, but not all,
338 uniprocessor machines. On a uniprocessor machine, the kernel
339 will run faster if you say N here.
340
341 Note that if you say Y here and choose architecture "586" or
342 "Pentium" under "Processor family", the kernel will not work on 486
343 architectures. Similarly, multiprocessor kernels for the "PPro"
344 architecture may not work on all Pentium based boards.
345
346 People using multiprocessor machines who say Y here should also say
347 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
348 Management" code will be disabled if you say Y here.
349
350 See also <file:Documentation/x86/i386/IO-APIC.txt>,
351 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
352 <http://www.tldp.org/docs.html#howto>.
353
354 If you don't know what to do here, say N.
355
356 config X86_FEATURE_NAMES
357 bool "Processor feature human-readable names" if EMBEDDED
358 default y
359 ---help---
360 This option compiles in a table of x86 feature bits and corresponding
361 names. This is required to support /proc/cpuinfo and a few kernel
362 messages. You can disable this to save space, at the expense of
363 making those few kernel messages show numeric feature bits instead.
364
365 If in doubt, say Y.
366
367 config X86_FAST_FEATURE_TESTS
368 bool "Fast CPU feature tests" if EMBEDDED
369 default y
370 ---help---
371 Some fast-paths in the kernel depend on the capabilities of the CPU.
372 Say Y here for the kernel to patch in the appropriate code at runtime
373 based on the capabilities of the CPU. The infrastructure for patching
374 code at runtime takes up some additional space; space-constrained
375 embedded systems may wish to say N here to produce smaller, slightly
376 slower code.
377
378 config X86_X2APIC
379 bool "Support x2apic"
380 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
381 ---help---
382 This enables x2apic support on CPUs that have this feature.
383
384 This allows 32-bit apic IDs (so it can support very large systems),
385 and accesses the local apic via MSRs not via mmio.
386
387 If you don't know what to do here, say N.
388
389 config X86_MPPARSE
390 bool "Enable MPS table" if ACPI || SFI
391 default y
392 depends on X86_LOCAL_APIC
393 ---help---
394 For old smp systems that do not have proper acpi support. Newer systems
395 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
396
397 config X86_BIGSMP
398 bool "Support for big SMP systems with more than 8 CPUs"
399 depends on X86_32 && SMP
400 ---help---
401 This option is needed for the systems that have more than 8 CPUs
402
403 config GOLDFISH
404 def_bool y
405 depends on X86_GOLDFISH
406
407 if X86_32
408 config X86_EXTENDED_PLATFORM
409 bool "Support for extended (non-PC) x86 platforms"
410 default y
411 ---help---
412 If you disable this option then the kernel will only support
413 standard PC platforms. (which covers the vast majority of
414 systems out there.)
415
416 If you enable this option then you'll be able to select support
417 for the following (non-PC) 32 bit x86 platforms:
418 Goldfish (Android emulator)
419 AMD Elan
420 RDC R-321x SoC
421 SGI 320/540 (Visual Workstation)
422 STA2X11-based (e.g. Northville)
423 Moorestown MID devices
424
425 If you have one of these systems, or if you want to build a
426 generic distribution kernel, say Y here - otherwise say N.
427 endif
428
429 if X86_64
430 config X86_EXTENDED_PLATFORM
431 bool "Support for extended (non-PC) x86 platforms"
432 default y
433 ---help---
434 If you disable this option then the kernel will only support
435 standard PC platforms. (which covers the vast majority of
436 systems out there.)
437
438 If you enable this option then you'll be able to select support
439 for the following (non-PC) 64 bit x86 platforms:
440 Numascale NumaChip
441 ScaleMP vSMP
442 SGI Ultraviolet
443
444 If you have one of these systems, or if you want to build a
445 generic distribution kernel, say Y here - otherwise say N.
446 endif
447 # This is an alphabetically sorted list of 64 bit extended platforms
448 # Please maintain the alphabetic order if and when there are additions
449 config X86_NUMACHIP
450 bool "Numascale NumaChip"
451 depends on X86_64
452 depends on X86_EXTENDED_PLATFORM
453 depends on NUMA
454 depends on SMP
455 depends on X86_X2APIC
456 depends on PCI_MMCONFIG
457 ---help---
458 Adds support for Numascale NumaChip large-SMP systems. Needed to
459 enable more than ~168 cores.
460 If you don't have one of these, you should say N here.
461
462 config X86_VSMP
463 bool "ScaleMP vSMP"
464 select HYPERVISOR_GUEST
465 select PARAVIRT
466 depends on X86_64 && PCI
467 depends on X86_EXTENDED_PLATFORM
468 depends on SMP
469 ---help---
470 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
471 supposed to run on these EM64T-based machines. Only choose this option
472 if you have one of these machines.
473
474 config X86_UV
475 bool "SGI Ultraviolet"
476 depends on X86_64
477 depends on X86_EXTENDED_PLATFORM
478 depends on NUMA
479 depends on EFI
480 depends on X86_X2APIC
481 depends on PCI
482 ---help---
483 This option is needed in order to support SGI Ultraviolet systems.
484 If you don't have one of these, you should say N here.
485
486 # Following is an alphabetically sorted list of 32 bit extended platforms
487 # Please maintain the alphabetic order if and when there are additions
488
489 config X86_GOLDFISH
490 bool "Goldfish (Virtual Platform)"
491 depends on X86_EXTENDED_PLATFORM
492 ---help---
493 Enable support for the Goldfish virtual platform used primarily
494 for Android development. Unless you are building for the Android
495 Goldfish emulator say N here.
496
497 config X86_INTEL_CE
498 bool "CE4100 TV platform"
499 depends on PCI
500 depends on PCI_GODIRECT
501 depends on X86_IO_APIC
502 depends on X86_32
503 depends on X86_EXTENDED_PLATFORM
504 select X86_REBOOTFIXUPS
505 select OF
506 select OF_EARLY_FLATTREE
507 ---help---
508 Select for the Intel CE media processor (CE4100) SOC.
509 This option compiles in support for the CE4100 SOC for settop
510 boxes and media devices.
511
512 config X86_INTEL_MID
513 bool "Intel MID platform support"
514 depends on X86_EXTENDED_PLATFORM
515 depends on X86_PLATFORM_DEVICES
516 depends on PCI
517 depends on X86_64 || (PCI_GOANY && X86_32)
518 depends on X86_IO_APIC
519 select SFI
520 select I2C
521 select DW_APB_TIMER
522 select APB_TIMER
523 select INTEL_SCU_IPC
524 select MFD_INTEL_MSIC
525 ---help---
526 Select to build a kernel capable of supporting Intel MID (Mobile
527 Internet Device) platform systems which do not have the PCI legacy
528 interfaces. If you are building for a PC class system say N here.
529
530 Intel MID platforms are based on an Intel processor and chipset which
531 consume less power than most of the x86 derivatives.
532
533 config X86_INTEL_QUARK
534 bool "Intel Quark platform support"
535 depends on X86_32
536 depends on X86_EXTENDED_PLATFORM
537 depends on X86_PLATFORM_DEVICES
538 depends on X86_TSC
539 depends on PCI
540 depends on PCI_GOANY
541 depends on X86_IO_APIC
542 select IOSF_MBI
543 select INTEL_IMR
544 select COMMON_CLK
545 ---help---
546 Select to include support for Quark X1000 SoC.
547 Say Y here if you have a Quark based system such as the Arduino
548 compatible Intel Galileo.
549
550 config X86_INTEL_LPSS
551 bool "Intel Low Power Subsystem Support"
552 depends on X86 && ACPI
553 select COMMON_CLK
554 select PINCTRL
555 select IOSF_MBI
556 ---help---
557 Select to build support for Intel Low Power Subsystem such as
558 found on Intel Lynxpoint PCH. Selecting this option enables
559 things like clock tree (common clock framework) and pincontrol
560 which are needed by the LPSS peripheral drivers.
561
562 config X86_AMD_PLATFORM_DEVICE
563 bool "AMD ACPI2Platform devices support"
564 depends on ACPI
565 select COMMON_CLK
566 select PINCTRL
567 ---help---
568 Select to interpret AMD specific ACPI device to platform device
569 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
570 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
571 implemented under PINCTRL subsystem.
572
573 config IOSF_MBI
574 tristate "Intel SoC IOSF Sideband support for SoC platforms"
575 depends on PCI
576 ---help---
577 This option enables sideband register access support for Intel SoC
578 platforms. On these platforms the IOSF sideband is used in lieu of
579 MSR's for some register accesses, mostly but not limited to thermal
580 and power. Drivers may query the availability of this device to
581 determine if they need the sideband in order to work on these
582 platforms. The sideband is available on the following SoC products.
583 This list is not meant to be exclusive.
584 - BayTrail
585 - Braswell
586 - Quark
587
588 You should say Y if you are running a kernel on one of these SoC's.
589
590 config IOSF_MBI_DEBUG
591 bool "Enable IOSF sideband access through debugfs"
592 depends on IOSF_MBI && DEBUG_FS
593 ---help---
594 Select this option to expose the IOSF sideband access registers (MCR,
595 MDR, MCRX) through debugfs to write and read register information from
596 different units on the SoC. This is most useful for obtaining device
597 state information for debug and analysis. As this is a general access
598 mechanism, users of this option would have specific knowledge of the
599 device they want to access.
600
601 If you don't require the option or are in doubt, say N.
602
603 config X86_RDC321X
604 bool "RDC R-321x SoC"
605 depends on X86_32
606 depends on X86_EXTENDED_PLATFORM
607 select M486
608 select X86_REBOOTFIXUPS
609 ---help---
610 This option is needed for RDC R-321x system-on-chip, also known
611 as R-8610-(G).
612 If you don't have one of these chips, you should say N here.
613
614 config X86_32_NON_STANDARD
615 bool "Support non-standard 32-bit SMP architectures"
616 depends on X86_32 && SMP
617 depends on X86_EXTENDED_PLATFORM
618 ---help---
619 This option compiles in the bigsmp and STA2X11 default
620 subarchitectures. It is intended for a generic binary
621 kernel. If you select them all, kernel will probe it one by
622 one and will fallback to default.
623
624 # Alphabetically sorted list of Non standard 32 bit platforms
625
626 config X86_SUPPORTS_MEMORY_FAILURE
627 def_bool y
628 # MCE code calls memory_failure():
629 depends on X86_MCE
630 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
631 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
632 depends on X86_64 || !SPARSEMEM
633 select ARCH_SUPPORTS_MEMORY_FAILURE
634
635 config STA2X11
636 bool "STA2X11 Companion Chip Support"
637 depends on X86_32_NON_STANDARD && PCI
638 select X86_DEV_DMA_OPS
639 select X86_DMA_REMAP
640 select SWIOTLB
641 select MFD_STA2X11
642 select GPIOLIB
643 default n
644 ---help---
645 This adds support for boards based on the STA2X11 IO-Hub,
646 a.k.a. "ConneXt". The chip is used in place of the standard
647 PC chipset, so all "standard" peripherals are missing. If this
648 option is selected the kernel will still be able to boot on
649 standard PC machines.
