4 select ARCH_CLOCKSOURCE_DATA
5 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
6 select ARCH_HAS_DEVMEM_IS_ALLOWED
7 select ARCH_HAS_ELF_RANDOMIZE
8 select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
9 select ARCH_HAVE_CUSTOM_GPIO_H
10 select ARCH_HAS_GCOV_PROFILE_ALL
11 select ARCH_MIGHT_HAVE_PC_PARPORT
12 select ARCH_SUPPORTS_ATOMIC_RMW
13 select ARCH_USE_BUILTIN_BSWAP
14 select ARCH_USE_CMPXCHG_LOCKREF
15 select ARCH_WANT_IPC_PARSE_VERSION
16 select BUILDTIME_EXTABLE_SORT if MMU
17 select CLONE_BACKWARDS
18 select CPU_PM if (SUSPEND || CPU_IDLE)
19 select DCACHE_WORD_ACCESS if HAVE_EFFICIENT_UNALIGNED_ACCESS
21 select EDAC_ATOMIC_SCRUB
22 select GENERIC_ALLOCATOR
23 select GENERIC_ATOMIC64 if (CPU_V7M || CPU_V6 || !CPU_32v6K || !AEABI)
24 select GENERIC_CLOCKEVENTS_BROADCAST if SMP
25 select GENERIC_EARLY_IOREMAP
26 select GENERIC_IDLE_POLL_SETUP
27 select GENERIC_IRQ_PROBE
28 select GENERIC_IRQ_SHOW
29 select GENERIC_IRQ_SHOW_LEVEL
30 select GENERIC_PCI_IOMAP
31 select GENERIC_SCHED_CLOCK
32 select GENERIC_SMP_IDLE_THREAD
33 select GENERIC_STRNCPY_FROM_USER
34 select GENERIC_STRNLEN_USER
35 select HANDLE_DOMAIN_IRQ
36 select HARDIRQS_SW_RESEND
37 select HAVE_ARCH_AUDITSYSCALL if (AEABI && !OABI_COMPAT)
38 select HAVE_ARCH_BITREVERSE if (CPU_32v7M || CPU_32v7) && !CPU_32v6
39 select HAVE_ARCH_HARDENED_USERCOPY
40 select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL && !CPU_ENDIAN_BE32 && MMU
41 select HAVE_ARCH_KGDB if !CPU_ENDIAN_BE32 && MMU
42 select HAVE_ARCH_MMAP_RND_BITS if MMU
43 select HAVE_ARCH_SECCOMP_FILTER if (AEABI && !OABI_COMPAT)
44 select HAVE_ARCH_TRACEHOOK
45 select HAVE_ARM_SMCCC if CPU_V7
47 select HAVE_CC_STACKPROTECTOR
48 select HAVE_CONTEXT_TRACKING
49 select HAVE_C_RECORDMCOUNT
50 select HAVE_DEBUG_KMEMLEAK
51 select HAVE_DMA_API_DEBUG
52 select HAVE_DMA_CONTIGUOUS if MMU
53 select HAVE_DYNAMIC_FTRACE if (!XIP_KERNEL) && !CPU_ENDIAN_BE32 && MMU
54 select HAVE_EFFICIENT_UNALIGNED_ACCESS if (CPU_V6 || CPU_V6K || CPU_V7) && MMU
55 select HAVE_EXIT_THREAD
56 select HAVE_FTRACE_MCOUNT_RECORD if (!XIP_KERNEL)
57 select HAVE_FUNCTION_GRAPH_TRACER if (!THUMB2_KERNEL)
58 select HAVE_FUNCTION_TRACER if (!XIP_KERNEL)
59 select HAVE_GCC_PLUGINS
60 select HAVE_GENERIC_DMA_COHERENT
61 select HAVE_HW_BREAKPOINT if (PERF_EVENTS && (CPU_V6 || CPU_V6K || CPU_V7))
62 select HAVE_IDE if PCI || ISA || PCMCIA
63 select HAVE_IRQ_TIME_ACCOUNTING
64 select HAVE_KERNEL_GZIP
65 select HAVE_KERNEL_LZ4
66 select HAVE_KERNEL_LZMA
67 select HAVE_KERNEL_LZO
69 select HAVE_KPROBES if !XIP_KERNEL && !CPU_ENDIAN_BE32 && !CPU_V7M
70 select HAVE_KRETPROBES if (HAVE_KPROBES)
72 select HAVE_MOD_ARCH_SPECIFIC
74 select HAVE_OPROFILE if (HAVE_PERF_EVENTS)
75 select HAVE_OPTPROBES if !THUMB2_KERNEL
76 select HAVE_PERF_EVENTS
78 select HAVE_PERF_USER_STACK_DUMP
79 select HAVE_RCU_TABLE_FREE if (SMP && ARM_LPAE)
80 select HAVE_REGS_AND_STACK_ACCESS_API
81 select HAVE_SYSCALL_TRACEPOINTS
83 select HAVE_VIRT_CPU_ACCOUNTING_GEN
84 select IRQ_FORCED_THREADING
85 select MODULES_USE_ELF_REL
87 select OF_EARLY_FLATTREE if OF
88 select OF_RESERVED_MEM if OF
90 select OLD_SIGSUSPEND3
91 select PERF_USE_VMALLOC
93 select SYS_SUPPORTS_APM_EMULATION
94 # Above selects are sorted alphabetically; please add new ones
95 # according to that. Thanks.
97 The ARM series is a line of low-power-consumption RISC chip designs
98 licensed by ARM Ltd and targeted at embedded applications and
99 handhelds such as the Compaq IPAQ. ARM-based PCs are no longer
100 manufactured, but legacy ARM-based PC hardware remains popular in
101 Europe. There is an ARM Linux project with a web page at
102 <http://www.arm.linux.org.uk/>.
104 config ARM_HAS_SG_CHAIN
105 select ARCH_HAS_SG_CHAIN
108 config NEED_SG_DMA_LENGTH
111 config ARM_DMA_USE_IOMMU
113 select ARM_HAS_SG_CHAIN
114 select NEED_SG_DMA_LENGTH
118 config ARM_DMA_IOMMU_ALIGNMENT
119 int "Maximum PAGE_SIZE order of alignment for DMA IOMMU buffers"
123 DMA mapping framework by default aligns all buffers to the smallest
124 PAGE_SIZE order which is greater than or equal to the requested buffer
125 size. This works well for buffers up to a few hundreds kilobytes, but
126 for larger buffers it just a waste of address space. Drivers which has
127 relatively small addressing window (like 64Mib) might run out of
128 virtual space with just a few allocations.
130 With this parameter you can specify the maximum PAGE_SIZE order for
131 DMA IOMMU buffers. Larger buffers will be aligned only to this
132 specified order. The order is expressed as a power of two multiplied
137 config MIGHT_HAVE_PCI
140 config SYS_SUPPORTS_APM_EMULATION
145 select GENERIC_ALLOCATOR
156 The Extended Industry Standard Architecture (EISA) bus was
157 developed as an open alternative to the IBM MicroChannel bus.
159 The EISA bus provided some of the features of the IBM MicroChannel
160 bus while maintaining backward compatibility with cards made for
161 the older ISA bus. The EISA bus saw limited use between 1988 and
162 1995 when it was made obsolete by the PCI bus.
164 Say Y here if you are building a kernel for an EISA-based machine.
171 config STACKTRACE_SUPPORT
175 config LOCKDEP_SUPPORT
179 config TRACE_IRQFLAGS_SUPPORT
183 config RWSEM_XCHGADD_ALGORITHM
187 config ARCH_HAS_ILOG2_U32
190 config ARCH_HAS_ILOG2_U64
193 config ARCH_HAS_BANDGAP
196 config FIX_EARLYCON_MEM
199 config GENERIC_HWEIGHT
203 config GENERIC_CALIBRATE_DELAY
207 config ARCH_MAY_HAVE_PC_FDC
213 config NEED_DMA_MAP_STATE
216 config ARCH_SUPPORTS_UPROBES
219 config ARCH_HAS_DMA_SET_COHERENT_MASK
222 config GENERIC_ISA_DMA
228 config NEED_RET_TO_USER
236 default 0xffff0000 if MMU || CPU_HIGH_VECTOR
237 default DRAM_BASE if REMAP_VECTORS_TO_RAM
240 The base address of exception vectors. This must be two pages
243 config ARM_PATCH_PHYS_VIRT
244 bool "Patch physical to virtual translations at runtime" if EMBEDDED
246 depends on !XIP_KERNEL && MMU
248 Patch phys-to-virt and virt-to-phys translation functions at
249 boot and module load time according to the position of the
250 kernel in system memory.
