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1 # Select 32 or 64 bit
2 config 64BIT
3 bool "64-bit kernel" if ARCH = "x86"
4 default ARCH != "i386"
5 ---help---
6 Say yes to build a 64-bit kernel - formerly known as x86_64
7 Say no to build a 32-bit kernel - formerly known as i386
8
9 config X86_32
10 def_bool y
11 depends on !64BIT
12
13 config X86_64
14 def_bool y
15 depends on 64BIT
16
17 ### Arch settings
18 config X86
19 def_bool y
20 select ACPI_LEGACY_TABLES_LOOKUP if ACPI
21 select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI
22 select ANON_INODES
23 select ARCH_CLOCKSOURCE_DATA
24 select ARCH_DISCARD_MEMBLOCK
25 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
26 select ARCH_HAS_DEBUG_STRICT_USER_COPY_CHECKS
27 select ARCH_HAS_ELF_RANDOMIZE
28 select ARCH_HAS_FAST_MULTIPLIER
29 select ARCH_HAS_GCOV_PROFILE_ALL
30 select ARCH_HAS_PMEM_API if X86_64
31 select ARCH_HAS_MMIO_FLUSH
32 select ARCH_HAS_SG_CHAIN
33 select ARCH_HAVE_NMI_SAFE_CMPXCHG
34 select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
35 select ARCH_MIGHT_HAVE_PC_PARPORT
36 select ARCH_MIGHT_HAVE_PC_SERIO
37 select ARCH_SUPPORTS_ATOMIC_RMW
38 select ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT
39 select ARCH_SUPPORTS_INT128 if X86_64
40 select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
41 select ARCH_USE_BUILTIN_BSWAP
42 select ARCH_USE_CMPXCHG_LOCKREF if X86_64
43 select ARCH_USE_QUEUED_RWLOCKS
44 select ARCH_USE_QUEUED_SPINLOCKS
45 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH if SMP
46 select ARCH_WANTS_DYNAMIC_TASK_STRUCT
47 select ARCH_WANT_FRAME_POINTERS
48 select ARCH_WANT_IPC_PARSE_VERSION if X86_32
49 select ARCH_WANT_OPTIONAL_GPIOLIB
50 select BUILDTIME_EXTABLE_SORT
51 select CLKEVT_I8253
52 select CLKSRC_I8253 if X86_32
53 select CLOCKSOURCE_VALIDATE_LAST_CYCLE
54 select CLOCKSOURCE_WATCHDOG
55 select CLONE_BACKWARDS if X86_32
56 select COMPAT_OLD_SIGACTION if IA32_EMULATION
57 select DCACHE_WORD_ACCESS
58 select EDAC_ATOMIC_SCRUB
59 select EDAC_SUPPORT
60 select GENERIC_CLOCKEVENTS
61 select GENERIC_CLOCKEVENTS_BROADCAST if X86_64 || (X86_32 && X86_LOCAL_APIC)
62 select GENERIC_CLOCKEVENTS_MIN_ADJUST
63 select GENERIC_CMOS_UPDATE
64 select GENERIC_CPU_AUTOPROBE
65 select GENERIC_EARLY_IOREMAP
66 select GENERIC_FIND_FIRST_BIT
67 select GENERIC_IOMAP
68 select GENERIC_IRQ_PROBE
69 select GENERIC_IRQ_SHOW
70 select GENERIC_PENDING_IRQ if SMP
71 select GENERIC_SMP_IDLE_THREAD
72 select GENERIC_STRNCPY_FROM_USER
73 select GENERIC_STRNLEN_USER
74 select GENERIC_TIME_VSYSCALL
75 select HAVE_ACPI_APEI if ACPI
76 select HAVE_ACPI_APEI_NMI if ACPI
77 select HAVE_ALIGNED_STRUCT_PAGE if SLUB
78 select HAVE_AOUT if X86_32
79 select HAVE_ARCH_AUDITSYSCALL
80 select HAVE_ARCH_HUGE_VMAP if X86_64 || X86_PAE
81 select HAVE_ARCH_JUMP_LABEL
82 select HAVE_ARCH_KASAN if X86_64 && SPARSEMEM_VMEMMAP
83 select HAVE_ARCH_KGDB
84 select HAVE_ARCH_KMEMCHECK
85 select HAVE_ARCH_SECCOMP_FILTER
86 select HAVE_ARCH_SOFT_DIRTY if X86_64
87 select HAVE_ARCH_TRACEHOOK
88 select HAVE_ARCH_TRANSPARENT_HUGEPAGE
89 select HAVE_BPF_JIT if X86_64
90 select HAVE_CC_STACKPROTECTOR
91 select HAVE_CMPXCHG_DOUBLE
92 select HAVE_CMPXCHG_LOCAL
93 select HAVE_CONTEXT_TRACKING if X86_64
94 select HAVE_COPY_THREAD_TLS
95 select HAVE_C_RECORDMCOUNT
96 select HAVE_DEBUG_KMEMLEAK
97 select HAVE_DEBUG_STACKOVERFLOW
98 select HAVE_DMA_API_DEBUG
99 select HAVE_DMA_ATTRS
100 select HAVE_DMA_CONTIGUOUS
101 select HAVE_DYNAMIC_FTRACE
102 select HAVE_DYNAMIC_FTRACE_WITH_REGS
103 select HAVE_EFFICIENT_UNALIGNED_ACCESS
104 select HAVE_FENTRY if X86_64
105 select HAVE_FTRACE_MCOUNT_RECORD
106 select HAVE_FUNCTION_GRAPH_FP_TEST
107 select HAVE_FUNCTION_GRAPH_TRACER
108 select HAVE_FUNCTION_TRACER
109 select HAVE_GENERIC_DMA_COHERENT if X86_32
110 select HAVE_HW_BREAKPOINT
111 select HAVE_IDE
112 select HAVE_IOREMAP_PROT
113 select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64
114 select HAVE_IRQ_TIME_ACCOUNTING
115 select HAVE_KERNEL_BZIP2
116 select HAVE_KERNEL_GZIP
117 select HAVE_KERNEL_LZ4
118 select HAVE_KERNEL_LZMA
119 select HAVE_KERNEL_LZO
120 select HAVE_KERNEL_XZ
121 select HAVE_KPROBES
122 select HAVE_KPROBES_ON_FTRACE
123 select HAVE_KRETPROBES
124 select HAVE_KVM
125 select HAVE_LIVEPATCH if X86_64
126 select HAVE_MEMBLOCK
127 select HAVE_MEMBLOCK_NODE_MAP
128 select HAVE_MIXED_BREAKPOINTS_REGS
129 select HAVE_OPROFILE
130 select HAVE_OPTPROBES
131 select HAVE_PCSPKR_PLATFORM
132 select HAVE_PERF_EVENTS
133 select HAVE_PERF_EVENTS_NMI
134 select HAVE_PERF_REGS
135 select HAVE_PERF_USER_STACK_DUMP
136 select HAVE_REGS_AND_STACK_ACCESS_API
137 select HAVE_SYSCALL_TRACEPOINTS
138 select HAVE_UID16 if X86_32 || IA32_EMULATION
139 select HAVE_UNSTABLE_SCHED_CLOCK
140 select HAVE_USER_RETURN_NOTIFIER
141 select IRQ_FORCED_THREADING
142 select MODULES_USE_ELF_RELA if X86_64
143 select MODULES_USE_ELF_REL if X86_32
144 select OLD_SIGACTION if X86_32
145 select OLD_SIGSUSPEND3 if X86_32 || IA32_EMULATION
146 select PERF_EVENTS
147 select RTC_LIB
148 select SPARSE_IRQ
149 select SRCU
150 select SYSCTL_EXCEPTION_TRACE
151 select USER_STACKTRACE_SUPPORT
152 select VIRT_TO_BUS
153 select X86_DEV_DMA_OPS if X86_64
154 select X86_FEATURE_NAMES if PROC_FS
155
156 config INSTRUCTION_DECODER
157 def_bool y
158 depends on KPROBES || PERF_EVENTS || UPROBES
159
160 config PERF_EVENTS_INTEL_UNCORE
161 def_bool y
162 depends on PERF_EVENTS && CPU_SUP_INTEL && PCI
163
164 config OUTPUT_FORMAT
165 string
166 default "elf32-i386" if X86_32
167 default "elf64-x86-64" if X86_64
168
169 config ARCH_DEFCONFIG
170 string
171 default "arch/x86/configs/i386_defconfig" if X86_32
172 default "arch/x86/configs/x86_64_defconfig" if X86_64
173
174 config LOCKDEP_SUPPORT
175 def_bool y
176
177 config STACKTRACE_SUPPORT
178 def_bool y
179
180 config HAVE_LATENCYTOP_SUPPORT
181 def_bool y
182
183 config MMU
184 def_bool y
185
186 config SBUS
187 bool
188
189 config NEED_DMA_MAP_STATE
190 def_bool y
191 depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB
192
193 config NEED_SG_DMA_LENGTH
194 def_bool y
195
196 config GENERIC_ISA_DMA
197 def_bool y
198 depends on ISA_DMA_API
199
200 config GENERIC_BUG
201 def_bool y
202 depends on BUG
203 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
204
205 config GENERIC_BUG_RELATIVE_POINTERS
206 bool
207
208 config GENERIC_HWEIGHT
209 def_bool y
210
211 config ARCH_MAY_HAVE_PC_FDC
212 def_bool y
213 depends on ISA_DMA_API
214
215 config RWSEM_XCHGADD_ALGORITHM
216 def_bool y
217
218 config GENERIC_CALIBRATE_DELAY
219 def_bool y
220
221 config ARCH_HAS_CPU_RELAX
222 def_bool y
223
224 config ARCH_HAS_CACHE_LINE_SIZE
225 def_bool y
226
227 config HAVE_SETUP_PER_CPU_AREA
228 def_bool y
229
230 config NEED_PER_CPU_EMBED_FIRST_CHUNK
231 def_bool y
232
233 config NEED_PER_CPU_PAGE_FIRST_CHUNK
234 def_bool y
235
236 config ARCH_HIBERNATION_POSSIBLE
237 def_bool y
238
239 config ARCH_SUSPEND_POSSIBLE
240 def_bool y
241
242 config ARCH_WANT_HUGE_PMD_SHARE
243 def_bool y
244
245 config ARCH_WANT_GENERAL_HUGETLB
246 def_bool y
247
248 config ZONE_DMA32
249 def_bool y if X86_64
250
251 config AUDIT_ARCH
252 def_bool y if X86_64
253
254 config ARCH_SUPPORTS_OPTIMIZED_INLINING
255 def_bool y
256
257 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
258 def_bool y
259
260 config KASAN_SHADOW_OFFSET
261 hex
262 depends on KASAN
263 default 0xdffffc0000000000
264
265 config HAVE_INTEL_TXT
266 def_bool y
267 depends on INTEL_IOMMU && ACPI
268
269 config X86_32_SMP
270 def_bool y
271 depends on X86_32 && SMP
272
273 config X86_64_SMP
274 def_bool y
275 depends on X86_64 && SMP
276
277 config X86_32_LAZY_GS
278 def_bool y
279 depends on X86_32 && !CC_STACKPROTECTOR
280
281 config ARCH_HWEIGHT_CFLAGS
282 string
283 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
284 default "-fcall-saved-rdi -fcall-saved-rsi -fcall-saved-rdx -fcall-saved-rcx -fcall-saved-r8 -fcall-saved-r9 -fcall-saved-r10 -fcall-saved-r11" if X86_64
285
286 config ARCH_SUPPORTS_UPROBES
287 def_bool y
288
289 config FIX_EARLYCON_MEM
290 def_bool y
291
292 config PGTABLE_LEVELS
293 int
294 default 4 if X86_64
295 default 3 if X86_PAE
296 default 2
297
298 source "init/Kconfig"
299 source "kernel/Kconfig.freezer"
300
301 menu "Processor type and features"
302
303 config ZONE_DMA
304 bool "DMA memory allocation support" if EXPERT
305 default y
306 help
307 DMA memory allocation support allows devices with less than 32-bit
308 addressing to allocate within the first 16MB of address space.
309 Disable if no such devices will be used.
310
311 If unsure, say Y.
312
313 config SMP
314 bool "Symmetric multi-processing support"
315 ---help---
316 This enables support for systems with more than one CPU. If you have
317 a system with only one CPU, say N. If you have a system with more
318 than one CPU, say Y.
319
320 If you say N here, the kernel will run on uni- and multiprocessor
321 machines, but will use only one CPU of a multiprocessor machine. If
322 you say Y here, the kernel will run on many, but not all,
323 uniprocessor machines. On a uniprocessor machine, the kernel
324 will run faster if you say N here.
