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_RIMT if ACPI 20 select ACPI_SPCR_TABLE if ACPI 21 select ARCH_DMA_DEFAULT_COHERENT 22 select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION 23 select ARCH_ENABLE_MEMORY_HOTPLUG if SPARSEMEM_VMEMMAP 24 select ARCH_ENABLE_MEMORY_HOTREMOVE if MEMORY_HOTPLUG 25 select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2 26 select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE 27 select ARCH_HAS_BINFMT_FLAT 28 select ARCH_HAS_CURRENT_STACK_POINTER 29 select ARCH_HAS_DEBUG_VIRTUAL if MMU 30 select ARCH_HAS_DEBUG_VM_PGTABLE 31 select ARCH_HAS_DEBUG_WX 32 select ARCH_HAS_ELF_CORE_EFLAGS 33 select ARCH_HAS_FAST_MULTIPLIER 34 select ARCH_HAS_FORTIFY_SOURCE 35 select ARCH_HAS_GCOV_PROFILE_ALL 36 select ARCH_HAS_GIGANTIC_PAGE 37 select ARCH_HAS_HW_PTE_YOUNG 38 select ARCH_HAS_KCOV 39 select ARCH_HAS_KERNEL_FPU_SUPPORT if 64BIT && FPU 40 select ARCH_HAS_MEMBARRIER_CALLBACKS 41 select ARCH_HAS_MEMBARRIER_SYNC_CORE 42 select ARCH_HAS_MMIOWB 43 select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 44 select ARCH_HAS_PMEM_API 45 select ARCH_HAS_PREEMPT_LAZY 46 select ARCH_HAS_PREPARE_SYNC_CORE_CMD 47 select ARCH_HAS_PTDUMP if MMU 48 select ARCH_HAS_PTE_SPECIAL 49 select ARCH_HAS_SET_DIRECT_MAP if MMU 50 select ARCH_HAS_SET_MEMORY if MMU 51 select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL 52 select ARCH_HAS_STRICT_MODULE_RWX if MMU && !XIP_KERNEL 53 select ARCH_HAS_SYNC_CORE_BEFORE_USERMODE 54 select ARCH_HAS_SYSCALL_WRAPPER 55 select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST 56 select ARCH_HAS_UBSAN 57 select ARCH_HAS_VDSO_ARCH_DATA if HAVE_GENERIC_VDSO 58 select ARCH_HAVE_NMI_SAFE_CMPXCHG 59 select ARCH_KEEP_MEMBLOCK if ACPI 60 select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE if 64BIT && MMU 61 select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX 62 select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT 63 select ARCH_STACKWALK 64 select ARCH_SUPPORTS_ATOMIC_RMW 65 # clang >= 17: https://github.com/llvm/llvm-project/commit/62fa708ceb027713b386c7e0efda994f8bdc27e2 66 select ARCH_SUPPORTS_CFI if (!CC_IS_CLANG || CLANG_VERSION >= 170000) 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 select ARCH_SUPPORTS_LTO_CLANG if CMODEL_MEDANY 71 select ARCH_SUPPORTS_LTO_CLANG_THIN 72 select ARCH_SUPPORTS_MSEAL_SYSTEM_MAPPINGS if 64BIT && MMU 73 select ARCH_SUPPORTS_PAGE_TABLE_CHECK if MMU 74 select ARCH_SUPPORTS_PER_VMA_LOCK if MMU 75 select ARCH_SUPPORTS_RT 76 select ARCH_SUPPORTS_SHADOW_CALL_STACK if HAVE_SHADOW_CALL_STACK 77 select ARCH_SUPPORTS_SCHED_MC if SMP 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 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_NO_EFFICIENT_FFS if !RISCV_ISA_ZBB 100 select CPU_PM if CPU_IDLE || HIBERNATION || SUSPEND 101 select DYNAMIC_FTRACE if FUNCTION_TRACER 102 select EDAC_SUPPORT 103 select FRAME_POINTER if PERF_EVENTS || (FUNCTION_TRACER && !DYNAMIC_FTRACE) 104 select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY if DYNAMIC_FTRACE 105 select FUNCTION_ALIGNMENT_8B if DYNAMIC_FTRACE_WITH_CALL_OPS 106 select GENERIC_ARCH_TOPOLOGY 107 select GENERIC_ATOMIC64 if !64BIT 108 select GENERIC_CLOCKEVENTS_BROADCAST if SMP 109 select GENERIC_CPU_DEVICES 110 select GENERIC_CPU_VULNERABILITIES 111 select GENERIC_EARLY_IOREMAP 112 select GENERIC_ENTRY 113 select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO && 64BIT 114 select GENERIC_IDLE_POLL_SETUP 115 select GENERIC_IOREMAP if MMU 116 select GENERIC_IRQ_IPI if SMP 117 select GENERIC_IRQ_IPI_MUX if SMP 118 select GENERIC_IRQ_MULTI_HANDLER 119 select GENERIC_IRQ_SHOW 120 select GENERIC_IRQ_SHOW_LEVEL 121 select GENERIC_LIB_DEVMEM_IS_ALLOWED 122 select GENERIC_PENDING_IRQ if SMP 123 select GENERIC_PCI_IOMAP 124 select GENERIC_SCHED_CLOCK 125 select GENERIC_SMP_IDLE_THREAD 126 select GENERIC_TIME_VSYSCALL if GENERIC_GETTIMEOFDAY 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_KSTACK_ERASE 139 select HAVE_ARCH_KGDB if !XIP_KERNEL 140 select HAVE_ARCH_KGDB_QXFER_PKT 141 select HAVE_ARCH_MMAP_RND_BITS if MMU 142 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT 143 select HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET 144 select HAVE_ARCH_SECCOMP_FILTER 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) 159 select HAVE_DYNAMIC_FTRACE_WITH_ARGS if HAVE_DYNAMIC_FTRACE 160 select HAVE_FTRACE_GRAPH_FUNC 161 select HAVE_FUNCTION_GRAPH_TRACER if HAVE_DYNAMIC_FTRACE_WITH_ARGS 162 select HAVE_FUNCTION_GRAPH_FREGS 163 select HAVE_FUNCTION_TRACER if !XIP_KERNEL && HAVE_DYNAMIC_FTRACE 164 select HAVE_EBPF_JIT if MMU 165 select HAVE_GENERIC_TIF_BITS 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 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 && 64BIT 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) 251 252# https://github.com/llvm/llvm-project/commit/bbc0f99f3bc96f1db16f649fc21dd18e5b0918f6 253config ARCH_HAS_BROKEN_DWARF5 254 def_bool y 255 # https://github.com/llvm/llvm-project/commit/1df5ea29b43690b6622db2cad7b745607ca4de6a 256 depends on AS_IS_LLVM && AS_VERSION < 180000 257 # https://github.com/llvm/llvm-project/commit/7ffabb61a5569444b5ac9322e22e5471cc5e4a77 258 depends on LD_IS_LLD && LLD_VERSION < 180000 259 260config ARCH_MMAP_RND_BITS_MIN 261 default 18 if 64BIT 262 default 8 263 264config ARCH_MMAP_RND_COMPAT_BITS_MIN 265 default 8 266 267# max bits determined by the following formula: 268# VA_BITS - PAGE_SHIFT - 3 269config ARCH_MMAP_RND_BITS_MAX 270 default 24 if 64BIT # SV39 based 271 default 17 272 273config ARCH_MMAP_RND_COMPAT_BITS_MAX 274 default 17 275 276# set if we run in machine mode, cleared if we run in supervisor mode 277config RISCV_M_MODE 278 bool "Build a kernel that runs in machine mode" 279 depends on !MMU 280 default y 281 help 282 Select this option if you want to run the kernel in M-mode, 283 without the assistance of any other firmware. 