650
651 config X86_32_IRIS
652 tristate "Eurobraille/Iris poweroff module"
653 depends on X86_32
654 ---help---
655 The Iris machines from EuroBraille do not have APM or ACPI support
656 to shut themselves down properly. A special I/O sequence is
657 needed to do so, which is what this module does at
658 kernel shutdown.
659
660 This is only for Iris machines from EuroBraille.
661
662 If unused, say N.
663
664 config SCHED_OMIT_FRAME_POINTER
665 def_bool y
666 prompt "Single-depth WCHAN output"
667 depends on X86
668 ---help---
669 Calculate simpler /proc/<PID>/wchan values. If this option
670 is disabled then wchan values will recurse back to the
671 caller function. This provides more accurate wchan values,
672 at the expense of slightly more scheduling overhead.
673
674 If in doubt, say "Y".
675
676 menuconfig HYPERVISOR_GUEST
677 bool "Linux guest support"
678 ---help---
679 Say Y here to enable options for running Linux under various hyper-
680 visors. This option enables basic hypervisor detection and platform
681 setup.
682
683 If you say N, all options in this submenu will be skipped and
684 disabled, and Linux guest support won't be built in.
685
686 if HYPERVISOR_GUEST
687
688 config PARAVIRT
689 bool "Enable paravirtualization code"
690 ---help---
691 This changes the kernel so it can modify itself when it is run
692 under a hypervisor, potentially improving performance significantly
693 over full virtualization. However, when run without a hypervisor
694 the kernel is theoretically slower and slightly larger.
695
696 config PARAVIRT_DEBUG
697 bool "paravirt-ops debugging"
698 depends on PARAVIRT && DEBUG_KERNEL
699 ---help---
700 Enable to debug paravirt_ops internals. Specifically, BUG if
701 a paravirt_op is missing when it is called.
702
703 config PARAVIRT_SPINLOCKS
704 bool "Paravirtualization layer for spinlocks"
705 depends on PARAVIRT && SMP
706 select UNINLINE_SPIN_UNLOCK if !QUEUED_SPINLOCKS
707 ---help---
708 Paravirtualized spinlocks allow a pvops backend to replace the
709 spinlock implementation with something virtualization-friendly
710 (for example, block the virtual CPU rather than spinning).
711
712 It has a minimal impact on native kernels and gives a nice performance
713 benefit on paravirtualized KVM / Xen kernels.
714
715 If you are unsure how to answer this question, answer Y.
716
717 config QUEUED_LOCK_STAT
718 bool "Paravirt queued spinlock statistics"
719 depends on PARAVIRT_SPINLOCKS && DEBUG_FS && QUEUED_SPINLOCKS
720 ---help---
721 Enable the collection of statistical data on the slowpath
722 behavior of paravirtualized queued spinlocks and report
723 them on debugfs.
724
725 source "arch/x86/xen/Kconfig"
726
727 config KVM_GUEST
728 bool "KVM Guest support (including kvmclock)"
729 depends on PARAVIRT
730 select PARAVIRT_CLOCK
731 default y
732 ---help---
733 This option enables various optimizations for running under the KVM
734 hypervisor. It includes a paravirtualized clock, so that instead
735 of relying on a PIT (or probably other) emulation by the
736 underlying device model, the host provides the guest with
737 timing infrastructure such as time of day, and system time
738
739 config KVM_DEBUG_FS
740 bool "Enable debug information for KVM Guests in debugfs"
741 depends on KVM_GUEST && DEBUG_FS
742 default n
743 ---help---
744 This option enables collection of various statistics for KVM guest.
745 Statistics are displayed in debugfs filesystem. Enabling this option
746 may incur significant overhead.
747
748 source "arch/x86/lguest/Kconfig"
749
750 config PARAVIRT_TIME_ACCOUNTING
751 bool "Paravirtual steal time accounting"
752 depends on PARAVIRT
753 default n
754 ---help---
755 Select this option to enable fine granularity task steal time
756 accounting. Time spent executing other tasks in parallel with
757 the current vCPU is discounted from the vCPU power. To account for
758 that, there can be a small performance impact.
759
760 If in doubt, say N here.
761
762 config PARAVIRT_CLOCK
763 bool
764
765 endif #HYPERVISOR_GUEST
766
767 config NO_BOOTMEM
768 def_bool y
769
770 source "arch/x86/Kconfig.cpu"
771
772 config HPET_TIMER
773 def_bool X86_64
774 prompt "HPET Timer Support" if X86_32
775 ---help---
776 Use the IA-PC HPET (High Precision Event Timer) to manage
777 time in preference to the PIT and RTC, if a HPET is
778 present.
779 HPET is the next generation timer replacing legacy 8254s.
780 The HPET provides a stable time base on SMP
781 systems, unlike the TSC, but it is more expensive to access,
782 as it is off-chip. The interface used is documented
783 in the HPET spec, revision 1.
784
785 You can safely choose Y here. However, HPET will only be
786 activated if the platform and the BIOS support this feature.
787 Otherwise the 8254 will be used for timing services.
788
789 Choose N to continue using the legacy 8254 timer.
790
791 config HPET_EMULATE_RTC
792 def_bool y
793 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
794
795 config APB_TIMER
796 def_bool y if X86_INTEL_MID
797 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
798 select DW_APB_TIMER
799 depends on X86_INTEL_MID && SFI
800 help
801 APB timer is the replacement for 8254, HPET on X86 MID platforms.
802 The APBT provides a stable time base on SMP
803 systems, unlike the TSC, but it is more expensive to access,
804 as it is off-chip. APB timers are always running regardless of CPU
805 C states, they are used as per CPU clockevent device when possible.
806
807 # Mark as expert because too many people got it wrong.
808 # The code disables itself when not needed.
809 config DMI
810 default y
811 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
812 bool "Enable DMI scanning" if EXPERT
813 ---help---
814 Enabled scanning of DMI to identify machine quirks. Say Y
815 here unless you have verified that your setup is not
816 affected by entries in the DMI blacklist. Required by PNP
817 BIOS code.
818
819 config GART_IOMMU
820 bool "Old AMD GART IOMMU support"
821 select SWIOTLB
822 depends on X86_64 && PCI && AMD_NB
823 ---help---
824 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
825 GART based hardware IOMMUs.
826
827 The GART supports full DMA access for devices with 32-bit access
828 limitations, on systems with more than 3 GB. This is usually needed
829 for USB, sound, many IDE/SATA chipsets and some other devices.
830
831 Newer systems typically have a modern AMD IOMMU, supported via
832 the CONFIG_AMD_IOMMU=y config option.
833
834 In normal configurations this driver is only active when needed:
835 there's more than 3 GB of memory and the system contains a
836 32-bit limited device.
837
838 If unsure, say Y.
839
840 config CALGARY_IOMMU
841 bool "IBM Calgary IOMMU support"
842 select SWIOTLB
843 depends on X86_64 && PCI
844 ---help---
845 Support for hardware IOMMUs in IBM's xSeries x366 and x460
846 systems. Needed to run systems with more than 3GB of memory
847 properly with 32-bit PCI devices that do not support DAC
848 (Double Address Cycle). Calgary also supports bus level
849 isolation, where all DMAs pass through the IOMMU. This
850 prevents them from going anywhere except their intended
851 destination. This catches hard-to-find kernel bugs and
852 mis-behaving drivers and devices that do not use the DMA-API
853 properly to set up their DMA buffers. The IOMMU can be
854 turned off at boot time with the iommu=off parameter.
855 Normally the kernel will make the right choice by itself.
856 If unsure, say Y.
857
858 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
859 def_bool y
860 prompt "Should Calgary be enabled by default?"
861 depends on CALGARY_IOMMU
862 ---help---
863 Should Calgary be enabled by default? if you choose 'y', Calgary
864 will be used (if it exists). If you choose 'n', Calgary will not be
865 used even if it exists. If you choose 'n' and would like to use
866 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
867 If unsure, say Y.
868
869 # need this always selected by IOMMU for the VIA workaround
870 config SWIOTLB
871 def_bool y if X86_64
872 ---help---
873 Support for software bounce buffers used on x86-64 systems
874 which don't have a hardware IOMMU. Using this PCI devices
875 which can only access 32-bits of memory can be used on systems
876 with more than 3 GB of memory.
877 If unsure, say Y.
878
879 config IOMMU_HELPER
880 def_bool y
881 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
882
883 config MAXSMP
884 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
885 depends on X86_64 && SMP && DEBUG_KERNEL
886 select CPUMASK_OFFSTACK
887 ---help---
888 Enable maximum number of CPUS and NUMA Nodes for this architecture.
889 If unsure, say N.
890
891 config NR_CPUS
892 int "Maximum number of CPUs" if SMP && !MAXSMP
893 range 2 8 if SMP && X86_32 && !X86_BIGSMP
894 range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK
895 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
896 default "1" if !SMP
897 default "8192" if MAXSMP
898 default "32" if SMP && X86_BIGSMP
899 default "8" if SMP && X86_32
900 default "64" if SMP
901 ---help---
902 This allows you to specify the maximum number of CPUs which this
903 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
904 supported value is 8192, otherwise the maximum value is 512. The
905 minimum value which makes sense is 2.
906
907 This is purely to save memory - each supported CPU adds
908 approximately eight kilobytes to the kernel image.
909
910 config SCHED_SMT
911 bool "SMT (Hyperthreading) scheduler support"
912 depends on SMP
913 ---help---
914 SMT scheduler support improves the CPU scheduler's decision making
915 when dealing with Intel Pentium 4 chips with HyperThreading at a
916 cost of slightly increased overhead in some places. If unsure say
917 N here.
918
919 config SCHED_MC
920 def_bool y
921 prompt "Multi-core scheduler support"
922 depends on SMP
923 ---help---
924 Multi-core scheduler support improves the CPU scheduler's decision
925 making when dealing with multi-core CPU chips at a cost of slightly
926 increased overhead in some places. If unsure say N here.
927
928 source "kernel/Kconfig.preempt"
929
930 config UP_LATE_INIT
931 def_bool y
932 depends on !SMP && X86_LOCAL_APIC
933
934 config X86_UP_APIC
935 bool "Local APIC support on uniprocessors" if !PCI_MSI
936 default PCI_MSI
937 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
938 ---help---
939 A local APIC (Advanced Programmable Interrupt Controller) is an
940 integrated interrupt controller in the CPU. If you have a single-CPU
941 system which has a processor with a local APIC, you can say Y here to
942 enable and use it. If you say Y here even though your machine doesn't
943 have a local APIC, then the kernel will still run with no slowdown at
944 all. The local APIC supports CPU-generated self-interrupts (timer,
945 performance counters), and the NMI watchdog which detects hard
946 lockups.
947
948 config X86_UP_IOAPIC
949 bool "IO-APIC support on uniprocessors"
950 depends on X86_UP_APIC
951 ---help---
952 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
953 SMP-capable replacement for PC-style interrupt controllers. Most
954 SMP systems and many recent uniprocessor systems have one.
955
956 If you have a single-CPU system with an IO-APIC, you can say Y here
957 to use it. If you say Y here even though your machine doesn't have
958 an IO-APIC, then the kernel will still run with no slowdown at all.
