1 comment "Processor Type"
3 # Select CPU types depending on the architecture selected. This selects
4 # which CPUs we support in the kernel image, and the compiler instruction
9 bool "Support ARM7TDMI processor"
14 select CPU_PABRT_LEGACY
16 A 32-bit RISC microprocessor based on the ARM7 processor core
17 which has no memory control unit and cache.
19 Say Y if you want support for the ARM7TDMI processor.
24 bool "Support ARM720T processor" if ARCH_INTEGRATOR
29 select CPU_COPY_V4WT if MMU
31 select CPU_PABRT_LEGACY
32 select CPU_TLB_V4WT if MMU
34 A 32-bit RISC processor with 8kByte Cache, Write Buffer and
35 MMU built around an ARM7TDMI core.
37 Say Y if you want support for the ARM720T processor.
42 bool "Support ARM740T processor" if ARCH_INTEGRATOR
48 select CPU_PABRT_LEGACY
50 A 32-bit RISC processor with 8KB cache or 4KB variants,
51 write buffer and MPU(Protection Unit) built around
54 Say Y if you want support for the ARM740T processor.
59 bool "Support ARM9TDMI processor"
64 select CPU_PABRT_LEGACY
66 A 32-bit RISC microprocessor based on the ARM9 processor core
67 which has no memory control unit and cache.
69 Say Y if you want support for the ARM9TDMI processor.
74 bool "Support ARM920T processor" if ARCH_INTEGRATOR
79 select CPU_COPY_V4WB if MMU
81 select CPU_PABRT_LEGACY
82 select CPU_TLB_V4WBI if MMU
84 The ARM920T is licensed to be produced by numerous vendors,
85 and is used in the Cirrus EP93xx and the Samsung S3C2410.
87 Say Y if you want support for the ARM920T processor.
92 bool "Support ARM922T processor" if ARCH_INTEGRATOR
97 select CPU_COPY_V4WB if MMU
99 select CPU_PABRT_LEGACY
100 select CPU_TLB_V4WBI if MMU
102 The ARM922T is a version of the ARM920T, but with smaller
103 instruction and data caches. It is used in Altera's
104 Excalibur XA device family and Micrel's KS8695 Centaur.
106 Say Y if you want support for the ARM922T processor.
111 bool "Support ARM925T processor" if ARCH_OMAP1
114 select CPU_CACHE_V4WT
115 select CPU_CACHE_VIVT
116 select CPU_COPY_V4WB if MMU
118 select CPU_PABRT_LEGACY
119 select CPU_TLB_V4WBI if MMU
121 The ARM925T is a mix between the ARM920T and ARM926T, but with
122 different instruction and data caches. It is used in TI's OMAP
125 Say Y if you want support for the ARM925T processor.
130 bool "Support ARM926T processor" if ARCH_INTEGRATOR || MACH_REALVIEW_EB
132 select CPU_ABRT_EV5TJ
133 select CPU_CACHE_VIVT
134 select CPU_COPY_V4WB if MMU
136 select CPU_PABRT_LEGACY
137 select CPU_TLB_V4WBI if MMU
139 This is a variant of the ARM920. It has slightly different
140 instruction sequences for cache and TLB operations. Curiously,
141 there is no documentation on it at the ARM corporate website.
143 Say Y if you want support for the ARM926T processor.
152 select CPU_CACHE_VIVT
153 select CPU_COPY_FA if MMU
155 select CPU_PABRT_LEGACY
156 select CPU_TLB_FA if MMU
158 The FA526 is a version of the ARMv4 compatible processor with
159 Branch Target Buffer, Unified TLB and cache line size 16.
161 Say Y if you want support for the FA526 processor.
166 bool "Support ARM940T processor" if ARCH_INTEGRATOR
169 select CPU_ABRT_NOMMU
170 select CPU_CACHE_VIVT
172 select CPU_PABRT_LEGACY
174 ARM940T is a member of the ARM9TDMI family of general-
175 purpose microprocessors with MPU and separate 4KB
176 instruction and 4KB data cases, each with a 4-word line
179 Say Y if you want support for the ARM940T processor.
184 bool "Support ARM946E-S processor" if ARCH_INTEGRATOR
187 select CPU_ABRT_NOMMU
188 select CPU_CACHE_VIVT
190 select CPU_PABRT_LEGACY
192 ARM946E-S is a member of the ARM9E-S family of high-
193 performance, 32-bit system-on-chip processor solutions.
