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_EXIT_THREAD
54 select HAVE_FTRACE_MCOUNT_RECORD if (!XIP_KERNEL)
55 select HAVE_FUNCTION_GRAPH_TRACER if (!THUMB2_KERNEL)
56 select HAVE_FUNCTION_TRACER if (!XIP_KERNEL)
57 select HAVE_GCC_PLUGINS
58 select HAVE_GENERIC_DMA_COHERENT
59 select HAVE_HW_BREAKPOINT if (PERF_EVENTS && (CPU_V6 || CPU_V6K || CPU_V7))
60 select HAVE_IDE if PCI || ISA || PCMCIA
61 select HAVE_IRQ_TIME_ACCOUNTING
62 select HAVE_KERNEL_GZIP
63 select HAVE_KERNEL_LZ4
64 select HAVE_KERNEL_LZMA
65 select HAVE_KERNEL_LZO
67 select HAVE_KPROBES if !XIP_KERNEL && !CPU_ENDIAN_BE32 && !CPU_V7M
68 select HAVE_KRETPROBES if (HAVE_KPROBES)
70 select HAVE_MOD_ARCH_SPECIFIC
72 select HAVE_OPROFILE if (HAVE_PERF_EVENTS)
73 select HAVE_OPTPROBES if !THUMB2_KERNEL
74 select HAVE_PERF_EVENTS
76 select HAVE_PERF_USER_STACK_DUMP
77 select HAVE_RCU_TABLE_FREE if (SMP && ARM_LPAE)
78 select HAVE_REGS_AND_STACK_ACCESS_API
79 select HAVE_SYSCALL_TRACEPOINTS
81 select HAVE_VIRT_CPU_ACCOUNTING_GEN
82 select IRQ_FORCED_THREADING
83 select MODULES_USE_ELF_REL
85 select OF_EARLY_FLATTREE if OF
86 select OF_RESERVED_MEM if OF
88 select OLD_SIGSUSPEND3
89 select PERF_USE_VMALLOC
91 select SYS_SUPPORTS_APM_EMULATION
92 # Above selects are sorted alphabetically; please add new ones
93 # according to that. Thanks.
95 The ARM series is a line of low-power-consumption RISC chip designs
96 licensed by ARM Ltd and targeted at embedded applications and
97 handhelds such as the Compaq IPAQ. ARM-based PCs are no longer
98 manufactured, but legacy ARM-based PC hardware remains popular in
99 Europe. There is an ARM Linux project with a web page at
100 <http://www.arm.linux.org.uk/>.
102 config ARM_HAS_SG_CHAIN
103 select ARCH_HAS_SG_CHAIN
106 config NEED_SG_DMA_LENGTH
109 config ARM_DMA_USE_IOMMU
111 select ARM_HAS_SG_CHAIN
112 select NEED_SG_DMA_LENGTH
116 config ARM_DMA_IOMMU_ALIGNMENT
117 int "Maximum PAGE_SIZE order of alignment for DMA IOMMU buffers"
121 DMA mapping framework by default aligns all buffers to the smallest
122 PAGE_SIZE order which is greater than or equal to the requested buffer
123 size. This works well for buffers up to a few hundreds kilobytes, but
124 for larger buffers it just a waste of address space. Drivers which has
125 relatively small addressing window (like 64Mib) might run out of
126 virtual space with just a few allocations.
128 With this parameter you can specify the maximum PAGE_SIZE order for
129 DMA IOMMU buffers. Larger buffers will be aligned only to this
130 specified order. The order is expressed as a power of two multiplied
135 config MIGHT_HAVE_PCI
138 config SYS_SUPPORTS_APM_EMULATION
143 select GENERIC_ALLOCATOR
154 The Extended Industry Standard Architecture (EISA) bus was
155 developed as an open alternative to the IBM MicroChannel bus.
157 The EISA bus provided some of the features of the IBM MicroChannel
158 bus while maintaining backward compatibility with cards made for
159 the older ISA bus. The EISA bus saw limited use between 1988 and
160 1995 when it was made obsolete by the PCI bus.
162 Say Y here if you are building a kernel for an EISA-based machine.
169 config STACKTRACE_SUPPORT
173 config LOCKDEP_SUPPORT
177 config TRACE_IRQFLAGS_SUPPORT
181 config RWSEM_XCHGADD_ALGORITHM
185 config ARCH_HAS_ILOG2_U32
188 config ARCH_HAS_ILOG2_U64
191 config ARCH_HAS_BANDGAP
194 config FIX_EARLYCON_MEM
197 config GENERIC_HWEIGHT
201 config GENERIC_CALIBRATE_DELAY
205 config ARCH_MAY_HAVE_PC_FDC
211 config NEED_DMA_MAP_STATE
214 config ARCH_SUPPORTS_UPROBES
217 config ARCH_HAS_DMA_SET_COHERENT_MASK
220 config GENERIC_ISA_DMA
226 config NEED_RET_TO_USER
234 default 0xffff0000 if MMU || CPU_HIGH_VECTOR
235 default DRAM_BASE if REMAP_VECTORS_TO_RAM
238 The base address of exception vectors. This must be two pages
241 config ARM_PATCH_PHYS_VIRT
242 bool "Patch physical to virtual translations at runtime" if EMBEDDED
244 depends on !XIP_KERNEL && MMU
246 Patch phys-to-virt and virt-to-phys translation functions at
247 boot and module load time according to the position of the
248 kernel in system memory.
250 This can only be used with non-XIP MMU kernels where the base
251 of physical memory is at a 16MB boundary.
253 Only disable this option if you know that you do not require
254 this feature (eg, building a kernel for a single machine) and
255 you need to shrink the kernel to the minimal size.
257 config NEED_MACH_IO_H
260 Select this when mach/io.h is required to provide special
261 definitions for this platform. The need for mach/io.h should
262 be avoided when possible.
264 config NEED_MACH_MEMORY_H
267 Select this when mach/memory.h is required to provide special
268 definitions for this platform. The need for mach/memory.h should
269 be avoided when possible.
272 hex "Physical address of main memory" if MMU
273 depends on !ARM_PATCH_PHYS_VIRT
274 default DRAM_BASE if !MMU
275 default 0x00000000 if ARCH_EBSA110 || \
280 (ARCH_REALVIEW && !REALVIEW_HIGH_PHYS_OFFSET)
281 default 0x10000000 if ARCH_OMAP1 || ARCH_RPC
282 default 0x20000000 if ARCH_S5PV210
283 default 0x70000000 if REALVIEW_HIGH_PHYS_OFFSET
284 default 0xc0000000 if ARCH_SA1100
286 Please provide the physical address corresponding to the
287 location of main memory in your system.
293 config PGTABLE_LEVELS
295 default 3 if ARM_LPAE
298 source "init/Kconfig"
300 source "kernel/Kconfig.freezer"
305 bool "MMU-based Paged Memory Management Support"
308 Select if you want MMU-based virtualised addressing space
309 support by paged memory management. If unsure, say 'Y'.
311 config ARCH_MMAP_RND_BITS_MIN
314 config ARCH_MMAP_RND_BITS_MAX
315 default 14 if PAGE_OFFSET=0x40000000
316 default 15 if PAGE_OFFSET=0x80000000
320 # The "ARM system type" choice list is ordered alphabetically by option
321 # text. Please add new entries in the option alphabetic order.
324 prompt "ARM system type"
325 default ARM_SINGLE_ARMV7M if !MMU
326 default ARCH_MULTIPLATFORM if MMU
328 config ARCH_MULTIPLATFORM
329 bool "Allow multiple platforms to be selected"
331 select ARM_HAS_SG_CHAIN
332 select ARM_PATCH_PHYS_VIRT
336 select GENERIC_CLOCKEVENTS
337 select MIGHT_HAVE_PCI
338 select MULTI_IRQ_HANDLER
342 config ARM_SINGLE_ARMV7M
343 bool "ARMv7-M based platforms (Cortex-M0/M3/M4)"
350 select GENERIC_CLOCKEVENTS
356 bool "Cortina Systems Gemini"
359 select GENERIC_CLOCKEVENTS
362 Support for the Cortina Systems Gemini family SoCs
366 select ARCH_USES_GETTIMEOFFSET
369 select NEED_MACH_IO_H
370 select NEED_MACH_MEMORY_H
373 This is an evaluation board for the StrongARM processor available
374 from Digital. It has limited hardware on-board, including an
375 Ethernet interface, two PCMCIA sockets, two serial ports and a
380 select ARCH_HAS_HOLES_MEMORYMODEL
382 select ARM_PATCH_PHYS_VIRT
388 select GENERIC_CLOCKEVENTS
391 This enables support for the Cirrus EP93xx series of CPUs.
393 config ARCH_FOOTBRIDGE
397 select GENERIC_CLOCKEVENTS
399 select NEED_MACH_IO_H if !MMU
400 select NEED_MACH_MEMORY_H
402 Support for systems based on the DC21285 companion chip
403 ("FootBridge"), such as the Simtec CATS and the Rebel NetWinder.
