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_MSEAL_SYSTEM_MAPPINGS if 64BIT && MMU 74 select ARCH_SUPPORTS_PAGE_TABLE_CHECK if MMU 75 select ARCH_SUPPORTS_PER_VMA_LOCK if MMU 76 select ARCH_SUPPORTS_RT 77 select ARCH_SUPPORTS_SHADOW_CALL_STACK if HAVE_SHADOW_CALL_STACK 78 select ARCH_USE_CMPXCHG_LOCKREF if 64BIT 79 select ARCH_USE_MEMTEST 80 select ARCH_USE_QUEUED_RWLOCKS 81 select ARCH_USE_SYM_ANNOTATIONS 82 select ARCH_USES_CFI_TRAPS if CFI_CLANG 83 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH if MMU 84 select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU 85 select ARCH_WANT_FRAME_POINTERS 86 select ARCH_WANT_GENERAL_HUGETLB if !RISCV_ISA_SVNAPOT 87 select ARCH_WANT_HUGE_PMD_SHARE if 64BIT 88 select ARCH_WANT_LD_ORPHAN_WARN if !XIP_KERNEL 89 select ARCH_WANT_OPTIMIZE_DAX_VMEMMAP 90 select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP 91 select ARCH_WANTS_NO_INSTR 92 select ARCH_WANTS_THP_SWAP if HAVE_ARCH_TRANSPARENT_HUGEPAGE 93 select ARCH_WEAK_RELEASE_ACQUIRE if ARCH_USE_QUEUED_SPINLOCKS 94 select BINFMT_FLAT_NO_DATA_START_OFFSET if !MMU 95 select BUILDTIME_TABLE_SORT if MMU 96 select CLINT_TIMER if RISCV_M_MODE 97 select CLONE_BACKWARDS 98 select COMMON_CLK 99 select CPU_PM if CPU_IDLE || HIBERNATION || SUSPEND 100 select EDAC_SUPPORT 101 select FRAME_POINTER if PERF_EVENTS || (FUNCTION_TRACER && !DYNAMIC_FTRACE) 102 select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY if DYNAMIC_FTRACE 103 select FUNCTION_ALIGNMENT_8B if DYNAMIC_FTRACE_WITH_CALL_OPS 104 select GENERIC_ARCH_TOPOLOGY 105 select GENERIC_ATOMIC64 if !64BIT 106 select GENERIC_CLOCKEVENTS_BROADCAST if SMP 107 select GENERIC_CPU_DEVICES 108 select GENERIC_CPU_VULNERABILITIES 109 select GENERIC_EARLY_IOREMAP 110 select GENERIC_ENTRY 111 select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO 112 select GENERIC_IDLE_POLL_SETUP 113 select GENERIC_IOREMAP if MMU 114 select GENERIC_IRQ_IPI if SMP 115 select GENERIC_IRQ_IPI_MUX if SMP 116 select GENERIC_IRQ_MULTI_HANDLER 117 select GENERIC_IRQ_SHOW 118 select GENERIC_IRQ_SHOW_LEVEL 119 select GENERIC_LIB_DEVMEM_IS_ALLOWED 120 select GENERIC_PENDING_IRQ if SMP 121 select GENERIC_PCI_IOMAP 122 select GENERIC_SCHED_CLOCK 123 select GENERIC_SMP_IDLE_THREAD 124 select GENERIC_TIME_VSYSCALL if MMU && 64BIT 125 select GENERIC_VDSO_DATA_STORE if MMU 126 select GENERIC_VDSO_TIME_NS if HAVE_GENERIC_VDSO 127 select HARDIRQS_SW_RESEND 128 select HAS_IOPORT if MMU 129 select HAVE_ALIGNED_STRUCT_PAGE 130 select HAVE_ARCH_AUDITSYSCALL 131 select HAVE_ARCH_HUGE_VMALLOC if HAVE_ARCH_HUGE_VMAP 132 select HAVE_ARCH_HUGE_VMAP if MMU && 64BIT 133 select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL 134 select HAVE_ARCH_JUMP_LABEL_RELATIVE if !XIP_KERNEL 135 select HAVE_ARCH_KASAN if MMU && 64BIT 136 select HAVE_ARCH_KASAN_VMALLOC if MMU && 64BIT 137 select HAVE_ARCH_KFENCE if MMU && 64BIT 138 select HAVE_ARCH_KGDB if !XIP_KERNEL 139 select HAVE_ARCH_KGDB_QXFER_PKT 140 select HAVE_ARCH_MMAP_RND_BITS if MMU 141 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT 142 select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET 143 select HAVE_ARCH_SECCOMP_FILTER 144 select HAVE_ARCH_STACKLEAK 145 select HAVE_ARCH_THREAD_STRUCT_WHITELIST 146 select HAVE_ARCH_TRACEHOOK 147 select HAVE_ARCH_TRANSPARENT_HUGEPAGE if 64BIT && MMU 148 select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if 64BIT && MMU 149 select HAVE_ARCH_USERFAULTFD_MINOR if 64BIT && USERFAULTFD 150 select HAVE_ARCH_VMAP_STACK if MMU && 64BIT 151 select HAVE_ASM_MODVERSIONS 152 select HAVE_CONTEXT_TRACKING_USER 153 select HAVE_DEBUG_KMEMLEAK 154 select HAVE_DMA_CONTIGUOUS if MMU 155 select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && MMU && (CLANG_SUPPORTS_DYNAMIC_FTRACE || GCC_SUPPORTS_DYNAMIC_FTRACE) 156 select FUNCTION_ALIGNMENT_4B if HAVE_DYNAMIC_FTRACE && RISCV_ISA_C 157 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS if HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS 158 select HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS if (DYNAMIC_FTRACE_WITH_ARGS && !CFI_CLANG) 159 select HAVE_DYNAMIC_FTRACE_WITH_ARGS if HAVE_DYNAMIC_FTRACE 160 select HAVE_FTRACE_GRAPH_FUNC 161 select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL 162 select HAVE_FUNCTION_GRAPH_TRACER if HAVE_DYNAMIC_FTRACE_WITH_ARGS 163 select HAVE_FUNCTION_GRAPH_FREGS 164 select HAVE_FUNCTION_TRACER if !XIP_KERNEL 165 select HAVE_EBPF_JIT if MMU 166 select HAVE_GUP_FAST if MMU 167 select HAVE_FUNCTION_ARG_ACCESS_API 168 select HAVE_FUNCTION_ERROR_INJECTION 169 select HAVE_GCC_PLUGINS 170 select HAVE_GENERIC_VDSO if MMU && 64BIT 171 select HAVE_IRQ_TIME_ACCOUNTING 172 select HAVE_KERNEL_BZIP2 if !XIP_KERNEL && !EFI_ZBOOT 173 select HAVE_KERNEL_GZIP if !XIP_KERNEL && !EFI_ZBOOT 174 select HAVE_KERNEL_LZ4 if !XIP_KERNEL && !EFI_ZBOOT 175 select HAVE_KERNEL_LZMA if !XIP_KERNEL && !EFI_ZBOOT 176 select HAVE_KERNEL_LZO if !XIP_KERNEL && !EFI_ZBOOT 177 select HAVE_KERNEL_UNCOMPRESSED if !XIP_KERNEL && !EFI_ZBOOT 178 select HAVE_KERNEL_ZSTD if !XIP_KERNEL && !EFI_ZBOOT 179 select HAVE_KERNEL_XZ if !XIP_KERNEL && !EFI_ZBOOT 180 select HAVE_KPROBES if !XIP_KERNEL 181 select HAVE_KRETPROBES if !XIP_KERNEL 182 # https://github.com/ClangBuiltLinux/linux/issues/1881 183 select HAVE_LD_DEAD_CODE_DATA_ELIMINATION if !LD_IS_LLD 184 select HAVE_MOVE_PMD 185 select HAVE_MOVE_PUD 186 select HAVE_PAGE_SIZE_4KB 187 select HAVE_PCI 188 select HAVE_PERF_EVENTS 189 select HAVE_PERF_REGS 190 select HAVE_PERF_USER_STACK_DUMP 191 select HAVE_POSIX_CPU_TIMERS_TASK_WORK 192 select HAVE_PREEMPT_DYNAMIC_KEY if !XIP_KERNEL 193 select HAVE_REGS_AND_STACK_ACCESS_API 194 select HAVE_RETHOOK if !XIP_KERNEL 195 select HAVE_RSEQ 196 select HAVE_RUST if RUSTC_SUPPORTS_RISCV && CC_IS_CLANG 197 select HAVE_SAMPLE_FTRACE_DIRECT 