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
530 select CLKSRC_LPC32XX
533 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 CPU_XSCALE if !CPU_XSC3
551 select GENERIC_CLOCKEVENTS
555 select MULTI_IRQ_HANDLER
559 Support for Intel/Marvell's PXA2xx/PXA3xx processor line.
565 select ARCH_MAY_HAVE_PC_FDC
566 select ARCH_SPARSEMEM_ENABLE
567 select ARCH_USES_GETTIMEOFFSET
571 select HAVE_PATA_PLATFORM
573 select NEED_MACH_IO_H
574 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
627 select GENERIC_ALLOCATOR
628 select GENERIC_CLOCKEVENTS
629 select GENERIC_IRQ_CHIP
634 Support for TI's DaVinci platform.
639 select ARCH_HAS_HOLES_MEMORYMODEL
641 select ARCH_REQUIRE_GPIOLIB
644 select GENERIC_CLOCKEVENTS
645 select GENERIC_IRQ_CHIP
648 select MULTI_IRQ_HANDLER
649 select NEED_MACH_IO_H if PCCARD
650 select NEED_MACH_MEMORY_H
653 Support for older TI OMAP1 (omap7xx, omap15xx or omap16xx)
657 menu "Multiple platform selection"
658 depends on ARCH_MULTIPLATFORM
660 comment "CPU Core family selection"
663 bool "ARMv4 based platforms (FA526)"
664 depends on !ARCH_MULTI_V6_V7
665 select ARCH_MULTI_V4_V5
668 config ARCH_MULTI_V4T
669 bool "ARMv4T based platforms (ARM720T, ARM920T, ...)"
670 depends on !ARCH_MULTI_V6_V7
671 select ARCH_MULTI_V4_V5
672 select CPU_ARM920T if !(CPU_ARM7TDMI || CPU_ARM720T || \
673 CPU_ARM740T || CPU_ARM9TDMI || CPU_ARM922T || \
674 CPU_ARM925T || CPU_ARM940T)
677 bool "ARMv5 based platforms (ARM926T, XSCALE, PJ1, ...)"
678 depends on !ARCH_MULTI_V6_V7
679 select ARCH_MULTI_V4_V5
680 select CPU_ARM926T if !(CPU_ARM946E || CPU_ARM1020 || \
681 CPU_ARM1020E || CPU_ARM1022 || CPU_ARM1026 || \
682 CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK || CPU_FEROCEON)
684 config ARCH_MULTI_V4_V5
688 bool "ARMv6 based platforms (ARM11)"
689 select ARCH_MULTI_V6_V7
693 bool "ARMv7 based platforms (Cortex-A, PJ4, Scorpion, Krait)"
695 select ARCH_MULTI_V6_V7
699 config ARCH_MULTI_V6_V7
701 select MIGHT_HAVE_CACHE_L2X0
703 config ARCH_MULTI_CPU_AUTO
704 def_bool !(ARCH_MULTI_V4 || ARCH_MULTI_V4T || ARCH_MULTI_V6_V7)
710 bool "Dummy Virtual Machine"
711 depends on ARCH_MULTI_V7
714 select ARM_GIC_V2M if PCI_MSI
717 select HAVE_ARM_ARCH_TIMER
720 # This is sorted alphabetically by mach-* pathname. However, plat-*
721 # Kconfigs may be included either alphabetically (according to the
722 # plat- suffix) or along side the corresponding mach-* source.
724 source "arch/arm/mach-mvebu/Kconfig"
726 source "arch/arm/mach-alpine/Kconfig"
728 source "arch/arm/mach-artpec/Kconfig"
730 source "arch/arm/mach-asm9260/Kconfig"
732 source "arch/arm/mach-at91/Kconfig"
734 source "arch/arm/mach-axxia/Kconfig"
736 source "arch/arm/mach-bcm/Kconfig"
738 source "arch/arm/mach-berlin/Kconfig"
740 source "arch/arm/mach-clps711x/Kconfig"
742 source "arch/arm/mach-cns3xxx/Kconfig"
744 source "arch/arm/mach-davinci/Kconfig"
746 source "arch/arm/mach-digicolor/Kconfig"
748 source "arch/arm/mach-dove/Kconfig"
750 source "arch/arm/mach-ep93xx/Kconfig"
752 source "arch/arm/mach-footbridge/Kconfig"
754 source "arch/arm/mach-gemini/Kconfig"
756 source "arch/arm/mach-highbank/Kconfig"
758 source "arch/arm/mach-hisi/Kconfig"
760 source "arch/arm/mach-integrator/Kconfig"
762 source "arch/arm/mach-iop32x/Kconfig"
764 source "arch/arm/mach-iop33x/Kconfig"
766 source "arch/arm/mach-iop13xx/Kconfig"
768 source "arch/arm/mach-ixp4xx/Kconfig"
770 source "arch/arm/mach-keystone/Kconfig"
772 source "arch/arm/mach-ks8695/Kconfig"
774 source "arch/arm/mach-meson/Kconfig"
776 source "arch/arm/mach-moxart/Kconfig"
778 source "arch/arm/mach-mv78xx0/Kconfig"
780 source "arch/arm/mach-imx/Kconfig"
782 source "arch/arm/mach-mediatek/Kconfig"
784 source "arch/arm/mach-mxs/Kconfig"
786 source "arch/arm/mach-netx/Kconfig"
788 source "arch/arm/mach-nomadik/Kconfig"
790 source "arch/arm/mach-nspire/Kconfig"
792 source "arch/arm/plat-omap/Kconfig"
794 source "arch/arm/mach-omap1/Kconfig"
796 source "arch/arm/mach-omap2/Kconfig"
798 source "arch/arm/mach-orion5x/Kconfig"
800 source "arch/arm/mach-picoxcell/Kconfig"
802 source "arch/arm/mach-pxa/Kconfig"
803 source "arch/arm/plat-pxa/Kconfig"
805 source "arch/arm/mach-mmp/Kconfig"
807 source "arch/arm/mach-qcom/Kconfig"
809 source "arch/arm/mach-realview/Kconfig"
811 source "arch/arm/mach-rockchip/Kconfig"
813 source "arch/arm/mach-sa1100/Kconfig"
815 source "arch/arm/mach-socfpga/Kconfig"
817 source "arch/arm/mach-spear/Kconfig"
819 source "arch/arm/mach-sti/Kconfig"
821 source "arch/arm/mach-s3c24xx/Kconfig"
823 source "arch/arm/mach-s3c64xx/Kconfig"
825 source "arch/arm/mach-s5pv210/Kconfig"
827 source "arch/arm/mach-exynos/Kconfig"
828 source "arch/arm/plat-samsung/Kconfig"
830 source "arch/arm/mach-shmobile/Kconfig"
832 source "arch/arm/mach-sunxi/Kconfig"
834 source "arch/arm/mach-prima2/Kconfig"
836 source "arch/arm/mach-tango/Kconfig"
838 source "arch/arm/mach-tegra/Kconfig"
840 source "arch/arm/mach-u300/Kconfig"
842 source "arch/arm/mach-uniphier/Kconfig"
844 source "arch/arm/mach-ux500/Kconfig"
846 source "arch/arm/mach-versatile/Kconfig"
848 source "arch/arm/mach-vexpress/Kconfig"
849 source "arch/arm/plat-versatile/Kconfig"
851 source "arch/arm/mach-vt8500/Kconfig"
853 source "arch/arm/mach-w90x900/Kconfig"
855 source "arch/arm/mach-zx/Kconfig"
857 source "arch/arm/mach-zynq/Kconfig"
859 # ARMv7-M architecture
861 bool "Energy Micro efm32"
862 depends on ARM_SINGLE_ARMV7M
863 select ARCH_REQUIRE_GPIOLIB
865 Support for Energy Micro's (now Silicon Labs) efm32 Giant Gecko
869 bool "NXP LPC18xx/LPC43xx"
870 depends on ARM_SINGLE_ARMV7M
871 select ARCH_HAS_RESET_CONTROLLER
873 select CLKSRC_LPC32XX
876 Support for NXP's LPC18xx Cortex-M3 and LPC43xx Cortex-M4
877 high performance microcontrollers.
