1 # SPDX-License-Identifier: GPL-2.0
5 select ARCH_CLOCKSOURCE_DATA
6 select ARCH_DISCARD_MEMBLOCK if !HAVE_ARCH_PFN_VALID
7 select ARCH_HAS_DEBUG_VIRTUAL
8 select ARCH_HAS_DEVMEM_IS_ALLOWED
9 select ARCH_HAS_ELF_RANDOMIZE
10 select ARCH_HAS_SET_MEMORY
11 select ARCH_HAS_PHYS_TO_DMA
12 select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL
13 select ARCH_HAS_STRICT_MODULE_RWX if MMU
14 select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
15 select ARCH_HAVE_CUSTOM_GPIO_H
16 select ARCH_HAS_GCOV_PROFILE_ALL
17 select ARCH_MIGHT_HAVE_PC_PARPORT
18 select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX
19 select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT if CPU_V7
20 select ARCH_SUPPORTS_ATOMIC_RMW
21 select ARCH_USE_BUILTIN_BSWAP
22 select ARCH_USE_CMPXCHG_LOCKREF
23 select ARCH_WANT_IPC_PARSE_VERSION
24 select BUILDTIME_EXTABLE_SORT if MMU
25 select CLONE_BACKWARDS
26 select CPU_PM if (SUSPEND || CPU_IDLE)
27 select DCACHE_WORD_ACCESS if HAVE_EFFICIENT_UNALIGNED_ACCESS
28 select DMA_DIRECT_OPS if !MMU
30 select EDAC_ATOMIC_SCRUB
31 select GENERIC_ALLOCATOR
32 select GENERIC_ARCH_TOPOLOGY if ARM_CPU_TOPOLOGY
33 select GENERIC_ATOMIC64 if (CPU_V7M || CPU_V6 || !CPU_32v6K || !AEABI)
34 select GENERIC_CLOCKEVENTS_BROADCAST if SMP
35 select GENERIC_CPU_AUTOPROBE
36 select GENERIC_EARLY_IOREMAP
37 select GENERIC_IDLE_POLL_SETUP
38 select GENERIC_IRQ_PROBE
39 select GENERIC_IRQ_SHOW
40 select GENERIC_IRQ_SHOW_LEVEL
41 select GENERIC_PCI_IOMAP
42 select GENERIC_SCHED_CLOCK
43 select GENERIC_SMP_IDLE_THREAD
44 select GENERIC_STRNCPY_FROM_USER
45 select GENERIC_STRNLEN_USER
46 select HANDLE_DOMAIN_IRQ
47 select HARDIRQS_SW_RESEND
48 select HAVE_ARCH_AUDITSYSCALL if (AEABI && !OABI_COMPAT)
49 select HAVE_ARCH_BITREVERSE if (CPU_32v7M || CPU_32v7) && !CPU_32v6
50 select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL && !CPU_ENDIAN_BE32 && MMU
51 select HAVE_ARCH_KGDB if !CPU_ENDIAN_BE32 && MMU
52 select HAVE_ARCH_MMAP_RND_BITS if MMU
53 select HAVE_ARCH_SECCOMP_FILTER if (AEABI && !OABI_COMPAT)
54 select HAVE_ARCH_TRACEHOOK
55 select HAVE_ARM_SMCCC if CPU_V7
56 select HAVE_EBPF_JIT if !CPU_ENDIAN_BE32
57 select HAVE_CC_STACKPROTECTOR
58 select HAVE_CONTEXT_TRACKING
59 select HAVE_C_RECORDMCOUNT
60 select HAVE_DEBUG_KMEMLEAK
61 select HAVE_DMA_API_DEBUG
62 select HAVE_DMA_CONTIGUOUS if MMU
63 select HAVE_DYNAMIC_FTRACE if (!XIP_KERNEL) && !CPU_ENDIAN_BE32 && MMU
64 select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
65 select HAVE_EFFICIENT_UNALIGNED_ACCESS if (CPU_V6 || CPU_V6K || CPU_V7) && MMU
66 select HAVE_EXIT_THREAD
67 select HAVE_FTRACE_MCOUNT_RECORD if (!XIP_KERNEL)
68 select HAVE_FUNCTION_GRAPH_TRACER if (!THUMB2_KERNEL)
69 select HAVE_FUNCTION_TRACER if (!XIP_KERNEL)
70 select HAVE_GCC_PLUGINS
71 select HAVE_GENERIC_DMA_COHERENT
72 select HAVE_HW_BREAKPOINT if (PERF_EVENTS && (CPU_V6 || CPU_V6K || CPU_V7))
73 select HAVE_IDE if PCI || ISA || PCMCIA
74 select HAVE_IRQ_TIME_ACCOUNTING
75 select HAVE_KERNEL_GZIP
76 select HAVE_KERNEL_LZ4
77 select HAVE_KERNEL_LZMA
78 select HAVE_KERNEL_LZO
80 select HAVE_KPROBES if !XIP_KERNEL && !CPU_ENDIAN_BE32 && !CPU_V7M
81 select HAVE_KRETPROBES if (HAVE_KPROBES)
83 select HAVE_MOD_ARCH_SPECIFIC
85 select HAVE_OPROFILE if (HAVE_PERF_EVENTS)
86 select HAVE_OPTPROBES if !THUMB2_KERNEL
87 select HAVE_PERF_EVENTS
89 select HAVE_PERF_USER_STACK_DUMP
90 select HAVE_RCU_TABLE_FREE if (SMP && ARM_LPAE)
91 select HAVE_REGS_AND_STACK_ACCESS_API
92 select HAVE_SYSCALL_TRACEPOINTS
94 select HAVE_VIRT_CPU_ACCOUNTING_GEN
95 select IRQ_FORCED_THREADING
96 select MODULES_USE_ELF_REL
98 select OF_EARLY_FLATTREE if OF
99 select OF_RESERVED_MEM if OF
101 select OLD_SIGSUSPEND3
102 select PERF_USE_VMALLOC
104 select SYS_SUPPORTS_APM_EMULATION
105 # Above selects are sorted alphabetically; please add new ones
106 # according to that. Thanks.
108 The ARM series is a line of low-power-consumption RISC chip designs
109 licensed by ARM Ltd and targeted at embedded applications and
110 handhelds such as the Compaq IPAQ. ARM-based PCs are no longer
111 manufactured, but legacy ARM-based PC hardware remains popular in
112 Europe. There is an ARM Linux project with a web page at
113 <http://www.arm.linux.org.uk/>.
115 config ARM_HAS_SG_CHAIN
116 select ARCH_HAS_SG_CHAIN
119 config NEED_SG_DMA_LENGTH
122 config ARM_DMA_USE_IOMMU
124 select ARM_HAS_SG_CHAIN
125 select NEED_SG_DMA_LENGTH
129 config ARM_DMA_IOMMU_ALIGNMENT
130 int "Maximum PAGE_SIZE order of alignment for DMA IOMMU buffers"
134 DMA mapping framework by default aligns all buffers to the smallest
135 PAGE_SIZE order which is greater than or equal to the requested buffer
136 size. This works well for buffers up to a few hundreds kilobytes, but
137 for larger buffers it just a waste of address space. Drivers which has
138 relatively small addressing window (like 64Mib) might run out of
139 virtual space with just a few allocations.
141 With this parameter you can specify the maximum PAGE_SIZE order for
142 DMA IOMMU buffers. Larger buffers will be aligned only to this
143 specified order. The order is expressed as a power of two multiplied
148 config MIGHT_HAVE_PCI
151 config SYS_SUPPORTS_APM_EMULATION
156 select GENERIC_ALLOCATOR
167 The Extended Industry Standard Architecture (EISA) bus was
168 developed as an open alternative to the IBM MicroChannel bus.
170 The EISA bus provided some of the features of the IBM MicroChannel
171 bus while maintaining backward compatibility with cards made for
172 the older ISA bus. The EISA bus saw limited use between 1988 and
173 1995 when it was made obsolete by the PCI bus.
175 Say Y here if you are building a kernel for an EISA-based machine.
182 config STACKTRACE_SUPPORT
186 config LOCKDEP_SUPPORT
190 config TRACE_IRQFLAGS_SUPPORT
194 config RWSEM_XCHGADD_ALGORITHM
198 config ARCH_HAS_ILOG2_U32
201 config ARCH_HAS_ILOG2_U64
204 config ARCH_HAS_BANDGAP
207 config FIX_EARLYCON_MEM
210 config GENERIC_HWEIGHT
214 config GENERIC_CALIBRATE_DELAY
218 config ARCH_MAY_HAVE_PC_FDC
224 config NEED_DMA_MAP_STATE
227 config ARCH_SUPPORTS_UPROBES
230 config ARCH_HAS_DMA_SET_COHERENT_MASK
233 config GENERIC_ISA_DMA
239 config NEED_RET_TO_USER
245 config ARM_PATCH_PHYS_VIRT
246 bool "Patch physical to virtual translations at runtime" if EMBEDDED
248 depends on !XIP_KERNEL && MMU
250 Patch phys-to-virt and virt-to-phys translation functions at
251 boot and module load time according to the position of the
252 kernel in system memory.