406 bool "Hilscher NetX based"
410 select GENERIC_CLOCKEVENTS
412 This enables support for systems based on the Hilscher NetX Soc
418 select NEED_MACH_MEMORY_H
419 select NEED_RET_TO_USER
425 Support for Intel's IOP13XX (XScale) family of processors.
433 select NEED_RET_TO_USER
437 Support for Intel's 80219 and IOP32X (XScale) family of
446 select NEED_RET_TO_USER
450 Support for Intel's IOP33X (XScale) family of processors.
455 select ARCH_HAS_DMA_SET_COHERENT_MASK
456 select ARCH_SUPPORTS_BIG_ENDIAN
459 select DMABOUNCE if PCI
460 select GENERIC_CLOCKEVENTS
462 select MIGHT_HAVE_PCI
463 select NEED_MACH_IO_H
464 select USB_EHCI_BIG_ENDIAN_DESC
465 select USB_EHCI_BIG_ENDIAN_MMIO
467 Support for Intel's IXP4XX (XScale) family of processors.
472 select GENERIC_CLOCKEVENTS
474 select MIGHT_HAVE_PCI
475 select MULTI_IRQ_HANDLER
479 select PLAT_ORION_LEGACY
481 select PM_GENERIC_DOMAINS if PM
483 Support for the Marvell Dove SoC 88AP510
486 bool "Micrel/Kendin KS8695"
489 select GENERIC_CLOCKEVENTS
491 select NEED_MACH_MEMORY_H
493 Support for Micrel/Kendin KS8695 "Centaur" (ARM922T) based
494 System-on-Chip devices.
497 bool "Nuvoton W90X900 CPU"
501 select GENERIC_CLOCKEVENTS
504 Support for Nuvoton (Winbond logic dept.) ARM9 processor,
505 At present, the w90x900 has been renamed nuc900, regarding
506 the ARM series product line, you can login the following
507 link address to know more.
509 <http://www.nuvoton.com/hq/enu/ProductAndSales/ProductLines/
510 ConsumerElectronicsIC/ARMMicrocontroller/ARMMicrocontroller>
516 select CLKSRC_LPC32XX
519 select GENERIC_CLOCKEVENTS
521 select MULTI_IRQ_HANDLER
525 Support for the NXP LPC32XX family of processors
528 bool "PXA2xx/PXA3xx-based"
531 select ARM_CPU_SUSPEND if PM
538 select CPU_XSCALE if !CPU_XSC3
539 select GENERIC_CLOCKEVENTS
544 select MULTI_IRQ_HANDLER
548 Support for Intel/Marvell's PXA2xx/PXA3xx processor line.
554 select ARCH_MAY_HAVE_PC_FDC
555 select ARCH_SPARSEMEM_ENABLE
556 select ARCH_USES_GETTIMEOFFSET
560 select HAVE_PATA_PLATFORM
562 select NEED_MACH_IO_H
563 select NEED_MACH_MEMORY_H
566 On the Acorn Risc-PC, Linux can support the internal IDE disk and
567 CD-ROM interface, serial and parallel port, and the floppy drive.
572 select ARCH_SPARSEMEM_ENABLE
576 select CLKSRC_OF if OF
579 select GENERIC_CLOCKEVENTS
584 select MULTI_IRQ_HANDLER
585 select NEED_MACH_MEMORY_H
588 Support for StrongARM 11x0 based boards.
591 bool "Samsung S3C24XX SoCs"
594 select CLKSRC_SAMSUNG_PWM
595 select GENERIC_CLOCKEVENTS
598 select HAVE_S3C2410_I2C if I2C
599 select HAVE_S3C2410_WATCHDOG if WATCHDOG
600 select HAVE_S3C_RTC if RTC_CLASS
601 select MULTI_IRQ_HANDLER
602 select NEED_MACH_IO_H
605 Samsung S3C2410, S3C2412, S3C2413, S3C2416, S3C2440, S3C2442, S3C2443
606 and S3C2450 SoCs based systems, such as the Simtec Electronics BAST
607 (<http://www.simtec.co.uk/products/EB110ITX/>), the IPAQ 1940 or the
608 Samsung SMDK2410 development board (and derivatives).
612 select ARCH_HAS_HOLES_MEMORYMODEL
615 select GENERIC_ALLOCATOR
616 select GENERIC_CLOCKEVENTS
617 select GENERIC_IRQ_CHIP
623 Support for TI's DaVinci platform.
628 select ARCH_HAS_HOLES_MEMORYMODEL
632 select GENERIC_CLOCKEVENTS
633 select GENERIC_IRQ_CHIP
637 select MULTI_IRQ_HANDLER
638 select NEED_MACH_IO_H if PCCARD
639 select NEED_MACH_MEMORY_H
642 Support for older TI OMAP1 (omap7xx, omap15xx or omap16xx)
646 menu "Multiple platform selection"
647 depends on ARCH_MULTIPLATFORM
649 comment "CPU Core family selection"
652 bool "ARMv4 based platforms (FA526)"
653 depends on !ARCH_MULTI_V6_V7
654 select ARCH_MULTI_V4_V5
657 config ARCH_MULTI_V4T
658 bool "ARMv4T based platforms (ARM720T, ARM920T, ...)"
659 depends on !ARCH_MULTI_V6_V7
660 select ARCH_MULTI_V4_V5
661 select CPU_ARM920T if !(CPU_ARM7TDMI || CPU_ARM720T || \
662 CPU_ARM740T || CPU_ARM9TDMI || CPU_ARM922T || \
663 CPU_ARM925T || CPU_ARM940T)
666 bool "ARMv5 based platforms (ARM926T, XSCALE, PJ1, ...)"
667 depends on !ARCH_MULTI_V6_V7
668 select ARCH_MULTI_V4_V5
669 select CPU_ARM926T if !(CPU_ARM946E || CPU_ARM1020 || \
670 CPU_ARM1020E || CPU_ARM1022 || CPU_ARM1026 || \
671 CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK || CPU_FEROCEON)
673 config ARCH_MULTI_V4_V5
677 bool "ARMv6 based platforms (ARM11)"
678 select ARCH_MULTI_V6_V7
682 bool "ARMv7 based platforms (Cortex-A, PJ4, Scorpion, Krait)"
684 select ARCH_MULTI_V6_V7
688 config ARCH_MULTI_V6_V7
690 select MIGHT_HAVE_CACHE_L2X0
692 config ARCH_MULTI_CPU_AUTO
693 def_bool !(ARCH_MULTI_V4 || ARCH_MULTI_V4T || ARCH_MULTI_V6_V7)
699 bool "Dummy Virtual Machine"
700 depends on ARCH_MULTI_V7
703 select ARM_GIC_V2M if PCI
706 select HAVE_ARM_ARCH_TIMER
709 # This is sorted alphabetically by mach-* pathname. However, plat-*
710 # Kconfigs may be included either alphabetically (according to the
711 # plat- suffix) or along side the corresponding mach-* source.
