2 # For a description of the syntax of this configuration file,
3 # see Documentation/kbuild/kconfig-language.txt.
6 mainmenu "Linux Kernel Configuration"
12 This is Linux's home port. Linux was originally native to the Intel
13 386, and runs on all the later x86 processors including the Intel
14 486, 586, Pentiums, and various instruction-set-compatible chips by
15 AMD, Cyrix, and others.
28 config GENERIC_ISA_DMA
35 menu "Processor type and features"
38 prompt "Subarchitecture Type"
44 Choose this option if your computer is a standard PC or compatible.
49 Voyager is a MCA based 32 way capable SMP architecture proprietary
50 to NCR Corp. Machine classes 345x/35xx/4100/51xx are voyager based.
54 If you do not specifically know you have a Voyager based machine,
55 say N here otherwise the kernel you build will not be bootable.
58 bool "NUMAQ (IBM/Sequent)"
60 This option is used for getting Linux to run on a (IBM/Sequent) NUMA
61 multiquad box. This changes the way that processors are bootstrapped,
62 and uses Clustered Logical APIC addressing mode instead of Flat Logical.
63 You will need a new lynxer.elf file to flash your firmware with - send
64 email to Martin.Bligh@us.ibm.com
67 bool "Summit/EXA (IBM x440)"
70 This option is needed for IBM systems that use the Summit/EXA chipset.
71 In particular, it is needed for the x440.
73 If you don't have one of these computers, you should say N here.
76 bool "Support for other sub-arch SMP systems with more than 8 CPUs"
79 This option is needed for the systems that have more than 8 CPUs
80 and if the system is not of any sub-arch type above.
82 If you don't have such a system, you should say N here.
85 bool "SGI 320/540 (Visual Workstation)"
87 The SGI Visual Workstation series is an IA32-based workstation
88 based on SGI systems chips with some legacy PC hardware attached.
90 Say Y here to create a kernel to run on the SGI 320 or 540.
92 A kernel compiled for the Visual Workstation will not run on PCs
93 and vice versa. See <file:Documentation/sgi-visws.txt> for details.
95 config X86_GENERICARCH
96 bool "Generic architecture (Summit, bigsmp, default)"
99 This option compiles in the Summit, bigsmp, default subarchitectures.
100 It is intended for a generic binary kernel.
103 bool "Support for Unisys ES7000 IA32 series"
106 Support for Unisys ES7000 systems. Say 'Y' here if this kernel is
107 supposed to run on an IA32-based Unisys ES7000 system.
108 Only choose this option if you have such a system, otherwise you
116 depends on NUMA && (X86_SUMMIT || X86_GENERICARCH)
118 config X86_SUMMIT_NUMA
121 depends on NUMA && (X86_SUMMIT || X86_GENERICARCH)
123 config X86_CYCLONE_TIMER
126 depends on X86_SUMMIT || X86_GENERICARCH
128 config ES7000_CLUSTERED_APIC
131 depends on SMP && X86_ES7000 && MPENTIUMIII
134 prompt "Processor family"
140 This is the processor type of your CPU. This information is used for
141 optimizing purposes. In order to compile a kernel that can run on
142 all x86 CPU types (albeit not optimally fast), you can specify
145 The kernel will not necessarily run on earlier architectures than
146 the one you have chosen, e.g. a Pentium optimized kernel will run on
147 a PPro, but not necessarily on a i486.
149 Here are the settings recommended for greatest speed:
150 - "386" for the AMD/Cyrix/Intel 386DX/DXL/SL/SLC/SX, Cyrix/TI
151 486DLC/DLC2, UMC 486SX-S and NexGen Nx586. Only "386" kernels
152 will run on a 386 class machine.
153 - "486" for the AMD/Cyrix/IBM/Intel 486DX/DX2/DX4 or
154 SL/SLC/SLC2/SLC3/SX/SX2 and UMC U5D or U5S.
155 - "586" for generic Pentium CPUs lacking the TSC
156 (time stamp counter) register.
157 - "Pentium-Classic" for the Intel Pentium.
158 - "Pentium-MMX" for the Intel Pentium MMX.
159 - "Pentium-Pro" for the Intel Pentium Pro.
160 - "Pentium-II" for the Intel Pentium II or pre-Coppermine Celeron.
161 - "Pentium-III" for the Intel Pentium III or Coppermine Celeron.
162 - "Pentium-4" for the Intel Pentium 4 or P4-based Celeron.
163 - "K6" for the AMD K6, K6-II and K6-III (aka K6-3D).
164 - "Athlon" for the AMD K7 family (Athlon/Duron/Thunderbird).
165 - "Crusoe" for the Transmeta Crusoe series.
166 - "Winchip-C6" for original IDT Winchip.
167 - "Winchip-2" for IDT Winchip 2.
168 - "Winchip-2A" for IDT Winchips with 3dNow! capabilities.
169 - "CyrixIII/VIA C3" for VIA Cyrix III or VIA C3.
170 - "VIA C3-2 for VIA C3-2 "Nehemiah" (model 9 and above).