325
326 Note that if you say Y here and choose architecture "586" or
327 "Pentium" under "Processor family", the kernel will not work on 486
328 architectures. Similarly, multiprocessor kernels for the "PPro"
329 architecture may not work on all Pentium based boards.
330
331 People using multiprocessor machines who say Y here should also say
332 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
333 Management" code will be disabled if you say Y here.
334
335 See also <file:Documentation/x86/i386/IO-APIC.txt>,
336 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
337 <http://www.tldp.org/docs.html#howto>.
338
339 If you don't know what to do here, say N.
340
341 config X86_FEATURE_NAMES
342 bool "Processor feature human-readable names" if EMBEDDED
343 default y
344 ---help---
345 This option compiles in a table of x86 feature bits and corresponding
346 names. This is required to support /proc/cpuinfo and a few kernel
347 messages. You can disable this to save space, at the expense of
348 making those few kernel messages show numeric feature bits instead.
349
350 If in doubt, say Y.
351
352 config X86_FAST_FEATURE_TESTS
353 bool "Fast CPU feature tests" if EMBEDDED
354 default y
355 ---help---
356 Some fast-paths in the kernel depend on the capabilities of the CPU.
357 Say Y here for the kernel to patch in the appropriate code at runtime
358 based on the capabilities of the CPU. The infrastructure for patching
359 code at runtime takes up some additional space; space-constrained
360 embedded systems may wish to say N here to produce smaller, slightly
361 slower code.
362
363 config X86_X2APIC
364 bool "Support x2apic"
365 depends on X86_LOCAL_APIC && X86_64 && (IRQ_REMAP || HYPERVISOR_GUEST)
366 ---help---
367 This enables x2apic support on CPUs that have this feature.
368
369 This allows 32-bit apic IDs (so it can support very large systems),
370 and accesses the local apic via MSRs not via mmio.
371
372 If you don't know what to do here, say N.
373
374 config X86_MPPARSE
375 bool "Enable MPS table" if ACPI || SFI
376 default y
377 depends on X86_LOCAL_APIC
378 ---help---
379 For old smp systems that do not have proper acpi support. Newer systems
380 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
381
382 config X86_BIGSMP
383 bool "Support for big SMP systems with more than 8 CPUs"
384 depends on X86_32 && SMP
385 ---help---
386 This option is needed for the systems that have more than 8 CPUs
387
388 config GOLDFISH
389 def_bool y
390 depends on X86_GOLDFISH
391
392 if X86_32
393 config X86_EXTENDED_PLATFORM
394 bool "Support for extended (non-PC) x86 platforms"
395 default y
396 ---help---
397 If you disable this option then the kernel will only support
398 standard PC platforms. (which covers the vast majority of
399 systems out there.)
400
401 If you enable this option then you'll be able to select support
402 for the following (non-PC) 32 bit x86 platforms:
403 Goldfish (Android emulator)
404 AMD Elan
405 RDC R-321x SoC
406 SGI 320/540 (Visual Workstation)
407 STA2X11-based (e.g. Northville)
408 Moorestown MID devices
409
410 If you have one of these systems, or if you want to build a
411 generic distribution kernel, say Y here - otherwise say N.
412 endif
413
414 if X86_64
415 config X86_EXTENDED_PLATFORM
416 bool "Support for extended (non-PC) x86 platforms"
417 default y
418 ---help---
419 If you disable this option then the kernel will only support
420 standard PC platforms. (which covers the vast majority of
421 systems out there.)
422
423 If you enable this option then you'll be able to select support
424 for the following (non-PC) 64 bit x86 platforms:
425 Numascale NumaChip
426 ScaleMP vSMP
427 SGI Ultraviolet
428
429 If you have one of these systems, or if you want to build a
430 generic distribution kernel, say Y here - otherwise say N.
431 endif
432 # This is an alphabetically sorted list of 64 bit extended platforms
433 # Please maintain the alphabetic order if and when there are additions
434 config X86_NUMACHIP
435 bool "Numascale NumaChip"
436 depends on X86_64
437 depends on X86_EXTENDED_PLATFORM
438 depends on NUMA
439 depends on SMP
440 depends on X86_X2APIC
441 depends on PCI_MMCONFIG
442 ---help---
443 Adds support for Numascale NumaChip large-SMP systems. Needed to
444 enable more than ~168 cores.
445 If you don't have one of these, you should say N here.
446
447 config X86_VSMP
448 bool "ScaleMP vSMP"
449 select HYPERVISOR_GUEST
450 select PARAVIRT
451 depends on X86_64 && PCI
452 depends on X86_EXTENDED_PLATFORM
453 depends on SMP
454 ---help---
455 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
456 supposed to run on these EM64T-based machines. Only choose this option
457 if you have one of these machines.
458
459 config X86_UV
460 bool "SGI Ultraviolet"
461 depends on X86_64
462 depends on X86_EXTENDED_PLATFORM
463 depends on NUMA
464 depends on X86_X2APIC
465 depends on PCI
466 ---help---
467 This option is needed in order to support SGI Ultraviolet systems.
468 If you don't have one of these, you should say N here.
469
470 # Following is an alphabetically sorted list of 32 bit extended platforms
471 # Please maintain the alphabetic order if and when there are additions
472
473 config X86_GOLDFISH
474 bool "Goldfish (Virtual Platform)"
475 depends on X86_EXTENDED_PLATFORM
476 ---help---
477 Enable support for the Goldfish virtual platform used primarily
478 for Android development. Unless you are building for the Android
479 Goldfish emulator say N here.
480
481 config X86_INTEL_CE
482 bool "CE4100 TV platform"
483 depends on PCI
484 depends on PCI_GODIRECT
485 depends on X86_IO_APIC
486 depends on X86_32
487 depends on X86_EXTENDED_PLATFORM
488 select X86_REBOOTFIXUPS
489 select OF
490 select OF_EARLY_FLATTREE
491 ---help---
492 Select for the Intel CE media processor (CE4100) SOC.
493 This option compiles in support for the CE4100 SOC for settop
494 boxes and media devices.
495
496 config X86_INTEL_MID
497 bool "Intel MID platform support"
498 depends on X86_32
499 depends on X86_EXTENDED_PLATFORM
500 depends on X86_PLATFORM_DEVICES
501 depends on PCI
502 depends on PCI_GOANY
503 depends on X86_IO_APIC
504 select SFI
505 select I2C
506 select DW_APB_TIMER
507 select APB_TIMER
508 select INTEL_SCU_IPC
509 select MFD_INTEL_MSIC
510 ---help---
511 Select to build a kernel capable of supporting Intel MID (Mobile
512 Internet Device) platform systems which do not have the PCI legacy
513 interfaces. If you are building for a PC class system say N here.
514
515 Intel MID platforms are based on an Intel processor and chipset which
516 consume less power than most of the x86 derivatives.
517
518 config X86_INTEL_QUARK
519 bool "Intel Quark platform support"
520 depends on X86_32
521 depends on X86_EXTENDED_PLATFORM
522 depends on X86_PLATFORM_DEVICES
523 depends on X86_TSC
524 depends on PCI
525 depends on PCI_GOANY
526 depends on X86_IO_APIC
527 select IOSF_MBI
528 select INTEL_IMR
529 select COMMON_CLK
530 ---help---
531 Select to include support for Quark X1000 SoC.
532 Say Y here if you have a Quark based system such as the Arduino
533 compatible Intel Galileo.
534
535 config X86_INTEL_LPSS
536 bool "Intel Low Power Subsystem Support"
537 depends on ACPI
538 select COMMON_CLK
539 select PINCTRL
540 ---help---
541 Select to build support for Intel Low Power Subsystem such as
542 found on Intel Lynxpoint PCH. Selecting this option enables
543 things like clock tree (common clock framework) and pincontrol
544 which are needed by the LPSS peripheral drivers.
545
546 config X86_AMD_PLATFORM_DEVICE
547 bool "AMD ACPI2Platform devices support"
548 depends on ACPI
549 select COMMON_CLK
550 select PINCTRL
551 ---help---
552 Select to interpret AMD specific ACPI device to platform device
553 such as I2C, UART, GPIO found on AMD Carrizo and later chipsets.
554 I2C and UART depend on COMMON_CLK to set clock. GPIO driver is
555 implemented under PINCTRL subsystem.
556
557 config IOSF_MBI
558 tristate "Intel SoC IOSF Sideband support for SoC platforms"
559 depends on PCI
560 ---help---
561 This option enables sideband register access support for Intel SoC
562 platforms. On these platforms the IOSF sideband is used in lieu of
563 MSR's for some register accesses, mostly but not limited to thermal
564 and power. Drivers may query the availability of this device to
565 determine if they need the sideband in order to work on these
566 platforms. The sideband is available on the following SoC products.
567 This list is not meant to be exclusive.
568 - BayTrail
569 - Braswell
570 - Quark
571
572 You should say Y if you are running a kernel on one of these SoC's.
573
574 config IOSF_MBI_DEBUG
575 bool "Enable IOSF sideband access through debugfs"
576 depends on IOSF_MBI && DEBUG_FS
577 ---help---
578 Select this option to expose the IOSF sideband access registers (MCR,
579 MDR, MCRX) through debugfs to write and read register information from
580 different units on the SoC. This is most useful for obtaining device
581 state information for debug and analysis. As this is a general access
582 mechanism, users of this option would have specific knowledge of the
583 device they want to access.
584
585 If you don't require the option or are in doubt, say N.
586
587 config X86_RDC321X
588 bool "RDC R-321x SoC"
589 depends on X86_32
590 depends on X86_EXTENDED_PLATFORM
591 select M486
592 select X86_REBOOTFIXUPS
593 ---help---
594 This option is needed for RDC R-321x system-on-chip, also known
595 as R-8610-(G).
596 If you don't have one of these chips, you should say N here.
597
598 config X86_32_NON_STANDARD
599 bool "Support non-standard 32-bit SMP architectures"
600 depends on X86_32 && SMP
601 depends on X86_EXTENDED_PLATFORM
602 ---help---
603 This option compiles in the bigsmp and STA2X11 default
604 subarchitectures. It is intended for a generic binary
605 kernel. If you select them all, kernel will probe it one by
606 one and will fallback to default.
607
608 # Alphabetically sorted list of Non standard 32 bit platforms
609
610 config X86_SUPPORTS_MEMORY_FAILURE
611 def_bool y
612 # MCE code calls memory_failure():
613 depends on X86_MCE
614 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
615 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
616 depends on X86_64 || !SPARSEMEM
617 select ARCH_SUPPORTS_MEMORY_FAILURE
618
619 config STA2X11
620 bool "STA2X11 Companion Chip Support"
621 depends on X86_32_NON_STANDARD && PCI
622 select X86_DEV_DMA_OPS
623 select X86_DMA_REMAP
624 select SWIOTLB
625 select MFD_STA2X11
626 select ARCH_REQUIRE_GPIOLIB
627 default n
628 ---help---
629 This adds support for boards based on the STA2X11 IO-Hub,
630 a.k.a. "ConneXt". The chip is used in place of the standard
631 PC chipset, so all "standard" peripherals are missing. If this
632 option is selected the kernel will still be able to boot on
633 standard PC machines.
634
635 config X86_32_IRIS
636 tristate "Eurobraille/Iris poweroff module"
637 depends on X86_32
638 ---help---
639 The Iris machines from EuroBraille do not have APM or ACPI support
640 to shut themselves down properly. A special I/O sequence is
641 needed to do so, which is what this module does at
642 kernel shutdown.
643
644 This is only for Iris machines from EuroBraille.
645
646 If unused, say N.
647
648 config SCHED_OMIT_FRAME_POINTER
649 def_bool y
650 prompt "Single-depth WCHAN output"
651 depends on X86
652 ---help---
653 Calculate simpler /proc/<PID>/wchan values. If this option
654 is disabled then wchan values will recurse back to the
655 caller function. This provides more accurate wchan values,
656 at the expense of slightly more scheduling overhead.
657
658 If in doubt, say "Y".
659
660 menuconfig HYPERVISOR_GUEST
661 bool "Linux guest support"
662 ---help---
663 Say Y here to enable options for running Linux under various hyper-
664 visors. This option enables basic hypervisor detection and platform
665 setup.
666
667 If you say N, all options in this submenu will be skipped and
668 disabled, and Linux guest support won't be built in.
669
670 if HYPERVISOR_GUEST
671
672 config PARAVIRT
673 bool "Enable paravirtualization code"
674 ---help---
675 This changes the kernel so it can modify itself when it is run
676 under a hypervisor, potentially improving performance significantly
677 over full virtualization. However, when run without a hypervisor
678 the kernel is theoretically slower and slightly larger.