880 bool "STMicrolectronics STM32"
881 depends on ARM_SINGLE_ARMV7M
882 select ARCH_HAS_RESET_CONTROLLER
883 select ARMV7M_SYSTICK
886 select RESET_CONTROLLER
888 Support for STMicroelectronics STM32 processors.
890 config MACH_STM32F429
891 bool "STMicrolectronics STM32F429"
892 depends on ARCH_STM32
895 # Definitions to make life easier
901 select GENERIC_CLOCKEVENTS
907 select GENERIC_IRQ_CHIP
910 config PLAT_ORION_LEGACY
917 config PLAT_VERSATILE
920 source "arch/arm/firmware/Kconfig"
922 source arch/arm/mm/Kconfig
925 bool "Enable iWMMXt support"
926 depends on CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK || CPU_PJ4 || CPU_PJ4B
927 default y if PXA27x || PXA3xx || ARCH_MMP || CPU_PJ4 || CPU_PJ4B
929 Enable support for iWMMXt context switching at run time if
930 running on a CPU that supports it.
932 config MULTI_IRQ_HANDLER
935 Allow each machine to specify it's own IRQ handler at run time.
938 source "arch/arm/Kconfig-nommu"
941 config PJ4B_ERRATA_4742
942 bool "PJ4B Errata 4742: IDLE Wake Up Commands can Cause the CPU Core to Cease Operation"
943 depends on CPU_PJ4B && MACH_ARMADA_370
946 When coming out of either a Wait for Interrupt (WFI) or a Wait for
947 Event (WFE) IDLE states, a specific timing sensitivity exists between
948 the retiring WFI/WFE instructions and the newly issued subsequent
949 instructions. This sensitivity can result in a CPU hang scenario.
951 The software must insert either a Data Synchronization Barrier (DSB)
952 or Data Memory Barrier (DMB) command immediately after the WFI/WFE
955 config ARM_ERRATA_326103
956 bool "ARM errata: FSR write bit incorrect on a SWP to read-only memory"
959 Executing a SWP instruction to read-only memory does not set bit 11
960 of the FSR on the ARM 1136 prior to r1p0. This causes the kernel to
961 treat the access as a read, preventing a COW from occurring and
962 causing the faulting task to livelock.
964 config ARM_ERRATA_411920
965 bool "ARM errata: Invalidation of the Instruction Cache operation can fail"
966 depends on CPU_V6 || CPU_V6K
968 Invalidation of the Instruction Cache operation can
969 fail. This erratum is present in 1136 (before r1p4), 1156 and 1176.
970 It does not affect the MPCore. This option enables the ARM Ltd.
971 recommended workaround.
973 config ARM_ERRATA_430973
974 bool "ARM errata: Stale prediction on replaced interworking branch"
977 This option enables the workaround for the 430973 Cortex-A8
978 r1p* erratum. If a code sequence containing an ARM/Thumb
979 interworking branch is replaced with another code sequence at the
980 same virtual address, whether due to self-modifying code or virtual
981 to physical address re-mapping, Cortex-A8 does not recover from the
982 stale interworking branch prediction. This results in Cortex-A8
983 executing the new code sequence in the incorrect ARM or Thumb state.
984 The workaround enables the BTB/BTAC operations by setting ACTLR.IBE
985 and also flushes the branch target cache at every context switch.
986 Note that setting specific bits in the ACTLR register may not be
987 available in non-secure mode.
989 config ARM_ERRATA_458693
990 bool "ARM errata: Processor deadlock when a false hazard is created"
992 depends on !ARCH_MULTIPLATFORM
994 This option enables the workaround for the 458693 Cortex-A8 (r2p0)
995 erratum. For very specific sequences of memory operations, it is
996 possible for a hazard condition intended for a cache line to instead
997 be incorrectly associated with a different cache line. This false
998 hazard might then cause a processor deadlock. The workaround enables
999 the L1 caching of the NEON accesses and disables the PLD instruction
1000 in the ACTLR register. Note that setting specific bits in the ACTLR
1001 register may not be available in non-secure mode.
1003 config ARM_ERRATA_460075
1004 bool "ARM errata: Data written to the L2 cache can be overwritten with stale data"
1006 depends on !ARCH_MULTIPLATFORM
1008 This option enables the workaround for the 460075 Cortex-A8 (r2p0)
1009 erratum. Any asynchronous access to the L2 cache may encounter a
1010 situation in which recent store transactions to the L2 cache are lost
1011 and overwritten with stale memory contents from external memory. The
1012 workaround disables the write-allocate mode for the L2 cache via the
1013 ACTLR register. Note that setting specific bits in the ACTLR register
1014 may not be available in non-secure mode.
