linux/arch/arm/Kconfig
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   1# SPDX-License-Identifier: GPL-2.0
   2config ARM
   3        bool
   4        default y
   5        select ARCH_32BIT_OFF_T
   6        select ARCH_HAS_BINFMT_FLAT
   7        select ARCH_HAS_DEBUG_VIRTUAL if MMU
   8        select ARCH_HAS_DMA_WRITE_COMBINE if !ARM_DMA_MEM_BUFFERABLE
   9        select ARCH_HAS_ELF_RANDOMIZE
  10        select ARCH_HAS_FORTIFY_SOURCE
  11        select ARCH_HAS_KEEPINITRD
  12        select ARCH_HAS_KCOV
  13        select ARCH_HAS_MEMBARRIER_SYNC_CORE
  14        select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
  15        select ARCH_HAS_PTE_SPECIAL if ARM_LPAE
  16        select ARCH_HAS_PHYS_TO_DMA
  17        select ARCH_HAS_SETUP_DMA_OPS
  18        select ARCH_HAS_SET_MEMORY
  19        select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL
  20        select ARCH_HAS_STRICT_MODULE_RWX if MMU
  21        select ARCH_HAS_SYNC_DMA_FOR_DEVICE if SWIOTLB || !MMU
  22        select ARCH_HAS_SYNC_DMA_FOR_CPU if SWIOTLB || !MMU
  23        select ARCH_HAS_TEARDOWN_DMA_OPS if MMU
  24        select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
  25        select ARCH_HAVE_CUSTOM_GPIO_H
  26        select ARCH_HAVE_NMI_SAFE_CMPXCHG if CPU_V7 || CPU_V7M || CPU_V6K
  27        select ARCH_HAS_GCOV_PROFILE_ALL
  28        select ARCH_KEEP_MEMBLOCK
  29        select ARCH_MIGHT_HAVE_PC_PARPORT
  30        select ARCH_NO_SG_CHAIN if !ARM_HAS_SG_CHAIN
  31        select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX
  32        select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT if CPU_V7
  33        select ARCH_SUPPORTS_ATOMIC_RMW
  34        select ARCH_SUPPORTS_HUGETLBFS if ARM_LPAE
  35        select ARCH_USE_BUILTIN_BSWAP
  36        select ARCH_USE_CMPXCHG_LOCKREF
  37        select ARCH_USE_MEMTEST
  38        select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
  39        select ARCH_WANT_IPC_PARSE_VERSION
  40        select ARCH_WANT_LD_ORPHAN_WARN
  41        select BINFMT_FLAT_ARGVP_ENVP_ON_STACK
  42        select BUILDTIME_TABLE_SORT if MMU
  43        select CLONE_BACKWARDS
  44        select CPU_PM if SUSPEND || CPU_IDLE
  45        select DCACHE_WORD_ACCESS if HAVE_EFFICIENT_UNALIGNED_ACCESS
  46        select DMA_DECLARE_COHERENT
  47        select DMA_GLOBAL_POOL if !MMU
  48        select DMA_OPS
  49        select DMA_REMAP if MMU
  50        select EDAC_SUPPORT
  51        select EDAC_ATOMIC_SCRUB
  52        select GENERIC_ALLOCATOR
  53        select GENERIC_ARCH_TOPOLOGY if ARM_CPU_TOPOLOGY
  54        select GENERIC_ATOMIC64 if CPU_V7M || CPU_V6 || !CPU_32v6K || !AEABI
  55        select GENERIC_CLOCKEVENTS_BROADCAST if SMP
  56        select GENERIC_IRQ_IPI if SMP
  57        select GENERIC_CPU_AUTOPROBE
  58        select GENERIC_EARLY_IOREMAP
  59        select GENERIC_IDLE_POLL_SETUP
  60        select GENERIC_IRQ_PROBE
  61        select GENERIC_IRQ_SHOW
  62        select GENERIC_IRQ_SHOW_LEVEL
  63        select GENERIC_LIB_DEVMEM_IS_ALLOWED
  64        select GENERIC_PCI_IOMAP
  65        select GENERIC_SCHED_CLOCK
  66        select GENERIC_SMP_IDLE_THREAD
  67        select HANDLE_DOMAIN_IRQ
  68        select HARDIRQS_SW_RESEND
  69        select HAVE_ARCH_AUDITSYSCALL if AEABI && !OABI_COMPAT
  70        select HAVE_ARCH_BITREVERSE if (CPU_32v7M || CPU_32v7) && !CPU_32v6
  71        select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL && !CPU_ENDIAN_BE32 && MMU
  72        select HAVE_ARCH_KGDB if !CPU_ENDIAN_BE32 && MMU
  73        select HAVE_ARCH_KASAN if MMU && !XIP_KERNEL
  74        select HAVE_ARCH_MMAP_RND_BITS if MMU
  75        select HAVE_ARCH_PFN_VALID
  76        select HAVE_ARCH_SECCOMP
  77        select HAVE_ARCH_SECCOMP_FILTER if AEABI && !OABI_COMPAT
  78        select HAVE_ARCH_THREAD_STRUCT_WHITELIST
  79        select HAVE_ARCH_TRACEHOOK
  80        select HAVE_ARCH_TRANSPARENT_HUGEPAGE if ARM_LPAE
  81        select HAVE_ARM_SMCCC if CPU_V7
  82        select HAVE_EBPF_JIT if !CPU_ENDIAN_BE32
  83        select HAVE_CONTEXT_TRACKING
  84        select HAVE_C_RECORDMCOUNT
  85        select HAVE_DEBUG_KMEMLEAK if !XIP_KERNEL
  86        select HAVE_DMA_CONTIGUOUS if MMU
  87        select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && !CPU_ENDIAN_BE32 && MMU
  88        select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
  89        select HAVE_EFFICIENT_UNALIGNED_ACCESS if (CPU_V6 || CPU_V6K || CPU_V7) && MMU
  90        select HAVE_EXIT_THREAD
  91        select HAVE_FAST_GUP if ARM_LPAE
  92        select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
  93        select HAVE_FUNCTION_GRAPH_TRACER if !THUMB2_KERNEL && !CC_IS_CLANG
  94        select HAVE_FUNCTION_TRACER if !XIP_KERNEL
  95        select HAVE_FUTEX_CMPXCHG if FUTEX
  96        select HAVE_GCC_PLUGINS
  97        select HAVE_HW_BREAKPOINT if PERF_EVENTS && (CPU_V6 || CPU_V6K || CPU_V7)
  98        select HAVE_IRQ_TIME_ACCOUNTING
  99        select HAVE_KERNEL_GZIP
 100        select HAVE_KERNEL_LZ4
 101        select HAVE_KERNEL_LZMA
 102        select HAVE_KERNEL_LZO
 103        select HAVE_KERNEL_XZ
 104        select HAVE_KPROBES if !XIP_KERNEL && !CPU_ENDIAN_BE32 && !CPU_V7M
 105        select HAVE_KRETPROBES if HAVE_KPROBES
 106        select HAVE_MOD_ARCH_SPECIFIC
 107        select HAVE_NMI
 108        select HAVE_OPTPROBES if !THUMB2_KERNEL
 109        select HAVE_PERF_EVENTS
 110        select HAVE_PERF_REGS
 111        select HAVE_PERF_USER_STACK_DUMP
 112        select MMU_GATHER_RCU_TABLE_FREE if SMP && ARM_LPAE
 113        select HAVE_REGS_AND_STACK_ACCESS_API
 114        select HAVE_RSEQ
 115        select HAVE_STACKPROTECTOR
 116        select HAVE_SYSCALL_TRACEPOINTS
 117        select HAVE_UID16
 118        select HAVE_VIRT_CPU_ACCOUNTING_GEN
 119        select IRQ_FORCED_THREADING
 120        select MODULES_USE_ELF_REL
 121        select NEED_DMA_MAP_STATE
 122        select OF_EARLY_FLATTREE if OF
 123        select OLD_SIGACTION
 124        select OLD_SIGSUSPEND3
 125        select PCI_SYSCALL if PCI
 126        select PERF_USE_VMALLOC
 127        select RTC_LIB
 128        select SYS_SUPPORTS_APM_EMULATION
 129        select TRACE_IRQFLAGS_SUPPORT if !CPU_V7M
 130        # Above selects are sorted alphabetically; please add new ones
 131        # according to that.  Thanks.
 132        help
 133          The ARM series is a line of low-power-consumption RISC chip designs
 134          licensed by ARM Ltd and targeted at embedded applications and
 135          handhelds such as the Compaq IPAQ.  ARM-based PCs are no longer
 136          manufactured, but legacy ARM-based PC hardware remains popular in
 137          Europe.  There is an ARM Linux project with a web page at
 138          <http://www.arm.linux.org.uk/>.
 139
 140config ARM_HAS_SG_CHAIN
 141        bool
 142
 143config ARM_DMA_USE_IOMMU
 144        bool
 145        select ARM_HAS_SG_CHAIN
 146        select NEED_SG_DMA_LENGTH
 147
 148if ARM_DMA_USE_IOMMU
 149
 150config ARM_DMA_IOMMU_ALIGNMENT
 151        int "Maximum PAGE_SIZE order of alignment for DMA IOMMU buffers"
 152        range 4 9
 153        default 8
 154        help
 155          DMA mapping framework by default aligns all buffers to the smallest
 156          PAGE_SIZE order which is greater than or equal to the requested buffer
 157          size. This works well for buffers up to a few hundreds kilobytes, but
 158          for larger buffers it just a waste of address space. Drivers which has
 159          relatively small addressing window (like 64Mib) might run out of
 160          virtual space with just a few allocations.
 161
 162          With this parameter you can specify the maximum PAGE_SIZE order for
 163          DMA IOMMU buffers. Larger buffers will be aligned only to this
 164          specified order. The order is expressed as a power of two multiplied
 165          by the PAGE_SIZE.
