2 # For a description of the syntax of this configuration file,
3 # see Documentation/kbuild/kconfig-language.txt.
6 mainmenu "Linux Kernel Configuration"
14 select SYS_SUPPORTS_APM_EMULATION
15 select GENERIC_ATOMIC64 if (!CPU_32v6K)
18 select HAVE_KPROBES if (!XIP_KERNEL)
19 select HAVE_KRETPROBES if (HAVE_KPROBES)
20 select HAVE_FUNCTION_TRACER if (!XIP_KERNEL)
21 select HAVE_GENERIC_DMA_COHERENT
22 select HAVE_KERNEL_GZIP
23 select HAVE_KERNEL_LZO
24 select HAVE_PERF_EVENTS
25 select PERF_USE_VMALLOC
27 The ARM series is a line of low-power-consumption RISC chip designs
28 licensed by ARM Ltd and targeted at embedded applications and
29 handhelds such as the Compaq IPAQ. ARM-based PCs are no longer
30 manufactured, but legacy ARM-based PC hardware remains popular in
31 Europe. There is an ARM Linux project with a web page at
32 <http://www.arm.linux.org.uk/>.
37 config SYS_SUPPORTS_APM_EMULATION
46 config GENERIC_CLOCKEVENTS
49 config GENERIC_CLOCKEVENTS_BROADCAST
51 depends on GENERIC_CLOCKEVENTS
52 default y if SMP && !LOCAL_TIMERS
56 select GENERIC_ALLOCATOR
67 The Extended Industry Standard Architecture (EISA) bus was
68 developed as an open alternative to the IBM MicroChannel bus.
70 The EISA bus provided some of the features of the IBM MicroChannel
71 bus while maintaining backward compatibility with cards made for
72 the older ISA bus. The EISA bus saw limited use between 1988 and
73 1995 when it was made obsolete by the PCI bus.
75 Say Y here if you are building a kernel for an EISA-based machine.
85 MicroChannel Architecture is found in some IBM PS/2 machines and
86 laptops. It is a bus system similar to PCI or ISA. See
87 <file:Documentation/mca.txt> (and especially the web page given
88 there) before attempting to build an MCA bus kernel.
90 config GENERIC_HARDIRQS
94 config STACKTRACE_SUPPORT
98 config HAVE_LATENCYTOP_SUPPORT
103 config LOCKDEP_SUPPORT
107 config TRACE_IRQFLAGS_SUPPORT
111 config HARDIRQS_SW_RESEND
115 config GENERIC_IRQ_PROBE
119 config GENERIC_LOCKBREAK
122 depends on SMP && PREEMPT
124 config RWSEM_GENERIC_SPINLOCK
128 config RWSEM_XCHGADD_ALGORITHM
131 config ARCH_HAS_ILOG2_U32
134 config ARCH_HAS_ILOG2_U64
137 config ARCH_HAS_CPUFREQ
140 Internal node to signify that the ARCH has CPUFREQ support
141 and that the relevant menu configurations are displayed for
144 config GENERIC_HWEIGHT
148 config GENERIC_CALIBRATE_DELAY
152 config ARCH_MAY_HAVE_PC_FDC
158 config NEED_DMA_MAP_STATE
161 config GENERIC_ISA_DMA
170 config GENERIC_HARDIRQS_NO__DO_IRQ
173 config ARM_L1_CACHE_SHIFT_6
176 Setting ARM L1 cache line size to 64 Bytes.
180 config OPROFILE_ARMV6
182 depends on CPU_V6 && !SMP
183 select OPROFILE_ARM11_CORE
185 config OPROFILE_MPCORE
187 depends on CPU_V6 && SMP
188 select OPROFILE_ARM11_CORE
190 config OPROFILE_ARM11_CORE
193 config OPROFILE_ARMV7
195 depends on CPU_V7 && !SMP
202 default 0xffff0000 if MMU || CPU_HIGH_VECTOR
203 default DRAM_BASE if REMAP_VECTORS_TO_RAM
206 The base address of exception vectors.
208 source "init/Kconfig"
210 source "kernel/Kconfig.freezer"
215 bool "MMU-based Paged Memory Management Support"
218 Select if you want MMU-based virtualised addressing space
219 support by paged memory management. If unsure, say 'Y'.
222 prompt "ARM system type"
223 default ARCH_VERSATILE
226 bool "Agilent AAEC-2000 based"
231 This enables support for systems based on the Agilent AAEC-2000
233 config ARCH_INTEGRATOR
234 bool "ARM Ltd. Integrator family"
236 select ARCH_HAS_CPUFREQ
241 Support for ARM's Integrator platform.
244 bool "ARM Ltd. RealView family"
250 select GENERIC_CLOCKEVENTS
251 select ARCH_WANT_OPTIONAL_GPIOLIB
253 This enables support for ARM Ltd RealView boards.
255 config ARCH_VERSATILE
256 bool "ARM Ltd. Versatile family"
