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_REDUCED_HARDWARE_ONLY if ACPI 17 select ARCH_DMA_DEFAULT_COHERENT 18 select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION 19 select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2 20 select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE 21 select ARCH_HAS_BINFMT_FLAT 22 select ARCH_HAS_CURRENT_STACK_POINTER 23 select ARCH_HAS_DEBUG_VIRTUAL if MMU 24 select ARCH_HAS_DEBUG_VM_PGTABLE 25 select ARCH_HAS_DEBUG_WX 26 select ARCH_HAS_FORTIFY_SOURCE 27 select ARCH_HAS_GCOV_PROFILE_ALL 28 select ARCH_HAS_GIGANTIC_PAGE 29 select ARCH_HAS_KCOV 30 select ARCH_HAS_MMIOWB 31 select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 32 select ARCH_HAS_PMEM_API 33 select ARCH_HAS_PTE_SPECIAL 34 select ARCH_HAS_SET_DIRECT_MAP if MMU 35 select ARCH_HAS_SET_MEMORY if MMU 36 select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL 37 select ARCH_HAS_STRICT_MODULE_RWX if MMU && !XIP_KERNEL 38 select ARCH_HAS_SYSCALL_WRAPPER 39 select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST 40 select ARCH_HAS_UBSAN_SANITIZE_ALL 41 select ARCH_HAS_VDSO_DATA 42 select ARCH_KEEP_MEMBLOCK if ACPI 43 select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX 44 select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT 45 select ARCH_STACKWALK 46 select ARCH_SUPPORTS_ATOMIC_RMW 47 select ARCH_SUPPORTS_CFI_CLANG 48 select ARCH_SUPPORTS_DEBUG_PAGEALLOC if MMU 49 select ARCH_SUPPORTS_HUGETLBFS if MMU 50 select ARCH_SUPPORTS_PAGE_TABLE_CHECK if MMU 51 select ARCH_SUPPORTS_PER_VMA_LOCK if MMU 52 select ARCH_USE_MEMTEST 53 select ARCH_USE_QUEUED_RWLOCKS 54 select ARCH_USES_CFI_TRAPS if CFI_CLANG 55 select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU 56 select ARCH_WANT_FRAME_POINTERS 57 select ARCH_WANT_GENERAL_HUGETLB if !RISCV_ISA_SVNAPOT 58 select ARCH_WANT_HUGE_PMD_SHARE if 64BIT 59 select ARCH_WANT_LD_ORPHAN_WARN if !XIP_KERNEL 60 select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP 61 select ARCH_WANTS_THP_SWAP if HAVE_ARCH_TRANSPARENT_HUGEPAGE 62 select BINFMT_FLAT_NO_DATA_START_OFFSET if !MMU 63 select BUILDTIME_TABLE_SORT if MMU 64 select CLINT_TIMER if !MMU 65 select CLONE_BACKWARDS 66 select COMMON_CLK 67 select CPU_PM if CPU_IDLE || HIBERNATION 68 select EDAC_SUPPORT 69 select FRAME_POINTER if PERF_EVENTS || (FUNCTION_TRACER && !DYNAMIC_FTRACE) 70 select GENERIC_ARCH_TOPOLOGY 71 select GENERIC_ATOMIC64 if !64BIT 72 select GENERIC_CLOCKEVENTS_BROADCAST if SMP 73 select GENERIC_EARLY_IOREMAP 74 select GENERIC_ENTRY 75 select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO 76 select GENERIC_IDLE_POLL_SETUP 77 select GENERIC_IOREMAP if MMU 78 select GENERIC_IRQ_IPI if SMP 79 select GENERIC_IRQ_IPI_MUX if SMP 80 select GENERIC_IRQ_MULTI_HANDLER 81 select GENERIC_IRQ_SHOW 82 select GENERIC_IRQ_SHOW_LEVEL 83 select GENERIC_LIB_DEVMEM_IS_ALLOWED 84 select GENERIC_PCI_IOMAP 85 select GENERIC_PTDUMP if MMU 86 select GENERIC_SCHED_CLOCK 87 select GENERIC_SMP_IDLE_THREAD 88 select GENERIC_TIME_VSYSCALL if MMU && 64BIT 89 select GENERIC_VDSO_TIME_NS if HAVE_GENERIC_VDSO 90 select HARDIRQS_SW_RESEND 91 select HAS_IOPORT if MMU 92 select HAVE_ARCH_AUDITSYSCALL 93 select HAVE_ARCH_HUGE_VMALLOC if HAVE_ARCH_HUGE_VMAP 94 select HAVE_ARCH_HUGE_VMAP if MMU && 64BIT && !XIP_KERNEL 95 select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL 96 select HAVE_ARCH_JUMP_LABEL_RELATIVE if !XIP_KERNEL 97 select HAVE_ARCH_KASAN if MMU && 64BIT 98 select HAVE_ARCH_KASAN_VMALLOC if MMU && 64BIT 99 select HAVE_ARCH_KFENCE if MMU && 64BIT 100 select HAVE_ARCH_KGDB if !XIP_KERNEL 101 select HAVE_ARCH_KGDB_QXFER_PKT 102 select HAVE_ARCH_MMAP_RND_BITS if MMU 103 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT 104 select HAVE_ARCH_SECCOMP_FILTER 105 select HAVE_ARCH_THREAD_STRUCT_WHITELIST 106 select HAVE_ARCH_TRACEHOOK 107 select HAVE_ARCH_TRANSPARENT_HUGEPAGE