252 This can only be used with non-XIP MMU kernels where the base
253 of physical memory is at a 16MB boundary.
255 Only disable this option if you know that you do not require
256 this feature (eg, building a kernel for a single machine) and
257 you need to shrink the kernel to the minimal size.
259 config NEED_MACH_IO_H
262 Select this when mach/io.h is required to provide special
263 definitions for this platform. The need for mach/io.h should
264 be avoided when possible.
266 config NEED_MACH_MEMORY_H
269 Select this when mach/memory.h is required to provide special
270 definitions for this platform. The need for mach/memory.h should
271 be avoided when possible.
274 hex "Physical address of main memory" if MMU
275 depends on !ARM_PATCH_PHYS_VIRT
276 default DRAM_BASE if !MMU
277 default 0x00000000 if ARCH_EBSA110 || \
282 (ARCH_REALVIEW && !REALVIEW_HIGH_PHYS_OFFSET)
283 default 0x10000000 if ARCH_OMAP1 || ARCH_RPC
284 default 0x20000000 if ARCH_S5PV210
285 default 0x70000000 if REALVIEW_HIGH_PHYS_OFFSET
286 default 0xc0000000 if ARCH_SA1100
288 Please provide the physical address corresponding to the
289 location of main memory in your system.
295 config PGTABLE_LEVELS
297 default 3 if ARM_LPAE
300 source "init/Kconfig"
302 source "kernel/Kconfig.freezer"
307 bool "MMU-based Paged Memory Management Support"
310 Select if you want MMU-based virtualised addressing space
311 support by paged memory management. If unsure, say 'Y'.
313 config ARCH_MMAP_RND_BITS_MIN
316 config ARCH_MMAP_RND_BITS_MAX
317 default 14 if PAGE_OFFSET=0x40000000
318 default 15 if PAGE_OFFSET=0x80000000
322 # The "ARM system type" choice list is ordered alphabetically by option
323 # text. Please add new entries in the option alphabetic order.
326 prompt "ARM system type"
327 default ARM_SINGLE_ARMV7M if !MMU
328 default ARCH_MULTIPLATFORM if MMU
330 config ARCH_MULTIPLATFORM
331 bool "Allow multiple platforms to be selected"
333 select ARM_HAS_SG_CHAIN
334 select ARM_PATCH_PHYS_VIRT
338 select GENERIC_CLOCKEVENTS
339 select MIGHT_HAVE_PCI
340 select MULTI_IRQ_HANDLER
344 config ARM_SINGLE_ARMV7M
345 bool "ARMv7-M based platforms (Cortex-M0/M3/M4)"
352 select GENERIC_CLOCKEVENTS
358 bool "Cortina Systems Gemini"
361 select GENERIC_CLOCKEVENTS
364 Support for the Cortina Systems Gemini family SoCs
368 select ARCH_USES_GETTIMEOFFSET
371 select NEED_MACH_IO_H
372 select NEED_MACH_MEMORY_H
375 This is an evaluation board for the StrongARM processor available
376 from Digital. It has limited hardware on-board, including an
377 Ethernet interface, two PCMCIA sockets, two serial ports and a
382 select ARCH_HAS_HOLES_MEMORYMODEL
384 select ARM_PATCH_PHYS_VIRT
390 select GENERIC_CLOCKEVENTS
393 This enables support for the Cirrus EP93xx series of CPUs.
395 config ARCH_FOOTBRIDGE
399 select GENERIC_CLOCKEVENTS
401 select NEED_MACH_IO_H if !MMU
402 select NEED_MACH_MEMORY_H
404 Support for systems based on the DC21285 companion chip
405 ("FootBridge"), such as the Simtec CATS and the Rebel NetWinder.
408 bool "Hilscher NetX based"
412 select GENERIC_CLOCKEVENTS
414 This enables support for systems based on the Hilscher NetX Soc
420 select NEED_MACH_MEMORY_H
421 select NEED_RET_TO_USER
427 Support for Intel's IOP13XX (XScale) family of processors.
435 select NEED_RET_TO_USER
439 Support for Intel's 80219 and IOP32X (XScale) family of
448 select NEED_RET_TO_USER
452 Support for Intel's IOP33X (XScale) family of processors.
457 select ARCH_HAS_DMA_SET_COHERENT_MASK
458 select ARCH_SUPPORTS_BIG_ENDIAN
461 select DMABOUNCE if PCI
462 select GENERIC_CLOCKEVENTS
464 select MIGHT_HAVE_PCI
465 select NEED_MACH_IO_H
466 select USB_EHCI_BIG_ENDIAN_DESC
467 select USB_EHCI_BIG_ENDIAN_MMIO
469 Support for Intel's IXP4XX (XScale) family of processors.
474 select GENERIC_CLOCKEVENTS
476 select MIGHT_HAVE_PCI
477 select MULTI_IRQ_HANDLER
481 select PLAT_ORION_LEGACY
483 select PM_GENERIC_DOMAINS if PM
485 Support for the Marvell Dove SoC 88AP510
488 bool "Micrel/Kendin KS8695"
491 select GENERIC_CLOCKEVENTS
493 select NEED_MACH_MEMORY_H
495 Support for Micrel/Kendin KS8695 "Centaur" (ARM922T) based
496 System-on-Chip devices.
499 bool "Nuvoton W90X900 CPU"
503 select GENERIC_CLOCKEVENTS
506 Support for Nuvoton (Winbond logic dept.) ARM9 processor,
507 At present, the w90x900 has been renamed nuc900, regarding
508 the ARM series product line, you can login the following
509 link address to know more.
511 <http://www.nuvoton.com/hq/enu/ProductAndSales/ProductLines/
512 ConsumerElectronicsIC/ARMMicrocontroller/ARMMicrocontroller>
518 select CLKSRC_LPC32XX
521 select GENERIC_CLOCKEVENTS
523 select MULTI_IRQ_HANDLER
527 Support for the NXP LPC32XX family of processors
530 bool "PXA2xx/PXA3xx-based"
533 select ARM_CPU_SUSPEND if PM
540 select CPU_XSCALE if !CPU_XSC3
541 select GENERIC_CLOCKEVENTS
546 select MULTI_IRQ_HANDLER
550 Support for Intel/Marvell's PXA2xx/PXA3xx processor line.
556 select ARCH_MAY_HAVE_PC_FDC
557 select ARCH_SPARSEMEM_ENABLE
558 select ARCH_USES_GETTIMEOFFSET
562 select HAVE_PATA_PLATFORM
564 select NEED_MACH_IO_H
565 select NEED_MACH_MEMORY_H
568 On the Acorn Risc-PC, Linux can support the internal IDE disk and
569 CD-ROM interface, serial and parallel port, and the floppy drive.
574 select ARCH_SPARSEMEM_ENABLE
578 select CLKSRC_OF if OF
581 select GENERIC_CLOCKEVENTS
586 select MULTI_IRQ_HANDLER
587 select NEED_MACH_MEMORY_H
590 Support for StrongARM 11x0 based boards.
593 bool "Samsung S3C24XX SoCs"
596 select CLKSRC_SAMSUNG_PWM
597 select GENERIC_CLOCKEVENTS
600 select HAVE_S3C2410_I2C if I2C
601 select HAVE_S3C2410_WATCHDOG if WATCHDOG
602 select HAVE_S3C_RTC if RTC_CLASS
603 select MULTI_IRQ_HANDLER
604 select NEED_MACH_IO_H
607 Samsung S3C2410, S3C2412, S3C2413, S3C2416, S3C2440, S3C2442, S3C2443
608 and S3C2450 SoCs based systems, such as the Simtec Electronics BAST
609 (<http://www.simtec.co.uk/products/EB110ITX/>), the IPAQ 1940 or the
610 Samsung SMDK2410 development board (and derivatives).
614 select ARCH_HAS_HOLES_MEMORYMODEL
617 select GENERIC_ALLOCATOR
618 select GENERIC_CLOCKEVENTS
619 select GENERIC_IRQ_CHIP
625 Support for TI's DaVinci platform.
630 select ARCH_HAS_HOLES_MEMORYMODEL
634 select GENERIC_CLOCKEVENTS
635 select GENERIC_IRQ_CHIP
639 select MULTI_IRQ_HANDLER
640 select NEED_MACH_IO_H if PCCARD
641 select NEED_MACH_MEMORY_H
644 Support for older TI OMAP1 (omap7xx, omap15xx or omap16xx)
648 menu "Multiple platform selection"
649 depends on ARCH_MULTIPLATFORM
651 comment "CPU Core family selection"
654 bool "ARMv4 based platforms (FA526)"
655 depends on !ARCH_MULTI_V6_V7
656 select ARCH_MULTI_V4_V5
659 config ARCH_MULTI_V4T
660 bool "ARMv4T based platforms (ARM720T, ARM920T, ...)"