263 select GENERIC_CLOCKEVENTS
264 select ARCH_WANT_OPTIONAL_GPIOLIB
266 This enables support for ARM Ltd Versatile board.
271 select ARCH_REQUIRE_GPIOLIB
274 This enables support for systems based on the Atmel AT91RM9200,
275 AT91SAM9 and AT91CAP9 processors.
278 bool "Cirrus Logic CLPS711x/EP721x-based"
281 Support for Cirrus Logic 711x/721x based boards.
284 bool "Cortina Systems Gemini"
287 select ARCH_REQUIRE_GPIOLIB
289 Support for the Cortina Systems Gemini family SoCs
297 This is an evaluation board for the StrongARM processor available
298 from Digital. It has limited hardware on-board, including an
299 Ethernet interface, two PCMCIA sockets, two serial ports and a
310 select ARCH_REQUIRE_GPIOLIB
311 select ARCH_HAS_HOLES_MEMORYMODEL
313 This enables support for the Cirrus EP93xx series of CPUs.
315 config ARCH_FOOTBRIDGE
320 Support for systems based on the DC21285 companion chip
321 ("FootBridge"), such as the Simtec CATS and the Rebel NetWinder.
324 bool "Freescale MXC/iMX-based"
326 select GENERIC_CLOCKEVENTS
329 select ARCH_REQUIRE_GPIOLIB
332 Support for Freescale MXC/iMX-based family of processors
335 bool "Freescale STMP3xxx"
339 select ARCH_REQUIRE_GPIOLIB
341 select GENERIC_CLOCKEVENTS
343 select USB_ARCH_HAS_EHCI
345 Support for systems based on the Freescale 3xxx CPUs.
348 bool "Hilscher NetX based"
351 select GENERIC_CLOCKEVENTS
354 This enables support for systems based on the Hilscher NetX Soc
357 bool "Hynix HMS720x-based"
361 This enables support for systems based on the Hynix HMS720x
364 bool "STMicroelectronics Nomadik"
371 select GENERIC_CLOCKEVENTS
373 select ARCH_REQUIRE_GPIOLIB
375 Support for the Nomadik platform by ST-Ericsson
383 select ARCH_SUPPORTS_MSI
386 Support for Intel's IOP13XX (XScale) family of processors.
395 select ARCH_REQUIRE_GPIOLIB
397 Support for Intel's 80219 and IOP32X (XScale) family of
407 select ARCH_REQUIRE_GPIOLIB
409 Support for Intel's IOP33X (XScale) family of processors.
417 Support for Intel's IXP23xx (XScale) family of processors.
420 bool "IXP2400/2800-based"
425 Support for Intel's IXP2400/2800 (XScale) family of processors.
433 select GENERIC_CLOCKEVENTS
434 select DMABOUNCE if PCI
436 Support for Intel's IXP4XX (XScale) family of processors.
443 Say Y here if you intend to run this kernel on a LinkUp Systems
444 L7200 Software Development Board which uses an ARM720T processor.
445 Information on this board can be obtained at:
447 <http://www.linkupsys.com/>
449 If you have any questions or comments about the Linux kernel port
450 to this board, send e-mail to <sjhill@cotw.com>.
456 select ARCH_REQUIRE_GPIOLIB
458 select GENERIC_CLOCKEVENTS
461 Support for the Marvell Dove SoC 88AP510
464 bool "Marvell Kirkwood"
468 select ARCH_REQUIRE_GPIOLIB
470 select GENERIC_CLOCKEVENTS
473 Support for the following Marvell Kirkwood series SoCs:
474 88F6180, 88F6192 and 88F6281.
477 bool "Marvell Loki (88RC8480)"
480 select GENERIC_CLOCKEVENTS
483 Support for the Marvell Loki (88RC8480) SoC.
486 bool "Marvell MV78xx0"
490 select ARCH_REQUIRE_GPIOLIB
492 select GENERIC_CLOCKEVENTS
495 Support for the following Marvell MV78xx0 series SoCs:
504 select ARCH_REQUIRE_GPIOLIB
506 select GENERIC_CLOCKEVENTS
509 Support for the following Marvell Orion 5x series SoCs:
510 Orion-1 (5181), Orion-VoIP (5181L), Orion-NAS (5182),
511 Orion-2 (5281), Orion-1-90 (6183).
514 bool "Marvell PXA168/910"
517 select ARCH_REQUIRE_GPIOLIB
521 select GENERIC_CLOCKEVENTS
525 Support for Marvell's PXA168/910 processor line.
528 bool "Micrel/Kendin KS8695"
531 select ARCH_REQUIRE_GPIOLIB
533 Support for Micrel/Kendin KS8695 "Centaur" (ARM922T) based
534 System-on-Chip devices.
537 bool "NetSilicon NS9xxx"
541 select GENERIC_CLOCKEVENTS
544 Say Y here if you intend to run this kernel on a NetSilicon NS9xxx
547 <http://www.digi.com/products/microprocessors/index.jsp>
550 bool "Nuvoton W90X900 CPU"
552 select ARCH_REQUIRE_GPIOLIB
557 select GENERIC_CLOCKEVENTS
559 Support for Nuvoton (Winbond logic dept.) ARM9 processor,
560 At present, the w90x900 has been renamed nuc900, regarding
561 the ARM series product line, you can login the following
562 link address to know more.
564 <http://www.nuvoton.com/hq/enu/ProductAndSales/ProductLines/
565 ConsumerElectronicsIC/ARMMicrocontroller/ARMMicrocontroller>
568 bool "Nuvoton NUC93X CPU"
573 Support for Nuvoton (Winbond logic dept.) NUC93X MCU,The NUC93X is a
574 low-power and high performance MPEG-4/JPEG multimedia controller chip.
