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_CURRENT_STACK_POINTER 28 select ARCH_HAS_DEBUG_VIRTUAL if MMU 29 select ARCH_HAS_DEBUG_VM_PGTABLE 30 select ARCH_HAS_DEBUG_WX 31 select ARCH_HAS_FAST_MULTIPLIER 32 select ARCH_HAS_FORTIFY_SOURCE 33 select ARCH_HAS_GCOV_PROFILE_ALL 34 select ARCH_HAS_GIGANTIC_PAGE 35 select ARCH_HAS_HW_PTE_YOUNG 36 select ARCH_HAS_KCOV 37 select ARCH_HAS_KERNEL_FPU_SUPPORT if 64BIT && FPU 38 select ARCH_HAS_MEMBARRIER_CALLBACKS 39 select ARCH_HAS_MEMBARRIER_SYNC_CORE 40 select ARCH_HAS_MMIOWB 41 select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 42 select ARCH_HAS_PMEM_API 43 select ARCH_HAS_PREEMPT_LAZY 44 select ARCH_HAS_PREPARE_SYNC_CORE_CMD 45 select ARCH_HAS_PTDUMP if MMU 46 select ARCH_HAS_PTE_SPECIAL 47 select ARCH_HAS_SET_DIRECT_MAP if MMU 48 select ARCH_HAS_SET_MEMORY if MMU 49 select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL 50 select ARCH_HAS_STRICT_MODULE_RWX if MMU && !XIP_KERNEL 51 select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE 52 select ARCH_HAS_SYSCALL_WRAPPER 53 select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST 54 select ARCH_HAS_UBSAN 55 select ARCH_HAS_VDSO_ARCH_DATA if GENERIC_VDSO_DATA_STORE 56 select ARCH_KEEP_MEMBLOCK if ACPI 57 select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE if 64BIT && MMU 58 select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX 59 select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT 60 select ARCH_STACKWALK 61 select ARCH_SUPPORTS_ATOMIC_RMW 62 # clang >= 17: https://github.com/llvm/llvm-project/commit/62fa708ceb027713b386c7e0efda994f8bdc27e2 63 select ARCH_SUPPORTS_CFI_CLANG if CLANG_VERSION >= 170000 64 select ARCH_SUPPORTS_DEBUG_PAGEALLOC if MMU 65 select ARCH_SUPPORTS_HUGE_PFNMAP if TRANSPARENT_HUGEPAGE 66 select ARCH_SUPPORTS_HUGETLBFS if MMU 67 # LLD >= 14: https://github.com/llvm/llvm-project/issues/50505 68 select ARCH_SUPPORTS_LTO_CLANG if LLD_VERSION >= 140000 && CMODEL_MEDANY 69 select ARCH_SUPPORTS_LTO_CLANG_THIN if LLD_VERSION >= 140000 70 select ARCH_SUPPORTS_MSEAL_SYSTEM_MAPPINGS if 64BIT && MMU 71 select ARCH_SUPPORTS_PAGE_TABLE_CHECK if MMU 72 select ARCH_SUPPORTS_PER_VMA_LOCK if MMU 73 select ARCH_SUPPORTS_RT 74 select ARCH_SUPPORTS_SHADOW_CALL_STACK if HAVE_SHADOW_CALL_STACK 75 select ARCH_USE_CMPXCHG_LOCKREF if 64BIT 76 select ARCH_USE_MEMTEST 77 select ARCH_USE_QUEUED_RWLOCKS 78 select ARCH_USE_SYM_ANNOTATIONS 79 select ARCH_USES_CFI_TRAPS if CFI_CLANG 80 select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH if MMU 81 select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU 82 select ARCH_WANT_FRAME_POINTERS 83 select ARCH_WANT_GENERAL_HUGETLB if !RISCV_ISA_SVNAPOT 84 select ARCH_WANT_HUGE_PMD_SHARE if 64BIT 85 select ARCH_WANT_LD_ORPHAN_WARN if !XIP_KERNEL 86 select ARCH_WANT_OPTIMIZE_DAX_VMEMMAP 87 select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP 88 select ARCH_WANTS_NO_INSTR 89 select ARCH_WANTS_THP_SWAP if HAVE_ARCH_TRANSPARENT_HUGEPAGE 90 select ARCH_WEAK_RELEASE_ACQUIRE if ARCH_USE_QUEUED_SPINLOCKS 91 select BINFMT_FLAT_NO_DATA_START_OFFSET if !MMU 92 select BUILDTIME_TABLE_SORT if MMU 93 select CLINT_TIMER if RISCV_M_MODE 94 select CLONE_BACKWARDS 95 select COMMON_CLK 96 select CPU_NO_EFFICIENT_FFS if !RISCV_ISA_ZBB 97 select CPU_PM if CPU_IDLE || HIBERNATION || SUSPEND 98 select DYNAMIC_FTRACE if FUNCTION_TRACER 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 FUNCTION_ALIGNMENT_8B if DYNAMIC_FTRACE_WITH_CALL_OPS 103 select GENERIC_ARCH_TOPOLOGY 104 select GENERIC_ATOMIC64 if !64BIT 105 select GENERIC_CLOCKEVENTS_BROADCAST if SMP 106 select GENERIC_CPU_DEVICES 107 select GENERIC_CPU_VULNERABILITIES 108 select GENERIC_EARLY_IOREMAP 109 select GENERIC_ENTRY 110 select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO 111 select GENERIC_IDLE_POLL_SETUP 112 select GENERIC_IOREMAP if MMU 113 select GENERIC_IRQ_IPI if SMP 114 select GENERIC_IRQ_IPI_MUX if SMP 115 select GENERIC_IRQ_MULTI_HANDLER 116 select GENERIC_IRQ_SHOW 117 select GENERIC_IRQ_SHOW_LEVEL 118 select GENERIC_LIB_DEVMEM_IS_ALLOWED 119 select GENERIC_PENDING_IRQ if SMP 120 select GENERIC_PCI_IOMAP 121 select GENERIC_SCHED_CLOCK 122 select GENERIC_SMP_IDLE_THREAD 123 select GENERIC_TIME_VSYSCALL if MMU && 64BIT 124 select GENERIC_VDSO_DATA_STORE if MMU 125 select GENERIC_VDSO_TIME_NS if HAVE_GENERIC_VDSO 126 select HARDIRQS_SW_RESEND 127 select HAS_IOPORT if MMU 128 select HAVE_ALIGNED_STRUCT_PAGE 129 select HAVE_ARCH_AUDITSYSCALL 130 select HAVE_ARCH_HUGE_VMALLOC if HAVE_ARCH_HUGE_VMAP 131 select HAVE_ARCH_HUGE_VMAP if MMU && 64BIT 132 select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL 133 select HAVE_ARCH_JUMP_LABEL_RELATIVE if !XIP_KERNEL 134 select HAVE_ARCH_KASAN if MMU && 64BIT 135 select HAVE_ARCH_KASAN_VMALLOC if MMU && 64BIT 136 select HAVE_ARCH_KFENCE if MMU && 64BIT 137 select HAVE_ARCH_KSTACK_ERASE 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_THREAD_STRUCT_WHITELIST 145 select HAVE_ARCH_TRACEHOOK 146 select HAVE_ARCH_TRANSPARENT_HUGEPAGE if 64BIT && MMU 147 select HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD if 64BIT && MMU 148 select HAVE_ARCH_USERFAULTFD_MINOR if 64BIT && USERFAULTFD 149 select HAVE_ARCH_VMAP_STACK if MMU && 64BIT 150 select HAVE_ASM_MODVERSIONS 151 select HAVE_CONTEXT_TRACKING_USER 152 select HAVE_DEBUG_KMEMLEAK 153 select HAVE_DMA_CONTIGUOUS if MMU 154 select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && MMU && (CLANG_SUPPORTS_DYNAMIC_FTRACE || GCC_SUPPORTS_DYNAMIC_FTRACE) 155 select FUNCTION_ALIGNMENT_4B if HAVE_DYNAMIC_FTRACE && RISCV_ISA_C 156 select HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS if HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS 157 select HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS if (DYNAMIC_FTRACE_WITH_ARGS && !CFI_CLANG) 158 select HAVE_DYNAMIC_FTRACE_WITH_ARGS if HAVE_DYNAMIC_FTRACE 159 select HAVE_FTRACE_GRAPH_FUNC 160 select HAVE_FUNCTION_GRAPH_TRACER if HAVE_DYNAMIC_FTRACE_WITH_ARGS 161 select