| blob | da349723d4115cef7d75aac4680ba2284deaf0d0 |
1 # Select 32 or 64 bit
2 config 64BIT
3 bool "64-bit kernel" if ARCH = "x86"
4 default ARCH = "x86_64"
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
9 config X86_32
10 def_bool !64BIT
11 select CLKSRC_I8253
13 config X86_64
14 def_bool 64BIT
16 ### Arch settings
17 config X86
18 def_bool y
19 select HAVE_AOUT if X86_32
20 select HAVE_UNSTABLE_SCHED_CLOCK
21 select HAVE_IDE
22 select HAVE_OPROFILE
23 select HAVE_PERF_EVENTS
24 select HAVE_IRQ_WORK
25 select HAVE_IOREMAP_PROT
26 select HAVE_KPROBES
27 select HAVE_MEMBLOCK
28 select ARCH_WANT_OPTIONAL_GPIOLIB
29 select ARCH_WANT_FRAME_POINTERS
30 select HAVE_DMA_ATTRS
31 select HAVE_KRETPROBES
32 select HAVE_OPTPROBES
33 select HAVE_FTRACE_MCOUNT_RECORD
34 select HAVE_C_RECORDMCOUNT
35 select HAVE_DYNAMIC_FTRACE
36 select HAVE_FUNCTION_TRACER
37 select HAVE_FUNCTION_GRAPH_TRACER
38 select HAVE_FUNCTION_GRAPH_FP_TEST
39 select HAVE_FUNCTION_TRACE_MCOUNT_TEST
40 select HAVE_FTRACE_NMI_ENTER if DYNAMIC_FTRACE
41 select HAVE_SYSCALL_TRACEPOINTS
42 select HAVE_KVM
43 select HAVE_ARCH_KGDB
44 select HAVE_ARCH_TRACEHOOK
45 select HAVE_GENERIC_DMA_COHERENT if X86_32
46 select HAVE_EFFICIENT_UNALIGNED_ACCESS
47 select USER_STACKTRACE_SUPPORT
48 select HAVE_REGS_AND_STACK_ACCESS_API
49 select HAVE_DMA_API_DEBUG
50 select HAVE_KERNEL_GZIP
51 select HAVE_KERNEL_BZIP2
52 select HAVE_KERNEL_LZMA
53 select HAVE_KERNEL_XZ
54 select HAVE_KERNEL_LZO
55 select HAVE_HW_BREAKPOINT
56 select HAVE_MIXED_BREAKPOINTS_REGS
57 select PERF_EVENTS
58 select HAVE_PERF_EVENTS_NMI
59 select ANON_INODES
60 select HAVE_ARCH_KMEMCHECK
61 select HAVE_USER_RETURN_NOTIFIER
62 select HAVE_ARCH_JUMP_LABEL
63 select HAVE_TEXT_POKE_SMP
64 select HAVE_GENERIC_HARDIRQS
65 select HAVE_SPARSE_IRQ
66 select GENERIC_FIND_FIRST_BIT
67 select GENERIC_IRQ_PROBE
68 select GENERIC_PENDING_IRQ if SMP
69 select GENERIC_IRQ_SHOW
70 select IRQ_FORCED_THREADING
71 select USE_GENERIC_SMP_HELPERS if SMP
72 select HAVE_BPF_JIT if (X86_64 && NET)
74 config INSTRUCTION_DECODER
75 def_bool (KPROBES || PERF_EVENTS)
77 config OUTPUT_FORMAT
78 string
79 default "elf32-i386" if X86_32
80 default "elf64-x86-64" if X86_64
82 config ARCH_DEFCONFIG
83 string
84 default "arch/x86/configs/i386_defconfig" if X86_32
85 default "arch/x86/configs/x86_64_defconfig" if X86_64
87 config GENERIC_CMOS_UPDATE
88 def_bool y
90 config CLOCKSOURCE_WATCHDOG
91 def_bool y
93 config GENERIC_CLOCKEVENTS
94 def_bool y
96 config GENERIC_CLOCKEVENTS_BROADCAST
97 def_bool y
98 depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
100 config LOCKDEP_SUPPORT
101 def_bool y
103 config STACKTRACE_SUPPORT
104 def_bool y
106 config HAVE_LATENCYTOP_SUPPORT
107 def_bool y
109 config MMU
110 def_bool y
112 config ZONE_DMA
113 bool "DMA memory allocation support" if EXPERT
114 default y
115 help
116 DMA memory allocation support allows devices with less than 32-bit
117 addressing to allocate within the first 16MB of address space.
118 Disable if no such devices will be used.
120 If unsure, say Y.
122 config SBUS
123 bool
125 config NEED_DMA_MAP_STATE
126 def_bool (X86_64 || DMAR || DMA_API_DEBUG)
128 config NEED_SG_DMA_LENGTH
129 def_bool y
131 config GENERIC_ISA_DMA
132 def_bool ISA_DMA_API
134 config GENERIC_IOMAP
135 def_bool y
137 config GENERIC_BUG
138 def_bool y
139 depends on BUG
140 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
142 config GENERIC_BUG_RELATIVE_POINTERS
143 bool
145 config GENERIC_HWEIGHT
146 def_bool y
148 config GENERIC_GPIO
149 bool
151 config ARCH_MAY_HAVE_PC_FDC
152 def_bool ISA_DMA_API
154 config RWSEM_GENERIC_SPINLOCK
155 def_bool !X86_XADD
157 config RWSEM_XCHGADD_ALGORITHM
158 def_bool X86_XADD
160 config ARCH_HAS_CPU_IDLE_WAIT
161 def_bool y
163 config GENERIC_CALIBRATE_DELAY
164 def_bool y
166 config GENERIC_TIME_VSYSCALL
167 bool
168 default X86_64
170 config ARCH_HAS_CPU_RELAX
171 def_bool y
173 config ARCH_HAS_DEFAULT_IDLE
174 def_bool y
176 config ARCH_HAS_CACHE_LINE_SIZE
177 def_bool y
179 config HAVE_SETUP_PER_CPU_AREA
180 def_bool y
182 config NEED_PER_CPU_EMBED_FIRST_CHUNK
183 def_bool y
185 config NEED_PER_CPU_PAGE_FIRST_CHUNK
186 def_bool y
188 config HAVE_CPUMASK_OF_CPU_MAP
189 def_bool X86_64_SMP
191 config ARCH_HIBERNATION_POSSIBLE
192 def_bool y
194 config ARCH_SUSPEND_POSSIBLE
195 def_bool y
197 config ZONE_DMA32
198 bool
199 default X86_64
201 config ARCH_POPULATES_NODE_MAP
202 def_bool y
204 config AUDIT_ARCH
205 bool
206 default X86_64
208 config ARCH_SUPPORTS_OPTIMIZED_INLINING
209 def_bool y
211 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
212 def_bool y
214 config HAVE_INTEL_TXT
215 def_bool y
216 depends on EXPERIMENTAL && DMAR && ACPI
218 config X86_32_SMP
219 def_bool y
220 depends on X86_32 && SMP
222 config X86_64_SMP
223 def_bool y
224 depends on X86_64 && SMP
226 config X86_HT
227 def_bool y
228 depends on SMP
230 config X86_32_LAZY_GS
231 def_bool y
232 depends on X86_32 && !CC_STACKPROTECTOR
234 config ARCH_HWEIGHT_CFLAGS
235 string
236 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
237 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
239 config KTIME_SCALAR
240 def_bool X86_32
242 config ARCH_CPU_PROBE_RELEASE
243 def_bool y
244 depends on HOTPLUG_CPU
246 source "init/Kconfig"
247 source "kernel/Kconfig.freezer"
249 menu "Processor type and features"
251 source "kernel/time/Kconfig"
253 config SMP
254 bool "Symmetric multi-processing support"
255 ---help---
256 This enables support for systems with more than one CPU. If you have
257 a system with only one CPU, like most personal computers, say N. If
258 you have a system with more than one CPU, say Y.
260 If you say N here, the kernel will run on single and multiprocessor
261 machines, but will use only one CPU of a multiprocessor machine. If
262 you say Y here, the kernel will run on many, but not all,
263 singleprocessor machines. On a singleprocessor machine, the kernel
264 will run faster if you say N here.
266 Note that if you say Y here and choose architecture "586" or
267 "Pentium" under "Processor family", the kernel will not work on 486
268 architectures. Similarly, multiprocessor kernels for the "PPro"
269 architecture may not work on all Pentium based boards.
271 People using multiprocessor machines who say Y here should also say
272 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
273 Management" code will be disabled if you say Y here.
275 See also <file:Documentation/i386/IO-APIC.txt>,
276 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
277 <http://www.tldp.org/docs.html#howto>.
279 If you don't know what to do here, say N.
281 config X86_X2APIC
282 bool "Support x2apic"
283 depends on X86_LOCAL_APIC && X86_64 && INTR_REMAP
284 ---help---
285 This enables x2apic support on CPUs that have this feature.
287 This allows 32-bit apic IDs (so it can support very large systems),
288 and accesses the local apic via MSRs not via mmio.
290 If you don't know what to do here, say N.
292 config X86_MPPARSE
293 bool "Enable MPS table" if ACPI
294 default y
295 depends on X86_LOCAL_APIC
296 ---help---
297 For old smp systems that do not have proper acpi support. Newer systems
298 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
300 config X86_BIGSMP
301 bool "Support for big SMP systems with more than 8 CPUs"
302 depends on X86_32 && SMP
303 ---help---
304 This option is needed for the systems that have more than 8 CPUs
306 if X86_32
307 config X86_EXTENDED_PLATFORM
308 bool "Support for extended (non-PC) x86 platforms"
309 default y
310 ---help---
311 If you disable this option then the kernel will only support
312 standard PC platforms. (which covers the vast majority of
313 systems out there.)