172 If you don't know what to do, choose "386".
177 Select this for a 486 series processor, either Intel or one of the
178 compatible processors from AMD, Cyrix, IBM, or Intel. Includes DX,
179 DX2, and DX4 variants; also SL/SLC/SLC2/SLC3/SX/SX2 and UMC U5D or
183 bool "586/K5/5x86/6x86/6x86MX"
185 Select this for an 586 or 686 series processor such as the AMD K5,
186 the Intel 5x86 or 6x86, or the Intel 6x86MX. This choice does not
187 assume the RDTSC (Read Time Stamp Counter) instruction.
190 bool "Pentium-Classic"
192 Select this for a Pentium Classic processor with the RDTSC (Read
193 Time Stamp Counter) instruction for benchmarking.
198 Select this for a Pentium with the MMX graphics/multimedia
199 extended instructions.
204 Select this for Intel Pentium Pro chips. This enables the use of
205 Pentium Pro extended instructions, and disables the init-time guard
206 against the f00f bug found in earlier Pentiums.
209 bool "Pentium-II/Celeron(pre-Coppermine)"
211 Select this for Intel chips based on the Pentium-II and
212 pre-Coppermine Celeron core. This option enables an unaligned
213 copy optimization, compiles the kernel with optimization flags
214 tailored for the chip, and applies any applicable Pentium Pro
218 bool "Pentium-III/Celeron(Coppermine)/Pentium-III Xeon"
220 Select this for Intel chips based on the Pentium-III and
221 Celeron-Coppermine core. This option enables use of some
222 extended prefetch instructions in addition to the Pentium II
226 bool "Pentium-4/Celeron(P4-based)/Xeon"
228 Select this for Intel Pentium 4 chips. This includes both
229 the Pentium 4 and P4-based Celeron chips. This option
230 enables compile flags optimized for the chip, uses the
231 correct cache shift, and applies any applicable Pentium III
235 bool "K6/K6-II/K6-III"
237 Select this for an AMD K6-family processor. Enables use of
238 some extended instructions, and passes appropriate optimization
242 bool "Athlon/Duron/K7"
244 Select this for an AMD Athlon K7-family processor. Enables use of
245 some extended instructions, and passes appropriate optimization
249 bool "Opteron/Athlon64/Hammer/K8"
251 Select this for an AMD Opteron or Athlon64 Hammer-family processor. Enables
252 use of some extended instructions, and passes appropriate optimization
261 Select this for a Transmeta Crusoe processor. Treats the processor
262 like a 586 with TSC, and sets some GCC optimization flags (like a
263 Pentium Pro with no alignment requirements).
268 Select this for an IDT Winchip C6 chip. Linux and GCC
269 treat this chip as a 586TSC with some extended instructions
270 and alignment requirements.
275 Select this for an IDT Winchip-2. Linux and GCC
276 treat this chip as a 586TSC with some extended instructions
277 and alignment requirements.
280 bool "Winchip-2A/Winchip-3"
282 Select this for an IDT Winchip-2A or 3. Linux and GCC
283 treat this chip as a 586TSC with some extended instructions
284 and alignment reqirements. Also enable out of order memory
285 stores for this CPU, which can increase performance of some
289 bool "CyrixIII/VIA-C3"
291 Select this for a Cyrix III or C3 chip. Presently Linux and GCC
292 treat this chip as a generic 586. Whilst the CPU is 686 class,
293 it lacks the cmov extension which gcc assumes is present when
295 Note that Nehemiah (Model 9) and above will not boot with this
296 kernel due to them lacking the 3DNow! instructions used in earlier
297 incarnations of the CPU.
300 bool "VIA C3-2 (Nehemiah)"
302 Select this for a VIA C3 "Nehemiah". Selecting this enables usage
303 of SSE and tells gcc to treat the CPU as a 686.
304 Note, this kernel will not boot on older (pre model 9) C3s.
309 bool "Generic x86 support"
311 Including some tuning for non selected x86 CPUs too.
312 when it has moderate overhead. This is intended for generic
313 distributions kernels.
316 # Define implied options from the CPU selection here
328 config X86_L1_CACHE_SHIFT
330 default "7" if MPENTIUM4 || X86_GENERIC
331 default "4" if MELAN || M486 || M386
332 default "5" if MWINCHIP3D || MWINCHIP2 || MWINCHIPC6 || MCRUSOE || MCYRIXIII || MK6 || MPENTIUMIII || MPENTIUMII || M686 || M586MMX || M586TSC || M586 || MVIAC3_2
333 default "6" if MK7 || MK8
335 config RWSEM_GENERIC_SPINLOCK
340 config RWSEM_XCHGADD_ALGORITHM
345 config X86_PPRO_FENCE
347 depends on M686 || M586MMX || M586TSC || M586 || M486 || M386
352 depends on M586MMX || M586TSC || M586 || M486 || M386
355 config X86_WP_WORKS_OK
375 config X86_ALIGNMENT_16
377 depends on MWINCHIP3D || MWINCHIP2 || MWINCHIPC6 || MCYRIXIII || MELAN || MK6 || M586MMX || M586TSC || M586 || M486 || MVIAC3_2
382 depends on MK7 || MPENTIUM4 || MPENTIUMIII || MPENTIUMII || M686 || M586MMX || MK8
385 config X86_INTEL_USERCOPY
387 depends on MPENTIUM4 || MPENTIUMIII || MPENTIUMII || M586MMX || X86_GENERIC || MK8 || MK7
390 config X86_USE_PPRO_CHECKSUM
392 depends on MWINCHIP3D || MWINCHIP2 || MWINCHIPC6 || MCYRIXIII || MK7 || MK6 || MPENTIUM4 || MPENTIUMIII || MPENTIUMII || M686 || MK8 || MVIAC3_2
397 depends on MCYRIXIII || MK7
402 depends on (MWINCHIP3D || MWINCHIP2 || MWINCHIPC6) && MTRR
406 bool "HPET Timer Support"
408 This enables the use of the HPET for the kernel's internal timer.
409 HPET is the next generation timer replacing legacy 8254s.
410 You can safely choose Y here. However, HPET will only be
411 activated if the platform and the BIOS support this feature.
