4 select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
5 select ARCH_HAS_DEVMEM_IS_ALLOWED
6 select ARCH_HAS_ELF_RANDOMIZE
7 select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
8 select ARCH_HAVE_CUSTOM_GPIO_H
9 select ARCH_HAS_GCOV_PROFILE_ALL
10 select ARCH_MIGHT_HAVE_PC_PARPORT
11 select ARCH_SUPPORTS_ATOMIC_RMW
12 select ARCH_USE_BUILTIN_BSWAP
13 select ARCH_USE_CMPXCHG_LOCKREF
14 select ARCH_WANT_IPC_PARSE_VERSION
15 select BUILDTIME_EXTABLE_SORT if MMU
16 select CLONE_BACKWARDS
17 select CPU_PM if (SUSPEND || CPU_IDLE)
18 select DCACHE_WORD_ACCESS if HAVE_EFFICIENT_UNALIGNED_ACCESS
20 select EDAC_ATOMIC_SCRUB
21 select GENERIC_ALLOCATOR
22 select GENERIC_ATOMIC64 if (CPU_V7M || CPU_V6 || !CPU_32v6K || !AEABI)
23 select GENERIC_CLOCKEVENTS_BROADCAST if SMP
24 select GENERIC_EARLY_IOREMAP
25 select GENERIC_IDLE_POLL_SETUP
26 select GENERIC_IRQ_PROBE
27 select GENERIC_IRQ_SHOW
28 select GENERIC_IRQ_SHOW_LEVEL
29 select GENERIC_PCI_IOMAP
30 select GENERIC_SCHED_CLOCK
31 select GENERIC_SMP_IDLE_THREAD
32 select GENERIC_STRNCPY_FROM_USER
33 select GENERIC_STRNLEN_USER
34 select HANDLE_DOMAIN_IRQ
35 select HARDIRQS_SW_RESEND
36 select HAVE_ARCH_AUDITSYSCALL if (AEABI && !OABI_COMPAT)
37 select HAVE_ARCH_BITREVERSE if (CPU_32v7M || CPU_32v7) && !CPU_32v6
38 select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL && !CPU_ENDIAN_BE32 && MMU
39 select HAVE_ARCH_KGDB if !CPU_ENDIAN_BE32 && MMU
40 select HAVE_ARCH_MMAP_RND_BITS if MMU
41 select HAVE_ARCH_SECCOMP_FILTER if (AEABI && !OABI_COMPAT)
42 select HAVE_ARCH_TRACEHOOK
43 select HAVE_ARM_SMCCC if CPU_V7
45 select HAVE_CC_STACKPROTECTOR
46 select HAVE_CONTEXT_TRACKING
47 select HAVE_C_RECORDMCOUNT
48 select HAVE_DEBUG_KMEMLEAK
49 select HAVE_DMA_API_DEBUG
50 select HAVE_DMA_CONTIGUOUS if MMU
51 select HAVE_DYNAMIC_FTRACE if (!XIP_KERNEL) && !CPU_ENDIAN_BE32 && MMU
52 select HAVE_EFFICIENT_UNALIGNED_ACCESS if (CPU_V6 || CPU_V6K || CPU_V7) && MMU
53 select HAVE_FTRACE_MCOUNT_RECORD if (!XIP_KERNEL)
54 select HAVE_FUNCTION_GRAPH_TRACER if (!THUMB2_KERNEL)
55 select HAVE_FUNCTION_TRACER if (!XIP_KERNEL)
56 select HAVE_GENERIC_DMA_COHERENT
57 select HAVE_HW_BREAKPOINT if (PERF_EVENTS && (CPU_V6 || CPU_V6K || CPU_V7))
58 select HAVE_IDE if PCI || ISA || PCMCIA
59 select HAVE_IRQ_TIME_ACCOUNTING
60 select HAVE_KERNEL_GZIP
61 select HAVE_KERNEL_LZ4
62 select HAVE_KERNEL_LZMA
63 select HAVE_KERNEL_LZO
65 select HAVE_KPROBES if !XIP_KERNEL && !CPU_ENDIAN_BE32 && !CPU_V7M
66 select HAVE_KRETPROBES if (HAVE_KPROBES)
68 select HAVE_MOD_ARCH_SPECIFIC
69 select HAVE_OPROFILE if (HAVE_PERF_EVENTS)
70 select HAVE_OPTPROBES if !THUMB2_KERNEL
71 select HAVE_PERF_EVENTS
73 select HAVE_PERF_USER_STACK_DUMP
74 select HAVE_RCU_TABLE_FREE if (SMP && ARM_LPAE)
75 select HAVE_REGS_AND_STACK_ACCESS_API
76 select HAVE_SYSCALL_TRACEPOINTS
78 select HAVE_VIRT_CPU_ACCOUNTING_GEN
79 select IRQ_FORCED_THREADING
80 select MODULES_USE_ELF_REL
82 select OF_EARLY_FLATTREE if OF
83 select OF_RESERVED_MEM if OF
85 select OLD_SIGSUSPEND3
86 select PERF_USE_VMALLOC
88 select SYS_SUPPORTS_APM_EMULATION
89 # Above selects are sorted alphabetically; please add new ones
90 # according to that. Thanks.
92 The ARM series is a line of low-power-consumption RISC chip designs
93 licensed by ARM Ltd and targeted at embedded applications and
94 handhelds such as the Compaq IPAQ. ARM-based PCs are no longer
95 manufactured, but legacy ARM-based PC hardware remains popular in
96 Europe. There is an ARM Linux project with a web page at
97 <http://www.arm.linux.org.uk/>.
99 config ARM_HAS_SG_CHAIN
100 select ARCH_HAS_SG_CHAIN
103 config NEED_SG_DMA_LENGTH
106 config ARM_DMA_USE_IOMMU
108 select ARM_HAS_SG_CHAIN
109 select NEED_SG_DMA_LENGTH
113 config ARM_DMA_IOMMU_ALIGNMENT
114 int "Maximum PAGE_SIZE order of alignment for DMA IOMMU buffers"
118 DMA mapping framework by default aligns all buffers to the smallest
119 PAGE_SIZE order which is greater than or equal to the requested buffer
120 size. This works well for buffers up to a few hundreds kilobytes, but
121 for larger buffers it just a waste of address space. Drivers which has
122 relatively small addressing window (like 64Mib) might run out of
123 virtual space with just a few allocations.
125 With this parameter you can specify the maximum PAGE_SIZE order for
126 DMA IOMMU buffers. Larger buffers will be aligned only to this
127 specified order. The order is expressed as a power of two multiplied
132 config MIGHT_HAVE_PCI
135 config SYS_SUPPORTS_APM_EMULATION
140 select GENERIC_ALLOCATOR
151 The Extended Industry Standard Architecture (EISA) bus was
152 developed as an open alternative to the IBM MicroChannel bus.
154 The EISA bus provided some of the features of the IBM MicroChannel
155 bus while maintaining backward compatibility with cards made for
156 the older ISA bus. The EISA bus saw limited use between 1988 and
157 1995 when it was made obsolete by the PCI bus.
159 Say Y here if you are building a kernel for an EISA-based machine.
166 config STACKTRACE_SUPPORT
170 config LOCKDEP_SUPPORT
174 config TRACE_IRQFLAGS_SUPPORT
178 config RWSEM_XCHGADD_ALGORITHM
182 config ARCH_HAS_ILOG2_U32
185 config ARCH_HAS_ILOG2_U64
188 config ARCH_HAS_BANDGAP
191 config FIX_EARLYCON_MEM
194 config GENERIC_HWEIGHT
198 config GENERIC_CALIBRATE_DELAY
202 config ARCH_MAY_HAVE_PC_FDC
208 config NEED_DMA_MAP_STATE
211 config ARCH_SUPPORTS_UPROBES
214 config ARCH_HAS_DMA_SET_COHERENT_MASK
217 config GENERIC_ISA_DMA
223 config NEED_RET_TO_USER
231 default 0xffff0000 if MMU || CPU_HIGH_VECTOR
232 default DRAM_BASE if REMAP_VECTORS_TO_RAM
235 The base address of exception vectors. This must be two pages
238 config ARM_PATCH_PHYS_VIRT
239 bool "Patch physical to virtual translations at runtime" if EMBEDDED
241 depends on !XIP_KERNEL && MMU
243 Patch phys-to-virt and virt-to-phys translation functions at
244 boot and module load time according to the position of the
245 kernel in system memory.
