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 GENERIC_ISA_DMA
167 config GENERIC_HARDIRQS_NO__DO_IRQ
170 config ARM_L1_CACHE_SHIFT_6
173 Setting ARM L1 cache line size to 64 Bytes.
177 config OPROFILE_ARMV6
179 depends on CPU_V6 && !SMP
180 select OPROFILE_ARM11_CORE
182 config OPROFILE_MPCORE
184 depends on CPU_V6 && SMP
185 select OPROFILE_ARM11_CORE
187 config OPROFILE_ARM11_CORE
190 config OPROFILE_ARMV7
192 depends on CPU_V7 && !SMP
199 default 0xffff0000 if MMU || CPU_HIGH_VECTOR
200 default DRAM_BASE if REMAP_VECTORS_TO_RAM
203 The base address of exception vectors.
205 source "init/Kconfig"
207 source "kernel/Kconfig.freezer"
212 bool "MMU-based Paged Memory Management Support"
215 Select if you want MMU-based virtualised addressing space
216 support by paged memory management. If unsure, say 'Y'.
219 prompt "ARM system type"
220 default ARCH_VERSATILE
223 bool "Agilent AAEC-2000 based"
228 This enables support for systems based on the Agilent AAEC-2000
230 config ARCH_INTEGRATOR
231 bool "ARM Ltd. Integrator family"
233 select ARCH_HAS_CPUFREQ
238 Support for ARM's Integrator platform.
241 bool "ARM Ltd. RealView family"
247 select GENERIC_CLOCKEVENTS
248 select ARCH_WANT_OPTIONAL_GPIOLIB
250 This enables support for ARM Ltd RealView boards.
252 config ARCH_VERSATILE
253 bool "ARM Ltd. Versatile family"
260 select GENERIC_CLOCKEVENTS
261 select ARCH_WANT_OPTIONAL_GPIOLIB
263 This enables support for ARM Ltd Versatile board.
268 select ARCH_REQUIRE_GPIOLIB
271 This enables support for systems based on the Atmel AT91RM9200,
272 AT91SAM9 and AT91CAP9 processors.
275 bool "Cirrus Logic CLPS711x/EP721x-based"
278 Support for Cirrus Logic 711x/721x based boards.
281 bool "Cortina Systems Gemini"
284 select ARCH_REQUIRE_GPIOLIB
286 Support for the Cortina Systems Gemini family SoCs
294 This is an evaluation board for the StrongARM processor available
295 from Digital. It has limited hardware on-board, including an
296 Ethernet interface, two PCMCIA sockets, two serial ports and a
307 select ARCH_REQUIRE_GPIOLIB
308 select ARCH_HAS_HOLES_MEMORYMODEL
310 This enables support for the Cirrus EP93xx series of CPUs.
312 config ARCH_FOOTBRIDGE
317 Support for systems based on the DC21285 companion chip
318 ("FootBridge"), such as the Simtec CATS and the Rebel NetWinder.
321 bool "Freescale MXC/iMX-based"
323 select GENERIC_CLOCKEVENTS
326 select ARCH_REQUIRE_GPIOLIB
329 Support for Freescale MXC/iMX-based family of processors
332 bool "Freescale STMP3xxx"
336 select ARCH_REQUIRE_GPIOLIB
338 select GENERIC_CLOCKEVENTS
340 select USB_ARCH_HAS_EHCI
342 Support for systems based on the Freescale 3xxx CPUs.
345 bool "Hilscher NetX based"
348 select GENERIC_CLOCKEVENTS
351 This enables support for systems based on the Hilscher NetX Soc
354 bool "Hynix HMS720x-based"
358 This enables support for systems based on the Hynix HMS720x
361 bool "STMicroelectronics Nomadik"
368 select GENERIC_CLOCKEVENTS
370 select ARCH_REQUIRE_GPIOLIB
372 Support for the Nomadik platform by ST-Ericsson
380 select ARCH_SUPPORTS_MSI
383 Support for Intel's IOP13XX (XScale) family of processors.
392 select ARCH_REQUIRE_GPIOLIB
394 Support for Intel's 80219 and IOP32X (XScale) family of
404 select ARCH_REQUIRE_GPIOLIB
406 Support for Intel's IOP33X (XScale) family of processors.
414 Support for Intel's IXP23xx (XScale) family of processors.
417 bool "IXP2400/2800-based"
422 Support for Intel's IXP2400/2800 (XScale) family of processors.
430 select GENERIC_CLOCKEVENTS
431 select DMABOUNCE if PCI
433 Support for Intel's IXP4XX (XScale) family of processors.
440 Say Y here if you intend to run this kernel on a LinkUp Systems
441 L7200 Software Development Board which uses an ARM720T processor.
442 Information on this board can be obtained at:
444 <http://www.linkupsys.com/>
446 If you have any questions or comments about the Linux kernel port
447 to this board, send e-mail to <sjhill@cotw.com>.