254 This can only be used with non-XIP MMU kernels where the base
255 of physical memory is at a 16MB boundary.
257 Only disable this option if you know that you do not require
258 this feature (eg, building a kernel for a single machine) and
259 you need to shrink the kernel to the minimal size.
261 config NEED_MACH_IO_H
264 Select this when mach/io.h is required to provide special
265 definitions for this platform. The need for mach/io.h should
266 be avoided when possible.
268 config NEED_MACH_MEMORY_H
271 Select this when mach/memory.h is required to provide special
272 definitions for this platform. The need for mach/memory.h should
273 be avoided when possible.
276 hex "Physical address of main memory" if MMU
277 depends on !ARM_PATCH_PHYS_VIRT
278 default DRAM_BASE if !MMU
279 default 0x00000000 if ARCH_EBSA110 || \
285 default 0x10000000 if ARCH_OMAP1 || ARCH_RPC
286 default 0x20000000 if ARCH_S5PV210
287 default 0xc0000000 if ARCH_SA1100
289 Please provide the physical address corresponding to the
290 location of main memory in your system.
296 config PGTABLE_LEVELS
298 default 3 if ARM_LPAE
301 source "init/Kconfig"
303 source "kernel/Kconfig.freezer"
308 bool "MMU-based Paged Memory Management Support"
311 Select if you want MMU-based virtualised addressing space
312 support by paged memory management. If unsure, say 'Y'.
314 config ARCH_MMAP_RND_BITS_MIN
317 config ARCH_MMAP_RND_BITS_MAX
318 default 14 if PAGE_OFFSET=0x40000000
319 default 15 if PAGE_OFFSET=0x80000000
323 # The "ARM system type" choice list is ordered alphabetically by option
324 # text. Please add new entries in the option alphabetic order.
327 prompt "ARM system type"
328 default ARM_SINGLE_ARMV7M if !MMU
329 default ARCH_MULTIPLATFORM if MMU
331 config ARCH_MULTIPLATFORM
332 bool "Allow multiple platforms to be selected"
334 select ARM_HAS_SG_CHAIN
335 select ARM_PATCH_PHYS_VIRT
339 select GENERIC_CLOCKEVENTS
340 select MIGHT_HAVE_PCI
341 select MULTI_IRQ_HANDLER
342 select PCI_DOMAINS if PCI
346 config ARM_SINGLE_ARMV7M
347 bool "ARMv7-M based platforms (Cortex-M0/M3/M4)"
354 select GENERIC_CLOCKEVENTS
361 select ARCH_USES_GETTIMEOFFSET
364 select NEED_MACH_IO_H
365 select NEED_MACH_MEMORY_H
368 This is an evaluation board for the StrongARM processor available
369 from Digital. It has limited hardware on-board, including an
370 Ethernet interface, two PCMCIA sockets, two serial ports and a
375 select ARCH_SPARSEMEM_ENABLE
377 imply ARM_PATCH_PHYS_VIRT
383 select GENERIC_CLOCKEVENTS
386 This enables support for the Cirrus EP93xx series of CPUs.
388 config ARCH_FOOTBRIDGE
392 select GENERIC_CLOCKEVENTS
394 select NEED_MACH_IO_H if !MMU
395 select NEED_MACH_MEMORY_H
397 Support for systems based on the DC21285 companion chip
398 ("FootBridge"), such as the Simtec CATS and the Rebel NetWinder.
401 bool "Hilscher NetX based"
405 select GENERIC_CLOCKEVENTS
407 This enables support for systems based on the Hilscher NetX Soc
413 select NEED_MACH_MEMORY_H
414 select NEED_RET_TO_USER
420 Support for Intel's IOP13XX (XScale) family of processors.
428 select NEED_RET_TO_USER
432 Support for Intel's 80219 and IOP32X (XScale) family of
441 select NEED_RET_TO_USER
445 Support for Intel's IOP33X (XScale) family of processors.
450 select ARCH_HAS_DMA_SET_COHERENT_MASK
451 select ARCH_SUPPORTS_BIG_ENDIAN
454 select DMABOUNCE if PCI
455 select GENERIC_CLOCKEVENTS
457 select MIGHT_HAVE_PCI
458 select NEED_MACH_IO_H
459 select USB_EHCI_BIG_ENDIAN_DESC
460 select USB_EHCI_BIG_ENDIAN_MMIO
462 Support for Intel's IXP4XX (XScale) family of processors.
467 select GENERIC_CLOCKEVENTS
469 select MIGHT_HAVE_PCI
470 select MULTI_IRQ_HANDLER
474 select PLAT_ORION_LEGACY
476 select PM_GENERIC_DOMAINS if PM
478 Support for the Marvell Dove SoC 88AP510
481 bool "Micrel/Kendin KS8695"
484 select GENERIC_CLOCKEVENTS
486 select NEED_MACH_MEMORY_H
488 Support for Micrel/Kendin KS8695 "Centaur" (ARM922T) based
489 System-on-Chip devices.
492 bool "Nuvoton W90X900 CPU"
496 select GENERIC_CLOCKEVENTS
499 Support for Nuvoton (Winbond logic dept.) ARM9 processor,
500 At present, the w90x900 has been renamed nuc900, regarding
501 the ARM series product line, you can login the following
502 link address to know more.
504 <http://www.nuvoton.com/hq/enu/ProductAndSales/ProductLines/
505 ConsumerElectronicsIC/ARMMicrocontroller/ARMMicrocontroller>
511 select CLKSRC_LPC32XX
514 select GENERIC_CLOCKEVENTS
516 select MULTI_IRQ_HANDLER
520 Support for the NXP LPC32XX family of processors
523 bool "PXA2xx/PXA3xx-based"
526 select ARM_CPU_SUSPEND if PM
533 select CPU_XSCALE if !CPU_XSC3
534 select GENERIC_CLOCKEVENTS
539 select MULTI_IRQ_HANDLER
543 Support for Intel/Marvell's PXA2xx/PXA3xx processor line.
549 select ARCH_MAY_HAVE_PC_FDC
550 select ARCH_SPARSEMEM_ENABLE
551 select ARCH_USES_GETTIMEOFFSET
555 select HAVE_PATA_PLATFORM
557 select NEED_MACH_IO_H
558 select NEED_MACH_MEMORY_H
561 On the Acorn Risc-PC, Linux can support the internal IDE disk and
562 CD-ROM interface, serial and parallel port, and the floppy drive.
567 select ARCH_SPARSEMEM_ENABLE
571 select TIMER_OF if OF
574 select GENERIC_CLOCKEVENTS
579 select MULTI_IRQ_HANDLER
580 select NEED_MACH_MEMORY_H
583 Support for StrongARM 11x0 based boards.
586 bool "Samsung S3C24XX SoCs"
589 select CLKSRC_SAMSUNG_PWM
590 select GENERIC_CLOCKEVENTS
593 select HAVE_S3C2410_I2C if I2C
594 select HAVE_S3C2410_WATCHDOG if WATCHDOG
595 select HAVE_S3C_RTC if RTC_CLASS
596 select MULTI_IRQ_HANDLER
597 select NEED_MACH_IO_H
600 Samsung S3C2410, S3C2412, S3C2413, S3C2416, S3C2440, S3C2442, S3C2443
601 and S3C2450 SoCs based systems, such as the Simtec Electronics BAST
602 (<http://www.simtec.co.uk/products/EB110ITX/>), the IPAQ 1940 or the
603 Samsung SMDK2410 development board (and derivatives).
607 select ARCH_HAS_HOLES_MEMORYMODEL
610 select GENERIC_ALLOCATOR
611 select GENERIC_CLOCKEVENTS
612 select GENERIC_IRQ_CHIP
618 Support for TI's DaVinci platform.
623 select ARCH_HAS_HOLES_MEMORYMODEL
627 select GENERIC_CLOCKEVENTS
628 select GENERIC_IRQ_CHIP
632 select MULTI_IRQ_HANDLER
633 select NEED_MACH_IO_H if PCCARD
634 select NEED_MACH_MEMORY_H
637 Support for older TI OMAP1 (omap7xx, omap15xx or omap16xx)
641 menu "Multiple platform selection"
642 depends on ARCH_MULTIPLATFORM
644 comment "CPU Core family selection"
647 bool "ARMv4 based platforms (FA526)"
648 depends on !ARCH_MULTI_V6_V7
649 select ARCH_MULTI_V4_V5
652 config ARCH_MULTI_V4T
653 bool "ARMv4T based platforms (ARM720T, ARM920T, ...)"
