1# SPDX-License-Identifier: GPL-2.0-only 2# 3# For a description of the syntax of this configuration file, 4# see Documentation/kbuild/kconfig-language.rst. 5# 6 7config 64BIT 8 bool 9 10config 32BIT 11 bool 12 13config RISCV 14 def_bool y 15 select ACPI_GENERIC_GSI if ACPI 16 select ACPI_MCFG if (ACPI && PCI) 17 select ACPI_PPTT if ACPI 18 select ACPI_REDUCED_HARDWARE_ONLY if ACPI 19 select ACPI_SPCR_TABLE if ACPI 20 select ARCH_DMA_DEFAULT_COHERENT 21 select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION 22 select ARCH_ENABLE_MEMORY_HOTPLUG if SPARSEMEM_VMEMMAP 23 select ARCH_ENABLE_MEMORY_HOTREMOVE if MEMORY_HOTPLUG 24 select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2 25 select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE 26 select ARCH_HAS_BINFMT_FLAT 27 select ARCH_HAS_CRC32 if RISCV_ISA_ZBC 28 select ARCH_HAS_CRC64 if 64BIT && RISCV_ISA_ZBC 29 select ARCH_HAS_CRC_T10DIF if RISCV_ISA_ZBC 30 select ARCH_HAS_CURRENT_STACK_POINTER 31 select ARCH_HAS_DEBUG_VIRTUAL if MMU 32 select ARCH_HAS_DEBUG_VM_PGTABLE 33 select ARCH_HAS_DEBUG_WX 34 select ARCH_HAS_FAST_MULTIPLIER 35 select ARCH_HAS_FORTIFY_SOURCE 36 select ARCH_HAS_GCOV_PROFILE_ALL 37 select ARCH_HAS_GIGANTIC_PAGE 38 select ARCH_HAS_HW_PTE_YOUNG 39 select ARCH_HAS_KCOV 40 select ARCH_HAS_KERNEL_FPU_SUPPORT if 64BIT && FPU 41 select ARCH_HAS_MEMBARRIER_CALLBACKS 42 select ARCH_HAS_MEMBARRIER_SYNC_CORE 43 select ARCH_HAS_MMIOWB 44 select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 45 select ARCH_HAS_PMEM_API 46 select ARCH_HAS_PREEMPT_LAZY 47 select ARCH_HAS_PREPARE_SYNC_CORE_CMD 48 select ARCH_HAS_PTDUMP if MMU 49 select ARCH_HAS_PTE_DEVMAP if 64BIT && MMU 50 select ARCH_HAS_PTE_SPECIAL 51 select ARCH_HAS_SET_DIRECT_MAP if MMU 52 select ARCH_HAS_SET_MEMORY if MMU 53 select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL 54 select ARCH_HAS_STRICT_MODULE_RWX if MMU && !XIP_KERNEL 55 select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE 56 select ARCH_HAS_SYSCALL_WRAPPER 57 select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST 58 select ARCH_HAS_UBSAN 59 select ARCH_HAS_VDSO_ARCH_DATA if GENERIC_VDSO_DATA_STORE 60 select ARCH_KEEP_MEMBLOCK if ACPI 61 select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE if 64BIT && MMU 62 select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX 63 select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT 64 select ARCH_STACKWALK 65 select ARCH_SUPPORTS_ATOMIC_RMW 66 select ARCH_SUPPORTS_CFI_CLANG 67 select ARCH_SUPPORTS_DEBUG_PAGEALLOC if MMU 68 select ARCH_SUPPORTS_HUGE_PFNMAP if TRANSPARENT_HUGEPAGE 69 select ARCH_SUPPORTS_HUGETLBFS if MMU 70 # LLD >= 14: https://github.com/llvm/llvm-project/issues/50505 71 select ARCH_SUPPORTS_LTO_CLANG if LLD_VERSION >= 140000 72 select ARCH_SUPPORTS_LTO_CLANG_THIN if LLD_VERSION >= 140000 73 select ARCH_SUPPORTS_PAGE_TABLE_CHECK if MMU 74 select ARCH_SUPPORTS_PER_VMA_LOCK if MMU 75 select ARCH_SUPPORTS_RT 76 select ARCH_SUPPORTS_SHADOW_CALL_STACK if HAVE_SHADOW_CALL_STACK 77 select ARCH_USE_CMPXCHG_LOCKREF if 64BIT 78 select ARCH_USE_MEMTEST 79 select ARCH_USE_QUEUED_RWLOCKS 80 select ARCH_USE_SYM_ANNOTATIONS 81 select ARCH_USES_CFI_TRAPS if CFI_CLANG 82 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH if MMU 83 select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU 84 select ARCH_WANT_FRAME_POINTERS 85 select ARCH_WANT_GENERAL_HUGETLB if !RISCV_ISA_SVNAPOT 86 select ARCH_WANT_HUGE_PMD_SHARE if 64BIT 87 select ARCH_WANT_LD_ORPHAN_WARN if !XIP_KERNEL 88 select ARCH_WANT_OPTIMIZE_DAX_VMEMMAP 89 select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP 90 select ARCH_WANTS_NO_INSTR 91 select ARCH_WANTS_THP_SWAP if HAVE_ARCH_TRANSPARENT_HUGEPAGE 92 select ARCH_WEAK_RELEASE_ACQUIRE if ARCH_USE_QUEUED_SPINLOCKS 93 select BINFMT_FLAT_NO_DATA_START_OFFSET if !MMU 94 select BUILDTIME_TABLE_SORT if MMU 95 select CLINT_TIMER if RISCV_M_MODE 96 select CLONE_BACKWARDS 97 select COMMON_CLK 98 select CPU_PM if CPU_IDLE || HIBERNATION || SUSPEND 99 select EDAC_SUPPORT 100 select FRAME_POINTER if PERF_EVENTS || (FUNCTION_TRACER && !DYNAMIC_FTRACE) 101 select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY if DYNAMIC_FTRACE 102 select GENERIC_ARCH_TOPOLOGY 103 select GENERIC_ATOMIC64 if !64BIT 104 select GENERIC_CLOCKEVENTS_BROADCAST if SMP 105 select GENERIC_CPU_DEVICES 106 select GENERIC_CPU_VULNERABILITIES 107 select GENERIC_EARLY_IOREMAP 108 select GENERIC_ENTRY 109 select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO 110 select GENERIC_IDLE_POLL_SETUP 111 select GENERIC_IOREMAP if MMU 112 select GENERIC_IRQ_IPI if SMP 113 select GENERIC_IRQ_IPI_MUX if SMP 114 select GENERIC_IRQ_MULTI_HANDLER 115 select GENERIC_IRQ_SHOW 116 select GENERIC_IRQ_SHOW_LEVEL 117 select GENERIC_LIB_DEVMEM_IS_ALLOWED 118 select GENERIC_PENDING_IRQ if SMP 119 select GENERIC_PCI_IOMAP 120 select GENERIC_SCHED_CLOCK 121 select GENERIC_SMP_IDLE_THREAD 122 select GENERIC_TIME_VSYSCALL if MMU && 64BIT 123 select GENERIC_VDSO_DATA_STORE if MMU 124 select GENERIC_VDSO_TIME_NS if HAVE_GENERIC_VDSO 125 select HARDIRQS_SW_RESEND 126 select HAS_IOPORT if MMU 127 select HAVE_ALIGNED_STRUCT_PAGE 128 select HAVE_ARCH_AUDITSYSCALL 129 select HAVE_ARCH_HUGE_VMALLOC if HAVE_ARCH_HUGE_VMAP 130 select HAVE_ARCH_HUGE_VMAP if MMU && 64BIT 131 select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL 132 select HAVE_ARCH_JUMP_LABEL_RELATIVE if !XIP_KERNEL 133 select HAVE_ARCH_KASAN if MMU && 64BIT 134 select HAVE_ARCH_KASAN_VMALLOC if MMU && 64BIT 135 select HAVE_ARCH_KFENCE if MMU && 64BIT 136 select HAVE_ARCH_KGDB if !XIP_KERNEL 137 select HAVE_ARCH_KGDB_QXFER_PKT 138 select HAVE_ARCH_MMAP_RND_BITS if MMU 139 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT 140 select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET 141 select HAVE_ARCH_SECCOMP_FILTER 142 select HAVE_ARCH_STACKLEAK 143 select HAVE_ARCH_THREAD_STRUCT_WHITELIST 144 select HAVE_ARCH_TRACEHOOK 145 select HAVE_ARCH_TRANSPARENT_HUGEPAGE if 64BIT && MMU 146 select HAVE_ARCH_USERFAULTFD_MINOR if 64BIT && USERFAULTFD 147 select HAVE_ARCH_VMAP_STACK if MMU && 64BIT 148 select HAVE_ASM_MODVERSIONS 149 select HAVE_CONTEXT_TRACKING_USER 150 select HAVE_DEBUG_KMEMLEAK 151 select HAVE_DMA_CONTIGUOUS if MMU 152 select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && MMU && (CLANG_SUPPORTS_DYNAMIC_FTRACE || GCC_SUPPORTS_DYNAMIC_FTRACE) 153 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS 154 select HAVE_DYNAMIC_FTRACE_WITH_ARGS if HAVE_DYNAMIC_FTRACE 155 select HAVE_FTRACE_GRAPH_FUNC 156 select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL 157 select HAVE_FUNCTION_GRAPH_TRACER if HAVE_DYNAMIC_FTRACE_WITH_ARGS 158 select HAVE_FUNCTION_GRAPH_FREGS 159 select HAVE_FUNCTION_TRACER if !XIP_KERNEL && !PREEMPTION 160 select HAVE_EBPF_JIT if MMU 161 select HAVE_GUP_FAST if MMU 162 select HAVE_FUNCTION_ARG_ACCESS_API 163 select HAVE_FUNCTION_ERROR_INJECTION 164 select HAVE_GCC_PLUGINS 165 select HAVE_GENERIC_VDSO if MMU && 64BIT 166 select HAVE_IRQ_TIME_ACCOUNTING 167 select HAVE_KERNEL_BZIP2 if !XIP_KERNEL && !EFI_ZBOOT 168 select HAVE_KERNEL_GZIP if !XIP_KERNEL && !EFI_ZBOOT 169 select HAVE_KERNEL_LZ4 if !XIP_KERNEL && !EFI_ZBOOT 170 select HAVE_KERNEL_LZMA if !XIP_KERNEL && !EFI_ZBOOT 171 select HAVE_KERNEL_LZO if !XIP_KERNEL && !EFI_ZBOOT 172 select HAVE_KERNEL_UNCOMPRESSED if !XIP_KERNEL && !EFI_ZBOOT 173 select HAVE_KERNEL_ZSTD if !XIP_KERNEL && !EFI_ZBOOT 174 select HAVE_KERNEL_XZ if !XIP_KERNEL && !EFI_ZBOOT 175 select HAVE_KPROBES if !XIP_KERNEL 176 select HAVE_KRETPROBES if !XIP_KERNEL 177 # https://github.com/ClangBuiltLinux/linux/issues/1881 178 select HAVE_LD_DEAD_CODE_DATA_ELIMINATION if !LD_IS_LLD 179 select HAVE_MOVE_PMD 180 select HAVE_MOVE_PUD 181 select HAVE_PAGE_SIZE_4KB 182 select HAVE_PCI 183 select HAVE_PERF_EVENTS 184 select HAVE_PERF_REGS 185 select HAVE_PERF_USER_STACK_DUMP 186 select HAVE_POSIX_CPU_TIMERS_TASK_WORK 187 select HAVE_PREEMPT_DYNAMIC_KEY if !XIP_KERNEL 188 select HAVE_REGS_AND_STACK_ACCESS_API 189 select HAVE_RETHOOK if !XIP_KERNEL 190 select HAVE_RSEQ 191 select HAVE_RUST if RUSTC_SUPPORTS_RISCV && CC_IS_CLANG 192 select HAVE_SAMPLE_FTRACE_DIRECT 193 select HAVE_SAMPLE_FTRACE_DIRECT_MULTI 194 select HAVE_STACKPROTECTOR 195 select HAVE_SYSCALL_TRACEPOINTS 196 select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU 197 select IRQ_DOMAIN 198 select IRQ_FORCED_THREADING 199 select KASAN_VMALLOC if KASAN 200 select LOCK_MM_AND_FIND_VMA 201 select MMU_GATHER_RCU_TABLE_FREE if SMP && MMU 202 select MODULES_USE_ELF_RELA if MODULES 203 select OF 204 select OF_EARLY_FLATTREE 205 select OF_IRQ 206 select PCI_DOMAINS_GENERIC if PCI 207 select PCI_ECAM if (ACPI && PCI) 208 select PCI_MSI if PCI 209 select RELOCATABLE if !MMU && !PHYS_RAM_BASE_FIXED 210 select RISCV_ALTERNATIVE if !XIP_KERNEL 211 select RISCV_APLIC 212 select RISCV_IMSIC 213 select RISCV_INTC 214 select RISCV_TIMER if RISCV_SBI 215 select SIFIVE_PLIC 216 select SPARSE_IRQ 217 select SYSCTL_EXCEPTION_TRACE 218 select THREAD_INFO_IN_TASK 219 select TRACE_IRQFLAGS_SUPPORT 220 select UACCESS_MEMCPY if !MMU 221 select USER_STACKTRACE_SUPPORT 222 select ZONE_DMA32 if 64BIT 223 224config RUSTC_SUPPORTS_RISCV 225 def_bool y 226 depends on 64BIT 227 # Shadow call stack requires rustc version 1.82+ due to use of the 228 # -Zsanitizer=shadow-call-stack flag. 229 depends on !SHADOW_CALL_STACK || RUSTC_VERSION >= 108200 230 231config CLANG_SUPPORTS_DYNAMIC_FTRACE 232 def_bool CC_IS_CLANG 233 # https://github.com/ClangBuiltLinux/linux/issues/1817 234 depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600)) 235 236config GCC_SUPPORTS_DYNAMIC_FTRACE 237 def_bool CC_IS_GCC 238 depends on $(cc-option,-fpatchable-function-entry=8) 239 240config HAVE_SHADOW_CALL_STACK 241 def_bool $(cc-option,-fsanitize=shadow-call-stack) 242 # https://github.com/riscv-non-isa/riscv-elf-psabi-doc/commit/a484e843e6eeb51f0cb7b8819e50da6d2444d769 243 depends on $(ld-option,--no-relax-gp) 244 245config RISCV_USE_LINKER_RELAXATION 246 def_bool y 247 # https://github.com/llvm/llvm-project/commit/6611d58f5bbcbec77262d392e2923e1d680f6985 248 depends on !LD_IS_LLD || LLD_VERSION >= 150000 249 250# https://github.com/llvm/llvm-project/commit/bbc0f99f3bc96f1db16f649fc21dd18e5b0918f6 251config ARCH_HAS_BROKEN_DWARF5 252 def_bool y 253 depends on RISCV_USE_LINKER_RELAXATION 254 # https://github.com/llvm/llvm-project/commit/1df5ea29b43690b6622db2cad7b745607ca4de6a 255 depends on AS_IS_LLVM && AS_VERSION < 180000 256 # https://github.com/llvm/llvm-project/commit/7ffabb61a5569444b5ac9322e22e5471cc5e4a77 257 depends on LD_IS_LLD && LLD_VERSION < 180000 258 259config ARCH_MMAP_RND_BITS_MIN 260 default 18 if 64BIT 261 default 8 262 263config ARCH_MMAP_RND_COMPAT_BITS_MIN 264 default 8 265 266# max bits determined by the following formula: 267# VA_BITS - PAGE_SHIFT - 3 268config ARCH_MMAP_RND_BITS_MAX 269 default 24 if 64BIT # SV39 based 270 default 17 271 272config ARCH_MMAP_RND_COMPAT_BITS_MAX 273 default 17 274 275# set if we run in machine mode, cleared if we run in supervisor mode 276config RISCV_M_MODE 277 bool "Build a kernel that runs in machine mode" 278 depends on !MMU 279 default y 280 help 281 Select this option if you want to run the kernel in M-mode, 282 without the assistance of any other firmware. 