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 # The "ARM system type" choice list is ordered alphabetically by option
223 # text. Please add new entries in the option alphabetic order.
226 prompt "ARM system type"
227 default ARCH_VERSATILE
230 bool "Agilent AAEC-2000 based"
235 This enables support for systems based on the Agilent AAEC-2000
237 config ARCH_INTEGRATOR
238 bool "ARM Ltd. Integrator family"
240 select ARCH_HAS_CPUFREQ
245 Support for ARM's Integrator platform.
248 bool "ARM Ltd. RealView family"
254 select GENERIC_CLOCKEVENTS
255 select ARCH_WANT_OPTIONAL_GPIOLIB
256 select GPIO_PL061 if GPIOLIB
258 This enables support for ARM Ltd RealView boards.
260 config ARCH_VERSATILE
261 bool "ARM Ltd. Versatile family"
268 select GENERIC_CLOCKEVENTS
269 select ARCH_WANT_OPTIONAL_GPIOLIB
271 This enables support for ARM Ltd Versatile board.
276 select ARCH_REQUIRE_GPIOLIB
279 This enables support for systems based on the Atmel AT91RM9200,
280 AT91SAM9 and AT91CAP9 processors.
283 bool "Broadcom BCMRING"
289 select GENERIC_CLOCKEVENTS
290 select ARCH_WANT_OPTIONAL_GPIOLIB
292 Support for Broadcom's BCMRing platform.
295 bool "Cirrus Logic CLPS711x/EP721x-based"
298 Support for Cirrus Logic 711x/721x based boards.
301 bool "Cortina Systems Gemini"
304 select ARCH_REQUIRE_GPIOLIB
306 Support for the Cortina Systems Gemini family SoCs
314 This is an evaluation board for the StrongARM processor available
315 from Digital. It has limited hardware on-board, including an
316 Ethernet interface, two PCMCIA sockets, two serial ports and a
327 select ARCH_REQUIRE_GPIOLIB
328 select ARCH_HAS_HOLES_MEMORYMODEL
330 This enables support for the Cirrus EP93xx series of CPUs.
332 config ARCH_FOOTBRIDGE
337 Support for systems based on the DC21285 companion chip
338 ("FootBridge"), such as the Simtec CATS and the Rebel NetWinder.
341 bool "Freescale MXC/iMX-based"
343 select GENERIC_CLOCKEVENTS
344 select ARCH_REQUIRE_GPIOLIB
348 Support for Freescale MXC/iMX-based family of processors
351 bool "Freescale STMP3xxx"
355 select ARCH_REQUIRE_GPIOLIB
357 select GENERIC_CLOCKEVENTS
359 select USB_ARCH_HAS_EHCI
361 Support for systems based on the Freescale 3xxx CPUs.
364 bool "Hilscher NetX based"
367 select GENERIC_CLOCKEVENTS
370 This enables support for systems based on the Hilscher NetX Soc
373 bool "Hynix HMS720x-based"
377 This enables support for systems based on the Hynix HMS720x
385 select ARCH_SUPPORTS_MSI
388 Support for Intel's IOP13XX (XScale) family of processors.
397 select ARCH_REQUIRE_GPIOLIB
399 Support for Intel's 80219 and IOP32X (XScale) family of
409 select ARCH_REQUIRE_GPIOLIB
411 Support for Intel's IOP33X (XScale) family of processors.
419 Support for Intel's IXP23xx (XScale) family of processors.
422 bool "IXP2400/2800-based"
427 Support for Intel's IXP2400/2800 (XScale) family of processors.
435 select GENERIC_CLOCKEVENTS
436 select DMABOUNCE if PCI
438 Support for Intel's IXP4XX (XScale) family of processors.
445 Say Y here if you intend to run this kernel on a LinkUp Systems
446 L7200 Software Development Board which uses an ARM720T processor.
447 Information on this board can be obtained at:
449 <http://www.linkupsys.com/>
451 If you have any questions or comments about the Linux kernel port
452 to this board, send e-mail to <sjhill@cotw.com>.
458 select ARCH_REQUIRE_GPIOLIB
460 select GENERIC_CLOCKEVENTS
463 Support for the Marvell Dove SoC 88AP510
466 bool "Marvell Kirkwood"
470 select ARCH_REQUIRE_GPIOLIB
472 select GENERIC_CLOCKEVENTS
475 Support for the following Marvell Kirkwood series SoCs:
476 88F6180, 88F6192 and 88F6281.