HAVE_FUNCTION_GRAPH_FREGS 162 select HAVE_FUNCTION_TRACER if !XIP_KERNEL && HAVE_DYNAMIC_FTRACE 163 select HAVE_EBPF_JIT if MMU 164 select HAVE_GUP_FAST if MMU 165 select HAVE_FUNCTION_ARG_ACCESS_API 166 select HAVE_FUNCTION_ERROR_INJECTION 167 select HAVE_GCC_PLUGINS 168 select HAVE_GENERIC_VDSO if MMU && 64BIT 169 select HAVE_IRQ_TIME_ACCOUNTING 170 select HAVE_KERNEL_BZIP2 if !XIP_KERNEL && !EFI_ZBOOT 171 select HAVE_KERNEL_GZIP if !XIP_KERNEL && !EFI_ZBOOT 172 select HAVE_KERNEL_LZ4 if !XIP_KERNEL && !EFI_ZBOOT 173 select HAVE_KERNEL_LZMA if !XIP_KERNEL && !EFI_ZBOOT 174 select HAVE_KERNEL_LZO if !XIP_KERNEL && !EFI_ZBOOT 175 select HAVE_KERNEL_UNCOMPRESSED if !XIP_KERNEL && !EFI_ZBOOT 176 select HAVE_KERNEL_ZSTD if !XIP_KERNEL && !EFI_ZBOOT 177 select HAVE_KERNEL_XZ if !XIP_KERNEL && !EFI_ZBOOT 178 select HAVE_KPROBES if !XIP_KERNEL 179 select HAVE_KRETPROBES if !XIP_KERNEL 180 # https://github.com/ClangBuiltLinux/linux/issues/1881 181 select HAVE_LD_DEAD_CODE_DATA_ELIMINATION if !LD_IS_LLD 182 select HAVE_MOVE_PMD 183 select HAVE_MOVE_PUD 184 select HAVE_PAGE_SIZE_4KB 185 select HAVE_PCI 186 select HAVE_PERF_EVENTS 187 select HAVE_PERF_REGS 188 select HAVE_PERF_USER_STACK_DUMP 189 select HAVE_POSIX_CPU_TIMERS_TASK_WORK 190 select HAVE_PREEMPT_DYNAMIC_KEY if !XIP_KERNEL 191 select HAVE_REGS_AND_STACK_ACCESS_API 192 select HAVE_RETHOOK if !XIP_KERNEL 193 select HAVE_RSEQ 194 select HAVE_RUST if RUSTC_SUPPORTS_RISCV && CC_IS_CLANG 195 select HAVE_SAMPLE_FTRACE_DIRECT 196 select HAVE_SAMPLE_FTRACE_DIRECT_MULTI 197 select HAVE_STACKPROTECTOR 198 select HAVE_SYSCALL_TRACEPOINTS 199 select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU 200 select IRQ_DOMAIN 201 select IRQ_FORCED_THREADING 202 select KASAN_VMALLOC if KASAN 203 select LOCK_MM_AND_FIND_VMA 204 select MMU_GATHER_RCU_TABLE_FREE if SMP && MMU 205 select MODULES_USE_ELF_RELA if MODULES 206 select OF 207 select OF_EARLY_FLATTREE 208 select OF_IRQ 209 select PCI_DOMAINS_GENERIC if PCI 210 select PCI_ECAM if (ACPI && PCI) 211 select PCI_MSI if PCI 212 select RELOCATABLE if !MMU && !PHYS_RAM_BASE_FIXED 213 select RISCV_ALTERNATIVE if !XIP_KERNEL 214 select RISCV_APLIC 215 select RISCV_IMSIC 216 select RISCV_INTC 217 select RISCV_TIMER if RISCV_SBI 218 select SIFIVE_PLIC 219 select SPARSE_IRQ 220 select SYSCTL_EXCEPTION_TRACE 221 select THREAD_INFO_IN_TASK 222 select TRACE_IRQFLAGS_SUPPORT 223 select UACCESS_MEMCPY if !MMU 224 select VDSO_GETRANDOM if HAVE_GENERIC_VDSO 225 select USER_STACKTRACE_SUPPORT 226 select ZONE_DMA32 if 64BIT 227 228config RUSTC_SUPPORTS_RISCV 229 def_bool y 230 depends on 64BIT 231 # Shadow call stack requires rustc version 1.82+ due to use of the 232 # -Zsanitizer=shadow-call-stack flag. 233 depends on !SHADOW_CALL_STACK || RUSTC_VERSION >= 108200 234 235config CLANG_SUPPORTS_DYNAMIC_FTRACE 236 def_bool CC_IS_CLANG 237 # https://github.com/ClangBuiltLinux/linux/issues/1817 238 depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600)) 239 240config GCC_SUPPORTS_DYNAMIC_FTRACE 241 def_bool CC_IS_GCC 242 depends on $(cc-option,-fpatchable-function-entry=8) 243 depends on CC_HAS_MIN_FUNCTION_ALIGNMENT || !RISCV_ISA_C 244 245config HAVE_SHADOW_CALL_STACK 246 def_bool $(cc-option,-fsanitize=shadow-call-stack) 247 # https://github.com/riscv-non-isa/riscv-elf-psabi-doc/commit/a484e843e6eeb51f0cb7b8819e50da6d2444d769 248 depends on $(ld-option,--no-relax-gp) 249 250config RISCV_USE_LINKER_RELAXATION 251 def_bool y 252 # https://github.com/llvm/llvm-project/commit/6611d58f5bbcbec77262d392e2923e1d680f6985 253 depends on !LD_IS_LLD || LLD_VERSION >= 150000 254 255# https://github.com/llvm/llvm-project/commit/bbc0f99f3bc96f1db16f649fc21dd18e5b0918f6 256config ARCH_HAS_BROKEN_DWARF5 257 def_bool y 258 depends on RISCV_USE_LINKER_RELAXATION 259 # https://github.com/llvm/llvm-project/commit/1df5ea29b43690b6622db2cad7b745607ca4de6a 260 depends on AS_IS_LLVM && AS_VERSION < 180000 261 # https://github.com/llvm/llvm-project/commit/7ffabb61a5569444b5ac9322e22e5471cc5e4a77 262 depends on LD_IS_LLD && LLD_VERSION < 180000 263 264config ARCH_MMAP_RND_BITS_MIN 265 default 18 if 64BIT 266 default 8 267 268config ARCH_MMAP_RND_COMPAT_BITS_MIN 269 default 8 270 271# max bits determined by the following formula: 272# VA_BITS - PAGE_SHIFT - 3 273config ARCH_MMAP_RND_BITS_MAX 274 default 24 if 64BIT # SV39 based 275 default 17 276 277config ARCH_MMAP_RND_COMPAT_BITS_MAX 278 default 17 279 280# set if we run in machine mode, cleared if we run in supervisor mode 281config RISCV_M_MODE 282 bool "Build a kernel that runs in machine mode" 283 depends on !MMU 284 default y 285 help 286 Select this option if you want to run the kernel in M-mode, 287 without the assistance of any other firmware. 288 289# set if we are running in S-mode and can use SBI calls 290config RISCV_SBI 291 bool 292 depends on !RISCV_M_MODE 293 default y 294 295config MMU 296 bool "MMU-based Paged Memory Management Support" 297 default y 298 help 299 Select if you want MMU-based virtualised addressing space 300 support by paged memory management. If unsure, say 'Y'. 301 302config KASAN_SHADOW_OFFSET 303 hex 304 depends on KASAN_GENERIC 305 default 0xdfffffff00000000 if 64BIT 306 default 0xffffffff if 32BIT 307 308config ARCH_FLATMEM_ENABLE 309 def_bool !NUMA 310 311config ARCH_SPARSEMEM_ENABLE 312 def_bool y 313 depends on MMU 314 select SPARSEMEM_STATIC if 32BIT && SPARSEMEM 315 select SPARSEMEM_VMEMMAP_ENABLE if 64BIT 316 317config ARCH_SELECT_MEMORY_MODEL 318 def_bool ARCH_SPARSEMEM_ENABLE 319 320config ARCH_SUPPORTS_UPROBES 321 def_bool y 322 323config STACKTRACE_SUPPORT 324 def_bool y 325 326config GENERIC_BUG 327 def_bool y 328 depends on BUG 329 select GENERIC_BUG_RELATIVE_POINTERS if 64BIT 330 331config GENERIC_BUG_RELATIVE_POINTERS 332 bool 333 334config GENERIC_CALIBRATE_DELAY 335 def_bool y 336 337config GENERIC_CSUM 338 def_bool y 339 340config GENERIC_HWEIGHT 341 def_bool y 342 343config FIX_EARLYCON_MEM 344 def_bool MMU 345 346config ILLEGAL_POINTER_VALUE 347 hex 348 default 0 if 32BIT 349 default 0xdead000000000000 if 64BIT 350 351config PGTABLE_LEVELS 352 int 353 default 5 if 64BIT 354 default 2 355 356config LOCKDEP_SUPPORT 357 def_bool y 358 359config RISCV_DMA_NONCOHERENT 360 bool 361 select ARCH_HAS_DMA_PREP_COHERENT 362 select ARCH_HAS_SETUP_DMA_OPS 363 select ARCH_HAS_SYNC_DMA_FOR_CPU 364 select ARCH_HAS_SYNC_DMA_FOR_DEVICE 365 select DMA_BOUNCE_UNALIGNED_KMALLOC if SWIOTLB 366 367config RISCV_NONSTANDARD_CACHE_OPS 368 bool 369 help 370 This enables function pointer support for non-standard noncoherent 371 systems to handle cache management. 