679
680 config PARAVIRT_DEBUG
681 bool "paravirt-ops debugging"
682 depends on PARAVIRT && DEBUG_KERNEL
683 ---help---
684 Enable to debug paravirt_ops internals. Specifically, BUG if
685 a paravirt_op is missing when it is called.
686
687 config PARAVIRT_SPINLOCKS
688 bool "Paravirtualization layer for spinlocks"
689 depends on PARAVIRT && SMP
690 select UNINLINE_SPIN_UNLOCK if !QUEUED_SPINLOCKS
691 ---help---
692 Paravirtualized spinlocks allow a pvops backend to replace the
693 spinlock implementation with something virtualization-friendly
694 (for example, block the virtual CPU rather than spinning).
695
696 It has a minimal impact on native kernels and gives a nice performance
697 benefit on paravirtualized KVM / Xen kernels.
698
699 If you are unsure how to answer this question, answer Y.
700
701 config QUEUED_LOCK_STAT
702 bool "Paravirt queued spinlock statistics"
703 depends on PARAVIRT_SPINLOCKS && DEBUG_FS && QUEUED_SPINLOCKS
704 ---help---
705 Enable the collection of statistical data on the slowpath
706 behavior of paravirtualized queued spinlocks and report
707 them on debugfs.
708
709 source "arch/x86/xen/Kconfig"
710
711 config KVM_GUEST
712 bool "KVM Guest support (including kvmclock)"
713 depends on PARAVIRT
714 select PARAVIRT_CLOCK
715 default y
716 ---help---
717 This option enables various optimizations for running under the KVM
718 hypervisor. It includes a paravirtualized clock, so that instead
719 of relying on a PIT (or probably other) emulation by the
720 underlying device model, the host provides the guest with
721 timing infrastructure such as time of day, and system time
722
723 config KVM_DEBUG_FS
724 bool "Enable debug information for KVM Guests in debugfs"
725 depends on KVM_GUEST && DEBUG_FS
726 default n
727 ---help---
728 This option enables collection of various statistics for KVM guest.
729 Statistics are displayed in debugfs filesystem. Enabling this option
730 may incur significant overhead.
731
732 source "arch/x86/lguest/Kconfig"
733
734 config PARAVIRT_TIME_ACCOUNTING
735 bool "Paravirtual steal time accounting"
736 depends on PARAVIRT
737 default n
738 ---help---
739 Select this option to enable fine granularity task steal time
740 accounting. Time spent executing other tasks in parallel with
741 the current vCPU is discounted from the vCPU power. To account for
742 that, there can be a small performance impact.
743
744 If in doubt, say N here.
745
746 config PARAVIRT_CLOCK
747 bool
748
749 endif #HYPERVISOR_GUEST
750
751 config NO_BOOTMEM
752 def_bool y
753
754 source "arch/x86/Kconfig.cpu"
755
756 config HPET_TIMER
757 def_bool X86_64
758 prompt "HPET Timer Support" if X86_32
759 ---help---
760 Use the IA-PC HPET (High Precision Event Timer) to manage
761 time in preference to the PIT and RTC, if a HPET is
762 present.
763 HPET is the next generation timer replacing legacy 8254s.
764 The HPET provides a stable time base on SMP
765 systems, unlike the TSC, but it is more expensive to access,
766 as it is off-chip. You can find the HPET spec at
767 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
768
769 You can safely choose Y here. However, HPET will only be
770 activated if the platform and the BIOS support this feature.
771 Otherwise the 8254 will be used for timing services.
772
773 Choose N to continue using the legacy 8254 timer.
774
775 config HPET_EMULATE_RTC
776 def_bool y
777 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
778
779 config APB_TIMER
780 def_bool y if X86_INTEL_MID
781 prompt "Intel MID APB Timer Support" if X86_INTEL_MID
782 select DW_APB_TIMER
783 depends on X86_INTEL_MID && SFI
784 help
785 APB timer is the replacement for 8254, HPET on X86 MID platforms.
786 The APBT provides a stable time base on SMP
787 systems, unlike the TSC, but it is more expensive to access,
788 as it is off-chip. APB timers are always running regardless of CPU
789 C states, they are used as per CPU clockevent device when possible.
790
791 # Mark as expert because too many people got it wrong.
792 # The code disables itself when not needed.
793 config DMI
794 default y
795 select DMI_SCAN_MACHINE_NON_EFI_FALLBACK
796 bool "Enable DMI scanning" if EXPERT
797 ---help---
798 Enabled scanning of DMI to identify machine quirks. Say Y
799 here unless you have verified that your setup is not
800 affected by entries in the DMI blacklist. Required by PNP
801 BIOS code.
802
803 config GART_IOMMU
804 bool "Old AMD GART IOMMU support"
805 select SWIOTLB
806 depends on X86_64 && PCI && AMD_NB
807 ---help---
808 Provides a driver for older AMD Athlon64/Opteron/Turion/Sempron
809 GART based hardware IOMMUs.
810
811 The GART supports full DMA access for devices with 32-bit access
812 limitations, on systems with more than 3 GB. This is usually needed
813 for USB, sound, many IDE/SATA chipsets and some other devices.
814
815 Newer systems typically have a modern AMD IOMMU, supported via
816 the CONFIG_AMD_IOMMU=y config option.
817
818 In normal configurations this driver is only active when needed:
819 there's more than 3 GB of memory and the system contains a
820 32-bit limited device.
821
822 If unsure, say Y.
823
824 config CALGARY_IOMMU
825 bool "IBM Calgary IOMMU support"
826 select SWIOTLB
827 depends on X86_64 && PCI
828 ---help---
829 Support for hardware IOMMUs in IBM's xSeries x366 and x460
830 systems. Needed to run systems with more than 3GB of memory
831 properly with 32-bit PCI devices that do not support DAC
832 (Double Address Cycle). Calgary also supports bus level
833 isolation, where all DMAs pass through the IOMMU. This
834 prevents them from going anywhere except their intended
835 destination. This catches hard-to-find kernel bugs and
836 mis-behaving drivers and devices that do not use the DMA-API
837 properly to set up their DMA buffers. The IOMMU can be
838 turned off at boot time with the iommu=off parameter.
839 Normally the kernel will make the right choice by itself.
840 If unsure, say Y.
841
842 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
843 def_bool y
844 prompt "Should Calgary be enabled by default?"
845 depends on CALGARY_IOMMU
846 ---help---
847 Should Calgary be enabled by default? if you choose 'y', Calgary
848 will be used (if it exists). If you choose 'n', Calgary will not be
849 used even if it exists. If you choose 'n' and would like to use
850 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
851 If unsure, say Y.
852
853 # need this always selected by IOMMU for the VIA workaround
854 config SWIOTLB
855 def_bool y if X86_64
856 ---help---
857 Support for software bounce buffers used on x86-64 systems
858 which don't have a hardware IOMMU. Using this PCI devices
859 which can only access 32-bits of memory can be used on systems
860 with more than 3 GB of memory.
861 If unsure, say Y.
862
863 config IOMMU_HELPER
864 def_bool y
865 depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
866
867 config MAXSMP
868 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
869 depends on X86_64 && SMP && DEBUG_KERNEL
870 select CPUMASK_OFFSTACK
871 ---help---
872 Enable maximum number of CPUS and NUMA Nodes for this architecture.
873 If unsure, say N.
874
875 config NR_CPUS
876 int "Maximum number of CPUs" if SMP && !MAXSMP
877 range 2 8 if SMP && X86_32 && !X86_BIGSMP
878 range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK
879 range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
880 default "1" if !SMP
881 default "8192" if MAXSMP
882 default "32" if SMP && X86_BIGSMP
883 default "8" if SMP && X86_32
884 default "64" if SMP
885 ---help---
886 This allows you to specify the maximum number of CPUs which this
887 kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum
888 supported value is 8192, otherwise the maximum value is 512. The
889 minimum value which makes sense is 2.
890
891 This is purely to save memory - each supported CPU adds
892 approximately eight kilobytes to the kernel image.
893
894 config SCHED_SMT
895 bool "SMT (Hyperthreading) scheduler support"
896 depends on SMP
897 ---help---
898 SMT scheduler support improves the CPU scheduler's decision making
899 when dealing with Intel Pentium 4 chips with HyperThreading at a
900 cost of slightly increased overhead in some places. If unsure say
901 N here.
902
903 config SCHED_MC
904 def_bool y
905 prompt "Multi-core scheduler support"
906 depends on SMP
907 ---help---
908 Multi-core scheduler support improves the CPU scheduler's decision
909 making when dealing with multi-core CPU chips at a cost of slightly
910 increased overhead in some places. If unsure say N here.
911
912 source "kernel/Kconfig.preempt"
913
914 config UP_LATE_INIT
915 def_bool y
916 depends on !SMP && X86_LOCAL_APIC
917
918 config X86_UP_APIC
919 bool "Local APIC support on uniprocessors" if !PCI_MSI
920 default PCI_MSI
921 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
922 ---help---
923 A local APIC (Advanced Programmable Interrupt Controller) is an
924 integrated interrupt controller in the CPU. If you have a single-CPU
925 system which has a processor with a local APIC, you can say Y here to
926 enable and use it. If you say Y here even though your machine doesn't
927 have a local APIC, then the kernel will still run with no slowdown at
928 all. The local APIC supports CPU-generated self-interrupts (timer,
929 performance counters), and the NMI watchdog which detects hard
930 lockups.
931
932 config X86_UP_IOAPIC
933 bool "IO-APIC support on uniprocessors"
934 depends on X86_UP_APIC
935 ---help---
936 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
937 SMP-capable replacement for PC-style interrupt controllers. Most
938 SMP systems and many recent uniprocessor systems have one.
939
940 If you have a single-CPU system with an IO-APIC, you can say Y here
941 to use it. If you say Y here even though your machine doesn't have
942 an IO-APIC, then the kernel will still run with no slowdown at all.
943
944 config X86_LOCAL_APIC
945 def_bool y
946 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC || PCI_MSI
947 select IRQ_DOMAIN_HIERARCHY
948 select PCI_MSI_IRQ_DOMAIN if PCI_MSI
949
950 config X86_IO_APIC
951 def_bool y
952 depends on X86_LOCAL_APIC || X86_UP_IOAPIC
953
954 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
955 bool "Reroute for broken boot IRQs"
956 depends on X86_IO_APIC
957 ---help---
958 This option enables a workaround that fixes a source of
959 spurious interrupts. This is recommended when threaded
960 interrupt handling is used on systems where the generation of
961 superfluous "boot interrupts" cannot be disabled.
962
963 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
964 entry in the chipset's IO-APIC is masked (as, e.g. the RT
965 kernel does during interrupt handling). On chipsets where this
966 boot IRQ generation cannot be disabled, this workaround keeps
967 the original IRQ line masked so that only the equivalent "boot
968 IRQ" is delivered to the CPUs. The workaround also tells the
969 kernel to set up the IRQ handler on the boot IRQ line. In this
970 way only one interrupt is delivered to the kernel. Otherwise
971 the spurious second interrupt may cause the kernel to bring
972 down (vital) interrupt lines.
973
974 Only affects "broken" chipsets. Interrupt sharing may be
975 increased on these systems.
976
977 config X86_MCE
978 bool "Machine Check / overheating reporting"
979 select GENERIC_ALLOCATOR
980 default y
981 ---help---
982 Machine Check support allows the processor to notify the
983 kernel if it detects a problem (e.g. overheating, data corruption).
984 The action the kernel takes depends on the severity of the problem,
985 ranging from warning messages to halting the machine.
986
987 config X86_MCE_INTEL
988 def_bool y
989 prompt "Intel MCE features"
990 depends on X86_MCE && X86_LOCAL_APIC
991 ---help---
992 Additional support for intel specific MCE features such as
993 the thermal monitor.
994
995 config X86_MCE_AMD
996 def_bool y
997 prompt "AMD MCE features"
998 depends on X86_MCE && X86_LOCAL_APIC
999 ---help---
1000 Additional support for AMD specific MCE features such as
1001 the DRAM Error Threshold.
1002
1003 config X86_ANCIENT_MCE
1004 bool "Support for old Pentium 5 / WinChip machine checks"
1005 depends on X86_32 && X86_MCE
1006 ---help---
1007 Include support for machine check handling on old Pentium 5 or WinChip
1008 systems. These typically need to be enabled explicitly on the command
1009 line.