198 select HAVE_SAMPLE_FTRACE_DIRECT_MULTI 199 select HAVE_STACKPROTECTOR 200 select HAVE_SYSCALL_TRACEPOINTS 201 select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU 202 select IRQ_DOMAIN 203 select IRQ_FORCED_THREADING 204 select KASAN_VMALLOC if KASAN 205 select LOCK_MM_AND_FIND_VMA 206 select MMU_GATHER_RCU_TABLE_FREE if SMP && MMU 207 select MODULES_USE_ELF_RELA if MODULES 208 select OF 209 select OF_EARLY_FLATTREE 210 select OF_IRQ 211 select PCI_DOMAINS_GENERIC if PCI 212 select PCI_ECAM if (ACPI && PCI) 213 select PCI_MSI if PCI 214 select RELOCATABLE if !MMU && !PHYS_RAM_BASE_FIXED 215 select RISCV_ALTERNATIVE if !XIP_KERNEL 216 select RISCV_APLIC 217 select RISCV_IMSIC 218 select RISCV_INTC 219 select RISCV_TIMER if RISCV_SBI 220 select SIFIVE_PLIC 221 select SPARSE_IRQ 222 select SYSCTL_EXCEPTION_TRACE 223 select THREAD_INFO_IN_TASK 224 select TRACE_IRQFLAGS_SUPPORT 225 select UACCESS_MEMCPY if !MMU 226 select VDSO_GETRANDOM if HAVE_GENERIC_VDSO 227 select USER_STACKTRACE_SUPPORT 228 select ZONE_DMA32 if 64BIT 229 230config RUSTC_SUPPORTS_RISCV 231 def_bool y 232 depends on 64BIT 233 # Shadow call stack requires rustc version 1.82+ due to use of the 234 # -Zsanitizer=shadow-call-stack flag. 235 depends on !SHADOW_CALL_STACK || RUSTC_VERSION >= 108200 236 237config CLANG_SUPPORTS_DYNAMIC_FTRACE 238 def_bool CC_IS_CLANG 239 # https://github.com/ClangBuiltLinux/linux/issues/1817 240 depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600)) 241 242config GCC_SUPPORTS_DYNAMIC_FTRACE 243 def_bool CC_IS_GCC 244 depends on $(cc-option,-fpatchable-function-entry=8) 245 depends on CC_HAS_MIN_FUNCTION_ALIGNMENT || !RISCV_ISA_C 246 247config HAVE_SHADOW_CALL_STACK 248 def_bool $(cc-option,-fsanitize=shadow-call-stack) 249 # https://github.com/riscv-non-isa/riscv-elf-psabi-doc/commit/a484e843e6eeb51f0cb7b8819e50da6d2444d769 250 depends on $(ld-option,--no-relax-gp) 251 252config RISCV_USE_LINKER_RELAXATION 253 def_bool y 254 # https://github.com/llvm/llvm-project/commit/6611d58f5bbcbec77262d392e2923e1d680f6985 255 depends on !LD_IS_LLD || LLD_VERSION >= 150000 256 257# https://github.com/llvm/llvm-project/commit/bbc0f99f3bc96f1db16f649fc21dd18e5b0918f6 258config ARCH_HAS_BROKEN_DWARF5 259 def_bool y 260 depends on RISCV_USE_LINKER_RELAXATION 261 # https://github.com/llvm/llvm-project/commit/1df5ea29b43690b6622db2cad7b745607ca4de6a 262 depends on AS_IS_LLVM && AS_VERSION < 180000 263 # https://github.com/llvm/llvm-project/commit/7ffabb61a5569444b5ac9322e22e5471cc5e4a77 264 depends on LD_IS_LLD && LLD_VERSION < 180000 265 266config ARCH_MMAP_RND_BITS_MIN 267 default 18 if 64BIT 268 default 8 269 270config ARCH_MMAP_RND_COMPAT_BITS_MIN 271 default 8 272 273# max bits determined by the following formula: 274# VA_BITS - PAGE_SHIFT - 3 275config ARCH_MMAP_RND_BITS_MAX 276 default 24 if 64BIT # SV39 based 277 default 17 278 279config ARCH_MMAP_RND_COMPAT_BITS_MAX 280 default 17 281 282# set if we run in machine mode, cleared if we run in supervisor mode 283config RISCV_M_MODE 284 bool "Build a kernel that runs in machine mode" 285 depends on !MMU 286 default y 287 help 288 Select this option if you want to run the kernel in M-mode, 289 without the assistance of any other firmware. 290 291# set if we are running in S-mode and can use SBI calls 292config RISCV_SBI 293 bool 294 depends on !RISCV_M_MODE 295 default y 296 297config MMU 298 bool "MMU-based Paged Memory Management Support" 299 default y 300 help 301 Select if you want MMU-based virtualised addressing space 302 support by paged memory management. If unsure, say 'Y'. 303 304config KASAN_SHADOW_OFFSET 305 hex 306 depends on KASAN_GENERIC 307 default 0xdfffffff00000000 if 64BIT 308 default 0xffffffff if 32BIT 309 310config ARCH_FLATMEM_ENABLE 311 def_bool !NUMA 312 313config ARCH_SPARSEMEM_ENABLE 314 def_bool y 315 depends on MMU 316 select SPARSEMEM_STATIC if 32BIT && SPARSEMEM 317 select SPARSEMEM_VMEMMAP_ENABLE if 64BIT 318 319config ARCH_SELECT_MEMORY_MODEL 320 def_bool ARCH_SPARSEMEM_ENABLE 321 322config ARCH_SUPPORTS_UPROBES 323 def_bool y 324 325config STACKTRACE_SUPPORT 326 def_bool y 327 328config GENERIC_BUG 329 def_bool y 330 depends on BUG 331 select GENERIC_BUG_RELATIVE_POINTERS if 64BIT 332 333config GENERIC_BUG_RELATIVE_POINTERS 334 bool 335 336config GENERIC_CALIBRATE_DELAY 337 def_bool y 338 339config GENERIC_CSUM 340 def_bool y 341 342config GENERIC_HWEIGHT 343 def_bool y 344 345config FIX_EARLYCON_MEM 346 def_bool MMU 347 348config ILLEGAL_POINTER_VALUE 349 hex 350 default 0 if 32BIT 351 default 0xdead000000000000 if 64BIT 352 353config PGTABLE_LEVELS 354 int 355 default 5 if 64BIT 356 default 2 357 358config LOCKDEP_SUPPORT 359 def_bool y 360 361config RISCV_DMA_NONCOHERENT 362 bool 363 select ARCH_HAS_DMA_PREP_COHERENT 364 select ARCH_HAS_SETUP_DMA_OPS 365 select ARCH_HAS_SYNC_DMA_FOR_CPU 366 select ARCH_HAS_SYNC_DMA_FOR_DEVICE 367 select DMA_BOUNCE_UNALIGNED_KMALLOC if SWIOTLB 368 369config RISCV_NONSTANDARD_CACHE_OPS 370 bool 371 help 372 This enables function pointer support for non-standard noncoherent 373 systems to handle cache management. 374 375config AS_HAS_INSN 376 def_bool $(as-instr,.insn r 51$(comma) 0$(comma) 0$(comma) t0$(comma) t0$(comma) zero) 377 378config AS_HAS_OPTION_ARCH 379 # https://github.com/llvm/llvm-project/commit/9e8ed3403c191ab9c4903e8eeb8f732ff8a43cb4 380 def_bool y 381 depends on $(as-instr, .option arch$(comma) +m) 382 383source "arch/riscv/Kconfig.socs" 384source "arch/riscv/Kconfig.errata" 385 386menu "Platform type" 387 388config NONPORTABLE 389 bool "Allow configurations that result in non-portable kernels" 390 help 391 RISC-V kernel binaries are compatible between all known systems 392 whenever possible, but there are some use cases that can only be 393 satisfied by configurations that result in kernel binaries that are 394 not portable between systems. 