372 373config AS_HAS_INSN 374 def_bool $(as-instr,.insn r 51$(comma) 0$(comma) 0$(comma) t0$(comma) t0$(comma) zero) 375 376config AS_HAS_OPTION_ARCH 377 # https://github.com/llvm/llvm-project/commit/9e8ed3403c191ab9c4903e8eeb8f732ff8a43cb4 378 def_bool y 379 depends on $(as-instr, .option arch$(comma) +m) 380 381source "arch/riscv/Kconfig.socs" 382source "arch/riscv/Kconfig.errata" 383 384menu "Platform type" 385 386config NONPORTABLE 387 bool "Allow configurations that result in non-portable kernels" 388 help 389 RISC-V kernel binaries are compatible between all known systems 390 whenever possible, but there are some use cases that can only be 391 satisfied by configurations that result in kernel binaries that are 392 not portable between systems. 393 394 Selecting N does not guarantee kernels will be portable to all known 395 systems. Selecting any of the options guarded by NONPORTABLE will 396 result in kernel binaries that are unlikely to be portable between 397 systems. 398 399 If unsure, say N. 400 401choice 402 prompt "Base ISA" 403 default ARCH_RV64I 404 help 405 This selects the base ISA that this kernel will target and must match 406 the target platform. 407 408config ARCH_RV32I 409 bool "RV32I" 410 depends on NONPORTABLE 411 select 32BIT 412 select GENERIC_LIB_ASHLDI3 413 select GENERIC_LIB_ASHRDI3 414 select GENERIC_LIB_LSHRDI3 415 select GENERIC_LIB_UCMPDI2 416 417config ARCH_RV64I 418 bool "RV64I" 419 select 64BIT 420 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 421 select SWIOTLB if MMU 422 423endchoice 424 425# We must be able to map all physical memory into the kernel, but the compiler 426# is still a bit more efficient when generating code if it's setup in a manner 427# such that it can only map 2GiB of memory. 428choice 429 prompt "Kernel Code Model" 430 default CMODEL_MEDLOW if 32BIT 431 default CMODEL_MEDANY if 64BIT 432 433 config CMODEL_MEDLOW 434 bool "medium low code model" 435 config CMODEL_MEDANY 436 bool "medium any code model" 437endchoice 438 439config MODULE_SECTIONS 440 bool 441 select HAVE_MOD_ARCH_SPECIFIC 442 443config SMP 444 bool "Symmetric Multi-Processing" 445 help 446 This enables support for systems with more than one CPU. If 447 you say N here, the kernel will run on single and 448 multiprocessor machines, but will use only one CPU of a 449 multiprocessor machine. If you say Y here, the kernel will run 450 on many, but not all, single processor machines. On a single 451 processor machine, the kernel will run faster if you say N 452 here. 453 454 If you don't know what to do here, say N. 455 456config SCHED_MC 457 bool "Multi-core scheduler support" 458 depends on SMP 459 help 460 Multi-core scheduler support improves the CPU scheduler's decision 461 making when dealing with multi-core CPU chips at a cost of slightly 462 increased overhead in some places. If unsure say N here. 463 464config NR_CPUS 465 int "Maximum number of CPUs (2-512)" 466 depends on SMP 467 range 2 512 if !RISCV_SBI_V01 468 range 2 32 if RISCV_SBI_V01 && 32BIT 469 range 2 64 if RISCV_SBI_V01 && 64BIT 470 default "32" if 32BIT 471 default "64" if 64BIT 472 473config HOTPLUG_CPU 474 bool "Support for hot-pluggable CPUs" 475 depends on SMP 476 select GENERIC_IRQ_MIGRATION 477 help 478 479 Say Y here to experiment with turning CPUs off and on. CPUs 480 can be controlled through /sys/devices/system/cpu. 481 482 Say N if you want to disable CPU hotplug. 483 484choice 485 prompt "CPU Tuning" 486 default TUNE_GENERIC 487 488config TUNE_GENERIC 489 bool "generic" 490 491endchoice 492 493# Common NUMA Features 494config NUMA 495 bool "NUMA Memory Allocation and Scheduler Support" 496 depends on SMP && MMU 497 select ARCH_SUPPORTS_NUMA_BALANCING 498 select GENERIC_ARCH_NUMA 499 select HAVE_SETUP_PER_CPU_AREA 500 select NEED_PER_CPU_EMBED_FIRST_CHUNK 501 select NEED_PER_CPU_PAGE_FIRST_CHUNK 502 select OF_NUMA 503 select USE_PERCPU_NUMA_NODE_ID 504 help 505 Enable NUMA (Non-Uniform Memory Access) support. 506 507 The kernel will try to allocate memory used by a CPU on the 508 local memory of the CPU and add some more NUMA awareness to the kernel. 509 510config NODES_SHIFT 511 int "Maximum NUMA Nodes (as a power of 2)" 512 range 1 10 513 default "2" 514 depends on NUMA 515 help 516 Specify the maximum number of NUMA Nodes available on the target 517 system. Increases memory reserved to accommodate various tables. 518 519choice 520 prompt "RISC-V spinlock type" 521 default RISCV_COMBO_SPINLOCKS 522 523config RISCV_TICKET_SPINLOCKS 524 bool "Using ticket spinlock" 525 526config RISCV_QUEUED_SPINLOCKS 527 bool "Using queued spinlock" 528 depends on SMP && MMU && NONPORTABLE 529 select ARCH_USE_QUEUED_SPINLOCKS 530 help 531 The queued spinlock implementation requires the forward progress 532 guarantee of cmpxchg()/xchg() atomic operations: CAS with Zabha or 533 LR/SC with Ziccrse provide such guarantee. 534 535 Select this if and only if Zabha or Ziccrse is available on your 536 platform, RISCV_QUEUED_SPINLOCKS must not be selected for platforms 537 without one of those extensions. 538 539 If unsure, select RISCV_COMBO_SPINLOCKS, which will use qspinlocks 540 when supported and otherwise ticket spinlocks. 541 542config RISCV_COMBO_SPINLOCKS 543 bool "Using combo spinlock" 544 depends on SMP && MMU 545 select ARCH_USE_QUEUED_SPINLOCKS 546 help 547 Embed both queued spinlock and ticket lock so that the spinlock 548 implementation can be chosen at runtime. 