1010
1011 config X86_MCE_THRESHOLD
1012 depends on X86_MCE_AMD || X86_MCE_INTEL
1013 def_bool y
1014
1015 config X86_MCE_INJECT
1016 depends on X86_MCE
1017 tristate "Machine check injector support"
1018 ---help---
1019 Provide support for injecting machine checks for testing purposes.
1020 If you don't know what a machine check is and you don't do kernel
1021 QA it is safe to say n.
1022
1023 config X86_THERMAL_VECTOR
1024 def_bool y
1025 depends on X86_MCE_INTEL
1026
1027 config X86_LEGACY_VM86
1028 bool "Legacy VM86 support"
1029 default n
1030 depends on X86_32
1031 ---help---
1032 This option allows user programs to put the CPU into V8086
1033 mode, which is an 80286-era approximation of 16-bit real mode.
1034
1035 Some very old versions of X and/or vbetool require this option
1036 for user mode setting. Similarly, DOSEMU will use it if
1037 available to accelerate real mode DOS programs. However, any
1038 recent version of DOSEMU, X, or vbetool should be fully
1039 functional even without kernel VM86 support, as they will all
1040 fall back to software emulation. Nevertheless, if you are using
1041 a 16-bit DOS program where 16-bit performance matters, vm86
1042 mode might be faster than emulation and you might want to
1043 enable this option.
1044
1045 Note that any app that works on a 64-bit kernel is unlikely to
1046 need this option, as 64-bit kernels don't, and can't, support
1047 V8086 mode. This option is also unrelated to 16-bit protected
1048 mode and is not needed to run most 16-bit programs under Wine.
1049
1050 Enabling this option increases the complexity of the kernel
1051 and slows down exception handling a tiny bit.
1052
1053 If unsure, say N here.
1054
1055 config VM86
1056 bool
1057 default X86_LEGACY_VM86
1058
1059 config X86_16BIT
1060 bool "Enable support for 16-bit segments" if EXPERT
1061 default y
1062 depends on MODIFY_LDT_SYSCALL
1063 ---help---
1064 This option is required by programs like Wine to run 16-bit
1065 protected mode legacy code on x86 processors. Disabling
1066 this option saves about 300 bytes on i386, or around 6K text
1067 plus 16K runtime memory on x86-64,
1068
1069 config X86_ESPFIX32
1070 def_bool y
1071 depends on X86_16BIT && X86_32
1072
1073 config X86_ESPFIX64
1074 def_bool y
1075 depends on X86_16BIT && X86_64
1076
1077 config X86_VSYSCALL_EMULATION
1078 bool "Enable vsyscall emulation" if EXPERT
1079 default y
1080 depends on X86_64
1081 ---help---
1082 This enables emulation of the legacy vsyscall page. Disabling
1083 it is roughly equivalent to booting with vsyscall=none, except
1084 that it will also disable the helpful warning if a program
1085 tries to use a vsyscall. With this option set to N, offending
1086 programs will just segfault, citing addresses of the form
1087 0xffffffffff600?00.
1088
1089 This option is required by many programs built before 2013, and
1090 care should be used even with newer programs if set to N.
1091
1092 Disabling this option saves about 7K of kernel size and
1093 possibly 4K of additional runtime pagetable memory.
1094
1095 config TOSHIBA
1096 tristate "Toshiba Laptop support"
1097 depends on X86_32
1098 ---help---
1099 This adds a driver to safely access the System Management Mode of
1100 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
1101 not work on models with a Phoenix BIOS. The System Management Mode
1102 is used to set the BIOS and power saving options on Toshiba portables.
1103
1104 For information on utilities to make use of this driver see the
1105 Toshiba Linux utilities web site at:
1106 <http://www.buzzard.org.uk/toshiba/>.
1107
1108 Say Y if you intend to run this kernel on a Toshiba portable.
1109 Say N otherwise.
1110
1111 config I8K
1112 tristate "Dell i8k legacy laptop support"
1113 select HWMON
1114 select SENSORS_DELL_SMM
1115 ---help---
1116 This option enables legacy /proc/i8k userspace interface in hwmon
1117 dell-smm-hwmon driver. Character file /proc/i8k reports bios version,
1118 temperature and allows controlling fan speeds of Dell laptops via
1119 System Management Mode. For old Dell laptops (like Dell Inspiron 8000)
1120 it reports also power and hotkey status. For fan speed control is
1121 needed userspace package i8kutils.
1122
1123 Say Y if you intend to run this kernel on old Dell laptops or want to
1124 use userspace package i8kutils.
1125 Say N otherwise.
1126
1127 config X86_REBOOTFIXUPS
1128 bool "Enable X86 board specific fixups for reboot"
1129 depends on X86_32
1130 ---help---
1131 This enables chipset and/or board specific fixups to be done
1132 in order to get reboot to work correctly. This is only needed on
1133 some combinations of hardware and BIOS. The symptom, for which
1134 this config is intended, is when reboot ends with a stalled/hung
1135 system.
1136
1137 Currently, the only fixup is for the Geode machines using
1138 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
1139
1140 Say Y if you want to enable the fixup. Currently, it's safe to
1141 enable this option even if you don't need it.
1142 Say N otherwise.
1143
1144 config MICROCODE
1145 bool "CPU microcode loading support"
1146 default y
1147 depends on CPU_SUP_AMD || CPU_SUP_INTEL
1148 depends on BLK_DEV_INITRD
1149 select FW_LOADER
1150 ---help---
1151
1152 If you say Y here, you will be able to update the microcode on
1153 certain Intel and AMD processors. The Intel support is for the
1154 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III, Pentium 4,
1155 Xeon etc. The AMD support is for families 0x10 and later. You will
1156 obviously need the actual microcode binary data itself which is not
1157 shipped with the Linux kernel.
1158
1159 This option selects the general module only, you need to select
1160 at least one vendor specific module as well.
1161
1162 To compile this driver as a module, choose M here: the module
1163 will be called microcode.
1164
1165 config MICROCODE_INTEL
1166 bool "Intel microcode loading support"
1167 depends on MICROCODE
1168 default MICROCODE
1169 select FW_LOADER
1170 ---help---
1171 This options enables microcode patch loading support for Intel
1172 processors.
1173
1174 For the current Intel microcode data package go to
1175 <https://downloadcenter.intel.com> and search for
1176 'Linux Processor Microcode Data File'.
1177
1178 config MICROCODE_AMD
1179 bool "AMD microcode loading support"
1180 depends on MICROCODE
1181 select FW_LOADER
1182 ---help---
1183 If you select this option, microcode patch loading support for AMD
1184 processors will be enabled.
1185
1186 config MICROCODE_OLD_INTERFACE
1187 def_bool y
1188 depends on MICROCODE
1189
1190 config X86_MSR
1191 tristate "/dev/cpu/*/msr - Model-specific register support"
1192 ---help---
1193 This device gives privileged processes access to the x86
1194 Model-Specific Registers (MSRs). It is a character device with
1195 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1196 MSR accesses are directed to a specific CPU on multi-processor
1197 systems.
1198
1199 config X86_CPUID
1200 tristate "/dev/cpu/*/cpuid - CPU information support"
1201 ---help---
1202 This device gives processes access to the x86 CPUID instruction to
1203 be executed on a specific processor. It is a character device
1204 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1205 /dev/cpu/31/cpuid.
1206
1207 choice
1208 prompt "High Memory Support"
1209 default HIGHMEM4G
1210 depends on X86_32
1211
1212 config NOHIGHMEM
1213 bool "off"
1214 ---help---
1215 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1216 However, the address space of 32-bit x86 processors is only 4
1217 Gigabytes large. That means that, if you have a large amount of
1218 physical memory, not all of it can be "permanently mapped" by the
1219 kernel. The physical memory that's not permanently mapped is called
1220 "high memory".
1221
1222 If you are compiling a kernel which will never run on a machine with
1223 more than 1 Gigabyte total physical RAM, answer "off" here (default
1224 choice and suitable for most users). This will result in a "3GB/1GB"
1225 split: 3GB are mapped so that each process sees a 3GB virtual memory
1226 space and the remaining part of the 4GB virtual memory space is used
1227 by the kernel to permanently map as much physical memory as
1228 possible.
1229
1230 If the machine has between 1 and 4 Gigabytes physical RAM, then
1231 answer "4GB" here.
1232
1233 If more than 4 Gigabytes is used then answer "64GB" here. This
1234 selection turns Intel PAE (Physical Address Extension) mode on.
1235 PAE implements 3-level paging on IA32 processors. PAE is fully
1236 supported by Linux, PAE mode is implemented on all recent Intel
1237 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1238 then the kernel will not boot on CPUs that don't support PAE!
1239
1240 The actual amount of total physical memory will either be
1241 auto detected or can be forced by using a kernel command line option
1242 such as "mem=256M". (Try "man bootparam" or see the documentation of
1243 your boot loader (lilo or loadlin) about how to pass options to the
1244 kernel at boot time.)
1245
1246 If unsure, say "off".
1247
1248 config HIGHMEM4G
1249 bool "4GB"
1250 ---help---
1251 Select this if you have a 32-bit processor and between 1 and 4
1252 gigabytes of physical RAM.
1253
1254 config HIGHMEM64G
1255 bool "64GB"
1256 depends on !M486
1257 select X86_PAE
1258 ---help---
1259 Select this if you have a 32-bit processor and more than 4
1260 gigabytes of physical RAM.
1261
1262 endchoice
1263
1264 choice
1265 prompt "Memory split" if EXPERT
1266 default VMSPLIT_3G
1267 depends on X86_32
1268 ---help---
1269 Select the desired split between kernel and user memory.
1270
1271 If the address range available to the kernel is less than the
1272 physical memory installed, the remaining memory will be available
1273 as "high memory". Accessing high memory is a little more costly
1274 than low memory, as it needs to be mapped into the kernel first.
1275 Note that increasing the kernel address space limits the range
1276 available to user programs, making the address space there
1277 tighter. Selecting anything other than the default 3G/1G split
1278 will also likely make your kernel incompatible with binary-only
1279 kernel modules.
1280
1281 If you are not absolutely sure what you are doing, leave this
1282 option alone!
1283
1284 config VMSPLIT_3G
1285 bool "3G/1G user/kernel split"
1286 config VMSPLIT_3G_OPT
1287 depends on !X86_PAE
1288 bool "3G/1G user/kernel split (for full 1G low memory)"
1289 config VMSPLIT_2G
1290 bool "2G/2G user/kernel split"
1291 config VMSPLIT_2G_OPT
1292 depends on !X86_PAE
1293 bool "2G/2G user/kernel split (for full 2G low memory)"
1294 config VMSPLIT_1G
1295 bool "1G/3G user/kernel split"
1296 endchoice
1297
1298 config PAGE_OFFSET
1299 hex
1300 default 0xB0000000 if VMSPLIT_3G_OPT
1301 default 0x80000000 if VMSPLIT_2G
1302 default 0x78000000 if VMSPLIT_2G_OPT
1303 default 0x40000000 if VMSPLIT_1G
1304 default 0xC0000000
1305 depends on X86_32
1306
1307 config HIGHMEM
1308 def_bool y
1309 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1310
1311 config X86_PAE
1312 bool "PAE (Physical Address Extension) Support"
1313 depends on X86_32 && !HIGHMEM4G
1314 select SWIOTLB
1315 ---help---
1316 PAE is required for NX support, and furthermore enables
1317 larger swapspace support for non-overcommit purposes. It
1318 has the cost of more pagetable lookup overhead, and also
1319 consumes more pagetable space per process.
1320
1321 config ARCH_PHYS_ADDR_T_64BIT
1322 def_bool y
1323 depends on X86_64 || X86_PAE
1324
1325 config ARCH_DMA_ADDR_T_64BIT
1326 def_bool y
1327 depends on X86_64 || HIGHMEM64G
1328
1329 config X86_DIRECT_GBPAGES
1330 def_bool y
1331 depends on X86_64 && !DEBUG_PAGEALLOC && !KMEMCHECK
1332 ---help---
1333 Certain kernel features effectively disable kernel
1334 linear 1 GB mappings (even if the CPU otherwise
1335 supports them), so don't confuse the user by printing
1336 that we have them enabled.
1337
1338 # Common NUMA Features
1339 config NUMA
1340 bool "Numa Memory Allocation and Scheduler Support"
1341 depends on SMP
1342 depends on X86_64 || (X86_32 && HIGHMEM64G && X86_BIGSMP)
1343 default y if X86_BIGSMP
1344 ---help---
1345 Enable NUMA (Non Uniform Memory Access) support.
1346
1347 The kernel will try to allocate memory used by a CPU on the
1348 local memory controller of the CPU and add some more
1349 NUMA awareness to the kernel.
1350
1351 For 64-bit this is recommended if the system is Intel Core i7
1352 (or later), AMD Opteron, or EM64T NUMA.
1353
1354 For 32-bit this is only needed if you boot a 32-bit
1355 kernel on a 64-bit NUMA platform.
