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_HARDENED_USERCOPY
39 select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL && !CPU_ENDIAN_BE32 && MMU
40 select HAVE_ARCH_KGDB if !CPU_ENDIAN_BE32 && MMU
41 select HAVE_ARCH_MMAP_RND_BITS if MMU
42 select HAVE_ARCH_SECCOMP_FILTER if (AEABI && !OABI_COMPAT)
43 select HAVE_ARCH_TRACEHOOK
44 select HAVE_ARM_SMCCC if CPU_V7
46 select HAVE_CC_STACKPROTECTOR
47 select HAVE_CONTEXT_TRACKING
48 select HAVE_C_RECORDMCOUNT
49 select HAVE_DEBUG_KMEMLEAK
50 select HAVE_DMA_API_DEBUG
51 select HAVE_DMA_CONTIGUOUS if MMU
52 select HAVE_DYNAMIC_FTRACE if (!XIP_KERNEL) && !CPU_ENDIAN_BE32 && MMU
53 select HAVE_EFFICIENT_UNALIGNED_ACCESS if (CPU_V6 || CPU_V6K || CPU_V7) && MMU
54 select HAVE_EXIT_THREAD
55 select HAVE_FTRACE_MCOUNT_RECORD if (!XIP_KERNEL)
56 select HAVE_FUNCTION_GRAPH_TRACER if (!THUMB2_KERNEL)
57 select HAVE_FUNCTION_TRACER if (!XIP_KERNEL)
58 select HAVE_GCC_PLUGINS
59 select HAVE_GENERIC_DMA_COHERENT
60 select HAVE_HW_BREAKPOINT if (PERF_EVENTS && (CPU_V6 || CPU_V6K || CPU_V7))
61 select HAVE_IDE if PCI || ISA || PCMCIA
62 select HAVE_IRQ_TIME_ACCOUNTING
63 select HAVE_KERNEL_GZIP
64 select HAVE_KERNEL_LZ4
65 select HAVE_KERNEL_LZMA
66 select HAVE_KERNEL_LZO
68 select HAVE_KPROBES if !XIP_KERNEL && !CPU_ENDIAN_BE32 && !CPU_V7M
69 select HAVE_KRETPROBES if (HAVE_KPROBES)
71 select HAVE_MOD_ARCH_SPECIFIC
73 select HAVE_OPROFILE if (HAVE_PERF_EVENTS)
74 select HAVE_OPTPROBES if !THUMB2_KERNEL
75 select HAVE_PERF_EVENTS
77 select HAVE_PERF_USER_STACK_DUMP
78 select HAVE_RCU_TABLE_FREE if (SMP && ARM_LPAE)
79 select HAVE_REGS_AND_STACK_ACCESS_API
80 select HAVE_SYSCALL_TRACEPOINTS
82 select HAVE_VIRT_CPU_ACCOUNTING_GEN
83 select IRQ_FORCED_THREADING
84 select MODULES_USE_ELF_REL
86 select OF_EARLY_FLATTREE if OF
87 select OF_RESERVED_MEM if OF
89 select OLD_SIGSUSPEND3
90 select PERF_USE_VMALLOC
92 select SYS_SUPPORTS_APM_EMULATION
93 # Above selects are sorted alphabetically; please add new ones
94 # according to that. Thanks.
96 The ARM series is a line of low-power-consumption RISC chip designs
97 licensed by ARM Ltd and targeted at embedded applications and
98 handhelds such as the Compaq IPAQ. ARM-based PCs are no longer
99 manufactured, but legacy ARM-based PC hardware remains popular in
100 Europe. There is an ARM Linux project with a web page at
101 <http://www.arm.linux.org.uk/>.
103 config ARM_HAS_SG_CHAIN
104 select ARCH_HAS_SG_CHAIN
107 config NEED_SG_DMA_LENGTH
110 config ARM_DMA_USE_IOMMU
112 select ARM_HAS_SG_CHAIN
113 select NEED_SG_DMA_LENGTH
117 config ARM_DMA_IOMMU_ALIGNMENT
118 int "Maximum PAGE_SIZE order of alignment for DMA IOMMU buffers"
122 DMA mapping framework by default aligns all buffers to the smallest
123 PAGE_SIZE order which is greater than or equal to the requested buffer
124 size. This works well for buffers up to a few hundreds kilobytes, but
125 for larger buffers it just a waste of address space. Drivers which has
126 relatively small addressing window (like 64Mib) might run out of
127 virtual space with just a few allocations.
129 With this parameter you can specify the maximum PAGE_SIZE order for
130 DMA IOMMU buffers. Larger buffers will be aligned only to this
131 specified order. The order is expressed as a power of two multiplied
136 config MIGHT_HAVE_PCI
139 config SYS_SUPPORTS_APM_EMULATION
144 select GENERIC_ALLOCATOR
155 The Extended Industry Standard Architecture (EISA) bus was
156 developed as an open alternative to the IBM MicroChannel bus.
158 The EISA bus provided some of the features of the IBM MicroChannel
159 bus while maintaining backward compatibility with cards made for
160 the older ISA bus. The EISA bus saw limited use between 1988 and
161 1995 when it was made obsolete by the PCI bus.
163 Say Y here if you are building a kernel for an EISA-based machine.
170 config STACKTRACE_SUPPORT
174 config LOCKDEP_SUPPORT
178 config TRACE_IRQFLAGS_SUPPORT
182 config RWSEM_XCHGADD_ALGORITHM
186 config ARCH_HAS_ILOG2_U32
189 config ARCH_HAS_ILOG2_U64
192 config ARCH_HAS_BANDGAP
195 config FIX_EARLYCON_MEM
198 config GENERIC_HWEIGHT
202 config GENERIC_CALIBRATE_DELAY
206 config ARCH_MAY_HAVE_PC_FDC
212 config NEED_DMA_MAP_STATE
215 config ARCH_SUPPORTS_UPROBES
218 config ARCH_HAS_DMA_SET_COHERENT_MASK
221 config GENERIC_ISA_DMA
227 config NEED_RET_TO_USER
235 default 0xffff0000 if MMU || CPU_HIGH_VECTOR
236 default DRAM_BASE if REMAP_VECTORS_TO_RAM
239 The base address of exception vectors. This must be two pages
242 config ARM_PATCH_PHYS_VIRT
243 bool "Patch physical to virtual translations at runtime" if EMBEDDED
245 depends on !XIP_KERNEL && MMU
247 Patch phys-to-virt and virt-to-phys translation functions at
248 boot and module load time according to the position of the
249 kernel in system memory.
251 This can only be used with non-XIP MMU kernels where the base
252 of physical memory is at a 16MB boundary.
254 Only disable this option if you know that you do not require
255 this feature (eg, building a kernel for a single machine) and
256 you need to shrink the kernel to the minimal size.
258 config NEED_MACH_IO_H
261 Select this when mach/io.h is required to provide special
262 definitions for this platform. The need for mach/io.h should
263 be avoided when possible.
265 config NEED_MACH_MEMORY_H
268 Select this when mach/memory.h is required to provide special
269 definitions for this platform. The need for mach/memory.h should
270 be avoided when possible.
273 hex "Physical address of main memory" if MMU
274 depends on !ARM_PATCH_PHYS_VIRT
275 default DRAM_BASE if !MMU
276 default 0x00000000 if ARCH_EBSA110 || \
281 (ARCH_REALVIEW && !REALVIEW_HIGH_PHYS_OFFSET)
282 default 0x10000000 if ARCH_OMAP1 || ARCH_RPC
283 default 0x20000000 if ARCH_S5PV210
284 default 0x70000000 if REALVIEW_HIGH_PHYS_OFFSET
285 default 0xc0000000 if ARCH_SA1100
287 Please provide the physical address corresponding to the
288 location of main memory in your system.
294 config PGTABLE_LEVELS
296 default 3 if ARM_LPAE
299 source "init/Kconfig"
301 source "kernel/Kconfig.freezer"
306 bool "MMU-based Paged Memory Management Support"
309 Select if you want MMU-based virtualised addressing space
310 support by paged memory management. If unsure, say 'Y'.
312 config ARCH_MMAP_RND_BITS_MIN
315 config ARCH_MMAP_RND_BITS_MAX
316 default 14 if PAGE_OFFSET=0x40000000
317 default 15 if PAGE_OFFSET=0x80000000
321 # The "ARM system type" choice list is ordered alphabetically by option
322 # text. Please add new entries in the option alphabetic order.
