1b2441318SGreg Kroah-Hartman# SPDX-License-Identifier: GPL-2.0 21da177e4SLinus Torvaldsconfig ARM 31da177e4SLinus Torvalds bool 41da177e4SLinus Torvalds default y 5942fa985SYury Norov select ARCH_32BIT_OFF_T 6fed240d9SMasami Hiramatsu select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE if HAVE_KRETPROBES && FRAME_POINTER && !ARM_UNWIND 7aef0f78eSChristoph Hellwig select ARCH_HAS_BINFMT_FLAT 82792d84eSKees Cook select ARCH_HAS_CURRENT_STACK_POINTER 9c7780ab5SVladimir Murzin select ARCH_HAS_DEBUG_VIRTUAL if MMU 10419e2f18SChristoph Hellwig select ARCH_HAS_DMA_WRITE_COMBINE if !ARM_DMA_MEM_BUFFERABLE 112b68f6caSKees Cook select ARCH_HAS_ELF_RANDOMIZE 12ee333554SJinbum Park select ARCH_HAS_FORTIFY_SOURCE 13d8ae8a37SChristoph Hellwig select ARCH_HAS_KEEPINITRD 1475851720SDmitry Vyukov select ARCH_HAS_KCOV 15e69244d2SWill Deacon select ARCH_HAS_MEMBARRIER_SYNC_CORE 160ebeea8cSDaniel Borkmann select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 173010a5eaSLaurent Dufour select ARCH_HAS_PTE_SPECIAL if ARM_LPAE 18347cb6afSChristoph Hellwig select ARCH_HAS_SETUP_DMA_OPS 1975851720SDmitry Vyukov select ARCH_HAS_SET_MEMORY 209fbed16cSLi Huafei select ARCH_STACKWALK 21ad21fc4fSLaura Abbott select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL 22ad21fc4fSLaura Abbott select ARCH_HAS_STRICT_MODULE_RWX if MMU 23ae626eb9SChristoph Hellwig select ARCH_HAS_SYNC_DMA_FOR_DEVICE 24ae626eb9SChristoph Hellwig select ARCH_HAS_SYNC_DMA_FOR_CPU 25dc2acdedSChristoph Hellwig select ARCH_HAS_TEARDOWN_DMA_OPS if MMU 263d06770eSMark Rutland select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST 279aaf9bb7SDaniel Thompson select ARCH_HAVE_NMI_SAFE_CMPXCHG if CPU_V7 || CPU_V7M || CPU_V6K 28957e3facSRiku Voipio select ARCH_HAS_GCOV_PROFILE_ALL 295e545df3SMike Rapoport select ARCH_KEEP_MEMBLOCK 30d539fee9SSeung-Woo Kim select ARCH_HAS_UBSAN_SANITIZE_ALL 31d7018848SMark Salter select ARCH_MIGHT_HAVE_PC_PARPORT 32ad21fc4fSLaura Abbott select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX 33ad21fc4fSLaura Abbott select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT if CPU_V7 344badad35SPeter Zijlstra select ARCH_SUPPORTS_ATOMIC_RMW 35855f9a8eSAnshuman Khandual select ARCH_SUPPORTS_HUGETLBFS if ARM_LPAE 36017f161aSKim Phillips select ARCH_USE_BUILTIN_BSWAP 370cbad9c9SWill Deacon select ARCH_USE_CMPXCHG_LOCKREF 38dce44566SAnshuman Khandual select ARCH_USE_MEMTEST 39dba79c3dSAlexandre Ghiti select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU 4007431506SAnshuman Khandual select ARCH_WANT_GENERAL_HUGETLB 41b1b3f49cSRussell King select ARCH_WANT_IPC_PARSE_VERSION 4259612b24SNathan Chancellor select ARCH_WANT_LD_ORPHAN_WARN 43bdd15a28SChristoph Hellwig select BINFMT_FLAT_ARGVP_ENVP_ON_STACK 4410916706SShile Zhang select BUILDTIME_TABLE_SORT if MMU 456fd09c9aSArnd Bergmann select COMMON_CLK if !(ARCH_RPC || ARCH_FOOTBRIDGE) 46171b3f0dSRussell King select CLONE_BACKWARDS 47f00790aaSRussell King select CPU_PM if SUSPEND || CPU_IDLE 48dce5c9e3SWill Deacon select DCACHE_WORD_ACCESS if HAVE_EFFICIENT_UNALIGNED_ACCESS 49ff4c25f2SChristoph Hellwig select DMA_DECLARE_COHERENT 5031b089bbSChristoph Hellwig select DMA_GLOBAL_POOL if !MMU 512f9237d4SChristoph Hellwig select DMA_OPS 52f5ff79fdSChristoph Hellwig select DMA_NONCOHERENT_MMAP if MMU 53b01aec9bSBorislav Petkov select EDAC_SUPPORT 54b01aec9bSBorislav Petkov select EDAC_ATOMIC_SCRUB 5536d0fd21SLaura Abbott select GENERIC_ALLOCATOR 562ef7a295SJuri Lelli select GENERIC_ARCH_TOPOLOGY if ARM_CPU_TOPOLOGY 57f00790aaSRussell King select GENERIC_ATOMIC64 if CPU_V7M || CPU_V6 || !CPU_32v6K || !AEABI 58b1b3f49cSRussell King select GENERIC_CLOCKEVENTS_BROADCAST if SMP 5956afcd3dSMarc Zyngier select GENERIC_IRQ_IPI if SMP 60ea2d9a96SArd Biesheuvel select GENERIC_CPU_AUTOPROBE 612937367bSArd Biesheuvel select GENERIC_EARLY_IOREMAP 62171b3f0dSRussell King select GENERIC_IDLE_POLL_SETUP 63234a0f20SArnd Bergmann select GENERIC_IRQ_MULTI_HANDLER 64b1b3f49cSRussell King select GENERIC_IRQ_PROBE 65b1b3f49cSRussell King select GENERIC_IRQ_SHOW 667c07005eSGeert Uytterhoeven select GENERIC_IRQ_SHOW_LEVEL 67914ee966SPalmer Dabbelt select GENERIC_LIB_DEVMEM_IS_ALLOWED 68b1b3f49cSRussell King select GENERIC_PCI_IOMAP 6938ff87f7SStephen Boyd select GENERIC_SCHED_CLOCK 70b1b3f49cSRussell King select GENERIC_SMP_IDLE_THREAD 71b1b3f49cSRussell King select HARDIRQS_SW_RESEND 72fcbfe812SNiklas Schnelle select HAS_IOPORT 73f00790aaSRussell King select HAVE_ARCH_AUDITSYSCALL if AEABI && !OABI_COMPAT 740b7857dbSYalin Wang select HAVE_ARCH_BITREVERSE if (CPU_32v7M || CPU_32v7) && !CPU_32v6 75437682eeSArnd Bergmann select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL && !CPU_ENDIAN_BE32 && MMU 7675969686SWang Kefeng select HAVE_ARCH_KFENCE if MMU && !XIP_KERNEL 77437682eeSArnd Bergmann select HAVE_ARCH_KGDB if !CPU_ENDIAN_BE32 && MMU 7842101571SLinus Walleij select HAVE_ARCH_KASAN if MMU && !XIP_KERNEL 79565cbaadSLecopzer Chen select HAVE_ARCH_KASAN_VMALLOC if HAVE_ARCH_KASAN 80e0c25d95SDaniel Cashman select HAVE_ARCH_MMAP_RND_BITS if MMU 814f5b0c17SMike Rapoport select HAVE_ARCH_PFN_VALID 82282a181bSYiFei Zhu select HAVE_ARCH_SECCOMP 83f00790aaSRussell King select HAVE_ARCH_SECCOMP_FILTER if AEABI && !OABI_COMPAT 8408626a60SKees Cook select HAVE_ARCH_THREAD_STRUCT_WHITELIST 850693bf68SWade Farnsworth select HAVE_ARCH_TRACEHOOK 86e8003bf6SAnshuman Khandual select HAVE_ARCH_TRANSPARENT_HUGEPAGE if ARM_LPAE 87b329f95dSJens Wiklander select HAVE_ARM_SMCCC if CPU_V7 8839c13c20SShubham Bansal select HAVE_EBPF_JIT if !CPU_ENDIAN_BE32 8924a9c541SFrederic Weisbecker select HAVE_CONTEXT_TRACKING_USER 90b1b3f49cSRussell King select HAVE_C_RECORDMCOUNT 914ed308c4SSteven Rostedt (Google) select HAVE_BUILDTIME_MCOUNT_SORT 92bc420c6cSVincenzo Frascino select HAVE_DEBUG_KMEMLEAK if !XIP_KERNEL 93b1b3f49cSRussell King select HAVE_DMA_CONTIGUOUS if MMU 94f00790aaSRussell King select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && !CPU_ENDIAN_BE32 && MMU 95620176f3SAbel Vesa select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE 96dce5c9e3SWill Deacon select HAVE_EFFICIENT_UNALIGNED_ACCESS if (CPU_V6 || CPU_V6K || CPU_V7) && MMU 975f56a5dfSJiri Slaby select HAVE_EXIT_THREAD 9867a929e0SChristoph Hellwig select HAVE_FAST_GUP if ARM_LPAE 99f00790aaSRussell King select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL 100aaa4dd1bSWang Kefeng select HAVE_FUNCTION_ERROR_INJECTION 10141918ec8SArd Biesheuvel select HAVE_FUNCTION_GRAPH_TRACER 102d6800ca7SArd Biesheuvel select HAVE_FUNCTION_TRACER if !XIP_KERNEL 1036b90bd4bSEmese Revfy select HAVE_GCC_PLUGINS 104f00790aaSRussell King select HAVE_HW_BREAKPOINT if PERF_EVENTS && (CPU_V6 || CPU_V6K || CPU_V7) 10587c46b6cSRussell King select HAVE_IRQ_TIME_ACCOUNTING 106b1b3f49cSRussell King select HAVE_KERNEL_GZIP 107f9b493acSKyungsik Lee select HAVE_KERNEL_LZ4 108b1b3f49cSRussell King select HAVE_KERNEL_LZMA 109b1b3f49cSRussell King select HAVE_KERNEL_LZO 110b1b3f49cSRussell King select HAVE_KERNEL_XZ 111cb1293e2SArnd Bergmann select HAVE_KPROBES if !XIP_KERNEL && !CPU_ENDIAN_BE32 && !CPU_V7M 112f00790aaSRussell King select HAVE_KRETPROBES if HAVE_KPROBES 1137d485f64SArd Biesheuvel select HAVE_MOD_ARCH_SPECIFIC 11442a0bb3fSPetr Mladek select HAVE_NMI 1150dc016dbSWang Nan select HAVE_OPTPROBES if !THUMB2_KERNEL 11647723de8SArnd Bergmann select HAVE_PCI if MMU 1177ada189fSJamie Iles select HAVE_PERF_EVENTS 11849863894SWill Deacon select HAVE_PERF_REGS 11949863894SWill Deacon select HAVE_PERF_USER_STACK_DUMP 120ff2e6d72SPeter Zijlstra select MMU_GATHER_RCU_TABLE_FREE if SMP && ARM_LPAE 121e513f8bfSWill Deacon select HAVE_REGS_AND_STACK_ACCESS_API 1229800b9dcSMathieu Desnoyers select HAVE_RSEQ 123d148eac0SMasahiro Yamada select HAVE_STACKPROTECTOR 124b1b3f49cSRussell King select HAVE_SYSCALL_TRACEPOINTS 125af1839ebSCatalin Marinas select HAVE_UID16 12631c1fc81SKevin Hilman select HAVE_VIRT_CPU_ACCOUNTING_GEN 127da0ec6f7SThomas Gleixner select IRQ_FORCED_THREADING 128171b3f0dSRussell King select MODULES_USE_ELF_REL 129f616ab59SChristoph Hellwig select NEED_DMA_MAP_STATE 130aa7d5f18SArnd Bergmann select OF_EARLY_FLATTREE if OF 131171b3f0dSRussell King select OLD_SIGACTION 132171b3f0dSRussell King select OLD_SIGSUSPEND3 1336fd09c9aSArnd Bergmann select PCI_DOMAINS_GENERIC if PCI 13420f1b79dSChristoph Hellwig select PCI_SYSCALL if PCI 135b1b3f49cSRussell King select PERF_USE_VMALLOC 136b1b3f49cSRussell King select RTC_LIB 1376fd09c9aSArnd Bergmann select SPARSE_IRQ if !(ARCH_FOOTBRIDGE || ARCH_RPC) 138b1b3f49cSRussell King select SYS_SUPPORTS_APM_EMULATION 1399c46929eSArd Biesheuvel select THREAD_INFO_IN_TASK 1406fd09c9aSArnd Bergmann select TIMER_OF if OF 141d6905849SArd Biesheuvel select HAVE_ARCH_VMAP_STACK if MMU && ARM_HAS_GROUP_RELOCS 1424aae683fSMasahiro Yamada select TRACE_IRQFLAGS_SUPPORT if !CPU_V7M 1436fd09c9aSArnd Bergmann select USE_OF if !(ARCH_FOOTBRIDGE || ARCH_RPC || ARCH_SA1100) 144171b3f0dSRussell King # Above selects are sorted alphabetically; please add new ones 145171b3f0dSRussell King # according to that. Thanks. 1461da177e4SLinus Torvalds help 1471da177e4SLinus Torvalds The ARM series is a line of low-power-consumption RISC chip designs 148f6c8965aSMartin Michlmayr licensed by ARM Ltd and targeted at embedded applications and 1491da177e4SLinus Torvalds handhelds such as the Compaq IPAQ. ARM-based PCs are no longer 1501da177e4SLinus Torvalds manufactured, but legacy ARM-based PC hardware remains popular in 1511da177e4SLinus Torvalds Europe. There is an ARM Linux project with a web page at 1521da177e4SLinus Torvalds <http://www.arm.linux.org.uk/>. 1531da177e4SLinus Torvalds 154d6905849SArd Biesheuvelconfig ARM_HAS_GROUP_RELOCS 155d6905849SArd Biesheuvel def_bool y 156d6905849SArd Biesheuvel depends on !LD_IS_LLD || LLD_VERSION >= 140000 157d6905849SArd Biesheuvel depends on !COMPILE_TEST 158d6905849SArd Biesheuvel help 159d6905849SArd Biesheuvel Whether or not to use R_ARM_ALU_PC_Gn or R_ARM_LDR_PC_Gn group 160d6905849SArd Biesheuvel relocations, which have been around for a long time, but were not 161d6905849SArd Biesheuvel supported in LLD until version 14. The combined range is -/+ 256 MiB, 162d6905849SArd Biesheuvel which is usually sufficient, but not for allyesconfig, so we disable 163d6905849SArd Biesheuvel this feature when doing compile testing. 164d6905849SArd Biesheuvel 1654ce63fcdSMarek Szyprowskiconfig ARM_DMA_USE_IOMMU 1664ce63fcdSMarek Szyprowski bool 167b1b3f49cSRussell King select NEED_SG_DMA_LENGTH 1684ce63fcdSMarek Szyprowski 16960460abfSSeung-Woo Kimif ARM_DMA_USE_IOMMU 17060460abfSSeung-Woo Kim 17160460abfSSeung-Woo Kimconfig ARM_DMA_IOMMU_ALIGNMENT 17260460abfSSeung-Woo Kim int "Maximum PAGE_SIZE order of alignment for DMA IOMMU buffers" 17360460abfSSeung-Woo Kim range 4 9 17460460abfSSeung-Woo Kim default 8 17560460abfSSeung-Woo Kim help 17660460abfSSeung-Woo Kim DMA mapping framework by default aligns all buffers to the smallest 17760460abfSSeung-Woo Kim PAGE_SIZE order which is greater than or equal to the requested buffer 17860460abfSSeung-Woo Kim size. This works well for buffers up to a few hundreds kilobytes, but 17960460abfSSeung-Woo Kim for larger buffers it just a waste of address space. Drivers which has 18060460abfSSeung-Woo Kim relatively small addressing window (like 64Mib) might run out of 18160460abfSSeung-Woo Kim virtual space with just a few allocations. 18260460abfSSeung-Woo Kim 18360460abfSSeung-Woo Kim With this parameter you can specify the maximum PAGE_SIZE order for 18460460abfSSeung-Woo Kim DMA IOMMU buffers. Larger buffers will be aligned only to this 18560460abfSSeung-Woo Kim specified order. The order is expressed as a power of two multiplied 18660460abfSSeung-Woo Kim by the PAGE_SIZE. 18760460abfSSeung-Woo Kim 18860460abfSSeung-Woo Kimendif 18960460abfSSeung-Woo Kim 19075e7153aSRalf Baechleconfig SYS_SUPPORTS_APM_EMULATION 19175e7153aSRalf Baechle bool 19275e7153aSRalf Baechle 193bc581770SLinus Walleijconfig HAVE_TCM 194bc581770SLinus Walleij bool 195bc581770SLinus Walleij select GENERIC_ALLOCATOR 196bc581770SLinus Walleij 197e119bfffSRussell Kingconfig HAVE_PROC_CPU 198e119bfffSRussell King bool 199e119bfffSRussell King 200ce816fa8SUwe Kleine-Königconfig NO_IOPORT_MAP 2015ea81769SAl Viro bool 2025ea81769SAl Viro 2031da177e4SLinus Torvaldsconfig SBUS 2041da177e4SLinus Torvalds bool 2051da177e4SLinus Torvalds 206f16fb1ecSRussell Kingconfig STACKTRACE_SUPPORT 207f16fb1ecSRussell King bool 208f16fb1ecSRussell King default y 209f16fb1ecSRussell King 210f16fb1ecSRussell Kingconfig LOCKDEP_SUPPORT 211f16fb1ecSRussell King bool 212f16fb1ecSRussell King default y 213f16fb1ecSRussell King 214f0d1b0b3SDavid Howellsconfig ARCH_HAS_ILOG2_U32 215f0d1b0b3SDavid Howells bool 216f0d1b0b3SDavid Howells 217f0d1b0b3SDavid Howellsconfig ARCH_HAS_ILOG2_U64 218f0d1b0b3SDavid Howells bool 219f0d1b0b3SDavid Howells 2204a1b5733SEduardo Valentinconfig ARCH_HAS_BANDGAP 2214a1b5733SEduardo Valentin bool 2224a1b5733SEduardo Valentin 223a5f4c561SStefan Agnerconfig FIX_EARLYCON_MEM 224a5f4c561SStefan Agner def_bool y if MMU 225a5f4c561SStefan Agner 226b89c3b16SAkinobu Mitaconfig GENERIC_HWEIGHT 227b89c3b16SAkinobu Mita bool 228b89c3b16SAkinobu Mita default y 229b89c3b16SAkinobu Mita 2301da177e4SLinus Torvaldsconfig GENERIC_CALIBRATE_DELAY 2311da177e4SLinus Torvalds bool 2321da177e4SLinus Torvalds default y 2331da177e4SLinus Torvalds 234a08b6b79Sviro@ZenIV.linux.org.ukconfig ARCH_MAY_HAVE_PC_FDC 235a08b6b79Sviro@ZenIV.linux.org.uk bool 236a08b6b79Sviro@ZenIV.linux.org.uk 237c7edc9e3SDavid A. Longconfig ARCH_SUPPORTS_UPROBES 238c7edc9e3SDavid A. Long def_bool y 239c7edc9e3SDavid A. Long 2401da177e4SLinus Torvaldsconfig GENERIC_ISA_DMA 2411da177e4SLinus Torvalds bool 2421da177e4SLinus Torvalds 2431da177e4SLinus Torvaldsconfig FIQ 2441da177e4SLinus Torvalds bool 2451da177e4SLinus Torvalds 246034d2f5aSAl Viroconfig ARCH_MTD_XIP 247034d2f5aSAl Viro bool 248034d2f5aSAl Viro 249dc21af99SRussell Kingconfig ARM_PATCH_PHYS_VIRT 250c1becedcSRussell King bool "Patch physical to virtual translations at runtime" if EMBEDDED 251c1becedcSRussell King default y 2525408445bSArnd Bergmann depends on MMU 253dc21af99SRussell King help 254111e9a5cSRussell King Patch phys-to-virt and virt-to-phys translation functions at 255111e9a5cSRussell King boot and module load time according to the position of the 256111e9a5cSRussell King kernel in system memory. 