453 select ARCH_REQUIRE_GPIOLIB
455 select GENERIC_CLOCKEVENTS
458 Support for the Marvell Dove SoC 88AP510
461 bool "Marvell Kirkwood"
465 select ARCH_REQUIRE_GPIOLIB
467 select GENERIC_CLOCKEVENTS
470 Support for the following Marvell Kirkwood series SoCs:
471 88F6180, 88F6192 and 88F6281.
474 bool "Marvell Loki (88RC8480)"
477 select GENERIC_CLOCKEVENTS
480 Support for the Marvell Loki (88RC8480) SoC.
483 bool "Marvell MV78xx0"
487 select ARCH_REQUIRE_GPIOLIB
489 select GENERIC_CLOCKEVENTS
492 Support for the following Marvell MV78xx0 series SoCs:
501 select ARCH_REQUIRE_GPIOLIB
503 select GENERIC_CLOCKEVENTS
506 Support for the following Marvell Orion 5x series SoCs:
507 Orion-1 (5181), Orion-VoIP (5181L), Orion-NAS (5182),
508 Orion-2 (5281), Orion-1-90 (6183).
511 bool "Marvell PXA168/910"
514 select ARCH_REQUIRE_GPIOLIB
518 select GENERIC_CLOCKEVENTS
522 Support for Marvell's PXA168/910 processor line.
525 bool "Micrel/Kendin KS8695"
528 select ARCH_REQUIRE_GPIOLIB
530 Support for Micrel/Kendin KS8695 "Centaur" (ARM922T) based
531 System-on-Chip devices.
534 bool "NetSilicon NS9xxx"
538 select GENERIC_CLOCKEVENTS
541 Say Y here if you intend to run this kernel on a NetSilicon NS9xxx
544 <http://www.digi.com/products/microprocessors/index.jsp>
547 bool "Nuvoton W90X900 CPU"
549 select ARCH_REQUIRE_GPIOLIB
554 select GENERIC_CLOCKEVENTS
556 Support for Nuvoton (Winbond logic dept.) ARM9 processor,
557 At present, the w90x900 has been renamed nuc900, regarding
558 the ARM series product line, you can login the following
559 link address to know more.
561 <http://www.nuvoton.com/hq/enu/ProductAndSales/ProductLines/
562 ConsumerElectronicsIC/ARMMicrocontroller/ARMMicrocontroller>
565 bool "Nuvoton NUC93X CPU"
570 Support for Nuvoton (Winbond logic dept.) NUC93X MCU,The NUC93X is a
571 low-power and high performance MPEG-4/JPEG multimedia controller chip.
574 bool "Philips Nexperia PNX4008 Mobile"
578 This enables support for Philips PNX4008 mobile platform.
581 bool "PXA2xx/PXA3xx-based"
584 select ARCH_HAS_CPUFREQ
588 select ARCH_REQUIRE_GPIOLIB
590 select GENERIC_CLOCKEVENTS
594 Support for Intel/Marvell's PXA2xx/PXA3xx processor line.
600 select GENERIC_CLOCKEVENTS
602 Support for Qualcomm MSM7K based systems. This runs on the ARM11
603 apps processor of the MSM7K and depends on a shared memory
604 interface to the ARM9 modem processor which runs the baseband stack
605 and controls some vital subsystems (clock and power control, etc).
612 select ARCH_MAY_HAVE_PC_FDC
613 select HAVE_PATA_PLATFORM
616 select ARCH_SPARSEMEM_ENABLE
618 On the Acorn Risc-PC, Linux can support the internal IDE disk and
619 CD-ROM interface, serial and parallel port, and the floppy drive.
625 select ARCH_SPARSEMEM_ENABLE
627 select ARCH_HAS_CPUFREQ
631 select GENERIC_CLOCKEVENTS
634 select ARCH_REQUIRE_GPIOLIB
636 Support for StrongARM 11x0 based boards.
639 bool "Samsung S3C2410, S3C2412, S3C2413, S3C2440, S3C2442, S3C2443"
641 select ARCH_HAS_CPUFREQ
644 Samsung S3C2410X CPU based systems, such as the Simtec Electronics
645 BAST (<http://www.simtec.co.uk/products/EB110ITX/>), the IPAQ 1940 or
646 the Samsung SMDK2410 development board (and derivatives).
649 bool "Samsung S3C64XX"
652 select ARCH_HAS_CPUFREQ
654 Samsung S3C64XX series based systems
657 bool "Samsung S5PC1XX"
661 select ARM_L1_CACHE_SHIFT_6
663 Samsung S5PC1XX series based systems
673 Support for the StrongARM based Digital DNARD machine, also known
674 as "Shark" (<http://www.shark-linux.de/shark.html>).
