3 bool "64-bit kernel" if ARCH = "x86"
4 default ARCH = "x86_64"
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
18 select HAVE_AOUT if X86_32
21 select HAVE_UNSTABLE_SCHED_CLOCK
24 select HAVE_PERF_EVENTS
26 select HAVE_IOREMAP_PROT
29 select ARCH_WANT_OPTIONAL_GPIOLIB
30 select ARCH_WANT_FRAME_POINTERS
32 select HAVE_KRETPROBES
34 select HAVE_FTRACE_MCOUNT_RECORD
35 select HAVE_C_RECORDMCOUNT
36 select HAVE_DYNAMIC_FTRACE
37 select HAVE_FUNCTION_TRACER
38 select HAVE_FUNCTION_GRAPH_TRACER
39 select HAVE_FUNCTION_GRAPH_FP_TEST
40 select HAVE_FUNCTION_TRACE_MCOUNT_TEST
41 select HAVE_FTRACE_NMI_ENTER if DYNAMIC_FTRACE
42 select HAVE_SYSCALL_TRACEPOINTS
45 select HAVE_ARCH_TRACEHOOK
46 select HAVE_GENERIC_DMA_COHERENT if X86_32
47 select HAVE_EFFICIENT_UNALIGNED_ACCESS
48 select USER_STACKTRACE_SUPPORT
49 select HAVE_REGS_AND_STACK_ACCESS_API
50 select HAVE_DMA_API_DEBUG
51 select HAVE_KERNEL_GZIP
52 select HAVE_KERNEL_BZIP2
53 select HAVE_KERNEL_LZMA
54 select HAVE_KERNEL_LZO
55 select HAVE_HW_BREAKPOINT
56 select HAVE_MIXED_BREAKPOINTS_REGS
58 select HAVE_PERF_EVENTS_NMI
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_IRQ_PROBE
67 select GENERIC_PENDING_IRQ if SMP
68 select USE_GENERIC_SMP_HELPERS if SMP
70 config INSTRUCTION_DECODER
71 def_bool (KPROBES || PERF_EVENTS)
75 default "elf32-i386" if X86_32
76 default "elf64-x86-64" if X86_64
80 default "arch/x86/configs/i386_defconfig" if X86_32
81 default "arch/x86/configs/x86_64_defconfig" if X86_64
83 config GENERIC_CMOS_UPDATE
86 config CLOCKSOURCE_WATCHDOG
89 config GENERIC_CLOCKEVENTS
92 config GENERIC_CLOCKEVENTS_BROADCAST
94 depends on X86_64 || (X86_32 && X86_LOCAL_APIC)
96 config LOCKDEP_SUPPORT
99 config STACKTRACE_SUPPORT
102 config HAVE_LATENCYTOP_SUPPORT
114 config NEED_DMA_MAP_STATE
115 def_bool (X86_64 || DMAR || DMA_API_DEBUG)
117 config NEED_SG_DMA_LENGTH
120 config GENERIC_ISA_DMA
129 select GENERIC_BUG_RELATIVE_POINTERS if X86_64
131 config GENERIC_BUG_RELATIVE_POINTERS
134 config GENERIC_HWEIGHT
140 config ARCH_MAY_HAVE_PC_FDC
143 config RWSEM_GENERIC_SPINLOCK
146 config RWSEM_XCHGADD_ALGORITHM
149 config ARCH_HAS_CPU_IDLE_WAIT
152 config GENERIC_CALIBRATE_DELAY
155 config GENERIC_TIME_VSYSCALL
159 config ARCH_HAS_CPU_RELAX
162 config ARCH_HAS_DEFAULT_IDLE
165 config ARCH_HAS_CACHE_LINE_SIZE
168 config HAVE_SETUP_PER_CPU_AREA
171 config NEED_PER_CPU_EMBED_FIRST_CHUNK
174 config NEED_PER_CPU_PAGE_FIRST_CHUNK
177 config HAVE_CPUMASK_OF_CPU_MAP
180 config ARCH_HIBERNATION_POSSIBLE
183 config ARCH_SUSPEND_POSSIBLE
190 config ARCH_POPULATES_NODE_MAP
197 config ARCH_SUPPORTS_OPTIMIZED_INLINING
200 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
203 config HAVE_INTEL_TXT
205 depends on EXPERIMENTAL && DMAR && ACPI
209 depends on X86_32 && SMP
213 depends on X86_64 && SMP
219 config X86_TRAMPOLINE
221 depends on SMP || (64BIT && ACPI_SLEEP)
223 config X86_32_LAZY_GS
225 depends on X86_32 && !CC_STACKPROTECTOR
227 config ARCH_HWEIGHT_CFLAGS
229 default "-fcall-saved-ecx -fcall-saved-edx" if X86_32
230 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
235 config ARCH_CPU_PROBE_RELEASE
237 depends on HOTPLUG_CPU
239 source "init/Kconfig"
240 source "kernel/Kconfig.freezer"
242 menu "Processor type and features"
244 source "kernel/time/Kconfig"
247 bool "Symmetric multi-processing support"
249 This enables support for systems with more than one CPU. If you have
250 a system with only one CPU, like most personal computers, say N. If
251 you have a system with more than one CPU, say Y.
253 If you say N here, the kernel will run on single and multiprocessor
254 machines, but will use only one CPU of a multiprocessor machine. If
255 you say Y here, the kernel will run on many, but not all,
256 singleprocessor machines. On a singleprocessor machine, the kernel
257 will run faster if you say N here.
259 Note that if you say Y here and choose architecture "586" or
260 "Pentium" under "Processor family", the kernel will not work on 486
261 architectures. Similarly, multiprocessor kernels for the "PPro"
262 architecture may not work on all Pentium based boards.