325 prompt "ARM system type"
326 default ARM_SINGLE_ARMV7M if !MMU
327 default ARCH_MULTIPLATFORM if MMU
329 config ARCH_MULTIPLATFORM
330 bool "Allow multiple platforms to be selected"
332 select ARM_HAS_SG_CHAIN
333 select ARM_PATCH_PHYS_VIRT
337 select GENERIC_CLOCKEVENTS
338 select MIGHT_HAVE_PCI
339 select MULTI_IRQ_HANDLER
343 config ARM_SINGLE_ARMV7M
344 bool "ARMv7-M based platforms (Cortex-M0/M3/M4)"
351 select GENERIC_CLOCKEVENTS
357 bool "Cortina Systems Gemini"
360 select GENERIC_CLOCKEVENTS
363 Support for the Cortina Systems Gemini family SoCs
367 select ARCH_USES_GETTIMEOFFSET
370 select NEED_MACH_IO_H
371 select NEED_MACH_MEMORY_H
374 This is an evaluation board for the StrongARM processor available
375 from Digital. It has limited hardware on-board, including an
376 Ethernet interface, two PCMCIA sockets, two serial ports and a
381 select ARCH_HAS_HOLES_MEMORYMODEL
383 select ARM_PATCH_PHYS_VIRT
389 select GENERIC_CLOCKEVENTS
392 This enables support for the Cirrus EP93xx series of CPUs.
394 config ARCH_FOOTBRIDGE
398 select GENERIC_CLOCKEVENTS
400 select NEED_MACH_IO_H if !MMU
401 select NEED_MACH_MEMORY_H
403 Support for systems based on the DC21285 companion chip
404 ("FootBridge"), such as the Simtec CATS and the Rebel NetWinder.
407 bool "Hilscher NetX based"
411 select GENERIC_CLOCKEVENTS
413 This enables support for systems based on the Hilscher NetX Soc
419 select NEED_MACH_MEMORY_H
420 select NEED_RET_TO_USER
426 Support for Intel's IOP13XX (XScale) family of processors.
434 select NEED_RET_TO_USER
438 Support for Intel's 80219 and IOP32X (XScale) family of
447 select NEED_RET_TO_USER
451 Support for Intel's IOP33X (XScale) family of processors.
456 select ARCH_HAS_DMA_SET_COHERENT_MASK
457 select ARCH_SUPPORTS_BIG_ENDIAN
460 select DMABOUNCE if PCI
461 select GENERIC_CLOCKEVENTS
463 select MIGHT_HAVE_PCI
464 select NEED_MACH_IO_H
465 select USB_EHCI_BIG_ENDIAN_DESC
466 select USB_EHCI_BIG_ENDIAN_MMIO
468 Support for Intel's IXP4XX (XScale) family of processors.
473 select GENERIC_CLOCKEVENTS
475 select MIGHT_HAVE_PCI
476 select MULTI_IRQ_HANDLER
480 select PLAT_ORION_LEGACY
482 select PM_GENERIC_DOMAINS if PM
484 Support for the Marvell Dove SoC 88AP510
487 bool "Micrel/Kendin KS8695"
490 select GENERIC_CLOCKEVENTS
492 select NEED_MACH_MEMORY_H
494 Support for Micrel/Kendin KS8695 "Centaur" (ARM922T) based
495 System-on-Chip devices.
498 bool "Nuvoton W90X900 CPU"
502 select GENERIC_CLOCKEVENTS
505 Support for Nuvoton (Winbond logic dept.) ARM9 processor,
506 At present, the w90x900 has been renamed nuc900, regarding
507 the ARM series product line, you can login the following
508 link address to know more.
510 <http://www.nuvoton.com/hq/enu/ProductAndSales/ProductLines/
511 ConsumerElectronicsIC/ARMMicrocontroller/ARMMicrocontroller>
517 select CLKSRC_LPC32XX
520 select GENERIC_CLOCKEVENTS
522 select MULTI_IRQ_HANDLER
526 Support for the NXP LPC32XX family of processors
529 bool "PXA2xx/PXA3xx-based"
532 select ARM_CPU_SUSPEND if PM
539 select CPU_XSCALE if !CPU_XSC3
540 select GENERIC_CLOCKEVENTS
545 select MULTI_IRQ_HANDLER
549 Support for Intel/Marvell's PXA2xx/PXA3xx processor line.
555 select ARCH_MAY_HAVE_PC_FDC
556 select ARCH_SPARSEMEM_ENABLE
557 select ARCH_USES_GETTIMEOFFSET
561 select HAVE_PATA_PLATFORM
563 select NEED_MACH_IO_H
564 select NEED_MACH_MEMORY_H
567 On the Acorn Risc-PC, Linux can support the internal IDE disk and
568 CD-ROM interface, serial and parallel port, and the floppy drive.
573 select ARCH_SPARSEMEM_ENABLE
577 select CLKSRC_OF if OF
580 select GENERIC_CLOCKEVENTS
585 select MULTI_IRQ_HANDLER
586 select NEED_MACH_MEMORY_H
589 Support for StrongARM 11x0 based boards.
592 bool "Samsung S3C24XX SoCs"
595 select CLKSRC_SAMSUNG_PWM
596 select GENERIC_CLOCKEVENTS
599 select HAVE_S3C2410_I2C if I2C
600 select HAVE_S3C2410_WATCHDOG if WATCHDOG
601 select HAVE_S3C_RTC if RTC_CLASS
602 select MULTI_IRQ_HANDLER
603 select NEED_MACH_IO_H
606 Samsung S3C2410, S3C2412, S3C2413, S3C2416, S3C2440, S3C2442, S3C2443
607 and S3C2450 SoCs based systems, such as the Simtec Electronics BAST
608 (<http://www.simtec.co.uk/products/EB110ITX/>), the IPAQ 1940 or the
609 Samsung SMDK2410 development board (and derivatives).
613 select ARCH_HAS_HOLES_MEMORYMODEL
616 select GENERIC_ALLOCATOR
617 select GENERIC_CLOCKEVENTS
618 select GENERIC_IRQ_CHIP
624 Support for TI's DaVinci platform.
629 select ARCH_HAS_HOLES_MEMORYMODEL
633 select GENERIC_CLOCKEVENTS
634 select GENERIC_IRQ_CHIP
638 select MULTI_IRQ_HANDLER
639 select NEED_MACH_IO_H if PCCARD
640 select NEED_MACH_MEMORY_H
643 Support for older TI OMAP1 (omap7xx, omap15xx or omap16xx)
647 menu "Multiple platform selection"
648 depends on ARCH_MULTIPLATFORM
650 comment "CPU Core family selection"
653 bool "ARMv4 based platforms (FA526)"
654 depends on !ARCH_MULTI_V6_V7
655 select ARCH_MULTI_V4_V5
658 config ARCH_MULTI_V4T
659 bool "ARMv4T based platforms (ARM720T, ARM920T, ...)"
660 depends on !ARCH_MULTI_V6_V7
661 select ARCH_MULTI_V4_V5
662 select CPU_ARM920T if !(CPU_ARM7TDMI || CPU_ARM720T || \
663 CPU_ARM740T || CPU_ARM9TDMI || CPU_ARM922T || \
664 CPU_ARM925T || CPU_ARM940T)
667 bool "ARMv5 based platforms (ARM926T, XSCALE, PJ1, ...)"
668 depends on !ARCH_MULTI_V6_V7
669 select ARCH_MULTI_V4_V5
670 select CPU_ARM926T if !(CPU_ARM946E || CPU_ARM1020 || \
671 CPU_ARM1020E || CPU_ARM1022 || CPU_ARM1026 || \
672 CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK || CPU_FEROCEON)
674 config ARCH_MULTI_V4_V5
678 bool "ARMv6 based platforms (ARM11)"
679 select ARCH_MULTI_V6_V7
683 bool "ARMv7 based platforms (Cortex-A, PJ4, Scorpion, Krait)"
685 select ARCH_MULTI_V6_V7
689 config ARCH_MULTI_V6_V7
691 select MIGHT_HAVE_CACHE_L2X0
693 config ARCH_MULTI_CPU_AUTO
694 def_bool !(ARCH_MULTI_V4 || ARCH_MULTI_V4T || ARCH_MULTI_V6_V7)
700 bool "Dummy Virtual Machine"
701 depends on ARCH_MULTI_V7
704 select ARM_GIC_V2M if PCI
707 select HAVE_ARM_ARCH_TIMER
710 # This is sorted alphabetically by mach-* pathname. However, plat-*
711 # Kconfigs may be included either alphabetically (according to the
712 # plat- suffix) or along side the corresponding mach-* source.