479 bool "Marvell Loki (88RC8480)"
482 select GENERIC_CLOCKEVENTS
485 Support for the Marvell Loki (88RC8480) SoC.
488 bool "Marvell MV78xx0"
492 select ARCH_REQUIRE_GPIOLIB
494 select GENERIC_CLOCKEVENTS
497 Support for the following Marvell MV78xx0 series SoCs:
506 select ARCH_REQUIRE_GPIOLIB
508 select GENERIC_CLOCKEVENTS
511 Support for the following Marvell Orion 5x series SoCs:
512 Orion-1 (5181), Orion-VoIP (5181L), Orion-NAS (5182),
513 Orion-2 (5281), Orion-1-90 (6183).
516 bool "Marvell PXA168/910/MMP2"
519 select ARCH_REQUIRE_GPIOLIB
523 select GENERIC_CLOCKEVENTS
527 Support for Marvell's PXA168/PXA910(MMP) and MMP2 processor line.
530 bool "Micrel/Kendin KS8695"
533 select ARCH_REQUIRE_GPIOLIB
535 Support for Micrel/Kendin KS8695 "Centaur" (ARM922T) based
536 System-on-Chip devices.
539 bool "NetSilicon NS9xxx"
543 select GENERIC_CLOCKEVENTS
546 Say Y here if you intend to run this kernel on a NetSilicon NS9xxx
549 <http://www.digi.com/products/microprocessors/index.jsp>
552 bool "Nuvoton W90X900 CPU"
554 select ARCH_REQUIRE_GPIOLIB
559 select GENERIC_CLOCKEVENTS
561 Support for Nuvoton (Winbond logic dept.) ARM9 processor,
562 At present, the w90x900 has been renamed nuc900, regarding
563 the ARM series product line, you can login the following
564 link address to know more.
566 <http://www.nuvoton.com/hq/enu/ProductAndSales/ProductLines/
567 ConsumerElectronicsIC/ARMMicrocontroller/ARMMicrocontroller>
570 bool "Nuvoton NUC93X CPU"
575 Support for Nuvoton (Winbond logic dept.) NUC93X MCU,The NUC93X is a
576 low-power and high performance MPEG-4/JPEG multimedia controller chip.
579 bool "Philips Nexperia PNX4008 Mobile"
584 This enables support for Philips PNX4008 mobile platform.
587 bool "PXA2xx/PXA3xx-based"
590 select ARCH_HAS_CPUFREQ
594 select ARCH_REQUIRE_GPIOLIB
596 select GENERIC_CLOCKEVENTS
600 Support for Intel/Marvell's PXA2xx/PXA3xx processor line.
606 select GENERIC_CLOCKEVENTS
608 Support for Qualcomm MSM7K based systems. This runs on the ARM11
609 apps processor of the MSM7K and depends on a shared memory
610 interface to the ARM9 modem processor which runs the baseband stack
611 and controls some vital subsystems (clock and power control, etc).
614 bool "Renesas SH-Mobile"
616 Support for Renesas's SH-Mobile ARM platforms
623 select ARCH_MAY_HAVE_PC_FDC
624 select HAVE_PATA_PLATFORM
627 select ARCH_SPARSEMEM_ENABLE
629 On the Acorn Risc-PC, Linux can support the internal IDE disk and
630 CD-ROM interface, serial and parallel port, and the floppy drive.
636 select ARCH_SPARSEMEM_ENABLE
638 select ARCH_HAS_CPUFREQ
642 select GENERIC_CLOCKEVENTS
645 select ARCH_REQUIRE_GPIOLIB
647 Support for StrongARM 11x0 based boards.
650 bool "Samsung S3C2410, S3C2412, S3C2413, S3C2416, S3C2440, S3C2442, S3C2443, S3C2450"
652 select ARCH_HAS_CPUFREQ
655 Samsung S3C2410X CPU based systems, such as the Simtec Electronics
656 BAST (<http://www.simtec.co.uk/products/EB110ITX/>), the IPAQ 1940 or
657 the Samsung SMDK2410 development board (and derivatives).
659 Note, the S3C2416 and the S3C2450 are so close that they even share
660 the same SoC ID code. This means that there is no seperate machine
661 directory (no arch/arm/mach-s3c2450) as the S3C2416 was first.
664 bool "Samsung S3C64XX"
671 select ARCH_HAS_CPUFREQ
672 select ARCH_REQUIRE_GPIOLIB
673 select SAMSUNG_CLKSRC
674 select SAMSUNG_IRQ_VIC_TIMER
675 select SAMSUNG_IRQ_UART
676 select S3C_GPIO_TRACK
677 select S3C_GPIO_PULL_UPDOWN
678 select S3C_GPIO_CFG_S3C24XX
679 select S3C_GPIO_CFG_S3C64XX
681 select USB_ARCH_HAS_OHCI
682 select SAMSUNG_GPIOLIB_4BIT
684 Samsung S3C64XX series based systems
687 bool "Samsung S5P6440"
691 select ARCH_USES_GETTIMEOFFSET
693 Samsung S5P6440 CPU based systems
696 bool "Samsung S5P6442"
700 select ARCH_USES_GETTIMEOFFSET
702 Samsung S5P6442 CPU based systems
705 bool "Samsung S5PC100"
709 select ARM_L1_CACHE_SHIFT_6
710 select ARCH_USES_GETTIMEOFFSET
712 Samsung S5PC100 series based systems
715 bool "Samsung S5PV210/S5PC110"
719 select ARM_L1_CACHE_SHIFT_6
720 select ARCH_USES_GETTIMEOFFSET
722 Samsung S5PV210/S5PC110 series based systems
732 Support for the StrongARM based Digital DNARD machine, also known
733 as "Shark" (<http://www.shark-linux.de/shark.html>).
