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 ARCH_DMA_DEFAULT_COHERENT 16 select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION 17 select ARCH_ENABLE_SPLIT_PMD_PTLOCK if PGTABLE_LEVELS > 2 18 select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE 19 select ARCH_HAS_BINFMT_FLAT 20 select ARCH_HAS_CURRENT_STACK_POINTER 21 select ARCH_HAS_DEBUG_VIRTUAL if MMU 22 select ARCH_HAS_DEBUG_VM_PGTABLE 23 select ARCH_HAS_DEBUG_WX 24 select ARCH_HAS_FORTIFY_SOURCE 25 select ARCH_HAS_GCOV_PROFILE_ALL 26 select ARCH_HAS_GIGANTIC_PAGE 27 select ARCH_HAS_KCOV 28 select ARCH_HAS_MMIOWB 29 select ARCH_HAS_PMEM_API 30 select ARCH_HAS_PTE_SPECIAL 31 select ARCH_HAS_SET_DIRECT_MAP if MMU 32 select ARCH_HAS_SET_MEMORY if MMU 33 select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL 34 select ARCH_HAS_STRICT_MODULE_RWX if MMU && !XIP_KERNEL 35 select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST 36 select ARCH_HAS_UBSAN_SANITIZE_ALL 37 select ARCH_HAS_VDSO_DATA 38 select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX 39 select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT 40 select ARCH_STACKWALK 41 select ARCH_SUPPORTS_ATOMIC_RMW 42 select ARCH_SUPPORTS_DEBUG_PAGEALLOC if MMU 43 select ARCH_SUPPORTS_HUGETLBFS if MMU 44 select ARCH_SUPPORTS_PAGE_TABLE_CHECK if MMU 45 select ARCH_USE_MEMTEST 46 select ARCH_USE_QUEUED_RWLOCKS 47 select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU 48 select ARCH_WANT_FRAME_POINTERS 49 select ARCH_WANT_GENERAL_HUGETLB if !RISCV_ISA_SVNAPOT 50 select ARCH_WANT_HUGE_PMD_SHARE if 64BIT 51 select ARCH_WANT_LD_ORPHAN_WARN if !XIP_KERNEL 52 select ARCH_WANT_OPTIMIZE_VMEMMAP 53 select ARCH_WANTS_THP_SWAP if HAVE_ARCH_TRANSPARENT_HUGEPAGE 54 select BINFMT_FLAT_NO_DATA_START_OFFSET if !MMU 55 select BUILDTIME_TABLE_SORT if MMU 56 select CLINT_TIMER if !MMU 57 select CLONE_BACKWARDS 58 select COMMON_CLK 59 select CPU_PM if CPU_IDLE || HIBERNATION 60 select EDAC_SUPPORT 61 select GENERIC_ARCH_TOPOLOGY 62 select GENERIC_ATOMIC64 if !64BIT 63 select GENERIC_CLOCKEVENTS_BROADCAST if SMP 64 select GENERIC_EARLY_IOREMAP 65 select GENERIC_ENTRY 66 select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO 67 select GENERIC_IDLE_POLL_SETUP 68 select GENERIC_IOREMAP if MMU 69 select GENERIC_IRQ_IPI if SMP 70 select GENERIC_IRQ_IPI_MUX if SMP 71 select GENERIC_IRQ_MULTI_HANDLER 72 select GENERIC_IRQ_SHOW 73 select GENERIC_IRQ_SHOW_LEVEL 74 select GENERIC_LIB_DEVMEM_IS_ALLOWED 75 select GENERIC_PCI_IOMAP 76 select GENERIC_PTDUMP if MMU 77 select GENERIC_SCHED_CLOCK 78 select GENERIC_SMP_IDLE_THREAD 79 select GENERIC_TIME_VSYSCALL if MMU && 64BIT 80 select GENERIC_VDSO_TIME_NS if HAVE_GENERIC_VDSO 81 select HARDIRQS_SW_RESEND 82 select HAS_IOPORT if MMU 83 select HAVE_ARCH_AUDITSYSCALL 84 select HAVE_ARCH_HUGE_VMALLOC if HAVE_ARCH_HUGE_VMAP 85 select HAVE_ARCH_HUGE_VMAP if MMU && 64BIT && !XIP_KERNEL 86 select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL 87 select HAVE_ARCH_JUMP_LABEL_RELATIVE if !XIP_KERNEL 88 select HAVE_ARCH_KASAN if MMU && 64BIT 89 select HAVE_ARCH_KASAN_VMALLOC if MMU && 64BIT 90 select HAVE_ARCH_KFENCE if MMU && 64BIT 91 select HAVE_ARCH_KGDB if !XIP_KERNEL 92 select HAVE_ARCH_KGDB_QXFER_PKT 93 select HAVE_ARCH_MMAP_RND_BITS if MMU 94 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT 95 select