257dc21af99SRussell King 258111e9a5cSRussell King This can only be used with non-XIP MMU kernels where the base 2599443076eSArd Biesheuvel of physical memory is at a 2 MiB boundary. 260dc21af99SRussell King 261c1becedcSRussell King Only disable this option if you know that you do not require 262c1becedcSRussell King this feature (eg, building a kernel for a single machine) and 263c1becedcSRussell King you need to shrink the kernel to the minimal size. 264c1becedcSRussell King 265c334bc15SRob Herringconfig NEED_MACH_IO_H 266c334bc15SRob Herring bool 267c334bc15SRob Herring help 268c334bc15SRob Herring Select this when mach/io.h is required to provide special 269c334bc15SRob Herring definitions for this platform. The need for mach/io.h should 270c334bc15SRob Herring be avoided when possible. 271c334bc15SRob Herring 2720cdc8b92SNicolas Pitreconfig NEED_MACH_MEMORY_H 2731b9f95f8SNicolas Pitre bool 274111e9a5cSRussell King help 2750cdc8b92SNicolas Pitre Select this when mach/memory.h is required to provide special 2760cdc8b92SNicolas Pitre definitions for this platform. The need for mach/memory.h should 2770cdc8b92SNicolas Pitre be avoided when possible. 2781b9f95f8SNicolas Pitre 2791b9f95f8SNicolas Pitreconfig PHYS_OFFSET 280974c0724SNicolas Pitre hex "Physical address of main memory" if MMU 28192481c7dSArnd Bergmann depends on !ARM_PATCH_PHYS_VIRT || !AUTO_ZRELADDR 282974c0724SNicolas Pitre default DRAM_BASE if !MMU 28306954b6aSLinus Walleij default 0x00000000 if ARCH_FOOTBRIDGE 284c6f54a9bSUwe Kleine-König default 0x10000000 if ARCH_OMAP1 || ARCH_RPC 285b91a69d1SArnd Bergmann default 0xa0000000 if ARCH_PXA 286c6e77bb6SArnd Bergmann default 0xc0000000 if ARCH_EP93XX || ARCH_SA1100 287c6e77bb6SArnd Bergmann default 0 2881b9f95f8SNicolas Pitre help 2891b9f95f8SNicolas Pitre Please provide the physical address corresponding to the 2901b9f95f8SNicolas Pitre location of main memory in your system. 291cada3c08SRussell King 29287e040b6SSimon Glassconfig GENERIC_BUG 29387e040b6SSimon Glass def_bool y 29487e040b6SSimon Glass depends on BUG 29587e040b6SSimon Glass 2961bcad26eSKirill A. Shutemovconfig PGTABLE_LEVELS 2971bcad26eSKirill A. Shutemov int 2981bcad26eSKirill A. Shutemov default 3 if ARM_LPAE 2991bcad26eSKirill A. Shutemov default 2 3001bcad26eSKirill A. Shutemov 3011da177e4SLinus Torvaldsmenu "System Type" 3021da177e4SLinus Torvalds 3033c427975SHyok S. Choiconfig MMU 3043c427975SHyok S. Choi bool "MMU-based Paged Memory Management Support" 3053c427975SHyok S. Choi default y 3063c427975SHyok S. Choi help 3073c427975SHyok S. Choi Select if you want MMU-based virtualised addressing space 3083c427975SHyok S. Choi support by paged memory management. If unsure, say 'Y'. 3093c427975SHyok S. Choi 3102f618d5eSArnd Bergmannconfig ARM_SINGLE_ARMV7M 3112f618d5eSArnd Bergmann def_bool !MMU 3122f618d5eSArnd Bergmann select ARM_NVIC 3132f618d5eSArnd Bergmann select CPU_V7M 3142f618d5eSArnd Bergmann select NO_IOPORT_MAP 3152f618d5eSArnd Bergmann 316e0c25d95SDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MIN 317e0c25d95SDaniel Cashman default 8 318e0c25d95SDaniel Cashman 319e0c25d95SDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MAX 320e0c25d95SDaniel Cashman default 14 if PAGE_OFFSET=0x40000000 321e0c25d95SDaniel Cashman default 15 if PAGE_OFFSET=0x80000000 322e0c25d95SDaniel Cashman default 16 323e0c25d95SDaniel Cashman 324387798b3SRob Herringconfig ARCH_MULTIPLATFORM 32584fc8636SArnd Bergmann bool "Require kernel to be portable to multiple machines" if EXPERT 32684fc8636SArnd Bergmann depends on MMU && !(ARCH_FOOTBRIDGE || ARCH_RPC || ARCH_SA1100) 32784fc8636SArnd Bergmann default y 328f999b8bdSMartin Michlmayr help 32984fc8636SArnd Bergmann In general, all Arm machines can be supported in a single 33084fc8636SArnd Bergmann kernel image, covering either Armv4/v5 or Armv6/v7. 3311da177e4SLinus Torvalds 33284fc8636SArnd Bergmann However, some configuration options require hardcoding machine 33384fc8636SArnd Bergmann specific physical addresses or enable errata workarounds that may 33484fc8636SArnd Bergmann break other machines. 3351da177e4SLinus Torvalds 33684fc8636SArnd Bergmann Selecting N here allows using those options, including 33784fc8636SArnd Bergmann DEBUG_UNCOMPRESS, XIP_KERNEL and ZBOOT_ROM. If unsure, say Y. 3381da177e4SLinus Torvalds 3396fd09c9aSArnd Bergmannmenu "Platform selection" 3406fd09c9aSArnd Bergmann depends on MMU 341387798b3SRob Herring 342387798b3SRob Herringcomment "CPU Core family selection" 343387798b3SRob Herring 344f8afae40SArnd Bergmannconfig ARCH_MULTI_V4 3456fd09c9aSArnd Bergmann bool "ARMv4 based platforms (FA526, StrongARM)" 346f8afae40SArnd Bergmann depends on !ARCH_MULTI_V6_V7 3475eb6e280SNathan Chancellor # https://github.com/llvm/llvm-project/issues/50764 3485eb6e280SNathan Chancellor depends on !LD_IS_LLD || LLD_VERSION >= 160000 349f8afae40SArnd Bergmann select ARCH_MULTI_V4_V5 3506fd09c9aSArnd Bergmann select CPU_FA526 if !(CPU_SA110 || CPU_SA1100) 351f8afae40SArnd Bergmann 352387798b3SRob Herringconfig ARCH_MULTI_V4T 353387798b3SRob Herring bool "ARMv4T based platforms (ARM720T, ARM920T, ...)" 354387798b3SRob Herring depends on !ARCH_MULTI_V6_V7 3555eb6e280SNathan Chancellor # https://github.com/llvm/llvm-project/issues/50764 3565eb6e280SNathan Chancellor depends on !LD_IS_LLD || LLD_VERSION >= 160000 357b1b3f49cSRussell King select ARCH_MULTI_V4_V5 35824e860fbSArnd Bergmann select CPU_ARM920T if !(CPU_ARM7TDMI || CPU_ARM720T || \ 35924e860fbSArnd Bergmann CPU_ARM740T || CPU_ARM9TDMI || CPU_ARM922T || \ 36024e860fbSArnd Bergmann CPU_ARM925T || CPU_ARM940T) 361387798b3SRob Herring 362387798b3SRob Herringconfig ARCH_MULTI_V5 363387798b3SRob Herring bool "ARMv5 based platforms (ARM926T, XSCALE, PJ1, ...)" 364387798b3SRob Herring depends on !ARCH_MULTI_V6_V7 365b1b3f49cSRussell King select ARCH_MULTI_V4_V5 36612567bbdSAndrew Lunn select CPU_ARM926T if !(CPU_ARM946E || CPU_ARM1020 || \ 36724e860fbSArnd Bergmann CPU_ARM1020E || CPU_ARM1022 || CPU_ARM1026 || \ 36824e860fbSArnd Bergmann CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK || CPU_FEROCEON) 369387798b3SRob Herring 370387798b3SRob Herringconfig ARCH_MULTI_V4_V5 371387798b3SRob Herring bool 372387798b3SRob Herring 373387798b3SRob Herringconfig ARCH_MULTI_V6 3748dda05ccSStephen Boyd bool "ARMv6 based platforms (ARM11)" 375387798b3SRob Herring select ARCH_MULTI_V6_V7 37642f4754aSRob Herring select CPU_V6K 377387798b3SRob Herring 378387798b3SRob Herringconfig ARCH_MULTI_V7 3798dda05ccSStephen Boyd bool "ARMv7 based platforms (Cortex-A, PJ4, Scorpion, Krait)" 380387798b3SRob Herring default y 381387798b3SRob Herring select ARCH_MULTI_V6_V7 382b1b3f49cSRussell King select CPU_V7 38390bc8ac7SRob Herring select HAVE_SMP 384387798b3SRob Herring 385387798b3SRob Herringconfig ARCH_MULTI_V6_V7 386387798b3SRob Herring bool 3879352b05bSRob Herring select MIGHT_HAVE_CACHE_L2X0 388387798b3SRob Herring 389387798b3SRob Herringconfig ARCH_MULTI_CPU_AUTO 390387798b3SRob Herring def_bool !(ARCH_MULTI_V4 || ARCH_MULTI_V4T || ARCH_MULTI_V6_V7) 391387798b3SRob Herring select ARCH_MULTI_V5 392387798b3SRob Herring 393387798b3SRob Herringendmenu 394387798b3SRob Herring 39505e2a3deSRob Herringconfig ARCH_VIRT 396e3246542SMasahiro Yamada bool "Dummy Virtual Machine" 397e3246542SMasahiro Yamada depends on ARCH_MULTI_V7 3984b8b5f25SRob Herring select ARM_AMBA 39905e2a3deSRob Herring select ARM_GIC 4003ee80364SArnd Bergmann select ARM_GIC_V2M if PCI 4010b28f1dbSJean-Philippe Brucker select ARM_GIC_V3 402bb29cecbSVladimir Murzin select ARM_GIC_V3_ITS if PCI 40305e2a3deSRob Herring select ARM_PSCI 4044b8b5f25SRob Herring select HAVE_ARM_ARCH_TIMER 40505e2a3deSRob Herring 4062cf1c348SJohn Crispinconfig ARCH_AIROHA 4072cf1c348SJohn Crispin bool "Airoha SoC Support" 4082cf1c348SJohn Crispin depends on ARCH_MULTI_V7 4092cf1c348SJohn Crispin select ARM_AMBA 4102cf1c348SJohn Crispin select ARM_GIC 4112cf1c348SJohn Crispin select ARM_GIC_V3 4122cf1c348SJohn Crispin select ARM_PSCI 4132cf1c348SJohn Crispin select HAVE_ARM_ARCH_TIMER 4142cf1c348SJohn Crispin help 4152cf1c348SJohn Crispin Support for Airoha EN7523 SoCs 4162cf1c348SJohn Crispin 417ccf50e23SRussell King# 418ccf50e23SRussell King# This is sorted alphabetically by mach-* pathname. However, plat-* 419ccf50e23SRussell King# Kconfigs may be included either alphabetically (according to the 420ccf50e23SRussell King# plat- suffix) or along side the corresponding mach-* source. 421ccf50e23SRussell King# 4226bb8536cSAndreas Färbersource "arch/arm/mach-actions/Kconfig" 4236bb8536cSAndreas Färber 424445d9b30STsahee Zidenbergsource "arch/arm/mach-alpine/Kconfig" 425445d9b30STsahee Zidenberg 426590b460cSLars Perssonsource "arch/arm/mach-artpec/Kconfig" 427590b460cSLars Persson 428d9bfc86dSOleksij Rempelsource "arch/arm/mach-asm9260/Kconfig" 429d9bfc86dSOleksij Rempel 430a66c51f9SAlexandre Bellonisource "arch/arm/mach-aspeed/Kconfig" 431a66c51f9SAlexandre Belloni 43295b8f20fSRussell Kingsource "arch/arm/mach-at91/Kconfig" 43395b8f20fSRussell King 4341d22924eSAnders Bergsource "arch/arm/mach-axxia/Kconfig" 4351d22924eSAnders Berg 4368ac49e04SChristian Daudtsource "arch/arm/mach-bcm/Kconfig" 4378ac49e04SChristian Daudt 4381c37fa10SSebastian Hesselbarthsource "arch/arm/mach-berlin/Kconfig" 4391c37fa10SSebastian Hesselbarth 4401da177e4SLinus Torvaldssource "arch/arm/mach-clps711x/Kconfig" 4411da177e4SLinus Torvalds 44295b8f20fSRussell Kingsource "arch/arm/mach-davinci/Kconfig" 44395b8f20fSRussell King 444df8d742eSBaruch Siachsource "arch/arm/mach-digicolor/Kconfig" 445df8d742eSBaruch Siach 44695b8f20fSRussell Kingsource "arch/arm/mach-dove/Kconfig" 44795b8f20fSRussell King 448e7736d47SLennert Buytenheksource "arch/arm/mach-ep93xx/Kconfig" 449e7736d47SLennert Buytenhek 450a66c51f9SAlexandre Bellonisource "arch/arm/mach-exynos/Kconfig" 451a66c51f9SAlexandre Belloni 4521da177e4SLinus Torvaldssource "arch/arm/mach-footbridge/Kconfig" 4531da177e4SLinus Torvalds 45459d3a193SPaulius Zaleckassource "arch/arm/mach-gemini/Kconfig" 45559d3a193SPaulius Zaleckas 456387798b3SRob Herringsource "arch/arm/mach-highbank/Kconfig" 457387798b3SRob Herring 458389ee0c2SHaojian Zhuangsource "arch/arm/mach-hisi/Kconfig" 459389ee0c2SHaojian Zhuang 46011d89440SNick Hawkinssource "arch/arm/mach-hpe/Kconfig" 46111d89440SNick Hawkins 462a66c51f9SAlexandre Bellonisource "arch/arm/mach-imx/Kconfig" 463a66c51f9SAlexandre Belloni 4641da177e4SLinus Torvaldssource "arch/arm/mach-ixp4xx/Kconfig" 4651da177e4SLinus Torvalds 466828989adSSantosh Shilimkarsource "arch/arm/mach-keystone/Kconfig" 467828989adSSantosh Shilimkar 46875bf1bd7SArnd Bergmannsource "arch/arm/mach-lpc32xx/Kconfig" 46995b8f20fSRussell King 470a66c51f9SAlexandre Bellonisource "arch/arm/mach-mediatek/Kconfig" 471a66c51f9SAlexandre Belloni 4723b8f5030SCarlo Caionesource "arch/arm/mach-meson/Kconfig" 4733b8f5030SCarlo Caione 4749fb29c73SSugaya Taichisource "arch/arm/mach-milbeaut/Kconfig" 4759fb29c73SSugaya Taichi 476a66c51f9SAlexandre Bellonisource "arch/arm/mach-mmp/Kconfig" 477a66c51f9SAlexandre Belloni 47817723fd3SJonas Jensensource "arch/arm/mach-moxart/Kconfig" 47917723fd3SJonas Jensen 480312b62b6SDaniel Palmersource "arch/arm/mach-mstar/Kconfig" 481312b62b6SDaniel Palmer 482794d15b2SStanislav Samsonovsource "arch/arm/mach-mv78xx0/Kconfig" 483794d15b2SStanislav Samsonov 484a66c51f9SAlexandre Bellonisource "arch/arm/mach-mvebu/Kconfig" 485f682a218SMatthias Brugger 4861d3f33d5SShawn Guosource "arch/arm/mach-mxs/Kconfig" 4871d3f33d5SShawn Guo 48895b8f20fSRussell Kingsource "arch/arm/mach-nomadik/Kconfig" 48995b8f20fSRussell King 4907bffa14cSBrendan Higginssource "arch/arm/mach-npcm/Kconfig" 4917bffa14cSBrendan Higgins 4929851ca57SDaniel Tangsource "arch/arm/mach-nspire/Kconfig" 4939851ca57SDaniel Tang 494d48af15eSTony Lindgrensource "arch/arm/mach-omap1/Kconfig" 4951da177e4SLinus Torvalds 4961dbae815STony Lindgrensource "arch/arm/mach-omap2/Kconfig" 4971dbae815STony Lindgren 4989dd0b194SLennert Buytenheksource "arch/arm/mach-orion5x/Kconfig" 499585cf175STzachi Perelstein 50095b8f20fSRussell Kingsource "arch/arm/mach-pxa/Kconfig" 5011da177e4SLinus Torvalds 5028fc1b0f8SKumar Galasource "arch/arm/mach-qcom/Kconfig" 5038fc1b0f8SKumar Gala 50478e3dbc1SAndreas Färbersource "arch/arm/mach-rda/Kconfig" 50578e3dbc1SAndreas Färber 50686aeee4dSAndreas Färbersource "arch/arm/mach-realtek/Kconfig" 50786aeee4dSAndreas Färber 5086fd09c9aSArnd Bergmannsource "arch/arm/mach-rpc/Kconfig" 5096fd09c9aSArnd Bergmann 510d63dc051SHeiko Stuebnersource "arch/arm/mach-rockchip/Kconfig" 