959
960 config X86_LOCAL_APIC
961 def_bool y
962 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
963 select IRQ_DOMAIN_HIERARCHY
964 select PCI_MSI_IRQ_DOMAIN if PCI_MSI
965
966 config X86_IO_APIC
967 def_bool y
968 depends on X86_LOCAL_APIC || X86_UP_IOAPIC
969
970 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
971 bool "Reroute for broken boot IRQs"
972 depends on X86_IO_APIC
973 ---help---
974 This option enables a workaround that fixes a source of
975 spurious interrupts. This is recommended when threaded
976 interrupt handling is used on systems where the generation of
977 superfluous "boot interrupts" cannot be disabled.
978
979 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
980 entry in the chipset's IO-APIC is masked (as, e.g. the RT
981 kernel does during interrupt handling). On chipsets where this
982 boot IRQ generation cannot be disabled, this workaround keeps
983 the original IRQ line masked so that only the equivalent "boot
984 IRQ" is delivered to the CPUs. The workaround also tells the
985 kernel to set up the IRQ handler on the boot IRQ line. In this
986 way only one interrupt is delivered to the kernel. Otherwise
987 the spurious second interrupt may cause the kernel to bring
988 down (vital) interrupt lines.
989
990 Only affects "broken" chipsets. Interrupt sharing may be
991 increased on these systems.
992
993 config X86_MCE
994 bool "Machine Check / overheating reporting"
995 select GENERIC_ALLOCATOR
996 default y
997 ---help---
998 Machine Check support allows the processor to notify the
999 kernel if it detects a problem (e.g. overheating, data corruption).
1000 The action the kernel takes depends on the severity of the problem,
1001 ranging from warning messages to halting the machine.
1002
1003 config X86_MCE_INTEL
1004 def_bool y
1005 prompt "Intel MCE features"
1006 depends on X86_MCE && X86_LOCAL_APIC
1007 ---help---
1008 Additional support for intel specific MCE features such as
1009 the thermal monitor.
1010
1011 config X86_MCE_AMD
1012 def_bool y
1013 prompt "AMD MCE features"
1014 depends on X86_MCE && X86_LOCAL_APIC
1015 ---help---
1016 Additional support for AMD specific MCE features such as
1017 the DRAM Error Threshold.
1018
1019 config X86_ANCIENT_MCE
1020 bool "Support for old Pentium 5 / WinChip machine checks"
1021 depends on X86_32 && X86_MCE
1022 ---help---
1023 Include support for machine check handling on old Pentium 5 or WinChip
1024 systems. These typically need to be enabled explicitly on the command
1025 line.
1026
1027 config X86_MCE_THRESHOLD
1028 depends on X86_MCE_AMD || X86_MCE_INTEL
1029 def_bool y
1030
1031 config X86_MCE_INJECT
1032 depends on X86_MCE
1033 tristate "Machine check injector support"
1034 ---help---
1035 Provide support for injecting machine checks for testing purposes.
1036 If you don't know what a machine check is and you don't do kernel
1037 QA it is safe to say n.
1038
1039 config X86_THERMAL_VECTOR
1040 def_bool y
1041 depends on X86_MCE_INTEL
1042
1043 source "arch/x86/events/Kconfig"
1044
1045 config X86_LEGACY_VM86
1046 bool "Legacy VM86 support"
1047 default n
1048 depends on X86_32
1049 ---help---
1050 This option allows user programs to put the CPU into V8086
1051 mode, which is an 80286-era approximation of 16-bit real mode.
1052
1053 Some very old versions of X and/or vbetool require this option
1054 for user mode setting. Similarly, DOSEMU will use it if
1055 available to accelerate real mode DOS programs. However, any
1056 recent version of DOSEMU, X, or vbetool should be fully
1057 functional even without kernel VM86 support, as they will all
1058 fall back to software emulation. Nevertheless, if you are using
1059 a 16-bit DOS program where 16-bit performance matters, vm86
1060 mode might be faster than emulation and you might want to
1061 enable this option.
1062
1063 Note that any app that works on a 64-bit kernel is unlikely to
1064 need this option, as 64-bit kernels don't, and can't, support
1065 V8086 mode. This option is also unrelated to 16-bit protected
1066 mode and is not needed to run most 16-bit programs under Wine.
1067
1068 Enabling this option increases the complexity of the kernel
1069 and slows down exception handling a tiny bit.
1070
1071 If unsure, say N here.
1072
1073 config VM86
1074 bool
1075 default X86_LEGACY_VM86
1076
1077 config X86_16BIT
1078 bool "Enable support for 16-bit segments" if EXPERT
1079 default y
1080 depends on MODIFY_LDT_SYSCALL
1081 ---help---
1082 This option is required by programs like Wine to run 16-bit
1083 protected mode legacy code on x86 processors. Disabling
1084 this option saves about 300 bytes on i386, or around 6K text
1085 plus 16K runtime memory on x86-64,
1086
1087 config X86_ESPFIX32
1088 def_bool y
1089 depends on X86_16BIT && X86_32
1090
1091 config X86_ESPFIX64
1092 def_bool y
1093 depends on X86_16BIT && X86_64
1094
1095 config X86_VSYSCALL_EMULATION
1096 bool "Enable vsyscall emulation" if EXPERT
1097 default y
1098 depends on X86_64
1099 ---help---
1100 This enables emulation of the legacy vsyscall page. Disabling
1101 it is roughly equivalent to booting with vsyscall=none, except
1102 that it will also disable the helpful warning if a program
1103 tries to use a vsyscall. With this option set to N, offending
1104 programs will just segfault, citing addresses of the form
1105 0xffffffffff600?00.
1106
1107 This option is required by many programs built before 2013, and
1108 care should be used even with newer programs if set to N.
1109
1110 Disabling this option saves about 7K of kernel size and
1111 possibly 4K of additional runtime pagetable memory.
1112
1113 config TOSHIBA
1114 tristate "Toshiba Laptop support"
1115 depends on X86_32
1116 ---help---
1117 This adds a driver to safely access the System Management Mode of
1118 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1119 not work on models with a Phoenix BIOS. The System Management Mode
1120 is used to set the BIOS and power saving options on Toshiba portables.
1121
1122 For information on utilities to make use of this driver see the
1123 Toshiba Linux utilities web site at:
1124 <http://www.buzzard.org.uk/toshiba/>.
1125
1126 Say Y if you intend to run this kernel on a Toshiba portable.
1127 Say N otherwise.
1128
1129 config I8K
1130 tristate "Dell i8k legacy laptop support"
1131 select HWMON
1132 select SENSORS_DELL_SMM
1133 ---help---
1134 This option enables legacy /proc/i8k userspace interface in hwmon
1135 dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1136 temperature and allows controlling fan speeds of Dell laptops via
1137 System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1138 it reports also power and hotkey status. For fan speed control is
1139 needed userspace package i8kutils.
1140
1141 Say Y if you intend to run this kernel on old Dell laptops or want to
1142 use userspace package i8kutils.
1143 Say N otherwise.
1144
1145 config X86_REBOOTFIXUPS
1146 bool "Enable X86 board specific fixups for reboot"
1147 depends on X86_32
1148 ---help---
1149 This enables chipset and/or board specific fixups to be done
1150 in order to get reboot to work correctly. This is only needed on
1151 some combinations of hardware and BIOS. The symptom, for which
1152 this config is intended, is when reboot ends with a stalled/hung
1153 system.
1154
1155 Currently, the only fixup is for the Geode machines using
1156 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1157
1158 Say Y if you want to enable the fixup. Currently, it's safe to
1159 enable this option even if you don't need it.
1160 Say N otherwise.
1161
1162 config MICROCODE
1163 bool "CPU microcode loading support"
1164 default y
1165 depends on CPU_SUP_AMD || CPU_SUP_INTEL
1166 select FW_LOADER
1167 ---help---
1168 If you say Y here, you will be able to update the microcode on
1169 Intel and AMD processors. The Intel support is for the IA32 family,
1170 e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4, Xeon etc. The
1171 AMD support is for families 0x10 and later. You will obviously need
1172 the actual microcode binary data itself which is not shipped with
1173 the Linux kernel.
1174
1175 The preferred method to load microcode from a detached initrd is described
1176 in Documentation/x86/early-microcode.txt. For that you need to enable
1177 CONFIG_BLK_DEV_INITRD in order for the loader to be able to scan the
1178 initrd for microcode blobs.
1179
1180 In addition, you can build-in the microcode into the kernel. For that you
1181 need to enable FIRMWARE_IN_KERNEL and add the vendor-supplied microcode
1182 to the CONFIG_EXTRA_FIRMWARE config option.
1183
1184 config MICROCODE_INTEL
1185 bool "Intel microcode loading support"
1186 depends on MICROCODE
1187 default MICROCODE
1188 select FW_LOADER
1189 ---help---
1190 This options enables microcode patch loading support for Intel
1191 processors.
1192
1193 For the current Intel microcode data package go to
1194 <https://downloadcenter.intel.com> and search for
1195 'Linux Processor Microcode Data File'.
1196
1197 config MICROCODE_AMD
1198 bool "AMD microcode loading support"
1199 depends on MICROCODE
1200 select FW_LOADER
1201 ---help---
1202 If you select this option, microcode patch loading support for AMD
1203 processors will be enabled.
1204
1205 config MICROCODE_OLD_INTERFACE
1206 def_bool y
1207 depends on MICROCODE
1208
1209 config X86_MSR
1210 tristate "/dev/cpu/*/msr - Model-specific register support"
1211 ---help---
1212 This device gives privileged processes access to the x86
1213 Model-Specific Registers (MSRs). It is a character device with
1214 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1215 MSR accesses are directed to a specific CPU on multi-processor
1216 systems.
1217
1218 config X86_CPUID
1219 tristate "/dev/cpu/*/cpuid - CPU information support"
1220 ---help---
1221 This device gives processes access to the x86 CPUID instruction to
1222 be executed on a specific processor. It is a character device
1223 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1224 /dev/cpu/31/cpuid.
1225
1226 choice
1227 prompt "High Memory Support"
1228 default HIGHMEM4G
1229 depends on X86_32
1230
1231 config NOHIGHMEM
1232 bool "off"
1233 ---help---
1234 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1235 However, the address space of 32-bit x86 processors is only 4
1236 Gigabytes large. That means that, if you have a large amount of
1237 physical memory, not all of it can be "permanently mapped" by the
1238 kernel. The physical memory that's not permanently mapped is called
1239 "high memory".
1240
1241 If you are compiling a kernel which will never run on a machine with
1242 more than 1 Gigabyte total physical RAM, answer "off" here (default
1243 choice and suitable for most users). This will result in a "3GB/1GB"
1244 split: 3GB are mapped so that each process sees a 3GB virtual memory
1245 space and the remaining part of the 4GB virtual memory space is used
1246 by the kernel to permanently map as much physical memory as
1247 possible.
1248
1249 If the machine has between 1 and 4 Gigabytes physical RAM, then
1250 answer "4GB" here.
1251
1252 If more than 4 Gigabytes is used then answer "64GB" here. This
1253 selection turns Intel PAE (Physical Address Extension) mode on.
