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_GCC_PLUGINS 96 select HAVE_HW_BREAKPOINT if PERF_EVENTS && (CPU_V6 || CPU_V6K || CPU_V7) 97 select HAVE_IRQ_TIME_ACCOUNTING 98 select HAVE_KERNEL_GZIP 99 select HAVE_KERNEL_LZ4 100 select HAVE_KERNEL_LZMA 101 select HAVE_KERNEL_LZO 102 select HAVE_KERNEL_XZ 103 select HAVE_KPROBES if !XIP_KERNEL && !CPU_ENDIAN_BE32 && !CPU_V7M 104 select HAVE_KRETPROBES if HAVE_KPROBES 105 select HAVE_MOD_ARCH_SPECIFIC 106 select HAVE_NMI 107 select HAVE_OPTPROBES if !THUMB2_KERNEL 108 select HAVE_PERF_EVENTS 109 select HAVE_PERF_REGS 110 select HAVE_PERF_USER_STACK_DUMP 111 select MMU_GATHER_RCU_TABLE_FREE if SMP && ARM_LPAE 112 select HAVE_REGS_AND_STACK_ACCESS_API 113 select HAVE_RSEQ 114 select HAVE_STACKPROTECTOR 115 select HAVE_SYSCALL_TRACEPOINTS 116 select HAVE_UID16 117 select HAVE_VIRT_CPU_ACCOUNTING_GEN 118 select IRQ_FORCED_THREADING 119 select MODULES_USE_ELF_REL 120 select NEED_DMA_MAP_STATE 121 select OF_EARLY_FLATTREE if OF 122 select OLD_SIGACTION 123 select OLD_SIGSUSPEND3 124 select PCI_SYSCALL if PCI 125 select PERF_USE_VMALLOC 126 select RTC_LIB 127 select SET_FS 128 select SYS_SUPPORTS_APM_EMULATION 129 # Above selects are sorted alphabetically; please add new ones 130 # according to that. Thanks. 131 help 132 The ARM series is a line of low-power-consumption RISC chip designs 133 licensed by ARM Ltd and targeted at embedded applications and 134 handhelds such as the Compaq IPAQ. ARM-based PCs are no longer 135 manufactured, but legacy ARM-based PC hardware remains popular in 136 Europe. There is an ARM Linux project with a web page at 137 <http://www.arm.linux.org.uk/>. 138 139config ARM_HAS_SG_CHAIN 140 bool 141 142config ARM_DMA_USE_IOMMU 143 bool 144 select ARM_HAS_SG_CHAIN 145 select NEED_SG_DMA_LENGTH 146 147if ARM_DMA_USE_IOMMU 148 149config ARM_DMA_IOMMU_ALIGNMENT 150 int "Maximum PAGE_SIZE order of alignment for DMA IOMMU buffers" 151 range 4 9 152 default 8 153 help 154 DMA mapping framework by default aligns all buffers to the smallest 155 PAGE_SIZE order which is greater than or equal to the requested buffer 156 size. This works well for buffers up to a few hundreds kilobytes, but 157 for larger buffers it just a waste of address space. Drivers which has 158 relatively small addressing window (like 64Mib) might run out of 159 virtual space with just a few allocations. 160 161 With this parameter you can specify the maximum PAGE_SIZE order for 162 DMA IOMMU buffers. Larger buffers will be aligned only to this 163 specified order. The order is expressed as a power of two multiplied 164 by the PAGE_SIZE. 165 166endif 167 168config SYS_SUPPORTS_APM_EMULATION 169 bool 170 171config HAVE_TCM 172 bool 173 select GENERIC_ALLOCATOR 174 175config HAVE_PROC_CPU 176 bool 177 178config NO_IOPORT_MAP 179 bool 180 181config SBUS 182 bool 183 184config STACKTRACE_SUPPORT 185 bool 186 default y 187 188config LOCKDEP_SUPPORT 189 bool 190 default y 191 192config TRACE_IRQFLAGS_SUPPORT 193 bool 194 default !CPU_V7M 195 196config ARCH_HAS_ILOG2_U32 197 bool 198 199config ARCH_HAS_ILOG2_U64 200 bool 201 202config ARCH_HAS_BANDGAP 203 bool 204 205config FIX_EARLYCON_MEM 206 def_bool y if MMU 207 208config GENERIC_HWEIGHT 209 bool 210 default y 211 212config GENERIC_CALIBRATE_DELAY 213 bool 214 default y 215 216config ARCH_MAY_HAVE_PC_FDC 217 bool 218 219config ARCH_SUPPORTS_UPROBES 220 def_bool y 221 222config ARCH_HAS_DMA_SET_COHERENT_MASK 223 bool 224 225config GENERIC_ISA_DMA 226 bool 227 228config FIQ 229 bool 230 231config NEED_RET_TO_USER 232 bool 233 234config ARCH_MTD_XIP 235 bool 236 237config ARM_PATCH_PHYS_VIRT 238 bool "Patch physical to virtual translations at runtime" if EMBEDDED 239 default y 240 depends on !XIP_KERNEL && MMU 241 help 242 Patch phys-to-virt and virt-to-phys translation functions at 243 boot and module load time according to the position of the 244 kernel in system memory. 245 246 This can only be used with non-XIP MMU kernels where the base 247 of physical memory is at a 2 MiB boundary. 248 249 Only disable this option if you know that you do not require 250 this feature (eg, building a kernel for a single machine) and 251 you need to shrink the kernel to the minimal size. 252 253config NEED_MACH_IO_H 254 bool 255 help 256 Select this when mach/io.h is required to provide special 257 definitions for this platform. The need for mach/io.h should 258 be avoided when possible. 259 260config NEED_MACH_MEMORY_H 261 bool 262 help 263 Select this when mach/memory.h is required to provide special 264 definitions for this platform. The need for mach/memory.h should 265 be avoided when possible. 266 267config PHYS_OFFSET 268 hex "Physical address of main memory" if MMU 269 depends on !ARM_PATCH_PHYS_VIRT 270 default DRAM_BASE if !MMU 271 default 0x00000000 if ARCH_FOOTBRIDGE 272 default 0x10000000 if ARCH_OMAP1 || ARCH_RPC 273 default 0x20000000 if ARCH_S5PV210 274 default 0xc0000000 if ARCH_SA1100 275 help 276 Please provide the physical address corresponding to the 277 location of main memory in your system. 278 279config GENERIC_BUG 280 def_bool y 281 depends on BUG 282 283config PGTABLE_LEVELS 284 int 285 default 3 if ARM_LPAE 286 default 2 287 288menu "System Type" 289 290config MMU 291 bool "MMU-based Paged Memory Management Support" 292 default y 293 help 294 Select if you want MMU-based virtualised addressing space 295 support by paged memory management. If unsure, say 'Y'. 296 297config ARCH_MMAP_RND_BITS_MIN 298 default 8 299 300config ARCH_MMAP_RND_BITS_MAX 301 default 14 if PAGE_OFFSET=0x40000000 302 default 15 if PAGE_OFFSET=0x80000000 303 default 16 304 305# 306# The "ARM system type" choice list is ordered alphabetically by option 307# text. Please add new entries in the option alphabetic order. 308# 309choice 310 prompt "ARM system type" 311 default ARM_SINGLE_ARMV7M if !MMU 312 default ARCH_MULTIPLATFORM if MMU 313 314config ARCH_MULTIPLATFORM 315 bool "Allow multiple platforms to be selected" 316 depends on MMU 317 select ARCH_FLATMEM_ENABLE 318 select ARCH_SPARSEMEM_ENABLE 319 select ARCH_SELECT_MEMORY_MODEL 320 select ARM_HAS_SG_CHAIN 321 select ARM_PATCH_PHYS_VIRT 322 select AUTO_ZRELADDR 323 select TIMER_OF 324 select COMMON_CLK 325 select GENERIC_IRQ_MULTI_HANDLER 326 select HAVE_PCI 327 select PCI_DOMAINS_GENERIC if PCI 328 select SPARSE_IRQ 329 select USE_OF 330 331config ARM_SINGLE_ARMV7M 332 bool "ARMv7-M based platforms (Cortex-M0/M3/M4)" 333 depends on !MMU 334 select ARM_NVIC 335 select AUTO_ZRELADDR 336 select TIMER_OF 337 select COMMON_CLK 338 select CPU_V7M 339 select NO_IOPORT_MAP 340 select SPARSE_IRQ 341 select USE_OF 342 343config ARCH_EP93XX 344 bool "EP93xx-based" 345 select ARCH_SPARSEMEM_ENABLE 346 select ARM_AMBA 347 imply ARM_PATCH_PHYS_VIRT 348 select ARM_VIC 349 select GENERIC_IRQ_MULTI_HANDLER 350 select AUTO_ZRELADDR 351 select CLKSRC_MMIO 352 select CPU_ARM920T 353 select GPIOLIB 354 select HAVE_LEGACY_CLK 355 help 356 This enables support for the Cirrus EP93xx series of CPUs. 357 358config ARCH_FOOTBRIDGE 359 bool "FootBridge" 360 select CPU_SA110 361 select FOOTBRIDGE 362 select NEED_MACH_IO_H if !MMU 363 select NEED_MACH_MEMORY_H 364 help 365 Support for systems based on the DC21285 companion chip 366 ("FootBridge"), such as the Simtec CATS and the Rebel NetWinder. 367 368config ARCH_IOP32X 369 bool "IOP32x-based" 370 depends on MMU 371 select CPU_XSCALE 372 select GPIO_IOP 373 select GPIOLIB 374 select NEED_RET_TO_USER 375 select FORCE_PCI 376 select PLAT_IOP 377 help 378 Support for Intel's 80219 and IOP32X (XScale) family of 379 processors. 380 381config ARCH_IXP4XX 382 bool "IXP4xx-based" 383 depends on MMU 384 select ARCH_HAS_DMA_SET_COHERENT_MASK 385 select ARCH_SUPPORTS_BIG_ENDIAN 386 select CPU_XSCALE 387 select DMABOUNCE if PCI 388 select GENERIC_IRQ_MULTI_HANDLER 389 select GPIO_IXP4XX 390 select GPIOLIB 391 select HAVE_PCI 392 select IXP4XX_IRQ 393 select IXP4XX_TIMER 394 # With the new PCI driver this is not needed 395 select NEED_MACH_IO_H if IXP4XX_PCI_LEGACY 396 select USB_EHCI_BIG_ENDIAN_DESC 397 select USB_EHCI_BIG_ENDIAN_MMIO 398 help 399 Support for Intel's IXP4XX (XScale) family of processors. 