1016 config ARM_ERRATA_742230
1017 bool "ARM errata: DMB operation may be faulty"
1018 depends on CPU_V7 && SMP
1019 depends on !ARCH_MULTIPLATFORM
1021 This option enables the workaround for the 742230 Cortex-A9
1022 (r1p0..r2p2) erratum. Under rare circumstances, a DMB instruction
1023 between two write operations may not ensure the correct visibility
1024 ordering of the two writes. This workaround sets a specific bit in
1025 the diagnostic register of the Cortex-A9 which causes the DMB
1026 instruction to behave as a DSB, ensuring the correct behaviour of
1029 config ARM_ERRATA_742231
1030 bool "ARM errata: Incorrect hazard handling in the SCU may lead to data corruption"
1031 depends on CPU_V7 && SMP
1032 depends on !ARCH_MULTIPLATFORM
1034 This option enables the workaround for the 742231 Cortex-A9
1035 (r2p0..r2p2) erratum. Under certain conditions, specific to the
1036 Cortex-A9 MPCore micro-architecture, two CPUs working in SMP mode,
1037 accessing some data located in the same cache line, may get corrupted
1038 data due to bad handling of the address hazard when the line gets
1039 replaced from one of the CPUs at the same time as another CPU is
1040 accessing it. This workaround sets specific bits in the diagnostic
1041 register of the Cortex-A9 which reduces the linefill issuing
1042 capabilities of the processor.
1044 config ARM_ERRATA_643719
1045 bool "ARM errata: LoUIS bit field in CLIDR register is incorrect"
1046 depends on CPU_V7 && SMP
1049 This option enables the workaround for the 643719 Cortex-A9 (prior to
1050 r1p0) erratum. On affected cores the LoUIS bit field of the CLIDR
1051 register returns zero when it should return one. The workaround
1052 corrects this value, ensuring cache maintenance operations which use
1053 it behave as intended and avoiding data corruption.
1055 config ARM_ERRATA_720789
1056 bool "ARM errata: TLBIASIDIS and TLBIMVAIS operations can broadcast a faulty ASID"
1059 This option enables the workaround for the 720789 Cortex-A9 (prior to
1060 r2p0) erratum. A faulty ASID can be sent to the other CPUs for the
1061 broadcasted CP15 TLB maintenance operations TLBIASIDIS and TLBIMVAIS.
1062 As a consequence of this erratum, some TLB entries which should be
1063 invalidated are not, resulting in an incoherency in the system page
1064 tables. The workaround changes the TLB flushing routines to invalidate
1065 entries regardless of the ASID.
1067 config ARM_ERRATA_743622
1068 bool "ARM errata: Faulty hazard checking in the Store Buffer may lead to data corruption"
1070 depends on !ARCH_MULTIPLATFORM
1072 This option enables the workaround for the 743622 Cortex-A9
1073 (r2p*) erratum. Under very rare conditions, a faulty
1074 optimisation in the Cortex-A9 Store Buffer may lead to data
1075 corruption. This workaround sets a specific bit in the diagnostic
1076 register of the Cortex-A9 which disables the Store Buffer
1077 optimisation, preventing the defect from occurring. This has no
1078 visible impact on the overall performance or power consumption of the
1081 config ARM_ERRATA_751472
1082 bool "ARM errata: Interrupted ICIALLUIS may prevent completion of broadcasted operation"
1084 depends on !ARCH_MULTIPLATFORM
1086 This option enables the workaround for the 751472 Cortex-A9 (prior
1087 to r3p0) erratum. An interrupted ICIALLUIS operation may prevent the
1088 completion of a following broadcasted operation if the second
1089 operation is received by a CPU before the ICIALLUIS has completed,
1090 potentially leading to corrupted entries in the cache or TLB.
1092 config ARM_ERRATA_754322
1093 bool "ARM errata: possible faulty MMU translations following an ASID switch"
1096 This option enables the workaround for the 754322 Cortex-A9 (r2p*,
1097 r3p*) erratum. A speculative memory access may cause a page table walk
1098 which starts prior to an ASID switch but completes afterwards. This
1099 can populate the micro-TLB with a stale entry which may be hit with
1100 the new ASID. This workaround places two dsb instructions in the mm
1101 switching code so that no page table walks can cross the ASID switch.
1103 config ARM_ERRATA_754327
1104 bool "ARM errata: no automatic Store Buffer drain"
1105 depends on CPU_V7 && SMP
1107 This option enables the workaround for the 754327 Cortex-A9 (prior to
1108 r2p0) erratum. The Store Buffer does not have any automatic draining
1109 mechanism and therefore a livelock may occur if an external agent
1110 continuously polls a memory location waiting to observe an update.
1111 This workaround defines cpu_relax() as smp_mb(), preventing correctly
1112 written polling loops from denying visibility of updates to memory.
1114 config ARM_ERRATA_364296
1115 bool "ARM errata: Possible cache data corruption with hit-under-miss enabled"
1118 This options enables the workaround for the 364296 ARM1136
1119 r0p2 erratum (possible cache data corruption with
1120 hit-under-miss enabled). It sets the undocumented bit 31 in
1121 the auxiliary control register and the FI bit in the control
1122 register, thus disabling hit-under-miss without putting the
1123 processor into full low interrupt latency mode. ARM11MPCore
1126 config ARM_ERRATA_764369
1127 bool "ARM errata: Data cache line maintenance operation by MVA may not succeed"
1128 depends on CPU_V7 && SMP
1130 This option enables the workaround for erratum 764369
1131 affecting Cortex-A9 MPCore with two or more processors (all
1132 current revisions). Under certain timing circumstances, a data
1133 cache line maintenance operation by MVA targeting an Inner
1134 Shareable memory region may fail to proceed up to either the
1135 Point of Coherency or to the Point of Unification of the
1136 system. This workaround adds a DSB instruction before the
1137 relevant cache maintenance functions and sets a specific bit
1138 in the diagnostic control register of the SCU.