549 550endchoice 551 552config RISCV_ALTERNATIVE 553 bool 554 depends on !XIP_KERNEL 555 help 556 This Kconfig allows the kernel to automatically patch the 557 erratum or cpufeature required by the execution platform at run 558 time. The code patching overhead is minimal, as it's only done 559 once at boot and once on each module load. 560 561config RISCV_ALTERNATIVE_EARLY 562 bool 563 depends on RISCV_ALTERNATIVE 564 help 565 Allows early patching of the kernel for special errata 566 567config RISCV_ISA_C 568 bool "Emit compressed instructions when building Linux" 569 default y 570 help 571 Adds "C" to the ISA subsets that the toolchain is allowed to emit 572 when building Linux, which results in compressed instructions in the 573 Linux binary. This option produces a kernel that will not run on 574 systems that do not support compressed instructions. 575 576 If you don't know what to do here, say Y. 577 578config RISCV_ISA_SUPM 579 bool "Supm extension for userspace pointer masking" 580 depends on 64BIT 581 default y 582 help 583 Add support for pointer masking in userspace (Supm) when the 584 underlying hardware extension (Smnpm or Ssnpm) is detected at boot. 585 586 If this option is disabled, userspace will be unable to use 587 the prctl(PR_{SET,GET}_TAGGED_ADDR_CTRL) API. 588 589config RISCV_ISA_SVNAPOT 590 bool "Svnapot extension support for supervisor mode NAPOT pages" 591 depends on 64BIT && MMU 592 depends on RISCV_ALTERNATIVE 593 default y 594 help 595 Enable support for the Svnapot ISA-extension when it is detected 596 at boot. 597 598 The Svnapot extension is used to mark contiguous PTEs as a range 599 of contiguous virtual-to-physical translations for a naturally 600 aligned power-of-2 (NAPOT) granularity larger than the base 4KB page 601 size. When HUGETLBFS is also selected this option unconditionally 602 allocates some memory for each NAPOT page size supported by the kernel. 603 When optimizing for low memory consumption and for platforms without 604 the Svnapot extension, it may be better to say N here. 605 606 If you don't know what to do here, say Y. 607 608config RISCV_ISA_SVPBMT 609 bool "Svpbmt extension support for supervisor mode page-based memory types" 610 depends on 64BIT && MMU 611 depends on RISCV_ALTERNATIVE 612 default y 613 help 614 Add support for the Svpbmt ISA-extension (Supervisor-mode: 615 page-based memory types) in the kernel when it is detected at boot. 616 617 The memory type for a page contains a combination of attributes 618 that indicate the cacheability, idempotency, and ordering 619 properties for access to that page. 620 621 The Svpbmt extension is only available on 64-bit cpus. 622 623 If you don't know what to do here, say Y. 624 625config TOOLCHAIN_HAS_V 626 bool 627 default y 628 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64imv) 629 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32imv) 630 depends on LLD_VERSION >= 140000 || LD_VERSION >= 23800 631 depends on AS_HAS_OPTION_ARCH 632 633config RISCV_ISA_V 634 bool "Vector extension support" 635 depends on TOOLCHAIN_HAS_V 636 depends on FPU 637 select DYNAMIC_SIGFRAME 638 default y 639 help 640 Add support for the Vector extension when it is detected at boot. 641 When this option is disabled, neither the kernel nor userspace may 642 use vector procedures. 643 644 If you don't know what to do here, say Y. 645 646config RISCV_ISA_V_DEFAULT_ENABLE 647 bool "Enable userspace Vector by default" 648 depends on RISCV_ISA_V 649 default y 650 help 651 Say Y here if you want to enable Vector in userspace by default. 652 Otherwise, userspace has to make explicit prctl() call to enable 653 Vector, or enable it via the sysctl interface. 654 655 If you don't know what to do here, say Y. 656 657config RISCV_ISA_V_UCOPY_THRESHOLD 658 int "Threshold size for vectorized user copies" 659 depends on RISCV_ISA_V 660 default 768 661 help 662 Prefer using vectorized copy_to_user()/copy_from_user() when the 663 workload size exceeds this value. 664 665config RISCV_ISA_V_PREEMPTIVE 666 bool "Run kernel-mode Vector with kernel preemption" 667 depends on PREEMPTION 668 depends on RISCV_ISA_V 669 default y 670 help 671 Usually, in-kernel SIMD routines are run with preemption disabled. 672 Functions which invoke long running SIMD thus must yield the core's 673 vector unit to prevent blocking other tasks for too long. 674 675 This config allows the kernel to run SIMD without explicitly disabling 676 preemption. Enabling this config will result in higher memory consumption 677 due to the allocation of per-task's kernel Vector context. 678 679config RISCV_ISA_ZAWRS 680 bool "Zawrs extension support for more efficient busy waiting" 681 depends on RISCV_ALTERNATIVE 682 default y 683 help 684 The Zawrs extension defines instructions to be used in polling loops 685 which allow a hart to enter a low-power state or to trap to the 686 hypervisor while waiting on a store to a memory location. Enable the 687 use of these instructions in the kernel when the Zawrs extension is 688 detected at boot. 689 690config TOOLCHAIN_HAS_ZABHA 691 bool 692 default y 693 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zabha) 694 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zabha) 695 depends on AS_HAS_OPTION_ARCH 696 697config RISCV_ISA_ZABHA 698 bool "Zabha extension support for atomic byte/halfword operations" 699 depends on TOOLCHAIN_HAS_ZABHA 700 depends on RISCV_ALTERNATIVE 701 default y 702 help 703 Enable the use of the Zabha ISA-extension to implement kernel 704 byte/halfword atomic memory operations when it is detected at boot. 705 706 If you don't know what to do here, say Y. 707 708config TOOLCHAIN_HAS_ZACAS 709 bool 710 default y 711 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zacas) 712 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zacas) 713 depends on AS_HAS_OPTION_ARCH 714 715config RISCV_ISA_ZACAS 716 bool "Zacas extension support