HAVE_ARCH_SECCOMP_FILTER 96 select HAVE_ARCH_THREAD_STRUCT_WHITELIST 97 select HAVE_ARCH_TRACEHOOK 98 select HAVE_ARCH_TRANSPARENT_HUGEPAGE if 64BIT && MMU 99 select HAVE_ARCH_VMAP_STACK if MMU && 64BIT 100 select HAVE_ASM_MODVERSIONS 101 select HAVE_CONTEXT_TRACKING_USER 102 select HAVE_DEBUG_KMEMLEAK 103 select HAVE_DMA_CONTIGUOUS if MMU 104 select HAVE_EBPF_JIT if MMU 105 select HAVE_FUNCTION_ARG_ACCESS_API 106 select HAVE_FUNCTION_ERROR_INJECTION 107 select HAVE_GCC_PLUGINS 108 select HAVE_GENERIC_VDSO if MMU && 64BIT 109 select HAVE_IRQ_TIME_ACCOUNTING 110 select HAVE_KPROBES if !XIP_KERNEL 111 select HAVE_KPROBES_ON_FTRACE if !XIP_KERNEL 112 select HAVE_KRETPROBES if !XIP_KERNEL 113 select HAVE_RETHOOK if !XIP_KERNEL 114 select HAVE_MOVE_PMD 115 select HAVE_MOVE_PUD 116 select HAVE_PCI 117 select HAVE_PERF_EVENTS 118 select HAVE_PERF_REGS 119 select HAVE_PERF_USER_STACK_DUMP 120 select HAVE_POSIX_CPU_TIMERS_TASK_WORK 121 select HAVE_REGS_AND_STACK_ACCESS_API 122 select HAVE_RSEQ 123 select HAVE_STACKPROTECTOR 124 select HAVE_SYSCALL_TRACEPOINTS 125 select IRQ_DOMAIN 126 select IRQ_FORCED_THREADING 127 select KASAN_VMALLOC if KASAN 128 select MODULES_USE_ELF_RELA if MODULES 129 select MODULE_SECTIONS if MODULES 130 select OF 131 select OF_EARLY_FLATTREE 132 select OF_IRQ 133 select PCI_DOMAINS_GENERIC if PCI 134 select PCI_MSI if PCI 135 select RISCV_ALTERNATIVE if !XIP_KERNEL 136 select RISCV_INTC 137 select RISCV_TIMER if RISCV_SBI 138 select SIFIVE_PLIC 139 select SPARSE_IRQ 140 select SYSCTL_EXCEPTION_TRACE 141 select THREAD_INFO_IN_TASK 142 select TRACE_IRQFLAGS_SUPPORT 143 select UACCESS_MEMCPY if !MMU 144 select ZONE_DMA32 if 64BIT 145 select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && MMU && (CLANG_SUPPORTS_DYNAMIC_FTRACE || GCC_SUPPORTS_DYNAMIC_FTRACE) 146 select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE 147 select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL 148 select HAVE_FUNCTION_GRAPH_TRACER 149 select HAVE_FUNCTION_TRACER if !XIP_KERNEL && !PREEMPTION 150 151config CLANG_SUPPORTS_DYNAMIC_FTRACE 152 def_bool CC_IS_CLANG 153 # https://github.com/llvm/llvm-project/commit/6ab8927931851bb42b2c93a00801dc499d7d9b1e 154 depends on CLANG_VERSION >= 130000 155 # https://github.com/ClangBuiltLinux/linux/issues/1817 156 depends on AS_IS_GNU || (AS_IS_LLVM && (LD_IS_LLD || LD_VERSION >= 23600)) 157 158config GCC_SUPPORTS_DYNAMIC_FTRACE 159 def_bool CC_IS_GCC 160 depends on $(cc-option,-fpatchable-function-entry=8) 161 162config ARCH_MMAP_RND_BITS_MIN 163 default 18 if 64BIT 164 default 8 165 166config ARCH_MMAP_RND_COMPAT_BITS_MIN 167 default 8 168 169# max bits determined by the following formula: 170# VA_BITS - PAGE_SHIFT - 3 171config ARCH_MMAP_RND_BITS_MAX 172 default 24 if 64BIT # SV39 based 173 default 17 174 175config ARCH_MMAP_RND_COMPAT_BITS_MAX 176 default 17 177 178# set if we run in machine mode, cleared if we run in supervisor mode 179config RISCV_M_MODE 180 bool 181 default !MMU 182 183# set if we are running in S-mode and can use SBI calls 184config RISCV_SBI 185 bool 186 depends on !RISCV_M_MODE 187 default y 188 189config MMU 190 bool "MMU-based Paged Memory Management Support" 191 default y 192 help 193 Select if you want MMU-based virtualised addressing space 194 support by paged memory management. If unsure, say 'Y'. 