1140 config ARM_ERRATA_775420
1141 bool "ARM errata: A data cache maintenance operation which aborts, might lead to deadlock"
1144 This option enables the workaround for the 775420 Cortex-A9 (r2p2,
1145 r2p6,r2p8,r2p10,r3p0) erratum. In case a date cache maintenance
1146 operation aborts with MMU exception, it might cause the processor
1147 to deadlock. This workaround puts DSB before executing ISB if
1148 an abort may occur on cache maintenance.
1150 config ARM_ERRATA_798181
1151 bool "ARM errata: TLBI/DSB failure on Cortex-A15"
1152 depends on CPU_V7 && SMP
1154 On Cortex-A15 (r0p0..r3p2) the TLBI*IS/DSB operations are not
1155 adequately shooting down all use of the old entries. This
1156 option enables the Linux kernel workaround for this erratum
1157 which sends an IPI to the CPUs that are running the same ASID
1158 as the one being invalidated.
1160 config ARM_ERRATA_773022
1161 bool "ARM errata: incorrect instructions may be executed from loop buffer"
1164 This option enables the workaround for the 773022 Cortex-A15
1165 (up to r0p4) erratum. In certain rare sequences of code, the
1166 loop buffer may deliver incorrect instructions. This
1167 workaround disables the loop buffer to avoid the erratum.
1171 source "arch/arm/common/Kconfig"
1178 Find out whether you have ISA slots on your motherboard. ISA is the
1179 name of a bus system, i.e. the way the CPU talks to the other stuff
1180 inside your box. Other bus systems are PCI, EISA, MicroChannel
1181 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1182 newer boards don't support it. If you have ISA, say Y, otherwise N.
1184 # Select ISA DMA controller support
1189 # Select ISA DMA interface
1194 bool "PCI support" if MIGHT_HAVE_PCI
1196 Find out whether you have a PCI motherboard. PCI is the name of a
1197 bus system, i.e. the way the CPU talks to the other stuff inside
1198 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1199 VESA. If you have PCI, say Y, otherwise N.
1205 config PCI_DOMAINS_GENERIC
1206 def_bool PCI_DOMAINS
1208 config PCI_NANOENGINE
1209 bool "BSE nanoEngine PCI support"
1210 depends on SA1100_NANOENGINE
1212 Enable PCI on the BSE nanoEngine board.
1217 config PCI_HOST_ITE8152
1219 depends on PCI && MACH_ARMCORE
1223 source "drivers/pci/Kconfig"
1225 source "drivers/pcmcia/Kconfig"
1229 menu "Kernel Features"
1234 This option should be selected by machines which have an SMP-
1237 The only effect of this option is to make the SMP-related
1238 options available to the user for configuration.
1241 bool "Symmetric Multi-Processing"
1242 depends on CPU_V6K || CPU_V7
1243 depends on GENERIC_CLOCKEVENTS
1245 depends on MMU || ARM_MPU
1248 This enables support for systems with more than one CPU. If you have
1249 a system with only one CPU, say N. If you have a system with more
1250 than one CPU, say Y.
1252 If you say N here, the kernel will run on uni- and multiprocessor
1253 machines, but will use only one CPU of a multiprocessor machine. If
1254 you say Y here, the kernel will run on many, but not all,
1255 uniprocessor machines. On a uniprocessor machine, the kernel
1256 will run faster if you say N here.
1258 See also <file:Documentation/x86/i386/IO-APIC.txt>,
1259 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
1260 <http://tldp.org/HOWTO/SMP-HOWTO.html>.
1262 If you don't know what to do here, say N.
1265 bool "Allow booting SMP kernel on uniprocessor systems"
1266 depends on SMP && !XIP_KERNEL && MMU
1269 SMP kernels contain instructions which fail on non-SMP processors.
1270 Enabling this option allows the kernel to modify itself to make
1271 these instructions safe. Disabling it allows about 1K of space
1274 If you don't know what to do here, say Y.
1276 config ARM_CPU_TOPOLOGY
1277 bool "Support cpu topology definition"
1278 depends on SMP && CPU_V7
1281 Support ARM cpu topology definition. The MPIDR register defines
1282 affinity between processors which is then used to describe the cpu
1283 topology of an ARM System.
1286 bool "Multi-core scheduler support"
1287 depends on ARM_CPU_TOPOLOGY
1289 Multi-core scheduler support improves the CPU scheduler's decision
1290 making when dealing with multi-core CPU chips at a cost of slightly
1291 increased overhead in some places. If unsure say N here.
1294 bool "SMT scheduler support"
1295 depends on ARM_CPU_TOPOLOGY
1297 Improves the CPU scheduler's decision making when dealing with
1298 MultiThreading at a cost of slightly increased overhead in some
1299 places. If unsure say N here.
1304 This option enables support for the ARM system coherency unit
1306 config HAVE_ARM_ARCH_TIMER
1307 bool "Architected timer support"
1309 select ARM_ARCH_TIMER
1310 select GENERIC_CLOCKEVENTS
1312 This option enables support for the ARM architected timer
1316 select CLKSRC_OF if OF
1318 This options enables support for the ARM timer and watchdog unit
1321 bool "Multi-Cluster Power Management"
1322 depends on CPU_V7 && SMP
1324 This option provides the common power management infrastructure
1325 for (multi-)cluster based systems, such as big.LITTLE based
1328 config MCPM_QUAD_CLUSTER
1332 To avoid wasting resources unnecessarily, MCPM only supports up
1333 to 2 clusters by default.
1334 Platforms with 3 or 4 clusters that use MCPM must select this
1335 option to allow the additional clusters to be managed.
1338 bool "big.LITTLE support (Experimental)"
1339 depends on CPU_V7 && SMP
1342 This option enables support selections for the big.LITTLE
1343 system architecture.
1346 bool "big.LITTLE switcher support"
1347 depends on BIG_LITTLE && MCPM && HOTPLUG_CPU && ARM_GIC
1350 The big.LITTLE "switcher" provides the core functionality to
1351 transparently handle transition between a cluster of A15's
1352 and a cluster of A7's in a big.LITTLE system.
1354 config BL_SWITCHER_DUMMY_IF
1355 tristate "Simple big.LITTLE switcher user interface"
1356 depends on BL_SWITCHER && DEBUG_KERNEL
1358 This is a simple and dummy char dev interface to control
1359 the big.LITTLE switcher core code. It is meant for
1360 debugging purposes only.