412 Otherwise the 8254 will be used for timing services.
414 Choose N to continue using the legacy 8254 timer.
416 config HPET_EMULATE_RTC
417 def_bool HPET_TIMER && RTC=y
420 bool "Symmetric multi-processing support"
422 This enables support for systems with more than one CPU. If you have
423 a system with only one CPU, like most personal computers, say N. If
424 you have a system with more than one CPU, say Y.
426 If you say N here, the kernel will run on single and multiprocessor
427 machines, but will use only one CPU of a multiprocessor machine. If
428 you say Y here, the kernel will run on many, but not all,
429 singleprocessor machines. On a singleprocessor machine, the kernel
430 will run faster if you say N here.
432 Note that if you say Y here and choose architecture "586" or
433 "Pentium" under "Processor family", the kernel will not work on 486
434 architectures. Similarly, multiprocessor kernels for the "PPro"
435 architecture may not work on all Pentium based boards.
437 People using multiprocessor machines who say Y here should also say
438 Y to "Enhanced Real Time Clock Support", below. The "Advanced Power
439 Management" code will be disabled if you say Y here.
441 See also the <file:Documentation/smp.tex>,
442 <file:Documentation/smp.txt>, <file:Documentation/i386/IO-APIC.txt>,
443 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
444 <http://www.tldp.org/docs.html#howto>.
446 If you don't know what to do here, say N.
449 int "Maximum number of CPUs (2-255)"
452 default "32" if X86_NUMAQ || X86_SUMMIT || X86_BIGSMP || X86_ES7000
455 This allows you to specify the maximum number of CPUs which this
456 kernel will support. The maximum supported value is 255 and the
457 minimum value which makes sense is 2.
459 This is purely to save memory - each supported CPU adds
460 approximately eight kilobytes to the kernel image.
463 bool "Preemptible Kernel"
465 This option reduces the latency of the kernel when reacting to
466 real-time or interactive events by allowing a low priority process to
467 be preempted even if it is in kernel mode executing a system call.
468 This allows applications to run more reliably even when the system is
471 Say Y here if you are building a kernel for a desktop, embedded
472 or real-time system. Say N if you are unsure.
475 bool "Local APIC support on uniprocessors" if !SMP
476 depends on !(X86_VISWS || X86_VOYAGER)
478 A local APIC (Advanced Programmable Interrupt Controller) is an
479 integrated interrupt controller in the CPU. If you have a single-CPU
480 system which has a processor with a local APIC, you can say Y here to
481 enable and use it. If you say Y here even though your machine doesn't
482 have a local APIC, then the kernel will still run with no slowdown at
483 all. The local APIC supports CPU-generated self-interrupts (timer,
484 performance counters), and the NMI watchdog which detects hard
487 If you have a system with several CPUs, you do not need to say Y
488 here: the local APIC will be used automatically.
491 bool "IO-APIC support on uniprocessors"
492 depends on !SMP && X86_UP_APIC
494 An IO-APIC (I/O Advanced Programmable Interrupt Controller) is an
495 SMP-capable replacement for PC-style interrupt controllers. Most
496 SMP systems and a small number of uniprocessor systems have one.
497 If you have a single-CPU system with an IO-APIC, you can say Y here
498 to use it. If you say Y here even though your machine doesn't have
499 an IO-APIC, then the kernel will still run with no slowdown at all.
501 If you have a system with several CPUs, you do not need to say Y
502 here: the IO-APIC will be used automatically.
504 config X86_LOCAL_APIC
506 depends on !SMP && X86_UP_APIC
511 depends on !SMP && X86_UP_IOAPIC
516 depends on (MWINCHIP3D || MWINCHIP2 || MCRUSOE || MCYRIXIII || MK7 || MK6 || MPENTIUM4 || MPENTIUMIII || MPENTIUMII || M686 || M586MMX || M586TSC || MK8 || MVIAC3_2) && !X86_NUMAQ
520 bool "Machine Check Exception"
522 Machine Check Exception support allows the processor to notify the
523 kernel if it detects a problem (e.g. overheating, component failure).
524 The action the kernel takes depends on the severity of the problem,
525 ranging from a warning message on the console, to halting the machine.
526 Your processor must be a Pentium or newer to support this - check the
527 flags in /proc/cpuinfo for mce. Note that some older Pentium systems
528 have a design flaw which leads to false MCE events - hence MCE is
529 disabled on all P5 processors, unless explicitly enabled with "mce"
530 as a boot argument. Similarly, if MCE is built in and creates a
531 problem on some new non-standard machine, you can boot with "nomce"
532 to disable it. MCE support simply ignores non-MCE processors like
533 the 386 and 486, so nearly everyone can say Y here.