679 select ARCH_DISCONTIGMEM_ENABLE if !LH7A40X_CONTIGMEM
680 select ARCH_SPARSEMEM_ENABLE if !LH7A40X_CONTIGMEM
682 Say Y here for systems based on one of the Sharp LH7A40X
683 System on a Chip processors. These CPUs include an ARM922T
684 core with a wide array of integrated devices for
685 hand-held and low-power applications.
688 bool "ST-Ericsson U300 Series"
695 select GENERIC_CLOCKEVENTS
700 Support for ST-Ericsson U300 series mobile platforms.
706 select GENERIC_CLOCKEVENTS
708 select ARCH_REQUIRE_GPIOLIB
713 select GENERIC_ALLOCATOR
714 select ARCH_HAS_HOLES_MEMORYMODEL
716 Support for TI's DaVinci platform.
722 select ARCH_REQUIRE_GPIOLIB
723 select ARCH_HAS_CPUFREQ
725 select GENERIC_CLOCKEVENTS
727 Support for TI's OMAP platform (OMAP1 and OMAP2).
730 bool "Broadcom BCMRING"
736 select GENERIC_CLOCKEVENTS
737 select ARCH_WANT_OPTIONAL_GPIOLIB
739 Support for Broadcom's BCMRing platform.
742 bool "ST-Ericsson U8500 Series"
746 select GENERIC_CLOCKEVENTS
749 Support for ST-Ericsson's Ux500 architecture
753 source "arch/arm/mach-aaec2000/Kconfig"
755 source "arch/arm/mach-at91/Kconfig"
757 source "arch/arm/mach-bcmring/Kconfig"
759 source "arch/arm/mach-clps711x/Kconfig"
761 source "arch/arm/mach-davinci/Kconfig"
763 source "arch/arm/mach-dove/Kconfig"
765 source "arch/arm/mach-ep93xx/Kconfig"
767 source "arch/arm/mach-footbridge/Kconfig"
769 source "arch/arm/mach-gemini/Kconfig"
771 source "arch/arm/mach-h720x/Kconfig"
773 source "arch/arm/mach-integrator/Kconfig"
775 source "arch/arm/mach-iop32x/Kconfig"
777 source "arch/arm/mach-iop33x/Kconfig"
779 source "arch/arm/mach-iop13xx/Kconfig"
781 source "arch/arm/mach-ixp4xx/Kconfig"
783 source "arch/arm/mach-ixp2000/Kconfig"
785 source "arch/arm/mach-ixp23xx/Kconfig"
787 source "arch/arm/mach-kirkwood/Kconfig"
789 source "arch/arm/mach-ks8695/Kconfig"
791 source "arch/arm/mach-lh7a40x/Kconfig"
793 source "arch/arm/mach-loki/Kconfig"
795 source "arch/arm/mach-msm/Kconfig"
797 source "arch/arm/mach-mv78xx0/Kconfig"
799 source "arch/arm/plat-mxc/Kconfig"
801 source "arch/arm/mach-netx/Kconfig"
803 source "arch/arm/mach-nomadik/Kconfig"
804 source "arch/arm/plat-nomadik/Kconfig"
806 source "arch/arm/mach-ns9xxx/Kconfig"
808 source "arch/arm/mach-nuc93x/Kconfig"
810 source "arch/arm/plat-omap/Kconfig"
812 source "arch/arm/mach-omap1/Kconfig"
814 source "arch/arm/mach-omap2/Kconfig"
816 source "arch/arm/mach-orion5x/Kconfig"
818 source "arch/arm/mach-pxa/Kconfig"
819 source "arch/arm/plat-pxa/Kconfig"
821 source "arch/arm/mach-mmp/Kconfig"
823 source "arch/arm/mach-realview/Kconfig"
825 source "arch/arm/mach-sa1100/Kconfig"
827 source "arch/arm/plat-samsung/Kconfig"
828 source "arch/arm/plat-s3c24xx/Kconfig"
829 source "arch/arm/plat-s3c64xx/Kconfig"
830 source "arch/arm/plat-s3c/Kconfig"
831 source "arch/arm/plat-s5pc1xx/Kconfig"
834 source "arch/arm/mach-s3c2400/Kconfig"
835 source "arch/arm/mach-s3c2410/Kconfig"
836 source "arch/arm/mach-s3c2412/Kconfig"
837 source "arch/arm/mach-s3c2440/Kconfig"
838 source "arch/arm/mach-s3c2442/Kconfig"
839 source "arch/arm/mach-s3c2443/Kconfig"
843 source "arch/arm/mach-s3c6400/Kconfig"
844 source "arch/arm/mach-s3c6410/Kconfig"
847 source "arch/arm/plat-stmp3xxx/Kconfig"
850 source "arch/arm/mach-s5pc100/Kconfig"
853 source "arch/arm/mach-u300/Kconfig"
855 source "arch/arm/mach-ux500/Kconfig"
857 source "arch/arm/mach-versatile/Kconfig"
859 source "arch/arm/mach-w90x900/Kconfig"
861 # Definitions to make life easier
867 select GENERIC_CLOCKEVENTS
876 source arch/arm/mm/Kconfig
879 bool "Enable iWMMXt support"
880 depends on CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK
881 default y if PXA27x || PXA3xx || ARCH_MMP
883 Enable support for iWMMXt context switching at run time if
884 running on a CPU that supports it.