714 source "arch/arm/mach-mvebu/Kconfig"
716 source "arch/arm/mach-alpine/Kconfig"
718 source "arch/arm/mach-artpec/Kconfig"
720 source "arch/arm/mach-asm9260/Kconfig"
722 source "arch/arm/mach-at91/Kconfig"
724 source "arch/arm/mach-axxia/Kconfig"
726 source "arch/arm/mach-bcm/Kconfig"
728 source "arch/arm/mach-berlin/Kconfig"
730 source "arch/arm/mach-clps711x/Kconfig"
732 source "arch/arm/mach-cns3xxx/Kconfig"
734 source "arch/arm/mach-davinci/Kconfig"
736 source "arch/arm/mach-digicolor/Kconfig"
738 source "arch/arm/mach-dove/Kconfig"
740 source "arch/arm/mach-ep93xx/Kconfig"
742 source "arch/arm/mach-footbridge/Kconfig"
744 source "arch/arm/mach-gemini/Kconfig"
746 source "arch/arm/mach-highbank/Kconfig"
748 source "arch/arm/mach-hisi/Kconfig"
750 source "arch/arm/mach-integrator/Kconfig"
752 source "arch/arm/mach-iop32x/Kconfig"
754 source "arch/arm/mach-iop33x/Kconfig"
756 source "arch/arm/mach-iop13xx/Kconfig"
758 source "arch/arm/mach-ixp4xx/Kconfig"
760 source "arch/arm/mach-keystone/Kconfig"
762 source "arch/arm/mach-ks8695/Kconfig"
764 source "arch/arm/mach-meson/Kconfig"
766 source "arch/arm/mach-moxart/Kconfig"
768 source "arch/arm/mach-aspeed/Kconfig"
770 source "arch/arm/mach-mv78xx0/Kconfig"
772 source "arch/arm/mach-imx/Kconfig"
774 source "arch/arm/mach-mediatek/Kconfig"
776 source "arch/arm/mach-mxs/Kconfig"
778 source "arch/arm/mach-netx/Kconfig"
780 source "arch/arm/mach-nomadik/Kconfig"
782 source "arch/arm/mach-nspire/Kconfig"
784 source "arch/arm/plat-omap/Kconfig"
786 source "arch/arm/mach-omap1/Kconfig"
788 source "arch/arm/mach-omap2/Kconfig"
790 source "arch/arm/mach-orion5x/Kconfig"
792 source "arch/arm/mach-picoxcell/Kconfig"
794 source "arch/arm/mach-pxa/Kconfig"
795 source "arch/arm/plat-pxa/Kconfig"
797 source "arch/arm/mach-mmp/Kconfig"
799 source "arch/arm/mach-oxnas/Kconfig"
801 source "arch/arm/mach-qcom/Kconfig"
803 source "arch/arm/mach-realview/Kconfig"
805 source "arch/arm/mach-rockchip/Kconfig"
807 source "arch/arm/mach-sa1100/Kconfig"
809 source "arch/arm/mach-socfpga/Kconfig"
811 source "arch/arm/mach-spear/Kconfig"
813 source "arch/arm/mach-sti/Kconfig"
815 source "arch/arm/mach-s3c24xx/Kconfig"
817 source "arch/arm/mach-s3c64xx/Kconfig"
819 source "arch/arm/mach-s5pv210/Kconfig"
821 source "arch/arm/mach-exynos/Kconfig"
822 source "arch/arm/plat-samsung/Kconfig"
824 source "arch/arm/mach-shmobile/Kconfig"
826 source "arch/arm/mach-sunxi/Kconfig"
828 source "arch/arm/mach-prima2/Kconfig"
830 source "arch/arm/mach-tango/Kconfig"
832 source "arch/arm/mach-tegra/Kconfig"
834 source "arch/arm/mach-u300/Kconfig"
836 source "arch/arm/mach-uniphier/Kconfig"
838 source "arch/arm/mach-ux500/Kconfig"
840 source "arch/arm/mach-versatile/Kconfig"
842 source "arch/arm/mach-vexpress/Kconfig"
843 source "arch/arm/plat-versatile/Kconfig"
845 source "arch/arm/mach-vt8500/Kconfig"
847 source "arch/arm/mach-w90x900/Kconfig"
849 source "arch/arm/mach-zx/Kconfig"
851 source "arch/arm/mach-zynq/Kconfig"
853 # ARMv7-M architecture
855 bool "Energy Micro efm32"
856 depends on ARM_SINGLE_ARMV7M
859 Support for Energy Micro's (now Silicon Labs) efm32 Giant Gecko
863 bool "NXP LPC18xx/LPC43xx"
864 depends on ARM_SINGLE_ARMV7M
865 select ARCH_HAS_RESET_CONTROLLER
867 select CLKSRC_LPC32XX
870 Support for NXP's LPC18xx Cortex-M3 and LPC43xx Cortex-M4
871 high performance microcontrollers.
874 bool "STMicrolectronics STM32"
875 depends on ARM_SINGLE_ARMV7M
876 select ARCH_HAS_RESET_CONTROLLER
877 select ARMV7M_SYSTICK
880 select RESET_CONTROLLER
882 Support for STMicroelectronics STM32 processors.
884 config MACH_STM32F429
885 bool "STMicrolectronics STM32F429"
886 depends on ARCH_STM32
890 bool "ARM MPS2 platform"
891 depends on ARM_SINGLE_ARMV7M
895 Support for Cortex-M Prototyping System (or V2M-MPS2) which comes
896 with a range of available cores like Cortex-M3/M4/M7.
898 Please, note that depends which Application Note is used memory map
899 for the platform may vary, so adjustment of RAM base might be needed.
901 # Definitions to make life easier
907 select GENERIC_CLOCKEVENTS
913 select GENERIC_IRQ_CHIP
916 config PLAT_ORION_LEGACY
923 config PLAT_VERSATILE
926 source "arch/arm/firmware/Kconfig"
928 source arch/arm/mm/Kconfig
931 bool "Enable iWMMXt support"
932 depends on CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK || CPU_PJ4 || CPU_PJ4B
933 default y if PXA27x || PXA3xx || ARCH_MMP || CPU_PJ4 || CPU_PJ4B
935 Enable support for iWMMXt context switching at run time if
936 running on a CPU that supports it.
938 config MULTI_IRQ_HANDLER
941 Allow each machine to specify it's own IRQ handler at run time.
944 source "arch/arm/Kconfig-nommu"
947 config PJ4B_ERRATA_4742
948 bool "PJ4B Errata 4742: IDLE Wake Up Commands can Cause the CPU Core to Cease Operation"
949 depends on CPU_PJ4B && MACH_ARMADA_370
952 When coming out of either a Wait for Interrupt (WFI) or a Wait for
953 Event (WFE) IDLE states, a specific timing sensitivity exists between
954 the retiring WFI/WFE instructions and the newly issued subsequent
955 instructions. This sensitivity can result in a CPU hang scenario.
957 The software must insert either a Data Synchronization Barrier (DSB)
958 or Data Memory Barrier (DMB) command immediately after the WFI/WFE
961 config ARM_ERRATA_326103
962 bool "ARM errata: FSR write bit incorrect on a SWP to read-only memory"
965 Executing a SWP instruction to read-only memory does not set bit 11
966 of the FSR on the ARM 1136 prior to r1p0. This causes the kernel to
967 treat the access as a read, preventing a COW from occurring and
968 causing the faulting task to livelock.
970 config ARM_ERRATA_411920
971 bool "ARM errata: Invalidation of the Instruction Cache operation can fail"
972 depends on CPU_V6 || CPU_V6K
974 Invalidation of the Instruction Cache operation can
975 fail. This erratum is present in 1136 (before r1p4), 1156 and 1176.
976 It does not affect the MPCore. This option enables the ARM Ltd.
977 recommended workaround.