284 285# set if we are running in S-mode and can use SBI calls 286config RISCV_SBI 287 bool 288 depends on !RISCV_M_MODE 289 default y 290 291config MMU 292 bool "MMU-based Paged Memory Management Support" 293 default y 294 help 295 Select if you want MMU-based virtualised addressing space 296 support by paged memory management. If unsure, say 'Y'. 297 298config KASAN_SHADOW_OFFSET 299 hex 300 depends on KASAN_GENERIC 301 default 0xdfffffff00000000 if 64BIT 302 default 0xffffffff if 32BIT 303 304config ARCH_FLATMEM_ENABLE 305 def_bool !NUMA 306 307config ARCH_SPARSEMEM_ENABLE 308 def_bool y 309 depends on MMU 310 select SPARSEMEM_STATIC if 32BIT && SPARSEMEM 311 select SPARSEMEM_VMEMMAP_ENABLE if 64BIT 312 313config ARCH_SELECT_MEMORY_MODEL 314 def_bool ARCH_SPARSEMEM_ENABLE 315 316config ARCH_SUPPORTS_UPROBES 317 def_bool y 318 319config STACKTRACE_SUPPORT 320 def_bool y 321 322config GENERIC_BUG 323 def_bool y 324 depends on BUG 325 select GENERIC_BUG_RELATIVE_POINTERS if 64BIT 326 327config GENERIC_BUG_RELATIVE_POINTERS 328 bool 329 330config GENERIC_CALIBRATE_DELAY 331 def_bool y 332 333config GENERIC_CSUM 334 def_bool y 335 336config GENERIC_HWEIGHT 337 def_bool y 338 339config FIX_EARLYCON_MEM 340 def_bool MMU 341 342config ILLEGAL_POINTER_VALUE 343 hex 344 default 0 if 32BIT 345 default 0xdead000000000000 if 64BIT 346 347config PGTABLE_LEVELS 348 int 349 default 5 if 64BIT 350 default 2 351 352config LOCKDEP_SUPPORT 353 def_bool y 354 355config RISCV_DMA_NONCOHERENT 356 bool 357 select ARCH_HAS_DMA_PREP_COHERENT 358 select ARCH_HAS_SETUP_DMA_OPS 359 select ARCH_HAS_SYNC_DMA_FOR_CPU 360 select ARCH_HAS_SYNC_DMA_FOR_DEVICE 361 select DMA_BOUNCE_UNALIGNED_KMALLOC if SWIOTLB 362 363config RISCV_NONSTANDARD_CACHE_OPS 364 bool 365 help 366 This enables function pointer support for non-standard noncoherent 367 systems to handle cache management. 368 369config AS_HAS_INSN 370 def_bool $(as-instr,.insn r 51$(comma) 0$(comma) 0$(comma) t0$(comma) t0$(comma) zero) 371 372config AS_HAS_OPTION_ARCH 373 # https://github.com/llvm/llvm-project/commit/9e8ed3403c191ab9c4903e8eeb8f732ff8a43cb4 374 def_bool y 375 depends on $(as-instr, .option arch$(comma) +m) 376 377source "arch/riscv/Kconfig.socs" 378source "arch/riscv/Kconfig.errata" 379 380menu "Platform type" 381 382config NONPORTABLE 383 bool "Allow configurations that result in non-portable kernels" 384 help 385 RISC-V kernel binaries are compatible between all known systems 386 whenever possible, but there are some use cases that can only be 387 satisfied by configurations that result in kernel binaries that are 388 not portable between systems. 389 390 Selecting N does not guarantee kernels will be portable to all known 391 systems. Selecting any of the options guarded by NONPORTABLE will 392 result in kernel binaries that are unlikely to be portable between 393 systems. 394 395 If unsure, say N. 396 397choice 398 prompt "Base ISA" 399 default ARCH_RV64I 400 help 401 This selects the base ISA that this kernel will target and must match 402 the target platform. 403 404config ARCH_RV32I 405 bool "RV32I" 406 depends on NONPORTABLE 407 select 32BIT 408 select GENERIC_LIB_ASHLDI3 409 select GENERIC_LIB_ASHRDI3 410 select GENERIC_LIB_LSHRDI3 411 select GENERIC_LIB_UCMPDI2 412 413config ARCH_RV64I 414 bool "RV64I" 415 select 64BIT 416 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 417 select SWIOTLB if MMU 418 419endchoice 420 421# We must be able to map all physical memory into the kernel, but the compiler 422# is still a bit more efficient when generating code if it's setup in a manner 423# such that it can only map 2GiB of memory. 424choice 425 prompt "Kernel Code Model" 426 default CMODEL_MEDLOW if 32BIT 427 default CMODEL_MEDANY if 64BIT 428 429 config CMODEL_MEDLOW 430 bool "medium low code model" 431 config CMODEL_MEDANY 432 bool "medium any code model" 433endchoice 434 435config MODULE_SECTIONS 436 bool 437 select HAVE_MOD_ARCH_SPECIFIC 438 439config SMP 440 bool "Symmetric Multi-Processing" 441 help 442 This enables support for systems with more than one CPU. If 443 you say N here, the kernel will run on single and 444 multiprocessor machines, but will use only one CPU of a 445 multiprocessor machine. If you say Y here, the kernel will run 446 on many, but not all, single processor machines. On a single 447 processor machine, the kernel will run faster if you say N 448 here. 449 450 If you don't know what to do here, say N. 451 452config NR_CPUS 453 int "Maximum number of CPUs (2-512)" 454 depends on SMP 455 range 2 512 if !RISCV_SBI_V01 456 range 2 32 if RISCV_SBI_V01 && 32BIT 457 range 2 64 if RISCV_SBI_V01 && 64BIT 458 default "32" if 32BIT 459 default "64" if 64BIT 460 461config HOTPLUG_CPU 462 bool "Support for hot-pluggable CPUs" 463 depends on SMP 464 select GENERIC_IRQ_MIGRATION 465 help 466 467 Say Y here to experiment with turning CPUs off and on. CPUs 468 can be controlled through /sys/devices/system/cpu. 469 470 Say N if you want to disable CPU hotplug. 