535 config X86_MCE_NONFATAL
536 bool "Check for non-fatal errors on AMD Athlon/Duron / Intel Pentium 4"
539 Enabling this feature starts a timer that triggers every 5 seconds which
540 will look at the machine check registers to see if anything happened.
541 Non-fatal problems automatically get corrected (but still logged).
542 Disable this if you don't want to see these messages.
543 Seeing the messages this option prints out may be indicative of dying hardware,
544 or out-of-spec (ie, overclocked) hardware.
545 This option only does something on certain CPUs.
546 (AMD Athlon/Duron and Intel Pentium 4)
548 config X86_MCE_P4THERMAL
549 bool "check for P4 thermal throttling interrupt."
550 depends on X86_MCE && (X86_UP_APIC || SMP)
552 Enabling this feature will cause a message to be printed when the P4
553 enters thermal throttling.
556 tristate "Toshiba Laptop support"
558 This adds a driver to safely access the System Management Mode of
559 the CPU on Toshiba portables with a genuine Toshiba BIOS. It does
560 not work on models with a Phoenix BIOS. The System Management Mode
561 is used to set the BIOS and power saving options on Toshiba portables.
563 For information on utilities to make use of this driver see the
564 Toshiba Linux utilities web site at:
565 <http://www.buzzard.org.uk/toshiba/>.
567 Say Y if you intend to run this kernel on a Toshiba portable.
571 tristate "Dell laptop support"
573 This adds a driver to safely access the System Management Mode
574 of the CPU on the Dell Inspiron 8000. The System Management Mode
575 is used to read cpu temperature and cooling fan status and to
576 control the fans on the I8K portables.
578 This driver has been tested only on the Inspiron 8000 but it may
579 also work with other Dell laptops. You can force loading on other
580 models by passing the parameter `force=1' to the module. Use at
583 For information on utilities to make use of this driver see the
584 I8K Linux utilities web site at:
585 <http://www.debian.org/~dz/i8k/>
587 Say Y if you intend to run this kernel on a Dell Inspiron 8000.
591 tristate "/dev/cpu/microcode - Intel IA32 CPU microcode support"
593 If you say Y here and also to "/dev file system support" in the
594 'File systems' section, you will be able to update the microcode on
595 Intel processors in the IA32 family, e.g. Pentium Pro, Pentium II,
596 Pentium III, Pentium 4, Xeon etc. You will obviously need the
597 actual microcode binary data itself which is not shipped with the
600 For latest news and information on obtaining all the required
601 ingredients for this driver, check:
602 <http://www.urbanmyth.org/microcode/>.
604 To compile this driver as a module, choose M here: the
605 module will be called microcode.
606 If you use modprobe or kmod you may also want to add the line
607 'alias char-major-10-184 microcode' to your /etc/modules.conf file.
610 tristate "/dev/cpu/*/msr - Model-specific register support"
612 This device gives privileged processes access to the x86
613 Model-Specific Registers (MSRs). It is a character device with
614 major 202 and minors 0 to 31 for /dev/cpu/0/msr to /dev/cpu/31/msr.
615 MSR accesses are directed to a specific CPU on multi-processor
619 tristate "/dev/cpu/*/cpuid - CPU information support"
621 This device gives processes access to the x86 CPUID instruction to
622 be executed on a specific processor. It is a character device
623 with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
627 tristate "BIOS Enhanced Disk Drive calls determine boot disk (EXPERIMENTAL)"
628 depends on EXPERIMENTAL
630 Say Y or M here if you want to enable BIOS Enhanced Disk Drive
631 Services real mode BIOS calls to determine which disk
632 BIOS tries boot from. This information is then exported via driverfs.
634 This option is experimental, but believed to be safe,
635 and most disk controller BIOS vendors do not yet implement this feature.
638 prompt "High Memory Support"
644 Linux can use up to 64 Gigabytes of physical memory on x86 systems.
645 However, the address space of 32-bit x86 processors is only 4
646 Gigabytes large. That means that, if you have a large amount of
647 physical memory, not all of it can be "permanently mapped" by the
648 kernel. The physical memory that's not permanently mapped is called
651 If you are compiling a kernel which will never run on a machine with
652 more than 1 Gigabyte total physical RAM, answer "off" here (default
653 choice and suitable for most users). This will result in a "3GB/1GB"
654 split: 3GB are mapped so that each process sees a 3GB virtual memory
655 space and the remaining part of the 4GB virtual memory space is used
656 by the kernel to permanently map as much physical memory as
659 If the machine has between 1 and 4 Gigabytes physical RAM, then
662 If more than 4 Gigabytes is used then answer "64GB" here. This
663 selection turns Intel PAE (Physical Address Extension) mode on.
664 PAE implements 3-level paging on IA32 processors. PAE is fully
665 supported by Linux, PAE mode is implemented on all recent Intel
666 processors (Pentium Pro and better). NOTE: If you say "64GB" here,
667 then the kernel will not boot on CPUs that don't support PAE!
669 The actual amount of total physical memory will either be
670 auto detected or can be forced by using a kernel command line option
671 such as "mem=256M". (Try "man bootparam" or see the documentation of
672 your boot loader (lilo or loadlin) about how to pass options to the
673 kernel at boot time.)