979 config ARM_ERRATA_430973
980 bool "ARM errata: Stale prediction on replaced interworking branch"
983 This option enables the workaround for the 430973 Cortex-A8
984 r1p* erratum. If a code sequence containing an ARM/Thumb
985 interworking branch is replaced with another code sequence at the
986 same virtual address, whether due to self-modifying code or virtual
987 to physical address re-mapping, Cortex-A8 does not recover from the
988 stale interworking branch prediction. This results in Cortex-A8
989 executing the new code sequence in the incorrect ARM or Thumb state.
990 The workaround enables the BTB/BTAC operations by setting ACTLR.IBE
991 and also flushes the branch target cache at every context switch.
992 Note that setting specific bits in the ACTLR register may not be
993 available in non-secure mode.
995 config ARM_ERRATA_458693
996 bool "ARM errata: Processor deadlock when a false hazard is created"
998 depends on !ARCH_MULTIPLATFORM
1000 This option enables the workaround for the 458693 Cortex-A8 (r2p0)
1001 erratum. For very specific sequences of memory operations, it is
1002 possible for a hazard condition intended for a cache line to instead
1003 be incorrectly associated with a different cache line. This false
1004 hazard might then cause a processor deadlock. The workaround enables
1005 the L1 caching of the NEON accesses and disables the PLD instruction
1006 in the ACTLR register. Note that setting specific bits in the ACTLR
1007 register may not be available in non-secure mode.
1009 config ARM_ERRATA_460075
1010 bool "ARM errata: Data written to the L2 cache can be overwritten with stale data"
1012 depends on !ARCH_MULTIPLATFORM
1014 This option enables the workaround for the 460075 Cortex-A8 (r2p0)
1015 erratum. Any asynchronous access to the L2 cache may encounter a
1016 situation in which recent store transactions to the L2 cache are lost
1017 and overwritten with stale memory contents from external memory. The
1018 workaround disables the write-allocate mode for the L2 cache via the
1019 ACTLR register. Note that setting specific bits in the ACTLR register
1020 may not be available in non-secure mode.
1022 config ARM_ERRATA_742230
1023 bool "ARM errata: DMB operation may be faulty"
1024 depends on CPU_V7 && SMP
1025 depends on !ARCH_MULTIPLATFORM
1027 This option enables the workaround for the 742230 Cortex-A9
1028 (r1p0..r2p2) erratum. Under rare circumstances, a DMB instruction
1029 between two write operations may not ensure the correct visibility
1030 ordering of the two writes. This workaround sets a specific bit in
1031 the diagnostic register of the Cortex-A9 which causes the DMB
1032 instruction to behave as a DSB, ensuring the correct behaviour of
1035 config ARM_ERRATA_742231
1036 bool "ARM errata: Incorrect hazard handling in the SCU may lead to data corruption"
1037 depends on CPU_V7 && SMP
1038 depends on !ARCH_MULTIPLATFORM
1040 This option enables the workaround for the 742231 Cortex-A9
1041 (r2p0..r2p2) erratum. Under certain conditions, specific to the
1042 Cortex-A9 MPCore micro-architecture, two CPUs working in SMP mode,
1043 accessing some data located in the same cache line, may get corrupted
1044 data due to bad handling of the address hazard when the line gets
1045 replaced from one of the CPUs at the same time as another CPU is
1046 accessing it. This workaround sets specific bits in the diagnostic
1047 register of the Cortex-A9 which reduces the linefill issuing
1048 capabilities of the processor.
1050 config ARM_ERRATA_643719
1051 bool "ARM errata: LoUIS bit field in CLIDR register is incorrect"
1052 depends on CPU_V7 && SMP
1055 This option enables the workaround for the 643719 Cortex-A9 (prior to
1056 r1p0) erratum. On affected cores the LoUIS bit field of the CLIDR
1057 register returns zero when it should return one. The workaround
1058 corrects this value, ensuring cache maintenance operations which use
1059 it behave as intended and avoiding data corruption.
1061 config ARM_ERRATA_720789
1062 bool "ARM errata: TLBIASIDIS and TLBIMVAIS operations can broadcast a faulty ASID"
1065 This option enables the workaround for the 720789 Cortex-A9 (prior to
1066 r2p0) erratum. A faulty ASID can be sent to the other CPUs for the
1067 broadcasted CP15 TLB maintenance operations TLBIASIDIS and TLBIMVAIS.
1068 As a consequence of this erratum, some TLB entries which should be
1069 invalidated are not, resulting in an incoherency in the system page
1070 tables. The workaround changes the TLB flushing routines to invalidate
1071 entries regardless of the ASID.
1073 config ARM_ERRATA_743622
1074 bool "ARM errata: Faulty hazard checking in the Store Buffer may lead to data corruption"
1076 depends on !ARCH_MULTIPLATFORM
1078 This option enables the workaround for the 743622 Cortex-A9
1079 (r2p*) erratum. Under very rare conditions, a faulty
1080 optimisation in the Cortex-A9 Store Buffer may lead to data
1081 corruption. This workaround sets a specific bit in the diagnostic
1082 register of the Cortex-A9 which disables the Store Buffer
1083 optimisation, preventing the defect from occurring. This has no
1084 visible impact on the overall performance or power consumption of the
1087 config ARM_ERRATA_751472
1088 bool "ARM errata: Interrupted ICIALLUIS may prevent completion of broadcasted operation"
1090 depends on !ARCH_MULTIPLATFORM
1092 This option enables the workaround for the 751472 Cortex-A9 (prior
1093 to r3p0) erratum. An interrupted ICIALLUIS operation may prevent the
1094 completion of a following broadcasted operation if the second
1095 operation is received by a CPU before the ICIALLUIS has completed,
1096 potentially leading to corrupted entries in the cache or TLB.
1098 config ARM_ERRATA_754322
1099 bool "ARM errata: possible faulty MMU translations following an ASID switch"
1102 This option enables the workaround for the 754322 Cortex-A9 (r2p*,
1103 r3p*) erratum. A speculative memory access may cause a page table walk
1104 which starts prior to an ASID switch but completes afterwards. This
1105 can populate the micro-TLB with a stale entry which may be hit with
1106 the new ASID. This workaround places two dsb instructions in the mm
1107 switching code so that no page table walks can cross the ASID switch.
1109 config ARM_ERRATA_754327
1110 bool "ARM errata: no automatic Store Buffer drain"
1111 depends on CPU_V7 && SMP
1113 This option enables the workaround for the 754327 Cortex-A9 (prior to
1114 r2p0) erratum. The Store Buffer does not have any automatic draining
1115 mechanism and therefore a livelock may occur if an external agent
1116 continuously polls a memory location waiting to observe an update.
1117 This workaround defines cpu_relax() as smp_mb(), preventing correctly
1118 written polling loops from denying visibility of updates to memory.
1120 config ARM_ERRATA_364296
1121 bool "ARM errata: Possible cache data corruption with hit-under-miss enabled"
1124 This options enables the workaround for the 364296 ARM1136
1125 r0p2 erratum (possible cache data corruption with
1126 hit-under-miss enabled). It sets the undocumented bit 31 in
1127 the auxiliary control register and the FI bit in the control
1128 register, thus disabling hit-under-miss without putting the
1129 processor into full low interrupt latency mode. ARM11MPCore
1132 config ARM_ERRATA_764369
1133 bool "ARM errata: Data cache line maintenance operation by MVA may not succeed"
1134 depends on CPU_V7 && SMP
1136 This option enables the workaround for erratum 764369
1137 affecting Cortex-A9 MPCore with two or more processors (all
1138 current revisions). Under certain timing circumstances, a data
1139 cache line maintenance operation by MVA targeting an Inner
1140 Shareable memory region may fail to proceed up to either the
1141 Point of Coherency or to the Point of Unification of the
1142 system. This workaround adds a DSB instruction before the
1143 relevant cache maintenance functions and sets a specific bit
1144 in the diagnostic control register of the SCU.
1146 config ARM_ERRATA_775420
1147 bool "ARM errata: A data cache maintenance operation which aborts, might lead to deadlock"
1150 This option enables the workaround for the 775420 Cortex-A9 (r2p2,
1151 r2p6,r2p8,r2p10,r3p0) erratum. In case a date cache maintenance
1152 operation aborts with MMU exception, it might cause the processor
1153 to deadlock. This workaround puts DSB before executing ISB if
1154 an abort may occur on cache maintenance.