194 The TCM and ARMv5TE 32-bit instruction set is supported.
196 Say Y if you want support for the ARM946E-S processor.
199 # ARM1020 - needs validating
201 bool "Support ARM1020T (rev 0) processor" if ARCH_INTEGRATOR
204 select CPU_CACHE_V4WT
205 select CPU_CACHE_VIVT
206 select CPU_COPY_V4WB if MMU
208 select CPU_PABRT_LEGACY
209 select CPU_TLB_V4WBI if MMU
211 The ARM1020 is the 32K cached version of the ARM10 processor,
212 with an addition of a floating-point unit.
214 Say Y if you want support for the ARM1020 processor.
217 # ARM1020E - needs validating
219 bool "Support ARM1020E processor" if ARCH_INTEGRATOR
223 select CPU_CACHE_V4WT
224 select CPU_CACHE_VIVT
225 select CPU_COPY_V4WB if MMU
227 select CPU_PABRT_LEGACY
228 select CPU_TLB_V4WBI if MMU
232 bool "Support ARM1022E processor" if ARCH_INTEGRATOR
235 select CPU_CACHE_VIVT
236 select CPU_COPY_V4WB if MMU # can probably do better
238 select CPU_PABRT_LEGACY
239 select CPU_TLB_V4WBI if MMU
241 The ARM1022E is an implementation of the ARMv5TE architecture
242 based upon the ARM10 integer core with a 16KiB L1 Harvard cache,
243 embedded trace macrocell, and a floating-point unit.
245 Say Y if you want support for the ARM1022E processor.
250 bool "Support ARM1026EJ-S processor" if ARCH_INTEGRATOR
252 select CPU_ABRT_EV5T # But need Jazelle, but EV5TJ ignores bit 10
253 select CPU_CACHE_VIVT
254 select CPU_COPY_V4WB if MMU # can probably do better
256 select CPU_PABRT_LEGACY
257 select CPU_TLB_V4WBI if MMU
259 The ARM1026EJ-S is an implementation of the ARMv5TEJ architecture
260 based upon the ARM10 integer core.
262 Say Y if you want support for the ARM1026EJ-S processor.
267 bool "Support StrongARM(R) SA-110 processor" if ARCH_RPC
268 select CPU_32v3 if ARCH_RPC
269 select CPU_32v4 if !ARCH_RPC
271 select CPU_CACHE_V4WB
272 select CPU_CACHE_VIVT
273 select CPU_COPY_V4WB if MMU
275 select CPU_PABRT_LEGACY
276 select CPU_TLB_V4WB if MMU
278 The Intel StrongARM(R) SA-110 is a 32-bit microprocessor and
279 is available at five speeds ranging from 100 MHz to 233 MHz.
280 More information is available at
281 <http://developer.intel.com/design/strong/sa110.htm>.
283 Say Y if you want support for the SA-110 processor.
291 select CPU_CACHE_V4WB
292 select CPU_CACHE_VIVT
294 select CPU_PABRT_LEGACY
295 select CPU_TLB_V4WB if MMU
302 select CPU_CACHE_VIVT
304 select CPU_PABRT_LEGACY
305 select CPU_TLB_V4WBI if MMU
307 # XScale Core Version 3
312 select CPU_CACHE_VIVT
314 select CPU_PABRT_LEGACY
315 select CPU_TLB_V4WBI if MMU
318 # Marvell PJ1 (Mohawk)
323 select CPU_CACHE_VIVT
324 select CPU_COPY_V4WB if MMU
326 select CPU_PABRT_LEGACY
327 select CPU_TLB_V4WBI if MMU
334 select CPU_CACHE_VIVT
335 select CPU_COPY_FEROCEON if MMU
337 select CPU_PABRT_LEGACY
338 select CPU_TLB_FEROCEON if MMU
340 config CPU_FEROCEON_OLD_ID
341 bool "Accept early Feroceon cores with an ARM926 ID"
342 depends on CPU_FEROCEON && !CPU_ARM926T
345 This enables the usage of some old Feroceon cores
346 for which the CPU ID is equal to the ARM926 ID.
