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_CLOCKSOURCE_DATA
   7        select ARCH_HAS_BINFMT_FLAT
   8        select ARCH_HAS_DEBUG_VIRTUAL if MMU
   9        select ARCH_HAS_DEVMEM_IS_ALLOWED
  10        select ARCH_HAS_DMA_COHERENT_TO_PFN if SWIOTLB
  11        select ARCH_HAS_DMA_MMAP_PGPROT if SWIOTLB
  12        select ARCH_HAS_ELF_RANDOMIZE
  13        select ARCH_HAS_FORTIFY_SOURCE
  14        select ARCH_HAS_KEEPINITRD
  15        select ARCH_HAS_KCOV
  16        select ARCH_HAS_MEMBARRIER_SYNC_CORE
  17        select ARCH_HAS_PTE_SPECIAL if ARM_LPAE
  18        select ARCH_HAS_PHYS_TO_DMA
  19        select ARCH_HAS_SETUP_DMA_OPS
  20        select ARCH_HAS_SET_MEMORY
  21        select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL
  22        select ARCH_HAS_STRICT_MODULE_RWX if MMU
  23        select ARCH_HAS_SYNC_DMA_FOR_DEVICE if SWIOTLB
  24        select ARCH_HAS_SYNC_DMA_FOR_CPU if SWIOTLB
  25        select ARCH_HAS_TEARDOWN_DMA_OPS if MMU
  26        select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
  27        select ARCH_HAVE_CUSTOM_GPIO_H
  28        select ARCH_HAS_GCOV_PROFILE_ALL
  29        select ARCH_KEEP_MEMBLOCK if HAVE_ARCH_PFN_VALID || KEXEC
  30        select ARCH_MIGHT_HAVE_PC_PARPORT
  31        select ARCH_NO_SG_CHAIN if !ARM_HAS_SG_CHAIN
  32        select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX
  33        select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT if CPU_V7
  34        select ARCH_SUPPORTS_ATOMIC_RMW
  35        select ARCH_USE_BUILTIN_BSWAP
  36        select ARCH_USE_CMPXCHG_LOCKREF
  37        select ARCH_WANT_IPC_PARSE_VERSION
  38        select BINFMT_FLAT_ARGVP_ENVP_ON_STACK
  39        select BUILDTIME_EXTABLE_SORT if MMU
  40        select CLONE_BACKWARDS
  41        select CPU_PM if SUSPEND || CPU_IDLE
  42        select DCACHE_WORD_ACCESS if HAVE_EFFICIENT_UNALIGNED_ACCESS
  43        select DMA_DECLARE_COHERENT
  44        select DMA_REMAP if MMU
  45        select EDAC_SUPPORT
  46        select EDAC_ATOMIC_SCRUB
  47        select GENERIC_ALLOCATOR
  48        select GENERIC_ARCH_TOPOLOGY if ARM_CPU_TOPOLOGY
  49        select GENERIC_ATOMIC64 if CPU_V7M || CPU_V6 || !CPU_32v6K || !AEABI
  50        select GENERIC_CLOCKEVENTS_BROADCAST if SMP
  51        select GENERIC_CPU_AUTOPROBE
  52        select GENERIC_EARLY_IOREMAP
  53        select GENERIC_IDLE_POLL_SETUP
  54        select GENERIC_IRQ_PROBE
  55        select GENERIC_IRQ_SHOW
  56        select GENERIC_IRQ_SHOW_LEVEL
  57        select GENERIC_PCI_IOMAP
  58        select GENERIC_SCHED_CLOCK
  59        select GENERIC_SMP_IDLE_THREAD
  60        select GENERIC_STRNCPY_FROM_USER
  61        select GENERIC_STRNLEN_USER
  62        select HANDLE_DOMAIN_IRQ
  63        select HARDIRQS_SW_RESEND
  64        select HAVE_ARCH_AUDITSYSCALL if AEABI && !OABI_COMPAT
  65        select HAVE_ARCH_BITREVERSE if (CPU_32v7M || CPU_32v7) && !CPU_32v6
  66        select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL && !CPU_ENDIAN_BE32 && MMU
  67        select HAVE_ARCH_KGDB if !CPU_ENDIAN_BE32 && MMU
  68        select HAVE_ARCH_MMAP_RND_BITS if MMU
  69        select HAVE_ARCH_SECCOMP_FILTER if AEABI && !OABI_COMPAT
  70        select HAVE_ARCH_THREAD_STRUCT_WHITELIST
  71        select HAVE_ARCH_TRACEHOOK
  72        select HAVE_ARM_SMCCC if CPU_V7
  73        select HAVE_EBPF_JIT if !CPU_ENDIAN_BE32
  74        select HAVE_CONTEXT_TRACKING
  75        select HAVE_C_RECORDMCOUNT
  76        select HAVE_DEBUG_KMEMLEAK
  77        select HAVE_DMA_CONTIGUOUS if MMU
  78        select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && !CPU_ENDIAN_BE32 && MMU
  79        select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE
  80        select HAVE_EFFICIENT_UNALIGNED_ACCESS if (CPU_V6 || CPU_V6K || CPU_V7) && MMU
  81        select HAVE_EXIT_THREAD
  82        select HAVE_FAST_GUP if ARM_LPAE
  83        select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL
  84        select HAVE_FUNCTION_GRAPH_TRACER if !THUMB2_KERNEL && !CC_IS_CLANG
  85        select HAVE_FUNCTION_TRACER if !XIP_KERNEL
  86        select HAVE_GCC_PLUGINS
  87        select HAVE_HW_BREAKPOINT if PERF_EVENTS && (CPU_V6 || CPU_V6K || CPU_V7)
  88        select HAVE_IDE if PCI || ISA || PCMCIA
  89        select HAVE_IRQ_TIME_ACCOUNTING
  90        select HAVE_KERNEL_GZIP
  91        select HAVE_KERNEL_LZ4
  92        select HAVE_KERNEL_LZMA
  93        select HAVE_KERNEL_LZO
  94        select HAVE_KERNEL_XZ
  95        select HAVE_KPROBES if !XIP_KERNEL && !CPU_ENDIAN_BE32 && !CPU_V7M
  96        select HAVE_KRETPROBES if HAVE_KPROBES
  97        select HAVE_MOD_ARCH_SPECIFIC
  98        select HAVE_NMI
  99        select HAVE_OPROFILE if HAVE_PERF_EVENTS
 100        select HAVE_OPTPROBES if !THUMB2_KERNEL
 101        select HAVE_PERF_EVENTS
 102        select HAVE_PERF_REGS
 103        select HAVE_PERF_USER_STACK_DUMP
 104        select HAVE_RCU_TABLE_FREE if SMP && ARM_LPAE
 105        select HAVE_REGS_AND_STACK_ACCESS_API
 106        select HAVE_RSEQ
 107        select HAVE_STACKPROTECTOR
 108        select HAVE_SYSCALL_TRACEPOINTS
 109        select HAVE_UID16
 110        select HAVE_VIRT_CPU_ACCOUNTING_GEN
 111        select IRQ_FORCED_THREADING
 112        select MODULES_USE_ELF_REL
 113        select NEED_DMA_MAP_STATE
 114        select OF_EARLY_FLATTREE if OF
 115        select OLD_SIGACTION
 116        select OLD_SIGSUSPEND3
 117        select PCI_SYSCALL if PCI
 118        select PERF_USE_VMALLOC
 119        select REFCOUNT_FULL
 120        select RTC_LIB
 121        select SYS_SUPPORTS_APM_EMULATION
 122        # Above selects are sorted alphabetically; please add new ones
 123        # according to that.  Thanks.
 124        help
 125          The ARM series is a line of low-power-consumption RISC chip designs
 126          licensed by ARM Ltd and targeted at embedded applications and
 127          handhelds such as the Compaq IPAQ.  ARM-based PCs are no longer
 128          manufactured, but legacy ARM-based PC hardware remains popular in
 129          Europe.  There is an ARM Linux project with a web page at
 130          <http://www.arm.linux.org.uk/>.
 131
 132config ARM_HAS_SG_CHAIN
 133        bool
 134
 135config ARM_DMA_USE_IOMMU
 136        bool
 137        select ARM_HAS_SG_CHAIN
 138        select NEED_SG_DMA_LENGTH
 139
 140if ARM_DMA_USE_IOMMU
 141
 142config ARM_DMA_IOMMU_ALIGNMENT
 143        int "Maximum PAGE_SIZE order of alignment for DMA IOMMU buffers"
 144        range 4 9
 145        default 8
 146        help
 147          DMA mapping framework by default aligns all buffers to the smallest
 148          PAGE_SIZE order which is greater than or equal to the requested buffer
 149          size. This works well for buffers up to a few hundreds kilobytes, but
 150          for larger buffers it just a waste of address space. Drivers which has
 151          relatively small addressing window (like 64Mib) might run out of
 152          virtual space with just a few allocations.
 153
 154          With this parameter you can specify the maximum PAGE_SIZE order for
 155          DMA IOMMU buffers. Larger buffers will be aligned only to this
 156          specified order. The order is expressed as a power of two multiplied
 157          by the PAGE_SIZE.
 158
 159endif
 160
 161config SYS_SUPPORTS_APM_EMULATION
 162        bool
 163
 164config HAVE_TCM
 165        bool
 166        select GENERIC_ALLOCATOR
 167
 168config HAVE_PROC_CPU
 169        bool
 170
 171config NO_IOPORT_MAP
 172        bool
 173
 174config SBUS
 175        bool
 176
 177config STACKTRACE_SUPPORT
 178        bool
 179        default y
 180
 181config LOCKDEP_SUPPORT
 182        bool
 183        default y
 184
 185config TRACE_IRQFLAGS_SUPPORT
 186        bool
 187        default !CPU_V7M
 188
 189config ARCH_HAS_ILOG2_U32
 190        bool
 191
 192config ARCH_HAS_ILOG2_U64
 193        bool
 194
 195config ARCH_HAS_BANDGAP
 196        bool
 197
 198config FIX_EARLYCON_MEM
 199        def_bool y if MMU
 200
 201config GENERIC_HWEIGHT
 202        bool
 203        default y
 204
 205config GENERIC_CALIBRATE_DELAY
 206        bool
 207        default y
 208
 209config ARCH_MAY_HAVE_PC_FDC
 210        bool
 211
 212config ZONE_DMA
 213        bool
 214
 215config ARCH_SUPPORTS_UPROBES
 216        def_bool y
 217
 218config ARCH_HAS_DMA_SET_COHERENT_MASK
 219        bool
 220
 221config GENERIC_ISA_DMA
 222        bool
 223
 224config FIQ
 225        bool
 226
 227config NEED_RET_TO_USER
 228        bool
 229
 230config ARCH_MTD_XIP
 231        bool
 232
 233config ARM_PATCH_PHYS_VIRT
 234        bool "Patch physical to virtual translations at runtime" if EMBEDDED
 235        default y
 236        depends on !XIP_KERNEL && MMU
 237        help
 238          Patch phys-to-virt and virt-to-phys translation functions at
 239          boot and module load time according to the position of the
 240          kernel in system memory.
 241
 242          This can only be used with non-XIP MMU kernels where the base
 243          of physical memory is at a 16MB boundary.