 166
 167endif
 168
 169config SYS_SUPPORTS_APM_EMULATION
 170        bool
 171
 172config HAVE_TCM
 173        bool
 174        select GENERIC_ALLOCATOR
 175
 176config HAVE_PROC_CPU
 177        bool
 178
 179config NO_IOPORT_MAP
 180        bool
 181
 182config SBUS
 183        bool
 184
 185config STACKTRACE_SUPPORT
 186        bool
 187        default y
 188
 189config LOCKDEP_SUPPORT
 190        bool
 191        default y
 192
 193config ARCH_HAS_ILOG2_U32
 194        bool
 195
 196config ARCH_HAS_ILOG2_U64
 197        bool
 198
 199config ARCH_HAS_BANDGAP
 200        bool
 201
 202config FIX_EARLYCON_MEM
 203        def_bool y if MMU
 204
 205config GENERIC_HWEIGHT
 206        bool
 207        default y
 208
 209config GENERIC_CALIBRATE_DELAY
 210        bool
 211        default y
 212
 213config ARCH_MAY_HAVE_PC_FDC
 214        bool
 215
 216config ARCH_SUPPORTS_UPROBES
 217        def_bool y
 218
 219config ARCH_HAS_DMA_SET_COHERENT_MASK
 220        bool
 221
 222config GENERIC_ISA_DMA
 223        bool
 224
 225config FIQ
 226        bool
 227
 228config NEED_RET_TO_USER
 229        bool
 230
 231config ARCH_MTD_XIP
 232        bool
 233
 234config ARM_PATCH_PHYS_VIRT
 235        bool "Patch physical to virtual translations at runtime" if EMBEDDED
 236        default y
 237        depends on !XIP_KERNEL && MMU
 238        help
 239          Patch phys-to-virt and virt-to-phys translation functions at
 240          boot and module load time according to the position of the
 241          kernel in system memory.
 242
 243          This can only be used with non-XIP MMU kernels where the base
 244          of physical memory is at a 2 MiB boundary.
 245
 246          Only disable this option if you know that you do not require
 247          this feature (eg, building a kernel for a single machine) and
 248          you need to shrink the kernel to the minimal size.
 249
 250config NEED_MACH_IO_H
 251        bool
 252        help
 253          Select this when mach/io.h is required to provide special
 254          definitions for this platform.  The need for mach/io.h should
 255          be avoided when possible.
 256
 257config NEED_MACH_MEMORY_H
 258        bool
 259        help
 260          Select this when mach/memory.h is required to provide special
 261          definitions for this platform.  The need for mach/memory.h should
 262          be avoided when possible.
 263
 264config PHYS_OFFSET
 265        hex "Physical address of main memory" if MMU
 266        depends on !ARM_PATCH_PHYS_VIRT
 267        default DRAM_BASE if !MMU
 268        default 0x00000000 if ARCH_FOOTBRIDGE
 269        default 0x10000000 if ARCH_OMAP1 || ARCH_RPC
 270        default 0x20000000 if ARCH_S5PV210
 271        default 0xc0000000 if ARCH_SA1100
 272        help
 273          Please provide the physical address corresponding to the
 274          location of main memory in your system.
 275
 276config GENERIC_BUG
 277        def_bool y
 278        depends on BUG
 279
 280config PGTABLE_LEVELS
 281        int
 282        default 3 if ARM_LPAE
 283        default 2
 284
 285menu "System Type"
 286
 287config MMU
 288        bool "MMU-based Paged Memory Management Support"
 289        default y
 290        help
 291          Select if you want MMU-based virtualised addressing space
 292          support by paged memory management. If unsure, say 'Y'.
 293
 294config ARCH_MMAP_RND_BITS_MIN
 295        default 8
 296
 297config ARCH_MMAP_RND_BITS_MAX
 298        default 14 if PAGE_OFFSET=0x40000000
 299        default 15 if PAGE_OFFSET=0x80000000
 300        default 16
 301
 302#
 303# The "ARM system type" choice list is ordered alphabetically by option
 304# text.  Please add new entries in the option alphabetic order.
 305#
 306choice
 307        prompt "ARM system type"
 308        default ARM_SINGLE_ARMV7M if !MMU
 309        default ARCH_MULTIPLATFORM if MMU
 310
 311config ARCH_MULTIPLATFORM
 312        bool "Allow multiple platforms to be selected"
 313        depends on MMU
 314        select ARCH_FLATMEM_ENABLE
 315        select ARCH_SPARSEMEM_ENABLE
 316        select ARCH_SELECT_MEMORY_MODEL
 317        select ARM_HAS_SG_CHAIN
 318        select ARM_PATCH_PHYS_VIRT
 319        select AUTO_ZRELADDR
 320        select TIMER_OF
 321        select COMMON_CLK
 322        select GENERIC_IRQ_MULTI_HANDLER
 323        select HAVE_PCI
 324        select PCI_DOMAINS_GENERIC if PCI
 325        select SPARSE_IRQ
 326        select USE_OF
 327
 328config ARM_SINGLE_ARMV7M
 329        bool "ARMv7-M based platforms (Cortex-M0/M3/M4)"
 330        depends on !MMU
 331        select ARM_NVIC
 332        select AUTO_ZRELADDR
 333        select TIMER_OF
 334        select COMMON_CLK
 335        select CPU_V7M
 336        select NO_IOPORT_MAP
 337        select SPARSE_IRQ
 338        select USE_OF
 339
 340config ARCH_EP93XX
 341        bool "EP93xx-based"
 342        select ARCH_SPARSEMEM_ENABLE
 343        select ARM_AMBA
 344        imply ARM_PATCH_PHYS_VIRT
 345        select ARM_VIC
 346        select GENERIC_IRQ_MULTI_HANDLER
 347        select AUTO_ZRELADDR
 348        select CLKSRC_MMIO
 349        select CPU_ARM920T
 350        select GPIOLIB
 351        select HAVE_LEGACY_CLK
 352        help
 353          This enables support for the Cirrus EP93xx series of CPUs.
 354
 355config ARCH_FOOTBRIDGE
 356        bool "FootBridge"
 357        select CPU_SA110
 358        select FOOTBRIDGE
 359        select NEED_MACH_IO_H if !MMU
 360        select NEED_MACH_MEMORY_H
 361        help
 362          Support for systems based on the DC21285 companion chip
 363          ("FootBridge"), such as the Simtec CATS and the Rebel NetWinder.
 364
 365config ARCH_IOP32X
 366        bool "IOP32x-based"
 367        depends on MMU
 368        select CPU_XSCALE
 369        select GPIO_IOP
 370        select GPIOLIB
 371        select NEED_RET_TO_USER
 372        select FORCE_PCI
 373        select PLAT_IOP
 374        help
 375          Support for Intel's 80219 and IOP32X (XScale) family of
 376          processors.
 377
 378config ARCH_IXP4XX
 379        bool "IXP4xx-based"
 380        depends on MMU
 381        select ARCH_HAS_DMA_SET_COHERENT_MASK
 382        select ARCH_SUPPORTS_BIG_ENDIAN
 383        select CPU_XSCALE
 384        select DMABOUNCE if PCI
 385        select GENERIC_IRQ_MULTI_HANDLER
 386        select GPIO_IXP4XX
 387        select GPIOLIB
 388        select HAVE_PCI
 389        select IXP4XX_IRQ
 390        select IXP4XX_TIMER
 391        # With the new PCI driver this is not needed
 392        select NEED_MACH_IO_H if IXP4XX_PCI_LEGACY
 393        select USB_EHCI_BIG_ENDIAN_DESC
 394        select USB_EHCI_BIG_ENDIAN_MMIO
 395        help
 396          Support for Intel's IXP4XX (XScale) family of processors.
 397
 398config ARCH_DOVE
 399        bool "Marvell Dove"
 400        select CPU_PJ4
 401        select GENERIC_IRQ_MULTI_HANDLER
 402        select GPIOLIB
 403        select HAVE_PCI
 404        select MVEBU_MBUS
 405        select PINCTRL
 406        select PINCTRL_DOVE
 407        select PLAT_ORION_LEGACY
 408        select SPARSE_IRQ
 409        select PM_GENERIC_DOMAINS if PM
 410        help
 411          Support for the Marvell Dove SoC 88AP510
 412
 413config ARCH_PXA
 414        bool "PXA2xx/PXA3xx-based"
 415        depends on MMU
 416        select ARCH_MTD_XIP
 417        select ARM_CPU_SUSPEND if PM
 418        select AUTO_ZRELADDR
 419        select COMMON_CLK
 420        select CLKSRC_PXA
 421        select CLKSRC_MMIO
 422        select TIMER_OF
 423        select CPU_XSCALE if !CPU_XSC3
 424        select GENERIC_IRQ_MULTI_HANDLER
 425        select GPIO_PXA
 426        select GPIOLIB
 427        select IRQ_DOMAIN
 428        select PLAT_PXA
 429        select SPARSE_IRQ
 430        help
 431          Support for Intel/Marvell's PXA2xx/PXA3xx processor line.
 432
 433config ARCH_RPC
 434        bool "RiscPC"
 435        depends on MMU
 436        select ARCH_ACORN
 437        select ARCH_MAY_HAVE_PC_FDC
 438        select ARCH_SPARSEMEM_ENABLE
 439        select ARM_HAS_SG_CHAIN
 440        select CPU_SA110
 441        select FIQ
 442        select HAVE_PATA_PLATFORM
 443        select ISA_DMA_API
 444        select LEGACY_TIMER_TICK
 445        select NEED_MACH_IO_H
 446        select NEED_MACH_MEMORY_H
 447        select NO_IOPORT_MAP
 448        help
 449          On the Acorn Risc-PC, Linux can support the internal IDE disk and
 450          CD-ROM interface, serial and parallel port, and the floppy drive.
 451
 452config ARCH_SA1100
 453        bool "SA1100-based"