511d63dc051SHeiko Stuebner 51271b9114dSArnd Bergmannsource "arch/arm/mach-s3c/Kconfig" 513a66c51f9SAlexandre Belloni 514a66c51f9SAlexandre Bellonisource "arch/arm/mach-s5pv210/Kconfig" 515a66c51f9SAlexandre Belloni 51695b8f20fSRussell Kingsource "arch/arm/mach-sa1100/Kconfig" 517edabd38eSSaeed Bishara 518a66c51f9SAlexandre Bellonisource "arch/arm/mach-shmobile/Kconfig" 519a66c51f9SAlexandre Belloni 520387798b3SRob Herringsource "arch/arm/mach-socfpga/Kconfig" 521387798b3SRob Herring 522a7ed099fSArnd Bergmannsource "arch/arm/mach-spear/Kconfig" 523a21765a7SBen Dooks 52465ebcc11SSrinivas Kandagatlasource "arch/arm/mach-sti/Kconfig" 52565ebcc11SSrinivas Kandagatla 526bcb84fb4SAlexandre TORGUEsource "arch/arm/mach-stm32/Kconfig" 527bcb84fb4SAlexandre TORGUE 5280aa94eeaSQin Jiansource "arch/arm/mach-sunplus/Kconfig" 5290aa94eeaSQin Jian 5303b52634fSMaxime Ripardsource "arch/arm/mach-sunxi/Kconfig" 5313b52634fSMaxime Ripard 532c5f80065SErik Gillingsource "arch/arm/mach-tegra/Kconfig" 533c5f80065SErik Gilling 534ba56a987SMasahiro Yamadasource "arch/arm/mach-uniphier/Kconfig" 535ba56a987SMasahiro Yamada 53695b8f20fSRussell Kingsource "arch/arm/mach-ux500/Kconfig" 5371da177e4SLinus Torvalds 5381da177e4SLinus Torvaldssource "arch/arm/mach-versatile/Kconfig" 5391da177e4SLinus Torvalds 5406f35f9a9STony Prisksource "arch/arm/mach-vt8500/Kconfig" 5416f35f9a9STony Prisk 5429a45eb69SJosh Cartwrightsource "arch/arm/mach-zynq/Kconfig" 5439a45eb69SJosh Cartwright 544499f1640SStefan Agner# ARMv7-M architecture 545499f1640SStefan Agnerconfig ARCH_LPC18XX 546499f1640SStefan Agner bool "NXP LPC18xx/LPC43xx" 547499f1640SStefan Agner depends on ARM_SINGLE_ARMV7M 548499f1640SStefan Agner select ARCH_HAS_RESET_CONTROLLER 549499f1640SStefan Agner select ARM_AMBA 550499f1640SStefan Agner select CLKSRC_LPC32XX 551499f1640SStefan Agner select PINCTRL 552499f1640SStefan Agner help 553499f1640SStefan Agner Support for NXP's LPC18xx Cortex-M3 and LPC43xx Cortex-M4 554499f1640SStefan Agner high performance microcontrollers. 555499f1640SStefan Agner 5561847119dSVladimir Murzinconfig ARCH_MPS2 55717bd274eSBaruch Siach bool "ARM MPS2 platform" 5581847119dSVladimir Murzin depends on ARM_SINGLE_ARMV7M 5591847119dSVladimir Murzin select ARM_AMBA 5601847119dSVladimir Murzin select CLKSRC_MPS2 5611847119dSVladimir Murzin help 5621847119dSVladimir Murzin Support for Cortex-M Prototyping System (or V2M-MPS2) which comes 5631847119dSVladimir Murzin with a range of available cores like Cortex-M3/M4/M7. 5641847119dSVladimir Murzin 5651847119dSVladimir Murzin Please, note that depends which Application Note is used memory map 5661847119dSVladimir Murzin for the platform may vary, so adjustment of RAM base might be needed. 5671847119dSVladimir Murzin 5681da177e4SLinus Torvalds# Definitions to make life easier 5691da177e4SLinus Torvaldsconfig ARCH_ACORN 5701da177e4SLinus Torvalds bool 5711da177e4SLinus Torvalds 57269b02f6aSLennert Buytenhekconfig PLAT_ORION 57369b02f6aSLennert Buytenhek bool 574bfe45e0bSRussell King select CLKSRC_MMIO 575dc7ad3b3SRussell King select GENERIC_IRQ_CHIP 576278b45b0SAndrew Lunn select IRQ_DOMAIN 57769b02f6aSLennert Buytenhek 578abcda1dcSThomas Petazzoniconfig PLAT_ORION_LEGACY 579abcda1dcSThomas Petazzoni bool 580abcda1dcSThomas Petazzoni select PLAT_ORION 581abcda1dcSThomas Petazzoni 582f4b8b319SRussell Kingconfig PLAT_VERSATILE 583f4b8b319SRussell King bool 584f4b8b319SRussell King 5858636a1f9SMasahiro Yamadasource "arch/arm/mm/Kconfig" 5861da177e4SLinus Torvalds 587afe4b25eSLennert Buytenhekconfig IWMMXT 588d93003e8SSebastian Hesselbarth bool "Enable iWMMXt support" 589d93003e8SSebastian Hesselbarth depends on CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK || CPU_PJ4 || CPU_PJ4B 590d93003e8SSebastian Hesselbarth default y if PXA27x || PXA3xx || ARCH_MMP || CPU_PJ4 || CPU_PJ4B 591afe4b25eSLennert Buytenhek help 592afe4b25eSLennert Buytenhek Enable support for iWMMXt context switching at run time if 593afe4b25eSLennert Buytenhek running on a CPU that supports it. 594afe4b25eSLennert Buytenhek 5953b93e7b0SHyok S. Choiif !MMU 5963b93e7b0SHyok S. Choisource "arch/arm/Kconfig-nommu" 5973b93e7b0SHyok S. Choiendif 5983b93e7b0SHyok S. Choi 5993e0a07f8SGregory CLEMENTconfig PJ4B_ERRATA_4742 6003e0a07f8SGregory CLEMENT bool "PJ4B Errata 4742: IDLE Wake Up Commands can Cause the CPU Core to Cease Operation" 6013e0a07f8SGregory CLEMENT depends on CPU_PJ4B && MACH_ARMADA_370 6023e0a07f8SGregory CLEMENT default y 6033e0a07f8SGregory CLEMENT help 6043e0a07f8SGregory CLEMENT When coming out of either a Wait for Interrupt (WFI) or a Wait for 6053e0a07f8SGregory CLEMENT Event (WFE) IDLE states, a specific timing sensitivity exists between 6063e0a07f8SGregory CLEMENT the retiring WFI/WFE instructions and the newly issued subsequent 6073e0a07f8SGregory CLEMENT instructions. This sensitivity can result in a CPU hang scenario. 6083e0a07f8SGregory CLEMENT Workaround: 6093e0a07f8SGregory CLEMENT The software must insert either a Data Synchronization Barrier (DSB) 6103e0a07f8SGregory CLEMENT or Data Memory Barrier (DMB) command immediately after the WFI/WFE 6113e0a07f8SGregory CLEMENT instruction 6123e0a07f8SGregory CLEMENT 613f0c4b8d6SWill Deaconconfig ARM_ERRATA_326103 614f0c4b8d6SWill Deacon bool "ARM errata: FSR write bit incorrect on a SWP to read-only memory" 615f0c4b8d6SWill Deacon depends on CPU_V6 616f0c4b8d6SWill Deacon help 617f0c4b8d6SWill Deacon Executing a SWP instruction to read-only memory does not set bit 11 618f0c4b8d6SWill Deacon of the FSR on the ARM 1136 prior to r1p0. This causes the kernel to 619f0c4b8d6SWill Deacon treat the access as a read, preventing a COW from occurring and 620f0c4b8d6SWill Deacon causing the faulting task to livelock. 621f0c4b8d6SWill Deacon 6229cba3cccSCatalin Marinasconfig ARM_ERRATA_411920 6239cba3cccSCatalin Marinas bool "ARM errata: Invalidation of the Instruction Cache operation can fail" 624e399b1a4SRussell King depends on CPU_V6 || CPU_V6K 6259cba3cccSCatalin Marinas help 6269cba3cccSCatalin Marinas Invalidation of the Instruction Cache operation can 6279cba3cccSCatalin Marinas fail. This erratum is present in 1136 (before r1p4), 1156 and 1176. 6289cba3cccSCatalin Marinas It does not affect the MPCore. This option enables the ARM Ltd. 6299cba3cccSCatalin Marinas recommended workaround. 6309cba3cccSCatalin Marinas 6317ce236fcSCatalin Marinasconfig ARM_ERRATA_430973 6327ce236fcSCatalin Marinas bool "ARM errata: Stale prediction on replaced interworking branch" 6337ce236fcSCatalin Marinas depends on CPU_V7 6347ce236fcSCatalin Marinas help 6357ce236fcSCatalin Marinas This option enables the workaround for the 430973 Cortex-A8 63679403cdaSRussell King r1p* erratum. If a code sequence containing an ARM/Thumb 6377ce236fcSCatalin Marinas interworking branch is replaced with another code sequence at the 6387ce236fcSCatalin Marinas same virtual address, whether due to self-modifying code or virtual 6397ce236fcSCatalin Marinas to physical address re-mapping, Cortex-A8 does not recover from the 6407ce236fcSCatalin Marinas stale interworking branch prediction. This results in Cortex-A8 6417ce236fcSCatalin Marinas executing the new code sequence in the incorrect ARM or Thumb state. 6427ce236fcSCatalin Marinas The workaround enables the BTB/BTAC operations by setting ACTLR.IBE 6437ce236fcSCatalin Marinas and also flushes the branch target cache at every context switch. 6447ce236fcSCatalin Marinas Note that setting specific bits in the ACTLR register may not be 6457ce236fcSCatalin Marinas available in non-secure mode. 6467ce236fcSCatalin Marinas 647855c551fSCatalin Marinasconfig ARM_ERRATA_458693 648855c551fSCatalin Marinas bool "ARM errata: Processor deadlock when a false hazard is created" 649855c551fSCatalin Marinas depends on CPU_V7 65062e4d357SRob Herring depends on !ARCH_MULTIPLATFORM 651855c551fSCatalin Marinas help 652855c551fSCatalin Marinas This option enables the workaround for the 458693 Cortex-A8 (r2p0) 653855c551fSCatalin Marinas erratum. For very specific sequences of memory operations, it is 654855c551fSCatalin Marinas possible for a hazard condition intended for a cache line to instead 655855c551fSCatalin Marinas be incorrectly associated with a different cache line. This false 656855c551fSCatalin Marinas hazard might then cause a processor deadlock. The workaround enables 657855c551fSCatalin Marinas the L1 caching of the NEON accesses and disables the PLD instruction 658855c551fSCatalin Marinas in the ACTLR register. Note that setting specific bits in the ACTLR 659368ccecdSSebastian Reichel register may not be available in non-secure mode and thus is not 660368ccecdSSebastian Reichel available on a multiplatform kernel. This should be applied by the 661368ccecdSSebastian Reichel bootloader instead. 662855c551fSCatalin Marinas 6630516e464SCatalin Marinasconfig ARM_ERRATA_460075 6640516e464SCatalin Marinas bool "ARM errata: Data written to the L2 cache can be overwritten with stale data" 6650516e464SCatalin Marinas depends on CPU_V7 66662e4d357SRob Herring depends on !ARCH_MULTIPLATFORM 6670516e464SCatalin Marinas help 6680516e464SCatalin Marinas This option enables the workaround for the 460075 Cortex-A8 (r2p0) 6690516e464SCatalin Marinas erratum. Any asynchronous access to the L2 cache may encounter a 6700516e464SCatalin Marinas situation in which recent store transactions to the L2 cache are lost 6710516e464SCatalin Marinas and overwritten with stale memory contents from external memory. The 6720516e464SCatalin Marinas workaround disables the write-allocate mode for the L2 cache via the 6730516e464SCatalin Marinas ACTLR register. Note that setting specific bits in the ACTLR register 674368ccecdSSebastian Reichel may not be available in non-secure mode and thus is not available on 675368ccecdSSebastian Reichel a multiplatform kernel. This should be applied by the bootloader 676368ccecdSSebastian Reichel instead. 6770516e464SCatalin Marinas 6789f05027cSWill Deaconconfig ARM_ERRATA_742230 6799f05027cSWill Deacon bool "ARM errata: DMB operation may be faulty" 6809f05027cSWill Deacon depends on CPU_V7 && SMP 68162e4d357SRob Herring depends on !ARCH_MULTIPLATFORM 6829f05027cSWill Deacon help 6839f05027cSWill Deacon This option enables the workaround for the 742230 Cortex-A9 6849f05027cSWill Deacon (r1p0..r2p2) erratum. Under rare circumstances, a DMB instruction 6859f05027cSWill Deacon between two write operations may not ensure the correct visibility 6869f05027cSWill Deacon ordering of the two writes. This workaround sets a specific bit in 6879f05027cSWill Deacon the diagnostic register of the Cortex-A9 which causes the DMB 6889f05027cSWill Deacon instruction to behave as a DSB, ensuring the correct behaviour of 689368ccecdSSebastian Reichel the two writes. Note that setting specific bits in the diagnostics 690368ccecdSSebastian Reichel register may not be available in non-secure mode and thus is not 691368ccecdSSebastian Reichel available on a multiplatform kernel. This should be applied by the 692368ccecdSSebastian Reichel bootloader instead. 6939f05027cSWill Deacon 694a672e99bSWill Deaconconfig ARM_ERRATA_742231 695a672e99bSWill Deacon bool "ARM errata: Incorrect hazard handling in the SCU may lead to data corruption" 696a672e99bSWill Deacon depends on CPU_V7 && SMP 69762e4d357SRob Herring depends on !ARCH_MULTIPLATFORM 698a672e99bSWill Deacon help 699a672e99bSWill Deacon This option enables the workaround for the 742231 Cortex-A9 700a672e99bSWill Deacon (r2p0..r2p2) erratum. Under certain conditions, specific to the 701a672e99bSWill Deacon Cortex-A9 MPCore micro-architecture, two CPUs working in SMP mode, 702a672e99bSWill Deacon accessing some data located in the same cache line, may get corrupted 703a672e99bSWill Deacon data due to bad handling of the address hazard when the line gets 704a672e99bSWill Deacon replaced from one of the CPUs at the same time as another CPU is 705a672e99bSWill Deacon accessing it. This workaround sets specific bits in the diagnostic 706a672e99bSWill Deacon register of the Cortex-A9 which reduces the linefill issuing 707368ccecdSSebastian Reichel capabilities of the processor. Note that setting specific bits in the 708368ccecdSSebastian Reichel diagnostics register may not be available in non-secure mode and thus 709368ccecdSSebastian Reichel is not available on a multiplatform kernel. This should be applied by 710368ccecdSSebastian Reichel the bootloader instead. 711a672e99bSWill Deacon 71269155794SJon Medhurstconfig ARM_ERRATA_643719 71369155794SJon Medhurst bool "ARM errata: LoUIS bit field in CLIDR register is incorrect" 71469155794SJon Medhurst depends on CPU_V7 && SMP 715e5a5de44SRussell King default y 71669155794SJon Medhurst help 71769155794SJon Medhurst This option enables the workaround for the 643719 Cortex-A9 (prior to 71869155794SJon Medhurst r1p0) erratum. On affected cores the LoUIS bit field of the CLIDR 71969155794SJon Medhurst register returns zero when it should return one. The workaround 72069155794SJon Medhurst corrects this value, ensuring cache maintenance operations which use 72169155794SJon Medhurst it behave as intended and avoiding data corruption. 72269155794SJon Medhurst 723cdf357f1SWill Deaconconfig ARM_ERRATA_720789 724cdf357f1SWill Deacon bool "ARM errata: TLBIASIDIS and TLBIMVAIS operations can broadcast a faulty ASID" 725e66dc745SDave Martin depends on CPU_V7 726cdf357f1SWill Deacon help 727cdf357f1SWill Deacon This option enables the workaround for the 720789 Cortex-A9 (prior to 728cdf357f1SWill Deacon r2p0) erratum. A faulty ASID can be sent to the other CPUs for the 729cdf357f1SWill Deacon broadcasted CP15 TLB maintenance operations TLBIASIDIS and TLBIMVAIS. 