661 depends on !ARCH_MULTI_V6_V7
662 select ARCH_MULTI_V4_V5
663 select CPU_ARM920T if !(CPU_ARM7TDMI || CPU_ARM720T || \
664 CPU_ARM740T || CPU_ARM9TDMI || CPU_ARM922T || \
665 CPU_ARM925T || CPU_ARM940T)
668 bool "ARMv5 based platforms (ARM926T, XSCALE, PJ1, ...)"
669 depends on !ARCH_MULTI_V6_V7
670 select ARCH_MULTI_V4_V5
671 select CPU_ARM926T if !(CPU_ARM946E || CPU_ARM1020 || \
672 CPU_ARM1020E || CPU_ARM1022 || CPU_ARM1026 || \
673 CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK || CPU_FEROCEON)
675 config ARCH_MULTI_V4_V5
679 bool "ARMv6 based platforms (ARM11)"
680 select ARCH_MULTI_V6_V7
684 bool "ARMv7 based platforms (Cortex-A, PJ4, Scorpion, Krait)"
686 select ARCH_MULTI_V6_V7
690 config ARCH_MULTI_V6_V7
692 select MIGHT_HAVE_CACHE_L2X0
694 config ARCH_MULTI_CPU_AUTO
695 def_bool !(ARCH_MULTI_V4 || ARCH_MULTI_V4T || ARCH_MULTI_V6_V7)
701 bool "Dummy Virtual Machine"
702 depends on ARCH_MULTI_V7
705 select ARM_GIC_V2M if PCI
708 select HAVE_ARM_ARCH_TIMER
711 # This is sorted alphabetically by mach-* pathname. However, plat-*
712 # Kconfigs may be included either alphabetically (according to the
713 # plat- suffix) or along side the corresponding mach-* source.
715 source "arch/arm/mach-mvebu/Kconfig"
717 source "arch/arm/mach-alpine/Kconfig"
719 source "arch/arm/mach-artpec/Kconfig"
721 source "arch/arm/mach-asm9260/Kconfig"
723 source "arch/arm/mach-at91/Kconfig"
725 source "arch/arm/mach-axxia/Kconfig"
727 source "arch/arm/mach-bcm/Kconfig"
729 source "arch/arm/mach-berlin/Kconfig"
731 source "arch/arm/mach-clps711x/Kconfig"
733 source "arch/arm/mach-cns3xxx/Kconfig"
735 source "arch/arm/mach-davinci/Kconfig"
737 source "arch/arm/mach-digicolor/Kconfig"
739 source "arch/arm/mach-dove/Kconfig"
741 source "arch/arm/mach-ep93xx/Kconfig"
743 source "arch/arm/mach-footbridge/Kconfig"
745 source "arch/arm/mach-gemini/Kconfig"
747 source "arch/arm/mach-highbank/Kconfig"
749 source "arch/arm/mach-hisi/Kconfig"
751 source "arch/arm/mach-integrator/Kconfig"
753 source "arch/arm/mach-iop32x/Kconfig"
755 source "arch/arm/mach-iop33x/Kconfig"
757 source "arch/arm/mach-iop13xx/Kconfig"
759 source "arch/arm/mach-ixp4xx/Kconfig"
761 source "arch/arm/mach-keystone/Kconfig"
763 source "arch/arm/mach-ks8695/Kconfig"
765 source "arch/arm/mach-meson/Kconfig"
767 source "arch/arm/mach-moxart/Kconfig"
769 source "arch/arm/mach-aspeed/Kconfig"
771 source "arch/arm/mach-mv78xx0/Kconfig"
773 source "arch/arm/mach-imx/Kconfig"
775 source "arch/arm/mach-mediatek/Kconfig"
777 source "arch/arm/mach-mxs/Kconfig"
779 source "arch/arm/mach-netx/Kconfig"
781 source "arch/arm/mach-nomadik/Kconfig"
783 source "arch/arm/mach-nspire/Kconfig"
785 source "arch/arm/plat-omap/Kconfig"
787 source "arch/arm/mach-omap1/Kconfig"
789 source "arch/arm/mach-omap2/Kconfig"
791 source "arch/arm/mach-orion5x/Kconfig"
793 source "arch/arm/mach-picoxcell/Kconfig"
795 source "arch/arm/mach-pxa/Kconfig"
796 source "arch/arm/plat-pxa/Kconfig"
798 source "arch/arm/mach-mmp/Kconfig"
800 source "arch/arm/mach-oxnas/Kconfig"
802 source "arch/arm/mach-qcom/Kconfig"
804 source "arch/arm/mach-realview/Kconfig"
806 source "arch/arm/mach-rockchip/Kconfig"
808 source "arch/arm/mach-sa1100/Kconfig"
810 source "arch/arm/mach-socfpga/Kconfig"
812 source "arch/arm/mach-spear/Kconfig"
814 source "arch/arm/mach-sti/Kconfig"
816 source "arch/arm/mach-s3c24xx/Kconfig"
818 source "arch/arm/mach-s3c64xx/Kconfig"
820 source "arch/arm/mach-s5pv210/Kconfig"
822 source "arch/arm/mach-exynos/Kconfig"
823 source "arch/arm/plat-samsung/Kconfig"
825 source "arch/arm/mach-shmobile/Kconfig"
827 source "arch/arm/mach-sunxi/Kconfig"
829 source "arch/arm/mach-prima2/Kconfig"
831 source "arch/arm/mach-tango/Kconfig"
833 source "arch/arm/mach-tegra/Kconfig"
835 source "arch/arm/mach-u300/Kconfig"
837 source "arch/arm/mach-uniphier/Kconfig"
839 source "arch/arm/mach-ux500/Kconfig"
841 source "arch/arm/mach-versatile/Kconfig"
843 source "arch/arm/mach-vexpress/Kconfig"
844 source "arch/arm/plat-versatile/Kconfig"
846 source "arch/arm/mach-vt8500/Kconfig"
848 source "arch/arm/mach-w90x900/Kconfig"
850 source "arch/arm/mach-zx/Kconfig"
852 source "arch/arm/mach-zynq/Kconfig"
854 # ARMv7-M architecture
856 bool "Energy Micro efm32"
857 depends on ARM_SINGLE_ARMV7M
860 Support for Energy Micro's (now Silicon Labs) efm32 Giant Gecko
864 bool "NXP LPC18xx/LPC43xx"
865 depends on ARM_SINGLE_ARMV7M
866 select ARCH_HAS_RESET_CONTROLLER
868 select CLKSRC_LPC32XX
871 Support for NXP's LPC18xx Cortex-M3 and LPC43xx Cortex-M4
872 high performance microcontrollers.
875 bool "STMicrolectronics STM32"
876 depends on ARM_SINGLE_ARMV7M
877 select ARCH_HAS_RESET_CONTROLLER
878 select ARMV7M_SYSTICK
881 select RESET_CONTROLLER
883 Support for STMicroelectronics STM32 processors.
885 config MACH_STM32F429
886 bool "STMicrolectronics STM32F429"
887 depends on ARCH_STM32
891 bool "ARM MPS2 platform"
892 depends on ARM_SINGLE_ARMV7M
896 Support for Cortex-M Prototyping System (or V2M-MPS2) which comes
897 with a range of available cores like Cortex-M3/M4/M7.
899 Please, note that depends which Application Note is used memory map
900 for the platform may vary, so adjustment of RAM base might be needed.
902 # Definitions to make life easier
908 select GENERIC_CLOCKEVENTS
914 select GENERIC_IRQ_CHIP
917 config PLAT_ORION_LEGACY
924 config PLAT_VERSATILE
927 source "arch/arm/firmware/Kconfig"
929 source arch/arm/mm/Kconfig
932 bool "Enable iWMMXt support"
933 depends on CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK || CPU_PJ4 || CPU_PJ4B
934 default y if PXA27x || PXA3xx || ARCH_MMP || CPU_PJ4 || CPU_PJ4B
936 Enable support for iWMMXt context switching at run time if
937 running on a CPU that supports it.