 454        select ARCH_MTD_XIP
 455        select ARCH_SPARSEMEM_ENABLE
 456        select CLKSRC_MMIO
 457        select CLKSRC_PXA
 458        select TIMER_OF if OF
 459        select COMMON_CLK
 460        select CPU_FREQ
 461        select CPU_SA1100
 462        select GENERIC_IRQ_MULTI_HANDLER
 463        select GPIOLIB
 464        select IRQ_DOMAIN
 465        select ISA
 466        select NEED_MACH_MEMORY_H
 467        select SPARSE_IRQ
 468        help
 469          Support for StrongARM 11x0 based boards.
 470
 471config ARCH_S3C24XX
 472        bool "Samsung S3C24XX SoCs"
 473        select ATAGS
 474        select CLKSRC_SAMSUNG_PWM
 475        select GPIO_SAMSUNG
 476        select GPIOLIB
 477        select GENERIC_IRQ_MULTI_HANDLER
 478        select HAVE_S3C2410_I2C if I2C
 479        select HAVE_S3C_RTC if RTC_CLASS
 480        select NEED_MACH_IO_H
 481        select S3C2410_WATCHDOG
 482        select SAMSUNG_ATAGS
 483        select USE_OF
 484        select WATCHDOG
 485        help
 486          Samsung S3C2410, S3C2412, S3C2413, S3C2416, S3C2440, S3C2442, S3C2443
 487          and S3C2450 SoCs based systems, such as the Simtec Electronics BAST
 488          (<http://www.simtec.co.uk/products/EB110ITX/>), the IPAQ 1940 or the
 489          Samsung SMDK2410 development board (and derivatives).
 490
 491config ARCH_OMAP1
 492        bool "TI OMAP1"
 493        depends on MMU
 494        select ARCH_OMAP
 495        select CLKSRC_MMIO
 496        select GENERIC_IRQ_CHIP
 497        select GENERIC_IRQ_MULTI_HANDLER
 498        select GPIOLIB
 499        select HAVE_LEGACY_CLK
 500        select IRQ_DOMAIN
 501        select NEED_MACH_IO_H if PCCARD
 502        select NEED_MACH_MEMORY_H
 503        select SPARSE_IRQ
 504        help
 505          Support for older TI OMAP1 (omap7xx, omap15xx or omap16xx)
 506
 507endchoice
 508
 509menu "Multiple platform selection"
 510        depends on ARCH_MULTIPLATFORM
 511
 512comment "CPU Core family selection"
 513
 514config ARCH_MULTI_V4
 515        bool "ARMv4 based platforms (FA526)"
 516        depends on !ARCH_MULTI_V6_V7
 517        select ARCH_MULTI_V4_V5
 518        select CPU_FA526
 519
 520config ARCH_MULTI_V4T
 521        bool "ARMv4T based platforms (ARM720T, ARM920T, ...)"
 522        depends on !ARCH_MULTI_V6_V7
 523        select ARCH_MULTI_V4_V5
 524        select CPU_ARM920T if !(CPU_ARM7TDMI || CPU_ARM720T || \
 525                CPU_ARM740T || CPU_ARM9TDMI || CPU_ARM922T || \
 526                CPU_ARM925T || CPU_ARM940T)
 527
 528config ARCH_MULTI_V5
 529        bool "ARMv5 based platforms (ARM926T, XSCALE, PJ1, ...)"
 530        depends on !ARCH_MULTI_V6_V7
 531        select ARCH_MULTI_V4_V5
 532        select CPU_ARM926T if !(CPU_ARM946E || CPU_ARM1020 || \
 533                CPU_ARM1020E || CPU_ARM1022 || CPU_ARM1026 || \
 534                CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK || CPU_FEROCEON)
 535
 536config ARCH_MULTI_V4_V5
 537        bool
 538
 539config ARCH_MULTI_V6
 540        bool "ARMv6 based platforms (ARM11)"
 541        select ARCH_MULTI_V6_V7
 542        select CPU_V6K
 543
 544config ARCH_MULTI_V7
 545        bool "ARMv7 based platforms (Cortex-A, PJ4, Scorpion, Krait)"
 546        default y
 547        select ARCH_MULTI_V6_V7
 548        select CPU_V7
 549        select HAVE_SMP
 550
 551config ARCH_MULTI_V6_V7
 552        bool
 553        select MIGHT_HAVE_CACHE_L2X0
 554
 555config ARCH_MULTI_CPU_AUTO
 556        def_bool !(ARCH_MULTI_V4 || ARCH_MULTI_V4T || ARCH_MULTI_V6_V7)
 557        select ARCH_MULTI_V5
 558
 559endmenu
 560
 561config ARCH_VIRT
 562        bool "Dummy Virtual Machine"
 563        depends on ARCH_MULTI_V7
 564        select ARM_AMBA
 565        select ARM_GIC
 566        select ARM_GIC_V2M if PCI
 567        select ARM_GIC_V3
 568        select ARM_GIC_V3_ITS if PCI
 569        select ARM_PSCI
 570        select HAVE_ARM_ARCH_TIMER
 571        select ARCH_SUPPORTS_BIG_ENDIAN
 572
 573#
 574# This is sorted alphabetically by mach-* pathname.  However, plat-*
 575# Kconfigs may be included either alphabetically (according to the
 576# plat- suffix) or along side the corresponding mach-* source.
 577#
 578source "arch/arm/mach-actions/Kconfig"
 579
 580source "arch/arm/mach-alpine/Kconfig"
 581
 582source "arch/arm/mach-artpec/Kconfig"
 583
 584source "arch/arm/mach-asm9260/Kconfig"
 585
 586source "arch/arm/mach-aspeed/Kconfig"
 587
 588source "arch/arm/mach-at91/Kconfig"
 589
 590source "arch/arm/mach-axxia/Kconfig"
 591
 592source "arch/arm/mach-bcm/Kconfig"
 593
 594source "arch/arm/mach-berlin/Kconfig"
 595
 596source "arch/arm/mach-clps711x/Kconfig"
 597
 598source "arch/arm/mach-cns3xxx/Kconfig"
 599
 600source "arch/arm/mach-davinci/Kconfig"
 601
 602source "arch/arm/mach-digicolor/Kconfig"
 603
 604source "arch/arm/mach-dove/Kconfig"
 605
 606source "arch/arm/mach-ep93xx/Kconfig"
 607
 608source "arch/arm/mach-exynos/Kconfig"
 609
 610source "arch/arm/mach-footbridge/Kconfig"
 611
 612source "arch/arm/mach-gemini/Kconfig"
 613
 614source "arch/arm/mach-highbank/Kconfig"
 615
 616source "arch/arm/mach-hisi/Kconfig"
 617
 618source "arch/arm/mach-imx/Kconfig"
 619
 620source "arch/arm/mach-integrator/Kconfig"
 621
 622source "arch/arm/mach-iop32x/Kconfig"
 623
 624source "arch/arm/mach-ixp4xx/Kconfig"
 625
 626source "arch/arm/mach-keystone/Kconfig"
 627
 628source "arch/arm/mach-lpc32xx/Kconfig"
 629
 630source "arch/arm/mach-mediatek/Kconfig"
 631
 632source "arch/arm/mach-meson/Kconfig"
 633
 634source "arch/arm/mach-milbeaut/Kconfig"
 635
 636source "arch/arm/mach-mmp/Kconfig"
 637
 638source "arch/arm/mach-moxart/Kconfig"
 639
 640source "arch/arm/mach-mstar/Kconfig"
 641
 642source "arch/arm/mach-mv78xx0/Kconfig"
 643
 644source "arch/arm/mach-mvebu/Kconfig"
 645
 646source "arch/arm/mach-mxs/Kconfig"
 647
 648source "arch/arm/mach-nomadik/Kconfig"
 649
 650source "arch/arm/mach-npcm/Kconfig"
 651
 652source "arch/arm/mach-nspire/Kconfig"
 653
 654source "arch/arm/plat-omap/Kconfig"
 655
 656source "arch/arm/mach-omap1/Kconfig"
 657
 658source "arch/arm/mach-omap2/Kconfig"
 659
 660source "arch/arm/mach-orion5x/Kconfig"
 661
 662source "arch/arm/mach-oxnas/Kconfig"
 663
 664source "arch/arm/mach-pxa/Kconfig"
 665source "arch/arm/plat-pxa/Kconfig"
 666
 667source "arch/arm/mach-qcom/Kconfig"
 668
 669source "arch/arm/mach-rda/Kconfig"
 670
 671source "arch/arm/mach-realtek/Kconfig"
 672
 673source "arch/arm/mach-realview/Kconfig"
 674
 675source "arch/arm/mach-rockchip/Kconfig"
 676
 677source "arch/arm/mach-s3c/Kconfig"
 678
 679source "arch/arm/mach-s5pv210/Kconfig"
 680
 681source "arch/arm/mach-sa1100/Kconfig"
 682
 683source "arch/arm/mach-shmobile/Kconfig"
 684
 685source "arch/arm/mach-socfpga/Kconfig"
 686
 687source "arch/arm/mach-spear/Kconfig"
 688
 689source "arch/arm/mach-sti/Kconfig"
 690
 691source "arch/arm/mach-stm32/Kconfig"
 692
 693source "arch/arm/mach-sunxi/Kconfig"
 694
 695source "arch/arm/mach-tegra/Kconfig"
 696
 697source "arch/arm/mach-uniphier/Kconfig"
 698
 699source "arch/arm/mach-ux500/Kconfig"
 700
 701source "arch/arm/mach-versatile/Kconfig"
 702
 703source "arch/arm/mach-vexpress/Kconfig"
 704
 705source "arch/arm/mach-vt8500/Kconfig"
 706
 707source "arch/arm/mach-zynq/Kconfig"
 708
 709# ARMv7-M architecture
 710config ARCH_LPC18XX
 711        bool "NXP LPC18xx/LPC43xx"
 712        depends on ARM_SINGLE_ARMV7M
 713        select ARCH_HAS_RESET_CONTROLLER
 714        select ARM_AMBA
 715        select CLKSRC_LPC32XX
 716        select PINCTRL
 717        help
 718          Support for NXP's LPC18xx Cortex-M3 and LPC43xx Cortex-M4
 719          high performance microcontrollers.
 720
 721config ARCH_MPS2
 722        bool "ARM MPS2 platform"
 723        depends on ARM_SINGLE_ARMV7M
 724        select ARM_AMBA
 725        select CLKSRC_MPS2
 726        help
 727          Support for Cortex-M Prototyping System (or V2M-MPS2) which comes
 728          with a range of available cores like Cortex-M3/M4/M7.
 729
 730          Please, note that depends which Application Note is used memory map
 731          for the platform may vary, so adjustment of RAM base might be needed.
 732
 733# Definitions to make life easier
 734config ARCH_ACORN
 735        bool
 736
 737config PLAT_IOP
 738        bool
 739
 740config PLAT_ORION
 741        bool
 742        select CLKSRC_MMIO
 743        select COMMON_CLK
 744        select GENERIC_IRQ_CHIP
 745        select IRQ_DOMAIN
 746
 747config PLAT_ORION_LEGACY
 748        bool
 749        select PLAT_ORION
 750
 751config PLAT_PXA
 752        bool
 753
 754config PLAT_VERSATILE
 755        bool
 756
 757source "arch/arm/mm/Kconfig"
 758
 759config IWMMXT
 760        bool "Enable iWMMXt support"
 761        depends on CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK || CPU_PJ4 || CPU_PJ4B
 762        default y if PXA27x || PXA3xx || ARCH_MMP || CPU_PJ4 || CPU_PJ4B
 763        help
 764          Enable support for iWMMXt context switching at run time if
 765          running on a CPU that supports it.