1156 config ARM_ERRATA_798181
1157 bool "ARM errata: TLBI/DSB failure on Cortex-A15"
1158 depends on CPU_V7 && SMP
1160 On Cortex-A15 (r0p0..r3p2) the TLBI*IS/DSB operations are not
1161 adequately shooting down all use of the old entries. This
1162 option enables the Linux kernel workaround for this erratum
1163 which sends an IPI to the CPUs that are running the same ASID
1164 as the one being invalidated.
1166 config ARM_ERRATA_773022
1167 bool "ARM errata: incorrect instructions may be executed from loop buffer"
1170 This option enables the workaround for the 773022 Cortex-A15
1171 (up to r0p4) erratum. In certain rare sequences of code, the
1172 loop buffer may deliver incorrect instructions. This
1173 workaround disables the loop buffer to avoid the erratum.
1175 config ARM_ERRATA_818325_852422
1176 bool "ARM errata: A12: some seqs of opposed cond code instrs => deadlock or corruption"
1179 This option enables the workaround for:
1180 - Cortex-A12 818325: Execution of an UNPREDICTABLE STR or STM
1181 instruction might deadlock. Fixed in r0p1.
1182 - Cortex-A12 852422: Execution of a sequence of instructions might
1183 lead to either a data corruption or a CPU deadlock. Not fixed in
1184 any Cortex-A12 cores yet.
1185 This workaround for all both errata involves setting bit[12] of the
1186 Feature Register. This bit disables an optimisation applied to a
1187 sequence of 2 instructions that use opposing condition codes.
1189 config ARM_ERRATA_821420
1190 bool "ARM errata: A12: sequence of VMOV to core registers might lead to a dead lock"
1193 This option enables the workaround for the 821420 Cortex-A12
1194 (all revs) erratum. In very rare timing conditions, a sequence
1195 of VMOV to Core registers instructions, for which the second
1196 one is in the shadow of a branch or abort, can lead to a
1197 deadlock when the VMOV instructions are issued out-of-order.
1199 config ARM_ERRATA_825619
1200 bool "ARM errata: A12: DMB NSHST/ISHST mixed ... might cause deadlock"
1203 This option enables the workaround for the 825619 Cortex-A12
1204 (all revs) erratum. Within rare timing constraints, executing a
1205 DMB NSHST or DMB ISHST instruction followed by a mix of Cacheable
1206 and Device/Strongly-Ordered loads and stores might cause deadlock
1208 config ARM_ERRATA_852421
1209 bool "ARM errata: A17: DMB ST might fail to create order between stores"
1212 This option enables the workaround for the 852421 Cortex-A17
1213 (r1p0, r1p1, r1p2) erratum. Under very rare timing conditions,
1214 execution of a DMB ST instruction might fail to properly order
1215 stores from GroupA and stores from GroupB.
1217 config ARM_ERRATA_852423
1218 bool "ARM errata: A17: some seqs of opposed cond code instrs => deadlock or corruption"
1221 This option enables the workaround for:
1222 - Cortex-A17 852423: Execution of a sequence of instructions might
1223 lead to either a data corruption or a CPU deadlock. Not fixed in
1224 any Cortex-A17 cores yet.
1225 This is identical to Cortex-A12 erratum 852422. It is a separate
1226 config option from the A12 erratum due to the way errata are checked
1231 source "arch/arm/common/Kconfig"
1238 Find out whether you have ISA slots on your motherboard. ISA is the
1239 name of a bus system, i.e. the way the CPU talks to the other stuff
1240 inside your box. Other bus systems are PCI, EISA, MicroChannel
1241 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1242 newer boards don't support it. If you have ISA, say Y, otherwise N.
1244 # Select ISA DMA controller support
1249 # Select ISA DMA interface
1254 bool "PCI support" if MIGHT_HAVE_PCI
1256 Find out whether you have a PCI motherboard. PCI is the name of a
1257 bus system, i.e. the way the CPU talks to the other stuff inside
1258 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1259 VESA. If you have PCI, say Y, otherwise N.
1265 config PCI_DOMAINS_GENERIC
1266 def_bool PCI_DOMAINS
1268 config PCI_NANOENGINE
1269 bool "BSE nanoEngine PCI support"
1270 depends on SA1100_NANOENGINE
1272 Enable PCI on the BSE nanoEngine board.
1277 config PCI_HOST_ITE8152
1279 depends on PCI && MACH_ARMCORE
1283 source "drivers/pci/Kconfig"
1285 source "drivers/pcmcia/Kconfig"
1289 menu "Kernel Features"
1294 This option should be selected by machines which have an SMP-
1297 The only effect of this option is to make the SMP-related
1298 options available to the user for configuration.
1301 bool "Symmetric Multi-Processing"
1302 depends on CPU_V6K || CPU_V7
1303 depends on GENERIC_CLOCKEVENTS
1305 depends on MMU || ARM_MPU
1308 This enables support for systems with more than one CPU. If you have
1309 a system with only one CPU, say N. If you have a system with more
1310 than one CPU, say Y.
1312 If you say N here, the kernel will run on uni- and multiprocessor
1313 machines, but will use only one CPU of a multiprocessor machine. If
1314 you say Y here, the kernel will run on many, but not all,
1315 uniprocessor machines. On a uniprocessor machine, the kernel
1316 will run faster if you say N here.
1318 See also <file:Documentation/x86/i386/IO-APIC.txt>,
1319 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
1320 <http://tldp.org/HOWTO/SMP-HOWTO.html>.
1322 If you don't know what to do here, say N.
1325 bool "Allow booting SMP kernel on uniprocessor systems"
1326 depends on SMP && !XIP_KERNEL && MMU
1329 SMP kernels contain instructions which fail on non-SMP processors.
1330 Enabling this option allows the kernel to modify itself to make
1331 these instructions safe. Disabling it allows about 1K of space
1334 If you don't know what to do here, say Y.
1336 config ARM_CPU_TOPOLOGY
1337 bool "Support cpu topology definition"
1338 depends on SMP && CPU_V7
1341 Support ARM cpu topology definition. The MPIDR register defines
1342 affinity between processors which is then used to describe the cpu
1343 topology of an ARM System.
1346 bool "Multi-core scheduler support"
1347 depends on ARM_CPU_TOPOLOGY
1349 Multi-core scheduler support improves the CPU scheduler's decision
1350 making when dealing with multi-core CPU chips at a cost of slightly
1351 increased overhead in some places. If unsure say N here.
1354 bool "SMT scheduler support"
1355 depends on ARM_CPU_TOPOLOGY
1357 Improves the CPU scheduler's decision making when dealing with
1358 MultiThreading at a cost of slightly increased overhead in some
1359 places. If unsure say N here.
1364 This option enables support for the ARM system coherency unit
1366 config HAVE_ARM_ARCH_TIMER
1367 bool "Architected timer support"
1369 select ARM_ARCH_TIMER
1370 select GENERIC_CLOCKEVENTS
1372 This option enables support for the ARM architected timer
1376 select CLKSRC_OF if OF
1378 This options enables support for the ARM timer and watchdog unit
1381 bool "Multi-Cluster Power Management"
1382 depends on CPU_V7 && SMP
1384 This option provides the common power management infrastructure
1385 for (multi-)cluster based systems, such as big.LITTLE based
1388 config MCPM_QUAD_CLUSTER
1392 To avoid wasting resources unnecessarily, MCPM only supports up
1393 to 2 clusters by default.
1394 Platforms with 3 or 4 clusters that use MCPM must select this
1395 option to allow the additional clusters to be managed.
1398 bool "big.LITTLE support (Experimental)"
1399 depends on CPU_V7 && SMP
1402 This option enables support selections for the big.LITTLE
1403 system architecture.
1406 bool "big.LITTLE switcher support"
1407 depends on BIG_LITTLE && MCPM && HOTPLUG_CPU && ARM_GIC
1410 The big.LITTLE "switcher" provides the core functionality to
1411 transparently handle transition between a cluster of A15's
1412 and a cluster of A7's in a big.LITTLE system.
1414 config BL_SWITCHER_DUMMY_IF
1415 tristate "Simple big.LITTLE switcher user interface"
1416 depends on BL_SWITCHER && DEBUG_KERNEL
1418 This is a simple and dummy char dev interface to control
1419 the big.LITTLE switcher core code. It is meant for
1420 debugging purposes only.