471 472choice 473 prompt "CPU Tuning" 474 default TUNE_GENERIC 475 476config TUNE_GENERIC 477 bool "generic" 478 479endchoice 480 481# Common NUMA Features 482config NUMA 483 bool "NUMA Memory Allocation and Scheduler Support" 484 depends on SMP && MMU 485 select ARCH_SUPPORTS_NUMA_BALANCING 486 select GENERIC_ARCH_NUMA 487 select HAVE_SETUP_PER_CPU_AREA 488 select NEED_PER_CPU_EMBED_FIRST_CHUNK 489 select NEED_PER_CPU_PAGE_FIRST_CHUNK 490 select OF_NUMA 491 select USE_PERCPU_NUMA_NODE_ID 492 help 493 Enable NUMA (Non-Uniform Memory Access) support. 494 495 The kernel will try to allocate memory used by a CPU on the 496 local memory of the CPU and add some more NUMA awareness to the kernel. 497 498config NODES_SHIFT 499 int "Maximum NUMA Nodes (as a power of 2)" 500 range 1 10 501 default "2" 502 depends on NUMA 503 help 504 Specify the maximum number of NUMA Nodes available on the target 505 system. Increases memory reserved to accommodate various tables. 506 507choice 508 prompt "RISC-V spinlock type" 509 default RISCV_COMBO_SPINLOCKS 510 511config RISCV_TICKET_SPINLOCKS 512 bool "Using ticket spinlock" 513 514config RISCV_QUEUED_SPINLOCKS 515 bool "Using queued spinlock" 516 depends on SMP && MMU && NONPORTABLE 517 select ARCH_USE_QUEUED_SPINLOCKS 518 help 519 The queued spinlock implementation requires the forward progress 520 guarantee of cmpxchg()/xchg() atomic operations: CAS with Zabha or 521 LR/SC with Ziccrse provide such guarantee. 522 523 Select this if and only if Zabha or Ziccrse is available on your 524 platform, RISCV_QUEUED_SPINLOCKS must not be selected for platforms 525 without one of those extensions. 526 527 If unsure, select RISCV_COMBO_SPINLOCKS, which will use qspinlocks 528 when supported and otherwise ticket spinlocks. 529 530config RISCV_COMBO_SPINLOCKS 531 bool "Using combo spinlock" 532 depends on SMP && MMU 533 select ARCH_USE_QUEUED_SPINLOCKS 534 help 535 Embed both queued spinlock and ticket lock so that the spinlock 536 implementation can be chosen at runtime. 537 538endchoice 539 540config RISCV_ALTERNATIVE 541 bool 542 depends on !XIP_KERNEL 543 help 544 This Kconfig allows the kernel to automatically patch the 545 erratum or cpufeature required by the execution platform at run 546 time. The code patching overhead is minimal, as it's only done 547 once at boot and once on each module load. 548 549config RISCV_ALTERNATIVE_EARLY 550 bool 551 depends on RISCV_ALTERNATIVE 552 help 553 Allows early patching of the kernel for special errata 554 555config RISCV_ISA_C 556 bool "Emit compressed instructions when building Linux" 557 default y 558 help 559 Adds "C" to the ISA subsets that the toolchain is allowed to emit 560 when building Linux, which results in compressed instructions in the 561 Linux binary. This option produces a kernel that will not run on 562 systems that do not support compressed instructions. 563 564 If you don't know what to do here, say Y. 565 566config RISCV_ISA_SUPM 567 bool "Supm extension for userspace pointer masking" 568 depends on 64BIT 569 default y 570 help 571 Add support for pointer masking in userspace (Supm) when the 572 underlying hardware extension (Smnpm or Ssnpm) is detected at boot. 573 574 If this option is disabled, userspace will be unable to use 575 the prctl(PR_{SET,GET}_TAGGED_ADDR_CTRL) API. 576 577config RISCV_ISA_SVNAPOT 578 bool "Svnapot extension support for supervisor mode NAPOT pages" 579 depends on 64BIT && MMU 580 depends on RISCV_ALTERNATIVE 581 default y 582 help 583 Enable support for the Svnapot ISA-extension when it is detected 584 at boot. 585 586 The Svnapot extension is used to mark contiguous PTEs as a range 587 of contiguous virtual-to-physical translations for a naturally 588 aligned power-of-2 (NAPOT) granularity larger than the base 4KB page 589 size. When HUGETLBFS is also selected this option unconditionally 590 allocates some memory for each NAPOT page size supported by the kernel. 591 When optimizing for low memory consumption and for platforms without 592 the Svnapot extension, it may be better to say N here. 593 594 If you don't know what to do here, say Y. 595 596config RISCV_ISA_SVPBMT 597 bool "Svpbmt extension support for supervisor mode page-based memory types" 598 depends on 64BIT && MMU 599 depends on RISCV_ALTERNATIVE 600 default y 601 help 602 Add support for the Svpbmt ISA-extension (Supervisor-mode: 603 page-based memory types) in the kernel when it is detected at boot. 604 605 The memory type for a page contains a combination of attributes 606 that indicate the cacheability, idempotency, and ordering 607 properties for access to that page. 608 609 The Svpbmt extension is only available on 64-bit cpus. 610 611 If you don't know what to do here, say Y. 612 613config TOOLCHAIN_HAS_V 614 bool 615 default y 616 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64imv) 617 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32imv) 618 depends on LD_IS_LLD || LD_VERSION >= 23800 619 depends on AS_HAS_OPTION_ARCH 620 621config RISCV_ISA_V 622 bool "Vector extension support" 623 depends on TOOLCHAIN_HAS_V 624 depends on FPU 625 select DYNAMIC_SIGFRAME 626 default y 627 help 628 Add support for the Vector extension when it is detected at boot. 629 When this option is disabled, neither the kernel nor userspace may 630 use vector procedures. 