675 If unsure, say "off".
680 Select this if you have a 32-bit processor and between 1 and 4
681 gigabytes of physical RAM.
686 Select this if you have a 32-bit processor and more than 4
687 gigabytes of physical RAM.
693 depends on HIGHMEM64G || HIGHMEM4G
698 depends on HIGHMEM64G
701 # Common NUMA Features
703 bool "Numa Memory Allocation Support"
704 depends on SMP && HIGHMEM64G && (X86_PC || X86_NUMAQ || X86_GENERICARCH || (X86_SUMMIT && ACPI))
706 default y if (X86_NUMAQ || X86_SUMMIT)
708 # Need comments to help the hapless user trying to turn on NUMA support
709 comment "NUMA (NUMA-Q) requires SMP, 64GB highmem support"
710 depends on X86_NUMAQ && (!HIGHMEM64G || !SMP)
712 comment "NUMA (Summit) requires SMP, 64GB highmem support, ACPI"
713 depends on X86_SUMMIT && (!HIGHMEM64G || !ACPI)
720 config HAVE_ARCH_BOOTMEM_NODE
726 bool "Allocate 3rd-level pagetables from highmem"
727 depends on HIGHMEM4G || HIGHMEM64G
729 The VM uses one page table entry for each page of physical memory.
730 For systems with a lot of RAM, this can be wasteful of precious
731 low memory. Setting this option will put user-space page table
732 entries in high memory.
734 config MATH_EMULATION
735 bool "Math emulation"
737 Linux can emulate a math coprocessor (used for floating point
738 operations) if you don't have one. 486DX and Pentium processors have
739 a math coprocessor built in, 486SX and 386 do not, unless you added
740 a 487DX or 387, respectively. (The messages during boot time can
741 give you some hints here ["man dmesg"].) Everyone needs either a
742 coprocessor or this emulation.
744 If you don't have a math coprocessor, you need to say Y here; if you
745 say Y here even though you have a coprocessor, the coprocessor will
746 be used nevertheless. (This behavior can be changed with the kernel
747 command line option "no387", which comes handy if your coprocessor
748 is broken. Try "man bootparam" or see the documentation of your boot
749 loader (lilo or loadlin) about how to pass options to the kernel at
750 boot time.) This means that it is a good idea to say Y here if you
751 intend to use this kernel on different machines.
753 More information about the internals of the Linux math coprocessor
754 emulation can be found in <file:arch/i386/math-emu/README>.
756 If you are not sure, say Y; apart from resulting in a 66 KB bigger
757 kernel, it won't hurt.
760 bool "MTRR (Memory Type Range Register) support"
762 On Intel P6 family processors (Pentium Pro, Pentium II and later)
763 the Memory Type Range Registers (MTRRs) may be used to control
764 processor access to memory ranges. This is most useful if you have
765 a video (VGA) card on a PCI or AGP bus. Enabling write-combining
766 allows bus write transfers to be combined into a larger transfer
767 before bursting over the PCI/AGP bus. This can increase performance
768 of image write operations 2.5 times or more. Saying Y here creates a
769 /proc/mtrr file which may be used to manipulate your processor's
770 MTRRs. Typically the X server should use this.
772 This code has a reasonably generic interface so that similar
773 control registers on other processors can be easily supported
776 The Cyrix 6x86, 6x86MX and M II processors have Address Range
777 Registers (ARRs) which provide a similar functionality to MTRRs. For
778 these, the ARRs are used to emulate the MTRRs.
779 The AMD K6-2 (stepping 8 and above) and K6-3 processors have two
780 MTRRs. The Centaur C6 (WinChip) has 8 MCRs, allowing
781 write-combining. All of these processors are supported by this code
782 and it makes sense to say Y here if you have one of them.
784 Saying Y here also fixes a problem with buggy SMP BIOSes which only
785 set the MTRRs for the boot CPU and not for the secondary CPUs. This
786 can lead to all sorts of problems, so it's good to say Y here.
788 You can safely say Y even if your machine doesn't have MTRRs, you'll
789 just add about 9 KB to your kernel.
791 See <file:Documentation/mtrr.txt> for more information.
794 bool "Boot from EFI support (EXPERIMENTAL)"
799 This enables the the kernel to boot on EFI platforms using
800 system configuration information passed to it from the firmware.
801 This also enables the kernel to use any EFI runtime services that are
802 available (such as the EFI variable services).
804 This option is only useful on systems that have EFI firmware
805 and will result in a kernel image that is ~8k larger. In addition,
806 you must use the latest ELILO loader available at
807 ftp.hpl.hp.com/pub/linux-ia64/ in order to take advantage of kernel
808 initialization using EFI information (neither GRUB nor LILO know
809 anything about EFI). However, even with this option, the resultant
810 kernel should continue to boot on existing non-EFI platforms.
814 depends on (SMP || PREEMPT) && X86_CMPXCHG
817 # turning this on wastes a bunch of space.
818 # Summit needs it only when NUMA is on
821 depends on (((X86_SUMMIT || X86_GENERICARCH) && NUMA) || (X86 && EFI))
825 bool "Use register arguments (EXPERIMENTAL)"
828 Compile the kernel with -mregparm=3. This uses an different ABI
829 and passes the first three arguments of a function call in registers.