247 This can only be used with non-XIP MMU kernels where the base
248 of physical memory is at a 16MB boundary.
250 Only disable this option if you know that you do not require
251 this feature (eg, building a kernel for a single machine) and
252 you need to shrink the kernel to the minimal size.
254 config NEED_MACH_IO_H
257 Select this when mach/io.h is required to provide special
258 definitions for this platform. The need for mach/io.h should
259 be avoided when possible.
261 config NEED_MACH_MEMORY_H
264 Select this when mach/memory.h is required to provide special
265 definitions for this platform. The need for mach/memory.h should
266 be avoided when possible.
269 hex "Physical address of main memory" if MMU
270 depends on !ARM_PATCH_PHYS_VIRT
271 default DRAM_BASE if !MMU
272 default 0x00000000 if ARCH_EBSA110 || \
277 (ARCH_REALVIEW && !REALVIEW_HIGH_PHYS_OFFSET)
278 default 0x10000000 if ARCH_OMAP1 || ARCH_RPC
279 default 0x20000000 if ARCH_S5PV210
280 default 0x70000000 if REALVIEW_HIGH_PHYS_OFFSET
281 default 0xc0000000 if ARCH_SA1100
283 Please provide the physical address corresponding to the
284 location of main memory in your system.
290 config PGTABLE_LEVELS
292 default 3 if ARM_LPAE
295 source "init/Kconfig"
297 source "kernel/Kconfig.freezer"
302 bool "MMU-based Paged Memory Management Support"
305 Select if you want MMU-based virtualised addressing space
306 support by paged memory management. If unsure, say 'Y'.
308 config ARCH_MMAP_RND_BITS_MIN
311 config ARCH_MMAP_RND_BITS_MAX
312 default 14 if PAGE_OFFSET=0x40000000
313 default 15 if PAGE_OFFSET=0x80000000
317 # The "ARM system type" choice list is ordered alphabetically by option
318 # text. Please add new entries in the option alphabetic order.
321 prompt "ARM system type"
322 default ARM_SINGLE_ARMV7M if !MMU
323 default ARCH_MULTIPLATFORM if MMU
325 config ARCH_MULTIPLATFORM
326 bool "Allow multiple platforms to be selected"
328 select ARCH_WANT_OPTIONAL_GPIOLIB
329 select ARM_HAS_SG_CHAIN
330 select ARM_PATCH_PHYS_VIRT
334 select GENERIC_CLOCKEVENTS
335 select MIGHT_HAVE_PCI
336 select MULTI_IRQ_HANDLER
340 config ARM_SINGLE_ARMV7M
341 bool "ARMv7-M based platforms (Cortex-M0/M3/M4)"
343 select ARCH_WANT_OPTIONAL_GPIOLIB
349 select GENERIC_CLOCKEVENTS
356 bool "Cirrus Logic CLPS711x/EP721x/EP731x-based"
357 select ARCH_REQUIRE_GPIOLIB
362 select GENERIC_CLOCKEVENTS
366 Support for Cirrus Logic 711x/721x/731x based boards.
369 bool "Cortina Systems Gemini"
370 select ARCH_REQUIRE_GPIOLIB
373 select GENERIC_CLOCKEVENTS
375 Support for the Cortina Systems Gemini family SoCs
379 select ARCH_USES_GETTIMEOFFSET
382 select NEED_MACH_IO_H
383 select NEED_MACH_MEMORY_H
386 This is an evaluation board for the StrongARM processor available
387 from Digital. It has limited hardware on-board, including an
388 Ethernet interface, two PCMCIA sockets, two serial ports and a
393 select ARCH_HAS_HOLES_MEMORYMODEL
394 select ARCH_REQUIRE_GPIOLIB
396 select ARM_PATCH_PHYS_VIRT
402 select GENERIC_CLOCKEVENTS
404 This enables support for the Cirrus EP93xx series of CPUs.
406 config ARCH_FOOTBRIDGE
410 select GENERIC_CLOCKEVENTS
412 select NEED_MACH_IO_H if !MMU
413 select NEED_MACH_MEMORY_H
415 Support for systems based on the DC21285 companion chip
416 ("FootBridge"), such as the Simtec CATS and the Rebel NetWinder.
419 bool "Hilscher NetX based"
423 select GENERIC_CLOCKEVENTS
425 This enables support for systems based on the Hilscher NetX Soc
431 select NEED_MACH_MEMORY_H
432 select NEED_RET_TO_USER
438 Support for Intel's IOP13XX (XScale) family of processors.
443 select ARCH_REQUIRE_GPIOLIB
446 select NEED_RET_TO_USER
450 Support for Intel's 80219 and IOP32X (XScale) family of
456 select ARCH_REQUIRE_GPIOLIB
459 select NEED_RET_TO_USER
463 Support for Intel's IOP33X (XScale) family of processors.
468 select ARCH_HAS_DMA_SET_COHERENT_MASK
469 select ARCH_REQUIRE_GPIOLIB
470 select ARCH_SUPPORTS_BIG_ENDIAN
473 select DMABOUNCE if PCI
474 select GENERIC_CLOCKEVENTS
475 select MIGHT_HAVE_PCI
476 select NEED_MACH_IO_H
477 select USB_EHCI_BIG_ENDIAN_DESC
478 select USB_EHCI_BIG_ENDIAN_MMIO
480 Support for Intel's IXP4XX (XScale) family of processors.
484 select ARCH_REQUIRE_GPIOLIB
486 select GENERIC_CLOCKEVENTS
487 select MIGHT_HAVE_PCI
488 select MULTI_IRQ_HANDLER
492 select PLAT_ORION_LEGACY
494 select PM_GENERIC_DOMAINS if PM
496 Support for the Marvell Dove SoC 88AP510
499 bool "Micrel/Kendin KS8695"
500 select ARCH_REQUIRE_GPIOLIB
503 select GENERIC_CLOCKEVENTS
504 select NEED_MACH_MEMORY_H
506 Support for Micrel/Kendin KS8695 "Centaur" (ARM922T) based
507 System-on-Chip devices.
510 bool "Nuvoton W90X900 CPU"
511 select ARCH_REQUIRE_GPIOLIB
515 select GENERIC_CLOCKEVENTS
517 Support for Nuvoton (Winbond logic dept.) ARM9 processor,
518 At present, the w90x900 has been renamed nuc900, regarding
519 the ARM series product line, you can login the following
520 link address to know more.
522 <http://www.nuvoton.com/hq/enu/ProductAndSales/ProductLines/
523 ConsumerElectronicsIC/ARMMicrocontroller/ARMMicrocontroller>
527 select ARCH_REQUIRE_GPIOLIB
532 select GENERIC_CLOCKEVENTS
536 Support for the NXP LPC32XX family of processors
539 bool "PXA2xx/PXA3xx-based"