400 401config ARCH_DOVE 402 bool "Marvell Dove" 403 select CPU_PJ4 404 select GENERIC_IRQ_MULTI_HANDLER 405 select GPIOLIB 406 select HAVE_PCI 407 select MVEBU_MBUS 408 select PINCTRL 409 select PINCTRL_DOVE 410 select PLAT_ORION_LEGACY 411 select SPARSE_IRQ 412 select PM_GENERIC_DOMAINS if PM 413 help 414 Support for the Marvell Dove SoC 88AP510 415 416config ARCH_PXA 417 bool "PXA2xx/PXA3xx-based" 418 depends on MMU 419 select ARCH_MTD_XIP 420 select ARM_CPU_SUSPEND if PM 421 select AUTO_ZRELADDR 422 select COMMON_CLK 423 select CLKSRC_PXA 424 select CLKSRC_MMIO 425 select TIMER_OF 426 select CPU_XSCALE if !CPU_XSC3 427 select GENERIC_IRQ_MULTI_HANDLER 428 select GPIO_PXA 429 select GPIOLIB 430 select IRQ_DOMAIN 431 select PLAT_PXA 432 select SPARSE_IRQ 433 help 434 Support for Intel/Marvell's PXA2xx/PXA3xx processor line. 435 436config ARCH_RPC 437 bool "RiscPC" 438 depends on MMU 439 select ARCH_ACORN 440 select ARCH_MAY_HAVE_PC_FDC 441 select ARCH_SPARSEMEM_ENABLE 442 select ARM_HAS_SG_CHAIN 443 select CPU_SA110 444 select FIQ 445 select HAVE_PATA_PLATFORM 446 select ISA_DMA_API 447 select LEGACY_TIMER_TICK 448 select NEED_MACH_IO_H 449 select NEED_MACH_MEMORY_H 450 select NO_IOPORT_MAP 451 help 452 On the Acorn Risc-PC, Linux can support the internal IDE disk and 453 CD-ROM interface, serial and parallel port, and the floppy drive. 454 455config ARCH_SA1100 456 bool "SA1100-based" 457 select ARCH_MTD_XIP 458 select ARCH_SPARSEMEM_ENABLE 459 select CLKSRC_MMIO 460 select CLKSRC_PXA 461 select TIMER_OF if OF 462 select COMMON_CLK 463 select CPU_FREQ 464 select CPU_SA1100 465 select GENERIC_IRQ_MULTI_HANDLER 466 select GPIOLIB 467 select IRQ_DOMAIN 468 select ISA 469 select NEED_MACH_MEMORY_H 470 select SPARSE_IRQ 471 help 472 Support for StrongARM 11x0 based boards. 473 474config ARCH_S3C24XX 475 bool "Samsung S3C24XX SoCs" 476 select ATAGS 477 select CLKSRC_SAMSUNG_PWM 478 select GPIO_SAMSUNG 479 select GPIOLIB 480 select GENERIC_IRQ_MULTI_HANDLER 481 select HAVE_S3C2410_I2C if I2C 482 select HAVE_S3C_RTC if RTC_CLASS 483 select NEED_MACH_IO_H 484 select S3C2410_WATCHDOG 485 select SAMSUNG_ATAGS 486 select USE_OF 487 select WATCHDOG 488 help 489 Samsung S3C2410, S3C2412, S3C2413, S3C2416, S3C2440, S3C2442, S3C2443 490 and S3C2450 SoCs based systems, such as the Simtec Electronics BAST 491 (<http://www.simtec.co.uk/products/EB110ITX/>), the IPAQ 1940 or the 492 Samsung SMDK2410 development board (and derivatives). 493 494config ARCH_OMAP1 495 bool "TI OMAP1" 496 depends on MMU 497 select ARCH_OMAP 498 select CLKSRC_MMIO 499 select GENERIC_IRQ_CHIP 500 select GENERIC_IRQ_MULTI_HANDLER 501 select GPIOLIB 502 select HAVE_LEGACY_CLK 503 select IRQ_DOMAIN 504 select NEED_MACH_IO_H if PCCARD 505 select NEED_MACH_MEMORY_H 506 select SPARSE_IRQ 507 help 508 Support for older TI OMAP1 (omap7xx, omap15xx or omap16xx) 509 510endchoice 511 512menu "Multiple platform selection" 513 depends on ARCH_MULTIPLATFORM 514 515comment "CPU Core family selection" 516 517config ARCH_MULTI_V4 518 bool "ARMv4 based platforms (FA526)" 519 depends on !ARCH_MULTI_V6_V7 520 select ARCH_MULTI_V4_V5 521 select CPU_FA526 522 523config ARCH_MULTI_V4T 524 bool "ARMv4T based platforms (ARM720T, ARM920T, ...)" 525 depends on !ARCH_MULTI_V6_V7 526 select ARCH_MULTI_V4_V5 527 select CPU_ARM920T if !(CPU_ARM7TDMI || CPU_ARM720T || \ 528 CPU_ARM740T || CPU_ARM9TDMI || CPU_ARM922T || \ 529 CPU_ARM925T || CPU_ARM940T) 530 531config ARCH_MULTI_V5 532 bool "ARMv5 based platforms (ARM926T, XSCALE, PJ1, ...)" 533 depends on !ARCH_MULTI_V6_V7 534 select ARCH_MULTI_V4_V5 535 select CPU_ARM926T if !(CPU_ARM946E || CPU_ARM1020 || \ 536 CPU_ARM1020E || CPU_ARM1022 || CPU_ARM1026 || \ 537 CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK || CPU_FEROCEON) 538 539config ARCH_MULTI_V4_V5 540 bool 541 542config ARCH_MULTI_V6 543 bool "ARMv6 based platforms (ARM11)" 544 select ARCH_MULTI_V6_V7 545 select CPU_V6K 546 547config ARCH_MULTI_V7 548 bool "ARMv7 based platforms (Cortex-A, PJ4, Scorpion, Krait)" 549 default y 550 select ARCH_MULTI_V6_V7 551 select CPU_V7 552 select HAVE_SMP 553 554config ARCH_MULTI_V6_V7 555 bool 556 select MIGHT_HAVE_CACHE_L2X0 557 558config ARCH_MULTI_CPU_AUTO 559 def_bool !(ARCH_MULTI_V4 || ARCH_MULTI_V4T || ARCH_MULTI_V6_V7) 560 select ARCH_MULTI_V5 561 562endmenu 563 564config ARCH_VIRT 565 bool "Dummy Virtual Machine" 566 depends on ARCH_MULTI_V7 567 select ARM_AMBA 568 select ARM_GIC 569 select ARM_GIC_V2M if PCI 570 select ARM_GIC_V3 571 select ARM_GIC_V3_ITS if PCI 572 select ARM_PSCI 573 select HAVE_ARM_ARCH_TIMER 574 select ARCH_SUPPORTS_BIG_ENDIAN 575 576# 577# This is sorted alphabetically by mach-* pathname. However, plat-* 578# Kconfigs may be included either alphabetically (according to the 579# plat- suffix) or along side the corresponding mach-* source. 580# 581source "arch/arm/mach-actions/Kconfig" 582 583source "arch/arm/mach-alpine/Kconfig" 584 585source "arch/arm/mach-artpec/Kconfig" 586 587source "arch/arm/mach-asm9260/Kconfig" 588 589source "arch/arm/mach-aspeed/Kconfig" 590 591source "arch/arm/mach-at91/Kconfig" 592 593source "arch/arm/mach-axxia/Kconfig" 594 595source "arch/arm/mach-bcm/Kconfig" 596 597source "arch/arm/mach-berlin/Kconfig" 598 599source "arch/arm/mach-clps711x/Kconfig" 600 601source "arch/arm/mach-cns3xxx/Kconfig" 602 603source "arch/arm/mach-davinci/Kconfig" 604 605source "arch/arm/mach-digicolor/Kconfig" 606 607source "arch/arm/mach-dove/Kconfig" 608 609source "arch/arm/mach-ep93xx/Kconfig" 610 611source "arch/arm/mach-exynos/Kconfig" 612 613source "arch/arm/mach-footbridge/Kconfig" 614 615source "arch/arm/mach-gemini/Kconfig" 616 617source "arch/arm/mach-highbank/Kconfig" 618 619source "arch/arm/mach-hisi/Kconfig" 620 621source "arch/arm/mach-imx/Kconfig" 622 623source "arch/arm/mach-integrator/Kconfig" 624 625source "arch/arm/mach-iop32x/Kconfig" 626 627source "arch/arm/mach-ixp4xx/Kconfig" 628 629source "arch/arm/mach-keystone/Kconfig" 630 631source "arch/arm/mach-lpc32xx/Kconfig" 632 633source "arch/arm/mach-mediatek/Kconfig" 634 635source "arch/arm/mach-meson/Kconfig" 636 637source "arch/arm/mach-milbeaut/Kconfig" 638 639source "arch/arm/mach-mmp/Kconfig" 640 641source "arch/arm/mach-moxart/Kconfig" 642 643source "arch/arm/mach-mstar/Kconfig" 644 645source "arch/arm/mach-mv78xx0/Kconfig" 646 647source "arch/arm/mach-mvebu/Kconfig" 648 649source "arch/arm/mach-mxs/Kconfig" 650 651source "arch/arm/mach-nomadik/Kconfig" 652 653source "arch/arm/mach-npcm/Kconfig" 654 655source "arch/arm/mach-nspire/Kconfig" 656 657source "arch/arm/plat-omap/Kconfig" 658 659source "arch/arm/mach-omap1/Kconfig" 660 661source "arch/arm/mach-omap2/Kconfig" 662 663source "arch/arm/mach-orion5x/Kconfig" 664 665source "arch/arm/mach-oxnas/Kconfig" 666 667source "arch/arm/mach-pxa/Kconfig" 668source "arch/arm/plat-pxa/Kconfig" 669 670source "arch/arm/mach-qcom/Kconfig" 671 672source "arch/arm/mach-rda/Kconfig" 673 674source "arch/arm/mach-realtek/Kconfig" 675 676source "arch/arm/mach-realview/Kconfig" 677 678source "arch/arm/mach-rockchip/Kconfig" 679 680source "arch/arm/mach-s3c/Kconfig" 681 682source "arch/arm/mach-s5pv210/Kconfig" 683 684source "arch/arm/mach-sa1100/Kconfig" 685 686source "arch/arm/mach-shmobile/Kconfig" 687 688source "arch/arm/mach-socfpga/Kconfig" 689 690source "arch/arm/mach-spear/Kconfig" 691 692source "arch/arm/mach-sti/Kconfig" 693 694source "arch/arm/mach-stm32/Kconfig" 695 696source "arch/arm/mach-sunxi/Kconfig" 697 698source "arch/arm/mach-tegra/Kconfig" 699 700source "arch/arm/mach-uniphier/Kconfig" 701 702source "arch/arm/mach-ux500/Kconfig" 703 704source "arch/arm/mach-versatile/Kconfig" 705 706source "arch/arm/mach-vexpress/Kconfig" 707 708source "arch/arm/mach-vt8500/Kconfig" 709 710source "arch/arm/mach-zynq/Kconfig" 711 712# ARMv7-M architecture 713config ARCH_LPC18XX 714 bool "NXP LPC18xx/LPC43xx" 715 depends on ARM_SINGLE_ARMV7M 716 select ARCH_HAS_RESET_CONTROLLER 717 select ARM_AMBA 718 select CLKSRC_LPC32XX 719 select PINCTRL 720 help 721 Support for NXP's LPC18xx Cortex-M3 and LPC43xx Cortex-M4 722 high performance microcontrollers. 