713 source "arch/arm/mach-mvebu/Kconfig"
715 source "arch/arm/mach-alpine/Kconfig"
717 source "arch/arm/mach-artpec/Kconfig"
719 source "arch/arm/mach-asm9260/Kconfig"
721 source "arch/arm/mach-at91/Kconfig"
723 source "arch/arm/mach-axxia/Kconfig"
725 source "arch/arm/mach-bcm/Kconfig"
727 source "arch/arm/mach-berlin/Kconfig"
729 source "arch/arm/mach-clps711x/Kconfig"
731 source "arch/arm/mach-cns3xxx/Kconfig"
733 source "arch/arm/mach-davinci/Kconfig"
735 source "arch/arm/mach-digicolor/Kconfig"
737 source "arch/arm/mach-dove/Kconfig"
739 source "arch/arm/mach-ep93xx/Kconfig"
741 source "arch/arm/mach-footbridge/Kconfig"
743 source "arch/arm/mach-gemini/Kconfig"
745 source "arch/arm/mach-highbank/Kconfig"
747 source "arch/arm/mach-hisi/Kconfig"
749 source "arch/arm/mach-integrator/Kconfig"
751 source "arch/arm/mach-iop32x/Kconfig"
753 source "arch/arm/mach-iop33x/Kconfig"
755 source "arch/arm/mach-iop13xx/Kconfig"
757 source "arch/arm/mach-ixp4xx/Kconfig"
759 source "arch/arm/mach-keystone/Kconfig"
761 source "arch/arm/mach-ks8695/Kconfig"
763 source "arch/arm/mach-meson/Kconfig"
765 source "arch/arm/mach-moxart/Kconfig"
767 source "arch/arm/mach-aspeed/Kconfig"
769 source "arch/arm/mach-mv78xx0/Kconfig"
771 source "arch/arm/mach-imx/Kconfig"
773 source "arch/arm/mach-mediatek/Kconfig"
775 source "arch/arm/mach-mxs/Kconfig"
777 source "arch/arm/mach-netx/Kconfig"
779 source "arch/arm/mach-nomadik/Kconfig"
781 source "arch/arm/mach-nspire/Kconfig"
783 source "arch/arm/plat-omap/Kconfig"
785 source "arch/arm/mach-omap1/Kconfig"
787 source "arch/arm/mach-omap2/Kconfig"
789 source "arch/arm/mach-orion5x/Kconfig"
791 source "arch/arm/mach-picoxcell/Kconfig"
793 source "arch/arm/mach-pxa/Kconfig"
794 source "arch/arm/plat-pxa/Kconfig"
796 source "arch/arm/mach-mmp/Kconfig"
798 source "arch/arm/mach-oxnas/Kconfig"
800 source "arch/arm/mach-qcom/Kconfig"
802 source "arch/arm/mach-realview/Kconfig"
804 source "arch/arm/mach-rockchip/Kconfig"
806 source "arch/arm/mach-sa1100/Kconfig"
808 source "arch/arm/mach-socfpga/Kconfig"
810 source "arch/arm/mach-spear/Kconfig"
812 source "arch/arm/mach-sti/Kconfig"
814 source "arch/arm/mach-s3c24xx/Kconfig"
816 source "arch/arm/mach-s3c64xx/Kconfig"
818 source "arch/arm/mach-s5pv210/Kconfig"
820 source "arch/arm/mach-exynos/Kconfig"
821 source "arch/arm/plat-samsung/Kconfig"
823 source "arch/arm/mach-shmobile/Kconfig"
825 source "arch/arm/mach-sunxi/Kconfig"
827 source "arch/arm/mach-prima2/Kconfig"
829 source "arch/arm/mach-tango/Kconfig"
831 source "arch/arm/mach-tegra/Kconfig"
833 source "arch/arm/mach-u300/Kconfig"
835 source "arch/arm/mach-uniphier/Kconfig"
837 source "arch/arm/mach-ux500/Kconfig"
839 source "arch/arm/mach-versatile/Kconfig"
841 source "arch/arm/mach-vexpress/Kconfig"
842 source "arch/arm/plat-versatile/Kconfig"
844 source "arch/arm/mach-vt8500/Kconfig"
846 source "arch/arm/mach-w90x900/Kconfig"
848 source "arch/arm/mach-zx/Kconfig"
850 source "arch/arm/mach-zynq/Kconfig"
852 # ARMv7-M architecture
854 bool "Energy Micro efm32"
855 depends on ARM_SINGLE_ARMV7M
858 Support for Energy Micro's (now Silicon Labs) efm32 Giant Gecko
862 bool "NXP LPC18xx/LPC43xx"
863 depends on ARM_SINGLE_ARMV7M
864 select ARCH_HAS_RESET_CONTROLLER
866 select CLKSRC_LPC32XX
869 Support for NXP's LPC18xx Cortex-M3 and LPC43xx Cortex-M4
870 high performance microcontrollers.
873 bool "STMicrolectronics STM32"
874 depends on ARM_SINGLE_ARMV7M
875 select ARCH_HAS_RESET_CONTROLLER
876 select ARMV7M_SYSTICK
879 select RESET_CONTROLLER
881 Support for STMicroelectronics STM32 processors.
883 config MACH_STM32F429
884 bool "STMicrolectronics STM32F429"
885 depends on ARCH_STM32
889 bool "ARM MPS2 platform"
890 depends on ARM_SINGLE_ARMV7M
894 Support for Cortex-M Prototyping System (or V2M-MPS2) which comes
895 with a range of available cores like Cortex-M3/M4/M7.
897 Please, note that depends which Application Note is used memory map
898 for the platform may vary, so adjustment of RAM base might be needed.
900 # Definitions to make life easier
906 select GENERIC_CLOCKEVENTS
912 select GENERIC_IRQ_CHIP
915 config PLAT_ORION_LEGACY
922 config PLAT_VERSATILE
925 source "arch/arm/firmware/Kconfig"
927 source arch/arm/mm/Kconfig
930 bool "Enable iWMMXt support"
931 depends on CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK || CPU_PJ4 || CPU_PJ4B
932 default y if PXA27x || PXA3xx || ARCH_MMP || CPU_PJ4 || CPU_PJ4B
934 Enable support for iWMMXt context switching at run time if
935 running on a CPU that supports it.
937 config MULTI_IRQ_HANDLER
940 Allow each machine to specify it's own IRQ handler at run time.
943 source "arch/arm/Kconfig-nommu"
946 config PJ4B_ERRATA_4742
947 bool "PJ4B Errata 4742: IDLE Wake Up Commands can Cause the CPU Core to Cease Operation"
948 depends on CPU_PJ4B && MACH_ARMADA_370
951 When coming out of either a Wait for Interrupt (WFI) or a Wait for
952 Event (WFE) IDLE states, a specific timing sensitivity exists between
953 the retiring WFI/WFE instructions and the newly issued subsequent
954 instructions. This sensitivity can result in a CPU hang scenario.
956 The software must insert either a Data Synchronization Barrier (DSB)
957 or Data Memory Barrier (DMB) command immediately after the WFI/WFE
960 config ARM_ERRATA_326103
961 bool "ARM errata: FSR write bit incorrect on a SWP to read-only memory"
964 Executing a SWP instruction to read-only memory does not set bit 11
965 of the FSR on the ARM 1136 prior to r1p0. This causes the kernel to
966 treat the access as a read, preventing a COW from occurring and
967 causing the faulting task to livelock.
969 config ARM_ERRATA_411920
970 bool "ARM errata: Invalidation of the Instruction Cache operation can fail"
971 depends on CPU_V6 || CPU_V6K
973 Invalidation of the Instruction Cache operation can
974 fail. This erratum is present in 1136 (before r1p4), 1156 and 1176.
975 It does not affect the MPCore. This option enables the ARM Ltd.
976 recommended workaround.
978 config ARM_ERRATA_430973
979 bool "ARM errata: Stale prediction on replaced interworking branch"
982 This option enables the workaround for the 430973 Cortex-A8
983 r1p* erratum. If a code sequence containing an ARM/Thumb
984 interworking branch is replaced with another code sequence at the
985 same virtual address, whether due to self-modifying code or virtual
986 to physical address re-mapping, Cortex-A8 does not recover from the
987 stale interworking branch prediction. This results in Cortex-A8
988 executing the new code sequence in the incorrect ARM or Thumb state.
989 The workaround enables the BTB/BTAC operations by setting ACTLR.IBE
990 and also flushes the branch target cache at every context switch.
991 Note that setting specific bits in the ACTLR register may not be
992 available in non-secure mode.