395 396 Selecting N does not guarantee kernels will be portable to all known 397 systems. Selecting any of the options guarded by NONPORTABLE will 398 result in kernel binaries that are unlikely to be portable between 399 systems. 400 401 If unsure, say N. 402 403choice 404 prompt "Base ISA" 405 default ARCH_RV64I 406 help 407 This selects the base ISA that this kernel will target and must match 408 the target platform. 409 410config ARCH_RV32I 411 bool "RV32I" 412 depends on NONPORTABLE 413 select 32BIT 414 select GENERIC_LIB_ASHLDI3 415 select GENERIC_LIB_ASHRDI3 416 select GENERIC_LIB_LSHRDI3 417 select GENERIC_LIB_UCMPDI2 418 419config ARCH_RV64I 420 bool "RV64I" 421 select 64BIT 422 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 423 select SWIOTLB if MMU 424 425endchoice 426 427# We must be able to map all physical memory into the kernel, but the compiler 428# is still a bit more efficient when generating code if it's setup in a manner 429# such that it can only map 2GiB of memory. 430choice 431 prompt "Kernel Code Model" 432 default CMODEL_MEDLOW if 32BIT 433 default CMODEL_MEDANY if 64BIT 434 435 config CMODEL_MEDLOW 436 bool "medium low code model" 437 config CMODEL_MEDANY 438 bool "medium any code model" 439endchoice 440 441config MODULE_SECTIONS 442 bool 443 select HAVE_MOD_ARCH_SPECIFIC 444 445config SMP 446 bool "Symmetric Multi-Processing" 447 help 448 This enables support for systems with more than one CPU. If 449 you say N here, the kernel will run on single and 450 multiprocessor machines, but will use only one CPU of a 451 multiprocessor machine. If you say Y here, the kernel will run 452 on many, but not all, single processor machines. On a single 453 processor machine, the kernel will run faster if you say N 454 here. 455 456 If you don't know what to do here, say N. 457 458config SCHED_MC 459 bool "Multi-core scheduler support" 460 depends on SMP 461 help 462 Multi-core scheduler support improves the CPU scheduler's decision 463 making when dealing with multi-core CPU chips at a cost of slightly 464 increased overhead in some places. If unsure say N here. 465 466config NR_CPUS 467 int "Maximum number of CPUs (2-512)" 468 depends on SMP 469 range 2 512 if !RISCV_SBI_V01 470 range 2 32 if RISCV_SBI_V01 && 32BIT 471 range 2 64 if RISCV_SBI_V01 && 64BIT 472 default "32" if 32BIT 473 default "64" if 64BIT 474 475config HOTPLUG_CPU 476 bool "Support for hot-pluggable CPUs" 477 depends on SMP 478 select GENERIC_IRQ_MIGRATION 479 help 480 481 Say Y here to experiment with turning CPUs off and on. CPUs 482 can be controlled through /sys/devices/system/cpu. 483 484 Say N if you want to disable CPU hotplug. 485 486choice 487 prompt "CPU Tuning" 488 default TUNE_GENERIC 489 490config TUNE_GENERIC 491 bool "generic" 492 493endchoice 494 495# Common NUMA Features 496config NUMA 497 bool "NUMA Memory Allocation and Scheduler Support" 498 depends on SMP && MMU 499 select ARCH_SUPPORTS_NUMA_BALANCING 500 select GENERIC_ARCH_NUMA 501 select HAVE_SETUP_PER_CPU_AREA 502 select NEED_PER_CPU_EMBED_FIRST_CHUNK 503 select NEED_PER_CPU_PAGE_FIRST_CHUNK 504 select OF_NUMA 505 select USE_PERCPU_NUMA_NODE_ID 506 help 507 Enable NUMA (Non-Uniform Memory Access) support. 508 509 The kernel will try to allocate memory used by a CPU on the 510 local memory of the CPU and add some more NUMA awareness to the kernel. 511 512config NODES_SHIFT 513 int "Maximum NUMA Nodes (as a power of 2)" 514 range 1 10 515 default "2" 516 depends on NUMA 517 help 518 Specify the maximum number of NUMA Nodes available on the target 519 system. Increases memory reserved to accommodate various tables. 520 521choice 522 prompt "RISC-V spinlock type" 523 default RISCV_COMBO_SPINLOCKS 524 525config RISCV_TICKET_SPINLOCKS 526 bool "Using ticket spinlock" 527 528config RISCV_QUEUED_SPINLOCKS 529 bool "Using queued spinlock" 530 depends on SMP && MMU && NONPORTABLE 531 select ARCH_USE_QUEUED_SPINLOCKS 532 help 533 The queued spinlock implementation requires the forward progress 534 guarantee of cmpxchg()/xchg() atomic operations: CAS with Zabha or 535 LR/SC with Ziccrse provide such guarantee. 536 537 Select this if and only if Zabha or Ziccrse is available on your 538 platform, RISCV_QUEUED_SPINLOCKS must not be selected for platforms 539 without one of those extensions. 540 541 If unsure, select RISCV_COMBO_SPINLOCKS, which will use qspinlocks 542 when supported and otherwise ticket spinlocks. 543 544config RISCV_COMBO_SPINLOCKS 545 bool "Using combo spinlock" 546 depends on SMP && MMU 547 select ARCH_USE_QUEUED_SPINLOCKS 548 help 549 Embed both queued spinlock and ticket lock so that the spinlock 550 implementation can be chosen at runtime. 551 552endchoice 553 554config RISCV_ALTERNATIVE 555 bool 556 depends on !XIP_KERNEL 557 help 558 This Kconfig allows the kernel to automatically patch the 559 erratum or cpufeature required by the execution platform at run 560 time. The code patching overhead is minimal, as it's only done 561 once at boot and once on each module load. 562 563config RISCV_ALTERNATIVE_EARLY 564 bool 565 depends on RISCV_ALTERNATIVE 566 help 567 Allows early patching of the kernel for special errata 568 569config RISCV_ISA_C 570 bool "Emit compressed instructions when building Linux" 571 default y 572 help 573 Adds "C" to the ISA subsets that the toolchain is allowed to emit 574 when building Linux, which results in compressed instructions in the 575 Linux binary. This option produces a kernel that will not run on 576 systems that do not support compressed instructions. 