738 select ARCH_DISCONTIGMEM_ENABLE if !LH7A40X_CONTIGMEM
739 select ARCH_SPARSEMEM_ENABLE if !LH7A40X_CONTIGMEM
741 Say Y here for systems based on one of the Sharp LH7A40X
742 System on a Chip processors. These CPUs include an ARM922T
743 core with a wide array of integrated devices for
744 hand-held and low-power applications.
747 bool "ST-Ericsson U300 Series"
754 select GENERIC_CLOCKEVENTS
759 Support for ST-Ericsson U300 series mobile platforms.
762 bool "ST-Ericsson U8500 Series"
766 select GENERIC_CLOCKEVENTS
769 Support for ST-Ericsson's Ux500 architecture
772 bool "STMicroelectronics Nomadik"
779 select GENERIC_CLOCKEVENTS
781 select ARCH_REQUIRE_GPIOLIB
783 Support for the Nomadik platform by ST-Ericsson
789 select GENERIC_CLOCKEVENTS
791 select ARCH_REQUIRE_GPIOLIB
796 select GENERIC_ALLOCATOR
797 select ARCH_HAS_HOLES_MEMORYMODEL
799 Support for TI's DaVinci platform.
805 select ARCH_REQUIRE_GPIOLIB
806 select ARCH_HAS_CPUFREQ
808 select GENERIC_CLOCKEVENTS
809 select ARCH_HAS_HOLES_MEMORYMODEL
811 Support for TI's OMAP platform (OMAP1 and OMAP2).
816 # This is sorted alphabetically by mach-* pathname. However, plat-*
817 # Kconfigs may be included either alphabetically (according to the
818 # plat- suffix) or along side the corresponding mach-* source.
820 source "arch/arm/mach-aaec2000/Kconfig"
822 source "arch/arm/mach-at91/Kconfig"
824 source "arch/arm/mach-bcmring/Kconfig"
826 source "arch/arm/mach-clps711x/Kconfig"
828 source "arch/arm/mach-davinci/Kconfig"
830 source "arch/arm/mach-dove/Kconfig"
832 source "arch/arm/mach-ep93xx/Kconfig"
834 source "arch/arm/mach-footbridge/Kconfig"
836 source "arch/arm/mach-gemini/Kconfig"
838 source "arch/arm/mach-h720x/Kconfig"
840 source "arch/arm/mach-integrator/Kconfig"
842 source "arch/arm/mach-iop32x/Kconfig"
844 source "arch/arm/mach-iop33x/Kconfig"
846 source "arch/arm/mach-iop13xx/Kconfig"
848 source "arch/arm/mach-ixp4xx/Kconfig"
850 source "arch/arm/mach-ixp2000/Kconfig"
852 source "arch/arm/mach-ixp23xx/Kconfig"
854 source "arch/arm/mach-kirkwood/Kconfig"
856 source "arch/arm/mach-ks8695/Kconfig"
858 source "arch/arm/mach-lh7a40x/Kconfig"
860 source "arch/arm/mach-loki/Kconfig"
862 source "arch/arm/mach-msm/Kconfig"
864 source "arch/arm/mach-mv78xx0/Kconfig"
866 source "arch/arm/plat-mxc/Kconfig"
868 source "arch/arm/mach-netx/Kconfig"
870 source "arch/arm/mach-nomadik/Kconfig"
871 source "arch/arm/plat-nomadik/Kconfig"
873 source "arch/arm/mach-ns9xxx/Kconfig"
875 source "arch/arm/mach-nuc93x/Kconfig"
877 source "arch/arm/plat-omap/Kconfig"
879 source "arch/arm/mach-omap1/Kconfig"
881 source "arch/arm/mach-omap2/Kconfig"
883 source "arch/arm/mach-orion5x/Kconfig"
885 source "arch/arm/mach-pxa/Kconfig"
886 source "arch/arm/plat-pxa/Kconfig"
888 source "arch/arm/mach-mmp/Kconfig"
890 source "arch/arm/mach-realview/Kconfig"
892 source "arch/arm/mach-sa1100/Kconfig"
894 source "arch/arm/plat-samsung/Kconfig"
895 source "arch/arm/plat-s3c24xx/Kconfig"
896 source "arch/arm/plat-s5p/Kconfig"
899 source "arch/arm/mach-s3c2400/Kconfig"
900 source "arch/arm/mach-s3c2410/Kconfig"
901 source "arch/arm/mach-s3c2412/Kconfig"
902 source "arch/arm/mach-s3c2416/Kconfig"
903 source "arch/arm/mach-s3c2440/Kconfig"
904 source "arch/arm/mach-s3c2443/Kconfig"
908 source "arch/arm/mach-s3c64xx/Kconfig"
911 source "arch/arm/mach-s5p6440/Kconfig"
913 source "arch/arm/mach-s5p6442/Kconfig"
915 source "arch/arm/mach-s5pc100/Kconfig"
917 source "arch/arm/mach-s5pv210/Kconfig"
919 source "arch/arm/mach-shmobile/Kconfig"
921 source "arch/arm/plat-stmp3xxx/Kconfig"
923 source "arch/arm/mach-u300/Kconfig"
925 source "arch/arm/mach-ux500/Kconfig"
927 source "arch/arm/mach-versatile/Kconfig"
929 source "arch/arm/mach-w90x900/Kconfig"
931 # Definitions to make life easier
937 select GENERIC_CLOCKEVENTS
946 source arch/arm/mm/Kconfig
949 bool "Enable iWMMXt support"
950 depends on CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK
951 default y if PXA27x || PXA3xx || ARCH_MMP
953 Enable support for iWMMXt context switching at run time if
954 running on a CPU that supports it.
