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"
579 This enables support for Philips PNX4008 mobile platform.
582 bool "PXA2xx/PXA3xx-based"
585 select ARCH_HAS_CPUFREQ
589 select ARCH_REQUIRE_GPIOLIB
591 select GENERIC_CLOCKEVENTS
595 Support for Intel/Marvell's PXA2xx/PXA3xx processor line.
601 select GENERIC_CLOCKEVENTS
603 Support for Qualcomm MSM7K based systems. This runs on the ARM11
604 apps processor of the MSM7K and depends on a shared memory
605 interface to the ARM9 modem processor which runs the baseband stack
606 and controls some vital subsystems (clock and power control, etc).
613 select ARCH_MAY_HAVE_PC_FDC
614 select HAVE_PATA_PLATFORM
617 select ARCH_SPARSEMEM_ENABLE
619 On the Acorn Risc-PC, Linux can support the internal IDE disk and
620 CD-ROM interface, serial and parallel port, and the floppy drive.
626 select ARCH_SPARSEMEM_ENABLE
628 select ARCH_HAS_CPUFREQ
632 select GENERIC_CLOCKEVENTS
635 select ARCH_REQUIRE_GPIOLIB
637 Support for StrongARM 11x0 based boards.
640 bool "Samsung S3C2410, S3C2412, S3C2413, S3C2440, S3C2442, S3C2443"
642 select ARCH_HAS_CPUFREQ
645 Samsung S3C2410X CPU based systems, such as the Simtec Electronics
646 BAST (<http://www.simtec.co.uk/products/EB110ITX/>), the IPAQ 1940 or
647 the Samsung SMDK2410 development board (and derivatives).
650 bool "Samsung S3C64XX"
653 select ARCH_HAS_CPUFREQ
655 Samsung S3C64XX series based systems
658 bool "Samsung S5PC1XX"
662 select ARM_L1_CACHE_SHIFT_6
664 Samsung S5PC1XX series based systems
674 Support for the StrongARM based Digital DNARD machine, also known
675 as "Shark" (<http://www.shark-linux.de/shark.html>).
680 select ARCH_DISCONTIGMEM_ENABLE if !LH7A40X_CONTIGMEM
681 select ARCH_SPARSEMEM_ENABLE if !LH7A40X_CONTIGMEM
683 Say Y here for systems based on one of the Sharp LH7A40X
684 System on a Chip processors. These CPUs include an ARM922T
685 core with a wide array of integrated devices for
686 hand-held and low-power applications.
689 bool "ST-Ericsson U300 Series"
696 select GENERIC_CLOCKEVENTS
701 Support for ST-Ericsson U300 series mobile platforms.
707 select GENERIC_CLOCKEVENTS
709 select ARCH_REQUIRE_GPIOLIB
714 select GENERIC_ALLOCATOR
715 select ARCH_HAS_HOLES_MEMORYMODEL
717 Support for TI's DaVinci platform.
723 select ARCH_REQUIRE_GPIOLIB
724 select ARCH_HAS_CPUFREQ
726 select GENERIC_CLOCKEVENTS
728 Support for TI's OMAP platform (OMAP1 and OMAP2).
731 bool "Broadcom BCMRING"