654 depends on !ARCH_MULTI_V6_V7
655 select ARCH_MULTI_V4_V5
656 select CPU_ARM920T if !(CPU_ARM7TDMI || CPU_ARM720T || \
657 CPU_ARM740T || CPU_ARM9TDMI || CPU_ARM922T || \
658 CPU_ARM925T || CPU_ARM940T)
661 bool "ARMv5 based platforms (ARM926T, XSCALE, PJ1, ...)"
662 depends on !ARCH_MULTI_V6_V7
663 select ARCH_MULTI_V4_V5
664 select CPU_ARM926T if !(CPU_ARM946E || CPU_ARM1020 || \
665 CPU_ARM1020E || CPU_ARM1022 || CPU_ARM1026 || \
666 CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK || CPU_FEROCEON)
668 config ARCH_MULTI_V4_V5
672 bool "ARMv6 based platforms (ARM11)"
673 select ARCH_MULTI_V6_V7
677 bool "ARMv7 based platforms (Cortex-A, PJ4, Scorpion, Krait)"
679 select ARCH_MULTI_V6_V7
683 config ARCH_MULTI_V6_V7
685 select MIGHT_HAVE_CACHE_L2X0
687 config ARCH_MULTI_CPU_AUTO
688 def_bool !(ARCH_MULTI_V4 || ARCH_MULTI_V4T || ARCH_MULTI_V6_V7)
694 bool "Dummy Virtual Machine"
695 depends on ARCH_MULTI_V7
698 select ARM_GIC_V2M if PCI
700 select ARM_GIC_V3_ITS if PCI
702 select HAVE_ARM_ARCH_TIMER
705 # This is sorted alphabetically by mach-* pathname. However, plat-*
706 # Kconfigs may be included either alphabetically (according to the
707 # plat- suffix) or along side the corresponding mach-* source.
709 source "arch/arm/mach-mvebu/Kconfig"
711 source "arch/arm/mach-actions/Kconfig"
713 source "arch/arm/mach-alpine/Kconfig"
715 source "arch/arm/mach-artpec/Kconfig"
717 source "arch/arm/mach-asm9260/Kconfig"
719 source "arch/arm/mach-at91/Kconfig"
721 source "arch/arm/mach-axxia/Kconfig"
723 source "arch/arm/mach-bcm/Kconfig"
725 source "arch/arm/mach-berlin/Kconfig"
727 source "arch/arm/mach-clps711x/Kconfig"
729 source "arch/arm/mach-cns3xxx/Kconfig"
731 source "arch/arm/mach-davinci/Kconfig"
733 source "arch/arm/mach-digicolor/Kconfig"
735 source "arch/arm/mach-dove/Kconfig"
737 source "arch/arm/mach-ep93xx/Kconfig"
739 source "arch/arm/mach-footbridge/Kconfig"
741 source "arch/arm/mach-gemini/Kconfig"
743 source "arch/arm/mach-highbank/Kconfig"
745 source "arch/arm/mach-hisi/Kconfig"
747 source "arch/arm/mach-integrator/Kconfig"
749 source "arch/arm/mach-iop32x/Kconfig"
751 source "arch/arm/mach-iop33x/Kconfig"
753 source "arch/arm/mach-iop13xx/Kconfig"
755 source "arch/arm/mach-ixp4xx/Kconfig"
757 source "arch/arm/mach-keystone/Kconfig"
759 source "arch/arm/mach-ks8695/Kconfig"
761 source "arch/arm/mach-meson/Kconfig"
763 source "arch/arm/mach-moxart/Kconfig"
765 source "arch/arm/mach-aspeed/Kconfig"
767 source "arch/arm/mach-mv78xx0/Kconfig"
769 source "arch/arm/mach-imx/Kconfig"
771 source "arch/arm/mach-mediatek/Kconfig"
773 source "arch/arm/mach-mxs/Kconfig"
775 source "arch/arm/mach-netx/Kconfig"
777 source "arch/arm/mach-nomadik/Kconfig"
779 source "arch/arm/mach-nspire/Kconfig"
781 source "arch/arm/plat-omap/Kconfig"
783 source "arch/arm/mach-omap1/Kconfig"
785 source "arch/arm/mach-omap2/Kconfig"
787 source "arch/arm/mach-orion5x/Kconfig"
789 source "arch/arm/mach-picoxcell/Kconfig"
791 source "arch/arm/mach-pxa/Kconfig"
792 source "arch/arm/plat-pxa/Kconfig"
794 source "arch/arm/mach-mmp/Kconfig"
796 source "arch/arm/mach-oxnas/Kconfig"
798 source "arch/arm/mach-qcom/Kconfig"
800 source "arch/arm/mach-realview/Kconfig"
802 source "arch/arm/mach-rockchip/Kconfig"
804 source "arch/arm/mach-sa1100/Kconfig"
806 source "arch/arm/mach-socfpga/Kconfig"
808 source "arch/arm/mach-spear/Kconfig"
810 source "arch/arm/mach-sti/Kconfig"
812 source "arch/arm/mach-stm32/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 "ARM MPS2 platform"
874 depends on ARM_SINGLE_ARMV7M
878 Support for Cortex-M Prototyping System (or V2M-MPS2) which comes
879 with a range of available cores like Cortex-M3/M4/M7.
881 Please, note that depends which Application Note is used memory map
882 for the platform may vary, so adjustment of RAM base might be needed.
884 # Definitions to make life easier
890 select GENERIC_CLOCKEVENTS
896 select GENERIC_IRQ_CHIP
899 config PLAT_ORION_LEGACY
906 config PLAT_VERSATILE
909 source "arch/arm/firmware/Kconfig"
911 source arch/arm/mm/Kconfig
914 bool "Enable iWMMXt support"
915 depends on CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK || CPU_PJ4 || CPU_PJ4B
916 default y if PXA27x || PXA3xx || ARCH_MMP || CPU_PJ4 || CPU_PJ4B
918 Enable support for iWMMXt context switching at run time if
919 running on a CPU that supports it.
921 config MULTI_IRQ_HANDLER
924 Allow each machine to specify it's own IRQ handler at run time.
927 source "arch/arm/Kconfig-nommu"
930 config PJ4B_ERRATA_4742
931 bool "PJ4B Errata 4742: IDLE Wake Up Commands can Cause the CPU Core to Cease Operation"
932 depends on CPU_PJ4B && MACH_ARMADA_370
935 When coming out of either a Wait for Interrupt (WFI) or a Wait for
936 Event (WFE) IDLE states, a specific timing sensitivity exists between
937 the retiring WFI/WFE instructions and the newly issued subsequent
938 instructions. This sensitivity can result in a CPU hang scenario.
940 The software must insert either a Data Synchronization Barrier (DSB)
941 or Data Memory Barrier (DMB) command immediately after the WFI/WFE
944 config ARM_ERRATA_326103
945 bool "ARM errata: FSR write bit incorrect on a SWP to read-only memory"
948 Executing a SWP instruction to read-only memory does not set bit 11
949 of the FSR on the ARM 1136 prior to r1p0. This causes the kernel to
950 treat the access as a read, preventing a COW from occurring and
951 causing the faulting task to livelock.
953 config ARM_ERRATA_411920
954 bool "ARM errata: Invalidation of the Instruction Cache operation can fail"
955 depends on CPU_V6 || CPU_V6K
957 Invalidation of the Instruction Cache operation can
958 fail. This erratum is present in 1136 (before r1p4), 1156 and 1176.
959 It does not affect the MPCore. This option enables the ARM Ltd.
960 recommended workaround.
962 config ARM_ERRATA_430973
963 bool "ARM errata: Stale prediction on replaced interworking branch"
966 This option enables the workaround for the 430973 Cortex-A8
967 r1p* erratum. If a code sequence containing an ARM/Thumb
968 interworking branch is replaced with another code sequence at the
969 same virtual address, whether due to self-modifying code or virtual
970 to physical address re-mapping, Cortex-A8 does not recover from the
971 stale interworking branch prediction. This results in Cortex-A8
972 executing the new code sequence in the incorrect ARM or Thumb state.