956 # bool 'Use XScale PMU as timer source' CONFIG_XSCALE_PMU_TIMER
959 depends on CPU_XSCALE && !XSCALE_PMU_TIMER
963 depends on CPU_V6 || CPU_V7 || XSCALE_PMU
968 source "arch/arm/Kconfig-nommu"
971 config ARM_ERRATA_411920
972 bool "ARM errata: Invalidation of the Instruction Cache operation can fail"
973 depends on CPU_V6 && !SMP
975 Invalidation of the Instruction Cache operation can
976 fail. This erratum is present in 1136 (before r1p4), 1156 and 1176.
977 It does not affect the MPCore. This option enables the ARM Ltd.
978 recommended workaround.
980 config ARM_ERRATA_430973
981 bool "ARM errata: Stale prediction on replaced interworking branch"
984 This option enables the workaround for the 430973 Cortex-A8
985 (r1p0..r1p2) erratum. If a code sequence containing an ARM/Thumb
986 interworking branch is replaced with another code sequence at the
987 same virtual address, whether due to self-modifying code or virtual
988 to physical address re-mapping, Cortex-A8 does not recover from the
989 stale interworking branch prediction. This results in Cortex-A8
990 executing the new code sequence in the incorrect ARM or Thumb state.
991 The workaround enables the BTB/BTAC operations by setting ACTLR.IBE
992 and also flushes the branch target cache at every context switch.
993 Note that setting specific bits in the ACTLR register may not be
994 available in non-secure mode.
996 config ARM_ERRATA_458693
997 bool "ARM errata: Processor deadlock when a false hazard is created"
1000 This option enables the workaround for the 458693 Cortex-A8 (r2p0)
1001 erratum. For very specific sequences of memory operations, it is
1002 possible for a hazard condition intended for a cache line to instead
1003 be incorrectly associated with a different cache line. This false
1004 hazard might then cause a processor deadlock. The workaround enables
1005 the L1 caching of the NEON accesses and disables the PLD instruction
1006 in the ACTLR register. Note that setting specific bits in the ACTLR
1007 register may not be available in non-secure mode.
1009 config ARM_ERRATA_460075
1010 bool "ARM errata: Data written to the L2 cache can be overwritten with stale data"
1013 This option enables the workaround for the 460075 Cortex-A8 (r2p0)
1014 erratum. Any asynchronous access to the L2 cache may encounter a
1015 situation in which recent store transactions to the L2 cache are lost
1016 and overwritten with stale memory contents from external memory. The
1017 workaround disables the write-allocate mode for the L2 cache via the
1018 ACTLR register. Note that setting specific bits in the ACTLR register
1019 may not be available in non-secure mode.
1021 config PL310_ERRATA_588369
1022 bool "Clean & Invalidate maintenance operations do not invalidate clean lines"
1023 depends on CACHE_L2X0 && ARCH_OMAP4
1025 The PL310 L2 cache controller implements three types of Clean &
1026 Invalidate maintenance operations: by Physical Address
1027 (offset 0x7F0), by Index/Way (0x7F8) and by Way (0x7FC).
1028 They are architecturally defined to behave as the execution of a
1029 clean operation followed immediately by an invalidate operation,
1030 both performing to the same memory location. This functionality
1031 is not correctly implemented in PL310 as clean lines are not
1032 invalidated as a result of these operations. Note that this errata
1033 uses Texas Instrument's secure monitor api.
1036 source "arch/arm/common/Kconfig"
1038 config FORCE_MAX_ZONEORDER
1051 Find out whether you have ISA slots on your motherboard. ISA is the
1052 name of a bus system, i.e. the way the CPU talks to the other stuff
1053 inside your box. Other bus systems are PCI, EISA, MicroChannel
1054 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1055 newer boards don't support it. If you have ISA, say Y, otherwise N.
1057 # Select ISA DMA controller support
1062 # Select ISA DMA interface
1067 bool "PCI support" if ARCH_INTEGRATOR_AP || ARCH_VERSATILE_PB || ARCH_IXP4XX || ARCH_KS8695 || MACH_ARMCORE
1069 Find out whether you have a PCI motherboard. PCI is the name of a
1070 bus system, i.e. the way the CPU talks to the other stuff inside
1071 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1072 VESA. If you have PCI, say Y, otherwise N.