 244
 245          Only disable this option if you know that you do not require
 246          this feature (eg, building a kernel for a single machine) and
 247          you need to shrink the kernel to the minimal size.
 248
 249config NEED_MACH_IO_H
 250        bool
 251        help
 252          Select this when mach/io.h is required to provide special
 253          definitions for this platform.  The need for mach/io.h should
 254          be avoided when possible.
 255
 256config NEED_MACH_MEMORY_H
 257        bool
 258        help
 259          Select this when mach/memory.h is required to provide special
 260          definitions for this platform.  The need for mach/memory.h should
 261          be avoided when possible.
 262
 263config PHYS_OFFSET
 264        hex "Physical address of main memory" if MMU
 265        depends on !ARM_PATCH_PHYS_VIRT
 266        default DRAM_BASE if !MMU
 267        default 0x00000000 if ARCH_EBSA110 || \
 268                        ARCH_FOOTBRIDGE || \
 269                        ARCH_INTEGRATOR || \
 270                        ARCH_IOP13XX || \
 271                        ARCH_KS8695 || \
 272                        ARCH_REALVIEW
 273        default 0x10000000 if ARCH_OMAP1 || ARCH_RPC
 274        default 0x20000000 if ARCH_S5PV210
 275        default 0xc0000000 if ARCH_SA1100
 276        help
 277          Please provide the physical address corresponding to the
 278          location of main memory in your system.
 279
 280config GENERIC_BUG
 281        def_bool y
 282        depends on BUG
 283
 284config PGTABLE_LEVELS
 285        int
 286        default 3 if ARM_LPAE
 287        default 2
 288
 289menu "System Type"
 290
 291config MMU
 292        bool "MMU-based Paged Memory Management Support"
 293        default y
 294        help
 295          Select if you want MMU-based virtualised addressing space
 296          support by paged memory management. If unsure, say 'Y'.
 297
 298config ARCH_MMAP_RND_BITS_MIN
 299        default 8
 300
 301config ARCH_MMAP_RND_BITS_MAX
 302        default 14 if PAGE_OFFSET=0x40000000
 303        default 15 if PAGE_OFFSET=0x80000000
 304        default 16
 305
 306#
 307# The "ARM system type" choice list is ordered alphabetically by option
 308# text.  Please add new entries in the option alphabetic order.
 309#
 310choice
 311        prompt "ARM system type"
 312        default ARM_SINGLE_ARMV7M if !MMU
 313        default ARCH_MULTIPLATFORM if MMU
 314
 315config ARCH_MULTIPLATFORM
 316        bool "Allow multiple platforms to be selected"
 317        depends on MMU
 318        select ARM_HAS_SG_CHAIN
 319        select ARM_PATCH_PHYS_VIRT
 320        select AUTO_ZRELADDR
 321        select TIMER_OF
 322        select COMMON_CLK
 323        select GENERIC_CLOCKEVENTS
 324        select GENERIC_IRQ_MULTI_HANDLER
 325        select HAVE_PCI
 326        select PCI_DOMAINS_GENERIC if PCI
 327        select SPARSE_IRQ
 328        select USE_OF
 329
 330config ARM_SINGLE_ARMV7M
 331        bool "ARMv7-M based platforms (Cortex-M0/M3/M4)"
 332        depends on !MMU
 333        select ARM_NVIC
 334        select AUTO_ZRELADDR
 335        select TIMER_OF
 336        select COMMON_CLK
 337        select CPU_V7M
 338        select GENERIC_CLOCKEVENTS
 339        select NO_IOPORT_MAP
 340        select SPARSE_IRQ
 341        select USE_OF
 342
 343config ARCH_EBSA110
 344        bool "EBSA-110"
 345        select ARCH_USES_GETTIMEOFFSET
 346        select CPU_SA110
 347        select ISA
 348        select NEED_MACH_IO_H
 349        select NEED_MACH_MEMORY_H
 350        select NO_IOPORT_MAP
 351        help
 352          This is an evaluation board for the StrongARM processor available
 353          from Digital. It has limited hardware on-board, including an
 354          Ethernet interface, two PCMCIA sockets, two serial ports and a
 355          parallel port.
 356
 357config ARCH_EP93XX
 358        bool "EP93xx-based"
 359        select ARCH_SPARSEMEM_ENABLE
 360        select ARM_AMBA
 361        imply ARM_PATCH_PHYS_VIRT
 362        select ARM_VIC
 363        select AUTO_ZRELADDR
 364        select CLKDEV_LOOKUP
 365        select CLKSRC_MMIO
 366        select CPU_ARM920T
 367        select GENERIC_CLOCKEVENTS
 368        select GPIOLIB
 369        help
 370          This enables support for the Cirrus EP93xx series of CPUs.
 371
 372config ARCH_FOOTBRIDGE
 373        bool "FootBridge"
 374        select CPU_SA110
 375        select FOOTBRIDGE
 376        select GENERIC_CLOCKEVENTS
 377        select HAVE_IDE
 378        select NEED_MACH_IO_H if !MMU
 379        select NEED_MACH_MEMORY_H
 380        help
 381          Support for systems based on the DC21285 companion chip
 382          ("FootBridge"), such as the Simtec CATS and the Rebel NetWinder.
 383
 384config ARCH_IOP13XX
 385        bool "IOP13xx-based"
 386        depends on MMU
 387        select CPU_XSC3
 388        select NEED_MACH_MEMORY_H
 389        select NEED_RET_TO_USER
 390        select FORCE_PCI
 391        select PLAT_IOP
 392        select VMSPLIT_1G
 393        select SPARSE_IRQ
 394        help
 395          Support for Intel's IOP13XX (XScale) family of processors.
 396
 397config ARCH_IOP32X
 398        bool "IOP32x-based"
 399        depends on MMU
 400        select CPU_XSCALE
 401        select GPIO_IOP
 402        select GPIOLIB
 403        select NEED_RET_TO_USER
 404        select FORCE_PCI
 405        select PLAT_IOP
 406        help
 407          Support for Intel's 80219 and IOP32X (XScale) family of
 408          processors.
 409
 410config ARCH_IOP33X
 411        bool "IOP33x-based"
 412        depends on MMU
 413        select CPU_XSCALE
 414        select GPIO_IOP
 415        select GPIOLIB
 416        select NEED_RET_TO_USER
 417        select FORCE_PCI
 418        select PLAT_IOP
 419        help
 420          Support for Intel's IOP33X (XScale) family of processors.
 421
 422config ARCH_IXP4XX
 423        bool "IXP4xx-based"
 424        depends on MMU
 425        select ARCH_HAS_DMA_SET_COHERENT_MASK
 426        select ARCH_SUPPORTS_BIG_ENDIAN
 427        select CPU_XSCALE
 428        select DMABOUNCE if PCI
 429        select GENERIC_CLOCKEVENTS
 430        select GENERIC_IRQ_MULTI_HANDLER
 431        select GPIO_IXP4XX
 432        select GPIOLIB
 433        select HAVE_PCI
 434        select IXP4XX_IRQ
 435        select IXP4XX_TIMER
 436        select NEED_MACH_IO_H
 437        select USB_EHCI_BIG_ENDIAN_DESC
 438        select USB_EHCI_BIG_ENDIAN_MMIO
 439        help
 440          Support for Intel's IXP4XX (XScale) family of processors.
 441
 442config ARCH_DOVE
 443        bool "Marvell Dove"
 444        select CPU_PJ4
 445        select GENERIC_CLOCKEVENTS
 446        select GENERIC_IRQ_MULTI_HANDLER
 447        select GPIOLIB
 448        select HAVE_PCI
 449        select MVEBU_MBUS
 450        select PINCTRL
 451        select PINCTRL_DOVE
 452        select PLAT_ORION_LEGACY
 453        select SPARSE_IRQ
 454        select PM_GENERIC_DOMAINS if PM
 455        help
 456          Support for the Marvell Dove SoC 88AP510
 457
 458config ARCH_KS8695
 459        bool "Micrel/Kendin KS8695"
 460        select CLKSRC_MMIO
 461        select CPU_ARM922T
 462        select GENERIC_CLOCKEVENTS
 463        select GPIOLIB
 464        select NEED_MACH_MEMORY_H
 465        help
 466          Support for Micrel/Kendin KS8695 "Centaur" (ARM922T) based
 467          System-on-Chip devices.
 468
 469config ARCH_W90X900
 470        bool "Nuvoton W90X900 CPU"
 471        select CLKDEV_LOOKUP
 472        select CLKSRC_MMIO
 473        select CPU_ARM926T
 474        select GENERIC_CLOCKEVENTS
 475        select GPIOLIB
 476        help
 477          Support for Nuvoton (Winbond logic dept.) ARM9 processor,
 478          At present, the w90x900 has been renamed nuc900, regarding
 479          the ARM series product line, you can login the following
 480          link address to know more.
 481
 482          <http://www.nuvoton.com/hq/enu/ProductAndSales/ProductLines/
 483                ConsumerElectronicsIC/ARMMicrocontroller/ARMMicrocontroller>
 484
 485config ARCH_LPC32XX
 486        bool "NXP LPC32XX"
 487        select ARM_AMBA
 488        select CLKDEV_LOOKUP
 489        select CLKSRC_LPC32XX
 490        select COMMON_CLK
 491        select CPU_ARM926T
 492        select GENERIC_CLOCKEVENTS
 493        select GENERIC_IRQ_MULTI_HANDLER
 494        select GPIOLIB
 495        select SPARSE_IRQ
 496        select USE_OF
 497        help
 498          Support for the NXP LPC32XX family of processors
 499
 500config ARCH_PXA
 501        bool "PXA2xx/PXA3xx-based"
 502        depends on MMU
 503        select ARCH_MTD_XIP
 504        select ARM_CPU_SUSPEND if PM
 505        select AUTO_ZRELADDR
 506        select COMMON_CLK
 507        select CLKDEV_LOOKUP
 508        select CLKSRC_PXA
 509        select CLKSRC_MMIO
 510        select TIMER_OF
 511        select CPU_XSCALE if !CPU_XSC3
 512        select GENERIC_CLOCKEVENTS
 513        select GENERIC_IRQ_MULTI_HANDLER
 514        select GPIO_PXA
 515        select GPIOLIB
 516        select HAVE_IDE
 517        select IRQ_DOMAIN
 518        select PLAT_PXA
 519        select SPARSE_IRQ
 520        help
 521          Support for Intel/Marvell's PXA2xx/PXA3xx processor line.
 522
 523config ARCH_RPC
 524        bool "RiscPC"