195 196config PAGE_OFFSET 197 hex 198 default 0xC0000000 if 32BIT && MMU 199 default 0x80000000 if !MMU 200 default 0xff60000000000000 if 64BIT 201 202config KASAN_SHADOW_OFFSET 203 hex 204 depends on KASAN_GENERIC 205 default 0xdfffffff00000000 if 64BIT 206 default 0xffffffff if 32BIT 207 208config ARCH_FLATMEM_ENABLE 209 def_bool !NUMA 210 211config ARCH_SPARSEMEM_ENABLE 212 def_bool y 213 depends on MMU 214 select SPARSEMEM_STATIC if 32BIT && SPARSEMEM 215 select SPARSEMEM_VMEMMAP_ENABLE if 64BIT 216 217config ARCH_SELECT_MEMORY_MODEL 218 def_bool ARCH_SPARSEMEM_ENABLE 219 220config ARCH_SUPPORTS_UPROBES 221 def_bool y 222 223config STACKTRACE_SUPPORT 224 def_bool y 225 226config GENERIC_BUG 227 def_bool y 228 depends on BUG 229 select GENERIC_BUG_RELATIVE_POINTERS if 64BIT 230 231config GENERIC_BUG_RELATIVE_POINTERS 232 bool 233 234config GENERIC_CALIBRATE_DELAY 235 def_bool y 236 237config GENERIC_CSUM 238 def_bool y 239 240config GENERIC_HWEIGHT 241 def_bool y 242 243config FIX_EARLYCON_MEM 244 def_bool MMU 245 246config PGTABLE_LEVELS 247 int 248 default 5 if 64BIT 249 default 2 250 251config LOCKDEP_SUPPORT 252 def_bool y 253 254config RISCV_DMA_NONCOHERENT 255 bool 256 select ARCH_HAS_DMA_PREP_COHERENT 257 select ARCH_HAS_SETUP_DMA_OPS 258 select ARCH_HAS_SYNC_DMA_FOR_CPU 259 select ARCH_HAS_SYNC_DMA_FOR_DEVICE 260 select DMA_DIRECT_REMAP 261 262config AS_HAS_INSN 263 def_bool $(as-instr,.insn r 51$(comma) 0$(comma) 0$(comma) t0$(comma) t0$(comma) zero) 264 265source "arch/riscv/Kconfig.socs" 266source "arch/riscv/Kconfig.errata" 267 268menu "Platform type" 269 270config NONPORTABLE 271 bool "Allow configurations that result in non-portable kernels" 272 help 273 RISC-V kernel binaries are compatible between all known systems 274 whenever possible, but there are some use cases that can only be 275 satisfied by configurations that result in kernel binaries that are 276 not portable between systems. 277 278 Selecting N does not guarantee kernels will be portable to all known 279 systems. Selecting any of the options guarded by NONPORTABLE will 280 result in kernel binaries that are unlikely to be portable between 281 systems. 282 283 If unsure, say N. 284 285choice 286 prompt "Base ISA" 287 default ARCH_RV64I 288 help 289 This selects the base ISA that this kernel will target and must match 290 the target platform. 291 292config ARCH_RV32I 293 bool "RV32I" 294 depends on NONPORTABLE 295 select 32BIT 296 select GENERIC_LIB_ASHLDI3 297 select GENERIC_LIB_ASHRDI3 298 select GENERIC_LIB_LSHRDI3 299 select GENERIC_LIB_UCMPDI2 300 301config ARCH_RV64I 302 bool "RV64I" 303 select 64BIT 304 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 305 select SWIOTLB if MMU 306 307endchoice 308 309# We must be able to map all physical memory into the kernel, but the compiler 310# is still a bit more efficient when generating code if it's setup in a manner 311# such that it can only map 2GiB of memory. 