723 724config ARCH_MPS2 725 bool "ARM MPS2 platform" 726 depends on ARM_SINGLE_ARMV7M 727 select ARM_AMBA 728 select CLKSRC_MPS2 729 help 730 Support for Cortex-M Prototyping System (or V2M-MPS2) which comes 731 with a range of available cores like Cortex-M3/M4/M7. 732 733 Please, note that depends which Application Note is used memory map 734 for the platform may vary, so adjustment of RAM base might be needed. 735 736# Definitions to make life easier 737config ARCH_ACORN 738 bool 739 740config PLAT_IOP 741 bool 742 743config PLAT_ORION 744 bool 745 select CLKSRC_MMIO 746 select COMMON_CLK 747 select GENERIC_IRQ_CHIP 748 select IRQ_DOMAIN 749 750config PLAT_ORION_LEGACY 751 bool 752 select PLAT_ORION 753 754config PLAT_PXA 755 bool 756 757config PLAT_VERSATILE 758 bool 759 760source "arch/arm/mm/Kconfig" 761 762config IWMMXT 763 bool "Enable iWMMXt support" 764 depends on CPU_XSCALE || CPU_XSC3 || CPU_MOHAWK || CPU_PJ4 || CPU_PJ4B 765 default y if PXA27x || PXA3xx || ARCH_MMP || CPU_PJ4 || CPU_PJ4B 766 help 767 Enable support for iWMMXt context switching at run time if 768 running on a CPU that supports it. 769 770if !MMU 771source "arch/arm/Kconfig-nommu" 772endif 773 774config PJ4B_ERRATA_4742 775 bool "PJ4B Errata 4742: IDLE Wake Up Commands can Cause the CPU Core to Cease Operation" 776 depends on CPU_PJ4B && MACH_ARMADA_370 777 default y 778 help 779 When coming out of either a Wait for Interrupt (WFI) or a Wait for 780 Event (WFE) IDLE states, a specific timing sensitivity exists between 781 the retiring WFI/WFE instructions and the newly issued subsequent 782 instructions. This sensitivity can result in a CPU hang scenario. 783 Workaround: 784 The software must insert either a Data Synchronization Barrier (DSB) 785 or Data Memory Barrier (DMB) command immediately after the WFI/WFE 786 instruction 787 788config ARM_ERRATA_326103 789 bool "ARM errata: FSR write bit incorrect on a SWP to read-only memory" 790 depends on CPU_V6 791 help 792 Executing a SWP instruction to read-only memory does not set bit 11 793 of the FSR on the ARM 1136 prior to r1p0. This causes the kernel to 794 treat the access as a read, preventing a COW from occurring and 795 causing the faulting task to livelock. 796 797config ARM_ERRATA_411920 798 bool "ARM errata: Invalidation of the Instruction Cache operation can fail" 799 depends on CPU_V6 || CPU_V6K 800 help 801 Invalidation of the Instruction Cache operation can 802 fail. This erratum is present in 1136 (before r1p4), 1156 and 1176. 803 It does not affect the MPCore. This option enables the ARM Ltd. 804 recommended workaround. 805 806config ARM_ERRATA_430973 807 bool "ARM errata: Stale prediction on replaced interworking branch" 808 depends on CPU_V7 809 help 810 This option enables the workaround for the 430973 Cortex-A8 811 r1p* erratum. If a code sequence containing an ARM/Thumb 812 interworking branch is replaced with another code sequence at the 813 same virtual address, whether due to self-modifying code or virtual 814 to physical address re-mapping, Cortex-A8 does not recover from the 815 stale interworking branch prediction. This results in Cortex-A8 816 executing the new code sequence in the incorrect ARM or Thumb state. 817 The workaround enables the BTB/BTAC operations by setting ACTLR.IBE 818 and also flushes the branch target cache at every context switch. 819 Note that setting specific bits in the ACTLR register may not be 820 available in non-secure mode. 821 822config ARM_ERRATA_458693 823 bool "ARM errata: Processor deadlock when a false hazard is created" 824 depends on CPU_V7 825 depends on !ARCH_MULTIPLATFORM 826 help 827 This option enables the workaround for the 458693 Cortex-A8 (r2p0) 828 erratum. For very specific sequences of memory operations, it is 829 possible for a hazard condition intended for a cache line to instead 830 be incorrectly associated with a different cache line. This false 831 hazard might then cause a processor deadlock. The workaround enables 832 the L1 caching of the NEON accesses and disables the PLD instruction 833 in the ACTLR register. Note that setting specific bits in the ACTLR 834 register may not be available in non-secure mode. 835 836config ARM_ERRATA_460075 837 bool "ARM errata: Data written to the L2 cache can be overwritten with stale data" 838 depends on CPU_V7 839 depends on !ARCH_MULTIPLATFORM 840 help 841 This option enables the workaround for the 460075 Cortex-A8 (r2p0) 842 erratum. Any asynchronous access to the L2 cache may encounter a 843 situation in which recent store transactions to the L2 cache are lost 844 and overwritten with stale memory contents from external memory. The 845 workaround disables the write-allocate mode for the L2 cache via the 846 ACTLR register. Note that setting specific bits in the ACTLR register 847 may not be available in non-secure mode. 848 849config ARM_ERRATA_742230 850 bool "ARM errata: DMB operation may be faulty" 851 depends on CPU_V7 && SMP 852 depends on !ARCH_MULTIPLATFORM 853 help 854 This option enables the workaround for the 742230 Cortex-A9 855 (r1p0..r2p2) erratum. Under rare circumstances, a DMB instruction 856 between two write operations may not ensure the correct visibility 857 ordering of the two writes. This workaround sets a specific bit in 858 the diagnostic register of the Cortex-A9 which causes the DMB 859 instruction to behave as a DSB, ensuring the correct behaviour of 860 the two writes. 861 862config ARM_ERRATA_742231 863 bool "ARM errata: Incorrect hazard handling in the SCU may lead to data corruption" 864 depends on CPU_V7 && SMP 865 depends on !ARCH_MULTIPLATFORM 866 help 867 This option enables the workaround for the 742231 Cortex-A9 868 (r2p0..r2p2) erratum. Under certain conditions, specific to the 869 Cortex-A9 MPCore micro-architecture, two CPUs working in SMP mode, 870 accessing some data located in the same cache line, may get corrupted 871 data due to bad handling of the address hazard when the line gets 872 replaced from one of the CPUs at the same time as another CPU is 873 accessing it. This workaround sets specific bits in the diagnostic 874 register of the Cortex-A9 which reduces the linefill issuing 875 capabilities of the processor. 876 877config ARM_ERRATA_643719 878 bool "ARM errata: LoUIS bit field in CLIDR register is incorrect" 879 depends on CPU_V7 && SMP 880 default y 881 help 882 This option enables the workaround for the 643719 Cortex-A9 (prior to 883 r1p0) erratum. On affected cores the LoUIS bit field of the CLIDR 884 register returns zero when it should return one. The workaround 885 corrects this value, ensuring cache maintenance operations which use 886 it behave as intended and avoiding data corruption. 887 888config ARM_ERRATA_720789 889 bool "ARM errata: TLBIASIDIS and TLBIMVAIS operations can broadcast a faulty ASID" 890 depends on CPU_V7 891 help 892 This option enables the workaround for the 720789 Cortex-A9 (prior to 893 r2p0) erratum. A faulty ASID can be sent to the other CPUs for the 894 broadcasted CP15 TLB maintenance operations TLBIASIDIS and TLBIMVAIS. 895 As a consequence of this erratum, some TLB entries which should be 896 invalidated are not, resulting in an incoherency in the system page 897 tables. The workaround changes the TLB flushing routines to invalidate 898 entries regardless of the ASID. 899 900config ARM_ERRATA_743622 901 bool "ARM errata: Faulty hazard checking in the Store Buffer may lead to data corruption" 902 depends on CPU_V7 903 depends on !ARCH_MULTIPLATFORM 904 help 905 This option enables the workaround for the 743622 Cortex-A9 906 (r2p*) erratum. Under very rare conditions, a faulty 907 optimisation in the Cortex-A9 Store Buffer may lead to data 908 corruption. This workaround sets a specific bit in the diagnostic 909 register of the Cortex-A9 which disables the Store Buffer 910 optimisation, preventing the defect from occurring. This has no 911 visible impact on the overall performance or power consumption of the 912 processor. 