577 bool "Philips Nexperia PNX4008 Mobile"
582 This enables support for Philips PNX4008 mobile platform.
585 bool "PXA2xx/PXA3xx-based"
588 select ARCH_HAS_CPUFREQ
592 select ARCH_REQUIRE_GPIOLIB
594 select GENERIC_CLOCKEVENTS
598 Support for Intel/Marvell's PXA2xx/PXA3xx processor line.
604 select GENERIC_CLOCKEVENTS
606 Support for Qualcomm MSM7K based systems. This runs on the ARM11
607 apps processor of the MSM7K and depends on a shared memory
608 interface to the ARM9 modem processor which runs the baseband stack
609 and controls some vital subsystems (clock and power control, etc).
616 select ARCH_MAY_HAVE_PC_FDC
617 select HAVE_PATA_PLATFORM
620 select ARCH_SPARSEMEM_ENABLE
622 On the Acorn Risc-PC, Linux can support the internal IDE disk and
623 CD-ROM interface, serial and parallel port, and the floppy drive.
629 select ARCH_SPARSEMEM_ENABLE
631 select ARCH_HAS_CPUFREQ
635 select GENERIC_CLOCKEVENTS
638 select ARCH_REQUIRE_GPIOLIB
640 Support for StrongARM 11x0 based boards.
643 bool "Samsung S3C2410, S3C2412, S3C2413, S3C2440, S3C2442, S3C2443"
645 select ARCH_HAS_CPUFREQ
648 Samsung S3C2410X CPU based systems, such as the Simtec Electronics
649 BAST (<http://www.simtec.co.uk/products/EB110ITX/>), the IPAQ 1940 or
650 the Samsung SMDK2410 development board (and derivatives).
653 bool "Samsung S3C64XX"
656 select ARCH_HAS_CPUFREQ
658 Samsung S3C64XX series based systems
661 bool "Samsung S5PC1XX"
665 select ARM_L1_CACHE_SHIFT_6
667 Samsung S5PC1XX series based systems
677 Support for the StrongARM based Digital DNARD machine, also known
678 as "Shark" (<http://www.shark-linux.de/shark.html>).
683 select ARCH_DISCONTIGMEM_ENABLE if !LH7A40X_CONTIGMEM
684 select ARCH_SPARSEMEM_ENABLE if !LH7A40X_CONTIGMEM
686 Say Y here for systems based on one of the Sharp LH7A40X
687 System on a Chip processors. These CPUs include an ARM922T
688 core with a wide array of integrated devices for
689 hand-held and low-power applications.
692 bool "ST-Ericsson U300 Series"
699 select GENERIC_CLOCKEVENTS
704 Support for ST-Ericsson U300 series mobile platforms.
710 select GENERIC_CLOCKEVENTS
712 select ARCH_REQUIRE_GPIOLIB
717 select GENERIC_ALLOCATOR
718 select ARCH_HAS_HOLES_MEMORYMODEL
720 Support for TI's DaVinci platform.
726 select ARCH_REQUIRE_GPIOLIB
727 select ARCH_HAS_CPUFREQ
729 select GENERIC_CLOCKEVENTS
730 select ARCH_HAS_HOLES_MEMORYMODEL
732 Support for TI's OMAP platform (OMAP1 and OMAP2).
735 bool "Broadcom BCMRING"
741 select GENERIC_CLOCKEVENTS
742 select ARCH_WANT_OPTIONAL_GPIOLIB
744 Support for Broadcom's BCMRing platform.
747 bool "ST-Ericsson U8500 Series"
751 select GENERIC_CLOCKEVENTS
754 Support for ST-Ericsson's Ux500 architecture
758 source "arch/arm/mach-aaec2000/Kconfig"
760 source "arch/arm/mach-at91/Kconfig"
762 source "arch/arm/mach-bcmring/Kconfig"
764 source "arch/arm/mach-clps711x/Kconfig"
766 source "arch/arm/mach-davinci/Kconfig"
768 source "arch/arm/mach-dove/Kconfig"
770 source "arch/arm/mach-ep93xx/Kconfig"
772 source "arch/arm/mach-footbridge/Kconfig"
774 source "arch/arm/mach-gemini/Kconfig"
776 source "arch/arm/mach-h720x/Kconfig"
778 source "arch/arm/mach-integrator/Kconfig"
780 source "arch/arm/mach-iop32x/Kconfig"
782 source "arch/arm/mach-iop33x/Kconfig"
784 source "arch/arm/mach-iop13xx/Kconfig"
786 source "arch/arm/mach-ixp4xx/Kconfig"
788 source "arch/arm/mach-ixp2000/Kconfig"
790 source "arch/arm/mach-ixp23xx/Kconfig"
792 source "arch/arm/mach-kirkwood/Kconfig"
794 source "arch/arm/mach-ks8695/Kconfig"
796 source "arch/arm/mach-lh7a40x/Kconfig"
798 source "arch/arm/mach-loki/Kconfig"
800 source "arch/arm/mach-msm/Kconfig"
802 source "arch/arm/mach-mv78xx0/Kconfig"
804 source "arch/arm/plat-mxc/Kconfig"
806 source "arch/arm/mach-netx/Kconfig"
808 source "arch/arm/mach-nomadik/Kconfig"
809 source "arch/arm/plat-nomadik/Kconfig"
811 source "arch/arm/mach-ns9xxx/Kconfig"
813 source "arch/arm/mach-nuc93x/Kconfig"
815 source "arch/arm/plat-omap/Kconfig"
817 source "arch/arm/mach-omap1/Kconfig"
819 source "arch/arm/mach-omap2/Kconfig"
821 source "arch/arm/mach-orion5x/Kconfig"
823 source "arch/arm/mach-pxa/Kconfig"
824 source "arch/arm/plat-pxa/Kconfig"
826 source "arch/arm/mach-mmp/Kconfig"