if 64BIT && MMU 108 select HAVE_ARCH_USERFAULTFD_MINOR if 64BIT && USERFAULTFD 109 select HAVE_ARCH_VMAP_STACK if MMU && 64BIT 110 select HAVE_ASM_MODVERSIONS 111 select HAVE_CONTEXT_TRACKING_USER 112 select HAVE_DEBUG_KMEMLEAK 113 select HAVE_DMA_CONTIGUOUS if MMU 114 select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && MMU && (CLANG_SUPPORTS_DYNAMIC_FTRACE || GCC_SUPPORTS_DYNAMIC_FTRACE) 115 select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE 116 select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL 117 select HAVE_FUNCTION_GRAPH_TRACER 118 select HAVE_FUNCTION_GRAPH_RETVAL if HAVE_FUNCTION_GRAPH_TRACER 119 select HAVE_FUNCTION_TRACER if !XIP_KERNEL && !PREEMPTION 120 select HAVE_EBPF_JIT if MMU 121 select HAVE_FUNCTION_ARG_ACCESS_API 122 select HAVE_FUNCTION_ERROR_INJECTION 123 select HAVE_GCC_PLUGINS 124 select HAVE_GENERIC_VDSO if MMU && 64BIT 125 select HAVE_IRQ_TIME_ACCOUNTING 126 select HAVE_KPROBES if !XIP_KERNEL 127 select HAVE_KPROBES_ON_FTRACE if !XIP_KERNEL 128 select HAVE_KRETPROBES if !XIP_KERNEL 129 # https://github.com/ClangBuiltLinux/linux/issues/1881 130 select HAVE_LD_DEAD_CODE_DATA_ELIMINATION if !LD_IS_LLD 131 select HAVE_MOVE_PMD 132 select HAVE_MOVE_PUD 133 select HAVE_PCI 134 select HAVE_PERF_EVENTS 135 select HAVE_PERF_REGS 136 select HAVE_PERF_USER_STACK_DUMP 137 select HAVE_POSIX_CPU_TIMERS_TASK_WORK 138 select HAVE_PREEMPT_DYNAMIC_KEY if !XIP_KERNEL 139 select HAVE_REGS_AND_STACK_ACCESS_API 140 select HAVE_RETHOOK if !XIP_KERNEL 141 select HAVE_RSEQ 142 select HAVE_STACKPROTECTOR 143 select HAVE_SYSCALL_TRACEPOINTS 144 select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU 145 select IRQ_DOMAIN 146 select IRQ_FORCED_THREADING 147 select KASAN_VMALLOC if KASAN 148 select LOCK_MM_AND_FIND_VMA 149 select MODULES_USE_ELF_RELA if MODULES 150 select MODULE_SECTIONS if MODULES 151 select OF 152 select OF_EARLY_FLATTREE 153 select OF_IRQ 154 select PCI_DOMAINS_GENERIC if PCI 155 select PCI_MSI if PCI 156 select RISCV_ALTERNATIVE if !XIP_KERNEL 157 select RISCV_INTC 158 select RISCV_TIMER if RISCV_SBI 159 select SIFIVE_PLIC 160 select SPARSE_IRQ 161 select SYSCTL_EXCEPTION_TRACE 162 select THREAD_INFO_IN_TASK 163 select TRACE_IRQFLAGS_SUPPORT 164 select UACCESS_MEMCPY if !MMU 165 select ZONE_DMA32 if 64BIT 166 167config CLANG_SUPPORTS_DYNAMIC_FTRACE 168 def_bool CC_IS_CLANG 169 # https://github.com/llvm/llvm-project/commit/6ab8927931851bb42b2c93a00801dc499d7d9b1e 170 depends on CLANG_VERSION >= 130000 171 # https://github.com/ClangBuiltLinux/linux/issues/1817 172 depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600)) 173 174config GCC_SUPPORTS_DYNAMIC_FTRACE 175 def_bool CC_IS_GCC 176 depends on $(cc-option,-fpatchable-function-entry=8) 177 178config ARCH_MMAP_RND_BITS_MIN 179 default 18 if 64BIT 180 default 8 181 182config ARCH_MMAP_RND_COMPAT_BITS_MIN 183 default 8 184 185# max bits determined by the following formula: 186# VA_BITS - PAGE_SHIFT - 3 187config ARCH_MMAP_RND_BITS_MAX 188 default 24 if 64BIT # SV39 based 189 default 17 190 191config ARCH_MMAP_RND_COMPAT_BITS_MAX 192 default 17 193 194# set if we run in machine mode, cleared if we run in supervisor mode 195config RISCV_M_MODE 196 bool 197 default !MMU 198 199# set if we are running in S-mode and can use SBI calls 200config RISCV_SBI 201 bool 202 depends on !RISCV_M_MODE 203 default y 204 205config MMU 206 bool "MMU-based Paged Memory Management Support" 207 default y 208 help 209 Select if you want MMU-based virtualised addressing space 210 support by paged memory management. If unsure, say 'Y'. 