542 select ARCH_REQUIRE_GPIOLIB
543 select ARM_CPU_SUSPEND if PM
550 select GENERIC_CLOCKEVENTS
554 select MULTI_IRQ_HANDLER
558 Support for Intel/Marvell's PXA2xx/PXA3xx processor line.
564 select ARCH_MAY_HAVE_PC_FDC
565 select ARCH_SPARSEMEM_ENABLE
566 select ARCH_USES_GETTIMEOFFSET
570 select HAVE_PATA_PLATFORM
572 select NEED_MACH_IO_H
573 select NEED_MACH_MEMORY_H
577 On the Acorn Risc-PC, Linux can support the internal IDE disk and
578 CD-ROM interface, serial and parallel port, and the floppy drive.
583 select ARCH_REQUIRE_GPIOLIB
584 select ARCH_SPARSEMEM_ENABLE
588 select CLKSRC_OF if OF
591 select GENERIC_CLOCKEVENTS
595 select MULTI_IRQ_HANDLER
596 select NEED_MACH_MEMORY_H
599 Support for StrongARM 11x0 based boards.
602 bool "Samsung S3C24XX SoCs"
603 select ARCH_REQUIRE_GPIOLIB
606 select CLKSRC_SAMSUNG_PWM
607 select GENERIC_CLOCKEVENTS
609 select HAVE_S3C2410_I2C if I2C
610 select HAVE_S3C2410_WATCHDOG if WATCHDOG
611 select HAVE_S3C_RTC if RTC_CLASS
612 select MULTI_IRQ_HANDLER
613 select NEED_MACH_IO_H
616 Samsung S3C2410, S3C2412, S3C2413, S3C2416, S3C2440, S3C2442, S3C2443
617 and S3C2450 SoCs based systems, such as the Simtec Electronics BAST
618 (<http://www.simtec.co.uk/products/EB110ITX/>), the IPAQ 1940 or the
619 Samsung SMDK2410 development board (and derivatives).
623 select ARCH_HAS_HOLES_MEMORYMODEL
624 select ARCH_REQUIRE_GPIOLIB
626 select GENERIC_ALLOCATOR
627 select GENERIC_CLOCKEVENTS
628 select GENERIC_IRQ_CHIP
633 Support for TI's DaVinci platform.
638 select ARCH_HAS_HOLES_MEMORYMODEL
640 select ARCH_REQUIRE_GPIOLIB
643 select GENERIC_CLOCKEVENTS
644 select GENERIC_IRQ_CHIP
647 select MULTI_IRQ_HANDLER
648 select NEED_MACH_IO_H if PCCARD
649 select NEED_MACH_MEMORY_H
652 Support for older TI OMAP1 (omap7xx, omap15xx or omap16xx)
656 menu "Multiple platform selection"
657 depends on ARCH_MULTIPLATFORM
659 comment "CPU Core family selection"
662 bool "ARMv4 based platforms (FA526)"
663 depends on !ARCH_MULTI_V6_V7
664 select ARCH_MULTI_V4_V5
667 config ARCH_MULTI_V4T
668 bool "ARMv4T based platforms (ARM720T, ARM920T, ...)"
669 depends on !ARCH_MULTI_V6_V7
670 select ARCH_MULTI_V4_V5
671 select CPU_ARM920T if !(CPU_ARM7TDMI || CPU_ARM720T || \
672 CPU_ARM740T || CPU_ARM9TDMI || CPU_ARM922T || \
673 CPU_ARM925T || CPU_ARM940T)
676 bool "ARMv5 based platforms (ARM926T, XSCALE, PJ1, ...)"
677 depends on !ARCH_MULTI_V6_V7
678 select ARCH_MULTI_V4_V5
679 select CPU_ARM926T if !(CPU_ARM946E || CPU_ARM1020 || \
680 CPU_ARM1020E || CPU_ARM1022 || CPU_ARM1026 || \
681 CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK || CPU_FEROCEON)
683 config ARCH_MULTI_V4_V5
687 bool "ARMv6 based platforms (ARM11)"
688 select ARCH_MULTI_V6_V7
692 bool "ARMv7 based platforms (Cortex-A, PJ4, Scorpion, Krait)"
694 select ARCH_MULTI_V6_V7
698 config ARCH_MULTI_V6_V7
700 select MIGHT_HAVE_CACHE_L2X0
702 config ARCH_MULTI_CPU_AUTO
703 def_bool !(ARCH_MULTI_V4 || ARCH_MULTI_V4T || ARCH_MULTI_V6_V7)
709 bool "Dummy Virtual Machine"
710 depends on ARCH_MULTI_V7
713 select ARM_GIC_V2M if PCI_MSI
716 select HAVE_ARM_ARCH_TIMER
719 # This is sorted alphabetically by mach-* pathname. However, plat-*
720 # Kconfigs may be included either alphabetically (according to the
721 # plat- suffix) or along side the corresponding mach-* source.
723 source "arch/arm/mach-mvebu/Kconfig"
725 source "arch/arm/mach-alpine/Kconfig"
727 source "arch/arm/mach-asm9260/Kconfig"
729 source "arch/arm/mach-at91/Kconfig"
731 source "arch/arm/mach-axxia/Kconfig"
733 source "arch/arm/mach-bcm/Kconfig"
735 source "arch/arm/mach-berlin/Kconfig"
737 source "arch/arm/mach-clps711x/Kconfig"
739 source "arch/arm/mach-cns3xxx/Kconfig"
741 source "arch/arm/mach-davinci/Kconfig"
743 source "arch/arm/mach-digicolor/Kconfig"
745 source "arch/arm/mach-dove/Kconfig"
747 source "arch/arm/mach-ep93xx/Kconfig"
749 source "arch/arm/mach-footbridge/Kconfig"
751 source "arch/arm/mach-gemini/Kconfig"
753 source "arch/arm/mach-highbank/Kconfig"
755 source "arch/arm/mach-hisi/Kconfig"
757 source "arch/arm/mach-integrator/Kconfig"
759 source "arch/arm/mach-iop32x/Kconfig"
761 source "arch/arm/mach-iop33x/Kconfig"
763 source "arch/arm/mach-iop13xx/Kconfig"
765 source "arch/arm/mach-ixp4xx/Kconfig"
767 source "arch/arm/mach-keystone/Kconfig"
769 source "arch/arm/mach-ks8695/Kconfig"
771 source "arch/arm/mach-meson/Kconfig"
773 source "arch/arm/mach-moxart/Kconfig"
775 source "arch/arm/mach-mv78xx0/Kconfig"
777 source "arch/arm/mach-imx/Kconfig"
779 source "arch/arm/mach-mediatek/Kconfig"
781 source "arch/arm/mach-mxs/Kconfig"
783 source "arch/arm/mach-netx/Kconfig"
785 source "arch/arm/mach-nomadik/Kconfig"
787 source "arch/arm/mach-nspire/Kconfig"
789 source "arch/arm/plat-omap/Kconfig"
791 source "arch/arm/mach-omap1/Kconfig"
793 source "arch/arm/mach-omap2/Kconfig"
795 source "arch/arm/mach-orion5x/Kconfig"
797 source "arch/arm/mach-picoxcell/Kconfig"
799 source "arch/arm/mach-pxa/Kconfig"
800 source "arch/arm/plat-pxa/Kconfig"
802 source "arch/arm/mach-mmp/Kconfig"
804 source "arch/arm/mach-qcom/Kconfig"
806 source "arch/arm/mach-realview/Kconfig"
808 source "arch/arm/mach-rockchip/Kconfig"
810 source "arch/arm/mach-sa1100/Kconfig"
812 source "arch/arm/mach-socfpga/Kconfig"
814 source "arch/arm/mach-spear/Kconfig"
816 source "arch/arm/mach-sti/Kconfig"
818 source "arch/arm/mach-s3c24xx/Kconfig"
820 source "arch/arm/mach-s3c64xx/Kconfig"
822 source "arch/arm/mach-s5pv210/Kconfig"
824 source "arch/arm/mach-exynos/Kconfig"
825 source "arch/arm/plat-samsung/Kconfig"
827 source "arch/arm/mach-shmobile/Kconfig"
829 source "arch/arm/mach-sunxi/Kconfig"
831 source "arch/arm/mach-prima2/Kconfig"
833 source "arch/arm/mach-tango/Kconfig"
835 source "arch/arm/mach-tegra/Kconfig"
837 source "arch/arm/mach-u300/Kconfig"
839 source "arch/arm/mach-uniphier/Kconfig"
841 source "arch/arm/mach-ux500/Kconfig"
843 source "arch/arm/mach-versatile/Kconfig"
845 source "arch/arm/mach-vexpress/Kconfig"
846 source "arch/arm/plat-versatile/Kconfig"
848 source "arch/arm/mach-vt8500/Kconfig"
850 source "arch/arm/mach-w90x900/Kconfig"
852 source "arch/arm/mach-zx/Kconfig"
854 source "arch/arm/mach-zynq/Kconfig"
856 # ARMv7-M architecture
858 bool "Energy Micro efm32"
859 depends on ARM_SINGLE_ARMV7M
860 select ARCH_REQUIRE_GPIOLIB
862 Support for Energy Micro's (now Silicon Labs) efm32 Giant Gecko
866 bool "NXP LPC18xx/LPC43xx"
867 depends on ARM_SINGLE_ARMV7M
868 select ARCH_HAS_RESET_CONTROLLER
870 select CLKSRC_LPC32XX
873 Support for NXP's LPC18xx Cortex-M3 and LPC43xx Cortex-M4
874 high performance microcontrollers.
