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