 525        depends on MMU
 526        select ARCH_ACORN
 527        select ARCH_MAY_HAVE_PC_FDC
 528        select ARCH_SPARSEMEM_ENABLE
 529        select ARM_HAS_SG_CHAIN
 530        select CPU_SA110
 531        select FIQ
 532        select HAVE_IDE
 533        select HAVE_PATA_PLATFORM
 534        select ISA_DMA_API
 535        select NEED_MACH_IO_H
 536        select NEED_MACH_MEMORY_H
 537        select NO_IOPORT_MAP
 538        help
 539          On the Acorn Risc-PC, Linux can support the internal IDE disk and
 540          CD-ROM interface, serial and parallel port, and the floppy drive.
 541
 542config ARCH_SA1100
 543        bool "SA1100-based"
 544        select ARCH_MTD_XIP
 545        select ARCH_SPARSEMEM_ENABLE
 546        select CLKDEV_LOOKUP
 547        select CLKSRC_MMIO
 548        select CLKSRC_PXA
 549        select TIMER_OF if OF
 550        select COMMON_CLK
 551        select CPU_FREQ
 552        select CPU_SA1100
 553        select GENERIC_CLOCKEVENTS
 554        select GENERIC_IRQ_MULTI_HANDLER
 555        select GPIOLIB
 556        select HAVE_IDE
 557        select IRQ_DOMAIN
 558        select ISA
 559        select NEED_MACH_MEMORY_H
 560        select SPARSE_IRQ
 561        help
 562          Support for StrongARM 11x0 based boards.
 563
 564config ARCH_S3C24XX
 565        bool "Samsung S3C24XX SoCs"
 566        select ATAGS
 567        select CLKDEV_LOOKUP
 568        select CLKSRC_SAMSUNG_PWM
 569        select GENERIC_CLOCKEVENTS
 570        select GPIO_SAMSUNG
 571        select GPIOLIB
 572        select GENERIC_IRQ_MULTI_HANDLER
 573        select HAVE_S3C2410_I2C if I2C
 574        select HAVE_S3C2410_WATCHDOG if WATCHDOG
 575        select HAVE_S3C_RTC if RTC_CLASS
 576        select NEED_MACH_IO_H
 577        select SAMSUNG_ATAGS
 578        select USE_OF
 579        help
 580          Samsung S3C2410, S3C2412, S3C2413, S3C2416, S3C2440, S3C2442, S3C2443
 581          and S3C2450 SoCs based systems, such as the Simtec Electronics BAST
 582          (<http://www.simtec.co.uk/products/EB110ITX/>), the IPAQ 1940 or the
 583          Samsung SMDK2410 development board (and derivatives).
 584
 585config ARCH_DAVINCI
 586        bool "TI DaVinci"
 587        select ARCH_HAS_HOLES_MEMORYMODEL
 588        select COMMON_CLK
 589        select CPU_ARM926T
 590        select GENERIC_ALLOCATOR
 591        select GENERIC_CLOCKEVENTS
 592        select GENERIC_IRQ_CHIP
 593        select GENERIC_IRQ_MULTI_HANDLER
 594        select GPIOLIB
 595        select HAVE_IDE
 596        select PM_GENERIC_DOMAINS if PM
 597        select PM_GENERIC_DOMAINS_OF if PM && OF
 598        select REGMAP_MMIO
 599        select RESET_CONTROLLER
 600        select SPARSE_IRQ
 601        select USE_OF
 602        select ZONE_DMA
 603        help
 604          Support for TI's DaVinci platform.
 605
 606config ARCH_OMAP1
 607        bool "TI OMAP1"
 608        depends on MMU
 609        select ARCH_HAS_HOLES_MEMORYMODEL
 610        select ARCH_OMAP
 611        select CLKDEV_LOOKUP
 612        select CLKSRC_MMIO
 613        select GENERIC_CLOCKEVENTS
 614        select GENERIC_IRQ_CHIP
 615        select GENERIC_IRQ_MULTI_HANDLER
 616        select GPIOLIB
 617        select HAVE_IDE
 618        select IRQ_DOMAIN
 619        select NEED_MACH_IO_H if PCCARD
 620        select NEED_MACH_MEMORY_H
 621        select SPARSE_IRQ
 622        help
 623          Support for older TI OMAP1 (omap7xx, omap15xx or omap16xx)
 624
 625endchoice
 626
 627menu "Multiple platform selection"
 628        depends on ARCH_MULTIPLATFORM
 629
 630comment "CPU Core family selection"
 631
 632config ARCH_MULTI_V4
 633        bool "ARMv4 based platforms (FA526)"
 634        depends on !ARCH_MULTI_V6_V7
 635        select ARCH_MULTI_V4_V5
 636        select CPU_FA526
 637
 638config ARCH_MULTI_V4T
 639        bool "ARMv4T based platforms (ARM720T, ARM920T, ...)"
 640        depends on !ARCH_MULTI_V6_V7
 641        select ARCH_MULTI_V4_V5
 642        select CPU_ARM920T if !(CPU_ARM7TDMI || CPU_ARM720T || \
 643                CPU_ARM740T || CPU_ARM9TDMI || CPU_ARM922T || \
 644                CPU_ARM925T || CPU_ARM940T)
 645
 646config ARCH_MULTI_V5
 647        bool "ARMv5 based platforms (ARM926T, XSCALE, PJ1, ...)"
 648        depends on !ARCH_MULTI_V6_V7
 649        select ARCH_MULTI_V4_V5
 650        select CPU_ARM926T if !(CPU_ARM946E || CPU_ARM1020 || \
 651                CPU_ARM1020E || CPU_ARM1022 || CPU_ARM1026 || \
 652                CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK || CPU_FEROCEON)
 653
 654config ARCH_MULTI_V4_V5
 655        bool
 656
 657config ARCH_MULTI_V6
 658        bool "ARMv6 based platforms (ARM11)"
 659        select ARCH_MULTI_V6_V7
 660        select CPU_V6K
 661
 662config ARCH_MULTI_V7
 663        bool "ARMv7 based platforms (Cortex-A, PJ4, Scorpion, Krait)"
 664        default y
 665        select ARCH_MULTI_V6_V7
 666        select CPU_V7
 667        select HAVE_SMP
 668
 669config ARCH_MULTI_V6_V7
 670        bool
 671        select MIGHT_HAVE_CACHE_L2X0
 672
 673config ARCH_MULTI_CPU_AUTO
 674        def_bool !(ARCH_MULTI_V4 || ARCH_MULTI_V4T || ARCH_MULTI_V6_V7)
 675        select ARCH_MULTI_V5
 676
 677endmenu
 678
 679config ARCH_VIRT
 680        bool "Dummy Virtual Machine"
 681        depends on ARCH_MULTI_V7
 682        select ARM_AMBA
 683        select ARM_GIC
 684        select ARM_GIC_V2M if PCI
 685        select ARM_GIC_V3
 686        select ARM_GIC_V3_ITS if PCI
 687        select ARM_PSCI
 688        select HAVE_ARM_ARCH_TIMER
 689        select ARCH_SUPPORTS_BIG_ENDIAN
 690
 691#
 692# This is sorted alphabetically by mach-* pathname.  However, plat-*
 693# Kconfigs may be included either alphabetically (according to the
 694# plat- suffix) or along side the corresponding mach-* source.
 695#
 696source "arch/arm/mach-actions/Kconfig"
 697
 698source "arch/arm/mach-alpine/Kconfig"
 699
 700source "arch/arm/mach-artpec/Kconfig"
 701
 702source "arch/arm/mach-asm9260/Kconfig"
 703
 704source "arch/arm/mach-aspeed/Kconfig"
 705
 706source "arch/arm/mach-at91/Kconfig"
 707
 708source "arch/arm/mach-axxia/Kconfig"
 709
 710source "arch/arm/mach-bcm/Kconfig"
 711
 712source "arch/arm/mach-berlin/Kconfig"
 713
 714source "arch/arm/mach-clps711x/Kconfig"
 715
 716source "arch/arm/mach-cns3xxx/Kconfig"
 717
 718source "arch/arm/mach-davinci/Kconfig"
 719
 720source "arch/arm/mach-digicolor/Kconfig"
 721
 722source "arch/arm/mach-dove/Kconfig"
 723
 724source "arch/arm/mach-ep93xx/Kconfig"
 725
 726source "arch/arm/mach-exynos/Kconfig"
 727source "arch/arm/plat-samsung/Kconfig"
 728
 729source "arch/arm/mach-footbridge/Kconfig"
 730
 731source "arch/arm/mach-gemini/Kconfig"
 732
 733source "arch/arm/mach-highbank/Kconfig"
 734
 735source "arch/arm/mach-hisi/Kconfig"
 736
 737source "arch/arm/mach-imx/Kconfig"
 738
 739source "arch/arm/mach-integrator/Kconfig"
 740
 741source "arch/arm/mach-iop13xx/Kconfig"
 742
 743source "arch/arm/mach-iop32x/Kconfig"
 744
 745source "arch/arm/mach-iop33x/Kconfig"
 746
 747source "arch/arm/mach-ixp4xx/Kconfig"
 748
 749source "arch/arm/mach-keystone/Kconfig"
 750
 751source "arch/arm/mach-ks8695/Kconfig"
 752
 753source "arch/arm/mach-mediatek/Kconfig"
 754
 755source "arch/arm/mach-meson/Kconfig"
 756
 757source "arch/arm/mach-milbeaut/Kconfig"
 758
 759source "arch/arm/mach-mmp/Kconfig"
 760
 761source "arch/arm/mach-moxart/Kconfig"
 762
 763source "arch/arm/mach-mv78xx0/Kconfig"
 764
 765source "arch/arm/mach-mvebu/Kconfig"
 766
 767source "arch/arm/mach-mxs/Kconfig"
 768
 769source "arch/arm/mach-nomadik/Kconfig"
 770
 771source "arch/arm/mach-npcm/Kconfig"
 772
 773source "arch/arm/mach-nspire/Kconfig"
 774
 775source "arch/arm/plat-omap/Kconfig"
 776
 777source "arch/arm/mach-omap1/Kconfig"
 778
 779source "arch/arm/mach-omap2/Kconfig"
 780
 781source "arch/arm/mach-orion5x/Kconfig"
 782
 783source "arch/arm/mach-oxnas/Kconfig"
 784
 785source "arch/arm/mach-picoxcell/Kconfig"
 786
 787source "arch/arm/mach-prima2/Kconfig"
 788
 789source "arch/arm/mach-pxa/Kconfig"
 790source "arch/arm/plat-pxa/Kconfig"
 791
 792source "arch/arm/mach-qcom/Kconfig"
 793
 794source "arch/arm/mach-rda/Kconfig"
 795
 796source "arch/arm/mach-realview/Kconfig"
 797
 798source "arch/arm/mach-rockchip/Kconfig"
 799
 800source "arch/arm/mach-s3c24xx/Kconfig"
 801
 802source "arch/arm/mach-s3c64xx/Kconfig"
 803
 804source "arch/arm/mach-s5pv210/Kconfig"
 805
 806source "arch/arm/mach-sa1100/Kconfig"
 807
 808source "arch/arm/mach-shmobile/Kconfig"
 809
 810source "arch/arm/mach-socfpga/Kconfig"
 811
 812source "arch/arm/mach-spear/Kconfig"
 813
 814source "arch/arm/mach-sti/Kconfig"
 815
 816source "arch/arm/mach-stm32/Kconfig"
 817
 818source "arch/arm/mach-sunxi/Kconfig"
 819
 820source "arch/arm/mach-tango/Kconfig"
 821
 822source "arch/arm/mach-tegra/Kconfig"
 823
 824source "arch/arm/mach-u300/Kconfig"
 825
 826source "arch/arm/mach-uniphier/Kconfig"
 827
 828source "arch/arm/mach-ux500/Kconfig"
 829
 830source "arch/arm/mach-versatile/Kconfig"
 831
 832source "arch/arm/mach-vexpress/Kconfig"
 833source "arch/arm/plat-versatile/Kconfig"
 834
 835source "arch/arm/mach-vt8500/Kconfig"
 836
 837source "arch/arm/mach-w90x900/Kconfig"
 838
 839source "arch/arm/mach-zx/Kconfig"
 840
 841source "arch/arm/mach-zynq/Kconfig"
 842
 843# ARMv7-M architecture
 844config ARCH_EFM32
 845        bool "Energy Micro efm32"
 846        depends on ARM_SINGLE_ARMV7M
 847        select GPIOLIB
 848        help
 849          Support for Energy Micro's (now Silicon Labs) efm32 Giant Gecko
 850          processors.