347 Relevant for Feroceon-1850 and early Feroceon-2850.
361 bool "Support ARM V6 processor" if ARCH_INTEGRATOR || MACH_REALVIEW_EB || MACH_REALVIEW_PBX
365 select CPU_CACHE_VIPT
366 select CPU_COPY_V6 if MMU
368 select CPU_HAS_ASID if MMU
370 select CPU_TLB_V6 if MMU
374 bool "Support ARM V6K processor" if ARCH_INTEGRATOR || MACH_REALVIEW_EB || MACH_REALVIEW_PBX
379 select CPU_CACHE_VIPT
380 select CPU_COPY_V6 if MMU
382 select CPU_HAS_ASID if MMU
384 select CPU_TLB_V6 if MMU
388 bool "Support ARM V7 processor" if ARCH_INTEGRATOR || MACH_REALVIEW_EB || MACH_REALVIEW_PBX
393 select CPU_CACHE_VIPT
394 select CPU_COPY_V6 if MMU
396 select CPU_HAS_ASID if MMU
398 select CPU_TLB_V7 if MMU
402 # There are no CPUs available with MMU that don't implement an ARM ISA:
405 Select this if your CPU doesn't support the 32 bit ARM instructions.
407 # Figure out what processor architecture version we should be using.
408 # This defines the compiler instruction set which depends on the machine type.
411 select CPU_USE_DOMAINS if MMU
412 select NEEDS_SYSCALL_FOR_CMPXCHG if SMP
413 select TLS_REG_EMUL if SMP || !MMU
414 select NEED_KUSER_HELPERS
418 select CPU_USE_DOMAINS if MMU
419 select NEEDS_SYSCALL_FOR_CMPXCHG if SMP
420 select TLS_REG_EMUL if SMP || !MMU
421 select NEED_KUSER_HELPERS
425 select CPU_USE_DOMAINS if MMU
426 select NEEDS_SYSCALL_FOR_CMPXCHG if SMP
427 select TLS_REG_EMUL if SMP || !MMU
428 select NEED_KUSER_HELPERS
432 select CPU_USE_DOMAINS if MMU
433 select NEEDS_SYSCALL_FOR_CMPXCHG if SMP
434 select TLS_REG_EMUL if SMP || !MMU
435 select NEED_KUSER_HELPERS
439 select TLS_REG_EMUL if !CPU_32v6K && !MMU
448 config CPU_ABRT_NOMMU
463 config CPU_ABRT_EV5TJ
472 config CPU_PABRT_LEGACY
485 config CPU_CACHE_V4WT
488 config CPU_CACHE_V4WB
497 config CPU_CACHE_VIVT
500 config CPU_CACHE_VIPT
507 # The copy-page model
514 config CPU_COPY_FEROCEON
523 # This selects the TLB model
527 ARM Architecture Version 4 TLB with writethrough cache.
532 ARM Architecture Version 4 TLB with writeback cache.
537 ARM Architecture Version 4 TLB with writeback cache and invalidate
538 instruction cache entry.
540 config CPU_TLB_FEROCEON
543 Feroceon TLB (v4wbi with non-outer-cachable page table walks).
548 Faraday ARM FA526 architecture, unified TLB with writeback cache
549 and invalidate instruction cache entry. Branch target buffer is
558 config VERIFY_PERMISSION_FAULT
565 This indicates whether the CPU has the ASID register; used to
566 tag TLB and possibly cache entries.
571 Processor has the CP15 register.
577 Processor has the CP15 register, which has MMU related registers.
583 Processor has the CP15 register, which has MPU related registers.
585 config CPU_USE_DOMAINS
588 This option enables or disables the use of domain switching
589 via the set_fs() function.