830 This will probably break binary only modules.
834 menu "Special options"
837 bool "proc/mm support"
839 /proc/mm is used by a User Mode Linux kernel to support SKAS
840 mode. If you need this, you'll know it.
844 menu "Power management options (ACPI, APM)"
845 depends on !X86_VOYAGER
847 source kernel/power/Kconfig
849 source "drivers/acpi/Kconfig"
851 menu "APM (Advanced Power Management) BIOS Support"
855 tristate "APM (Advanced Power Management) BIOS support"
858 APM is a BIOS specification for saving power using several different
859 techniques. This is mostly useful for battery powered laptops with
860 APM compliant BIOSes. If you say Y here, the system time will be
861 reset after a RESUME operation, the /proc/apm device will provide
862 battery status information, and user-space programs will receive
863 notification of APM "events" (e.g. battery status change).
865 If you select "Y" here, you can disable actual use of the APM
866 BIOS by passing the "apm=off" option to the kernel at boot time.
868 Note that the APM support is almost completely disabled for
869 machines with more than one CPU.
871 In order to use APM, you will need supporting software. For location
872 and more information, read <file:Documentation/pm.txt> and the
873 Battery Powered Linux mini-HOWTO, available from
874 <http://www.tldp.org/docs.html#howto>.
876 This driver does not spin down disk drives (see the hdparm(8)
877 manpage ("man 8 hdparm") for that), and it doesn't turn off
878 VESA-compliant "green" monitors.
880 This driver does not support the TI 4000M TravelMate and the ACER
881 486/DX4/75 because they don't have compliant BIOSes. Many "green"
882 desktop machines also don't have compliant BIOSes, and this driver
883 may cause those machines to panic during the boot phase.
885 Generally, if you don't have a battery in your machine, there isn't
886 much point in using this driver and you should say N. If you get
887 random kernel OOPSes or reboots that don't seem to be related to
888 anything, try disabling/enabling this option (or disabling/enabling
891 Some other things you should try when experiencing seemingly random,
894 1) make sure that you have enough swap space and that it is
896 2) pass the "no-hlt" option to the kernel
897 3) switch on floating point emulation in the kernel and pass
898 the "no387" option to the kernel
899 4) pass the "floppy=nodma" option to the kernel
900 5) pass the "mem=4M" option to the kernel (thereby disabling
901 all but the first 4 MB of RAM)
902 6) make sure that the CPU is not over clocked.
903 7) read the sig11 FAQ at <http://www.bitwizard.nl/sig11/>
904 8) disable the cache from your BIOS settings
905 9) install a fan for the video card or exchange video RAM
906 10) install a better fan for the CPU
907 11) exchange RAM chips
908 12) exchange the motherboard.
910 To compile this driver as a module, choose M here: the
911 module will be called apm.
913 config APM_IGNORE_USER_SUSPEND
914 bool "Ignore USER SUSPEND"
917 This option will ignore USER SUSPEND requests. On machines with a
918 compliant APM BIOS, you want to say N. However, on the NEC Versa M
919 series notebooks, it is necessary to say Y because of a BIOS bug.
922 bool "Enable PM at boot time"
925 Enable APM features at boot time. From page 36 of the APM BIOS
926 specification: "When disabled, the APM BIOS does not automatically
927 power manage devices, enter the Standby State, enter the Suspend
928 State, or take power saving steps in response to CPU Idle calls."
929 This driver will make CPU Idle calls when Linux is idle (unless this
930 feature is turned off -- see "Do CPU IDLE calls", below). This
931 should always save battery power, but more complicated APM features
932 will be dependent on your BIOS implementation. You may need to turn
933 this option off if your computer hangs at boot time when using APM
934 support, or if it beeps continuously instead of suspending. Turn
935 this off if you have a NEC UltraLite Versa 33/C or a Toshiba
936 T400CDT. This is off by default since most machines do fine without
940 bool "Make CPU Idle calls when idle"
943 Enable calls to APM CPU Idle/CPU Busy inside the kernel's idle loop.
944 On some machines, this can activate improved power savings, such as
945 a slowed CPU clock rate, when the machine is idle. These idle calls
946 are made after the idle loop has run for some length of time (e.g.,
947 333 mS). On some machines, this will cause a hang at boot time or
948 whenever the CPU becomes idle. (On machines with more than one CPU,
949 this option does nothing.)
951 config APM_DISPLAY_BLANK
952 bool "Enable console blanking using APM"
955 Enable console blanking using the APM. Some laptops can use this to
956 turn off the LCD backlight when the screen blanker of the Linux
957 virtual console blanks the screen. Note that this is only used by
958 the virtual console screen blanker, and won't turn off the backlight
959 when using the X Window system. This also doesn't have anything to
960 do with your VESA-compliant power-saving monitor. Further, this
961 option doesn't work for all laptops -- it might not turn off your
962 backlight at all, or it might print a lot of errors to the console,
963 especially if you are using gpm.
965 config APM_RTC_IS_GMT
966 bool "RTC stores time in GMT"
969 Say Y here if your RTC (Real Time Clock a.k.a. hardware clock)
970 stores the time in GMT (Greenwich Mean Time). Say N if your RTC
973 It is in fact recommended to store GMT in your RTC, because then you
974 don't have to worry about daylight savings time changes. The only
975 reason not to use GMT in your RTC is if you also run a broken OS
976 that doesn't understand GMT.