283 284# set if we are running in S-mode and can use SBI calls 285config RISCV_SBI 286 bool 287 depends on !RISCV_M_MODE 288 default y 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 KASAN_SHADOW_OFFSET 298 hex 299 depends on KASAN_GENERIC 300 default 0xdfffffff00000000 if 64BIT 301 default 0xffffffff if 32BIT 302 303config ARCH_FLATMEM_ENABLE 304 def_bool !NUMA 305 306config ARCH_SPARSEMEM_ENABLE 307 def_bool y 308 depends on MMU 309 select SPARSEMEM_STATIC if 32BIT && SPARSEMEM 310 select SPARSEMEM_VMEMMAP_ENABLE if 64BIT 311 312config ARCH_SELECT_MEMORY_MODEL 313 def_bool ARCH_SPARSEMEM_ENABLE 314 315config ARCH_SUPPORTS_UPROBES 316 def_bool y 317 318config STACKTRACE_SUPPORT 319 def_bool y 320 321config GENERIC_BUG 322 def_bool y 323 depends on BUG 324 select GENERIC_BUG_RELATIVE_POINTERS if 64BIT 325 326config GENERIC_BUG_RELATIVE_POINTERS 327 bool 328 329config GENERIC_CALIBRATE_DELAY 330 def_bool y 331 332config GENERIC_CSUM 333 def_bool y 334 335config GENERIC_HWEIGHT 336 def_bool y 337 338config FIX_EARLYCON_MEM 339 def_bool MMU 340 341config ILLEGAL_POINTER_VALUE 342 hex 343 default 0 if 32BIT 344 default 0xdead000000000000 if 64BIT 345 346config PGTABLE_LEVELS 347 int 348 default 5 if 64BIT 349 default 2 350 351config LOCKDEP_SUPPORT 352 def_bool y 353 354config RISCV_DMA_NONCOHERENT 355 bool 356 select ARCH_HAS_DMA_PREP_COHERENT 357 select ARCH_HAS_SETUP_DMA_OPS 358 select ARCH_HAS_SYNC_DMA_FOR_CPU 359 select ARCH_HAS_SYNC_DMA_FOR_DEVICE 360 select DMA_BOUNCE_UNALIGNED_KMALLOC if SWIOTLB 361 362config RISCV_NONSTANDARD_CACHE_OPS 363 bool 364 help 365 This enables function pointer support for non-standard noncoherent 366 systems to handle cache management. 367 368config AS_HAS_INSN 369 def_bool $(as-instr,.insn r 51$(comma) 0$(comma) 0$(comma) t0$(comma) t0$(comma) zero) 370 371config AS_HAS_OPTION_ARCH 372 # https://github.com/llvm/llvm-project/commit/9e8ed3403c191ab9c4903e8eeb8f732ff8a43cb4 373 def_bool y 374 depends on $(as-instr, .option arch$(comma) +m) 375 376source "arch/riscv/Kconfig.socs" 377source "arch/riscv/Kconfig.errata" 378 379menu "Platform type" 380 381config NONPORTABLE 382 bool "Allow configurations that result in non-portable kernels" 383 help 384 RISC-V kernel binaries are compatible between all known systems 385 whenever possible, but there are some use cases that can only be 386 satisfied by configurations that result in kernel binaries that are 387 not portable between systems. 388 389 Selecting N does not guarantee kernels will be portable to all known 390 systems. Selecting any of the options guarded by NONPORTABLE will 391 result in kernel binaries that are unlikely to be portable between 392 systems. 393 394 If unsure, say N. 395 396choice 397 prompt "Base ISA" 398 default ARCH_RV64I 399 help 400 This selects the base ISA that this kernel will target and must match 401 the target platform. 402 403config ARCH_RV32I 404 bool "RV32I" 405 depends on NONPORTABLE 406 select 32BIT 407 select GENERIC_LIB_ASHLDI3 408 select GENERIC_LIB_ASHRDI3 409 select GENERIC_LIB_LSHRDI3 410 select GENERIC_LIB_UCMPDI2 411 412config ARCH_RV64I 413 bool "RV64I" 414 select 64BIT 415 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 416 select SWIOTLB if MMU 417 418endchoice 419 420# We must be able to map all physical memory into the kernel, but the compiler 421# is still a bit more efficient when generating code if it's setup in a manner 422# such that it can only map 2GiB of memory. 423choice 424 prompt "Kernel Code Model" 425 default CMODEL_MEDLOW if 32BIT 426 default CMODEL_MEDANY if 64BIT 427 428 config CMODEL_MEDLOW 429 bool "medium low code model" 430 config CMODEL_MEDANY 431 bool "medium any code model" 432endchoice 433 434config MODULE_SECTIONS 435 bool 436 select HAVE_MOD_ARCH_SPECIFIC 437 438config SMP 439 bool "Symmetric Multi-Processing" 440 help 441 This enables support for systems with more than one CPU. If 442 you say N here, the kernel will run on single and 443 multiprocessor machines, but will use only one CPU of a 444 multiprocessor machine. If you say Y here, the kernel will run 445 on many, but not all, single processor machines. On a single 446 processor machine, the kernel will run faster if you say N 447 here. 448 449 If you don't know what to do here, say N. 450 451config SCHED_MC 452 bool "Multi-core scheduler support" 453 depends on SMP 454 help 455 Multi-core scheduler support improves the CPU scheduler's decision 456 making when dealing with multi-core CPU chips at a cost of slightly 457 increased overhead in some places. If unsure say N here. 458 459config NR_CPUS 460 int "Maximum number of CPUs (2-512)" 461 depends on SMP 462 range 2 512 if !RISCV_SBI_V01 463 range 2 32 if RISCV_SBI_V01 && 32BIT 464 range 2 64 if RISCV_SBI_V01 && 64BIT 465 default "32" if 32BIT 466 default "64" if 64BIT 467 468config HOTPLUG_CPU 469 bool "Support for hot-pluggable CPUs" 470 depends on SMP 471 select GENERIC_IRQ_MIGRATION 472 help 473 474 Say Y here to experiment with turning CPUs off and on. CPUs 475 can be controlled through /sys/devices/system/cpu. 476 477 Say N if you want to disable CPU hotplug. 478 479choice 480 prompt "CPU Tuning" 481 default TUNE_GENERIC 482 483config TUNE_GENERIC 484 bool "generic" 485 486endchoice 487 488# Common NUMA Features 489config NUMA 490 bool "NUMA Memory Allocation and Scheduler Support" 491 depends on SMP && MMU 492 select ARCH_SUPPORTS_NUMA_BALANCING 493 select GENERIC_ARCH_NUMA 494 select HAVE_SETUP_PER_CPU_AREA 495 select NEED_PER_CPU_EMBED_FIRST_CHUNK 496 select NEED_PER_CPU_PAGE_FIRST_CHUNK 497 select OF_NUMA 498 select USE_PERCPU_NUMA_NODE_ID 499 help 500 Enable NUMA (Non-Uniform Memory Access) support. 501 502 The kernel will try to allocate memory used by a CPU on the 503 local memory of the CPU and add some more NUMA awareness to the kernel. 504 505config NODES_SHIFT 506 int "Maximum NUMA Nodes (as a power of 2)" 507 range 1 10 508 default "2" 509 depends on NUMA 510 help 511 Specify the maximum number of NUMA Nodes available on the target 512 system. Increases memory reserved to accommodate various tables. 513 514choice 515 prompt "RISC-V spinlock type" 516 default RISCV_COMBO_SPINLOCKS 517 518config RISCV_TICKET_SPINLOCKS 519 bool "Using ticket spinlock" 520 521config RISCV_QUEUED_SPINLOCKS 522 bool "Using queued spinlock" 523 depends on SMP && MMU && NONPORTABLE 524 select ARCH_USE_QUEUED_SPINLOCKS 525 help 526 The queued spinlock implementation requires the forward progress 527 guarantee of cmpxchg()/xchg() atomic operations: CAS with Zabha or 528 LR/SC with Ziccrse provide such guarantee. 