315 If you enable this option then you'll be able to select support
316 for the following (non-PC) 32 bit x86 platforms:
317 AMD Elan
318 NUMAQ (IBM/Sequent)
319 RDC R-321x SoC
320 SGI 320/540 (Visual Workstation)
321 Summit/EXA (IBM x440)
322 Unisys ES7000 IA32 series
323 Moorestown MID devices
325 If you have one of these systems, or if you want to build a
326 generic distribution kernel, say Y here - otherwise say N.
327 endif
329 if X86_64
330 config X86_EXTENDED_PLATFORM
331 bool "Support for extended (non-PC) x86 platforms"
332 default y
333 ---help---
334 If you disable this option then the kernel will only support
335 standard PC platforms. (which covers the vast majority of
336 systems out there.)
338 If you enable this option then you'll be able to select support
339 for the following (non-PC) 64 bit x86 platforms:
340 ScaleMP vSMP
341 SGI Ultraviolet
343 If you have one of these systems, or if you want to build a
344 generic distribution kernel, say Y here - otherwise say N.
345 endif
346 # This is an alphabetically sorted list of 64 bit extended platforms
347 # Please maintain the alphabetic order if and when there are additions
349 config X86_VSMP
350 bool "ScaleMP vSMP"
351 select PARAVIRT_GUEST
352 select PARAVIRT
353 depends on X86_64 && PCI
354 depends on X86_EXTENDED_PLATFORM
355 ---help---
356 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
357 supposed to run on these EM64T-based machines. Only choose this option
358 if you have one of these machines.
360 config X86_UV
361 bool "SGI Ultraviolet"
362 depends on X86_64
363 depends on X86_EXTENDED_PLATFORM
364 depends on NUMA
365 depends on X86_X2APIC
366 ---help---
367 This option is needed in order to support SGI Ultraviolet systems.
368 If you don't have one of these, you should say N here.
370 # Following is an alphabetically sorted list of 32 bit extended platforms
371 # Please maintain the alphabetic order if and when there are additions
373 config X86_INTEL_CE
374 bool "CE4100 TV platform"
375 depends on PCI
376 depends on PCI_GODIRECT
377 depends on X86_32
378 depends on X86_EXTENDED_PLATFORM
379 select X86_REBOOTFIXUPS
380 select OF
381 select OF_EARLY_FLATTREE
382 ---help---
383 Select for the Intel CE media processor (CE4100) SOC.
384 This option compiles in support for the CE4100 SOC for settop
385 boxes and media devices.
387 config X86_MRST
388 bool "Moorestown MID platform"
389 depends on PCI
390 depends on PCI_GOANY
391 depends on X86_32
392 depends on X86_EXTENDED_PLATFORM
393 depends on X86_IO_APIC
394 select APB_TIMER
395 select I2C
396 select SPI
397 select INTEL_SCU_IPC
398 select X86_PLATFORM_DEVICES
399 ---help---
400 Moorestown is Intel's Low Power Intel Architecture (LPIA) based Moblin
401 Internet Device(MID) platform. Moorestown consists of two chips:
402 Lincroft (CPU core, graphics, and memory controller) and Langwell IOH.
403 Unlike standard x86 PCs, Moorestown does not have many legacy devices
404 nor standard legacy replacement devices/features. e.g. Moorestown does
405 not contain i8259, i8254, HPET, legacy BIOS, most of the io ports.
407 config X86_RDC321X
408 bool "RDC R-321x SoC"
409 depends on X86_32
410 depends on X86_EXTENDED_PLATFORM
411 select M486
412 select X86_REBOOTFIXUPS
413 ---help---
414 This option is needed for RDC R-321x system-on-chip, also known
415 as R-8610-(G).
416 If you don't have one of these chips, you should say N here.
418 config X86_32_NON_STANDARD
419 bool "Support non-standard 32-bit SMP architectures"
420 depends on X86_32 && SMP
421 depends on X86_EXTENDED_PLATFORM
422 ---help---
423 This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
424 subarchitectures. It is intended for a generic binary kernel.
425 if you select them all, kernel will probe it one by one. and will
426 fallback to default.
428 # Alphabetically sorted list of Non standard 32 bit platforms
430 config X86_NUMAQ
431 bool "NUMAQ (IBM/Sequent)"
432 depends on X86_32_NON_STANDARD
433 depends on PCI
434 select NUMA
435 select X86_MPPARSE
436 ---help---
437 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
438 NUMA multiquad box. This changes the way that processors are
439 bootstrapped, and uses Clustered Logical APIC addressing mode instead
440 of Flat Logical. You will need a new lynxer.elf file to flash your
441 firmware with - send email to <Martin.Bligh@us.ibm.com>.
443 config X86_SUPPORTS_MEMORY_FAILURE
444 def_bool y
445 # MCE code calls memory_failure():
446 depends on X86_MCE
447 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
448 depends on !X86_NUMAQ
449 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
450 depends on X86_64 || !SPARSEMEM
451 select ARCH_SUPPORTS_MEMORY_FAILURE
453 config X86_VISWS
454 bool "SGI 320/540 (Visual Workstation)"
455 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
456 depends on X86_32_NON_STANDARD
457 ---help---
458 The SGI Visual Workstation series is an IA32-based workstation
459 based on SGI systems chips with some legacy PC hardware attached.
461 Say Y here to create a kernel to run on the SGI 320 or 540.
463 A kernel compiled for the Visual Workstation will run on general
464 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
466 config X86_SUMMIT
467 bool "Summit/EXA (IBM x440)"
468 depends on X86_32_NON_STANDARD
469 ---help---
470 This option is needed for IBM systems that use the Summit/EXA chipset.
471 In particular, it is needed for the x440.
473 config X86_ES7000
474 bool "Unisys ES7000 IA32 series"
475 depends on X86_32_NON_STANDARD && X86_BIGSMP
476 ---help---
477 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
478 supposed to run on an IA32-based Unisys ES7000 system.
480 config X86_32_IRIS
481 tristate "Eurobraille/Iris poweroff module"
482 depends on X86_32
483 ---help---
484 The Iris machines from EuroBraille do not have APM or ACPI support
485 to shut themselves down properly. A special I/O sequence is
486 needed to do so, which is what this module does at
487 kernel shutdown.
489 This is only for Iris machines from EuroBraille.
491 If unused, say N.
493 config SCHED_OMIT_FRAME_POINTER
494 def_bool y
495 prompt "Single-depth WCHAN output"
496 depends on X86
497 ---help---
498 Calculate simpler /proc/<PID>/wchan values. If this option
499 is disabled then wchan values will recurse back to the
500 caller function. This provides more accurate wchan values,
501 at the expense of slightly more scheduling overhead.
503 If in doubt, say "Y".
505 menuconfig PARAVIRT_GUEST
506 bool "Paravirtualized guest support"
507 ---help---
508 Say Y here to get to see options related to running Linux under
509 various hypervisors. This option alone does not add any kernel code.
511 If you say N, all options in this submenu will be skipped and disabled.
513 if PARAVIRT_GUEST
515 source "arch/x86/xen/Kconfig"
517 config KVM_CLOCK
518 bool "KVM paravirtualized clock"
519 select PARAVIRT
520 select PARAVIRT_CLOCK
521 ---help---
522 Turning on this option will allow you to run a paravirtualized clock
523 when running over the KVM hypervisor. Instead of relying on a PIT
524 (or probably other) emulation by the underlying device model, the host
525 provides the guest with timing infrastructure such as time of day, and
526 system time
528 config KVM_GUEST
529 bool "KVM Guest support"
530 select PARAVIRT
531 ---help---
532 This option enables various optimizations for running under the KVM
533 hypervisor.
535 source "arch/x86/lguest/Kconfig"
537 config PARAVIRT
538 bool "Enable paravirtualization code"
539 ---help---
540 This changes the kernel so it can modify itself when it is run
541 under a hypervisor, potentially improving performance significantly
542 over full virtualization. However, when run without a hypervisor
543 the kernel is theoretically slower and slightly larger.
545 config PARAVIRT_SPINLOCKS
546 bool "Paravirtualization layer for spinlocks"
547 depends on PARAVIRT && SMP && EXPERIMENTAL
548 ---help---
549 Paravirtualized spinlocks allow a pvops backend to replace the
550 spinlock implementation with something virtualization-friendly
551 (for example, block the virtual CPU rather than spinning).
553 Unfortunately the downside is an up to 5% performance hit on
554 native kernels, with various workloads.
556 If you are unsure how to answer this question, answer N.
558 config PARAVIRT_CLOCK
559 bool
561 endif
563 config PARAVIRT_DEBUG
564 bool "paravirt-ops debugging"
565 depends on PARAVIRT && DEBUG_KERNEL
566 ---help---
567 Enable to debug paravirt_ops internals. Specifically, BUG if
568 a paravirt_op is missing when it is called.
570 config NO_BOOTMEM
571 def_bool y
573 config MEMTEST
574 bool "Memtest"
575 ---help---
576 This option adds a kernel parameter 'memtest', which allows memtest
577 to be set.
578 memtest=0, mean disabled; -- default
579 memtest=1, mean do 1 test pattern;
580 ...
581 memtest=4, mean do 4 test patterns.