737 select GENERIC_CLOCKEVENTS
738 select ARCH_WANT_OPTIONAL_GPIOLIB
740 Support for Broadcom's BCMRing platform.
743 bool "ST-Ericsson U8500 Series"
747 select GENERIC_CLOCKEVENTS
750 Support for ST-Ericsson's Ux500 architecture
754 source "arch/arm/mach-aaec2000/Kconfig"
756 source "arch/arm/mach-at91/Kconfig"
758 source "arch/arm/mach-bcmring/Kconfig"
760 source "arch/arm/mach-clps711x/Kconfig"
762 source "arch/arm/mach-davinci/Kconfig"
764 source "arch/arm/mach-dove/Kconfig"
766 source "arch/arm/mach-ep93xx/Kconfig"
768 source "arch/arm/mach-footbridge/Kconfig"
770 source "arch/arm/mach-gemini/Kconfig"
772 source "arch/arm/mach-h720x/Kconfig"
774 source "arch/arm/mach-integrator/Kconfig"
776 source "arch/arm/mach-iop32x/Kconfig"
778 source "arch/arm/mach-iop33x/Kconfig"
780 source "arch/arm/mach-iop13xx/Kconfig"
782 source "arch/arm/mach-ixp4xx/Kconfig"
784 source "arch/arm/mach-ixp2000/Kconfig"
786 source "arch/arm/mach-ixp23xx/Kconfig"
788 source "arch/arm/mach-kirkwood/Kconfig"
790 source "arch/arm/mach-ks8695/Kconfig"
792 source "arch/arm/mach-lh7a40x/Kconfig"
794 source "arch/arm/mach-loki/Kconfig"
796 source "arch/arm/mach-msm/Kconfig"
798 source "arch/arm/mach-mv78xx0/Kconfig"
800 source "arch/arm/plat-mxc/Kconfig"
802 source "arch/arm/mach-netx/Kconfig"
804 source "arch/arm/mach-nomadik/Kconfig"
805 source "arch/arm/plat-nomadik/Kconfig"
807 source "arch/arm/mach-ns9xxx/Kconfig"
809 source "arch/arm/mach-nuc93x/Kconfig"
811 source "arch/arm/plat-omap/Kconfig"
813 source "arch/arm/mach-omap1/Kconfig"
815 source "arch/arm/mach-omap2/Kconfig"
817 source "arch/arm/mach-orion5x/Kconfig"
819 source "arch/arm/mach-pxa/Kconfig"
820 source "arch/arm/plat-pxa/Kconfig"
822 source "arch/arm/mach-mmp/Kconfig"
824 source "arch/arm/mach-realview/Kconfig"
826 source "arch/arm/mach-sa1100/Kconfig"
828 source "arch/arm/plat-samsung/Kconfig"
829 source "arch/arm/plat-s3c24xx/Kconfig"
830 source "arch/arm/plat-s3c64xx/Kconfig"
831 source "arch/arm/plat-s3c/Kconfig"
832 source "arch/arm/plat-s5pc1xx/Kconfig"
835 source "arch/arm/mach-s3c2400/Kconfig"
836 source "arch/arm/mach-s3c2410/Kconfig"
837 source "arch/arm/mach-s3c2412/Kconfig"
838 source "arch/arm/mach-s3c2440/Kconfig"
839 source "arch/arm/mach-s3c2442/Kconfig"
840 source "arch/arm/mach-s3c2443/Kconfig"
844 source "arch/arm/mach-s3c6400/Kconfig"
845 source "arch/arm/mach-s3c6410/Kconfig"
848 source "arch/arm/plat-stmp3xxx/Kconfig"
851 source "arch/arm/mach-s5pc100/Kconfig"
854 source "arch/arm/mach-u300/Kconfig"
856 source "arch/arm/mach-ux500/Kconfig"
858 source "arch/arm/mach-versatile/Kconfig"
860 source "arch/arm/mach-w90x900/Kconfig"
862 # Definitions to make life easier
868 select GENERIC_CLOCKEVENTS
877 source arch/arm/mm/Kconfig
880 bool "Enable iWMMXt support"
881 depends on CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK
882 default y if PXA27x || PXA3xx || ARCH_MMP
884 Enable support for iWMMXt context switching at run time if
885 running on a CPU that supports it.
887 # bool 'Use XScale PMU as timer source' CONFIG_XSCALE_PMU_TIMER
890 depends on CPU_XSCALE && !XSCALE_PMU_TIMER
894 depends on CPU_V6 || CPU_V7 || XSCALE_PMU
899 source "arch/arm/Kconfig-nommu"
902 config ARM_ERRATA_411920
903 bool "ARM errata: Invalidation of the Instruction Cache operation can fail"
904 depends on CPU_V6 && !SMP
906 Invalidation of the Instruction Cache operation can
907 fail. This erratum is present in 1136 (before r1p4), 1156 and 1176.