529 530 Select this if and only if Zabha or Ziccrse is available on your 531 platform, RISCV_QUEUED_SPINLOCKS must not be selected for platforms 532 without one of those extensions. 533 534 If unsure, select RISCV_COMBO_SPINLOCKS, which will use qspinlocks 535 when supported and otherwise ticket spinlocks. 536 537config RISCV_COMBO_SPINLOCKS 538 bool "Using combo spinlock" 539 depends on SMP && MMU 540 select ARCH_USE_QUEUED_SPINLOCKS 541 help 542 Embed both queued spinlock and ticket lock so that the spinlock 543 implementation can be chosen at runtime. 544 545endchoice 546 547config RISCV_ALTERNATIVE 548 bool 549 depends on !XIP_KERNEL 550 help 551 This Kconfig allows the kernel to automatically patch the 552 erratum or cpufeature required by the execution platform at run 553 time. The code patching overhead is minimal, as it's only done 554 once at boot and once on each module load. 555 556config RISCV_ALTERNATIVE_EARLY 557 bool 558 depends on RISCV_ALTERNATIVE 559 help 560 Allows early patching of the kernel for special errata 561 562config RISCV_ISA_C 563 bool "Emit compressed instructions when building Linux" 564 default y 565 help 566 Adds "C" to the ISA subsets that the toolchain is allowed to emit 567 when building Linux, which results in compressed instructions in the 568 Linux binary. This option produces a kernel that will not run on 569 systems that do not support compressed instructions. 570 571 If you don't know what to do here, say Y. 572 573config RISCV_ISA_SUPM 574 bool "Supm extension for userspace pointer masking" 575 depends on 64BIT 576 default y 577 help 578 Add support for pointer masking in userspace (Supm) when the 579 underlying hardware extension (Smnpm or Ssnpm) is detected at boot. 580 581 If this option is disabled, userspace will be unable to use 582 the prctl(PR_{SET,GET}_TAGGED_ADDR_CTRL) API. 583 584config RISCV_ISA_SVNAPOT 585 bool "Svnapot extension support for supervisor mode NAPOT pages" 586 depends on 64BIT && MMU 587 depends on RISCV_ALTERNATIVE 588 default y 589 help 590 Enable support for the Svnapot ISA-extension when it is detected 591 at boot. 592 593 The Svnapot extension is used to mark contiguous PTEs as a range 594 of contiguous virtual-to-physical translations for a naturally 595 aligned power-of-2 (NAPOT) granularity larger than the base 4KB page 596 size. When HUGETLBFS is also selected this option unconditionally 597 allocates some memory for each NAPOT page size supported by the kernel. 598 When optimizing for low memory consumption and for platforms without 599 the Svnapot extension, it may be better to say N here. 600 601 If you don't know what to do here, say Y. 602 603config RISCV_ISA_SVPBMT 604 bool "Svpbmt extension support for supervisor mode page-based memory types" 605 depends on 64BIT && MMU 606 depends on RISCV_ALTERNATIVE 607 default y 608 help 609 Add support for the Svpbmt ISA-extension (Supervisor-mode: 610 page-based memory types) in the kernel when it is detected at boot. 611 612 The memory type for a page contains a combination of attributes 613 that indicate the cacheability, idempotency, and ordering 614 properties for access to that page. 615 616 The Svpbmt extension is only available on 64-bit cpus. 617 618 If you don't know what to do here, say Y. 619 620config TOOLCHAIN_HAS_V 621 bool 622 default y 623 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64imv) 624 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32imv) 625 depends on LLD_VERSION >= 140000 || LD_VERSION >= 23800 626 depends on AS_HAS_OPTION_ARCH 627 628config RISCV_ISA_V 629 bool "Vector extension support" 630 depends on TOOLCHAIN_HAS_V 631 depends on FPU 632 select DYNAMIC_SIGFRAME 633 default y 634 help 635 Add support for the Vector extension when it is detected at boot. 636 When this option is disabled, neither the kernel nor userspace may 637 use vector procedures. 638 639 If you don't know what to do here, say Y. 640 641config RISCV_ISA_V_DEFAULT_ENABLE 642 bool "Enable userspace Vector by default" 643 depends on RISCV_ISA_V 644 default y 645 help 646 Say Y here if you want to enable Vector in userspace by default. 647 Otherwise, userspace has to make explicit prctl() call to enable 648 Vector, or enable it via the sysctl interface. 649 650 If you don't know what to do here, say Y. 651 652config RISCV_ISA_V_UCOPY_THRESHOLD 653 int "Threshold size for vectorized user copies" 654 depends on RISCV_ISA_V 655 default 768 656 help 657 Prefer using vectorized copy_to_user()/copy_from_user() when the 658 workload size exceeds this value. 659 660config RISCV_ISA_V_PREEMPTIVE 661 bool "Run kernel-mode Vector with kernel preemption" 662 depends on PREEMPTION 663 depends on RISCV_ISA_V 664 default y 665 help 666 Usually, in-kernel SIMD routines are run with preemption disabled. 667 Functions which envoke long running SIMD thus must yield core's 668 vector unit to prevent blocking other tasks for too long. 669 670 This config allows kernel to run SIMD without explicitly disable 671 preemption. Enabling this config will result in higher memory 672 consumption due to the allocation of per-task's kernel Vector context. 673 674config RISCV_ISA_ZAWRS 675 bool "Zawrs extension support for more efficient busy waiting" 676 depends on RISCV_ALTERNATIVE 677 default y 678 help 679 The Zawrs extension defines instructions to be used in polling loops 680 which allow a hart to enter a low-power state or to trap to the 681 hypervisor while waiting on a store to a memory location. Enable the 682 use of these instructions in the kernel when the Zawrs extension is 683 detected at boot. 684 685config TOOLCHAIN_HAS_ZABHA 686 bool 687 default y 688 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zabha) 689 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zabha) 690 depends on AS_HAS_OPTION_ARCH 691 692config RISCV_ISA_ZABHA 693 bool "Zabha extension support for atomic byte/halfword operations" 694 depends on TOOLCHAIN_HAS_ZABHA 695 depends on RISCV_ALTERNATIVE 696 default y 697 help 698 Enable the use of the Zabha ISA-extension to implement