 851
 852config ARCH_LPC18XX
 853        bool "NXP LPC18xx/LPC43xx"
 854        depends on ARM_SINGLE_ARMV7M
 855        select ARCH_HAS_RESET_CONTROLLER
 856        select ARM_AMBA
 857        select CLKSRC_LPC32XX
 858        select PINCTRL
 859        help
 860          Support for NXP's LPC18xx Cortex-M3 and LPC43xx Cortex-M4
 861          high performance microcontrollers.
 862
 863config ARCH_MPS2
 864        bool "ARM MPS2 platform"
 865        depends on ARM_SINGLE_ARMV7M
 866        select ARM_AMBA
 867        select CLKSRC_MPS2
 868        help
 869          Support for Cortex-M Prototyping System (or V2M-MPS2) which comes
 870          with a range of available cores like Cortex-M3/M4/M7.
 871
 872          Please, note that depends which Application Note is used memory map
 873          for the platform may vary, so adjustment of RAM base might be needed.
 874
 875# Definitions to make life easier
 876config ARCH_ACORN
 877        bool
 878
 879config PLAT_IOP
 880        bool
 881        select GENERIC_CLOCKEVENTS
 882
 883config PLAT_ORION
 884        bool
 885        select CLKSRC_MMIO
 886        select COMMON_CLK
 887        select GENERIC_IRQ_CHIP
 888        select IRQ_DOMAIN
 889
 890config PLAT_ORION_LEGACY
 891        bool
 892        select PLAT_ORION
 893
 894config PLAT_PXA
 895        bool
 896
 897config PLAT_VERSATILE
 898        bool
 899
 900source "arch/arm/mm/Kconfig"
 901
 902config IWMMXT
 903        bool "Enable iWMMXt support"
 904        depends on CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK || CPU_PJ4 || CPU_PJ4B
 905        default y if PXA27x || PXA3xx || ARCH_MMP || CPU_PJ4 || CPU_PJ4B
 906        help
 907          Enable support for iWMMXt context switching at run time if
 908          running on a CPU that supports it.
 909
 910if !MMU
 911source "arch/arm/Kconfig-nommu"
 912endif
 913
 914config PJ4B_ERRATA_4742
 915        bool "PJ4B Errata 4742: IDLE Wake Up Commands can Cause the CPU Core to Cease Operation"
 916        depends on CPU_PJ4B && MACH_ARMADA_370
 917        default y
 918        help
 919          When coming out of either a Wait for Interrupt (WFI) or a Wait for
 920          Event (WFE) IDLE states, a specific timing sensitivity exists between
 921          the retiring WFI/WFE instructions and the newly issued subsequent
 922          instructions.  This sensitivity can result in a CPU hang scenario.
 923          Workaround:
 924          The software must insert either a Data Synchronization Barrier (DSB)
 925          or Data Memory Barrier (DMB) command immediately after the WFI/WFE
 926          instruction
 927
 928config ARM_ERRATA_326103
 929        bool "ARM errata: FSR write bit incorrect on a SWP to read-only memory"
 930        depends on CPU_V6
 931        help
 932          Executing a SWP instruction to read-only memory does not set bit 11
 933          of the FSR on the ARM 1136 prior to r1p0. This causes the kernel to
 934          treat the access as a read, preventing a COW from occurring and
 935          causing the faulting task to livelock.
 936
 937config ARM_ERRATA_411920
 938        bool "ARM errata: Invalidation of the Instruction Cache operation can fail"
 939        depends on CPU_V6 || CPU_V6K
 940        help
 941          Invalidation of the Instruction Cache operation can
 942          fail. This erratum is present in 1136 (before r1p4), 1156 and 1176.
 943          It does not affect the MPCore. This option enables the ARM Ltd.
 944          recommended workaround.
 945
 946config ARM_ERRATA_430973
 947        bool "ARM errata: Stale prediction on replaced interworking branch"
 948        depends on CPU_V7
 949        help
 950          This option enables the workaround for the 430973 Cortex-A8
 951          r1p* erratum. If a code sequence containing an ARM/Thumb
 952          interworking branch is replaced with another code sequence at the
 953          same virtual address, whether due to self-modifying code or virtual
 954          to physical address re-mapping, Cortex-A8 does not recover from the
 955          stale interworking branch prediction. This results in Cortex-A8
 956          executing the new code sequence in the incorrect ARM or Thumb state.
 957          The workaround enables the BTB/BTAC operations by setting ACTLR.IBE
 958          and also flushes the branch target cache at every context switch.
 959          Note that setting specific bits in the ACTLR register may not be
 960          available in non-secure mode.
 961
 962config ARM_ERRATA_458693
 963        bool "ARM errata: Processor deadlock when a false hazard is created"
 964        depends on CPU_V7
 965        depends on !ARCH_MULTIPLATFORM
 966        help
 967          This option enables the workaround for the 458693 Cortex-A8 (r2p0)
 968          erratum. For very specific sequences of memory operations, it is
 969          possible for a hazard condition intended for a cache line to instead
 970          be incorrectly associated with a different cache line. This false
 971          hazard might then cause a processor deadlock. The workaround enables
 972          the L1 caching of the NEON accesses and disables the PLD instruction
 973          in the ACTLR register. Note that setting specific bits in the ACTLR
 974          register may not be available in non-secure mode.
 975
 976config ARM_ERRATA_460075
 977        bool "ARM errata: Data written to the L2 cache can be overwritten with stale data"
 978        depends on CPU_V7
 979        depends on !ARCH_MULTIPLATFORM
 980        help
 981          This option enables the workaround for the 460075 Cortex-A8 (r2p0)
 982          erratum. Any asynchronous access to the L2 cache may encounter a
 983          situation in which recent store transactions to the L2 cache are lost
 984          and overwritten with stale memory contents from external memory. The
 985          workaround disables the write-allocate mode for the L2 cache via the
 986          ACTLR register. Note that setting specific bits in the ACTLR register
 987          may not be available in non-secure mode.
 988
 989config ARM_ERRATA_742230
 990        bool "ARM errata: DMB operation may be faulty"
 991        depends on CPU_V7 && SMP
 992        depends on !ARCH_MULTIPLATFORM
 993        help
 994          This option enables the workaround for the 742230 Cortex-A9
 995          (r1p0..r2p2) erratum. Under rare circumstances, a DMB instruction
 996          between two write operations may not ensure the correct visibility
 997          ordering of the two writes. This workaround sets a specific bit in
 998          the diagnostic register of the Cortex-A9 which causes the DMB
 999          instruction to behave as a DSB, ensuring the correct behaviour of
1000          the two writes.
1001
1002config ARM_ERRATA_742231
1003        bool "ARM errata: Incorrect hazard handling in the SCU may lead to data corruption"
1004        depends on CPU_V7 && SMP
1005        depends on !ARCH_MULTIPLATFORM
1006        help
1007          This option enables the workaround for the 742231 Cortex-A9
1008          (r2p0..r2p2) erratum. Under certain conditions, specific to the
1009          Cortex-A9 MPCore micro-architecture, two CPUs working in SMP mode,
1010          accessing some data located in the same cache line, may get corrupted
1011          data due to bad handling of the address hazard when the line gets
1012          replaced from one of the CPUs at the same time as another CPU is
1013          accessing it. This workaround sets specific bits in the diagnostic
1014          register of the Cortex-A9 which reduces the linefill issuing
1015          capabilities of the processor.
1016
1017config ARM_ERRATA_643719
1018        bool "ARM errata: LoUIS bit field in CLIDR register is incorrect"
1019        depends on CPU_V7 && SMP
1020        default y
1021        help
1022          This option enables the workaround for the 643719 Cortex-A9 (prior to
1023          r1p0) erratum. On affected cores the LoUIS bit field of the CLIDR
1024          register returns zero when it should return one. The workaround
1025          corrects this value, ensuring cache maintenance operations which use
1026          it behave as intended and avoiding data corruption.
1027
1028config ARM_ERRATA_720789
1029        bool "ARM errata: TLBIASIDIS and TLBIMVAIS operations can broadcast a faulty ASID"
1030        depends on CPU_V7
1031        help
1032          This option enables the workaround for the 720789 Cortex-A9 (prior to
1033          r2p0) erratum. A faulty ASID can be sent to the other CPUs for the
1034          broadcasted CP15 TLB maintenance operations TLBIASIDIS and TLBIMVAIS.
1035          As a consequence of this erratum, some TLB entries which should be
1036          invalidated are not, resulting in an incoherency in the system page
1037          tables. The workaround changes the TLB flushing routines to invalidate
1038          entries regardless of the ASID.
1039
1040config ARM_ERRATA_743622
1041        bool "ARM errata: Faulty hazard checking in the Store Buffer may lead to data corruption"
1042        depends on CPU_V7
1043        depends on !ARCH_MULTIPLATFORM
1044        help
1045          This option enables the workaround for the 743622 Cortex-A9
1046          (r2p*) erratum. Under very rare conditions, a faulty
1047          optimisation in the Cortex-A9 Store Buffer may lead to data
1048          corruption. This workaround sets a specific bit in the diagnostic
1049          register of the Cortex-A9 which disables the Store Buffer
1050          optimisation, preventing the defect from occurring. This has no
1051          visible impact on the overall performance or power consumption of the
1052          processor.
1053
1054config ARM_ERRATA_751472
1055        bool "ARM errata: Interrupted ICIALLUIS may prevent completion of broadcasted operation"
1056        depends on CPU_V7
1057        depends on !ARCH_MULTIPLATFORM
1058        help
1059          This option enables the workaround for the 751472 Cortex-A9 (prior
1060          to r3p0) erratum. An interrupted ICIALLUIS operation may prevent the
1061          completion of a following broadcasted operation if the second
1062          operation is received by a CPU before the ICIALLUIS has completed,
1063          potentially leading to corrupted entries in the cache or TLB.
1064
1065config ARM_ERRATA_754322
1066        bool "ARM errata: possible faulty MMU translations following an ASID switch"
1067        depends on CPU_V7
1068        help
1069          This option enables the workaround for the 754322 Cortex-A9 (r2p*,
1070          r3p*) erratum. A speculative memory access may cause a page table walk
1071          which starts prior to an ASID switch but completes afterwards. This
1072          can populate the micro-TLB with a stale entry which may be hit with
1073          the new ASID. This workaround places two dsb instructions in the mm
1074          switching code so that no page table walks can cross the ASID switch.