211 212config PAGE_OFFSET 213 hex 214 default 0xC0000000 if 32BIT && MMU 215 default 0x80000000 if !MMU 216 default 0xff60000000000000 if 64BIT 217 218config KASAN_SHADOW_OFFSET 219 hex 220 depends on KASAN_GENERIC 221 default 0xdfffffff00000000 if 64BIT 222 default 0xffffffff if 32BIT 223 224config ARCH_FLATMEM_ENABLE 225 def_bool !NUMA 226 227config ARCH_SPARSEMEM_ENABLE 228 def_bool y 229 depends on MMU 230 select SPARSEMEM_STATIC if 32BIT && SPARSEMEM 231 select SPARSEMEM_VMEMMAP_ENABLE if 64BIT 232 233config ARCH_SELECT_MEMORY_MODEL 234 def_bool ARCH_SPARSEMEM_ENABLE 235 236config ARCH_SUPPORTS_UPROBES 237 def_bool y 238 239config STACKTRACE_SUPPORT 240 def_bool y 241 242config GENERIC_BUG 243 def_bool y 244 depends on BUG 245 select GENERIC_BUG_RELATIVE_POINTERS if 64BIT 246 247config GENERIC_BUG_RELATIVE_POINTERS 248 bool 249 250config GENERIC_CALIBRATE_DELAY 251 def_bool y 252 253config GENERIC_CSUM 254 def_bool y 255 256config GENERIC_HWEIGHT 257 def_bool y 258 259config FIX_EARLYCON_MEM 260 def_bool MMU 261 262config PGTABLE_LEVELS 263 int 264 default 5 if 64BIT 265 default 2 266 267config LOCKDEP_SUPPORT 268 def_bool y 269 270config RISCV_DMA_NONCOHERENT 271 bool 272 select ARCH_HAS_DMA_PREP_COHERENT 273 select ARCH_HAS_SETUP_DMA_OPS 274 select ARCH_HAS_SYNC_DMA_FOR_CPU 275 select ARCH_HAS_SYNC_DMA_FOR_DEVICE 276 select DMA_BOUNCE_UNALIGNED_KMALLOC if SWIOTLB 277 select DMA_DIRECT_REMAP if MMU 278 279config RISCV_NONSTANDARD_CACHE_OPS 280 bool 281 depends on RISCV_DMA_NONCOHERENT 282 help 283 This enables function pointer support for non-standard noncoherent 284 systems to handle cache management. 285 286config AS_HAS_INSN 287 def_bool $(as-instr,.insn r 51$(comma) 0$(comma) 0$(comma) t0$(comma) t0$(comma) zero) 288 289config AS_HAS_OPTION_ARCH 290 # https://reviews.llvm.org/D123515 291 def_bool y 292 depends on $(as-instr, .option arch$(comma) +m) 293 depends on !$(as-instr, .option arch$(comma) -i) 294 295source "arch/riscv/Kconfig.socs" 296source "arch/riscv/Kconfig.errata" 297 298menu "Platform type" 299 300config NONPORTABLE 301 bool "Allow configurations that result in non-portable kernels" 302 help 303 RISC-V kernel binaries are compatible between all known systems 304 whenever possible, but there are some use cases that can only be 305 satisfied by configurations that result in kernel binaries that are 306 not portable between systems. 307 308 Selecting N does not guarantee kernels will be portable to all known 309 systems. Selecting any of the options guarded by NONPORTABLE will 310 result in kernel binaries that are unlikely to be portable between 311 systems. 312 313 If unsure, say N. 314 315choice 316 prompt "Base ISA" 317 default ARCH_RV64I 318 help 319 This selects the base ISA that this kernel will target and must match 320 the target platform. 321 322config ARCH_RV32I 323 bool "RV32I" 324 depends on NONPORTABLE 325 select 32BIT 326 select GENERIC_LIB_ASHLDI3 327 select GENERIC_LIB_ASHRDI3 328 select GENERIC_LIB_LSHRDI3 329 select GENERIC_LIB_UCMPDI2 330 331config ARCH_RV64I 332 bool "RV64I" 333 select 64BIT 334 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 335 select SWIOTLB if MMU 336 337endchoice 338 339# We must be able to map all physical memory into the kernel, but the compiler 340# is still a bit more efficient when generating code if it's setup in a manner 341# such that it can only map 2GiB of memory. 342choice 343 prompt "Kernel Code Model" 344 default CMODEL_MEDLOW if 32BIT 345 default CMODEL_MEDANY if 64BIT 346 347 config CMODEL_MEDLOW 348 bool "medium low code model" 349 config CMODEL_MEDANY 350 bool "medium any code model" 351endchoice 352 353config MODULE_SECTIONS 354 bool 355 select HAVE_MOD_ARCH_SPECIFIC 356 357config SMP 358 bool "Symmetric Multi-Processing" 359 help 360 This enables support for systems with more than one CPU. If 361 you say N here, the kernel will run on single and 362 multiprocessor machines, but will use only one CPU of a 363 multiprocessor machine. If you say Y here, the kernel will run 364 on many, but not all, single processor machines. On a single 365 processor machine, the kernel will run faster if you say N 366 here. 367 368 If you don't know what