577 578 If you don't know what to do here, say Y. 579 580config RISCV_ISA_SUPM 581 bool "Supm extension for userspace pointer masking" 582 depends on 64BIT 583 default y 584 help 585 Add support for pointer masking in userspace (Supm) when the 586 underlying hardware extension (Smnpm or Ssnpm) is detected at boot. 587 588 If this option is disabled, userspace will be unable to use 589 the prctl(PR_{SET,GET}_TAGGED_ADDR_CTRL) API. 590 591config RISCV_ISA_SVNAPOT 592 bool "Svnapot extension support for supervisor mode NAPOT pages" 593 depends on 64BIT && MMU 594 depends on RISCV_ALTERNATIVE 595 default y 596 help 597 Enable support for the Svnapot ISA-extension when it is detected 598 at boot. 599 600 The Svnapot extension is used to mark contiguous PTEs as a range 601 of contiguous virtual-to-physical translations for a naturally 602 aligned power-of-2 (NAPOT) granularity larger than the base 4KB page 603 size. When HUGETLBFS is also selected this option unconditionally 604 allocates some memory for each NAPOT page size supported by the kernel. 605 When optimizing for low memory consumption and for platforms without 606 the Svnapot extension, it may be better to say N here. 607 608 If you don't know what to do here, say Y. 609 610config RISCV_ISA_SVPBMT 611 bool "Svpbmt extension support for supervisor mode page-based memory types" 612 depends on 64BIT && MMU 613 depends on RISCV_ALTERNATIVE 614 default y 615 help 616 Add support for the Svpbmt ISA-extension (Supervisor-mode: 617 page-based memory types) in the kernel when it is detected at boot. 618 619 The memory type for a page contains a combination of attributes 620 that indicate the cacheability, idempotency, and ordering 621 properties for access to that page. 622 623 The Svpbmt extension is only available on 64-bit cpus. 624 625 If you don't know what to do here, say Y. 626 627config TOOLCHAIN_HAS_V 628 bool 629 default y 630 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64imv) 631 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32imv) 632 depends on LLD_VERSION >= 140000 || LD_VERSION >= 23800 633 depends on AS_HAS_OPTION_ARCH 634 635config RISCV_ISA_V 636 bool "Vector extension support" 637 depends on TOOLCHAIN_HAS_V 638 depends on FPU 639 select DYNAMIC_SIGFRAME 640 default y 641 help 642 Add support for the Vector extension when it is detected at boot. 643 When this option is disabled, neither the kernel nor userspace may 644 use vector procedures. 645 646 If you don't know what to do here, say Y. 647 648config RISCV_ISA_V_DEFAULT_ENABLE 649 bool "Enable userspace Vector by default" 650 depends on RISCV_ISA_V 651 default y 652 help 653 Say Y here if you want to enable Vector in userspace by default. 654 Otherwise, userspace has to make explicit prctl() call to enable 655 Vector, or enable it via the sysctl interface. 656 657 If you don't know what to do here, say Y. 658 659config RISCV_ISA_V_UCOPY_THRESHOLD 660 int "Threshold size for vectorized user copies" 661 depends on RISCV_ISA_V 662 default 768 663 help 664 Prefer using vectorized copy_to_user()/copy_from_user() when the 665 workload size exceeds this value. 666 667config RISCV_ISA_V_PREEMPTIVE 668 bool "Run kernel-mode Vector with kernel preemption" 669 depends on PREEMPTION 670 depends on RISCV_ISA_V 671 default y 672 help 673 Usually, in-kernel SIMD routines are run with preemption disabled. 674 Functions which invoke long running SIMD thus must yield the core's 675 vector unit to prevent blocking other tasks for too long. 676 677 This config allows the kernel to run SIMD without explicitly disabling 678 preemption. Enabling this config will result in higher memory consumption 679 due to the allocation of per-task's kernel Vector context. 680 681config RISCV_ISA_ZAWRS 682 bool "Zawrs extension support for more efficient busy waiting" 683 depends on RISCV_ALTERNATIVE 684 default y 685 help 686 The Zawrs extension defines instructions to be used in polling loops 687 which allow a hart to enter a low-power state or to trap to the 688 hypervisor while waiting on a store to a memory location. Enable the 689 use of these instructions in the kernel when the Zawrs extension is 690 detected at boot. 691 692config TOOLCHAIN_HAS_ZABHA 693 bool 694 default y 695 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zabha) 696 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zabha) 697 depends on AS_HAS_OPTION_ARCH 698 699config RISCV_ISA_ZABHA 700 bool "Zabha extension support for atomic byte/halfword operations" 701 depends on TOOLCHAIN_HAS_ZABHA 702 depends on RISCV_ALTERNATIVE 703 default y 704 help 705 Enable the use of the Zabha ISA-extension to implement kernel 706 byte/halfword atomic memory operations when it is detected at boot. 707 708 If you don't know what to do here, say Y. 709 710config TOOLCHAIN_HAS_ZACAS 711 bool 712 default y 713 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zacas) 714 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zacas) 715 depends on AS_HAS_OPTION_ARCH 716 717config RISCV_ISA_ZACAS 718 bool "Zacas extension support for atomic CAS" 719 depends on TOOLCHAIN_HAS_ZACAS 720 depends on RISCV_ALTERNATIVE 721 default y 722 help 723 Enable the use of the Zacas ISA-extension to implement kernel atomic 724 cmpxchg operations when it is detected at boot. 725 726 If you don't know what to do here, say Y. 727 728config TOOLCHAIN_HAS_ZBB 729 bool 730 default y 731 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbb) 732 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbb) 733 depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900 734 depends on AS_HAS_OPTION_ARCH 735 736# This symbol indicates that the toolchain supports all v1.0 vector crypto 737# extensions, including Zvk*, Zvbb, and Zvbc. LLVM added all of these at once. 738# binutils added all except Zvkb, then added Zvkb. So we just check for Zvkb. 739config TOOLCHAIN_HAS_VECTOR_CRYPTO 740 def_bool $(as-instr, .option arch$(comma) +v$(comma) +zvkb) 741 depends on AS_HAS_OPTION_ARCH 742 743config TOOLCHAIN_HAS_ZBA 744 bool 745 default y 746 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zba) 747 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zba) 748 depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900 749 depends on AS_HAS_OPTION_ARCH 750 751config RISCV_ISA_ZBA 752 bool "Zba extension support for bit manipulation instructions" 753 default y 754 help 755 Add support for enabling optimisations in the kernel when the Zba 756 extension is detected at boot. 757 758 The Zba extension provides instructions to accelerate the generation 759 of addresses that index into arrays of basic data types. 