1075
1076config ARM_ERRATA_754327
1077        bool "ARM errata: no automatic Store Buffer drain"
1078        depends on CPU_V7 && SMP
1079        help
1080          This option enables the workaround for the 754327 Cortex-A9 (prior to
1081          r2p0) erratum. The Store Buffer does not have any automatic draining
1082          mechanism and therefore a livelock may occur if an external agent
1083          continuously polls a memory location waiting to observe an update.
1084          This workaround defines cpu_relax() as smp_mb(), preventing correctly
1085          written polling loops from denying visibility of updates to memory.
1086
1087config ARM_ERRATA_364296
1088        bool "ARM errata: Possible cache data corruption with hit-under-miss enabled"
1089        depends on CPU_V6
1090        help
1091          This options enables the workaround for the 364296 ARM1136
1092          r0p2 erratum (possible cache data corruption with
1093          hit-under-miss enabled). It sets the undocumented bit 31 in
1094          the auxiliary control register and the FI bit in the control
1095          register, thus disabling hit-under-miss without putting the
1096          processor into full low interrupt latency mode. ARM11MPCore
1097          is not affected.
1098
1099config ARM_ERRATA_764369
1100        bool "ARM errata: Data cache line maintenance operation by MVA may not succeed"
1101        depends on CPU_V7 && SMP
1102        help
1103          This option enables the workaround for erratum 764369
1104          affecting Cortex-A9 MPCore with two or more processors (all
1105          current revisions). Under certain timing circumstances, a data
1106          cache line maintenance operation by MVA targeting an Inner
1107          Shareable memory region may fail to proceed up to either the
1108          Point of Coherency or to the Point of Unification of the
1109          system. This workaround adds a DSB instruction before the
1110          relevant cache maintenance functions and sets a specific bit
1111          in the diagnostic control register of the SCU.
1112
1113config ARM_ERRATA_775420
1114       bool "ARM errata: A data cache maintenance operation which aborts, might lead to deadlock"
1115       depends on CPU_V7
1116       help
1117         This option enables the workaround for the 775420 Cortex-A9 (r2p2,
1118         r2p6,r2p8,r2p10,r3p0) erratum. In case a date cache maintenance
1119         operation aborts with MMU exception, it might cause the processor
1120         to deadlock. This workaround puts DSB before executing ISB if
1121         an abort may occur on cache maintenance.
1122
1123config ARM_ERRATA_798181
1124        bool "ARM errata: TLBI/DSB failure on Cortex-A15"
1125        depends on CPU_V7 && SMP
1126        help
1127          On Cortex-A15 (r0p0..r3p2) the TLBI*IS/DSB operations are not
1128          adequately shooting down all use of the old entries. This
1129          option enables the Linux kernel workaround for this erratum
1130          which sends an IPI to the CPUs that are running the same ASID
1131          as the one being invalidated.
1132
1133config ARM_ERRATA_773022
1134        bool "ARM errata: incorrect instructions may be executed from loop buffer"
1135        depends on CPU_V7
1136        help
1137          This option enables the workaround for the 773022 Cortex-A15
1138          (up to r0p4) erratum. In certain rare sequences of code, the
1139          loop buffer may deliver incorrect instructions. This
1140          workaround disables the loop buffer to avoid the erratum.
1141
1142config ARM_ERRATA_818325_852422
1143        bool "ARM errata: A12: some seqs of opposed cond code instrs => deadlock or corruption"
1144        depends on CPU_V7
1145        help
1146          This option enables the workaround for:
1147          - Cortex-A12 818325: Execution of an UNPREDICTABLE STR or STM
1148            instruction might deadlock.  Fixed in r0p1.
1149          - Cortex-A12 852422: Execution of a sequence of instructions might
1150            lead to either a data corruption or a CPU deadlock.  Not fixed in
1151            any Cortex-A12 cores yet.
1152          This workaround for all both errata involves setting bit[12] of the
1153          Feature Register. This bit disables an optimisation applied to a
1154          sequence of 2 instructions that use opposing condition codes.
1155
1156config ARM_ERRATA_821420
1157        bool "ARM errata: A12: sequence of VMOV to core registers might lead to a dead lock"
1158        depends on CPU_V7
1159        help
1160          This option enables the workaround for the 821420 Cortex-A12
1161          (all revs) erratum. In very rare timing conditions, a sequence
1162          of VMOV to Core registers instructions, for which the second
1163          one is in the shadow of a branch or abort, can lead to a
1164          deadlock when the VMOV instructions are issued out-of-order.
1165
1166config ARM_ERRATA_825619
1167        bool "ARM errata: A12: DMB NSHST/ISHST mixed ... might cause deadlock"
1168        depends on CPU_V7
1169        help
1170          This option enables the workaround for the 825619 Cortex-A12
1171          (all revs) erratum. Within rare timing constraints, executing a
1172          DMB NSHST or DMB ISHST instruction followed by a mix of Cacheable
1173          and Device/Strongly-Ordered loads and stores might cause deadlock
1174
1175config ARM_ERRATA_857271
1176        bool "ARM errata: A12: CPU might deadlock under some very rare internal conditions"
1177        depends on CPU_V7
1178        help
1179          This option enables the workaround for the 857271 Cortex-A12
1180          (all revs) erratum. Under very rare timing conditions, the CPU might
1181          hang. The workaround is expected to have a < 1% performance impact.
1182
1183config ARM_ERRATA_852421
1184        bool "ARM errata: A17: DMB ST might fail to create order between stores"
1185        depends on CPU_V7
1186        help
1187          This option enables the workaround for the 852421 Cortex-A17
1188          (r1p0, r1p1, r1p2) erratum. Under very rare timing conditions,
1189          execution of a DMB ST instruction might fail to properly order
1190          stores from GroupA and stores from GroupB.
1191
1192config ARM_ERRATA_852423
1193        bool "ARM errata: A17: some seqs of opposed cond code instrs => deadlock or corruption"
1194        depends on CPU_V7
1195        help
1196          This option enables the workaround for:
1197          - Cortex-A17 852423: Execution of a sequence of instructions might
1198            lead to either a data corruption or a CPU deadlock.  Not fixed in
1199            any Cortex-A17 cores yet.
1200          This is identical to Cortex-A12 erratum 852422.  It is a separate
1201          config option from the A12 erratum due to the way errata are checked
1202          for and handled.
1203
1204config ARM_ERRATA_857272
1205        bool "ARM errata: A17: CPU might deadlock under some very rare internal conditions"
1206        depends on CPU_V7
1207        help
1208          This option enables the workaround for the 857272 Cortex-A17 erratum.
1209          This erratum is not known to be fixed in any A17 revision.
1210          This is identical to Cortex-A12 erratum 857271.  It is a separate
1211          config option from the A12 erratum due to the way errata are checked
1212          for and handled.
1213
1214endmenu
1215
1216source "arch/arm/common/Kconfig"
1217
1218menu "Bus support"
1219
1220config ISA
1221        bool
1222        help
1223          Find out whether you have ISA slots on your motherboard.  ISA is the
1224          name of a bus system, i.e. the way the CPU talks to the other stuff
1225          inside your box.  Other bus systems are PCI, EISA, MicroChannel
1226          (MCA) or VESA.  ISA is an older system, now being displaced by PCI;
1227          newer boards don't support it.  If you have ISA, say Y, otherwise N.
1228
1229# Select ISA DMA controller support
1230config ISA_DMA
1231        bool
1232        select ISA_DMA_API
1233
1234# Select ISA DMA interface
1235config ISA_DMA_API
1236        bool
1237
1238config PCI_NANOENGINE
1239        bool "BSE nanoEngine PCI support"
1240        depends on SA1100_NANOENGINE
1241        help
1242          Enable PCI on the BSE nanoEngine board.
1243
1244config PCI_HOST_ITE8152
1245        bool
1246        depends on PCI && MACH_ARMCORE
1247        default y
1248        select DMABOUNCE
1249
1250config ARM_ERRATA_814220
1251        bool "ARM errata: Cache maintenance by set/way operations can execute out of order"
1252        depends on CPU_V7
1253        help
1254          The v7 ARM states that all cache and branch predictor maintenance
1255          operations that do not specify an address execute, relative to
1256          each other, in program order.
1257          However, because of this erratum, an L2 set/way cache maintenance
1258          operation can overtake an L1 set/way cache maintenance operation.
1259          This ERRATA only affected the Cortex-A7 and present in r0p2, r0p3,
1260          r0p4, r0p5.
1261
1262endmenu
1263
1264menu "Kernel Features"
1265
1266config HAVE_SMP
1267        bool
1268        help
1269          This option should be selected by machines which have an SMP-
1270          capable CPU.
1271
1272          The only effect of this option is to make the SMP-related
1273          options available to the user for configuration.
1274
1275config SMP
1276        bool "Symmetric Multi-Processing"
1277        depends on CPU_V6K || CPU_V7
1278        depends on GENERIC_CLOCKEVENTS
1279        depends on HAVE_SMP
1280        depends on MMU || ARM_MPU
1281        select IRQ_WORK
1282        help
1283          This enables support for systems with more than one CPU. If you have
1284          a system with only one CPU, say N. If you have a system with more
1285          than one CPU, say Y.
1286
1287          If you say N here, the kernel will run on uni- and multiprocessor
1288          machines, but will use only one CPU of a multiprocessor machine. If
1289          you say Y here, the kernel will run on many, but not all,
1290          uniprocessor machines. On a uniprocessor machine, the kernel
1291          will run faster if you say N here.
1292
1293          See also <file:Documentation/x86/i386/IO-APIC.rst>,
1294          <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at
1295          <http://tldp.org/HOWTO/SMP-HOWTO.html>.
1296
1297          If you don't know what to do here, say N.
1298
1299config SMP_ON_UP
1300        bool "Allow booting SMP kernel on uniprocessor systems"
1301        depends on SMP && !XIP_KERNEL && MMU
1302        default y
1303        help
1304          SMP kernels contain instructions which fail on non-SMP processors.
1305          Enabling this option allows the kernel to modify itself to make
1306          these instructions safe.  Disabling it allows about 1K of space
1307          savings.
1308
1309          If you don't know what to do here, say Y.
1310
1311config ARM_CPU_TOPOLOGY
1312        bool "Support cpu topology definition"
1313        depends on SMP && CPU_V7
1314        default y
1315        help
1316          Support ARM cpu topology definition. The MPIDR register defines
1317          affinity between processors which is then used to describe the cpu
1318          topology of an ARM System.
1319
1320config SCHED_MC
1321        bool "Multi-core scheduler support"
1322        depends on ARM_CPU_TOPOLOGY
1323        help
1324          Multi-core scheduler support improves the CPU scheduler's decision
1325          making when dealing with multi-core CPU chips at a cost of slightly
1326          increased overhead in some places. If unsure say N here.
1327
1328config SCHED_SMT
1329        bool "SMT scheduler support"
1330        depends on ARM_CPU_TOPOLOGY
1331        help
1332          Improves the CPU scheduler's decision making when dealing with
1333          MultiThreading at a cost of slightly increased overhead in some
1334          places. If unsure say N here.