1254 PAE implements 3-level paging on IA32 processors. PAE is fully
1255 supported by Linux, PAE mode is implemented on all recent Intel
1256 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1257 then the kernel will not boot on CPUs that don't support PAE!
1258
1259 The actual amount of total physical memory will either be
1260 auto detected or can be forced by using a kernel command line option
1261 such as "mem=256M". (Try "man bootparam" or see the documentation of
1262 your boot loader (lilo or loadlin) about how to pass options to the
1263 kernel at boot time.)
1264
1265 If unsure, say "off".
1266
1267 config HIGHMEM4G
1268 bool "4GB"
1269 ---help---
1270 Select this if you have a 32-bit processor and between 1 and 4
1271 gigabytes of physical RAM.
1272
1273 config HIGHMEM64G
1274 bool "64GB"
1275 depends on !M486
1276 select X86_PAE
1277 ---help---
1278 Select this if you have a 32-bit processor and more than 4
1279 gigabytes of physical RAM.
1280
1281 endchoice
1282
1283 choice
1284 prompt "Memory split" if EXPERT
1285 default VMSPLIT_3G
1286 depends on X86_32
1287 ---help---
1288 Select the desired split between kernel and user memory.
1289
1290 If the address range available to the kernel is less than the
1291 physical memory installed, the remaining memory will be available
1292 as "high memory". Accessing high memory is a little more costly
1293 than low memory, as it needs to be mapped into the kernel first.
1294 Note that increasing the kernel address space limits the range
1295 available to user programs, making the address space there
1296 tighter. Selecting anything other than the default 3G/1G split
1297 will also likely make your kernel incompatible with binary-only
1298 kernel modules.
1299
1300 If you are not absolutely sure what you are doing, leave this
1301 option alone!
1302
1303 config VMSPLIT_3G
1304 bool "3G/1G user/kernel split"
1305 config VMSPLIT_3G_OPT
1306 depends on !X86_PAE
1307 bool "3G/1G user/kernel split (for full 1G low memory)"
1308 config VMSPLIT_2G
1309 bool "2G/2G user/kernel split"
1310 config VMSPLIT_2G_OPT
1311 depends on !X86_PAE
1312 bool "2G/2G user/kernel split (for full 2G low memory)"
1313 config VMSPLIT_1G
1314 bool "1G/3G user/kernel split"
1315 endchoice
1316
1317 config PAGE_OFFSET
1318 hex
1319 default 0xB0000000 if VMSPLIT_3G_OPT
1320 default 0x80000000 if VMSPLIT_2G
1321 default 0x78000000 if VMSPLIT_2G_OPT
1322 default 0x40000000 if VMSPLIT_1G
1323 default 0xC0000000
1324 depends on X86_32
1325
1326 config HIGHMEM
1327 def_bool y
1328 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1329
1330 config X86_PAE
1331 bool "PAE (Physical Address Extension) Support"
1332 depends on X86_32 && !HIGHMEM4G
1333 select SWIOTLB
1334 ---help---
1335 PAE is required for NX support, and furthermore enables
1336 larger swapspace support for non-overcommit purposes. It
1337 has the cost of more pagetable lookup overhead, and also
1338 consumes more pagetable space per process.
1339
1340 config ARCH_PHYS_ADDR_T_64BIT
1341 def_bool y
1342 depends on X86_64 || X86_PAE
1343
1344 config ARCH_DMA_ADDR_T_64BIT
1345 def_bool y
1346 depends on X86_64 || HIGHMEM64G
1347
1348 config X86_DIRECT_GBPAGES
1349 def_bool y
1350 depends on X86_64 && !DEBUG_PAGEALLOC && !KMEMCHECK
1351 ---help---
1352 Certain kernel features effectively disable kernel
1353 linear 1 GB mappings (even if the CPU otherwise
1354 supports them), so don't confuse the user by printing
1355 that we have them enabled.
1356
1357 # Common NUMA Features
1358 config NUMA
1359 bool "Numa Memory Allocation and Scheduler Support"
1360 depends on SMP
1361 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1362 default y if X86_BIGSMP
1363 ---help---
1364 Enable NUMA (Non Uniform Memory Access) support.
1365
1366 The kernel will try to allocate memory used by a CPU on the
1367 local memory controller of the CPU and add some more
1368 NUMA awareness to the kernel.
1369
1370 For 64-bit this is recommended if the system is Intel Core i7
1371 (or later), AMD Opteron, or EM64T NUMA.
1372
1373 For 32-bit this is only needed if you boot a 32-bit
1374 kernel on a 64-bit NUMA platform.
1375
1376 Otherwise, you should say N.
1377
1378 config AMD_NUMA
1379 def_bool y
1380 prompt "Old style AMD Opteron NUMA detection"
1381 depends on X86_64 && NUMA && PCI
1382 ---help---
1383 Enable AMD NUMA node topology detection. You should say Y here if
1384 you have a multi processor AMD system. This uses an old method to
1385 read the NUMA configuration directly from the builtin Northbridge
1386 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1387 which also takes priority if both are compiled in.
1388
1389 config X86_64_ACPI_NUMA
1390 def_bool y
1391 prompt "ACPI NUMA detection"
1392 depends on X86_64 && NUMA && ACPI && PCI
1393 select ACPI_NUMA
1394 ---help---
1395 Enable ACPI SRAT based node topology detection.
1396
1397 # Some NUMA nodes have memory ranges that span
1398 # other nodes. Even though a pfn is valid and
1399 # between a node's start and end pfns, it may not
1400 # reside on that node. See memmap_init_zone()
1401 # for details.
1402 config NODES_SPAN_OTHER_NODES
1403 def_bool y
1404 depends on X86_64_ACPI_NUMA
1405
1406 config NUMA_EMU
1407 bool "NUMA emulation"
1408 depends on NUMA
1409 ---help---
1410 Enable NUMA emulation. A flat machine will be split
1411 into virtual nodes when booted with "numa=fake=N", where N is the
1412 number of nodes. This is only useful for debugging.
1413
1414 config NODES_SHIFT
1415 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1416 range 1 10
1417 default "10" if MAXSMP
1418 default "6" if X86_64
1419 default "3"
1420 depends on NEED_MULTIPLE_NODES
1421 ---help---
1422 Specify the maximum number of NUMA Nodes available on the target
1423 system. Increases memory reserved to accommodate various tables.
1424
1425 config ARCH_HAVE_MEMORY_PRESENT
1426 def_bool y
1427 depends on X86_32 && DISCONTIGMEM
1428
1429 config NEED_NODE_MEMMAP_SIZE
1430 def_bool y
1431 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1432
1433 config ARCH_FLATMEM_ENABLE
1434 def_bool y
1435 depends on X86_32 && !NUMA
1436
1437 config ARCH_DISCONTIGMEM_ENABLE
1438 def_bool y
1439 depends on NUMA && X86_32
1440
1441 config ARCH_DISCONTIGMEM_DEFAULT
1442 def_bool y
1443 depends on NUMA && X86_32
1444
1445 config ARCH_SPARSEMEM_ENABLE
1446 def_bool y
1447 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1448 select SPARSEMEM_STATIC if X86_32
1449 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1450
1451 config ARCH_SPARSEMEM_DEFAULT
1452 def_bool y
1453 depends on X86_64
1454
1455 config ARCH_SELECT_MEMORY_MODEL
1456 def_bool y
1457 depends on ARCH_SPARSEMEM_ENABLE
1458
1459 config ARCH_MEMORY_PROBE
1460 bool "Enable sysfs memory/probe interface"
1461 depends on X86_64 && MEMORY_HOTPLUG
1462 help
1463 This option enables a sysfs memory/probe interface for testing.
1464 See Documentation/memory-hotplug.txt for more information.
1465 If you are unsure how to answer this question, answer N.
1466
1467 config ARCH_PROC_KCORE_TEXT
1468 def_bool y
1469 depends on X86_64 && PROC_KCORE
1470
1471 config ILLEGAL_POINTER_VALUE
1472 hex
1473 default 0 if X86_32
1474 default 0xdead000000000000 if X86_64
1475
1476 source "mm/Kconfig"
1477
1478 config X86_PMEM_LEGACY_DEVICE
1479 bool
1480
1481 config X86_PMEM_LEGACY
1482 tristate "Support non-standard NVDIMMs and ADR protected memory"
1483 depends on PHYS_ADDR_T_64BIT
1484 depends on BLK_DEV
1485 select X86_PMEM_LEGACY_DEVICE
1486 select LIBNVDIMM
1487 help
1488 Treat memory marked using the non-standard e820 type of 12 as used
1489 by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1490 The kernel will offer these regions to the 'pmem' driver so
1491 they can be used for persistent storage.
1492
1493 Say Y if unsure.
1494
1495 config HIGHPTE
1496 bool "Allocate 3rd-level pagetables from highmem"
1497 depends on HIGHMEM
1498 ---help---
1499 The VM uses one page table entry for each page of physical memory.
1500 For systems with a lot of RAM, this can be wasteful of precious
1501 low memory. Setting this option will put user-space page table
1502 entries in high memory.
1503
1504 config X86_CHECK_BIOS_CORRUPTION
1505 bool "Check for low memory corruption"
1506 ---help---
1507 Periodically check for memory corruption in low memory, which
1508 is suspected to be caused by BIOS. Even when enabled in the
1509 configuration, it is disabled at runtime. Enable it by
1510 setting "memory_corruption_check=1" on the kernel command
1511 line. By default it scans the low 64k of memory every 60
1512 seconds; see the memory_corruption_check_size and
1513 memory_corruption_check_period parameters in
1514 Documentation/kernel-parameters.txt to adjust this.
1515
1516 When enabled with the default parameters, this option has
1517 almost no overhead, as it reserves a relatively small amount
1518 of memory and scans it infrequently. It both detects corruption
1519 and prevents it from affecting the running system.
1520
1521 It is, however, intended as a diagnostic tool; if repeatable
1522 BIOS-originated corruption always affects the same memory,
1523 you can use memmap= to prevent the kernel from using that
1524 memory.
1525
1526 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1527 bool "Set the default setting of memory_corruption_check"
1528 depends on X86_CHECK_BIOS_CORRUPTION
1529 default y
1530 ---help---
1531 Set whether the default state of memory_corruption_check is
1532 on or off.
1533
1534 config X86_RESERVE_LOW
1535 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1536 default 64
1537 range 4 640
1538 ---help---
1539 Specify the amount of low memory to reserve for the BIOS.
1540
1541 The first page contains BIOS data structures that the kernel
1542 must not use, so that page must always be reserved.
1543
1544 By default we reserve the first 64K of physical RAM, as a
1545 number of BIOSes are known to corrupt that memory range
1546 during events such as suspend/resume or monitor cable
1547 insertion, so it must not be used by the kernel.
1548
1549 You can set this to 4 if you are absolutely sure that you
1550 trust the BIOS to get all its memory reservations and usages
1551 right. If you know your BIOS have problems beyond the
1552 default 64K area, you can set this to 640 to avoid using the
1553 entire low memory range.
1554
1555 If you have doubts about the BIOS (e.g. suspend/resume does
1556 not work or there's kernel crashes after certain hardware
1557 hotplug events) then you might want to enable
1558 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1559 typical corruption patterns.