264 People using multiprocessor machines who say Y here should also say
265 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
266 Management" code will be disabled if you say Y here.
268 See also <file:Documentation/i386/IO-APIC.txt>,
269 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
270 <http://www.tldp.org/docs.html#howto>.
272 If you don't know what to do here, say N.
275 bool "Support x2apic"
276 depends on X86_LOCAL_APIC && X86_64 && INTR_REMAP
278 This enables x2apic support on CPUs that have this feature.
280 This allows 32-bit apic IDs (so it can support very large systems),
281 and accesses the local apic via MSRs not via mmio.
283 If you don't know what to do here, say N.
286 bool "Enable MPS table" if ACPI
288 depends on X86_LOCAL_APIC
290 For old smp systems that do not have proper acpi support. Newer systems
291 (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
294 bool "Support for big SMP systems with more than 8 CPUs"
295 depends on X86_32 && SMP
297 This option is needed for the systems that have more than 8 CPUs
300 config X86_EXTENDED_PLATFORM
301 bool "Support for extended (non-PC) x86 platforms"
304 If you disable this option then the kernel will only support
305 standard PC platforms. (which covers the vast majority of
308 If you enable this option then you'll be able to select support
309 for the following (non-PC) 32 bit x86 platforms:
313 SGI 320/540 (Visual Workstation)
314 Summit/EXA (IBM x440)
315 Unisys ES7000 IA32 series
316 Moorestown MID devices
318 If you have one of these systems, or if you want to build a
319 generic distribution kernel, say Y here - otherwise say N.
323 config X86_EXTENDED_PLATFORM
324 bool "Support for extended (non-PC) x86 platforms"
327 If you disable this option then the kernel will only support
328 standard PC platforms. (which covers the vast majority of
331 If you enable this option then you'll be able to select support
332 for the following (non-PC) 64 bit x86 platforms:
336 If you have one of these systems, or if you want to build a
337 generic distribution kernel, say Y here - otherwise say N.
339 # This is an alphabetically sorted list of 64 bit extended platforms
340 # Please maintain the alphabetic order if and when there are additions
344 select PARAVIRT_GUEST
346 depends on X86_64 && PCI
347 depends on X86_EXTENDED_PLATFORM
349 Support for ScaleMP vSMP systems. Say 'Y' here if this kernel is
350 supposed to run on these EM64T-based machines. Only choose this option
351 if you have one of these machines.
354 bool "SGI Ultraviolet"
356 depends on X86_EXTENDED_PLATFORM
358 depends on X86_X2APIC
360 This option is needed in order to support SGI Ultraviolet systems.
361 If you don't have one of these, you should say N here.
363 # Following is an alphabetically sorted list of 32 bit extended platforms
364 # Please maintain the alphabetic order if and when there are additions
369 depends on X86_EXTENDED_PLATFORM
371 Select this for an AMD Elan processor.
373 Do not use this option for K6/Athlon/Opteron processors!
375 If unsure, choose "PC-compatible" instead.
378 bool "CE4100 TV platform"
380 depends on PCI_GODIRECT
382 depends on X86_EXTENDED_PLATFORM
383 select X86_REBOOTFIXUPS
385 Select for the Intel CE media processor (CE4100) SOC.
386 This option compiles in support for the CE4100 SOC for settop
387 boxes and media devices.
390 bool "Moorestown MID platform"
394 depends on X86_EXTENDED_PLATFORM
395 depends on X86_IO_APIC
400 select X86_PLATFORM_DEVICES
402 Moorestown is Intel's Low Power Intel Architecture (LPIA) based Moblin
403 Internet Device(MID) platform. Moorestown consists of two chips:
404 Lincroft (CPU core, graphics, and memory controller) and Langwell IOH.
405 Unlike standard x86 PCs, Moorestown does not have many legacy devices
406 nor standard legacy replacement devices/features. e.g. Moorestown does
407 not contain i8259, i8254, HPET, legacy BIOS, most of the io ports.
410 bool "RDC R-321x SoC"
412 depends on X86_EXTENDED_PLATFORM
414 select X86_REBOOTFIXUPS
416 This option is needed for RDC R-321x system-on-chip, also known
418 If you don't have one of these chips, you should say N here.
420 config X86_32_NON_STANDARD
421 bool "Support non-standard 32-bit SMP architectures"
422 depends on X86_32 && SMP
423 depends on X86_EXTENDED_PLATFORM
425 This option compiles in the NUMAQ, Summit, bigsmp, ES7000, default
426 subarchitectures. It is intended for a generic binary kernel.
427 if you select them all, kernel will probe it one by one. and will
430 # Alphabetically sorted list of Non standard 32 bit platforms
433 bool "NUMAQ (IBM/Sequent)"
434 depends on X86_32_NON_STANDARD
439 This option is used for getting Linux to run on a NUMAQ (IBM/Sequent)
440 NUMA multiquad box. This changes the way that processors are
441 bootstrapped, and uses Clustered Logical APIC addressing mode instead
442 of Flat Logical. You will need a new lynxer.elf file to flash your
443 firmware with - send email to <Martin.Bligh@us.ibm.com>.
445 config X86_SUPPORTS_MEMORY_FAILURE
447 # MCE code calls memory_failure():
449 # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
450 depends on !X86_NUMAQ
451 # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
452 depends on X86_64 || !SPARSEMEM
453 select ARCH_SUPPORTS_MEMORY_FAILURE
456 bool "SGI 320/540 (Visual Workstation)"
457 depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
458 depends on X86_32_NON_STANDARD
460 The SGI Visual Workstation series is an IA32-based workstation
461 based on SGI systems chips with some legacy PC hardware attached.