913 914config ARM_ERRATA_751472 915 bool "ARM errata: Interrupted ICIALLUIS may prevent completion of broadcasted operation" 916 depends on CPU_V7 917 depends on !ARCH_MULTIPLATFORM 918 help 919 This option enables the workaround for the 751472 Cortex-A9 (prior 920 to r3p0) erratum. An interrupted ICIALLUIS operation may prevent the 921 completion of a following broadcasted operation if the second 922 operation is received by a CPU before the ICIALLUIS has completed, 923 potentially leading to corrupted entries in the cache or TLB. 924 925config ARM_ERRATA_754322 926 bool "ARM errata: possible faulty MMU translations following an ASID switch" 927 depends on CPU_V7 928 help 929 This option enables the workaround for the 754322 Cortex-A9 (r2p*, 930 r3p*) erratum. A speculative memory access may cause a page table walk 931 which starts prior to an ASID switch but completes afterwards. This 932 can populate the micro-TLB with a stale entry which may be hit with 933 the new ASID. This workaround places two dsb instructions in the mm 934 switching code so that no page table walks can cross the ASID switch. 935 936config ARM_ERRATA_754327 937 bool "ARM errata: no automatic Store Buffer drain" 938 depends on CPU_V7 && SMP 939 help 940 This option enables the workaround for the 754327 Cortex-A9 (prior to 941 r2p0) erratum. The Store Buffer does not have any automatic draining 942 mechanism and therefore a livelock may occur if an external agent 943 continuously polls a memory location waiting to observe an update. 944 This workaround defines cpu_relax() as smp_mb(), preventing correctly 945 written polling loops from denying visibility of updates to memory. 946 947config ARM_ERRATA_364296 948 bool "ARM errata: Possible cache data corruption with hit-under-miss enabled" 949 depends on CPU_V6 950 help 951 This options enables the workaround for the 364296 ARM1136 952 r0p2 erratum (possible cache data corruption with 953 hit-under-miss enabled). It sets the undocumented bit 31 in 954 the auxiliary control register and the FI bit in the control 955 register, thus disabling hit-under-miss without putting the 956 processor into full low interrupt latency mode. ARM11MPCore 957 is not affected. 958 959config ARM_ERRATA_764369 960 bool "ARM errata: Data cache line maintenance operation by MVA may not succeed" 961 depends on CPU_V7 && SMP 962 help 963 This option enables the workaround for erratum 764369 964 affecting Cortex-A9 MPCore with two or more processors (all 965 current revisions). Under certain timing circumstances, a data 966 cache line maintenance operation by MVA targeting an Inner 967 Shareable memory region may fail to proceed up to either the 968 Point of Coherency or to the Point of Unification of the 969 system. This workaround adds a DSB instruction before the 970 relevant cache maintenance functions and sets a specific bit 971 in the diagnostic control register of the SCU. 972 973config ARM_ERRATA_775420 974 bool "ARM errata: A data cache maintenance operation which aborts, might lead to deadlock" 975 depends on CPU_V7 976 help 977 This option enables the workaround for the 775420 Cortex-A9 (r2p2, 978 r2p6,r2p8,r2p10,r3p0) erratum. In case a data cache maintenance 979 operation aborts with MMU exception, it might cause the processor 980 to deadlock. This workaround puts DSB before executing ISB if 981 an abort may occur on cache maintenance. 982 983config ARM_ERRATA_798181 984 bool "ARM errata: TLBI/DSB failure on Cortex-A15" 985 depends on CPU_V7 && SMP 986 help 987 On Cortex-A15 (r0p0..r3p2) the TLBI*IS/DSB operations are not 988 adequately shooting down all use of the old entries. This 989 option enables the Linux kernel workaround for this erratum 990 which sends an IPI to the CPUs that are running the same ASID 991 as the one being invalidated. 992 993config ARM_ERRATA_773022 994 bool "ARM errata: incorrect instructions may be executed from loop buffer" 995 depends on CPU_V7 996 help 997 This option enables the workaround for the 773022 Cortex-A15 998 (up to r0p4) erratum. In certain rare sequences of code, the 999 loop buffer may deliver incorrect instructions. This 1000 workaround disables the loop buffer to avoid the erratum. 1001 1002config ARM_ERRATA_818325_852422 1003 bool "ARM errata: A12: some seqs of opposed cond code instrs => deadlock or corruption" 1004 depends on CPU_V7 1005 help 1006 This option enables the workaround for: 1007 - Cortex-A12 818325: Execution of an UNPREDICTABLE STR or STM 1008 instruction might deadlock. Fixed in r0p1. 1009 - Cortex-A12 852422: Execution of a sequence of instructions might 1010 lead to either a data corruption or a CPU deadlock. Not fixed in 1011 any Cortex-A12 cores yet. 1012 This workaround for all both errata involves setting bit[12] of the 1013 Feature Register. This bit disables an optimisation applied to a 1014 sequence of 2 instructions that use opposing condition codes. 1015 1016config ARM_ERRATA_821420 1017 bool "ARM errata: A12: sequence of VMOV to core registers might lead to a dead lock" 1018 depends on CPU_V7 1019 help 1020 This option enables the workaround for the 821420 Cortex-A12 1021 (all revs) erratum. In very rare timing conditions, a sequence 1022 of VMOV to Core registers instructions, for which the second 1023 one is in the shadow of a branch or abort, can lead to a 1024 deadlock when the VMOV instructions are issued out-of-order. 1025 1026config ARM_ERRATA_825619 1027 bool "ARM errata: A12: DMB NSHST/ISHST mixed ... might cause deadlock" 1028 depends on CPU_V7 1029 help 1030 This option enables the workaround for the 825619 Cortex-A12 1031 (all revs) erratum. Within rare timing constraints, executing a 1032 DMB NSHST or DMB ISHST instruction followed by a mix of Cacheable 1033 and Device/Strongly-Ordered loads and stores might cause deadlock 1034 1035config ARM_ERRATA_857271 1036 bool "ARM errata: A12: CPU might deadlock under some very rare internal conditions" 1037 depends on CPU_V7 1038 help 1039 This option enables the workaround for the 857271 Cortex-A12 1040 (all revs) erratum. Under very rare timing conditions, the CPU might 1041 hang. The workaround is expected to have a < 1% performance impact. 1042 1043config ARM_ERRATA_852421 1044 bool "ARM errata: A17: DMB ST might fail to create order between stores" 1045 depends on CPU_V7 1046 help 1047 This option enables the workaround for the 852421 Cortex-A17 1048 (r1p0, r1p1, r1p2) erratum. Under very rare timing conditions, 1049 execution of a DMB ST instruction might fail to properly order 1050 stores from GroupA and stores from GroupB. 1051 1052config ARM_ERRATA_852423 1053 bool "ARM errata: A17: some seqs of opposed cond code instrs => deadlock or corruption" 1054 depends on CPU_V7 1055 help 1056 This option enables the workaround for: 1057 - Cortex-A17 852423: Execution of a sequence of instructions might 1058 lead to either a data corruption or a CPU deadlock. Not fixed in 1059 any Cortex-A17 cores yet. 1060 This is identical to Cortex-A12 erratum 852422. It is a separate 1061 config option from the A12 erratum due to the way errata are checked 1062 for and handled. 1063 1064config ARM_ERRATA_857272 1065 bool "ARM errata: A17: CPU might deadlock under some very rare internal conditions" 1066 depends on CPU_V7 1067 help 1068 This option enables the workaround for the 857272 Cortex-A17 erratum. 1069 This erratum is not known to be fixed in any A17 revision. 1070 This is identical to Cortex-A12 erratum 857271. It is a separate 1071 config option from the A12 erratum due to the way errata are checked 1072 for and handled. 1073 1074endmenu 1075 1076source "arch/arm/common/Kconfig" 1077 1078menu "Bus support" 1079 1080config ISA 1081 bool 1082 help 1083 Find out whether you have ISA slots on your motherboard. ISA is the 1084 name of a bus system, i.e. the way the CPU talks to the other stuff 1085 inside your box. Other bus systems are PCI, EISA, MicroChannel 1086 (MCA) or VESA. ISA is an older system, now being displaced by PCI; 1087 newer boards don't support it. If you have ISA, say Y, otherwise N. 1088 1089# Select ISA DMA controller support 1090config ISA_DMA 1091 bool 1092 select ISA_DMA_API 1093 1094# Select ISA DMA interface 1095config ISA_DMA_API 1096 bool 1097 1098config PCI_NANOENGINE 1099 bool "BSE nanoEngine PCI support" 1100 depends on SA1100_NANOENGINE 1101 help 1102 Enable PCI on the BSE nanoEngine board. 