994 config ARM_ERRATA_458693
995 bool "ARM errata: Processor deadlock when a false hazard is created"
997 depends on !ARCH_MULTIPLATFORM
999 This option enables the workaround for the 458693 Cortex-A8 (r2p0)
1000 erratum. For very specific sequences of memory operations, it is
1001 possible for a hazard condition intended for a cache line to instead
1002 be incorrectly associated with a different cache line. This false
1003 hazard might then cause a processor deadlock. The workaround enables
1004 the L1 caching of the NEON accesses and disables the PLD instruction
1005 in the ACTLR register. Note that setting specific bits in the ACTLR
1006 register may not be available in non-secure mode.
1008 config ARM_ERRATA_460075
1009 bool "ARM errata: Data written to the L2 cache can be overwritten with stale data"
1011 depends on !ARCH_MULTIPLATFORM
1013 This option enables the workaround for the 460075 Cortex-A8 (r2p0)
1014 erratum. Any asynchronous access to the L2 cache may encounter a
1015 situation in which recent store transactions to the L2 cache are lost
1016 and overwritten with stale memory contents from external memory. The
1017 workaround disables the write-allocate mode for the L2 cache via the
1018 ACTLR register. Note that setting specific bits in the ACTLR register
1019 may not be available in non-secure mode.
1021 config ARM_ERRATA_742230
1022 bool "ARM errata: DMB operation may be faulty"
1023 depends on CPU_V7 && SMP
1024 depends on !ARCH_MULTIPLATFORM
1026 This option enables the workaround for the 742230 Cortex-A9
1027 (r1p0..r2p2) erratum. Under rare circumstances, a DMB instruction
1028 between two write operations may not ensure the correct visibility
1029 ordering of the two writes. This workaround sets a specific bit in
1030 the diagnostic register of the Cortex-A9 which causes the DMB
1031 instruction to behave as a DSB, ensuring the correct behaviour of
1034 config ARM_ERRATA_742231
1035 bool "ARM errata: Incorrect hazard handling in the SCU may lead to data corruption"
1036 depends on CPU_V7 && SMP
1037 depends on !ARCH_MULTIPLATFORM
1039 This option enables the workaround for the 742231 Cortex-A9
1040 (r2p0..r2p2) erratum. Under certain conditions, specific to the
1041 Cortex-A9 MPCore micro-architecture, two CPUs working in SMP mode,
1042 accessing some data located in the same cache line, may get corrupted
1043 data due to bad handling of the address hazard when the line gets
1044 replaced from one of the CPUs at the same time as another CPU is
1045 accessing it. This workaround sets specific bits in the diagnostic
1046 register of the Cortex-A9 which reduces the linefill issuing
1047 capabilities of the processor.
1049 config ARM_ERRATA_643719
1050 bool "ARM errata: LoUIS bit field in CLIDR register is incorrect"
1051 depends on CPU_V7 && SMP
1054 This option enables the workaround for the 643719 Cortex-A9 (prior to
1055 r1p0) erratum. On affected cores the LoUIS bit field of the CLIDR
1056 register returns zero when it should return one. The workaround
1057 corrects this value, ensuring cache maintenance operations which use
1058 it behave as intended and avoiding data corruption.
1060 config ARM_ERRATA_720789
1061 bool "ARM errata: TLBIASIDIS and TLBIMVAIS operations can broadcast a faulty ASID"
1064 This option enables the workaround for the 720789 Cortex-A9 (prior to
1065 r2p0) erratum. A faulty ASID can be sent to the other CPUs for the
1066 broadcasted CP15 TLB maintenance operations TLBIASIDIS and TLBIMVAIS.
1067 As a consequence of this erratum, some TLB entries which should be
1068 invalidated are not, resulting in an incoherency in the system page
1069 tables. The workaround changes the TLB flushing routines to invalidate
1070 entries regardless of the ASID.
1072 config ARM_ERRATA_743622
1073 bool "ARM errata: Faulty hazard checking in the Store Buffer may lead to data corruption"
1075 depends on !ARCH_MULTIPLATFORM
1077 This option enables the workaround for the 743622 Cortex-A9
1078 (r2p*) erratum. Under very rare conditions, a faulty
1079 optimisation in the Cortex-A9 Store Buffer may lead to data
1080 corruption. This workaround sets a specific bit in the diagnostic
1081 register of the Cortex-A9 which disables the Store Buffer
1082 optimisation, preventing the defect from occurring. This has no
1083 visible impact on the overall performance or power consumption of the
1086 config ARM_ERRATA_751472
1087 bool "ARM errata: Interrupted ICIALLUIS may prevent completion of broadcasted operation"
1089 depends on !ARCH_MULTIPLATFORM
1091 This option enables the workaround for the 751472 Cortex-A9 (prior
1092 to r3p0) erratum. An interrupted ICIALLUIS operation may prevent the
1093 completion of a following broadcasted operation if the second
1094 operation is received by a CPU before the ICIALLUIS has completed,
1095 potentially leading to corrupted entries in the cache or TLB.
1097 config ARM_ERRATA_754322
1098 bool "ARM errata: possible faulty MMU translations following an ASID switch"
1101 This option enables the workaround for the 754322 Cortex-A9 (r2p*,
1102 r3p*) erratum. A speculative memory access may cause a page table walk
1103 which starts prior to an ASID switch but completes afterwards. This
1104 can populate the micro-TLB with a stale entry which may be hit with
1105 the new ASID. This workaround places two dsb instructions in the mm
1106 switching code so that no page table walks can cross the ASID switch.
1108 config ARM_ERRATA_754327
1109 bool "ARM errata: no automatic Store Buffer drain"
1110 depends on CPU_V7 && SMP
1112 This option enables the workaround for the 754327 Cortex-A9 (prior to
1113 r2p0) erratum. The Store Buffer does not have any automatic draining
1114 mechanism and therefore a livelock may occur if an external agent
1115 continuously polls a memory location waiting to observe an update.
1116 This workaround defines cpu_relax() as smp_mb(), preventing correctly
1117 written polling loops from denying visibility of updates to memory.
1119 config ARM_ERRATA_364296
1120 bool "ARM errata: Possible cache data corruption with hit-under-miss enabled"
1123 This options enables the workaround for the 364296 ARM1136
1124 r0p2 erratum (possible cache data corruption with
1125 hit-under-miss enabled). It sets the undocumented bit 31 in
1126 the auxiliary control register and the FI bit in the control
1127 register, thus disabling hit-under-miss without putting the
1128 processor into full low interrupt latency mode. ARM11MPCore
1131 config ARM_ERRATA_764369
1132 bool "ARM errata: Data cache line maintenance operation by MVA may not succeed"
1133 depends on CPU_V7 && SMP
1135 This option enables the workaround for erratum 764369
1136 affecting Cortex-A9 MPCore with two or more processors (all
1137 current revisions). Under certain timing circumstances, a data
1138 cache line maintenance operation by MVA targeting an Inner
1139 Shareable memory region may fail to proceed up to either the
1140 Point of Coherency or to the Point of Unification of the
1141 system. This workaround adds a DSB instruction before the
1142 relevant cache maintenance functions and sets a specific bit
1143 in the diagnostic control register of the SCU.
1145 config ARM_ERRATA_775420
1146 bool "ARM errata: A data cache maintenance operation which aborts, might lead to deadlock"
1149 This option enables the workaround for the 775420 Cortex-A9 (r2p2,
1150 r2p6,r2p8,r2p10,r3p0) erratum. In case a date cache maintenance
1151 operation aborts with MMU exception, it might cause the processor
1152 to deadlock. This workaround puts DSB before executing ISB if
1153 an abort may occur on cache maintenance.
1155 config ARM_ERRATA_798181
1156 bool "ARM errata: TLBI/DSB failure on Cortex-A15"
1157 depends on CPU_V7 && SMP
1159 On Cortex-A15 (r0p0..r3p2) the TLBI*IS/DSB operations are not
1160 adequately shooting down all use of the old entries. This
1161 option enables the Linux kernel workaround for this erratum
1162 which sends an IPI to the CPUs that are running the same ASID
1163 as the one being invalidated.
1165 config ARM_ERRATA_773022
1166 bool "ARM errata: incorrect instructions may be executed from loop buffer"
1169 This option enables the workaround for the 773022 Cortex-A15
1170 (up to r0p4) erratum. In certain rare sequences of code, the
1171 loop buffer may deliver incorrect instructions. This
1172 workaround disables the loop buffer to avoid the erratum.