463 Say Y here to create a kernel to run on the SGI 320 or 540.
465 A kernel compiled for the Visual Workstation will run on general
466 PCs as well. See <file:Documentation/sgi-visws.txt> for details.
469 bool "Summit/EXA (IBM x440)"
470 depends on X86_32_NON_STANDARD
472 This option is needed for IBM systems that use the Summit/EXA chipset.
473 In particular, it is needed for the x440.
476 bool "Unisys ES7000 IA32 series"
477 depends on X86_32_NON_STANDARD && X86_BIGSMP
479 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
480 supposed to run on an IA32-based Unisys ES7000 system.
483 tristate "Eurobraille/Iris poweroff module"
486 The Iris machines from EuroBraille do not have APM or ACPI support
487 to shut themselves down properly. A special I/O sequence is
488 needed to do so, which is what this module does at
491 This is only for Iris machines from EuroBraille.
495 config SCHED_OMIT_FRAME_POINTER
497 prompt "Single-depth WCHAN output"
500 Calculate simpler /proc/<PID>/wchan values. If this option
501 is disabled then wchan values will recurse back to the
502 caller function. This provides more accurate wchan values,
503 at the expense of slightly more scheduling overhead.
505 If in doubt, say "Y".
507 menuconfig PARAVIRT_GUEST
508 bool "Paravirtualized guest support"
510 Say Y here to get to see options related to running Linux under
511 various hypervisors. This option alone does not add any kernel code.
513 If you say N, all options in this submenu will be skipped and disabled.
517 source "arch/x86/xen/Kconfig"
520 bool "KVM paravirtualized clock"
522 select PARAVIRT_CLOCK
524 Turning on this option will allow you to run a paravirtualized clock
525 when running over the KVM hypervisor. Instead of relying on a PIT
526 (or probably other) emulation by the underlying device model, the host
527 provides the guest with timing infrastructure such as time of day, and
531 bool "KVM Guest support"
534 This option enables various optimizations for running under the KVM
537 source "arch/x86/lguest/Kconfig"
540 bool "Enable paravirtualization code"
542 This changes the kernel so it can modify itself when it is run
543 under a hypervisor, potentially improving performance significantly
544 over full virtualization. However, when run without a hypervisor
545 the kernel is theoretically slower and slightly larger.
547 config PARAVIRT_SPINLOCKS
548 bool "Paravirtualization layer for spinlocks"
549 depends on PARAVIRT && SMP && EXPERIMENTAL
551 Paravirtualized spinlocks allow a pvops backend to replace the
552 spinlock implementation with something virtualization-friendly
553 (for example, block the virtual CPU rather than spinning).
555 Unfortunately the downside is an up to 5% performance hit on
556 native kernels, with various workloads.
558 If you are unsure how to answer this question, answer N.
560 config PARAVIRT_CLOCK
565 config PARAVIRT_DEBUG
566 bool "paravirt-ops debugging"
567 depends on PARAVIRT && DEBUG_KERNEL
569 Enable to debug paravirt_ops internals. Specifically, BUG if
570 a paravirt_op is missing when it is called.
578 This option adds a kernel parameter 'memtest', which allows memtest
580 memtest=0, mean disabled; -- default
581 memtest=1, mean do 1 test pattern;
583 memtest=4, mean do 4 test patterns.
584 If you are unsure how to answer this question, answer N.
586 config X86_SUMMIT_NUMA
588 depends on X86_32 && NUMA && X86_32_NON_STANDARD
590 config X86_CYCLONE_TIMER
592 depends on X86_32_NON_STANDARD
594 source "arch/x86/Kconfig.cpu"
598 prompt "HPET Timer Support" if X86_32
600 Use the IA-PC HPET (High Precision Event Timer) to manage
601 time in preference to the PIT and RTC, if a HPET is
603 HPET is the next generation timer replacing legacy 8254s.
604 The HPET provides a stable time base on SMP
605 systems, unlike the TSC, but it is more expensive to access,
606 as it is off-chip. You can find the HPET spec at
607 <http://www.intel.com/hardwaredesign/hpetspec_1.pdf>.
609 You can safely choose Y here. However, HPET will only be
610 activated if the platform and the BIOS support this feature.
611 Otherwise the 8254 will be used for timing services.
613 Choose N to continue using the legacy 8254 timer.
615 config HPET_EMULATE_RTC
617 depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)
621 prompt "Langwell APB Timer Support" if X86_MRST
623 APB timer is the replacement for 8254, HPET on X86 MID platforms.
624 The APBT provides a stable time base on SMP
625 systems, unlike the TSC, but it is more expensive to access,
626 as it is off-chip. APB timers are always running regardless of CPU
627 C states, they are used as per CPU clockevent device when possible.
629 # Mark as embedded because too many people got it wrong.
630 # The code disables itself when not needed.
633 bool "Enable DMI scanning" if EMBEDDED
635 Enabled scanning of DMI to identify machine quirks. Say Y
636 here unless you have verified that your setup is not
637 affected by entries in the DMI blacklist. Required by PNP
641 bool "GART IOMMU support" if EMBEDDED
644 depends on X86_64 && PCI && AMD_NB
646 Support for full DMA access of devices with 32bit memory access only
647 on systems with more than 3GB. This is usually needed for USB,
648 sound, many IDE/SATA chipsets and some other devices.
649 Provides a driver for the AMD Athlon64/Opteron/Turion/Sempron GART
650 based hardware IOMMU and a software bounce buffer based IOMMU used
651 on Intel systems and as fallback.
652 The code is only active when needed (enough memory and limited
653 device) unless CONFIG_IOMMU_DEBUG or iommu=force is specified
657 bool "IBM Calgary IOMMU support"
659 depends on X86_64 && PCI && EXPERIMENTAL
661 Support for hardware IOMMUs in IBM's xSeries x366 and x460
662 systems. Needed to run systems with more than 3GB of memory
663 properly with 32-bit PCI devices that do not support DAC
664 (Double Address Cycle). Calgary also supports bus level
665 isolation, where all DMAs pass through the IOMMU. This
666 prevents them from going anywhere except their intended
667 destination. This catches hard-to-find kernel bugs and
668 mis-behaving drivers and devices that do not use the DMA-API
669 properly to set up their DMA buffers. The IOMMU can be
670 turned off at boot time with the iommu=off parameter.