760 761 If you don't know what to do here, say Y. 762 763config RISCV_ISA_ZBB 764 bool "Zbb extension support for bit manipulation instructions" 765 depends on RISCV_ALTERNATIVE 766 default y 767 help 768 Add support for enabling optimisations in the kernel when the 769 Zbb extension is detected at boot. Some optimisations may 770 additionally depend on toolchain support for Zbb. 771 772 The Zbb extension provides instructions to accelerate a number 773 of bit-specific operations (count bit population, sign extending, 774 bitrotation, etc). 775 776 If you don't know what to do here, say Y. 777 778config TOOLCHAIN_HAS_ZBC 779 bool 780 default y 781 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbc) 782 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbc) 783 depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900 784 depends on AS_HAS_OPTION_ARCH 785 786config RISCV_ISA_ZBC 787 bool "Zbc extension support for carry-less multiplication instructions" 788 depends on TOOLCHAIN_HAS_ZBC 789 depends on MMU 790 depends on RISCV_ALTERNATIVE 791 default y 792 help 793 Adds support to dynamically detect the presence of the Zbc 794 extension (carry-less multiplication) and enable its usage. 795 796 The Zbc extension could accelerate CRC (cyclic redundancy check) 797 calculations. 798 799 If you don't know what to do here, say Y. 800 801config TOOLCHAIN_HAS_ZBKB 802 bool 803 default y 804 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbkb) 805 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbkb) 806 depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900 807 depends on AS_HAS_OPTION_ARCH 808 809config RISCV_ISA_ZBKB 810 bool "Zbkb extension support for bit manipulation instructions" 811 depends on TOOLCHAIN_HAS_ZBKB 812 depends on RISCV_ALTERNATIVE 813 default y 814 help 815 Adds support to dynamically detect the presence of the ZBKB 816 extension (bit manipulation for cryptography) and enable its usage. 817 818 The Zbkb extension provides instructions to accelerate a number 819 of common cryptography operations (pack, zip, etc). 820 821 If you don't know what to do here, say Y. 822 823config RISCV_ISA_ZICBOM 824 bool "Zicbom extension support for non-coherent DMA operation" 825 depends on MMU 826 depends on RISCV_ALTERNATIVE 827 default y 828 select RISCV_DMA_NONCOHERENT 829 select DMA_DIRECT_REMAP 830 help 831 Add support for the Zicbom extension (Cache Block Management 832 Operations) and enable its use in the kernel when it is detected 833 at boot. 834 835 The Zicbom extension can be used to handle for example 836 non-coherent DMA support on devices that need it. 837 838 If you don't know what to do here, say Y. 839 840config RISCV_ISA_ZICBOZ 841 bool "Zicboz extension support for faster zeroing of memory" 842 depends on RISCV_ALTERNATIVE 843 default y 844 help 845 Enable the use of the Zicboz extension (cbo.zero instruction) 846 in the kernel when it is detected at boot. 847 848 The Zicboz extension is used for faster zeroing of memory. 849 850 If you don't know what to do here, say Y. 851 852config RISCV_ISA_ZICBOP 853 bool "Zicbop extension support for cache block prefetch" 854 depends on MMU 855 depends on RISCV_ALTERNATIVE 856 default y 857 help 858 Adds support to dynamically detect the presence of the ZICBOP 859 extension (Cache Block Prefetch Operations) and enable its 860 usage. 861 862 The Zicbop extension can be used to prefetch cache blocks for 863 read/write fetch. 864 865 If you don't know what to do here, say Y. 866 867config TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI 868 def_bool y 869 # https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=aed44286efa8ae8717a77d94b51ac3614e2ca6dc 870 # https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=98416dbb0a62579d4a7a4a76bab51b5b52fec2cd 871 depends on AS_IS_GNU && AS_VERSION >= 23600 872 help 873 Binutils-2.38 and GCC-12.1.0 bumped the default ISA spec to the newer 874 20191213 version, which moves some instructions from the I extension to 875 the Zicsr and Zifencei extensions. This requires explicitly specifying 876 Zicsr and Zifencei when binutils >= 2.38 or GCC >= 12.1.0. Zicsr 877 and Zifencei are supported in binutils from version 2.36 onwards. 878 To make life easier, and avoid forcing toolchains that default to a 879 newer ISA spec to version 2.2, relax the check to binutils >= 2.36. 880 For clang < 17 or GCC < 11.3.0, for which this is not possible or need 881 special treatment, this is dealt with in TOOLCHAIN_NEEDS_OLD_ISA_SPEC. 882 883config TOOLCHAIN_NEEDS_OLD_ISA_SPEC 884 def_bool y 885 depends on TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI 886 # https://github.com/llvm/llvm-project/commit/22e199e6afb1263c943c0c0d4498694e15bf8a16 887 # https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=d29f5d6ab513c52fd872f532c492e35ae9fd6671 888 depends on (CC_IS_CLANG && CLANG_VERSION < 170000) || (CC_IS_GCC && GCC_VERSION < 110300) 889 help 890 Certain versions of clang and GCC do not support zicsr and zifencei via 891 -march. This option causes an older ISA spec compatible with these older 892 versions of clang and GCC to be passed to GAS, which has the same result 893 as passing zicsr and zifencei to -march. 