1174 config ARM_ERRATA_818325_852422
1175 bool "ARM errata: A12: some seqs of opposed cond code instrs => deadlock or corruption"
1178 This option enables the workaround for:
1179 - Cortex-A12 818325: Execution of an UNPREDICTABLE STR or STM
1180 instruction might deadlock. Fixed in r0p1.
1181 - Cortex-A12 852422: Execution of a sequence of instructions might
1182 lead to either a data corruption or a CPU deadlock. Not fixed in
1183 any Cortex-A12 cores yet.
1184 This workaround for all both errata involves setting bit[12] of the
1185 Feature Register. This bit disables an optimisation applied to a
1186 sequence of 2 instructions that use opposing condition codes.
1188 config ARM_ERRATA_821420
1189 bool "ARM errata: A12: sequence of VMOV to core registers might lead to a dead lock"
1192 This option enables the workaround for the 821420 Cortex-A12
1193 (all revs) erratum. In very rare timing conditions, a sequence
1194 of VMOV to Core registers instructions, for which the second
1195 one is in the shadow of a branch or abort, can lead to a
1196 deadlock when the VMOV instructions are issued out-of-order.
1198 config ARM_ERRATA_825619
1199 bool "ARM errata: A12: DMB NSHST/ISHST mixed ... might cause deadlock"
1202 This option enables the workaround for the 825619 Cortex-A12
1203 (all revs) erratum. Within rare timing constraints, executing a
1204 DMB NSHST or DMB ISHST instruction followed by a mix of Cacheable
1205 and Device/Strongly-Ordered loads and stores might cause deadlock
1207 config ARM_ERRATA_852421
1208 bool "ARM errata: A17: DMB ST might fail to create order between stores"
1211 This option enables the workaround for the 852421 Cortex-A17
1212 (r1p0, r1p1, r1p2) erratum. Under very rare timing conditions,
1213 execution of a DMB ST instruction might fail to properly order
1214 stores from GroupA and stores from GroupB.
1216 config ARM_ERRATA_852423
1217 bool "ARM errata: A17: some seqs of opposed cond code instrs => deadlock or corruption"
1220 This option enables the workaround for:
1221 - Cortex-A17 852423: Execution of a sequence of instructions might
1222 lead to either a data corruption or a CPU deadlock. Not fixed in
1223 any Cortex-A17 cores yet.
1224 This is identical to Cortex-A12 erratum 852422. It is a separate
1225 config option from the A12 erratum due to the way errata are checked
1230 source "arch/arm/common/Kconfig"
1237 Find out whether you have ISA slots on your motherboard. ISA is the
1238 name of a bus system, i.e. the way the CPU talks to the other stuff
1239 inside your box. Other bus systems are PCI, EISA, MicroChannel
1240 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1241 newer boards don't support it. If you have ISA, say Y, otherwise N.
1243 # Select ISA DMA controller support
1248 # Select ISA DMA interface
1253 bool "PCI support" if MIGHT_HAVE_PCI
1255 Find out whether you have a PCI motherboard. PCI is the name of a
1256 bus system, i.e. the way the CPU talks to the other stuff inside
1257 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1258 VESA. If you have PCI, say Y, otherwise N.
1264 config PCI_DOMAINS_GENERIC
1265 def_bool PCI_DOMAINS
1267 config PCI_NANOENGINE
1268 bool "BSE nanoEngine PCI support"
1269 depends on SA1100_NANOENGINE
1271 Enable PCI on the BSE nanoEngine board.
1276 config PCI_HOST_ITE8152
1278 depends on PCI && MACH_ARMCORE
1282 source "drivers/pci/Kconfig"
1284 source "drivers/pcmcia/Kconfig"
1288 menu "Kernel Features"
1293 This option should be selected by machines which have an SMP-
1296 The only effect of this option is to make the SMP-related
1297 options available to the user for configuration.
1300 bool "Symmetric Multi-Processing"
1301 depends on CPU_V6K || CPU_V7
1302 depends on GENERIC_CLOCKEVENTS
1304 depends on MMU || ARM_MPU
1307 This enables support for systems with more than one CPU. If you have
1308 a system with only one CPU, say N. If you have a system with more
1309 than one CPU, say Y.
1311 If you say N here, the kernel will run on uni- and multiprocessor
1312 machines, but will use only one CPU of a multiprocessor machine. If
1313 you say Y here, the kernel will run on many, but not all,
1314 uniprocessor machines. On a uniprocessor machine, the kernel
1315 will run faster if you say N here.
1317 See also <file:Documentation/x86/i386/IO-APIC.txt>,
1318 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
1319 <http://tldp.org/HOWTO/SMP-HOWTO.html>.
1321 If you don't know what to do here, say N.
1324 bool "Allow booting SMP kernel on uniprocessor systems"
1325 depends on SMP && !XIP_KERNEL && MMU
1328 SMP kernels contain instructions which fail on non-SMP processors.
1329 Enabling this option allows the kernel to modify itself to make
1330 these instructions safe. Disabling it allows about 1K of space
1333 If you don't know what to do here, say Y.
1335 config ARM_CPU_TOPOLOGY
1336 bool "Support cpu topology definition"
1337 depends on SMP && CPU_V7
1340 Support ARM cpu topology definition. The MPIDR register defines
1341 affinity between processors which is then used to describe the cpu
1342 topology of an ARM System.
1345 bool "Multi-core scheduler support"
1346 depends on ARM_CPU_TOPOLOGY
1348 Multi-core scheduler support improves the CPU scheduler's decision
1349 making when dealing with multi-core CPU chips at a cost of slightly
1350 increased overhead in some places. If unsure say N here.
1353 bool "SMT scheduler support"
1354 depends on ARM_CPU_TOPOLOGY
1356 Improves the CPU scheduler's decision making when dealing with
1357 MultiThreading at a cost of slightly increased overhead in some
1358 places. If unsure say N here.
1363 This option enables support for the ARM system coherency unit
1365 config HAVE_ARM_ARCH_TIMER
1366 bool "Architected timer support"
1368 select ARM_ARCH_TIMER
1369 select GENERIC_CLOCKEVENTS
1371 This option enables support for the ARM architected timer
1375 select CLKSRC_OF if OF
1377 This options enables support for the ARM timer and watchdog unit
1380 bool "Multi-Cluster Power Management"
1381 depends on CPU_V7 && SMP
1383 This option provides the common power management infrastructure
1384 for (multi-)cluster based systems, such as big.LITTLE based
1387 config MCPM_QUAD_CLUSTER
1391 To avoid wasting resources unnecessarily, MCPM only supports up
1392 to 2 clusters by default.
1393 Platforms with 3 or 4 clusters that use MCPM must select this
1394 option to allow the additional clusters to be managed.
1397 bool "big.LITTLE support (Experimental)"
1398 depends on CPU_V7 && SMP
1401 This option enables support selections for the big.LITTLE
1402 system architecture.
1405 bool "big.LITTLE switcher support"
1406 depends on BIG_LITTLE && MCPM && HOTPLUG_CPU && ARM_GIC
1409 The big.LITTLE "switcher" provides the core functionality to
1410 transparently handle transition between a cluster of A15's
1411 and a cluster of A7's in a big.LITTLE system.
1413 config BL_SWITCHER_DUMMY_IF
1414 tristate "Simple big.LITTLE switcher user interface"
1415 depends on BL_SWITCHER && DEBUG_KERNEL
1417 This is a simple and dummy char dev interface to control
1418 the big.LITTLE switcher core code. It is meant for
1419 debugging purposes only.
1422 prompt "Memory split"
1426 Select the desired split between kernel and user memory.
1428 If you are not absolutely sure what you are doing, leave this
1432 bool "3G/1G user/kernel split"
1433 config VMSPLIT_3G_OPT
1434 bool "3G/1G user/kernel split (for full 1G low memory)"
1436 bool "2G/2G user/kernel split"
1438 bool "1G/3G user/kernel split"
1443 default PHYS_OFFSET if !MMU
1444 default 0x40000000 if VMSPLIT_1G
1445 default 0x80000000 if VMSPLIT_2G
1446 default 0xB0000000 if VMSPLIT_3G_OPT
1450 int "Maximum number of CPUs (2-32)"
1456 bool "Support for hot-pluggable CPUs"
1459 Say Y here to experiment with turning CPUs off and on. CPUs
1460 can be controlled through /sys/devices/system/cpu.