828 source "arch/arm/mach-realview/Kconfig"
830 source "arch/arm/mach-sa1100/Kconfig"
832 source "arch/arm/plat-samsung/Kconfig"
833 source "arch/arm/plat-s3c24xx/Kconfig"
834 source "arch/arm/plat-s3c64xx/Kconfig"
835 source "arch/arm/plat-s3c/Kconfig"
836 source "arch/arm/plat-s5pc1xx/Kconfig"
839 source "arch/arm/mach-s3c2400/Kconfig"
840 source "arch/arm/mach-s3c2410/Kconfig"
841 source "arch/arm/mach-s3c2412/Kconfig"
842 source "arch/arm/mach-s3c2440/Kconfig"
843 source "arch/arm/mach-s3c2442/Kconfig"
844 source "arch/arm/mach-s3c2443/Kconfig"
848 source "arch/arm/mach-s3c6400/Kconfig"
849 source "arch/arm/mach-s3c6410/Kconfig"
852 source "arch/arm/plat-stmp3xxx/Kconfig"
855 source "arch/arm/mach-s5pc100/Kconfig"
858 source "arch/arm/mach-u300/Kconfig"
860 source "arch/arm/mach-ux500/Kconfig"
862 source "arch/arm/mach-versatile/Kconfig"
864 source "arch/arm/mach-w90x900/Kconfig"
866 # Definitions to make life easier
872 select GENERIC_CLOCKEVENTS
881 source arch/arm/mm/Kconfig
884 bool "Enable iWMMXt support"
885 depends on CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK
886 default y if PXA27x || PXA3xx || ARCH_MMP
888 Enable support for iWMMXt context switching at run time if
889 running on a CPU that supports it.
891 # bool 'Use XScale PMU as timer source' CONFIG_XSCALE_PMU_TIMER
894 depends on CPU_XSCALE && !XSCALE_PMU_TIMER
898 depends on CPU_V6 || CPU_V7 || XSCALE_PMU
903 source "arch/arm/Kconfig-nommu"
906 config ARM_ERRATA_411920
907 bool "ARM errata: Invalidation of the Instruction Cache operation can fail"
908 depends on CPU_V6 && !SMP
910 Invalidation of the Instruction Cache operation can
911 fail. This erratum is present in 1136 (before r1p4), 1156 and 1176.
912 It does not affect the MPCore. This option enables the ARM Ltd.
913 recommended workaround.
915 config ARM_ERRATA_430973
916 bool "ARM errata: Stale prediction on replaced interworking branch"
919 This option enables the workaround for the 430973 Cortex-A8
920 (r1p0..r1p2) erratum. If a code sequence containing an ARM/Thumb
921 interworking branch is replaced with another code sequence at the
922 same virtual address, whether due to self-modifying code or virtual
923 to physical address re-mapping, Cortex-A8 does not recover from the
924 stale interworking branch prediction. This results in Cortex-A8
925 executing the new code sequence in the incorrect ARM or Thumb state.
926 The workaround enables the BTB/BTAC operations by setting ACTLR.IBE
927 and also flushes the branch target cache at every context switch.
928 Note that setting specific bits in the ACTLR register may not be
929 available in non-secure mode.
931 config ARM_ERRATA_458693
932 bool "ARM errata: Processor deadlock when a false hazard is created"
935 This option enables the workaround for the 458693 Cortex-A8 (r2p0)
936 erratum. For very specific sequences of memory operations, it is
937 possible for a hazard condition intended for a cache line to instead
938 be incorrectly associated with a different cache line. This false
939 hazard might then cause a processor deadlock. The workaround enables
940 the L1 caching of the NEON accesses and disables the PLD instruction
941 in the ACTLR register. Note that setting specific bits in the ACTLR
942 register may not be available in non-secure mode.
944 config ARM_ERRATA_460075
945 bool "ARM errata: Data written to the L2 cache can be overwritten with stale data"
948 This option enables the workaround for the 460075 Cortex-A8 (r2p0)
949 erratum. Any asynchronous access to the L2 cache may encounter a
950 situation in which recent store transactions to the L2 cache are lost
951 and overwritten with stale memory contents from external memory. The
952 workaround disables the write-allocate mode for the L2 cache via the
953 ACTLR register. Note that setting specific bits in the ACTLR register
954 may not be available in non-secure mode.
956 config PL310_ERRATA_588369
957 bool "Clean & Invalidate maintenance operations do not invalidate clean lines"
958 depends on CACHE_L2X0 && ARCH_OMAP4
960 The PL310 L2 cache controller implements three types of Clean &
961 Invalidate maintenance operations: by Physical Address
962 (offset 0x7F0), by Index/Way (0x7F8) and by Way (0x7FC).