for atomic CAS" 717 depends on RISCV_ALTERNATIVE 718 default y 719 help 720 Enable the use of the Zacas ISA-extension to implement kernel atomic 721 cmpxchg operations when it is detected at boot. 722 723 If you don't know what to do here, say Y. 724 725config TOOLCHAIN_HAS_ZBB 726 bool 727 default y 728 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbb) 729 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbb) 730 depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900 731 depends on AS_HAS_OPTION_ARCH 732 733# This symbol indicates that the toolchain supports all v1.0 vector crypto 734# extensions, including Zvk*, Zvbb, and Zvbc. LLVM added all of these at once. 735# binutils added all except Zvkb, then added Zvkb. So we just check for Zvkb. 736config TOOLCHAIN_HAS_VECTOR_CRYPTO 737 def_bool $(as-instr, .option arch$(comma) +v$(comma) +zvkb) 738 depends on AS_HAS_OPTION_ARCH 739 740config TOOLCHAIN_HAS_ZBA 741 bool 742 default y 743 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zba) 744 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zba) 745 depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900 746 depends on AS_HAS_OPTION_ARCH 747 748config RISCV_ISA_ZBA 749 bool "Zba extension support for bit manipulation instructions" 750 default y 751 help 752 Add support for enabling optimisations in the kernel when the Zba 753 extension is detected at boot. 754 755 The Zba extension provides instructions to accelerate the generation 756 of addresses that index into arrays of basic data types. 757 758 If you don't know what to do here, say Y. 759 760config RISCV_ISA_ZBB 761 bool "Zbb extension support for bit manipulation instructions" 762 depends on RISCV_ALTERNATIVE 763 default y 764 help 765 Add support for enabling optimisations in the kernel when the 766 Zbb extension is detected at boot. Some optimisations may 767 additionally depend on toolchain support for Zbb. 768 769 The Zbb extension provides instructions to accelerate a number 770 of bit-specific operations (count bit population, sign extending, 771 bitrotation, etc). 772 773 If you don't know what to do here, say Y. 774 775config TOOLCHAIN_HAS_ZBC 776 bool 777 default y 778 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbc) 779 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbc) 780 depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900 781 depends on AS_HAS_OPTION_ARCH 782 783config RISCV_ISA_ZBC 784 bool "Zbc extension support for carry-less multiplication instructions" 785 depends on TOOLCHAIN_HAS_ZBC 786 depends on MMU 787 depends on RISCV_ALTERNATIVE 788 default y 789 help 790 Adds support to dynamically detect the presence of the Zbc 791 extension (carry-less multiplication) and enable its usage. 792 793 The Zbc extension could accelerate CRC (cyclic redundancy check) 794 calculations. 795 796 If you don't know what to do here, say Y. 797 798config TOOLCHAIN_HAS_ZBKB 799 bool 800 default y 801 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbkb) 802 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbkb) 803 depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900 804 depends on AS_HAS_OPTION_ARCH 805 806config RISCV_ISA_ZBKB 807 bool "Zbkb extension support for bit manipulation instructions" 808 depends on TOOLCHAIN_HAS_ZBKB 809 depends on RISCV_ALTERNATIVE 810 default y 811 help 812 Adds support to dynamically detect the presence of the ZBKB 813 extension (bit manipulation for cryptography) and enable its usage. 814 815 The Zbkb extension provides instructions to accelerate a number 816 of common cryptography operations (pack, zip, etc). 817 818 If you don't know what to do here, say Y. 819 820config RISCV_ISA_ZICBOM 821 bool "Zicbom extension support for non-coherent DMA operation" 822 depends on MMU 823 depends on RISCV_ALTERNATIVE 824 default y 825 select RISCV_DMA_NONCOHERENT 826 select DMA_DIRECT_REMAP 827 help 828 Add support for the Zicbom extension (Cache Block Management 829 Operations) and enable its use in the kernel when it is detected 830 at boot. 831 832 The Zicbom extension can be used to handle for example 833 non-coherent DMA support on devices that need it. 834 835 If you don't know what to do here, say Y. 836 837config RISCV_ISA_ZICBOZ 838 bool "Zicboz extension support for faster zeroing of memory" 839 depends on RISCV_ALTERNATIVE 840 default y 841 help 842 Enable the use of the Zicboz extension (cbo.zero instruction) 843 in the kernel when it is detected at boot. 844 845 The Zicboz extension is used for faster zeroing of memory. 846 847 If you don't know what to do here, say Y. 848 849config RISCV_ISA_ZICBOP 850 bool "Zicbop extension support for cache block prefetch" 851 depends on MMU 852 depends on RISCV_ALTERNATIVE 853 default y 854 help 855 Adds support to dynamically detect the presence of the ZICBOP 856 extension (Cache Block Prefetch Operations) and enable its 857 usage. 858 859 The Zicbop extension can be used to prefetch cache blocks for 860 read/write fetch. 861 862 If you don't know what to do here, say Y. 863 864config TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI 865 def_bool y 866 # https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=aed44286efa8ae8717a77d94b51ac3614e2ca6dc 867 # https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=98416dbb0a62579d4a7a4a76bab51b5b52fec2cd 868 depends on AS_IS_GNU && AS_VERSION >= 23600 869 help 870 Binutils-2.38 and GCC-12.1.0 bumped the default ISA spec to the newer 871 20191213 version, which moves some instructions from the I extension to 872 the Zicsr and Zifencei extensions. This requires explicitly specifying 873 Zicsr and Zifencei when binutils >= 2.38 or GCC >= 12.1.0. Zicsr 874 and Zifencei are supported in binutils from version 2.36 onwards. 875 To make life easier, and avoid forcing toolchains that default to a 876 newer ISA spec to version 2.2, relax the check to binutils >= 2.36. 