1560
1561 Leave this to the default value of 64 if you are unsure.
1562
1563 config MATH_EMULATION
1564 bool
1565 depends on MODIFY_LDT_SYSCALL
1566 prompt "Math emulation" if X86_32
1567 ---help---
1568 Linux can emulate a math coprocessor (used for floating point
1569 operations) if you don't have one. 486DX and Pentium processors have
1570 a math coprocessor built in, 486SX and 386 do not, unless you added
1571 a 487DX or 387, respectively. (The messages during boot time can
1572 give you some hints here ["man dmesg"].) Everyone needs either a
1573 coprocessor or this emulation.
1574
1575 If you don't have a math coprocessor, you need to say Y here; if you
1576 say Y here even though you have a coprocessor, the coprocessor will
1577 be used nevertheless. (This behavior can be changed with the kernel
1578 command line option "no387", which comes handy if your coprocessor
1579 is broken. Try "man bootparam" or see the documentation of your boot
1580 loader (lilo or loadlin) about how to pass options to the kernel at
1581 boot time.) This means that it is a good idea to say Y here if you
1582 intend to use this kernel on different machines.
1583
1584 More information about the internals of the Linux math coprocessor
1585 emulation can be found in <file:arch/x86/math-emu/README>.
1586
1587 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1588 kernel, it won't hurt.
1589
1590 config MTRR
1591 def_bool y
1592 prompt "MTRR (Memory Type Range Register) support" if EXPERT
1593 ---help---
1594 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1595 the Memory Type Range Registers (MTRRs) may be used to control
1596 processor access to memory ranges. This is most useful if you have
1597 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1598 allows bus write transfers to be combined into a larger transfer
1599 before bursting over the PCI/AGP bus. This can increase performance
1600 of image write operations 2.5 times or more. Saying Y here creates a
1601 /proc/mtrr file which may be used to manipulate your processor's
1602 MTRRs. Typically the X server should use this.
1603
1604 This code has a reasonably generic interface so that similar
1605 control registers on other processors can be easily supported
1606 as well:
1607
1608 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1609 Registers (ARRs) which provide a similar functionality to MTRRs. For
1610 these, the ARRs are used to emulate the MTRRs.
1611 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1612 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1613 write-combining. All of these processors are supported by this code
1614 and it makes sense to say Y here if you have one of them.
1615
1616 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1617 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1618 can lead to all sorts of problems, so it's good to say Y here.
1619
1620 You can safely say Y even if your machine doesn't have MTRRs, you'll
1621 just add about 9 KB to your kernel.
1622
1623 See <file:Documentation/x86/mtrr.txt> for more information.
1624
1625 config MTRR_SANITIZER
1626 def_bool y
1627 prompt "MTRR cleanup support"
1628 depends on MTRR
1629 ---help---
1630 Convert MTRR layout from continuous to discrete, so X drivers can
1631 add writeback entries.
1632
1633 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1634 The largest mtrr entry size for a continuous block can be set with
1635 mtrr_chunk_size.
1636
1637 If unsure, say Y.
1638
1639 config MTRR_SANITIZER_ENABLE_DEFAULT
1640 int "MTRR cleanup enable value (0-1)"
1641 range 0 1
1642 default "0"
1643 depends on MTRR_SANITIZER
1644 ---help---
1645 Enable mtrr cleanup default value
1646
1647 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1648 int "MTRR cleanup spare reg num (0-7)"
1649 range 0 7
1650 default "1"
1651 depends on MTRR_SANITIZER
1652 ---help---
1653 mtrr cleanup spare entries default, it can be changed via
1654 mtrr_spare_reg_nr=N on the kernel command line.
1655
1656 config X86_PAT
1657 def_bool y
1658 prompt "x86 PAT support" if EXPERT
1659 depends on MTRR
1660 ---help---
1661 Use PAT attributes to setup page level cache control.
1662
1663 PATs are the modern equivalents of MTRRs and are much more
1664 flexible than MTRRs.
1665
1666 Say N here if you see bootup problems (boot crash, boot hang,
1667 spontaneous reboots) or a non-working video driver.
1668
1669 If unsure, say Y.
1670
1671 config ARCH_USES_PG_UNCACHED
1672 def_bool y
1673 depends on X86_PAT
1674
1675 config ARCH_RANDOM
1676 def_bool y
1677 prompt "x86 architectural random number generator" if EXPERT
1678 ---help---
1679 Enable the x86 architectural RDRAND instruction
1680 (Intel Bull Mountain technology) to generate random numbers.
1681 If supported, this is a high bandwidth, cryptographically
1682 secure hardware random number generator.
1683
1684 config X86_SMAP
1685 def_bool y
1686 prompt "Supervisor Mode Access Prevention" if EXPERT
1687 ---help---
1688 Supervisor Mode Access Prevention (SMAP) is a security
1689 feature in newer Intel processors. There is a small
1690 performance cost if this enabled and turned on; there is
1691 also a small increase in the kernel size if this is enabled.
1692
1693 If unsure, say Y.
1694
1695 config X86_INTEL_MPX
1696 prompt "Intel MPX (Memory Protection Extensions)"
1697 def_bool n
1698 depends on CPU_SUP_INTEL
1699 ---help---
1700 MPX provides hardware features that can be used in
1701 conjunction with compiler-instrumented code to check
1702 memory references. It is designed to detect buffer
1703 overflow or underflow bugs.
1704
1705 This option enables running applications which are
1706 instrumented or otherwise use MPX. It does not use MPX
1707 itself inside the kernel or to protect the kernel
1708 against bad memory references.
1709
1710 Enabling this option will make the kernel larger:
1711 ~8k of kernel text and 36 bytes of data on a 64-bit
1712 defconfig. It adds a long to the 'mm_struct' which
1713 will increase the kernel memory overhead of each
1714 process and adds some branches to paths used during
1715 exec() and munmap().
1716
1717 For details, see Documentation/x86/intel_mpx.txt
1718
1719 If unsure, say N.
1720
1721 config X86_INTEL_MEMORY_PROTECTION_KEYS
1722 prompt "Intel Memory Protection Keys"
1723 def_bool y
1724 # Note: only available in 64-bit mode
1725 depends on CPU_SUP_INTEL && X86_64
1726 ---help---
1727 Memory Protection Keys provides a mechanism for enforcing
1728 page-based protections, but without requiring modification of the
1729 page tables when an application changes protection domains.
1730
1731 For details, see Documentation/x86/protection-keys.txt
1732
1733 If unsure, say y.
1734
1735 config EFI
1736 bool "EFI runtime service support"
1737 depends on ACPI
1738 select UCS2_STRING
1739 select EFI_RUNTIME_WRAPPERS
1740 ---help---
1741 This enables the kernel to use EFI runtime services that are
1742 available (such as the EFI variable services).
1743
1744 This option is only useful on systems that have EFI firmware.
1745 In addition, you should use the latest ELILO loader available
1746 at <http://elilo.sourceforge.net> in order to take advantage
1747 of EFI runtime services. However, even with this option, the
1748 resultant kernel should continue to boot on existing non-EFI
1749 platforms.
1750
1751 config EFI_STUB
1752 bool "EFI stub support"
1753 depends on EFI && !X86_USE_3DNOW
1754 select RELOCATABLE
1755 ---help---
1756 This kernel feature allows a bzImage to be loaded directly
1757 by EFI firmware without the use of a bootloader.
1758
1759 See Documentation/efi-stub.txt for more information.
1760
1761 config EFI_MIXED
1762 bool "EFI mixed-mode support"
1763 depends on EFI_STUB && X86_64
1764 ---help---
1765 Enabling this feature allows a 64-bit kernel to be booted
1766 on a 32-bit firmware, provided that your CPU supports 64-bit
1767 mode.
1768
1769 Note that it is not possible to boot a mixed-mode enabled
1770 kernel via the EFI boot stub - a bootloader that supports
1771 the EFI handover protocol must be used.
1772
1773 If unsure, say N.
1774
1775 config SECCOMP
1776 def_bool y
1777 prompt "Enable seccomp to safely compute untrusted bytecode"
1778 ---help---
1779 This kernel feature is useful for number crunching applications
1780 that may need to compute untrusted bytecode during their
1781 execution. By using pipes or other transports made available to
1782 the process as file descriptors supporting the read/write
1783 syscalls, it's possible to isolate those applications in
1784 their own address space using seccomp. Once seccomp is
1785 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1786 and the task is only allowed to execute a few safe syscalls
1787 defined by each seccomp mode.
1788
1789 If unsure, say Y. Only embedded should say N here.
1790
1791 source kernel/Kconfig.hz
1792
1793 config KEXEC
1794 bool "kexec system call"
1795 select KEXEC_CORE
1796 ---help---
1797 kexec is a system call that implements the ability to shutdown your
1798 current kernel, and to start another kernel. It is like a reboot
1799 but it is independent of the system firmware. And like a reboot
1800 you can start any kernel with it, not just Linux.
1801
1802 The name comes from the similarity to the exec system call.
1803
1804 It is an ongoing process to be certain the hardware in a machine
1805 is properly shutdown, so do not be surprised if this code does not
1806 initially work for you. As of this writing the exact hardware
1807 interface is strongly in flux, so no good recommendation can be
1808 made.
1809
1810 config KEXEC_FILE
1811 bool "kexec file based system call"
1812 select KEXEC_CORE
1813 select BUILD_BIN2C
1814 depends on X86_64
1815 depends on CRYPTO=y
1816 depends on CRYPTO_SHA256=y
1817 ---help---
1818 This is new version of kexec system call. This system call is
1819 file based and takes file descriptors as system call argument
1820 for kernel and initramfs as opposed to list of segments as
1821 accepted by previous system call.
1822
1823 config KEXEC_VERIFY_SIG
1824 bool "Verify kernel signature during kexec_file_load() syscall"
1825 depends on KEXEC_FILE
1826 ---help---
1827 This option makes kernel signature verification mandatory for
1828 the kexec_file_load() syscall.
1829
1830 In addition to that option, you need to enable signature
1831 verification for the corresponding kernel image type being
1832 loaded in order for this to work.
1833
1834 config KEXEC_BZIMAGE_VERIFY_SIG
1835 bool "Enable bzImage signature verification support"
1836 depends on KEXEC_VERIFY_SIG
1837 depends on SIGNED_PE_FILE_VERIFICATION
1838 select SYSTEM_TRUSTED_KEYRING
1839 ---help---
1840 Enable bzImage signature verification support.
1841
1842 config CRASH_DUMP
1843 bool "kernel crash dumps"
1844 depends on X86_64 || (X86_32 && HIGHMEM)
1845 ---help---
1846 Generate crash dump after being started by kexec.
1847 This should be normally only set in special crash dump kernels
1848 which are loaded in the main kernel with kexec-tools into
1849 a specially reserved region and then later executed after
1850 a crash by kdump/kexec. The crash dump kernel must be compiled
1851 to a memory address not used by the main kernel or BIOS using
1852 PHYSICAL_START, or it must be built as a relocatable image
1853 (CONFIG_RELOCATABLE=y).