886 # bool 'Use XScale PMU as timer source' CONFIG_XSCALE_PMU_TIMER
889 depends on CPU_XSCALE && !XSCALE_PMU_TIMER
893 depends on CPU_V6 || CPU_V7 || XSCALE_PMU
898 source "arch/arm/Kconfig-nommu"
901 config ARM_ERRATA_411920
902 bool "ARM errata: Invalidation of the Instruction Cache operation can fail"
903 depends on CPU_V6 && !SMP
905 Invalidation of the Instruction Cache operation can
906 fail. This erratum is present in 1136 (before r1p4), 1156 and 1176.
907 It does not affect the MPCore. This option enables the ARM Ltd.
908 recommended workaround.
910 config ARM_ERRATA_430973
911 bool "ARM errata: Stale prediction on replaced interworking branch"
914 This option enables the workaround for the 430973 Cortex-A8
915 (r1p0..r1p2) erratum. If a code sequence containing an ARM/Thumb
916 interworking branch is replaced with another code sequence at the
917 same virtual address, whether due to self-modifying code or virtual
918 to physical address re-mapping, Cortex-A8 does not recover from the
919 stale interworking branch prediction. This results in Cortex-A8
920 executing the new code sequence in the incorrect ARM or Thumb state.
921 The workaround enables the BTB/BTAC operations by setting ACTLR.IBE
922 and also flushes the branch target cache at every context switch.
923 Note that setting specific bits in the ACTLR register may not be
924 available in non-secure mode.
926 config ARM_ERRATA_458693
927 bool "ARM errata: Processor deadlock when a false hazard is created"
930 This option enables the workaround for the 458693 Cortex-A8 (r2p0)
931 erratum. For very specific sequences of memory operations, it is
932 possible for a hazard condition intended for a cache line to instead
933 be incorrectly associated with a different cache line. This false
934 hazard might then cause a processor deadlock. The workaround enables
935 the L1 caching of the NEON accesses and disables the PLD instruction
936 in the ACTLR register. Note that setting specific bits in the ACTLR
937 register may not be available in non-secure mode.
939 config ARM_ERRATA_460075
940 bool "ARM errata: Data written to the L2 cache can be overwritten with stale data"
943 This option enables the workaround for the 460075 Cortex-A8 (r2p0)
944 erratum. Any asynchronous access to the L2 cache may encounter a
945 situation in which recent store transactions to the L2 cache are lost
946 and overwritten with stale memory contents from external memory. The
947 workaround disables the write-allocate mode for the L2 cache via the
948 ACTLR register. Note that setting specific bits in the ACTLR register
949 may not be available in non-secure mode.
951 config PL310_ERRATA_588369
952 bool "Clean & Invalidate maintenance operations do not invalidate clean lines"
953 depends on CACHE_L2X0 && ARCH_OMAP4
955 The PL310 L2 cache controller implements three types of Clean &
956 Invalidate maintenance operations: by Physical Address
957 (offset 0x7F0), by Index/Way (0x7F8) and by Way (0x7FC).
958 They are architecturally defined to behave as the execution of a
959 clean operation followed immediately by an invalidate operation,
960 both performing to the same memory location. This functionality
961 is not correctly implemented in PL310 as clean lines are not
962 invalidated as a result of these operations. Note that this errata
963 uses Texas Instrument's secure monitor api.
966 source "arch/arm/common/Kconfig"
968 config FORCE_MAX_ZONEORDER
981 Find out whether you have ISA slots on your motherboard. ISA is the
982 name of a bus system, i.e. the way the CPU talks to the other stuff
983 inside your box. Other bus systems are PCI, EISA, MicroChannel
984 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
985 newer boards don't support it. If you have ISA, say Y, otherwise N.
987 # Select ISA DMA controller support
992 # Select ISA DMA interface
997 bool "PCI support" if ARCH_INTEGRATOR_AP || ARCH_VERSATILE_PB || ARCH_IXP4XX || ARCH_KS8695 || MACH_ARMCORE
999 Find out whether you have a PCI motherboard. PCI is the name of a
1000 bus system, i.e. the way the CPU talks to the other stuff inside
1001 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1002 VESA. If you have PCI, say Y, otherwise N.