1423 prompt "Memory split"
1427 Select the desired split between kernel and user memory.
1429 If you are not absolutely sure what you are doing, leave this
1433 bool "3G/1G user/kernel split"
1434 config VMSPLIT_3G_OPT
1435 bool "3G/1G user/kernel split (for full 1G low memory)"
1437 bool "2G/2G user/kernel split"
1439 bool "1G/3G user/kernel split"
1444 default PHYS_OFFSET if !MMU
1445 default 0x40000000 if VMSPLIT_1G
1446 default 0x80000000 if VMSPLIT_2G
1447 default 0xB0000000 if VMSPLIT_3G_OPT
1451 int "Maximum number of CPUs (2-32)"
1457 bool "Support for hot-pluggable CPUs"
1460 Say Y here to experiment with turning CPUs off and on. CPUs
1461 can be controlled through /sys/devices/system/cpu.
1464 bool "Support for the ARM Power State Coordination Interface (PSCI)"
1465 depends on HAVE_ARM_SMCCC
1468 Say Y here if you want Linux to communicate with system firmware
1469 implementing the PSCI specification for CPU-centric power
1470 management operations described in ARM document number ARM DEN
1471 0022A ("Power State Coordination Interface System Software on
1474 # The GPIO number here must be sorted by descending number. In case of
1475 # a multiplatform kernel, we just want the highest value required by the
1476 # selected platforms.
1479 default 1024 if ARCH_BRCMSTB || ARCH_SHMOBILE || ARCH_TEGRA || \
1481 default 512 if ARCH_EXYNOS || ARCH_KEYSTONE || SOC_OMAP5 || \
1482 SOC_DRA7XX || ARCH_S3C24XX || ARCH_S3C64XX || ARCH_S5PV210
1483 default 416 if ARCH_SUNXI
1484 default 392 if ARCH_U8500
1485 default 352 if ARCH_VT8500
1486 default 288 if ARCH_ROCKCHIP
1487 default 264 if MACH_H4700
1490 Maximum number of GPIOs in the system.
1492 If unsure, leave the default value.
1494 source kernel/Kconfig.preempt
1498 default 200 if ARCH_EBSA110 || ARCH_S3C24XX || \
1499 ARCH_S5PV210 || ARCH_EXYNOS4
1500 default 128 if SOC_AT91RM9200
1504 depends on HZ_FIXED = 0
1505 prompt "Timer frequency"
1529 default HZ_FIXED if HZ_FIXED != 0
1530 default 100 if HZ_100
1531 default 200 if HZ_200
1532 default 250 if HZ_250
1533 default 300 if HZ_300
1534 default 500 if HZ_500
1538 def_bool HIGH_RES_TIMERS
1540 config THUMB2_KERNEL
1541 bool "Compile the kernel in Thumb-2 mode" if !CPU_THUMBONLY
1542 depends on (CPU_V7 || CPU_V7M) && !CPU_V6 && !CPU_V6K
1543 default y if CPU_THUMBONLY
1545 select ARM_ASM_UNIFIED
1548 By enabling this option, the kernel will be compiled in
1549 Thumb-2 mode. A compiler/assembler that understand the unified
1550 ARM-Thumb syntax is needed.
1554 config THUMB2_AVOID_R_ARM_THM_JUMP11
1555 bool "Work around buggy Thumb-2 short branch relocations in gas"
1556 depends on THUMB2_KERNEL && MODULES
1559 Various binutils versions can resolve Thumb-2 branches to
1560 locally-defined, preemptible global symbols as short-range "b.n"
1561 branch instructions.
1563 This is a problem, because there's no guarantee the final
1564 destination of the symbol, or any candidate locations for a
1565 trampoline, are within range of the branch. For this reason, the
1566 kernel does not support fixing up the R_ARM_THM_JUMP11 (102)
1567 relocation in modules at all, and it makes little sense to add
1570 The symptom is that the kernel fails with an "unsupported
1571 relocation" error when loading some modules.
1573 Until fixed tools are available, passing
1574 -fno-optimize-sibling-calls to gcc should prevent gcc generating
1575 code which hits this problem, at the cost of a bit of extra runtime
1576 stack usage in some cases.
1578 The problem is described in more detail at:
1579 https://bugs.launchpad.net/binutils-linaro/+bug/725126
1581 Only Thumb-2 kernels are affected.
1583 Unless you are sure your tools don't have this problem, say Y.
1585 config ARM_ASM_UNIFIED
1588 config ARM_PATCH_IDIV
1589 bool "Runtime patch udiv/sdiv instructions into __aeabi_{u}idiv()"
1590 depends on CPU_32v7 && !XIP_KERNEL
1593 The ARM compiler inserts calls to __aeabi_idiv() and
1594 __aeabi_uidiv() when it needs to perform division on signed
1595 and unsigned integers. Some v7 CPUs have support for the sdiv
1596 and udiv instructions that can be used to implement those
1599 Enabling this option allows the kernel to modify itself to
1600 replace the first two instructions of these library functions
1601 with the sdiv or udiv plus "bx lr" instructions when the CPU
1602 it is running on supports them. Typically this will be faster
1603 and less power intensive than running the original library
1604 code to do integer division.
1607 bool "Use the ARM EABI to compile the kernel"
1609 This option allows for the kernel to be compiled using the latest
1610 ARM ABI (aka EABI). This is only useful if you are using a user
1611 space environment that is also compiled with EABI.
1613 Since there are major incompatibilities between the legacy ABI and
1614 EABI, especially with regard to structure member alignment, this
1615 option also changes the kernel syscall calling convention to
1616 disambiguate both ABIs and allow for backward compatibility support
1617 (selected with CONFIG_OABI_COMPAT).
1619 To use this you need GCC version 4.0.0 or later.
1622 bool "Allow old ABI binaries to run with this kernel (EXPERIMENTAL)"
1623 depends on AEABI && !THUMB2_KERNEL
1625 This option preserves the old syscall interface along with the
1626 new (ARM EABI) one. It also provides a compatibility layer to
1627 intercept syscalls that have structure arguments which layout
1628 in memory differs between the legacy ABI and the new ARM EABI
1629 (only for non "thumb" binaries). This option adds a tiny
1630 overhead to all syscalls and produces a slightly larger kernel.
1632 The seccomp filter system will not be available when this is
1633 selected, since there is no way yet to sensibly distinguish
1634 between calling conventions during filtering.
1636 If you know you'll be using only pure EABI user space then you
1637 can say N here. If this option is not selected and you attempt
1638 to execute a legacy ABI binary then the result will be
1639 UNPREDICTABLE (in fact it can be predicted that it won't work
1640 at all). If in doubt say N.
1642 config ARCH_HAS_HOLES_MEMORYMODEL
1645 config ARCH_SPARSEMEM_ENABLE
1648 config ARCH_SPARSEMEM_DEFAULT
1649 def_bool ARCH_SPARSEMEM_ENABLE
1651 config ARCH_SELECT_MEMORY_MODEL
1652 def_bool ARCH_SPARSEMEM_ENABLE
1654 config HAVE_ARCH_PFN_VALID
1655 def_bool ARCH_HAS_HOLES_MEMORYMODEL || !SPARSEMEM
1657 config HAVE_GENERIC_RCU_GUP
1662 bool "High Memory Support"
1665 The address space of ARM processors is only 4 Gigabytes large
1666 and it has to accommodate user address space, kernel address
1667 space as well as some memory mapped IO. That means that, if you
1668 have a large amount of physical memory and/or IO, not all of the
1669 memory can be "permanently mapped" by the kernel. The physical
1670 memory that is not permanently mapped is called "high memory".
1672 Depending on the selected kernel/user memory split, minimum
1673 vmalloc space and actual amount of RAM, you may not need this
1674 option which should result in a slightly faster kernel.
1679 bool "Allocate 2nd-level pagetables from highmem" if EXPERT
1683 The VM uses one page of physical memory for each page table.
1684 For systems with a lot of processes, this can use a lot of
1685 precious low memory, eventually leading to low memory being
1686 consumed by page tables. Setting this option will allow
1687 user-space 2nd level page tables to reside in high memory.
1689 config CPU_SW_DOMAIN_PAN
1690 bool "Enable use of CPU domains to implement privileged no-access"
1691 depends on MMU && !ARM_LPAE
1694 Increase kernel security by ensuring that normal kernel accesses
1695 are unable to access userspace addresses. This can help prevent
1696 use-after-free bugs becoming an exploitable privilege escalation
1697 by ensuring that magic values (such as LIST_POISON) will always
1698 fault when dereferenced.