to do here, say N. 369 370config SCHED_MC 371 bool "Multi-core scheduler support" 372 depends on SMP 373 help 374 Multi-core scheduler support improves the CPU scheduler's decision 375 making when dealing with multi-core CPU chips at a cost of slightly 376 increased overhead in some places. If unsure say N here. 377 378config NR_CPUS 379 int "Maximum number of CPUs (2-512)" 380 depends on SMP 381 range 2 512 if !RISCV_SBI_V01 382 range 2 32 if RISCV_SBI_V01 && 32BIT 383 range 2 64 if RISCV_SBI_V01 && 64BIT 384 default "32" if 32BIT 385 default "64" if 64BIT 386 387config HOTPLUG_CPU 388 bool "Support for hot-pluggable CPUs" 389 depends on SMP 390 select GENERIC_IRQ_MIGRATION 391 help 392 393 Say Y here to experiment with turning CPUs off and on. CPUs 394 can be controlled through /sys/devices/system/cpu. 395 396 Say N if you want to disable CPU hotplug. 397 398choice 399 prompt "CPU Tuning" 400 default TUNE_GENERIC 401 402config TUNE_GENERIC 403 bool "generic" 404 405endchoice 406 407# Common NUMA Features 408config NUMA 409 bool "NUMA Memory Allocation and Scheduler Support" 410 depends on SMP && MMU 411 select ARCH_SUPPORTS_NUMA_BALANCING 412 select GENERIC_ARCH_NUMA 413 select NEED_PER_CPU_EMBED_FIRST_CHUNK 414 select OF_NUMA 415 select USE_PERCPU_NUMA_NODE_ID 416 help 417 Enable NUMA (Non-Uniform Memory Access) support. 418 419 The kernel will try to allocate memory used by a CPU on the 420 local memory of the CPU and add some more NUMA awareness to the kernel. 421 422config NODES_SHIFT 423 int "Maximum NUMA Nodes (as a power of 2)" 424 range 1 10 425 default "2" 426 depends on NUMA 427 help 428 Specify the maximum number of NUMA Nodes available on the target 429 system. Increases memory reserved to accommodate various tables. 430 431config RISCV_ALTERNATIVE 432 bool 433 depends on !XIP_KERNEL 434 help 435 This Kconfig allows the kernel to automatically patch the 436 erratum or cpufeature required by the execution platform at run 437 time. The code patching overhead is minimal, as it's only done 438 once at boot and once on each module load. 439 440config RISCV_ALTERNATIVE_EARLY 441 bool 442 depends on RISCV_ALTERNATIVE 443 help 444 Allows early patching of the kernel for special errata 445 446config RISCV_ISA_C 447 bool "Emit compressed instructions when building Linux" 448 default y 449 help 450 Adds "C" to the ISA subsets that the toolchain is allowed to emit 451 when building Linux, which results in compressed instructions in the 452 Linux binary. 453 454 If you don't know what to do here, say Y. 455 456config RISCV_ISA_SVNAPOT 457 bool "Svnapot extension support for supervisor mode NAPOT pages" 458 depends on 64BIT && MMU 459 depends on RISCV_ALTERNATIVE 460 default y 461 help 462 Allow kernel to detect the Svnapot ISA-extension dynamically at boot 463 time and enable its usage. 464 465 The Svnapot extension is used to mark contiguous PTEs as a range 466 of contiguous virtual-to-physical translations for a naturally 467 aligned power-of-2 (NAPOT) granularity larger than the base 4KB page 468 size. When HUGETLBFS is also selected this option unconditionally 469 allocates some memory for each NAPOT page size supported by the kernel. 470 When optimizing for low memory consumption and for platforms without 471 the Svnapot extension, it may be better to say N here. 472 473 If you don't know what to do here, say Y. 474 475config RISCV_ISA_SVPBMT 476 bool "Svpbmt extension support for supervisor mode page-based memory types" 477 depends on 64BIT && MMU 478 depends on RISCV_ALTERNATIVE 479 default y 480 help 481 Adds support to dynamically detect the presence of the Svpbmt 482 ISA-extension (Supervisor-mode: page-based memory types) and 483 enable its usage. 