730cdf357f1SWill Deacon As a consequence of this erratum, some TLB entries which should be 731cdf357f1SWill Deacon invalidated are not, resulting in an incoherency in the system page 732cdf357f1SWill Deacon tables. The workaround changes the TLB flushing routines to invalidate 733cdf357f1SWill Deacon entries regardless of the ASID. 734475d92fcSWill Deacon 735475d92fcSWill Deaconconfig ARM_ERRATA_743622 736475d92fcSWill Deacon bool "ARM errata: Faulty hazard checking in the Store Buffer may lead to data corruption" 737475d92fcSWill Deacon depends on CPU_V7 73862e4d357SRob Herring depends on !ARCH_MULTIPLATFORM 739475d92fcSWill Deacon help 740475d92fcSWill Deacon This option enables the workaround for the 743622 Cortex-A9 741efbc74acSWill Deacon (r2p*) erratum. Under very rare conditions, a faulty 742475d92fcSWill Deacon optimisation in the Cortex-A9 Store Buffer may lead to data 743475d92fcSWill Deacon corruption. This workaround sets a specific bit in the diagnostic 744475d92fcSWill Deacon register of the Cortex-A9 which disables the Store Buffer 745475d92fcSWill Deacon optimisation, preventing the defect from occurring. This has no 746475d92fcSWill Deacon visible impact on the overall performance or power consumption of the 747368ccecdSSebastian Reichel processor. Note that setting specific bits in the diagnostics register 748368ccecdSSebastian Reichel may not be available in non-secure mode and thus is not available on a 749368ccecdSSebastian Reichel multiplatform kernel. This should be applied by the bootloader instead. 750475d92fcSWill Deacon 7519a27c27cSWill Deaconconfig ARM_ERRATA_751472 7529a27c27cSWill Deacon bool "ARM errata: Interrupted ICIALLUIS may prevent completion of broadcasted operation" 753ba90c516SDave Martin depends on CPU_V7 75462e4d357SRob Herring depends on !ARCH_MULTIPLATFORM 7559a27c27cSWill Deacon help 7569a27c27cSWill Deacon This option enables the workaround for the 751472 Cortex-A9 (prior 7579a27c27cSWill Deacon to r3p0) erratum. An interrupted ICIALLUIS operation may prevent the 7589a27c27cSWill Deacon completion of a following broadcasted operation if the second 7599a27c27cSWill Deacon operation is received by a CPU before the ICIALLUIS has completed, 7609a27c27cSWill Deacon potentially leading to corrupted entries in the cache or TLB. 761368ccecdSSebastian Reichel Note that setting specific bits in the diagnostics register may 762368ccecdSSebastian Reichel not be available in non-secure mode and thus is not available on 763368ccecdSSebastian Reichel a multiplatform kernel. This should be applied by the bootloader 764368ccecdSSebastian Reichel instead. 7659a27c27cSWill Deacon 766fcbdc5feSWill Deaconconfig ARM_ERRATA_754322 767fcbdc5feSWill Deacon bool "ARM errata: possible faulty MMU translations following an ASID switch" 768fcbdc5feSWill Deacon depends on CPU_V7 769fcbdc5feSWill Deacon help 770fcbdc5feSWill Deacon This option enables the workaround for the 754322 Cortex-A9 (r2p*, 771fcbdc5feSWill Deacon r3p*) erratum. A speculative memory access may cause a page table walk 772fcbdc5feSWill Deacon which starts prior to an ASID switch but completes afterwards. This 773fcbdc5feSWill Deacon can populate the micro-TLB with a stale entry which may be hit with 774fcbdc5feSWill Deacon the new ASID. This workaround places two dsb instructions in the mm 775fcbdc5feSWill Deacon switching code so that no page table walks can cross the ASID switch. 776fcbdc5feSWill Deacon 7775dab26afSWill Deaconconfig ARM_ERRATA_754327 7785dab26afSWill Deacon bool "ARM errata: no automatic Store Buffer drain" 7795dab26afSWill Deacon depends on CPU_V7 && SMP 7805dab26afSWill Deacon help 7815dab26afSWill Deacon This option enables the workaround for the 754327 Cortex-A9 (prior to 7825dab26afSWill Deacon r2p0) erratum. The Store Buffer does not have any automatic draining 7835dab26afSWill Deacon mechanism and therefore a livelock may occur if an external agent 7845dab26afSWill Deacon continuously polls a memory location waiting to observe an update. 7855dab26afSWill Deacon This workaround defines cpu_relax() as smp_mb(), preventing correctly 7865dab26afSWill Deacon written polling loops from denying visibility of updates to memory. 7875dab26afSWill Deacon 788145e10e1SCatalin Marinasconfig ARM_ERRATA_364296 789145e10e1SCatalin Marinas bool "ARM errata: Possible cache data corruption with hit-under-miss enabled" 790fd832478SFabio Estevam depends on CPU_V6 791145e10e1SCatalin Marinas help 792145e10e1SCatalin Marinas This options enables the workaround for the 364296 ARM1136 793145e10e1SCatalin Marinas r0p2 erratum (possible cache data corruption with 794145e10e1SCatalin Marinas hit-under-miss enabled). It sets the undocumented bit 31 in 795145e10e1SCatalin Marinas the auxiliary control register and the FI bit in the control 796145e10e1SCatalin Marinas register, thus disabling hit-under-miss without putting the 797145e10e1SCatalin Marinas processor into full low interrupt latency mode. ARM11MPCore 798145e10e1SCatalin Marinas is not affected. 799145e10e1SCatalin Marinas 800f630c1bdSWill Deaconconfig ARM_ERRATA_764369 801f630c1bdSWill Deacon bool "ARM errata: Data cache line maintenance operation by MVA may not succeed" 802f630c1bdSWill Deacon depends on CPU_V7 && SMP 803f630c1bdSWill Deacon help 804f630c1bdSWill Deacon This option enables the workaround for erratum 764369 805f630c1bdSWill Deacon affecting Cortex-A9 MPCore with two or more processors (all 806f630c1bdSWill Deacon current revisions). Under certain timing circumstances, a data 807f630c1bdSWill Deacon cache line maintenance operation by MVA targeting an Inner 808f630c1bdSWill Deacon Shareable memory region may fail to proceed up to either the 809f630c1bdSWill Deacon Point of Coherency or to the Point of Unification of the 810f630c1bdSWill Deacon system. This workaround adds a DSB instruction before the 811f630c1bdSWill Deacon relevant cache maintenance functions and sets a specific bit 812f630c1bdSWill Deacon in the diagnostic control register of the SCU. 813f630c1bdSWill Deacon 8148294fec1SNick Hawkinsconfig ARM_ERRATA_764319 8158294fec1SNick Hawkins bool "ARM errata: Read to DBGPRSR and DBGOSLSR may generate Undefined instruction" 8168294fec1SNick Hawkins depends on CPU_V7 8178294fec1SNick Hawkins help 8188294fec1SNick Hawkins This option enables the workaround for the 764319 Cortex A-9 erratum. 8198294fec1SNick Hawkins CP14 read accesses to the DBGPRSR and DBGOSLSR registers generate an 8208294fec1SNick Hawkins unexpected Undefined Instruction exception when the DBGSWENABLE 8218294fec1SNick Hawkins external pin is set to 0, even when the CP14 accesses are performed 8228294fec1SNick Hawkins from a privileged mode. This work around catches the exception in a 8238294fec1SNick Hawkins way the kernel does not stop execution. 8248294fec1SNick Hawkins 8257253b85cSSimon Hormanconfig ARM_ERRATA_775420 8267253b85cSSimon Horman bool "ARM errata: A data cache maintenance operation which aborts, might lead to deadlock" 8277253b85cSSimon Horman depends on CPU_V7 8287253b85cSSimon Horman help 8297253b85cSSimon Horman This option enables the workaround for the 775420 Cortex-A9 (r2p2, 830cb73737eSGeert Uytterhoeven r2p6,r2p8,r2p10,r3p0) erratum. In case a data cache maintenance 8317253b85cSSimon Horman operation aborts with MMU exception, it might cause the processor 8327253b85cSSimon Horman to deadlock. This workaround puts DSB before executing ISB if 8337253b85cSSimon Horman an abort may occur on cache maintenance. 8347253b85cSSimon Horman 83593dc6887SCatalin Marinasconfig ARM_ERRATA_798181 83693dc6887SCatalin Marinas bool "ARM errata: TLBI/DSB failure on Cortex-A15" 83793dc6887SCatalin Marinas depends on CPU_V7 && SMP 83893dc6887SCatalin Marinas help 83993dc6887SCatalin Marinas On Cortex-A15 (r0p0..r3p2) the TLBI*IS/DSB operations are not 84093dc6887SCatalin Marinas adequately shooting down all use of the old entries. This 84193dc6887SCatalin Marinas option enables the Linux kernel workaround for this erratum 84293dc6887SCatalin Marinas which sends an IPI to the CPUs that are running the same ASID 84393dc6887SCatalin Marinas as the one being invalidated. 84493dc6887SCatalin Marinas 84584b6504fSWill Deaconconfig ARM_ERRATA_773022 84684b6504fSWill Deacon bool "ARM errata: incorrect instructions may be executed from loop buffer" 84784b6504fSWill Deacon depends on CPU_V7 84884b6504fSWill Deacon help 84984b6504fSWill Deacon This option enables the workaround for the 773022 Cortex-A15 85084b6504fSWill Deacon (up to r0p4) erratum. In certain rare sequences of code, the 85184b6504fSWill Deacon loop buffer may deliver incorrect instructions. This 85284b6504fSWill Deacon workaround disables the loop buffer to avoid the erratum. 85384b6504fSWill Deacon 85462c0f4a5SDoug Andersonconfig ARM_ERRATA_818325_852422 85562c0f4a5SDoug Anderson bool "ARM errata: A12: some seqs of opposed cond code instrs => deadlock or corruption" 85662c0f4a5SDoug Anderson depends on CPU_V7 85762c0f4a5SDoug Anderson help 85862c0f4a5SDoug Anderson This option enables the workaround for: 85962c0f4a5SDoug Anderson - Cortex-A12 818325: Execution of an UNPREDICTABLE STR or STM 86062c0f4a5SDoug Anderson instruction might deadlock. Fixed in r0p1. 86162c0f4a5SDoug Anderson - Cortex-A12 852422: Execution of a sequence of instructions might 86262c0f4a5SDoug Anderson lead to either a data corruption or a CPU deadlock. Not fixed in 86362c0f4a5SDoug Anderson any Cortex-A12 cores yet. 86462c0f4a5SDoug Anderson This workaround for all both errata involves setting bit[12] of the 86562c0f4a5SDoug Anderson Feature Register. This bit disables an optimisation applied to a 86662c0f4a5SDoug Anderson sequence of 2 instructions that use opposing condition codes. 86762c0f4a5SDoug Anderson 868416bcf21SDoug Andersonconfig ARM_ERRATA_821420 869416bcf21SDoug Anderson bool "ARM errata: A12: sequence of VMOV to core registers might lead to a dead lock" 870416bcf21SDoug Anderson depends on CPU_V7 871416bcf21SDoug Anderson help 872416bcf21SDoug Anderson This option enables the workaround for the 821420 Cortex-A12 873416bcf21SDoug Anderson (all revs) erratum. In very rare timing conditions, a sequence 874416bcf21SDoug Anderson of VMOV to Core registers instructions, for which the second 875416bcf21SDoug Anderson one is in the shadow of a branch or abort, can lead to a 876416bcf21SDoug Anderson deadlock when the VMOV instructions are issued out-of-order. 877416bcf21SDoug Anderson 8789f6f9354SDoug Andersonconfig ARM_ERRATA_825619 8799f6f9354SDoug Anderson bool "ARM errata: A12: DMB NSHST/ISHST mixed ... might cause deadlock" 8809f6f9354SDoug Anderson depends on CPU_V7 8819f6f9354SDoug Anderson help 8829f6f9354SDoug Anderson This option enables the workaround for the 825619 Cortex-A12 8839f6f9354SDoug Anderson (all revs) erratum. Within rare timing constraints, executing a 8849f6f9354SDoug Anderson DMB NSHST or DMB ISHST instruction followed by a mix of Cacheable 8859f6f9354SDoug Anderson and Device/Strongly-Ordered loads and stores might cause deadlock 8869f6f9354SDoug Anderson 887304009a1SDoug Andersonconfig ARM_ERRATA_857271 888304009a1SDoug Anderson bool "ARM errata: A12: CPU might deadlock under some very rare internal conditions" 889304009a1SDoug Anderson depends on CPU_V7 890304009a1SDoug Anderson help 891304009a1SDoug Anderson This option enables the workaround for the 857271 Cortex-A12 892304009a1SDoug Anderson (all revs) erratum. Under very rare timing conditions, the CPU might 893304009a1SDoug Anderson hang. The workaround is expected to have a < 1% performance impact. 894304009a1SDoug Anderson 8959f6f9354SDoug Andersonconfig ARM_ERRATA_852421 8969f6f9354SDoug Anderson bool "ARM errata: A17: DMB ST might fail to create order between stores" 8979f6f9354SDoug Anderson depends on CPU_V7 8989f6f9354SDoug Anderson help 8999f6f9354SDoug Anderson This option enables the workaround for the 852421 Cortex-A17 9009f6f9354SDoug Anderson (r1p0, r1p1, r1p2) erratum. Under very rare timing conditions, 9019f6f9354SDoug Anderson execution of a DMB ST instruction might fail to properly order 9029f6f9354SDoug Anderson stores from GroupA and stores from GroupB. 9039f6f9354SDoug Anderson 90462c0f4a5SDoug Andersonconfig ARM_ERRATA_852423 90562c0f4a5SDoug Anderson bool "ARM errata: A17: some seqs of opposed cond code instrs => deadlock or corruption" 90662c0f4a5SDoug Anderson depends on CPU_V7 90762c0f4a5SDoug Anderson help 90862c0f4a5SDoug Anderson This option enables the workaround for: 90962c0f4a5SDoug Anderson - Cortex-A17 852423: Execution of a sequence of instructions might 91062c0f4a5SDoug Anderson lead to either a data corruption or a CPU deadlock. Not fixed in 91162c0f4a5SDoug Anderson any Cortex-A17 cores yet. 91262c0f4a5SDoug Anderson This is identical to Cortex-A12 erratum 852422. It is a separate 91362c0f4a5SDoug Anderson config option from the A12 erratum due to the way errata are checked 91462c0f4a5SDoug Anderson for and handled. 91562c0f4a5SDoug Anderson 916304009a1SDoug Andersonconfig ARM_ERRATA_857272 917304009a1SDoug Anderson bool "ARM errata: A17: CPU might deadlock under some very rare internal conditions" 918304009a1SDoug Anderson depends on CPU_V7 919304009a1SDoug Anderson help 920304009a1SDoug Anderson This option enables the workaround for the 857272 Cortex-A17 erratum. 