1077 # Select the host bridge type
1078 config PCI_HOST_VIA82C505
1080 depends on PCI && ARCH_SHARK
1083 config PCI_HOST_ITE8152
1085 depends on PCI && MACH_ARMCORE
1089 source "drivers/pci/Kconfig"
1091 source "drivers/pcmcia/Kconfig"
1095 menu "Kernel Features"
1097 source "kernel/time/Kconfig"
1100 bool "Symmetric Multi-Processing (EXPERIMENTAL)"
1101 depends on EXPERIMENTAL && (REALVIEW_EB_ARM11MP || REALVIEW_EB_A9MP ||\
1102 MACH_REALVIEW_PB11MP || MACH_REALVIEW_PBX || ARCH_OMAP4 || ARCH_U8500)
1103 depends on GENERIC_CLOCKEVENTS
1104 select USE_GENERIC_SMP_HELPERS
1105 select HAVE_ARM_SCU if (ARCH_REALVIEW || ARCH_OMAP4 || ARCH_U8500)
1107 This enables support for systems with more than one CPU. If you have
1108 a system with only one CPU, like most personal computers, say N. If
1109 you have a system with more than one CPU, say Y.
1111 If you say N here, the kernel will run on single and multiprocessor
1112 machines, but will use only one CPU of a multiprocessor machine. If
1113 you say Y here, the kernel will run on many, but not all, single
1114 processor machines. On a single processor machine, the kernel will
1115 run faster if you say N here.
1117 See also <file:Documentation/i386/IO-APIC.txt>,
1118 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
1119 <http://www.linuxdoc.org/docs.html#howto>.
1121 If you don't know what to do here, say N.
1127 This option enables support for the ARM system coherency unit
1133 This options enables support for the ARM timer and watchdog unit
1136 prompt "Memory split"
1139 Select the desired split between kernel and user memory.
1141 If you are not absolutely sure what you are doing, leave this
1145 bool "3G/1G user/kernel split"
1147 bool "2G/2G user/kernel split"
1149 bool "1G/3G user/kernel split"
1154 default 0x40000000 if VMSPLIT_1G
1155 default 0x80000000 if VMSPLIT_2G
1159 int "Maximum number of CPUs (2-32)"
1165 bool "Support for hot-pluggable CPUs (EXPERIMENTAL)"
1166 depends on SMP && HOTPLUG && EXPERIMENTAL
1168 Say Y here to experiment with turning CPUs off and on. CPUs
1169 can be controlled through /sys/devices/system/cpu.
1172 bool "Use local timer interrupts"
1173 depends on SMP && (REALVIEW_EB_ARM11MP || MACH_REALVIEW_PB11MP || \
1174 REALVIEW_EB_A9MP || MACH_REALVIEW_PBX || ARCH_OMAP4 || ARCH_U8500)
1176 select HAVE_ARM_TWD if (ARCH_REALVIEW || ARCH_OMAP4 || ARCH_U8500)
1178 Enable support for local timers on SMP platforms, rather then the
1179 legacy IPI broadcast method. Local timers allows the system
1180 accounting to be spread across the timer interval, preventing a
1181 "thundering herd" at every timer tick.
1183 source kernel/Kconfig.preempt
1187 default 128 if ARCH_L7200
1188 default 200 if ARCH_EBSA110 || ARCH_S3C2410 || ARCH_S5P6440 || ARCH_S5P6442 || ARCH_S5PV210
1189 default OMAP_32K_TIMER_HZ if ARCH_OMAP && OMAP_32K_TIMER
1190 default AT91_TIMER_HZ if ARCH_AT91
1193 config THUMB2_KERNEL
1194 bool "Compile the kernel in Thumb-2 mode"
1195 depends on CPU_V7 && EXPERIMENTAL
1197 select ARM_ASM_UNIFIED
1199 By enabling this option, the kernel will be compiled in
1200 Thumb-2 mode. A compiler/assembler that understand the unified
1201 ARM-Thumb syntax is needed.
1205 config ARM_ASM_UNIFIED
1209 bool "Use the ARM EABI to compile the kernel"
1211 This option allows for the kernel to be compiled using the latest
1212 ARM ABI (aka EABI). This is only useful if you are using a user
1213 space environment that is also compiled with EABI.
1215 Since there are major incompatibilities between the legacy ABI and
1216 EABI, especially with regard to structure member alignment, this
1217 option also changes the kernel syscall calling convention to
1218 disambiguate both ABIs and allow for backward compatibility support
1219 (selected with CONFIG_OABI_COMPAT).
1221 To use this you need GCC version 4.0.0 or later.
1224 bool "Allow old ABI binaries to run with this kernel (EXPERIMENTAL)"
1225 depends on AEABI && EXPERIMENTAL
1228 This option preserves the old syscall interface along with the
1229 new (ARM EABI) one. It also provides a compatibility layer to
1230 intercept syscalls that have structure arguments which layout
1231 in memory differs between the legacy ABI and the new ARM EABI
1232 (only for non "thumb" binaries). This option adds a tiny
1233 overhead to all syscalls and produces a slightly larger kernel.