1335
1336config HAVE_ARM_SCU
1337        bool
1338        help
1339          This option enables support for the ARM snoop control unit
1340
1341config HAVE_ARM_ARCH_TIMER
1342        bool "Architected timer support"
1343        depends on CPU_V7
1344        select ARM_ARCH_TIMER
1345        select GENERIC_CLOCKEVENTS
1346        help
1347          This option enables support for the ARM architected timer
1348
1349config HAVE_ARM_TWD
1350        bool
1351        help
1352          This options enables support for the ARM timer and watchdog unit
1353
1354config MCPM
1355        bool "Multi-Cluster Power Management"
1356        depends on CPU_V7 && SMP
1357        help
1358          This option provides the common power management infrastructure
1359          for (multi-)cluster based systems, such as big.LITTLE based
1360          systems.
1361
1362config MCPM_QUAD_CLUSTER
1363        bool
1364        depends on MCPM
1365        help
1366          To avoid wasting resources unnecessarily, MCPM only supports up
1367          to 2 clusters by default.
1368          Platforms with 3 or 4 clusters that use MCPM must select this
1369          option to allow the additional clusters to be managed.
1370
1371config BIG_LITTLE
1372        bool "big.LITTLE support (Experimental)"
1373        depends on CPU_V7 && SMP
1374        select MCPM
1375        help
1376          This option enables support selections for the big.LITTLE
1377          system architecture.
1378
1379config BL_SWITCHER
1380        bool "big.LITTLE switcher support"
1381        depends on BIG_LITTLE && MCPM && HOTPLUG_CPU && ARM_GIC
1382        select CPU_PM
1383        help
1384          The big.LITTLE "switcher" provides the core functionality to
1385          transparently handle transition between a cluster of A15's
1386          and a cluster of A7's in a big.LITTLE system.
1387
1388config BL_SWITCHER_DUMMY_IF
1389        tristate "Simple big.LITTLE switcher user interface"
1390        depends on BL_SWITCHER && DEBUG_KERNEL
1391        help
1392          This is a simple and dummy char dev interface to control
1393          the big.LITTLE switcher core code.  It is meant for
1394          debugging purposes only.
1395
1396choice
1397        prompt "Memory split"
1398        depends on MMU
1399        default VMSPLIT_3G
1400        help
1401          Select the desired split between kernel and user memory.
1402
1403          If you are not absolutely sure what you are doing, leave this
1404          option alone!
1405
1406        config VMSPLIT_3G
1407                bool "3G/1G user/kernel split"
1408        config VMSPLIT_3G_OPT
1409                depends on !ARM_LPAE
1410                bool "3G/1G user/kernel split (for full 1G low memory)"
1411        config VMSPLIT_2G
1412                bool "2G/2G user/kernel split"
1413        config VMSPLIT_1G
1414                bool "1G/3G user/kernel split"
1415endchoice
1416
1417config PAGE_OFFSET
1418        hex
1419        default PHYS_OFFSET if !MMU
1420        default 0x40000000 if VMSPLIT_1G
1421        default 0x80000000 if VMSPLIT_2G
1422        default 0xB0000000 if VMSPLIT_3G_OPT
1423        default 0xC0000000
1424
1425config NR_CPUS
1426        int "Maximum number of CPUs (2-32)"
1427        range 2 32
1428        depends on SMP
1429        default "4"
1430
1431config HOTPLUG_CPU
1432        bool "Support for hot-pluggable CPUs"
1433        depends on SMP
1434        select GENERIC_IRQ_MIGRATION
1435        help
1436          Say Y here to experiment with turning CPUs off and on.  CPUs
1437          can be controlled through /sys/devices/system/cpu.
1438
1439config ARM_PSCI
1440        bool "Support for the ARM Power State Coordination Interface (PSCI)"
1441        depends on HAVE_ARM_SMCCC
1442        select ARM_PSCI_FW
1443        help
1444          Say Y here if you want Linux to communicate with system firmware
1445          implementing the PSCI specification for CPU-centric power
1446          management operations described in ARM document number ARM DEN
1447          0022A ("Power State Coordination Interface System Software on
1448          ARM processors").
1449
1450# The GPIO number here must be sorted by descending number. In case of
1451# a multiplatform kernel, we just want the highest value required by the
1452# selected platforms.
1453config ARCH_NR_GPIO
1454        int
1455        default 2048 if ARCH_SOCFPGA
1456        default 1024 if ARCH_BRCMSTB || ARCH_RENESAS || ARCH_TEGRA || \
1457                ARCH_ZYNQ
1458        default 512 if ARCH_EXYNOS || ARCH_KEYSTONE || SOC_OMAP5 || \
1459                SOC_DRA7XX || ARCH_S3C24XX || ARCH_S3C64XX || ARCH_S5PV210
1460        default 416 if ARCH_SUNXI
1461        default 392 if ARCH_U8500
1462        default 352 if ARCH_VT8500
1463        default 288 if ARCH_ROCKCHIP
1464        default 264 if MACH_H4700
1465        default 0
1466        help
1467          Maximum number of GPIOs in the system.
1468
1469          If unsure, leave the default value.
1470
1471config HZ_FIXED
1472        int
1473        default 200 if ARCH_EBSA110
1474        default 128 if SOC_AT91RM9200
1475        default 0
1476
1477choice
1478        depends on HZ_FIXED = 0
1479        prompt "Timer frequency"
1480
1481config HZ_100
1482        bool "100 Hz"
1483
1484config HZ_200
1485        bool "200 Hz"
1486
1487config HZ_250
1488        bool "250 Hz"
1489
1490config HZ_300
1491        bool "300 Hz"
1492
1493config HZ_500
1494        bool "500 Hz"
1495
1496config HZ_1000
1497        bool "1000 Hz"
1498
1499endchoice
1500
1501config HZ
1502        int
1503        default HZ_FIXED if HZ_FIXED != 0
1504        default 100 if HZ_100
1505        default 200 if HZ_200
1506        default 250 if HZ_250
1507        default 300 if HZ_300
1508        default 500 if HZ_500
1509        default 1000
1510
1511config SCHED_HRTICK
1512        def_bool HIGH_RES_TIMERS
1513
1514config THUMB2_KERNEL
1515        bool "Compile the kernel in Thumb-2 mode" if !CPU_THUMBONLY
1516        depends on (CPU_V7 || CPU_V7M) && !CPU_V6 && !CPU_V6K
1517        default y if CPU_THUMBONLY
1518        select ARM_UNWIND
1519        help
1520          By enabling this option, the kernel will be compiled in
1521          Thumb-2 mode.
1522
1523          If unsure, say N.
1524
1525config THUMB2_AVOID_R_ARM_THM_JUMP11
1526        bool "Work around buggy Thumb-2 short branch relocations in gas"
1527        depends on THUMB2_KERNEL && MODULES
1528        default y
1529        help
1530          Various binutils versions can resolve Thumb-2 branches to
1531          locally-defined, preemptible global symbols as short-range "b.n"
1532          branch instructions.
1533
1534          This is a problem, because there's no guarantee the final
1535          destination of the symbol, or any candidate locations for a
1536          trampoline, are within range of the branch.  For this reason, the
1537          kernel does not support fixing up the R_ARM_THM_JUMP11 (102)
1538          relocation in modules at all, and it makes little sense to add
1539          support.
1540
1541          The symptom is that the kernel fails with an "unsupported
1542          relocation" error when loading some modules.
1543
1544          Until fixed tools are available, passing
1545          -fno-optimize-sibling-calls to gcc should prevent gcc generating
1546          code which hits this problem, at the cost of a bit of extra runtime
1547          stack usage in some cases.
1548
1549          The problem is described in more detail at:
1550              https://bugs.launchpad.net/binutils-linaro/+bug/725126
1551
1552          Only Thumb-2 kernels are affected.
1553
1554          Unless you are sure your tools don't have this problem, say Y.
1555
1556config ARM_PATCH_IDIV
1557        bool "Runtime patch udiv/sdiv instructions into __aeabi_{u}idiv()"
1558        depends on CPU_32v7 && !XIP_KERNEL
1559        default y
1560        help
1561          The ARM compiler inserts calls to __aeabi_idiv() and
1562          __aeabi_uidiv() when it needs to perform division on signed
1563          and unsigned integers. Some v7 CPUs have support for the sdiv
1564          and udiv instructions that can be used to implement those
1565          functions.
1566
1567          Enabling this option allows the kernel to modify itself to
1568          replace the first two instructions of these library functions
1569          with the sdiv or udiv plus "bx lr" instructions when the CPU
1570          it is running on supports them. Typically this will be faster
1571          and less power intensive than running the original library
1572          code to do integer division.
1573
1574config AEABI
1575        bool "Use the ARM EABI to compile the kernel" if !CPU_V7 && !CPU_V7M && !CPU_V6 && !CPU_V6K
1576        default CPU_V7 || CPU_V7M || CPU_V6 || CPU_V6K
1577        help
1578          This option allows for the kernel to be compiled using the latest
1579          ARM ABI (aka EABI).  This is only useful if you are using a user
1580          space environment that is also compiled with EABI.
1581
1582          Since there are major incompatibilities between the legacy ABI and
1583          EABI, especially with regard to structure member alignment, this
1584          option also changes the kernel syscall calling convention to
1585          disambiguate both ABIs and allow for backward compatibility support
1586          (selected with CONFIG_OABI_COMPAT).
1587
1588          To use this you need GCC version 4.0.0 or later.
1589
1590config OABI_COMPAT
1591        bool "Allow old ABI binaries to run with this kernel (EXPERIMENTAL)"
1592        depends on AEABI && !THUMB2_KERNEL
1593        help
1594          This option preserves the old syscall interface along with the
1595          new (ARM EABI) one. It also provides a compatibility layer to
1596          intercept syscalls that have structure arguments which layout
1597          in memory differs between the legacy ABI and the new ARM EABI
1598          (only for non "thumb" binaries). This option adds a tiny
1599          overhead to all syscalls and produces a slightly larger kernel.
1600
1601          The seccomp filter system will not be available when this is
1602          selected, since there is no way yet to sensibly distinguish
1603          between calling conventions during filtering.
1604
1605          If you know you'll be using only pure EABI user space then you
1606          can say N here. If this option is not selected and you attempt
1607          to execute a legacy ABI binary then the result will be
1608          UNPREDICTABLE (in fact it can be predicted that it won't work
1609          at all). If in doubt say N.
1610
1611config ARCH_HAS_HOLES_MEMORYMODEL
1612        bool
1613
1614config ARCH_SPARSEMEM_ENABLE
1615        bool
1616
1617config ARCH_SPARSEMEM_DEFAULT
1618        def_bool ARCH_SPARSEMEM_ENABLE
1619
1620config HAVE_ARCH_PFN_VALID
1621        def_bool ARCH_HAS_HOLES_MEMORYMODEL || !SPARSEMEM
1622
1623config HIGHMEM
1624        bool "High Memory Support"
1625        depends on MMU
1626        help
1627          The address space of ARM processors is only 4 Gigabytes large
1628          and it has to accommodate user address space, kernel address
1629          space as well as some memory mapped IO. That means that, if you
1630          have a large amount of physical memory and/or IO, not all of the
1631          memory can be "permanently mapped" by the kernel. The physical
1632          memory that is not permanently mapped is called "high memory".