1363 prompt "Memory split"
1367 Select the desired split between kernel and user memory.
1369 If you are not absolutely sure what you are doing, leave this
1373 bool "3G/1G user/kernel split"
1374 config VMSPLIT_3G_OPT
1375 bool "3G/1G user/kernel split (for full 1G low memory)"
1377 bool "2G/2G user/kernel split"
1379 bool "1G/3G user/kernel split"
1384 default PHYS_OFFSET if !MMU
1385 default 0x40000000 if VMSPLIT_1G
1386 default 0x80000000 if VMSPLIT_2G
1387 default 0xB0000000 if VMSPLIT_3G_OPT
1391 int "Maximum number of CPUs (2-32)"
1397 bool "Support for hot-pluggable CPUs"
1400 Say Y here to experiment with turning CPUs off and on. CPUs
1401 can be controlled through /sys/devices/system/cpu.
1404 bool "Support for the ARM Power State Coordination Interface (PSCI)"
1405 depends on HAVE_ARM_SMCCC
1408 Say Y here if you want Linux to communicate with system firmware
1409 implementing the PSCI specification for CPU-centric power
1410 management operations described in ARM document number ARM DEN
1411 0022A ("Power State Coordination Interface System Software on
1414 # The GPIO number here must be sorted by descending number. In case of
1415 # a multiplatform kernel, we just want the highest value required by the
1416 # selected platforms.
1419 default 1024 if ARCH_BRCMSTB || ARCH_SHMOBILE || ARCH_TEGRA || \
1421 default 512 if ARCH_EXYNOS || ARCH_KEYSTONE || SOC_OMAP5 || \
1422 SOC_DRA7XX || ARCH_S3C24XX || ARCH_S3C64XX || ARCH_S5PV210
1423 default 416 if ARCH_SUNXI
1424 default 392 if ARCH_U8500
1425 default 352 if ARCH_VT8500
1426 default 288 if ARCH_ROCKCHIP
1427 default 264 if MACH_H4700
1430 Maximum number of GPIOs in the system.
1432 If unsure, leave the default value.
1434 source kernel/Kconfig.preempt
1438 default 200 if ARCH_EBSA110 || ARCH_S3C24XX || \
1439 ARCH_S5PV210 || ARCH_EXYNOS4
1440 default 128 if SOC_AT91RM9200
1444 depends on HZ_FIXED = 0
1445 prompt "Timer frequency"
1469 default HZ_FIXED if HZ_FIXED != 0
1470 default 100 if HZ_100
1471 default 200 if HZ_200
1472 default 250 if HZ_250
1473 default 300 if HZ_300
1474 default 500 if HZ_500
1478 def_bool HIGH_RES_TIMERS
1480 config THUMB2_KERNEL
1481 bool "Compile the kernel in Thumb-2 mode" if !CPU_THUMBONLY
1482 depends on (CPU_V7 || CPU_V7M) && !CPU_V6 && !CPU_V6K
1483 default y if CPU_THUMBONLY
1485 select ARM_ASM_UNIFIED
1488 By enabling this option, the kernel will be compiled in
1489 Thumb-2 mode. A compiler/assembler that understand the unified
1490 ARM-Thumb syntax is needed.
1494 config THUMB2_AVOID_R_ARM_THM_JUMP11
1495 bool "Work around buggy Thumb-2 short branch relocations in gas"
1496 depends on THUMB2_KERNEL && MODULES
1499 Various binutils versions can resolve Thumb-2 branches to
1500 locally-defined, preemptible global symbols as short-range "b.n"
1501 branch instructions.
1503 This is a problem, because there's no guarantee the final
1504 destination of the symbol, or any candidate locations for a
1505 trampoline, are within range of the branch. For this reason, the
1506 kernel does not support fixing up the R_ARM_THM_JUMP11 (102)
1507 relocation in modules at all, and it makes little sense to add
1510 The symptom is that the kernel fails with an "unsupported
1511 relocation" error when loading some modules.
1513 Until fixed tools are available, passing
1514 -fno-optimize-sibling-calls to gcc should prevent gcc generating
1515 code which hits this problem, at the cost of a bit of extra runtime
1516 stack usage in some cases.
1518 The problem is described in more detail at:
1519 https://bugs.launchpad.net/binutils-linaro/+bug/725126
1521 Only Thumb-2 kernels are affected.
1523 Unless you are sure your tools don't have this problem, say Y.
1525 config ARM_ASM_UNIFIED
1528 config ARM_PATCH_IDIV
1529 bool "Runtime patch udiv/sdiv instructions into __aeabi_{u}idiv()"
1530 depends on CPU_32v7 && !XIP_KERNEL
1533 The ARM compiler inserts calls to __aeabi_idiv() and
1534 __aeabi_uidiv() when it needs to perform division on signed
1535 and unsigned integers. Some v7 CPUs have support for the sdiv
1536 and udiv instructions that can be used to implement those
1539 Enabling this option allows the kernel to modify itself to
1540 replace the first two instructions of these library functions
1541 with the sdiv or udiv plus "bx lr" instructions when the CPU
1542 it is running on supports them. Typically this will be faster
1543 and less power intensive than running the original library
1544 code to do integer division.
1547 bool "Use the ARM EABI to compile the kernel"
1549 This option allows for the kernel to be compiled using the latest
1550 ARM ABI (aka EABI). This is only useful if you are using a user
1551 space environment that is also compiled with EABI.
1553 Since there are major incompatibilities between the legacy ABI and
1554 EABI, especially with regard to structure member alignment, this
1555 option also changes the kernel syscall calling convention to
1556 disambiguate both ABIs and allow for backward compatibility support
1557 (selected with CONFIG_OABI_COMPAT).
1559 To use this you need GCC version 4.0.0 or later.
1562 bool "Allow old ABI binaries to run with this kernel (EXPERIMENTAL)"
1563 depends on AEABI && !THUMB2_KERNEL
1565 This option preserves the old syscall interface along with the
1566 new (ARM EABI) one. It also provides a compatibility layer to
1567 intercept syscalls that have structure arguments which layout
1568 in memory differs between the legacy ABI and the new ARM EABI
1569 (only for non "thumb" binaries). This option adds a tiny
1570 overhead to all syscalls and produces a slightly larger kernel.
1572 The seccomp filter system will not be available when this is
1573 selected, since there is no way yet to sensibly distinguish
1574 between calling conventions during filtering.
