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Howto configure the Linux kernel / arch / arm / mm


"Processor Type"


  • Option: CPU_32
    • Kernel Versions: 2.6.15.6 ...
    • (on/off)
    • default y
Select CPU types depending on the architecture selected. This selects
which CPUs we support in the kernel image, and the compiler instruction
optimiser behaviour.
ARM610


  • Option: CPU_ARM610
    • Kernel Versions: 2.6.15.6 ...
    • (on/off) Support ARM610 processor
    • depends on ARCH_RPC
    • select CPU_32v3
    • select CPU_CACHE_V3
    • select CPU_CACHE_VIVT
    • select CPU_COPY_V3
    • select CPU_TLB_V3
      The ARM610 is the successor to the ARM3 processor and was produced by VLSI Technology Inc.
      Say Y if you want support for the ARM610 processor. Otherwise, say N.
ARM710


  • Option: CPU_ARM710
    • Kernel Versions: 2.6.15.6 ...
    • (on/off) Support ARM710 processor if !ARCH_CLPS7500 && ARCH_RPC
    • default y if ARCH_CLPS7500
    • select CPU_32v3
    • select CPU_CACHE_V3
    • select CPU_CACHE_VIVT
    • select CPU_COPY_V3
    • select CPU_TLB_V3
      A 32-bit RISC microprocessor based on the ARM7 processor core designed by Advanced RISC Machines Ltd. The ARM710 is the successor to the ARM610 processor. It was released in July 1994 by VLSI Technology Inc.
      Say Y if you want support for the ARM710 processor. Otherwise, say N.
ARM720T


  • Option: CPU_ARM720T
    • Kernel Versions: 2.6.15.6 ...
    • (on/off) Support ARM720T processor if !ARCH_CLPS711X && !ARCH_L7200 && !ARCH_CDB89712 && ARCH_INTEGRATOR
    • default y if ARCH_CLPS711X || ARCH_L7200 || ARCH_CDB89712 || ARCH_H720X
    • select CPU_32v4
    • select CPU_ABRT_LV4T
    • select CPU_CACHE_V4
    • select CPU_CACHE_VIVT
    • select CPU_COPY_V4WT
    • select CPU_TLB_V4WT
      A 32-bit RISC processor with 8kByte Cache, Write Buffer and MMU built around an ARM7TDMI core.
      Say Y if you want support for the ARM720T processor. Otherwise, say N.
ARM920T


  • Option: CPU_ARM920T
    • Kernel Versions: 2.6.15.6 ...
    • (on/off) Support ARM920T processor if !ARCH_S3C2410
    • depends on ARCH_INTEGRATOR || ARCH_S3C2410 || ARCH_IMX || ARCH_AAEC2000
    • default y if ARCH_S3C2410
    • select CPU_32v4
    • select CPU_ABRT_EV4T
    • select CPU_CACHE_V4WT
    • select CPU_CACHE_VIVT
    • select CPU_COPY_V4WB
    • select CPU_TLB_V4WBI
      The ARM920T is licensed to be produced by numerous vendors, and is used in the Maverick EP9312 and the Samsung S3C2410.
      More information on the Maverick EP9312 at <http://linuxdevices.com/products/PD2382866068.html>.
      Say Y if you want support for the ARM920T processor. Otherwise, say N.
ARM922T


  • Option: CPU_ARM922T
    • Kernel Versions: 2.6.15.6 ...
    • (on/off) Support ARM922T processor if ARCH_INTEGRATOR
    • depends on ARCH_CAMELOT || ARCH_LH7A40X || ARCH_INTEGRATOR
    • default y if ARCH_CAMELOT || ARCH_LH7A40X
    • select CPU_32v4
    • select CPU_ABRT_EV4T
    • select CPU_CACHE_V4WT
    • select CPU_CACHE_VIVT
    • select CPU_COPY_V4WB
    • select CPU_TLB_V4WBI
      The ARM922T is a version of the ARM920T, but with smaller instruction and data caches. It is used in Altera's Excalibur XA device family.
      Say Y if you want support for the ARM922T processor. Otherwise, say N.
ARM925T


  • Option: CPU_ARM925T
    • Kernel Versions: 2.6.15.6 ...bool Support ARM925T processor if ARCH_OMAP1depends on ARCH_OMAP15XXdefault y if ARCH_OMAP15XX
    • select CPU_32v4
    • select CPU_ABRT_EV4T
    • select CPU_CACHE_V4WT
    • select CPU_CACHE_VIVT
    • select CPU_COPY_V4WB
    • select CPU_TLB_V4WBIhelp The ARM925T is a mix between the ARM920T and ARM926T, but with different instruction and data caches. It is used in TI's OMAP device family.
      Say Y if you want support for the ARM925T processor. Otherwise, say N.
ARM926T


