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_CLOCKSOURCE_INIT 16 select ARCH_SUPPORTS_ATOMIC_RMW 17 select ARCH_HAS_BINFMT_FLAT 18 select ARCH_HAS_DEBUG_VIRTUAL if MMU 19 select ARCH_HAS_DEBUG_WX 20 select ARCH_HAS_GCOV_PROFILE_ALL 21 select ARCH_HAS_GIGANTIC_PAGE 22 select ARCH_HAS_MMIOWB 23 select ARCH_HAS_PTE_SPECIAL 24 select ARCH_HAS_SET_DIRECT_MAP 25 select ARCH_HAS_SET_MEMORY 26 select ARCH_HAS_STRICT_KERNEL_RWX if MMU 27 select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU 28 select ARCH_WANT_FRAME_POINTERS 29 select ARCH_WANT_HUGE_PMD_SHARE if 64BIT 30 select CLONE_BACKWARDS 31 select COMMON_CLK 32 select EDAC_SUPPORT 33 select GENERIC_ARCH_TOPOLOGY if SMP 34 select GENERIC_ATOMIC64 if !64BIT 35 select GENERIC_CLOCKEVENTS 36 select GENERIC_GETTIMEOFDAY if HAVE_GENERIC_VDSO 37 select GENERIC_IOREMAP 38 select GENERIC_IRQ_MULTI_HANDLER 39 select GENERIC_IRQ_SHOW 40 select GENERIC_PCI_IOMAP 41 select GENERIC_PTDUMP if MMU 42 select GENERIC_SCHED_CLOCK 43 select GENERIC_SMP_IDLE_THREAD 44 select GENERIC_STRNCPY_FROM_USER if MMU 45 select GENERIC_STRNLEN_USER if MMU 46 select GENERIC_TIME_VSYSCALL if MMU && 64BIT 47 select HANDLE_DOMAIN_IRQ 48 select HAVE_ARCH_AUDITSYSCALL 49 select HAVE_ARCH_KASAN if MMU && 64BIT 50 select HAVE_ARCH_KGDB 51 select HAVE_ARCH_KGDB_QXFER_PKT 52 select HAVE_ARCH_MMAP_RND_BITS if MMU 53 select HAVE_ARCH_SECCOMP_FILTER 54 select HAVE_ARCH_TRACEHOOK 55 select HAVE_ASM_MODVERSIONS 56 select HAVE_CONTEXT_TRACKING 57 select HAVE_COPY_THREAD_TLS 58 select HAVE_DMA_CONTIGUOUS if MMU 59 select HAVE_EBPF_JIT if MMU 60 select HAVE_FUTEX_CMPXCHG if FUTEX 61 select HAVE_GENERIC_VDSO if MMU && 64BIT 62 select HAVE_PCI 63 select HAVE_PERF_EVENTS 64 select HAVE_PERF_REGS 65 select HAVE_PERF_USER_STACK_DUMP 66 select HAVE_SYSCALL_TRACEPOINTS 67 select IRQ_DOMAIN 68 select MODULES_USE_ELF_RELA if MODULES 69 select MODULE_SECTIONS if MODULES 70 select OF 71 select OF_EARLY_FLATTREE 72 select OF_IRQ 73 select PCI_DOMAINS_GENERIC if PCI 74 select PCI_MSI if PCI 75 select RISCV_INTC 76 select RISCV_TIMER 77 select SPARSEMEM_STATIC if 32BIT 78 select SPARSE_IRQ 79 select SYSCTL_EXCEPTION_TRACE 80 select THREAD_INFO_IN_TASK 81 82config ARCH_MMAP_RND_BITS_MIN 83 default 18 if 64BIT 84 default 8 85 86# max bits determined by the following formula: 87# VA_BITS - PAGE_SHIFT - 3 88config ARCH_MMAP_RND_BITS_MAX 89 default 24 if 64BIT # SV39 based 90 default 17 91 92# set if we run in machine mode, cleared if we run in supervisor mode 93config RISCV_M_MODE 94 bool 95 default !MMU 96 97# set if we are running in S-mode and can use SBI calls 98config RISCV_SBI 99 bool 100 depends on !RISCV_M_MODE 101 default y 102 103config MMU 104 bool "MMU-based Paged Memory Management Support" 105 default y 106 help 107 Select if you want MMU-based virtualised addressing space 108 support by paged memory management. If unsure, say 'Y'. 109 110config ZONE_DMA32 111 bool 112 default y if 64BIT 113 114config VA_BITS 115 int 116 default 32 if 32BIT 117 default 39 if 64BIT 118 119config PA_BITS 120 int 121 default 34 if 32BIT 122 default 56 if 64BIT 123 124config PAGE_OFFSET 125 hex 126 default 0xC0000000 if 32BIT && MAXPHYSMEM_2GB 127 default 0x80000000 if 64BIT && !MMU 128 default 0xffffffff80000000 if 64BIT && MAXPHYSMEM_2GB 129 default 0xffffffe000000000 if 64BIT && MAXPHYSMEM_128GB 130 131config ARCH_FLATMEM_ENABLE 132 def_bool y 133 134config ARCH_SPARSEMEM_ENABLE 135 def_bool y 136 depends on MMU 137 select SPARSEMEM_VMEMMAP_ENABLE 138 139config ARCH_SELECT_MEMORY_MODEL 140 def_bool