939 config MULTI_IRQ_HANDLER
942 Allow each machine to specify it's own IRQ handler at run time.
945 source "arch/arm/Kconfig-nommu"
948 config PJ4B_ERRATA_4742
949 bool "PJ4B Errata 4742: IDLE Wake Up Commands can Cause the CPU Core to Cease Operation"
950 depends on CPU_PJ4B && MACH_ARMADA_370
953 When coming out of either a Wait for Interrupt (WFI) or a Wait for
954 Event (WFE) IDLE states, a specific timing sensitivity exists between
955 the retiring WFI/WFE instructions and the newly issued subsequent
956 instructions. This sensitivity can result in a CPU hang scenario.
958 The software must insert either a Data Synchronization Barrier (DSB)
959 or Data Memory Barrier (DMB) command immediately after the WFI/WFE
962 config ARM_ERRATA_326103
963 bool "ARM errata: FSR write bit incorrect on a SWP to read-only memory"
966 Executing a SWP instruction to read-only memory does not set bit 11
967 of the FSR on the ARM 1136 prior to r1p0. This causes the kernel to
968 treat the access as a read, preventing a COW from occurring and
969 causing the faulting task to livelock.
971 config ARM_ERRATA_411920
972 bool "ARM errata: Invalidation of the Instruction Cache operation can fail"
973 depends on CPU_V6 || CPU_V6K
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 r1p* 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"
999 depends on !ARCH_MULTIPLATFORM
1001 This option enables the workaround for the 458693 Cortex-A8 (r2p0)
1002 erratum. For very specific sequences of memory operations, it is
1003 possible for a hazard condition intended for a cache line to instead
1004 be incorrectly associated with a different cache line. This false
1005 hazard might then cause a processor deadlock. The workaround enables
1006 the L1 caching of the NEON accesses and disables the PLD instruction
1007 in the ACTLR register. Note that setting specific bits in the ACTLR
1008 register may not be available in non-secure mode.
1010 config ARM_ERRATA_460075
1011 bool "ARM errata: Data written to the L2 cache can be overwritten with stale data"
1013 depends on !ARCH_MULTIPLATFORM
1015 This option enables the workaround for the 460075 Cortex-A8 (r2p0)
1016 erratum. Any asynchronous access to the L2 cache may encounter a
1017 situation in which recent store transactions to the L2 cache are lost
1018 and overwritten with stale memory contents from external memory. The
1019 workaround disables the write-allocate mode for the L2 cache via the
1020 ACTLR register. Note that setting specific bits in the ACTLR register
1021 may not be available in non-secure mode.
1023 config ARM_ERRATA_742230
1024 bool "ARM errata: DMB operation may be faulty"
1025 depends on CPU_V7 && SMP
1026 depends on !ARCH_MULTIPLATFORM
1028 This option enables the workaround for the 742230 Cortex-A9
1029 (r1p0..r2p2) erratum. Under rare circumstances, a DMB instruction
1030 between two write operations may not ensure the correct visibility
1031 ordering of the two writes. This workaround sets a specific bit in
1032 the diagnostic register of the Cortex-A9 which causes the DMB
1033 instruction to behave as a DSB, ensuring the correct behaviour of
1036 config ARM_ERRATA_742231
1037 bool "ARM errata: Incorrect hazard handling in the SCU may lead to data corruption"
1038 depends on CPU_V7 && SMP
1039 depends on !ARCH_MULTIPLATFORM
1041 This option enables the workaround for the 742231 Cortex-A9
1042 (r2p0..r2p2) erratum. Under certain conditions, specific to the
1043 Cortex-A9 MPCore micro-architecture, two CPUs working in SMP mode,
1044 accessing some data located in the same cache line, may get corrupted
1045 data due to bad handling of the address hazard when the line gets
1046 replaced from one of the CPUs at the same time as another CPU is
1047 accessing it. This workaround sets specific bits in the diagnostic
1048 register of the Cortex-A9 which reduces the linefill issuing
1049 capabilities of the processor.
1051 config ARM_ERRATA_643719
1052 bool "ARM errata: LoUIS bit field in CLIDR register is incorrect"
1053 depends on CPU_V7 && SMP
1056 This option enables the workaround for the 643719 Cortex-A9 (prior to
1057 r1p0) erratum. On affected cores the LoUIS bit field of the CLIDR
1058 register returns zero when it should return one. The workaround
1059 corrects this value, ensuring cache maintenance operations which use
1060 it behave as intended and avoiding data corruption.
1062 config ARM_ERRATA_720789
1063 bool "ARM errata: TLBIASIDIS and TLBIMVAIS operations can broadcast a faulty ASID"
1066 This option enables the workaround for the 720789 Cortex-A9 (prior to
1067 r2p0) erratum. A faulty ASID can be sent to the other CPUs for the
1068 broadcasted CP15 TLB maintenance operations TLBIASIDIS and TLBIMVAIS.
1069 As a consequence of this erratum, some TLB entries which should be
1070 invalidated are not, resulting in an incoherency in the system page
1071 tables. The workaround changes the TLB flushing routines to invalidate
1072 entries regardless of the ASID.
1074 config ARM_ERRATA_743622
1075 bool "ARM errata: Faulty hazard checking in the Store Buffer may lead to data corruption"
1077 depends on !ARCH_MULTIPLATFORM
1079 This option enables the workaround for the 743622 Cortex-A9
1080 (r2p*) erratum. Under very rare conditions, a faulty
1081 optimisation in the Cortex-A9 Store Buffer may lead to data
1082 corruption. This workaround sets a specific bit in the diagnostic
1083 register of the Cortex-A9 which disables the Store Buffer
1084 optimisation, preventing the defect from occurring. This has no
1085 visible impact on the overall performance or power consumption of the
1088 config ARM_ERRATA_751472
1089 bool "ARM errata: Interrupted ICIALLUIS may prevent completion of broadcasted operation"
1091 depends on !ARCH_MULTIPLATFORM
1093 This option enables the workaround for the 751472 Cortex-A9 (prior
1094 to r3p0) erratum. An interrupted ICIALLUIS operation may prevent the
1095 completion of a following broadcasted operation if the second
1096 operation is received by a CPU before the ICIALLUIS has completed,
1097 potentially leading to corrupted entries in the cache or TLB.
1099 config ARM_ERRATA_754322
1100 bool "ARM errata: possible faulty MMU translations following an ASID switch"
1103 This option enables the workaround for the 754322 Cortex-A9 (r2p*,
1104 r3p*) erratum. A speculative memory access may cause a page table walk
1105 which starts prior to an ASID switch but completes afterwards. This
1106 can populate the micro-TLB with a stale entry which may be hit with
1107 the new ASID. This workaround places two dsb instructions in the mm
1108 switching code so that no page table walks can cross the ASID switch.
1110 config ARM_ERRATA_754327
1111 bool "ARM errata: no automatic Store Buffer drain"
1112 depends on CPU_V7 && SMP
1114 This option enables the workaround for the 754327 Cortex-A9 (prior to
1115 r2p0) erratum. The Store Buffer does not have any automatic draining
1116 mechanism and therefore a livelock may occur if an external agent
1117 continuously polls a memory location waiting to observe an update.
1118 This workaround defines cpu_relax() as smp_mb(), preventing correctly
1119 written polling loops from denying visibility of updates to memory.
1121 config ARM_ERRATA_364296
1122 bool "ARM errata: Possible cache data corruption with hit-under-miss enabled"
1125 This options enables the workaround for the 364296 ARM1136
1126 r0p2 erratum (possible cache data corruption with
1127 hit-under-miss enabled). It sets the undocumented bit 31 in
1128 the auxiliary control register and the FI bit in the control
1129 register, thus disabling hit-under-miss without putting the
1130 processor into full low interrupt latency mode. ARM11MPCore
1133 config ARM_ERRATA_764369
1134 bool "ARM errata: Data cache line maintenance operation by MVA may not succeed"
1135 depends on CPU_V7 && SMP
1137 This option enables the workaround for erratum 764369
1138 affecting Cortex-A9 MPCore with two or more processors (all
1139 current revisions). Under certain timing circumstances, a data
1140 cache line maintenance operation by MVA targeting an Inner
1141 Shareable memory region may fail to proceed up to either the
1142 Point of Coherency or to the Point of Unification of the
1143 system. This workaround adds a DSB instruction before the
1144 relevant cache maintenance functions and sets a specific bit
1145 in the diagnostic control register of the SCU.