671 Normally the kernel will make the right choice by itself.
674 config CALGARY_IOMMU_ENABLED_BY_DEFAULT
676 prompt "Should Calgary be enabled by default?"
677 depends on CALGARY_IOMMU
679 Should Calgary be enabled by default? if you choose 'y', Calgary
680 will be used (if it exists). If you choose 'n', Calgary will not be
681 used even if it exists. If you choose 'n' and would like to use
682 Calgary anyway, pass 'iommu=calgary' on the kernel command line.
686 bool "AMD IOMMU support"
689 depends on X86_64 && PCI && ACPI
691 With this option you can enable support for AMD IOMMU hardware in
692 your system. An IOMMU is a hardware component which provides
693 remapping of DMA memory accesses from devices. With an AMD IOMMU you
694 can isolate the the DMA memory of different devices and protect the
695 system from misbehaving device drivers or hardware.
697 You can find out if your system has an AMD IOMMU if you look into
698 your BIOS for an option to enable it or if you have an IVRS ACPI
701 config AMD_IOMMU_STATS
702 bool "Export AMD IOMMU statistics to debugfs"
706 This option enables code in the AMD IOMMU driver to collect various
707 statistics about whats happening in the driver and exports that
708 information to userspace via debugfs.
711 # need this always selected by IOMMU for the VIA workaround
715 Support for software bounce buffers used on x86-64 systems
716 which don't have a hardware IOMMU (e.g. the current generation
717 of Intel's x86-64 CPUs). Using this PCI devices which can only
718 access 32-bits of memory can be used on systems with more than
719 3 GB of memory. If unsure, say Y.
722 def_bool (CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU)
725 def_bool (AMD_IOMMU || DMAR)
728 bool "Enable Maximum number of SMP Processors and NUMA Nodes"
729 depends on X86_64 && SMP && DEBUG_KERNEL && EXPERIMENTAL
730 select CPUMASK_OFFSTACK
732 Enable maximum number of CPUS and NUMA Nodes for this architecture.
736 int "Maximum number of CPUs" if SMP && !MAXSMP
737 range 2 8 if SMP && X86_32 && !X86_BIGSMP
738 range 2 512 if SMP && !MAXSMP
740 default "4096" if MAXSMP
741 default "32" if SMP && (X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000)
744 This allows you to specify the maximum number of CPUs which this
745 kernel will support. The maximum supported value is 512 and the
746 minimum value which makes sense is 2.
748 This is purely to save memory - each supported CPU adds
749 approximately eight kilobytes to the kernel image.
752 bool "SMT (Hyperthreading) scheduler support"
755 SMT scheduler support improves the CPU scheduler's decision making
756 when dealing with Intel Pentium 4 chips with HyperThreading at a
757 cost of slightly increased overhead in some places. If unsure say
762 prompt "Multi-core scheduler support"
765 Multi-core scheduler support improves the CPU scheduler's decision
766 making when dealing with multi-core CPU chips at a cost of slightly
767 increased overhead in some places. If unsure say N here.
769 config IRQ_TIME_ACCOUNTING
770 bool "Fine granularity task level IRQ time accounting"
773 Select this option to enable fine granularity task irq time
774 accounting. This is done by reading a timestamp on each
775 transitions between softirq and hardirq state, so there can be a
776 small performance impact.
778 If in doubt, say N here.
780 source "kernel/Kconfig.preempt"
783 bool "Local APIC support on uniprocessors"
784 depends on X86_32 && !SMP && !X86_32_NON_STANDARD
786 A local APIC (Advanced Programmable Interrupt Controller) is an
787 integrated interrupt controller in the CPU. If you have a single-CPU
788 system which has a processor with a local APIC, you can say Y here to
789 enable and use it. If you say Y here even though your machine doesn't
790 have a local APIC, then the kernel will still run with no slowdown at
791 all. The local APIC supports CPU-generated self-interrupts (timer,
792 performance counters), and the NMI watchdog which detects hard
796 bool "IO-APIC support on uniprocessors"
797 depends on X86_UP_APIC
799 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
800 SMP-capable replacement for PC-style interrupt controllers. Most
801 SMP systems and many recent uniprocessor systems have one.
803 If you have a single-CPU system with an IO-APIC, you can say Y here
804 to use it. If you say Y here even though your machine doesn't have
805 an IO-APIC, then the kernel will still run with no slowdown at all.
807 config X86_LOCAL_APIC
809 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
813 depends on X86_64 || SMP || X86_32_NON_STANDARD || X86_UP_APIC
815 config X86_VISWS_APIC
817 depends on X86_32 && X86_VISWS
819 config X86_REROUTE_FOR_BROKEN_BOOT_IRQS
820 bool "Reroute for broken boot IRQs"
821 depends on X86_IO_APIC
823 This option enables a workaround that fixes a source of
824 spurious interrupts. This is recommended when threaded
825 interrupt handling is used on systems where the generation of
826 superfluous "boot interrupts" cannot be disabled.
828 Some chipsets generate a legacy INTx "boot IRQ" when the IRQ
829 entry in the chipset's IO-APIC is masked (as, e.g. the RT
830 kernel does during interrupt handling). On chipsets where this
831 boot IRQ generation cannot be disabled, this workaround keeps
832 the original IRQ line masked so that only the equivalent "boot
833 IRQ" is delivered to the CPUs. The workaround also tells the
834 kernel to set up the IRQ handler on the boot IRQ line. In this
835 way only one interrupt is delivered to the kernel. Otherwise
836 the spurious second interrupt may cause the kernel to bring
837 down (vital) interrupt lines.