908 It does not affect the MPCore. This option enables the ARM Ltd.
909 recommended workaround.
911 config ARM_ERRATA_430973
912 bool "ARM errata: Stale prediction on replaced interworking branch"
915 This option enables the workaround for the 430973 Cortex-A8
916 (r1p0..r1p2) erratum. If a code sequence containing an ARM/Thumb
917 interworking branch is replaced with another code sequence at the
918 same virtual address, whether due to self-modifying code or virtual
919 to physical address re-mapping, Cortex-A8 does not recover from the
920 stale interworking branch prediction. This results in Cortex-A8
921 executing the new code sequence in the incorrect ARM or Thumb state.
922 The workaround enables the BTB/BTAC operations by setting ACTLR.IBE
923 and also flushes the branch target cache at every context switch.
924 Note that setting specific bits in the ACTLR register may not be
925 available in non-secure mode.
927 config ARM_ERRATA_458693
928 bool "ARM errata: Processor deadlock when a false hazard is created"
931 This option enables the workaround for the 458693 Cortex-A8 (r2p0)
932 erratum. For very specific sequences of memory operations, it is
933 possible for a hazard condition intended for a cache line to instead
934 be incorrectly associated with a different cache line. This false
935 hazard might then cause a processor deadlock. The workaround enables
936 the L1 caching of the NEON accesses and disables the PLD instruction
937 in the ACTLR register. Note that setting specific bits in the ACTLR
938 register may not be available in non-secure mode.
940 config ARM_ERRATA_460075
941 bool "ARM errata: Data written to the L2 cache can be overwritten with stale data"
944 This option enables the workaround for the 460075 Cortex-A8 (r2p0)
945 erratum. Any asynchronous access to the L2 cache may encounter a
946 situation in which recent store transactions to the L2 cache are lost
947 and overwritten with stale memory contents from external memory. The
948 workaround disables the write-allocate mode for the L2 cache via the
949 ACTLR register. Note that setting specific bits in the ACTLR register
950 may not be available in non-secure mode.
952 config PL310_ERRATA_588369
953 bool "Clean & Invalidate maintenance operations do not invalidate clean lines"
954 depends on CACHE_L2X0 && ARCH_OMAP4
956 The PL310 L2 cache controller implements three types of Clean &
957 Invalidate maintenance operations: by Physical Address
958 (offset 0x7F0), by Index/Way (0x7F8) and by Way (0x7FC).
959 They are architecturally defined to behave as the execution of a
960 clean operation followed immediately by an invalidate operation,
961 both performing to the same memory location. This functionality
962 is not correctly implemented in PL310 as clean lines are not
963 invalidated as a result of these operations. Note that this errata
964 uses Texas Instrument's secure monitor api.
967 source "arch/arm/common/Kconfig"
969 config FORCE_MAX_ZONEORDER
982 Find out whether you have ISA slots on your motherboard. ISA is the
983 name of a bus system, i.e. the way the CPU talks to the other stuff
984 inside your box. Other bus systems are PCI, EISA, MicroChannel
985 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
986 newer boards don't support it. If you have ISA, say Y, otherwise N.
988 # Select ISA DMA controller support
993 # Select ISA DMA interface
998 bool "PCI support" if ARCH_INTEGRATOR_AP || ARCH_VERSATILE_PB || ARCH_IXP4XX || ARCH_KS8695 || MACH_ARMCORE
1000 Find out whether you have a PCI motherboard. PCI is the name of a
1001 bus system, i.e. the way the CPU talks to the other stuff inside
1002 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1003 VESA. If you have PCI, say Y, otherwise N.