  • Option: CPU_ARM926T
    • Kernel Versions: 2.6.15.6 ...
    • (on/off) Support ARM926T processor
    • depends on ARCH_INTEGRATOR || ARCH_VERSATILE_PB || MACH_VERSATILE_AB || ARCH_OMAP730 || ARCH_OMAP16XX || MACH_REALVIEW_EB
    • default y if ARCH_VERSATILE_PB || MACH_VERSATILE_AB || ARCH_OMAP730 || ARCH_OMAP16XX
    • select CPU_32v5
    • select CPU_ABRT_EV5TJ
    • select CPU_CACHE_VIVT
    • select CPU_COPY_V4WB
    • select CPU_TLB_V4WBI
      This is a variant of the ARM920. It has slightly different instruction sequences for cache and TLB operations. Curiously, there is no documentation on it at the ARM corporate website.
      Say Y if you want support for the ARM926T processor. Otherwise, say N.
ARM1020 - needs validating


  • Option: CPU_ARM1020
    • Kernel Versions: 2.6.15.6 ...
    • (on/off) Support ARM1020T (rev 0) processor
    • depends on ARCH_INTEGRATOR
    • select CPU_32v5
    • select CPU_ABRT_EV4T
    • select CPU_CACHE_V4WT
    • select CPU_CACHE_VIVT
    • select CPU_COPY_V4WB
    • select CPU_TLB_V4WBI
      The ARM1020 is the 32K cached version of the ARM10 processor, with an addition of a floating-point unit.
      Say Y if you want support for the ARM1020 processor. Otherwise, say N.
ARM1020E - needs validating


  • Option: CPU_ARM1020E
    • Kernel Versions: 2.6.15.6 ...
    • (on/off) Support ARM1020E processor
    • depends on ARCH_INTEGRATOR
    • select CPU_32v5
    • select CPU_ABRT_EV4T
    • select CPU_CACHE_V4WT
    • select CPU_CACHE_VIVT
    • select CPU_COPY_V4WB
    • select CPU_TLB_V4WBI
    • depends on n
ARM1022E


  • Option: CPU_ARM1022
    • Kernel Versions: 2.6.15.6 ...
    • (on/off) Support ARM1022E processor
    • depends on ARCH_INTEGRATOR
    • select CPU_32v5
    • select CPU_ABRT_EV4T
    • select CPU_CACHE_VIVT
    • select CPU_COPY_V4WB # can probably do better
    • select CPU_TLB_V4WBI
      The ARM1022E is an implementation of the ARMv5TE architecture based upon the ARM10 integer core with a 16KiB L1 Harvard cache, embedded trace macrocell, and a floating-point unit.
      Say Y if you want support for the ARM1022E processor. Otherwise, say N.
ARM1026EJ-S


  • Option: CPU_ARM1026
    • Kernel Versions: 2.6.15.6 ...
    • (on/off) Support ARM1026EJ-S processor
    • depends on ARCH_INTEGRATOR
    • select CPU_32v5
    • select CPU_ABRT_EV5T # But need Jazelle, but EV5TJ ignores bit 10
    • select CPU_CACHE_VIVT
    • select CPU_COPY_V4WB # can probably do better
    • select CPU_TLB_V4WBI
      The ARM1026EJ-S is an implementation of the ARMv5TEJ architecture based upon the ARM10 integer core.
      Say Y if you want support for the ARM1026EJ-S processor. Otherwise, say N.
SA110


  • Option: CPU_SA110
    • Kernel Versions: 2.6.15.6 ...
    • (on/off) Support StrongARM(R) SA-110 processor if !ARCH_EBSA110 && !FOOTBRIDGE && !ARCH_TBOX && !ARCH_SHARK && !ARCH_NEXUSPCI && ARCH_RPC
    • default y if ARCH_EBSA110 || FOOTBRIDGE || ARCH_TBOX || ARCH_SHARK || ARCH_NEXUSPCI
    • select CPU_32v3 if ARCH_RPC
    • select CPU_32v4 if !ARCH_RPC
    • select CPU_ABRT_EV4
    • select CPU_CACHE_V4WB
    • select CPU_CACHE_VIVT
    • select CPU_COPY_V4WB
    • select CPU_TLB_V4WB
      The Intel StrongARM(R) SA-110 is a 32-bit microprocessor and is available at five speeds ranging from 100 MHz to 233 MHz. More information is available at <http://developer.intel.com/design/strong/sa110.htm>.
      Say Y if you want support for the SA-110 processor. Otherwise, say N.
SA1100