839 Only affects "broken" chipsets. Interrupt sharing may be
840 increased on these systems.
843 bool "Machine Check / overheating reporting"
845 Machine Check support allows the processor to notify the
846 kernel if it detects a problem (e.g. overheating, data corruption).
847 The action the kernel takes depends on the severity of the problem,
848 ranging from warning messages to halting the machine.
852 prompt "Intel MCE features"
853 depends on X86_MCE && X86_LOCAL_APIC
855 Additional support for intel specific MCE features such as
860 prompt "AMD MCE features"
861 depends on X86_MCE && X86_LOCAL_APIC
863 Additional support for AMD specific MCE features such as
864 the DRAM Error Threshold.
866 config X86_ANCIENT_MCE
867 bool "Support for old Pentium 5 / WinChip machine checks"
868 depends on X86_32 && X86_MCE
870 Include support for machine check handling on old Pentium 5 or WinChip
871 systems. These typically need to be enabled explicitely on the command
874 config X86_MCE_THRESHOLD
875 depends on X86_MCE_AMD || X86_MCE_INTEL
878 config X86_MCE_INJECT
880 tristate "Machine check injector support"
882 Provide support for injecting machine checks for testing purposes.
883 If you don't know what a machine check is and you don't do kernel
884 QA it is safe to say n.
886 config X86_THERMAL_VECTOR
888 depends on X86_MCE_INTEL
891 bool "Enable VM86 support" if EMBEDDED
895 This option is required by programs like DOSEMU to run 16-bit legacy
896 code on X86 processors. It also may be needed by software like
897 XFree86 to initialize some video cards via BIOS. Disabling this
898 option saves about 6k.
901 tristate "Toshiba Laptop support"
904 This adds a driver to safely access the System Management Mode of
905 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
906 not work on models with a Phoenix BIOS. The System Management Mode
907 is used to set the BIOS and power saving options on Toshiba portables.
909 For information on utilities to make use of this driver see the
910 Toshiba Linux utilities web site at:
911 <http://www.buzzard.org.uk/toshiba/>.
913 Say Y if you intend to run this kernel on a Toshiba portable.
917 tristate "Dell laptop support"
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
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.
936 config X86_REBOOTFIXUPS
937 bool "Enable X86 board specific fixups for reboot"
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
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.
954 tristate "/dev/cpu/microcode - microcode support"
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"
977 This options enables microcode patch loading support for Intel
980 For latest news and information on obtaining all the required
981 Intel ingredients for this driver, check:
982 <http://www.urbanmyth.org/microcode/>.
985 bool "AMD microcode patch loading support"
989 If you select this option, microcode patch loading support for AMD
990 processors will be enabled.
992 config MICROCODE_OLD_INTERFACE
997 tristate "/dev/cpu/*/msr - Model-specific register support"
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
1006 tristate "/dev/cpu/*/cpuid - CPU information support"
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
1014 prompt "High Memory Support"
1015 default HIGHMEM64G if X86_NUMAQ
1021 depends on !X86_NUMAQ
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
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
1038 If the machine has between 1 and 4 Gigabytes physical RAM, then
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".
1058 depends on !X86_NUMAQ
1060 Select this if you have a 32-bit processor and between 1 and 4
1061 gigabytes of physical RAM.
1065 depends on !M386 && !M486
1068 Select this if you have a 32-bit processor and more than 4
1069 gigabytes of physical RAM.
1074 depends on EXPERIMENTAL
1075 prompt "Memory split" if EMBEDDED
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
1091 If you are not absolutely sure what you are doing, leave this
1095 bool "3G/1G user/kernel split"
1096 config VMSPLIT_3G_OPT
1098 bool "3G/1G user/kernel split (for full 1G low memory)"
1100 bool "2G/2G user/kernel split"
1101 config VMSPLIT_2G_OPT
1103 bool "2G/2G user/kernel split (for full 2G low memory)"
1105 bool "1G/3G user/kernel split"
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
1119 depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
1122 bool "PAE (Physical Address Extension) Support"
1123 depends on X86_32 && !HIGHMEM4G
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 EMBEDDED
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
1147 bool "Numa Memory Allocation and Scheduler Support"
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)
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)
1172 prompt "Old style AMD Opteron NUMA detection"
1173 depends on X86_64 && NUMA && PCI
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
1183 prompt "ACPI NUMA detection"
1184 depends on X86_64 && NUMA && ACPI && PCI
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()
1194 config NODES_SPAN_OTHER_NODES
1196 depends on X86_64_ACPI_NUMA
1199 bool "NUMA emulation"
1200 depends on X86_64 && NUMA
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.