 766
 767if !MMU
 768source "arch/arm/Kconfig-nommu"
 769endif
 770
 771config PJ4B_ERRATA_4742
 772        bool "PJ4B Errata 4742: IDLE Wake Up Commands can Cause the CPU Core to Cease Operation"
 773        depends on CPU_PJ4B && MACH_ARMADA_370
 774        default y
 775        help
 776          When coming out of either a Wait for Interrupt (WFI) or a Wait for
 777          Event (WFE) IDLE states, a specific timing sensitivity exists between
 778          the retiring WFI/WFE instructions and the newly issued subsequent
 779          instructions.  This sensitivity can result in a CPU hang scenario.
 780          Workaround:
 781          The software must insert either a Data Synchronization Barrier (DSB)
 782          or Data Memory Barrier (DMB) command immediately after the WFI/WFE
 783          instruction
 784
 785config ARM_ERRATA_326103
 786        bool "ARM errata: FSR write bit incorrect on a SWP to read-only memory"
 787        depends on CPU_V6
 788        help
 789          Executing a SWP instruction to read-only memory does not set bit 11
 790          of the FSR on the ARM 1136 prior to r1p0. This causes the kernel to
 791          treat the access as a read, preventing a COW from occurring and
 792          causing the faulting task to livelock.
 793
 794config ARM_ERRATA_411920
 795        bool "ARM errata: Invalidation of the Instruction Cache operation can fail"
 796        depends on CPU_V6 || CPU_V6K
 797        help
 798          Invalidation of the Instruction Cache operation can
 799          fail. This erratum is present in 1136 (before r1p4), 1156 and 1176.
 800          It does not affect the MPCore. This option enables the ARM Ltd.
 801          recommended workaround.
 802
 803config ARM_ERRATA_430973
 804        bool "ARM errata: Stale prediction on replaced interworking branch"
 805        depends on CPU_V7
 806        help
 807          This option enables the workaround for the 430973 Cortex-A8
 808          r1p* erratum. If a code sequence containing an ARM/Thumb
 809          interworking branch is replaced with another code sequence at the
 810          same virtual address, whether due to self-modifying code or virtual
 811          to physical address re-mapping, Cortex-A8 does not recover from the
 812          stale interworking branch prediction. This results in Cortex-A8
 813          executing the new code sequence in the incorrect ARM or Thumb state.
 814          The workaround enables the BTB/BTAC operations by setting ACTLR.IBE
 815          and also flushes the branch target cache at every context switch.
 816          Note that setting specific bits in the ACTLR register may not be
 817          available in non-secure mode.
 818
 819config ARM_ERRATA_458693
 820        bool "ARM errata: Processor deadlock when a false hazard is created"
 821        depends on CPU_V7
 822        depends on !ARCH_MULTIPLATFORM
 823        help
 824          This option enables the workaround for the 458693 Cortex-A8 (r2p0)
 825          erratum. For very specific sequences of memory operations, it is
 826          possible for a hazard condition intended for a cache line to instead
 827          be incorrectly associated with a different cache line. This false
 828          hazard might then cause a processor deadlock. The workaround enables
 829          the L1 caching of the NEON accesses and disables the PLD instruction
 830          in the ACTLR register. Note that setting specific bits in the ACTLR
 831          register may not be available in non-secure mode.
 832
 833config ARM_ERRATA_460075
 834        bool "ARM errata: Data written to the L2 cache can be overwritten with stale data"
 835        depends on CPU_V7
 836        depends on !ARCH_MULTIPLATFORM
 837        help
 838          This option enables the workaround for the 460075 Cortex-A8 (r2p0)
 839          erratum. Any asynchronous access to the L2 cache may encounter a
 840          situation in which recent store transactions to the L2 cache are lost
 841          and overwritten with stale memory contents from external memory. The
 842          workaround disables the write-allocate mode for the L2 cache via the
 843          ACTLR register. Note that setting specific bits in the ACTLR register
 844          may not be available in non-secure mode.
 845
 846config ARM_ERRATA_742230
 847        bool "ARM errata: DMB operation may be faulty"
 848        depends on CPU_V7 && SMP
 849        depends on !ARCH_MULTIPLATFORM
 850        help
 851          This option enables the workaround for the 742230 Cortex-A9
 852          (r1p0..r2p2) erratum. Under rare circumstances, a DMB instruction
 853          between two write operations may not ensure the correct visibility
 854          ordering of the two writes. This workaround sets a specific bit in
 855          the diagnostic register of the Cortex-A9 which causes the DMB
 856          instruction to behave as a DSB, ensuring the correct behaviour of
 857          the two writes.
 858
 859config ARM_ERRATA_742231
 860        bool "ARM errata: Incorrect hazard handling in the SCU may lead to data corruption"
 861        depends on CPU_V7 && SMP
 862        depends on !ARCH_MULTIPLATFORM
 863        help
 864          This option enables the workaround for the 742231 Cortex-A9
 865          (r2p0..r2p2) erratum. Under certain conditions, specific to the
 866          Cortex-A9 MPCore micro-architecture, two CPUs working in SMP mode,
 867          accessing some data located in the same cache line, may get corrupted
 868          data due to bad handling of the address hazard when the line gets
 869          replaced from one of the CPUs at the same time as another CPU is
 870          accessing it. This workaround sets specific bits in the diagnostic
 871          register of the Cortex-A9 which reduces the linefill issuing
 872          capabilities of the processor.
 873
 874config ARM_ERRATA_643719
 875        bool "ARM errata: LoUIS bit field in CLIDR register is incorrect"
 876        depends on CPU_V7 && SMP
 877        default y
 878        help
 879          This option enables the workaround for the 643719 Cortex-A9 (prior to
 880          r1p0) erratum. On affected cores the LoUIS bit field of the CLIDR
 881          register returns zero when it should return one. The workaround
 882          corrects this value, ensuring cache maintenance operations which use
 883          it behave as intended and avoiding data corruption.
 884
 885config ARM_ERRATA_720789
 886        bool "ARM errata: TLBIASIDIS and TLBIMVAIS operations can broadcast a faulty ASID"
 887        depends on CPU_V7
 888        help
 889          This option enables the workaround for the 720789 Cortex-A9 (prior to
 890          r2p0) erratum. A faulty ASID can be sent to the other CPUs for the
 891          broadcasted CP15 TLB maintenance operations TLBIASIDIS and TLBIMVAIS.
 892          As a consequence of this erratum, some TLB entries which should be
 893          invalidated are not, resulting in an incoherency in the system page
 894          tables. The workaround changes the TLB flushing routines to invalidate
 895          entries regardless of the ASID.
 896
 897config ARM_ERRATA_743622
 898        bool "ARM errata: Faulty hazard checking in the Store Buffer may lead to data corruption"
 899        depends on CPU_V7
 900        depends on !ARCH_MULTIPLATFORM
 901        help
 902          This option enables the workaround for the 743622 Cortex-A9
 903          (r2p*) erratum. Under very rare conditions, a faulty
 904          optimisation in the Cortex-A9 Store Buffer may lead to data
 905          corruption. This workaround sets a specific bit in the diagnostic
 906          register of the Cortex-A9 which disables the Store Buffer
 907          optimisation, preventing the defect from occurring. This has no
 908          visible impact on the overall performance or power consumption of the
 909          processor.
 910
 911config ARM_ERRATA_751472
 912        bool "ARM errata: Interrupted ICIALLUIS may prevent completion of broadcasted operation"
 913        depends on CPU_V7
 914        depends on !ARCH_MULTIPLATFORM
 915        help
 916          This option enables the workaround for the 751472 Cortex-A9 (prior
 917          to r3p0) erratum. An interrupted ICIALLUIS operation may prevent the
 918          completion of a following broadcasted operation if the second
 919          operation is received by a CPU before the ICIALLUIS has completed,
 920          potentially leading to corrupted entries in the cache or TLB.
 921
 922config ARM_ERRATA_754322
 923        bool "ARM errata: possible faulty MMU translations following an ASID switch"
 924        depends on CPU_V7
 925        help
 926          This option enables the workaround for the 754322 Cortex-A9 (r2p*,
 927          r3p*) erratum. A speculative memory access may cause a page table walk
 928          which starts prior to an ASID switch but completes afterwards. This
 929          can populate the micro-TLB with a stale entry which may be hit with
 930          the new ASID. This workaround places two dsb instructions in the mm
 931          switching code so that no page table walks can cross the ASID switch.
 932
 933config ARM_ERRATA_754327
 934        bool "ARM errata: no automatic Store Buffer drain"
 935        depends on CPU_V7 && SMP
 936        help
 937          This option enables the workaround for the 754327 Cortex-A9 (prior to
 938          r2p0) erratum. The Store Buffer does not have any automatic draining
 939          mechanism and therefore a livelock may occur if an external agent
 940          continuously polls a memory location waiting to observe an update.
 941          This workaround defines cpu_relax() as smp_mb(), preventing correctly
 942          written polling loops from denying visibility of updates to memory.
 943
 944config ARM_ERRATA_364296
 945        bool "ARM errata: Possible cache data corruption with hit-under-miss enabled"
 946        depends on CPU_V6
 947        help
 948          This options enables the workaround for the 364296 ARM1136
 949          r0p2 erratum (possible cache data corruption with
 950          hit-under-miss enabled). It sets the undocumented bit 31 in
 951          the auxiliary control register and the FI bit in the control
 952          register, thus disabling hit-under-miss without putting the
 953          processor into full low interrupt latency mode. ARM11MPCore
 954          is not affected.
 955
 956config ARM_ERRATA_764369
 957        bool "ARM errata: Data cache line maintenance operation by MVA may not succeed"
 958        depends on CPU_V7 && SMP
 959        help
 960          This option enables the workaround for erratum 764369
 961          affecting Cortex-A9 MPCore with two or more processors (all
 962          current revisions). Under certain timing circumstances, a data
 963          cache line maintenance operation by MVA targeting an Inner
 964          Shareable memory region may fail to proceed up to either the
 965          Point of Coherency or to the Point of Unification of the
 966          system. This workaround adds a DSB instruction before the
 967          relevant cache maintenance functions and sets a specific bit
 968          in the diagnostic control register of the SCU.