kernel 699 byte/halfword atomic memory operations when it is detected at boot. 700 701 If you don't know what to do here, say Y. 702 703config TOOLCHAIN_HAS_ZACAS 704 bool 705 default y 706 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zacas) 707 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zacas) 708 depends on AS_HAS_OPTION_ARCH 709 710config RISCV_ISA_ZACAS 711 bool "Zacas extension support for atomic CAS" 712 depends on TOOLCHAIN_HAS_ZACAS 713 depends on RISCV_ALTERNATIVE 714 default y 715 help 716 Enable the use of the Zacas ISA-extension to implement kernel atomic 717 cmpxchg operations when it is detected at boot. 718 719 If you don't know what to do here, say Y. 720 721config TOOLCHAIN_HAS_ZBB 722 bool 723 default y 724 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbb) 725 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbb) 726 depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900 727 depends on AS_HAS_OPTION_ARCH 728 729# This symbol indicates that the toolchain supports all v1.0 vector crypto 730# extensions, including Zvk*, Zvbb, and Zvbc. LLVM added all of these at once. 731# binutils added all except Zvkb, then added Zvkb. So we just check for Zvkb. 732config TOOLCHAIN_HAS_VECTOR_CRYPTO 733 def_bool $(as-instr, .option arch$(comma) +v$(comma) +zvkb) 734 depends on AS_HAS_OPTION_ARCH 735 736config TOOLCHAIN_HAS_ZBA 737 bool 738 default y 739 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zba) 740 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zba) 741 depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900 742 depends on AS_HAS_OPTION_ARCH 743 744config RISCV_ISA_ZBA 745 bool "Zba extension support for bit manipulation instructions" 746 default y 747 help 748 Add support for enabling optimisations in the kernel when the Zba 749 extension is detected at boot. 750 751 The Zba extension provides instructions to accelerate the generation 752 of addresses that index into arrays of basic data types. 753 754 If you don't know what to do here, say Y. 755 756config RISCV_ISA_ZBB 757 bool "Zbb extension support for bit manipulation instructions" 758 depends on RISCV_ALTERNATIVE 759 default y 760 help 761 Add support for enabling optimisations in the kernel when the 762 Zbb extension is detected at boot. Some optimisations may 763 additionally depend on toolchain support for Zbb. 764 765 The Zbb extension provides instructions to accelerate a number 766 of bit-specific operations (count bit population, sign extending, 767 bitrotation, etc). 768 769 If you don't know what to do here, say Y. 770 771config TOOLCHAIN_HAS_ZBC 772 bool 773 default y 774 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbc) 775 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbc) 776 depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900 777 depends on AS_HAS_OPTION_ARCH 778 779config RISCV_ISA_ZBC 780 bool "Zbc extension support for carry-less multiplication instructions" 781 depends on TOOLCHAIN_HAS_ZBC 782 depends on MMU 783 depends on RISCV_ALTERNATIVE 784 default y 785 help 786 Adds support to dynamically detect the presence of the Zbc 787 extension (carry-less multiplication) and enable its usage. 788 789 The Zbc extension could accelerate CRC (cyclic redundancy check) 790 calculations. 791 792 If you don't know what to do here, say Y. 793 794config TOOLCHAIN_HAS_ZBKB 795 bool 796 default y 797 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbkb) 798 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbkb) 799 depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900 800 depends on AS_HAS_OPTION_ARCH 801 802config RISCV_ISA_ZBKB 803 bool "Zbkb extension support for bit manipulation instructions" 804 depends on TOOLCHAIN_HAS_ZBKB 805 depends on RISCV_ALTERNATIVE 806 default y 807 help 808 Adds support to dynamically detect the presence of the ZBKB 809 extension (bit manipulation for cryptography) and enable its usage. 810 811 The Zbkb extension provides instructions to accelerate a number 812 of common cryptography operations (pack, zip, etc). 813 814 If you don't know what to do here, say Y. 815 816config RISCV_ISA_ZICBOM 817 bool "Zicbom extension support for non-coherent DMA operation" 818 depends on MMU 819 depends on RISCV_ALTERNATIVE 820 default y 821 select RISCV_DMA_NONCOHERENT 822 select DMA_DIRECT_REMAP 823 help 824 Add support for the Zicbom extension (Cache Block Management 825 Operations) and enable its use in the kernel when it is detected 826 at boot. 827 828 The Zicbom extension can be used to handle for example 829 non-coherent DMA support on devices that need it. 830 831 If you don't know what to do here, say Y. 832 833config RISCV_ISA_ZICBOZ 834 bool "Zicboz extension support for faster zeroing of memory" 835 depends on RISCV_ALTERNATIVE 836 default y 837 help 838 Enable the use of the Zicboz extension (cbo.zero instruction) 839 in the kernel when it is detected at boot. 840 841 The Zicboz extension is used for faster zeroing of memory. 842 843 If you don't know what to do here, say Y. 844 845config TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI 846 def_bool y 847 # https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=aed44286efa8ae8717a77d94b51ac3614e2ca6dc 848 # https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=98416dbb0a62579d4a7a4a76bab51b5b52fec2cd 849 depends on AS_IS_GNU && AS_VERSION >= 23600 850 help 851 Binutils-2.38 and GCC-12.1.0 bumped the default ISA spec to the newer 852 20191213 version, which moves some instructions from the I extension to 853 the Zicsr and Zifencei extensions. This requires explicitly specifying 854 Zicsr and Zifencei when binutils >= 2.38 or GCC >= 12.1.0. Zicsr 855 and Zifencei are supported in binutils from version 2.36 onwards. 856 To make life easier, and avoid forcing toolchains that default to a 857 newer ISA spec to version 2.2, relax the check to binutils >= 2.36. 