1207 int "Maximum NUMA Nodes (as a power of 2)" if !MAXSMP
1209 default "10" if MAXSMP
1210 default "6" if X86_64
1211 default "4" if X86_NUMAQ
1213 depends on NEED_MULTIPLE_NODES
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
1220 depends on X86_32 && NUMA
1222 config ARCH_HAVE_MEMORY_PRESENT
1224 depends on X86_32 && DISCONTIGMEM
1226 config NEED_NODE_MEMMAP_SIZE
1228 depends on X86_32 && (DISCONTIGMEM || SPARSEMEM)
1230 config HAVE_ARCH_ALLOC_REMAP
1232 depends on X86_32 && NUMA
1234 config ARCH_FLATMEM_ENABLE
1236 depends on X86_32 && ARCH_SELECT_MEMORY_MODEL && !NUMA
1238 config ARCH_DISCONTIGMEM_ENABLE
1240 depends on NUMA && X86_32
1242 config ARCH_DISCONTIGMEM_DEFAULT
1244 depends on NUMA && X86_32
1246 config ARCH_PROC_KCORE_TEXT
1248 depends on X86_64 && PROC_KCORE
1250 config ARCH_SPARSEMEM_DEFAULT
1254 config ARCH_SPARSEMEM_ENABLE
1256 depends on X86_64 || NUMA || (EXPERIMENTAL && X86_32) || X86_32_NON_STANDARD
1257 select SPARSEMEM_STATIC if X86_32
1258 select SPARSEMEM_VMEMMAP_ENABLE if X86_64
1260 config ARCH_SELECT_MEMORY_MODEL
1262 depends on ARCH_SPARSEMEM_ENABLE
1264 config ARCH_MEMORY_PROBE
1266 depends on MEMORY_HOTPLUG
1268 config ILLEGAL_POINTER_VALUE
1271 default 0xdead000000000000 if X86_64
1276 bool "Allocate 3rd-level pagetables from highmem"
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"
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
1306 config X86_BOOTPARAM_MEMORY_CORRUPTION_CHECK
1307 bool "Set the default setting of memory_corruption_check"
1308 depends on X86_CHECK_BIOS_CORRUPTION
1311 Set whether the default state of memory_corruption_check is
1314 config X86_RESERVE_LOW
1315 int "Amount of low memory, in kilobytes, to reserve for the BIOS"
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
1345 prompt "Math emulation" if X86_32
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.
1371 prompt "MTRR (Memory Type Range Register) support" if EMBEDDED
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
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
1406 prompt "MTRR cleanup support"
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
1418 config MTRR_SANITIZER_ENABLE_DEFAULT
1419 int "MTRR cleanup enable value (0-1)"
1422 depends on MTRR_SANITIZER
1424 Enable mtrr cleanup default value
1426 config MTRR_SANITIZER_SPARE_REG_NR_DEFAULT
1427 int "MTRR cleanup spare reg num (0-7)"
1430 depends on MTRR_SANITIZER
1432 mtrr cleanup spare entries default, it can be changed via
1433 mtrr_spare_reg_nr=N on the kernel command line.
1437 prompt "x86 PAT support" if EMBEDDED
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.
1450 config ARCH_USES_PG_UNCACHED
1455 bool "EFI runtime service support"
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
1470 prompt "Enable seccomp to safely compute untrusted bytecode"
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)"
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
1503 bool "kexec system call"
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.
1519 bool "kernel crash dumps"
1520 depends on X86_64 || (X86_32 && HIGHMEM)
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
1533 bool "kexec jump (EXPERIMENTAL)"
1534 depends on EXPERIMENTAL
1535 depends on KEXEC && HIBERNATION
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 (EMBEDDED || CRASH_DUMP)
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
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
1579 Don't change this unless you know what you are doing.
1582 bool "Build a relocatable kernel"
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
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
1601 depends on X86_32 && RELOCATABLE
1603 config PHYSICAL_ALIGN
1604 hex "Alignment value to which kernel should be aligned" if X86_32
1606 range 0x2000 0x1000000
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.
1627 bool "Support for hot-pluggable CPUs"
1628 depends on SMP && HOTPLUG
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.
1638 prompt "Compat VDSO support"
1639 depends on X86_32 || IA32_EMULATION
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.
1650 bool "Built-in kernel command line"
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'.
1666 string "Built-in kernel command string"
1667 depends on CMDLINE_BOOL
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
1682 config CMDLINE_OVERRIDE
1683 bool "Built-in command line overrides boot loader arguments"
1684 depends on CMDLINE_BOOL
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.
1694 config ARCH_ENABLE_MEMORY_HOTPLUG
1696 depends on X86_64 || (X86_32 && HIGHMEM)
1698 config ARCH_ENABLE_MEMORY_HOTREMOVE
1700 depends on MEMORY_HOTPLUG
1702 config HAVE_ARCH_EARLY_PFN_TO_NID
1706 config USE_PERCPU_NUMA_NODE_ID
1710 menu "Power management and ACPI options"
1712 config ARCH_HIBERNATION_HEADER
1714 depends on X86_64 && HIBERNATION
1716 source "kernel/power/Kconfig"
1718 source "drivers/acpi/Kconfig"
1720 source "drivers/sfi/Kconfig"
1724 depends on APM || APM_MODULE
1727 tristate "APM (Advanced Power Management) BIOS support"
1728 depends on X86_32 && PM_SLEEP
1730 APM is a BIOS specification for saving power using several different
1731 techniques. This is mostly useful for battery powered laptops with
1732 APM compliant BIOSes. If you say Y here, the system time will be
1733 reset after a RESUME operation, the /proc/apm device will provide
1734 battery status information, and user-space programs will receive
1735 notification of APM "events" (e.g. battery status change).
1737 If you select "Y" here, you can disable actual use of the APM
1738 BIOS by passing the "apm=off" option to the kernel at boot time.
1740 Note that the APM support is almost completely disabled for
1741 machines with more than one CPU.
1743 In order to use APM, you will need supporting software. For location
1744 and more information, read <file:Documentation/power/pm.txt> and the
1745 Battery Powered Linux mini-HOWTO, available from
1746 <http://www.tldp.org/docs.html#howto>.
1748 This driver does not spin down disk drives (see the hdparm(8)
1749 manpage ("man 8 hdparm") for that), and it doesn't turn off
1750 VESA-compliant "green" monitors.
1752 This driver does not support the TI 4000M TravelMate and the ACER
1753 486/DX4/75 because they don't have compliant BIOSes. Many "green"
1754 desktop machines also don't have compliant BIOSes, and this driver
1755 may cause those machines to panic during the boot phase.