973 The workaround enables the BTB/BTAC operations by setting ACTLR.IBE
974 and also flushes the branch target cache at every context switch.
975 Note that setting specific bits in the ACTLR register may not be
976 available in non-secure mode.
978 config ARM_ERRATA_458693
979 bool "ARM errata: Processor deadlock when a false hazard is created"
981 depends on !ARCH_MULTIPLATFORM
983 This option enables the workaround for the 458693 Cortex-A8 (r2p0)
984 erratum. For very specific sequences of memory operations, it is
985 possible for a hazard condition intended for a cache line to instead
986 be incorrectly associated with a different cache line. This false
987 hazard might then cause a processor deadlock. The workaround enables
988 the L1 caching of the NEON accesses and disables the PLD instruction
989 in the ACTLR register. Note that setting specific bits in the ACTLR
990 register may not be available in non-secure mode.
992 config ARM_ERRATA_460075
993 bool "ARM errata: Data written to the L2 cache can be overwritten with stale data"
995 depends on !ARCH_MULTIPLATFORM
997 This option enables the workaround for the 460075 Cortex-A8 (r2p0)
998 erratum. Any asynchronous access to the L2 cache may encounter a
999 situation in which recent store transactions to the L2 cache are lost
1000 and overwritten with stale memory contents from external memory. The
1001 workaround disables the write-allocate mode for the L2 cache via the
1002 ACTLR register. Note that setting specific bits in the ACTLR register
1003 may not be available in non-secure mode.
1005 config ARM_ERRATA_742230
1006 bool "ARM errata: DMB operation may be faulty"
1007 depends on CPU_V7 && SMP
1008 depends on !ARCH_MULTIPLATFORM
1010 This option enables the workaround for the 742230 Cortex-A9
1011 (r1p0..r2p2) erratum. Under rare circumstances, a DMB instruction
1012 between two write operations may not ensure the correct visibility
1013 ordering of the two writes. This workaround sets a specific bit in
1014 the diagnostic register of the Cortex-A9 which causes the DMB
1015 instruction to behave as a DSB, ensuring the correct behaviour of
1018 config ARM_ERRATA_742231
1019 bool "ARM errata: Incorrect hazard handling in the SCU may lead to data corruption"
1020 depends on CPU_V7 && SMP
1021 depends on !ARCH_MULTIPLATFORM
1023 This option enables the workaround for the 742231 Cortex-A9
1024 (r2p0..r2p2) erratum. Under certain conditions, specific to the
1025 Cortex-A9 MPCore micro-architecture, two CPUs working in SMP mode,
1026 accessing some data located in the same cache line, may get corrupted
1027 data due to bad handling of the address hazard when the line gets
1028 replaced from one of the CPUs at the same time as another CPU is
1029 accessing it. This workaround sets specific bits in the diagnostic
1030 register of the Cortex-A9 which reduces the linefill issuing
1031 capabilities of the processor.
1033 config ARM_ERRATA_643719
1034 bool "ARM errata: LoUIS bit field in CLIDR register is incorrect"
1035 depends on CPU_V7 && SMP
1038 This option enables the workaround for the 643719 Cortex-A9 (prior to
1039 r1p0) erratum. On affected cores the LoUIS bit field of the CLIDR
1040 register returns zero when it should return one. The workaround
1041 corrects this value, ensuring cache maintenance operations which use
1042 it behave as intended and avoiding data corruption.
1044 config ARM_ERRATA_720789
1045 bool "ARM errata: TLBIASIDIS and TLBIMVAIS operations can broadcast a faulty ASID"
1048 This option enables the workaround for the 720789 Cortex-A9 (prior to
1049 r2p0) erratum. A faulty ASID can be sent to the other CPUs for the
1050 broadcasted CP15 TLB maintenance operations TLBIASIDIS and TLBIMVAIS.
1051 As a consequence of this erratum, some TLB entries which should be
1052 invalidated are not, resulting in an incoherency in the system page
1053 tables. The workaround changes the TLB flushing routines to invalidate
1054 entries regardless of the ASID.
1056 config ARM_ERRATA_743622
1057 bool "ARM errata: Faulty hazard checking in the Store Buffer may lead to data corruption"
1059 depends on !ARCH_MULTIPLATFORM
1061 This option enables the workaround for the 743622 Cortex-A9
1062 (r2p*) erratum. Under very rare conditions, a faulty
1063 optimisation in the Cortex-A9 Store Buffer may lead to data
1064 corruption. This workaround sets a specific bit in the diagnostic
1065 register of the Cortex-A9 which disables the Store Buffer
1066 optimisation, preventing the defect from occurring. This has no
1067 visible impact on the overall performance or power consumption of the
1070 config ARM_ERRATA_751472
1071 bool "ARM errata: Interrupted ICIALLUIS may prevent completion of broadcasted operation"
1073 depends on !ARCH_MULTIPLATFORM
1075 This option enables the workaround for the 751472 Cortex-A9 (prior
1076 to r3p0) erratum. An interrupted ICIALLUIS operation may prevent the
1077 completion of a following broadcasted operation if the second
1078 operation is received by a CPU before the ICIALLUIS has completed,
1079 potentially leading to corrupted entries in the cache or TLB.
1081 config ARM_ERRATA_754322
1082 bool "ARM errata: possible faulty MMU translations following an ASID switch"
1085 This option enables the workaround for the 754322 Cortex-A9 (r2p*,
1086 r3p*) erratum. A speculative memory access may cause a page table walk
1087 which starts prior to an ASID switch but completes afterwards. This
1088 can populate the micro-TLB with a stale entry which may be hit with
1089 the new ASID. This workaround places two dsb instructions in the mm
1090 switching code so that no page table walks can cross the ASID switch.
1092 config ARM_ERRATA_754327
1093 bool "ARM errata: no automatic Store Buffer drain"
1094 depends on CPU_V7 && SMP
1096 This option enables the workaround for the 754327 Cortex-A9 (prior to
1097 r2p0) erratum. The Store Buffer does not have any automatic draining
1098 mechanism and therefore a livelock may occur if an external agent
1099 continuously polls a memory location waiting to observe an update.
1100 This workaround defines cpu_relax() as smp_mb(), preventing correctly
1101 written polling loops from denying visibility of updates to memory.
1103 config ARM_ERRATA_364296
1104 bool "ARM errata: Possible cache data corruption with hit-under-miss enabled"
1107 This options enables the workaround for the 364296 ARM1136
1108 r0p2 erratum (possible cache data corruption with
1109 hit-under-miss enabled). It sets the undocumented bit 31 in
1110 the auxiliary control register and the FI bit in the control
1111 register, thus disabling hit-under-miss without putting the
1112 processor into full low interrupt latency mode. ARM11MPCore
1115 config ARM_ERRATA_764369
1116 bool "ARM errata: Data cache line maintenance operation by MVA may not succeed"
1117 depends on CPU_V7 && SMP
1119 This option enables the workaround for erratum 764369
1120 affecting Cortex-A9 MPCore with two or more processors (all
1121 current revisions). Under certain timing circumstances, a data
1122 cache line maintenance operation by MVA targeting an Inner
1123 Shareable memory region may fail to proceed up to either the
1124 Point of Coherency or to the Point of Unification of the
1125 system. This workaround adds a DSB instruction before the
1126 relevant cache maintenance functions and sets a specific bit
1127 in the diagnostic control register of the SCU.
1129 config ARM_ERRATA_775420
1130 bool "ARM errata: A data cache maintenance operation which aborts, might lead to deadlock"
1133 This option enables the workaround for the 775420 Cortex-A9 (r2p2,
1134 r2p6,r2p8,r2p10,r3p0) erratum. In case a date cache maintenance
1135 operation aborts with MMU exception, it might cause the processor
1136 to deadlock. This workaround puts DSB before executing ISB if
1137 an abort may occur on cache maintenance.
1139 config ARM_ERRATA_798181
1140 bool "ARM errata: TLBI/DSB failure on Cortex-A15"
1141 depends on CPU_V7 && SMP
1143 On Cortex-A15 (r0p0..r3p2) the TLBI*IS/DSB operations are not
1144 adequately shooting down all use of the old entries. This
1145 option enables the Linux kernel workaround for this erratum
1146 which sends an IPI to the CPUs that are running the same ASID
1147 as the one being invalidated.
1149 config ARM_ERRATA_773022
1150 bool "ARM errata: incorrect instructions may be executed from loop buffer"
1153 This option enables the workaround for the 773022 Cortex-A15
1154 (up to r0p4) erratum. In certain rare sequences of code, the
1155 loop buffer may deliver incorrect instructions. This
1156 workaround disables the loop buffer to avoid the erratum.