921304009a1SDoug Anderson This erratum is not known to be fixed in any A17 revision. 922304009a1SDoug Anderson This is identical to Cortex-A12 erratum 857271. It is a separate 923304009a1SDoug Anderson config option from the A12 erratum due to the way errata are checked 924304009a1SDoug Anderson for and handled. 925304009a1SDoug Anderson 9261da177e4SLinus Torvaldsendmenu 9271da177e4SLinus Torvalds 9281da177e4SLinus Torvaldssource "arch/arm/common/Kconfig" 9291da177e4SLinus Torvalds 9301da177e4SLinus Torvaldsmenu "Bus support" 9311da177e4SLinus Torvalds 9321da177e4SLinus Torvaldsconfig ISA 9331da177e4SLinus Torvalds bool 9341da177e4SLinus Torvalds help 9351da177e4SLinus Torvalds Find out whether you have ISA slots on your motherboard. ISA is the 9361da177e4SLinus Torvalds name of a bus system, i.e. the way the CPU talks to the other stuff 9371da177e4SLinus Torvalds inside your box. Other bus systems are PCI, EISA, MicroChannel 9381da177e4SLinus Torvalds (MCA) or VESA. ISA is an older system, now being displaced by PCI; 9391da177e4SLinus Torvalds newer boards don't support it. If you have ISA, say Y, otherwise N. 9401da177e4SLinus Torvalds 941065909b9SRussell King# Select ISA DMA interface 9425cae841bSAl Viroconfig ISA_DMA_API 9435cae841bSAl Viro bool 9445cae841bSAl Viro 945779eb41cSBenjamin Gaignardconfig ARM_ERRATA_814220 946779eb41cSBenjamin Gaignard bool "ARM errata: Cache maintenance by set/way operations can execute out of order" 947779eb41cSBenjamin Gaignard depends on CPU_V7 948779eb41cSBenjamin Gaignard help 949779eb41cSBenjamin Gaignard The v7 ARM states that all cache and branch predictor maintenance 950779eb41cSBenjamin Gaignard operations that do not specify an address execute, relative to 951779eb41cSBenjamin Gaignard each other, in program order. 952779eb41cSBenjamin Gaignard However, because of this erratum, an L2 set/way cache maintenance 953779eb41cSBenjamin Gaignard operation can overtake an L1 set/way cache maintenance operation. 954779eb41cSBenjamin Gaignard This ERRATA only affected the Cortex-A7 and present in r0p2, r0p3, 955779eb41cSBenjamin Gaignard r0p4, r0p5. 956779eb41cSBenjamin Gaignard 9571da177e4SLinus Torvaldsendmenu 9581da177e4SLinus Torvalds 9591da177e4SLinus Torvaldsmenu "Kernel Features" 9601da177e4SLinus Torvalds 9613b55658aSDave Martinconfig HAVE_SMP 9623b55658aSDave Martin bool 9633b55658aSDave Martin help 9643b55658aSDave Martin This option should be selected by machines which have an SMP- 9653b55658aSDave Martin capable CPU. 9663b55658aSDave Martin 9673b55658aSDave Martin The only effect of this option is to make the SMP-related 9683b55658aSDave Martin options available to the user for configuration. 9693b55658aSDave Martin 9701da177e4SLinus Torvaldsconfig SMP 971bb2d8130SRussell King bool "Symmetric Multi-Processing" 972fbb4ddacSRussell King depends on CPU_V6K || CPU_V7 9733b55658aSDave Martin depends on HAVE_SMP 974801bb21cSJonathan Austin depends on MMU || ARM_MPU 9750361748fSArnd Bergmann select IRQ_WORK 9761da177e4SLinus Torvalds help 9771da177e4SLinus Torvalds This enables support for systems with more than one CPU. If you have 9784a474157SRobert Graffham a system with only one CPU, say N. If you have a system with more 9794a474157SRobert Graffham than one CPU, say Y. 9801da177e4SLinus Torvalds 9814a474157SRobert Graffham If you say N here, the kernel will run on uni- and multiprocessor 9821da177e4SLinus Torvalds machines, but will use only one CPU of a multiprocessor machine. If 9834a474157SRobert Graffham you say Y here, the kernel will run on many, but not all, 9844a474157SRobert Graffham uniprocessor machines. On a uniprocessor machine, the kernel 9854a474157SRobert Graffham will run faster if you say N here. 9861da177e4SLinus Torvalds 987ff61f079SJonathan Corbet See also <file:Documentation/arch/x86/i386/IO-APIC.rst>, 9884f4cfa6cSMauro Carvalho Chehab <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at 98950a23e6eSJustin P. Mattock <http://tldp.org/HOWTO/SMP-HOWTO.html>. 9901da177e4SLinus Torvalds 9911da177e4SLinus Torvalds If you don't know what to do here, say N. 9921da177e4SLinus Torvalds 993f00ec48fSRussell Kingconfig SMP_ON_UP 9945744ff43SRussell King bool "Allow booting SMP kernel on uniprocessor systems" 9955408445bSArnd Bergmann depends on SMP && MMU 996f00ec48fSRussell King default y 997f00ec48fSRussell King help 998f00ec48fSRussell King SMP kernels contain instructions which fail on non-SMP processors. 999f00ec48fSRussell King Enabling this option allows the kernel to modify itself to make 1000f00ec48fSRussell King these instructions safe. Disabling it allows about 1K of space 1001f00ec48fSRussell King savings. 1002f00ec48fSRussell King 1003f00ec48fSRussell King If you don't know what to do here, say Y. 1004f00ec48fSRussell King 100550596b75SArd Biesheuvel 100650596b75SArd Biesheuvelconfig CURRENT_POINTER_IN_TPIDRURO 100750596b75SArd Biesheuvel def_bool y 1008b87cf911SArd Biesheuvel depends on CPU_32v6K && !CPU_V6 100950596b75SArd Biesheuvel 1010d4664b6cSArd Biesheuvelconfig IRQSTACKS 1011d4664b6cSArd Biesheuvel def_bool y 10129974f857SArd Biesheuvel select HAVE_IRQ_EXIT_ON_IRQ_STACK 10139974f857SArd Biesheuvel select HAVE_SOFTIRQ_ON_OWN_STACK 10141da177e4SLinus Torvalds 1015c9018aabSVincent Guittotconfig ARM_CPU_TOPOLOGY 1016c9018aabSVincent Guittot bool "Support cpu topology definition" 1017c9018aabSVincent Guittot depends on SMP && CPU_V7 1018c9018aabSVincent Guittot default y 1019c9018aabSVincent Guittot help 1020c9018aabSVincent Guittot Support ARM cpu topology definition. The MPIDR register defines 1021c9018aabSVincent Guittot affinity between processors which is then used to describe the cpu 1022c9018aabSVincent Guittot topology of an ARM System. 1023c9018aabSVincent Guittot 1024c9018aabSVincent Guittotconfig SCHED_MC 1025c9018aabSVincent Guittot bool "Multi-core scheduler support" 1026c9018aabSVincent Guittot depends on ARM_CPU_TOPOLOGY 1027c9018aabSVincent Guittot help 1028c9018aabSVincent Guittot Multi-core scheduler support improves the CPU scheduler's decision 1029c9018aabSVincent Guittot making when dealing with multi-core CPU chips at a cost of slightly 1030c9018aabSVincent Guittot increased overhead in some places. If unsure say N here. 1031c9018aabSVincent Guittot 1032c9018aabSVincent Guittotconfig SCHED_SMT 1033c9018aabSVincent Guittot bool "SMT scheduler support" 1034c9018aabSVincent Guittot depends on ARM_CPU_TOPOLOGY 1035c9018aabSVincent Guittot help 1036c9018aabSVincent Guittot Improves the CPU scheduler's decision making when dealing with 1037c9018aabSVincent Guittot MultiThreading at a cost of slightly increased overhead in some 1038c9018aabSVincent Guittot places. If unsure say N here. 1039c9018aabSVincent Guittot 1040a8cbcd92SRussell Kingconfig HAVE_ARM_SCU 1041a8cbcd92SRussell King bool 1042a8cbcd92SRussell King help 10438f433ec4SGeert Uytterhoeven This option enables support for the ARM snoop control unit 1044a8cbcd92SRussell King 10458a4da6e3SMark Rutlandconfig HAVE_ARM_ARCH_TIMER 1046022c03a2SMarc Zyngier bool "Architected timer support" 1047022c03a2SMarc Zyngier depends on CPU_V7 10488a4da6e3SMark Rutland select ARM_ARCH_TIMER 1049022c03a2SMarc Zyngier help 1050022c03a2SMarc Zyngier This option enables support for the ARM architected timer 1051022c03a2SMarc Zyngier 1052f32f4ce2SRussell Kingconfig HAVE_ARM_TWD 1053f32f4ce2SRussell King bool 1054f32f4ce2SRussell King help 1055f32f4ce2SRussell King This options enables support for the ARM timer and watchdog unit 1056f32f4ce2SRussell King 1057e8db288eSNicolas Pitreconfig MCPM 1058e8db288eSNicolas Pitre bool "Multi-Cluster Power Management" 1059e8db288eSNicolas Pitre depends on CPU_V7 && SMP 1060e8db288eSNicolas Pitre help 1061e8db288eSNicolas Pitre This option provides the common power management infrastructure 1062e8db288eSNicolas Pitre for (multi-)cluster based systems, such as big.LITTLE based 1063e8db288eSNicolas Pitre systems. 1064e8db288eSNicolas Pitre 1065ebf4a5c5SHaojian Zhuangconfig MCPM_QUAD_CLUSTER 1066ebf4a5c5SHaojian Zhuang bool 1067ebf4a5c5SHaojian Zhuang depends on MCPM 1068ebf4a5c5SHaojian Zhuang help 1069ebf4a5c5SHaojian Zhuang To avoid wasting resources unnecessarily, MCPM only supports up 1070ebf4a5c5SHaojian Zhuang to 2 clusters by default. 1071ebf4a5c5SHaojian Zhuang Platforms with 3 or 4 clusters that use MCPM must select this 1072ebf4a5c5SHaojian Zhuang option to allow the additional clusters to be managed. 1073ebf4a5c5SHaojian Zhuang 10741c33be57SNicolas Pitreconfig BIG_LITTLE 10751c33be57SNicolas Pitre bool "big.LITTLE support (Experimental)" 10761c33be57SNicolas Pitre depends on CPU_V7 && SMP 10771c33be57SNicolas Pitre select MCPM 10781c33be57SNicolas Pitre help 10791c33be57SNicolas Pitre This option enables support selections for the big.LITTLE 10801c33be57SNicolas Pitre system architecture. 10811c33be57SNicolas Pitre 10821c33be57SNicolas Pitreconfig BL_SWITCHER 10831c33be57SNicolas Pitre bool "big.LITTLE switcher support" 10846c044fecSArnd Bergmann depends on BIG_LITTLE && MCPM && HOTPLUG_CPU && ARM_GIC 108551aaf81fSRussell King select CPU_PM 10861c33be57SNicolas Pitre help 10871c33be57SNicolas Pitre The big.LITTLE "switcher" provides the core functionality to 10881c33be57SNicolas Pitre transparently handle transition between a cluster of A15's 10891c33be57SNicolas Pitre and a cluster of A7's in a big.LITTLE system. 10901c33be57SNicolas Pitre 1091b22537c6SNicolas Pitreconfig BL_SWITCHER_DUMMY_IF 1092b22537c6SNicolas Pitre tristate "Simple big.LITTLE switcher user interface" 1093b22537c6SNicolas Pitre depends on BL_SWITCHER && DEBUG_KERNEL 1094b22537c6SNicolas Pitre help 1095b22537c6SNicolas Pitre This is a simple and dummy char dev interface to control 1096b22537c6SNicolas Pitre the big.LITTLE switcher core code. It is meant for 1097b22537c6SNicolas Pitre debugging purposes only. 1098b22537c6SNicolas Pitre 10998d5796d2SLennert Buytenhekchoice 11008d5796d2SLennert Buytenhek prompt "Memory split" 1101006fa259SRussell King depends on MMU 11028d5796d2SLennert Buytenhek default VMSPLIT_3G 11038d5796d2SLennert Buytenhek help 11048d5796d2SLennert Buytenhek Select the desired split between kernel and user memory. 11058d5796d2SLennert Buytenhek 11068d5796d2SLennert Buytenhek If you are not absolutely sure what you are doing, leave this 11078d5796d2SLennert Buytenhek option alone! 11088d5796d2SLennert Buytenhek 11098d5796d2SLennert Buytenhek config VMSPLIT_3G 11108d5796d2SLennert Buytenhek bool "3G/1G user/kernel split" 111163ce446cSNicolas Pitre config VMSPLIT_3G_OPT 1112bbeedfdaSYisheng Xie depends on !ARM_LPAE 111363ce446cSNicolas Pitre bool "3G/1G user/kernel split (for full 1G low memory)" 11148d5796d2SLennert Buytenhek config VMSPLIT_2G 11158d5796d2SLennert Buytenhek bool "2G/2G user/kernel split" 11168d5796d2SLennert Buytenhek config VMSPLIT_1G 11178d5796d2SLennert Buytenhek bool "1G/3G user/kernel split" 11188d5796d2SLennert Buytenhekendchoice 11198d5796d2SLennert Buytenhek 11208d5796d2SLennert Buytenhekconfig PAGE_OFFSET 11218d5796d2SLennert Buytenhek hex 1122006fa259SRussell King default PHYS_OFFSET if !MMU 11238d5796d2SLennert Buytenhek default 0x40000000 if VMSPLIT_1G 11248d5796d2SLennert Buytenhek default 0x80000000 if VMSPLIT_2G 112563ce446cSNicolas Pitre default 0xB0000000 if VMSPLIT_3G_OPT 11268d5796d2SLennert Buytenhek default 0xC0000000 11278d5796d2SLennert Buytenhek 1128c12366baSLinus Walleijconfig KASAN_SHADOW_OFFSET 1129c12366baSLinus Walleij hex 1130c12366baSLinus Walleij depends on KASAN 1131c12366baSLinus Walleij default 0x1f000000 if PAGE_OFFSET=0x40000000 1132c12366baSLinus Walleij default 0x5f000000 if PAGE_OFFSET=0x80000000 1133c12366baSLinus Walleij default 0x9f000000 if PAGE_OFFSET=0xC0000000 1134c12366baSLinus Walleij default 0x8f000000 if PAGE_OFFSET=0xB0000000 1135c12366baSLinus Walleij default 0xffffffff 1136c12366baSLinus Walleij 11371da177e4SLinus Torvaldsconfig NR_CPUS 11381da177e4SLinus Torvalds int "Maximum number of CPUs (2-32)" 1139d624833fSArd Biesheuvel range 2 16 if DEBUG_KMAP_LOCAL 1140d624833fSArd Biesheuvel range 2 32 if !DEBUG_KMAP_LOCAL 11411da177e4SLinus Torvalds depends on SMP 11421da177e4SLinus Torvalds default "4" 1143d624833fSArd Biesheuvel help 1144d624833fSArd Biesheuvel The maximum number of CPUs that the kernel can support. 1145d624833fSArd Biesheuvel Up to 32 CPUs can be supported, or up to 16 if kmap_local() 1146d624833fSArd Biesheuvel debugging is enabled, which uses half of the per-CPU fixmap 1147d624833fSArd Biesheuvel slots as guard regions. 11481da177e4SLinus Torvalds 1149a054a811SRussell Kingconfig HOTPLUG_CPU 115000b7dedeSRussell King bool "Support for hot-pluggable CPUs" 115140b31360SStephen Rothwell depends on SMP 11521b5ba350SDietmar Eggemann select GENERIC_IRQ_MIGRATION 1153a054a811SRussell King help 1154a054a811SRussell King Say Y here to experiment with turning CPUs off and on. CPUs 1155a054a811SRussell King can be controlled through /sys/devices/system/cpu. 1156a054a811SRussell King 11572bdd424fSWill Deaconconfig ARM_PSCI 11582bdd424fSWill Deacon bool "Support for the ARM Power State Coordination Interface (PSCI)" 1159e679660dSJens Wiklander depends on HAVE_ARM_SMCCC 1160be120397SMark Rutland select ARM_PSCI_FW 11612bdd424fSWill Deacon help 11622bdd424fSWill Deacon Say Y here if you want Linux to communicate with system firmware 11632bdd424fSWill Deacon implementing the PSCI specification for CPU-centric power 11642bdd424fSWill Deacon management operations described in ARM document number ARM DEN 11652bdd424fSWill Deacon 0022A ("Power State Coordination Interface System Software on 11662bdd424fSWill Deacon ARM processors"). 