312choice 313 prompt "Kernel Code Model" 314 default CMODEL_MEDLOW if 32BIT 315 default CMODEL_MEDANY if 64BIT 316 317 config CMODEL_MEDLOW 318 bool "medium low code model" 319 config CMODEL_MEDANY 320 bool "medium any code model" 321endchoice 322 323config MODULE_SECTIONS 324 bool 325 select HAVE_MOD_ARCH_SPECIFIC 326 327config SMP 328 bool "Symmetric Multi-Processing" 329 help 330 This enables support for systems with more than one CPU. If 331 you say N here, the kernel will run on single and 332 multiprocessor machines, but will use only one CPU of a 333 multiprocessor machine. If you say Y here, the kernel will run 334 on many, but not all, single processor machines. On a single 335 processor machine, the kernel will run faster if you say N 336 here. 337 338 If you don't know what to do here, say N. 339 340config SCHED_MC 341 bool "Multi-core scheduler support" 342 depends on SMP 343 help 344 Multi-core scheduler support improves the CPU scheduler's decision 345 making when dealing with multi-core CPU chips at a cost of slightly 346 increased overhead in some places. If unsure say N here. 347 348config NR_CPUS 349 int "Maximum number of CPUs (2-512)" 350 depends on SMP 351 range 2 512 if !RISCV_SBI_V01 352 range 2 32 if RISCV_SBI_V01 && 32BIT 353 range 2 64 if RISCV_SBI_V01 && 64BIT 354 default "32" if 32BIT 355 default "64" if 64BIT 356 357config HOTPLUG_CPU 358 bool "Support for hot-pluggable CPUs" 359 depends on SMP 360 select GENERIC_IRQ_MIGRATION 361 help 362 363 Say Y here to experiment with turning CPUs off and on. CPUs 364 can be controlled through /sys/devices/system/cpu. 365 366 Say N if you want to disable CPU hotplug. 367 368choice 369 prompt "CPU Tuning" 370 default TUNE_GENERIC 371 372config TUNE_GENERIC 373 bool "generic" 374 375endchoice 376 377# Common NUMA Features 378config NUMA 379 bool "NUMA Memory Allocation and Scheduler Support" 380 depends on SMP && MMU 381 select ARCH_SUPPORTS_NUMA_BALANCING 382 select GENERIC_ARCH_NUMA 383 select NEED_PER_CPU_EMBED_FIRST_CHUNK 384 select OF_NUMA 385 select USE_PERCPU_NUMA_NODE_ID 386 help 387 Enable NUMA (Non-Uniform Memory Access) support. 388 389 The kernel will try to allocate memory used by a CPU on the 390 local memory of the CPU and add some more NUMA awareness to the kernel. 391 392config NODES_SHIFT 393 int "Maximum NUMA Nodes (as a power of 2)" 394 range 1 10 395 default "2" 396 depends on NUMA 397 help 398 Specify the maximum number of NUMA Nodes available on the target 399 system. Increases memory reserved to accommodate various tables. 400 401config RISCV_ALTERNATIVE 402 bool 403 depends on !XIP_KERNEL 404 help 405 This Kconfig allows the kernel to automatically patch the 406 erratum or cpufeature required by the execution platform at run 407 time. The code patching overhead is minimal, as it's only done 408 once at boot and once on each module load. 409 410config RISCV_ALTERNATIVE_EARLY 411 bool 412 depends on RISCV_ALTERNATIVE 413 help 414 Allows early patching of the kernel for special errata 415 416config RISCV_ISA_C 417 bool "Emit compressed instructions when building Linux" 418 default y 419 help 420 Adds "C" to the ISA subsets that the toolchain is allowed to emit 421 when building Linux, which results in compressed instructions in the 422 Linux binary. 423 424 If you don't know what to do here, say Y. 425 426config RISCV_ISA_SVNAPOT 427 bool "Svnapot extension support for supervisor mode NAPOT pages" 428 depends on 64BIT && MMU 429 depends on RISCV_ALTERNATIVE 430 default y 431 help 432 Allow kernel to detect the Svnapot ISA-extension dynamically at boot 433 time and enable its usage. 