582 If you are unsure how to answer this question, answer N.
584 config X86_SUMMIT_NUMA
585 def_bool y
586 depends on X86_32 && NUMA && X86_32_NON_STANDARD
588 config X86_CYCLONE_TIMER
589 def_bool y
590 depends on X86_32_NON_STANDARD
592 source "arch/x86/Kconfig.cpu"
594 config HPET_TIMER
595 def_bool X86_64
596 prompt "HPET Timer Support" if X86_32
597 ---help---
598 Use the IA-PC HPET (High Precision Event Timer) to manage
599 time in preference to the PIT and RTC, if a HPET is
600 present.
601 HPET is the next generation timer replacing legacy 8254s.
602 The HPET provides a stable time base on SMP
603 systems, unlike the TSC, but it is more expensive to access,
604 as it is off-chip. You can find the HPET spec at
605 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
607 You can safely choose Y here. However, HPET will only be
608 activated if the platform and the BIOS support this feature.
609 Otherwise the 8254 will be used for timing services.
611 Choose N to continue using the legacy 8254 timer.
613 config HPET_EMULATE_RTC
614 def_bool y
615 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
617 config APB_TIMER
618 def_bool y if MRST
619 prompt "Langwell APB Timer Support" if X86_MRST
620 help
621 APB timer is the replacement for 8254, HPET on X86 MID platforms.
622 The APBT provides a stable time base on SMP
623 systems, unlike the TSC, but it is more expensive to access,
624 as it is off-chip. APB timers are always running regardless of CPU
625 C states, they are used as per CPU clockevent device when possible.
627 # Mark as expert because too many people got it wrong.
628 # The code disables itself when not needed.
629 config DMI
630 default y
631 bool "Enable DMI scanning" if EXPERT
632 ---help---
633 Enabled scanning of DMI to identify machine quirks. Say Y
634 here unless you have verified that your setup is not
635 affected by entries in the DMI blacklist. Required by PNP
636 BIOS code.
638 config GART_IOMMU
639 bool "GART IOMMU support" if EXPERT
640 default y
641 select SWIOTLB
642 depends on X86_64 && PCI && AMD_NB
643 ---help---
644 Support for full DMA access of devices with 32bit memory access only
645 on systems with more than 3GB. This is usually needed for USB,
646 sound, many IDE/SATA chipsets and some other devices.
647 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
648 based hardware IOMMU and a software bounce buffer based IOMMU used
649 on Intel systems and as fallback.
650 The code is only active when needed (enough memory and limited
651 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
652 too.
654 config CALGARY_IOMMU
655 bool "IBM Calgary IOMMU support"
656 select SWIOTLB
657 depends on X86_64 && PCI && EXPERIMENTAL
658 ---help---
659 Support for hardware IOMMUs in IBM's xSeries x366 and x460
660 systems. Needed to run systems with more than 3GB of memory
661 properly with 32-bit PCI devices that do not support DAC
662 (Double Address Cycle). Calgary also supports bus level
663 isolation, where all DMAs pass through the IOMMU. This
664 prevents them from going anywhere except their intended
665 destination. This catches hard-to-find kernel bugs and
666 mis-behaving drivers and devices that do not use the DMA-API
667 properly to set up their DMA buffers. The IOMMU can be
668 turned off at boot time with the iommu=off parameter.
669 Normally the kernel will make the right choice by itself.
670 If unsure, say Y.
672 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
673 def_bool y
674 prompt "Should Calgary be enabled by default?"
675 depends on CALGARY_IOMMU
676 ---help---
677 Should Calgary be enabled by default? if you choose 'y', Calgary
678 will be used (if it exists). If you choose 'n', Calgary will not be
679 used even if it exists. If you choose 'n' and would like to use
680 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
681 If unsure, say Y.
683 config AMD_IOMMU
684 bool "AMD IOMMU support"
685 select SWIOTLB
686 select PCI_MSI
687 select PCI_IOV
688 depends on X86_64 && PCI && ACPI
689 ---help---
690 With this option you can enable support for AMD IOMMU hardware in
691 your system. An IOMMU is a hardware component which provides
692 remapping of DMA memory accesses from devices. With an AMD IOMMU you
693 can isolate the the DMA memory of different devices and protect the
694 system from misbehaving device drivers or hardware.
696 You can find out if your system has an AMD IOMMU if you look into
697 your BIOS for an option to enable it or if you have an IVRS ACPI
698 table.
700 config AMD_IOMMU_STATS
701 bool "Export AMD IOMMU statistics to debugfs"
702 depends on AMD_IOMMU
703 select DEBUG_FS
704 ---help---
705 This option enables code in the AMD IOMMU driver to collect various
706 statistics about whats happening in the driver and exports that
707 information to userspace via debugfs.
708 If unsure, say N.
710 # need this always selected by IOMMU for the VIA workaround
711 config SWIOTLB
712 def_bool y if X86_64
713 ---help---
714 Support for software bounce buffers used on x86-64 systems
715 which don't have a hardware IOMMU (e.g. the current generation
716 of Intel's x86-64 CPUs). Using this PCI devices which can only
717 access 32-bits of memory can be used on systems with more than
718 3 GB of memory. If unsure, say Y.
720 config IOMMU_HELPER
721 def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
723 config IOMMU_API
724 def_bool (AMD_IOMMU || DMAR)
726 config MAXSMP
727 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
728 depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
729 select CPUMASK_OFFSTACK
730 ---help---
731 Enable maximum number of CPUS and NUMA Nodes for this architecture.
732 If unsure, say N.
734 config NR_CPUS
735 int "Maximum number of CPUs" if SMP && !MAXSMP
736 range 2 8 if SMP && X86_32 && !X86_BIGSMP
737 range 2 512 if SMP && !MAXSMP
738 default "1" if !SMP
739 default "4096" if MAXSMP
740 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
741 default "8" if SMP
742 ---help---
743 This allows you to specify the maximum number of CPUs which this
744 kernel will support. The maximum supported value is 512 and the
745 minimum value which makes sense is 2.
747 This is purely to save memory - each supported CPU adds
748 approximately eight kilobytes to the kernel image.
750 config SCHED_SMT
751 bool "SMT (Hyperthreading) scheduler support"
752 depends on X86_HT
753 ---help---
754 SMT scheduler support improves the CPU scheduler's decision making
755 when dealing with Intel Pentium 4 chips with HyperThreading at a
756 cost of slightly increased overhead in some places. If unsure say
757 N here.
759 config SCHED_MC
760 def_bool y
761 prompt "Multi-core scheduler support"
762 depends on X86_HT
763 ---help---
764 Multi-core scheduler support improves the CPU scheduler's decision
765 making when dealing with multi-core CPU chips at a cost of slightly
766 increased overhead in some places. If unsure say N here.
768 config IRQ_TIME_ACCOUNTING
769 bool "Fine granularity task level IRQ time accounting"
770 default n
771 ---help---
772 Select this option to enable fine granularity task irq time
773 accounting. This is done by reading a timestamp on each
774 transitions between softirq and hardirq state, so there can be a
775 small performance impact.
777 If in doubt, say N here.
779 source "kernel/Kconfig.preempt"
781 config X86_UP_APIC
782 bool "Local APIC support on uniprocessors"
783 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
784 ---help---
785 A local APIC (Advanced Programmable Interrupt Controller) is an
786 integrated interrupt controller in the CPU. If you have a single-CPU
787 system which has a processor with a local APIC, you can say Y here to
788 enable and use it. If you say Y here even though your machine doesn't
789 have a local APIC, then the kernel will still run with no slowdown at
790 all. The local APIC supports CPU-generated self-interrupts (timer,
791 performance counters), and the NMI watchdog which detects hard
792 lockups.
794 config X86_UP_IOAPIC
795 bool "IO-APIC support on uniprocessors"
796 depends on X86_UP_APIC
797 ---help---
798 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
799 SMP-capable replacement for PC-style interrupt controllers. Most
800 SMP systems and many recent uniprocessor systems have one.
802 If you have a single-CPU system with an IO-APIC, you can say Y here
803 to use it. If you say Y here even though your machine doesn't have
804 an IO-APIC, then the kernel will still run with no slowdown at all.
806 config X86_LOCAL_APIC
807 def_bool y
808 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
810 config X86_IO_APIC
811 def_bool y
812 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_IOAPIC
814 config X86_VISWS_APIC
815 def_bool y
816 depends on X86_32 && X86_VISWS
818 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
819 bool "Reroute for broken boot IRQs"
820 depends on X86_IO_APIC
821 ---help---
822 This option enables a workaround that fixes a source of
823 spurious interrupts. This is recommended when threaded
824 interrupt handling is used on systems where the generation of
825 superfluous "boot interrupts" cannot be disabled.
827 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
828 entry in the chipset's IO-APIC is masked (as, e.g. the RT
829 kernel does during interrupt handling). On chipsets where this
830 boot IRQ generation cannot be disabled, this workaround keeps
831 the original IRQ line masked so that only the equivalent "boot
832 IRQ" is delivered to the CPUs. The workaround also tells the
833 kernel to set up the IRQ handler on the boot IRQ line. In this
834 way only one interrupt is delivered to the kernel. Otherwise
835 the spurious second interrupt may cause the kernel to bring
836 down (vital) interrupt lines.
838 Only affects "broken" chipsets. Interrupt sharing may be
839 increased on these systems.
841 config X86_MCE
842 bool "Machine Check / overheating reporting"
843 ---help---
844 Machine Check support allows the processor to notify the
845 kernel if it detects a problem (e.g. overheating, data corruption).
846 The action the kernel takes depends on the severity of the problem,
847 ranging from warning messages to halting the machine.