877 bool "STMicrolectronics STM32"
878 depends on ARM_SINGLE_ARMV7M
879 select ARCH_HAS_RESET_CONTROLLER
880 select ARMV7M_SYSTICK
882 select RESET_CONTROLLER
884 Support for STMicroelectronics STM32 processors.
886 # Definitions to make life easier
892 select GENERIC_CLOCKEVENTS
898 select GENERIC_IRQ_CHIP
901 config PLAT_ORION_LEGACY
908 config PLAT_VERSATILE
911 source "arch/arm/firmware/Kconfig"
913 source arch/arm/mm/Kconfig
916 bool "Enable iWMMXt support"
917 depends on CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK || CPU_PJ4 || CPU_PJ4B
918 default y if PXA27x || PXA3xx || ARCH_MMP || CPU_PJ4 || CPU_PJ4B
920 Enable support for iWMMXt context switching at run time if
921 running on a CPU that supports it.
923 config MULTI_IRQ_HANDLER
926 Allow each machine to specify it's own IRQ handler at run time.
929 source "arch/arm/Kconfig-nommu"
932 config PJ4B_ERRATA_4742
933 bool "PJ4B Errata 4742: IDLE Wake Up Commands can Cause the CPU Core to Cease Operation"
934 depends on CPU_PJ4B && MACH_ARMADA_370
937 When coming out of either a Wait for Interrupt (WFI) or a Wait for
938 Event (WFE) IDLE states, a specific timing sensitivity exists between
939 the retiring WFI/WFE instructions and the newly issued subsequent
940 instructions. This sensitivity can result in a CPU hang scenario.
942 The software must insert either a Data Synchronization Barrier (DSB)
943 or Data Memory Barrier (DMB) command immediately after the WFI/WFE
946 config ARM_ERRATA_326103
947 bool "ARM errata: FSR write bit incorrect on a SWP to read-only memory"
950 Executing a SWP instruction to read-only memory does not set bit 11
951 of the FSR on the ARM 1136 prior to r1p0. This causes the kernel to
952 treat the access as a read, preventing a COW from occurring and
953 causing the faulting task to livelock.
955 config ARM_ERRATA_411920
956 bool "ARM errata: Invalidation of the Instruction Cache operation can fail"
957 depends on CPU_V6 || CPU_V6K
959 Invalidation of the Instruction Cache operation can
960 fail. This erratum is present in 1136 (before r1p4), 1156 and 1176.
961 It does not affect the MPCore. This option enables the ARM Ltd.
962 recommended workaround.
964 config ARM_ERRATA_430973
965 bool "ARM errata: Stale prediction on replaced interworking branch"
968 This option enables the workaround for the 430973 Cortex-A8
969 r1p* erratum. If a code sequence containing an ARM/Thumb
970 interworking branch is replaced with another code sequence at the
971 same virtual address, whether due to self-modifying code or virtual
972 to physical address re-mapping, Cortex-A8 does not recover from the
973 stale interworking branch prediction. This results in Cortex-A8
974 executing the new code sequence in the incorrect ARM or Thumb state.
975 The workaround enables the BTB/BTAC operations by setting ACTLR.IBE
976 and also flushes the branch target cache at every context switch.
977 Note that setting specific bits in the ACTLR register may not be
978 available in non-secure mode.
980 config ARM_ERRATA_458693
981 bool "ARM errata: Processor deadlock when a false hazard is created"
983 depends on !ARCH_MULTIPLATFORM
985 This option enables the workaround for the 458693 Cortex-A8 (r2p0)
986 erratum. For very specific sequences of memory operations, it is
987 possible for a hazard condition intended for a cache line to instead
988 be incorrectly associated with a different cache line. This false
989 hazard might then cause a processor deadlock. The workaround enables
990 the L1 caching of the NEON accesses and disables the PLD instruction
991 in the ACTLR register. Note that setting specific bits in the ACTLR
992 register may not be available in non-secure mode.
994 config ARM_ERRATA_460075
995 bool "ARM errata: Data written to the L2 cache can be overwritten with stale data"
997 depends on !ARCH_MULTIPLATFORM
999 This option enables the workaround for the 460075 Cortex-A8 (r2p0)
1000 erratum. Any asynchronous access to the L2 cache may encounter a
1001 situation in which recent store transactions to the L2 cache are lost
1002 and overwritten with stale memory contents from external memory. The
1003 workaround disables the write-allocate mode for the L2 cache via the
1004 ACTLR register. Note that setting specific bits in the ACTLR register
1005 may not be available in non-secure mode.
1007 config ARM_ERRATA_742230
1008 bool "ARM errata: DMB operation may be faulty"
1009 depends on CPU_V7 && SMP
1010 depends on !ARCH_MULTIPLATFORM
1012 This option enables the workaround for the 742230 Cortex-A9
1013 (r1p0..r2p2) erratum. Under rare circumstances, a DMB instruction
1014 between two write operations may not ensure the correct visibility
1015 ordering of the two writes. This workaround sets a specific bit in
1016 the diagnostic register of the Cortex-A9 which causes the DMB
1017 instruction to behave as a DSB, ensuring the correct behaviour of
1020 config ARM_ERRATA_742231
1021 bool "ARM errata: Incorrect hazard handling in the SCU may lead to data corruption"
1022 depends on CPU_V7 && SMP
1023 depends on !ARCH_MULTIPLATFORM
1025 This option enables the workaround for the 742231 Cortex-A9
1026 (r2p0..r2p2) erratum. Under certain conditions, specific to the
1027 Cortex-A9 MPCore micro-architecture, two CPUs working in SMP mode,
1028 accessing some data located in the same cache line, may get corrupted
1029 data due to bad handling of the address hazard when the line gets
1030 replaced from one of the CPUs at the same time as another CPU is
1031 accessing it. This workaround sets specific bits in the diagnostic
1032 register of the Cortex-A9 which reduces the linefill issuing
1033 capabilities of the processor.
1035 config ARM_ERRATA_643719
1036 bool "ARM errata: LoUIS bit field in CLIDR register is incorrect"
1037 depends on CPU_V7 && SMP
1040 This option enables the workaround for the 643719 Cortex-A9 (prior to
1041 r1p0) erratum. On affected cores the LoUIS bit field of the CLIDR
1042 register returns zero when it should return one. The workaround
1043 corrects this value, ensuring cache maintenance operations which use
1044 it behave as intended and avoiding data corruption.
1046 config ARM_ERRATA_720789
1047 bool "ARM errata: TLBIASIDIS and TLBIMVAIS operations can broadcast a faulty ASID"
1050 This option enables the workaround for the 720789 Cortex-A9 (prior to
1051 r2p0) erratum. A faulty ASID can be sent to the other CPUs for the
1052 broadcasted CP15 TLB maintenance operations TLBIASIDIS and TLBIMVAIS.
1053 As a consequence of this erratum, some TLB entries which should be
1054 invalidated are not, resulting in an incoherency in the system page
1055 tables. The workaround changes the TLB flushing routines to invalidate
1056 entries regardless of the ASID.
1058 config ARM_ERRATA_743622
1059 bool "ARM errata: Faulty hazard checking in the Store Buffer may lead to data corruption"
1061 depends on !ARCH_MULTIPLATFORM
1063 This option enables the workaround for the 743622 Cortex-A9
1064 (r2p*) erratum. Under very rare conditions, a faulty
1065 optimisation in the Cortex-A9 Store Buffer may lead to data
1066 corruption. This workaround sets a specific bit in the diagnostic
1067 register of the Cortex-A9 which disables the Store Buffer
1068 optimisation, preventing the defect from occurring. This has no
1069 visible impact on the overall performance or power consumption of the
1072 config ARM_ERRATA_751472
1073 bool "ARM errata: Interrupted ICIALLUIS may prevent completion of broadcasted operation"
1075 depends on !ARCH_MULTIPLATFORM
1077 This option enables the workaround for the 751472 Cortex-A9 (prior
1078 to r3p0) erratum. An interrupted ICIALLUIS operation may prevent the
1079 completion of a following broadcasted operation if the second
1080 operation is received by a CPU before the ICIALLUIS has completed,
1081 potentially leading to corrupted entries in the cache or TLB.
1083 config ARM_ERRATA_754322
1084 bool "ARM errata: possible faulty MMU translations following an ASID switch"
1087 This option enables the workaround for the 754322 Cortex-A9 (r2p*,
1088 r3p*) erratum. A speculative memory access may cause a page table walk
1089 which starts prior to an ASID switch but completes afterwards. This
1090 can populate the micro-TLB with a stale entry which may be hit with
1091 the new ASID. This workaround places two dsb instructions in the mm
1092 switching code so that no page table walks can cross the ASID switch.