877 For clang < 17 or GCC < 11.3.0, for which this is not possible or need 878 special treatment, this is dealt with in TOOLCHAIN_NEEDS_OLD_ISA_SPEC. 879 880config TOOLCHAIN_NEEDS_OLD_ISA_SPEC 881 def_bool y 882 depends on TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI 883 # https://github.com/llvm/llvm-project/commit/22e199e6afb1263c943c0c0d4498694e15bf8a16 884 # https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=d29f5d6ab513c52fd872f532c492e35ae9fd6671 885 depends on (CC_IS_CLANG && CLANG_VERSION < 170000) || (CC_IS_GCC && GCC_VERSION < 110300) 886 help 887 Certain versions of clang and GCC do not support zicsr and zifencei via 888 -march. This option causes an older ISA spec compatible with these older 889 versions of clang and GCC to be passed to GAS, which has the same result 890 as passing zicsr and zifencei to -march. 891 892config FPU 893 bool "FPU support" 894 default y 895 help 896 Add support for floating point operations when an FPU is detected at 897 boot. When this option is disabled, neither the kernel nor userspace 898 may use the floating point unit. 899 900 If you don't know what to do here, say Y. 901 902config IRQ_STACKS 903 bool "Independent irq & softirq stacks" if EXPERT 904 default y 905 select HAVE_IRQ_EXIT_ON_IRQ_STACK 906 select HAVE_SOFTIRQ_ON_OWN_STACK 907 help 908 Add independent irq & softirq stacks for percpu to prevent kernel stack 909 overflows. We may save some memory footprint by disabling IRQ_STACKS. 910 911config THREAD_SIZE_ORDER 912 int "Kernel stack size (in power-of-two numbers of page size)" if VMAP_STACK && EXPERT 913 range 0 4 914 default 1 if 32BIT 915 default 2 916 help 917 Specify the Pages of thread stack size (from 4KB to 64KB), which also 918 affects irq stack size, which is equal to thread stack size. 919 920config RISCV_MISALIGNED 921 bool 922 help 923 Embed support for detecting and emulating misaligned 924 scalar or vector loads and stores. 925 926config RISCV_SCALAR_MISALIGNED 927 bool 928 select RISCV_MISALIGNED 929 select SYSCTL_ARCH_UNALIGN_ALLOW 930 help 931 Embed support for emulating misaligned loads and stores. 932 933config RISCV_VECTOR_MISALIGNED 934 bool 935 select RISCV_MISALIGNED 936 depends on RISCV_ISA_V 937 help 938 Enable detecting support for vector misaligned loads and stores. 939 940choice 941 prompt "Unaligned Accesses Support" 942 default RISCV_PROBE_UNALIGNED_ACCESS 943 help 944 This determines the level of support for unaligned accesses. This 945 information is used by the kernel to perform optimizations. It is also 946 exposed to user space via the hwprobe syscall. The hardware will be 947 probed at boot by default. 948 949config RISCV_PROBE_UNALIGNED_ACCESS 950 bool "Probe for hardware unaligned access support" 951 select RISCV_SCALAR_MISALIGNED 952 help 953 During boot, the kernel will run a series of tests to determine the 954 speed of unaligned accesses. This probing will dynamically determine 955 the speed of unaligned accesses on the underlying system. If unaligned 956 memory accesses trap into the kernel as they are not supported by the 957 system, the kernel will emulate the unaligned accesses to preserve the 958 UABI. 959 960config RISCV_EMULATED_UNALIGNED_ACCESS 961 bool "Emulate unaligned access where system support is missing" 962 select RISCV_SCALAR_MISALIGNED 963 help 964 If unaligned memory accesses trap into the kernel as they are not 965 supported by the system, the kernel will emulate the unaligned 966 accesses to preserve the UABI. When the underlying system does support 967 unaligned accesses, the unaligned accesses are assumed to be slow. 968 969config RISCV_SLOW_UNALIGNED_ACCESS 970 bool "Assume the system supports slow unaligned memory accesses" 971 depends on NONPORTABLE 972 help 973 Assume that the system supports slow unaligned memory accesses. The 974 kernel and userspace programs may not be able to run at all on systems 975 that do not support unaligned memory accesses. 976 977config RISCV_EFFICIENT_UNALIGNED_ACCESS 978 bool "Assume the system supports fast unaligned memory accesses" 979 depends on NONPORTABLE 980 select DCACHE_WORD_ACCESS if MMU 981 select HAVE_EFFICIENT_UNALIGNED_ACCESS 982 help 983 Assume that the system supports fast unaligned memory accesses. When 984 enabled, this option improves the performance of the kernel on such 985 systems. However, the kernel and userspace programs will run much more 986 slowly, or will not be able to run at all, on systems that do not 987 support efficient unaligned memory accesses. 988 989endchoice 990 991choice 992 prompt "Vector unaligned Accesses Support" 993 depends on RISCV_ISA_V 994 default RISCV_PROBE_VECTOR_UNALIGNED_ACCESS 995 help 996 This determines the level of support for vector unaligned accesses. This 997 information is used by the kernel to perform optimizations. It is also 998 exposed to user space via the hwprobe syscall. The hardware will be 999 probed at boot by default. 1000 1001config RISCV_PROBE_VECTOR_UNALIGNED_ACCESS 1002 bool "Probe speed of vector unaligned accesses" 1003 select RISCV_VECTOR_MISALIGNED 1004 depends on RISCV_ISA_V 1005 help 1006 During boot, the kernel will run a series of tests to determine the 1007 speed of vector unaligned accesses if they are supported. This probing 1008 will dynamically determine the speed of vector unaligned accesses on 1009 the underlying system if they are supported. 1010 1011config RISCV_SLOW_VECTOR_UNALIGNED_ACCESS 1012 bool "Assume the system supports slow vector unaligned memory accesses" 1013 depends on NONPORTABLE 1014 help 1015 Assume that the system supports slow vector unaligned memory accesses. The 1016 kernel and userspace programs may not be able to run at all on systems 1017 that do not support unaligned memory accesses. 1018 1019config RISCV_EFFICIENT_VECTOR_UNALIGNED_ACCESS 1020 bool "Assume the system supports fast vector unaligned memory accesses" 1021 depends on NONPORTABLE 1022 help 1023 Assume that the system supports fast vector unaligned memory accesses. When 1024 enabled, this option improves the performance of the kernel on such 1025 systems. However, the kernel and userspace programs will run much more 1026 slowly, or will not be able to run at all, on systems that do not 1027 support efficient unaligned memory accesses. 