849 config X86_MCE_INTEL
850 def_bool y
851 prompt "Intel MCE features"
852 depends on X86_MCE && X86_LOCAL_APIC
853 ---help---
854 Additional support for intel specific MCE features such as
855 the thermal monitor.
857 config X86_MCE_AMD
858 def_bool y
859 prompt "AMD MCE features"
860 depends on X86_MCE && X86_LOCAL_APIC
861 ---help---
862 Additional support for AMD specific MCE features such as
863 the DRAM Error Threshold.
865 config X86_ANCIENT_MCE
866 bool "Support for old Pentium 5 / WinChip machine checks"
867 depends on X86_32 && X86_MCE
868 ---help---
869 Include support for machine check handling on old Pentium 5 or WinChip
870 systems. These typically need to be enabled explicitely on the command
871 line.
873 config X86_MCE_THRESHOLD
874 depends on X86_MCE_AMD || X86_MCE_INTEL
875 def_bool y
877 config X86_MCE_INJECT
878 depends on X86_MCE
879 tristate "Machine check injector support"
880 ---help---
881 Provide support for injecting machine checks for testing purposes.
882 If you don't know what a machine check is and you don't do kernel
883 QA it is safe to say n.
885 config X86_THERMAL_VECTOR
886 def_bool y
887 depends on X86_MCE_INTEL
889 config VM86
890 bool "Enable VM86 support" if EXPERT
891 default y
892 depends on X86_32
893 ---help---
894 This option is required by programs like DOSEMU to run 16-bit legacy
895 code on X86 processors. It also may be needed by software like
896 XFree86 to initialize some video cards via BIOS. Disabling this
897 option saves about 6k.
899 config TOSHIBA
900 tristate "Toshiba Laptop support"
901 depends on X86_32
902 ---help---
903 This adds a driver to safely access the System Management Mode of
904 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
905 not work on models with a Phoenix BIOS. The System Management Mode
906 is used to set the BIOS and power saving options on Toshiba portables.
908 For information on utilities to make use of this driver see the
909 Toshiba Linux utilities web site at:
910 <http://www.buzzard.org.uk/toshiba/>.
912 Say Y if you intend to run this kernel on a Toshiba portable.
913 Say N otherwise.
915 config I8K
916 tristate "Dell laptop support"
917 select HWMON
918 ---help---
919 This adds a driver to safely access the System Management Mode
920 of the CPU on the Dell Inspiron 8000. The System Management Mode
921 is used to read cpu temperature and cooling fan status and to
922 control the fans on the I8K portables.
924 This driver has been tested only on the Inspiron 8000 but it may
925 also work with other Dell laptops. You can force loading on other
926 models by passing the parameter `force=1' to the module. Use at
927 your own risk.
929 For information on utilities to make use of this driver see the
930 I8K Linux utilities web site at:
931 <http://people.debian.org/~dz/i8k/>
933 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
934 Say N otherwise.
936 config X86_REBOOTFIXUPS
937 bool "Enable X86 board specific fixups for reboot"
938 depends on X86_32
939 ---help---
940 This enables chipset and/or board specific fixups to be done
941 in order to get reboot to work correctly. This is only needed on
942 some combinations of hardware and BIOS. The symptom, for which
943 this config is intended, is when reboot ends with a stalled/hung
944 system.
946 Currently, the only fixup is for the Geode machines using
947 CS5530A and CS5536 chipsets and the RDC R-321x SoC.
949 Say Y if you want to enable the fixup. Currently, it's safe to
950 enable this option even if you don't need it.
951 Say N otherwise.
953 config MICROCODE
954 tristate "/dev/cpu/microcode - microcode support"
955 select FW_LOADER
956 ---help---
957 If you say Y here, you will be able to update the microcode on
958 certain Intel and AMD processors. The Intel support is for the
959 IA32 family, e.g. Pentium Pro, Pentium II, Pentium III,
960 Pentium 4, Xeon etc. The AMD support is for family 0x10 and
961 0x11 processors, e.g. Opteron, Phenom and Turion 64 Ultra.
962 You will obviously need the actual microcode binary data itself
963 which is not shipped with the Linux kernel.
965 This option selects the general module only, you need to select
966 at least one vendor specific module as well.
968 To compile this driver as a module, choose M here: the
969 module will be called microcode.
971 config MICROCODE_INTEL
972 bool "Intel microcode patch loading support"
973 depends on MICROCODE
974 default MICROCODE
975 select FW_LOADER
976 ---help---
977 This options enables microcode patch loading support for Intel
978 processors.
980 For latest news and information on obtaining all the required
981 Intel ingredients for this driver, check:
982 <http://www.urbanmyth.org/microcode/>.
984 config MICROCODE_AMD
985 bool "AMD microcode patch loading support"
986 depends on MICROCODE
987 select FW_LOADER
988 ---help---
989 If you select this option, microcode patch loading support for AMD
990 processors will be enabled.
992 config MICROCODE_OLD_INTERFACE
993 def_bool y
994 depends on MICROCODE
996 config X86_MSR
997 tristate "/dev/cpu/*/msr - Model-specific register support"
998 ---help---
999 This device gives privileged processes access to the x86
1000 Model-Specific Registers (MSRs). It is a character device with
1001 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
1002 MSR accesses are directed to a specific CPU on multi-processor
1003 systems.
1005 config X86_CPUID
1006 tristate "/dev/cpu/*/cpuid - CPU information support"
1007 ---help---
1008 This device gives processes access to the x86 CPUID instruction to
1009 be executed on a specific processor. It is a character device
1010 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
1011 /dev/cpu/31/cpuid.
1013 choice
1014 prompt "High Memory Support"
1015 default HIGHMEM64G if X86_NUMAQ
1016 default HIGHMEM4G
1017 depends on X86_32
1019 config NOHIGHMEM
1020 bool "off"
1021 depends on !X86_NUMAQ
1022 ---help---
1023 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
1024 However, the address space of 32-bit x86 processors is only 4
1025 Gigabytes large. That means that, if you have a large amount of
1026 physical memory, not all of it can be "permanently mapped" by the
1027 kernel. The physical memory that's not permanently mapped is called
1028 "high memory".
1030 If you are compiling a kernel which will never run on a machine with
1031 more than 1 Gigabyte total physical RAM, answer "off" here (default
1032 choice and suitable for most users). This will result in a "3GB/1GB"
1033 split: 3GB are mapped so that each process sees a 3GB virtual memory
1034 space and the remaining part of the 4GB virtual memory space is used
1035 by the kernel to permanently map as much physical memory as
1036 possible.
1038 If the machine has between 1 and 4 Gigabytes physical RAM, then
1039 answer "4GB" here.
1041 If more than 4 Gigabytes is used then answer "64GB" here. This
1042 selection turns Intel PAE (Physical Address Extension) mode on.
1043 PAE implements 3-level paging on IA32 processors. PAE is fully
1044 supported by Linux, PAE mode is implemented on all recent Intel
1045 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
1046 then the kernel will not boot on CPUs that don't support PAE!
1048 The actual amount of total physical memory will either be
1049 auto detected or can be forced by using a kernel command line option
1050 such as "mem=256M". (Try "man bootparam" or see the documentation of
1051 your boot loader (lilo or loadlin) about how to pass options to the
1052 kernel at boot time.)
1054 If unsure, say "off".
1056 config HIGHMEM4G
1057 bool "4GB"
1058 depends on !X86_NUMAQ
1059 ---help---
1060 Select this if you have a 32-bit processor and between 1 and 4
1061 gigabytes of physical RAM.
1063 config HIGHMEM64G
1064 bool "64GB"
1065 depends on !M386 && !M486
1066 select X86_PAE
1067 ---help---
1068 Select this if you have a 32-bit processor and more than 4
1069 gigabytes of physical RAM.
1071 endchoice
1073 choice
1074 depends on EXPERIMENTAL
1075 prompt "Memory split" if EXPERT
1076 default VMSPLIT_3G
1077 depends on X86_32
1078 ---help---
1079 Select the desired split between kernel and user memory.
1081 If the address range available to the kernel is less than the
1082 physical memory installed, the remaining memory will be available
1083 as "high memory". Accessing high memory is a little more costly
1084 than low memory, as it needs to be mapped into the kernel first.
1085 Note that increasing the kernel address space limits the range
1086 available to user programs, making the address space there
1087 tighter. Selecting anything other than the default 3G/1G split
1088 will also likely make your kernel incompatible with binary-only
1089 kernel modules.
1091 If you are not absolutely sure what you are doing, leave this
1092 option alone!
1094 config VMSPLIT_3G
1095 bool "3G/1G user/kernel split"
1096 config VMSPLIT_3G_OPT
1097 depends on !X86_PAE
1098 bool "3G/1G user/kernel split (for full 1G low memory)"
1099 config VMSPLIT_2G
1100 bool "2G/2G user/kernel split"
1101 config VMSPLIT_2G_OPT
1102 depends on !X86_PAE
1103 bool "2G/2G user/kernel split (for full 2G low memory)"
1104 config VMSPLIT_1G
1105 bool "1G/3G user/kernel split"
1106 endchoice
1108 config PAGE_OFFSET
1109 hex
1110 default 0xB0000000 if VMSPLIT_3G_OPT
1111 default 0x80000000 if VMSPLIT_2G
1112 default 0x78000000 if VMSPLIT_2G_OPT
1113 default 0x40000000 if VMSPLIT_1G
1114 default 0xC0000000
1115 depends on X86_32
1117 config HIGHMEM
1118 def_bool y
1119 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1121 config X86_PAE
1122 bool "PAE (Physical Address Extension) Support"
1123 depends on X86_32 && !HIGHMEM4G
1124 ---help---
1125 PAE is required for NX support, and furthermore enables
1126 larger swapspace support for non-overcommit purposes. It
1127 has the cost of more pagetable lookup overhead, and also
1128 consumes more pagetable space per process.