1147 config ARM_ERRATA_775420
1148 bool "ARM errata: A data cache maintenance operation which aborts, might lead to deadlock"
1151 This option enables the workaround for the 775420 Cortex-A9 (r2p2,
1152 r2p6,r2p8,r2p10,r3p0) erratum. In case a date cache maintenance
1153 operation aborts with MMU exception, it might cause the processor
1154 to deadlock. This workaround puts DSB before executing ISB if
1155 an abort may occur on cache maintenance.
1157 config ARM_ERRATA_798181
1158 bool "ARM errata: TLBI/DSB failure on Cortex-A15"
1159 depends on CPU_V7 && SMP
1161 On Cortex-A15 (r0p0..r3p2) the TLBI*IS/DSB operations are not
1162 adequately shooting down all use of the old entries. This
1163 option enables the Linux kernel workaround for this erratum
1164 which sends an IPI to the CPUs that are running the same ASID
1165 as the one being invalidated.
1167 config ARM_ERRATA_773022
1168 bool "ARM errata: incorrect instructions may be executed from loop buffer"
1171 This option enables the workaround for the 773022 Cortex-A15
1172 (up to r0p4) erratum. In certain rare sequences of code, the
1173 loop buffer may deliver incorrect instructions. This
1174 workaround disables the loop buffer to avoid the erratum.
1176 config ARM_ERRATA_818325_852422
1177 bool "ARM errata: A12: some seqs of opposed cond code instrs => deadlock or corruption"
1180 This option enables the workaround for:
1181 - Cortex-A12 818325: Execution of an UNPREDICTABLE STR or STM
1182 instruction might deadlock. Fixed in r0p1.
1183 - Cortex-A12 852422: Execution of a sequence of instructions might
1184 lead to either a data corruption or a CPU deadlock. Not fixed in
1185 any Cortex-A12 cores yet.
1186 This workaround for all both errata involves setting bit[12] of the
1187 Feature Register. This bit disables an optimisation applied to a
1188 sequence of 2 instructions that use opposing condition codes.
1190 config ARM_ERRATA_821420
1191 bool "ARM errata: A12: sequence of VMOV to core registers might lead to a dead lock"
1194 This option enables the workaround for the 821420 Cortex-A12
1195 (all revs) erratum. In very rare timing conditions, a sequence
1196 of VMOV to Core registers instructions, for which the second
1197 one is in the shadow of a branch or abort, can lead to a
1198 deadlock when the VMOV instructions are issued out-of-order.
1200 config ARM_ERRATA_825619
1201 bool "ARM errata: A12: DMB NSHST/ISHST mixed ... might cause deadlock"
1204 This option enables the workaround for the 825619 Cortex-A12
1205 (all revs) erratum. Within rare timing constraints, executing a
1206 DMB NSHST or DMB ISHST instruction followed by a mix of Cacheable
1207 and Device/Strongly-Ordered loads and stores might cause deadlock
1209 config ARM_ERRATA_852421
1210 bool "ARM errata: A17: DMB ST might fail to create order between stores"
1213 This option enables the workaround for the 852421 Cortex-A17
1214 (r1p0, r1p1, r1p2) erratum. Under very rare timing conditions,
1215 execution of a DMB ST instruction might fail to properly order
1216 stores from GroupA and stores from GroupB.
1218 config ARM_ERRATA_852423
1219 bool "ARM errata: A17: some seqs of opposed cond code instrs => deadlock or corruption"
1222 This option enables the workaround for:
1223 - Cortex-A17 852423: Execution of a sequence of instructions might
1224 lead to either a data corruption or a CPU deadlock. Not fixed in
1225 any Cortex-A17 cores yet.
1226 This is identical to Cortex-A12 erratum 852422. It is a separate
1227 config option from the A12 erratum due to the way errata are checked
1232 source "arch/arm/common/Kconfig"
1239 Find out whether you have ISA slots on your motherboard. ISA is the
1240 name of a bus system, i.e. the way the CPU talks to the other stuff
1241 inside your box. Other bus systems are PCI, EISA, MicroChannel
1242 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1243 newer boards don't support it. If you have ISA, say Y, otherwise N.
1245 # Select ISA DMA controller support
1250 # Select ISA DMA interface
1255 bool "PCI support" if MIGHT_HAVE_PCI
1257 Find out whether you have a PCI motherboard. PCI is the name of a
1258 bus system, i.e. the way the CPU talks to the other stuff inside
1259 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1260 VESA. If you have PCI, say Y, otherwise N.
1266 config PCI_DOMAINS_GENERIC
1267 def_bool PCI_DOMAINS
1269 config PCI_NANOENGINE
1270 bool "BSE nanoEngine PCI support"
1271 depends on SA1100_NANOENGINE
1273 Enable PCI on the BSE nanoEngine board.
1278 config PCI_HOST_ITE8152
1280 depends on PCI && MACH_ARMCORE
1284 source "drivers/pci/Kconfig"
1286 source "drivers/pcmcia/Kconfig"
1290 menu "Kernel Features"
1295 This option should be selected by machines which have an SMP-
1298 The only effect of this option is to make the SMP-related
1299 options available to the user for configuration.
1302 bool "Symmetric Multi-Processing"
1303 depends on CPU_V6K || CPU_V7
1304 depends on GENERIC_CLOCKEVENTS
1306 depends on MMU || ARM_MPU
1309 This enables support for systems with more than one CPU. If you have
1310 a system with only one CPU, say N. If you have a system with more
1311 than one CPU, say Y.
1313 If you say N here, the kernel will run on uni- and multiprocessor
1314 machines, but will use only one CPU of a multiprocessor machine. If
1315 you say Y here, the kernel will run on many, but not all,
1316 uniprocessor machines. On a uniprocessor machine, the kernel
1317 will run faster if you say N here.
1319 See also <file:Documentation/x86/i386/IO-APIC.txt>,
1320 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
1321 <http://tldp.org/HOWTO/SMP-HOWTO.html>.
1323 If you don't know what to do here, say N.
1326 bool "Allow booting SMP kernel on uniprocessor systems"
1327 depends on SMP && !XIP_KERNEL && MMU
1330 SMP kernels contain instructions which fail on non-SMP processors.
1331 Enabling this option allows the kernel to modify itself to make
1332 these instructions safe. Disabling it allows about 1K of space
1335 If you don't know what to do here, say Y.
1337 config ARM_CPU_TOPOLOGY
1338 bool "Support cpu topology definition"
1339 depends on SMP && CPU_V7
1342 Support ARM cpu topology definition. The MPIDR register defines
1343 affinity between processors which is then used to describe the cpu
1344 topology of an ARM System.
1347 bool "Multi-core scheduler support"
1348 depends on ARM_CPU_TOPOLOGY
1350 Multi-core scheduler support improves the CPU scheduler's decision
1351 making when dealing with multi-core CPU chips at a cost of slightly
1352 increased overhead in some places. If unsure say N here.
1355 bool "SMT scheduler support"
1356 depends on ARM_CPU_TOPOLOGY
1358 Improves the CPU scheduler's decision making when dealing with
1359 MultiThreading at a cost of slightly increased overhead in some
1360 places. If unsure say N here.
1365 This option enables support for the ARM system coherency unit
1367 config HAVE_ARM_ARCH_TIMER
1368 bool "Architected timer support"
1370 select ARM_ARCH_TIMER
1371 select GENERIC_CLOCKEVENTS
1373 This option enables support for the ARM architected timer
1377 select CLKSRC_OF if OF
1379 This options enables support for the ARM timer and watchdog unit
1382 bool "Multi-Cluster Power Management"
1383 depends on CPU_V7 && SMP
1385 This option provides the common power management infrastructure
1386 for (multi-)cluster based systems, such as big.LITTLE based
1389 config MCPM_QUAD_CLUSTER
1393 To avoid wasting resources unnecessarily, MCPM only supports up
1394 to 2 clusters by default.
1395 Platforms with 3 or 4 clusters that use MCPM must select this
1396 option to allow the additional clusters to be managed.
1399 bool "big.LITTLE support (Experimental)"
1400 depends on CPU_V7 && SMP
1403 This option enables support selections for the big.LITTLE
1404 system architecture.
1407 bool "big.LITTLE switcher support"
1408 depends on BIG_LITTLE && MCPM && HOTPLUG_CPU && ARM_GIC
1411 The big.LITTLE "switcher" provides the core functionality to
1412 transparently handle transition between a cluster of A15's
1413 and a cluster of A7's in a big.LITTLE system.