1094 config ARM_ERRATA_754327
1095 bool "ARM errata: no automatic Store Buffer drain"
1096 depends on CPU_V7 && SMP
1098 This option enables the workaround for the 754327 Cortex-A9 (prior to
1099 r2p0) erratum. The Store Buffer does not have any automatic draining
1100 mechanism and therefore a livelock may occur if an external agent
1101 continuously polls a memory location waiting to observe an update.
1102 This workaround defines cpu_relax() as smp_mb(), preventing correctly
1103 written polling loops from denying visibility of updates to memory.
1105 config ARM_ERRATA_364296
1106 bool "ARM errata: Possible cache data corruption with hit-under-miss enabled"
1109 This options enables the workaround for the 364296 ARM1136
1110 r0p2 erratum (possible cache data corruption with
1111 hit-under-miss enabled). It sets the undocumented bit 31 in
1112 the auxiliary control register and the FI bit in the control
1113 register, thus disabling hit-under-miss without putting the
1114 processor into full low interrupt latency mode. ARM11MPCore
1117 config ARM_ERRATA_764369
1118 bool "ARM errata: Data cache line maintenance operation by MVA may not succeed"
1119 depends on CPU_V7 && SMP
1121 This option enables the workaround for erratum 764369
1122 affecting Cortex-A9 MPCore with two or more processors (all
1123 current revisions). Under certain timing circumstances, a data
1124 cache line maintenance operation by MVA targeting an Inner
1125 Shareable memory region may fail to proceed up to either the
1126 Point of Coherency or to the Point of Unification of the
1127 system. This workaround adds a DSB instruction before the
1128 relevant cache maintenance functions and sets a specific bit
1129 in the diagnostic control register of the SCU.
1131 config ARM_ERRATA_775420
1132 bool "ARM errata: A data cache maintenance operation which aborts, might lead to deadlock"
1135 This option enables the workaround for the 775420 Cortex-A9 (r2p2,
1136 r2p6,r2p8,r2p10,r3p0) erratum. In case a date cache maintenance
1137 operation aborts with MMU exception, it might cause the processor
1138 to deadlock. This workaround puts DSB before executing ISB if
1139 an abort may occur on cache maintenance.
1141 config ARM_ERRATA_798181
1142 bool "ARM errata: TLBI/DSB failure on Cortex-A15"
1143 depends on CPU_V7 && SMP
1145 On Cortex-A15 (r0p0..r3p2) the TLBI*IS/DSB operations are not
1146 adequately shooting down all use of the old entries. This
1147 option enables the Linux kernel workaround for this erratum
1148 which sends an IPI to the CPUs that are running the same ASID
1149 as the one being invalidated.
1151 config ARM_ERRATA_773022
1152 bool "ARM errata: incorrect instructions may be executed from loop buffer"
1155 This option enables the workaround for the 773022 Cortex-A15
1156 (up to r0p4) erratum. In certain rare sequences of code, the
1157 loop buffer may deliver incorrect instructions. This
1158 workaround disables the loop buffer to avoid the erratum.
1162 source "arch/arm/common/Kconfig"
1169 Find out whether you have ISA slots on your motherboard. ISA is the
1170 name of a bus system, i.e. the way the CPU talks to the other stuff
1171 inside your box. Other bus systems are PCI, EISA, MicroChannel
1172 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1173 newer boards don't support it. If you have ISA, say Y, otherwise N.
1175 # Select ISA DMA controller support
1180 # Select ISA DMA interface
1185 bool "PCI support" if MIGHT_HAVE_PCI
1187 Find out whether you have a PCI motherboard. PCI is the name of a
1188 bus system, i.e. the way the CPU talks to the other stuff inside
1189 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1190 VESA. If you have PCI, say Y, otherwise N.
1196 config PCI_DOMAINS_GENERIC
1197 def_bool PCI_DOMAINS
1199 config PCI_NANOENGINE
1200 bool "BSE nanoEngine PCI support"
1201 depends on SA1100_NANOENGINE
1203 Enable PCI on the BSE nanoEngine board.
1208 config PCI_HOST_ITE8152
1210 depends on PCI && MACH_ARMCORE
1214 source "drivers/pci/Kconfig"
1215 source "drivers/pci/pcie/Kconfig"
1217 source "drivers/pcmcia/Kconfig"
1221 menu "Kernel Features"
1226 This option should be selected by machines which have an SMP-
1229 The only effect of this option is to make the SMP-related
1230 options available to the user for configuration.
1233 bool "Symmetric Multi-Processing"
1234 depends on CPU_V6K || CPU_V7
1235 depends on GENERIC_CLOCKEVENTS
1237 depends on MMU || ARM_MPU
1240 This enables support for systems with more than one CPU. If you have
1241 a system with only one CPU, say N. If you have a system with more
1242 than one CPU, say Y.
1244 If you say N here, the kernel will run on uni- and multiprocessor
1245 machines, but will use only one CPU of a multiprocessor machine. If
1246 you say Y here, the kernel will run on many, but not all,
1247 uniprocessor machines. On a uniprocessor machine, the kernel
1248 will run faster if you say N here.
1250 See also <file:Documentation/x86/i386/IO-APIC.txt>,
1251 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
1252 <http://tldp.org/HOWTO/SMP-HOWTO.html>.
1254 If you don't know what to do here, say N.
1257 bool "Allow booting SMP kernel on uniprocessor systems"
1258 depends on SMP && !XIP_KERNEL && MMU
1261 SMP kernels contain instructions which fail on non-SMP processors.
1262 Enabling this option allows the kernel to modify itself to make
1263 these instructions safe. Disabling it allows about 1K of space
1266 If you don't know what to do here, say Y.
1268 config ARM_CPU_TOPOLOGY
1269 bool "Support cpu topology definition"
1270 depends on SMP && CPU_V7
1273 Support ARM cpu topology definition. The MPIDR register defines
1274 affinity between processors which is then used to describe the cpu
1275 topology of an ARM System.
1278 bool "Multi-core scheduler support"
1279 depends on ARM_CPU_TOPOLOGY
1281 Multi-core scheduler support improves the CPU scheduler's decision
1282 making when dealing with multi-core CPU chips at a cost of slightly
1283 increased overhead in some places. If unsure say N here.
1286 bool "SMT scheduler support"
1287 depends on ARM_CPU_TOPOLOGY
1289 Improves the CPU scheduler's decision making when dealing with
1290 MultiThreading at a cost of slightly increased overhead in some
1291 places. If unsure say N here.
1296 This option enables support for the ARM system coherency unit
1298 config HAVE_ARM_ARCH_TIMER
1299 bool "Architected timer support"
1301 select ARM_ARCH_TIMER
1302 select GENERIC_CLOCKEVENTS
1304 This option enables support for the ARM architected timer
1308 select CLKSRC_OF if OF
1310 This options enables support for the ARM timer and watchdog unit
1313 bool "Multi-Cluster Power Management"
1314 depends on CPU_V7 && SMP
1316 This option provides the common power management infrastructure
1317 for (multi-)cluster based systems, such as big.LITTLE based
1320 config MCPM_QUAD_CLUSTER
1324 To avoid wasting resources unnecessarily, MCPM only supports up
1325 to 2 clusters by default.
1326 Platforms with 3 or 4 clusters that use MCPM must select this
1327 option to allow the additional clusters to be managed.
1330 bool "big.LITTLE support (Experimental)"
1331 depends on CPU_V7 && SMP
1334 This option enables support selections for the big.LITTLE
1335 system architecture.
1338 bool "big.LITTLE switcher support"
1339 depends on BIG_LITTLE && MCPM && HOTPLUG_CPU && ARM_GIC
1340 select ARM_CPU_SUSPEND
1343 The big.LITTLE "switcher" provides the core functionality to
1344 transparently handle transition between a cluster of A15's
1345 and a cluster of A7's in a big.LITTLE system.
1347 config BL_SWITCHER_DUMMY_IF
1348 tristate "Simple big.LITTLE switcher user interface"
1349 depends on BL_SWITCHER && DEBUG_KERNEL
1351 This is a simple and dummy char dev interface to control
1352 the big.LITTLE switcher core code. It is meant for
1353 debugging purposes only.