1576 If you know you'll be using only pure EABI user space then you
1577 can say N here. If this option is not selected and you attempt
1578 to execute a legacy ABI binary then the result will be
1579 UNPREDICTABLE (in fact it can be predicted that it won't work
1580 at all). If in doubt say N.
1582 config ARCH_HAS_HOLES_MEMORYMODEL
1585 config ARCH_SPARSEMEM_ENABLE
1588 config ARCH_SPARSEMEM_DEFAULT
1589 def_bool ARCH_SPARSEMEM_ENABLE
1591 config ARCH_SELECT_MEMORY_MODEL
1592 def_bool ARCH_SPARSEMEM_ENABLE
1594 config HAVE_ARCH_PFN_VALID
1595 def_bool ARCH_HAS_HOLES_MEMORYMODEL || !SPARSEMEM
1597 config HAVE_GENERIC_RCU_GUP
1602 bool "High Memory Support"
1605 The address space of ARM processors is only 4 Gigabytes large
1606 and it has to accommodate user address space, kernel address
1607 space as well as some memory mapped IO. That means that, if you
1608 have a large amount of physical memory and/or IO, not all of the
1609 memory can be "permanently mapped" by the kernel. The physical
1610 memory that is not permanently mapped is called "high memory".
1612 Depending on the selected kernel/user memory split, minimum
1613 vmalloc space and actual amount of RAM, you may not need this
1614 option which should result in a slightly faster kernel.
1619 bool "Allocate 2nd-level pagetables from highmem" if EXPERT
1623 The VM uses one page of physical memory for each page table.
1624 For systems with a lot of processes, this can use a lot of
1625 precious low memory, eventually leading to low memory being
1626 consumed by page tables. Setting this option will allow
1627 user-space 2nd level page tables to reside in high memory.
1629 config CPU_SW_DOMAIN_PAN
1630 bool "Enable use of CPU domains to implement privileged no-access"
1631 depends on MMU && !ARM_LPAE
1634 Increase kernel security by ensuring that normal kernel accesses
1635 are unable to access userspace addresses. This can help prevent
1636 use-after-free bugs becoming an exploitable privilege escalation
1637 by ensuring that magic values (such as LIST_POISON) will always
1638 fault when dereferenced.
1640 CPUs with low-vector mappings use a best-efforts implementation.
1641 Their lower 1MB needs to remain accessible for the vectors, but
1642 the remainder of userspace will become appropriately inaccessible.
1644 config HW_PERF_EVENTS
1648 config SYS_SUPPORTS_HUGETLBFS
1652 config HAVE_ARCH_TRANSPARENT_HUGEPAGE
1656 config ARCH_WANT_GENERAL_HUGETLB
1659 config ARM_MODULE_PLTS
1660 bool "Use PLTs to allow module memory to spill over into vmalloc area"
1663 Allocate PLTs when loading modules so that jumps and calls whose
1664 targets are too far away for their relative offsets to be encoded
1665 in the instructions themselves can be bounced via veneers in the
1666 module's PLT. This allows modules to be allocated in the generic
1667 vmalloc area after the dedicated module memory area has been
1668 exhausted. The modules will use slightly more memory, but after
1669 rounding up to page size, the actual memory footprint is usually
1672 Say y if you are getting out of memory errors while loading modules
1676 config FORCE_MAX_ZONEORDER
1677 int "Maximum zone order"
1678 default "12" if SOC_AM33XX
1679 default "9" if SA1111 || ARCH_EFM32
1682 The kernel memory allocator divides physically contiguous memory
1683 blocks into "zones", where each zone is a power of two number of
1684 pages. This option selects the largest power of two that the kernel
1685 keeps in the memory allocator. If you need to allocate very large
1686 blocks of physically contiguous memory, then you may need to
1687 increase this value.
1689 This config option is actually maximum order plus one. For example,
1690 a value of 11 means that the largest free memory block is 2^10 pages.
1692 config ALIGNMENT_TRAP
1694 depends on CPU_CP15_MMU
1695 default y if !ARCH_EBSA110
1696 select HAVE_PROC_CPU if PROC_FS
1698 ARM processors cannot fetch/store information which is not
1699 naturally aligned on the bus, i.e., a 4 byte fetch must start at an
1700 address divisible by 4. On 32-bit ARM processors, these non-aligned
1701 fetch/store instructions will be emulated in software if you say
1702 here, which has a severe performance impact. This is necessary for
1703 correct operation of some network protocols. With an IP-only
1704 configuration it is safe to say N, otherwise say Y.
1706 config UACCESS_WITH_MEMCPY
1707 bool "Use kernel mem{cpy,set}() for {copy_to,clear}_user()"
1709 default y if CPU_FEROCEON
1711 Implement faster copy_to_user and clear_user methods for CPU
1712 cores where a 8-word STM instruction give significantly higher
1713 memory write throughput than a sequence of individual 32bit stores.
1715 A possible side effect is a slight increase in scheduling latency
1716 between threads sharing the same address space if they invoke
1717 such copy operations with large buffers.
1719 However, if the CPU data cache is using a write-allocate mode,
1720 this option is unlikely to provide any performance gain.
1724 prompt "Enable seccomp to safely compute untrusted bytecode"
1726 This kernel feature is useful for number crunching applications
1727 that may need to compute untrusted bytecode during their
1728 execution. By using pipes or other transports made available to
1729 the process as file descriptors supporting the read/write
1730 syscalls, it's possible to isolate those applications in
1731 their own address space using seccomp. Once seccomp is
1732 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1733 and the task is only allowed to execute a few safe syscalls
1734 defined by each seccomp mode.
1743 bool "Enable paravirtualization code"
1745 This changes the kernel so it can modify itself when it is run
1746 under a hypervisor, potentially improving performance significantly
1747 over full virtualization.
1749 config PARAVIRT_TIME_ACCOUNTING
1750 bool "Paravirtual steal time accounting"
1754 Select this option to enable fine granularity task steal time
1755 accounting. Time spent executing other tasks in parallel with
1756 the current vCPU is discounted from the vCPU power. To account for
1757 that, there can be a small performance impact.