 969
 970config ARM_ERRATA_775420
 971       bool "ARM errata: A data cache maintenance operation which aborts, might lead to deadlock"
 972       depends on CPU_V7
 973       help
 974         This option enables the workaround for the 775420 Cortex-A9 (r2p2,
 975         r2p6,r2p8,r2p10,r3p0) erratum. In case a data cache maintenance
 976         operation aborts with MMU exception, it might cause the processor
 977         to deadlock. This workaround puts DSB before executing ISB if
 978         an abort may occur on cache maintenance.
 979
 980config ARM_ERRATA_798181
 981        bool "ARM errata: TLBI/DSB failure on Cortex-A15"
 982        depends on CPU_V7 && SMP
 983        help
 984          On Cortex-A15 (r0p0..r3p2) the TLBI*IS/DSB operations are not
 985          adequately shooting down all use of the old entries. This
 986          option enables the Linux kernel workaround for this erratum
 987          which sends an IPI to the CPUs that are running the same ASID
 988          as the one being invalidated.
 989
 990config ARM_ERRATA_773022
 991        bool "ARM errata: incorrect instructions may be executed from loop buffer"
 992        depends on CPU_V7
 993        help
 994          This option enables the workaround for the 773022 Cortex-A15
 995          (up to r0p4) erratum. In certain rare sequences of code, the
 996          loop buffer may deliver incorrect instructions. This
 997          workaround disables the loop buffer to avoid the erratum.
 998
 999config ARM_ERRATA_818325_852422
1000        bool "ARM errata: A12: some seqs of opposed cond code instrs => deadlock or corruption"
1001        depends on CPU_V7
1002        help
1003          This option enables the workaround for:
1004          - Cortex-A12 818325: Execution of an UNPREDICTABLE STR or STM
1005            instruction might deadlock.  Fixed in r0p1.
1006          - Cortex-A12 852422: Execution of a sequence of instructions might
1007            lead to either a data corruption or a CPU deadlock.  Not fixed in
1008            any Cortex-A12 cores yet.
1009          This workaround for all both errata involves setting bit[12] of the
1010          Feature Register. This bit disables an optimisation applied to a
1011          sequence of 2 instructions that use opposing condition codes.
1012
1013config ARM_ERRATA_821420
1014        bool "ARM errata: A12: sequence of VMOV to core registers might lead to a dead lock"
1015        depends on CPU_V7
1016        help
1017          This option enables the workaround for the 821420 Cortex-A12
1018          (all revs) erratum. In very rare timing conditions, a sequence
1019          of VMOV to Core registers instructions, for which the second
1020          one is in the shadow of a branch or abort, can lead to a
1021          deadlock when the VMOV instructions are issued out-of-order.
1022
1023config ARM_ERRATA_825619
1024        bool "ARM errata: A12: DMB NSHST/ISHST mixed ... might cause deadlock"
1025        depends on CPU_V7
1026        help
1027          This option enables the workaround for the 825619 Cortex-A12
1028          (all revs) erratum. Within rare timing constraints, executing a
1029          DMB NSHST or DMB ISHST instruction followed by a mix of Cacheable
1030          and Device/Strongly-Ordered loads and stores might cause deadlock
1031
1032config ARM_ERRATA_857271
1033        bool "ARM errata: A12: CPU might deadlock under some very rare internal conditions"
1034        depends on CPU_V7
1035        help
1036          This option enables the workaround for the 857271 Cortex-A12
1037          (all revs) erratum. Under very rare timing conditions, the CPU might
1038          hang. The workaround is expected to have a < 1% performance impact.
1039
1040config ARM_ERRATA_852421
1041        bool "ARM errata: A17: DMB ST might fail to create order between stores"
1042        depends on CPU_V7
1043        help
1044          This option enables the workaround for the 852421 Cortex-A17
1045          (r1p0, r1p1, r1p2) erratum. Under very rare timing conditions,
1046          execution of a DMB ST instruction might fail to properly order
1047          stores from GroupA and stores from GroupB.
1048
1049config ARM_ERRATA_852423
1050        bool "ARM errata: A17: some seqs of opposed cond code instrs => deadlock or corruption"
1051        depends on CPU_V7
1052        help
1053          This option enables the workaround for:
1054          - Cortex-A17 852423: Execution of a sequence of instructions might
1055            lead to either a data corruption or a CPU deadlock.  Not fixed in
1056            any Cortex-A17 cores yet.
1057          This is identical to Cortex-A12 erratum 852422.  It is a separate
1058          config option from the A12 erratum due to the way errata are checked
1059          for and handled.
1060
1061config ARM_ERRATA_857272
1062        bool "ARM errata: A17: CPU might deadlock under some very rare internal conditions"
1063        depends on CPU_V7
1064        help
1065          This option enables the workaround for the 857272 Cortex-A17 erratum.
1066          This erratum is not known to be fixed in any A17 revision.
1067          This is identical to Cortex-A12 erratum 857271.  It is a separate
1068          config option from the A12 erratum due to the way errata are checked
1069          for and handled.
1070
1071endmenu
1072
1073source "arch/arm/common/Kconfig"
1074
1075menu "Bus support"
1076
1077config ISA
1078        bool
1079        help
1080          Find out whether you have ISA slots on your motherboard.  ISA is the
1081          name of a bus system, i.e. the way the CPU talks to the other stuff
1082          inside your box.  Other bus systems are PCI, EISA, MicroChannel
1083          (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
1084          newer boards don't support it.  If you have ISA, say Y, otherwise N.
1085
1086# Select ISA DMA controller support
1087config ISA_DMA
1088        bool
1089        select ISA_DMA_API
1090
1091# Select ISA DMA interface
1092config ISA_DMA_API
1093        bool
1094
1095config PCI_NANOENGINE
1096        bool "BSE nanoEngine PCI support"
1097        depends on SA1100_NANOENGINE
1098        help
1099          Enable PCI on the BSE nanoEngine board.
1100
1101config ARM_ERRATA_814220
1102        bool "ARM errata: Cache maintenance by set/way operations can execute out of order"
1103        depends on CPU_V7
1104        help
1105          The v7 ARM states that all cache and branch predictor maintenance
1106          operations that do not specify an address execute, relative to
1107          each other, in program order.
1108          However, because of this erratum, an L2 set/way cache maintenance
1109          operation can overtake an L1 set/way cache maintenance operation.
1110          This ERRATA only affected the Cortex-A7 and present in r0p2, r0p3,
1111          r0p4, r0p5.
1112
1113endmenu
1114
1115menu "Kernel Features"
1116
1117config HAVE_SMP
1118        bool
1119        help
1120          This option should be selected by machines which have an SMP-
1121          capable CPU.
1122
1123          The only effect of this option is to make the SMP-related
1124          options available to the user for configuration.
1125
1126config SMP
1127        bool "Symmetric Multi-Processing"
1128        depends on CPU_V6K || CPU_V7
1129        depends on HAVE_SMP
1130        depends on MMU || ARM_MPU
1131        select IRQ_WORK
1132        help
1133          This enables support for systems with more than one CPU. If you have
1134          a system with only one CPU, say N. If you have a system with more
1135          than one CPU, say Y.
1136
1137          If you say N here, the kernel will run on uni- and multiprocessor
1138          machines, but will use only one CPU of a multiprocessor machine. If
1139          you say Y here, the kernel will run on many, but not all,
1140          uniprocessor machines. On a uniprocessor machine, the kernel
1141          will run faster if you say N here.
1142
1143          See also <file:Documentation/x86/i386/IO-APIC.rst>,
1144          <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
1145          <http://tldp.org/HOWTO/SMP-HOWTO.html>.
1146
1147          If you don't know what to do here, say N.
1148
1149config SMP_ON_UP
1150        bool "Allow booting SMP kernel on uniprocessor systems"
1151        depends on SMP && !XIP_KERNEL && MMU
1152        default y
1153        help
1154          SMP kernels contain instructions which fail on non-SMP processors.
1155          Enabling this option allows the kernel to modify itself to make
1156          these instructions safe.  Disabling it allows about 1K of space
1157          savings.
1158
1159          If you don't know what to do here, say Y.
1160
1161config ARM_CPU_TOPOLOGY
1162        bool "Support cpu topology definition"
1163        depends on SMP && CPU_V7
1164        default y
1165        help
1166          Support ARM cpu topology definition. The MPIDR register defines
1167          affinity between processors which is then used to describe the cpu
1168          topology of an ARM System.
1169
1170config SCHED_MC
1171        bool "Multi-core scheduler support"
1172        depends on ARM_CPU_TOPOLOGY
1173        help
1174          Multi-core scheduler support improves the CPU scheduler's decision
1175          making when dealing with multi-core CPU chips at a cost of slightly
1176          increased overhead in some places. If unsure say N here.
1177
1178config SCHED_SMT
1179        bool "SMT scheduler support"
1180        depends on ARM_CPU_TOPOLOGY
1181        help
1182          Improves the CPU scheduler's decision making when dealing with
1183          MultiThreading at a cost of slightly increased overhead in some
1184          places. If unsure say N here.
1185
1186config HAVE_ARM_SCU
1187        bool
1188        help
1189          This option enables support for the ARM snoop control unit
1190
1191config HAVE_ARM_ARCH_TIMER
1192        bool "Architected timer support"
1193        depends on CPU_V7
1194        select ARM_ARCH_TIMER
1195        help
1196          This option enables support for the ARM architected timer
1197
1198config HAVE_ARM_TWD
1199        bool
1200        help
1201          This options enables support for the ARM timer and watchdog unit
1202
1203config MCPM
1204        bool "Multi-Cluster Power Management"
1205        depends on CPU_V7 && SMP
1206        help
1207          This option provides the common power management infrastructure
1208          for (multi-)cluster based systems, such as big.LITTLE based
1209          systems.
1210
1211config MCPM_QUAD_CLUSTER
1212        bool
1213        depends on MCPM
1214        help
1215          To avoid wasting resources unnecessarily, MCPM only supports up
1216          to 2 clusters by default.
1217          Platforms with 3 or 4 clusters that use MCPM must select this
1218          option to allow the additional clusters to be managed.