434 435 The Svnapot extension is used to mark contiguous PTEs as a range 436 of contiguous virtual-to-physical translations for a naturally 437 aligned power-of-2 (NAPOT) granularity larger than the base 4KB page 438 size. When HUGETLBFS is also selected this option unconditionally 439 allocates some memory for each NAPOT page size supported by the kernel. 440 When optimizing for low memory consumption and for platforms without 441 the Svnapot extension, it may be better to say N here. 442 443 If you don't know what to do here, say Y. 444 445config RISCV_ISA_SVPBMT 446 bool "Svpbmt extension support for supervisor mode page-based memory types" 447 depends on 64BIT && MMU 448 depends on RISCV_ALTERNATIVE 449 default y 450 help 451 Adds support to dynamically detect the presence of the Svpbmt 452 ISA-extension (Supervisor-mode: page-based memory types) and 453 enable its usage. 454 455 The memory type for a page contains a combination of attributes 456 that indicate the cacheability, idempotency, and ordering 457 properties for access to that page. 458 459 The Svpbmt extension is only available on 64-bit cpus. 460 461 If you don't know what to do here, say Y. 462 463config TOOLCHAIN_HAS_ZBB 464 bool 465 default y 466 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbb) 467 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbb) 468 depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900 469 depends on AS_IS_GNU 470 471config RISCV_ISA_ZBB 472 bool "Zbb extension support for bit manipulation instructions" 473 depends on TOOLCHAIN_HAS_ZBB 474 depends on MMU 475 depends on RISCV_ALTERNATIVE 476 default y 477 help 478 Adds support to dynamically detect the presence of the ZBB 479 extension (basic bit manipulation) and enable its usage. 480 481 The Zbb extension provides instructions to accelerate a number 482 of bit-specific operations (count bit population, sign extending, 483 bitrotation, etc). 484 485 If you don't know what to do here, say Y. 486 487config RISCV_ISA_ZICBOM 488 bool "Zicbom extension support for non-coherent DMA operation" 489 depends on MMU 490 depends on RISCV_ALTERNATIVE 491 default y 492 select RISCV_DMA_NONCOHERENT 493 help 494 Adds support to dynamically detect the presence of the ZICBOM 495 extension (Cache Block Management Operations) and enable its 496 usage. 497 498 The Zicbom extension can be used to handle for example 499 non-coherent DMA support on devices that need it. 500 501 If you don't know what to do here, say Y. 502 503config RISCV_ISA_ZICBOZ 504 bool "Zicboz extension support for faster zeroing of memory" 505 depends on MMU 506 depends on RISCV_ALTERNATIVE 507 default y 508 help 509 Enable the use of the Zicboz extension (cbo.zero instruction) 510 when available. 511 512 The Zicboz extension is used for faster zeroing of memory. 513 514 If you don't know what to do here, say Y. 515 516config TOOLCHAIN_HAS_ZIHINTPAUSE 517 bool 518 default y 519 depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zihintpause) 520 depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zihintpause) 521 depends on LLD_VERSION >= 150000 || LD_VERSION >= 23600 522 523config TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI 524 def_bool y 525 # https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=aed44286efa8ae8717a77d94b51ac3614e2ca6dc 526 depends on AS_IS_GNU && AS_VERSION >= 23800 527 help 528 Newer binutils versions default to ISA spec version 20191213 which 529 moves some instructions from the I extension to the Zicsr and Zifencei 530 extensions. 