1757 Generally, if you don't have a battery in your machine, there isn't
1758 much point in using this driver and you should say N. If you get
1759 random kernel OOPSes or reboots that don't seem to be related to
1760 anything, try disabling/enabling this option (or disabling/enabling
1763 Some other things you should try when experiencing seemingly random,
1766 1) make sure that you have enough swap space and that it is
1768 2) pass the "no-hlt" option to the kernel
1769 3) switch on floating point emulation in the kernel and pass
1770 the "no387" option to the kernel
1771 4) pass the "floppy=nodma" option to the kernel
1772 5) pass the "mem=4M" option to the kernel (thereby disabling
1773 all but the first 4 MB of RAM)
1774 6) make sure that the CPU is not over clocked.
1775 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
1776 8) disable the cache from your BIOS settings
1777 9) install a fan for the video card or exchange video RAM
1778 10) install a better fan for the CPU
1779 11) exchange RAM chips
1780 12) exchange the motherboard.
1782 To compile this driver as a module, choose M here: the
1783 module will be called apm.
1787 config APM_IGNORE_USER_SUSPEND
1788 bool "Ignore USER SUSPEND"
1790 This option will ignore USER SUSPEND requests. On machines with a
1791 compliant APM BIOS, you want to say N. However, on the NEC Versa M
1792 series notebooks, it is necessary to say Y because of a BIOS bug.
1794 config APM_DO_ENABLE
1795 bool "Enable PM at boot time"
1797 Enable APM features at boot time. From page 36 of the APM BIOS
1798 specification: "When disabled, the APM BIOS does not automatically
1799 power manage devices, enter the Standby State, enter the Suspend
1800 State, or take power saving steps in response to CPU Idle calls."
1801 This driver will make CPU Idle calls when Linux is idle (unless this
1802 feature is turned off -- see "Do CPU IDLE calls", below). This
1803 should always save battery power, but more complicated APM features
1804 will be dependent on your BIOS implementation. You may need to turn
1805 this option off if your computer hangs at boot time when using APM
1806 support, or if it beeps continuously instead of suspending. Turn
1807 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
1808 T400CDT. This is off by default since most machines do fine without
1812 bool "Make CPU Idle calls when idle"
1814 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
1815 On some machines, this can activate improved power savings, such as
1816 a slowed CPU clock rate, when the machine is idle. These idle calls
1817 are made after the idle loop has run for some length of time (e.g.,
1818 333 mS). On some machines, this will cause a hang at boot time or
1819 whenever the CPU becomes idle. (On machines with more than one CPU,
1820 this option does nothing.)
1822 config APM_DISPLAY_BLANK
1823 bool "Enable console blanking using APM"
1825 Enable console blanking using the APM. Some laptops can use this to
1826 turn off the LCD backlight when the screen blanker of the Linux
1827 virtual console blanks the screen. Note that this is only used by
1828 the virtual console screen blanker, and won't turn off the backlight
1829 when using the X Window system. This also doesn't have anything to
1830 do with your VESA-compliant power-saving monitor. Further, this
1831 option doesn't work for all laptops -- it might not turn off your
1832 backlight at all, or it might print a lot of errors to the console,
1833 especially if you are using gpm.
1835 config APM_ALLOW_INTS
1836 bool "Allow interrupts during APM BIOS calls"
1838 Normally we disable external interrupts while we are making calls to
1839 the APM BIOS as a measure to lessen the effects of a badly behaving
1840 BIOS implementation. The BIOS should reenable interrupts if it
1841 needs to. Unfortunately, some BIOSes do not -- especially those in
1842 many of the newer IBM Thinkpads. If you experience hangs when you
1843 suspend, try setting this to Y. Otherwise, say N.
1847 source "arch/x86/kernel/cpu/cpufreq/Kconfig"
1849 source "drivers/cpuidle/Kconfig"
1851 source "drivers/idle/Kconfig"
1856 menu "Bus options (PCI etc.)"
1861 select ARCH_SUPPORTS_MSI if (X86_LOCAL_APIC && X86_IO_APIC)
1863 Find out whether you have a PCI motherboard. PCI is the name of a
1864 bus system, i.e. the way the CPU talks to the other stuff inside
1865 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1866 VESA. If you have PCI, say Y, otherwise N.
1869 prompt "PCI access mode"
1870 depends on X86_32 && PCI
1873 On PCI systems, the BIOS can be used to detect the PCI devices and
1874 determine their configuration. However, some old PCI motherboards
1875 have BIOS bugs and may crash if this is done. Also, some embedded
1876 PCI-based systems don't have any BIOS at all. Linux can also try to
1877 detect the PCI hardware directly without using the BIOS.
1879 With this option, you can specify how Linux should detect the
1880 PCI devices. If you choose "BIOS", the BIOS will be used,
1881 if you choose "Direct", the BIOS won't be used, and if you
1882 choose "MMConfig", then PCI Express MMCONFIG will be used.
1883 If you choose "Any", the kernel will try MMCONFIG, then the
1884 direct access method and falls back to the BIOS if that doesn't
1885 work. If unsure, go with the default, which is "Any".
1890 config PCI_GOMMCONFIG
1907 depends on X86_32 && PCI && (PCI_GOBIOS || PCI_GOANY)
1909 # x86-64 doesn't support PCI BIOS access from long mode so always go direct.
1912 depends on PCI && (X86_64 || (PCI_GODIRECT || PCI_GOANY || PCI_GOOLPC))
1916 depends on X86_32 && PCI && (ACPI || SFI) && (PCI_GOMMCONFIG || PCI_GOANY)
1920 depends on PCI && OLPC && (PCI_GOOLPC || PCI_GOANY)
1924 depends on PCI && XEN
1932 bool "Support mmconfig PCI config space access"
1933 depends on X86_64 && PCI && ACPI
1935 config PCI_CNB20LE_QUIRK
1936 bool "Read CNB20LE Host Bridge Windows"
1939 Read the PCI windows out of the CNB20LE host bridge. This allows
1940 PCI hotplug to work on systems with the CNB20LE chipset which do
1944 bool "Support for DMA Remapping Devices (EXPERIMENTAL)"
1945 depends on PCI_MSI && ACPI && EXPERIMENTAL
1947 DMA remapping (DMAR) devices support enables independent address
1948 translations for Direct Memory Access (DMA) from devices.