858 For clang < 17 or GCC < 11.3.0, for which this is not possible or need 859 special treatment, this is dealt with in TOOLCHAIN_NEEDS_OLD_ISA_SPEC. 860 861config TOOLCHAIN_NEEDS_OLD_ISA_SPEC 862 def_bool y 863 depends on TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI 864 # https://github.com/llvm/llvm-project/commit/22e199e6afb1263c943c0c0d4498694e15bf8a16 865 # https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=d29f5d6ab513c52fd872f532c492e35ae9fd6671 866 depends on (CC_IS_CLANG && CLANG_VERSION < 170000) || (CC_IS_GCC && GCC_VERSION < 110300) 867 help 868 Certain versions of clang and GCC do not support zicsr and zifencei via 869 -march. This option causes an older ISA spec compatible with these older 870 versions of clang and GCC to be passed to GAS, which has the same result 871 as passing zicsr and zifencei to -march. 872 873config FPU 874 bool "FPU support" 875 default y 876 help 877 Add support for floating point operations when an FPU is detected at 878 boot. When this option is disabled, neither the kernel nor userspace 879 may use the floating point unit. 880 881 If you don't know what to do here, say Y. 882 883config IRQ_STACKS 884 bool "Independent irq & softirq stacks" if EXPERT 885 default y 886 select HAVE_IRQ_EXIT_ON_IRQ_STACK 887 select HAVE_SOFTIRQ_ON_OWN_STACK 888 help 889 Add independent irq & softirq stacks for percpu to prevent kernel stack 890 overflows. We may save some memory footprint by disabling IRQ_STACKS. 891 892config THREAD_SIZE_ORDER 893 int "Kernel stack size (in power-of-two numbers of page size)" if VMAP_STACK && EXPERT 894 range 0 4 895 default 1 if 32BIT 896 default 2 897 help 898 Specify the Pages of thread stack size (from 4KB to 64KB), which also 899 affects irq stack size, which is equal to thread stack size. 900 901config RISCV_MISALIGNED 902 bool 903 help 904 Embed support for detecting and emulating misaligned 905 scalar or vector loads and stores. 906 907config RISCV_SCALAR_MISALIGNED 908 bool 909 select RISCV_MISALIGNED 910 select SYSCTL_ARCH_UNALIGN_ALLOW 911 help 912 Embed support for emulating misaligned loads and stores. 913 914config RISCV_VECTOR_MISALIGNED 915 bool 916 select RISCV_MISALIGNED 917 depends on RISCV_ISA_V 918 help 919 Enable detecting support for vector misaligned loads and stores. 920 921choice 922 prompt "Unaligned Accesses Support" 923 default RISCV_PROBE_UNALIGNED_ACCESS 924 help 925 This determines the level of support for unaligned accesses. This 926 information is used by the kernel to perform optimizations. It is also 927 exposed to user space via the hwprobe syscall. The hardware will be 928 probed at boot by default. 929 930config RISCV_PROBE_UNALIGNED_ACCESS 931 bool "Probe for hardware unaligned access support" 932 select RISCV_SCALAR_MISALIGNED 933 help 934 During boot, the kernel will run a series of tests to determine the 935 speed of unaligned accesses. This probing will dynamically determine 936 the speed of unaligned accesses on the underlying system. If unaligned 937 memory accesses trap into the kernel as they are not supported by the 938 system, the kernel will emulate the unaligned accesses to preserve the 939 UABI. 940 941config RISCV_EMULATED_UNALIGNED_ACCESS 942 bool "Emulate unaligned access where system support is missing" 943 select RISCV_SCALAR_MISALIGNED 944 help 945 If unaligned memory accesses trap into the kernel as they are not 946 supported by the system, the kernel will emulate the unaligned 947 accesses to preserve the UABI. When the underlying system does support 948 unaligned accesses, the unaligned accesses are assumed to be slow. 949 950config RISCV_SLOW_UNALIGNED_ACCESS 951 bool "Assume the system supports slow unaligned memory accesses" 952 depends on NONPORTABLE 953 help 954 Assume that the system supports slow unaligned memory accesses. The 955 kernel and userspace programs may not be able to run at all on systems 956 that do not support unaligned memory accesses. 957 958config RISCV_EFFICIENT_UNALIGNED_ACCESS 959 bool "Assume the system supports fast unaligned memory accesses" 960 depends on NONPORTABLE 961 select DCACHE_WORD_ACCESS if MMU 962 select HAVE_EFFICIENT_UNALIGNED_ACCESS 963 help 964 Assume that the system supports fast unaligned memory accesses. When 965 enabled, this option improves the performance of the kernel on such 966 systems. However, the kernel and userspace programs will run much more 967 slowly, or will not be able to run at all, on systems that do not 968 support efficient unaligned memory accesses. 969 970endchoice 971 972choice 973 prompt "Vector unaligned Accesses Support" 974 depends on RISCV_ISA_V 975 default RISCV_PROBE_VECTOR_UNALIGNED_ACCESS 976 help 977 This determines the level of support for vector unaligned accesses. This 978 information is used by the kernel to perform optimizations. It is also 979 exposed to user space via the hwprobe syscall. The hardware will be 980 probed at boot by default. 981 982config RISCV_PROBE_VECTOR_UNALIGNED_ACCESS 983 bool "Probe speed of vector unaligned accesses" 984 select RISCV_VECTOR_MISALIGNED 985 depends on RISCV_ISA_V 986 help 987 During boot, the kernel will run a series of tests to determine the 988 speed of vector unaligned accesses if they are supported. This probing 989 will dynamically determine the speed of vector unaligned accesses on 990 the underlying system if they are supported. 991 992config RISCV_SLOW_VECTOR_UNALIGNED_ACCESS 993 bool "Assume the system supports slow vector unaligned memory accesses" 994 depends on NONPORTABLE 995 help 996 Assume that the system supports slow vector unaligned memory accesses. The 997 kernel and userspace programs may not be able to run at all on systems 998 that do not support unaligned memory accesses. 999 1000config RISCV_EFFICIENT_VECTOR_UNALIGNED_ACCESS 1001 bool "Assume the system supports fast vector unaligned memory accesses" 1002 depends on NONPORTABLE 1003 help 1004 Assume that the system supports fast vector unaligned memory accesses. When 1005 enabled, this option improves the performance of the kernel on such 1006 systems. However, the kernel and userspace programs will run much more 1007 slowly, or will not be able to run at all, on systems that do not 1008 support efficient unaligned memory accesses. 