1854 For more details see Documentation/kdump/kdump.txt
1855
1856 config KEXEC_JUMP
1857 bool "kexec jump"
1858 depends on KEXEC && HIBERNATION
1859 ---help---
1860 Jump between original kernel and kexeced kernel and invoke
1861 code in physical address mode via KEXEC
1862
1863 config PHYSICAL_START
1864 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1865 default "0x1000000"
1866 ---help---
1867 This gives the physical address where the kernel is loaded.
1868
1869 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1870 bzImage will decompress itself to above physical address and
1871 run from there. Otherwise, bzImage will run from the address where
1872 it has been loaded by the boot loader and will ignore above physical
1873 address.
1874
1875 In normal kdump cases one does not have to set/change this option
1876 as now bzImage can be compiled as a completely relocatable image
1877 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1878 address. This option is mainly useful for the folks who don't want
1879 to use a bzImage for capturing the crash dump and want to use a
1880 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1881 to be specifically compiled to run from a specific memory area
1882 (normally a reserved region) and this option comes handy.
1883
1884 So if you are using bzImage for capturing the crash dump,
1885 leave the value here unchanged to 0x1000000 and set
1886 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1887 for capturing the crash dump change this value to start of
1888 the reserved region. In other words, it can be set based on
1889 the "X" value as specified in the "crashkernel=YM@XM"
1890 command line boot parameter passed to the panic-ed
1891 kernel. Please take a look at Documentation/kdump/kdump.txt
1892 for more details about crash dumps.
1893
1894 Usage of bzImage for capturing the crash dump is recommended as
1895 one does not have to build two kernels. Same kernel can be used
1896 as production kernel and capture kernel. Above option should have
1897 gone away after relocatable bzImage support is introduced. But it
1898 is present because there are users out there who continue to use
1899 vmlinux for dump capture. This option should go away down the
1900 line.
1901
1902 Don't change this unless you know what you are doing.
1903
1904 config RELOCATABLE
1905 bool "Build a relocatable kernel"
1906 default y
1907 ---help---
1908 This builds a kernel image that retains relocation information
1909 so it can be loaded someplace besides the default 1MB.
1910 The relocations tend to make the kernel binary about 10% larger,
1911 but are discarded at runtime.
1912
1913 One use is for the kexec on panic case where the recovery kernel
1914 must live at a different physical address than the primary
1915 kernel.
1916
1917 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1918 it has been loaded at and the compile time physical address
1919 (CONFIG_PHYSICAL_START) is used as the minimum location.
1920
1921 config RANDOMIZE_BASE
1922 bool "Randomize the address of the kernel image (KASLR)"
1923 depends on RELOCATABLE
1924 default n
1925 ---help---
1926 In support of Kernel Address Space Layout Randomization (KASLR),
1927 this randomizes the physical address at which the kernel image
1928 is decompressed and the virtual address where the kernel
1929 image is mapped, as a security feature that deters exploit
1930 attempts relying on knowledge of the location of kernel
1931 code internals.
1932
1933 On 64-bit, the kernel physical and virtual addresses are
1934 randomized separately. The physical address will be anywhere
1935 between 16MB and the top of physical memory (up to 64TB). The
1936 virtual address will be randomized from 16MB up to 1GB (9 bits
1937 of entropy). Note that this also reduces the memory space
1938 available to kernel modules from 1.5GB to 1GB.
1939
1940 On 32-bit, the kernel physical and virtual addresses are
1941 randomized together. They will be randomized from 16MB up to
1942 512MB (8 bits of entropy).
1943
1944 Entropy is generated using the RDRAND instruction if it is
1945 supported. If RDTSC is supported, its value is mixed into
1946 the entropy pool as well. If neither RDRAND nor RDTSC are
1947 supported, then entropy is read from the i8254 timer. The
1948 usable entropy is limited by the kernel being built using
1949 2GB addressing, and that PHYSICAL_ALIGN must be at a
1950 minimum of 2MB. As a result, only 10 bits of entropy are
1951 theoretically possible, but the implementations are further
1952 limited due to memory layouts.
1953
1954 If CONFIG_HIBERNATE is also enabled, KASLR is disabled at boot
1955 time. To enable it, boot with "kaslr" on the kernel command
1956 line (which will also disable hibernation).
1957
1958 If unsure, say N.
1959
1960 # Relocation on x86 needs some additional build support
1961 config X86_NEED_RELOCS
1962 def_bool y
1963 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
1964
1965 config PHYSICAL_ALIGN
1966 hex "Alignment value to which kernel should be aligned"
1967 default "0x200000"
1968 range 0x2000 0x1000000 if X86_32
1969 range 0x200000 0x1000000 if X86_64
1970 ---help---
1971 This value puts the alignment restrictions on physical address
1972 where kernel is loaded and run from. Kernel is compiled for an
1973 address which meets above alignment restriction.
1974
1975 If bootloader loads the kernel at a non-aligned address and
1976 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1977 address aligned to above value and run from there.
1978
1979 If bootloader loads the kernel at a non-aligned address and
1980 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1981 load address and decompress itself to the address it has been
1982 compiled for and run from there. The address for which kernel is
1983 compiled already meets above alignment restrictions. Hence the
1984 end result is that kernel runs from a physical address meeting
1985 above alignment restrictions.
1986
1987 On 32-bit this value must be a multiple of 0x2000. On 64-bit
1988 this value must be a multiple of 0x200000.
1989
1990 Don't change this unless you know what you are doing.
1991
1992 config RANDOMIZE_MEMORY
1993 bool "Randomize the kernel memory sections"
1994 depends on X86_64
1995 depends on RANDOMIZE_BASE
1996 default RANDOMIZE_BASE
1997 ---help---
1998 Randomizes the base virtual address of kernel memory sections
1999 (physical memory mapping, vmalloc & vmemmap). This security feature
2000 makes exploits relying on predictable memory locations less reliable.
2001
2002 The order of allocations remains unchanged. Entropy is generated in
2003 the same way as RANDOMIZE_BASE. Current implementation in the optimal
2004 configuration have in average 30,000 different possible virtual
2005 addresses for each memory section.
2006
2007 If unsure, say N.
2008
2009 config RANDOMIZE_MEMORY_PHYSICAL_PADDING
2010 hex "Physical memory mapping padding" if EXPERT
2011 depends on RANDOMIZE_MEMORY
2012 default "0xa" if MEMORY_HOTPLUG
2013 default "0x0"
2014 range 0x1 0x40 if MEMORY_HOTPLUG
2015 range 0x0 0x40
2016 ---help---
2017 Define the padding in terabytes added to the existing physical
2018 memory size during kernel memory randomization. It is useful
2019 for memory hotplug support but reduces the entropy available for
2020 address randomization.
2021
2022 If unsure, leave at the default value.
2023
2024 config HOTPLUG_CPU
2025 bool "Support for hot-pluggable CPUs"
2026 depends on SMP
2027 ---help---
2028 Say Y here to allow turning CPUs off and on. CPUs can be
2029 controlled through /sys/devices/system/cpu.
2030 ( Note: power management support will enable this option
2031 automatically on SMP systems. )
2032 Say N if you want to disable CPU hotplug.
2033
2034 config BOOTPARAM_HOTPLUG_CPU0
2035 bool "Set default setting of cpu0_hotpluggable"
2036 default n
2037 depends on HOTPLUG_CPU
2038 ---help---
2039 Set whether default state of cpu0_hotpluggable is on or off.
2040
2041 Say Y here to enable CPU0 hotplug by default. If this switch
2042 is turned on, there is no need to give cpu0_hotplug kernel
2043 parameter and the CPU0 hotplug feature is enabled by default.
2044
2045 Please note: there are two known CPU0 dependencies if you want
2046 to enable the CPU0 hotplug feature either by this switch or by
2047 cpu0_hotplug kernel parameter.
2048
2049 First, resume from hibernate or suspend always starts from CPU0.
2050 So hibernate and suspend are prevented if CPU0 is offline.
2051
2052 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
2053 offline if any interrupt can not migrate out of CPU0. There may
2054 be other CPU0 dependencies.
2055
2056 Please make sure the dependencies are under your control before
2057 you enable this feature.
2058
2059 Say N if you don't want to enable CPU0 hotplug feature by default.
2060 You still can enable the CPU0 hotplug feature at boot by kernel
2061 parameter cpu0_hotplug.
2062
2063 config DEBUG_HOTPLUG_CPU0
2064 def_bool n
2065 prompt "Debug CPU0 hotplug"
2066 depends on HOTPLUG_CPU
2067 ---help---
2068 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2069 soon as possible and boots up userspace with CPU0 offlined. User
2070 can online CPU0 back after boot time.
2071
2072 To debug CPU0 hotplug, you need to enable CPU0 offline/online
2073 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2074 compilation or giving cpu0_hotplug kernel parameter at boot.
2075
2076 If unsure, say N.
2077
2078 config COMPAT_VDSO
2079 def_bool n
2080 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2081 depends on X86_32 || IA32_EMULATION
2082 ---help---
2083 Certain buggy versions of glibc will crash if they are
2084 presented with a 32-bit vDSO that is not mapped at the address
2085 indicated in its segment table.
2086
2087 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2088 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2089 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
2090 the only released version with the bug, but OpenSUSE 9
2091 contains a buggy "glibc 2.3.2".
2092
2093 The symptom of the bug is that everything crashes on startup, saying:
2094 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2095
2096 Saying Y here changes the default value of the vdso32 boot
2097 option from 1 to 0, which turns off the 32-bit vDSO entirely.
2098 This works around the glibc bug but hurts performance.
2099
2100 If unsure, say N: if you are compiling your own kernel, you
2101 are unlikely to be using a buggy version of glibc.
2102
2103 choice
2104 prompt "vsyscall table for legacy applications"
2105 depends on X86_64
2106 default LEGACY_VSYSCALL_EMULATE
2107 help
2108 Legacy user code that does not know how to find the vDSO expects
2109 to be able to issue three syscalls by calling fixed addresses in
2110 kernel space. Since this location is not randomized with ASLR,
2111 it can be used to assist security vulnerability exploitation.
2112
2113 This setting can be changed at boot time via the kernel command
2114 line parameter vsyscall=[native|emulate|none].
2115
2116 On a system with recent enough glibc (2.14 or newer) and no
2117 static binaries, you can say None without a performance penalty
2118 to improve security.
2119
2120 If unsure, select "Emulate".
2121
2122 config LEGACY_VSYSCALL_NATIVE
2123 bool "Native"
2124 help
2125 Actual executable code is located in the fixed vsyscall
2126 address mapping, implementing time() efficiently. Since
2127 this makes the mapping executable, it can be used during
2128 security vulnerability exploitation (traditionally as
2129 ROP gadgets). This configuration is not recommended.
2130
2131 config LEGACY_VSYSCALL_EMULATE
2132 bool "Emulate"
2133 help
2134 The kernel traps and emulates calls into the fixed
2135 vsyscall address mapping. This makes the mapping
2136 non-executable, but it still contains known contents,
2137 which could be used in certain rare security vulnerability
2138 exploits. This configuration is recommended when userspace
2139 still uses the vsyscall area.