631 632 If you don't know what to do here, say Y. 633 634config RISCV_ISA_V_DEFAULT_ENABLE 635 bool "Enable userspace Vector by default" 636 depends on RISCV_ISA_V 637 default y 638 help 639 Say Y here if you want to enable Vector in userspace by default. 640 Otherwise, userspace has to make explicit prctl() call to enable 641 Vector, or enable it via the sysctl interface. 642 643 If you don't know what to do here, say Y. 644 645config RISCV_ISA_V_UCOPY_THRESHOLD 646 int "Threshold size for vectorized user copies" 647 depends on RISCV_ISA_V 648 default 768 649 help 650 Prefer using vectorized copy_to_user()/copy_from_user() when the 651 workload size exceeds this value. 652 653config RISCV_ISA_V_PREEMPTIVE 654 bool "Run kernel-mode Vector with kernel preemption" 655 depends on PREEMPTION 656 depends on RISCV_ISA_V 657 default y 658 help 659 Usually, in-kernel SIMD routines are run with preemption disabled. 660 Functions which invoke long running SIMD thus must yield the core's 661 vector unit to prevent blocking other tasks for too long. 662 663 This config allows the kernel to run SIMD without explicitly disabling 664 preemption. Enabling this config will result in higher memory consumption 665 due to the allocation of per-task's kernel Vector context. 666 667config RISCV_ISA_ZAWRS 668 bool "Zawrs extension support for more efficient busy waiting" 669 depends on RISCV_ALTERNATIVE 670 default y 671 help 672 The Zawrs extension defines instructions to be used in polling loops 673 which allow a hart to enter a low-power state or to trap to the 674 hypervisor while waiting on a store to a memory location. Enable the 675 use of these instructions in the kernel when the Zawrs extension is 676 detected at boot. 677 678config TOOLCHAIN_HAS_ZABHA 679 bool 680 default y 681 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zabha) 682 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zabha) 683 depends on AS_HAS_OPTION_ARCH 684 685config RISCV_ISA_ZABHA 686 bool "Zabha extension support for atomic byte/halfword operations" 687 depends on TOOLCHAIN_HAS_ZABHA 688 depends on RISCV_ALTERNATIVE 689 default y 690 help 691 Enable the use of the Zabha ISA-extension to implement kernel 692 byte/halfword atomic memory operations when it is detected at boot. 693 694 If you don't know what to do here, say Y. 695 696config TOOLCHAIN_HAS_ZACAS 697 bool 698 default y 699 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zacas) 700 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zacas) 701 depends on AS_HAS_OPTION_ARCH 702 703config RISCV_ISA_ZACAS 704 bool "Zacas extension support for atomic CAS" 705 depends on RISCV_ALTERNATIVE 706 default y 707 help 708 Enable the use of the Zacas ISA-extension to implement kernel atomic 709 cmpxchg operations when it is detected at boot. 710 711 If you don't know what to do here, say Y. 712 713config TOOLCHAIN_HAS_ZBB 714 bool 715 default y 716 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbb) 717 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbb) 718 depends on LD_IS_LLD || LD_VERSION >= 23900 719 depends on AS_HAS_OPTION_ARCH 720 721# This symbol indicates that the toolchain supports all v1.0 vector crypto 722# extensions, including Zvk*, Zvbb, and Zvbc. LLVM added all of these at once. 723# binutils added all except Zvkb, then added Zvkb. So we just check for Zvkb. 724config TOOLCHAIN_HAS_VECTOR_CRYPTO 725 def_bool $(as-instr, .option arch$(comma) +v$(comma) +zvkb) 726 depends on AS_HAS_OPTION_ARCH 727 728config TOOLCHAIN_HAS_ZBA 729 bool 730 default y 731 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zba) 732 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zba) 733 depends on LD_IS_LLD || LD_VERSION >= 23900 734 depends on AS_HAS_OPTION_ARCH 735 736config RISCV_ISA_ZBA 737 bool "Zba extension support for bit manipulation instructions" 738 default y 739 help 740 Add support for enabling optimisations in the kernel when the Zba 741 extension is detected at boot. 742 743 The Zba extension provides instructions to accelerate the generation 744 of addresses that index into arrays of basic data types. 745 746 If you don't know what to do here, say Y. 747 748config RISCV_ISA_ZBB 749 bool "Zbb extension support for bit manipulation instructions" 750 depends on RISCV_ALTERNATIVE 751 default y 752 help 753 Add support for enabling optimisations in the kernel when the 754 Zbb extension is detected at boot. Some optimisations may 755 additionally depend on toolchain support for Zbb. 756 757 The Zbb extension provides instructions to accelerate a number 758 of bit-specific operations (count bit population, sign extending, 759 bitrotation, etc). 760 761 If you don't know what to do here, say Y. 762 763config TOOLCHAIN_HAS_ZBC 764 bool 765 default y 766 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbc) 767 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbc) 768 depends on LD_IS_LLD || LD_VERSION >= 23900 769 depends on AS_HAS_OPTION_ARCH 770 771config RISCV_ISA_ZBC 772 bool "Zbc extension support for carry-less multiplication instructions" 773 depends on TOOLCHAIN_HAS_ZBC 774 depends on MMU 775 depends on RISCV_ALTERNATIVE 776 default y 777 help 778 Adds support to dynamically detect the presence of the Zbc 779 extension (carry-less multiplication) and enable its usage. 