1463 bool "Support for the ARM Power State Coordination Interface (PSCI)"
1464 depends on HAVE_ARM_SMCCC
1467 Say Y here if you want Linux to communicate with system firmware
1468 implementing the PSCI specification for CPU-centric power
1469 management operations described in ARM document number ARM DEN
1470 0022A ("Power State Coordination Interface System Software on
1473 # The GPIO number here must be sorted by descending number. In case of
1474 # a multiplatform kernel, we just want the highest value required by the
1475 # selected platforms.
1478 default 1024 if ARCH_BRCMSTB || ARCH_SHMOBILE || ARCH_TEGRA || \
1480 default 512 if ARCH_EXYNOS || ARCH_KEYSTONE || SOC_OMAP5 || \
1481 SOC_DRA7XX || ARCH_S3C24XX || ARCH_S3C64XX || ARCH_S5PV210
1482 default 416 if ARCH_SUNXI
1483 default 392 if ARCH_U8500
1484 default 352 if ARCH_VT8500
1485 default 288 if ARCH_ROCKCHIP
1486 default 264 if MACH_H4700
1489 Maximum number of GPIOs in the system.
1491 If unsure, leave the default value.
1493 source kernel/Kconfig.preempt
1497 default 200 if ARCH_EBSA110 || ARCH_S3C24XX || \
1498 ARCH_S5PV210 || ARCH_EXYNOS4
1499 default 128 if SOC_AT91RM9200
1503 depends on HZ_FIXED = 0
1504 prompt "Timer frequency"
1528 default HZ_FIXED if HZ_FIXED != 0
1529 default 100 if HZ_100
1530 default 200 if HZ_200
1531 default 250 if HZ_250
1532 default 300 if HZ_300
1533 default 500 if HZ_500
1537 def_bool HIGH_RES_TIMERS
1539 config THUMB2_KERNEL
1540 bool "Compile the kernel in Thumb-2 mode" if !CPU_THUMBONLY
1541 depends on (CPU_V7 || CPU_V7M) && !CPU_V6 && !CPU_V6K
1542 default y if CPU_THUMBONLY
1544 select ARM_ASM_UNIFIED
1547 By enabling this option, the kernel will be compiled in
1548 Thumb-2 mode. A compiler/assembler that understand the unified
1549 ARM-Thumb syntax is needed.
1553 config THUMB2_AVOID_R_ARM_THM_JUMP11
1554 bool "Work around buggy Thumb-2 short branch relocations in gas"
1555 depends on THUMB2_KERNEL && MODULES
1558 Various binutils versions can resolve Thumb-2 branches to
1559 locally-defined, preemptible global symbols as short-range "b.n"
1560 branch instructions.
1562 This is a problem, because there's no guarantee the final
1563 destination of the symbol, or any candidate locations for a
1564 trampoline, are within range of the branch. For this reason, the
1565 kernel does not support fixing up the R_ARM_THM_JUMP11 (102)
1566 relocation in modules at all, and it makes little sense to add
1569 The symptom is that the kernel fails with an "unsupported
1570 relocation" error when loading some modules.
1572 Until fixed tools are available, passing
1573 -fno-optimize-sibling-calls to gcc should prevent gcc generating
1574 code which hits this problem, at the cost of a bit of extra runtime
1575 stack usage in some cases.
1577 The problem is described in more detail at:
1578 https://bugs.launchpad.net/binutils-linaro/+bug/725126
1580 Only Thumb-2 kernels are affected.
1582 Unless you are sure your tools don't have this problem, say Y.
1584 config ARM_ASM_UNIFIED
1587 config ARM_PATCH_IDIV
1588 bool "Runtime patch udiv/sdiv instructions into __aeabi_{u}idiv()"
1589 depends on CPU_32v7 && !XIP_KERNEL
1592 The ARM compiler inserts calls to __aeabi_idiv() and
1593 __aeabi_uidiv() when it needs to perform division on signed
1594 and unsigned integers. Some v7 CPUs have support for the sdiv
1595 and udiv instructions that can be used to implement those
1598 Enabling this option allows the kernel to modify itself to
1599 replace the first two instructions of these library functions
1600 with the sdiv or udiv plus "bx lr" instructions when the CPU
1601 it is running on supports them. Typically this will be faster
1602 and less power intensive than running the original library
1603 code to do integer division.
1606 bool "Use the ARM EABI to compile the kernel"
1608 This option allows for the kernel to be compiled using the latest
1609 ARM ABI (aka EABI). This is only useful if you are using a user
1610 space environment that is also compiled with EABI.
1612 Since there are major incompatibilities between the legacy ABI and
1613 EABI, especially with regard to structure member alignment, this
1614 option also changes the kernel syscall calling convention to
1615 disambiguate both ABIs and allow for backward compatibility support
1616 (selected with CONFIG_OABI_COMPAT).
1618 To use this you need GCC version 4.0.0 or later.
1621 bool "Allow old ABI binaries to run with this kernel (EXPERIMENTAL)"
1622 depends on AEABI && !THUMB2_KERNEL
1624 This option preserves the old syscall interface along with the
1625 new (ARM EABI) one. It also provides a compatibility layer to
1626 intercept syscalls that have structure arguments which layout
1627 in memory differs between the legacy ABI and the new ARM EABI
1628 (only for non "thumb" binaries). This option adds a tiny
1629 overhead to all syscalls and produces a slightly larger kernel.
1631 The seccomp filter system will not be available when this is
1632 selected, since there is no way yet to sensibly distinguish
1633 between calling conventions during filtering.
1635 If you know you'll be using only pure EABI user space then you
1636 can say N here. If this option is not selected and you attempt
1637 to execute a legacy ABI binary then the result will be
1638 UNPREDICTABLE (in fact it can be predicted that it won't work
1639 at all). If in doubt say N.
1641 config ARCH_HAS_HOLES_MEMORYMODEL
1644 config ARCH_SPARSEMEM_ENABLE
1647 config ARCH_SPARSEMEM_DEFAULT
1648 def_bool ARCH_SPARSEMEM_ENABLE
1650 config ARCH_SELECT_MEMORY_MODEL
1651 def_bool ARCH_SPARSEMEM_ENABLE
1653 config HAVE_ARCH_PFN_VALID
1654 def_bool ARCH_HAS_HOLES_MEMORYMODEL || !SPARSEMEM
1656 config HAVE_GENERIC_RCU_GUP
1661 bool "High Memory Support"
1664 The address space of ARM processors is only 4 Gigabytes large
1665 and it has to accommodate user address space, kernel address
1666 space as well as some memory mapped IO. That means that, if you
1667 have a large amount of physical memory and/or IO, not all of the
1668 memory can be "permanently mapped" by the kernel. The physical
1669 memory that is not permanently mapped is called "high memory".
1671 Depending on the selected kernel/user memory split, minimum
1672 vmalloc space and actual amount of RAM, you may not need this
1673 option which should result in a slightly faster kernel.
1678 bool "Allocate 2nd-level pagetables from highmem" if EXPERT
1682 The VM uses one page of physical memory for each page table.
1683 For systems with a lot of processes, this can use a lot of
1684 precious low memory, eventually leading to low memory being
1685 consumed by page tables. Setting this option will allow
1686 user-space 2nd level page tables to reside in high memory.
1688 config CPU_SW_DOMAIN_PAN
1689 bool "Enable use of CPU domains to implement privileged no-access"
1690 depends on MMU && !ARM_LPAE
1693 Increase kernel security by ensuring that normal kernel accesses
1694 are unable to access userspace addresses. This can help prevent
1695 use-after-free bugs becoming an exploitable privilege escalation
1696 by ensuring that magic values (such as LIST_POISON) will always
1697 fault when dereferenced.
1699 CPUs with low-vector mappings use a best-efforts implementation.
1700 Their lower 1MB needs to remain accessible for the vectors, but
1701 the remainder of userspace will become appropriately inaccessible.