484 485 The memory type for a page contains a combination of attributes 486 that indicate the cacheability, idempotency, and ordering 487 properties for access to that page. 488 489 The Svpbmt extension is only available on 64-bit cpus. 490 491 If you don't know what to do here, say Y. 492 493config TOOLCHAIN_HAS_V 494 bool 495 default y 496 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64iv) 497 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32iv) 498 depends on LLD_VERSION >= 140000 || LD_VERSION >= 23800 499 depends on AS_HAS_OPTION_ARCH 500 501config RISCV_ISA_V 502 bool "VECTOR extension support" 503 depends on TOOLCHAIN_HAS_V 504 depends on FPU 505 select DYNAMIC_SIGFRAME 506 default y 507 help 508 Say N here if you want to disable all vector related procedure 509 in the kernel. 510 511 If you don't know what to do here, say Y. 512 513config RISCV_ISA_V_DEFAULT_ENABLE 514 bool "Enable userspace Vector by default" 515 depends on RISCV_ISA_V 516 default y 517 help 518 Say Y here if you want to enable Vector in userspace by default. 519 Otherwise, userspace has to make explicit prctl() call to enable 520 Vector, or enable it via the sysctl interface. 521 522 If you don't know what to do here, say Y. 523 524config TOOLCHAIN_HAS_ZBB 525 bool 526 default y 527 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbb) 528 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbb) 529 depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900 530 depends on AS_HAS_OPTION_ARCH 531 532config RISCV_ISA_ZBB 533 bool "Zbb extension support for bit manipulation instructions" 534 depends on TOOLCHAIN_HAS_ZBB 535 depends on MMU 536 depends on RISCV_ALTERNATIVE 537 default y 538 help 539 Adds support to dynamically detect the presence of the ZBB 540 extension (basic bit manipulation) and enable its usage. 541 542 The Zbb extension provides instructions to accelerate a number 543 of bit-specific operations (count bit population, sign extending, 544 bitrotation, etc). 545 546 If you don't know what to do here, say Y. 547 548config RISCV_ISA_ZICBOM 549 bool "Zicbom extension support for non-coherent DMA operation" 550 depends on MMU 551 depends on RISCV_ALTERNATIVE 552 default y 553 select RISCV_DMA_NONCOHERENT 554 help 555 Adds support to dynamically detect the presence of the ZICBOM 556 extension (Cache Block Management Operations) and enable its 557 usage. 558 559 The Zicbom extension can be used to handle for example 560 non-coherent DMA support on devices that need it. 561 562 If you don't know what to do here, say Y. 563 564config RISCV_ISA_ZICBOZ 565 bool "Zicboz extension support for faster zeroing of memory" 566 depends on MMU 567 depends on RISCV_ALTERNATIVE 568 default y 569 help 570 Enable the use of the Zicboz extension (cbo.zero instruction) 571 when available. 572 573 The Zicboz extension is used for faster zeroing of memory. 574 575 If you don't know what to do here, say Y. 576 577config TOOLCHAIN_HAS_ZIHINTPAUSE 578 bool 579 default y 580 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zihintpause) 581 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zihintpause) 582 depends on LLD_VERSION >= 150000 || LD_VERSION >= 23600 583 584config TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI 585 def_bool y 586 # https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=aed44286efa8ae8717a77d94b51ac3614e2ca6dc 587 # https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=98416dbb0a62579d4a7a4a76bab51b5b52fec2cd 588 depends on AS_IS_GNU && AS_VERSION >= 23600 589 help 590 Binutils-2.38 and GCC-12.1.0 bumped the default ISA spec to the newer 591 20191213 version, which moves some instructions from the I extension to 592 the Zicsr and Zifencei extensions. This requires explicitly specifying 593 Zicsr and Zifencei when binutils >= 2.38 or GCC >= 12.1.0. Zicsr 594 and Zifencei are supported in binutils from version 2.36 onwards. 595 To make life easier, and avoid forcing toolchains that default to a 596 newer ISA spec to version 2.2, relax the check to binutils >= 2.36. 