1008 # Select the host bridge type
1009 config PCI_HOST_VIA82C505
1011 depends on PCI && ARCH_SHARK
1014 config PCI_HOST_ITE8152
1016 depends on PCI && MACH_ARMCORE
1020 source "drivers/pci/Kconfig"
1022 source "drivers/pcmcia/Kconfig"
1026 menu "Kernel Features"
1028 source "kernel/time/Kconfig"
1031 bool "Symmetric Multi-Processing (EXPERIMENTAL)"
1032 depends on EXPERIMENTAL && (REALVIEW_EB_ARM11MP || REALVIEW_EB_A9MP ||\
1033 MACH_REALVIEW_PB11MP || MACH_REALVIEW_PBX || ARCH_OMAP4 || ARCH_U8500)
1034 depends on GENERIC_CLOCKEVENTS
1035 select USE_GENERIC_SMP_HELPERS
1036 select HAVE_ARM_SCU if (ARCH_REALVIEW || ARCH_OMAP4 || ARCH_U8500)
1038 This enables support for systems with more than one CPU. If you have
1039 a system with only one CPU, like most personal computers, say N. If
1040 you have a system with more than one CPU, say Y.
1042 If you say N here, the kernel will run on single and multiprocessor
1043 machines, but will use only one CPU of a multiprocessor machine. If
1044 you say Y here, the kernel will run on many, but not all, single
1045 processor machines. On a single processor machine, the kernel will
1046 run faster if you say N here.
1048 See also <file:Documentation/i386/IO-APIC.txt>,
1049 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
1050 <http://www.linuxdoc.org/docs.html#howto>.
1052 If you don't know what to do here, say N.
1058 This option enables support for the ARM system coherency unit
1064 This options enables support for the ARM timer and watchdog unit
1067 prompt "Memory split"
1070 Select the desired split between kernel and user memory.
1072 If you are not absolutely sure what you are doing, leave this
1076 bool "3G/1G user/kernel split"
1078 bool "2G/2G user/kernel split"
1080 bool "1G/3G user/kernel split"
1085 default 0x40000000 if VMSPLIT_1G
1086 default 0x80000000 if VMSPLIT_2G
1090 int "Maximum number of CPUs (2-32)"
1096 bool "Support for hot-pluggable CPUs (EXPERIMENTAL)"
1097 depends on SMP && HOTPLUG && EXPERIMENTAL
1099 Say Y here to experiment with turning CPUs off and on. CPUs
1100 can be controlled through /sys/devices/system/cpu.
1103 bool "Use local timer interrupts"
1104 depends on SMP && (REALVIEW_EB_ARM11MP || MACH_REALVIEW_PB11MP || \
1105 REALVIEW_EB_A9MP || MACH_REALVIEW_PBX || ARCH_OMAP4 || ARCH_U8500)
1107 select HAVE_ARM_TWD if (ARCH_REALVIEW || ARCH_OMAP4 || ARCH_U8500)
1109 Enable support for local timers on SMP platforms, rather then the
1110 legacy IPI broadcast method. Local timers allows the system
1111 accounting to be spread across the timer interval, preventing a
1112 "thundering herd" at every timer tick.
1114 source kernel/Kconfig.preempt
1118 default 128 if ARCH_L7200
1119 default 200 if ARCH_EBSA110 || ARCH_S3C2410
1120 default OMAP_32K_TIMER_HZ if ARCH_OMAP && OMAP_32K_TIMER
1121 default AT91_TIMER_HZ if ARCH_AT91
1124 config THUMB2_KERNEL
1125 bool "Compile the kernel in Thumb-2 mode"
1126 depends on CPU_V7 && EXPERIMENTAL
1128 select ARM_ASM_UNIFIED
1130 By enabling this option, the kernel will be compiled in
1131 Thumb-2 mode. A compiler/assembler that understand the unified
1132 ARM-Thumb syntax is needed.
1136 config ARM_ASM_UNIFIED
1140 bool "Use the ARM EABI to compile the kernel"
1142 This option allows for the kernel to be compiled using the latest
1143 ARM ABI (aka EABI). This is only useful if you are using a user
1144 space environment that is also compiled with EABI.