  • Option: CPU_SA1100
    • Kernel Versions: 2.6.15.6 ...
    • (on/off)
    • depends on ARCH_SA1100
    • default y
    • select CPU_32v4
    • select CPU_ABRT_EV4
    • select CPU_CACHE_V4WB
    • select CPU_CACHE_VIVT
    • select CPU_TLB_V4WB
XScale


  • Option: CPU_XSCALE
    • Kernel Versions: 2.6.15.6 ...
    • (on/off)
    • depends on ARCH_IOP3XX || ARCH_PXA || ARCH_IXP4XX || ARCH_IXP2000
    • default y
    • select CPU_32v5
    • select CPU_ABRT_EV5T
    • select CPU_CACHE_VIVT
    • select CPU_TLB_V4WBI
ARMv6


  • Option: CPU_V6
    • Kernel Versions: 2.6.15.6 ...
    • (on/off) Support ARM V6 processor
    • depends on ARCH_INTEGRATOR || MACH_REALVIEW_EB || ARCH_OMAP2
    • select CPU_32v6
    • select CPU_ABRT_EV6
    • select CPU_CACHE_V6
    • select CPU_CACHE_VIPT
    • select CPU_COPY_V6
    • select CPU_TLB_V6
ARMv6k


  • Option: CPU_32v6K
    • Kernel Versions: 2.6.15.6 ...
    • (on/off) Support ARM V6K processor extensions if !SMP
    • depends on CPU_V6
    • default y if SMP
      Say Y here if your ARMv6 processor supports the 'K' extension. This enables the kernel to use some instructions not present on previous processors, and as such a kernel build with this enabled will not boot on processors with do not support these instructions.
Figure out what processor architecture version we should be using.
This defines the compiler instruction set which depends on the machine type.


  • Option: CPU_32v3
    • Kernel Versions: 2.6.15.6 ...
    • (on/off)


  • Option: CPU_32v4
    • Kernel Versions: 2.6.15.6 ...
    • (on/off)


  • Option: CPU_32v5
    • Kernel Versions: 2.6.15.6 ...
    • (on/off)


  • Option: CPU_32v6
    • Kernel Versions: 2.6.15.6 ...
    • (on/off)
The abort model


  • Option: CPU_ABRT_EV4
    • Kernel Versions: 2.6.15.6 ...
    • (on/off)


  • Option: CPU_ABRT_EV4T
    • Kernel Versions: 2.6.15.6 ...
    • (on/off)


  • Option: CPU_ABRT_LV4T
    • Kernel Versions: 2.6.15.6 ...
    • (on/off)


  • Option: CPU_ABRT_EV5T
    • Kernel Versions: 2.6.15.6 ...
    • (on/off)


  • Option: CPU_ABRT_EV5TJ
    • Kernel Versions: 2.6.15.6 ...
    • (on/off)


  • Option: CPU_ABRT_EV6
    • Kernel Versions: 2.6.15.6 ...
    • (on/off)
The cache model


  • Option: CPU_CACHE_V3
    • Kernel Versions: 2.6.15.6 ...
    • (on/off)


  • Option: CPU_CACHE_V4
    • Kernel Versions: 2.6.15.6 ...
    • (on/off)


  • Option: CPU_CACHE_V4WT
    • Kernel Versions: 2.6.15.6 ...
    • (on/off)


  • Option: CPU_CACHE_V4WB
    • Kernel Versions: 2.6.15.6 ...
    • (on/off)


  • Option: CPU_CACHE_V6
    • Kernel Versions: 2.6.15.6 ...
    • (on/off)


  • Option: CPU_CACHE_VIVT
    • Kernel Versions: 2.6.15.6 ...
    • (on/off)


  • Option: CPU_CACHE_VIPT
    • Kernel Versions: 2.6.15.6 ...
    • (on/off)
The copy-page model


  • Option: CPU_COPY_V3
    • Kernel Versions: 2.6.15.6 ...
    • (on/off)


  • Option: CPU_COPY_V4WT
    • Kernel Versions: 2.6.15.6 ...
    • (on/off)


  • Option: CPU_COPY_V4WB
    • Kernel Versions: 2.6.15.6 ...
    • (on/off)


  • Option: CPU_COPY_V6
    • Kernel Versions: 2.6.15.6 ...
    • (on/off)
This selects the TLB model


  • Option: CPU_TLB_V3
    • Kernel Versions: 2.6.15.6 ...
    • (on/off)
      ARM Architecture Version 3 TLB.


  • Option: CPU_TLB_V4WT
    • Kernel Versions: 2.6.15.6 ...
    • (on/off)
      ARM Architecture Version 4 TLB with writethrough cache.