1219
1220config BIG_LITTLE
1221        bool "big.LITTLE support (Experimental)"
1222        depends on CPU_V7 && SMP
1223        select MCPM
1224        help
1225          This option enables support selections for the big.LITTLE
1226          system architecture.
1227
1228config BL_SWITCHER
1229        bool "big.LITTLE switcher support"
1230        depends on BIG_LITTLE && MCPM && HOTPLUG_CPU && ARM_GIC
1231        select CPU_PM
1232        help
1233          The big.LITTLE "switcher" provides the core functionality to
1234          transparently handle transition between a cluster of A15's
1235          and a cluster of A7's in a big.LITTLE system.
1236
1237config BL_SWITCHER_DUMMY_IF
1238        tristate "Simple big.LITTLE switcher user interface"
1239        depends on BL_SWITCHER && DEBUG_KERNEL
1240        help
1241          This is a simple and dummy char dev interface to control
1242          the big.LITTLE switcher core code.  It is meant for
1243          debugging purposes only.
1244
1245choice
1246        prompt "Memory split"
1247        depends on MMU
1248        default VMSPLIT_3G
1249        help
1250          Select the desired split between kernel and user memory.
1251
1252          If you are not absolutely sure what you are doing, leave this
1253          option alone!
1254
1255        config VMSPLIT_3G
1256                bool "3G/1G user/kernel split"
1257        config VMSPLIT_3G_OPT
1258                depends on !ARM_LPAE
1259                bool "3G/1G user/kernel split (for full 1G low memory)"
1260        config VMSPLIT_2G
1261                bool "2G/2G user/kernel split"
1262        config VMSPLIT_1G
1263                bool "1G/3G user/kernel split"
1264endchoice
1265
1266config PAGE_OFFSET
1267        hex
1268        default PHYS_OFFSET if !MMU
1269        default 0x40000000 if VMSPLIT_1G
1270        default 0x80000000 if VMSPLIT_2G
1271        default 0xB0000000 if VMSPLIT_3G_OPT
1272        default 0xC0000000
1273
1274config KASAN_SHADOW_OFFSET
1275        hex
1276        depends on KASAN
1277        default 0x1f000000 if PAGE_OFFSET=0x40000000
1278        default 0x5f000000 if PAGE_OFFSET=0x80000000
1279        default 0x9f000000 if PAGE_OFFSET=0xC0000000
1280        default 0x8f000000 if PAGE_OFFSET=0xB0000000
1281        default 0xffffffff
1282
1283config NR_CPUS
1284        int "Maximum number of CPUs (2-32)"
1285        range 2 16 if DEBUG_KMAP_LOCAL
1286        range 2 32 if !DEBUG_KMAP_LOCAL
1287        depends on SMP
1288        default "4"
1289        help
1290          The maximum number of CPUs that the kernel can support.
1291          Up to 32 CPUs can be supported, or up to 16 if kmap_local()
1292          debugging is enabled, which uses half of the per-CPU fixmap
1293          slots as guard regions.
1294
1295config HOTPLUG_CPU
1296        bool "Support for hot-pluggable CPUs"
1297        depends on SMP
1298        select GENERIC_IRQ_MIGRATION
1299        help
1300          Say Y here to experiment with turning CPUs off and on.  CPUs
1301          can be controlled through /sys/devices/system/cpu.
1302
1303config ARM_PSCI
1304        bool "Support for the ARM Power State Coordination Interface (PSCI)"
1305        depends on HAVE_ARM_SMCCC
1306        select ARM_PSCI_FW
1307        help
1308          Say Y here if you want Linux to communicate with system firmware
1309          implementing the PSCI specification for CPU-centric power
1310          management operations described in ARM document number ARM DEN
1311          0022A ("Power State Coordination Interface System Software on
1312          ARM processors").
1313
1314# The GPIO number here must be sorted by descending number. In case of
1315# a multiplatform kernel, we just want the highest value required by the
1316# selected platforms.
1317config ARCH_NR_GPIO
1318        int
1319        default 2048 if ARCH_INTEL_SOCFPGA
1320        default 1024 if ARCH_BRCMSTB || ARCH_RENESAS || ARCH_TEGRA || \
1321                ARCH_ZYNQ || ARCH_ASPEED
1322        default 512 if ARCH_EXYNOS || ARCH_KEYSTONE || SOC_OMAP5 || \
1323                SOC_DRA7XX || ARCH_S3C24XX || ARCH_S3C64XX || ARCH_S5PV210
1324        default 416 if ARCH_SUNXI
1325        default 392 if ARCH_U8500
1326        default 352 if ARCH_VT8500
1327        default 288 if ARCH_ROCKCHIP
1328        default 264 if MACH_H4700
1329        default 0
1330        help
1331          Maximum number of GPIOs in the system.
1332
1333          If unsure, leave the default value.
1334
1335config HZ_FIXED
1336        int
1337        default 128 if SOC_AT91RM9200
1338        default 0
1339
1340choice
1341        depends on HZ_FIXED = 0
1342        prompt "Timer frequency"
1343
1344config HZ_100
1345        bool "100 Hz"
1346
1347config HZ_200
1348        bool "200 Hz"
1349
1350config HZ_250
1351        bool "250 Hz"
1352
1353config HZ_300
1354        bool "300 Hz"
1355
1356config HZ_500
1357        bool "500 Hz"
1358
1359config HZ_1000
1360        bool "1000 Hz"
1361
1362endchoice
1363
1364config HZ
1365        int
1366        default HZ_FIXED if HZ_FIXED != 0
1367        default 100 if HZ_100
1368        default 200 if HZ_200
1369        default 250 if HZ_250
1370        default 300 if HZ_300
1371        default 500 if HZ_500
1372        default 1000
1373
1374config SCHED_HRTICK
1375        def_bool HIGH_RES_TIMERS
1376
1377config THUMB2_KERNEL
1378        bool "Compile the kernel in Thumb-2 mode" if !CPU_THUMBONLY
1379        depends on (CPU_V7 || CPU_V7M) && !CPU_V6 && !CPU_V6K
1380        default y if CPU_THUMBONLY
1381        select ARM_UNWIND
1382        help
1383          By enabling this option, the kernel will be compiled in
1384          Thumb-2 mode.
1385
1386          If unsure, say N.
1387
1388config ARM_PATCH_IDIV
1389        bool "Runtime patch udiv/sdiv instructions into __aeabi_{u}idiv()"
1390        depends on CPU_32v7 && !XIP_KERNEL
1391        default y
1392        help
1393          The ARM compiler inserts calls to __aeabi_idiv() and
1394          __aeabi_uidiv() when it needs to perform division on signed
1395          and unsigned integers. Some v7 CPUs have support for the sdiv
1396          and udiv instructions that can be used to implement those
1397          functions.
1398
1399          Enabling this option allows the kernel to modify itself to
1400          replace the first two instructions of these library functions
1401          with the sdiv or udiv plus "bx lr" instructions when the CPU
1402          it is running on supports them. Typically this will be faster
1403          and less power intensive than running the original library
1404          code to do integer division.
1405
1406config AEABI
1407        bool "Use the ARM EABI to compile the kernel" if !CPU_V7 && \
1408                !CPU_V7M && !CPU_V6 && !CPU_V6K && !CC_IS_CLANG
1409        default CPU_V7 || CPU_V7M || CPU_V6 || CPU_V6K || CC_IS_CLANG
1410        help
1411          This option allows for the kernel to be compiled using the latest
1412          ARM ABI (aka EABI).  This is only useful if you are using a user
1413          space environment that is also compiled with EABI.
1414
1415          Since there are major incompatibilities between the legacy ABI and
1416          EABI, especially with regard to structure member alignment, this
1417          option also changes the kernel syscall calling convention to
1418          disambiguate both ABIs and allow for backward compatibility support
1419          (selected with CONFIG_OABI_COMPAT).
1420
1421          To use this you need GCC version 4.0.0 or later.
1422
1423config OABI_COMPAT
1424        bool "Allow old ABI binaries to run with this kernel (EXPERIMENTAL)"
1425        depends on AEABI && !THUMB2_KERNEL
1426        help
1427          This option preserves the old syscall interface along with the
1428          new (ARM EABI) one. It also provides a compatibility layer to
1429          intercept syscalls that have structure arguments which layout
1430          in memory differs between the legacy ABI and the new ARM EABI
1431          (only for non "thumb" binaries). This option adds a tiny
1432          overhead to all syscalls and produces a slightly larger kernel.
1433
1434          The seccomp filter system will not be available when this is
1435          selected, since there is no way yet to sensibly distinguish
1436          between calling conventions during filtering.
1437
1438          If you know you'll be using only pure EABI user space then you
1439          can say N here. If this option is not selected and you attempt
1440          to execute a legacy ABI binary then the result will be
1441          UNPREDICTABLE (in fact it can be predicted that it won't work
1442          at all). If in doubt say N.
1443
1444config ARCH_SELECT_MEMORY_MODEL
1445        bool
1446
1447config ARCH_FLATMEM_ENABLE
1448        bool
1449
1450config ARCH_SPARSEMEM_ENABLE
1451        bool
1452        select SPARSEMEM_STATIC if SPARSEMEM
1453
1454config HIGHMEM
1455        bool "High Memory Support"
1456        depends on MMU
1457        select KMAP_LOCAL
1458        help
1459          The address space of ARM processors is only 4 Gigabytes large
1460          and it has to accommodate user address space, kernel address
1461          space as well as some memory mapped IO. That means that, if you
1462          have a large amount of physical memory and/or IO, not all of the
1463          memory can be "permanently mapped" by the kernel. The physical
1464          memory that is not permanently mapped is called "high memory".
1465
1466          Depending on the selected kernel/user memory split, minimum
1467          vmalloc space and actual amount of RAM, you may not need this
1468          option which should result in a slightly faster kernel.
1469
1470          If unsure, say n.
1471
1472config HIGHPTE
1473        bool "Allocate 2nd-level pagetables from highmem" if EXPERT
1474        depends on HIGHMEM
1475        default y
1476        help
1477          The VM uses one page of physical memory for each page table.
1478          For systems with a lot of processes, this can use a lot of
1479          precious low memory, eventually leading to low memory being
1480          consumed by page tables.  Setting this option will allow
1481          user-space 2nd level page tables to reside in high memory.