780 781 The Zbc extension could accelerate CRC (cyclic redundancy check) 782 calculations. 783 784 If you don't know what to do here, say Y. 785 786config TOOLCHAIN_HAS_ZBKB 787 bool 788 default y 789 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbkb) 790 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbkb) 791 depends on LD_IS_LLD || LD_VERSION >= 23900 792 depends on AS_HAS_OPTION_ARCH 793 794config RISCV_ISA_ZBKB 795 bool "Zbkb extension support for bit manipulation instructions" 796 depends on TOOLCHAIN_HAS_ZBKB 797 depends on RISCV_ALTERNATIVE 798 default y 799 help 800 Adds support to dynamically detect the presence of the ZBKB 801 extension (bit manipulation for cryptography) and enable its usage. 802 803 The Zbkb extension provides instructions to accelerate a number 804 of common cryptography operations (pack, zip, etc). 805 806 If you don't know what to do here, say Y. 807 808config RISCV_ISA_ZICBOM 809 bool "Zicbom extension support for non-coherent DMA operation" 810 depends on MMU 811 depends on RISCV_ALTERNATIVE 812 default y 813 select RISCV_DMA_NONCOHERENT 814 select DMA_DIRECT_REMAP 815 help 816 Add support for the Zicbom extension (Cache Block Management 817 Operations) and enable its use in the kernel when it is detected 818 at boot. 819 820 The Zicbom extension can be used to handle for example 821 non-coherent DMA support on devices that need it. 822 823 If you don't know what to do here, say Y. 824 825config RISCV_ISA_ZICBOZ 826 bool "Zicboz extension support for faster zeroing of memory" 827 depends on RISCV_ALTERNATIVE 828 default y 829 help 830 Enable the use of the Zicboz extension (cbo.zero instruction) 831 in the kernel when it is detected at boot. 832 833 The Zicboz extension is used for faster zeroing of memory. 834 835 If you don't know what to do here, say Y. 836 837config RISCV_ISA_ZICBOP 838 bool "Zicbop extension support for cache block prefetch" 839 depends on MMU 840 depends on RISCV_ALTERNATIVE 841 default y 842 help 843 Adds support to dynamically detect the presence of the ZICBOP 844 extension (Cache Block Prefetch Operations) and enable its 845 usage. 846 847 The Zicbop extension can be used to prefetch cache blocks for 848 read/write fetch. 849 850 If you don't know what to do here, say Y. 851 852config TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI 853 def_bool y 854 # https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=aed44286efa8ae8717a77d94b51ac3614e2ca6dc 855 # https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=98416dbb0a62579d4a7a4a76bab51b5b52fec2cd 856 depends on AS_IS_GNU && AS_VERSION >= 23600 857 help 858 Binutils-2.38 and GCC-12.1.0 bumped the default ISA spec to the newer 859 20191213 version, which moves some instructions from the I extension to 860 the Zicsr and Zifencei extensions. This requires explicitly specifying 861 Zicsr and Zifencei when binutils >= 2.38 or GCC >= 12.1.0. Zicsr 862 and Zifencei are supported in binutils from version 2.36 onwards. 863 To make life easier, and avoid forcing toolchains that default to a 864 newer ISA spec to version 2.2, relax the check to binutils >= 2.36. 865 For clang < 17 or GCC < 11.3.0, for which this is not possible or need 866 special treatment, this is dealt with in TOOLCHAIN_NEEDS_OLD_ISA_SPEC. 867 868config TOOLCHAIN_NEEDS_OLD_ISA_SPEC 869 def_bool y 870 depends on TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI 871 # https://github.com/llvm/llvm-project/commit/22e199e6afb1263c943c0c0d4498694e15bf8a16 872 # https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=d29f5d6ab513c52fd872f532c492e35ae9fd6671 873 depends on (CC_IS_CLANG && CLANG_VERSION < 170000) || (CC_IS_GCC && GCC_VERSION < 110300) 874 help 875 Certain versions of clang and GCC do not support zicsr and zifencei via 876 -march. This option causes an older ISA spec compatible with these older 877 versions of clang and GCC to be passed to GAS, which has the same result 878 as passing zicsr and zifencei to -march. 879 880config FPU 881 bool "FPU support" 882 default y 883 help 884 Add support for floating point operations when an FPU is detected at 885 boot. When this option is disabled, neither the kernel nor userspace 886 may use the floating point unit. 887 888 If you don't know what to do here, say Y. 889 890config IRQ_STACKS 891 bool "Independent irq & softirq stacks" if EXPERT 892 default y 893 select HAVE_IRQ_EXIT_ON_IRQ_STACK 894 select HAVE_SOFTIRQ_ON_OWN_STACK 895 help 896 Add independent irq & softirq stacks for percpu to prevent kernel stack 897 overflows. We may save some memory footprint by disabling IRQ_STACKS. 898 899config THREAD_SIZE_ORDER 900 int "Kernel stack size (in power-of-two numbers of page size)" if VMAP_STACK && EXPERT 901 range 0 4 902 default 1 if 32BIT 903 default 2 904 help 905 Specify the Pages of thread stack size (from 4KB to 64KB), which also 906 affects irq stack size, which is equal to thread stack size. 907 908config RISCV_MISALIGNED 909 bool 910 help 911 Embed support for detecting and emulating misaligned 912 scalar or vector loads and stores. 