1234 If you know you'll be using only pure EABI user space then you
1235 can say N here. If this option is not selected and you attempt
1236 to execute a legacy ABI binary then the result will be
1237 UNPREDICTABLE (in fact it can be predicted that it won't work
1238 at all). If in doubt say Y.
1240 config ARCH_HAS_HOLES_MEMORYMODEL
1243 # Discontigmem is deprecated
1244 config ARCH_DISCONTIGMEM_ENABLE
1247 config ARCH_SPARSEMEM_ENABLE
1250 config ARCH_SPARSEMEM_DEFAULT
1251 def_bool ARCH_SPARSEMEM_ENABLE
1253 config ARCH_SELECT_MEMORY_MODEL
1254 def_bool ARCH_DISCONTIGMEM_ENABLE && ARCH_SPARSEMEM_ENABLE
1258 default "4" if ARCH_LH7A40X
1260 depends on NEED_MULTIPLE_NODES
1263 bool "High Memory Support (EXPERIMENTAL)"
1264 depends on MMU && EXPERIMENTAL
1266 The address space of ARM processors is only 4 Gigabytes large
1267 and it has to accommodate user address space, kernel address
1268 space as well as some memory mapped IO. That means that, if you
1269 have a large amount of physical memory and/or IO, not all of the
1270 memory can be "permanently mapped" by the kernel. The physical
1271 memory that is not permanently mapped is called "high memory".
1273 Depending on the selected kernel/user memory split, minimum
1274 vmalloc space and actual amount of RAM, you may not need this
1275 option which should result in a slightly faster kernel.
1280 bool "Allocate 2nd-level pagetables from highmem"
1282 depends on !OUTER_CACHE
1284 config HW_PERF_EVENTS
1285 bool "Enable hardware performance counter support for perf events"
1286 depends on PERF_EVENTS && CPU_HAS_PMU && (CPU_V6 || CPU_V7)
1289 Enable hardware performance counter support for perf events. If
1290 disabled, perf events will use software events only.
1295 bool "Timer and CPU usage LEDs"
1296 depends on ARCH_CDB89712 || ARCH_EBSA110 || \
1297 ARCH_EBSA285 || ARCH_INTEGRATOR || \
1298 ARCH_LUBBOCK || MACH_MAINSTONE || ARCH_NETWINDER || \
1299 ARCH_OMAP || ARCH_P720T || ARCH_PXA_IDP || \
1300 ARCH_SA1100 || ARCH_SHARK || ARCH_VERSATILE || \
1301 ARCH_AT91 || ARCH_DAVINCI || \
1302 ARCH_KS8695 || MACH_RD88F5182 || ARCH_REALVIEW
1304 If you say Y here, the LEDs on your machine will be used
1305 to provide useful information about your current system status.
1307 If you are compiling a kernel for a NetWinder or EBSA-285, you will
1308 be able to select which LEDs are active using the options below. If
1309 you are compiling a kernel for the EBSA-110 or the LART however, the
1310 red LED will simply flash regularly to indicate that the system is
1311 still functional. It is safe to say Y here if you have a CATS
1312 system, but the driver will do nothing.
1315 bool "Timer LED" if (!ARCH_CDB89712 && !ARCH_OMAP) || \
1316 OMAP_OSK_MISTRAL || MACH_OMAP_H2 \
1317 || MACH_OMAP_PERSEUS2
1319 depends on !GENERIC_CLOCKEVENTS
1320 default y if ARCH_EBSA110
1322 If you say Y here, one of the system LEDs (the green one on the
1323 NetWinder, the amber one on the EBSA285, or the red one on the LART)
1324 will flash regularly to indicate that the system is still
1325 operational. This is mainly useful to kernel hackers who are
1326 debugging unstable kernels.
1328 The LART uses the same LED for both Timer LED and CPU usage LED
1329 functions. You may choose to use both, but the Timer LED function
1330 will overrule the CPU usage LED.
1333 bool "CPU usage LED" if (!ARCH_CDB89712 && !ARCH_EBSA110 && \
1335 || OMAP_OSK_MISTRAL || MACH_OMAP_H2 \
1336 || MACH_OMAP_PERSEUS2
1339 If you say Y here, the red LED will be used to give a good real
1340 time indication of CPU usage, by lighting whenever the idle task
1341 is not currently executing.
1343 The LART uses the same LED for both Timer LED and CPU usage LED
1344 functions. You may choose to use both, but the Timer LED function
1345 will overrule the CPU usage LED.