531 532config TOOLCHAIN_NEEDS_OLD_ISA_SPEC 533 def_bool y 534 depends on TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI 535 # https://github.com/llvm/llvm-project/commit/22e199e6afb1263c943c0c0d4498694e15bf8a16 536 depends on CC_IS_CLANG && CLANG_VERSION < 170000 537 help 538 Certain versions of clang do not support zicsr and zifencei via -march 539 but newer versions of binutils require it for the reasons noted in the 540 help text of CONFIG_TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI. This 541 option causes an older ISA spec compatible with these older versions 542 of clang to be passed to GAS, which has the same result as passing zicsr 543 and zifencei to -march. 544 545config FPU 546 bool "FPU support" 547 default y 548 help 549 Say N here if you want to disable all floating-point related procedure 550 in the kernel. 551 552 If you don't know what to do here, say Y. 553 554endmenu # "Platform type" 555 556menu "Kernel features" 557 558source "kernel/Kconfig.hz" 559 560config RISCV_SBI_V01 561 bool "SBI v0.1 support" 562 depends on RISCV_SBI 563 help 564 This config allows kernel to use SBI v0.1 APIs. This will be 565 deprecated in future once legacy M-mode software are no longer in use. 566 567config RISCV_BOOT_SPINWAIT 568 bool "Spinwait booting method" 569 depends on SMP 570 default y if RISCV_SBI_V01 || RISCV_M_MODE 571 help 572 This enables support for booting Linux via spinwait method. In the 573 spinwait method, all cores randomly jump to Linux. One of the cores 574 gets chosen via lottery and all other keep spinning on a percpu 575 variable. This method cannot support CPU hotplug and sparse hartid 576 scheme. It should be only enabled for M-mode Linux or platforms relying 577 on older firmware without SBI HSM extension. All other platforms should 578 rely on ordered booting via SBI HSM extension which gets chosen 579 dynamically at runtime if the firmware supports it. 580 581 Since spinwait is incompatible with sparse hart IDs, it requires 582 NR_CPUS be large enough to contain the physical hart ID of the first 583 hart to enter Linux. 584 585 If unsure what to do here, say N. 586 587config KEXEC 588 bool "Kexec system call" 589 depends on MMU 590 select HOTPLUG_CPU if SMP 591 select KEXEC_CORE 592 help 593 kexec is a system call that implements the ability to shutdown your 594 current kernel, and to start another kernel. It is like a reboot 595 but it is independent of the system firmware. And like a reboot 596 you can start any kernel with it, not just Linux. 597 598 The name comes from the similarity to the exec system call. 599 600config KEXEC_FILE 601 bool "kexec file based systmem call" 602 depends on 64BIT && MMU 603 select HAVE_IMA_KEXEC if IMA 604 select KEXEC_CORE 605 select KEXEC_ELF 606 help 607 This is new version of kexec system call. This system call is 608 file based and takes file descriptors as system call argument 609 for kernel and initramfs as opposed to list of segments as 610 accepted by previous system call. 611 612 If you don't know what to do here, say Y. 613 614config ARCH_HAS_KEXEC_PURGATORY 615 def_bool KEXEC_FILE 616 depends on CRYPTO=y 617 depends on CRYPTO_SHA256=y 618 619config CRASH_DUMP 620 bool "Build kdump crash kernel" 621 help 622 Generate crash dump after being started by kexec. This should 623 be normally only set in special crash dump kernels which are 624 loaded in the main kernel with kexec-tools into a specially 625 reserved region and then later executed after a crash by 626 kdump/kexec. 