1007 # Select the host bridge type
1008 config PCI_HOST_VIA82C505
1010 depends on PCI && ARCH_SHARK
1013 config PCI_HOST_ITE8152
1015 depends on PCI && MACH_ARMCORE
1019 source "drivers/pci/Kconfig"
1021 source "drivers/pcmcia/Kconfig"
1025 menu "Kernel Features"
1027 source "kernel/time/Kconfig"
1030 bool "Symmetric Multi-Processing (EXPERIMENTAL)"
1031 depends on EXPERIMENTAL && (REALVIEW_EB_ARM11MP || REALVIEW_EB_A9MP ||\
1032 MACH_REALVIEW_PB11MP || MACH_REALVIEW_PBX || ARCH_OMAP4 || ARCH_U8500)
1033 depends on GENERIC_CLOCKEVENTS
1034 select USE_GENERIC_SMP_HELPERS
1035 select HAVE_ARM_SCU if (ARCH_REALVIEW || ARCH_OMAP4 || ARCH_U8500)
1037 This enables support for systems with more than one CPU. If you have
1038 a system with only one CPU, like most personal computers, say N. If
1039 you have a system with more than one CPU, say Y.
1041 If you say N here, the kernel will run on single and multiprocessor
1042 machines, but will use only one CPU of a multiprocessor machine. If
1043 you say Y here, the kernel will run on many, but not all, single
1044 processor machines. On a single processor machine, the kernel will
1045 run faster if you say N here.
1047 See also <file:Documentation/i386/IO-APIC.txt>,
1048 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
1049 <http://www.linuxdoc.org/docs.html#howto>.
1051 If you don't know what to do here, say N.
1057 This option enables support for the ARM system coherency unit
1063 This options enables support for the ARM timer and watchdog unit
1066 prompt "Memory split"
1069 Select the desired split between kernel and user memory.
1071 If you are not absolutely sure what you are doing, leave this
1075 bool "3G/1G user/kernel split"
1077 bool "2G/2G user/kernel split"
1079 bool "1G/3G user/kernel split"
1084 default 0x40000000 if VMSPLIT_1G
1085 default 0x80000000 if VMSPLIT_2G
1089 int "Maximum number of CPUs (2-32)"
1095 bool "Support for hot-pluggable CPUs (EXPERIMENTAL)"
1096 depends on SMP && HOTPLUG && EXPERIMENTAL
1098 Say Y here to experiment with turning CPUs off and on. CPUs
1099 can be controlled through /sys/devices/system/cpu.
1102 bool "Use local timer interrupts"
1103 depends on SMP && (REALVIEW_EB_ARM11MP || MACH_REALVIEW_PB11MP || \
1104 REALVIEW_EB_A9MP || MACH_REALVIEW_PBX || ARCH_OMAP4 || ARCH_U8500)
1106 select HAVE_ARM_TWD if (ARCH_REALVIEW || ARCH_OMAP4 || ARCH_U8500)
1108 Enable support for local timers on SMP platforms, rather then the
1109 legacy IPI broadcast method. Local timers allows the system
1110 accounting to be spread across the timer interval, preventing a
1111 "thundering herd" at every timer tick.
1113 source kernel/Kconfig.preempt
1117 default 128 if ARCH_L7200
1118 default 200 if ARCH_EBSA110 || ARCH_S3C2410
1119 default OMAP_32K_TIMER_HZ if ARCH_OMAP && OMAP_32K_TIMER
1120 default AT91_TIMER_HZ if ARCH_AT91
1123 config THUMB2_KERNEL
1124 bool "Compile the kernel in Thumb-2 mode"
1125 depends on CPU_V7 && EXPERIMENTAL
1127 select ARM_ASM_UNIFIED
1129 By enabling this option, the kernel will be compiled in
1130 Thumb-2 mode. A compiler/assembler that understand the unified
1131 ARM-Thumb syntax is needed.
1135 config ARM_ASM_UNIFIED
1139 bool "Use the ARM EABI to compile the kernel"
1141 This option allows for the kernel to be compiled using the latest
1142 ARM ABI (aka EABI). This is only useful if you are using a user
1143 space environment that is also compiled with EABI.
1145 Since there are major incompatibilities between the legacy ABI and
1146 EABI, especially with regard to structure member alignment, this
1147 option also changes the kernel syscall calling convention to
1148 disambiguate both ABIs and allow for backward compatibility support
1149 (selected with CONFIG_OABI_COMPAT).
1151 To use this you need GCC version 4.0.0 or later.
1154 bool "Allow old ABI binaries to run with this kernel (EXPERIMENTAL)"
1155 depends on AEABI && EXPERIMENTAL
1158 This option preserves the old syscall interface along with the
1159 new (ARM EABI) one. It also provides a compatibility layer to
1160 intercept syscalls that have structure arguments which layout
1161 in memory differs between the legacy ABI and the new ARM EABI
1162 (only for non "thumb" binaries). This option adds a tiny
1163 overhead to all syscalls and produces a slightly larger kernel.
1164 If you know you'll be using only pure EABI user space then you
1165 can say N here. If this option is not selected and you attempt
1166 to execute a legacy ABI binary then the result will be
1167 UNPREDICTABLE (in fact it can be predicted that it won't work
1168 at all). If in doubt say Y.