1146 Since there are major incompatibilities between the legacy ABI and
1147 EABI, especially with regard to structure member alignment, this
1148 option also changes the kernel syscall calling convention to
1149 disambiguate both ABIs and allow for backward compatibility support
1150 (selected with CONFIG_OABI_COMPAT).
1152 To use this you need GCC version 4.0.0 or later.
1155 bool "Allow old ABI binaries to run with this kernel (EXPERIMENTAL)"
1156 depends on AEABI && EXPERIMENTAL
1159 This option preserves the old syscall interface along with the
1160 new (ARM EABI) one. It also provides a compatibility layer to
1161 intercept syscalls that have structure arguments which layout
1162 in memory differs between the legacy ABI and the new ARM EABI
1163 (only for non "thumb" binaries). This option adds a tiny
1164 overhead to all syscalls and produces a slightly larger kernel.
1165 If you know you'll be using only pure EABI user space then you
1166 can say N here. If this option is not selected and you attempt
1167 to execute a legacy ABI binary then the result will be
1168 UNPREDICTABLE (in fact it can be predicted that it won't work
1169 at all). If in doubt say Y.
1171 config ARCH_HAS_HOLES_MEMORYMODEL
1174 # Discontigmem is deprecated
1175 config ARCH_DISCONTIGMEM_ENABLE
1178 config ARCH_SPARSEMEM_ENABLE
1181 config ARCH_SPARSEMEM_DEFAULT
1182 def_bool ARCH_SPARSEMEM_ENABLE
1184 config ARCH_SELECT_MEMORY_MODEL
1185 def_bool ARCH_DISCONTIGMEM_ENABLE && ARCH_SPARSEMEM_ENABLE
1189 default "4" if ARCH_LH7A40X
1191 depends on NEED_MULTIPLE_NODES
1194 bool "High Memory Support (EXPERIMENTAL)"
1195 depends on MMU && EXPERIMENTAL
1197 The address space of ARM processors is only 4 Gigabytes large
1198 and it has to accommodate user address space, kernel address
1199 space as well as some memory mapped IO. That means that, if you
1200 have a large amount of physical memory and/or IO, not all of the
1201 memory can be "permanently mapped" by the kernel. The physical
1202 memory that is not permanently mapped is called "high memory".
1204 Depending on the selected kernel/user memory split, minimum
1205 vmalloc space and actual amount of RAM, you may not need this
1206 option which should result in a slightly faster kernel.
1211 bool "Allocate 2nd-level pagetables from highmem"
1213 depends on !OUTER_CACHE
1215 config HW_PERF_EVENTS
1216 bool "Enable hardware performance counter support for perf events"
1217 depends on PERF_EVENTS && CPU_HAS_PMU && (CPU_V6 || CPU_V7)
1220 Enable hardware performance counter support for perf events. If
1221 disabled, perf events will use software events only.
1226 bool "Timer and CPU usage LEDs"
1227 depends on ARCH_CDB89712 || ARCH_EBSA110 || \
1228 ARCH_EBSA285 || ARCH_INTEGRATOR || \
1229 ARCH_LUBBOCK || MACH_MAINSTONE || ARCH_NETWINDER || \
1230 ARCH_OMAP || ARCH_P720T || ARCH_PXA_IDP || \
1231 ARCH_SA1100 || ARCH_SHARK || ARCH_VERSATILE || \
1232 ARCH_AT91 || ARCH_DAVINCI || \
1233 ARCH_KS8695 || MACH_RD88F5182 || ARCH_REALVIEW
1235 If you say Y here, the LEDs on your machine will be used
1236 to provide useful information about your current system status.
1238 If you are compiling a kernel for a NetWinder or EBSA-285, you will
1239 be able to select which LEDs are active using the options below. If
1240 you are compiling a kernel for the EBSA-110 or the LART however, the
1241 red LED will simply flash regularly to indicate that the system is
1242 still functional. It is safe to say Y here if you have a CATS
1243 system, but the driver will do nothing.