913 914config RISCV_SCALAR_MISALIGNED 915 bool 916 select RISCV_MISALIGNED 917 select SYSCTL_ARCH_UNALIGN_ALLOW 918 help 919 Embed support for emulating misaligned loads and stores. 920 921config RISCV_VECTOR_MISALIGNED 922 bool 923 select RISCV_MISALIGNED 924 depends on RISCV_ISA_V 925 help 926 Enable detecting support for vector misaligned loads and stores. 927 928choice 929 prompt "Unaligned Accesses Support" 930 default RISCV_PROBE_UNALIGNED_ACCESS 931 help 932 This determines the level of support for unaligned accesses. This 933 information is used by the kernel to perform optimizations. It is also 934 exposed to user space via the hwprobe syscall. The hardware will be 935 probed at boot by default. 936 937config RISCV_PROBE_UNALIGNED_ACCESS 938 bool "Probe for hardware unaligned access support" 939 select RISCV_SCALAR_MISALIGNED 940 help 941 During boot, the kernel will run a series of tests to determine the 942 speed of unaligned accesses. This probing will dynamically determine 943 the speed of unaligned accesses on the underlying system. If unaligned 944 memory accesses trap into the kernel as they are not supported by the 945 system, the kernel will emulate the unaligned accesses to preserve the 946 UABI. 947 948config RISCV_EMULATED_UNALIGNED_ACCESS 949 bool "Emulate unaligned access where system support is missing" 950 select RISCV_SCALAR_MISALIGNED 951 help 952 If unaligned memory accesses trap into the kernel as they are not 953 supported by the system, the kernel will emulate the unaligned 954 accesses to preserve the UABI. When the underlying system does support 955 unaligned accesses, the unaligned accesses are assumed to be slow. 956 957config RISCV_SLOW_UNALIGNED_ACCESS 958 bool "Assume the system supports slow unaligned memory accesses" 959 depends on NONPORTABLE 960 help 961 Assume that the system supports slow unaligned memory accesses. The 962 kernel and userspace programs may not be able to run at all on systems 963 that do not support unaligned memory accesses. 964 965config RISCV_EFFICIENT_UNALIGNED_ACCESS 966 bool "Assume the system supports fast unaligned memory accesses" 967 depends on NONPORTABLE 968 select DCACHE_WORD_ACCESS if MMU 969 select HAVE_EFFICIENT_UNALIGNED_ACCESS 970 help 971 Assume that the system supports fast unaligned memory accesses. When 972 enabled, this option improves the performance of the kernel on such 973 systems. However, the kernel and userspace programs will run much more 974 slowly, or will not be able to run at all, on systems that do not 975 support efficient unaligned memory accesses. 976 977endchoice 978 979choice 980 prompt "Vector unaligned Accesses Support" 981 depends on RISCV_ISA_V 982 default RISCV_PROBE_VECTOR_UNALIGNED_ACCESS 983 help 984 This determines the level of support for vector unaligned accesses. This 985 information is used by the kernel to perform optimizations. It is also 986 exposed to user space via the hwprobe syscall. The hardware will be 987 probed at boot by default. 988 989config RISCV_PROBE_VECTOR_UNALIGNED_ACCESS 990 bool "Probe speed of vector unaligned accesses" 991 select RISCV_VECTOR_MISALIGNED 992 depends on RISCV_ISA_V 993 help 994 During boot, the kernel will run a series of tests to determine the 995 speed of vector unaligned accesses if they are supported. This probing 996 will dynamically determine the speed of vector unaligned accesses on 997 the underlying system if they are supported. 998 999config RISCV_SLOW_VECTOR_UNALIGNED_ACCESS 1000 bool "Assume the system supports slow vector unaligned memory accesses" 1001 depends on NONPORTABLE 1002 help 1003 Assume that the system supports slow vector unaligned memory accesses. The 1004 kernel and userspace programs may not be able to run at all on systems 1005 that do not support unaligned memory accesses. 1006 1007config RISCV_EFFICIENT_VECTOR_UNALIGNED_ACCESS 1008 bool "Assume the system supports fast vector unaligned memory accesses" 1009 depends on NONPORTABLE 1010 help 1011 Assume that the system supports fast vector unaligned memory accesses. When 1012 enabled, this option improves the performance of the kernel on such 1013 systems. However, the kernel and userspace programs will run much more 1014 slowly, or will not be able to run at all, on systems that do not 1015 support efficient unaligned memory accesses. 1016 1017endchoice 1018 1019source "arch/riscv/Kconfig.vendor" 1020 1021endmenu # "Platform type" 1022 1023menu "Kernel features" 1024 1025source "kernel/Kconfig.hz" 1026 1027config RISCV_SBI_V01 1028 bool "SBI v0.1 support" 1029 depends on RISCV_SBI 1030 help 1031 This config allows kernel to use SBI v0.1 APIs. This will be 1032 deprecated in future once legacy M-mode software are no longer in use. 1033 1034config RISCV_BOOT_SPINWAIT 1035 bool "Spinwait booting method" 1036 depends on SMP 1037 default y if RISCV_SBI_V01 || RISCV_M_MODE 1038 help 1039 This enables support for booting Linux via spinwait method. In the 1040 spinwait method, all cores randomly jump to Linux. One of the cores 1041 gets chosen via lottery and all other keep spinning on a percpu 1042 variable. This method cannot support CPU hotplug and sparse hartid 1043 scheme. It should be only enabled for M-mode Linux or platforms relying 1044 on older firmware without SBI HSM extension. All other platforms should 1045 rely on ordered booting via SBI HSM extension which gets chosen 1046 dynamically at runtime if the firmware supports it. 1047 1048 Since spinwait is incompatible with sparse hart IDs, it requires 1049 NR_CPUS be large enough to contain the physical hart ID of the first 1050 hart to enter Linux. 