592 # CPU supports 36-bit I/O
597 comment "Processor Features"
600 bool "Support for the Large Physical Address Extension"
601 depends on MMU && CPU_32v7 && !CPU_32v6 && !CPU_32v5 && \
602 !CPU_32v4 && !CPU_32v3
604 Say Y if you have an ARMv7 processor supporting the LPAE page
605 table format and you would like to access memory beyond the
606 4GB limit. The resulting kernel image will not run on
607 processors without the LPA extension.
611 config ARCH_PHYS_ADDR_T_64BIT
614 config ARCH_DMA_ADDR_T_64BIT
618 bool "Support Thumb user binaries" if !CPU_THUMBONLY
619 depends on CPU_ARM720T || CPU_ARM740T || CPU_ARM920T || CPU_ARM922T || CPU_ARM925T || CPU_ARM926T || CPU_ARM940T || CPU_ARM946E || CPU_ARM1020 || CPU_ARM1020E || CPU_ARM1022 || CPU_ARM1026 || CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK || CPU_V6 || CPU_V6K || CPU_V7 || CPU_FEROCEON
622 Say Y if you want to include kernel support for running user space
625 The Thumb instruction set is a compressed form of the standard ARM
626 instruction set resulting in smaller binaries at the expense of
627 slightly less efficient code.
629 If you don't know what this all is, saying Y is a safe choice.
632 bool "Enable ThumbEE CPU extension"
635 Say Y here if you have a CPU with the ThumbEE extension and code to
636 make use of it. Say N for code that can run on CPUs without ThumbEE.
643 Enable the kernel to make use of the ARM Virtualization
644 Extensions to install hypervisors without run-time firmware
647 A compliant bootloader is required in order to make maximum
648 use of this feature. Refer to Documentation/arm/Booting for
652 bool "Emulate SWP/SWPB instructions"
655 select HAVE_PROC_CPU if PROC_FS
657 ARMv6 architecture deprecates use of the SWP/SWPB instructions.
658 ARMv7 multiprocessing extensions introduce the ability to disable
659 these instructions, triggering an undefined instruction exception
660 when executed. Say Y here to enable software emulation of these
661 instructions for userspace (not kernel) using LDREX/STREX.
662 Also creates /proc/cpu/swp_emulation for statistics.
664 In some older versions of glibc [<=2.8] SWP is used during futex
665 trylock() operations with the assumption that the code will not
666 be preempted. This invalid assumption may be more likely to fail
667 with SWP emulation enabled, leading to deadlock of the user
670 NOTE: when accessing uncached shared regions, LDREX/STREX rely
671 on an external transaction monitoring block called a global
672 monitor to maintain update atomicity. If your system does not
673 implement a global monitor, this option can cause programs that
674 perform SWP operations to uncached memory to deadlock.
678 config CPU_BIG_ENDIAN
679 bool "Build big-endian kernel"
680 depends on ARCH_SUPPORTS_BIG_ENDIAN
682 Say Y if you plan on running a kernel in big-endian mode.
683 Note that your board must be properly built and your board
684 port must properly enable any big-endian related features
685 of your chipset/board/processor.
687 config CPU_ENDIAN_BE8
689 depends on CPU_BIG_ENDIAN
690 default CPU_V6 || CPU_V6K || CPU_V7
692 Support for the BE-8 (big-endian) mode on ARMv6 and ARMv7 processors.
694 config CPU_ENDIAN_BE32
696 depends on CPU_BIG_ENDIAN
697 default !CPU_ENDIAN_BE8
699 Support for the BE-32 (big-endian) mode on pre-ARMv6 processors.
701 config CPU_HIGH_VECTOR
702 depends on !MMU && CPU_CP15 && !CPU_ARM740T
703 bool "Select the High exception vector"
705 Say Y here to select high exception vector(0xFFFF0000~).
706 The exception vector can vary depending on the platform
707 design in nommu mode. If your platform needs to select
708 high exception vector, say Y.