11672bdd424fSWill Deacon 1168c9218b16SRussell Kingconfig HZ_FIXED 1169f8065813SRussell King int 11701164f672SAlexandre Belloni default 128 if SOC_AT91RM9200 117147d84682SRussell King default 0 1172c9218b16SRussell King 1173c9218b16SRussell Kingchoice 117447d84682SRussell King depends on HZ_FIXED = 0 1175c9218b16SRussell King prompt "Timer frequency" 1176c9218b16SRussell King 1177c9218b16SRussell Kingconfig HZ_100 1178c9218b16SRussell King bool "100 Hz" 1179c9218b16SRussell King 1180c9218b16SRussell Kingconfig HZ_200 1181c9218b16SRussell King bool "200 Hz" 1182c9218b16SRussell King 1183c9218b16SRussell Kingconfig HZ_250 1184c9218b16SRussell King bool "250 Hz" 1185c9218b16SRussell King 1186c9218b16SRussell Kingconfig HZ_300 1187c9218b16SRussell King bool "300 Hz" 1188c9218b16SRussell King 1189c9218b16SRussell Kingconfig HZ_500 1190c9218b16SRussell King bool "500 Hz" 1191c9218b16SRussell King 1192c9218b16SRussell Kingconfig HZ_1000 1193c9218b16SRussell King bool "1000 Hz" 1194c9218b16SRussell King 1195c9218b16SRussell Kingendchoice 1196c9218b16SRussell King 1197c9218b16SRussell Kingconfig HZ 1198c9218b16SRussell King int 119947d84682SRussell King default HZ_FIXED if HZ_FIXED != 0 1200c9218b16SRussell King default 100 if HZ_100 1201c9218b16SRussell King default 200 if HZ_200 1202c9218b16SRussell King default 250 if HZ_250 1203c9218b16SRussell King default 300 if HZ_300 1204c9218b16SRussell King default 500 if HZ_500 1205c9218b16SRussell King default 1000 1206c9218b16SRussell King 1207c9218b16SRussell Kingconfig SCHED_HRTICK 1208c9218b16SRussell King def_bool HIGH_RES_TIMERS 1209f8065813SRussell King 121016c79651SCatalin Marinasconfig THUMB2_KERNEL 1211bc7dea00SUwe Kleine-König bool "Compile the kernel in Thumb-2 mode" if !CPU_THUMBONLY 12124477ca45SUwe Kleine-König depends on (CPU_V7 || CPU_V7M) && !CPU_V6 && !CPU_V6K 1213bc7dea00SUwe Kleine-König default y if CPU_THUMBONLY 121489bace65SArnd Bergmann select ARM_UNWIND 121516c79651SCatalin Marinas help 121616c79651SCatalin Marinas By enabling this option, the kernel will be compiled in 121775fea300SNicolas Pitre Thumb-2 mode. 121816c79651SCatalin Marinas 121916c79651SCatalin Marinas If unsure, say N. 122016c79651SCatalin Marinas 122142f25bddSNicolas Pitreconfig ARM_PATCH_IDIV 122242f25bddSNicolas Pitre bool "Runtime patch udiv/sdiv instructions into __aeabi_{u}idiv()" 12235408445bSArnd Bergmann depends on CPU_32v7 122442f25bddSNicolas Pitre default y 122542f25bddSNicolas Pitre help 122642f25bddSNicolas Pitre The ARM compiler inserts calls to __aeabi_idiv() and 122742f25bddSNicolas Pitre __aeabi_uidiv() when it needs to perform division on signed 122842f25bddSNicolas Pitre and unsigned integers. Some v7 CPUs have support for the sdiv 122942f25bddSNicolas Pitre and udiv instructions that can be used to implement those 123042f25bddSNicolas Pitre functions. 123142f25bddSNicolas Pitre 123242f25bddSNicolas Pitre Enabling this option allows the kernel to modify itself to 123342f25bddSNicolas Pitre replace the first two instructions of these library functions 123442f25bddSNicolas Pitre with the sdiv or udiv plus "bx lr" instructions when the CPU 123542f25bddSNicolas Pitre it is running on supports them. Typically this will be faster 123642f25bddSNicolas Pitre and less power intensive than running the original library 123742f25bddSNicolas Pitre code to do integer division. 123842f25bddSNicolas Pitre 1239704bdda0SNicolas Pitreconfig AEABI 1240a05b9608SNick Desaulniers bool "Use the ARM EABI to compile the kernel" if !CPU_V7 && \ 1241a05b9608SNick Desaulniers !CPU_V7M && !CPU_V6 && !CPU_V6K && !CC_IS_CLANG 1242a05b9608SNick Desaulniers default CPU_V7 || CPU_V7M || CPU_V6 || CPU_V6K || CC_IS_CLANG 1243704bdda0SNicolas Pitre help 1244704bdda0SNicolas Pitre This option allows for the kernel to be compiled using the latest 1245704bdda0SNicolas Pitre ARM ABI (aka EABI). This is only useful if you are using a user 1246704bdda0SNicolas Pitre space environment that is also compiled with EABI. 1247704bdda0SNicolas Pitre 1248704bdda0SNicolas Pitre Since there are major incompatibilities between the legacy ABI and 1249704bdda0SNicolas Pitre EABI, especially with regard to structure member alignment, this 1250704bdda0SNicolas Pitre option also changes the kernel syscall calling convention to 1251704bdda0SNicolas Pitre disambiguate both ABIs and allow for backward compatibility support 1252704bdda0SNicolas Pitre (selected with CONFIG_OABI_COMPAT). 1253704bdda0SNicolas Pitre 1254704bdda0SNicolas Pitre To use this you need GCC version 4.0.0 or later. 1255704bdda0SNicolas Pitre 12566c90c872SNicolas Pitreconfig OABI_COMPAT 1257a73a3ff1SRussell King bool "Allow old ABI binaries to run with this kernel (EXPERIMENTAL)" 1258d6f94fa0SKees Cook depends on AEABI && !THUMB2_KERNEL 12596c90c872SNicolas Pitre help 12606c90c872SNicolas Pitre This option preserves the old syscall interface along with the 12616c90c872SNicolas Pitre new (ARM EABI) one. It also provides a compatibility layer to 12626c90c872SNicolas Pitre intercept syscalls that have structure arguments which layout 12636c90c872SNicolas Pitre in memory differs between the legacy ABI and the new ARM EABI 12646c90c872SNicolas Pitre (only for non "thumb" binaries). This option adds a tiny 12656c90c872SNicolas Pitre overhead to all syscalls and produces a slightly larger kernel. 126691702175SKees Cook 126791702175SKees Cook The seccomp filter system will not be available when this is 126891702175SKees Cook selected, since there is no way yet to sensibly distinguish 126991702175SKees Cook between calling conventions during filtering. 127091702175SKees Cook 12716c90c872SNicolas Pitre If you know you'll be using only pure EABI user space then you 12726c90c872SNicolas Pitre can say N here. If this option is not selected and you attempt 12736c90c872SNicolas Pitre to execute a legacy ABI binary then the result will be 12746c90c872SNicolas Pitre UNPREDICTABLE (in fact it can be predicted that it won't work 1275b02f8467SKees Cook at all). If in doubt say N. 12766c90c872SNicolas Pitre 1277fb597f2aSGregory Fongconfig ARCH_SELECT_MEMORY_MODEL 12786fd09c9aSArnd Bergmann def_bool y 127905944d74SRussell King 1280fb597f2aSGregory Fongconfig ARCH_FLATMEM_ENABLE 12816fd09c9aSArnd Bergmann def_bool !(ARCH_RPC || ARCH_SA1100) 1282fb597f2aSGregory Fong 128305944d74SRussell Kingconfig ARCH_SPARSEMEM_ENABLE 12846fd09c9aSArnd Bergmann def_bool !ARCH_FOOTBRIDGE 1285fb597f2aSGregory Fong select SPARSEMEM_STATIC if SPARSEMEM 128607a2f737SRussell King 1287053a96caSNicolas Pitreconfig HIGHMEM 1288e8db89a2SRussell King bool "High Memory Support" 1289e8db89a2SRussell King depends on MMU 12902a15ba82SThomas Gleixner select KMAP_LOCAL 1291825c43f5SArd Biesheuvel select KMAP_LOCAL_NON_LINEAR_PTE_ARRAY 1292053a96caSNicolas Pitre help 1293053a96caSNicolas Pitre The address space of ARM processors is only 4 Gigabytes large 1294053a96caSNicolas Pitre and it has to accommodate user address space, kernel address 1295053a96caSNicolas Pitre space as well as some memory mapped IO. That means that, if you 1296053a96caSNicolas Pitre have a large amount of physical memory and/or IO, not all of the 1297053a96caSNicolas Pitre memory can be "permanently mapped" by the kernel. The physical 1298053a96caSNicolas Pitre memory that is not permanently mapped is called "high memory". 1299053a96caSNicolas Pitre 1300053a96caSNicolas Pitre Depending on the selected kernel/user memory split, minimum 1301053a96caSNicolas Pitre vmalloc space and actual amount of RAM, you may not need this 1302053a96caSNicolas Pitre option which should result in a slightly faster kernel. 1303053a96caSNicolas Pitre 1304053a96caSNicolas Pitre If unsure, say n. 1305053a96caSNicolas Pitre 130665cec8e3SRussell Kingconfig HIGHPTE 13079a431bd5SRussell King bool "Allocate 2nd-level pagetables from highmem" if EXPERT 130865cec8e3SRussell King depends on HIGHMEM 13099a431bd5SRussell King default y 1310b4d103d1SRussell King help 1311b4d103d1SRussell King The VM uses one page of physical memory for each page table. 1312b4d103d1SRussell King For systems with a lot of processes, this can use a lot of 1313b4d103d1SRussell King precious low memory, eventually leading to low memory being 1314b4d103d1SRussell King consumed by page tables. Setting this option will allow 1315b4d103d1SRussell King user-space 2nd level page tables to reside in high memory. 131665cec8e3SRussell King 1317a5e090acSRussell Kingconfig CPU_SW_DOMAIN_PAN 1318a5e090acSRussell King bool "Enable use of CPU domains to implement privileged no-access" 1319a5e090acSRussell King depends on MMU && !ARM_LPAE 13201b8873a0SJamie Iles default y 13211b8873a0SJamie Iles help 1322a5e090acSRussell King Increase kernel security by ensuring that normal kernel accesses 1323a5e090acSRussell King are unable to access userspace addresses. This can help prevent 1324a5e090acSRussell King use-after-free bugs becoming an exploitable privilege escalation 1325a5e090acSRussell King by ensuring that magic values (such as LIST_POISON) will always 1326a5e090acSRussell King fault when dereferenced. 1327a5e090acSRussell King 1328a5e090acSRussell King CPUs with low-vector mappings use a best-efforts implementation. 1329a5e090acSRussell King Their lower 1MB needs to remain accessible for the vectors, but 1330a5e090acSRussell King the remainder of userspace will become appropriately inaccessible. 1331c80d79d7SYasunori Goto 1332c80d79d7SYasunori Gotoconfig HW_PERF_EVENTS 1333fa8ad788SMark Rutland def_bool y 1334fa8ad788SMark Rutland depends on ARM_PMU 13351b8873a0SJamie Iles 13367d485f64SArd Biesheuvelconfig ARM_MODULE_PLTS 13377d485f64SArd Biesheuvel bool "Use PLTs to allow module memory to spill over into vmalloc area" 13387d485f64SArd Biesheuvel depends on MODULES 13398fa7ea40SLecopzer Chen select KASAN_VMALLOC if KASAN 1340e7229f7dSAnders Roxell default y 13417d485f64SArd Biesheuvel help 13427d485f64SArd Biesheuvel Allocate PLTs when loading modules so that jumps and calls whose 13437d485f64SArd Biesheuvel targets are too far away for their relative offsets to be encoded 13447d485f64SArd Biesheuvel in the instructions themselves can be bounced via veneers in the 13457d485f64SArd Biesheuvel module's PLT. This allows modules to be allocated in the generic 13467d485f64SArd Biesheuvel vmalloc area after the dedicated module memory area has been 13477d485f64SArd Biesheuvel exhausted. The modules will use slightly more memory, but after 13487d485f64SArd Biesheuvel rounding up to page size, the actual memory footprint is usually 13497d485f64SArd Biesheuvel the same. 13507d485f64SArd Biesheuvel 1351e7229f7dSAnders Roxell Disabling this is usually safe for small single-platform 1352e7229f7dSAnders Roxell configurations. If unsure, say y. 13537d485f64SArd Biesheuvel 13540192445cSZi Yanconfig ARCH_FORCE_MAX_ORDER 13558c907785SMike Rapoport (IBM) int "Order of maximal physically contiguous allocations" 135623baf831SKirill A. Shutemov default "11" if SOC_AM33XX 135723baf831SKirill A. Shutemov default "8" if SA1111 135823baf831SKirill A. Shutemov default "10" 1359c1b2d970SMagnus Damm help 13608c907785SMike Rapoport (IBM) The kernel page allocator limits the size of maximal physically 13618c907785SMike Rapoport (IBM) contiguous allocations. The limit is called MAX_ORDER and it 13628c907785SMike Rapoport (IBM) defines the maximal power of two of number of pages that can be 13638c907785SMike Rapoport (IBM) allocated as a single contiguous block. This option allows 13648c907785SMike Rapoport (IBM) overriding the default setting when ability to allocate very 13658c907785SMike Rapoport (IBM) large blocks of physically contiguous memory is required. 1366c1b2d970SMagnus Damm 13678c907785SMike Rapoport (IBM) Don't change if unsure. 1368c1b2d970SMagnus Damm 13691da177e4SLinus Torvaldsconfig ALIGNMENT_TRAP 13703e3f354bSArnd Bergmann def_bool CPU_CP15_MMU 1371e119bfffSRussell King select HAVE_PROC_CPU if PROC_FS 13721da177e4SLinus Torvalds help 13731da177e4SLinus Torvalds ARM processors cannot fetch/store information which is not 13741da177e4SLinus Torvalds naturally aligned on the bus, i.e., a 4 byte fetch must start at an 13751da177e4SLinus Torvalds address divisible by 4. On 32-bit ARM processors, these non-aligned 13761da177e4SLinus Torvalds fetch/store instructions will be emulated in software if you say 13771da177e4SLinus Torvalds here, which has a severe performance impact. This is necessary for 13781da177e4SLinus Torvalds correct operation of some network protocols. With an IP-only 13791da177e4SLinus Torvalds configuration it is safe to say N, otherwise say Y. 13801da177e4SLinus Torvalds 138139ec58f3SLennert Buytenhekconfig UACCESS_WITH_MEMCPY 138238ef2ad5SLinus Walleij bool "Use kernel mem{cpy,set}() for {copy_to,clear}_user()" 138338ef2ad5SLinus Walleij depends on MMU 138439ec58f3SLennert Buytenhek default y if CPU_FEROCEON 138539ec58f3SLennert Buytenhek help 138639ec58f3SLennert Buytenhek Implement faster copy_to_user and clear_user methods for CPU 138739ec58f3SLennert Buytenhek cores where a 8-word STM instruction give significantly higher 138839ec58f3SLennert Buytenhek memory write throughput than a sequence of individual 32bit stores. 