1356
1357 Otherwise, you should say N.
1358
1359 config AMD_NUMA
1360 def_bool y
1361 prompt "Old style AMD Opteron NUMA detection"
1362 depends on X86_64 && NUMA && PCI
1363 ---help---
1364 Enable AMD NUMA node topology detection. You should say Y here if
1365 you have a multi processor AMD system. This uses an old method to
1366 read the NUMA configuration directly from the builtin Northbridge
1367 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1368 which also takes priority if both are compiled in.
1369
1370 config X86_64_ACPI_NUMA
1371 def_bool y
1372 prompt "ACPI NUMA detection"
1373 depends on X86_64 && NUMA && ACPI && PCI
1374 select ACPI_NUMA
1375 ---help---
1376 Enable ACPI SRAT based node topology detection.
1377
1378 # Some NUMA nodes have memory ranges that span
1379 # other nodes. Even though a pfn is valid and
1380 # between a node's start and end pfns, it may not
1381 # reside on that node. See memmap_init_zone()
1382 # for details.
1383 config NODES_SPAN_OTHER_NODES
1384 def_bool y
1385 depends on X86_64_ACPI_NUMA
1386
1387 config NUMA_EMU
1388 bool "NUMA emulation"
1389 depends on NUMA
1390 ---help---
1391 Enable NUMA emulation. A flat machine will be split
1392 into virtual nodes when booted with "numa=fake=N", where N is the
1393 number of nodes. This is only useful for debugging.
1394
1395 config NODES_SHIFT
1396 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1397 range 1 10
1398 default "10" if MAXSMP
1399 default "6" if X86_64
1400 default "3"
1401 depends on NEED_MULTIPLE_NODES
1402 ---help---
1403 Specify the maximum number of NUMA Nodes available on the target
1404 system. Increases memory reserved to accommodate various tables.
1405
1406 config ARCH_HAVE_MEMORY_PRESENT
1407 def_bool y
1408 depends on X86_32 && DISCONTIGMEM
1409
1410 config NEED_NODE_MEMMAP_SIZE
1411 def_bool y
1412 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1413
1414 config ARCH_FLATMEM_ENABLE
1415 def_bool y
1416 depends on X86_32 && !NUMA
1417
1418 config ARCH_DISCONTIGMEM_ENABLE
1419 def_bool y
1420 depends on NUMA && X86_32
1421
1422 config ARCH_DISCONTIGMEM_DEFAULT
1423 def_bool y
1424 depends on NUMA && X86_32
1425
1426 config ARCH_SPARSEMEM_ENABLE
1427 def_bool y
1428 depends on X86_64 || NUMA || X86_32 || X86_32_NON_STANDARD
1429 select SPARSEMEM_STATIC if X86_32
1430 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1431
1432 config ARCH_SPARSEMEM_DEFAULT
1433 def_bool y
1434 depends on X86_64
1435
1436 config ARCH_SELECT_MEMORY_MODEL
1437 def_bool y
1438 depends on ARCH_SPARSEMEM_ENABLE
1439
1440 config ARCH_MEMORY_PROBE
1441 bool "Enable sysfs memory/probe interface"
1442 depends on X86_64 && MEMORY_HOTPLUG
1443 help
1444 This option enables a sysfs memory/probe interface for testing.
1445 See Documentation/memory-hotplug.txt for more information.
1446 If you are unsure how to answer this question, answer N.
1447
1448 config ARCH_PROC_KCORE_TEXT
1449 def_bool y
1450 depends on X86_64 && PROC_KCORE
1451
1452 config ILLEGAL_POINTER_VALUE
1453 hex
1454 default 0 if X86_32
1455 default 0xdead000000000000 if X86_64
1456
1457 source "mm/Kconfig"
1458
1459 config X86_PMEM_LEGACY_DEVICE
1460 bool
1461
1462 config X86_PMEM_LEGACY
1463 tristate "Support non-standard NVDIMMs and ADR protected memory"
1464 depends on PHYS_ADDR_T_64BIT
1465 depends on BLK_DEV
1466 select X86_PMEM_LEGACY_DEVICE
1467 select LIBNVDIMM
1468 help
1469 Treat memory marked using the non-standard e820 type of 12 as used
1470 by the Intel Sandy Bridge-EP reference BIOS as protected memory.
1471 The kernel will offer these regions to the 'pmem' driver so
1472 they can be used for persistent storage.
1473
1474 Say Y if unsure.
1475
1476 config HIGHPTE
1477 bool "Allocate 3rd-level pagetables from highmem"
1478 depends on HIGHMEM
1479 ---help---
1480 The VM uses one page table entry for each page of physical memory.
1481 For systems with a lot of RAM, this can be wasteful of precious
1482 low memory. Setting this option will put user-space page table
1483 entries in high memory.
1484
1485 config X86_CHECK_BIOS_CORRUPTION
1486 bool "Check for low memory corruption"
1487 ---help---
1488 Periodically check for memory corruption in low memory, which
1489 is suspected to be caused by BIOS. Even when enabled in the
1490 configuration, it is disabled at runtime. Enable it by
1491 setting "memory_corruption_check=1" on the kernel command
1492 line. By default it scans the low 64k of memory every 60
1493 seconds; see the memory_corruption_check_size and
1494 memory_corruption_check_period parameters in
1495 Documentation/kernel-parameters.txt to adjust this.
1496
1497 When enabled with the default parameters, this option has
1498 almost no overhead, as it reserves a relatively small amount
1499 of memory and scans it infrequently. It both detects corruption
1500 and prevents it from affecting the running system.
1501
1502 It is, however, intended as a diagnostic tool; if repeatable
1503 BIOS-originated corruption always affects the same memory,
1504 you can use memmap= to prevent the kernel from using that
1505 memory.
1506
1507 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1508 bool "Set the default setting of memory_corruption_check"
1509 depends on X86_CHECK_BIOS_CORRUPTION
1510 default y
1511 ---help---
1512 Set whether the default state of memory_corruption_check is
1513 on or off.
1514
1515 config X86_RESERVE_LOW
1516 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1517 default 64
1518 range 4 640
1519 ---help---
1520 Specify the amount of low memory to reserve for the BIOS.
1521
1522 The first page contains BIOS data structures that the kernel
1523 must not use, so that page must always be reserved.
1524
1525 By default we reserve the first 64K of physical RAM, as a
1526 number of BIOSes are known to corrupt that memory range
1527 during events such as suspend/resume or monitor cable
1528 insertion, so it must not be used by the kernel.
1529
1530 You can set this to 4 if you are absolutely sure that you
1531 trust the BIOS to get all its memory reservations and usages
1532 right. If you know your BIOS have problems beyond the
1533 default 64K area, you can set this to 640 to avoid using the
1534 entire low memory range.
1535
1536 If you have doubts about the BIOS (e.g. suspend/resume does
1537 not work or there's kernel crashes after certain hardware
1538 hotplug events) then you might want to enable
1539 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1540 typical corruption patterns.
1541
1542 Leave this to the default value of 64 if you are unsure.
1543
1544 config MATH_EMULATION
1545 bool
1546 depends on MODIFY_LDT_SYSCALL
1547 prompt "Math emulation" if X86_32
1548 ---help---
1549 Linux can emulate a math coprocessor (used for floating point
1550 operations) if you don't have one. 486DX and Pentium processors have
1551 a math coprocessor built in, 486SX and 386 do not, unless you added
1552 a 487DX or 387, respectively. (The messages during boot time can
1553 give you some hints here ["man dmesg"].) Everyone needs either a
1554 coprocessor or this emulation.
1555
1556 If you don't have a math coprocessor, you need to say Y here; if you
1557 say Y here even though you have a coprocessor, the coprocessor will
1558 be used nevertheless. (This behavior can be changed with the kernel
1559 command line option "no387", which comes handy if your coprocessor
1560 is broken. Try "man bootparam" or see the documentation of your boot
1561 loader (lilo or loadlin) about how to pass options to the kernel at
1562 boot time.) This means that it is a good idea to say Y here if you
1563 intend to use this kernel on different machines.
1564
1565 More information about the internals of the Linux math coprocessor
1566 emulation can be found in <file:arch/x86/math-emu/README>.
1567
1568 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1569 kernel, it won't hurt.
1570
1571 config MTRR
1572 def_bool y
1573 prompt "MTRR (Memory Type Range Register) support" if EXPERT
1574 ---help---
1575 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1576 the Memory Type Range Registers (MTRRs) may be used to control
1577 processor access to memory ranges. This is most useful if you have
1578 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1579 allows bus write transfers to be combined into a larger transfer
1580 before bursting over the PCI/AGP bus. This can increase performance
1581 of image write operations 2.5 times or more. Saying Y here creates a
1582 /proc/mtrr file which may be used to manipulate your processor's
1583 MTRRs. Typically the X server should use this.
1584
1585 This code has a reasonably generic interface so that similar
1586 control registers on other processors can be easily supported
1587 as well:
1588
1589 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1590 Registers (ARRs) which provide a similar functionality to MTRRs. For
1591 these, the ARRs are used to emulate the MTRRs.
1592 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1593 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1594 write-combining. All of these processors are supported by this code
1595 and it makes sense to say Y here if you have one of them.
1596
1597 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1598 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1599 can lead to all sorts of problems, so it's good to say Y here.
1600
1601 You can safely say Y even if your machine doesn't have MTRRs, you'll
1602 just add about 9 KB to your kernel.
1603
1604 See <file:Documentation/x86/mtrr.txt> for more information.
1605
1606 config MTRR_SANITIZER
1607 def_bool y
1608 prompt "MTRR cleanup support"
1609 depends on MTRR
1610 ---help---
1611 Convert MTRR layout from continuous to discrete, so X drivers can
1612 add writeback entries.
1613
1614 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1615 The largest mtrr entry size for a continuous block can be set with
1616 mtrr_chunk_size.
1617
1618 If unsure, say Y.
1619
1620 config MTRR_SANITIZER_ENABLE_DEFAULT
1621 int "MTRR cleanup enable value (0-1)"
1622 range 0 1
1623 default "0"
1624 depends on MTRR_SANITIZER
1625 ---help---
1626 Enable mtrr cleanup default value
1627
1628 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1629 int "MTRR cleanup spare reg num (0-7)"
1630 range 0 7
1631 default "1"
1632 depends on MTRR_SANITIZER
1633 ---help---
1634 mtrr cleanup spare entries default, it can be changed via
1635 mtrr_spare_reg_nr=N on the kernel command line.
1636
1637 config X86_PAT
1638 def_bool y
1639 prompt "x86 PAT support" if EXPERT
1640 depends on MTRR
1641 ---help---
1642 Use PAT attributes to setup page level cache control.
1643
1644 PATs are the modern equivalents of MTRRs and are much more
1645 flexible than MTRRs.
1646
1647 Say N here if you see bootup problems (boot crash, boot hang,
1648 spontaneous reboots) or a non-working video driver.
1649
1650 If unsure, say Y.
1651
1652 config ARCH_USES_PG_UNCACHED
1653 def_bool y
1654 depends on X86_PAT
1655
1656 config ARCH_RANDOM
1657 def_bool y
1658 prompt "x86 architectural random number generator" if EXPERT
1659 ---help---
1660 Enable the x86 architectural RDRAND instruction
1661 (Intel Bull Mountain technology) to generate random numbers.
1662 If supported, this is a high bandwidth, cryptographically
1663 secure hardware random number generator.
1664
1665 config X86_SMAP
1666 def_bool y
1667 prompt "Supervisor Mode Access Prevention" if EXPERT
1668 ---help---
1669 Supervisor Mode Access Prevention (SMAP) is a security
1670 feature in newer Intel processors. There is a small
1671 performance cost if this enabled and turned on; there is
1672 also a small increase in the kernel size if this is enabled.
1673
1674 If unsure, say Y.
1675
1676 config X86_INTEL_MPX
1677 prompt "Intel MPX (Memory Protection Extensions)"
1678 def_bool n
1679 depends on CPU_SUP_INTEL
1680 ---help---
1681 MPX provides hardware features that can be used in
1682 conjunction with compiler-instrumented code to check
1683 memory references. It is designed to detect buffer
1684 overflow or underflow bugs.
1685
1686 This option enables running applications which are
1687 instrumented or otherwise use MPX. It does not use MPX
1688 itself inside the kernel or to protect the kernel
1689 against bad memory references.
1690
1691 Enabling this option will make the kernel larger:
1692 ~8k of kernel text and 36 bytes of data on a 64-bit
1693 defconfig. It adds a long to the 'mm_struct' which
1694 will increase the kernel memory overhead of each
1695 process and adds some branches to paths used during
1696 exec() and munmap().