1170 config ARCH_HAS_HOLES_MEMORYMODEL
1173 # Discontigmem is deprecated
1174 config ARCH_DISCONTIGMEM_ENABLE
1177 config ARCH_SPARSEMEM_ENABLE
1180 config ARCH_SPARSEMEM_DEFAULT
1181 def_bool ARCH_SPARSEMEM_ENABLE
1183 config ARCH_SELECT_MEMORY_MODEL
1184 def_bool ARCH_DISCONTIGMEM_ENABLE && ARCH_SPARSEMEM_ENABLE
1188 default "4" if ARCH_LH7A40X
1190 depends on NEED_MULTIPLE_NODES
1193 bool "High Memory Support (EXPERIMENTAL)"
1194 depends on MMU && EXPERIMENTAL
1196 The address space of ARM processors is only 4 Gigabytes large
1197 and it has to accommodate user address space, kernel address
1198 space as well as some memory mapped IO. That means that, if you
1199 have a large amount of physical memory and/or IO, not all of the
1200 memory can be "permanently mapped" by the kernel. The physical
1201 memory that is not permanently mapped is called "high memory".
1203 Depending on the selected kernel/user memory split, minimum
1204 vmalloc space and actual amount of RAM, you may not need this
1205 option which should result in a slightly faster kernel.
1210 bool "Allocate 2nd-level pagetables from highmem"
1212 depends on !OUTER_CACHE
1214 config HW_PERF_EVENTS
1215 bool "Enable hardware performance counter support for perf events"
1216 depends on PERF_EVENTS && CPU_HAS_PMU && (CPU_V6 || CPU_V7)
1219 Enable hardware performance counter support for perf events. If
1220 disabled, perf events will use software events only.
1225 bool "Timer and CPU usage LEDs"
1226 depends on ARCH_CDB89712 || ARCH_EBSA110 || \
1227 ARCH_EBSA285 || ARCH_INTEGRATOR || \
1228 ARCH_LUBBOCK || MACH_MAINSTONE || ARCH_NETWINDER || \
1229 ARCH_OMAP || ARCH_P720T || ARCH_PXA_IDP || \
1230 ARCH_SA1100 || ARCH_SHARK || ARCH_VERSATILE || \
1231 ARCH_AT91 || ARCH_DAVINCI || \
1232 ARCH_KS8695 || MACH_RD88F5182 || ARCH_REALVIEW
1234 If you say Y here, the LEDs on your machine will be used
1235 to provide useful information about your current system status.
1237 If you are compiling a kernel for a NetWinder or EBSA-285, you will
1238 be able to select which LEDs are active using the options below. If
1239 you are compiling a kernel for the EBSA-110 or the LART however, the
1240 red LED will simply flash regularly to indicate that the system is
1241 still functional. It is safe to say Y here if you have a CATS
1242 system, but the driver will do nothing.
1245 bool "Timer LED" if (!ARCH_CDB89712 && !ARCH_OMAP) || \
1246 OMAP_OSK_MISTRAL || MACH_OMAP_H2 \
1247 || MACH_OMAP_PERSEUS2
1249 depends on !GENERIC_CLOCKEVENTS
1250 default y if ARCH_EBSA110
1252 If you say Y here, one of the system LEDs (the green one on the
1253 NetWinder, the amber one on the EBSA285, or the red one on the LART)
1254 will flash regularly to indicate that the system is still
1255 operational. This is mainly useful to kernel hackers who are
1256 debugging unstable kernels.
1258 The LART uses the same LED for both Timer LED and CPU usage LED
1259 functions. You may choose to use both, but the Timer LED function
1260 will overrule the CPU usage LED.
1263 bool "CPU usage LED" if (!ARCH_CDB89712 && !ARCH_EBSA110 && \
1265 || OMAP_OSK_MISTRAL || MACH_OMAP_H2 \
1266 || MACH_OMAP_PERSEUS2
1269 If you say Y here, the red LED will be used to give a good real
1270 time indication of CPU usage, by lighting whenever the idle task
1271 is not currently executing.
1273 The LART uses the same LED for both Timer LED and CPU usage LED
1274 functions. You may choose to use both, but the Timer LED function
1275 will overrule the CPU usage LED.
1277 config ALIGNMENT_TRAP
1279 depends on CPU_CP15_MMU
1280 default y if !ARCH_EBSA110
1281 select HAVE_PROC_CPU if PROC_FS
1283 ARM processors cannot fetch/store information which is not
1284 naturally aligned on the bus, i.e., a 4 byte fetch must start at an
1285 address divisible by 4. On 32-bit ARM processors, these non-aligned
1286 fetch/store instructions will be emulated in software if you say
1287 here, which has a severe performance impact. This is necessary for
1288 correct operation of some network protocols. With an IP-only
1289 configuration it is safe to say N, otherwise say Y.