1356 prompt "Memory split"
1360 Select the desired split between kernel and user memory.
1362 If you are not absolutely sure what you are doing, leave this
1366 bool "3G/1G user/kernel split"
1367 config VMSPLIT_3G_OPT
1368 bool "3G/1G user/kernel split (for full 1G low memory)"
1370 bool "2G/2G user/kernel split"
1372 bool "1G/3G user/kernel split"
1377 default PHYS_OFFSET if !MMU
1378 default 0x40000000 if VMSPLIT_1G
1379 default 0x80000000 if VMSPLIT_2G
1380 default 0xB0000000 if VMSPLIT_3G_OPT
1384 int "Maximum number of CPUs (2-32)"
1390 bool "Support for hot-pluggable CPUs"
1393 Say Y here to experiment with turning CPUs off and on. CPUs
1394 can be controlled through /sys/devices/system/cpu.
1397 bool "Support for the ARM Power State Coordination Interface (PSCI)"
1398 depends on HAVE_ARM_SMCCC
1401 Say Y here if you want Linux to communicate with system firmware
1402 implementing the PSCI specification for CPU-centric power
1403 management operations described in ARM document number ARM DEN
1404 0022A ("Power State Coordination Interface System Software on
1407 # The GPIO number here must be sorted by descending number. In case of
1408 # a multiplatform kernel, we just want the highest value required by the
1409 # selected platforms.
1412 default 1024 if ARCH_BRCMSTB || ARCH_SHMOBILE || ARCH_TEGRA || \
1414 default 512 if ARCH_EXYNOS || ARCH_KEYSTONE || SOC_OMAP5 || \
1415 SOC_DRA7XX || ARCH_S3C24XX || ARCH_S3C64XX || ARCH_S5PV210
1416 default 416 if ARCH_SUNXI
1417 default 392 if ARCH_U8500
1418 default 352 if ARCH_VT8500
1419 default 288 if ARCH_ROCKCHIP
1420 default 264 if MACH_H4700
1423 Maximum number of GPIOs in the system.
1425 If unsure, leave the default value.
1427 source kernel/Kconfig.preempt
1431 default 200 if ARCH_EBSA110 || ARCH_S3C24XX || \
1432 ARCH_S5PV210 || ARCH_EXYNOS4
1433 default 128 if SOC_AT91RM9200
1437 depends on HZ_FIXED = 0
1438 prompt "Timer frequency"
1462 default HZ_FIXED if HZ_FIXED != 0
1463 default 100 if HZ_100
1464 default 200 if HZ_200
1465 default 250 if HZ_250
1466 default 300 if HZ_300
1467 default 500 if HZ_500
1471 def_bool HIGH_RES_TIMERS
1473 config THUMB2_KERNEL
1474 bool "Compile the kernel in Thumb-2 mode" if !CPU_THUMBONLY
1475 depends on (CPU_V7 || CPU_V7M) && !CPU_V6 && !CPU_V6K
1476 default y if CPU_THUMBONLY
1478 select ARM_ASM_UNIFIED
1481 By enabling this option, the kernel will be compiled in
1482 Thumb-2 mode. A compiler/assembler that understand the unified
1483 ARM-Thumb syntax is needed.
1487 config THUMB2_AVOID_R_ARM_THM_JUMP11
1488 bool "Work around buggy Thumb-2 short branch relocations in gas"
1489 depends on THUMB2_KERNEL && MODULES
1492 Various binutils versions can resolve Thumb-2 branches to
1493 locally-defined, preemptible global symbols as short-range "b.n"
1494 branch instructions.
1496 This is a problem, because there's no guarantee the final
1497 destination of the symbol, or any candidate locations for a
1498 trampoline, are within range of the branch. For this reason, the
1499 kernel does not support fixing up the R_ARM_THM_JUMP11 (102)
1500 relocation in modules at all, and it makes little sense to add
1503 The symptom is that the kernel fails with an "unsupported
1504 relocation" error when loading some modules.
1506 Until fixed tools are available, passing
1507 -fno-optimize-sibling-calls to gcc should prevent gcc generating
1508 code which hits this problem, at the cost of a bit of extra runtime
1509 stack usage in some cases.
1511 The problem is described in more detail at:
1512 https://bugs.launchpad.net/binutils-linaro/+bug/725126
1514 Only Thumb-2 kernels are affected.
1516 Unless you are sure your tools don't have this problem, say Y.
1518 config ARM_ASM_UNIFIED
1521 config ARM_PATCH_IDIV
1522 bool "Runtime patch udiv/sdiv instructions into __aeabi_{u}idiv()"
1523 depends on CPU_32v7 && !XIP_KERNEL
1526 The ARM compiler inserts calls to __aeabi_idiv() and
1527 __aeabi_uidiv() when it needs to perform division on signed
1528 and unsigned integers. Some v7 CPUs have support for the sdiv
1529 and udiv instructions that can be used to implement those
1532 Enabling this option allows the kernel to modify itself to
1533 replace the first two instructions of these library functions
1534 with the sdiv or udiv plus "bx lr" instructions when the CPU
1535 it is running on supports them. Typically this will be faster
1536 and less power intensive than running the original library
1537 code to do integer division.
1540 bool "Use the ARM EABI to compile the kernel"
1542 This option allows for the kernel to be compiled using the latest
1543 ARM ABI (aka EABI). This is only useful if you are using a user
1544 space environment that is also compiled with EABI.
1546 Since there are major incompatibilities between the legacy ABI and
1547 EABI, especially with regard to structure member alignment, this
1548 option also changes the kernel syscall calling convention to
1549 disambiguate both ABIs and allow for backward compatibility support
1550 (selected with CONFIG_OABI_COMPAT).
1552 To use this you need GCC version 4.0.0 or later.
1555 bool "Allow old ABI binaries to run with this kernel (EXPERIMENTAL)"
1556 depends on AEABI && !THUMB2_KERNEL
1558 This option preserves the old syscall interface along with the
1559 new (ARM EABI) one. It also provides a compatibility layer to
1560 intercept syscalls that have structure arguments which layout
1561 in memory differs between the legacy ABI and the new ARM EABI
1562 (only for non "thumb" binaries). This option adds a tiny
1563 overhead to all syscalls and produces a slightly larger kernel.
1565 The seccomp filter system will not be available when this is
1566 selected, since there is no way yet to sensibly distinguish
1567 between calling conventions during filtering.
1569 If you know you'll be using only pure EABI user space then you
1570 can say N here. If this option is not selected and you attempt
1571 to execute a legacy ABI binary then the result will be
1572 UNPREDICTABLE (in fact it can be predicted that it won't work
1573 at all). If in doubt say N.
1575 config ARCH_HAS_HOLES_MEMORYMODEL
1578 config ARCH_SPARSEMEM_ENABLE
1581 config ARCH_SPARSEMEM_DEFAULT
1582 def_bool ARCH_SPARSEMEM_ENABLE
1584 config ARCH_SELECT_MEMORY_MODEL
1585 def_bool ARCH_SPARSEMEM_ENABLE
1587 config HAVE_ARCH_PFN_VALID
1588 def_bool ARCH_HAS_HOLES_MEMORYMODEL || !SPARSEMEM
1590 config HAVE_GENERIC_RCU_GUP
1595 bool "High Memory Support"
1598 The address space of ARM processors is only 4 Gigabytes large
1599 and it has to accommodate user address space, kernel address
1600 space as well as some memory mapped IO. That means that, if you
1601 have a large amount of physical memory and/or IO, not all of the
1602 memory can be "permanently mapped" by the kernel. The physical
1603 memory that is not permanently mapped is called "high memory".
1605 Depending on the selected kernel/user memory split, minimum
1606 vmalloc space and actual amount of RAM, you may not need this
1607 option which should result in a slightly faster kernel.
1612 bool "Allocate 2nd-level pagetables from highmem" if EXPERT
1616 The VM uses one page of physical memory for each page table.
1617 For systems with a lot of processes, this can use a lot of
1618 precious low memory, eventually leading to low memory being
1619 consumed by page tables. Setting this option will allow
1620 user-space 2nd level page tables to reside in high memory.
1622 config CPU_SW_DOMAIN_PAN
1623 bool "Enable use of CPU domains to implement privileged no-access"
1624 depends on MMU && !ARM_LPAE
1627 Increase kernel security by ensuring that normal kernel accesses
1628 are unable to access userspace addresses. This can help prevent
1629 use-after-free bugs becoming an exploitable privilege escalation
1630 by ensuring that magic values (such as LIST_POISON) will always
1631 fault when dereferenced.