1697
1698 For details, see Documentation/x86/intel_mpx.txt
1699
1700 If unsure, say N.
1701
1702 config EFI
1703 bool "EFI runtime service support"
1704 depends on ACPI
1705 select UCS2_STRING
1706 select EFI_RUNTIME_WRAPPERS
1707 ---help---
1708 This enables the kernel to use EFI runtime services that are
1709 available (such as the EFI variable services).
1710
1711 This option is only useful on systems that have EFI firmware.
1712 In addition, you should use the latest ELILO loader available
1713 at <http://elilo.sourceforge.net> in order to take advantage
1714 of EFI runtime services. However, even with this option, the
1715 resultant kernel should continue to boot on existing non-EFI
1716 platforms.
1717
1718 config EFI_STUB
1719 bool "EFI stub support"
1720 depends on EFI && !X86_USE_3DNOW
1721 select RELOCATABLE
1722 ---help---
1723 This kernel feature allows a bzImage to be loaded directly
1724 by EFI firmware without the use of a bootloader.
1725
1726 See Documentation/efi-stub.txt for more information.
1727
1728 config EFI_MIXED
1729 bool "EFI mixed-mode support"
1730 depends on EFI_STUB && X86_64
1731 ---help---
1732 Enabling this feature allows a 64-bit kernel to be booted
1733 on a 32-bit firmware, provided that your CPU supports 64-bit
1734 mode.
1735
1736 Note that it is not possible to boot a mixed-mode enabled
1737 kernel via the EFI boot stub - a bootloader that supports
1738 the EFI handover protocol must be used.
1739
1740 If unsure, say N.
1741
1742 config SECCOMP
1743 def_bool y
1744 prompt "Enable seccomp to safely compute untrusted bytecode"
1745 ---help---
1746 This kernel feature is useful for number crunching applications
1747 that may need to compute untrusted bytecode during their
1748 execution. By using pipes or other transports made available to
1749 the process as file descriptors supporting the read/write
1750 syscalls, it's possible to isolate those applications in
1751 their own address space using seccomp. Once seccomp is
1752 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1753 and the task is only allowed to execute a few safe syscalls
1754 defined by each seccomp mode.
1755
1756 If unsure, say Y. Only embedded should say N here.
1757
1758 source kernel/Kconfig.hz
1759
1760 config KEXEC
1761 bool "kexec system call"
1762 select KEXEC_CORE
1763 ---help---
1764 kexec is a system call that implements the ability to shutdown your
1765 current kernel, and to start another kernel. It is like a reboot
1766 but it is independent of the system firmware. And like a reboot
1767 you can start any kernel with it, not just Linux.
1768
1769 The name comes from the similarity to the exec system call.
1770
1771 It is an ongoing process to be certain the hardware in a machine
1772 is properly shutdown, so do not be surprised if this code does not
1773 initially work for you. As of this writing the exact hardware
1774 interface is strongly in flux, so no good recommendation can be
1775 made.
1776
1777 config KEXEC_FILE
1778 bool "kexec file based system call"
1779 select KEXEC_CORE
1780 select BUILD_BIN2C
1781 depends on X86_64
1782 depends on CRYPTO=y
1783 depends on CRYPTO_SHA256=y
1784 ---help---
1785 This is new version of kexec system call. This system call is
1786 file based and takes file descriptors as system call argument
1787 for kernel and initramfs as opposed to list of segments as
1788 accepted by previous system call.
1789
1790 config KEXEC_VERIFY_SIG
1791 bool "Verify kernel signature during kexec_file_load() syscall"
1792 depends on KEXEC_FILE
1793 ---help---
1794 This option makes kernel signature verification mandatory for
1795 the kexec_file_load() syscall.
1796
1797 In addition to that option, you need to enable signature
1798 verification for the corresponding kernel image type being
1799 loaded in order for this to work.
1800
1801 config KEXEC_BZIMAGE_VERIFY_SIG
1802 bool "Enable bzImage signature verification support"
1803 depends on KEXEC_VERIFY_SIG
1804 depends on SIGNED_PE_FILE_VERIFICATION
1805 select SYSTEM_TRUSTED_KEYRING
1806 ---help---
1807 Enable bzImage signature verification support.
1808
1809 config CRASH_DUMP
1810 bool "kernel crash dumps"
1811 depends on X86_64 || (X86_32 && HIGHMEM)
1812 ---help---
1813 Generate crash dump after being started by kexec.
1814 This should be normally only set in special crash dump kernels
1815 which are loaded in the main kernel with kexec-tools into
1816 a specially reserved region and then later executed after
1817 a crash by kdump/kexec. The crash dump kernel must be compiled
1818 to a memory address not used by the main kernel or BIOS using
1819 PHYSICAL_START, or it must be built as a relocatable image
1820 (CONFIG_RELOCATABLE=y).
1821 For more details see Documentation/kdump/kdump.txt
1822
1823 config KEXEC_JUMP
1824 bool "kexec jump"
1825 depends on KEXEC && HIBERNATION
1826 ---help---
1827 Jump between original kernel and kexeced kernel and invoke
1828 code in physical address mode via KEXEC
1829
1830 config PHYSICAL_START
1831 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1832 default "0x1000000"
1833 ---help---
1834 This gives the physical address where the kernel is loaded.
1835
1836 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1837 bzImage will decompress itself to above physical address and
1838 run from there. Otherwise, bzImage will run from the address where
1839 it has been loaded by the boot loader and will ignore above physical
1840 address.
1841
1842 In normal kdump cases one does not have to set/change this option
1843 as now bzImage can be compiled as a completely relocatable image
1844 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1845 address. This option is mainly useful for the folks who don't want
1846 to use a bzImage for capturing the crash dump and want to use a
1847 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1848 to be specifically compiled to run from a specific memory area
1849 (normally a reserved region) and this option comes handy.
1850
1851 So if you are using bzImage for capturing the crash dump,
1852 leave the value here unchanged to 0x1000000 and set
1853 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1854 for capturing the crash dump change this value to start of
1855 the reserved region. In other words, it can be set based on
1856 the "X" value as specified in the "crashkernel=YM@XM"
1857 command line boot parameter passed to the panic-ed
1858 kernel. Please take a look at Documentation/kdump/kdump.txt
1859 for more details about crash dumps.
1860
1861 Usage of bzImage for capturing the crash dump is recommended as
1862 one does not have to build two kernels. Same kernel can be used
1863 as production kernel and capture kernel. Above option should have
1864 gone away after relocatable bzImage support is introduced. But it
1865 is present because there are users out there who continue to use
1866 vmlinux for dump capture. This option should go away down the
1867 line.
1868
1869 Don't change this unless you know what you are doing.
1870
1871 config RELOCATABLE
1872 bool "Build a relocatable kernel"
1873 default y
1874 ---help---
1875 This builds a kernel image that retains relocation information
1876 so it can be loaded someplace besides the default 1MB.
1877 The relocations tend to make the kernel binary about 10% larger,
1878 but are discarded at runtime.
1879
1880 One use is for the kexec on panic case where the recovery kernel
1881 must live at a different physical address than the primary
1882 kernel.
1883
1884 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1885 it has been loaded at and the compile time physical address
1886 (CONFIG_PHYSICAL_START) is used as the minimum location.
1887
1888 config RANDOMIZE_BASE
1889 bool "Randomize the address of the kernel image"
1890 depends on RELOCATABLE
1891 default n
1892 ---help---
1893 Randomizes the physical and virtual address at which the
1894 kernel image is decompressed, as a security feature that
1895 deters exploit attempts relying on knowledge of the location
1896 of kernel internals.
1897
1898 Entropy is generated using the RDRAND instruction if it is
1899 supported. If RDTSC is supported, it is used as well. If
1900 neither RDRAND nor RDTSC are supported, then randomness is
1901 read from the i8254 timer.
1902
1903 The kernel will be offset by up to RANDOMIZE_BASE_MAX_OFFSET,
1904 and aligned according to PHYSICAL_ALIGN. Since the kernel is
1905 built using 2GiB addressing, and PHYSICAL_ALGIN must be at a
1906 minimum of 2MiB, only 10 bits of entropy is theoretically
1907 possible. At best, due to page table layouts, 64-bit can use
1908 9 bits of entropy and 32-bit uses 8 bits.
1909
1910 If unsure, say N.
1911
1912 config RANDOMIZE_BASE_MAX_OFFSET
1913 hex "Maximum kASLR offset allowed" if EXPERT
1914 depends on RANDOMIZE_BASE
1915 range 0x0 0x20000000 if X86_32
1916 default "0x20000000" if X86_32
1917 range 0x0 0x40000000 if X86_64
1918 default "0x40000000" if X86_64
1919 ---help---
1920 The lesser of RANDOMIZE_BASE_MAX_OFFSET and available physical
1921 memory is used to determine the maximal offset in bytes that will
1922 be applied to the kernel when kernel Address Space Layout
1923 Randomization (kASLR) is active. This must be a multiple of
1924 PHYSICAL_ALIGN.
1925
1926 On 32-bit this is limited to 512MiB by page table layouts. The
1927 default is 512MiB.
1928
1929 On 64-bit this is limited by how the kernel fixmap page table is
1930 positioned, so this cannot be larger than 1GiB currently. Without
1931 RANDOMIZE_BASE, there is a 512MiB to 1.5GiB split between kernel
1932 and modules. When RANDOMIZE_BASE_MAX_OFFSET is above 512MiB, the
1933 modules area will shrink to compensate, up to the current maximum
1934 1GiB to 1GiB split. The default is 1GiB.
1935
1936 If unsure, leave at the default value.
1937
1938 # Relocation on x86 needs some additional build support
1939 config X86_NEED_RELOCS
1940 def_bool y
1941 depends on RANDOMIZE_BASE || (X86_32 && RELOCATABLE)
1942
1943 config PHYSICAL_ALIGN
1944 hex "Alignment value to which kernel should be aligned"
1945 default "0x200000"
1946 range 0x2000 0x1000000 if X86_32
1947 range 0x200000 0x1000000 if X86_64
1948 ---help---
1949 This value puts the alignment restrictions on physical address
1950 where kernel is loaded and run from. Kernel is compiled for an
1951 address which meets above alignment restriction.
1952
1953 If bootloader loads the kernel at a non-aligned address and
1954 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1955 address aligned to above value and run from there.
1956
1957 If bootloader loads the kernel at a non-aligned address and
1958 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1959 load address and decompress itself to the address it has been
1960 compiled for and run from there. The address for which kernel is
1961 compiled already meets above alignment restrictions. Hence the
1962 end result is that kernel runs from a physical address meeting
1963 above alignment restrictions.
1964
1965 On 32-bit this value must be a multiple of 0x2000. On 64-bit
1966 this value must be a multiple of 0x200000.
1967
1968 Don't change this unless you know what you are doing.
1969
1970 config HOTPLUG_CPU
1971 bool "Support for hot-pluggable CPUs"
1972 depends on SMP
1973 ---help---
1974 Say Y here to allow turning CPUs off and on. CPUs can be
1975 controlled through /sys/devices/system/cpu.
1976 ( Note: power management support will enable this option
1977 automatically on SMP systems. )
1978 Say N if you want to disable CPU hotplug.
1979
1980 config BOOTPARAM_HOTPLUG_CPU0
1981 bool "Set default setting of cpu0_hotpluggable"
1982 default n
1983 depends on HOTPLUG_CPU
1984 ---help---
1985 Set whether default state of cpu0_hotpluggable is on or off.
1986
1987 Say Y here to enable CPU0 hotplug by default. If this switch
1988 is turned on, there is no need to give cpu0_hotplug kernel
1989 parameter and the CPU0 hotplug feature is enabled by default.
1990
1991 Please note: there are two known CPU0 dependencies if you want
1992 to enable the CPU0 hotplug feature either by this switch or by
1993 cpu0_hotplug kernel parameter.
1994
1995 First, resume from hibernate or suspend always starts from CPU0.
1996 So hibernate and suspend are prevented if CPU0 is offline.
1997
1998 Second dependency is PIC interrupts always go to CPU0. CPU0 can not
1999 offline if any interrupt can not migrate out of CPU0. There may
2000 be other CPU0 dependencies.
2001
2002 Please make sure the dependencies are under your control before
2003 you enable this feature.
2004
2005 Say N if you don't want to enable CPU0 hotplug feature by default.
2006 You still can enable the CPU0 hotplug feature at boot by kernel
2007 parameter cpu0_hotplug.
2008
2009 config DEBUG_HOTPLUG_CPU0
2010 def_bool n
2011 prompt "Debug CPU0 hotplug"
2012 depends on HOTPLUG_CPU
2013 ---help---
2014 Enabling this option offlines CPU0 (if CPU0 can be offlined) as
2015 soon as possible and boots up userspace with CPU0 offlined. User
2016 can online CPU0 back after boot time.