1482
1483config CPU_SW_DOMAIN_PAN
1484        bool "Enable use of CPU domains to implement privileged no-access"
1485        depends on MMU && !ARM_LPAE
1486        default y
1487        help
1488          Increase kernel security by ensuring that normal kernel accesses
1489          are unable to access userspace addresses.  This can help prevent
1490          use-after-free bugs becoming an exploitable privilege escalation
1491          by ensuring that magic values (such as LIST_POISON) will always
1492          fault when dereferenced.
1493
1494          CPUs with low-vector mappings use a best-efforts implementation.
1495          Their lower 1MB needs to remain accessible for the vectors, but
1496          the remainder of userspace will become appropriately inaccessible.
1497
1498config HW_PERF_EVENTS
1499        def_bool y
1500        depends on ARM_PMU
1501
1502config ARCH_WANT_GENERAL_HUGETLB
1503        def_bool y
1504
1505config ARM_MODULE_PLTS
1506        bool "Use PLTs to allow module memory to spill over into vmalloc area"
1507        depends on MODULES
1508        default y
1509        help
1510          Allocate PLTs when loading modules so that jumps and calls whose
1511          targets are too far away for their relative offsets to be encoded
1512          in the instructions themselves can be bounced via veneers in the
1513          module's PLT. This allows modules to be allocated in the generic
1514          vmalloc area after the dedicated module memory area has been
1515          exhausted. The modules will use slightly more memory, but after
1516          rounding up to page size, the actual memory footprint is usually
1517          the same.
1518
1519          Disabling this is usually safe for small single-platform
1520          configurations. If unsure, say y.
1521
1522config FORCE_MAX_ZONEORDER
1523        int "Maximum zone order"
1524        default "12" if SOC_AM33XX
1525        default "9" if SA1111
1526        default "11"
1527        help
1528          The kernel memory allocator divides physically contiguous memory
1529          blocks into "zones", where each zone is a power of two number of
1530          pages.  This option selects the largest power of two that the kernel
1531          keeps in the memory allocator.  If you need to allocate very large
1532          blocks of physically contiguous memory, then you may need to
1533          increase this value.
1534
1535          This config option is actually maximum order plus one. For example,
1536          a value of 11 means that the largest free memory block is 2^10 pages.
1537
1538config ALIGNMENT_TRAP
1539        def_bool CPU_CP15_MMU
1540        select HAVE_PROC_CPU if PROC_FS
1541        help
1542          ARM processors cannot fetch/store information which is not
1543          naturally aligned on the bus, i.e., a 4 byte fetch must start at an
1544          address divisible by 4. On 32-bit ARM processors, these non-aligned
1545          fetch/store instructions will be emulated in software if you say
1546          here, which has a severe performance impact. This is necessary for
1547          correct operation of some network protocols. With an IP-only
1548          configuration it is safe to say N, otherwise say Y.
1549
1550config UACCESS_WITH_MEMCPY
1551        bool "Use kernel mem{cpy,set}() for {copy_to,clear}_user()"
1552        depends on MMU
1553        default y if CPU_FEROCEON
1554        help
1555          Implement faster copy_to_user and clear_user methods for CPU
1556          cores where a 8-word STM instruction give significantly higher
1557          memory write throughput than a sequence of individual 32bit stores.
1558
1559          A possible side effect is a slight increase in scheduling latency
1560          between threads sharing the same address space if they invoke
1561          such copy operations with large buffers.
1562
1563          However, if the CPU data cache is using a write-allocate mode,
1564          this option is unlikely to provide any performance gain.
1565
1566config PARAVIRT
1567        bool "Enable paravirtualization code"
1568        help
1569          This changes the kernel so it can modify itself when it is run
1570          under a hypervisor, potentially improving performance significantly
1571          over full virtualization.
1572
1573config PARAVIRT_TIME_ACCOUNTING
1574        bool "Paravirtual steal time accounting"
1575        select PARAVIRT
1576        help
1577          Select this option to enable fine granularity task steal time
1578          accounting. Time spent executing other tasks in parallel with
1579          the current vCPU is discounted from the vCPU power. To account for
1580          that, there can be a small performance impact.
1581
1582          If in doubt, say N here.
1583
1584config XEN_DOM0
1585        def_bool y
1586        depends on XEN
1587
1588config XEN
1589        bool "Xen guest support on ARM"
1590        depends on ARM && AEABI && OF
1591        depends on CPU_V7 && !CPU_V6
1592        depends on !GENERIC_ATOMIC64
1593        depends on MMU
1594        select ARCH_DMA_ADDR_T_64BIT
1595        select ARM_PSCI
1596        select SWIOTLB
1597        select SWIOTLB_XEN
1598        select PARAVIRT
1599        help
1600          Say Y if you want to run Linux in a Virtual Machine on Xen on ARM.
1601
1602config STACKPROTECTOR_PER_TASK
1603        bool "Use a unique stack canary value for each task"
1604        depends on GCC_PLUGINS && STACKPROTECTOR && SMP && !XIP_DEFLATED_DATA
1605        select GCC_PLUGIN_ARM_SSP_PER_TASK
1606        default y
1607        help
1608          Due to the fact that GCC uses an ordinary symbol reference from
1609          which to load the value of the stack canary, this value can only
1610          change at reboot time on SMP systems, and all tasks running in the
1611          kernel's address space are forced to use the same canary value for
1612          the entire duration that the system is up.
1613
1614          Enable this option to switch to a different method that uses a
1615          different canary value for each task.
1616
1617endmenu
1618
1619menu "Boot options"
1620
1621config USE_OF
1622        bool "Flattened Device Tree support"
1623        select IRQ_DOMAIN
1624        select OF
1625        help
1626          Include support for flattened device tree machine descriptions.
1627
1628config ATAGS
1629        bool "Support for the traditional ATAGS boot data passing" if USE_OF
1630        default y
1631        help
1632          This is the traditional way of passing data to the kernel at boot
1633          time. If you are solely relying on the flattened device tree (or
1634          the ARM_ATAG_DTB_COMPAT option) then you may unselect this option
1635          to remove ATAGS support from your kernel binary.  If unsure,
1636          leave this to y.
1637
1638config DEPRECATED_PARAM_STRUCT
1639        bool "Provide old way to pass kernel parameters"
1640        depends on ATAGS
1641        help
1642          This was deprecated in 2001 and announced to live on for 5 years.
1643          Some old boot loaders still use this way.
1644
1645# Compressed boot loader in ROM.  Yes, we really want to ask about
1646# TEXT and BSS so we preserve their values in the config files.
1647config ZBOOT_ROM_TEXT
1648        hex "Compressed ROM boot loader base address"
1649        default 0x0
1650        help
1651          The physical address at which the ROM-able zImage is to be
1652          placed in the target.  Platforms which normally make use of
1653          ROM-able zImage formats normally set this to a suitable
1654          value in their defconfig file.
1655
1656          If ZBOOT_ROM is not enabled, this has no effect.
1657
1658config ZBOOT_ROM_BSS
1659        hex "Compressed ROM boot loader BSS address"
1660        default 0x0
1661        help
1662          The base address of an area of read/write memory in the target
1663          for the ROM-able zImage which must be available while the
1664          decompressor is running. It must be large enough to hold the
1665          entire decompressed kernel plus an additional 128 KiB.
1666          Platforms which normally make use of ROM-able zImage formats
1667          normally set this to a suitable value in their defconfig file.
1668
1669          If ZBOOT_ROM is not enabled, this has no effect.
1670
1671config ZBOOT_ROM
1672        bool "Compressed boot loader in ROM/flash"
1673        depends on ZBOOT_ROM_TEXT != ZBOOT_ROM_BSS
1674        depends on !ARM_APPENDED_DTB && !XIP_KERNEL && !AUTO_ZRELADDR
1675        help
1676          Say Y here if you intend to execute your compressed kernel image
1677          (zImage) directly from ROM or flash.  If unsure, say N.
1678
1679config ARM_APPENDED_DTB
1680        bool "Use appended device tree blob to zImage (EXPERIMENTAL)"
1681        depends on OF
1682        help
1683          With this option, the boot code will look for a device tree binary
1684          (DTB) appended to zImage
1685          (e.g. cat zImage <filename>.dtb > zImage_w_dtb).
1686
1687          This is meant as a backward compatibility convenience for those
1688          systems with a bootloader that can't be upgraded to accommodate
1689          the documented boot protocol using a device tree.
1690
1691          Beware that there is very little in terms of protection against
1692          this option being confused by leftover garbage in memory that might
1693          look like a DTB header after a reboot if no actual DTB is appended
1694          to zImage.  Do not leave this option active in a production kernel
1695          if you don't intend to always append a DTB.  Proper passing of the
1696          location into r2 of a bootloader provided DTB is always preferable
1697          to this option.
1698
1699config ARM_ATAG_DTB_COMPAT
1700        bool "Supplement the appended DTB with traditional ATAG information"
1701        depends on ARM_APPENDED_DTB
1702        help
1703          Some old bootloaders can't be updated to a DTB capable one, yet
1704          they provide ATAGs with memory configuration, the ramdisk address,
1705          the kernel cmdline string, etc.  Such information is dynamically
1706          provided by the bootloader and can't always be stored in a static
1707          DTB.  To allow a device tree enabled kernel to be used with such
1708          bootloaders, this option allows zImage to extract the information
1709          from the ATAG list and store it at run time into the appended DTB.
1710
1711choice
1712        prompt "Kernel command line type" if ARM_ATAG_DTB_COMPAT
1713        default ARM_ATAG_DTB_COMPAT_CMDLINE_FROM_BOOTLOADER
1714
1715config ARM_ATAG_DTB_COMPAT_CMDLINE_FROM_BOOTLOADER
1716        bool "Use bootloader kernel arguments if available"
1717        help
1718          Uses the command-line options passed by the boot loader instead of
1719          the device tree bootargs property. If the boot loader doesn't provide
1720          any, the device tree bootargs property will be used.
1721
1722config ARM_ATAG_DTB_COMPAT_CMDLINE_EXTEND
1723        bool "Extend with bootloader kernel arguments"
1724        help
1725          The command-line arguments provided by the boot loader will be
1726          appended to the the device tree bootargs property.