1103 1104config ARM_ERRATA_814220 1105 bool "ARM errata: Cache maintenance by set/way operations can execute out of order" 1106 depends on CPU_V7 1107 help 1108 The v7 ARM states that all cache and branch predictor maintenance 1109 operations that do not specify an address execute, relative to 1110 each other, in program order. 1111 However, because of this erratum, an L2 set/way cache maintenance 1112 operation can overtake an L1 set/way cache maintenance operation. 1113 This ERRATA only affected the Cortex-A7 and present in r0p2, r0p3, 1114 r0p4, r0p5. 1115 1116endmenu 1117 1118menu "Kernel Features" 1119 1120config HAVE_SMP 1121 bool 1122 help 1123 This option should be selected by machines which have an SMP- 1124 capable CPU. 1125 1126 The only effect of this option is to make the SMP-related 1127 options available to the user for configuration. 1128 1129config SMP 1130 bool "Symmetric Multi-Processing" 1131 depends on CPU_V6K || CPU_V7 1132 depends on HAVE_SMP 1133 depends on MMU || ARM_MPU 1134 select IRQ_WORK 1135 help 1136 This enables support for systems with more than one CPU. If you have 1137 a system with only one CPU, say N. If you have a system with more 1138 than one CPU, say Y. 1139 1140 If you say N here, the kernel will run on uni- and multiprocessor 1141 machines, but will use only one CPU of a multiprocessor machine. If 1142 you say Y here, the kernel will run on many, but not all, 1143 uniprocessor machines. On a uniprocessor machine, the kernel 1144 will run faster if you say N here. 1145 1146 See also <file:Documentation/x86/i386/IO-APIC.rst>, 1147 <file:Documentation/admin-guide/lockup-watchdogs.rst> and the SMP-HOWTO available at 1148 <http://tldp.org/HOWTO/SMP-HOWTO.html>. 1149 1150 If you don't know what to do here, say N. 1151 1152config SMP_ON_UP 1153 bool "Allow booting SMP kernel on uniprocessor systems" 1154 depends on SMP && !XIP_KERNEL && MMU 1155 default y 1156 help 1157 SMP kernels contain instructions which fail on non-SMP processors. 1158 Enabling this option allows the kernel to modify itself to make 1159 these instructions safe. Disabling it allows about 1K of space 1160 savings. 1161 1162 If you don't know what to do here, say Y. 1163 1164config ARM_CPU_TOPOLOGY 1165 bool "Support cpu topology definition" 1166 depends on SMP && CPU_V7 1167 default y 1168 help 1169 Support ARM cpu topology definition. The MPIDR register defines 1170 affinity between processors which is then used to describe the cpu 1171 topology of an ARM System. 1172 1173config SCHED_MC 1174 bool "Multi-core scheduler support" 1175 depends on ARM_CPU_TOPOLOGY 1176 help 1177 Multi-core scheduler support improves the CPU scheduler's decision 1178 making when dealing with multi-core CPU chips at a cost of slightly 1179 increased overhead in some places. If unsure say N here. 1180 1181config SCHED_SMT 1182 bool "SMT scheduler support" 1183 depends on ARM_CPU_TOPOLOGY 1184 help 1185 Improves the CPU scheduler's decision making when dealing with 1186 MultiThreading at a cost of slightly increased overhead in some 1187 places. If unsure say N here. 1188 1189config HAVE_ARM_SCU 1190 bool 1191 help 1192 This option enables support for the ARM snoop control unit 1193 1194config HAVE_ARM_ARCH_TIMER 1195 bool "Architected timer support" 1196 depends on CPU_V7 1197 select ARM_ARCH_TIMER 1198 help 1199 This option enables support for the ARM architected timer 1200 1201config HAVE_ARM_TWD 1202 bool 1203 help 1204 This options enables support for the ARM timer and watchdog unit 1205 1206config MCPM 1207 bool "Multi-Cluster Power Management" 1208 depends on CPU_V7 && SMP 1209 help 1210 This option provides the common power management infrastructure 1211 for (multi-)cluster based systems, such as big.LITTLE based 1212 systems. 1213 1214config MCPM_QUAD_CLUSTER 1215 bool 1216 depends on MCPM 1217 help 1218 To avoid wasting resources unnecessarily, MCPM only supports up 1219 to 2 clusters by default. 1220 Platforms with 3 or 4 clusters that use MCPM must select this 1221 option to allow the additional clusters to be managed. 1222 1223config BIG_LITTLE 1224 bool "big.LITTLE support (Experimental)" 1225 depends on CPU_V7 && SMP 1226 select MCPM 1227 help 1228 This option enables support selections for the big.LITTLE 1229 system architecture. 1230 1231config BL_SWITCHER 1232 bool "big.LITTLE switcher support" 1233 depends on BIG_LITTLE && MCPM && HOTPLUG_CPU && ARM_GIC 1234 select CPU_PM 1235 help 1236 The big.LITTLE "switcher" provides the core functionality to 1237 transparently handle transition between a cluster of A15's 1238 and a cluster of A7's in a big.LITTLE system. 1239 1240config BL_SWITCHER_DUMMY_IF 1241 tristate "Simple big.LITTLE switcher user interface" 1242 depends on BL_SWITCHER && DEBUG_KERNEL 1243 help 1244 This is a simple and dummy char dev interface to control 1245 the big.LITTLE switcher core code. It is meant for 1246 debugging purposes only. 1247 1248choice 1249 prompt "Memory split" 1250 depends on MMU 1251 default VMSPLIT_3G 1252 help 1253 Select the desired split between kernel and user memory. 1254 1255 If you are not absolutely sure what you are doing, leave this 1256 option alone! 1257 1258 config VMSPLIT_3G 1259 bool "3G/1G user/kernel split" 1260 config VMSPLIT_3G_OPT 1261 depends on !ARM_LPAE 1262 bool "3G/1G user/kernel split (for full 1G low memory)" 1263 config VMSPLIT_2G 1264 bool "2G/2G user/kernel split" 1265 config VMSPLIT_1G 1266 bool "1G/3G user/kernel split" 1267endchoice 1268 1269config PAGE_OFFSET 1270 hex 1271 default PHYS_OFFSET if !MMU 1272 default 0x40000000 if VMSPLIT_1G 1273 default 0x80000000 if VMSPLIT_2G 1274 default 0xB0000000 if VMSPLIT_3G_OPT 1275 default 0xC0000000 1276 1277config KASAN_SHADOW_OFFSET 1278 hex 1279 depends on KASAN 1280 default 0x1f000000 if PAGE_OFFSET=0x40000000 1281 default 0x5f000000 if PAGE_OFFSET=0x80000000 1282 default 0x9f000000 if PAGE_OFFSET=0xC0000000 1283 default 0x8f000000 if PAGE_OFFSET=0xB0000000 1284 default 0xffffffff 1285 1286config NR_CPUS 1287 int "Maximum number of CPUs (2-32)" 1288 range 2 16 if DEBUG_KMAP_LOCAL 1289 range 2 32 if !DEBUG_KMAP_LOCAL 1290 depends on SMP 1291 default "4" 1292 help 1293 The maximum number of CPUs that the kernel can support. 1294 Up to 32 CPUs can be supported, or up to 16 if kmap_local() 1295 debugging is enabled, which uses half of the per-CPU fixmap 1296 slots as guard regions. 1297 1298config HOTPLUG_CPU 1299 bool "Support for hot-pluggable CPUs" 1300 depends on SMP 1301 select GENERIC_IRQ_MIGRATION 1302 help 1303 Say Y here to experiment with turning CPUs off and on. CPUs 1304 can be controlled through /sys/devices/system/cpu. 1305 1306config ARM_PSCI 1307 bool "Support for the ARM Power State Coordination Interface (PSCI)" 1308 depends on HAVE_ARM_SMCCC 1309 select ARM_PSCI_FW 1310 help 1311 Say Y here if you want Linux to communicate with system firmware 1312 implementing the PSCI specification for CPU-centric power 1313 management operations described in ARM document number ARM DEN 1314 0022A ("Power State Coordination Interface System Software on 1315 ARM processors"). 1316 1317# The GPIO number here must be sorted by descending number. In case of 1318# a multiplatform kernel, we just want the highest value required by the 1319# selected platforms. 1320config ARCH_NR_GPIO 1321 int 1322 default 2048 if ARCH_INTEL_SOCFPGA 1323 default 1024 if ARCH_BRCMSTB || ARCH_RENESAS || ARCH_TEGRA || \ 1324 ARCH_ZYNQ || ARCH_ASPEED 1325 default 512 if ARCH_EXYNOS || ARCH_KEYSTONE || SOC_OMAP5 || \ 1326 SOC_DRA7XX || ARCH_S3C24XX || ARCH_S3C64XX || ARCH_S5PV210 1327 default 416 if ARCH_SUNXI 1328 default 392 if ARCH_U8500 1329 default 352 if ARCH_VT8500 1330 default 288 if ARCH_ROCKCHIP 1331 default 264 if MACH_H4700 1332 default 0 1333 help 1334 Maximum number of GPIOs in the system. 1335 1336 If unsure, leave the default value. 