1130 config ARCH_PHYS_ADDR_T_64BIT
1131 def_bool X86_64 || X86_PAE
1133 config ARCH_DMA_ADDR_T_64BIT
1134 def_bool X86_64 || HIGHMEM64G
1136 config DIRECT_GBPAGES
1137 bool "Enable 1GB pages for kernel pagetables" if EXPERT
1138 default y
1139 depends on X86_64
1140 ---help---
1141 Allow the kernel linear mapping to use 1GB pages on CPUs that
1142 support it. This can improve the kernel's performance a tiny bit by
1143 reducing TLB pressure. If in doubt, say "Y".
1145 # Common NUMA Features
1146 config NUMA
1147 bool "Numa Memory Allocation and Scheduler Support"
1148 depends on SMP
1149 depends on X86_64 || (X86_32 && HIGHMEM64G && (X86_NUMAQ || X86_BIGSMP || X86_SUMMIT && ACPI) && EXPERIMENTAL)
1150 default y if (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP)
1151 ---help---
1152 Enable NUMA (Non Uniform Memory Access) support.
1154 The kernel will try to allocate memory used by a CPU on the
1155 local memory controller of the CPU and add some more
1156 NUMA awareness to the kernel.
1158 For 64-bit this is recommended if the system is Intel Core i7
1159 (or later), AMD Opteron, or EM64T NUMA.
1161 For 32-bit this is only needed on (rare) 32-bit-only platforms
1162 that support NUMA topologies, such as NUMAQ / Summit, or if you
1163 boot a 32-bit kernel on a 64-bit NUMA platform.
1165 Otherwise, you should say N.
1167 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
1168 depends on X86_32 && X86_SUMMIT && (!HIGHMEM64G || !ACPI)
1170 config AMD_NUMA
1171 def_bool y
1172 prompt "Old style AMD Opteron NUMA detection"
1173 depends on NUMA && PCI
1174 ---help---
1175 Enable AMD NUMA node topology detection. You should say Y here if
1176 you have a multi processor AMD system. This uses an old method to
1177 read the NUMA configuration directly from the builtin Northbridge
1178 of Opteron. It is recommended to use X86_64_ACPI_NUMA instead,
1179 which also takes priority if both are compiled in.
1181 config X86_64_ACPI_NUMA
1182 def_bool y
1183 prompt "ACPI NUMA detection"
1184 depends on X86_64 && NUMA && ACPI && PCI
1185 select ACPI_NUMA
1186 ---help---
1187 Enable ACPI SRAT based node topology detection.
1189 # Some NUMA nodes have memory ranges that span
1190 # other nodes. Even though a pfn is valid and
1191 # between a node's start and end pfns, it may not
1192 # reside on that node. See memmap_init_zone()
1193 # for details.
1194 config NODES_SPAN_OTHER_NODES
1195 def_bool y
1196 depends on X86_64_ACPI_NUMA
1198 config NUMA_EMU
1199 bool "NUMA emulation"
1200 depends on NUMA
1201 ---help---
1202 Enable NUMA emulation. A flat machine will be split
1203 into virtual nodes when booted with "numa=fake=N", where N is the
1204 number of nodes. This is only useful for debugging.
1206 config NODES_SHIFT
1207 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1208 range 1 10
1209 default "10" if MAXSMP
1210 default "6" if X86_64
1211 default "4" if X86_NUMAQ
1212 default "3"
1213 depends on NEED_MULTIPLE_NODES
1214 ---help---
1215 Specify the maximum number of NUMA Nodes available on the target
1216 system. Increases memory reserved to accommodate various tables.
1218 config HAVE_ARCH_BOOTMEM
1219 def_bool y
1220 depends on X86_32 && NUMA
1222 config HAVE_ARCH_ALLOC_REMAP
1223 def_bool y
1224 depends on X86_32 && NUMA
1226 config ARCH_HAVE_MEMORY_PRESENT
1227 def_bool y
1228 depends on X86_32 && DISCONTIGMEM
1230 config NEED_NODE_MEMMAP_SIZE
1231 def_bool y
1232 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1234 config ARCH_FLATMEM_ENABLE
1235 def_bool y
1236 depends on X86_32 && !NUMA
1238 config ARCH_DISCONTIGMEM_ENABLE
1239 def_bool y
1240 depends on NUMA && X86_32
1242 config ARCH_DISCONTIGMEM_DEFAULT
1243 def_bool y
1244 depends on NUMA && X86_32
1246 config ARCH_SPARSEMEM_ENABLE
1247 def_bool y
1248 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
1249 select SPARSEMEM_STATIC if X86_32
1250 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1252 config ARCH_SPARSEMEM_DEFAULT
1253 def_bool y
1254 depends on X86_64
1256 config ARCH_SELECT_MEMORY_MODEL
1257 def_bool y
1258 depends on ARCH_SPARSEMEM_ENABLE
1260 config ARCH_MEMORY_PROBE
1261 def_bool X86_64
1262 depends on MEMORY_HOTPLUG
1264 config ARCH_PROC_KCORE_TEXT
1265 def_bool y
1266 depends on X86_64 && PROC_KCORE
1268 config ILLEGAL_POINTER_VALUE
1269 hex
1270 default 0 if X86_32
1271 default 0xdead000000000000 if X86_64
1273 source "mm/Kconfig"
1275 config HIGHPTE
1276 bool "Allocate 3rd-level pagetables from highmem"
1277 depends on HIGHMEM
1278 ---help---
1279 The VM uses one page table entry for each page of physical memory.
1280 For systems with a lot of RAM, this can be wasteful of precious
1281 low memory. Setting this option will put user-space page table
1282 entries in high memory.
1284 config X86_CHECK_BIOS_CORRUPTION
1285 bool "Check for low memory corruption"
1286 ---help---
1287 Periodically check for memory corruption in low memory, which
1288 is suspected to be caused by BIOS. Even when enabled in the
1289 configuration, it is disabled at runtime. Enable it by
1290 setting "memory_corruption_check=1" on the kernel command
1291 line. By default it scans the low 64k of memory every 60
1292 seconds; see the memory_corruption_check_size and
1293 memory_corruption_check_period parameters in
1294 Documentation/kernel-parameters.txt to adjust this.
1296 When enabled with the default parameters, this option has
1297 almost no overhead, as it reserves a relatively small amount
1298 of memory and scans it infrequently. It both detects corruption
1299 and prevents it from affecting the running system.
1301 It is, however, intended as a diagnostic tool; if repeatable
1302 BIOS-originated corruption always affects the same memory,
1303 you can use memmap= to prevent the kernel from using that
1304 memory.
1306 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1307 bool "Set the default setting of memory_corruption_check"
1308 depends on X86_CHECK_BIOS_CORRUPTION
1309 default y
1310 ---help---
1311 Set whether the default state of memory_corruption_check is
1312 on or off.
1314 config X86_RESERVE_LOW
1315 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
1316 default 64
1317 range 4 640
1318 ---help---
1319 Specify the amount of low memory to reserve for the BIOS.
1321 The first page contains BIOS data structures that the kernel
1322 must not use, so that page must always be reserved.
1324 By default we reserve the first 64K of physical RAM, as a
1325 number of BIOSes are known to corrupt that memory range
1326 during events such as suspend/resume or monitor cable
1327 insertion, so it must not be used by the kernel.
1329 You can set this to 4 if you are absolutely sure that you
1330 trust the BIOS to get all its memory reservations and usages
1331 right. If you know your BIOS have problems beyond the
1332 default 64K area, you can set this to 640 to avoid using the
1333 entire low memory range.
1335 If you have doubts about the BIOS (e.g. suspend/resume does
1336 not work or there's kernel crashes after certain hardware
1337 hotplug events) then you might want to enable
1338 X86_CHECK_BIOS_CORRUPTION=y to allow the kernel to check
1339 typical corruption patterns.
1341 Leave this to the default value of 64 if you are unsure.
1343 config MATH_EMULATION
1344 bool
1345 prompt "Math emulation" if X86_32
1346 ---help---
1347 Linux can emulate a math coprocessor (used for floating point
1348 operations) if you don't have one. 486DX and Pentium processors have
1349 a math coprocessor built in, 486SX and 386 do not, unless you added
1350 a 487DX or 387, respectively. (The messages during boot time can
1351 give you some hints here ["man dmesg"].) Everyone needs either a
1352 coprocessor or this emulation.
1354 If you don't have a math coprocessor, you need to say Y here; if you
1355 say Y here even though you have a coprocessor, the coprocessor will
1356 be used nevertheless. (This behavior can be changed with the kernel
1357 command line option "no387", which comes handy if your coprocessor
1358 is broken. Try "man bootparam" or see the documentation of your boot
1359 loader (lilo or loadlin) about how to pass options to the kernel at
1360 boot time.) This means that it is a good idea to say Y here if you
1361 intend to use this kernel on different machines.
1363 More information about the internals of the Linux math coprocessor
1364 emulation can be found in <file:arch/x86/math-emu/README>.
1366 If you are not sure, say Y; apart from resulting in a 66 KB bigger
1367 kernel, it won't hurt.