1291 config UACCESS_WITH_MEMCPY
1292 bool "Use kernel mem{cpy,set}() for {copy_to,clear}_user() (EXPERIMENTAL)"
1293 depends on MMU && EXPERIMENTAL
1294 default y if CPU_FEROCEON
1296 Implement faster copy_to_user and clear_user methods for CPU
1297 cores where a 8-word STM instruction give significantly higher
1298 memory write throughput than a sequence of individual 32bit stores.
1300 A possible side effect is a slight increase in scheduling latency
1301 between threads sharing the same address space if they invoke
1302 such copy operations with large buffers.
1304 However, if the CPU data cache is using a write-allocate mode,
1305 this option is unlikely to provide any performance gain.
1311 # Compressed boot loader in ROM. Yes, we really want to ask about
1312 # TEXT and BSS so we preserve their values in the config files.
1313 config ZBOOT_ROM_TEXT
1314 hex "Compressed ROM boot loader base address"
1317 The physical address at which the ROM-able zImage is to be
1318 placed in the target. Platforms which normally make use of
1319 ROM-able zImage formats normally set this to a suitable
1320 value in their defconfig file.
1322 If ZBOOT_ROM is not enabled, this has no effect.
1324 config ZBOOT_ROM_BSS
1325 hex "Compressed ROM boot loader BSS address"
1328 The base address of an area of read/write memory in the target
1329 for the ROM-able zImage which must be available while the
1330 decompressor is running. It must be large enough to hold the
1331 entire decompressed kernel plus an additional 128 KiB.
1332 Platforms which normally make use of ROM-able zImage formats
1333 normally set this to a suitable value in their defconfig file.
1335 If ZBOOT_ROM is not enabled, this has no effect.
1338 bool "Compressed boot loader in ROM/flash"
1339 depends on ZBOOT_ROM_TEXT != ZBOOT_ROM_BSS
1341 Say Y here if you intend to execute your compressed kernel image
1342 (zImage) directly from ROM or flash. If unsure, say N.
1345 string "Default kernel command string"
1348 On some architectures (EBSA110 and CATS), there is currently no way
1349 for the boot loader to pass arguments to the kernel. For these
1350 architectures, you should supply some command-line options at build
1351 time by entering them here. As a minimum, you should specify the
1352 memory size and the root device (e.g., mem=64M root=/dev/nfs).
1355 bool "Kernel Execute-In-Place from ROM"
1356 depends on !ZBOOT_ROM
1358 Execute-In-Place allows the kernel to run from non-volatile storage
1359 directly addressable by the CPU, such as NOR flash. This saves RAM
1360 space since the text section of the kernel is not loaded from flash
1361 to RAM. Read-write sections, such as the data section and stack,
1362 are still copied to RAM. The XIP kernel is not compressed since
1363 it has to run directly from flash, so it will take more space to
1364 store it. The flash address used to link the kernel object files,
1365 and for storing it, is configuration dependent. Therefore, if you
1366 say Y here, you must know the proper physical address where to
1367 store the kernel image depending on your own flash memory usage.
1369 Also note that the make target becomes "make xipImage" rather than
1370 "make zImage" or "make Image". The final kernel binary to put in
1371 ROM memory will be arch/arm/boot/xipImage.
1375 config XIP_PHYS_ADDR
1376 hex "XIP Kernel Physical Location"
1377 depends on XIP_KERNEL
1378 default "0x00080000"
1380 This is the physical address in your flash memory the kernel will
1381 be linked for and stored to. This address is dependent on your
1385 bool "Kexec system call (EXPERIMENTAL)"
1386 depends on EXPERIMENTAL
1388 kexec is a system call that implements the ability to shutdown your
1389 current kernel, and to start another kernel. It is like a reboot
1390 but it is independent of the system firmware. And like a reboot
1391 you can start any kernel with it, not just Linux.
1393 It is an ongoing process to be certain the hardware in a machine
1394 is properly shutdown, so do not be surprised if this code does not
1395 initially work for you. It may help to enable device hotplugging
1399 bool "Export atags in procfs"
1403 Should the atags used to boot the kernel be exported in an "atags"
1404 file in procfs. Useful with kexec.