1633 CPUs with low-vector mappings use a best-efforts implementation.
1634 Their lower 1MB needs to remain accessible for the vectors, but
1635 the remainder of userspace will become appropriately inaccessible.
1637 config HW_PERF_EVENTS
1641 config SYS_SUPPORTS_HUGETLBFS
1645 config HAVE_ARCH_TRANSPARENT_HUGEPAGE
1649 config ARCH_WANT_GENERAL_HUGETLB
1652 config ARM_MODULE_PLTS
1653 bool "Use PLTs to allow module memory to spill over into vmalloc area"
1656 Allocate PLTs when loading modules so that jumps and calls whose
1657 targets are too far away for their relative offsets to be encoded
1658 in the instructions themselves can be bounced via veneers in the
1659 module's PLT. This allows modules to be allocated in the generic
1660 vmalloc area after the dedicated module memory area has been
1661 exhausted. The modules will use slightly more memory, but after
1662 rounding up to page size, the actual memory footprint is usually
1665 Say y if you are getting out of memory errors while loading modules
1669 config FORCE_MAX_ZONEORDER
1670 int "Maximum zone order"
1671 default "12" if SOC_AM33XX
1672 default "9" if SA1111 || ARCH_EFM32
1675 The kernel memory allocator divides physically contiguous memory
1676 blocks into "zones", where each zone is a power of two number of
1677 pages. This option selects the largest power of two that the kernel
1678 keeps in the memory allocator. If you need to allocate very large
1679 blocks of physically contiguous memory, then you may need to
1680 increase this value.
1682 This config option is actually maximum order plus one. For example,
1683 a value of 11 means that the largest free memory block is 2^10 pages.
1685 config ALIGNMENT_TRAP
1687 depends on CPU_CP15_MMU
1688 default y if !ARCH_EBSA110
1689 select HAVE_PROC_CPU if PROC_FS
1691 ARM processors cannot fetch/store information which is not
1692 naturally aligned on the bus, i.e., a 4 byte fetch must start at an
1693 address divisible by 4. On 32-bit ARM processors, these non-aligned
1694 fetch/store instructions will be emulated in software if you say
1695 here, which has a severe performance impact. This is necessary for
1696 correct operation of some network protocols. With an IP-only
1697 configuration it is safe to say N, otherwise say Y.
1699 config UACCESS_WITH_MEMCPY
1700 bool "Use kernel mem{cpy,set}() for {copy_to,clear}_user()"
1702 default y if CPU_FEROCEON
1704 Implement faster copy_to_user and clear_user methods for CPU
1705 cores where a 8-word STM instruction give significantly higher
1706 memory write throughput than a sequence of individual 32bit stores.
1708 A possible side effect is a slight increase in scheduling latency
1709 between threads sharing the same address space if they invoke
1710 such copy operations with large buffers.
1712 However, if the CPU data cache is using a write-allocate mode,
1713 this option is unlikely to provide any performance gain.
1717 prompt "Enable seccomp to safely compute untrusted bytecode"
1719 This kernel feature is useful for number crunching applications
1720 that may need to compute untrusted bytecode during their
1721 execution. By using pipes or other transports made available to
1722 the process as file descriptors supporting the read/write
1723 syscalls, it's possible to isolate those applications in
1724 their own address space using seccomp. Once seccomp is
1725 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1726 and the task is only allowed to execute a few safe syscalls
1727 defined by each seccomp mode.
1736 bool "Enable paravirtualization code"
1738 This changes the kernel so it can modify itself when it is run
1739 under a hypervisor, potentially improving performance significantly
1740 over full virtualization.
1742 config PARAVIRT_TIME_ACCOUNTING
1743 bool "Paravirtual steal time accounting"
1747 Select this option to enable fine granularity task steal time
1748 accounting. Time spent executing other tasks in parallel with
1749 the current vCPU is discounted from the vCPU power. To account for
1750 that, there can be a small performance impact.
1752 If in doubt, say N here.
1759 bool "Xen guest support on ARM"
1760 depends on ARM && AEABI && OF
1761 depends on CPU_V7 && !CPU_V6
1762 depends on !GENERIC_ATOMIC64
1764 select ARCH_DMA_ADDR_T_64BIT
1769 Say Y if you want to run Linux in a Virtual Machine on Xen on ARM.
1776 bool "Flattened Device Tree support"
1780 Include support for flattened device tree machine descriptions.
1783 bool "Support for the traditional ATAGS boot data passing" if USE_OF
1786 This is the traditional way of passing data to the kernel at boot
1787 time. If you are solely relying on the flattened device tree (or
1788 the ARM_ATAG_DTB_COMPAT option) then you may unselect this option
1789 to remove ATAGS support from your kernel binary. If unsure,
1792 config DEPRECATED_PARAM_STRUCT
1793 bool "Provide old way to pass kernel parameters"
1796 This was deprecated in 2001 and announced to live on for 5 years.
1797 Some old boot loaders still use this way.
1799 # Compressed boot loader in ROM. Yes, we really want to ask about
1800 # TEXT and BSS so we preserve their values in the config files.
1801 config ZBOOT_ROM_TEXT
1802 hex "Compressed ROM boot loader base address"
1805 The physical address at which the ROM-able zImage is to be
1806 placed in the target. Platforms which normally make use of
1807 ROM-able zImage formats normally set this to a suitable
1808 value in their defconfig file.
1810 If ZBOOT_ROM is not enabled, this has no effect.
1812 config ZBOOT_ROM_BSS
1813 hex "Compressed ROM boot loader BSS address"
1816 The base address of an area of read/write memory in the target
1817 for the ROM-able zImage which must be available while the
1818 decompressor is running. It must be large enough to hold the
1819 entire decompressed kernel plus an additional 128 KiB.
1820 Platforms which normally make use of ROM-able zImage formats
1821 normally set this to a suitable value in their defconfig file.
1823 If ZBOOT_ROM is not enabled, this has no effect.
1826 bool "Compressed boot loader in ROM/flash"
1827 depends on ZBOOT_ROM_TEXT != ZBOOT_ROM_BSS
1828 depends on !ARM_APPENDED_DTB && !XIP_KERNEL && !AUTO_ZRELADDR
1830 Say Y here if you intend to execute your compressed kernel image
1831 (zImage) directly from ROM or flash. If unsure, say N.
1833 config ARM_APPENDED_DTB
1834 bool "Use appended device tree blob to zImage (EXPERIMENTAL)"
1837 With this option, the boot code will look for a device tree binary
1838 (DTB) appended to zImage
1839 (e.g. cat zImage <filename>.dtb > zImage_w_dtb).
1841 This is meant as a backward compatibility convenience for those
1842 systems with a bootloader that can't be upgraded to accommodate
1843 the documented boot protocol using a device tree.
1845 Beware that there is very little in terms of protection against
1846 this option being confused by leftover garbage in memory that might
1847 look like a DTB header after a reboot if no actual DTB is appended
1848 to zImage. Do not leave this option active in a production kernel
1849 if you don't intend to always append a DTB. Proper passing of the
1850 location into r2 of a bootloader provided DTB is always preferable
1853 config ARM_ATAG_DTB_COMPAT
1854 bool "Supplement the appended DTB with traditional ATAG information"
1855 depends on ARM_APPENDED_DTB
1857 Some old bootloaders can't be updated to a DTB capable one, yet
1858 they provide ATAGs with memory configuration, the ramdisk address,
1859 the kernel cmdline string, etc. Such information is dynamically
1860 provided by the bootloader and can't always be stored in a static
1861 DTB. To allow a device tree enabled kernel to be used with such
1862 bootloaders, this option allows zImage to extract the information
1863 from the ATAG list and store it at run time into the appended DTB.
1866 prompt "Kernel command line type" if ARM_ATAG_DTB_COMPAT
1867 default ARM_ATAG_DTB_COMPAT_CMDLINE_FROM_BOOTLOADER
1869 config ARM_ATAG_DTB_COMPAT_CMDLINE_FROM_BOOTLOADER
1870 bool "Use bootloader kernel arguments if available"
1872 Uses the command-line options passed by the boot loader instead of
1873 the device tree bootargs property. If the boot loader doesn't provide
1874 any, the device tree bootargs property will be used.