1369 config MTRR
1370 def_bool y
1371 prompt "MTRR (Memory Type Range Register) support" if EXPERT
1372 ---help---
1373 On Intel P6 family processors (Pentium Pro, Pentium II and later)
1374 the Memory Type Range Registers (MTRRs) may be used to control
1375 processor access to memory ranges. This is most useful if you have
1376 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
1377 allows bus write transfers to be combined into a larger transfer
1378 before bursting over the PCI/AGP bus. This can increase performance
1379 of image write operations 2.5 times or more. Saying Y here creates a
1380 /proc/mtrr file which may be used to manipulate your processor's
1381 MTRRs. Typically the X server should use this.
1383 This code has a reasonably generic interface so that similar
1384 control registers on other processors can be easily supported
1385 as well:
1387 The Cyrix 6x86, 6x86MX and M II processors have Address Range
1388 Registers (ARRs) which provide a similar functionality to MTRRs. For
1389 these, the ARRs are used to emulate the MTRRs.
1390 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
1391 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
1392 write-combining. All of these processors are supported by this code
1393 and it makes sense to say Y here if you have one of them.
1395 Saying Y here also fixes a problem with buggy SMP BIOSes which only
1396 set the MTRRs for the boot CPU and not for the secondary CPUs. This
1397 can lead to all sorts of problems, so it's good to say Y here.
1399 You can safely say Y even if your machine doesn't have MTRRs, you'll
1400 just add about 9 KB to your kernel.
1402 See <file:Documentation/x86/mtrr.txt> for more information.
1404 config MTRR_SANITIZER
1405 def_bool y
1406 prompt "MTRR cleanup support"
1407 depends on MTRR
1408 ---help---
1409 Convert MTRR layout from continuous to discrete, so X drivers can
1410 add writeback entries.
1412 Can be disabled with disable_mtrr_cleanup on the kernel command line.
1413 The largest mtrr entry size for a continuous block can be set with
1414 mtrr_chunk_size.
1416 If unsure, say Y.
1418 config MTRR_SANITIZER_ENABLE_DEFAULT
1419 int "MTRR cleanup enable value (0-1)"
1420 range 0 1
1421 default "0"
1422 depends on MTRR_SANITIZER
1423 ---help---
1424 Enable mtrr cleanup default value
1426 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1427 int "MTRR cleanup spare reg num (0-7)"
1428 range 0 7
1429 default "1"
1430 depends on MTRR_SANITIZER
1431 ---help---
1432 mtrr cleanup spare entries default, it can be changed via
1433 mtrr_spare_reg_nr=N on the kernel command line.
1435 config X86_PAT
1436 def_bool y
1437 prompt "x86 PAT support" if EXPERT
1438 depends on MTRR
1439 ---help---
1440 Use PAT attributes to setup page level cache control.
1442 PATs are the modern equivalents of MTRRs and are much more
1443 flexible than MTRRs.
1445 Say N here if you see bootup problems (boot crash, boot hang,
1446 spontaneous reboots) or a non-working video driver.
1448 If unsure, say Y.
1450 config ARCH_USES_PG_UNCACHED
1451 def_bool y
1452 depends on X86_PAT
1454 config EFI
1455 bool "EFI runtime service support"
1456 depends on ACPI
1457 ---help---
1458 This enables the kernel to use EFI runtime services that are
1459 available (such as the EFI variable services).
1461 This option is only useful on systems that have EFI firmware.
1462 In addition, you should use the latest ELILO loader available
1463 at <http://elilo.sourceforge.net> in order to take advantage
1464 of EFI runtime services. However, even with this option, the
1465 resultant kernel should continue to boot on existing non-EFI
1466 platforms.
1468 config SECCOMP
1469 def_bool y
1470 prompt "Enable seccomp to safely compute untrusted bytecode"
1471 ---help---
1472 This kernel feature is useful for number crunching applications
1473 that may need to compute untrusted bytecode during their
1474 execution. By using pipes or other transports made available to
1475 the process as file descriptors supporting the read/write
1476 syscalls, it's possible to isolate those applications in
1477 their own address space using seccomp. Once seccomp is
1478 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1479 and the task is only allowed to execute a few safe syscalls
1480 defined by each seccomp mode.
1482 If unsure, say Y. Only embedded should say N here.
1484 config CC_STACKPROTECTOR
1485 bool "Enable -fstack-protector buffer overflow detection (EXPERIMENTAL)"
1486 ---help---
1487 This option turns on the -fstack-protector GCC feature. This
1488 feature puts, at the beginning of functions, a canary value on
1489 the stack just before the return address, and validates
1490 the value just before actually returning. Stack based buffer
1491 overflows (that need to overwrite this return address) now also
1492 overwrite the canary, which gets detected and the attack is then
1493 neutralized via a kernel panic.
1495 This feature requires gcc version 4.2 or above, or a distribution
1496 gcc with the feature backported. Older versions are automatically
1497 detected and for those versions, this configuration option is
1498 ignored. (and a warning is printed during bootup)
1500 source kernel/Kconfig.hz
1502 config KEXEC
1503 bool "kexec system call"
1504 ---help---
1505 kexec is a system call that implements the ability to shutdown your
1506 current kernel, and to start another kernel. It is like a reboot
1507 but it is independent of the system firmware. And like a reboot
1508 you can start any kernel with it, not just Linux.
1510 The name comes from the similarity to the exec system call.
1512 It is an ongoing process to be certain the hardware in a machine
1513 is properly shutdown, so do not be surprised if this code does not
1514 initially work for you. It may help to enable device hotplugging
1515 support. As of this writing the exact hardware interface is
1516 strongly in flux, so no good recommendation can be made.
1518 config CRASH_DUMP
1519 bool "kernel crash dumps"
1520 depends on X86_64 || (X86_32 && HIGHMEM)
1521 ---help---
1522 Generate crash dump after being started by kexec.
1523 This should be normally only set in special crash dump kernels
1524 which are loaded in the main kernel with kexec-tools into
1525 a specially reserved region and then later executed after
1526 a crash by kdump/kexec. The crash dump kernel must be compiled
1527 to a memory address not used by the main kernel or BIOS using
1528 PHYSICAL_START, or it must be built as a relocatable image
1529 (CONFIG_RELOCATABLE=y).
1530 For more details see Documentation/kdump/kdump.txt
1532 config KEXEC_JUMP
1533 bool "kexec jump (EXPERIMENTAL)"
1534 depends on EXPERIMENTAL
1535 depends on KEXEC && HIBERNATION
1536 ---help---
1537 Jump between original kernel and kexeced kernel and invoke
1538 code in physical address mode via KEXEC
1540 config PHYSICAL_START
1541 hex "Physical address where the kernel is loaded" if (EXPERT || CRASH_DUMP)
1542 default "0x1000000"
1543 ---help---
1544 This gives the physical address where the kernel is loaded.
1546 If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then
1547 bzImage will decompress itself to above physical address and
1548 run from there. Otherwise, bzImage will run from the address where
1549 it has been loaded by the boot loader and will ignore above physical
1550 address.
1552 In normal kdump cases one does not have to set/change this option
1553 as now bzImage can be compiled as a completely relocatable image
1554 (CONFIG_RELOCATABLE=y) and be used to load and run from a different
1555 address. This option is mainly useful for the folks who don't want
1556 to use a bzImage for capturing the crash dump and want to use a
1557 vmlinux instead. vmlinux is not relocatable hence a kernel needs
1558 to be specifically compiled to run from a specific memory area
1559 (normally a reserved region) and this option comes handy.
1561 So if you are using bzImage for capturing the crash dump,
1562 leave the value here unchanged to 0x1000000 and set
1563 CONFIG_RELOCATABLE=y. Otherwise if you plan to use vmlinux
1564 for capturing the crash dump change this value to start of
1565 the reserved region. In other words, it can be set based on
1566 the "X" value as specified in the "crashkernel=YM@XM"
1567 command line boot parameter passed to the panic-ed
1568 kernel. Please take a look at Documentation/kdump/kdump.txt
1569 for more details about crash dumps.
1571 Usage of bzImage for capturing the crash dump is recommended as
1572 one does not have to build two kernels. Same kernel can be used
1573 as production kernel and capture kernel. Above option should have
1574 gone away after relocatable bzImage support is introduced. But it
1575 is present because there are users out there who continue to use
1576 vmlinux for dump capture. This option should go away down the
1577 line.
1579 Don't change this unless you know what you are doing.
1581 config RELOCATABLE
1582 bool "Build a relocatable kernel"
1583 default y
1584 ---help---
1585 This builds a kernel image that retains relocation information
1586 so it can be loaded someplace besides the default 1MB.
1587 The relocations tend to make the kernel binary about 10% larger,
1588 but are discarded at runtime.
1590 One use is for the kexec on panic case where the recovery kernel
1591 must live at a different physical address than the primary
1592 kernel.
1594 Note: If CONFIG_RELOCATABLE=y, then the kernel runs from the address
1595 it has been loaded at and the compile time physical address
1596 (CONFIG_PHYSICAL_START) is ignored.
1598 # Relocation on x86-32 needs some additional build support
1599 config X86_NEED_RELOCS
1600 def_bool y
1601 depends on X86_32 && RELOCATABLE
1603 config PHYSICAL_ALIGN
1604 hex "Alignment value to which kernel should be aligned" if X86_32
1605 default "0x1000000"
1606 range 0x2000 0x1000000
1607 ---help---
1608 This value puts the alignment restrictions on physical address
1609 where kernel is loaded and run from. Kernel is compiled for an
1610 address which meets above alignment restriction.
1612 If bootloader loads the kernel at a non-aligned address and
1613 CONFIG_RELOCATABLE is set, kernel will move itself to nearest
1614 address aligned to above value and run from there.