978 config APM_ALLOW_INTS
979 bool "Allow interrupts during APM BIOS calls"
982 Normally we disable external interrupts while we are making calls to
983 the APM BIOS as a measure to lessen the effects of a badly behaving
984 BIOS implementation. The BIOS should reenable interrupts if it
985 needs to. Unfortunately, some BIOSes do not -- especially those in
986 many of the newer IBM Thinkpads. If you experience hangs when you
987 suspend, try setting this to Y. Otherwise, say N.
989 config APM_REAL_MODE_POWER_OFF
990 bool "Use real mode APM BIOS call to power off"
993 Use real mode APM BIOS calls to switch off the computer. This is
994 a work-around for a number of buggy BIOSes. Switch this option on if
995 your computer crashes instead of powering off properly.
999 source "arch/i386/kernel/cpu/cpufreq/Kconfig"
1004 menu "Bus options (PCI, PCMCIA, EISA, MCA, ISA)"
1006 config X86_VISWS_APIC
1008 depends on X86_VISWS
1011 config X86_LOCAL_APIC
1013 depends on (X86_VISWS || SMP) && !X86_VOYAGER
1018 depends on SMP && !(X86_VISWS || X86_VOYAGER)
1022 bool "PCI support" if !X86_VISWS
1023 depends on !X86_VOYAGER
1024 default y if X86_VISWS
1026 Find out whether you have a PCI motherboard. PCI is the name of a
1027 bus system, i.e. the way the CPU talks to the other stuff inside
1028 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1029 VESA. If you have PCI, say Y, otherwise N.
1031 The PCI-HOWTO, available from
1032 <http://www.tldp.org/docs.html#howto>, contains valuable
1033 information about which PCI hardware does work under Linux and which
1037 prompt "PCI access mode"
1038 depends on PCI && !X86_VISWS
1044 On PCI systems, the BIOS can be used to detect the PCI devices and
1045 determine their configuration. However, some old PCI motherboards
1046 have BIOS bugs and may crash if this is done. Also, some embedded
1047 PCI-based systems don't have any BIOS at all. Linux can also try to
1048 detect the PCI hardware directly without using the BIOS.
1050 With this option, you can specify how Linux should detect the PCI
1051 devices. If you choose "BIOS", the BIOS will be used, if you choose
1052 "Direct", the BIOS won't be used, and if you choose "Any", the
1053 kernel will try the direct access method and falls back to the BIOS
1054 if that doesn't work. If unsure, go with the default, which is
1067 depends on !X86_VISWS && PCI && (PCI_GOBIOS || PCI_GOANY)
1072 depends on PCI && ((PCI_GODIRECT || PCI_GOANY) || X86_VISWS)
1075 config PCI_USE_VECTOR
1076 bool "Vector-based interrupt indexing"
1077 depends on X86_LOCAL_APIC && X86_IO_APIC
1080 This replaces the current existing IRQ-based index interrupt scheme
1081 with the vector-base index scheme. The advantages of vector base
1082 over IRQ base are listed below:
1083 1) Support MSI implementation.
1084 2) Support future IOxAPIC hotplug
1086 Note that this enables MSI, Message Signaled Interrupt, on all
1087 MSI capable device functions detected if users also install the
1088 MSI patch. Message Signal Interrupt enables an MSI-capable
1089 hardware device to send an inbound Memory Write on its PCI bus
1090 instead of asserting IRQ signal on device IRQ pin.
1092 If you don't know what to do here, say N.
1094 source "drivers/pci/Kconfig"
1098 depends on !(X86_VOYAGER || X86_VISWS)
1100 Find out whether you have ISA slots on your motherboard. ISA is the
1101 name of a bus system, i.e. the way the CPU talks to the other stuff
1102 inside your box. Other bus systems are PCI, EISA, MicroChannel
1103 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1104 newer boards don't support it. If you have ISA, say Y, otherwise N.
1110 The Extended Industry Standard Architecture (EISA) bus was
1111 developed as an open alternative to the IBM MicroChannel bus.
1113 The EISA bus provided some of the features of the IBM MicroChannel
1114 bus while maintaining backward compatibility with cards made for
1115 the older ISA bus. The EISA bus saw limited use between 1988 and
1116 1995 when it was made obsolete by the PCI bus.
1118 Say Y here if you are building a kernel for an EISA-based machine.
1122 source "drivers/eisa/Kconfig"
1126 depends on !(X86_VISWS || X86_VOYAGER)
1128 MicroChannel Architecture is found in some IBM PS/2 machines and
1129 laptops. It is a bus system similar to PCI or ISA. See
1130 <file:Documentation/mca.txt> (and especially the web page given
1131 there) before attempting to build an MCA bus kernel.
1134 depends on X86_VOYAGER
1135 default y if X86_VOYAGER
1137 source "drivers/mca/Kconfig"
1140 tristate "NatSemi SCx200 support"
1141 depends on !X86_VOYAGER
1143 This provides basic support for the National Semiconductor SCx200
1144 processor. Right now this is just a driver for the GPIO pins.