1415 config BL_SWITCHER_DUMMY_IF
1416 tristate "Simple big.LITTLE switcher user interface"
1417 depends on BL_SWITCHER && DEBUG_KERNEL
1419 This is a simple and dummy char dev interface to control
1420 the big.LITTLE switcher core code. It is meant for
1421 debugging purposes only.
1424 prompt "Memory split"
1428 Select the desired split between kernel and user memory.
1430 If you are not absolutely sure what you are doing, leave this
1434 bool "3G/1G user/kernel split"
1435 config VMSPLIT_3G_OPT
1436 bool "3G/1G user/kernel split (for full 1G low memory)"
1438 bool "2G/2G user/kernel split"
1440 bool "1G/3G user/kernel split"
1445 default PHYS_OFFSET if !MMU
1446 default 0x40000000 if VMSPLIT_1G
1447 default 0x80000000 if VMSPLIT_2G
1448 default 0xB0000000 if VMSPLIT_3G_OPT
1452 int "Maximum number of CPUs (2-32)"
1458 bool "Support for hot-pluggable CPUs"
1461 Say Y here to experiment with turning CPUs off and on. CPUs
1462 can be controlled through /sys/devices/system/cpu.
1465 bool "Support for the ARM Power State Coordination Interface (PSCI)"
1466 depends on HAVE_ARM_SMCCC
1469 Say Y here if you want Linux to communicate with system firmware
1470 implementing the PSCI specification for CPU-centric power
1471 management operations described in ARM document number ARM DEN
1472 0022A ("Power State Coordination Interface System Software on
1475 # The GPIO number here must be sorted by descending number. In case of
1476 # a multiplatform kernel, we just want the highest value required by the
1477 # selected platforms.
1480 default 1024 if ARCH_BRCMSTB || ARCH_SHMOBILE || ARCH_TEGRA || \
1482 default 512 if ARCH_EXYNOS || ARCH_KEYSTONE || SOC_OMAP5 || \
1483 SOC_DRA7XX || ARCH_S3C24XX || ARCH_S3C64XX || ARCH_S5PV210
1484 default 416 if ARCH_SUNXI
1485 default 392 if ARCH_U8500
1486 default 352 if ARCH_VT8500
1487 default 288 if ARCH_ROCKCHIP
1488 default 264 if MACH_H4700
1491 Maximum number of GPIOs in the system.
1493 If unsure, leave the default value.
1495 source kernel/Kconfig.preempt
1499 default 200 if ARCH_EBSA110 || ARCH_S3C24XX || \
1500 ARCH_S5PV210 || ARCH_EXYNOS4
1501 default 128 if SOC_AT91RM9200
1505 depends on HZ_FIXED = 0
1506 prompt "Timer frequency"
1530 default HZ_FIXED if HZ_FIXED != 0
1531 default 100 if HZ_100
1532 default 200 if HZ_200
1533 default 250 if HZ_250
1534 default 300 if HZ_300
1535 default 500 if HZ_500
1539 def_bool HIGH_RES_TIMERS
1541 config THUMB2_KERNEL
1542 bool "Compile the kernel in Thumb-2 mode" if !CPU_THUMBONLY
1543 depends on (CPU_V7 || CPU_V7M) && !CPU_V6 && !CPU_V6K
1544 default y if CPU_THUMBONLY
1546 select ARM_ASM_UNIFIED
1549 By enabling this option, the kernel will be compiled in
1550 Thumb-2 mode. A compiler/assembler that understand the unified
1551 ARM-Thumb syntax is needed.
1555 config THUMB2_AVOID_R_ARM_THM_JUMP11
1556 bool "Work around buggy Thumb-2 short branch relocations in gas"
1557 depends on THUMB2_KERNEL && MODULES
1560 Various binutils versions can resolve Thumb-2 branches to
1561 locally-defined, preemptible global symbols as short-range "b.n"
1562 branch instructions.
1564 This is a problem, because there's no guarantee the final
1565 destination of the symbol, or any candidate locations for a
1566 trampoline, are within range of the branch. For this reason, the
1567 kernel does not support fixing up the R_ARM_THM_JUMP11 (102)
1568 relocation in modules at all, and it makes little sense to add
1571 The symptom is that the kernel fails with an "unsupported
1572 relocation" error when loading some modules.
1574 Until fixed tools are available, passing
1575 -fno-optimize-sibling-calls to gcc should prevent gcc generating
1576 code which hits this problem, at the cost of a bit of extra runtime
1577 stack usage in some cases.
1579 The problem is described in more detail at:
1580 https://bugs.launchpad.net/binutils-linaro/+bug/725126
1582 Only Thumb-2 kernels are affected.
1584 Unless you are sure your tools don't have this problem, say Y.
1586 config ARM_ASM_UNIFIED
1589 config ARM_PATCH_IDIV
1590 bool "Runtime patch udiv/sdiv instructions into __aeabi_{u}idiv()"
1591 depends on CPU_32v7 && !XIP_KERNEL
1594 The ARM compiler inserts calls to __aeabi_idiv() and
1595 __aeabi_uidiv() when it needs to perform division on signed
1596 and unsigned integers. Some v7 CPUs have support for the sdiv
1597 and udiv instructions that can be used to implement those
1600 Enabling this option allows the kernel to modify itself to
1601 replace the first two instructions of these library functions
1602 with the sdiv or udiv plus "bx lr" instructions when the CPU
1603 it is running on supports them. Typically this will be faster
1604 and less power intensive than running the original library
1605 code to do integer division.
1608 bool "Use the ARM EABI to compile the kernel"
1610 This option allows for the kernel to be compiled using the latest
1611 ARM ABI (aka EABI). This is only useful if you are using a user
1612 space environment that is also compiled with EABI.
1614 Since there are major incompatibilities between the legacy ABI and
1615 EABI, especially with regard to structure member alignment, this
1616 option also changes the kernel syscall calling convention to
1617 disambiguate both ABIs and allow for backward compatibility support
1618 (selected with CONFIG_OABI_COMPAT).
1620 To use this you need GCC version 4.0.0 or later.
1623 bool "Allow old ABI binaries to run with this kernel (EXPERIMENTAL)"
1624 depends on AEABI && !THUMB2_KERNEL
1626 This option preserves the old syscall interface along with the
1627 new (ARM EABI) one. It also provides a compatibility layer to
1628 intercept syscalls that have structure arguments which layout
1629 in memory differs between the legacy ABI and the new ARM EABI
1630 (only for non "thumb" binaries). This option adds a tiny
1631 overhead to all syscalls and produces a slightly larger kernel.
1633 The seccomp filter system will not be available when this is
1634 selected, since there is no way yet to sensibly distinguish
1635 between calling conventions during filtering.
1637 If you know you'll be using only pure EABI user space then you
1638 can say N here. If this option is not selected and you attempt
1639 to execute a legacy ABI binary then the result will be
1640 UNPREDICTABLE (in fact it can be predicted that it won't work
1641 at all). If in doubt say N.
1643 config ARCH_HAS_HOLES_MEMORYMODEL
1646 config ARCH_SPARSEMEM_ENABLE
1649 config ARCH_SPARSEMEM_DEFAULT
1650 def_bool ARCH_SPARSEMEM_ENABLE
1652 config ARCH_SELECT_MEMORY_MODEL
1653 def_bool ARCH_SPARSEMEM_ENABLE
1655 config HAVE_ARCH_PFN_VALID
1656 def_bool ARCH_HAS_HOLES_MEMORYMODEL || !SPARSEMEM
1658 config HAVE_GENERIC_RCU_GUP
1663 bool "High Memory Support"
1666 The address space of ARM processors is only 4 Gigabytes large
1667 and it has to accommodate user address space, kernel address
1668 space as well as some memory mapped IO. That means that, if you
1669 have a large amount of physical memory and/or IO, not all of the
1670 memory can be "permanently mapped" by the kernel. The physical
1671 memory that is not permanently mapped is called "high memory".
1673 Depending on the selected kernel/user memory split, minimum
1674 vmalloc space and actual amount of RAM, you may not need this
1675 option which should result in a slightly faster kernel.
1680 bool "Allocate 2nd-level pagetables from highmem" if EXPERT
1684 The VM uses one page of physical memory for each page table.
1685 For systems with a lot of processes, this can use a lot of
1686 precious low memory, eventually leading to low memory being
1687 consumed by page tables. Setting this option will allow
1688 user-space 2nd level page tables to reside in high memory.