597 For clang < 17 or GCC < 11.3.0, for which this is not possible or need 598 special treatment, this is dealt with in TOOLCHAIN_NEEDS_OLD_ISA_SPEC. 599 600config TOOLCHAIN_NEEDS_OLD_ISA_SPEC 601 def_bool y 602 depends on TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI 603 # https://github.com/llvm/llvm-project/commit/22e199e6afb1263c943c0c0d4498694e15bf8a16 604 # https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=d29f5d6ab513c52fd872f532c492e35ae9fd6671 605 depends on (CC_IS_CLANG && CLANG_VERSION < 170000) || (CC_IS_GCC && GCC_VERSION < 110300) 606 help 607 Certain versions of clang and GCC do not support zicsr and zifencei via 608 -march. This option causes an older ISA spec compatible with these older 609 versions of clang and GCC to be passed to GAS, which has the same result 610 as passing zicsr and zifencei to -march. 611 612config FPU 613 bool "FPU support" 614 default y 615 help 616 Say N here if you want to disable all floating-point related procedure 617 in the kernel. 618 619 If you don't know what to do here, say Y. 620 621config IRQ_STACKS 622 bool "Independent irq & softirq stacks" if EXPERT 623 default y 624 select HAVE_IRQ_EXIT_ON_IRQ_STACK 625 select HAVE_SOFTIRQ_ON_OWN_STACK 626 help 627 Add independent irq & softirq stacks for percpu to prevent kernel stack 628 overflows. We may save some memory footprint by disabling IRQ_STACKS. 629 630config THREAD_SIZE_ORDER 631 int "Kernel stack size (in power-of-two numbers of page size)" if VMAP_STACK && EXPERT 632 range 0 4 633 default 1 if 32BIT && !KASAN 634 default 3 if 64BIT && KASAN 635 default 2 636 help 637 Specify the Pages of thread stack size (from 4KB to 64KB), which also 638 affects irq stack size, which is equal to thread stack size. 639 640endmenu # "Platform type" 641 642menu "Kernel features" 643 644source "kernel/Kconfig.hz" 645 646config RISCV_SBI_V01 647 bool "SBI v0.1 support" 648 depends on RISCV_SBI 649 help 650 This config allows kernel to use SBI v0.1 APIs. This will be 651 deprecated in future once legacy M-mode software are no longer in use. 652 653config RISCV_BOOT_SPINWAIT 654 bool "Spinwait booting method" 655 depends on SMP 656 default y if RISCV_SBI_V01 || RISCV_M_MODE 657 help 658 This enables support for booting Linux via spinwait method. In the 659 spinwait method, all cores randomly jump to Linux. One of the cores 660 gets chosen via lottery and all other keep spinning on a percpu 661 variable. This method cannot support CPU hotplug and sparse hartid 662 scheme. It should be only enabled for M-mode Linux or platforms relying 663 on older firmware without SBI HSM extension. All other platforms should 664 rely on ordered booting via SBI HSM extension which gets chosen 665 dynamically at runtime if the firmware supports it. 666 667 Since spinwait is incompatible with sparse hart IDs, it requires 668 NR_CPUS be large enough to contain the physical hart ID of the first 669 hart to enter Linux. 670 671 If unsure what to do here, say N. 672 673config ARCH_SUPPORTS_KEXEC 674 def_bool MMU 675 676config ARCH_SELECTS_KEXEC 677 def_bool y 678 depends on KEXEC 679 select HOTPLUG_CPU if SMP 680 681config ARCH_SUPPORTS_KEXEC_FILE 682 def_bool 64BIT && MMU 683 684config ARCH_SELECTS_KEXEC_FILE 685 def_bool y 686 depends on KEXEC_FILE 687 select HAVE_IMA_KEXEC if IMA 688 select KEXEC_ELF 689 690config ARCH_SUPPORTS_KEXEC_PURGATORY 691 def_bool KEXEC_FILE 692 depends on CRYPTO=y 693 depends on CRYPTO_SHA256=y 694 695config ARCH_SUPPORTS_CRASH_DUMP 696 def_bool y 697 698config COMPAT 699 bool "Kernel support for 32-bit U-mode" 700 default 64BIT 701 depends on 64BIT && MMU 702 help 703 This option enables support for a 32-bit U-mode running under a 64-bit 704 kernel at S-mode. riscv32-specific components such as system calls, 705 the user helper functions (vdso), signal rt_frame functions and the 706 ptrace interface are handled appropriately by the kernel. 