2017
2018 To debug CPU0 hotplug, you need to enable CPU0 offline/online
2019 feature by either turning on CONFIG_BOOTPARAM_HOTPLUG_CPU0 during
2020 compilation or giving cpu0_hotplug kernel parameter at boot.
2021
2022 If unsure, say N.
2023
2024 config COMPAT_VDSO
2025 def_bool n
2026 prompt "Disable the 32-bit vDSO (needed for glibc 2.3.3)"
2027 depends on X86_32 || IA32_EMULATION
2028 ---help---
2029 Certain buggy versions of glibc will crash if they are
2030 presented with a 32-bit vDSO that is not mapped at the address
2031 indicated in its segment table.
2032
2033 The bug was introduced by f866314b89d56845f55e6f365e18b31ec978ec3a
2034 and fixed by 3b3ddb4f7db98ec9e912ccdf54d35df4aa30e04a and
2035 49ad572a70b8aeb91e57483a11dd1b77e31c4468. Glibc 2.3.3 is
2036 the only released version with the bug, but OpenSUSE 9
2037 contains a buggy "glibc 2.3.2".
2038
2039 The symptom of the bug is that everything crashes on startup, saying:
2040 dl_main: Assertion `(void *) ph->p_vaddr == _rtld_local._dl_sysinfo_dso' failed!
2041
2042 Saying Y here changes the default value of the vdso32 boot
2043 option from 1 to 0, which turns off the 32-bit vDSO entirely.
2044 This works around the glibc bug but hurts performance.
2045
2046 If unsure, say N: if you are compiling your own kernel, you
2047 are unlikely to be using a buggy version of glibc.
2048
2049 choice
2050 prompt "vsyscall table for legacy applications"
2051 depends on X86_64
2052 default LEGACY_VSYSCALL_EMULATE
2053 help
2054 Legacy user code that does not know how to find the vDSO expects
2055 to be able to issue three syscalls by calling fixed addresses in
2056 kernel space. Since this location is not randomized with ASLR,
2057 it can be used to assist security vulnerability exploitation.
2058
2059 This setting can be changed at boot time via the kernel command
2060 line parameter vsyscall=[native|emulate|none].
2061
2062 On a system with recent enough glibc (2.14 or newer) and no
2063 static binaries, you can say None without a performance penalty
2064 to improve security.
2065
2066 If unsure, select "Emulate".
2067
2068 config LEGACY_VSYSCALL_NATIVE
2069 bool "Native"
2070 help
2071 Actual executable code is located in the fixed vsyscall
2072 address mapping, implementing time() efficiently. Since
2073 this makes the mapping executable, it can be used during
2074 security vulnerability exploitation (traditionally as
2075 ROP gadgets). This configuration is not recommended.
2076
2077 config LEGACY_VSYSCALL_EMULATE
2078 bool "Emulate"
2079 help
2080 The kernel traps and emulates calls into the fixed
2081 vsyscall address mapping. This makes the mapping
2082 non-executable, but it still contains known contents,
2083 which could be used in certain rare security vulnerability
2084 exploits. This configuration is recommended when userspace
2085 still uses the vsyscall area.
2086
2087 config LEGACY_VSYSCALL_NONE
2088 bool "None"
2089 help
2090 There will be no vsyscall mapping at all. This will
2091 eliminate any risk of ASLR bypass due to the vsyscall
2092 fixed address mapping. Attempts to use the vsyscalls
2093 will be reported to dmesg, so that either old or
2094 malicious userspace programs can be identified.
2095
2096 endchoice
2097
2098 config CMDLINE_BOOL
2099 bool "Built-in kernel command line"
2100 ---help---
2101 Allow for specifying boot arguments to the kernel at
2102 build time. On some systems (e.g. embedded ones), it is
2103 necessary or convenient to provide some or all of the
2104 kernel boot arguments with the kernel itself (that is,
2105 to not rely on the boot loader to provide them.)
2106
2107 To compile command line arguments into the kernel,
2108 set this option to 'Y', then fill in the
2109 boot arguments in CONFIG_CMDLINE.
2110
2111 Systems with fully functional boot loaders (i.e. non-embedded)
2112 should leave this option set to 'N'.
2113
2114 config CMDLINE
2115 string "Built-in kernel command string"
2116 depends on CMDLINE_BOOL
2117 default ""
2118 ---help---
2119 Enter arguments here that should be compiled into the kernel
2120 image and used at boot time. If the boot loader provides a
2121 command line at boot time, it is appended to this string to
2122 form the full kernel command line, when the system boots.
2123
2124 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
2125 change this behavior.
2126
2127 In most cases, the command line (whether built-in or provided
2128 by the boot loader) should specify the device for the root
2129 file system.
2130
2131 config CMDLINE_OVERRIDE
2132 bool "Built-in command line overrides boot loader arguments"
2133 depends on CMDLINE_BOOL
2134 ---help---
2135 Set this option to 'Y' to have the kernel ignore the boot loader
2136 command line, and use ONLY the built-in command line.
2137
2138 This is used to work around broken boot loaders. This should
2139 be set to 'N' under normal conditions.
2140
2141 config MODIFY_LDT_SYSCALL
2142 bool "Enable the LDT (local descriptor table)" if EXPERT
2143 default y
2144 ---help---
2145 Linux can allow user programs to install a per-process x86
2146 Local Descriptor Table (LDT) using the modify_ldt(2) system
2147 call. This is required to run 16-bit or segmented code such as
2148 DOSEMU or some Wine programs. It is also used by some very old
2149 threading libraries.
2150
2151 Enabling this feature adds a small amount of overhead to
2152 context switches and increases the low-level kernel attack
2153 surface. Disabling it removes the modify_ldt(2) system call.
2154
2155 Saying 'N' here may make sense for embedded or server kernels.
2156
2157 source "kernel/livepatch/Kconfig"
2158
2159 endmenu
2160
2161 config ARCH_ENABLE_MEMORY_HOTPLUG
2162 def_bool y
2163 depends on X86_64 || (X86_32 && HIGHMEM)
2164
2165 config ARCH_ENABLE_MEMORY_HOTREMOVE
2166 def_bool y
2167 depends on MEMORY_HOTPLUG
2168
2169 config USE_PERCPU_NUMA_NODE_ID
2170 def_bool y
2171 depends on NUMA
2172
2173 config ARCH_ENABLE_SPLIT_PMD_PTLOCK
2174 def_bool y
2175 depends on X86_64 || X86_PAE
2176
2177 config ARCH_ENABLE_HUGEPAGE_MIGRATION
2178 def_bool y
2179 depends on X86_64 && HUGETLB_PAGE && MIGRATION
2180
2181 menu "Power management and ACPI options"
2182
2183 config ARCH_HIBERNATION_HEADER
2184 def_bool y
2185 depends on X86_64 && HIBERNATION
2186
2187 source "kernel/power/Kconfig"
2188
2189 source "drivers/acpi/Kconfig"
2190
2191 source "drivers/sfi/Kconfig"
2192
2193 config X86_APM_BOOT
2194 def_bool y
2195 depends on APM
2196
2197 menuconfig APM
2198 tristate "APM (Advanced Power Management) BIOS support"
2199 depends on X86_32 && PM_SLEEP
2200 ---help---
2201 APM is a BIOS specification for saving power using several different
2202 techniques. This is mostly useful for battery powered laptops with
2203 APM compliant BIOSes. If you say Y here, the system time will be
2204 reset after a RESUME operation, the /proc/apm device will provide
2205 battery status information, and user-space programs will receive
2206 notification of APM "events" (e.g. battery status change).
2207
2208 If you select "Y" here, you can disable actual use of the APM
2209 BIOS by passing the "apm=off" option to the kernel at boot time.
2210
2211 Note that the APM support is almost completely disabled for
2212 machines with more than one CPU.
2213
2214 In order to use APM, you will need supporting software. For location
2215 and more information, read <file:Documentation/power/apm-acpi.txt>
2216 and the Battery Powered Linux mini-HOWTO, available from
2217 <http://www.tldp.org/docs.html#howto>.
2218
2219 This driver does not spin down disk drives (see the hdparm(8)
2220 manpage ("man 8 hdparm") for that), and it doesn't turn off
2221 VESA-compliant "green" monitors.
2222
2223 This driver does not support the TI 4000M TravelMate and the ACER
2224 486/DX4/75 because they don't have compliant BIOSes. Many "green"
2225 desktop machines also don't have compliant BIOSes, and this driver
2226 may cause those machines to panic during the boot phase.
2227
2228 Generally, if you don't have a battery in your machine, there isn't
2229 much point in using this driver and you should say N. If you get
2230 random kernel OOPSes or reboots that don't seem to be related to
2231 anything, try disabling/enabling this option (or disabling/enabling
2232 APM in your BIOS).
2233
2234 Some other things you should try when experiencing seemingly random,
2235 "weird" problems:
2236
2237 1) make sure that you have enough swap space and that it is
2238 enabled.
2239 2) pass the "no-hlt" option to the kernel
2240 3) switch on floating point emulation in the kernel and pass
2241 the "no387" option to the kernel
2242 4) pass the "floppy=nodma" option to the kernel
2243 5) pass the "mem=4M" option to the kernel (thereby disabling
2244 all but the first 4 MB of RAM)
2245 6) make sure that the CPU is not over clocked.
2246 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
2247 8) disable the cache from your BIOS settings
2248 9) install a fan for the video card or exchange video RAM
2249 10) install a better fan for the CPU
2250 11) exchange RAM chips
2251 12) exchange the motherboard.
2252
2253 To compile this driver as a module, choose M here: the
2254 module will be called apm.
2255
2256 if APM
2257
2258 config APM_IGNORE_USER_SUSPEND
2259 bool "Ignore USER SUSPEND"
2260 ---help---
2261 This option will ignore USER SUSPEND requests. On machines with a
2262 compliant APM BIOS, you want to say N. However, on the NEC Versa M
2263 series notebooks, it is necessary to say Y because of a BIOS bug.
2264
2265 config APM_DO_ENABLE
2266 bool "Enable PM at boot time"
2267 ---help---
2268 Enable APM features at boot time. From page 36 of the APM BIOS
2269 specification: "When disabled, the APM BIOS does not automatically
2270 power manage devices, enter the Standby State, enter the Suspend
2271 State, or take power saving steps in response to CPU Idle calls."
2272 This driver will make CPU Idle calls when Linux is idle (unless this
2273 feature is turned off -- see "Do CPU IDLE calls", below). This
2274 should always save battery power, but more complicated APM features
2275 will be dependent on your BIOS implementation. You may need to turn
2276 this option off if your computer hangs at boot time when using APM
2277 support, or if it beeps continuously instead of suspending. Turn
2278 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
2279 T400CDT. This is off by default since most machines do fine without
2280 this feature.
2281
2282 config APM_CPU_IDLE
2283 depends on CPU_IDLE
2284 bool "Make CPU Idle calls when idle"
2285 ---help---
2286 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
2287 On some machines, this can activate improved power savings, such as
2288 a slowed CPU clock rate, when the machine is idle. These idle calls
2289 are made after the idle loop has run for some length of time (e.g.,
2290 333 mS). On some machines, this will cause a hang at boot time or
2291 whenever the CPU becomes idle. (On machines with more than one CPU,
2292 this option does nothing.)
2293
2294 config APM_DISPLAY_BLANK
2295 bool "Enable console blanking using APM"
2296 ---help---
2297 Enable console blanking using the APM. Some laptops can use this to
2298 turn off the LCD backlight when the screen blanker of the Linux
2299 virtual console blanks the screen. Note that this is only used by
2300 the virtual console screen blanker, and won't turn off the backlight
2301 when using the X Window system. This also doesn't have anything to
2302 do with your VESA-compliant power-saving monitor. Further, this
2303 option doesn't work for all laptops -- it might not turn off your
2304 backlight at all, or it might print a lot of errors to the console,
2305 especially if you are using gpm.
2306
2307 config APM_ALLOW_INTS
2308 bool "Allow interrupts during APM BIOS calls"
2309 ---help---
2310 Normally we disable external interrupts while we are making calls to
2311 the APM BIOS as a measure to lessen the effects of a badly behaving
2312 BIOS implementation. The BIOS should reenable interrupts if it
2313 needs to. Unfortunately, some BIOSes do not -- especially those in
2314 many of the newer IBM Thinkpads. If you experience hangs when you
2315 suspend, try setting this to Y. Otherwise, say N.
2316
2317 endif # APM
2318
2319 source "drivers/cpufreq/Kconfig"
2320
2321 source "drivers/cpuidle/Kconfig"
2322
2323 source "drivers/idle/Kconfig"
2324
2325 endmenu
2326
2327
2328 menu "Bus options (PCI etc.)"