1633
1634          Depending on the selected kernel/user memory split, minimum
1635          vmalloc space and actual amount of RAM, you may not need this
1636          option which should result in a slightly faster kernel.
1637
1638          If unsure, say n.
1639
1640config HIGHPTE
1641        bool "Allocate 2nd-level pagetables from highmem" if EXPERT
1642        depends on HIGHMEM
1643        default y
1644        help
1645          The VM uses one page of physical memory for each page table.
1646          For systems with a lot of processes, this can use a lot of
1647          precious low memory, eventually leading to low memory being
1648          consumed by page tables.  Setting this option will allow
1649          user-space 2nd level page tables to reside in high memory.
1650
1651config CPU_SW_DOMAIN_PAN
1652        bool "Enable use of CPU domains to implement privileged no-access"
1653        depends on MMU && !ARM_LPAE
1654        default y
1655        help
1656          Increase kernel security by ensuring that normal kernel accesses
1657          are unable to access userspace addresses.  This can help prevent
1658          use-after-free bugs becoming an exploitable privilege escalation
1659          by ensuring that magic values (such as LIST_POISON) will always
1660          fault when dereferenced.
1661
1662          CPUs with low-vector mappings use a best-efforts implementation.
1663          Their lower 1MB needs to remain accessible for the vectors, but
1664          the remainder of userspace will become appropriately inaccessible.
1665
1666config HW_PERF_EVENTS
1667        def_bool y
1668        depends on ARM_PMU
1669
1670config SYS_SUPPORTS_HUGETLBFS
1671       def_bool y
1672       depends on ARM_LPAE
1673
1674config HAVE_ARCH_TRANSPARENT_HUGEPAGE
1675       def_bool y
1676       depends on ARM_LPAE
1677
1678config ARCH_WANT_GENERAL_HUGETLB
1679        def_bool y
1680
1681config ARM_MODULE_PLTS
1682        bool "Use PLTs to allow module memory to spill over into vmalloc area"
1683        depends on MODULES
1684        default y
1685        help
1686          Allocate PLTs when loading modules so that jumps and calls whose
1687          targets are too far away for their relative offsets to be encoded
1688          in the instructions themselves can be bounced via veneers in the
1689          module's PLT. This allows modules to be allocated in the generic
1690          vmalloc area after the dedicated module memory area has been
1691          exhausted. The modules will use slightly more memory, but after
1692          rounding up to page size, the actual memory footprint is usually
1693          the same.
1694
1695          Disabling this is usually safe for small single-platform
1696          configurations. If unsure, say y.
1697
1698config FORCE_MAX_ZONEORDER
1699        int "Maximum zone order"
1700        default "12" if SOC_AM33XX
1701        default "9" if SA1111 || ARCH_EFM32
1702        default "11"
1703        help
1704          The kernel memory allocator divides physically contiguous memory
1705          blocks into "zones", where each zone is a power of two number of
1706          pages.  This option selects the largest power of two that the kernel
1707          keeps in the memory allocator.  If you need to allocate very large
1708          blocks of physically contiguous memory, then you may need to
1709          increase this value.
1710
1711          This config option is actually maximum order plus one. For example,
1712          a value of 11 means that the largest free memory block is 2^10 pages.
1713
1714config ALIGNMENT_TRAP
1715        bool
1716        depends on CPU_CP15_MMU
1717        default y if !ARCH_EBSA110
1718        select HAVE_PROC_CPU if PROC_FS
1719        help
1720          ARM processors cannot fetch/store information which is not
1721          naturally aligned on the bus, i.e., a 4 byte fetch must start at an
1722          address divisible by 4. On 32-bit ARM processors, these non-aligned
1723          fetch/store instructions will be emulated in software if you say
1724          here, which has a severe performance impact. This is necessary for
1725          correct operation of some network protocols. With an IP-only
1726          configuration it is safe to say N, otherwise say Y.
1727
1728config UACCESS_WITH_MEMCPY
1729        bool "Use kernel mem{cpy,set}() for {copy_to,clear}_user()"
1730        depends on MMU
1731        default y if CPU_FEROCEON
1732        help
1733          Implement faster copy_to_user and clear_user methods for CPU
1734          cores where a 8-word STM instruction give significantly higher
1735          memory write throughput than a sequence of individual 32bit stores.
1736
1737          A possible side effect is a slight increase in scheduling latency
1738          between threads sharing the same address space if they invoke
1739          such copy operations with large buffers.
1740
1741          However, if the CPU data cache is using a write-allocate mode,
1742          this option is unlikely to provide any performance gain.
1743
1744config SECCOMP
1745        bool
1746        prompt "Enable seccomp to safely compute untrusted bytecode"
1747        ---help---
1748          This kernel feature is useful for number crunching applications
1749          that may need to compute untrusted bytecode during their
1750          execution. By using pipes or other transports made available to
1751          the process as file descriptors supporting the read/write
1752          syscalls, it's possible to isolate those applications in
1753          their own address space using seccomp. Once seccomp is
1754          enabled via prctl(PR_SET_SECCOMP), it cannot be disabled
1755          and the task is only allowed to execute a few safe syscalls
1756          defined by each seccomp mode.
1757
1758config PARAVIRT
1759        bool "Enable paravirtualization code"
1760        help
1761          This changes the kernel so it can modify itself when it is run
1762          under a hypervisor, potentially improving performance significantly
1763          over full virtualization.
1764
1765config PARAVIRT_TIME_ACCOUNTING
1766        bool "Paravirtual steal time accounting"
1767        select PARAVIRT
1768        help
1769          Select this option to enable fine granularity task steal time
1770          accounting. Time spent executing other tasks in parallel with
1771          the current vCPU is discounted from the vCPU power. To account for
1772          that, there can be a small performance impact.
1773
1774          If in doubt, say N here.
1775
1776config XEN_DOM0
1777        def_bool y
1778        depends on XEN
1779
1780config XEN
1781        bool "Xen guest support on ARM"
1782        depends on ARM && AEABI && OF
1783        depends on CPU_V7 && !CPU_V6
1784        depends on !GENERIC_ATOMIC64
1785        depends on MMU
1786        select ARCH_DMA_ADDR_T_64BIT
1787        select ARM_PSCI
1788        select SWIOTLB
1789        select SWIOTLB_XEN
1790        select PARAVIRT
1791        help
1792          Say Y if you want to run Linux in a Virtual Machine on Xen on ARM.
1793
1794config STACKPROTECTOR_PER_TASK
1795        bool "Use a unique stack canary value for each task"
1796        depends on GCC_PLUGINS && STACKPROTECTOR && SMP && !XIP_DEFLATED_DATA
1797        select GCC_PLUGIN_ARM_SSP_PER_TASK
1798        default y
1799        help
1800          Due to the fact that GCC uses an ordinary symbol reference from
1801          which to load the value of the stack canary, this value can only
1802          change at reboot time on SMP systems, and all tasks running in the
1803          kernel's address space are forced to use the same canary value for
1804          the entire duration that the system is up.
1805
1806          Enable this option to switch to a different method that uses a
1807          different canary value for each task.
1808
1809endmenu
1810
1811menu "Boot options"
1812
1813config USE_OF
1814        bool "Flattened Device Tree support"
1815        select IRQ_DOMAIN
1816        select OF
1817        help
1818          Include support for flattened device tree machine descriptions.
1819
1820config ATAGS
1821        bool "Support for the traditional ATAGS boot data passing" if USE_OF
1822        default y
1823        help
1824          This is the traditional way of passing data to the kernel at boot
1825          time. If you are solely relying on the flattened device tree (or
1826          the ARM_ATAG_DTB_COMPAT option) then you may unselect this option
1827          to remove ATAGS support from your kernel binary.  If unsure,
1828          leave this to y.
1829
1830config DEPRECATED_PARAM_STRUCT
1831        bool "Provide old way to pass kernel parameters"
1832        depends on ATAGS
1833        help
1834          This was deprecated in 2001 and announced to live on for 5 years.
1835          Some old boot loaders still use this way.
1836
1837# Compressed boot loader in ROM.  Yes, we really want to ask about
1838# TEXT and BSS so we preserve their values in the config files.
1839config ZBOOT_ROM_TEXT
1840        hex "Compressed ROM boot loader base address"
1841        default "0"
1842        help
1843          The physical address at which the ROM-able zImage is to be
1844          placed in the target.  Platforms which normally make use of
1845          ROM-able zImage formats normally set this to a suitable
1846          value in their defconfig file.
1847
1848          If ZBOOT_ROM is not enabled, this has no effect.
1849
1850config ZBOOT_ROM_BSS
1851        hex "Compressed ROM boot loader BSS address"
1852        default "0"
1853        help
1854          The base address of an area of read/write memory in the target
1855          for the ROM-able zImage which must be available while the
1856          decompressor is running. It must be large enough to hold the
1857          entire decompressed kernel plus an additional 128 KiB.
1858          Platforms which normally make use of ROM-able zImage formats
1859          normally set this to a suitable value in their defconfig file.
1860
1861          If ZBOOT_ROM is not enabled, this has no effect.
1862
1863config ZBOOT_ROM
1864        bool "Compressed boot loader in ROM/flash"
1865        depends on ZBOOT_ROM_TEXT != ZBOOT_ROM_BSS
1866        depends on !ARM_APPENDED_DTB && !XIP_KERNEL && !AUTO_ZRELADDR
1867        help
1868          Say Y here if you intend to execute your compressed kernel image
1869          (zImage) directly from ROM or flash.  If unsure, say N.
1870
1871config ARM_APPENDED_DTB
1872        bool "Use appended device tree blob to zImage (EXPERIMENTAL)"
1873        depends on OF
1874        help
1875          With this option, the boot code will look for a device tree binary
1876          (DTB) appended to zImage
1877          (e.g. cat zImage <filename>.dtb > zImage_w_dtb).
1878
1879          This is meant as a backward compatibility convenience for those
1880          systems with a bootloader that can't be upgraded to accommodate
1881          the documented boot protocol using a device tree.
1882
1883          Beware that there is very little in terms of protection against
1884          this option being confused by leftover garbage in memory that might
1885          look like a DTB header after a reboot if no actual DTB is appended
1886          to zImage.  Do not leave this option active in a production kernel
1887          if you don't intend to always append a DTB.  Proper passing of the
1888          location into r2 of a bootloader provided DTB is always preferable
1889          to this option.
1890
1891config ARM_ATAG_DTB_COMPAT
1892        bool "Supplement the appended DTB with traditional ATAG information"
1893        depends on ARM_APPENDED_DTB
1894        help
1895          Some old bootloaders can't be updated to a DTB capable one, yet
1896          they provide ATAGs with memory configuration, the ramdisk address,
1897          the kernel cmdline string, etc.  Such information is dynamically
1898          provided by the bootloader and can't always be stored in a static
1899          DTB.  To allow a device tree enabled kernel to be used with such
1900          bootloaders, this option allows zImage to extract the information
1901          from the ATAG list and store it at run time into the appended DTB.