707 708 If you want to execute 32-bit userspace applications, say Y. 709 710config RELOCATABLE 711 bool "Build a relocatable kernel" 712 depends on MMU && 64BIT && !XIP_KERNEL 713 help 714 This builds a kernel as a Position Independent Executable (PIE), 715 which retains all relocation metadata required to relocate the 716 kernel binary at runtime to a different virtual address than the 717 address it was linked at. 718 Since RISCV uses the RELA relocation format, this requires a 719 relocation pass at runtime even if the kernel is loaded at the 720 same address it was linked at. 721 722 If unsure, say N. 723 724config RANDOMIZE_BASE 725 bool "Randomize the address of the kernel image" 726 select RELOCATABLE 727 depends on MMU && 64BIT && !XIP_KERNEL 728 help 729 Randomizes the virtual address at which the kernel image is 730 loaded, as a security feature that deters exploit attempts 731 relying on knowledge of the location of kernel internals. 732 733 It is the bootloader's job to provide entropy, by passing a 734 random u64 value in /chosen/kaslr-seed at kernel entry. 735 736 When booting via the UEFI stub, it will invoke the firmware's 737 EFI_RNG_PROTOCOL implementation (if available) to supply entropy 738 to the kernel proper. In addition, it will randomise the physical 739 location of the kernel Image as well. 740 741 If unsure, say N. 742 743endmenu # "Kernel features" 744 745menu "Boot options" 746 747config CMDLINE 748 string "Built-in kernel command line" 749 help 750 For most platforms, the arguments for the kernel's command line 751 are provided at run-time, during boot. However, there are cases 752 where either no arguments are being provided or the provided 753 arguments are insufficient or even invalid. 754 755 When that occurs, it is possible to define a built-in command 756 line here and choose how the kernel should use it later on. 757 758choice 759 prompt "Built-in command line usage" if CMDLINE != "" 760 default CMDLINE_FALLBACK 761 help 762 Choose how the kernel will handle the provided built-in command 763 line. 764 765config CMDLINE_FALLBACK 766 bool "Use bootloader kernel arguments if available" 767 help 768 Use the built-in command line as fallback in case we get nothing 769 during boot. This is the default behaviour. 770 771config CMDLINE_EXTEND 772 bool "Extend bootloader kernel arguments" 773 help 774 The command-line arguments provided during boot will be 775 appended to the built-in command line. This is useful in 776 cases where the provided arguments are insufficient and 777 you don't want to or cannot modify them. 778 779config CMDLINE_FORCE 780 bool "Always use the default kernel command string" 781 help 782 Always use the built-in command line, even if we get one during 783 boot. This is useful in case you need to override the provided 784 command line on systems where you don't have or want control 785 over it. 786 787endchoice 788 789config EFI_STUB 790 bool 791 792config EFI 793 bool "UEFI runtime support" 794 depends on OF && !XIP_KERNEL 795 depends on MMU 796 default y 797 select ARCH_SUPPORTS_ACPI if 64BIT 798 select EFI_GENERIC_STUB 799 select EFI_PARAMS_FROM_FDT 800 select EFI_RUNTIME_WRAPPERS 801 select EFI_STUB 802 select LIBFDT 803 select RISCV_ISA_C 804 select UCS2_STRING 805 help 806 This option provides support for runtime services provided 807 by UEFI firmware (such as non-volatile variables, realtime 808 clock, and platform reset). A UEFI stub is also provided to 809 allow the kernel to be booted as an EFI application. This 810 is only useful on systems that have UEFI firmware. 