1337 1338config HZ_FIXED 1339 int 1340 default 128 if SOC_AT91RM9200 1341 default 0 1342 1343choice 1344 depends on HZ_FIXED = 0 1345 prompt "Timer frequency" 1346 1347config HZ_100 1348 bool "100 Hz" 1349 1350config HZ_200 1351 bool "200 Hz" 1352 1353config HZ_250 1354 bool "250 Hz" 1355 1356config HZ_300 1357 bool "300 Hz" 1358 1359config HZ_500 1360 bool "500 Hz" 1361 1362config HZ_1000 1363 bool "1000 Hz" 1364 1365endchoice 1366 1367config HZ 1368 int 1369 default HZ_FIXED if HZ_FIXED != 0 1370 default 100 if HZ_100 1371 default 200 if HZ_200 1372 default 250 if HZ_250 1373 default 300 if HZ_300 1374 default 500 if HZ_500 1375 default 1000 1376 1377config SCHED_HRTICK 1378 def_bool HIGH_RES_TIMERS 1379 1380config THUMB2_KERNEL 1381 bool "Compile the kernel in Thumb-2 mode" if !CPU_THUMBONLY 1382 depends on (CPU_V7 || CPU_V7M) && !CPU_V6 && !CPU_V6K 1383 default y if CPU_THUMBONLY 1384 select ARM_UNWIND 1385 help 1386 By enabling this option, the kernel will be compiled in 1387 Thumb-2 mode. 1388 1389 If unsure, say N. 1390 1391config ARM_PATCH_IDIV 1392 bool "Runtime patch udiv/sdiv instructions into __aeabi_{u}idiv()" 1393 depends on CPU_32v7 && !XIP_KERNEL 1394 default y 1395 help 1396 The ARM compiler inserts calls to __aeabi_idiv() and 1397 __aeabi_uidiv() when it needs to perform division on signed 1398 and unsigned integers. Some v7 CPUs have support for the sdiv 1399 and udiv instructions that can be used to implement those 1400 functions. 1401 1402 Enabling this option allows the kernel to modify itself to 1403 replace the first two instructions of these library functions 1404 with the sdiv or udiv plus "bx lr" instructions when the CPU 1405 it is running on supports them. Typically this will be faster 1406 and less power intensive than running the original library 1407 code to do integer division. 1408 1409config AEABI 1410 bool "Use the ARM EABI to compile the kernel" if !CPU_V7 && \ 1411 !CPU_V7M && !CPU_V6 && !CPU_V6K && !CC_IS_CLANG 1412 default CPU_V7 || CPU_V7M || CPU_V6 || CPU_V6K || CC_IS_CLANG 1413 help 1414 This option allows for the kernel to be compiled using the latest 1415 ARM ABI (aka EABI). This is only useful if you are using a user 1416 space environment that is also compiled with EABI. 1417 1418 Since there are major incompatibilities between the legacy ABI and 1419 EABI, especially with regard to structure member alignment, this 1420 option also changes the kernel syscall calling convention to 1421 disambiguate both ABIs and allow for backward compatibility support 1422 (selected with CONFIG_OABI_COMPAT). 1423 1424 To use this you need GCC version 4.0.0 or later. 1425 1426config OABI_COMPAT 1427 bool "Allow old ABI binaries to run with this kernel (EXPERIMENTAL)" 1428 depends on AEABI && !THUMB2_KERNEL 1429 help 1430 This option preserves the old syscall interface along with the 1431 new (ARM EABI) one. It also provides a compatibility layer to 1432 intercept syscalls that have structure arguments which layout 1433 in memory differs between the legacy ABI and the new ARM EABI 1434 (only for non "thumb" binaries). This option adds a tiny 1435 overhead to all syscalls and produces a slightly larger kernel. 1436 1437 The seccomp filter system will not be available when this is 1438 selected, since there is no way yet to sensibly distinguish 1439 between calling conventions during filtering. 1440 1441 If you know you'll be using only pure EABI user space then you 1442 can say N here. If this option is not selected and you attempt 1443 to execute a legacy ABI binary then the result will be 1444 UNPREDICTABLE (in fact it can be predicted that it won't work 1445 at all). If in doubt say N. 1446 1447config ARCH_SELECT_MEMORY_MODEL 1448 bool 1449 1450config ARCH_FLATMEM_ENABLE 1451 bool 1452 1453config ARCH_SPARSEMEM_ENABLE 1454 bool 1455 select SPARSEMEM_STATIC if SPARSEMEM 1456 1457config HIGHMEM 1458 bool "High Memory Support" 1459 depends on MMU 1460 select KMAP_LOCAL 1461 help 1462 The address space of ARM processors is only 4 Gigabytes large 1463 and it has to accommodate user address space, kernel address 1464 space as well as some memory mapped IO. That means that, if you 1465 have a large amount of physical memory and/or IO, not all of the 1466 memory can be "permanently mapped" by the kernel. The physical 1467 memory that is not permanently mapped is called "high memory". 1468 1469 Depending on the selected kernel/user memory split, minimum 1470 vmalloc space and actual amount of RAM, you may not need this 1471 option which should result in a slightly faster kernel. 1472 1473 If unsure, say n. 1474 1475config HIGHPTE 1476 bool "Allocate 2nd-level pagetables from highmem" if EXPERT 1477 depends on HIGHMEM 1478 default y 1479 help 1480 The VM uses one page of physical memory for each page table. 1481 For systems with a lot of processes, this can use a lot of 1482 precious low memory, eventually leading to low memory being 1483 consumed by page tables. Setting this option will allow 1484 user-space 2nd level page tables to reside in high memory. 1485 1486config CPU_SW_DOMAIN_PAN 1487 bool "Enable use of CPU domains to implement privileged no-access" 1488 depends on MMU && !ARM_LPAE 1489 default y 1490 help 1491 Increase kernel security by ensuring that normal kernel accesses 1492 are unable to access userspace addresses. This can help prevent 1493 use-after-free bugs becoming an exploitable privilege escalation 1494 by ensuring that magic values (such as LIST_POISON) will always 1495 fault when dereferenced. 1496 1497 CPUs with low-vector mappings use a best-efforts implementation. 1498 Their lower 1MB needs to remain accessible for the vectors, but 1499 the remainder of userspace will become appropriately inaccessible. 1500 1501config HW_PERF_EVENTS 1502 def_bool y 1503 depends on ARM_PMU 1504 1505config ARCH_WANT_GENERAL_HUGETLB 1506 def_bool y 1507 1508config ARM_MODULE_PLTS 1509 bool "Use PLTs to allow module memory to spill over into vmalloc area" 1510 depends on MODULES 1511 default y 1512 help 1513 Allocate PLTs when loading modules so that jumps and calls whose 1514 targets are too far away for their relative offsets to be encoded 1515 in the instructions themselves can be bounced via veneers in the 1516 module's PLT. This allows modules to be allocated in the generic 1517 vmalloc area after the dedicated module memory area has been 1518 exhausted. The modules will use slightly more memory, but after 1519 rounding up to page size, the actual memory footprint is usually 1520 the same. 1521 1522 Disabling this is usually safe for small single-platform 1523 configurations. If unsure, say y. 1524 1525config FORCE_MAX_ZONEORDER 1526 int "Maximum zone order" 1527 default "12" if SOC_AM33XX 1528 default "9" if SA1111 1529 default "11" 1530 help 1531 The kernel memory allocator divides physically contiguous memory 1532 blocks into "zones", where each zone is a power of two number of 1533 pages. This option selects the largest power of two that the kernel 1534 keeps in the memory allocator. If you need to allocate very large 1535 blocks of physically contiguous memory, then you may need to 1536 increase this value. 1537 1538 This config option is actually maximum order plus one. For example, 1539 a value of 11 means that the largest free memory block is 2^10 pages. 1540 1541config ALIGNMENT_TRAP 1542 def_bool CPU_CP15_MMU 1543 select HAVE_PROC_CPU if PROC_FS 1544 help 1545 ARM processors cannot fetch/store information which is not 1546 naturally aligned on the bus, i.e., a 4 byte fetch must start at an 1547 address divisible by 4. On 32-bit ARM processors, these non-aligned 1548 fetch/store instructions will be emulated in software if you say 1549 here, which has a severe performance impact. This is necessary for 1550 correct operation of some network protocols. With an IP-only 1551 configuration it is safe to say N, otherwise say Y. 1552 1553config UACCESS_WITH_MEMCPY 1554 bool "Use kernel mem{cpy,set}() for {copy_to,clear}_user()" 1555 depends on MMU 1556 default y if CPU_FEROCEON 1557 help 1558 Implement faster copy_to_user and clear_user methods for CPU 1559 cores where a 8-word STM instruction give significantly higher 1560 memory write throughput than a sequence of individual 32bit stores. 1561 1562 A possible side effect is a slight increase in scheduling latency 1563 between threads sharing the same address space if they invoke 1564 such copy operations with large buffers. 