138939ec58f3SLennert Buytenhek 139039ec58f3SLennert Buytenhek A possible side effect is a slight increase in scheduling latency 139139ec58f3SLennert Buytenhek between threads sharing the same address space if they invoke 139239ec58f3SLennert Buytenhek such copy operations with large buffers. 139339ec58f3SLennert Buytenhek 139439ec58f3SLennert Buytenhek However, if the CPU data cache is using a write-allocate mode, 139539ec58f3SLennert Buytenhek this option is unlikely to provide any performance gain. 139639ec58f3SLennert Buytenhek 139702c2433bSStefano Stabelliniconfig PARAVIRT 139802c2433bSStefano Stabellini bool "Enable paravirtualization code" 139902c2433bSStefano Stabellini help 140002c2433bSStefano Stabellini This changes the kernel so it can modify itself when it is run 140102c2433bSStefano Stabellini under a hypervisor, potentially improving performance significantly 140202c2433bSStefano Stabellini over full virtualization. 140302c2433bSStefano Stabellini 140402c2433bSStefano Stabelliniconfig PARAVIRT_TIME_ACCOUNTING 140502c2433bSStefano Stabellini bool "Paravirtual steal time accounting" 140602c2433bSStefano Stabellini select PARAVIRT 140702c2433bSStefano Stabellini help 140802c2433bSStefano Stabellini Select this option to enable fine granularity task steal time 140902c2433bSStefano Stabellini accounting. Time spent executing other tasks in parallel with 141002c2433bSStefano Stabellini the current vCPU is discounted from the vCPU power. To account for 141102c2433bSStefano Stabellini that, there can be a small performance impact. 141202c2433bSStefano Stabellini 141302c2433bSStefano Stabellini If in doubt, say N here. 141402c2433bSStefano Stabellini 1415eff8d644SStefano Stabelliniconfig XEN_DOM0 1416eff8d644SStefano Stabellini def_bool y 1417eff8d644SStefano Stabellini depends on XEN 1418eff8d644SStefano Stabellini 1419eff8d644SStefano Stabelliniconfig XEN 1420c2ba1f7dSJulien Grall bool "Xen guest support on ARM" 142185323a99SIan Campbell depends on ARM && AEABI && OF 1422f880b67dSArnd Bergmann depends on CPU_V7 && !CPU_V6 142385323a99SIan Campbell depends on !GENERIC_ATOMIC64 14247693deccSUwe Kleine-König depends on MMU 142551aaf81fSRussell King select ARCH_DMA_ADDR_T_64BIT 142617b7ab80SStefano Stabellini select ARM_PSCI 1427f21254cdSChristoph Hellwig select SWIOTLB 142883862ccfSStefano Stabellini select SWIOTLB_XEN 142902c2433bSStefano Stabellini select PARAVIRT 1430eff8d644SStefano Stabellini help 1431eff8d644SStefano Stabellini Say Y if you want to run Linux in a Virtual Machine on Xen on ARM. 1432eff8d644SStefano Stabellini 1433f05eb1d2SArd Biesheuvelconfig CC_HAVE_STACKPROTECTOR_TLS 1434f05eb1d2SArd Biesheuvel def_bool $(cc-option,-mtp=cp15 -mstack-protector-guard=tls -mstack-protector-guard-offset=0) 1435f05eb1d2SArd Biesheuvel 1436189af465SArd Biesheuvelconfig STACKPROTECTOR_PER_TASK 1437189af465SArd Biesheuvel bool "Use a unique stack canary value for each task" 14389c46929eSArd Biesheuvel depends on STACKPROTECTOR && CURRENT_POINTER_IN_TPIDRURO && !XIP_DEFLATED_DATA 1439f05eb1d2SArd Biesheuvel depends on GCC_PLUGINS || CC_HAVE_STACKPROTECTOR_TLS 1440f05eb1d2SArd Biesheuvel select GCC_PLUGIN_ARM_SSP_PER_TASK if !CC_HAVE_STACKPROTECTOR_TLS 1441189af465SArd Biesheuvel default y 1442189af465SArd Biesheuvel help 1443189af465SArd Biesheuvel Due to the fact that GCC uses an ordinary symbol reference from 1444189af465SArd Biesheuvel which to load the value of the stack canary, this value can only 1445189af465SArd Biesheuvel change at reboot time on SMP systems, and all tasks running in the 1446189af465SArd Biesheuvel kernel's address space are forced to use the same canary value for 1447189af465SArd Biesheuvel the entire duration that the system is up. 1448189af465SArd Biesheuvel 1449189af465SArd Biesheuvel Enable this option to switch to a different method that uses a 1450189af465SArd Biesheuvel different canary value for each task. 1451189af465SArd Biesheuvel 14521da177e4SLinus Torvaldsendmenu 14531da177e4SLinus Torvalds 14541da177e4SLinus Torvaldsmenu "Boot options" 14551da177e4SLinus Torvalds 14569eb8f674SGrant Likelyconfig USE_OF 14579eb8f674SGrant Likely bool "Flattened Device Tree support" 1458b1b3f49cSRussell King select IRQ_DOMAIN 14599eb8f674SGrant Likely select OF 14609eb8f674SGrant Likely help 14619eb8f674SGrant Likely Include support for flattened device tree machine descriptions. 14629eb8f674SGrant Likely 1463bd51e2f5SNicolas Pitreconfig ATAGS 146496a4ce30SArnd Bergmann bool "Support for the traditional ATAGS boot data passing" 1465bd51e2f5SNicolas Pitre default y 1466bd51e2f5SNicolas Pitre help 1467bd51e2f5SNicolas Pitre This is the traditional way of passing data to the kernel at boot 1468bd51e2f5SNicolas Pitre time. If you are solely relying on the flattened device tree (or 1469bd51e2f5SNicolas Pitre the ARM_ATAG_DTB_COMPAT option) then you may unselect this option 1470acb926d6SArnd Bergmann to remove ATAGS support from your kernel binary. 1471acb926d6SArnd Bergmann 1472bd51e2f5SNicolas Pitreconfig DEPRECATED_PARAM_STRUCT 1473bd51e2f5SNicolas Pitre bool "Provide old way to pass kernel parameters" 1474bd51e2f5SNicolas Pitre depends on ATAGS 1475bd51e2f5SNicolas Pitre help 1476bd51e2f5SNicolas Pitre This was deprecated in 2001 and announced to live on for 5 years. 1477bd51e2f5SNicolas Pitre Some old boot loaders still use this way. 1478bd51e2f5SNicolas Pitre 14791da177e4SLinus Torvalds# Compressed boot loader in ROM. Yes, we really want to ask about 14801da177e4SLinus Torvalds# TEXT and BSS so we preserve their values in the config files. 14811da177e4SLinus Torvaldsconfig ZBOOT_ROM_TEXT 14821da177e4SLinus Torvalds hex "Compressed ROM boot loader base address" 148339c3e304SChris Packham default 0x0 14841da177e4SLinus Torvalds help 14851da177e4SLinus Torvalds The physical address at which the ROM-able zImage is to be 14861da177e4SLinus Torvalds placed in the target. Platforms which normally make use of 14871da177e4SLinus Torvalds ROM-able zImage formats normally set this to a suitable 14881da177e4SLinus Torvalds value in their defconfig file. 14891da177e4SLinus Torvalds 14901da177e4SLinus Torvalds If ZBOOT_ROM is not enabled, this has no effect. 14911da177e4SLinus Torvalds 14921da177e4SLinus Torvaldsconfig ZBOOT_ROM_BSS 14931da177e4SLinus Torvalds hex "Compressed ROM boot loader BSS address" 149439c3e304SChris Packham default 0x0 14951da177e4SLinus Torvalds help 1496f8c440b2SDan Fandrich The base address of an area of read/write memory in the target 1497f8c440b2SDan Fandrich for the ROM-able zImage which must be available while the 1498f8c440b2SDan Fandrich decompressor is running. It must be large enough to hold the 1499f8c440b2SDan Fandrich entire decompressed kernel plus an additional 128 KiB. 1500f8c440b2SDan Fandrich Platforms which normally make use of ROM-able zImage formats 1501f8c440b2SDan Fandrich normally set this to a suitable value in their defconfig file. 15021da177e4SLinus Torvalds 15031da177e4SLinus Torvalds If ZBOOT_ROM is not enabled, this has no effect. 15041da177e4SLinus Torvalds 15051da177e4SLinus Torvaldsconfig ZBOOT_ROM 15061da177e4SLinus Torvalds bool "Compressed boot loader in ROM/flash" 15071da177e4SLinus Torvalds depends on ZBOOT_ROM_TEXT != ZBOOT_ROM_BSS 150810968131SRussell King depends on !ARM_APPENDED_DTB && !XIP_KERNEL && !AUTO_ZRELADDR 15091da177e4SLinus Torvalds help 15101da177e4SLinus Torvalds Say Y here if you intend to execute your compressed kernel image 15111da177e4SLinus Torvalds (zImage) directly from ROM or flash. If unsure, say N. 15121da177e4SLinus Torvalds 1513e2a6a3aaSJohn Bonesioconfig ARM_APPENDED_DTB 1514e2a6a3aaSJohn Bonesio bool "Use appended device tree blob to zImage (EXPERIMENTAL)" 151510968131SRussell King depends on OF 1516e2a6a3aaSJohn Bonesio help 1517e2a6a3aaSJohn Bonesio With this option, the boot code will look for a device tree binary 1518e2a6a3aaSJohn Bonesio (DTB) appended to zImage 1519e2a6a3aaSJohn Bonesio (e.g. cat zImage <filename>.dtb > zImage_w_dtb). 1520e2a6a3aaSJohn Bonesio 1521e2a6a3aaSJohn Bonesio This is meant as a backward compatibility convenience for those 1522e2a6a3aaSJohn Bonesio systems with a bootloader that can't be upgraded to accommodate 1523e2a6a3aaSJohn Bonesio the documented boot protocol using a device tree. 1524e2a6a3aaSJohn Bonesio 1525e2a6a3aaSJohn Bonesio Beware that there is very little in terms of protection against 1526e2a6a3aaSJohn Bonesio this option being confused by leftover garbage in memory that might 1527e2a6a3aaSJohn Bonesio look like a DTB header after a reboot if no actual DTB is appended 1528e2a6a3aaSJohn Bonesio to zImage. Do not leave this option active in a production kernel 1529e2a6a3aaSJohn Bonesio if you don't intend to always append a DTB. Proper passing of the 1530e2a6a3aaSJohn Bonesio location into r2 of a bootloader provided DTB is always preferable 1531e2a6a3aaSJohn Bonesio to this option. 1532e2a6a3aaSJohn Bonesio 1533b90b9a38SNicolas Pitreconfig ARM_ATAG_DTB_COMPAT 1534b90b9a38SNicolas Pitre bool "Supplement the appended DTB with traditional ATAG information" 1535b90b9a38SNicolas Pitre depends on ARM_APPENDED_DTB 1536b90b9a38SNicolas Pitre help 1537b90b9a38SNicolas Pitre Some old bootloaders can't be updated to a DTB capable one, yet 1538b90b9a38SNicolas Pitre they provide ATAGs with memory configuration, the ramdisk address, 1539b90b9a38SNicolas Pitre the kernel cmdline string, etc. Such information is dynamically 1540b90b9a38SNicolas Pitre provided by the bootloader and can't always be stored in a static 1541b90b9a38SNicolas Pitre DTB. To allow a device tree enabled kernel to be used with such 1542b90b9a38SNicolas Pitre bootloaders, this option allows zImage to extract the information 1543b90b9a38SNicolas Pitre from the ATAG list and store it at run time into the appended DTB. 1544b90b9a38SNicolas Pitre 1545d0f34a11SGenoud Richardchoice 1546d0f34a11SGenoud Richard prompt "Kernel command line type" if ARM_ATAG_DTB_COMPAT 1547d0f34a11SGenoud Richard default ARM_ATAG_DTB_COMPAT_CMDLINE_FROM_BOOTLOADER 1548d0f34a11SGenoud Richard 1549d0f34a11SGenoud Richardconfig ARM_ATAG_DTB_COMPAT_CMDLINE_FROM_BOOTLOADER 1550d0f34a11SGenoud Richard bool "Use bootloader kernel arguments if available" 1551d0f34a11SGenoud Richard help 1552d0f34a11SGenoud Richard Uses the command-line options passed by the boot loader instead of 1553d0f34a11SGenoud Richard the device tree bootargs property. If the boot loader doesn't provide 1554d0f34a11SGenoud Richard any, the device tree bootargs property will be used. 1555d0f34a11SGenoud Richard 1556d0f34a11SGenoud Richardconfig ARM_ATAG_DTB_COMPAT_CMDLINE_EXTEND 1557d0f34a11SGenoud Richard bool "Extend with bootloader kernel arguments" 1558d0f34a11SGenoud Richard help 1559d0f34a11SGenoud Richard The command-line arguments provided by the boot loader will be 1560d0f34a11SGenoud Richard appended to the the device tree bootargs property. 1561d0f34a11SGenoud Richard 1562d0f34a11SGenoud Richardendchoice 1563d0f34a11SGenoud Richard 15641da177e4SLinus Torvaldsconfig CMDLINE 15651da177e4SLinus Torvalds string "Default kernel command string" 15661da177e4SLinus Torvalds default "" 15671da177e4SLinus Torvalds help 15683e3f354bSArnd Bergmann On some architectures (e.g. CATS), there is currently no way 15691da177e4SLinus Torvalds for the boot loader to pass arguments to the kernel. For these 15701da177e4SLinus Torvalds architectures, you should supply some command-line options at build 15711da177e4SLinus Torvalds time by entering them here. As a minimum, you should specify the 15721da177e4SLinus Torvalds memory size and the root device (e.g., mem=64M root=/dev/nfs). 15731da177e4SLinus Torvalds 15744394c124SVictor Boiviechoice 15754394c124SVictor Boivie prompt "Kernel command line type" if CMDLINE != "" 15764394c124SVictor Boivie default CMDLINE_FROM_BOOTLOADER 15774394c124SVictor Boivie 15784394c124SVictor Boivieconfig CMDLINE_FROM_BOOTLOADER 15794394c124SVictor Boivie bool "Use bootloader kernel arguments if available" 15804394c124SVictor Boivie help 15814394c124SVictor Boivie Uses the command-line options passed by the boot loader. If 15824394c124SVictor Boivie the boot loader doesn't provide any, the default kernel command 15834394c124SVictor Boivie string provided in CMDLINE will be used. 15844394c124SVictor Boivie 15854394c124SVictor Boivieconfig CMDLINE_EXTEND 15864394c124SVictor Boivie bool "Extend bootloader kernel arguments" 15874394c124SVictor Boivie help 15884394c124SVictor Boivie The command-line arguments provided by the boot loader will be 15894394c124SVictor Boivie appended to the default kernel command string. 15904394c124SVictor Boivie 159192d2040dSAlexander Hollerconfig CMDLINE_FORCE 159292d2040dSAlexander Holler bool "Always use the default kernel command string" 159392d2040dSAlexander Holler help 159492d2040dSAlexander Holler Always use the default kernel command string, even if the boot 159592d2040dSAlexander Holler loader passes other arguments to the kernel. 159692d2040dSAlexander Holler This is useful if you cannot or don't want to change the 159792d2040dSAlexander Holler command-line options your boot loader passes to the kernel. 