ARCH_SPARSEMEM_ENABLE 141 142config ARCH_WANT_GENERAL_HUGETLB 143 def_bool y 144 145config ARCH_SUPPORTS_DEBUG_PAGEALLOC 146 def_bool y 147 148config SYS_SUPPORTS_HUGETLBFS 149 depends on MMU 150 def_bool y 151 152config STACKTRACE_SUPPORT 153 def_bool y 154 155config TRACE_IRQFLAGS_SUPPORT 156 def_bool y 157 158config GENERIC_BUG 159 def_bool y 160 depends on BUG 161 select GENERIC_BUG_RELATIVE_POINTERS if 64BIT 162 163config GENERIC_BUG_RELATIVE_POINTERS 164 bool 165 166config GENERIC_CALIBRATE_DELAY 167 def_bool y 168 169config GENERIC_CSUM 170 def_bool y 171 172config GENERIC_HWEIGHT 173 def_bool y 174 175config FIX_EARLYCON_MEM 176 def_bool MMU 177 178config PGTABLE_LEVELS 179 int 180 default 3 if 64BIT 181 default 2 182 183config LOCKDEP_SUPPORT 184 def_bool y 185 186source "arch/riscv/Kconfig.socs" 187 188menu "Platform type" 189 190choice 191 prompt "Base ISA" 192 default ARCH_RV64I 193 help 194 This selects the base ISA that this kernel will target and must match 195 the target platform. 196 197config ARCH_RV32I 198 bool "RV32I" 199 select 32BIT 200 select GENERIC_LIB_ASHLDI3 201 select GENERIC_LIB_ASHRDI3 202 select GENERIC_LIB_LSHRDI3 203 select GENERIC_LIB_UCMPDI2 204 select MMU 205 206config ARCH_RV64I 207 bool "RV64I" 208 select 64BIT 209 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 && GCC_VERSION >= 50000 210 select HAVE_DYNAMIC_FTRACE if MMU 211 select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE 212 select HAVE_FTRACE_MCOUNT_RECORD 213 select HAVE_FUNCTION_GRAPH_TRACER 214 select HAVE_FUNCTION_TRACER 215 select SWIOTLB if MMU 216 217endchoice 218 219# We must be able to map all physical memory into the kernel, but the compiler 220# is still a bit more efficient when generating code if it's setup in a manner 221# such that it can only map 2GiB of memory. 222choice 223 prompt "Kernel Code Model" 224 default CMODEL_MEDLOW if 32BIT 225 default CMODEL_MEDANY if 64BIT 226 227 config CMODEL_MEDLOW 228 bool "medium low code model" 229 config CMODEL_MEDANY 230 bool "medium any code model" 231endchoice 232 233config MODULE_SECTIONS 234 bool 235 select HAVE_MOD_ARCH_SPECIFIC 236 237choice 238 prompt "Maximum Physical Memory" 239 default MAXPHYSMEM_2GB if 32BIT 240 default MAXPHYSMEM_2GB if 64BIT && CMODEL_MEDLOW 241 default MAXPHYSMEM_128GB if 64BIT && CMODEL_MEDANY 242 243 config MAXPHYSMEM_2GB 244 bool "2GiB" 245 config MAXPHYSMEM_128GB 246 depends on 64BIT && CMODEL_MEDANY 247 bool "128GiB" 248endchoice 249 250 251config SMP 252 bool "Symmetric Multi-Processing" 253 help 254 This enables support for systems with more than one CPU. If 255 you say N here, the kernel will run on single and 256 multiprocessor machines, but will use only one CPU of a 257 multiprocessor machine. If you say Y here, the kernel will run 258 on many, but not all, single processor machines. On a single 259 processor machine, the kernel will run faster if you say N 260 here. 261 262 If you don't know what to do here, say N. 263 264config NR_CPUS 265 int "Maximum number of CPUs (2-32)" 266 range 2 32 267 depends on SMP 268 default "8" 269 270config HOTPLUG_CPU 271 bool "Support for hot-pluggable CPUs" 272 depends on SMP 273 select GENERIC_IRQ_MIGRATION 274 help 275 276 Say Y here to experiment with turning CPUs off and on. CPUs 277 can be controlled through /sys/devices/system/cpu. 278 279 Say N if you want to disable CPU hotplug. 