1347 config ALIGNMENT_TRAP
1349 depends on CPU_CP15_MMU
1350 default y if !ARCH_EBSA110
1351 select HAVE_PROC_CPU if PROC_FS
1353 ARM processors cannot fetch/store information which is not
1354 naturally aligned on the bus, i.e., a 4 byte fetch must start at an
1355 address divisible by 4. On 32-bit ARM processors, these non-aligned
1356 fetch/store instructions will be emulated in software if you say
1357 here, which has a severe performance impact. This is necessary for
1358 correct operation of some network protocols. With an IP-only
1359 configuration it is safe to say N, otherwise say Y.
1361 config UACCESS_WITH_MEMCPY
1362 bool "Use kernel mem{cpy,set}() for {copy_to,clear}_user() (EXPERIMENTAL)"
1363 depends on MMU && EXPERIMENTAL
1364 default y if CPU_FEROCEON
1366 Implement faster copy_to_user and clear_user methods for CPU
1367 cores where a 8-word STM instruction give significantly higher
1368 memory write throughput than a sequence of individual 32bit stores.
1370 A possible side effect is a slight increase in scheduling latency
1371 between threads sharing the same address space if they invoke
1372 such copy operations with large buffers.
1374 However, if the CPU data cache is using a write-allocate mode,
1375 this option is unlikely to provide any performance gain.
1381 # Compressed boot loader in ROM. Yes, we really want to ask about
1382 # TEXT and BSS so we preserve their values in the config files.
1383 config ZBOOT_ROM_TEXT
1384 hex "Compressed ROM boot loader base address"
1387 The physical address at which the ROM-able zImage is to be
1388 placed in the target. Platforms which normally make use of
1389 ROM-able zImage formats normally set this to a suitable
1390 value in their defconfig file.
1392 If ZBOOT_ROM is not enabled, this has no effect.
1394 config ZBOOT_ROM_BSS
1395 hex "Compressed ROM boot loader BSS address"
1398 The base address of an area of read/write memory in the target
1399 for the ROM-able zImage which must be available while the
1400 decompressor is running. It must be large enough to hold the
1401 entire decompressed kernel plus an additional 128 KiB.
1402 Platforms which normally make use of ROM-able zImage formats
1403 normally set this to a suitable value in their defconfig file.
1405 If ZBOOT_ROM is not enabled, this has no effect.
1408 bool "Compressed boot loader in ROM/flash"
1409 depends on ZBOOT_ROM_TEXT != ZBOOT_ROM_BSS
1411 Say Y here if you intend to execute your compressed kernel image
1412 (zImage) directly from ROM or flash. If unsure, say N.
1415 string "Default kernel command string"
1418 On some architectures (EBSA110 and CATS), there is currently no way
1419 for the boot loader to pass arguments to the kernel. For these
1420 architectures, you should supply some command-line options at build
1421 time by entering them here. As a minimum, you should specify the
1422 memory size and the root device (e.g., mem=64M root=/dev/nfs).
1425 bool "Kernel Execute-In-Place from ROM"
1426 depends on !ZBOOT_ROM
1428 Execute-In-Place allows the kernel to run from non-volatile storage
1429 directly addressable by the CPU, such as NOR flash. This saves RAM
1430 space since the text section of the kernel is not loaded from flash
1431 to RAM. Read-write sections, such as the data section and stack,
1432 are still copied to RAM. The XIP kernel is not compressed since
1433 it has to run directly from flash, so it will take more space to
1434 store it. The flash address used to link the kernel object files,
1435 and for storing it, is configuration dependent. Therefore, if you
1436 say Y here, you must know the proper physical address where to
1437 store the kernel image depending on your own flash memory usage.
1439 Also note that the make target becomes "make xipImage" rather than
1440 "make zImage" or "make Image". The final kernel binary to put in
1441 ROM memory will be arch/arm/boot/xipImage.
1445 config XIP_PHYS_ADDR
1446 hex "XIP Kernel Physical Location"
1447 depends on XIP_KERNEL
1448 default "0x00080000"
1450 This is the physical address in your flash memory the kernel will
1451 be linked for and stored to. This address is dependent on your
1455 bool "Kexec system call (EXPERIMENTAL)"
1456 depends on EXPERIMENTAL
1458 kexec is a system call that implements the ability to shutdown your
1459 current kernel, and to start another kernel. It is like a reboot
1460 but it is independent of the system firmware. And like a reboot
1461 you can start any kernel with it, not just Linux.
1463 It is an ongoing process to be certain the hardware in a machine
1464 is properly shutdown, so do not be surprised if this code does not
1465 initially work for you. It may help to enable device hotplugging
1469 bool "Export atags in procfs"
1473 Should the atags used to boot the kernel be exported in an "atags"
1474 file in procfs. Useful with kexec.