1703 config HW_PERF_EVENTS
1707 config SYS_SUPPORTS_HUGETLBFS
1711 config HAVE_ARCH_TRANSPARENT_HUGEPAGE
1715 config ARCH_WANT_GENERAL_HUGETLB
1718 config ARM_MODULE_PLTS
1719 bool "Use PLTs to allow module memory to spill over into vmalloc area"
1722 Allocate PLTs when loading modules so that jumps and calls whose
1723 targets are too far away for their relative offsets to be encoded
1724 in the instructions themselves can be bounced via veneers in the
1725 module's PLT. This allows modules to be allocated in the generic
1726 vmalloc area after the dedicated module memory area has been
1727 exhausted. The modules will use slightly more memory, but after
1728 rounding up to page size, the actual memory footprint is usually
1731 Say y if you are getting out of memory errors while loading modules
1735 config FORCE_MAX_ZONEORDER
1736 int "Maximum zone order"
1737 default "12" if SOC_AM33XX
1738 default "9" if SA1111 || ARCH_EFM32
1741 The kernel memory allocator divides physically contiguous memory
1742 blocks into "zones", where each zone is a power of two number of
1743 pages. This option selects the largest power of two that the kernel
1744 keeps in the memory allocator. If you need to allocate very large
1745 blocks of physically contiguous memory, then you may need to
1746 increase this value.
1748 This config option is actually maximum order plus one. For example,
1749 a value of 11 means that the largest free memory block is 2^10 pages.
1751 config ALIGNMENT_TRAP
1753 depends on CPU_CP15_MMU
1754 default y if !ARCH_EBSA110
1755 select HAVE_PROC_CPU if PROC_FS
1757 ARM processors cannot fetch/store information which is not
1758 naturally aligned on the bus, i.e., a 4 byte fetch must start at an
1759 address divisible by 4. On 32-bit ARM processors, these non-aligned
1760 fetch/store instructions will be emulated in software if you say
1761 here, which has a severe performance impact. This is necessary for
1762 correct operation of some network protocols. With an IP-only
1763 configuration it is safe to say N, otherwise say Y.
1765 config UACCESS_WITH_MEMCPY
1766 bool "Use kernel mem{cpy,set}() for {copy_to,clear}_user()"
1768 default y if CPU_FEROCEON
1770 Implement faster copy_to_user and clear_user methods for CPU
1771 cores where a 8-word STM instruction give significantly higher
1772 memory write throughput than a sequence of individual 32bit stores.
1774 A possible side effect is a slight increase in scheduling latency
1775 between threads sharing the same address space if they invoke
1776 such copy operations with large buffers.
1778 However, if the CPU data cache is using a write-allocate mode,
1779 this option is unlikely to provide any performance gain.
1783 prompt "Enable seccomp to safely compute untrusted bytecode"
1785 This kernel feature is useful for number crunching applications
1786 that may need to compute untrusted bytecode during their
1787 execution. By using pipes or other transports made available to
1788 the process as file descriptors supporting the read/write
1789 syscalls, it's possible to isolate those applications in
1790 their own address space using seccomp. Once seccomp is
1791 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1792 and the task is only allowed to execute a few safe syscalls
1793 defined by each seccomp mode.
1802 bool "Enable paravirtualization code"
1804 This changes the kernel so it can modify itself when it is run
1805 under a hypervisor, potentially improving performance significantly
1806 over full virtualization.
1808 config PARAVIRT_TIME_ACCOUNTING
1809 bool "Paravirtual steal time accounting"
1813 Select this option to enable fine granularity task steal time
1814 accounting. Time spent executing other tasks in parallel with
1815 the current vCPU is discounted from the vCPU power. To account for
1816 that, there can be a small performance impact.
1818 If in doubt, say N here.
1825 bool "Xen guest support on ARM"
1826 depends on ARM && AEABI && OF
1827 depends on CPU_V7 && !CPU_V6
1828 depends on !GENERIC_ATOMIC64
1830 select ARCH_DMA_ADDR_T_64BIT
1835 Say Y if you want to run Linux in a Virtual Machine on Xen on ARM.
1842 bool "Flattened Device Tree support"
1846 Include support for flattened device tree machine descriptions.
1849 bool "Support for the traditional ATAGS boot data passing" if USE_OF
1852 This is the traditional way of passing data to the kernel at boot
1853 time. If you are solely relying on the flattened device tree (or
1854 the ARM_ATAG_DTB_COMPAT option) then you may unselect this option
1855 to remove ATAGS support from your kernel binary. If unsure,
1858 config DEPRECATED_PARAM_STRUCT
1859 bool "Provide old way to pass kernel parameters"
1862 This was deprecated in 2001 and announced to live on for 5 years.
1863 Some old boot loaders still use this way.
1865 # Compressed boot loader in ROM. Yes, we really want to ask about
1866 # TEXT and BSS so we preserve their values in the config files.
1867 config ZBOOT_ROM_TEXT
1868 hex "Compressed ROM boot loader base address"
1871 The physical address at which the ROM-able zImage is to be
1872 placed in the target. Platforms which normally make use of
1873 ROM-able zImage formats normally set this to a suitable
1874 value in their defconfig file.
1876 If ZBOOT_ROM is not enabled, this has no effect.
1878 config ZBOOT_ROM_BSS
1879 hex "Compressed ROM boot loader BSS address"
1882 The base address of an area of read/write memory in the target
1883 for the ROM-able zImage which must be available while the
1884 decompressor is running. It must be large enough to hold the
1885 entire decompressed kernel plus an additional 128 KiB.
1886 Platforms which normally make use of ROM-able zImage formats
1887 normally set this to a suitable value in their defconfig file.
1889 If ZBOOT_ROM is not enabled, this has no effect.
1892 bool "Compressed boot loader in ROM/flash"
1893 depends on ZBOOT_ROM_TEXT != ZBOOT_ROM_BSS
1894 depends on !ARM_APPENDED_DTB && !XIP_KERNEL && !AUTO_ZRELADDR
1896 Say Y here if you intend to execute your compressed kernel image
1897 (zImage) directly from ROM or flash. If unsure, say N.
1899 config ARM_APPENDED_DTB
1900 bool "Use appended device tree blob to zImage (EXPERIMENTAL)"
1903 With this option, the boot code will look for a device tree binary
1904 (DTB) appended to zImage
1905 (e.g. cat zImage <filename>.dtb > zImage_w_dtb).
1907 This is meant as a backward compatibility convenience for those
1908 systems with a bootloader that can't be upgraded to accommodate
1909 the documented boot protocol using a device tree.
1911 Beware that there is very little in terms of protection against
1912 this option being confused by leftover garbage in memory that might
1913 look like a DTB header after a reboot if no actual DTB is appended
1914 to zImage. Do not leave this option active in a production kernel
1915 if you don't intend to always append a DTB. Proper passing of the
1916 location into r2 of a bootloader provided DTB is always preferable
1919 config ARM_ATAG_DTB_COMPAT
1920 bool "Supplement the appended DTB with traditional ATAG information"
1921 depends on ARM_APPENDED_DTB
1923 Some old bootloaders can't be updated to a DTB capable one, yet
1924 they provide ATAGs with memory configuration, the ramdisk address,
1925 the kernel cmdline string, etc. Such information is dynamically
1926 provided by the bootloader and can't always be stored in a static
1927 DTB. To allow a device tree enabled kernel to be used with such
1928 bootloaders, this option allows zImage to extract the information
1929 from the ATAG list and store it at run time into the appended DTB.
1932 prompt "Kernel command line type" if ARM_ATAG_DTB_COMPAT
1933 default ARM_ATAG_DTB_COMPAT_CMDLINE_FROM_BOOTLOADER
1935 config ARM_ATAG_DTB_COMPAT_CMDLINE_FROM_BOOTLOADER
1936 bool "Use bootloader kernel arguments if available"
1938 Uses the command-line options passed by the boot loader instead of
1939 the device tree bootargs property. If the boot loader doesn't provide
1940 any, the device tree bootargs property will be used.
1942 config ARM_ATAG_DTB_COMPAT_CMDLINE_EXTEND
1943 bool "Extend with bootloader kernel arguments"
1945 The command-line arguments provided by the boot loader will be
1946 appended to the the device tree bootargs property.