1727
1728endchoice
1729
1730config CMDLINE
1731        string "Default kernel command string"
1732        default ""
1733        help
1734          On some architectures (e.g. CATS), there is currently no way
1735          for the boot loader to pass arguments to the kernel. For these
1736          architectures, you should supply some command-line options at build
1737          time by entering them here. As a minimum, you should specify the
1738          memory size and the root device (e.g., mem=64M root=/dev/nfs).
1739
1740choice
1741        prompt "Kernel command line type" if CMDLINE != ""
1742        default CMDLINE_FROM_BOOTLOADER
1743        depends on ATAGS
1744
1745config CMDLINE_FROM_BOOTLOADER
1746        bool "Use bootloader kernel arguments if available"
1747        help
1748          Uses the command-line options passed by the boot loader. If
1749          the boot loader doesn't provide any, the default kernel command
1750          string provided in CMDLINE will be used.
1751
1752config CMDLINE_EXTEND
1753        bool "Extend bootloader kernel arguments"
1754        help
1755          The command-line arguments provided by the boot loader will be
1756          appended to the default kernel command string.
1757
1758config CMDLINE_FORCE
1759        bool "Always use the default kernel command string"
1760        help
1761          Always use the default kernel command string, even if the boot
1762          loader passes other arguments to the kernel.
1763          This is useful if you cannot or don't want to change the
1764          command-line options your boot loader passes to the kernel.
1765endchoice
1766
1767config XIP_KERNEL
1768        bool "Kernel Execute-In-Place from ROM"
1769        depends on !ARM_LPAE && !ARCH_MULTIPLATFORM
1770        help
1771          Execute-In-Place allows the kernel to run from non-volatile storage
1772          directly addressable by the CPU, such as NOR flash. This saves RAM
1773          space since the text section of the kernel is not loaded from flash
1774          to RAM.  Read-write sections, such as the data section and stack,
1775          are still copied to RAM.  The XIP kernel is not compressed since
1776          it has to run directly from flash, so it will take more space to
1777          store it.  The flash address used to link the kernel object files,
1778          and for storing it, is configuration dependent. Therefore, if you
1779          say Y here, you must know the proper physical address where to
1780          store the kernel image depending on your own flash memory usage.
1781
1782          Also note that the make target becomes "make xipImage" rather than
1783          "make zImage" or "make Image".  The final kernel binary to put in
1784          ROM memory will be arch/arm/boot/xipImage.
1785
1786          If unsure, say N.
1787
1788config XIP_PHYS_ADDR
1789        hex "XIP Kernel Physical Location"
1790        depends on XIP_KERNEL
1791        default "0x00080000"
1792        help
1793          This is the physical address in your flash memory the kernel will
1794          be linked for and stored to.  This address is dependent on your
1795          own flash usage.
1796
1797config XIP_DEFLATED_DATA
1798        bool "Store kernel .data section compressed in ROM"
1799        depends on XIP_KERNEL
1800        select ZLIB_INFLATE
1801        help
1802          Before the kernel is actually executed, its .data section has to be
1803          copied to RAM from ROM. This option allows for storing that data
1804          in compressed form and decompressed to RAM rather than merely being
1805          copied, saving some precious ROM space. A possible drawback is a
1806          slightly longer boot delay.
1807
1808config KEXEC
1809        bool "Kexec system call (EXPERIMENTAL)"
1810        depends on (!SMP || PM_SLEEP_SMP)
1811        depends on MMU
1812        select KEXEC_CORE
1813        help
1814          kexec is a system call that implements the ability to shutdown your
1815          current kernel, and to start another kernel.  It is like a reboot
1816          but it is independent of the system firmware.   And like a reboot
1817          you can start any kernel with it, not just Linux.
1818
1819          It is an ongoing process to be certain the hardware in a machine
1820          is properly shutdown, so do not be surprised if this code does not
1821          initially work for you.
1822
1823config ATAGS_PROC
1824        bool "Export atags in procfs"
1825        depends on ATAGS && KEXEC
1826        default y
1827        help
1828          Should the atags used to boot the kernel be exported in an "atags"
1829          file in procfs. Useful with kexec.
1830
1831config CRASH_DUMP
1832        bool "Build kdump crash kernel (EXPERIMENTAL)"
1833        help
1834          Generate crash dump after being started by kexec. This should
1835          be normally only set in special crash dump kernels which are
1836          loaded in the main kernel with kexec-tools into a specially
1837          reserved region and then later executed after a crash by
1838          kdump/kexec. The crash dump kernel must be compiled to a
1839          memory address not used by the main kernel
1840
1841          For more details see Documentation/admin-guide/kdump/kdump.rst
1842
1843config AUTO_ZRELADDR
1844        bool "Auto calculation of the decompressed kernel image address"
1845        help
1846          ZRELADDR is the physical address where the decompressed kernel
1847          image will be placed. If AUTO_ZRELADDR is selected, the address
1848          will be determined at run-time, either by masking the current IP
1849          with 0xf8000000, or, if invalid, from the DTB passed in r2.
1850          This assumes the zImage being placed in the first 128MB from
1851          start of memory.
1852
1853config EFI_STUB
1854        bool
1855
1856config EFI
1857        bool "UEFI runtime support"
1858        depends on OF && !CPU_BIG_ENDIAN && MMU && AUTO_ZRELADDR && !XIP_KERNEL
1859        select UCS2_STRING
1860        select EFI_PARAMS_FROM_FDT
1861        select EFI_STUB
1862        select EFI_GENERIC_STUB
1863        select EFI_RUNTIME_WRAPPERS
1864        help
1865          This option provides support for runtime services provided
1866          by UEFI firmware (such as non-volatile variables, realtime
1867          clock, and platform reset). A UEFI stub is also provided to
1868          allow the kernel to be booted as an EFI application. This
1869          is only useful for kernels that may run on systems that have
1870          UEFI firmware.
1871
1872config DMI
1873        bool "Enable support for SMBIOS (DMI) tables"
1874        depends on EFI
1875        default y
1876        help
1877          This enables SMBIOS/DMI feature for systems.
1878
1879          This option is only useful on systems that have UEFI firmware.
1880          However, even with this option, the resultant kernel should
1881          continue to boot on existing non-UEFI platforms.
1882
1883          NOTE: This does *NOT* enable or encourage the use of DMI quirks,
1884          i.e., the the practice of identifying the platform via DMI to
1885          decide whether certain workarounds for buggy hardware and/or
1886          firmware need to be enabled. This would require the DMI subsystem
1887          to be enabled much earlier than we do on ARM, which is non-trivial.
1888
1889endmenu
1890
1891menu "CPU Power Management"
1892
1893source "drivers/cpufreq/Kconfig"
1894
1895source "drivers/cpuidle/Kconfig"
1896
1897endmenu
1898
1899menu "Floating point emulation"
1900
1901comment "At least one emulation must be selected"
1902
1903config FPE_NWFPE
1904        bool "NWFPE math emulation"
1905        depends on (!AEABI || OABI_COMPAT) && !THUMB2_KERNEL
1906        help
1907          Say Y to include the NWFPE floating point emulator in the kernel.
1908          This is necessary to run most binaries. Linux does not currently
1909          support floating point hardware so you need to say Y here even if
1910          your machine has an FPA or floating point co-processor podule.
1911
1912          You may say N here if you are going to load the Acorn FPEmulator
1913          early in the bootup.
1914
1915config FPE_NWFPE_XP
1916        bool "Support extended precision"
1917        depends on FPE_NWFPE
1918        help
1919          Say Y to include 80-bit support in the kernel floating-point
1920          emulator.  Otherwise, only 32 and 64-bit support is compiled in.
1921          Note that gcc does not generate 80-bit operations by default,
1922          so in most cases this option only enlarges the size of the
1923          floating point emulator without any good reason.
1924
1925          You almost surely want to say N here.
1926
1927config FPE_FASTFPE
1928        bool "FastFPE math emulation (EXPERIMENTAL)"
1929        depends on (!AEABI || OABI_COMPAT) && !CPU_32v3
1930        help
1931          Say Y here to include the FAST floating point emulator in the kernel.
1932          This is an experimental much faster emulator which now also has full
1933          precision for the mantissa.  It does not support any exceptions.
1934          It is very simple, and approximately 3-6 times faster than NWFPE.
1935
1936          It should be sufficient for most programs.  It may be not suitable
1937          for scientific calculations, but you have to check this for yourself.
1938          If you do not feel you need a faster FP emulation you should better
1939          choose NWFPE.
1940
1941config VFP
1942        bool "VFP-format floating point maths"
1943        depends on CPU_V6 || CPU_V6K || CPU_ARM926T || CPU_V7 || CPU_FEROCEON
1944        help
1945          Say Y to include VFP support code in the kernel. This is needed
1946          if your hardware includes a VFP unit.
1947
1948          Please see <file:Documentation/arm/vfp/release-notes.rst> for
1949          release notes and additional status information.
1950
1951          Say N if your target does not have VFP hardware.
1952
1953config VFPv3
1954        bool
1955        depends on VFP
1956        default y if CPU_V7
1957
1958config NEON
1959        bool "Advanced SIMD (NEON) Extension support"
1960        depends on VFPv3 && CPU_V7
1961        help
1962          Say Y to include support code for NEON, the ARMv7 Advanced SIMD
1963          Extension.
1964
1965config KERNEL_MODE_NEON
1966        bool "Support for NEON in kernel mode"
1967        depends on NEON && AEABI
1968        help
1969          Say Y to include support for NEON in kernel mode.
1970
1971endmenu
1972
1973menu "Power management options"
1974
1975source "kernel/power/Kconfig"
1976
1977config ARCH_SUSPEND_POSSIBLE
1978        depends on CPU_ARM920T || CPU_ARM926T || CPU_FEROCEON || CPU_SA1100 || \
1979                CPU_V6 || CPU_V6K || CPU_V7 || CPU_V7M || CPU_XSC3 || CPU_XSCALE || CPU_MOHAWK
1980        def_bool y
1981
1982config ARM_CPU_SUSPEND
1983        def_bool PM_SLEEP || BL_SWITCHER || ARM_PSCI_FW
1984        depends on ARCH_SUSPEND_POSSIBLE
1985
1986config ARCH_HIBERNATION_POSSIBLE
1987        bool
1988        depends on MMU
1989        default y if ARCH_SUSPEND_POSSIBLE
1990
1991endmenu
1992
1993if CRYPTO
1994source "arch/arm/crypto/Kconfig"
1995endif
1996
1997source "arch/arm/Kconfig.assembler"
1998