1902
1903choice
1904        prompt "Kernel command line type" if ARM_ATAG_DTB_COMPAT
1905        default ARM_ATAG_DTB_COMPAT_CMDLINE_FROM_BOOTLOADER
1906
1907config ARM_ATAG_DTB_COMPAT_CMDLINE_FROM_BOOTLOADER
1908        bool "Use bootloader kernel arguments if available"
1909        help
1910          Uses the command-line options passed by the boot loader instead of
1911          the device tree bootargs property. If the boot loader doesn't provide
1912          any, the device tree bootargs property will be used.
1913
1914config ARM_ATAG_DTB_COMPAT_CMDLINE_EXTEND
1915        bool "Extend with bootloader kernel arguments"
1916        help
1917          The command-line arguments provided by the boot loader will be
1918          appended to the the device tree bootargs property.
1919
1920endchoice
1921
1922config CMDLINE
1923        string "Default kernel command string"
1924        default ""
1925        help
1926          On some architectures (EBSA110 and CATS), there is currently no way
1927          for the boot loader to pass arguments to the kernel. For these
1928          architectures, you should supply some command-line options at build
1929          time by entering them here. As a minimum, you should specify the
1930          memory size and the root device (e.g., mem=64M root=/dev/nfs).
1931
1932choice
1933        prompt "Kernel command line type" if CMDLINE != ""
1934        default CMDLINE_FROM_BOOTLOADER
1935        depends on ATAGS
1936
1937config CMDLINE_FROM_BOOTLOADER
1938        bool "Use bootloader kernel arguments if available"
1939        help
1940          Uses the command-line options passed by the boot loader. If
1941          the boot loader doesn't provide any, the default kernel command
1942          string provided in CMDLINE will be used.
1943
1944config CMDLINE_EXTEND
1945        bool "Extend bootloader kernel arguments"
1946        help
1947          The command-line arguments provided by the boot loader will be
1948          appended to the default kernel command string.
1949
1950config CMDLINE_FORCE
1951        bool "Always use the default kernel command string"
1952        help
1953          Always use the default kernel command string, even if the boot
1954          loader passes other arguments to the kernel.
1955          This is useful if you cannot or don't want to change the
1956          command-line options your boot loader passes to the kernel.
1957endchoice
1958
1959config XIP_KERNEL
1960        bool "Kernel Execute-In-Place from ROM"
1961        depends on !ARM_LPAE && !ARCH_MULTIPLATFORM
1962        help
1963          Execute-In-Place allows the kernel to run from non-volatile storage
1964          directly addressable by the CPU, such as NOR flash. This saves RAM
1965          space since the text section of the kernel is not loaded from flash
1966          to RAM.  Read-write sections, such as the data section and stack,
1967          are still copied to RAM.  The XIP kernel is not compressed since
1968          it has to run directly from flash, so it will take more space to
1969          store it.  The flash address used to link the kernel object files,
1970          and for storing it, is configuration dependent. Therefore, if you
1971          say Y here, you must know the proper physical address where to
1972          store the kernel image depending on your own flash memory usage.
1973
1974          Also note that the make target becomes "make xipImage" rather than
1975          "make zImage" or "make Image".  The final kernel binary to put in
1976          ROM memory will be arch/arm/boot/xipImage.
1977
1978          If unsure, say N.
1979
1980config XIP_PHYS_ADDR
1981        hex "XIP Kernel Physical Location"
1982        depends on XIP_KERNEL
1983        default "0x00080000"
1984        help
1985          This is the physical address in your flash memory the kernel will
1986          be linked for and stored to.  This address is dependent on your
1987          own flash usage.
1988
1989config XIP_DEFLATED_DATA
1990        bool "Store kernel .data section compressed in ROM"
1991        depends on XIP_KERNEL
1992        select ZLIB_INFLATE
1993        help
1994          Before the kernel is actually executed, its .data section has to be
1995          copied to RAM from ROM. This option allows for storing that data
1996          in compressed form and decompressed to RAM rather than merely being
1997          copied, saving some precious ROM space. A possible drawback is a
1998          slightly longer boot delay.
1999
2000config KEXEC
2001        bool "Kexec system call (EXPERIMENTAL)"
2002        depends on (!SMP || PM_SLEEP_SMP)
2003        depends on !CPU_V7M
2004        select KEXEC_CORE
2005        help
2006          kexec is a system call that implements the ability to shutdown your
2007          current kernel, and to start another kernel.  It is like a reboot
2008          but it is independent of the system firmware.   And like a reboot
2009          you can start any kernel with it, not just Linux.
2010
2011          It is an ongoing process to be certain the hardware in a machine
2012          is properly shutdown, so do not be surprised if this code does not
2013          initially work for you.
2014
2015config ATAGS_PROC
2016        bool "Export atags in procfs"
2017        depends on ATAGS && KEXEC
2018        default y
2019        help
2020          Should the atags used to boot the kernel be exported in an "atags"
2021          file in procfs. Useful with kexec.
2022
2023config CRASH_DUMP
2024        bool "Build kdump crash kernel (EXPERIMENTAL)"
2025        help
2026          Generate crash dump after being started by kexec. This should
2027          be normally only set in special crash dump kernels which are
2028          loaded in the main kernel with kexec-tools into a specially
2029          reserved region and then later executed after a crash by
2030          kdump/kexec. The crash dump kernel must be compiled to a
2031          memory address not used by the main kernel
2032
2033          For more details see Documentation/admin-guide/kdump/kdump.rst
2034
2035config AUTO_ZRELADDR
2036        bool "Auto calculation of the decompressed kernel image address"
2037        help
2038          ZRELADDR is the physical address where the decompressed kernel
2039          image will be placed. If AUTO_ZRELADDR is selected, the address
2040          will be determined at run-time by masking the current IP with
2041          0xf8000000. This assumes the zImage being placed in the first 128MB
2042          from start of memory.
2043
2044config EFI_STUB
2045        bool
2046
2047config EFI
2048        bool "UEFI runtime support"
2049        depends on OF && !CPU_BIG_ENDIAN && MMU && AUTO_ZRELADDR && !XIP_KERNEL
2050        select UCS2_STRING
2051        select EFI_PARAMS_FROM_FDT
2052        select EFI_STUB
2053        select EFI_ARMSTUB
2054        select EFI_RUNTIME_WRAPPERS
2055        ---help---
2056          This option provides support for runtime services provided
2057          by UEFI firmware (such as non-volatile variables, realtime
2058          clock, and platform reset). A UEFI stub is also provided to
2059          allow the kernel to be booted as an EFI application. This
2060          is only useful for kernels that may run on systems that have
2061          UEFI firmware.
2062
2063config DMI
2064        bool "Enable support for SMBIOS (DMI) tables"
2065        depends on EFI
2066        default y
2067        help
2068          This enables SMBIOS/DMI feature for systems.
2069
2070          This option is only useful on systems that have UEFI firmware.
2071          However, even with this option, the resultant kernel should
2072          continue to boot on existing non-UEFI platforms.
2073
2074          NOTE: This does *NOT* enable or encourage the use of DMI quirks,
2075          i.e., the the practice of identifying the platform via DMI to
2076          decide whether certain workarounds for buggy hardware and/or
2077          firmware need to be enabled. This would require the DMI subsystem
2078          to be enabled much earlier than we do on ARM, which is non-trivial.
2079
2080endmenu
2081
2082menu "CPU Power Management"
2083
2084source "drivers/cpufreq/Kconfig"
2085
2086source "drivers/cpuidle/Kconfig"
2087
2088endmenu
2089
2090menu "Floating point emulation"
2091
2092comment "At least one emulation must be selected"
2093
2094config FPE_NWFPE
2095        bool "NWFPE math emulation"
2096        depends on (!AEABI || OABI_COMPAT) && !THUMB2_KERNEL
2097        ---help---
2098          Say Y to include the NWFPE floating point emulator in the kernel.
2099          This is necessary to run most binaries. Linux does not currently
2100          support floating point hardware so you need to say Y here even if
2101          your machine has an FPA or floating point co-processor podule.
2102
2103          You may say N here if you are going to load the Acorn FPEmulator
2104          early in the bootup.
2105
2106config FPE_NWFPE_XP
2107        bool "Support extended precision"
2108        depends on FPE_NWFPE
2109        help
2110          Say Y to include 80-bit support in the kernel floating-point
2111          emulator.  Otherwise, only 32 and 64-bit support is compiled in.
2112          Note that gcc does not generate 80-bit operations by default,
2113          so in most cases this option only enlarges the size of the
2114          floating point emulator without any good reason.
2115
2116          You almost surely want to say N here.
2117
2118config FPE_FASTFPE
2119        bool "FastFPE math emulation (EXPERIMENTAL)"
2120        depends on (!AEABI || OABI_COMPAT) && !CPU_32v3
2121        ---help---
2122          Say Y here to include the FAST floating point emulator in the kernel.
2123          This is an experimental much faster emulator which now also has full
2124          precision for the mantissa.  It does not support any exceptions.
2125          It is very simple, and approximately 3-6 times faster than NWFPE.
2126
2127          It should be sufficient for most programs.  It may be not suitable
2128          for scientific calculations, but you have to check this for yourself.
2129          If you do not feel you need a faster FP emulation you should better
2130          choose NWFPE.
2131
2132config VFP
2133        bool "VFP-format floating point maths"
2134        depends on CPU_V6 || CPU_V6K || CPU_ARM926T || CPU_V7 || CPU_FEROCEON
2135        help
2136          Say Y to include VFP support code in the kernel. This is needed
2137          if your hardware includes a VFP unit.
2138
2139          Please see <file:Documentation/arm/vfp/release-notes.rst> for
2140          release notes and additional status information.
2141
2142          Say N if your target does not have VFP hardware.
2143
2144config VFPv3
2145        bool
2146        depends on VFP
2147        default y if CPU_V7
2148
2149config NEON
2150        bool "Advanced SIMD (NEON) Extension support"
2151        depends on VFPv3 && CPU_V7
2152        help
2153          Say Y to include support code for NEON, the ARMv7 Advanced SIMD
2154          Extension.
2155
2156config KERNEL_MODE_NEON
2157        bool "Support for NEON in kernel mode"
2158        depends on NEON && AEABI
2159        help
2160          Say Y to include support for NEON in kernel mode.
2161
2162endmenu
2163
2164menu "Power management options"
2165
2166source "kernel/power/Kconfig"
2167
2168config ARCH_SUSPEND_POSSIBLE
2169        depends on CPU_ARM920T || CPU_ARM926T || CPU_FEROCEON || CPU_SA1100 || \
2170                CPU_V6 || CPU_V6K || CPU_V7 || CPU_V7M || CPU_XSC3 || CPU_XSCALE || CPU_MOHAWK
2171        def_bool y
2172
2173config ARM_CPU_SUSPEND
2174        def_bool PM_SLEEP || BL_SWITCHER || ARM_PSCI_FW
2175        depends on ARCH_SUSPEND_POSSIBLE
2176
2177config ARCH_HIBERNATION_POSSIBLE
2178        bool
2179        depends on MMU
2180        default y if ARCH_SUSPEND_POSSIBLE
2181
2182endmenu
2183
2184source "drivers/firmware/Kconfig"
2185
2186if CRYPTO
2187source "arch/arm/crypto/Kconfig"
2188endif
2189
2190source "arch/arm/kvm/Kconfig"
2191