1158 config ARM_ERRATA_818325_852422
1159 bool "ARM errata: A12: some seqs of opposed cond code instrs => deadlock or corruption"
1162 This option enables the workaround for:
1163 - Cortex-A12 818325: Execution of an UNPREDICTABLE STR or STM
1164 instruction might deadlock. Fixed in r0p1.
1165 - Cortex-A12 852422: Execution of a sequence of instructions might
1166 lead to either a data corruption or a CPU deadlock. Not fixed in
1167 any Cortex-A12 cores yet.
1168 This workaround for all both errata involves setting bit[12] of the
1169 Feature Register. This bit disables an optimisation applied to a
1170 sequence of 2 instructions that use opposing condition codes.
1172 config ARM_ERRATA_821420
1173 bool "ARM errata: A12: sequence of VMOV to core registers might lead to a dead lock"
1176 This option enables the workaround for the 821420 Cortex-A12
1177 (all revs) erratum. In very rare timing conditions, a sequence
1178 of VMOV to Core registers instructions, for which the second
1179 one is in the shadow of a branch or abort, can lead to a
1180 deadlock when the VMOV instructions are issued out-of-order.
1182 config ARM_ERRATA_825619
1183 bool "ARM errata: A12: DMB NSHST/ISHST mixed ... might cause deadlock"
1186 This option enables the workaround for the 825619 Cortex-A12
1187 (all revs) erratum. Within rare timing constraints, executing a
1188 DMB NSHST or DMB ISHST instruction followed by a mix of Cacheable
1189 and Device/Strongly-Ordered loads and stores might cause deadlock
1191 config ARM_ERRATA_852421
1192 bool "ARM errata: A17: DMB ST might fail to create order between stores"
1195 This option enables the workaround for the 852421 Cortex-A17
1196 (r1p0, r1p1, r1p2) erratum. Under very rare timing conditions,
1197 execution of a DMB ST instruction might fail to properly order
1198 stores from GroupA and stores from GroupB.
1200 config ARM_ERRATA_852423
1201 bool "ARM errata: A17: some seqs of opposed cond code instrs => deadlock or corruption"
1204 This option enables the workaround for:
1205 - Cortex-A17 852423: Execution of a sequence of instructions might
1206 lead to either a data corruption or a CPU deadlock. Not fixed in
1207 any Cortex-A17 cores yet.
1208 This is identical to Cortex-A12 erratum 852422. It is a separate
1209 config option from the A12 erratum due to the way errata are checked
1214 source "arch/arm/common/Kconfig"
1221 Find out whether you have ISA slots on your motherboard. ISA is the
1222 name of a bus system, i.e. the way the CPU talks to the other stuff
1223 inside your box. Other bus systems are PCI, EISA, MicroChannel
1224 (MCA) or VESA. ISA is an older system, now being displaced by PCI;
1225 newer boards don't support it. If you have ISA, say Y, otherwise N.
1227 # Select ISA DMA controller support
1232 # Select ISA DMA interface
1237 bool "PCI support" if MIGHT_HAVE_PCI
1239 Find out whether you have a PCI motherboard. PCI is the name of a
1240 bus system, i.e. the way the CPU talks to the other stuff inside
1241 your box. Other bus systems are ISA, EISA, MicroChannel (MCA) or
1242 VESA. If you have PCI, say Y, otherwise N.
1248 config PCI_DOMAINS_GENERIC
1249 def_bool PCI_DOMAINS
1251 config PCI_NANOENGINE
1252 bool "BSE nanoEngine PCI support"
1253 depends on SA1100_NANOENGINE
1255 Enable PCI on the BSE nanoEngine board.
1260 config PCI_HOST_ITE8152
1262 depends on PCI && MACH_ARMCORE
1266 source "drivers/pci/Kconfig"
1268 source "drivers/pcmcia/Kconfig"
1272 menu "Kernel Features"
1277 This option should be selected by machines which have an SMP-
1280 The only effect of this option is to make the SMP-related
1281 options available to the user for configuration.
1284 bool "Symmetric Multi-Processing"
1285 depends on CPU_V6K || CPU_V7
1286 depends on GENERIC_CLOCKEVENTS
1288 depends on MMU || ARM_MPU
1291 This enables support for systems with more than one CPU. If you have
1292 a system with only one CPU, say N. If you have a system with more
1293 than one CPU, say Y.
1295 If you say N here, the kernel will run on uni- and multiprocessor
1296 machines, but will use only one CPU of a multiprocessor machine. If
1297 you say Y here, the kernel will run on many, but not all,
1298 uniprocessor machines. On a uniprocessor machine, the kernel
1299 will run faster if you say N here.
1301 See also <file:Documentation/x86/i386/IO-APIC.txt>,
1302 <file:Documentation/nmi_watchdog.txt> and the SMP-HOWTO available at
1303 <http://tldp.org/HOWTO/SMP-HOWTO.html>.
1305 If you don't know what to do here, say N.
1308 bool "Allow booting SMP kernel on uniprocessor systems"
1309 depends on SMP && !XIP_KERNEL && MMU
1312 SMP kernels contain instructions which fail on non-SMP processors.
1313 Enabling this option allows the kernel to modify itself to make
1314 these instructions safe. Disabling it allows about 1K of space
1317 If you don't know what to do here, say Y.
1319 config ARM_CPU_TOPOLOGY
1320 bool "Support cpu topology definition"
1321 depends on SMP && CPU_V7
1324 Support ARM cpu topology definition. The MPIDR register defines
1325 affinity between processors which is then used to describe the cpu
1326 topology of an ARM System.
1329 bool "Multi-core scheduler support"
1330 depends on ARM_CPU_TOPOLOGY
1332 Multi-core scheduler support improves the CPU scheduler's decision
1333 making when dealing with multi-core CPU chips at a cost of slightly
1334 increased overhead in some places. If unsure say N here.
1337 bool "SMT scheduler support"
1338 depends on ARM_CPU_TOPOLOGY
1340 Improves the CPU scheduler's decision making when dealing with
1341 MultiThreading at a cost of slightly increased overhead in some
1342 places. If unsure say N here.
1347 This option enables support for the ARM system coherency unit
1349 config HAVE_ARM_ARCH_TIMER
1350 bool "Architected timer support"
1352 select ARM_ARCH_TIMER
1353 select GENERIC_CLOCKEVENTS
1355 This option enables support for the ARM architected timer
1359 select TIMER_OF if OF
1361 This options enables support for the ARM timer and watchdog unit
1364 bool "Multi-Cluster Power Management"
1365 depends on CPU_V7 && SMP
1367 This option provides the common power management infrastructure
1368 for (multi-)cluster based systems, such as big.LITTLE based
1371 config MCPM_QUAD_CLUSTER
1375 To avoid wasting resources unnecessarily, MCPM only supports up
1376 to 2 clusters by default.
1377 Platforms with 3 or 4 clusters that use MCPM must select this
1378 option to allow the additional clusters to be managed.
1381 bool "big.LITTLE support (Experimental)"
1382 depends on CPU_V7 && SMP
1385 This option enables support selections for the big.LITTLE
1386 system architecture.
1389 bool "big.LITTLE switcher support"
1390 depends on BIG_LITTLE && MCPM && HOTPLUG_CPU && ARM_GIC
1393 The big.LITTLE "switcher" provides the core functionality to
1394 transparently handle transition between a cluster of A15's
1395 and a cluster of A7's in a big.LITTLE system.
1397 config BL_SWITCHER_DUMMY_IF
1398 tristate "Simple big.LITTLE switcher user interface"
1399 depends on BL_SWITCHER && DEBUG_KERNEL
1401 This is a simple and dummy char dev interface to control
1402 the big.LITTLE switcher core code. It is meant for
1403 debugging purposes only.
1406 prompt "Memory split"
1410 Select the desired split between kernel and user memory.
1412 If you are not absolutely sure what you are doing, leave this
1416 bool "3G/1G user/kernel split"
1417 config VMSPLIT_3G_OPT
1418 depends on !ARM_LPAE
1419 bool "3G/1G user/kernel split (for full 1G low memory)"
1421 bool "2G/2G user/kernel split"
1423 bool "1G/3G user/kernel split"
1428 default PHYS_OFFSET if !MMU
1429 default 0x40000000 if VMSPLIT_1G
1430 default 0x80000000 if VMSPLIT_2G
1431 default 0xB0000000 if VMSPLIT_3G_OPT
1435 int "Maximum number of CPUs (2-32)"
1441 bool "Support for hot-pluggable CPUs"
1444 Say Y here to experiment with turning CPUs off and on. CPUs
1445 can be controlled through /sys/devices/system/cpu.