15984394c124SVictor Boivieendchoice 159992d2040dSAlexander Holler 16001da177e4SLinus Torvaldsconfig XIP_KERNEL 16011da177e4SLinus Torvalds bool "Kernel Execute-In-Place from ROM" 160210968131SRussell King depends on !ARM_LPAE && !ARCH_MULTIPLATFORM 16035408445bSArnd Bergmann depends on !ARM_PATCH_IDIV && !ARM_PATCH_PHYS_VIRT && !SMP_ON_UP 16041da177e4SLinus Torvalds help 16051da177e4SLinus Torvalds Execute-In-Place allows the kernel to run from non-volatile storage 16061da177e4SLinus Torvalds directly addressable by the CPU, such as NOR flash. This saves RAM 16071da177e4SLinus Torvalds space since the text section of the kernel is not loaded from flash 16081da177e4SLinus Torvalds to RAM. Read-write sections, such as the data section and stack, 16091da177e4SLinus Torvalds are still copied to RAM. The XIP kernel is not compressed since 16101da177e4SLinus Torvalds it has to run directly from flash, so it will take more space to 16111da177e4SLinus Torvalds store it. The flash address used to link the kernel object files, 16121da177e4SLinus Torvalds and for storing it, is configuration dependent. Therefore, if you 16131da177e4SLinus Torvalds say Y here, you must know the proper physical address where to 16141da177e4SLinus Torvalds store the kernel image depending on your own flash memory usage. 16151da177e4SLinus Torvalds 16161da177e4SLinus Torvalds Also note that the make target becomes "make xipImage" rather than 16171da177e4SLinus Torvalds "make zImage" or "make Image". The final kernel binary to put in 16181da177e4SLinus Torvalds ROM memory will be arch/arm/boot/xipImage. 16191da177e4SLinus Torvalds 16201da177e4SLinus Torvalds If unsure, say N. 16211da177e4SLinus Torvalds 16221da177e4SLinus Torvaldsconfig XIP_PHYS_ADDR 16231da177e4SLinus Torvalds hex "XIP Kernel Physical Location" 16241da177e4SLinus Torvalds depends on XIP_KERNEL 16251da177e4SLinus Torvalds default "0x00080000" 16261da177e4SLinus Torvalds help 16271da177e4SLinus Torvalds This is the physical address in your flash memory the kernel will 16281da177e4SLinus Torvalds be linked for and stored to. This address is dependent on your 16291da177e4SLinus Torvalds own flash usage. 16301da177e4SLinus Torvalds 1631ca8b5d97SNicolas Pitreconfig XIP_DEFLATED_DATA 1632ca8b5d97SNicolas Pitre bool "Store kernel .data section compressed in ROM" 1633ca8b5d97SNicolas Pitre depends on XIP_KERNEL 1634ca8b5d97SNicolas Pitre select ZLIB_INFLATE 1635ca8b5d97SNicolas Pitre help 1636ca8b5d97SNicolas Pitre Before the kernel is actually executed, its .data section has to be 1637ca8b5d97SNicolas Pitre copied to RAM from ROM. This option allows for storing that data 1638ca8b5d97SNicolas Pitre in compressed form and decompressed to RAM rather than merely being 1639ca8b5d97SNicolas Pitre copied, saving some precious ROM space. A possible drawback is a 1640ca8b5d97SNicolas Pitre slightly longer boot delay. 1641ca8b5d97SNicolas Pitre 1642c587e4a6SRichard Purdieconfig KEXEC 1643c587e4a6SRichard Purdie bool "Kexec system call (EXPERIMENTAL)" 164419ab428fSStephen Warren depends on (!SMP || PM_SLEEP_SMP) 164576950f71SVincenzo Frascino depends on MMU 16462965faa5SDave Young select KEXEC_CORE 1647c587e4a6SRichard Purdie help 1648c587e4a6SRichard Purdie kexec is a system call that implements the ability to shutdown your 1649c587e4a6SRichard Purdie current kernel, and to start another kernel. It is like a reboot 165001dd2fbfSMatt LaPlante but it is independent of the system firmware. And like a reboot 1651c587e4a6SRichard Purdie you can start any kernel with it, not just Linux. 1652c587e4a6SRichard Purdie 1653c587e4a6SRichard Purdie It is an ongoing process to be certain the hardware in a machine 1654c587e4a6SRichard Purdie is properly shutdown, so do not be surprised if this code does not 1655bf220695SGeert Uytterhoeven initially work for you. 1656c587e4a6SRichard Purdie 16574cd9d6f7SRichard Purdieconfig ATAGS_PROC 16584cd9d6f7SRichard Purdie bool "Export atags in procfs" 1659bd51e2f5SNicolas Pitre depends on ATAGS && KEXEC 1660b98d7291SUli Luckas default y 16614cd9d6f7SRichard Purdie help 16624cd9d6f7SRichard Purdie Should the atags used to boot the kernel be exported in an "atags" 16634cd9d6f7SRichard Purdie file in procfs. Useful with kexec. 16644cd9d6f7SRichard Purdie 1665cb5d39b3SMika Westerbergconfig CRASH_DUMP 1666cb5d39b3SMika Westerberg bool "Build kdump crash kernel (EXPERIMENTAL)" 1667cb5d39b3SMika Westerberg help 1668cb5d39b3SMika Westerberg Generate crash dump after being started by kexec. This should 1669cb5d39b3SMika Westerberg be normally only set in special crash dump kernels which are 1670cb5d39b3SMika Westerberg loaded in the main kernel with kexec-tools into a specially 1671cb5d39b3SMika Westerberg reserved region and then later executed after a crash by 1672cb5d39b3SMika Westerberg kdump/kexec. The crash dump kernel must be compiled to a 1673cb5d39b3SMika Westerberg memory address not used by the main kernel 1674cb5d39b3SMika Westerberg 1675330d4810SMauro Carvalho Chehab For more details see Documentation/admin-guide/kdump/kdump.rst 1676cb5d39b3SMika Westerberg 1677e69edc79SEric Miaoconfig AUTO_ZRELADDR 16786fd09c9aSArnd Bergmann bool "Auto calculation of the decompressed kernel image address" if !ARCH_MULTIPLATFORM 16796fd09c9aSArnd Bergmann default !(ARCH_FOOTBRIDGE || ARCH_RPC || ARCH_SA1100) 1680e69edc79SEric Miao help 1681e69edc79SEric Miao ZRELADDR is the physical address where the decompressed kernel 1682e69edc79SEric Miao image will be placed. If AUTO_ZRELADDR is selected, the address 16830673cb38SGeert Uytterhoeven will be determined at run-time, either by masking the current IP 16840673cb38SGeert Uytterhoeven with 0xf8000000, or, if invalid, from the DTB passed in r2. 16850673cb38SGeert Uytterhoeven This assumes the zImage being placed in the first 128MB from 16860673cb38SGeert Uytterhoeven start of memory. 1687e69edc79SEric Miao 168881a0bc39SRoy Franzconfig EFI_STUB 168981a0bc39SRoy Franz bool 169081a0bc39SRoy Franz 169181a0bc39SRoy Franzconfig EFI 169281a0bc39SRoy Franz bool "UEFI runtime support" 169381a0bc39SRoy Franz depends on OF && !CPU_BIG_ENDIAN && MMU && AUTO_ZRELADDR && !XIP_KERNEL 169481a0bc39SRoy Franz select UCS2_STRING 169581a0bc39SRoy Franz select EFI_PARAMS_FROM_FDT 169681a0bc39SRoy Franz select EFI_STUB 16972e0eb483SAtish Patra select EFI_GENERIC_STUB 169881a0bc39SRoy Franz select EFI_RUNTIME_WRAPPERS 1699a7f7f624SMasahiro Yamada help 170081a0bc39SRoy Franz This option provides support for runtime services provided 170181a0bc39SRoy Franz by UEFI firmware (such as non-volatile variables, realtime 170281a0bc39SRoy Franz clock, and platform reset). A UEFI stub is also provided to 170381a0bc39SRoy Franz allow the kernel to be booted as an EFI application. This 170481a0bc39SRoy Franz is only useful for kernels that may run on systems that have 170581a0bc39SRoy Franz UEFI firmware. 170681a0bc39SRoy Franz 1707bb817befSArd Biesheuvelconfig DMI 1708bb817befSArd Biesheuvel bool "Enable support for SMBIOS (DMI) tables" 1709bb817befSArd Biesheuvel depends on EFI 1710bb817befSArd Biesheuvel default y 1711bb817befSArd Biesheuvel help 1712bb817befSArd Biesheuvel This enables SMBIOS/DMI feature for systems. 1713bb817befSArd Biesheuvel 1714bb817befSArd Biesheuvel This option is only useful on systems that have UEFI firmware. 1715bb817befSArd Biesheuvel However, even with this option, the resultant kernel should 1716bb817befSArd Biesheuvel continue to boot on existing non-UEFI platforms. 1717bb817befSArd Biesheuvel 1718bb817befSArd Biesheuvel NOTE: This does *NOT* enable or encourage the use of DMI quirks, 1719bb817befSArd Biesheuvel i.e., the the practice of identifying the platform via DMI to 1720bb817befSArd Biesheuvel decide whether certain workarounds for buggy hardware and/or 1721bb817befSArd Biesheuvel firmware need to be enabled. This would require the DMI subsystem 1722bb817befSArd Biesheuvel to be enabled much earlier than we do on ARM, which is non-trivial. 1723bb817befSArd Biesheuvel 17241da177e4SLinus Torvaldsendmenu 17251da177e4SLinus Torvalds 1726ac9d7efcSRussell Kingmenu "CPU Power Management" 17271da177e4SLinus Torvalds 17281da177e4SLinus Torvaldssource "drivers/cpufreq/Kconfig" 17291da177e4SLinus Torvalds 1730ac9d7efcSRussell Kingsource "drivers/cpuidle/Kconfig" 1731ac9d7efcSRussell King 1732ac9d7efcSRussell Kingendmenu 1733ac9d7efcSRussell King 17341da177e4SLinus Torvaldsmenu "Floating point emulation" 17351da177e4SLinus Torvalds 17361da177e4SLinus Torvaldscomment "At least one emulation must be selected" 17371da177e4SLinus Torvalds 17381da177e4SLinus Torvaldsconfig FPE_NWFPE 17391da177e4SLinus Torvalds bool "NWFPE math emulation" 1740593c252aSDave Martin depends on (!AEABI || OABI_COMPAT) && !THUMB2_KERNEL 1741a7f7f624SMasahiro Yamada help 17421da177e4SLinus Torvalds Say Y to include the NWFPE floating point emulator in the kernel. 17431da177e4SLinus Torvalds This is necessary to run most binaries. Linux does not currently 17441da177e4SLinus Torvalds support floating point hardware so you need to say Y here even if 17451da177e4SLinus Torvalds your machine has an FPA or floating point co-processor podule. 17461da177e4SLinus Torvalds 17471da177e4SLinus Torvalds You may say N here if you are going to load the Acorn FPEmulator 17481da177e4SLinus Torvalds early in the bootup. 17491da177e4SLinus Torvalds 17501da177e4SLinus Torvaldsconfig FPE_NWFPE_XP 17511da177e4SLinus Torvalds bool "Support extended precision" 1752bedf142bSLennert Buytenhek depends on FPE_NWFPE 17531da177e4SLinus Torvalds help 17541da177e4SLinus Torvalds Say Y to include 80-bit support in the kernel floating-point 17551da177e4SLinus Torvalds emulator. Otherwise, only 32 and 64-bit support is compiled in. 17561da177e4SLinus Torvalds Note that gcc does not generate 80-bit operations by default, 17571da177e4SLinus Torvalds so in most cases this option only enlarges the size of the 17581da177e4SLinus Torvalds floating point emulator without any good reason. 17591da177e4SLinus Torvalds 17601da177e4SLinus Torvalds You almost surely want to say N here. 17611da177e4SLinus Torvalds 17621da177e4SLinus Torvaldsconfig FPE_FASTFPE 17631da177e4SLinus Torvalds bool "FastFPE math emulation (EXPERIMENTAL)" 1764d6f94fa0SKees Cook depends on (!AEABI || OABI_COMPAT) && !CPU_32v3 1765a7f7f624SMasahiro Yamada help 17661da177e4SLinus Torvalds Say Y here to include the FAST floating point emulator in the kernel. 17671da177e4SLinus Torvalds This is an experimental much faster emulator which now also has full 17681da177e4SLinus Torvalds precision for the mantissa. It does not support any exceptions. 17691da177e4SLinus Torvalds It is very simple, and approximately 3-6 times faster than NWFPE. 17701da177e4SLinus Torvalds 17711da177e4SLinus Torvalds It should be sufficient for most programs. It may be not suitable 17721da177e4SLinus Torvalds for scientific calculations, but you have to check this for yourself. 17731da177e4SLinus Torvalds If you do not feel you need a faster FP emulation you should better 17741da177e4SLinus Torvalds choose NWFPE. 17751da177e4SLinus Torvalds 17761da177e4SLinus Torvaldsconfig VFP 17771da177e4SLinus Torvalds bool "VFP-format floating point maths" 1778e399b1a4SRussell King depends on CPU_V6 || CPU_V6K || CPU_ARM926T || CPU_V7 || CPU_FEROCEON 17791da177e4SLinus Torvalds help 17801da177e4SLinus Torvalds Say Y to include VFP support code in the kernel. This is needed 17811da177e4SLinus Torvalds if your hardware includes a VFP unit. 17821da177e4SLinus Torvalds 1783*e318b36eSJonathan Corbet Please see <file:Documentation/arch/arm/vfp/release-notes.rst> for 17841da177e4SLinus Torvalds release notes and additional status information. 17851da177e4SLinus Torvalds 17861da177e4SLinus Torvalds Say N if your target does not have VFP hardware. 17871da177e4SLinus Torvalds 178825ebee02SCatalin Marinasconfig VFPv3 178925ebee02SCatalin Marinas bool 179025ebee02SCatalin Marinas depends on VFP 179125ebee02SCatalin Marinas default y if CPU_V7 179225ebee02SCatalin Marinas 1793b5872db4SCatalin Marinasconfig NEON 1794b5872db4SCatalin Marinas bool "Advanced SIMD (NEON) Extension support" 1795b5872db4SCatalin Marinas depends on VFPv3 && CPU_V7 1796b5872db4SCatalin Marinas help 1797b5872db4SCatalin Marinas Say Y to include support code for NEON, the ARMv7 Advanced SIMD 1798b5872db4SCatalin Marinas Extension. 1799b5872db4SCatalin Marinas 180073c132c1SArd Biesheuvelconfig KERNEL_MODE_NEON 180173c132c1SArd Biesheuvel bool "Support for NEON in kernel mode" 1802c4a30c3bSRussell King depends on NEON && AEABI 180373c132c1SArd Biesheuvel help 180473c132c1SArd Biesheuvel Say Y to include support for NEON in kernel mode. 180573c132c1SArd Biesheuvel 18061da177e4SLinus Torvaldsendmenu 18071da177e4SLinus Torvalds 18081da177e4SLinus Torvaldsmenu "Power management options" 18091da177e4SLinus Torvalds 1810eceab4acSRussell Kingsource "kernel/power/Kconfig" 18111da177e4SLinus Torvalds 1812f4cb5700SJohannes Bergconfig ARCH_SUSPEND_POSSIBLE 181319a0519dSEzequiel Garcia depends on CPU_ARM920T || CPU_ARM926T || CPU_FEROCEON || CPU_SA1100 || \ 1814f0d75153SUwe Kleine-König CPU_V6 || CPU_V6K || CPU_V7 || CPU_V7M || CPU_XSC3 || CPU_XSCALE || CPU_MOHAWK 1815f4cb5700SJohannes Berg def_bool y 1816f4cb5700SJohannes Berg 181715e0d9e3SArnd Bergmannconfig ARM_CPU_SUSPEND 18188b6f2499SLorenzo Pieralisi def_bool PM_SLEEP || BL_SWITCHER || ARM_PSCI_FW 18191b9bdf5cSLorenzo Pieralisi depends on ARCH_SUSPEND_POSSIBLE 182015e0d9e3SArnd Bergmann 1821603fb42aSSebastian Capellaconfig ARCH_HIBERNATION_POSSIBLE 1822603fb42aSSebastian Capella bool 1823603fb42aSSebastian Capella depends on MMU 1824603fb42aSSebastian Capella default y if ARCH_SUSPEND_POSSIBLE 1825603fb42aSSebastian Capella 18261da177e4SLinus Torvaldsendmenu 18271da177e4SLinus Torvalds 18282cbd1cc3SStefan Agnersource "arch/arm/Kconfig.assembler" 1829