1616 If bootloader loads the kernel at a non-aligned address and
1617 CONFIG_RELOCATABLE is not set, kernel will ignore the run time
1618 load address and decompress itself to the address it has been
1619 compiled for and run from there. The address for which kernel is
1620 compiled already meets above alignment restrictions. Hence the
1621 end result is that kernel runs from a physical address meeting
1622 above alignment restrictions.
1624 Don't change this unless you know what you are doing.
1626 config HOTPLUG_CPU
1627 bool "Support for hot-pluggable CPUs"
1628 depends on SMP && HOTPLUG
1629 ---help---
1630 Say Y here to allow turning CPUs off and on. CPUs can be
1631 controlled through /sys/devices/system/cpu.
1632 ( Note: power management support will enable this option
1633 automatically on SMP systems. )
1634 Say N if you want to disable CPU hotplug.
1636 config COMPAT_VDSO
1637 def_bool y
1638 prompt "Compat VDSO support"
1639 depends on X86_32 || IA32_EMULATION
1640 ---help---
1641 Map the 32-bit VDSO to the predictable old-style address too.
1643 Say N here if you are running a sufficiently recent glibc
1644 version (2.3.3 or later), to remove the high-mapped
1645 VDSO mapping and to exclusively use the randomized VDSO.
1647 If unsure, say Y.
1649 config CMDLINE_BOOL
1650 bool "Built-in kernel command line"
1651 ---help---
1652 Allow for specifying boot arguments to the kernel at
1653 build time. On some systems (e.g. embedded ones), it is
1654 necessary or convenient to provide some or all of the
1655 kernel boot arguments with the kernel itself (that is,
1656 to not rely on the boot loader to provide them.)
1658 To compile command line arguments into the kernel,
1659 set this option to 'Y', then fill in the
1660 the boot arguments in CONFIG_CMDLINE.
1662 Systems with fully functional boot loaders (i.e. non-embedded)
1663 should leave this option set to 'N'.
1665 config CMDLINE
1666 string "Built-in kernel command string"
1667 depends on CMDLINE_BOOL
1668 default ""
1669 ---help---
1670 Enter arguments here that should be compiled into the kernel
1671 image and used at boot time. If the boot loader provides a
1672 command line at boot time, it is appended to this string to
1673 form the full kernel command line, when the system boots.
1675 However, you can use the CONFIG_CMDLINE_OVERRIDE option to
1676 change this behavior.
1678 In most cases, the command line (whether built-in or provided
1679 by the boot loader) should specify the device for the root
1680 file system.
1682 config CMDLINE_OVERRIDE
1683 bool "Built-in command line overrides boot loader arguments"
1684 depends on CMDLINE_BOOL
1685 ---help---
1686 Set this option to 'Y' to have the kernel ignore the boot loader
1687 command line, and use ONLY the built-in command line.
1689 This is used to work around broken boot loaders. This should
1690 be set to 'N' under normal conditions.
1692 endmenu
1694 config ARCH_ENABLE_MEMORY_HOTPLUG
1695 def_bool y
1696 depends on X86_64 || (X86_32 && HIGHMEM)
1698 config ARCH_ENABLE_MEMORY_HOTREMOVE
1699 def_bool y
1700 depends on MEMORY_HOTPLUG
1702 config USE_PERCPU_NUMA_NODE_ID
1703 def_bool y
1704 depends on NUMA
1706 menu "Power management and ACPI options"
1708 config ARCH_HIBERNATION_HEADER
1709 def_bool y
1710 depends on X86_64 && HIBERNATION
1712 source "kernel/power/Kconfig"
1714 source "drivers/acpi/Kconfig"
1716 source "drivers/sfi/Kconfig"
1718 config X86_APM_BOOT
1719 def_bool y
1720 depends on APM || APM_MODULE
1722 menuconfig APM
1723 tristate "APM (Advanced Power Management) BIOS support"
1724 depends on X86_32 && PM_SLEEP
1725 ---help---
1726 APM is a BIOS specification for saving power using several different
1727 techniques. This is mostly useful for battery powered laptops with
1728 APM compliant BIOSes. If you say Y here, the system time will be
1729 reset after a RESUME operation, the /proc/apm device will provide
1730 battery status information, and user-space programs will receive
1731 notification of APM "events" (e.g. battery status change).
1733 If you select "Y" here, you can disable actual use of the APM
1734 BIOS by passing the "apm=off" option to the kernel at boot time.
1736 Note that the APM support is almost completely disabled for
1737 machines with more than one CPU.
1739 In order to use APM, you will need supporting software. For location
1740 and more information, read <file:Documentation/power/pm.txt> and the
1741 Battery Powered Linux mini-HOWTO, available from
1742 <http://www.tldp.org/docs.html#howto>.
1744 This driver does not spin down disk drives (see the hdparm(8)
1745 manpage ("man 8 hdparm") for that), and it doesn't turn off
1746 VESA-compliant "green" monitors.
1748 This driver does not support the TI 4000M TravelMate and the ACER
1749 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1750 desktop machines also don't have compliant BIOSes, and this driver
1751 may cause those machines to panic during the boot phase.
1753 Generally, if you don't have a battery in your machine, there isn't
1754 much point in using this driver and you should say N. If you get
1755 random kernel OOPSes or reboots that don't seem to be related to
1756 anything, try disabling/enabling this option (or disabling/enabling
1757 APM in your BIOS).
1759 Some other things you should try when experiencing seemingly random,
1760 "weird" problems:
1762 1) make sure that you have enough swap space and that it is
1763 enabled.
1764 2) pass the "no-hlt" option to the kernel
1765 3) switch on floating point emulation in the kernel and pass
1766 the "no387" option to the kernel
1767 4) pass the "floppy=nodma" option to the kernel
1768 5) pass the "mem=4M" option to the kernel (thereby disabling
1769 all but the first 4 MB of RAM)
1770 6) make sure that the CPU is not over clocked.
1771 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1772 8) disable the cache from your BIOS settings
1773 9) install a fan for the video card or exchange video RAM
1774 10) install a better fan for the CPU
1775 11) exchange RAM chips
1776 12) exchange the motherboard.
1778 To compile this driver as a module, choose M here: the
1779 module will be called apm.
1781 if APM
1783 config APM_IGNORE_USER_SUSPEND
1784 bool "Ignore USER SUSPEND"
1785 ---help---
1786 This option will ignore USER SUSPEND requests. On machines with a
1787 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1788 series notebooks, it is necessary to say Y because of a BIOS bug.
1790 config APM_DO_ENABLE
1791 bool "Enable PM at boot time"
1792 ---help---
1793 Enable APM features at boot time. From page 36 of the APM BIOS
1794 specification: "When disabled, the APM BIOS does not automatically
1795 power manage devices, enter the Standby State, enter the Suspend
1796 State, or take power saving steps in response to CPU Idle calls."
1797 This driver will make CPU Idle calls when Linux is idle (unless this
1798 feature is turned off -- see "Do CPU IDLE calls", below). This
1799 should always save battery power, but more complicated APM features
1800 will be dependent on your BIOS implementation. You may need to turn
1801 this option off if your computer hangs at boot time when using APM
1802 support, or if it beeps continuously instead of suspending. Turn
1803 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1804 T400CDT. This is off by default since most machines do fine without
1805 this feature.
1807 config APM_CPU_IDLE
1808 bool "Make CPU Idle calls when idle"
1809 ---help---
1810 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1811 On some machines, this can activate improved power savings, such as
1812 a slowed CPU clock rate, when the machine is idle. These idle calls
1813 are made after the idle loop has run for some length of time (e.g.,
1814 333 mS). On some machines, this will cause a hang at boot time or
1815 whenever the CPU becomes idle. (On machines with more than one CPU,
1816 this option does nothing.)
1818 config APM_DISPLAY_BLANK
1819 bool "Enable console blanking using APM"
1820 ---help---
1821 Enable console blanking using the APM. Some laptops can use this to
1822 turn off the LCD backlight when the screen blanker of the Linux
1823 virtual console blanks the screen. Note that this is only used by
1824 the virtual console screen blanker, and won't turn off the backlight
1825 when using the X Window system. This also doesn't have anything to
1826 do with your VESA-compliant power-saving monitor. Further, this
1827 option doesn't work for all laptops -- it might not turn off your
1828 backlight at all, or it might print a lot of errors to the console,
1829 especially if you are using gpm.
1831 config APM_ALLOW_INTS
1832 bool "Allow interrupts during APM BIOS calls"
1833 ---help---
1834 Normally we disable external interrupts while we are making calls to
1835 the APM BIOS as a measure to lessen the effects of a badly behaving
1836 BIOS implementation. The BIOS should reenable interrupts if it
1837 needs to. Unfortunately, some BIOSes do not -- especially those in
1838 many of the newer IBM Thinkpads. If you experience hangs when you
1839 suspend, try setting this to Y. Otherwise, say N.
1841 endif # APM
1843 source "drivers/cpufreq/Kconfig"
1845 source "drivers/cpuidle/Kconfig"
1847 source "drivers/idle/Kconfig"
1849 endmenu
1852 menu "Bus options (PCI etc.)"
1854 config PCI
1855 bool "PCI support"
1856 default y
1857 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1858 ---help---
1859 Find out whether you have a PCI motherboard. PCI is the name of a
1860 bus system, i.e. the way the CPU talks to the other stuff inside
1861 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1862 VESA. If you have PCI, say Y, otherwise N.