1028 1029endchoice 1030 1031source "arch/riscv/Kconfig.vendor" 1032 1033endmenu # "Platform type" 1034 1035menu "Kernel features" 1036 1037source "kernel/Kconfig.hz" 1038 1039config RISCV_SBI_V01 1040 bool "SBI v0.1 support" 1041 depends on RISCV_SBI 1042 help 1043 This config allows kernel to use SBI v0.1 APIs. This will be 1044 deprecated in future once legacy M-mode software are no longer in use. 1045 1046config RISCV_BOOT_SPINWAIT 1047 bool "Spinwait booting method" 1048 depends on SMP 1049 default y if RISCV_SBI_V01 || RISCV_M_MODE 1050 help 1051 This enables support for booting Linux via spinwait method. In the 1052 spinwait method, all cores randomly jump to Linux. One of the cores 1053 gets chosen via lottery and all other keep spinning on a percpu 1054 variable. This method cannot support CPU hotplug and sparse hartid 1055 scheme. It should be only enabled for M-mode Linux or platforms relying 1056 on older firmware without SBI HSM extension. All other platforms should 1057 rely on ordered booting via SBI HSM extension which gets chosen 1058 dynamically at runtime if the firmware supports it. 1059 1060 Since spinwait is incompatible with sparse hart IDs, it requires 1061 NR_CPUS be large enough to contain the physical hart ID of the first 1062 hart to enter Linux. 1063 1064 If unsure what to do here, say N. 1065 1066config ARCH_SUPPORTS_KEXEC 1067 def_bool y 1068 1069config ARCH_SELECTS_KEXEC 1070 def_bool y 1071 depends on KEXEC 1072 select HOTPLUG_CPU if SMP 1073 1074config ARCH_SUPPORTS_KEXEC_FILE 1075 def_bool 64BIT 1076 1077config ARCH_SELECTS_KEXEC_FILE 1078 def_bool y 1079 depends on KEXEC_FILE 1080 select HAVE_IMA_KEXEC if IMA 1081 select KEXEC_ELF 1082 1083config ARCH_SUPPORTS_KEXEC_PURGATORY 1084 def_bool ARCH_SUPPORTS_KEXEC_FILE 1085 1086config ARCH_SUPPORTS_CRASH_DUMP 1087 def_bool y 1088 1089config ARCH_DEFAULT_CRASH_DUMP 1090 def_bool y 1091 1092config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION 1093 def_bool CRASH_RESERVE 1094 1095config COMPAT 1096 bool "Kernel support for 32-bit U-mode" 1097 default 64BIT 1098 depends on 64BIT && MMU 1099 help 1100 This option enables support for a 32-bit U-mode running under a 64-bit 1101 kernel at S-mode. riscv32-specific components such as system calls, 1102 the user helper functions (vdso), signal rt_frame functions and the 1103 ptrace interface are handled appropriately by the kernel. 1104 1105 If you want to execute 32-bit userspace applications, say Y. 1106 1107config PARAVIRT 1108 bool "Enable paravirtualization code" 1109 depends on RISCV_SBI 1110 help 1111 This changes the kernel so it can modify itself when it is run 1112 under a hypervisor, potentially improving performance significantly 1113 over full virtualization. 1114 1115config PARAVIRT_TIME_ACCOUNTING 1116 bool "Paravirtual steal time accounting" 1117 depends on PARAVIRT 1118 help 1119 Select this option to enable fine granularity task steal time 1120 accounting. Time spent executing other tasks in parallel with 1121 the current vCPU is discounted from the vCPU power. To account for 1122 that, there can be a small performance impact. 1123 1124 If in doubt, say N here. 1125 1126config RELOCATABLE 1127 bool "Build a relocatable kernel" 1128 depends on !XIP_KERNEL 1129 select MODULE_SECTIONS if MODULES 1130 select ARCH_VMLINUX_NEEDS_RELOCS 1131 help 1132 This builds a kernel as a Position Independent Executable (PIE), 1133 which retains all relocation metadata required to relocate the 1134 kernel binary at runtime to a different virtual address than the 1135 address it was linked at. 1136 Since RISCV uses the RELA relocation format, this requires a 1137 relocation pass at runtime even if the kernel is loaded at the 1138 same address it was linked at. 1139 1140 If unsure, say N. 1141 1142config RANDOMIZE_BASE 1143 bool "Randomize the address of the kernel image" 1144 select RELOCATABLE 1145 depends on MMU && 64BIT && !XIP_KERNEL 1146 help 1147 Randomizes the virtual address at which the kernel image is 1148 loaded, as a security feature that deters exploit attempts 1149 relying on knowledge of the location of kernel internals. 1150 1151 It is the bootloader's job to provide entropy, by passing a 1152 random u64 value in /chosen/kaslr-seed at kernel entry. 1153 1154 When booting via the UEFI stub, it will invoke the firmware's 1155 EFI_RNG_PROTOCOL implementation (if available) to supply entropy 1156 to the kernel proper. In addition, it will randomise the physical 1157 location of the kernel Image as well. 1158 1159 If unsure, say N. 1160 1161endmenu # "Kernel features" 1162 1163menu "Boot options" 1164 1165config CMDLINE 1166 string "Built-in kernel command line" 1167 help 1168 For most platforms, the arguments for the kernel's command line 1169 are provided at run-time, during boot. However, there are cases 1170 where either no arguments are being provided or the provided 1171 arguments are insufficient or even invalid. 1172 1173 When that occurs, it is possible to define a built-in command 1174 line here and choose how the kernel should use it later on. 1175 1176choice 1177 prompt "Built-in command line usage" 1178 depends on CMDLINE != "" 1179 default CMDLINE_FALLBACK 1180 help 1181 Choose how the kernel will handle the provided built-in command 1182 line. 1183 1184config CMDLINE_FALLBACK 1185 bool "Use bootloader kernel arguments if available" 1186 help 1187 Use the built-in command line as fallback in case we get nothing 1188 during boot. This is the default behaviour. 