1448 bool "Support for the ARM Power State Coordination Interface (PSCI)"
1449 depends on HAVE_ARM_SMCCC
1452 Say Y here if you want Linux to communicate with system firmware
1453 implementing the PSCI specification for CPU-centric power
1454 management operations described in ARM document number ARM DEN
1455 0022A ("Power State Coordination Interface System Software on
1458 # The GPIO number here must be sorted by descending number. In case of
1459 # a multiplatform kernel, we just want the highest value required by the
1460 # selected platforms.
1463 default 2048 if ARCH_SOCFPGA
1464 default 1024 if ARCH_BRCMSTB || ARCH_SHMOBILE || ARCH_TEGRA || \
1466 default 512 if ARCH_EXYNOS || ARCH_KEYSTONE || SOC_OMAP5 || \
1467 SOC_DRA7XX || ARCH_S3C24XX || ARCH_S3C64XX || ARCH_S5PV210
1468 default 416 if ARCH_SUNXI
1469 default 392 if ARCH_U8500
1470 default 352 if ARCH_VT8500
1471 default 288 if ARCH_ROCKCHIP
1472 default 264 if MACH_H4700
1475 Maximum number of GPIOs in the system.
1477 If unsure, leave the default value.
1479 source kernel/Kconfig.preempt
1483 default 200 if ARCH_EBSA110
1484 default 128 if SOC_AT91RM9200
1488 depends on HZ_FIXED = 0
1489 prompt "Timer frequency"
1513 default HZ_FIXED if HZ_FIXED != 0
1514 default 100 if HZ_100
1515 default 200 if HZ_200
1516 default 250 if HZ_250
1517 default 300 if HZ_300
1518 default 500 if HZ_500
1522 def_bool HIGH_RES_TIMERS
1524 config THUMB2_KERNEL
1525 bool "Compile the kernel in Thumb-2 mode" if !CPU_THUMBONLY
1526 depends on (CPU_V7 || CPU_V7M) && !CPU_V6 && !CPU_V6K
1527 default y if CPU_THUMBONLY
1528 select ARM_ASM_UNIFIED
1531 By enabling this option, the kernel will be compiled in
1532 Thumb-2 mode. A compiler/assembler that understand the unified
1533 ARM-Thumb syntax is needed.
1537 config THUMB2_AVOID_R_ARM_THM_JUMP11
1538 bool "Work around buggy Thumb-2 short branch relocations in gas"
1539 depends on THUMB2_KERNEL && MODULES
1542 Various binutils versions can resolve Thumb-2 branches to
1543 locally-defined, preemptible global symbols as short-range "b.n"
1544 branch instructions.
1546 This is a problem, because there's no guarantee the final
1547 destination of the symbol, or any candidate locations for a
1548 trampoline, are within range of the branch. For this reason, the
1549 kernel does not support fixing up the R_ARM_THM_JUMP11 (102)
1550 relocation in modules at all, and it makes little sense to add
1553 The symptom is that the kernel fails with an "unsupported
1554 relocation" error when loading some modules.
1556 Until fixed tools are available, passing
1557 -fno-optimize-sibling-calls to gcc should prevent gcc generating
1558 code which hits this problem, at the cost of a bit of extra runtime
1559 stack usage in some cases.
1561 The problem is described in more detail at:
1562 https://bugs.launchpad.net/binutils-linaro/+bug/725126
1564 Only Thumb-2 kernels are affected.
1566 Unless you are sure your tools don't have this problem, say Y.
1568 config ARM_ASM_UNIFIED
1571 config ARM_PATCH_IDIV
1572 bool "Runtime patch udiv/sdiv instructions into __aeabi_{u}idiv()"
1573 depends on CPU_32v7 && !XIP_KERNEL
1576 The ARM compiler inserts calls to __aeabi_idiv() and
1577 __aeabi_uidiv() when it needs to perform division on signed
1578 and unsigned integers. Some v7 CPUs have support for the sdiv
1579 and udiv instructions that can be used to implement those
1582 Enabling this option allows the kernel to modify itself to
1583 replace the first two instructions of these library functions
1584 with the sdiv or udiv plus "bx lr" instructions when the CPU
1585 it is running on supports them. Typically this will be faster
1586 and less power intensive than running the original library
1587 code to do integer division.
1590 bool "Use the ARM EABI to compile the kernel" if !CPU_V7 && !CPU_V7M && !CPU_V6 && !CPU_V6K
1591 default CPU_V7 || CPU_V7M || CPU_V6 || CPU_V6K
1593 This option allows for the kernel to be compiled using the latest
1594 ARM ABI (aka EABI). This is only useful if you are using a user
1595 space environment that is also compiled with EABI.
1597 Since there are major incompatibilities between the legacy ABI and
1598 EABI, especially with regard to structure member alignment, this
1599 option also changes the kernel syscall calling convention to
1600 disambiguate both ABIs and allow for backward compatibility support
1601 (selected with CONFIG_OABI_COMPAT).
1603 To use this you need GCC version 4.0.0 or later.
1606 bool "Allow old ABI binaries to run with this kernel (EXPERIMENTAL)"
1607 depends on AEABI && !THUMB2_KERNEL
1609 This option preserves the old syscall interface along with the
1610 new (ARM EABI) one. It also provides a compatibility layer to
1611 intercept syscalls that have structure arguments which layout
1612 in memory differs between the legacy ABI and the new ARM EABI
1613 (only for non "thumb" binaries). This option adds a tiny
1614 overhead to all syscalls and produces a slightly larger kernel.
1616 The seccomp filter system will not be available when this is
1617 selected, since there is no way yet to sensibly distinguish
1618 between calling conventions during filtering.
1620 If you know you'll be using only pure EABI user space then you
1621 can say N here. If this option is not selected and you attempt
1622 to execute a legacy ABI binary then the result will be
1623 UNPREDICTABLE (in fact it can be predicted that it won't work
1624 at all). If in doubt say N.
1626 config ARCH_HAS_HOLES_MEMORYMODEL
1629 config ARCH_SPARSEMEM_ENABLE
1632 config ARCH_SPARSEMEM_DEFAULT
1633 def_bool ARCH_SPARSEMEM_ENABLE
1635 config ARCH_SELECT_MEMORY_MODEL
1636 def_bool ARCH_SPARSEMEM_ENABLE
1638 config HAVE_ARCH_PFN_VALID
1639 def_bool ARCH_HAS_HOLES_MEMORYMODEL || !SPARSEMEM
1641 config HAVE_GENERIC_GUP
1646 bool "High Memory Support"
1649 The address space of ARM processors is only 4 Gigabytes large
1650 and it has to accommodate user address space, kernel address
1651 space as well as some memory mapped IO. That means that, if you
1652 have a large amount of physical memory and/or IO, not all of the
1653 memory can be "permanently mapped" by the kernel. The physical
1654 memory that is not permanently mapped is called "high memory".
1656 Depending on the selected kernel/user memory split, minimum
1657 vmalloc space and actual amount of RAM, you may not need this
1658 option which should result in a slightly faster kernel.
1663 bool "Allocate 2nd-level pagetables from highmem" if EXPERT
1667 The VM uses one page of physical memory for each page table.
1668 For systems with a lot of processes, this can use a lot of
1669 precious low memory, eventually leading to low memory being
1670 consumed by page tables. Setting this option will allow
1671 user-space 2nd level page tables to reside in high memory.
1673 config CPU_SW_DOMAIN_PAN
1674 bool "Enable use of CPU domains to implement privileged no-access"
1675 depends on MMU && !ARM_LPAE
1678 Increase kernel security by ensuring that normal kernel accesses
1679 are unable to access userspace addresses. This can help prevent
1680 use-after-free bugs becoming an exploitable privilege escalation
1681 by ensuring that magic values (such as LIST_POISON) will always
1682 fault when dereferenced.
1684 CPUs with low-vector mappings use a best-efforts implementation.
1685 Their lower 1MB needs to remain accessible for the vectors, but
1686 the remainder of userspace will become appropriately inaccessible.