1690 config CPU_SW_DOMAIN_PAN
1691 bool "Enable use of CPU domains to implement privileged no-access"
1692 depends on MMU && !ARM_LPAE
1695 Increase kernel security by ensuring that normal kernel accesses
1696 are unable to access userspace addresses. This can help prevent
1697 use-after-free bugs becoming an exploitable privilege escalation
1698 by ensuring that magic values (such as LIST_POISON) will always
1699 fault when dereferenced.
1701 CPUs with low-vector mappings use a best-efforts implementation.
1702 Their lower 1MB needs to remain accessible for the vectors, but
1703 the remainder of userspace will become appropriately inaccessible.
1705 config HW_PERF_EVENTS
1709 config SYS_SUPPORTS_HUGETLBFS
1713 config HAVE_ARCH_TRANSPARENT_HUGEPAGE
1717 config ARCH_WANT_GENERAL_HUGETLB
1720 config ARM_MODULE_PLTS
1721 bool "Use PLTs to allow module memory to spill over into vmalloc area"
1724 Allocate PLTs when loading modules so that jumps and calls whose
1725 targets are too far away for their relative offsets to be encoded
1726 in the instructions themselves can be bounced via veneers in the
1727 module's PLT. This allows modules to be allocated in the generic
1728 vmalloc area after the dedicated module memory area has been
1729 exhausted. The modules will use slightly more memory, but after
1730 rounding up to page size, the actual memory footprint is usually
1733 Say y if you are getting out of memory errors while loading modules
1737 config FORCE_MAX_ZONEORDER
1738 int "Maximum zone order"
1739 default "12" if SOC_AM33XX
1740 default "9" if SA1111 || ARCH_EFM32
1743 The kernel memory allocator divides physically contiguous memory
1744 blocks into "zones", where each zone is a power of two number of
1745 pages. This option selects the largest power of two that the kernel
1746 keeps in the memory allocator. If you need to allocate very large
1747 blocks of physically contiguous memory, then you may need to
1748 increase this value.
1750 This config option is actually maximum order plus one. For example,
1751 a value of 11 means that the largest free memory block is 2^10 pages.
1753 config ALIGNMENT_TRAP
1755 depends on CPU_CP15_MMU
1756 default y if !ARCH_EBSA110
1757 select HAVE_PROC_CPU if PROC_FS
1759 ARM processors cannot fetch/store information which is not
1760 naturally aligned on the bus, i.e., a 4 byte fetch must start at an
1761 address divisible by 4. On 32-bit ARM processors, these non-aligned
1762 fetch/store instructions will be emulated in software if you say
1763 here, which has a severe performance impact. This is necessary for
1764 correct operation of some network protocols. With an IP-only
1765 configuration it is safe to say N, otherwise say Y.
1767 config UACCESS_WITH_MEMCPY
1768 bool "Use kernel mem{cpy,set}() for {copy_to,clear}_user()"
1770 default y if CPU_FEROCEON
1772 Implement faster copy_to_user and clear_user methods for CPU
1773 cores where a 8-word STM instruction give significantly higher
1774 memory write throughput than a sequence of individual 32bit stores.
1776 A possible side effect is a slight increase in scheduling latency
1777 between threads sharing the same address space if they invoke
1778 such copy operations with large buffers.
1780 However, if the CPU data cache is using a write-allocate mode,
1781 this option is unlikely to provide any performance gain.
1785 prompt "Enable seccomp to safely compute untrusted bytecode"
1787 This kernel feature is useful for number crunching applications
1788 that may need to compute untrusted bytecode during their
1789 execution. By using pipes or other transports made available to
1790 the process as file descriptors supporting the read/write
1791 syscalls, it's possible to isolate those applications in
1792 their own address space using seccomp. Once seccomp is
1793 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1794 and the task is only allowed to execute a few safe syscalls
1795 defined by each seccomp mode.
1804 bool "Enable paravirtualization code"
1806 This changes the kernel so it can modify itself when it is run
1807 under a hypervisor, potentially improving performance significantly
1808 over full virtualization.
1810 config PARAVIRT_TIME_ACCOUNTING
1811 bool "Paravirtual steal time accounting"
1815 Select this option to enable fine granularity task steal time
1816 accounting. Time spent executing other tasks in parallel with
1817 the current vCPU is discounted from the vCPU power. To account for
1818 that, there can be a small performance impact.
1820 If in doubt, say N here.
1827 bool "Xen guest support on ARM"
1828 depends on ARM && AEABI && OF
1829 depends on CPU_V7 && !CPU_V6
1830 depends on !GENERIC_ATOMIC64
1832 select ARCH_DMA_ADDR_T_64BIT
1837 Say Y if you want to run Linux in a Virtual Machine on Xen on ARM.
1844 bool "Flattened Device Tree support"
1848 Include support for flattened device tree machine descriptions.
1851 bool "Support for the traditional ATAGS boot data passing" if USE_OF
1854 This is the traditional way of passing data to the kernel at boot
1855 time. If you are solely relying on the flattened device tree (or
1856 the ARM_ATAG_DTB_COMPAT option) then you may unselect this option
1857 to remove ATAGS support from your kernel binary. If unsure,
1860 config DEPRECATED_PARAM_STRUCT
1861 bool "Provide old way to pass kernel parameters"
1864 This was deprecated in 2001 and announced to live on for 5 years.
1865 Some old boot loaders still use this way.
1867 # Compressed boot loader in ROM. Yes, we really want to ask about
1868 # TEXT and BSS so we preserve their values in the config files.
1869 config ZBOOT_ROM_TEXT
1870 hex "Compressed ROM boot loader base address"
1873 The physical address at which the ROM-able zImage is to be
1874 placed in the target. Platforms which normally make use of
1875 ROM-able zImage formats normally set this to a suitable
1876 value in their defconfig file.
1878 If ZBOOT_ROM is not enabled, this has no effect.
1880 config ZBOOT_ROM_BSS
1881 hex "Compressed ROM boot loader BSS address"
1884 The base address of an area of read/write memory in the target
1885 for the ROM-able zImage which must be available while the
1886 decompressor is running. It must be large enough to hold the
1887 entire decompressed kernel plus an additional 128 KiB.
1888 Platforms which normally make use of ROM-able zImage formats
1889 normally set this to a suitable value in their defconfig file.
1891 If ZBOOT_ROM is not enabled, this has no effect.
1894 bool "Compressed boot loader in ROM/flash"
1895 depends on ZBOOT_ROM_TEXT != ZBOOT_ROM_BSS
1896 depends on !ARM_APPENDED_DTB && !XIP_KERNEL && !AUTO_ZRELADDR
1898 Say Y here if you intend to execute your compressed kernel image
1899 (zImage) directly from ROM or flash. If unsure, say N.
1901 config ARM_APPENDED_DTB
1902 bool "Use appended device tree blob to zImage (EXPERIMENTAL)"
1905 With this option, the boot code will look for a device tree binary
1906 (DTB) appended to zImage
1907 (e.g. cat zImage <filename>.dtb > zImage_w_dtb).
1909 This is meant as a backward compatibility convenience for those
1910 systems with a bootloader that can't be upgraded to accommodate
1911 the documented boot protocol using a device tree.
1913 Beware that there is very little in terms of protection against
1914 this option being confused by leftover garbage in memory that might
1915 look like a DTB header after a reboot if no actual DTB is appended
1916 to zImage. Do not leave this option active in a production kernel
1917 if you don't intend to always append a DTB. Proper passing of the
1918 location into r2 of a bootloader provided DTB is always preferable
1921 config ARM_ATAG_DTB_COMPAT
1922 bool "Supplement the appended DTB with traditional ATAG information"
1923 depends on ARM_APPENDED_DTB
1925 Some old bootloaders can't be updated to a DTB capable one, yet
1926 they provide ATAGs with memory configuration, the ramdisk address,
1927 the kernel cmdline string, etc. Such information is dynamically
1928 provided by the bootloader and can't always be stored in a static
1929 DTB. To allow a device tree enabled kernel to be used with such
1930 bootloaders, this option allows zImage to extract the information
1931 from the ATAG list and store it at run time into the appended DTB.
1934 prompt "Kernel command line type" if ARM_ATAG_DTB_COMPAT
1935 default ARM_ATAG_DTB_COMPAT_CMDLINE_FROM_BOOTLOADER
1937 config ARM_ATAG_DTB_COMPAT_CMDLINE_FROM_BOOTLOADER
1938 bool "Use bootloader kernel arguments if available"
1940 Uses the command-line options passed by the boot loader instead of
1941 the device tree bootargs property. If the boot loader doesn't provide
1942 any, the device tree bootargs property will be used.