709 Otherwise or if you are unsure, say N, and the low exception
710 vector (0x00000000~) will be used.
712 config CPU_ICACHE_DISABLE
713 bool "Disable I-Cache (I-bit)"
714 depends on CPU_CP15 && !(CPU_ARM720T || CPU_ARM740T || CPU_XSCALE || CPU_XSC3)
716 Say Y here to disable the processor instruction cache. Unless
717 you have a reason not to or are unsure, say N.
719 config CPU_DCACHE_DISABLE
720 bool "Disable D-Cache (C-bit)"
723 Say Y here to disable the processor data cache. Unless
724 you have a reason not to or are unsure, say N.
726 config CPU_DCACHE_SIZE
728 depends on CPU_ARM740T || CPU_ARM946E
729 default 0x00001000 if CPU_ARM740T
730 default 0x00002000 # default size for ARM946E-S
732 Some cores are synthesizable to have various sized cache. For
733 ARM946E-S case, it can vary from 0KB to 1MB.
734 To support such cache operations, it is efficient to know the size
736 If your SoC is configured to have a different size, define the value
737 here with proper conditions.
739 config CPU_DCACHE_WRITETHROUGH
740 bool "Force write through D-cache"
741 depends on (CPU_ARM740T || CPU_ARM920T || CPU_ARM922T || CPU_ARM925T || CPU_ARM926T || CPU_ARM940T || CPU_ARM946E || CPU_ARM1020 || CPU_FA526) && !CPU_DCACHE_DISABLE
742 default y if CPU_ARM925T
744 Say Y here to use the data cache in writethrough mode. Unless you
745 specifically require this or are unsure, say N.
747 config CPU_CACHE_ROUND_ROBIN
748 bool "Round robin I and D cache replacement algorithm"
749 depends on (CPU_ARM926T || CPU_ARM946E || CPU_ARM1020) && (!CPU_ICACHE_DISABLE || !CPU_DCACHE_DISABLE)
751 Say Y here to use the predictable round-robin cache replacement
752 policy. Unless you specifically require this or are unsure, say N.
754 config CPU_BPREDICT_DISABLE
755 bool "Disable branch prediction"
756 depends on CPU_ARM1020 || CPU_V6 || CPU_V6K || CPU_MOHAWK || CPU_XSC3 || CPU_V7 || CPU_FA526
758 Say Y here to disable branch prediction. If unsure, say N.
762 select NEED_KUSER_HELPERS
764 An SMP system using a pre-ARMv6 processor (there are apparently
765 a few prototypes like that in existence) and therefore access to
766 that required register must be emulated.
768 config NEEDS_SYSCALL_FOR_CMPXCHG
770 select NEED_KUSER_HELPERS
772 SMP on a pre-ARMv6 processor? Well OK then.
773 Forget about fast user space cmpxchg support.
774 It is just not possible.
776 config NEED_KUSER_HELPERS
780 bool "Enable kuser helpers in vector page" if !NEED_KUSER_HELPERS
783 Warning: disabling this option may break user programs.
785 Provide kuser helpers in the vector page. The kernel provides
786 helper code to userspace in read only form at a fixed location
787 in the high vector page to allow userspace to be independent of
788 the CPU type fitted to the system. This permits binaries to be
789 run on ARMv4 through to ARMv7 without modification.
791 See Documentation/arm/kernel_user_helpers.txt for details.
793 However, the fixed address nature of these helpers can be used
794 by ROP (return orientated programming) authors when creating
797 If all of the binaries and libraries which run on your platform
798 are built specifically for your platform, and make no use of
799 these helpers, then you can turn this option off to hinder
800 such exploits. However, in that case, if a binary or library
801 relying on those helpers is run, it will receive a SIGILL signal,
802 which will terminate the program.
804 Say N here only if you are absolutely certain that you do not
805 need these helpers; otherwise, the safe option is to say Y.