1688 config HW_PERF_EVENTS
1692 config SYS_SUPPORTS_HUGETLBFS
1696 config HAVE_ARCH_TRANSPARENT_HUGEPAGE
1700 config ARCH_WANT_GENERAL_HUGETLB
1703 config ARM_MODULE_PLTS
1704 bool "Use PLTs to allow module memory to spill over into vmalloc area"
1707 Allocate PLTs when loading modules so that jumps and calls whose
1708 targets are too far away for their relative offsets to be encoded
1709 in the instructions themselves can be bounced via veneers in the
1710 module's PLT. This allows modules to be allocated in the generic
1711 vmalloc area after the dedicated module memory area has been
1712 exhausted. The modules will use slightly more memory, but after
1713 rounding up to page size, the actual memory footprint is usually
1716 Say y if you are getting out of memory errors while loading modules
1720 config FORCE_MAX_ZONEORDER
1721 int "Maximum zone order"
1722 default "12" if SOC_AM33XX
1723 default "9" if SA1111 || ARCH_EFM32
1726 The kernel memory allocator divides physically contiguous memory
1727 blocks into "zones", where each zone is a power of two number of
1728 pages. This option selects the largest power of two that the kernel
1729 keeps in the memory allocator. If you need to allocate very large
1730 blocks of physically contiguous memory, then you may need to
1731 increase this value.
1733 This config option is actually maximum order plus one. For example,
1734 a value of 11 means that the largest free memory block is 2^10 pages.
1736 config ALIGNMENT_TRAP
1738 depends on CPU_CP15_MMU
1739 default y if !ARCH_EBSA110
1740 select HAVE_PROC_CPU if PROC_FS
1742 ARM processors cannot fetch/store information which is not
1743 naturally aligned on the bus, i.e., a 4 byte fetch must start at an
1744 address divisible by 4. On 32-bit ARM processors, these non-aligned
1745 fetch/store instructions will be emulated in software if you say
1746 here, which has a severe performance impact. This is necessary for
1747 correct operation of some network protocols. With an IP-only
1748 configuration it is safe to say N, otherwise say Y.
1750 config UACCESS_WITH_MEMCPY
1751 bool "Use kernel mem{cpy,set}() for {copy_to,clear}_user()"
1753 default y if CPU_FEROCEON
1755 Implement faster copy_to_user and clear_user methods for CPU
1756 cores where a 8-word STM instruction give significantly higher
1757 memory write throughput than a sequence of individual 32bit stores.
1759 A possible side effect is a slight increase in scheduling latency
1760 between threads sharing the same address space if they invoke
1761 such copy operations with large buffers.
1763 However, if the CPU data cache is using a write-allocate mode,
1764 this option is unlikely to provide any performance gain.
1768 prompt "Enable seccomp to safely compute untrusted bytecode"
1770 This kernel feature is useful for number crunching applications
1771 that may need to compute untrusted bytecode during their
1772 execution. By using pipes or other transports made available to
1773 the process as file descriptors supporting the read/write
1774 syscalls, it's possible to isolate those applications in
1775 their own address space using seccomp. Once seccomp is
1776 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1777 and the task is only allowed to execute a few safe syscalls
1778 defined by each seccomp mode.
1787 bool "Enable paravirtualization code"
1789 This changes the kernel so it can modify itself when it is run
1790 under a hypervisor, potentially improving performance significantly
1791 over full virtualization.
1793 config PARAVIRT_TIME_ACCOUNTING
1794 bool "Paravirtual steal time accounting"
1798 Select this option to enable fine granularity task steal time
1799 accounting. Time spent executing other tasks in parallel with
1800 the current vCPU is discounted from the vCPU power. To account for
1801 that, there can be a small performance impact.
1803 If in doubt, say N here.
1810 bool "Xen guest support on ARM"
1811 depends on ARM && AEABI && OF
1812 depends on CPU_V7 && !CPU_V6
1813 depends on !GENERIC_ATOMIC64
1815 select ARCH_DMA_ADDR_T_64BIT
1820 Say Y if you want to run Linux in a Virtual Machine on Xen on ARM.
1827 bool "Flattened Device Tree support"
1831 Include support for flattened device tree machine descriptions.
1834 bool "Support for the traditional ATAGS boot data passing" if USE_OF
1837 This is the traditional way of passing data to the kernel at boot
1838 time. If you are solely relying on the flattened device tree (or
1839 the ARM_ATAG_DTB_COMPAT option) then you may unselect this option
1840 to remove ATAGS support from your kernel binary. If unsure,
1843 config DEPRECATED_PARAM_STRUCT
1844 bool "Provide old way to pass kernel parameters"
1847 This was deprecated in 2001 and announced to live on for 5 years.
1848 Some old boot loaders still use this way.
1850 # Compressed boot loader in ROM. Yes, we really want to ask about
1851 # TEXT and BSS so we preserve their values in the config files.
1852 config ZBOOT_ROM_TEXT
1853 hex "Compressed ROM boot loader base address"
1856 The physical address at which the ROM-able zImage is to be
1857 placed in the target. Platforms which normally make use of
1858 ROM-able zImage formats normally set this to a suitable
1859 value in their defconfig file.
1861 If ZBOOT_ROM is not enabled, this has no effect.
1863 config ZBOOT_ROM_BSS
1864 hex "Compressed ROM boot loader BSS address"
1867 The base address of an area of read/write memory in the target
1868 for the ROM-able zImage which must be available while the
1869 decompressor is running. It must be large enough to hold the
1870 entire decompressed kernel plus an additional 128 KiB.
1871 Platforms which normally make use of ROM-able zImage formats
1872 normally set this to a suitable value in their defconfig file.
1874 If ZBOOT_ROM is not enabled, this has no effect.
1877 bool "Compressed boot loader in ROM/flash"
1878 depends on ZBOOT_ROM_TEXT != ZBOOT_ROM_BSS
1879 depends on !ARM_APPENDED_DTB && !XIP_KERNEL && !AUTO_ZRELADDR
1881 Say Y here if you intend to execute your compressed kernel image
1882 (zImage) directly from ROM or flash. If unsure, say N.
1884 config ARM_APPENDED_DTB
1885 bool "Use appended device tree blob to zImage (EXPERIMENTAL)"
1888 With this option, the boot code will look for a device tree binary
1889 (DTB) appended to zImage
1890 (e.g. cat zImage <filename>.dtb > zImage_w_dtb).
1892 This is meant as a backward compatibility convenience for those
1893 systems with a bootloader that can't be upgraded to accommodate
1894 the documented boot protocol using a device tree.
1896 Beware that there is very little in terms of protection against
1897 this option being confused by leftover garbage in memory that might
1898 look like a DTB header after a reboot if no actual DTB is appended
1899 to zImage. Do not leave this option active in a production kernel
1900 if you don't intend to always append a DTB. Proper passing of the
1901 location into r2 of a bootloader provided DTB is always preferable
1904 config ARM_ATAG_DTB_COMPAT
1905 bool "Supplement the appended DTB with traditional ATAG information"
1906 depends on ARM_APPENDED_DTB
1908 Some old bootloaders can't be updated to a DTB capable one, yet
1909 they provide ATAGs with memory configuration, the ramdisk address,
1910 the kernel cmdline string, etc. Such information is dynamically
1911 provided by the bootloader and can't always be stored in a static
1912 DTB. To allow a device tree enabled kernel to be used with such
1913 bootloaders, this option allows zImage to extract the information
1914 from the ATAG list and store it at run time into the appended DTB.
1917 prompt "Kernel command line type" if ARM_ATAG_DTB_COMPAT
1918 default ARM_ATAG_DTB_COMPAT_CMDLINE_FROM_BOOTLOADER
1920 config ARM_ATAG_DTB_COMPAT_CMDLINE_FROM_BOOTLOADER
1921 bool "Use bootloader kernel arguments if available"
1923 Uses the command-line options passed by the boot loader instead of
1924 the device tree bootargs property. If the boot loader doesn't provide
1925 any, the device tree bootargs property will be used.
1927 config ARM_ATAG_DTB_COMPAT_CMDLINE_EXTEND
1928 bool "Extend with bootloader kernel arguments"
1930 The command-line arguments provided by the boot loader will be
1931 appended to the the device tree bootargs property.
1936 string "Default kernel command string"
1939 On some architectures (EBSA110 and CATS), there is currently no way
1940 for the boot loader to pass arguments to the kernel. For these
1941 architectures, you should supply some command-line options at build
1942 time by entering them here. As a minimum, you should specify the
1943 memory size and the root device (e.g., mem=64M root=/dev/nfs).
1946 prompt "Kernel command line type" if CMDLINE != ""
1947 default CMDLINE_FROM_BOOTLOADER
1950 config CMDLINE_FROM_BOOTLOADER
1951 bool "Use bootloader kernel arguments if available"
1953 Uses the command-line options passed by the boot loader. If
1954 the boot loader doesn't provide any, the default kernel command
1955 string provided in CMDLINE will be used.