627 628 For more details see Documentation/admin-guide/kdump/kdump.rst 629 630config COMPAT 631 bool "Kernel support for 32-bit U-mode" 632 default 64BIT 633 depends on 64BIT && MMU 634 help 635 This option enables support for a 32-bit U-mode running under a 64-bit 636 kernel at S-mode. riscv32-specific components such as system calls, 637 the user helper functions (vdso), signal rt_frame functions and the 638 ptrace interface are handled appropriately by the kernel. 639 640 If you want to execute 32-bit userspace applications, say Y. 641 642config RELOCATABLE 643 bool "Build a relocatable kernel" 644 depends on MMU && 64BIT && !XIP_KERNEL 645 help 646 This builds a kernel as a Position Independent Executable (PIE), 647 which retains all relocation metadata required to relocate the 648 kernel binary at runtime to a different virtual address than the 649 address it was linked at. 650 Since RISCV uses the RELA relocation format, this requires a 651 relocation pass at runtime even if the kernel is loaded at the 652 same address it was linked at. 653 654 If unsure, say N. 655 656endmenu # "Kernel features" 657 658menu "Boot options" 659 660config CMDLINE 661 string "Built-in kernel command line" 662 help 663 For most platforms, the arguments for the kernel's command line 664 are provided at run-time, during boot. However, there are cases 665 where either no arguments are being provided or the provided 666 arguments are insufficient or even invalid. 667 668 When that occurs, it is possible to define a built-in command 669 line here and choose how the kernel should use it later on. 670 671choice 672 prompt "Built-in command line usage" if CMDLINE != "" 673 default CMDLINE_FALLBACK 674 help 675 Choose how the kernel will handle the provided built-in command 676 line. 677 678config CMDLINE_FALLBACK 679 bool "Use bootloader kernel arguments if available" 680 help 681 Use the built-in command line as fallback in case we get nothing 682 during boot. This is the default behaviour. 683 684config CMDLINE_EXTEND 685 bool "Extend bootloader kernel arguments" 686 help 687 The command-line arguments provided during boot will be 688 appended to the built-in command line. This is useful in 689 cases where the provided arguments are insufficient and 690 you don't want to or cannot modify them. 691 692config CMDLINE_FORCE 693 bool "Always use the default kernel command string" 694 help 695 Always use the built-in command line, even if we get one during 696 boot. This is useful in case you need to override the provided 697 command line on systems where you don't have or want control 698 over it. 699 700endchoice 701 702config EFI_STUB 703 bool 704 705config EFI 706 bool "UEFI runtime support" 707 depends on OF && !XIP_KERNEL 708 depends on MMU 709 default y 710 select EFI_GENERIC_STUB 711 select EFI_PARAMS_FROM_FDT 712 select EFI_RUNTIME_WRAPPERS 713 select EFI_STUB 714 select LIBFDT 715 select RISCV_ISA_C 716 select UCS2_STRING 717 help 718 This option provides support for runtime services provided 719 by UEFI firmware (such as non-volatile variables, realtime 720 clock, and platform reset). A UEFI stub is also provided to 721 allow the kernel to be booted as an EFI application. This 722 is only useful on systems that have UEFI firmware. 