811 812config CC_HAVE_STACKPROTECTOR_TLS 813 def_bool $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=tp -mstack-protector-guard-offset=0) 814 815config STACKPROTECTOR_PER_TASK 816 def_bool y 817 depends on !RANDSTRUCT 818 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_TLS 819 820config PHYS_RAM_BASE_FIXED 821 bool "Explicitly specified physical RAM address" 822 depends on NONPORTABLE 823 default n 824 825config PHYS_RAM_BASE 826 hex "Platform Physical RAM address" 827 depends on PHYS_RAM_BASE_FIXED 828 default "0x80000000" 829 help 830 This is the physical address of RAM in the system. It has to be 831 explicitly specified to run early relocations of read-write data 832 from flash to RAM. 833 834config XIP_KERNEL 835 bool "Kernel Execute-In-Place from ROM" 836 depends on MMU && SPARSEMEM && NONPORTABLE 837 # This prevents XIP from being enabled by all{yes,mod}config, which 838 # fail to build since XIP doesn't support large kernels. 839 depends on !COMPILE_TEST 840 select PHYS_RAM_BASE_FIXED 841 help 842 Execute-In-Place allows the kernel to run from non-volatile storage 843 directly addressable by the CPU, such as NOR flash. This saves RAM 844 space since the text section of the kernel is not loaded from flash 845 to RAM. Read-write sections, such as the data section and stack, 846 are still copied to RAM. The XIP kernel is not compressed since 847 it has to run directly from flash, so it will take more space to 848 store it. The flash address used to link the kernel object files, 849 and for storing it, is configuration dependent. Therefore, if you 850 say Y here, you must know the proper physical address where to 851 store the kernel image depending on your own flash memory usage. 852 853 Also note that the make target becomes "make xipImage" rather than 854 "make zImage" or "make Image". The final kernel binary to put in 855 ROM memory will be arch/riscv/boot/xipImage. 856 857 SPARSEMEM is required because the kernel text and rodata that are 858 flash resident are not backed by memmap, then any attempt to get 859 a struct page on those regions will trigger a fault. 860 861 If unsure, say N. 862 863config XIP_PHYS_ADDR 864 hex "XIP Kernel Physical Location" 865 depends on XIP_KERNEL 866 default "0x21000000" 867 help 868 This is the physical address in your flash memory the kernel will 869 be linked for and stored to. This address is dependent on your 870 own flash usage. 871 872config RISCV_ISA_FALLBACK 873 bool "Permit falling back to parsing riscv,isa for extension support by default" 874 default y 875 help 876 Parsing the "riscv,isa" devicetree property has been deprecated and 877 replaced by a list of explicitly defined strings. For compatibility 878 with existing platforms, the kernel will fall back to parsing the 879 "riscv,isa" property if the replacements are not found. 880 881 Selecting N here will result in a kernel that does not use the 882 fallback, unless the commandline "riscv_isa_fallback" parameter is 883 present. 884 885 Please see the dt-binding, located at 886 Documentation/devicetree/bindings/riscv/extensions.yaml for details 887 on the replacement properties, "riscv,isa-base" and 888 "riscv,isa-extensions". 889 890endmenu # "Boot options" 891 892config BUILTIN_DTB 893 bool 894 depends on OF && NONPORTABLE 895 default y if XIP_KERNEL 896 897config PORTABLE 898 bool 899 default !NONPORTABLE 900 select EFI 901 select MMU 902 select OF 903 904menu "Power management options" 905 906source "kernel/power/Kconfig" 907 908# Hibernation is only possible on systems where the SBI implementation has 909# marked its reserved memory as not accessible from, or does not run 910# from the same memory as, Linux 911config ARCH_HIBERNATION_POSSIBLE 912 def_bool NONPORTABLE 913 914config ARCH_HIBERNATION_HEADER 915 def_bool HIBERNATION 916 917config ARCH_SUSPEND_POSSIBLE 918 def_bool y 919 920endmenu # "Power management options" 921 922menu "CPU Power Management" 923 924source "drivers/cpuidle/Kconfig" 925 926source "drivers/cpufreq/Kconfig" 927 928endmenu # "CPU Power Management" 929 930source "arch/riscv/kvm/Kconfig" 931 932source "drivers/acpi/Kconfig" 933