1957 config CMDLINE_EXTEND
1958 bool "Extend bootloader kernel arguments"
1960 The command-line arguments provided by the boot loader will be
1961 appended to the default kernel command string.
1963 config CMDLINE_FORCE
1964 bool "Always use the default kernel command string"
1966 Always use the default kernel command string, even if the boot
1967 loader passes other arguments to the kernel.
1968 This is useful if you cannot or don't want to change the
1969 command-line options your boot loader passes to the kernel.
1973 bool "Kernel Execute-In-Place from ROM"
1974 depends on !ARM_LPAE && !ARCH_MULTIPLATFORM
1976 Execute-In-Place allows the kernel to run from non-volatile storage
1977 directly addressable by the CPU, such as NOR flash. This saves RAM
1978 space since the text section of the kernel is not loaded from flash
1979 to RAM. Read-write sections, such as the data section and stack,
1980 are still copied to RAM. The XIP kernel is not compressed since
1981 it has to run directly from flash, so it will take more space to
1982 store it. The flash address used to link the kernel object files,
1983 and for storing it, is configuration dependent. Therefore, if you
1984 say Y here, you must know the proper physical address where to
1985 store the kernel image depending on your own flash memory usage.
1987 Also note that the make target becomes "make xipImage" rather than
1988 "make zImage" or "make Image". The final kernel binary to put in
1989 ROM memory will be arch/arm/boot/xipImage.
1993 config XIP_PHYS_ADDR
1994 hex "XIP Kernel Physical Location"
1995 depends on XIP_KERNEL
1996 default "0x00080000"
1998 This is the physical address in your flash memory the kernel will
1999 be linked for and stored to. This address is dependent on your
2002 config XIP_DEFLATED_DATA
2003 bool "Store kernel .data section compressed in ROM"
2004 depends on XIP_KERNEL
2007 Before the kernel is actually executed, its .data section has to be
2008 copied to RAM from ROM. This option allows for storing that data
2009 in compressed form and decompressed to RAM rather than merely being
2010 copied, saving some precious ROM space. A possible drawback is a
2011 slightly longer boot delay.
2014 bool "Kexec system call (EXPERIMENTAL)"
2015 depends on (!SMP || PM_SLEEP_SMP)
2019 kexec is a system call that implements the ability to shutdown your
2020 current kernel, and to start another kernel. It is like a reboot
2021 but it is independent of the system firmware. And like a reboot
2022 you can start any kernel with it, not just Linux.
2024 It is an ongoing process to be certain the hardware in a machine
2025 is properly shutdown, so do not be surprised if this code does not
2026 initially work for you.
2029 bool "Export atags in procfs"
2030 depends on ATAGS && KEXEC
2033 Should the atags used to boot the kernel be exported in an "atags"
2034 file in procfs. Useful with kexec.
2037 bool "Build kdump crash kernel (EXPERIMENTAL)"
2039 Generate crash dump after being started by kexec. This should
2040 be normally only set in special crash dump kernels which are
2041 loaded in the main kernel with kexec-tools into a specially
2042 reserved region and then later executed after a crash by
2043 kdump/kexec. The crash dump kernel must be compiled to a
2044 memory address not used by the main kernel
2046 For more details see Documentation/kdump/kdump.txt
2048 config AUTO_ZRELADDR
2049 bool "Auto calculation of the decompressed kernel image address"
2051 ZRELADDR is the physical address where the decompressed kernel
2052 image will be placed. If AUTO_ZRELADDR is selected, the address
2053 will be determined at run-time by masking the current IP with
2054 0xf8000000. This assumes the zImage being placed in the first 128MB
2055 from start of memory.
2061 bool "UEFI runtime support"
2062 depends on OF && !CPU_BIG_ENDIAN && MMU && AUTO_ZRELADDR && !XIP_KERNEL
2064 select EFI_PARAMS_FROM_FDT
2067 select EFI_RUNTIME_WRAPPERS
2069 This option provides support for runtime services provided
2070 by UEFI firmware (such as non-volatile variables, realtime
2071 clock, and platform reset). A UEFI stub is also provided to
2072 allow the kernel to be booted as an EFI application. This
2073 is only useful for kernels that may run on systems that have
2077 bool "Enable support for SMBIOS (DMI) tables"
2081 This enables SMBIOS/DMI feature for systems.
2083 This option is only useful on systems that have UEFI firmware.
2084 However, even with this option, the resultant kernel should
2085 continue to boot on existing non-UEFI platforms.
2087 NOTE: This does *NOT* enable or encourage the use of DMI quirks,
2088 i.e., the the practice of identifying the platform via DMI to
2089 decide whether certain workarounds for buggy hardware and/or
2090 firmware need to be enabled. This would require the DMI subsystem
2091 to be enabled much earlier than we do on ARM, which is non-trivial.
2095 menu "CPU Power Management"
2097 source "drivers/cpufreq/Kconfig"
2099 source "drivers/cpuidle/Kconfig"
2103 menu "Floating point emulation"
2105 comment "At least one emulation must be selected"
2108 bool "NWFPE math emulation"
2109 depends on (!AEABI || OABI_COMPAT) && !THUMB2_KERNEL
2111 Say Y to include the NWFPE floating point emulator in the kernel.
2112 This is necessary to run most binaries. Linux does not currently
2113 support floating point hardware so you need to say Y here even if
2114 your machine has an FPA or floating point co-processor podule.
2116 You may say N here if you are going to load the Acorn FPEmulator
2117 early in the bootup.
2120 bool "Support extended precision"
2121 depends on FPE_NWFPE
2123 Say Y to include 80-bit support in the kernel floating-point
2124 emulator. Otherwise, only 32 and 64-bit support is compiled in.
2125 Note that gcc does not generate 80-bit operations by default,
2126 so in most cases this option only enlarges the size of the
2127 floating point emulator without any good reason.
2129 You almost surely want to say N here.
2132 bool "FastFPE math emulation (EXPERIMENTAL)"
2133 depends on (!AEABI || OABI_COMPAT) && !CPU_32v3
2135 Say Y here to include the FAST floating point emulator in the kernel.
2136 This is an experimental much faster emulator which now also has full
2137 precision for the mantissa. It does not support any exceptions.
2138 It is very simple, and approximately 3-6 times faster than NWFPE.
2140 It should be sufficient for most programs. It may be not suitable
2141 for scientific calculations, but you have to check this for yourself.
2142 If you do not feel you need a faster FP emulation you should better
2146 bool "VFP-format floating point maths"
2147 depends on CPU_V6 || CPU_V6K || CPU_ARM926T || CPU_V7 || CPU_FEROCEON
2149 Say Y to include VFP support code in the kernel. This is needed
2150 if your hardware includes a VFP unit.
2152 Please see <file:Documentation/arm/VFP/release-notes.txt> for
2153 release notes and additional status information.
2155 Say N if your target does not have VFP hardware.
2163 bool "Advanced SIMD (NEON) Extension support"
2164 depends on VFPv3 && CPU_V7
2166 Say Y to include support code for NEON, the ARMv7 Advanced SIMD
2169 config KERNEL_MODE_NEON
2170 bool "Support for NEON in kernel mode"
2171 depends on NEON && AEABI
2173 Say Y to include support for NEON in kernel mode.
2177 menu "Userspace binary formats"
2179 source "fs/Kconfig.binfmt"
2183 menu "Power management options"
2185 source "kernel/power/Kconfig"
2187 config ARCH_SUSPEND_POSSIBLE
2188 depends on CPU_ARM920T || CPU_ARM926T || CPU_FEROCEON || CPU_SA1100 || \
2189 CPU_V6 || CPU_V6K || CPU_V7 || CPU_V7M || CPU_XSC3 || CPU_XSCALE || CPU_MOHAWK
2192 config ARM_CPU_SUSPEND
2193 def_bool PM_SLEEP || BL_SWITCHER || ARM_PSCI_FW
2194 depends on ARCH_SUSPEND_POSSIBLE
2196 config ARCH_HIBERNATION_POSSIBLE
2199 default y if ARCH_SUSPEND_POSSIBLE
2203 source "net/Kconfig"
2205 source "drivers/Kconfig"
2207 source "drivers/firmware/Kconfig"
2211 source "arch/arm/Kconfig.debug"
2213 source "security/Kconfig"
2215 source "crypto/Kconfig"
2217 source "arch/arm/crypto/Kconfig"
2220 source "lib/Kconfig"
2222 source "arch/arm/kvm/Kconfig"