723 724config CC_HAVE_STACKPROTECTOR_TLS 725 def_bool $(cc-option,-mstack-protector-guard=tls -mstack-protector-guard-reg=tp -mstack-protector-guard-offset=0) 726 727config STACKPROTECTOR_PER_TASK 728 def_bool y 729 depends on !RANDSTRUCT 730 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_TLS 731 732config PHYS_RAM_BASE_FIXED 733 bool "Explicitly specified physical RAM address" 734 depends on NONPORTABLE 735 default n 736 737config PHYS_RAM_BASE 738 hex "Platform Physical RAM address" 739 depends on PHYS_RAM_BASE_FIXED 740 default "0x80000000" 741 help 742 This is the physical address of RAM in the system. It has to be 743 explicitly specified to run early relocations of read-write data 744 from flash to RAM. 745 746config XIP_KERNEL 747 bool "Kernel Execute-In-Place from ROM" 748 depends on MMU && SPARSEMEM && NONPORTABLE 749 # This prevents XIP from being enabled by all{yes,mod}config, which 750 # fail to build since XIP doesn't support large kernels. 751 depends on !COMPILE_TEST 752 select PHYS_RAM_BASE_FIXED 753 help 754 Execute-In-Place allows the kernel to run from non-volatile storage 755 directly addressable by the CPU, such as NOR flash. This saves RAM 756 space since the text section of the kernel is not loaded from flash 757 to RAM. Read-write sections, such as the data section and stack, 758 are still copied to RAM. The XIP kernel is not compressed since 759 it has to run directly from flash, so it will take more space to 760 store it. The flash address used to link the kernel object files, 761 and for storing it, is configuration dependent. Therefore, if you 762 say Y here, you must know the proper physical address where to 763 store the kernel image depending on your own flash memory usage. 764 765 Also note that the make target becomes "make xipImage" rather than 766 "make zImage" or "make Image". The final kernel binary to put in 767 ROM memory will be arch/riscv/boot/xipImage. 768 769 SPARSEMEM is required because the kernel text and rodata that are 770 flash resident are not backed by memmap, then any attempt to get 771 a struct page on those regions will trigger a fault. 772 773 If unsure, say N. 774 775config XIP_PHYS_ADDR 776 hex "XIP Kernel Physical Location" 777 depends on XIP_KERNEL 778 default "0x21000000" 779 help 780 This is the physical address in your flash memory the kernel will 781 be linked for and stored to. This address is dependent on your 782 own flash usage. 783 784endmenu # "Boot options" 785 786config BUILTIN_DTB 787 bool 788 depends on OF && NONPORTABLE 789 default y if XIP_KERNEL 790 791config PORTABLE 792 bool 793 default !NONPORTABLE 794 select EFI 795 select MMU 796 select OF 797 798menu "Power management options" 799 800source "kernel/power/Kconfig" 801 802config ARCH_HIBERNATION_POSSIBLE 803 def_bool y 804 805config ARCH_HIBERNATION_HEADER 806 def_bool HIBERNATION 807 808endmenu # "Power management options" 809 810menu "CPU Power Management" 811 812source "drivers/cpuidle/Kconfig" 813 814source "drivers/cpufreq/Kconfig" 815 816endmenu # "CPU Power Management" 817 818source "arch/riscv/kvm/Kconfig" 819