963 They are architecturally defined to behave as the execution of a
964 clean operation followed immediately by an invalidate operation,
965 both performing to the same memory location. This functionality
966 is not correctly implemented in PL310 as clean lines are not
967 invalidated as a result of these operations. Note that this errata
968 uses Texas Instrument's secure monitor api.
971 source "arch/arm/common/Kconfig"
973 config FORCE_MAX_ZONEORDER
986 Find out whether you have ISA slots on your motherboard. ISA is the
987 name of a bus system, i.e. the way the CPU talks to the other stuff
988 inside your box. Other bus systems are PCI, EISA, MicroChannel
989 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
990 newer boards don't support it. If you have ISA, say Y, otherwise N.
992 # Select ISA DMA controller support
997 # Select ISA DMA interface
1002 bool "PCI support" if ARCH_INTEGRATOR_AP || ARCH_VERSATILE_PB || ARCH_IXP4XX || ARCH_KS8695 || MACH_ARMCORE
1004 Find out whether you have a PCI motherboard. PCI is the name of a
1005 bus system, i.e. the way the CPU talks to the other stuff inside
1006 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1007 VESA. If you have PCI, say Y, otherwise N.
1012 # Select the host bridge type
1013 config PCI_HOST_VIA82C505
1015 depends on PCI && ARCH_SHARK
1018 config PCI_HOST_ITE8152
1020 depends on PCI && MACH_ARMCORE
1024 source "drivers/pci/Kconfig"
1026 source "drivers/pcmcia/Kconfig"
1030 menu "Kernel Features"
1032 source "kernel/time/Kconfig"
1035 bool "Symmetric Multi-Processing (EXPERIMENTAL)"
1036 depends on EXPERIMENTAL && (REALVIEW_EB_ARM11MP || REALVIEW_EB_A9MP ||\
1037 MACH_REALVIEW_PB11MP || MACH_REALVIEW_PBX || ARCH_OMAP4 || ARCH_U8500)
1038 depends on GENERIC_CLOCKEVENTS
1039 select USE_GENERIC_SMP_HELPERS
1040 select HAVE_ARM_SCU if (ARCH_REALVIEW || ARCH_OMAP4 || ARCH_U8500)
1042 This enables support for systems with more than one CPU. If you have
1043 a system with only one CPU, like most personal computers, say N. If
1044 you have a system with more than one CPU, say Y.
1046 If you say N here, the kernel will run on single and multiprocessor
1047 machines, but will use only one CPU of a multiprocessor machine. If
1048 you say Y here, the kernel will run on many, but not all, single
1049 processor machines. On a single processor machine, the kernel will
1050 run faster if you say N here.
1052 See also <file:Documentation/i386/IO-APIC.txt>,
1053 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
1054 <http://www.linuxdoc.org/docs.html#howto>.
1056 If you don't know what to do here, say N.
1062 This option enables support for the ARM system coherency unit
1068 This options enables support for the ARM timer and watchdog unit
1071 prompt "Memory split"
1074 Select the desired split between kernel and user memory.
1076 If you are not absolutely sure what you are doing, leave this
1080 bool "3G/1G user/kernel split"
1082 bool "2G/2G user/kernel split"
1084 bool "1G/3G user/kernel split"
1089 default 0x40000000 if VMSPLIT_1G
1090 default 0x80000000 if VMSPLIT_2G
1094 int "Maximum number of CPUs (2-32)"
1100 bool "Support for hot-pluggable CPUs (EXPERIMENTAL)"
1101 depends on SMP && HOTPLUG && EXPERIMENTAL
1103 Say Y here to experiment with turning CPUs off and on. CPUs
1104 can be controlled through /sys/devices/system/cpu.
1107 bool "Use local timer interrupts"
1108 depends on SMP && (REALVIEW_EB_ARM11MP || MACH_REALVIEW_PB11MP || \
1109 REALVIEW_EB_A9MP || MACH_REALVIEW_PBX || ARCH_OMAP4 || ARCH_U8500)
1111 select HAVE_ARM_TWD if (ARCH_REALVIEW || ARCH_OMAP4 || ARCH_U8500)
1113 Enable support for local timers on SMP platforms, rather then the
1114 legacy IPI broadcast method. Local timers allows the system
1115 accounting to be spread across the timer interval, preventing a
1116 "thundering herd" at every timer tick.
1118 source kernel/Kconfig.preempt
1122 default 128 if ARCH_L7200
1123 default 200 if ARCH_EBSA110 || ARCH_S3C2410
1124 default OMAP_32K_TIMER_HZ if ARCH_OMAP && OMAP_32K_TIMER
1125 default AT91_TIMER_HZ if ARCH_AT91
1128 config THUMB2_KERNEL
1129 bool "Compile the kernel in Thumb-2 mode"
1130 depends on CPU_V7 && EXPERIMENTAL
1132 select ARM_ASM_UNIFIED
1134 By enabling this option, the kernel will be compiled in
1135 Thumb-2 mode. A compiler/assembler that understand the unified
1136 ARM-Thumb syntax is needed.
1140 config ARM_ASM_UNIFIED
1144 bool "Use the ARM EABI to compile the kernel"
1146 This option allows for the kernel to be compiled using the latest
1147 ARM ABI (aka EABI). This is only useful if you are using a user
1148 space environment that is also compiled with EABI.