1246 bool "Timer LED" if (!ARCH_CDB89712 && !ARCH_OMAP) || \
1247 OMAP_OSK_MISTRAL || MACH_OMAP_H2 \
1248 || MACH_OMAP_PERSEUS2
1250 depends on !GENERIC_CLOCKEVENTS
1251 default y if ARCH_EBSA110
1253 If you say Y here, one of the system LEDs (the green one on the
1254 NetWinder, the amber one on the EBSA285, or the red one on the LART)
1255 will flash regularly to indicate that the system is still
1256 operational. This is mainly useful to kernel hackers who are
1257 debugging unstable kernels.
1259 The LART uses the same LED for both Timer LED and CPU usage LED
1260 functions. You may choose to use both, but the Timer LED function
1261 will overrule the CPU usage LED.
1264 bool "CPU usage LED" if (!ARCH_CDB89712 && !ARCH_EBSA110 && \
1266 || OMAP_OSK_MISTRAL || MACH_OMAP_H2 \
1267 || MACH_OMAP_PERSEUS2
1270 If you say Y here, the red LED will be used to give a good real
1271 time indication of CPU usage, by lighting whenever the idle task
1272 is not currently executing.
1274 The LART uses the same LED for both Timer LED and CPU usage LED
1275 functions. You may choose to use both, but the Timer LED function
1276 will overrule the CPU usage LED.
1278 config ALIGNMENT_TRAP
1280 depends on CPU_CP15_MMU
1281 default y if !ARCH_EBSA110
1282 select HAVE_PROC_CPU if PROC_FS
1284 ARM processors cannot fetch/store information which is not
1285 naturally aligned on the bus, i.e., a 4 byte fetch must start at an
1286 address divisible by 4. On 32-bit ARM processors, these non-aligned
1287 fetch/store instructions will be emulated in software if you say
1288 here, which has a severe performance impact. This is necessary for
1289 correct operation of some network protocols. With an IP-only
1290 configuration it is safe to say N, otherwise say Y.
1292 config UACCESS_WITH_MEMCPY
1293 bool "Use kernel mem{cpy,set}() for {copy_to,clear}_user() (EXPERIMENTAL)"
1294 depends on MMU && EXPERIMENTAL
1295 default y if CPU_FEROCEON
1297 Implement faster copy_to_user and clear_user methods for CPU
1298 cores where a 8-word STM instruction give significantly higher
1299 memory write throughput than a sequence of individual 32bit stores.
1301 A possible side effect is a slight increase in scheduling latency
1302 between threads sharing the same address space if they invoke
1303 such copy operations with large buffers.
1305 However, if the CPU data cache is using a write-allocate mode,
1306 this option is unlikely to provide any performance gain.
1312 # Compressed boot loader in ROM. Yes, we really want to ask about
1313 # TEXT and BSS so we preserve their values in the config files.
1314 config ZBOOT_ROM_TEXT
1315 hex "Compressed ROM boot loader base address"
1318 The physical address at which the ROM-able zImage is to be
1319 placed in the target. Platforms which normally make use of
1320 ROM-able zImage formats normally set this to a suitable
1321 value in their defconfig file.
1323 If ZBOOT_ROM is not enabled, this has no effect.
1325 config ZBOOT_ROM_BSS
1326 hex "Compressed ROM boot loader BSS address"
1329 The base address of an area of read/write memory in the target
1330 for the ROM-able zImage which must be available while the
1331 decompressor is running. It must be large enough to hold the
1332 entire decompressed kernel plus an additional 128 KiB.
1333 Platforms which normally make use of ROM-able zImage formats
1334 normally set this to a suitable value in their defconfig file.
1336 If ZBOOT_ROM is not enabled, this has no effect.
1339 bool "Compressed boot loader in ROM/flash"
1340 depends on ZBOOT_ROM_TEXT != ZBOOT_ROM_BSS
1342 Say Y here if you intend to execute your compressed kernel image
1343 (zImage) directly from ROM or flash. If unsure, say N.