1759 If in doubt, say N here.
1766 bool "Xen guest support on ARM"
1767 depends on ARM && AEABI && OF
1768 depends on CPU_V7 && !CPU_V6
1769 depends on !GENERIC_ATOMIC64
1771 select ARCH_DMA_ADDR_T_64BIT
1776 Say Y if you want to run Linux in a Virtual Machine on Xen on ARM.
1783 bool "Flattened Device Tree support"
1787 Include support for flattened device tree machine descriptions.
1790 bool "Support for the traditional ATAGS boot data passing" if USE_OF
1793 This is the traditional way of passing data to the kernel at boot
1794 time. If you are solely relying on the flattened device tree (or
1795 the ARM_ATAG_DTB_COMPAT option) then you may unselect this option
1796 to remove ATAGS support from your kernel binary. If unsure,
1799 config DEPRECATED_PARAM_STRUCT
1800 bool "Provide old way to pass kernel parameters"
1803 This was deprecated in 2001 and announced to live on for 5 years.
1804 Some old boot loaders still use this way.
1806 # Compressed boot loader in ROM. Yes, we really want to ask about
1807 # TEXT and BSS so we preserve their values in the config files.
1808 config ZBOOT_ROM_TEXT
1809 hex "Compressed ROM boot loader base address"
1812 The physical address at which the ROM-able zImage is to be
1813 placed in the target. Platforms which normally make use of
1814 ROM-able zImage formats normally set this to a suitable
1815 value in their defconfig file.
1817 If ZBOOT_ROM is not enabled, this has no effect.
1819 config ZBOOT_ROM_BSS
1820 hex "Compressed ROM boot loader BSS address"
1823 The base address of an area of read/write memory in the target
1824 for the ROM-able zImage which must be available while the
1825 decompressor is running. It must be large enough to hold the
1826 entire decompressed kernel plus an additional 128 KiB.
1827 Platforms which normally make use of ROM-able zImage formats
1828 normally set this to a suitable value in their defconfig file.
1830 If ZBOOT_ROM is not enabled, this has no effect.
1833 bool "Compressed boot loader in ROM/flash"
1834 depends on ZBOOT_ROM_TEXT != ZBOOT_ROM_BSS
1835 depends on !ARM_APPENDED_DTB && !XIP_KERNEL && !AUTO_ZRELADDR
1837 Say Y here if you intend to execute your compressed kernel image
1838 (zImage) directly from ROM or flash. If unsure, say N.
1840 config ARM_APPENDED_DTB
1841 bool "Use appended device tree blob to zImage (EXPERIMENTAL)"
1844 With this option, the boot code will look for a device tree binary
1845 (DTB) appended to zImage
1846 (e.g. cat zImage <filename>.dtb > zImage_w_dtb).
1848 This is meant as a backward compatibility convenience for those
1849 systems with a bootloader that can't be upgraded to accommodate
1850 the documented boot protocol using a device tree.
1852 Beware that there is very little in terms of protection against
1853 this option being confused by leftover garbage in memory that might
1854 look like a DTB header after a reboot if no actual DTB is appended
1855 to zImage. Do not leave this option active in a production kernel
1856 if you don't intend to always append a DTB. Proper passing of the
1857 location into r2 of a bootloader provided DTB is always preferable
1860 config ARM_ATAG_DTB_COMPAT
1861 bool "Supplement the appended DTB with traditional ATAG information"
1862 depends on ARM_APPENDED_DTB
1864 Some old bootloaders can't be updated to a DTB capable one, yet
1865 they provide ATAGs with memory configuration, the ramdisk address,
1866 the kernel cmdline string, etc. Such information is dynamically
1867 provided by the bootloader and can't always be stored in a static
1868 DTB. To allow a device tree enabled kernel to be used with such
1869 bootloaders, this option allows zImage to extract the information
1870 from the ATAG list and store it at run time into the appended DTB.
1873 prompt "Kernel command line type" if ARM_ATAG_DTB_COMPAT
1874 default ARM_ATAG_DTB_COMPAT_CMDLINE_FROM_BOOTLOADER
1876 config ARM_ATAG_DTB_COMPAT_CMDLINE_FROM_BOOTLOADER
1877 bool "Use bootloader kernel arguments if available"
1879 Uses the command-line options passed by the boot loader instead of
1880 the device tree bootargs property. If the boot loader doesn't provide
1881 any, the device tree bootargs property will be used.
1883 config ARM_ATAG_DTB_COMPAT_CMDLINE_EXTEND
1884 bool "Extend with bootloader kernel arguments"
1886 The command-line arguments provided by the boot loader will be
1887 appended to the the device tree bootargs property.
1892 string "Default kernel command string"
1895 On some architectures (EBSA110 and CATS), there is currently no way
1896 for the boot loader to pass arguments to the kernel. For these
1897 architectures, you should supply some command-line options at build
1898 time by entering them here. As a minimum, you should specify the
1899 memory size and the root device (e.g., mem=64M root=/dev/nfs).
1902 prompt "Kernel command line type" if CMDLINE != ""
1903 default CMDLINE_FROM_BOOTLOADER
1906 config CMDLINE_FROM_BOOTLOADER
1907 bool "Use bootloader kernel arguments if available"
1909 Uses the command-line options passed by the boot loader. If
1910 the boot loader doesn't provide any, the default kernel command
1911 string provided in CMDLINE will be used.
1913 config CMDLINE_EXTEND
1914 bool "Extend bootloader kernel arguments"
1916 The command-line arguments provided by the boot loader will be
1917 appended to the default kernel command string.
1919 config CMDLINE_FORCE
1920 bool "Always use the default kernel command string"
1922 Always use the default kernel command string, even if the boot
1923 loader passes other arguments to the kernel.
1924 This is useful if you cannot or don't want to change the
1925 command-line options your boot loader passes to the kernel.
1929 bool "Kernel Execute-In-Place from ROM"
1930 depends on !ARM_LPAE && !ARCH_MULTIPLATFORM
1932 Execute-In-Place allows the kernel to run from non-volatile storage
1933 directly addressable by the CPU, such as NOR flash. This saves RAM
1934 space since the text section of the kernel is not loaded from flash
1935 to RAM. Read-write sections, such as the data section and stack,
1936 are still copied to RAM. The XIP kernel is not compressed since
1937 it has to run directly from flash, so it will take more space to
1938 store it. The flash address used to link the kernel object files,
1939 and for storing it, is configuration dependent. Therefore, if you
1940 say Y here, you must know the proper physical address where to
1941 store the kernel image depending on your own flash memory usage.