1565 1566 However, if the CPU data cache is using a write-allocate mode, 1567 this option is unlikely to provide any performance gain. 1568 1569config PARAVIRT 1570 bool "Enable paravirtualization code" 1571 help 1572 This changes the kernel so it can modify itself when it is run 1573 under a hypervisor, potentially improving performance significantly 1574 over full virtualization. 1575 1576config PARAVIRT_TIME_ACCOUNTING 1577 bool "Paravirtual steal time accounting" 1578 select PARAVIRT 1579 help 1580 Select this option to enable fine granularity task steal time 1581 accounting. Time spent executing other tasks in parallel with 1582 the current vCPU is discounted from the vCPU power. To account for 1583 that, there can be a small performance impact. 1584 1585 If in doubt, say N here. 1586 1587config XEN_DOM0 1588 def_bool y 1589 depends on XEN 1590 1591config XEN 1592 bool "Xen guest support on ARM" 1593 depends on ARM && AEABI && OF 1594 depends on CPU_V7 && !CPU_V6 1595 depends on !GENERIC_ATOMIC64 1596 depends on MMU 1597 select ARCH_DMA_ADDR_T_64BIT 1598 select ARM_PSCI 1599 select SWIOTLB 1600 select SWIOTLB_XEN 1601 select PARAVIRT 1602 help 1603 Say Y if you want to run Linux in a Virtual Machine on Xen on ARM. 1604 1605config STACKPROTECTOR_PER_TASK 1606 bool "Use a unique stack canary value for each task" 1607 depends on GCC_PLUGINS && STACKPROTECTOR && SMP && !XIP_DEFLATED_DATA 1608 select GCC_PLUGIN_ARM_SSP_PER_TASK 1609 default y 1610 help 1611 Due to the fact that GCC uses an ordinary symbol reference from 1612 which to load the value of the stack canary, this value can only 1613 change at reboot time on SMP systems, and all tasks running in the 1614 kernel's address space are forced to use the same canary value for 1615 the entire duration that the system is up. 1616 1617 Enable this option to switch to a different method that uses a 1618 different canary value for each task. 1619 1620endmenu 1621 1622menu "Boot options" 1623 1624config USE_OF 1625 bool "Flattened Device Tree support" 1626 select IRQ_DOMAIN 1627 select OF 1628 help 1629 Include support for flattened device tree machine descriptions. 1630 1631config ATAGS 1632 bool "Support for the traditional ATAGS boot data passing" if USE_OF 1633 default y 1634 help 1635 This is the traditional way of passing data to the kernel at boot 1636 time. If you are solely relying on the flattened device tree (or 1637 the ARM_ATAG_DTB_COMPAT option) then you may unselect this option 1638 to remove ATAGS support from your kernel binary. If unsure, 1639 leave this to y. 1640 1641config DEPRECATED_PARAM_STRUCT 1642 bool "Provide old way to pass kernel parameters" 1643 depends on ATAGS 1644 help 1645 This was deprecated in 2001 and announced to live on for 5 years. 1646 Some old boot loaders still use this way. 1647 1648# Compressed boot loader in ROM. Yes, we really want to ask about 1649# TEXT and BSS so we preserve their values in the config files. 1650config ZBOOT_ROM_TEXT 1651 hex "Compressed ROM boot loader base address" 1652 default 0x0 1653 help 1654 The physical address at which the ROM-able zImage is to be 1655 placed in the target. Platforms which normally make use of 1656 ROM-able zImage formats normally set this to a suitable 1657 value in their defconfig file. 1658 1659 If ZBOOT_ROM is not enabled, this has no effect. 1660 1661config ZBOOT_ROM_BSS 1662 hex "Compressed ROM boot loader BSS address" 1663 default 0x0 1664 help 1665 The base address of an area of read/write memory in the target 1666 for the ROM-able zImage which must be available while the 1667 decompressor is running. It must be large enough to hold the 1668 entire decompressed kernel plus an additional 128 KiB. 1669 Platforms which normally make use of ROM-able zImage formats 1670 normally set this to a suitable value in their defconfig file. 1671 1672 If ZBOOT_ROM is not enabled, this has no effect. 1673 1674config ZBOOT_ROM 1675 bool "Compressed boot loader in ROM/flash" 1676 depends on ZBOOT_ROM_TEXT != ZBOOT_ROM_BSS 1677 depends on !ARM_APPENDED_DTB && !XIP_KERNEL && !AUTO_ZRELADDR 1678 help 1679 Say Y here if you intend to execute your compressed kernel image 1680 (zImage) directly from ROM or flash. If unsure, say N. 1681 1682config ARM_APPENDED_DTB 1683 bool "Use appended device tree blob to zImage (EXPERIMENTAL)" 1684 depends on OF 1685 help 1686 With this option, the boot code will look for a device tree binary 1687 (DTB) appended to zImage 1688 (e.g. cat zImage <filename>.dtb > zImage_w_dtb). 1689 1690 This is meant as a backward compatibility convenience for those 1691 systems with a bootloader that can't be upgraded to accommodate 1692 the documented boot protocol using a device tree. 1693 1694 Beware that there is very little in terms of protection against 1695 this option being confused by leftover garbage in memory that might 1696 look like a DTB header after a reboot if no actual DTB is appended 1697 to zImage. Do not leave this option active in a production kernel 1698 if you don't intend to always append a DTB. Proper passing of the 1699 location into r2 of a bootloader provided DTB is always preferable 1700 to this option. 1701 1702config ARM_ATAG_DTB_COMPAT 1703 bool "Supplement the appended DTB with traditional ATAG information" 1704 depends on ARM_APPENDED_DTB 1705 help 1706 Some old bootloaders can't be updated to a DTB capable one, yet 1707 they provide ATAGs with memory configuration, the ramdisk address, 1708 the kernel cmdline string, etc. Such information is dynamically 1709 provided by the bootloader and can't always be stored in a static 1710 DTB. To allow a device tree enabled kernel to be used with such 1711 bootloaders, this option allows zImage to extract the information 1712 from the ATAG list and store it at run time into the appended DTB. 1713 1714choice 1715 prompt "Kernel command line type" if ARM_ATAG_DTB_COMPAT 1716 default ARM_ATAG_DTB_COMPAT_CMDLINE_FROM_BOOTLOADER 1717 1718config ARM_ATAG_DTB_COMPAT_CMDLINE_FROM_BOOTLOADER 1719 bool "Use bootloader kernel arguments if available" 1720 help 1721 Uses the command-line options passed by the boot loader instead of 1722 the device tree bootargs property. If the boot loader doesn't provide 1723 any, the device tree bootargs property will be used. 1724 1725config ARM_ATAG_DTB_COMPAT_CMDLINE_EXTEND 1726 bool "Extend with bootloader kernel arguments" 1727 help 1728 The command-line arguments provided by the boot loader will be 1729 appended to the the device tree bootargs property. 1730 1731endchoice 1732 1733config CMDLINE 1734 string "Default kernel command string" 1735 default "" 1736 help 1737 On some architectures (e.g. CATS), there is currently no way 1738 for the boot loader to pass arguments to the kernel. For these 1739 architectures, you should supply some command-line options at build 1740 time by entering them here. As a minimum, you should specify the 1741 memory size and the root device (e.g., mem=64M root=/dev/nfs). 1742 1743choice 1744 prompt "Kernel command line type" if CMDLINE != "" 1745 default CMDLINE_FROM_BOOTLOADER 1746 depends on ATAGS 1747 1748config CMDLINE_FROM_BOOTLOADER 1749 bool "Use bootloader kernel arguments if available" 1750 help 1751 Uses the command-line options passed by the boot loader. If 1752 the boot loader doesn't provide any, the default kernel command 1753 string provided in CMDLINE will be used. 1754 1755config CMDLINE_EXTEND 1756 bool "Extend bootloader kernel arguments" 1757 help 1758 The command-line arguments provided by the boot loader will be 1759 appended to the default kernel command string. 1760 1761config CMDLINE_FORCE 1762 bool "Always use the default kernel command string" 1763 help 1764 Always use the default kernel command string, even if the boot 1765 loader passes other arguments to the kernel. 1766 This is useful if you cannot or don't want to change the 1767 command-line options your boot loader passes to the kernel. 