1146 If you don't know what to do here, say N.
1148 This support is also available as a module. If compiled as a
1149 module, it will be called scx200.
1152 bool "Support for hot-pluggable devices"
1154 Say Y here if you want to plug devices into your computer while
1155 the system is running, and be able to use them quickly. In many
1156 cases, the devices can likewise be unplugged at any time too.
1158 One well known example of this is PCMCIA- or PC-cards, credit-card
1159 size devices such as network cards, modems or hard drives which are
1160 plugged into slots found on all modern laptop computers. Another
1161 example, used on modern desktops as well as laptops, is USB.
1163 Enable HOTPLUG and KMOD, and build a modular kernel. Get agent
1164 software (at <http://linux-hotplug.sourceforge.net/>) and install it.
1165 Then your kernel will automatically call out to a user mode "policy
1166 agent" (/sbin/hotplug) to load modules and set up software needed
1167 to use devices as you hotplug them.
1169 source "drivers/pcmcia/Kconfig"
1171 source "drivers/pci/hotplug/Kconfig"
1176 menu "Executable file formats"
1178 source "fs/Kconfig.binfmt"
1182 source "drivers/Kconfig"
1186 source "arch/i386/oprofile/Kconfig"
1189 menu "Kernel hacking"
1192 bool "Kernel debugging"
1194 Say Y here if you are developing drivers or trying to debug and
1195 identify kernel problems.
1201 config DEBUG_STACKOVERFLOW
1202 bool "Check for stack overflows"
1203 depends on DEBUG_KERNEL
1206 bool "Debug memory allocations"
1207 depends on DEBUG_KERNEL
1209 Say Y here to have the kernel do limited verification on memory
1210 allocation as well as poisoning memory on free to catch use of freed
1214 bool "Memory mapped I/O debugging"
1215 depends on DEBUG_KERNEL
1217 Say Y here to get warned whenever an attempt is made to do I/O on
1218 obviously invalid addresses such as those generated when ioremap()
1219 calls are forgotten. Memory mapped I/O will go through an extra
1220 check to catch access to unmapped ISA addresses, an access method
1221 that can still be used by old drivers that are being ported from
1225 bool "Magic SysRq key"
1226 depends on DEBUG_KERNEL
1228 If you say Y here, you will have some control over the system even
1229 if the system crashes for example during kernel debugging (e.g., you
1230 will be able to flush the buffer cache to disk, reboot the system
1231 immediately or dump some status information). This is accomplished
1232 by pressing various keys while holding SysRq (Alt+PrintScreen). It
1233 also works on a serial console (on PC hardware at least), if you
1234 send a BREAK and then within 5 seconds a command keypress. The
1235 keys are documented in <file:Documentation/sysrq.txt>. Don't say Y
1236 unless you really know what this hack does.
1238 config DEBUG_SPINLOCK
1239 bool "Spinlock debugging"
1240 depends on DEBUG_KERNEL
1242 Say Y here and build SMP to catch missing spinlock initialization
1243 and certain other kinds of spinlock errors commonly made. This is
1244 best used in conjunction with the NMI watchdog so that spinlock
1245 deadlocks are also debuggable.
1247 config DEBUG_PAGEALLOC
1248 bool "Page alloc debugging"
1249 depends on DEBUG_KERNEL
1251 Unmap pages from the kernel linear mapping after free_pages().
1252 This results in a large slowdown, but helps to find certain types
1253 of memory corruptions.
1255 config DEBUG_HIGHMEM
1256 bool "Highmem debugging"
1257 depends on DEBUG_KERNEL && HIGHMEM
1259 This options enables addition error checking for high memory systems.
1260 Disable for production systems.
1263 bool "Compile the kernel with debug info"
1264 depends on DEBUG_KERNEL
1266 If you say Y here the resulting kernel image will include
1267 debugging info resulting in a larger kernel image.
1268 Say Y here only if you plan to use gdb to debug the kernel.
1269 If you don't debug the kernel, you can say N.
1271 config DEBUG_SPINLOCK_SLEEP
1272 bool "Sleep-inside-spinlock checking"
1274 If you say Y here, various routines which may sleep will become very
1275 noisy if they are called with a spinlock held.
1277 config FRAME_POINTER
1278 bool "Compile the kernel with frame pointers"
1280 If you say Y here the resulting kernel image will be slightly larger
1281 and slower, but it will give very useful debugging information.
1282 If you don't debug the kernel, you can say N, but we may not be able
1283 to solve problems without frame pointers.
1285 config X86_FIND_SMP_CONFIG
1287 depends on X86_LOCAL_APIC || X86_VOYAGER
1292 depends on X86_LOCAL_APIC && !X86_VISWS
1297 source "security/Kconfig"
1299 source "crypto/Kconfig"
1301 source "lib/Kconfig"
1303 source "rpmify/Kconfig"
1307 depends on SMP && !X86_VOYAGER
1312 depends on SMP && !(X86_VISWS || X86_VOYAGER)
1315 config X86_BIOS_REBOOT
1317 depends on !(X86_VISWS || X86_VOYAGER)
1320 config X86_TRAMPOLINE
1322 depends on SMP || X86_VISWS
1327 depends on X86 && !EMBEDDED
projects / linux-flexiantxendom0-3.2.10.git / blob