1150 Since there are major incompatibilities between the legacy ABI and
1151 EABI, especially with regard to structure member alignment, this
1152 option also changes the kernel syscall calling convention to
1153 disambiguate both ABIs and allow for backward compatibility support
1154 (selected with CONFIG_OABI_COMPAT).
1156 To use this you need GCC version 4.0.0 or later.
1159 bool "Allow old ABI binaries to run with this kernel (EXPERIMENTAL)"
1160 depends on AEABI && EXPERIMENTAL
1163 This option preserves the old syscall interface along with the
1164 new (ARM EABI) one. It also provides a compatibility layer to
1165 intercept syscalls that have structure arguments which layout
1166 in memory differs between the legacy ABI and the new ARM EABI
1167 (only for non "thumb" binaries). This option adds a tiny
1168 overhead to all syscalls and produces a slightly larger kernel.
1169 If you know you'll be using only pure EABI user space then you
1170 can say N here. If this option is not selected and you attempt
1171 to execute a legacy ABI binary then the result will be
1172 UNPREDICTABLE (in fact it can be predicted that it won't work
1173 at all). If in doubt say Y.
1175 config ARCH_HAS_HOLES_MEMORYMODEL
1178 # Discontigmem is deprecated
1179 config ARCH_DISCONTIGMEM_ENABLE
1182 config ARCH_SPARSEMEM_ENABLE
1185 config ARCH_SPARSEMEM_DEFAULT
1186 def_bool ARCH_SPARSEMEM_ENABLE
1188 config ARCH_SELECT_MEMORY_MODEL
1189 def_bool ARCH_DISCONTIGMEM_ENABLE && ARCH_SPARSEMEM_ENABLE
1193 default "4" if ARCH_LH7A40X
1195 depends on NEED_MULTIPLE_NODES
1198 bool "High Memory Support (EXPERIMENTAL)"
1199 depends on MMU && EXPERIMENTAL
1201 The address space of ARM processors is only 4 Gigabytes large
1202 and it has to accommodate user address space, kernel address
1203 space as well as some memory mapped IO. That means that, if you
1204 have a large amount of physical memory and/or IO, not all of the
1205 memory can be "permanently mapped" by the kernel. The physical
1206 memory that is not permanently mapped is called "high memory".
1208 Depending on the selected kernel/user memory split, minimum
1209 vmalloc space and actual amount of RAM, you may not need this
1210 option which should result in a slightly faster kernel.
1215 bool "Allocate 2nd-level pagetables from highmem"
1217 depends on !OUTER_CACHE
1219 config HW_PERF_EVENTS
1220 bool "Enable hardware performance counter support for perf events"
1221 depends on PERF_EVENTS && CPU_HAS_PMU && (CPU_V6 || CPU_V7)
1224 Enable hardware performance counter support for perf events. If
1225 disabled, perf events will use software events only.
1230 bool "Timer and CPU usage LEDs"
1231 depends on ARCH_CDB89712 || ARCH_EBSA110 || \
1232 ARCH_EBSA285 || ARCH_INTEGRATOR || \
1233 ARCH_LUBBOCK || MACH_MAINSTONE || ARCH_NETWINDER || \
1234 ARCH_OMAP || ARCH_P720T || ARCH_PXA_IDP || \
1235 ARCH_SA1100 || ARCH_SHARK || ARCH_VERSATILE || \
1236 ARCH_AT91 || ARCH_DAVINCI || \
1237 ARCH_KS8695 || MACH_RD88F5182 || ARCH_REALVIEW
1239 If you say Y here, the LEDs on your machine will be used
1240 to provide useful information about your current system status.
1242 If you are compiling a kernel for a NetWinder or EBSA-285, you will
1243 be able to select which LEDs are active using the options below. If
1244 you are compiling a kernel for the EBSA-110 or the LART however, the
1245 red LED will simply flash regularly to indicate that the system is
1246 still functional. It is safe to say Y here if you have a CATS
1247 system, but the driver will do nothing.
1250 bool "Timer LED" if (!ARCH_CDB89712 && !ARCH_OMAP) || \
1251 OMAP_OSK_MISTRAL || MACH_OMAP_H2 \
1252 || MACH_OMAP_PERSEUS2
1254 depends on !GENERIC_CLOCKEVENTS
1255 default y if ARCH_EBSA110
1257 If you say Y here, one of the system LEDs (the green one on the
1258 NetWinder, the amber one on the EBSA285, or the red one on the LART)
1259 will flash regularly to indicate that the system is still
1260 operational. This is mainly useful to kernel hackers who are
1261 debugging unstable kernels.
1263 The LART uses the same LED for both Timer LED and CPU usage LED
1264 functions. You may choose to use both, but the Timer LED function
1265 will overrule the CPU usage LED.
1268 bool "CPU usage LED" if (!ARCH_CDB89712 && !ARCH_EBSA110 && \
1270 || OMAP_OSK_MISTRAL || MACH_OMAP_H2 \
1271 || MACH_OMAP_PERSEUS2
1274 If you say Y here, the red LED will be used to give a good real
1275 time indication of CPU usage, by lighting whenever the idle task
1276 is not currently executing.