1051 1052 If unsure what to do here, say N. 1053 1054config ARCH_SUPPORTS_KEXEC 1055 def_bool y 1056 1057config ARCH_SELECTS_KEXEC 1058 def_bool y 1059 depends on KEXEC 1060 select HOTPLUG_CPU if SMP 1061 1062config ARCH_SUPPORTS_KEXEC_FILE 1063 def_bool 64BIT 1064 1065config ARCH_SELECTS_KEXEC_FILE 1066 def_bool y 1067 depends on KEXEC_FILE 1068 select HAVE_IMA_KEXEC if IMA 1069 select KEXEC_ELF 1070 1071config ARCH_SUPPORTS_KEXEC_PURGATORY 1072 def_bool ARCH_SUPPORTS_KEXEC_FILE 1073 1074config ARCH_SUPPORTS_CRASH_DUMP 1075 def_bool y 1076 1077config ARCH_DEFAULT_CRASH_DUMP 1078 def_bool y 1079 1080config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION 1081 def_bool CRASH_RESERVE 1082 1083config COMPAT 1084 bool "Kernel support for 32-bit U-mode" 1085 default 64BIT 1086 depends on 64BIT && MMU 1087 help 1088 This option enables support for a 32-bit U-mode running under a 64-bit 1089 kernel at S-mode. riscv32-specific components such as system calls, 1090 the user helper functions (vdso), signal rt_frame functions and the 1091 ptrace interface are handled appropriately by the kernel. 1092 1093 If you want to execute 32-bit userspace applications, say Y. 1094 1095config PARAVIRT 1096 bool "Enable paravirtualization code" 1097 depends on RISCV_SBI 1098 help 1099 This changes the kernel so it can modify itself when it is run 1100 under a hypervisor, potentially improving performance significantly 1101 over full virtualization. 1102 1103config PARAVIRT_TIME_ACCOUNTING 1104 bool "Paravirtual steal time accounting" 1105 depends on PARAVIRT 1106 help 1107 Select this option to enable fine granularity task steal time 1108 accounting. Time spent executing other tasks in parallel with 1109 the current vCPU is discounted from the vCPU power. To account for 1110 that, there can be a small performance impact. 1111 1112 If in doubt, say N here. 1113 1114config RELOCATABLE 1115 bool "Build a relocatable kernel" 1116 depends on !XIP_KERNEL 1117 select MODULE_SECTIONS if MODULES 1118 select ARCH_VMLINUX_NEEDS_RELOCS 1119 help 1120 This builds a kernel as a Position Independent Executable (PIE), 1121 which retains all relocation metadata required to relocate the 1122 kernel binary at runtime to a different virtual address than the 1123 address it was linked at. 1124 Since RISCV uses the RELA relocation format, this requires a 1125 relocation pass at runtime even if the kernel is loaded at the 1126 same address it was linked at. 1127 1128 If unsure, say N. 1129 1130config RANDOMIZE_BASE 1131 bool "Randomize the address of the kernel image" 1132 select RELOCATABLE 1133 depends on MMU && 64BIT && !XIP_KERNEL 1134 help 1135 Randomizes the virtual address at which the kernel image is 1136 loaded, as a security feature that deters exploit attempts 1137 relying on knowledge of the location of kernel internals. 1138 1139 It is the bootloader's job to provide entropy, by passing a 1140 random u64 value in /chosen/kaslr-seed at kernel entry. 1141 1142 When booting via the UEFI stub, it will invoke the firmware's 1143 EFI_RNG_PROTOCOL implementation (if available) to supply entropy 1144 to the kernel proper. In addition, it will randomise the physical 1145 location of the kernel Image as well. 1146 1147 If unsure, say N. 1148 1149endmenu # "Kernel features" 1150 1151menu "Boot options" 1152 1153config CMDLINE 1154 string "Built-in kernel command line" 1155 help 1156 For most platforms, the arguments for the kernel's command line 1157 are provided at run-time, during boot. However, there are cases 1158 where either no arguments are being provided or the provided 1159 arguments are insufficient or even invalid. 1160 1161 When that occurs, it is possible to define a built-in command 1162 line here and choose how the kernel should use it later on. 1163 1164choice 1165 prompt "Built-in command line usage" 1166 depends on CMDLINE != "" 1167 default CMDLINE_FALLBACK 1168 help 1169 Choose how the kernel will handle the provided built-in command 1170 line. 1171 1172config CMDLINE_FALLBACK 1173 bool "Use bootloader kernel arguments if available" 1174 help 1175 Use the built-in command line as fallback in case we get nothing 1176 during boot. This is the default behaviour. 1177 1178config CMDLINE_EXTEND 1179 bool "Extend bootloader kernel arguments" 1180 help 1181 The built-in command line will be appended to the command- 1182 line arguments provided during boot. This is useful in 1183 cases where the provided arguments are insufficient and 1184 you don't want to or cannot modify them. 1185 1186config CMDLINE_FORCE 1187 bool "Always use the default kernel command string" 1188 help 1189 Always use the built-in command line, even if we get one during 1190 boot. This is useful in case you need to override the provided 1191 command line on systems where you don't have or want control 1192 over it. 1193 1194endchoice 1195 1196config EFI_STUB 1197 bool 1198 1199config EFI 1200 bool "UEFI runtime support" 1201 depends on OF && !XIP_KERNEL 1202 depends on MMU 1203 default y 1204 select ARCH_SUPPORTS_ACPI if 64BIT 1205 select EFI_GENERIC_STUB 1206 select EFI_PARAMS_FROM_FDT 1207 select EFI_RUNTIME_WRAPPERS 1208 select EFI_STUB 1209 select LIBFDT 1210 select RISCV_ISA_C 1211 select UCS2_STRING 1212 help 1213 This option provides support for runtime services provided 1214 by UEFI firmware (such as non-volatile variables, realtime 1215 clock, and platform reset). A UEFI stub is also provided to 1216 allow the kernel to be booted as an EFI application. This 1217 is only useful on systems that have UEFI firmware. 