1700 CPUs with low-vector mappings use a best-efforts implementation.
1701 Their lower 1MB needs to remain accessible for the vectors, but
1702 the remainder of userspace will become appropriately inaccessible.
1704 config HW_PERF_EVENTS
1708 config SYS_SUPPORTS_HUGETLBFS
1712 config HAVE_ARCH_TRANSPARENT_HUGEPAGE
1716 config ARCH_WANT_GENERAL_HUGETLB
1719 config ARM_MODULE_PLTS
1720 bool "Use PLTs to allow module memory to spill over into vmalloc area"
1723 Allocate PLTs when loading modules so that jumps and calls whose
1724 targets are too far away for their relative offsets to be encoded
1725 in the instructions themselves can be bounced via veneers in the
1726 module's PLT. This allows modules to be allocated in the generic
1727 vmalloc area after the dedicated module memory area has been
1728 exhausted. The modules will use slightly more memory, but after
1729 rounding up to page size, the actual memory footprint is usually
1732 Say y if you are getting out of memory errors while loading modules
1736 config FORCE_MAX_ZONEORDER
1737 int "Maximum zone order"
1738 default "12" if SOC_AM33XX
1739 default "9" if SA1111 || ARCH_EFM32
1742 The kernel memory allocator divides physically contiguous memory
1743 blocks into "zones", where each zone is a power of two number of
1744 pages. This option selects the largest power of two that the kernel
1745 keeps in the memory allocator. If you need to allocate very large
1746 blocks of physically contiguous memory, then you may need to
1747 increase this value.
1749 This config option is actually maximum order plus one. For example,
1750 a value of 11 means that the largest free memory block is 2^10 pages.
1752 config ALIGNMENT_TRAP
1754 depends on CPU_CP15_MMU
1755 default y if !ARCH_EBSA110
1756 select HAVE_PROC_CPU if PROC_FS
1758 ARM processors cannot fetch/store information which is not
1759 naturally aligned on the bus, i.e., a 4 byte fetch must start at an
1760 address divisible by 4. On 32-bit ARM processors, these non-aligned
1761 fetch/store instructions will be emulated in software if you say
1762 here, which has a severe performance impact. This is necessary for
1763 correct operation of some network protocols. With an IP-only
1764 configuration it is safe to say N, otherwise say Y.
1766 config UACCESS_WITH_MEMCPY
1767 bool "Use kernel mem{cpy,set}() for {copy_to,clear}_user()"
1769 default y if CPU_FEROCEON
1771 Implement faster copy_to_user and clear_user methods for CPU
1772 cores where a 8-word STM instruction give significantly higher
1773 memory write throughput than a sequence of individual 32bit stores.
1775 A possible side effect is a slight increase in scheduling latency
1776 between threads sharing the same address space if they invoke
1777 such copy operations with large buffers.
1779 However, if the CPU data cache is using a write-allocate mode,
1780 this option is unlikely to provide any performance gain.
1784 prompt "Enable seccomp to safely compute untrusted bytecode"
1786 This kernel feature is useful for number crunching applications
1787 that may need to compute untrusted bytecode during their
1788 execution. By using pipes or other transports made available to
1789 the process as file descriptors supporting the read/write
1790 syscalls, it's possible to isolate those applications in
1791 their own address space using seccomp. Once seccomp is
1792 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1793 and the task is only allowed to execute a few safe syscalls
1794 defined by each seccomp mode.
1803 bool "Enable paravirtualization code"
1805 This changes the kernel so it can modify itself when it is run
1806 under a hypervisor, potentially improving performance significantly
1807 over full virtualization.
1809 config PARAVIRT_TIME_ACCOUNTING
1810 bool "Paravirtual steal time accounting"
1814 Select this option to enable fine granularity task steal time
1815 accounting. Time spent executing other tasks in parallel with
1816 the current vCPU is discounted from the vCPU power. To account for
1817 that, there can be a small performance impact.
1819 If in doubt, say N here.
1826 bool "Xen guest support on ARM"
1827 depends on ARM && AEABI && OF
1828 depends on CPU_V7 && !CPU_V6
1829 depends on !GENERIC_ATOMIC64
1831 select ARCH_DMA_ADDR_T_64BIT
1836 Say Y if you want to run Linux in a Virtual Machine on Xen on ARM.
1843 bool "Flattened Device Tree support"
1847 Include support for flattened device tree machine descriptions.
1850 bool "Support for the traditional ATAGS boot data passing" if USE_OF
1853 This is the traditional way of passing data to the kernel at boot
1854 time. If you are solely relying on the flattened device tree (or
1855 the ARM_ATAG_DTB_COMPAT option) then you may unselect this option
1856 to remove ATAGS support from your kernel binary. If unsure,
1859 config DEPRECATED_PARAM_STRUCT
1860 bool "Provide old way to pass kernel parameters"
1863 This was deprecated in 2001 and announced to live on for 5 years.
1864 Some old boot loaders still use this way.
1866 # Compressed boot loader in ROM. Yes, we really want to ask about
1867 # TEXT and BSS so we preserve their values in the config files.
1868 config ZBOOT_ROM_TEXT
1869 hex "Compressed ROM boot loader base address"
1872 The physical address at which the ROM-able zImage is to be
1873 placed in the target. Platforms which normally make use of
1874 ROM-able zImage formats normally set this to a suitable
1875 value in their defconfig file.
1877 If ZBOOT_ROM is not enabled, this has no effect.
1879 config ZBOOT_ROM_BSS
1880 hex "Compressed ROM boot loader BSS address"
1883 The base address of an area of read/write memory in the target
1884 for the ROM-able zImage which must be available while the
1885 decompressor is running. It must be large enough to hold the
1886 entire decompressed kernel plus an additional 128 KiB.
1887 Platforms which normally make use of ROM-able zImage formats
1888 normally set this to a suitable value in their defconfig file.
1890 If ZBOOT_ROM is not enabled, this has no effect.
1893 bool "Compressed boot loader in ROM/flash"
1894 depends on ZBOOT_ROM_TEXT != ZBOOT_ROM_BSS
1895 depends on !ARM_APPENDED_DTB && !XIP_KERNEL && !AUTO_ZRELADDR
1897 Say Y here if you intend to execute your compressed kernel image
1898 (zImage) directly from ROM or flash. If unsure, say N.
1900 config ARM_APPENDED_DTB
1901 bool "Use appended device tree blob to zImage (EXPERIMENTAL)"
1904 With this option, the boot code will look for a device tree binary
1905 (DTB) appended to zImage
1906 (e.g. cat zImage <filename>.dtb > zImage_w_dtb).
1908 This is meant as a backward compatibility convenience for those
1909 systems with a bootloader that can't be upgraded to accommodate
1910 the documented boot protocol using a device tree.
1912 Beware that there is very little in terms of protection against
1913 this option being confused by leftover garbage in memory that might
1914 look like a DTB header after a reboot if no actual DTB is appended
1915 to zImage. Do not leave this option active in a production kernel
1916 if you don't intend to always append a DTB. Proper passing of the
1917 location into r2 of a bootloader provided DTB is always preferable
1920 config ARM_ATAG_DTB_COMPAT
1921 bool "Supplement the appended DTB with traditional ATAG information"
1922 depends on ARM_APPENDED_DTB
1924 Some old bootloaders can't be updated to a DTB capable one, yet
1925 they provide ATAGs with memory configuration, the ramdisk address,
1926 the kernel cmdline string, etc. Such information is dynamically
1927 provided by the bootloader and can't always be stored in a static
1928 DTB. To allow a device tree enabled kernel to be used with such
1929 bootloaders, this option allows zImage to extract the information
1930 from the ATAG list and store it at run time into the appended DTB.
1933 prompt "Kernel command line type" if ARM_ATAG_DTB_COMPAT
1934 default ARM_ATAG_DTB_COMPAT_CMDLINE_FROM_BOOTLOADER
1936 config ARM_ATAG_DTB_COMPAT_CMDLINE_FROM_BOOTLOADER
1937 bool "Use bootloader kernel arguments if available"
1939 Uses the command-line options passed by the boot loader instead of
1940 the device tree bootargs property. If the boot loader doesn't provide
1941 any, the device tree bootargs property will be used.