1278 The LART uses the same LED for both Timer LED and CPU usage LED
1279 functions. You may choose to use both, but the Timer LED function
1280 will overrule the CPU usage LED.
1282 config ALIGNMENT_TRAP
1284 depends on CPU_CP15_MMU
1285 default y if !ARCH_EBSA110
1286 select HAVE_PROC_CPU if PROC_FS
1288 ARM processors cannot fetch/store information which is not
1289 naturally aligned on the bus, i.e., a 4 byte fetch must start at an
1290 address divisible by 4. On 32-bit ARM processors, these non-aligned
1291 fetch/store instructions will be emulated in software if you say
1292 here, which has a severe performance impact. This is necessary for
1293 correct operation of some network protocols. With an IP-only
1294 configuration it is safe to say N, otherwise say Y.
1296 config UACCESS_WITH_MEMCPY
1297 bool "Use kernel mem{cpy,set}() for {copy_to,clear}_user() (EXPERIMENTAL)"
1298 depends on MMU && EXPERIMENTAL
1299 default y if CPU_FEROCEON
1301 Implement faster copy_to_user and clear_user methods for CPU
1302 cores where a 8-word STM instruction give significantly higher
1303 memory write throughput than a sequence of individual 32bit stores.
1305 A possible side effect is a slight increase in scheduling latency
1306 between threads sharing the same address space if they invoke
1307 such copy operations with large buffers.
1309 However, if the CPU data cache is using a write-allocate mode,
1310 this option is unlikely to provide any performance gain.
1316 # Compressed boot loader in ROM. Yes, we really want to ask about
1317 # TEXT and BSS so we preserve their values in the config files.
1318 config ZBOOT_ROM_TEXT
1319 hex "Compressed ROM boot loader base address"
1322 The physical address at which the ROM-able zImage is to be
1323 placed in the target. Platforms which normally make use of
1324 ROM-able zImage formats normally set this to a suitable
1325 value in their defconfig file.
1327 If ZBOOT_ROM is not enabled, this has no effect.
1329 config ZBOOT_ROM_BSS
1330 hex "Compressed ROM boot loader BSS address"
1333 The base address of an area of read/write memory in the target
1334 for the ROM-able zImage which must be available while the
1335 decompressor is running. It must be large enough to hold the
1336 entire decompressed kernel plus an additional 128 KiB.
1337 Platforms which normally make use of ROM-able zImage formats
1338 normally set this to a suitable value in their defconfig file.
1340 If ZBOOT_ROM is not enabled, this has no effect.
1343 bool "Compressed boot loader in ROM/flash"
1344 depends on ZBOOT_ROM_TEXT != ZBOOT_ROM_BSS
1346 Say Y here if you intend to execute your compressed kernel image
1347 (zImage) directly from ROM or flash. If unsure, say N.
1350 string "Default kernel command string"
1353 On some architectures (EBSA110 and CATS), there is currently no way
1354 for the boot loader to pass arguments to the kernel. For these
1355 architectures, you should supply some command-line options at build
1356 time by entering them here. As a minimum, you should specify the
1357 memory size and the root device (e.g., mem=64M root=/dev/nfs).
1360 bool "Kernel Execute-In-Place from ROM"
1361 depends on !ZBOOT_ROM
1363 Execute-In-Place allows the kernel to run from non-volatile storage
1364 directly addressable by the CPU, such as NOR flash. This saves RAM
1365 space since the text section of the kernel is not loaded from flash
1366 to RAM. Read-write sections, such as the data section and stack,
1367 are still copied to RAM. The XIP kernel is not compressed since
1368 it has to run directly from flash, so it will take more space to
1369 store it. The flash address used to link the kernel object files,
1370 and for storing it, is configuration dependent. Therefore, if you
1371 say Y here, you must know the proper physical address where to
1372 store the kernel image depending on your own flash memory usage.
1374 Also note that the make target becomes "make xipImage" rather than
1375 "make zImage" or "make Image". The final kernel binary to put in
1376 ROM memory will be arch/arm/boot/xipImage.
1380 config XIP_PHYS_ADDR
1381 hex "XIP Kernel Physical Location"
1382 depends on XIP_KERNEL
1383 default "0x00080000"
1385 This is the physical address in your flash memory the kernel will
1386 be linked for and stored to. This address is dependent on your
1390 bool "Kexec system call (EXPERIMENTAL)"
1391 depends on EXPERIMENTAL
1393 kexec is a system call that implements the ability to shutdown your
1394 current kernel, and to start another kernel. It is like a reboot
1395 but it is independent of the system firmware. And like a reboot
1396 you can start any kernel with it, not just Linux.
1398 It is an ongoing process to be certain the hardware in a machine
1399 is properly shutdown, so do not be surprised if this code does not
1400 initially work for you. It may help to enable device hotplugging
1404 bool "Export atags in procfs"
1408 Should the atags used to boot the kernel be exported in an "atags"
1409 file in procfs. Useful with kexec.