894 895config FPU 896 bool "FPU support" 897 default y 898 help 899 Add support for floating point operations when an FPU is detected at 900 boot. When this option is disabled, neither the kernel nor userspace 901 may use the floating point unit. 902 903 If you don't know what to do here, say Y. 904 905config IRQ_STACKS 906 bool "Independent irq & softirq stacks" if EXPERT 907 default y 908 select HAVE_IRQ_EXIT_ON_IRQ_STACK 909 select HAVE_SOFTIRQ_ON_OWN_STACK 910 help 911 Add independent irq & softirq stacks for percpu to prevent kernel stack 912 overflows. We may save some memory footprint by disabling IRQ_STACKS. 913 914config THREAD_SIZE_ORDER 915 int "Kernel stack size (in power-of-two numbers of page size)" if VMAP_STACK && EXPERT 916 range 0 4 917 default 1 if 32BIT 918 default 2 919 help 920 Specify the Pages of thread stack size (from 4KB to 64KB), which also 921 affects irq stack size, which is equal to thread stack size. 922 923config RISCV_MISALIGNED 924 bool 925 help 926 Embed support for detecting and emulating misaligned 927 scalar or vector loads and stores. 928 929config RISCV_SCALAR_MISALIGNED 930 bool 931 select RISCV_MISALIGNED 932 select SYSCTL_ARCH_UNALIGN_ALLOW 933 help 934 Embed support for emulating misaligned loads and stores. 935 936config RISCV_VECTOR_MISALIGNED 937 bool 938 select RISCV_MISALIGNED 939 depends on RISCV_ISA_V 940 help 941 Enable detecting support for vector misaligned loads and stores. 942 943choice 944 prompt "Unaligned Accesses Support" 945 default RISCV_PROBE_UNALIGNED_ACCESS 946 help 947 This determines the level of support for unaligned accesses. This 948 information is used by the kernel to perform optimizations. It is also 949 exposed to user space via the hwprobe syscall. The hardware will be 950 probed at boot by default. 951 952config RISCV_PROBE_UNALIGNED_ACCESS 953 bool "Probe for hardware unaligned access support" 954 select RISCV_SCALAR_MISALIGNED 955 help 956 During boot, the kernel will run a series of tests to determine the 957 speed of unaligned accesses. This probing will dynamically determine 958 the speed of unaligned accesses on the underlying system. If unaligned 959 memory accesses trap into the kernel as they are not supported by the 960 system, the kernel will emulate the unaligned accesses to preserve the 961 UABI. 962 963config RISCV_EMULATED_UNALIGNED_ACCESS 964 bool "Emulate unaligned access where system support is missing" 965 select RISCV_SCALAR_MISALIGNED 966 help 967 If unaligned memory accesses trap into the kernel as they are not 968 supported by the system, the kernel will emulate the unaligned 969 accesses to preserve the UABI. When the underlying system does support 970 unaligned accesses, the unaligned accesses are assumed to be slow. 971 972config RISCV_SLOW_UNALIGNED_ACCESS 973 bool "Assume the system supports slow unaligned memory accesses" 974 depends on NONPORTABLE 975 help 976 Assume that the system supports slow unaligned memory accesses. The 977 kernel and userspace programs may not be able to run at all on systems 978 that do not support unaligned memory accesses. 979 980config RISCV_EFFICIENT_UNALIGNED_ACCESS 981 bool "Assume the system supports fast unaligned memory accesses" 982 depends on NONPORTABLE 983 select DCACHE_WORD_ACCESS if MMU 984 select HAVE_EFFICIENT_UNALIGNED_ACCESS 985 help 986 Assume that the system supports fast unaligned memory accesses. When 987 enabled, this option improves the performance of the kernel on such 988 systems. However, the kernel and userspace programs will run much more 989 slowly, or will not be able to run at all, on systems that do not 990 support efficient unaligned memory accesses. 991 992endchoice 993 994choice 995 prompt "Vector unaligned Accesses Support" 996 depends on RISCV_ISA_V 997 default RISCV_PROBE_VECTOR_UNALIGNED_ACCESS 998 help 999 This determines the level of support for vector unaligned accesses. This 1000 information is used by the kernel to perform optimizations. It is also 1001 exposed to user space via the hwprobe syscall. The hardware will be 1002 probed at boot by default. 1003 1004config RISCV_PROBE_VECTOR_UNALIGNED_ACCESS 1005 bool "Probe speed of vector unaligned accesses" 1006 select RISCV_VECTOR_MISALIGNED 1007 depends on RISCV_ISA_V 1008 help 1009 During boot, the kernel will run a series of tests to determine the 1010 speed of vector unaligned accesses if they are supported. This probing 1011 will dynamically determine the speed of vector unaligned accesses on 1012 the underlying system if they are supported. 1013 1014config RISCV_SLOW_VECTOR_UNALIGNED_ACCESS 1015 bool "Assume the system supports slow vector unaligned memory accesses" 1016 depends on NONPORTABLE 1017 help 1018 Assume that the system supports slow vector unaligned memory accesses. The 1019 kernel and userspace programs may not be able to run at all on systems 1020 that do not support unaligned memory accesses. 1021 1022config RISCV_EFFICIENT_VECTOR_UNALIGNED_ACCESS 1023 bool "Assume the system supports fast vector unaligned memory accesses" 1024 depends on NONPORTABLE 1025 help 1026 Assume that the system supports fast vector unaligned memory accesses. When 1027 enabled, this option improves the performance of the kernel on such 1028 systems. However, the kernel and userspace programs will run much more 1029 slowly, or will not be able to run at all, on systems that do not 1030 support efficient unaligned memory accesses. 