1346 string "Default kernel command string"
1349 On some architectures (EBSA110 and CATS), there is currently no way
1350 for the boot loader to pass arguments to the kernel. For these
1351 architectures, you should supply some command-line options at build
1352 time by entering them here. As a minimum, you should specify the
1353 memory size and the root device (e.g., mem=64M root=/dev/nfs).
1356 bool "Kernel Execute-In-Place from ROM"
1357 depends on !ZBOOT_ROM
1359 Execute-In-Place allows the kernel to run from non-volatile storage
1360 directly addressable by the CPU, such as NOR flash. This saves RAM
1361 space since the text section of the kernel is not loaded from flash
1362 to RAM. Read-write sections, such as the data section and stack,
1363 are still copied to RAM. The XIP kernel is not compressed since
1364 it has to run directly from flash, so it will take more space to
1365 store it. The flash address used to link the kernel object files,
1366 and for storing it, is configuration dependent. Therefore, if you
1367 say Y here, you must know the proper physical address where to
1368 store the kernel image depending on your own flash memory usage.
1370 Also note that the make target becomes "make xipImage" rather than
1371 "make zImage" or "make Image". The final kernel binary to put in
1372 ROM memory will be arch/arm/boot/xipImage.
1376 config XIP_PHYS_ADDR
1377 hex "XIP Kernel Physical Location"
1378 depends on XIP_KERNEL
1379 default "0x00080000"
1381 This is the physical address in your flash memory the kernel will
1382 be linked for and stored to. This address is dependent on your
1386 bool "Kexec system call (EXPERIMENTAL)"
1387 depends on EXPERIMENTAL
1389 kexec is a system call that implements the ability to shutdown your
1390 current kernel, and to start another kernel. It is like a reboot
1391 but it is independent of the system firmware. And like a reboot
1392 you can start any kernel with it, not just Linux.
1394 It is an ongoing process to be certain the hardware in a machine
1395 is properly shutdown, so do not be surprised if this code does not
1396 initially work for you. It may help to enable device hotplugging
1400 bool "Export atags in procfs"
1404 Should the atags used to boot the kernel be exported in an "atags"
1405 file in procfs. Useful with kexec.
1409 menu "CPU Power Management"
1413 source "drivers/cpufreq/Kconfig"
1415 config CPU_FREQ_SA1100
1418 config CPU_FREQ_SA1110
1421 config CPU_FREQ_INTEGRATOR
1422 tristate "CPUfreq driver for ARM Integrator CPUs"
1423 depends on ARCH_INTEGRATOR && CPU_FREQ
1426 This enables the CPUfreq driver for ARM Integrator CPUs.
1428 For details, take a look at <file:Documentation/cpu-freq>.
1434 depends on CPU_FREQ && ARCH_PXA && PXA25x
1436 select CPU_FREQ_DEFAULT_GOV_USERSPACE
1438 config CPU_FREQ_S3C64XX
1439 bool "CPUfreq support for Samsung S3C64XX CPUs"
1440 depends on CPU_FREQ && CPU_S3C6410
1445 Internal configuration node for common cpufreq on Samsung SoC
1447 config CPU_FREQ_S3C24XX
1448 bool "CPUfreq driver for Samsung S3C24XX series CPUs"
1449 depends on ARCH_S3C2410 && CPU_FREQ && EXPERIMENTAL
1452 This enables the CPUfreq driver for the Samsung S3C24XX family
1455 For details, take a look at <file:Documentation/cpu-freq>.
1459 config CPU_FREQ_S3C24XX_PLL
1460 bool "Support CPUfreq changing of PLL frequency"
1461 depends on CPU_FREQ_S3C24XX && EXPERIMENTAL
1463 Compile in support for changing the PLL frequency from the
1464 S3C24XX series CPUfreq driver. The PLL takes time to settle
1465 after a frequency change, so by default it is not enabled.