1949 These DMA remapping devices are reported via ACPI tables
1950 and include PCI device scope covered by these DMA
1953 config DMAR_DEFAULT_ON
1955 prompt "Enable DMA Remapping Devices by default"
1958 Selecting this option will enable a DMAR device at boot time if
1959 one is found. If this option is not selected, DMAR support can
1960 be enabled by passing intel_iommu=on to the kernel. It is
1961 recommended you say N here while the DMAR code remains
1964 config DMAR_BROKEN_GFX_WA
1965 bool "Workaround broken graphics drivers (going away soon)"
1966 depends on DMAR && BROKEN
1968 Current Graphics drivers tend to use physical address
1969 for DMA and avoid using DMA APIs. Setting this config
1970 option permits the IOMMU driver to set a unity map for
1971 all the OS-visible memory. Hence the driver can continue
1972 to use physical addresses for DMA, at least until this
1973 option is removed in the 2.6.32 kernel.
1975 config DMAR_FLOPPY_WA
1979 Floppy disk drivers are known to bypass DMA API calls
1980 thereby failing to work when IOMMU is enabled. This
1981 workaround will setup a 1:1 mapping for the first
1982 16MiB to make floppy (an ISA device) work.
1985 bool "Support for Interrupt Remapping (EXPERIMENTAL)"
1986 depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL
1988 Supports Interrupt remapping for IO-APIC and MSI devices.
1989 To use x2apic mode in the CPU's which support x2APIC enhancements or
1990 to support platforms with CPU's having > 8 bit APIC ID, say Y.
1992 source "drivers/pci/pcie/Kconfig"
1994 source "drivers/pci/Kconfig"
1996 # x86_64 have no ISA slots, but do have ISA-style DMA.
2005 Find out whether you have ISA slots on your motherboard. ISA is the
2006 name of a bus system, i.e. the way the CPU talks to the other stuff
2007 inside your box. Other bus systems are PCI, EISA, MicroChannel
2008 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
2009 newer boards don't support it. If you have ISA, say Y, otherwise N.
2015 The Extended Industry Standard Architecture (EISA) bus was
2016 developed as an open alternative to the IBM MicroChannel bus.
2018 The EISA bus provided some of the features of the IBM MicroChannel
2019 bus while maintaining backward compatibility with cards made for
2020 the older ISA bus. The EISA bus saw limited use between 1988 and
2021 1995 when it was made obsolete by the PCI bus.
2023 Say Y here if you are building a kernel for an EISA-based machine.
2027 source "drivers/eisa/Kconfig"
2032 MicroChannel Architecture is found in some IBM PS/2 machines and
2033 laptops. It is a bus system similar to PCI or ISA. See
2034 <file:Documentation/mca.txt> (and especially the web page given
2035 there) before attempting to build an MCA bus kernel.
2037 source "drivers/mca/Kconfig"
2040 tristate "NatSemi SCx200 support"
2042 This provides basic support for National Semiconductor's
2043 (now AMD's) Geode processors. The driver probes for the
2044 PCI-IDs of several on-chip devices, so its a good dependency
2045 for other scx200_* drivers.
2047 If compiled as a module, the driver is named scx200.
2049 config SCx200HR_TIMER
2050 tristate "NatSemi SCx200 27MHz High-Resolution Timer Support"
2054 This driver provides a clocksource built upon the on-chip
2055 27MHz high-resolution timer. Its also a workaround for
2056 NSC Geode SC-1100's buggy TSC, which loses time when the
2057 processor goes idle (as is done by the scheduler). The
2058 other workaround is idle=poll boot option.
2061 bool "One Laptop Per Child support"
2063 select OLPC_OPENFIRMWARE
2065 Add support for detecting the unique features of the OLPC
2069 tristate "OLPC XO-1 support"
2070 depends on OLPC && PCI
2072 Add support for non-essential features of the OLPC XO-1 laptop.
2074 config OLPC_OPENFIRMWARE
2075 bool "Support for OLPC's Open Firmware"
2076 depends on !X86_64 && !X86_PAE
2079 This option adds support for the implementation of Open Firmware
2080 that is used on the OLPC XO-1 Children's Machine.
2081 If unsure, say N here.
2087 depends on CPU_SUP_AMD && PCI
2089 source "drivers/pcmcia/Kconfig"
2091 source "drivers/pci/hotplug/Kconfig"
2096 menu "Executable file formats / Emulations"
2098 source "fs/Kconfig.binfmt"
2100 config IA32_EMULATION
2101 bool "IA32 Emulation"
2103 select COMPAT_BINFMT_ELF
2105 Include code to run 32-bit programs under a 64-bit kernel. You should
2106 likely turn this on, unless you're 100% sure that you don't have any
2107 32-bit programs left.
2110 tristate "IA32 a.out support"
2111 depends on IA32_EMULATION
2113 Support old a.out binaries in the 32bit emulation.
2117 depends on IA32_EMULATION
2119 config COMPAT_FOR_U64_ALIGNMENT
2123 config SYSVIPC_COMPAT
2125 depends on COMPAT && SYSVIPC
2130 config HAVE_ATOMIC_IOMAP
2134 config HAVE_TEXT_POKE_SMP
2136 select STOP_MACHINE if SMP
2138 source "net/Kconfig"
2140 source "drivers/Kconfig"
2142 source "drivers/firmware/Kconfig"
2146 source "arch/x86/Kconfig.debug"
2148 source "security/Kconfig"
2150 source "crypto/Kconfig"
2152 source "arch/x86/kvm/Kconfig"
2154 source "lib/Kconfig"