2329
2330 config PCI
2331 bool "PCI support"
2332 default y
2333 ---help---
2334 Find out whether you have a PCI motherboard. PCI is the name of a
2335 bus system, i.e. the way the CPU talks to the other stuff inside
2336 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
2337 VESA. If you have PCI, say Y, otherwise N.
2338
2339 choice
2340 prompt "PCI access mode"
2341 depends on X86_32 && PCI
2342 default PCI_GOANY
2343 ---help---
2344 On PCI systems, the BIOS can be used to detect the PCI devices and
2345 determine their configuration. However, some old PCI motherboards
2346 have BIOS bugs and may crash if this is done. Also, some embedded
2347 PCI-based systems don't have any BIOS at all. Linux can also try to
2348 detect the PCI hardware directly without using the BIOS.
2349
2350 With this option, you can specify how Linux should detect the
2351 PCI devices. If you choose "BIOS", the BIOS will be used,
2352 if you choose "Direct", the BIOS won't be used, and if you
2353 choose "MMConfig", then PCI Express MMCONFIG will be used.
2354 If you choose "Any", the kernel will try MMCONFIG, then the
2355 direct access method and falls back to the BIOS if that doesn't
2356 work. If unsure, go with the default, which is "Any".
2357
2358 config PCI_GOBIOS
2359 bool "BIOS"
2360
2361 config PCI_GOMMCONFIG
2362 bool "MMConfig"
2363
2364 config PCI_GODIRECT
2365 bool "Direct"
2366
2367 config PCI_GOOLPC
2368 bool "OLPC XO-1"
2369 depends on OLPC
2370
2371 config PCI_GOANY
2372 bool "Any"
2373
2374 endchoice
2375
2376 config PCI_BIOS
2377 def_bool y
2378 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
2379
2380 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
2381 config PCI_DIRECT
2382 def_bool y
2383 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC || PCI_GOMMCONFIG))
2384
2385 config PCI_MMCONFIG
2386 def_bool y
2387 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
2388
2389 config PCI_OLPC
2390 def_bool y
2391 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
2392
2393 config PCI_XEN
2394 def_bool y
2395 depends on PCI && XEN
2396 select SWIOTLB_XEN
2397
2398 config PCI_DOMAINS
2399 def_bool y
2400 depends on PCI
2401
2402 config PCI_MMCONFIG
2403 bool "Support mmconfig PCI config space access"
2404 depends on X86_64 && PCI && ACPI
2405
2406 config PCI_CNB20LE_QUIRK
2407 bool "Read CNB20LE Host Bridge Windows" if EXPERT
2408 depends on PCI
2409 help
2410 Read the PCI windows out of the CNB20LE host bridge. This allows
2411 PCI hotplug to work on systems with the CNB20LE chipset which do
2412 not have ACPI.
2413
2414 There's no public spec for this chipset, and this functionality
2415 is known to be incomplete.
2416
2417 You should say N unless you know you need this.
2418
2419 source "drivers/pci/pcie/Kconfig"
2420
2421 source "drivers/pci/Kconfig"
2422
2423 # x86_64 have no ISA slots, but can have ISA-style DMA.
2424 config ISA_DMA_API
2425 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2426 default y
2427 help
2428 Enables ISA-style DMA support for devices requiring such controllers.
2429 If unsure, say Y.
2430
2431 if X86_32
2432
2433 config ISA
2434 bool "ISA support"
2435 ---help---
2436 Find out whether you have ISA slots on your motherboard. ISA is the
2437 name of a bus system, i.e. the way the CPU talks to the other stuff
2438 inside your box. Other bus systems are PCI, EISA, MicroChannel
2439 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2440 newer boards don't support it. If you have ISA, say Y, otherwise N.
2441
2442 config EISA
2443 bool "EISA support"
2444 depends on ISA
2445 ---help---
2446 The Extended Industry Standard Architecture (EISA) bus was
2447 developed as an open alternative to the IBM MicroChannel bus.
2448
2449 The EISA bus provided some of the features of the IBM MicroChannel
2450 bus while maintaining backward compatibility with cards made for
2451 the older ISA bus. The EISA bus saw limited use between 1988 and
2452 1995 when it was made obsolete by the PCI bus.
2453
2454 Say Y here if you are building a kernel for an EISA-based machine.
2455
2456 Otherwise, say N.
2457
2458 source "drivers/eisa/Kconfig"
2459
2460 config SCx200
2461 tristate "NatSemi SCx200 support"
2462 ---help---
2463 This provides basic support for National Semiconductor's
2464 (now AMD's) Geode processors. The driver probes for the
2465 PCI-IDs of several on-chip devices, so its a good dependency
2466 for other scx200_* drivers.
2467
2468 If compiled as a module, the driver is named scx200.
2469
2470 config SCx200HR_TIMER
2471 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2472 depends on SCx200
2473 default y
2474 ---help---
2475 This driver provides a clocksource built upon the on-chip
2476 27MHz high-resolution timer. Its also a workaround for
2477 NSC Geode SC-1100's buggy TSC, which loses time when the
2478 processor goes idle (as is done by the scheduler). The
2479 other workaround is idle=poll boot option.
2480
2481 config OLPC
2482 bool "One Laptop Per Child support"
2483 depends on !X86_PAE
2484 select GPIOLIB
2485 select OF
2486 select OF_PROMTREE
2487 select IRQ_DOMAIN
2488 ---help---
2489 Add support for detecting the unique features of the OLPC
2490 XO hardware.
2491
2492 config OLPC_XO1_PM
2493 bool "OLPC XO-1 Power Management"
2494 depends on OLPC && MFD_CS5535 && PM_SLEEP
2495 select MFD_CORE
2496 ---help---
2497 Add support for poweroff and suspend of the OLPC XO-1 laptop.
2498
2499 config OLPC_XO1_RTC
2500 bool "OLPC XO-1 Real Time Clock"
2501 depends on OLPC_XO1_PM && RTC_DRV_CMOS
2502 ---help---
2503 Add support for the XO-1 real time clock, which can be used as a
2504 programmable wakeup source.
2505
2506 config OLPC_XO1_SCI
2507 bool "OLPC XO-1 SCI extras"
2508 depends on OLPC && OLPC_XO1_PM
2509 depends on INPUT=y
2510 select POWER_SUPPLY
2511 select GPIO_CS5535
2512 select MFD_CORE
2513 ---help---
2514 Add support for SCI-based features of the OLPC XO-1 laptop:
2515 - EC-driven system wakeups
2516 - Power button
2517 - Ebook switch
2518 - Lid switch
2519 - AC adapter status updates
2520 - Battery status updates
2521
2522 config OLPC_XO15_SCI
2523 bool "OLPC XO-1.5 SCI extras"
2524 depends on OLPC && ACPI
2525 select POWER_SUPPLY
2526 ---help---
2527 Add support for SCI-based features of the OLPC XO-1.5 laptop:
2528 - EC-driven system wakeups
2529 - AC adapter status updates
2530 - Battery status updates
2531
2532 config ALIX
2533 bool "PCEngines ALIX System Support (LED setup)"
2534 select GPIOLIB
2535 ---help---
2536 This option enables system support for the PCEngines ALIX.
2537 At present this just sets up LEDs for GPIO control on
2538 ALIX2/3/6 boards. However, other system specific setup should
2539 get added here.
2540
2541 Note: You must still enable the drivers for GPIO and LED support
2542 (GPIO_CS5535 & LEDS_GPIO) to actually use the LEDs
2543
2544 Note: You have to set alix.force=1 for boards with Award BIOS.
2545
2546 config NET5501
2547 bool "Soekris Engineering net5501 System Support (LEDS, GPIO, etc)"
2548 select GPIOLIB
2549 ---help---
2550 This option enables system support for the Soekris Engineering net5501.
2551
2552 config GEOS
2553 bool "Traverse Technologies GEOS System Support (LEDS, GPIO, etc)"
2554 select GPIOLIB
2555 depends on DMI
2556 ---help---
2557 This option enables system support for the Traverse Technologies GEOS.
2558
2559 config TS5500
2560 bool "Technologic Systems TS-5500 platform support"
2561 depends on MELAN
2562 select CHECK_SIGNATURE
2563 select NEW_LEDS
2564 select LEDS_CLASS
2565 ---help---
2566 This option enables system support for the Technologic Systems TS-5500.
2567
2568 endif # X86_32
2569
2570 config AMD_NB
2571 def_bool y
2572 depends on CPU_SUP_AMD && PCI
2573
2574 source "drivers/pcmcia/Kconfig"
2575
2576 source "drivers/pci/hotplug/Kconfig"
2577
2578 config RAPIDIO
2579 tristate "RapidIO support"
2580 depends on PCI
2581 default n
2582 help
2583 If enabled this option will include drivers and the core
2584 infrastructure code to support RapidIO interconnect devices.
2585
2586 source "drivers/rapidio/Kconfig"
2587
2588 config X86_SYSFB
2589 bool "Mark VGA/VBE/EFI FB as generic system framebuffer"
2590 help
2591 Firmwares often provide initial graphics framebuffers so the BIOS,
2592 bootloader or kernel can show basic video-output during boot for
2593 user-guidance and debugging. Historically, x86 used the VESA BIOS
2594 Extensions and EFI-framebuffers for this, which are mostly limited
2595 to x86.
2596 This option, if enabled, marks VGA/VBE/EFI framebuffers as generic
2597 framebuffers so the new generic system-framebuffer drivers can be
2598 used on x86. If the framebuffer is not compatible with the generic
2599 modes, it is adverticed as fallback platform framebuffer so legacy
2600 drivers like efifb, vesafb and uvesafb can pick it up.
2601 If this option is not selected, all system framebuffers are always
2602 marked as fallback platform framebuffers as usual.
2603
2604 Note: Legacy fbdev drivers, including vesafb, efifb, uvesafb, will
2605 not be able to pick up generic system framebuffers if this option
2606 is selected. You are highly encouraged to enable simplefb as
2607 replacement if you select this option. simplefb can correctly deal
2608 with generic system framebuffers. But you should still keep vesafb
2609 and others enabled as fallback if a system framebuffer is
2610 incompatible with simplefb.
2611
2612 If unsure, say Y.
2613
2614 endmenu
2615
2616
2617 menu "Executable file formats / Emulations"
2618
2619 source "fs/Kconfig.binfmt"
2620
2621 config IA32_EMULATION
2622 bool "IA32 Emulation"
2623 depends on X86_64
2624 select BINFMT_ELF
2625 select COMPAT_BINFMT_ELF
2626 select ARCH_WANT_OLD_COMPAT_IPC
2627 ---help---
2628 Include code to run legacy 32-bit programs under a
2629 64-bit kernel. You should likely turn this on, unless you're
2630 100% sure that you don't have any 32-bit programs left.
2631
2632 config IA32_AOUT
2633 tristate "IA32 a.out support"
2634 depends on IA32_EMULATION
2635 ---help---
2636 Support old a.out binaries in the 32bit emulation.
2637
2638 config X86_X32
2639 bool "x32 ABI for 64-bit mode"
2640 depends on X86_64
2641 ---help---
2642 Include code to run binaries for the x32 native 32-bit ABI
2643 for 64-bit processors. An x32 process gets access to the
2644 full 64-bit register file and wide data path while leaving
2645 pointers at 32 bits for smaller memory footprint.
2646
2647 You will need a recent binutils (2.22 or later) with
2648 elf32_x86_64 support enabled to compile a kernel with this
2649 option set.
2650
2651 config COMPAT
2652 def_bool y
2653 depends on IA32_EMULATION || X86_X32
2654
2655 if COMPAT
2656 config COMPAT_FOR_U64_ALIGNMENT
2657 def_bool y
2658
2659 config SYSVIPC_COMPAT
2660 def_bool y
2661 depends on SYSVIPC
2662
2663 config KEYS_COMPAT
2664 def_bool y
2665 depends on KEYS
2666 endif
2667
2668 endmenu
2669
2670
2671 config HAVE_ATOMIC_IOMAP
2672 def_bool y
2673 depends on X86_32
2674
2675 config X86_DEV_DMA_OPS
2676 bool
2677 depends on X86_64 || STA2X11
2678
2679 config X86_DMA_REMAP
2680 bool
2681 depends on STA2X11
2682
2683 config PMC_ATOM
2684 def_bool y
2685 depends on PCI
2686
2687 source "net/Kconfig"
2688
2689 source "drivers/Kconfig"
2690
2691 source "drivers/firmware/Kconfig"
2692
2693 source "fs/Kconfig"
2694
2695 source "arch/x86/Kconfig.debug"
2696
2697 source "security/Kconfig"
2698
2699 source "crypto/Kconfig"
2700
2701 source "arch/x86/kvm/Kconfig"
2702
2703 source "lib/Kconfig"