1943 Also note that the make target becomes "make xipImage" rather than
1944 "make zImage" or "make Image". The final kernel binary to put in
1945 ROM memory will be arch/arm/boot/xipImage.
1949 config XIP_PHYS_ADDR
1950 hex "XIP Kernel Physical Location"
1951 depends on XIP_KERNEL
1952 default "0x00080000"
1954 This is the physical address in your flash memory the kernel will
1955 be linked for and stored to. This address is dependent on your
1959 bool "Kexec system call (EXPERIMENTAL)"
1960 depends on (!SMP || PM_SLEEP_SMP)
1964 kexec is a system call that implements the ability to shutdown your
1965 current kernel, and to start another kernel. It is like a reboot
1966 but it is independent of the system firmware. And like a reboot
1967 you can start any kernel with it, not just Linux.
1969 It is an ongoing process to be certain the hardware in a machine
1970 is properly shutdown, so do not be surprised if this code does not
1971 initially work for you.
1974 bool "Export atags in procfs"
1975 depends on ATAGS && KEXEC
1978 Should the atags used to boot the kernel be exported in an "atags"
1979 file in procfs. Useful with kexec.
1982 bool "Build kdump crash kernel (EXPERIMENTAL)"
1984 Generate crash dump after being started by kexec. This should
1985 be normally only set in special crash dump kernels which are
1986 loaded in the main kernel with kexec-tools into a specially
1987 reserved region and then later executed after a crash by
1988 kdump/kexec. The crash dump kernel must be compiled to a
1989 memory address not used by the main kernel
1991 For more details see Documentation/kdump/kdump.txt
1993 config AUTO_ZRELADDR
1994 bool "Auto calculation of the decompressed kernel image address"
1996 ZRELADDR is the physical address where the decompressed kernel
1997 image will be placed. If AUTO_ZRELADDR is selected, the address
1998 will be determined at run-time by masking the current IP with
1999 0xf8000000. This assumes the zImage being placed in the first 128MB
2000 from start of memory.
2006 bool "UEFI runtime support"
2007 depends on OF && !CPU_BIG_ENDIAN && MMU && AUTO_ZRELADDR && !XIP_KERNEL
2009 select EFI_PARAMS_FROM_FDT
2012 select EFI_RUNTIME_WRAPPERS
2014 This option provides support for runtime services provided
2015 by UEFI firmware (such as non-volatile variables, realtime
2016 clock, and platform reset). A UEFI stub is also provided to
2017 allow the kernel to be booted as an EFI application. This
2018 is only useful for kernels that may run on systems that have
2023 menu "CPU Power Management"
2025 source "drivers/cpufreq/Kconfig"
2027 source "drivers/cpuidle/Kconfig"
2031 menu "Floating point emulation"
2033 comment "At least one emulation must be selected"
2036 bool "NWFPE math emulation"
2037 depends on (!AEABI || OABI_COMPAT) && !THUMB2_KERNEL
2039 Say Y to include the NWFPE floating point emulator in the kernel.
2040 This is necessary to run most binaries. Linux does not currently
2041 support floating point hardware so you need to say Y here even if
2042 your machine has an FPA or floating point co-processor podule.
2044 You may say N here if you are going to load the Acorn FPEmulator
2045 early in the bootup.
2048 bool "Support extended precision"
2049 depends on FPE_NWFPE
2051 Say Y to include 80-bit support in the kernel floating-point
2052 emulator. Otherwise, only 32 and 64-bit support is compiled in.
2053 Note that gcc does not generate 80-bit operations by default,
2054 so in most cases this option only enlarges the size of the
2055 floating point emulator without any good reason.
2057 You almost surely want to say N here.
2060 bool "FastFPE math emulation (EXPERIMENTAL)"
2061 depends on (!AEABI || OABI_COMPAT) && !CPU_32v3
2063 Say Y here to include the FAST floating point emulator in the kernel.
2064 This is an experimental much faster emulator which now also has full
2065 precision for the mantissa. It does not support any exceptions.
2066 It is very simple, and approximately 3-6 times faster than NWFPE.
2068 It should be sufficient for most programs. It may be not suitable
2069 for scientific calculations, but you have to check this for yourself.
2070 If you do not feel you need a faster FP emulation you should better
2074 bool "VFP-format floating point maths"
2075 depends on CPU_V6 || CPU_V6K || CPU_ARM926T || CPU_V7 || CPU_FEROCEON
2077 Say Y to include VFP support code in the kernel. This is needed
2078 if your hardware includes a VFP unit.
2080 Please see <file:Documentation/arm/VFP/release-notes.txt> for
2081 release notes and additional status information.
2083 Say N if your target does not have VFP hardware.
2091 bool "Advanced SIMD (NEON) Extension support"
2092 depends on VFPv3 && CPU_V7
2094 Say Y to include support code for NEON, the ARMv7 Advanced SIMD
2097 config KERNEL_MODE_NEON
2098 bool "Support for NEON in kernel mode"
2099 depends on NEON && AEABI
2101 Say Y to include support for NEON in kernel mode.
2105 menu "Userspace binary formats"
2107 source "fs/Kconfig.binfmt"
2111 menu "Power management options"
2113 source "kernel/power/Kconfig"
2115 config ARCH_SUSPEND_POSSIBLE
2116 depends on CPU_ARM920T || CPU_ARM926T || CPU_FEROCEON || CPU_SA1100 || \
2117 CPU_V6 || CPU_V6K || CPU_V7 || CPU_V7M || CPU_XSC3 || CPU_XSCALE || CPU_MOHAWK
2120 config ARM_CPU_SUSPEND
2121 def_bool PM_SLEEP || BL_SWITCHER || ARM_PSCI_FW
2122 depends on ARCH_SUSPEND_POSSIBLE
2124 config ARCH_HIBERNATION_POSSIBLE
2127 default y if ARCH_SUSPEND_POSSIBLE
2131 source "net/Kconfig"
2133 source "drivers/Kconfig"
2135 source "drivers/firmware/Kconfig"
2139 source "arch/arm/Kconfig.debug"
2141 source "security/Kconfig"
2143 source "crypto/Kconfig"
2145 source "arch/arm/crypto/Kconfig"
2148 source "lib/Kconfig"
2150 source "arch/arm/kvm/Kconfig"