1768endchoice 1769 1770config XIP_KERNEL 1771 bool "Kernel Execute-In-Place from ROM" 1772 depends on !ARM_LPAE && !ARCH_MULTIPLATFORM 1773 help 1774 Execute-In-Place allows the kernel to run from non-volatile storage 1775 directly addressable by the CPU, such as NOR flash. This saves RAM 1776 space since the text section of the kernel is not loaded from flash 1777 to RAM. Read-write sections, such as the data section and stack, 1778 are still copied to RAM. The XIP kernel is not compressed since 1779 it has to run directly from flash, so it will take more space to 1780 store it. The flash address used to link the kernel object files, 1781 and for storing it, is configuration dependent. Therefore, if you 1782 say Y here, you must know the proper physical address where to 1783 store the kernel image depending on your own flash memory usage. 1784 1785 Also note that the make target becomes "make xipImage" rather than 1786 "make zImage" or "make Image". The final kernel binary to put in 1787 ROM memory will be arch/arm/boot/xipImage. 1788 1789 If unsure, say N. 1790 1791config XIP_PHYS_ADDR 1792 hex "XIP Kernel Physical Location" 1793 depends on XIP_KERNEL 1794 default "0x00080000" 1795 help 1796 This is the physical address in your flash memory the kernel will 1797 be linked for and stored to. This address is dependent on your 1798 own flash usage. 1799 1800config XIP_DEFLATED_DATA 1801 bool "Store kernel .data section compressed in ROM" 1802 depends on XIP_KERNEL 1803 select ZLIB_INFLATE 1804 help 1805 Before the kernel is actually executed, its .data section has to be 1806 copied to RAM from ROM. This option allows for storing that data 1807 in compressed form and decompressed to RAM rather than merely being 1808 copied, saving some precious ROM space. A possible drawback is a 1809 slightly longer boot delay. 1810 1811config KEXEC 1812 bool "Kexec system call (EXPERIMENTAL)" 1813 depends on (!SMP || PM_SLEEP_SMP) 1814 depends on MMU 1815 select KEXEC_CORE 1816 help 1817 kexec is a system call that implements the ability to shutdown your 1818 current kernel, and to start another kernel. It is like a reboot 1819 but it is independent of the system firmware. And like a reboot 1820 you can start any kernel with it, not just Linux. 1821 1822 It is an ongoing process to be certain the hardware in a machine 1823 is properly shutdown, so do not be surprised if this code does not 1824 initially work for you. 1825 1826config ATAGS_PROC 1827 bool "Export atags in procfs" 1828 depends on ATAGS && KEXEC 1829 default y 1830 help 1831 Should the atags used to boot the kernel be exported in an "atags" 1832 file in procfs. Useful with kexec. 1833 1834config CRASH_DUMP 1835 bool "Build kdump crash kernel (EXPERIMENTAL)" 1836 help 1837 Generate crash dump after being started by kexec. This should 1838 be normally only set in special crash dump kernels which are 1839 loaded in the main kernel with kexec-tools into a specially 1840 reserved region and then later executed after a crash by 1841 kdump/kexec. The crash dump kernel must be compiled to a 1842 memory address not used by the main kernel 1843 1844 For more details see Documentation/admin-guide/kdump/kdump.rst 1845 1846config AUTO_ZRELADDR 1847 bool "Auto calculation of the decompressed kernel image address" 1848 help 1849 ZRELADDR is the physical address where the decompressed kernel 1850 image will be placed. If AUTO_ZRELADDR is selected, the address 1851 will be determined at run-time, either by masking the current IP 1852 with 0xf8000000, or, if invalid, from the DTB passed in r2. 1853 This assumes the zImage being placed in the first 128MB from 1854 start of memory. 1855 1856config EFI_STUB 1857 bool 1858 1859config EFI 1860 bool "UEFI runtime support" 1861 depends on OF && !CPU_BIG_ENDIAN && MMU && AUTO_ZRELADDR && !XIP_KERNEL 1862 select UCS2_STRING 1863 select EFI_PARAMS_FROM_FDT 1864 select EFI_STUB 1865 select EFI_GENERIC_STUB 1866 select EFI_RUNTIME_WRAPPERS 1867 help 1868 This option provides support for runtime services provided 1869 by UEFI firmware (such as non-volatile variables, realtime 1870 clock, and platform reset). A UEFI stub is also provided to 1871 allow the kernel to be booted as an EFI application. This 1872 is only useful for kernels that may run on systems that have 1873 UEFI firmware. 1874 1875config DMI 1876 bool "Enable support for SMBIOS (DMI) tables" 1877 depends on EFI 1878 default y 1879 help 1880 This enables SMBIOS/DMI feature for systems. 1881 1882 This option is only useful on systems that have UEFI firmware. 1883 However, even with this option, the resultant kernel should 1884 continue to boot on existing non-UEFI platforms. 1885 1886 NOTE: This does *NOT* enable or encourage the use of DMI quirks, 1887 i.e., the the practice of identifying the platform via DMI to 1888 decide whether certain workarounds for buggy hardware and/or 1889 firmware need to be enabled. This would require the DMI subsystem 1890 to be enabled much earlier than we do on ARM, which is non-trivial. 1891 1892endmenu 1893 1894menu "CPU Power Management" 1895 1896source "drivers/cpufreq/Kconfig" 1897 1898source "drivers/cpuidle/Kconfig" 1899 1900endmenu 1901 1902menu "Floating point emulation" 1903 1904comment "At least one emulation must be selected" 1905 1906config FPE_NWFPE 1907 bool "NWFPE math emulation" 1908 depends on (!AEABI || OABI_COMPAT) && !THUMB2_KERNEL 1909 help 1910 Say Y to include the NWFPE floating point emulator in the kernel. 1911 This is necessary to run most binaries. Linux does not currently 1912 support floating point hardware so you need to say Y here even if 1913 your machine has an FPA or floating point co-processor podule. 1914 1915 You may say N here if you are going to load the Acorn FPEmulator 1916 early in the bootup. 1917 1918config FPE_NWFPE_XP 1919 bool "Support extended precision" 1920 depends on FPE_NWFPE 1921 help 1922 Say Y to include 80-bit support in the kernel floating-point 1923 emulator. Otherwise, only 32 and 64-bit support is compiled in. 1924 Note that gcc does not generate 80-bit operations by default, 1925 so in most cases this option only enlarges the size of the 1926 floating point emulator without any good reason. 1927 1928 You almost surely want to say N here. 1929 1930config FPE_FASTFPE 1931 bool "FastFPE math emulation (EXPERIMENTAL)" 1932 depends on (!AEABI || OABI_COMPAT) && !CPU_32v3 1933 help 1934 Say Y here to include the FAST floating point emulator in the kernel. 1935 This is an experimental much faster emulator which now also has full 1936 precision for the mantissa. It does not support any exceptions. 1937 It is very simple, and approximately 3-6 times faster than NWFPE. 1938 1939 It should be sufficient for most programs. It may be not suitable 1940 for scientific calculations, but you have to check this for yourself. 1941 If you do not feel you need a faster FP emulation you should better 1942 choose NWFPE. 1943 1944config VFP 1945 bool "VFP-format floating point maths" 1946 depends on CPU_V6 || CPU_V6K || CPU_ARM926T || CPU_V7 || CPU_FEROCEON 1947 help 1948 Say Y to include VFP support code in the kernel. This is needed 1949 if your hardware includes a VFP unit. 1950 1951 Please see <file:Documentation/arm/vfp/release-notes.rst> for 1952 release notes and additional status information. 1953 1954 Say N if your target does not have VFP hardware. 1955 1956config VFPv3 1957 bool 1958 depends on VFP 1959 default y if CPU_V7 1960 1961config NEON 1962 bool "Advanced SIMD (NEON) Extension support" 1963 depends on VFPv3 && CPU_V7 1964 help 1965 Say Y to include support code for NEON, the ARMv7 Advanced SIMD 1966 Extension. 1967 1968config KERNEL_MODE_NEON 1969 bool "Support for NEON in kernel mode" 1970 depends on NEON && AEABI 1971 help 1972 Say Y to include support for NEON in kernel mode. 1973 1974endmenu 1975 1976menu "Power management options" 1977 1978source "kernel/power/Kconfig" 1979 1980config ARCH_SUSPEND_POSSIBLE 1981 depends on CPU_ARM920T || CPU_ARM926T || CPU_FEROCEON || CPU_SA1100 || \ 1982 CPU_V6 || CPU_V6K || CPU_V7 || CPU_V7M || CPU_XSC3 || CPU_XSCALE || CPU_MOHAWK 1983 def_bool y 1984 1985config ARM_CPU_SUSPEND 1986 def_bool PM_SLEEP || BL_SWITCHER || ARM_PSCI_FW 1987 depends on ARCH_SUSPEND_POSSIBLE 1988 1989config ARCH_HIBERNATION_POSSIBLE 1990 bool 1991 depends on MMU 1992 default y if ARCH_SUSPEND_POSSIBLE 1993 1994endmenu 1995 1996source "drivers/firmware/Kconfig" 1997 1998if CRYPTO 1999source "arch/arm/crypto/Kconfig" 2000endif 2001 2002source "arch/arm/Kconfig.assembler" 2003