  • Option: CPU_TLB_V4WB
    • Kernel Versions: 2.6.15.6 ...
    • (on/off)
      ARM Architecture Version 4 TLB with writeback cache.


  • Option: CPU_TLB_V4WBI
    • Kernel Versions: 2.6.15.6 ...
    • (on/off)
      ARM Architecture Version 4 TLB with writeback cache and invalidate instruction cache entry.


  • Option: CPU_TLB_V6
    • Kernel Versions: 2.6.15.6 ...
    • (on/off)

"Processor Features"


  • Option: ARM_THUMB
    • Kernel Versions: 2.6.15.6 ...
    • (on/off) Support Thumb user binaries
    • depends on CPU_ARM720T || CPU_ARM920T || CPU_ARM922T || CPU_ARM925T || CPU_ARM926T || CPU_ARM1020 || CPU_ARM1020E || CPU_ARM1022 || CPU_ARM1026 || CPU_XSCALE || CPU_V6
    • default y
      Say Y if you want to include kernel support for running user space Thumb binaries.
      The Thumb instruction set is a compressed form of the standard ARM instruction set resulting in smaller binaries at the expense of slightly less efficient code.
      If you don't know what this all is, saying Y is a safe choice.


  • Option: CPU_BIG_ENDIAN
    • Kernel Versions: 2.6.15.6 ...
    • (on/off) Build big-endian kernel
    • depends on ARCH_SUPPORTS_BIG_ENDIAN
      Say Y if you plan on running a kernel in big-endian mode. Note that your board must be properly built and your board port must properly enable any big-endian related features of your chipset/board/processor.


  • Option: CPU_ICACHE_DISABLE
    • Kernel Versions: 2.6.15.6 ...
    • (on/off) Disable I-Cache
    • depends on CPU_ARM920T || CPU_ARM922T || CPU_ARM925T || CPU_ARM926T || CPU_ARM1020 || CPU_V6
      Say Y here to disable the processor instruction cache. Unless you have a reason not to or are unsure, say N.


  • Option: CPU_DCACHE_DISABLE
    • Kernel Versions: 2.6.15.6 ...
    • (on/off) Disable D-Cache
    • depends on CPU_ARM920T || CPU_ARM922T || CPU_ARM925T || CPU_ARM926T || CPU_ARM1020 || CPU_V6
      Say Y here to disable the processor data cache. Unless you have a reason not to or are unsure, say N.


  • Option: CPU_DCACHE_WRITETHROUGH
    • Kernel Versions: 2.6.15.6 ...
    • (on/off) Force write through D-cache
    • depends on (CPU_ARM920T || CPU_ARM922T || CPU_ARM925T || CPU_ARM926T || CPU_ARM1020 || CPU_V6) && !CPU_DCACHE_DISABLE
    • default y if CPU_ARM925T
      Say Y here to use the data cache in writethrough mode. Unless you specifically require this or are unsure, say N.


  • Option: CPU_CACHE_ROUND_ROBIN
    • Kernel Versions: 2.6.15.6 ...
    • (on/off) Round robin I and D cache replacement algorithm
    • depends on (CPU_ARM926T || CPU_ARM1020) && (!CPU_ICACHE_DISABLE || !CPU_DCACHE_DISABLE)
      Say Y here to use the predictable round-robin cache replacement policy. Unless you specifically require this or are unsure, say N.


  • Option: CPU_BPREDICT_DISABLE
    • Kernel Versions: 2.6.15.6 ...
    • (on/off) Disable branch prediction
    • depends on CPU_ARM1020 || CPU_V6
      Say Y here to disable branch prediction. If unsure, say N.


  • Option: TLS_REG_EMUL
    • Kernel Versions: 2.6.15.6 ...
    • (on/off)
    • default y if SMP && (CPU_32v5 || CPU_32v4 || CPU_32v3)
      An SMP system using a pre-ARMv6 processor (there are apparently a few prototypes like that in existence) and therefore access to that required register must be emulated.


  • Option: HAS_TLS_REG
    • Kernel Versions: 2.6.15.6 ...
    • (on/off)
    • depends on !TLS_REG_EMUL
    • default y if SMP || CPU_32v7
      This selects support for the CP15 thread register. It is defined to be available on some ARMv6 processors (including all SMP capable ARMv6's) or later processors. User space may assume directly accessing that register and always obtain the expected value only on ARMv7 and above.


  • Option: NEEDS_SYSCALL_FOR_CMPXCHG
    • Kernel Versions: 2.6.15.6 ...
    • (on/off)
    • default y if SMP && (CPU_32v5 || CPU_32v4 || CPU_32v3)
      SMP on a pre-ARMv6 processor? Well OK then. Forget about fast user space cmpxchg support. It is just not possible.


Linux Kernel Configuration

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