2140
2141 config LEGACY_VSYSCALL_NONE
2142 bool "None"
2143 help
2144 There will be no vsyscall mapping at all. This will
2145 eliminate any risk of ASLR bypass due to the vsyscall
2146 fixed address mapping. Attempts to use the vsyscalls
2147 will be reported to dmesg, so that either old or
2148 malicious userspace programs can be identified.
2149
2150 endchoice
2151
2152 config CMDLINE_BOOL
2153 bool "Built-in kernel command line"
2154 ---help---
2155 Allow for specifying boot arguments to the kernel at
2156 build time. On some systems (e.g. embedded ones), it is
2157 necessary or convenient to provide some or all of the
2158 kernel boot arguments with the kernel itself (that is,
2159 to not rely on the boot loader to provide them.)
2160
2161 To compile command line arguments into the kernel,
2162 set this option to 'Y', then fill in the
2163 boot arguments in CONFIG_CMDLINE.
2164
2165 Systems with fully functional boot loaders (i.e. non-embedded)
2166 should leave this option set to 'N'.
2167
2168 config CMDLINE
2169 string "Built-in kernel command string"
2170 depends on CMDLINE_BOOL
2171 default ""
2172 ---help---
2173 Enter arguments here that should be compiled into the kernel
2174 image and used at boot time. If the boot loader provides a
2175 command line at boot time, it is appended to this string to
2176 form the full kernel command line, when the system boots.
2177
2178 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2179 change this behavior.
2180
2181 In most cases, the command line (whether built-in or provided
2182 by the boot loader) should specify the device for the root
2183 file system.
2184
2185 config CMDLINE_OVERRIDE
2186 bool "Built-in command line overrides boot loader arguments"
2187 depends on CMDLINE_BOOL
2188 ---help---
2189 Set this option to 'Y' to have the kernel ignore the boot loader
2190 command line, and use ONLY the built-in command line.
2191
2192 This is used to work around broken boot loaders. This should
2193 be set to 'N' under normal conditions.
2194
2195 config MODIFY_LDT_SYSCALL
2196 bool "Enable the LDT (local descriptor table)" if EXPERT
2197 default y
2198 ---help---
2199 Linux can allow user programs to install a per-process x86
2200 Local Descriptor Table (LDT) using the modify_ldt(2) system
2201 call. This is required to run 16-bit or segmented code such as
2202 DOSEMU or some Wine programs. It is also used by some very old
2203 threading libraries.
2204
2205 Enabling this feature adds a small amount of overhead to
2206 context switches and increases the low-level kernel attack
2207 surface. Disabling it removes the modify_ldt(2) system call.
2208
2209 Saying 'N' here may make sense for embedded or server kernels.
2210
2211 source "kernel/livepatch/Kconfig"
2212
2213 endmenu
2214
2215 config ARCH_ENABLE_MEMORY_HOTPLUG
2216 def_bool y
2217 depends on X86_64 || (X86_32 && HIGHMEM)
2218
2219 config ARCH_ENABLE_MEMORY_HOTREMOVE
2220 def_bool y
2221 depends on MEMORY_HOTPLUG
2222
2223 config USE_PERCPU_NUMA_NODE_ID
2224 def_bool y
2225 depends on NUMA
2226
2227 config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2228 def_bool y
2229 depends on X86_64 || X86_PAE
2230
2231 config ARCH_ENABLE_HUGEPAGE_MIGRATION
2232 def_bool y
2233 depends on X86_64 && HUGETLB_PAGE && MIGRATION
2234
2235 menu "Power management and ACPI options"
2236
2237 config ARCH_HIBERNATION_HEADER
2238 def_bool y
2239 depends on X86_64 && HIBERNATION
2240
2241 source "kernel/power/Kconfig"
2242
2243 source "drivers/acpi/Kconfig"
2244
2245 source "drivers/sfi/Kconfig"
2246
2247 config X86_APM_BOOT
2248 def_bool y
2249 depends on APM
2250
2251 menuconfig APM
2252 tristate "APM (Advanced Power Management) BIOS support"
2253 depends on X86_32 && PM_SLEEP
2254 ---help---
2255 APM is a BIOS specification for saving power using several different
2256 techniques. This is mostly useful for battery powered laptops with
2257 APM compliant BIOSes. If you say Y here, the system time will be
2258 reset after a RESUME operation, the /proc/apm device will provide
2259 battery status information, and user-space programs will receive
2260 notification of APM "events" (e.g. battery status change).
2261
2262 If you select "Y" here, you can disable actual use of the APM
2263 BIOS by passing the "apm=off" option to the kernel at boot time.
2264
2265 Note that the APM support is almost completely disabled for
2266 machines with more than one CPU.
2267
2268 In order to use APM, you will need supporting software. For location
2269 and more information, read <file:Documentation/power/apm-acpi.txt>
2270 and the Battery Powered Linux mini-HOWTO, available from
2271 <http://www.tldp.org/docs.html#howto>.
2272
2273 This driver does not spin down disk drives (see the hdparm(8)
2274 manpage ("man 8 hdparm") for that), and it doesn't turn off
2275 VESA-compliant "green" monitors.
2276
2277 This driver does not support the TI 4000M TravelMate and the ACER
2278 486/DX4/75 because they don't have compliant BIOSes. Many "green"
2279 desktop machines also don't have compliant BIOSes, and this driver
2280 may cause those machines to panic during the boot phase.
2281
2282 Generally, if you don't have a battery in your machine, there isn't
2283 much point in using this driver and you should say N. If you get
2284 random kernel OOPSes or reboots that don't seem to be related to
2285 anything, try disabling/enabling this option (or disabling/enabling
2286 APM in your BIOS).
2287
2288 Some other things you should try when experiencing seemingly random,
2289 "weird" problems:
2290
2291 1) make sure that you have enough swap space and that it is
2292 enabled.
2293 2) pass the "no-hlt" option to the kernel
2294 3) switch on floating point emulation in the kernel and pass
2295 the "no387" option to the kernel
2296 4) pass the "floppy=nodma" option to the kernel
2297 5) pass the "mem=4M" option to the kernel (thereby disabling
2298 all but the first 4 MB of RAM)
2299 6) make sure that the CPU is not over clocked.
2300 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2301 8) disable the cache from your BIOS settings
2302 9) install a fan for the video card or exchange video RAM
2303 10) install a better fan for the CPU
2304 11) exchange RAM chips
2305 12) exchange the motherboard.
2306
2307 To compile this driver as a module, choose M here: the
2308 module will be called apm.
2309
2310 if APM
2311
2312 config APM_IGNORE_USER_SUSPEND
2313 bool "Ignore USER SUSPEND"
2314 ---help---
2315 This option will ignore USER SUSPEND requests. On machines with a
2316 compliant APM BIOS, you want to say N. However, on the NEC Versa M
2317 series notebooks, it is necessary to say Y because of a BIOS bug.
2318
2319 config APM_DO_ENABLE
2320 bool "Enable PM at boot time"
2321 ---help---
2322 Enable APM features at boot time. From page 36 of the APM BIOS
2323 specification: "When disabled, the APM BIOS does not automatically
2324 power manage devices, enter the Standby State, enter the Suspend
2325 State, or take power saving steps in response to CPU Idle calls."
2326 This driver will make CPU Idle calls when Linux is idle (unless this
2327 feature is turned off -- see "Do CPU IDLE calls", below). This
2328 should always save battery power, but more complicated APM features
2329 will be dependent on your BIOS implementation. You may need to turn
2330 this option off if your computer hangs at boot time when using APM
2331 support, or if it beeps continuously instead of suspending. Turn
2332 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2333 T400CDT. This is off by default since most machines do fine without
2334 this feature.
2335
2336 config APM_CPU_IDLE
2337 depends on CPU_IDLE
2338 bool "Make CPU Idle calls when idle"
2339 ---help---
2340 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2341 On some machines, this can activate improved power savings, such as
2342 a slowed CPU clock rate, when the machine is idle. These idle calls
2343 are made after the idle loop has run for some length of time (e.g.,
2344 333 mS). On some machines, this will cause a hang at boot time or
2345 whenever the CPU becomes idle. (On machines with more than one CPU,
2346 this option does nothing.)
2347
2348 config APM_DISPLAY_BLANK
2349 bool "Enable console blanking using APM"
2350 ---help---
2351 Enable console blanking using the APM. Some laptops can use this to
2352 turn off the LCD backlight when the screen blanker of the Linux
2353 virtual console blanks the screen. Note that this is only used by
2354 the virtual console screen blanker, and won't turn off the backlight
2355 when using the X Window system. This also doesn't have anything to
2356 do with your VESA-compliant power-saving monitor. Further, this
2357 option doesn't work for all laptops -- it might not turn off your
2358 backlight at all, or it might print a lot of errors to the console,
2359 especially if you are using gpm.
2360
2361 config APM_ALLOW_INTS
2362 bool "Allow interrupts during APM BIOS calls"
2363 ---help---
2364 Normally we disable external interrupts while we are making calls to
2365 the APM BIOS as a measure to lessen the effects of a badly behaving
2366 BIOS implementation. The BIOS should reenable interrupts if it
2367 needs to. Unfortunately, some BIOSes do not -- especially those in
2368 many of the newer IBM Thinkpads. If you experience hangs when you
2369 suspend, try setting this to Y. Otherwise, say N.
2370
2371 endif # APM
2372
2373 source "drivers/cpufreq/Kconfig"
2374
2375 source "drivers/cpuidle/Kconfig"
2376
2377 source "drivers/idle/Kconfig"
2378
2379 endmenu
2380
2381
2382 menu "Bus options (PCI etc.)"
2383
2384 config PCI
2385 bool "PCI support"
2386 default y
2387 ---help---
2388 Find out whether you have a PCI motherboard. PCI is the name of a
2389 bus system, i.e. the way the CPU talks to the other stuff inside
2390 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2391 VESA. If you have PCI, say Y, otherwise N.
2392
2393 choice
2394 prompt "PCI access mode"
2395 depends on X86_32 && PCI
2396 default PCI_GOANY
2397 ---help---
2398 On PCI systems, the BIOS can be used to detect the PCI devices and
2399 determine their configuration. However, some old PCI motherboards
2400 have BIOS bugs and may crash if this is done. Also, some embedded
2401 PCI-based systems don't have any BIOS at all. Linux can also try to
2402 detect the PCI hardware directly without using the BIOS.
2403
2404 With this option, you can specify how Linux should detect the
2405 PCI devices. If you choose "BIOS", the BIOS will be used,
2406 if you choose "Direct", the BIOS won't be used, and if you
2407 choose "MMConfig", then PCI Express MMCONFIG will be used.
2408 If you choose "Any", the kernel will try MMCONFIG, then the
2409 direct access method and falls back to the BIOS if that doesn't
2410 work. If unsure, go with the default, which is "Any".