1467 This also means that the PLL tables for the selected CPU(s) will
1468 be built which may increase the size of the kernel image.
1470 config CPU_FREQ_S3C24XX_DEBUG
1471 bool "Debug CPUfreq Samsung driver core"
1472 depends on CPU_FREQ_S3C24XX
1474 Enable s3c_freq_dbg for the Samsung S3C CPUfreq core
1476 config CPU_FREQ_S3C24XX_IODEBUG
1477 bool "Debug CPUfreq Samsung driver IO timing"
1478 depends on CPU_FREQ_S3C24XX
1480 Enable s3c_freq_iodbg for the Samsung S3C CPUfreq core
1482 config CPU_FREQ_S3C24XX_DEBUGFS
1483 bool "Export debugfs for CPUFreq"
1484 depends on CPU_FREQ_S3C24XX && DEBUG_FS
1486 Export status information via debugfs.
1490 source "drivers/cpuidle/Kconfig"
1494 menu "Floating point emulation"
1496 comment "At least one emulation must be selected"
1499 bool "NWFPE math emulation"
1500 depends on !AEABI || OABI_COMPAT
1502 Say Y to include the NWFPE floating point emulator in the kernel.
1503 This is necessary to run most binaries. Linux does not currently
1504 support floating point hardware so you need to say Y here even if
1505 your machine has an FPA or floating point co-processor podule.
1507 You may say N here if you are going to load the Acorn FPEmulator
1508 early in the bootup.
1511 bool "Support extended precision"
1512 depends on FPE_NWFPE
1514 Say Y to include 80-bit support in the kernel floating-point
1515 emulator. Otherwise, only 32 and 64-bit support is compiled in.
1516 Note that gcc does not generate 80-bit operations by default,
1517 so in most cases this option only enlarges the size of the
1518 floating point emulator without any good reason.
1520 You almost surely want to say N here.
1523 bool "FastFPE math emulation (EXPERIMENTAL)"
1524 depends on (!AEABI || OABI_COMPAT) && !CPU_32v3 && EXPERIMENTAL
1526 Say Y here to include the FAST floating point emulator in the kernel.
1527 This is an experimental much faster emulator which now also has full
1528 precision for the mantissa. It does not support any exceptions.
1529 It is very simple, and approximately 3-6 times faster than NWFPE.
1531 It should be sufficient for most programs. It may be not suitable
1532 for scientific calculations, but you have to check this for yourself.
1533 If you do not feel you need a faster FP emulation you should better
1537 bool "VFP-format floating point maths"
1538 depends on CPU_V6 || CPU_ARM926T || CPU_V7 || CPU_FEROCEON
1540 Say Y to include VFP support code in the kernel. This is needed
1541 if your hardware includes a VFP unit.
1543 Please see <file:Documentation/arm/VFP/release-notes.txt> for
1544 release notes and additional status information.
1546 Say N if your target does not have VFP hardware.
1554 bool "Advanced SIMD (NEON) Extension support"
1555 depends on VFPv3 && CPU_V7
1557 Say Y to include support code for NEON, the ARMv7 Advanced SIMD
1562 menu "Userspace binary formats"
1564 source "fs/Kconfig.binfmt"
1567 tristate "RISC OS personality"
1570 Say Y here to include the kernel code necessary if you want to run
1571 Acorn RISC OS/Arthur binaries under Linux. This code is still very
1572 experimental; if this sounds frightening, say N and sleep in peace.
1573 You can also say M here to compile this support as a module (which
1574 will be called arthur).
1578 menu "Power management options"
1580 source "kernel/power/Kconfig"
1582 config ARCH_SUSPEND_POSSIBLE
1587 source "net/Kconfig"
1589 source "drivers/Kconfig"
1593 source "arch/arm/Kconfig.debug"
1595 source "security/Kconfig"
1597 source "crypto/Kconfig"
1599 source "lib/Kconfig"