1943 config ARM_ATAG_DTB_COMPAT_CMDLINE_EXTEND
1944 bool "Extend with bootloader kernel arguments"
1946 The command-line arguments provided by the boot loader will be
1947 appended to the the device tree bootargs property.
1952 string "Default kernel command string"
1955 On some architectures (EBSA110 and CATS), there is currently no way
1956 for the boot loader to pass arguments to the kernel. For these
1957 architectures, you should supply some command-line options at build
1958 time by entering them here. As a minimum, you should specify the
1959 memory size and the root device (e.g., mem=64M root=/dev/nfs).
1962 prompt "Kernel command line type" if CMDLINE != ""
1963 default CMDLINE_FROM_BOOTLOADER
1966 config CMDLINE_FROM_BOOTLOADER
1967 bool "Use bootloader kernel arguments if available"
1969 Uses the command-line options passed by the boot loader. If
1970 the boot loader doesn't provide any, the default kernel command
1971 string provided in CMDLINE will be used.
1973 config CMDLINE_EXTEND
1974 bool "Extend bootloader kernel arguments"
1976 The command-line arguments provided by the boot loader will be
1977 appended to the default kernel command string.
1979 config CMDLINE_FORCE
1980 bool "Always use the default kernel command string"
1982 Always use the default kernel command string, even if the boot
1983 loader passes other arguments to the kernel.
1984 This is useful if you cannot or don't want to change the
1985 command-line options your boot loader passes to the kernel.
1989 bool "Kernel Execute-In-Place from ROM"
1990 depends on !ARM_LPAE && !ARCH_MULTIPLATFORM
1992 Execute-In-Place allows the kernel to run from non-volatile storage
1993 directly addressable by the CPU, such as NOR flash. This saves RAM
1994 space since the text section of the kernel is not loaded from flash
1995 to RAM. Read-write sections, such as the data section and stack,
1996 are still copied to RAM. The XIP kernel is not compressed since
1997 it has to run directly from flash, so it will take more space to
1998 store it. The flash address used to link the kernel object files,
1999 and for storing it, is configuration dependent. Therefore, if you
2000 say Y here, you must know the proper physical address where to
2001 store the kernel image depending on your own flash memory usage.
2003 Also note that the make target becomes "make xipImage" rather than
2004 "make zImage" or "make Image". The final kernel binary to put in
2005 ROM memory will be arch/arm/boot/xipImage.
2009 config XIP_PHYS_ADDR
2010 hex "XIP Kernel Physical Location"
2011 depends on XIP_KERNEL
2012 default "0x00080000"
2014 This is the physical address in your flash memory the kernel will
2015 be linked for and stored to. This address is dependent on your
2019 bool "Kexec system call (EXPERIMENTAL)"
2020 depends on (!SMP || PM_SLEEP_SMP)
2024 kexec is a system call that implements the ability to shutdown your
2025 current kernel, and to start another kernel. It is like a reboot
2026 but it is independent of the system firmware. And like a reboot
2027 you can start any kernel with it, not just Linux.
2029 It is an ongoing process to be certain the hardware in a machine
2030 is properly shutdown, so do not be surprised if this code does not
2031 initially work for you.
2034 bool "Export atags in procfs"
2035 depends on ATAGS && KEXEC
2038 Should the atags used to boot the kernel be exported in an "atags"
2039 file in procfs. Useful with kexec.
2042 bool "Build kdump crash kernel (EXPERIMENTAL)"
2044 Generate crash dump after being started by kexec. This should
2045 be normally only set in special crash dump kernels which are
2046 loaded in the main kernel with kexec-tools into a specially
2047 reserved region and then later executed after a crash by
2048 kdump/kexec. The crash dump kernel must be compiled to a
2049 memory address not used by the main kernel
2051 For more details see Documentation/kdump/kdump.txt
2053 config AUTO_ZRELADDR
2054 bool "Auto calculation of the decompressed kernel image address"
2056 ZRELADDR is the physical address where the decompressed kernel
2057 image will be placed. If AUTO_ZRELADDR is selected, the address
2058 will be determined at run-time by masking the current IP with
2059 0xf8000000. This assumes the zImage being placed in the first 128MB
2060 from start of memory.
2066 bool "UEFI runtime support"
2067 depends on OF && !CPU_BIG_ENDIAN && MMU && AUTO_ZRELADDR && !XIP_KERNEL
2069 select EFI_PARAMS_FROM_FDT
2072 select EFI_RUNTIME_WRAPPERS
2074 This option provides support for runtime services provided
2075 by UEFI firmware (such as non-volatile variables, realtime
2076 clock, and platform reset). A UEFI stub is also provided to
2077 allow the kernel to be booted as an EFI application. This
2078 is only useful for kernels that may run on systems that have
2083 menu "CPU Power Management"
2085 source "drivers/cpufreq/Kconfig"
2087 source "drivers/cpuidle/Kconfig"
2091 menu "Floating point emulation"
2093 comment "At least one emulation must be selected"
2096 bool "NWFPE math emulation"
2097 depends on (!AEABI || OABI_COMPAT) && !THUMB2_KERNEL
2099 Say Y to include the NWFPE floating point emulator in the kernel.
2100 This is necessary to run most binaries. Linux does not currently
2101 support floating point hardware so you need to say Y here even if
2102 your machine has an FPA or floating point co-processor podule.
2104 You may say N here if you are going to load the Acorn FPEmulator
2105 early in the bootup.
2108 bool "Support extended precision"
2109 depends on FPE_NWFPE
2111 Say Y to include 80-bit support in the kernel floating-point
2112 emulator. Otherwise, only 32 and 64-bit support is compiled in.
2113 Note that gcc does not generate 80-bit operations by default,
2114 so in most cases this option only enlarges the size of the
2115 floating point emulator without any good reason.
2117 You almost surely want to say N here.
2120 bool "FastFPE math emulation (EXPERIMENTAL)"
2121 depends on (!AEABI || OABI_COMPAT) && !CPU_32v3
2123 Say Y here to include the FAST floating point emulator in the kernel.
2124 This is an experimental much faster emulator which now also has full
2125 precision for the mantissa. It does not support any exceptions.
2126 It is very simple, and approximately 3-6 times faster than NWFPE.
2128 It should be sufficient for most programs. It may be not suitable
2129 for scientific calculations, but you have to check this for yourself.
2130 If you do not feel you need a faster FP emulation you should better
2134 bool "VFP-format floating point maths"
2135 depends on CPU_V6 || CPU_V6K || CPU_ARM926T || CPU_V7 || CPU_FEROCEON
2137 Say Y to include VFP support code in the kernel. This is needed
2138 if your hardware includes a VFP unit.
2140 Please see <file:Documentation/arm/VFP/release-notes.txt> for
2141 release notes and additional status information.
2143 Say N if your target does not have VFP hardware.
2151 bool "Advanced SIMD (NEON) Extension support"
2152 depends on VFPv3 && CPU_V7
2154 Say Y to include support code for NEON, the ARMv7 Advanced SIMD
2157 config KERNEL_MODE_NEON
2158 bool "Support for NEON in kernel mode"
2159 depends on NEON && AEABI
2161 Say Y to include support for NEON in kernel mode.
2165 menu "Userspace binary formats"
2167 source "fs/Kconfig.binfmt"
2171 menu "Power management options"
2173 source "kernel/power/Kconfig"
2175 config ARCH_SUSPEND_POSSIBLE
2176 depends on CPU_ARM920T || CPU_ARM926T || CPU_FEROCEON || CPU_SA1100 || \
2177 CPU_V6 || CPU_V6K || CPU_V7 || CPU_V7M || CPU_XSC3 || CPU_XSCALE || CPU_MOHAWK
2180 config ARM_CPU_SUSPEND
2181 def_bool PM_SLEEP || BL_SWITCHER || ARM_PSCI_FW
2182 depends on ARCH_SUSPEND_POSSIBLE
2184 config ARCH_HIBERNATION_POSSIBLE
2187 default y if ARCH_SUSPEND_POSSIBLE
2191 source "net/Kconfig"
2193 source "drivers/Kconfig"
2195 source "drivers/firmware/Kconfig"
2199 source "arch/arm/Kconfig.debug"
2201 source "security/Kconfig"
2203 source "crypto/Kconfig"
2205 source "arch/arm/crypto/Kconfig"
2208 source "lib/Kconfig"
2210 source "arch/arm/kvm/Kconfig"