1413 menu "CPU Power Management"
1417 source "drivers/cpufreq/Kconfig"
1419 config CPU_FREQ_SA1100
1422 config CPU_FREQ_SA1110
1425 config CPU_FREQ_INTEGRATOR
1426 tristate "CPUfreq driver for ARM Integrator CPUs"
1427 depends on ARCH_INTEGRATOR && CPU_FREQ
1430 This enables the CPUfreq driver for ARM Integrator CPUs.
1432 For details, take a look at <file:Documentation/cpu-freq>.
1438 depends on CPU_FREQ && ARCH_PXA && PXA25x
1440 select CPU_FREQ_DEFAULT_GOV_USERSPACE
1442 config CPU_FREQ_S3C64XX
1443 bool "CPUfreq support for Samsung S3C64XX CPUs"
1444 depends on CPU_FREQ && CPU_S3C6410
1449 Internal configuration node for common cpufreq on Samsung SoC
1451 config CPU_FREQ_S3C24XX
1452 bool "CPUfreq driver for Samsung S3C24XX series CPUs"
1453 depends on ARCH_S3C2410 && CPU_FREQ && EXPERIMENTAL
1456 This enables the CPUfreq driver for the Samsung S3C24XX family
1459 For details, take a look at <file:Documentation/cpu-freq>.
1463 config CPU_FREQ_S3C24XX_PLL
1464 bool "Support CPUfreq changing of PLL frequency"
1465 depends on CPU_FREQ_S3C24XX && EXPERIMENTAL
1467 Compile in support for changing the PLL frequency from the
1468 S3C24XX series CPUfreq driver. The PLL takes time to settle
1469 after a frequency change, so by default it is not enabled.
1471 This also means that the PLL tables for the selected CPU(s) will
1472 be built which may increase the size of the kernel image.
1474 config CPU_FREQ_S3C24XX_DEBUG
1475 bool "Debug CPUfreq Samsung driver core"
1476 depends on CPU_FREQ_S3C24XX
1478 Enable s3c_freq_dbg for the Samsung S3C CPUfreq core
1480 config CPU_FREQ_S3C24XX_IODEBUG
1481 bool "Debug CPUfreq Samsung driver IO timing"
1482 depends on CPU_FREQ_S3C24XX
1484 Enable s3c_freq_iodbg for the Samsung S3C CPUfreq core
1486 config CPU_FREQ_S3C24XX_DEBUGFS
1487 bool "Export debugfs for CPUFreq"
1488 depends on CPU_FREQ_S3C24XX && DEBUG_FS
1490 Export status information via debugfs.
1494 source "drivers/cpuidle/Kconfig"
1498 menu "Floating point emulation"
1500 comment "At least one emulation must be selected"
1503 bool "NWFPE math emulation"
1504 depends on !AEABI || OABI_COMPAT
1506 Say Y to include the NWFPE floating point emulator in the kernel.
1507 This is necessary to run most binaries. Linux does not currently
1508 support floating point hardware so you need to say Y here even if
1509 your machine has an FPA or floating point co-processor podule.
1511 You may say N here if you are going to load the Acorn FPEmulator
1512 early in the bootup.
1515 bool "Support extended precision"
1516 depends on FPE_NWFPE
1518 Say Y to include 80-bit support in the kernel floating-point
1519 emulator. Otherwise, only 32 and 64-bit support is compiled in.
1520 Note that gcc does not generate 80-bit operations by default,
1521 so in most cases this option only enlarges the size of the
1522 floating point emulator without any good reason.
1524 You almost surely want to say N here.
1527 bool "FastFPE math emulation (EXPERIMENTAL)"
1528 depends on (!AEABI || OABI_COMPAT) && !CPU_32v3 && EXPERIMENTAL
1530 Say Y here to include the FAST floating point emulator in the kernel.
1531 This is an experimental much faster emulator which now also has full
1532 precision for the mantissa. It does not support any exceptions.
1533 It is very simple, and approximately 3-6 times faster than NWFPE.
1535 It should be sufficient for most programs. It may be not suitable
1536 for scientific calculations, but you have to check this for yourself.
1537 If you do not feel you need a faster FP emulation you should better
1541 bool "VFP-format floating point maths"
1542 depends on CPU_V6 || CPU_ARM926T || CPU_V7 || CPU_FEROCEON
1544 Say Y to include VFP support code in the kernel. This is needed
1545 if your hardware includes a VFP unit.
1547 Please see <file:Documentation/arm/VFP/release-notes.txt> for
1548 release notes and additional status information.
1550 Say N if your target does not have VFP hardware.
1558 bool "Advanced SIMD (NEON) Extension support"
1559 depends on VFPv3 && CPU_V7
1561 Say Y to include support code for NEON, the ARMv7 Advanced SIMD
1566 menu "Userspace binary formats"
1568 source "fs/Kconfig.binfmt"
1571 tristate "RISC OS personality"
1574 Say Y here to include the kernel code necessary if you want to run
1575 Acorn RISC OS/Arthur binaries under Linux. This code is still very
1576 experimental; if this sounds frightening, say N and sleep in peace.
1577 You can also say M here to compile this support as a module (which
1578 will be called arthur).
1582 menu "Power management options"
1584 source "kernel/power/Kconfig"
1586 config ARCH_SUSPEND_POSSIBLE
1591 source "net/Kconfig"
1593 source "drivers/Kconfig"
1597 source "arch/arm/Kconfig.debug"
1599 source "security/Kconfig"
1601 source "crypto/Kconfig"
1603 source "lib/Kconfig"