807 config DMA_CACHE_RWFO
808 bool "Enable read/write for ownership DMA cache maintenance"
809 depends on CPU_V6K && SMP
812 The Snoop Control Unit on ARM11MPCore does not detect the
813 cache maintenance operations and the dma_{map,unmap}_area()
814 functions may leave stale cache entries on other CPUs. By
815 enabling this option, Read or Write For Ownership in the ARMv6
816 DMA cache maintenance functions is performed. These LDR/STR
817 instructions change the cache line state to shared or modified
818 so that the cache operation has the desired effect.
820 Note that the workaround is only valid on processors that do
821 not perform speculative loads into the D-cache. For such
822 processors, if cache maintenance operations are not broadcast
823 in hardware, other workarounds are needed (e.g. cache
824 maintenance broadcasting in software via FIQ).
829 config OUTER_CACHE_SYNC
832 The outer cache has a outer_cache_fns.sync function pointer
833 that can be used to drain the write buffer of the outer cache.
835 config CACHE_FEROCEON_L2
836 bool "Enable the Feroceon L2 cache controller"
837 depends on ARCH_KIRKWOOD || ARCH_MV78XX0
841 This option enables the Feroceon L2 cache controller.
843 config CACHE_FEROCEON_L2_WRITETHROUGH
844 bool "Force Feroceon L2 cache write through"
845 depends on CACHE_FEROCEON_L2
847 Say Y here to use the Feroceon L2 cache in writethrough mode.
848 Unless you specifically require this, say N for writeback mode.
850 config MIGHT_HAVE_CACHE_L2X0
853 This option should be selected by machines which have a L2x0
854 or PL310 cache controller, but where its use is optional.
856 The only effect of this option is to make CACHE_L2X0 and
857 related options available to the user for configuration.
859 Boards or SoCs which always require the cache controller
860 support to be present should select CACHE_L2X0 directly
861 instead of this option, thus preventing the user from
862 inadvertently configuring a broken kernel.
865 bool "Enable the L2x0 outer cache controller" if MIGHT_HAVE_CACHE_L2X0
866 default MIGHT_HAVE_CACHE_L2X0
868 select OUTER_CACHE_SYNC
870 This option enables the L2x0 PrimeCell.
874 depends on CACHE_L2X0
875 default y if CPU_V7 && !(CPU_V6 || CPU_V6K)
877 This option enables optimisations for the PL310 cache
881 bool "Enable the Tauros2 L2 cache controller"
882 depends on (ARCH_DOVE || ARCH_MMP || CPU_PJ4)
886 This option enables the Tauros2 L2 cache controller (as
890 bool "Enable the L2 cache on XScale3"
895 This option enables the L2 cache on XScale3.
897 config ARM_L1_CACHE_SHIFT_6
901 Setting ARM L1 cache line size to 64 Bytes.
903 config ARM_L1_CACHE_SHIFT
905 default 6 if ARM_L1_CACHE_SHIFT_6
908 config ARM_DMA_MEM_BUFFERABLE
909 bool "Use non-cacheable memory for DMA" if (CPU_V6 || CPU_V6K) && !CPU_V7
910 depends on !(MACH_REALVIEW_PB1176 || REALVIEW_EB_ARM11MP || \
911 MACH_REALVIEW_PB11MP)
912 default y if CPU_V6 || CPU_V6K || CPU_V7
914 Historically, the kernel has used strongly ordered mappings to
915 provide DMA coherent memory. With the advent of ARMv7, mapping
916 memory with differing types results in unpredictable behaviour,
917 so on these CPUs, this option is forced on.
919 Multiple mappings with differing attributes is also unpredictable
920 on ARMv6 CPUs, but since they do not have aggressive speculative
921 prefetch, no harm appears to occur.
923 However, drivers may be missing the necessary barriers for ARMv6,
924 and therefore turning this on may result in unpredictable driver
925 behaviour. Therefore, we offer this as an option.
927 You are recommended say 'Y' here and debug any affected drivers.
929 config ARCH_HAS_BARRIERS
932 This option allows the use of custom mandatory barriers
933 included via the mach/barriers.h file.
935 config ARCH_SUPPORTS_BIG_ENDIAN
938 This option specifies the architecture can support big endian