1031 1032endchoice 1033 1034source "arch/riscv/Kconfig.vendor" 1035 1036endmenu # "Platform type" 1037 1038menu "Kernel features" 1039 1040source "kernel/Kconfig.hz" 1041 1042config RISCV_SBI_V01 1043 bool "SBI v0.1 support" 1044 depends on RISCV_SBI 1045 help 1046 This config allows kernel to use SBI v0.1 APIs. This will be 1047 deprecated in future once legacy M-mode software are no longer in use. 1048 1049config RISCV_BOOT_SPINWAIT 1050 bool "Spinwait booting method" 1051 depends on SMP 1052 default y if RISCV_SBI_V01 || RISCV_M_MODE 1053 help 1054 This enables support for booting Linux via spinwait method. In the 1055 spinwait method, all cores randomly jump to Linux. One of the cores 1056 gets chosen via lottery and all other keep spinning on a percpu 1057 variable. This method cannot support CPU hotplug and sparse hartid 1058 scheme. It should be only enabled for M-mode Linux or platforms relying 1059 on older firmware without SBI HSM extension. All other platforms should 1060 rely on ordered booting via SBI HSM extension which gets chosen 1061 dynamically at runtime if the firmware supports it. 1062 1063 Since spinwait is incompatible with sparse hart IDs, it requires 1064 NR_CPUS be large enough to contain the physical hart ID of the first 1065 hart to enter Linux. 1066 1067 If unsure what to do here, say N. 1068 1069config ARCH_SUPPORTS_KEXEC 1070 def_bool y 1071 1072config ARCH_SELECTS_KEXEC 1073 def_bool y 1074 depends on KEXEC 1075 select HOTPLUG_CPU if SMP 1076 1077config ARCH_SUPPORTS_KEXEC_FILE 1078 def_bool 64BIT 1079 1080config ARCH_SELECTS_KEXEC_FILE 1081 def_bool y 1082 depends on KEXEC_FILE 1083 select HAVE_IMA_KEXEC if IMA 1084 select KEXEC_ELF 1085 1086config ARCH_SUPPORTS_KEXEC_PURGATORY 1087 def_bool ARCH_SUPPORTS_KEXEC_FILE 1088 1089config ARCH_SUPPORTS_CRASH_DUMP 1090 def_bool y 1091 1092config ARCH_DEFAULT_CRASH_DUMP 1093 def_bool y 1094 1095config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION 1096 def_bool CRASH_RESERVE 1097 1098config COMPAT 1099 bool "Kernel support for 32-bit U-mode" 1100 default 64BIT 1101 depends on 64BIT && MMU 1102 help 1103 This option enables support for a 32-bit U-mode running under a 64-bit 1104 kernel at S-mode. riscv32-specific components such as system calls, 1105 the user helper functions (vdso), signal rt_frame functions and the 1106 ptrace interface are handled appropriately by the kernel. 1107 1108 If you want to execute 32-bit userspace applications, say Y. 1109 1110config PARAVIRT 1111 bool "Enable paravirtualization code" 1112 depends on RISCV_SBI 1113 help 1114 This changes the kernel so it can modify itself when it is run 1115 under a hypervisor, potentially improving performance significantly 1116 over full virtualization. 1117 1118config PARAVIRT_TIME_ACCOUNTING 1119 bool "Paravirtual steal time accounting" 1120 depends on PARAVIRT 1121 help 1122 Select this option to enable fine granularity task steal time 1123 accounting. Time spent executing other tasks in parallel with 1124 the current vCPU is discounted from the vCPU power. To account for 1125 that, there can be a small performance impact. 1126 1127 If in doubt, say N here. 1128 1129config RELOCATABLE 1130 bool "Build a relocatable kernel" 1131 depends on !XIP_KERNEL 1132 select MODULE_SECTIONS if MODULES 1133 select ARCH_VMLINUX_NEEDS_RELOCS 1134 help 1135 This builds a kernel as a Position Independent Executable (PIE), 1136 which retains all relocation metadata required to relocate the 1137 kernel binary at runtime to a different virtual address than the 1138 address it was linked at. 1139 Since RISCV uses the RELA relocation format, this requires a 1140 relocation pass at runtime even if the kernel is loaded at the 1141 same address it was linked at. 1142 1143 If unsure, say N. 1144 1145config RANDOMIZE_BASE 1146 bool "Randomize the address of the kernel image" 1147 select RELOCATABLE 1148 depends on MMU && 64BIT && !XIP_KERNEL 1149 help 1150 Randomizes the virtual address at which the kernel image is 1151 loaded, as a security feature that deters exploit attempts 1152 relying on knowledge of the location of kernel internals. 1153 1154 It is the bootloader's job to provide entropy, by passing a 1155 random u64 value in /chosen/kaslr-seed at kernel entry. 1156 1157 When booting via the UEFI stub, it will invoke the firmware's 1158 EFI_RNG_PROTOCOL implementation (if available) to supply entropy 1159 to the kernel proper. In addition, it will randomise the physical 1160 location of the kernel Image as well. 1161 1162 If unsure, say N. 1163 1164endmenu # "Kernel features" 1165 1166menu "Boot options" 1167 1168config CMDLINE 1169 string "Built-in kernel command line" 1170 help 1171 For most platforms, the arguments for the kernel's command line 1172 are provided at run-time, during boot. However, there are cases 1173 where either no arguments are being provided or the provided 1174 arguments are insufficient or even invalid. 1175 1176 When that occurs, it is possible to define a built-in command 1177 line here and choose how the kernel should use it later on. 1178 1179choice 1180 prompt "Built-in command line usage" 1181 depends on CMDLINE != "" 1182 default CMDLINE_FALLBACK 1183 help 1184 Choose how the kernel will handle the provided built-in command 1185 line. 1186 1187config CMDLINE_FALLBACK 1188 bool "Use bootloader kernel arguments if available" 1189 help 1190 Use the built-in command line as fallback in case we get nothing 1191 during boot. This is the default behaviour. 