1864 choice
1865 prompt "PCI access mode"
1866 depends on X86_32 && PCI
1867 default PCI_GOANY
1868 ---help---
1869 On PCI systems, the BIOS can be used to detect the PCI devices and
1870 determine their configuration. However, some old PCI motherboards
1871 have BIOS bugs and may crash if this is done. Also, some embedded
1872 PCI-based systems don't have any BIOS at all. Linux can also try to
1873 detect the PCI hardware directly without using the BIOS.
1875 With this option, you can specify how Linux should detect the
1876 PCI devices. If you choose "BIOS", the BIOS will be used,
1877 if you choose "Direct", the BIOS won't be used, and if you
1878 choose "MMConfig", then PCI Express MMCONFIG will be used.
1879 If you choose "Any", the kernel will try MMCONFIG, then the
1880 direct access method and falls back to the BIOS if that doesn't
1881 work. If unsure, go with the default, which is "Any".
1883 config PCI_GOBIOS
1884 bool "BIOS"
1886 config PCI_GOMMCONFIG
1887 bool "MMConfig"
1889 config PCI_GODIRECT
1890 bool "Direct"
1892 config PCI_GOOLPC
1893 bool "OLPC XO-1"
1894 depends on OLPC
1896 config PCI_GOANY
1897 bool "Any"
1899 endchoice
1901 config PCI_BIOS
1902 def_bool y
1903 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1905 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1906 config PCI_DIRECT
1907 def_bool y
1908 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC))
1910 config PCI_MMCONFIG
1911 def_bool y
1912 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
1914 config PCI_OLPC
1915 def_bool y
1916 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1918 config PCI_XEN
1919 def_bool y
1920 depends on PCI && XEN
1921 select SWIOTLB_XEN
1923 config PCI_DOMAINS
1924 def_bool y
1925 depends on PCI
1927 config PCI_MMCONFIG
1928 bool "Support mmconfig PCI config space access"
1929 depends on X86_64 && PCI && ACPI
1931 config PCI_CNB20LE_QUIRK
1932 bool "Read CNB20LE Host Bridge Windows" if EXPERT
1933 default n
1934 depends on PCI && EXPERIMENTAL
1935 help
1936 Read the PCI windows out of the CNB20LE host bridge. This allows
1937 PCI hotplug to work on systems with the CNB20LE chipset which do
1938 not have ACPI.
1940 There's no public spec for this chipset, and this functionality
1941 is known to be incomplete.
1943 You should say N unless you know you need this.
1945 config DMAR
1946 bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
1947 depends on PCI_MSI && ACPI && EXPERIMENTAL
1948 help
1949 DMA remapping (DMAR) devices support enables independent address
1950 translations for Direct Memory Access (DMA) from devices.
1951 These DMA remapping devices are reported via ACPI tables
1952 and include PCI device scope covered by these DMA
1953 remapping devices.
1955 config DMAR_DEFAULT_ON
1956 def_bool y
1957 prompt "Enable DMA Remapping Devices by default"
1958 depends on DMAR
1959 help
1960 Selecting this option will enable a DMAR device at boot time if
1961 one is found. If this option is not selected, DMAR support can
1962 be enabled by passing intel_iommu=on to the kernel. It is
1963 recommended you say N here while the DMAR code remains
1964 experimental.
1966 config DMAR_BROKEN_GFX_WA
1967 bool "Workaround broken graphics drivers (going away soon)"
1968 depends on DMAR && BROKEN
1969 ---help---
1970 Current Graphics drivers tend to use physical address
1971 for DMA and avoid using DMA APIs. Setting this config
1972 option permits the IOMMU driver to set a unity map for
1973 all the OS-visible memory. Hence the driver can continue
1974 to use physical addresses for DMA, at least until this
1975 option is removed in the 2.6.32 kernel.
1977 config DMAR_FLOPPY_WA
1978 def_bool y
1979 depends on DMAR
1980 ---help---
1981 Floppy disk drivers are known to bypass DMA API calls
1982 thereby failing to work when IOMMU is enabled. This
1983 workaround will setup a 1:1 mapping for the first
1984 16MiB to make floppy (an ISA device) work.
1986 config INTR_REMAP
1987 bool "Support for Interrupt Remapping (EXPERIMENTAL)"
1988 depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL
1989 ---help---
1990 Supports Interrupt remapping for IO-APIC and MSI devices.
1991 To use x2apic mode in the CPU's which support x2APIC enhancements or
1992 to support platforms with CPU's having > 8 bit APIC ID, say Y.
1994 source "drivers/pci/pcie/Kconfig"
1996 source "drivers/pci/Kconfig"
1998 # x86_64 have no ISA slots, but can have ISA-style DMA.
1999 config ISA_DMA_API
2000 bool "ISA-style DMA support" if (X86_64 && EXPERT)
2001 default y
2002 help
2003 Enables ISA-style DMA support for devices requiring such controllers.
2004 If unsure, say Y.
2006 if X86_32
2008 config ISA
2009 bool "ISA support"
2010 ---help---
2011 Find out whether you have ISA slots on your motherboard. ISA is the
2012 name of a bus system, i.e. the way the CPU talks to the other stuff
2013 inside your box. Other bus systems are PCI, EISA, MicroChannel
2014 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2015 newer boards don't support it. If you have ISA, say Y, otherwise N.
2017 config EISA
2018 bool "EISA support"
2019 depends on ISA
2020 ---help---
2021 The Extended Industry Standard Architecture (EISA) bus was
2022 developed as an open alternative to the IBM MicroChannel bus.
2024 The EISA bus provided some of the features of the IBM MicroChannel
2025 bus while maintaining backward compatibility with cards made for
2026 the older ISA bus. The EISA bus saw limited use between 1988 and
2027 1995 when it was made obsolete by the PCI bus.
2029 Say Y here if you are building a kernel for an EISA-based machine.
2031 Otherwise, say N.
2033 source "drivers/eisa/Kconfig"
2035 config MCA
2036 bool "MCA support"
2037 ---help---
2038 MicroChannel Architecture is found in some IBM PS/2 machines and
2039 laptops. It is a bus system similar to PCI or ISA. See
2040 <file:Documentation/mca.txt> (and especially the web page given
2041 there) before attempting to build an MCA bus kernel.
2043 source "drivers/mca/Kconfig"
2045 config SCx200
2046 tristate "NatSemi SCx200 support"
2047 ---help---
2048 This provides basic support for National Semiconductor's
2049 (now AMD's) Geode processors. The driver probes for the
2050 PCI-IDs of several on-chip devices, so its a good dependency
2051 for other scx200_* drivers.
2053 If compiled as a module, the driver is named scx200.
2055 config SCx200HR_TIMER
2056 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2057 depends on SCx200
2058 default y
2059 ---help---
2060 This driver provides a clocksource built upon the on-chip
2061 27MHz high-resolution timer. Its also a workaround for
2062 NSC Geode SC-1100's buggy TSC, which loses time when the
2063 processor goes idle (as is done by the scheduler). The
2064 other workaround is idle=poll boot option.
2066 config OLPC
2067 bool "One Laptop Per Child support"
2068 depends on !X86_PAE
2069 select GPIOLIB
2070 select OF
2071 select OF_PROMTREE
2072 ---help---
2073 Add support for detecting the unique features of the OLPC
2074 XO hardware.
2076 config OLPC_XO1
2077 tristate "OLPC XO-1 support"
2078 depends on OLPC && MFD_CS5535
2079 ---help---
2080 Add support for non-essential features of the OLPC XO-1 laptop.
2082 endif # X86_32
2084 config AMD_NB
2085 def_bool y
2086 depends on CPU_SUP_AMD && PCI
2088 source "drivers/pcmcia/Kconfig"
2090 source "drivers/pci/hotplug/Kconfig"
2092 config RAPIDIO
2093 bool "RapidIO support"
2094 depends on PCI
2095 default n
2096 help
2097 If you say Y here, the kernel will include drivers and
2098 infrastructure code to support RapidIO interconnect devices.
2100 source "drivers/rapidio/Kconfig"
2102 endmenu
2105 menu "Executable file formats / Emulations"
2107 source "fs/Kconfig.binfmt"
2109 config IA32_EMULATION
2110 bool "IA32 Emulation"
2111 depends on X86_64
2112 select COMPAT_BINFMT_ELF
2113 ---help---
2114 Include code to run 32-bit programs under a 64-bit kernel. You should
2115 likely turn this on, unless you're 100% sure that you don't have any
2116 32-bit programs left.
2118 config IA32_AOUT
2119 tristate "IA32 a.out support"
2120 depends on IA32_EMULATION
2121 ---help---
2122 Support old a.out binaries in the 32bit emulation.
2124 config COMPAT
2125 def_bool y
2126 depends on IA32_EMULATION
2128 config COMPAT_FOR_U64_ALIGNMENT
2129 def_bool COMPAT
2130 depends on X86_64
2132 config SYSVIPC_COMPAT
2133 def_bool y
2134 depends on COMPAT && SYSVIPC
2136 config KEYS_COMPAT
2137 bool
2138 depends on COMPAT && KEYS
2139 default y
2141 endmenu
2144 config HAVE_ATOMIC_IOMAP
2145 def_bool y
2146 depends on X86_32
2148 config HAVE_TEXT_POKE_SMP
2149 bool
2150 select STOP_MACHINE if SMP
2152 source "net/Kconfig"
2154 source "drivers/Kconfig"
2156 source "drivers/firmware/Kconfig"
2158 source "fs/Kconfig"
2160 source "arch/x86/Kconfig.debug"
2162 source "security/Kconfig"
2164 source "crypto/Kconfig"
2166 source "arch/x86/kvm/Kconfig"
2168 source "lib/Kconfig"