1189 1190config CMDLINE_EXTEND 1191 bool "Extend bootloader kernel arguments" 1192 help 1193 The built-in command line will be appended to the command- 1194 line arguments provided during boot. This is useful in 1195 cases where the provided arguments are insufficient and 1196 you don't want to or cannot modify them. 1197 1198config CMDLINE_FORCE 1199 bool "Always use the default kernel command string" 1200 help 1201 Always use the built-in command line, even if we get one during 1202 boot. This is useful in case you need to override the provided 1203 command line on systems where you don't have or want control 1204 over it. 1205 1206endchoice 1207 1208config EFI_STUB 1209 bool 1210 1211config EFI 1212 bool "UEFI runtime support" 1213 depends on OF && !XIP_KERNEL 1214 depends on MMU 1215 default y 1216 select ARCH_SUPPORTS_ACPI if 64BIT 1217 select EFI_GENERIC_STUB 1218 select EFI_PARAMS_FROM_FDT 1219 select EFI_RUNTIME_WRAPPERS 1220 select EFI_STUB 1221 select LIBFDT 1222 select RISCV_ISA_C 1223 select UCS2_STRING 1224 help 1225 This option provides support for runtime services provided 1226 by UEFI firmware (such as non-volatile variables, realtime 1227 clock, and platform reset). A UEFI stub is also provided to 1228 allow the kernel to be booted as an EFI application. This 1229 is only useful on systems that have UEFI firmware. 1230 1231config DMI 1232 bool "Enable support for SMBIOS (DMI) tables" 1233 depends on EFI 1234 default y 1235 help 1236 This enables SMBIOS/DMI feature for systems. 1237 1238 This option is only useful on systems that have UEFI firmware. 1239 However, even with this option, the resultant kernel should 1240 continue to boot on existing non-UEFI platforms. 1241 1242config CC_HAVE_STACKPROTECTOR_TLS 1243 def_bool $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=tp -mstack-protector-guard-offset=0) 1244 1245config STACKPROTECTOR_PER_TASK 1246 def_bool y 1247 depends on !RANDSTRUCT 1248 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_TLS 1249 1250config PHYS_RAM_BASE_FIXED 1251 bool "Explicitly specified physical RAM address" 1252 depends on NONPORTABLE 1253 default n 1254 1255config PHYS_RAM_BASE 1256 hex "Platform Physical RAM address" 1257 depends on PHYS_RAM_BASE_FIXED 1258 default "0x80000000" 1259 help 1260 This is the physical address of RAM in the system. It has to be 1261 explicitly specified to run early relocations of read-write data 1262 from flash to RAM. 1263 1264config XIP_KERNEL 1265 bool "Kernel Execute-In-Place from ROM" 1266 depends on MMU && SPARSEMEM && NONPORTABLE 1267 # This prevents XIP from being enabled by all{yes,mod}config, which 1268 # fail to build since XIP doesn't support large kernels. 1269 depends on !COMPILE_TEST 1270 select PHYS_RAM_BASE_FIXED 1271 help 1272 Execute-In-Place allows the kernel to run from non-volatile storage 1273 directly addressable by the CPU, such as NOR flash. This saves RAM 1274 space since the text section of the kernel is not loaded from flash 1275 to RAM. Read-write sections, such as the data section and stack, 1276 are still copied to RAM. The XIP kernel is not compressed since 1277 it has to run directly from flash, so it will take more space to 1278 store it. The flash address used to link the kernel object files, 1279 and for storing it, is configuration dependent. Therefore, if you 1280 say Y here, you must know the proper physical address where to 1281 store the kernel image depending on your own flash memory usage. 1282 1283 Also note that the make target becomes "make xipImage" rather than 1284 "make zImage" or "make Image". The final kernel binary to put in 1285 ROM memory will be arch/riscv/boot/xipImage. 1286 1287 SPARSEMEM is required because the kernel text and rodata that are 1288 flash resident are not backed by memmap, then any attempt to get 1289 a struct page on those regions will trigger a fault. 1290 1291 If unsure, say N. 1292 1293config XIP_PHYS_ADDR 1294 hex "XIP Kernel Physical Location" 1295 depends on XIP_KERNEL 1296 default "0x21000000" 1297 help 1298 This is the physical address in your flash memory the kernel will 1299 be linked for and stored to. This address is dependent on your 1300 own flash usage. 1301 1302config RISCV_ISA_FALLBACK 1303 bool "Permit falling back to parsing riscv,isa for extension support by default" 1304 default y 1305 help 1306 Parsing the "riscv,isa" devicetree property has been deprecated and 1307 replaced by a list of explicitly defined strings. For compatibility 1308 with existing platforms, the kernel will fall back to parsing the 1309 "riscv,isa" property if the replacements are not found. 1310 1311 Selecting N here will result in a kernel that does not use the 1312 fallback, unless the commandline "riscv_isa_fallback" parameter is 1313 present. 1314 1315 Please see the dt-binding, located at 1316 Documentation/devicetree/bindings/riscv/extensions.yaml for details 1317 on the replacement properties, "riscv,isa-base" and 1318 "riscv,isa-extensions". 1319 1320config BUILTIN_DTB 1321 bool "Built-in device tree" 1322 depends on OF && NONPORTABLE 1323 select GENERIC_BUILTIN_DTB 1324 help 1325 Build a device tree into the Linux image. 1326 This option should be selected if no bootloader is being used. 1327 If unsure, say N. 1328 1329 1330config BUILTIN_DTB_NAME 1331 string "Built-in device tree source" 1332 depends on BUILTIN_DTB 1333 help 1334 DTS file path (without suffix, relative to arch/riscv/boot/dts) 1335 for the DTS file that will be used to produce the DTB linked into the 1336 kernel. 1337 1338endmenu # "Boot options" 1339 1340config PORTABLE 1341 bool 1342 default !NONPORTABLE 1343 select EFI 1344 select MMU 1345 select OF 1346 1347config ARCH_PROC_KCORE_TEXT 1348 def_bool y 1349 1350menu "Power management options" 1351 1352source "kernel/power/Kconfig" 1353 1354config ARCH_HIBERNATION_POSSIBLE 1355 def_bool y 1356 1357config ARCH_HIBERNATION_HEADER 1358 def_bool HIBERNATION 1359 1360config ARCH_SUSPEND_POSSIBLE 1361 def_bool y 1362 1363endmenu # "Power management options" 1364 1365menu "CPU Power Management" 1366 1367source "drivers/cpuidle/Kconfig" 1368 1369source "drivers/cpufreq/Kconfig" 1370 1371endmenu # "CPU Power Management" 1372 1373source "arch/riscv/kvm/Kconfig" 1374 1375source "drivers/acpi/Kconfig" 1376