2411
2412 config PCI_GOBIOS
2413 bool "BIOS"
2414
2415 config PCI_GOMMCONFIG
2416 bool "MMConfig"
2417
2418 config PCI_GODIRECT
2419 bool "Direct"
2420
2421 config PCI_GOOLPC
2422 bool "OLPC XO-1"
2423 depends on OLPC
2424
2425 config PCI_GOANY
2426 bool "Any"
2427
2428 endchoice
2429
2430 config PCI_BIOS
2431 def_bool y
2432 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2433
2434 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2435 config PCI_DIRECT
2436 def_bool y
2437 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2438
2439 config PCI_MMCONFIG
2440 def_bool y
2441 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
2442
2443 config PCI_OLPC
2444 def_bool y
2445 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2446
2447 config PCI_XEN
2448 def_bool y
2449 depends on PCI && XEN
2450 select SWIOTLB_XEN
2451
2452 config PCI_DOMAINS
2453 def_bool y
2454 depends on PCI
2455
2456 config PCI_MMCONFIG
2457 bool "Support mmconfig PCI config space access"
2458 depends on X86_64 && PCI && ACPI
2459
2460 config PCI_CNB20LE_QUIRK
2461 bool "Read CNB20LE Host Bridge Windows" if EXPERT
2462 depends on PCI
2463 help
2464 Read the PCI windows out of the CNB20LE host bridge. This allows
2465 PCI hotplug to work on systems with the CNB20LE chipset which do
2466 not have ACPI.
2467
2468 There's no public spec for this chipset, and this functionality
2469 is known to be incomplete.
2470
2471 You should say N unless you know you need this.
2472
2473 source "drivers/pci/Kconfig"
2474
2475 config ISA_BUS
2476 bool "ISA-style bus support on modern systems" if EXPERT
2477 select ISA_BUS_API
2478 help
2479 Enables ISA-style drivers on modern systems. This is necessary to
2480 support PC/104 devices on X86_64 platforms.
2481
2482 If unsure, say N.
2483
2484 # x86_64 have no ISA slots, but can have ISA-style DMA.
2485 config ISA_DMA_API
2486 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2487 default y
2488 help
2489 Enables ISA-style DMA support for devices requiring such controllers.
2490 If unsure, say Y.
2491
2492 if X86_32
2493
2494 config ISA
2495 bool "ISA support"
2496 ---help---
2497 Find out whether you have ISA slots on your motherboard. ISA is the
2498 name of a bus system, i.e. the way the CPU talks to the other stuff
2499 inside your box. Other bus systems are PCI, EISA, MicroChannel
2500 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2501 newer boards don't support it. If you have ISA, say Y, otherwise N.
2502
2503 config EISA
2504 bool "EISA support"
2505 depends on ISA
2506 ---help---
2507 The Extended Industry Standard Architecture (EISA) bus was
2508 developed as an open alternative to the IBM MicroChannel bus.
2509
2510 The EISA bus provided some of the features of the IBM MicroChannel
2511 bus while maintaining backward compatibility with cards made for
2512 the older ISA bus. The EISA bus saw limited use between 1988 and
2513 1995 when it was made obsolete by the PCI bus.
2514
2515 Say Y here if you are building a kernel for an EISA-based machine.
2516
2517 Otherwise, say N.
2518
2519 source "drivers/eisa/Kconfig"
2520
2521 config SCx200
2522 tristate "NatSemi SCx200 support"
2523 ---help---
2524 This provides basic support for National Semiconductor's
2525 (now AMD's) Geode processors. The driver probes for the
2526 PCI-IDs of several on-chip devices, so its a good dependency
2527 for other scx200_* drivers.
2528
2529 If compiled as a module, the driver is named scx200.
2530
2531 config SCx200HR_TIMER
2532 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2533 depends on SCx200
2534 default y
2535 ---help---
2536 This driver provides a clocksource built upon the on-chip
2537 27MHz high-resolution timer. Its also a workaround for
2538 NSC Geode SC-1100's buggy TSC, which loses time when the
2539 processor goes idle (as is done by the scheduler). The
2540 other workaround is idle=poll boot option.
2541
2542 config OLPC
2543 bool "One Laptop Per Child support"
2544 depends on !X86_PAE
2545 select GPIOLIB
2546 select OF
2547 select OF_PROMTREE
2548 select IRQ_DOMAIN
2549 ---help---
2550 Add support for detecting the unique features of the OLPC
2551 XO hardware.
2552
2553 config OLPC_XO1_PM
2554 bool "OLPC XO-1 Power Management"
2555 depends on OLPC && MFD_CS5535 && PM_SLEEP
2556 select MFD_CORE
2557 ---help---
2558 Add support for poweroff and suspend of the OLPC XO-1 laptop.
2559
2560 config OLPC_XO1_RTC
2561 bool "OLPC XO-1 Real Time Clock"
2562 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2563 ---help---
2564 Add support for the XO-1 real time clock, which can be used as a
2565 programmable wakeup source.
2566
2567 config OLPC_XO1_SCI
2568 bool "OLPC XO-1 SCI extras"
2569 depends on OLPC && OLPC_XO1_PM
2570 depends on INPUT=y
2571 select POWER_SUPPLY
2572 select GPIO_CS5535
2573 select MFD_CORE
2574 ---help---
2575 Add support for SCI-based features of the OLPC XO-1 laptop:
2576 - EC-driven system wakeups
2577 - Power button
2578 - Ebook switch
2579 - Lid switch
2580 - AC adapter status updates
2581 - Battery status updates
2582
2583 config OLPC_XO15_SCI
2584 bool "OLPC XO-1.5 SCI extras"
2585 depends on OLPC && ACPI
2586 select POWER_SUPPLY
2587 ---help---
2588 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2589 - EC-driven system wakeups
2590 - AC adapter status updates
2591 - Battery status updates
2592
2593 config ALIX
2594 bool "PCEngines ALIX System Support (LED setup)"
2595 select GPIOLIB
2596 ---help---
2597 This option enables system support for the PCEngines ALIX.
2598 At present this just sets up LEDs for GPIO control on
2599 ALIX2/3/6 boards. However, other system specific setup should
2600 get added here.
2601
2602 Note: You must still enable the drivers for GPIO and LED support
2603 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2604
2605 Note: You have to set alix.force=1 for boards with Award BIOS.
2606
2607 config NET5501
2608 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2609 select GPIOLIB
2610 ---help---
2611 This option enables system support for the Soekris Engineering net5501.
2612
2613 config GEOS
2614 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2615 select GPIOLIB
2616 depends on DMI
2617 ---help---
2618 This option enables system support for the Traverse Technologies GEOS.
2619
2620 config TS5500
2621 bool "Technologic Systems TS-5500 platform support"
2622 depends on MELAN
2623 select CHECK_SIGNATURE
2624 select NEW_LEDS
2625 select LEDS_CLASS
2626 ---help---
2627 This option enables system support for the Technologic Systems TS-5500.
2628
2629 endif # X86_32
2630
2631 config AMD_NB
2632 def_bool y
2633 depends on CPU_SUP_AMD && PCI
2634
2635 source "drivers/pcmcia/Kconfig"
2636
2637 config RAPIDIO
2638 tristate "RapidIO support"
2639 depends on PCI
2640 default n
2641 help
2642 If enabled this option will include drivers and the core
2643 infrastructure code to support RapidIO interconnect devices.
2644
2645 source "drivers/rapidio/Kconfig"
2646
2647 config X86_SYSFB
2648 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2649 help
2650 Firmwares often provide initial graphics framebuffers so the BIOS,
2651 bootloader or kernel can show basic video-output during boot for
2652 user-guidance and debugging. Historically, x86 used the VESA BIOS
2653 Extensions and EFI-framebuffers for this, which are mostly limited
2654 to x86.
2655 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2656 framebuffers so the new generic system-framebuffer drivers can be
2657 used on x86. If the framebuffer is not compatible with the generic
2658 modes, it is adverticed as fallback platform framebuffer so legacy
2659 drivers like efifb, vesafb and uvesafb can pick it up.
2660 If this option is not selected, all system framebuffers are always
2661 marked as fallback platform framebuffers as usual.
2662
2663 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2664 not be able to pick up generic system framebuffers if this option
2665 is selected. You are highly encouraged to enable simplefb as
2666 replacement if you select this option. simplefb can correctly deal
2667 with generic system framebuffers. But you should still keep vesafb
2668 and others enabled as fallback if a system framebuffer is
2669 incompatible with simplefb.
2670
2671 If unsure, say Y.
2672
2673 endmenu
2674
2675
2676 menu "Executable file formats / Emulations"
2677
2678 source "fs/Kconfig.binfmt"
2679
2680 config IA32_EMULATION
2681 bool "IA32 Emulation"
2682 depends on X86_64
2683 select BINFMT_ELF
2684 select COMPAT_BINFMT_ELF
2685 select ARCH_WANT_OLD_COMPAT_IPC
2686 ---help---
2687 Include code to run legacy 32-bit programs under a
2688 64-bit kernel. You should likely turn this on, unless you're
2689 100% sure that you don't have any 32-bit programs left.
2690
2691 config IA32_AOUT
2692 tristate "IA32 a.out support"
2693 depends on IA32_EMULATION
2694 ---help---
2695 Support old a.out binaries in the 32bit emulation.
2696
2697 config X86_X32
2698 bool "x32 ABI for 64-bit mode"
2699 depends on X86_64
2700 ---help---
2701 Include code to run binaries for the x32 native 32-bit ABI
2702 for 64-bit processors. An x32 process gets access to the
2703 full 64-bit register file and wide data path while leaving
2704 pointers at 32 bits for smaller memory footprint.
2705
2706 You will need a recent binutils (2.22 or later) with
2707 elf32_x86_64 support enabled to compile a kernel with this
2708 option set.
2709
2710 config COMPAT
2711 def_bool y
2712 depends on IA32_EMULATION || X86_X32
2713
2714 if COMPAT
2715 config COMPAT_FOR_U64_ALIGNMENT
2716 def_bool y
2717
2718 config SYSVIPC_COMPAT
2719 def_bool y
2720 depends on SYSVIPC
2721
2722 config KEYS_COMPAT
2723 def_bool y
2724 depends on KEYS
2725 endif
2726
2727 endmenu
2728
2729
2730 config HAVE_ATOMIC_IOMAP
2731 def_bool y
2732 depends on X86_32
2733
2734 config X86_DEV_DMA_OPS
2735 bool
2736 depends on X86_64 || STA2X11
2737
2738 config X86_DMA_REMAP
2739 bool
2740 depends on STA2X11
2741
2742 config PMC_ATOM
2743 def_bool y
2744 depends on PCI
2745
2746 config VMD
2747 depends on PCI_MSI
2748 tristate "Volume Management Device Driver"
2749 default N
2750 ---help---
2751 Adds support for the Intel Volume Management Device (VMD). VMD is a
2752 secondary PCI host bridge that allows PCI Express root ports,
2753 and devices attached to them, to be removed from the default
2754 PCI domain and placed within the VMD domain. This provides
2755 more bus resources than are otherwise possible with a
2756 single domain. If you know your system provides one of these and
2757 has devices attached to it, say Y; if you are not sure, say N.
2758
2759 source "net/Kconfig"
2760
2761 source "drivers/Kconfig"
2762
2763 source "drivers/firmware/Kconfig"
2764
2765 source "fs/Kconfig"
2766
2767 source "arch/x86/Kconfig.debug"
2768
2769 source "security/Kconfig"
2770
2771 source "crypto/Kconfig"
2772
2773 source "arch/x86/kvm/Kconfig"
2774
2775 source "lib/Kconfig"
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