1009 1010endchoice 1011 1012source "arch/riscv/Kconfig.vendor" 1013 1014endmenu # "Platform type" 1015 1016menu "Kernel features" 1017 1018source "kernel/Kconfig.hz" 1019 1020config RISCV_SBI_V01 1021 bool "SBI v0.1 support" 1022 depends on RISCV_SBI 1023 help 1024 This config allows kernel to use SBI v0.1 APIs. This will be 1025 deprecated in future once legacy M-mode software are no longer in use. 1026 1027config RISCV_BOOT_SPINWAIT 1028 bool "Spinwait booting method" 1029 depends on SMP 1030 default y if RISCV_SBI_V01 || RISCV_M_MODE 1031 help 1032 This enables support for booting Linux via spinwait method. In the 1033 spinwait method, all cores randomly jump to Linux. One of the cores 1034 gets chosen via lottery and all other keep spinning on a percpu 1035 variable. This method cannot support CPU hotplug and sparse hartid 1036 scheme. It should be only enabled for M-mode Linux or platforms relying 1037 on older firmware without SBI HSM extension. All other platforms should 1038 rely on ordered booting via SBI HSM extension which gets chosen 1039 dynamically at runtime if the firmware supports it. 1040 1041 Since spinwait is incompatible with sparse hart IDs, it requires 1042 NR_CPUS be large enough to contain the physical hart ID of the first 1043 hart to enter Linux. 1044 1045 If unsure what to do here, say N. 1046 1047config ARCH_SUPPORTS_KEXEC 1048 def_bool y 1049 1050config ARCH_SELECTS_KEXEC 1051 def_bool y 1052 depends on KEXEC 1053 select HOTPLUG_CPU if SMP 1054 1055config ARCH_SUPPORTS_KEXEC_FILE 1056 def_bool 64BIT 1057 1058config ARCH_SELECTS_KEXEC_FILE 1059 def_bool y 1060 depends on KEXEC_FILE 1061 select HAVE_IMA_KEXEC if IMA 1062 select KEXEC_ELF 1063 1064config ARCH_SUPPORTS_KEXEC_PURGATORY 1065 def_bool ARCH_SUPPORTS_KEXEC_FILE 1066 1067config ARCH_SUPPORTS_CRASH_DUMP 1068 def_bool y 1069 1070config ARCH_DEFAULT_CRASH_DUMP 1071 def_bool y 1072 1073config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION 1074 def_bool CRASH_RESERVE 1075 1076config COMPAT 1077 bool "Kernel support for 32-bit U-mode" 1078 default 64BIT 1079 depends on 64BIT && MMU 1080 help 1081 This option enables support for a 32-bit U-mode running under a 64-bit 1082 kernel at S-mode. riscv32-specific components such as system calls, 1083 the user helper functions (vdso), signal rt_frame functions and the 1084 ptrace interface are handled appropriately by the kernel. 1085 1086 If you want to execute 32-bit userspace applications, say Y. 1087 1088config PARAVIRT 1089 bool "Enable paravirtualization code" 1090 depends on RISCV_SBI 1091 help 1092 This changes the kernel so it can modify itself when it is run 1093 under a hypervisor, potentially improving performance significantly 1094 over full virtualization. 1095 1096config PARAVIRT_TIME_ACCOUNTING 1097 bool "Paravirtual steal time accounting" 1098 depends on PARAVIRT 1099 help 1100 Select this option to enable fine granularity task steal time 1101 accounting. Time spent executing other tasks in parallel with 1102 the current vCPU is discounted from the vCPU power. To account for 1103 that, there can be a small performance impact. 1104 1105 If in doubt, say N here. 1106 1107config RELOCATABLE 1108 bool "Build a relocatable kernel" 1109 depends on !XIP_KERNEL 1110 select MODULE_SECTIONS if MODULES 1111 select ARCH_VMLINUX_NEEDS_RELOCS 1112 help 1113 This builds a kernel as a Position Independent Executable (PIE), 1114 which retains all relocation metadata required to relocate the 1115 kernel binary at runtime to a different virtual address than the 1116 address it was linked at. 1117 Since RISCV uses the RELA relocation format, this requires a 1118 relocation pass at runtime even if the kernel is loaded at the 1119 same address it was linked at. 1120 1121 If unsure, say N. 1122 1123config RANDOMIZE_BASE 1124 bool "Randomize the address of the kernel image" 1125 select RELOCATABLE 1126 depends on MMU && 64BIT && !XIP_KERNEL 1127 help 1128 Randomizes the virtual address at which the kernel image is 1129 loaded, as a security feature that deters exploit attempts 1130 relying on knowledge of the location of kernel internals. 1131 1132 It is the bootloader's job to provide entropy, by passing a 1133 random u64 value in /chosen/kaslr-seed at kernel entry. 1134 1135 When booting via the UEFI stub, it will invoke the firmware's 1136 EFI_RNG_PROTOCOL implementation (if available) to supply entropy 1137 to the kernel proper. In addition, it will randomise the physical 1138 location of the kernel Image as well. 1139 1140 If unsure, say N. 1141 1142endmenu # "Kernel features" 1143 1144menu "Boot options" 1145 1146config CMDLINE 1147 string "Built-in kernel command line" 1148 help 1149 For most platforms, the arguments for the kernel's command line 1150 are provided at run-time, during boot. However, there are cases 1151 where either no arguments are being provided or the provided 1152 arguments are insufficient or even invalid. 1153 1154 When that occurs, it is possible to define a built-in command 1155 line here and choose how the kernel should use it later on. 1156 1157choice 1158 prompt "Built-in command line usage" 1159 depends on CMDLINE != "" 1160 default CMDLINE_FALLBACK 1161 help 1162 Choose how the kernel will handle the provided built-in command 1163 line. 1164 1165config CMDLINE_FALLBACK 1166 bool "Use bootloader kernel arguments if available" 1167 help 1168 Use the built-in command line as fallback in case we get nothing 1169 during boot. This is the default behaviour. 