1192 1193config CMDLINE_EXTEND 1194 bool "Extend bootloader kernel arguments" 1195 help 1196 The built-in command line will be appended to the command- 1197 line arguments provided during boot. This is useful in 1198 cases where the provided arguments are insufficient and 1199 you don't want to or cannot modify them. 1200 1201config CMDLINE_FORCE 1202 bool "Always use the default kernel command string" 1203 help 1204 Always use the built-in command line, even if we get one during 1205 boot. This is useful in case you need to override the provided 1206 command line on systems where you don't have or want control 1207 over it. 1208 1209endchoice 1210 1211config EFI_STUB 1212 bool 1213 1214config EFI 1215 bool "UEFI runtime support" 1216 depends on OF && !XIP_KERNEL 1217 depends on MMU 1218 default y 1219 select ARCH_SUPPORTS_ACPI if 64BIT 1220 select EFI_GENERIC_STUB 1221 select EFI_PARAMS_FROM_FDT 1222 select EFI_RUNTIME_WRAPPERS 1223 select EFI_STUB 1224 select LIBFDT 1225 select RISCV_ISA_C 1226 select UCS2_STRING 1227 help 1228 This option provides support for runtime services provided 1229 by UEFI firmware (such as non-volatile variables, realtime 1230 clock, and platform reset). A UEFI stub is also provided to 1231 allow the kernel to be booted as an EFI application. This 1232 is only useful on systems that have UEFI firmware. 1233 1234config DMI 1235 bool "Enable support for SMBIOS (DMI) tables" 1236 depends on EFI 1237 default y 1238 help 1239 This enables SMBIOS/DMI feature for systems. 1240 1241 This option is only useful on systems that have UEFI firmware. 1242 However, even with this option, the resultant kernel should 1243 continue to boot on existing non-UEFI platforms. 1244 1245config CC_HAVE_STACKPROTECTOR_TLS 1246 def_bool $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=tp -mstack-protector-guard-offset=0) 1247 1248config STACKPROTECTOR_PER_TASK 1249 def_bool y 1250 depends on !RANDSTRUCT 1251 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_TLS 1252 1253config PHYS_RAM_BASE_FIXED 1254 bool "Explicitly specified physical RAM address" 1255 depends on NONPORTABLE 1256 default n 1257 1258config PHYS_RAM_BASE 1259 hex "Platform Physical RAM address" 1260 depends on PHYS_RAM_BASE_FIXED 1261 default "0x80000000" 1262 help 1263 This is the physical address of RAM in the system. It has to be 1264 explicitly specified to run early relocations of read-write data 1265 from flash to RAM. 1266 1267config XIP_KERNEL 1268 bool "Kernel Execute-In-Place from ROM" 1269 depends on MMU && SPARSEMEM && NONPORTABLE 1270 # This prevents XIP from being enabled by all{yes,mod}config, which 1271 # fail to build since XIP doesn't support large kernels. 1272 depends on !COMPILE_TEST 1273 select PHYS_RAM_BASE_FIXED 1274 help 1275 Execute-In-Place allows the kernel to run from non-volatile storage 1276 directly addressable by the CPU, such as NOR flash. This saves RAM 1277 space since the text section of the kernel is not loaded from flash 1278 to RAM. Read-write sections, such as the data section and stack, 1279 are still copied to RAM. The XIP kernel is not compressed since 1280 it has to run directly from flash, so it will take more space to 1281 store it. The flash address used to link the kernel object files, 1282 and for storing it, is configuration dependent. Therefore, if you 1283 say Y here, you must know the proper physical address where to 1284 store the kernel image depending on your own flash memory usage. 1285 1286 Also note that the make target becomes "make xipImage" rather than 1287 "make zImage" or "make Image". The final kernel binary to put in 1288 ROM memory will be arch/riscv/boot/xipImage. 1289 1290 SPARSEMEM is required because the kernel text and rodata that are 1291 flash resident are not backed by memmap, then any attempt to get 1292 a struct page on those regions will trigger a fault. 1293 1294 If unsure, say N. 1295 1296config XIP_PHYS_ADDR 1297 hex "XIP Kernel Physical Location" 1298 depends on XIP_KERNEL 1299 default "0x21000000" 1300 help 1301 This is the physical address in your flash memory the kernel will 1302 be linked for and stored to. This address is dependent on your 1303 own flash usage. 1304 1305config RISCV_ISA_FALLBACK 1306 bool "Permit falling back to parsing riscv,isa for extension support by default" 1307 default y 1308 help 1309 Parsing the "riscv,isa" devicetree property has been deprecated and 1310 replaced by a list of explicitly defined strings. For compatibility 1311 with existing platforms, the kernel will fall back to parsing the 1312 "riscv,isa" property if the replacements are not found. 1313 1314 Selecting N here will result in a kernel that does not use the 1315 fallback, unless the commandline "riscv_isa_fallback" parameter is 1316 present. 1317 1318 Please see the dt-binding, located at 1319 Documentation/devicetree/bindings/riscv/extensions.yaml for details 1320 on the replacement properties, "riscv,isa-base" and 1321 "riscv,isa-extensions". 1322 1323config BUILTIN_DTB 1324 bool "Built-in device tree" 1325 depends on OF && NONPORTABLE 1326 select GENERIC_BUILTIN_DTB 1327 help 1328 Build a device tree into the Linux image. 1329 This option should be selected if no bootloader is being used. 1330 If unsure, say N. 1331 1332 1333config BUILTIN_DTB_NAME 1334 string "Built-in device tree source" 1335 depends on BUILTIN_DTB 1336 help 1337 DTS file path (without suffix, relative to arch/riscv/boot/dts) 1338 for the DTS file that will be used to produce the DTB linked into the 1339 kernel. 1340 1341endmenu # "Boot options" 1342 1343config PORTABLE 1344 bool 1345 default !NONPORTABLE 1346 select EFI 1347 select MMU 1348 select OF 1349 1350config ARCH_PROC_KCORE_TEXT 1351 def_bool y 1352 1353menu "Power management options" 1354 1355source "kernel/power/Kconfig" 1356 1357config ARCH_HIBERNATION_POSSIBLE 1358 def_bool y 1359 1360config ARCH_HIBERNATION_HEADER 1361 def_bool HIBERNATION 1362 1363config ARCH_SUSPEND_POSSIBLE 1364 def_bool y 1365 1366endmenu # "Power management options" 1367 1368menu "CPU Power Management" 1369 1370source "drivers/cpuidle/Kconfig" 1371 1372source "drivers/cpufreq/Kconfig" 1373 1374endmenu # "CPU Power Management" 1375 1376source "arch/riscv/kvm/Kconfig" 1377 1378source "drivers/acpi/Kconfig" 1379