1951 string "Default kernel command string"
1954 On some architectures (EBSA110 and CATS), there is currently no way
1955 for the boot loader to pass arguments to the kernel. For these
1956 architectures, you should supply some command-line options at build
1957 time by entering them here. As a minimum, you should specify the
1958 memory size and the root device (e.g., mem=64M root=/dev/nfs).
1961 prompt "Kernel command line type" if CMDLINE != ""
1962 default CMDLINE_FROM_BOOTLOADER
1965 config CMDLINE_FROM_BOOTLOADER
1966 bool "Use bootloader kernel arguments if available"
1968 Uses the command-line options passed by the boot loader. If
1969 the boot loader doesn't provide any, the default kernel command
1970 string provided in CMDLINE will be used.
1972 config CMDLINE_EXTEND
1973 bool "Extend bootloader kernel arguments"
1975 The command-line arguments provided by the boot loader will be
1976 appended to the default kernel command string.
1978 config CMDLINE_FORCE
1979 bool "Always use the default kernel command string"
1981 Always use the default kernel command string, even if the boot
1982 loader passes other arguments to the kernel.
1983 This is useful if you cannot or don't want to change the
1984 command-line options your boot loader passes to the kernel.
1988 bool "Kernel Execute-In-Place from ROM"
1989 depends on !ARM_LPAE && !ARCH_MULTIPLATFORM
1991 Execute-In-Place allows the kernel to run from non-volatile storage
1992 directly addressable by the CPU, such as NOR flash. This saves RAM
1993 space since the text section of the kernel is not loaded from flash
1994 to RAM. Read-write sections, such as the data section and stack,
1995 are still copied to RAM. The XIP kernel is not compressed since
1996 it has to run directly from flash, so it will take more space to
1997 store it. The flash address used to link the kernel object files,
1998 and for storing it, is configuration dependent. Therefore, if you
1999 say Y here, you must know the proper physical address where to
2000 store the kernel image depending on your own flash memory usage.
2002 Also note that the make target becomes "make xipImage" rather than
2003 "make zImage" or "make Image". The final kernel binary to put in
2004 ROM memory will be arch/arm/boot/xipImage.
2008 config XIP_PHYS_ADDR
2009 hex "XIP Kernel Physical Location"
2010 depends on XIP_KERNEL
2011 default "0x00080000"
2013 This is the physical address in your flash memory the kernel will
2014 be linked for and stored to. This address is dependent on your
2018 bool "Kexec system call (EXPERIMENTAL)"
2019 depends on (!SMP || PM_SLEEP_SMP)
2023 kexec is a system call that implements the ability to shutdown your
2024 current kernel, and to start another kernel. It is like a reboot
2025 but it is independent of the system firmware. And like a reboot
2026 you can start any kernel with it, not just Linux.
2028 It is an ongoing process to be certain the hardware in a machine
2029 is properly shutdown, so do not be surprised if this code does not
2030 initially work for you.
2033 bool "Export atags in procfs"
2034 depends on ATAGS && KEXEC
2037 Should the atags used to boot the kernel be exported in an "atags"
2038 file in procfs. Useful with kexec.
2041 bool "Build kdump crash kernel (EXPERIMENTAL)"
2043 Generate crash dump after being started by kexec. This should
2044 be normally only set in special crash dump kernels which are
2045 loaded in the main kernel with kexec-tools into a specially
2046 reserved region and then later executed after a crash by
2047 kdump/kexec. The crash dump kernel must be compiled to a
2048 memory address not used by the main kernel
2050 For more details see Documentation/kdump/kdump.txt
2052 config AUTO_ZRELADDR
2053 bool "Auto calculation of the decompressed kernel image address"
2055 ZRELADDR is the physical address where the decompressed kernel
2056 image will be placed. If AUTO_ZRELADDR is selected, the address
2057 will be determined at run-time by masking the current IP with
2058 0xf8000000. This assumes the zImage being placed in the first 128MB
2059 from start of memory.
2065 bool "UEFI runtime support"
2066 depends on OF && !CPU_BIG_ENDIAN && MMU && AUTO_ZRELADDR && !XIP_KERNEL
2068 select EFI_PARAMS_FROM_FDT
2071 select EFI_RUNTIME_WRAPPERS
2073 This option provides support for runtime services provided
2074 by UEFI firmware (such as non-volatile variables, realtime
2075 clock, and platform reset). A UEFI stub is also provided to
2076 allow the kernel to be booted as an EFI application. This
2077 is only useful for kernels that may run on systems that have
2082 menu "CPU Power Management"
2084 source "drivers/cpufreq/Kconfig"
2086 source "drivers/cpuidle/Kconfig"
2090 menu "Floating point emulation"
2092 comment "At least one emulation must be selected"
2095 bool "NWFPE math emulation"
2096 depends on (!AEABI || OABI_COMPAT) && !THUMB2_KERNEL
2098 Say Y to include the NWFPE floating point emulator in the kernel.
2099 This is necessary to run most binaries. Linux does not currently
2100 support floating point hardware so you need to say Y here even if
2101 your machine has an FPA or floating point co-processor podule.
2103 You may say N here if you are going to load the Acorn FPEmulator
2104 early in the bootup.
2107 bool "Support extended precision"
2108 depends on FPE_NWFPE
2110 Say Y to include 80-bit support in the kernel floating-point
2111 emulator. Otherwise, only 32 and 64-bit support is compiled in.
2112 Note that gcc does not generate 80-bit operations by default,
2113 so in most cases this option only enlarges the size of the
2114 floating point emulator without any good reason.
2116 You almost surely want to say N here.
2119 bool "FastFPE math emulation (EXPERIMENTAL)"
2120 depends on (!AEABI || OABI_COMPAT) && !CPU_32v3
2122 Say Y here to include the FAST floating point emulator in the kernel.
2123 This is an experimental much faster emulator which now also has full
2124 precision for the mantissa. It does not support any exceptions.
2125 It is very simple, and approximately 3-6 times faster than NWFPE.
2127 It should be sufficient for most programs. It may be not suitable
2128 for scientific calculations, but you have to check this for yourself.
2129 If you do not feel you need a faster FP emulation you should better
2133 bool "VFP-format floating point maths"
2134 depends on CPU_V6 || CPU_V6K || CPU_ARM926T || CPU_V7 || CPU_FEROCEON
2136 Say Y to include VFP support code in the kernel. This is needed
2137 if your hardware includes a VFP unit.
2139 Please see <file:Documentation/arm/VFP/release-notes.txt> for
2140 release notes and additional status information.
2142 Say N if your target does not have VFP hardware.
2150 bool "Advanced SIMD (NEON) Extension support"
2151 depends on VFPv3 && CPU_V7
2153 Say Y to include support code for NEON, the ARMv7 Advanced SIMD
2156 config KERNEL_MODE_NEON
2157 bool "Support for NEON in kernel mode"
2158 depends on NEON && AEABI
2160 Say Y to include support for NEON in kernel mode.
2164 menu "Userspace binary formats"
2166 source "fs/Kconfig.binfmt"
2170 menu "Power management options"
2172 source "kernel/power/Kconfig"
2174 config ARCH_SUSPEND_POSSIBLE
2175 depends on CPU_ARM920T || CPU_ARM926T || CPU_FEROCEON || CPU_SA1100 || \
2176 CPU_V6 || CPU_V6K || CPU_V7 || CPU_V7M || CPU_XSC3 || CPU_XSCALE || CPU_MOHAWK
2179 config ARM_CPU_SUSPEND
2180 def_bool PM_SLEEP || BL_SWITCHER || ARM_PSCI_FW
2181 depends on ARCH_SUSPEND_POSSIBLE
2183 config ARCH_HIBERNATION_POSSIBLE
2186 default y if ARCH_SUSPEND_POSSIBLE
2190 source "net/Kconfig"
2192 source "drivers/Kconfig"
2194 source "drivers/firmware/Kconfig"
2198 source "arch/arm/Kconfig.debug"
2200 source "security/Kconfig"
2202 source "crypto/Kconfig"
2204 source "arch/arm/crypto/Kconfig"
2207 source "lib/Kconfig"
2209 source "arch/arm/kvm/Kconfig"