280 281choice 282 prompt "CPU Tuning" 283 default TUNE_GENERIC 284 285config TUNE_GENERIC 286 bool "generic" 287 288endchoice 289 290config RISCV_ISA_C 291 bool "Emit compressed instructions when building Linux" 292 default y 293 help 294 Adds "C" to the ISA subsets that the toolchain is allowed to emit 295 when building Linux, which results in compressed instructions in the 296 Linux binary. 297 298 If you don't know what to do here, say Y. 299 300menu "supported PMU type" 301 depends on PERF_EVENTS 302 303config RISCV_BASE_PMU 304 bool "Base Performance Monitoring Unit" 305 def_bool y 306 help 307 A base PMU that serves as a reference implementation and has limited 308 feature of perf. It can run on any RISC-V machines so serves as the 309 fallback, but this option can also be disable to reduce kernel size. 310 311endmenu 312 313config FPU 314 bool "FPU support" 315 default y 316 help 317 Say N here if you want to disable all floating-point related procedure 318 in the kernel. 319 320 If you don't know what to do here, say Y. 321 322endmenu 323 324menu "Kernel features" 325 326source "kernel/Kconfig.hz" 327 328config SECCOMP 329 bool "Enable seccomp to safely compute untrusted bytecode" 330 help 331 This kernel feature is useful for number crunching applications 332 that may need to compute untrusted bytecode during their 333 execution. By using pipes or other transports made available to 334 the process as file descriptors supporting the read/write 335 syscalls, it's possible to isolate those applications in 336 their own address space using seccomp. Once seccomp is 337 enabled via prctl(PR_SET_SECCOMP), it cannot be disabled 338 and the task is only allowed to execute a few safe syscalls 339 defined by each seccomp mode. 340 341config RISCV_SBI_V01 342 bool "SBI v0.1 support" 343 default y 344 depends on RISCV_SBI 345 help 346 This config allows kernel to use SBI v0.1 APIs. This will be 347 deprecated in future once legacy M-mode software are no longer in use. 348endmenu 349 350menu "Boot options" 351 352config CMDLINE 353 string "Built-in kernel command line" 354 help 355 For most platforms, the arguments for the kernel's command line 356 are provided at run-time, during boot. However, there are cases 357 where either no arguments are being provided or the provided 358 arguments are insufficient or even invalid. 359 360 When that occurs, it is possible to define a built-in command 361 line here and choose how the kernel should use it later on. 362 363choice 364 prompt "Built-in command line usage" if CMDLINE != "" 365 default CMDLINE_FALLBACK 366 help 367 Choose how the kernel will handle the provided built-in command 368 line. 369 370config CMDLINE_FALLBACK 371 bool "Use bootloader kernel arguments if available" 372 help 373 Use the built-in command line as fallback in case we get nothing 374 during boot. This is the default behaviour. 375 376config CMDLINE_EXTEND 377 bool "Extend bootloader kernel arguments" 378 help 379 The command-line arguments provided during boot will be 380 appended to the built-in command line. This is useful in 381 cases where the provided arguments are insufficient and 382 you don't want to or cannot modify them. 383 384 385config CMDLINE_FORCE 386 bool "Always use the default kernel command string" 387 help 388 Always use the built-in command line, even if we get one during 389 boot. This is useful in case you need to override the provided 390 command line on systems where you don't have or want control 391 over it. 392 393endchoice 394 395endmenu 396 397config BUILTIN_DTB 398 def_bool n 399 depends on RISCV_M_MODE 400 depends on OF 401 402menu "Power management options" 403 404source "kernel/power/Kconfig" 405 406endmenu 407