1218 1219config DMI 1220 bool "Enable support for SMBIOS (DMI) tables" 1221 depends on EFI 1222 default y 1223 help 1224 This enables SMBIOS/DMI feature for systems. 1225 1226 This option is only useful on systems that have UEFI firmware. 1227 However, even with this option, the resultant kernel should 1228 continue to boot on existing non-UEFI platforms. 1229 1230config CC_HAVE_STACKPROTECTOR_TLS 1231 def_bool $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=tp -mstack-protector-guard-offset=0) 1232 1233config STACKPROTECTOR_PER_TASK 1234 def_bool y 1235 depends on !RANDSTRUCT 1236 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_TLS 1237 1238config PHYS_RAM_BASE_FIXED 1239 bool "Explicitly specified physical RAM address" 1240 depends on NONPORTABLE 1241 default n 1242 1243config PHYS_RAM_BASE 1244 hex "Platform Physical RAM address" 1245 depends on PHYS_RAM_BASE_FIXED 1246 default "0x80000000" 1247 help 1248 This is the physical address of RAM in the system. It has to be 1249 explicitly specified to run early relocations of read-write data 1250 from flash to RAM. 1251 1252config XIP_KERNEL 1253 bool "Kernel Execute-In-Place from ROM" 1254 depends on MMU && SPARSEMEM && NONPORTABLE 1255 # This prevents XIP from being enabled by all{yes,mod}config, which 1256 # fail to build since XIP doesn't support large kernels. 1257 depends on !COMPILE_TEST 1258 select PHYS_RAM_BASE_FIXED 1259 help 1260 Execute-In-Place allows the kernel to run from non-volatile storage 1261 directly addressable by the CPU, such as NOR flash. This saves RAM 1262 space since the text section of the kernel is not loaded from flash 1263 to RAM. Read-write sections, such as the data section and stack, 1264 are still copied to RAM. The XIP kernel is not compressed since 1265 it has to run directly from flash, so it will take more space to 1266 store it. The flash address used to link the kernel object files, 1267 and for storing it, is configuration dependent. Therefore, if you 1268 say Y here, you must know the proper physical address where to 1269 store the kernel image depending on your own flash memory usage. 1270 1271 Also note that the make target becomes "make xipImage" rather than 1272 "make zImage" or "make Image". The final kernel binary to put in 1273 ROM memory will be arch/riscv/boot/xipImage. 1274 1275 SPARSEMEM is required because the kernel text and rodata that are 1276 flash resident are not backed by memmap, then any attempt to get 1277 a struct page on those regions will trigger a fault. 1278 1279 If unsure, say N. 1280 1281config XIP_PHYS_ADDR 1282 hex "XIP Kernel Physical Location" 1283 depends on XIP_KERNEL 1284 default "0x21000000" 1285 help 1286 This is the physical address in your flash memory the kernel will 1287 be linked for and stored to. This address is dependent on your 1288 own flash usage. 1289 1290config RISCV_ISA_FALLBACK 1291 bool "Permit falling back to parsing riscv,isa for extension support by default" 1292 default y 1293 help 1294 Parsing the "riscv,isa" devicetree property has been deprecated and 1295 replaced by a list of explicitly defined strings. For compatibility 1296 with existing platforms, the kernel will fall back to parsing the 1297 "riscv,isa" property if the replacements are not found. 1298 1299 Selecting N here will result in a kernel that does not use the 1300 fallback, unless the commandline "riscv_isa_fallback" parameter is 1301 present. 1302 1303 Please see the dt-binding, located at 1304 Documentation/devicetree/bindings/riscv/extensions.yaml for details 1305 on the replacement properties, "riscv,isa-base" and 1306 "riscv,isa-extensions". 1307 1308config BUILTIN_DTB 1309 bool "Built-in device tree" 1310 depends on OF && NONPORTABLE 1311 select GENERIC_BUILTIN_DTB 1312 help 1313 Build a device tree into the Linux image. 1314 This option should be selected if no bootloader is being used. 1315 If unsure, say N. 1316 1317 1318config BUILTIN_DTB_NAME 1319 string "Built-in device tree source" 1320 depends on BUILTIN_DTB 1321 help 1322 DTS file path (without suffix, relative to arch/riscv/boot/dts) 1323 for the DTS file that will be used to produce the DTB linked into the 1324 kernel. 1325 1326endmenu # "Boot options" 1327 1328config PORTABLE 1329 bool 1330 default !NONPORTABLE 1331 select EFI 1332 select MMU 1333 select OF 1334 1335config ARCH_PROC_KCORE_TEXT 1336 def_bool y 1337 1338menu "Power management options" 1339 1340source "kernel/power/Kconfig" 1341 1342config ARCH_HIBERNATION_POSSIBLE 1343 def_bool y 1344 1345config ARCH_HIBERNATION_HEADER 1346 def_bool HIBERNATION 1347 1348config ARCH_SUSPEND_POSSIBLE 1349 def_bool y 1350 1351endmenu # "Power management options" 1352 1353menu "CPU Power Management" 1354 1355source "drivers/cpuidle/Kconfig" 1356 1357source "drivers/cpufreq/Kconfig" 1358 1359endmenu # "CPU Power Management" 1360 1361source "arch/riscv/kvm/Kconfig" 1362 1363source "drivers/acpi/Kconfig" 1364