1944 config ARM_ATAG_DTB_COMPAT_CMDLINE_EXTEND
1945 bool "Extend with bootloader kernel arguments"
1947 The command-line arguments provided by the boot loader will be
1948 appended to the the device tree bootargs property.
1953 string "Default kernel command string"
1956 On some architectures (EBSA110 and CATS), there is currently no way
1957 for the boot loader to pass arguments to the kernel. For these
1958 architectures, you should supply some command-line options at build
1959 time by entering them here. As a minimum, you should specify the
1960 memory size and the root device (e.g., mem=64M root=/dev/nfs).
1963 prompt "Kernel command line type" if CMDLINE != ""
1964 default CMDLINE_FROM_BOOTLOADER
1967 config CMDLINE_FROM_BOOTLOADER
1968 bool "Use bootloader kernel arguments if available"
1970 Uses the command-line options passed by the boot loader. If
1971 the boot loader doesn't provide any, the default kernel command
1972 string provided in CMDLINE will be used.
1974 config CMDLINE_EXTEND
1975 bool "Extend bootloader kernel arguments"
1977 The command-line arguments provided by the boot loader will be
1978 appended to the default kernel command string.
1980 config CMDLINE_FORCE
1981 bool "Always use the default kernel command string"
1983 Always use the default kernel command string, even if the boot
1984 loader passes other arguments to the kernel.
1985 This is useful if you cannot or don't want to change the
1986 command-line options your boot loader passes to the kernel.
1990 bool "Kernel Execute-In-Place from ROM"
1991 depends on !ARM_LPAE && !ARCH_MULTIPLATFORM
1993 Execute-In-Place allows the kernel to run from non-volatile storage
1994 directly addressable by the CPU, such as NOR flash. This saves RAM
1995 space since the text section of the kernel is not loaded from flash
1996 to RAM. Read-write sections, such as the data section and stack,
1997 are still copied to RAM. The XIP kernel is not compressed since
1998 it has to run directly from flash, so it will take more space to
1999 store it. The flash address used to link the kernel object files,
2000 and for storing it, is configuration dependent. Therefore, if you
2001 say Y here, you must know the proper physical address where to
2002 store the kernel image depending on your own flash memory usage.
2004 Also note that the make target becomes "make xipImage" rather than
2005 "make zImage" or "make Image". The final kernel binary to put in
2006 ROM memory will be arch/arm/boot/xipImage.
2010 config XIP_PHYS_ADDR
2011 hex "XIP Kernel Physical Location"
2012 depends on XIP_KERNEL
2013 default "0x00080000"
2015 This is the physical address in your flash memory the kernel will
2016 be linked for and stored to. This address is dependent on your
2020 bool "Kexec system call (EXPERIMENTAL)"
2021 depends on (!SMP || PM_SLEEP_SMP)
2025 kexec is a system call that implements the ability to shutdown your
2026 current kernel, and to start another kernel. It is like a reboot
2027 but it is independent of the system firmware. And like a reboot
2028 you can start any kernel with it, not just Linux.
2030 It is an ongoing process to be certain the hardware in a machine
2031 is properly shutdown, so do not be surprised if this code does not
2032 initially work for you.
2035 bool "Export atags in procfs"
2036 depends on ATAGS && KEXEC
2039 Should the atags used to boot the kernel be exported in an "atags"
2040 file in procfs. Useful with kexec.
2043 bool "Build kdump crash kernel (EXPERIMENTAL)"
2045 Generate crash dump after being started by kexec. This should
2046 be normally only set in special crash dump kernels which are
2047 loaded in the main kernel with kexec-tools into a specially
2048 reserved region and then later executed after a crash by
2049 kdump/kexec. The crash dump kernel must be compiled to a
2050 memory address not used by the main kernel
2052 For more details see Documentation/kdump/kdump.txt
2054 config AUTO_ZRELADDR
2055 bool "Auto calculation of the decompressed kernel image address"
2057 ZRELADDR is the physical address where the decompressed kernel
2058 image will be placed. If AUTO_ZRELADDR is selected, the address
2059 will be determined at run-time by masking the current IP with
2060 0xf8000000. This assumes the zImage being placed in the first 128MB
2061 from start of memory.
2067 bool "UEFI runtime support"
2068 depends on OF && !CPU_BIG_ENDIAN && MMU && AUTO_ZRELADDR && !XIP_KERNEL
2070 select EFI_PARAMS_FROM_FDT
2073 select EFI_RUNTIME_WRAPPERS
2075 This option provides support for runtime services provided
2076 by UEFI firmware (such as non-volatile variables, realtime
2077 clock, and platform reset). A UEFI stub is also provided to
2078 allow the kernel to be booted as an EFI application. This
2079 is only useful for kernels that may run on systems that have
2084 menu "CPU Power Management"
2086 source "drivers/cpufreq/Kconfig"
2088 source "drivers/cpuidle/Kconfig"
2092 menu "Floating point emulation"
2094 comment "At least one emulation must be selected"
2097 bool "NWFPE math emulation"
2098 depends on (!AEABI || OABI_COMPAT) && !THUMB2_KERNEL
2100 Say Y to include the NWFPE floating point emulator in the kernel.
2101 This is necessary to run most binaries. Linux does not currently
2102 support floating point hardware so you need to say Y here even if
2103 your machine has an FPA or floating point co-processor podule.
2105 You may say N here if you are going to load the Acorn FPEmulator
2106 early in the bootup.
2109 bool "Support extended precision"
2110 depends on FPE_NWFPE
2112 Say Y to include 80-bit support in the kernel floating-point
2113 emulator. Otherwise, only 32 and 64-bit support is compiled in.
2114 Note that gcc does not generate 80-bit operations by default,
2115 so in most cases this option only enlarges the size of the
2116 floating point emulator without any good reason.
2118 You almost surely want to say N here.
2121 bool "FastFPE math emulation (EXPERIMENTAL)"
2122 depends on (!AEABI || OABI_COMPAT) && !CPU_32v3
2124 Say Y here to include the FAST floating point emulator in the kernel.
2125 This is an experimental much faster emulator which now also has full
2126 precision for the mantissa. It does not support any exceptions.
2127 It is very simple, and approximately 3-6 times faster than NWFPE.
2129 It should be sufficient for most programs. It may be not suitable
2130 for scientific calculations, but you have to check this for yourself.
2131 If you do not feel you need a faster FP emulation you should better
2135 bool "VFP-format floating point maths"
2136 depends on CPU_V6 || CPU_V6K || CPU_ARM926T || CPU_V7 || CPU_FEROCEON
2138 Say Y to include VFP support code in the kernel. This is needed
2139 if your hardware includes a VFP unit.
2141 Please see <file:Documentation/arm/VFP/release-notes.txt> for
2142 release notes and additional status information.
2144 Say N if your target does not have VFP hardware.
2152 bool "Advanced SIMD (NEON) Extension support"
2153 depends on VFPv3 && CPU_V7
2155 Say Y to include support code for NEON, the ARMv7 Advanced SIMD
2158 config KERNEL_MODE_NEON
2159 bool "Support for NEON in kernel mode"
2160 depends on NEON && AEABI
2162 Say Y to include support for NEON in kernel mode.
2166 menu "Userspace binary formats"
2168 source "fs/Kconfig.binfmt"
2172 menu "Power management options"
2174 source "kernel/power/Kconfig"
2176 config ARCH_SUSPEND_POSSIBLE
2177 depends on CPU_ARM920T || CPU_ARM926T || CPU_FEROCEON || CPU_SA1100 || \
2178 CPU_V6 || CPU_V6K || CPU_V7 || CPU_V7M || CPU_XSC3 || CPU_XSCALE || CPU_MOHAWK
2181 config ARM_CPU_SUSPEND
2182 def_bool PM_SLEEP || BL_SWITCHER || ARM_PSCI_FW
2183 depends on ARCH_SUSPEND_POSSIBLE
2185 config ARCH_HIBERNATION_POSSIBLE
2188 default y if ARCH_SUSPEND_POSSIBLE
2192 source "net/Kconfig"
2194 source "drivers/Kconfig"
2196 source "drivers/firmware/Kconfig"
2200 source "arch/arm/Kconfig.debug"
2202 source "security/Kconfig"
2204 source "crypto/Kconfig"
2206 source "arch/arm/crypto/Kconfig"
2209 source "lib/Kconfig"
2211 source "arch/arm/kvm/Kconfig"