1408 menu "CPU Power Management"
1412 source "drivers/cpufreq/Kconfig"
1414 config CPU_FREQ_SA1100
1417 config CPU_FREQ_SA1110
1420 config CPU_FREQ_INTEGRATOR
1421 tristate "CPUfreq driver for ARM Integrator CPUs"
1422 depends on ARCH_INTEGRATOR && CPU_FREQ
1425 This enables the CPUfreq driver for ARM Integrator CPUs.
1427 For details, take a look at <file:Documentation/cpu-freq>.
1433 depends on CPU_FREQ && ARCH_PXA && PXA25x
1435 select CPU_FREQ_DEFAULT_GOV_USERSPACE
1437 config CPU_FREQ_S3C64XX
1438 bool "CPUfreq support for Samsung S3C64XX CPUs"
1439 depends on CPU_FREQ && CPU_S3C6410
1444 Internal configuration node for common cpufreq on Samsung SoC
1446 config CPU_FREQ_S3C24XX
1447 bool "CPUfreq driver for Samsung S3C24XX series CPUs"
1448 depends on ARCH_S3C2410 && CPU_FREQ && EXPERIMENTAL
1451 This enables the CPUfreq driver for the Samsung S3C24XX family
1454 For details, take a look at <file:Documentation/cpu-freq>.
1458 config CPU_FREQ_S3C24XX_PLL
1459 bool "Support CPUfreq changing of PLL frequency"
1460 depends on CPU_FREQ_S3C24XX && EXPERIMENTAL
1462 Compile in support for changing the PLL frequency from the
1463 S3C24XX series CPUfreq driver. The PLL takes time to settle
1464 after a frequency change, so by default it is not enabled.
1466 This also means that the PLL tables for the selected CPU(s) will
1467 be built which may increase the size of the kernel image.
1469 config CPU_FREQ_S3C24XX_DEBUG
1470 bool "Debug CPUfreq Samsung driver core"
1471 depends on CPU_FREQ_S3C24XX
1473 Enable s3c_freq_dbg for the Samsung S3C CPUfreq core
1475 config CPU_FREQ_S3C24XX_IODEBUG
1476 bool "Debug CPUfreq Samsung driver IO timing"
1477 depends on CPU_FREQ_S3C24XX
1479 Enable s3c_freq_iodbg for the Samsung S3C CPUfreq core
1481 config CPU_FREQ_S3C24XX_DEBUGFS
1482 bool "Export debugfs for CPUFreq"
1483 depends on CPU_FREQ_S3C24XX && DEBUG_FS
1485 Export status information via debugfs.
1489 source "drivers/cpuidle/Kconfig"
1493 menu "Floating point emulation"
1495 comment "At least one emulation must be selected"
1498 bool "NWFPE math emulation"
1499 depends on !AEABI || OABI_COMPAT
1501 Say Y to include the NWFPE floating point emulator in the kernel.
1502 This is necessary to run most binaries. Linux does not currently
1503 support floating point hardware so you need to say Y here even if
1504 your machine has an FPA or floating point co-processor podule.
1506 You may say N here if you are going to load the Acorn FPEmulator
1507 early in the bootup.
1510 bool "Support extended precision"
1511 depends on FPE_NWFPE
1513 Say Y to include 80-bit support in the kernel floating-point
1514 emulator. Otherwise, only 32 and 64-bit support is compiled in.
1515 Note that gcc does not generate 80-bit operations by default,
1516 so in most cases this option only enlarges the size of the
1517 floating point emulator without any good reason.
1519 You almost surely want to say N here.
1522 bool "FastFPE math emulation (EXPERIMENTAL)"
1523 depends on (!AEABI || OABI_COMPAT) && !CPU_32v3 && EXPERIMENTAL
1525 Say Y here to include the FAST floating point emulator in the kernel.
1526 This is an experimental much faster emulator which now also has full
1527 precision for the mantissa. It does not support any exceptions.
1528 It is very simple, and approximately 3-6 times faster than NWFPE.
1530 It should be sufficient for most programs. It may be not suitable
1531 for scientific calculations, but you have to check this for yourself.
1532 If you do not feel you need a faster FP emulation you should better
1536 bool "VFP-format floating point maths"
1537 depends on CPU_V6 || CPU_ARM926T || CPU_V7 || CPU_FEROCEON
1539 Say Y to include VFP support code in the kernel. This is needed
1540 if your hardware includes a VFP unit.
1542 Please see <file:Documentation/arm/VFP/release-notes.txt> for
1543 release notes and additional status information.
1545 Say N if your target does not have VFP hardware.
1553 bool "Advanced SIMD (NEON) Extension support"
1554 depends on VFPv3 && CPU_V7
1556 Say Y to include support code for NEON, the ARMv7 Advanced SIMD
1561 menu "Userspace binary formats"
1563 source "fs/Kconfig.binfmt"
1566 tristate "RISC OS personality"
1569 Say Y here to include the kernel code necessary if you want to run
1570 Acorn RISC OS/Arthur binaries under Linux. This code is still very
1571 experimental; if this sounds frightening, say N and sleep in peace.
1572 You can also say M here to compile this support as a module (which
1573 will be called arthur).
1577 menu "Power management options"
1579 source "kernel/power/Kconfig"
1581 config ARCH_SUSPEND_POSSIBLE
1586 source "net/Kconfig"
1588 source "drivers/Kconfig"
1592 source "arch/arm/Kconfig.debug"
1594 source "security/Kconfig"
1596 source "crypto/Kconfig"
1598 source "lib/Kconfig"