1876 config ARM_ATAG_DTB_COMPAT_CMDLINE_EXTEND
1877 bool "Extend with bootloader kernel arguments"
1879 The command-line arguments provided by the boot loader will be
1880 appended to the the device tree bootargs property.
1885 string "Default kernel command string"
1888 On some architectures (EBSA110 and CATS), there is currently no way
1889 for the boot loader to pass arguments to the kernel. For these
1890 architectures, you should supply some command-line options at build
1891 time by entering them here. As a minimum, you should specify the
1892 memory size and the root device (e.g., mem=64M root=/dev/nfs).
1895 prompt "Kernel command line type" if CMDLINE != ""
1896 default CMDLINE_FROM_BOOTLOADER
1899 config CMDLINE_FROM_BOOTLOADER
1900 bool "Use bootloader kernel arguments if available"
1902 Uses the command-line options passed by the boot loader. If
1903 the boot loader doesn't provide any, the default kernel command
1904 string provided in CMDLINE will be used.
1906 config CMDLINE_EXTEND
1907 bool "Extend bootloader kernel arguments"
1909 The command-line arguments provided by the boot loader will be
1910 appended to the default kernel command string.
1912 config CMDLINE_FORCE
1913 bool "Always use the default kernel command string"
1915 Always use the default kernel command string, even if the boot
1916 loader passes other arguments to the kernel.
1917 This is useful if you cannot or don't want to change the
1918 command-line options your boot loader passes to the kernel.
1922 bool "Kernel Execute-In-Place from ROM"
1923 depends on !ARM_LPAE && !ARCH_MULTIPLATFORM
1925 Execute-In-Place allows the kernel to run from non-volatile storage
1926 directly addressable by the CPU, such as NOR flash. This saves RAM
1927 space since the text section of the kernel is not loaded from flash
1928 to RAM. Read-write sections, such as the data section and stack,
1929 are still copied to RAM. The XIP kernel is not compressed since
1930 it has to run directly from flash, so it will take more space to
1931 store it. The flash address used to link the kernel object files,
1932 and for storing it, is configuration dependent. Therefore, if you
1933 say Y here, you must know the proper physical address where to
1934 store the kernel image depending on your own flash memory usage.
1936 Also note that the make target becomes "make xipImage" rather than
1937 "make zImage" or "make Image". The final kernel binary to put in
1938 ROM memory will be arch/arm/boot/xipImage.
1942 config XIP_PHYS_ADDR
1943 hex "XIP Kernel Physical Location"
1944 depends on XIP_KERNEL
1945 default "0x00080000"
1947 This is the physical address in your flash memory the kernel will
1948 be linked for and stored to. This address is dependent on your
1952 bool "Kexec system call (EXPERIMENTAL)"
1953 depends on (!SMP || PM_SLEEP_SMP)
1957 kexec is a system call that implements the ability to shutdown your
1958 current kernel, and to start another kernel. It is like a reboot
1959 but it is independent of the system firmware. And like a reboot
1960 you can start any kernel with it, not just Linux.
1962 It is an ongoing process to be certain the hardware in a machine
1963 is properly shutdown, so do not be surprised if this code does not
1964 initially work for you.
1967 bool "Export atags in procfs"
1968 depends on ATAGS && KEXEC
1971 Should the atags used to boot the kernel be exported in an "atags"
1972 file in procfs. Useful with kexec.
1975 bool "Build kdump crash kernel (EXPERIMENTAL)"
1977 Generate crash dump after being started by kexec. This should
1978 be normally only set in special crash dump kernels which are
1979 loaded in the main kernel with kexec-tools into a specially
1980 reserved region and then later executed after a crash by
1981 kdump/kexec. The crash dump kernel must be compiled to a
1982 memory address not used by the main kernel
1984 For more details see Documentation/kdump/kdump.txt
1986 config AUTO_ZRELADDR
1987 bool "Auto calculation of the decompressed kernel image address"
1989 ZRELADDR is the physical address where the decompressed kernel
1990 image will be placed. If AUTO_ZRELADDR is selected, the address
1991 will be determined at run-time by masking the current IP with
1992 0xf8000000. This assumes the zImage being placed in the first 128MB
1993 from start of memory.
1999 bool "UEFI runtime support"
2000 depends on OF && !CPU_BIG_ENDIAN && MMU && AUTO_ZRELADDR && !XIP_KERNEL
2002 select EFI_PARAMS_FROM_FDT
2005 select EFI_RUNTIME_WRAPPERS
2007 This option provides support for runtime services provided
2008 by UEFI firmware (such as non-volatile variables, realtime
2009 clock, and platform reset). A UEFI stub is also provided to
2010 allow the kernel to be booted as an EFI application. This
2011 is only useful for kernels that may run on systems that have
2016 menu "CPU Power Management"
2018 source "drivers/cpufreq/Kconfig"
2020 source "drivers/cpuidle/Kconfig"
2024 menu "Floating point emulation"
2026 comment "At least one emulation must be selected"
2029 bool "NWFPE math emulation"
2030 depends on (!AEABI || OABI_COMPAT) && !THUMB2_KERNEL
2032 Say Y to include the NWFPE floating point emulator in the kernel.
2033 This is necessary to run most binaries. Linux does not currently
2034 support floating point hardware so you need to say Y here even if
2035 your machine has an FPA or floating point co-processor podule.
2037 You may say N here if you are going to load the Acorn FPEmulator
2038 early in the bootup.
2041 bool "Support extended precision"
2042 depends on FPE_NWFPE
2044 Say Y to include 80-bit support in the kernel floating-point
2045 emulator. Otherwise, only 32 and 64-bit support is compiled in.
2046 Note that gcc does not generate 80-bit operations by default,
2047 so in most cases this option only enlarges the size of the
2048 floating point emulator without any good reason.
2050 You almost surely want to say N here.
2053 bool "FastFPE math emulation (EXPERIMENTAL)"
2054 depends on (!AEABI || OABI_COMPAT) && !CPU_32v3
2056 Say Y here to include the FAST floating point emulator in the kernel.
2057 This is an experimental much faster emulator which now also has full
2058 precision for the mantissa. It does not support any exceptions.
2059 It is very simple, and approximately 3-6 times faster than NWFPE.
2061 It should be sufficient for most programs. It may be not suitable
2062 for scientific calculations, but you have to check this for yourself.
2063 If you do not feel you need a faster FP emulation you should better
2067 bool "VFP-format floating point maths"
2068 depends on CPU_V6 || CPU_V6K || CPU_ARM926T || CPU_V7 || CPU_FEROCEON
2070 Say Y to include VFP support code in the kernel. This is needed
2071 if your hardware includes a VFP unit.
2073 Please see <file:Documentation/arm/VFP/release-notes.txt> for
2074 release notes and additional status information.
2076 Say N if your target does not have VFP hardware.
2084 bool "Advanced SIMD (NEON) Extension support"
2085 depends on VFPv3 && CPU_V7
2087 Say Y to include support code for NEON, the ARMv7 Advanced SIMD
2090 config KERNEL_MODE_NEON
2091 bool "Support for NEON in kernel mode"
2092 depends on NEON && AEABI
2094 Say Y to include support for NEON in kernel mode.
2098 menu "Userspace binary formats"
2100 source "fs/Kconfig.binfmt"
2104 menu "Power management options"
2106 source "kernel/power/Kconfig"
2108 config ARCH_SUSPEND_POSSIBLE
2109 depends on CPU_ARM920T || CPU_ARM926T || CPU_FEROCEON || CPU_SA1100 || \
2110 CPU_V6 || CPU_V6K || CPU_V7 || CPU_V7M || CPU_XSC3 || CPU_XSCALE || CPU_MOHAWK
2113 config ARM_CPU_SUSPEND
2116 config ARCH_HIBERNATION_POSSIBLE
2119 default y if ARCH_SUSPEND_POSSIBLE
2123 source "net/Kconfig"
2125 source "drivers/Kconfig"
2127 source "drivers/firmware/Kconfig"
2131 source "arch/arm/Kconfig.debug"
2133 source "security/Kconfig"
2135 source "crypto/Kconfig"
2137 source "arch/arm/crypto/Kconfig"
2140 source "lib/Kconfig"
2142 source "arch/arm/kvm/Kconfig"