1478 menu "CPU Power Management"
1482 source "drivers/cpufreq/Kconfig"
1484 config CPU_FREQ_SA1100
1487 config CPU_FREQ_SA1110
1490 config CPU_FREQ_INTEGRATOR
1491 tristate "CPUfreq driver for ARM Integrator CPUs"
1492 depends on ARCH_INTEGRATOR && CPU_FREQ
1495 This enables the CPUfreq driver for ARM Integrator CPUs.
1497 For details, take a look at <file:Documentation/cpu-freq>.
1503 depends on CPU_FREQ && ARCH_PXA && PXA25x
1505 select CPU_FREQ_DEFAULT_GOV_USERSPACE
1507 config CPU_FREQ_S3C64XX
1508 bool "CPUfreq support for Samsung S3C64XX CPUs"
1509 depends on CPU_FREQ && CPU_S3C6410
1514 Internal configuration node for common cpufreq on Samsung SoC
1516 config CPU_FREQ_S3C24XX
1517 bool "CPUfreq driver for Samsung S3C24XX series CPUs"
1518 depends on ARCH_S3C2410 && CPU_FREQ && EXPERIMENTAL
1521 This enables the CPUfreq driver for the Samsung S3C24XX family
1524 For details, take a look at <file:Documentation/cpu-freq>.
1528 config CPU_FREQ_S3C24XX_PLL
1529 bool "Support CPUfreq changing of PLL frequency"
1530 depends on CPU_FREQ_S3C24XX && EXPERIMENTAL
1532 Compile in support for changing the PLL frequency from the
1533 S3C24XX series CPUfreq driver. The PLL takes time to settle
1534 after a frequency change, so by default it is not enabled.
1536 This also means that the PLL tables for the selected CPU(s) will
1537 be built which may increase the size of the kernel image.
1539 config CPU_FREQ_S3C24XX_DEBUG
1540 bool "Debug CPUfreq Samsung driver core"
1541 depends on CPU_FREQ_S3C24XX
1543 Enable s3c_freq_dbg for the Samsung S3C CPUfreq core
1545 config CPU_FREQ_S3C24XX_IODEBUG
1546 bool "Debug CPUfreq Samsung driver IO timing"
1547 depends on CPU_FREQ_S3C24XX
1549 Enable s3c_freq_iodbg for the Samsung S3C CPUfreq core
1551 config CPU_FREQ_S3C24XX_DEBUGFS
1552 bool "Export debugfs for CPUFreq"
1553 depends on CPU_FREQ_S3C24XX && DEBUG_FS
1555 Export status information via debugfs.
1559 source "drivers/cpuidle/Kconfig"
1563 menu "Floating point emulation"
1565 comment "At least one emulation must be selected"
1568 bool "NWFPE math emulation"
1569 depends on !AEABI || OABI_COMPAT
1571 Say Y to include the NWFPE floating point emulator in the kernel.
1572 This is necessary to run most binaries. Linux does not currently
1573 support floating point hardware so you need to say Y here even if
1574 your machine has an FPA or floating point co-processor podule.
1576 You may say N here if you are going to load the Acorn FPEmulator
1577 early in the bootup.
1580 bool "Support extended precision"
1581 depends on FPE_NWFPE
1583 Say Y to include 80-bit support in the kernel floating-point
1584 emulator. Otherwise, only 32 and 64-bit support is compiled in.
1585 Note that gcc does not generate 80-bit operations by default,
1586 so in most cases this option only enlarges the size of the
1587 floating point emulator without any good reason.
1589 You almost surely want to say N here.
1592 bool "FastFPE math emulation (EXPERIMENTAL)"
1593 depends on (!AEABI || OABI_COMPAT) && !CPU_32v3 && EXPERIMENTAL
1595 Say Y here to include the FAST floating point emulator in the kernel.
1596 This is an experimental much faster emulator which now also has full
1597 precision for the mantissa. It does not support any exceptions.
1598 It is very simple, and approximately 3-6 times faster than NWFPE.
1600 It should be sufficient for most programs. It may be not suitable
1601 for scientific calculations, but you have to check this for yourself.
1602 If you do not feel you need a faster FP emulation you should better
1606 bool "VFP-format floating point maths"
1607 depends on CPU_V6 || CPU_ARM926T || CPU_V7 || CPU_FEROCEON
1609 Say Y to include VFP support code in the kernel. This is needed
1610 if your hardware includes a VFP unit.
1612 Please see <file:Documentation/arm/VFP/release-notes.txt> for
1613 release notes and additional status information.
1615 Say N if your target does not have VFP hardware.
1623 bool "Advanced SIMD (NEON) Extension support"
1624 depends on VFPv3 && CPU_V7
1626 Say Y to include support code for NEON, the ARMv7 Advanced SIMD
1631 menu "Userspace binary formats"
1633 source "fs/Kconfig.binfmt"
1636 tristate "RISC OS personality"
1639 Say Y here to include the kernel code necessary if you want to run
1640 Acorn RISC OS/Arthur binaries under Linux. This code is still very
1641 experimental; if this sounds frightening, say N and sleep in peace.
1642 You can also say M here to compile this support as a module (which
1643 will be called arthur).
1647 menu "Power management options"
1649 source "kernel/power/Kconfig"
1651 config ARCH_SUSPEND_POSSIBLE
1656 source "net/Kconfig"
1658 source "drivers/Kconfig"
1662 source "arch/arm/Kconfig.debug"
1664 source "security/Kconfig"
1666 source "crypto/Kconfig"
1668 source "lib/Kconfig"