1170 1171config CMDLINE_EXTEND 1172 bool "Extend bootloader kernel arguments" 1173 help 1174 The command-line arguments provided during boot will be 1175 appended to the built-in command line. This is useful in 1176 cases where the provided arguments are insufficient and 1177 you don't want to or cannot modify them. 1178 1179config CMDLINE_FORCE 1180 bool "Always use the default kernel command string" 1181 help 1182 Always use the built-in command line, even if we get one during 1183 boot. This is useful in case you need to override the provided 1184 command line on systems where you don't have or want control 1185 over it. 1186 1187endchoice 1188 1189config EFI_STUB 1190 bool 1191 1192config EFI 1193 bool "UEFI runtime support" 1194 depends on OF && !XIP_KERNEL 1195 depends on MMU 1196 default y 1197 select ARCH_SUPPORTS_ACPI if 64BIT 1198 select EFI_GENERIC_STUB 1199 select EFI_PARAMS_FROM_FDT 1200 select EFI_RUNTIME_WRAPPERS 1201 select EFI_STUB 1202 select LIBFDT 1203 select RISCV_ISA_C 1204 select UCS2_STRING 1205 help 1206 This option provides support for runtime services provided 1207 by UEFI firmware (such as non-volatile variables, realtime 1208 clock, and platform reset). A UEFI stub is also provided to 1209 allow the kernel to be booted as an EFI application. This 1210 is only useful on systems that have UEFI firmware. 1211 1212config DMI 1213 bool "Enable support for SMBIOS (DMI) tables" 1214 depends on EFI 1215 default y 1216 help 1217 This enables SMBIOS/DMI feature for systems. 1218 1219 This option is only useful on systems that have UEFI firmware. 1220 However, even with this option, the resultant kernel should 1221 continue to boot on existing non-UEFI platforms. 1222 1223config CC_HAVE_STACKPROTECTOR_TLS 1224 def_bool $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=tp -mstack-protector-guard-offset=0) 1225 1226config STACKPROTECTOR_PER_TASK 1227 def_bool y 1228 depends on !RANDSTRUCT 1229 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_TLS 1230 1231config PHYS_RAM_BASE_FIXED 1232 bool "Explicitly specified physical RAM address" 1233 depends on NONPORTABLE 1234 default n 1235 1236config PHYS_RAM_BASE 1237 hex "Platform Physical RAM address" 1238 depends on PHYS_RAM_BASE_FIXED 1239 default "0x80000000" 1240 help 1241 This is the physical address of RAM in the system. It has to be 1242 explicitly specified to run early relocations of read-write data 1243 from flash to RAM. 1244 1245config XIP_KERNEL 1246 bool "Kernel Execute-In-Place from ROM" 1247 depends on MMU && SPARSEMEM && NONPORTABLE 1248 # This prevents XIP from being enabled by all{yes,mod}config, which 1249 # fail to build since XIP doesn't support large kernels. 1250 depends on !COMPILE_TEST 1251 select PHYS_RAM_BASE_FIXED 1252 help 1253 Execute-In-Place allows the kernel to run from non-volatile storage 1254 directly addressable by the CPU, such as NOR flash. This saves RAM 1255 space since the text section of the kernel is not loaded from flash 1256 to RAM. Read-write sections, such as the data section and stack, 1257 are still copied to RAM. The XIP kernel is not compressed since 1258 it has to run directly from flash, so it will take more space to 1259 store it. The flash address used to link the kernel object files, 1260 and for storing it, is configuration dependent. Therefore, if you 1261 say Y here, you must know the proper physical address where to 1262 store the kernel image depending on your own flash memory usage. 1263 1264 Also note that the make target becomes "make xipImage" rather than 1265 "make zImage" or "make Image". The final kernel binary to put in 1266 ROM memory will be arch/riscv/boot/xipImage. 1267 1268 SPARSEMEM is required because the kernel text and rodata that are 1269 flash resident are not backed by memmap, then any attempt to get 1270 a struct page on those regions will trigger a fault. 1271 1272 If unsure, say N. 1273 1274config XIP_PHYS_ADDR 1275 hex "XIP Kernel Physical Location" 1276 depends on XIP_KERNEL 1277 default "0x21000000" 1278 help 1279 This is the physical address in your flash memory the kernel will 1280 be linked for and stored to. This address is dependent on your 1281 own flash usage. 1282 1283config RISCV_ISA_FALLBACK 1284 bool "Permit falling back to parsing riscv,isa for extension support by default" 1285 default y 1286 help 1287 Parsing the "riscv,isa" devicetree property has been deprecated and 1288 replaced by a list of explicitly defined strings. For compatibility 1289 with existing platforms, the kernel will fall back to parsing the 1290 "riscv,isa" property if the replacements are not found. 1291 1292 Selecting N here will result in a kernel that does not use the 1293 fallback, unless the commandline "riscv_isa_fallback" parameter is 1294 present. 1295 1296 Please see the dt-binding, located at 1297 Documentation/devicetree/bindings/riscv/extensions.yaml for details 1298 on the replacement properties, "riscv,isa-base" and 1299 "riscv,isa-extensions". 1300 1301config BUILTIN_DTB 1302 bool "Built-in device tree" 1303 depends on OF && NONPORTABLE 1304 select GENERIC_BUILTIN_DTB 1305 help 1306 Build a device tree into the Linux image. 1307 This option should be selected if no bootloader is being used. 1308 If unsure, say N. 1309 1310 1311config BUILTIN_DTB_NAME 1312 string "Built-in device tree source" 1313 depends on BUILTIN_DTB 1314 help 1315 DTS file path (without suffix, relative to arch/riscv/boot/dts) 1316 for the DTS file that will be used to produce the DTB linked into the 1317 kernel. 1318 1319endmenu # "Boot options" 1320 1321config PORTABLE 1322 bool 1323 default !NONPORTABLE 1324 select EFI 1325 select MMU 1326 select OF 1327 1328config ARCH_PROC_KCORE_TEXT 1329 def_bool y 1330 1331menu "Power management options" 1332 1333source "kernel/power/Kconfig" 1334 1335config ARCH_HIBERNATION_POSSIBLE 1336 def_bool y 1337 1338config ARCH_HIBERNATION_HEADER 1339 def_bool HIBERNATION 1340 1341config ARCH_SUSPEND_POSSIBLE 1342 def_bool y 1343 1344endmenu # "Power management options" 1345 1346menu "CPU Power Management" 1347 1348source "drivers/cpuidle/Kconfig" 1349 1350source "drivers/cpufreq/Kconfig" 1351 1352endmenu # "CPU Power Management" 1353 1354source "arch/riscv/kvm/Kconfig" 1355 1356source "drivers/acpi/Kconfig" 1357