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