Kconfig - OpenGrok cross reference for /openbmc/linux/init/Kconfig

1 # SPDX-License-Identifier: GPL-2.0-only
8 	  - Re-run Kconfig when the compiler is updated
13 	  - Ensure full rebuild when the compiler is updated
14 	    include/linux/compiler-version.h contains this option in the comment
16 	    auto-generated dependency. When the compiler is updated, syncconfig
20 	def_bool $(success,test "$(cc-name)" = GCC)
24 	default $(cc-version) if CC_IS_GCC
28 	def_bool $(success,test "$(cc-name)" = Clang)
32 	default $(cc-version) if CC_IS_CLANG
36 	def_bool $(success,test "$(as-name)" = GNU)
39 	def_bool $(success,test "$(as-name)" = LLVM)
45 	default $(as-version)
48 	def_bool $(success,test "$(ld-name)" = BFD)
52 	default $(ld-version) if LD_IS_BFD
56 	def_bool $(success,test "$(ld-name)" = LLD)
60 	default $(ld-version) if LD_IS_LLD
68 	  Please see Documentation/rust/quick-start.rst for instructions on how
76 	default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(USERCFLAGS) $(USERLDFLAGS) $(m64-flag)) if 64BIT
77 	default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(USERCFLAGS) $(USERLDFLAGS) $(m32-flag))
81 	default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(USERCFLAGS) $(USERLDFLAGS) $(m64-flag) -static) if 64BIT
82 	default $(success,$(srctree)/scripts/cc-can-link.sh $(CC) $(CLANG_FLAGS) $(USERCFLAGS) $(USERLDFLAGS) $(m32-flag) -static)
85 	def_bool $(success,echo 'int foo(int x) { asm goto ("": "=r"(x) ::: bar); return x; bar: return 0; }' | $(CC) -x c - -c -o /dev/null)
89 	# Detect buggy gcc and clang, fixed in gcc-11 clang-14.
90 	def_bool $(success,echo 'int foo(int *x) { asm goto (".long (%l[bar]) - .": "+m"(*x) ::: bar); return *x; bar: return 0; }' | $CC -x c - -c -o /dev/null)
102 	def_bool $(success,env "CC=$(CC)" "LD=$(LD)" "NM=$(NM)" "OBJCOPY=$(OBJCOPY)" $(srctree)/scripts/tools-support-relr.sh)
105 	def_bool $(success,echo 'void foo(void) { asm inline (""); }' | $(CC) -x c - -c -o /dev/null)
108 	def_bool $(success,echo '__attribute__((no_profile_instrument_function)) int x();' | $(CC) -x c - -c -o /dev/null -Werror)
113 	def_bool $(success,echo 'struct flex { int count; int array[] __attribute__((__counted_by__(count))); };' | $(CC) $(CLANG_FLAGS) -x c - -c -o /dev/null -Werror)
115 	# https://github.com/llvm/llvm-project/pull/110497
116 	# https://github.com/llvm/llvm-project/pull/112636
121 	default $(shell,$(srctree)/scripts/pahole-version.sh $(PAHOLE))
168 	  drivers to compile-test them.
179 	  enables the '-Werror' (for C) and '-Dwarnings' (for Rust) flags
195 	  Compile test headers exported to user-space to ensure they are
196 	  self-contained, i.e. compilable as standalone units.
199 	  headers are self-contained, say Y here. Otherwise, choose N.
202 	string "Local version - append to kernel release"
220 	  A string of the format -gxxxxxxxx will be added to the localversion
221 	  if a git-based tree is found.  The string generated by this will be
228 	    $ git rev-parse --verify HEAD
270 	  The linux kernel is a kind of self-extracting executable.
320 	  filter (i386, x86_64, ARM, IA-64, PowerPC, and SPARC), XZ
339 	  LZ4 is an LZ77-type compressor with a fixed, byte-oriented encoding.
373 	  This option determines the default init for the system if no init=
383 	  This option determines the default system hostname before userspace
386 	  system more usable with less configuration.
389 	bool "System V IPC"
392 	  system calls which let processes (running programs) synchronize and
396 	  DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
445 	  See Documentation/core-api/watch_queue.rst
452 	  Enabling this option adds the system calls process_vm_readv and
461 	  This option enables the uselib syscall, a system call used in the
463 	  system call.  If you intend to run programs built on libc5 or
473 	  logging of avc messages output).  System call auditing is included
504 	  statistics about user, system and idle time spent on per jiffies
517 	  between system, softirq and hardirq state, so there is a
519 	  this also enables accounting of stolen time on logically-partitioned
532 	  kernel-user boundaries using the context tracking subsystem.
562 	default y if ARM64
583 	  kernel (via a special system call) to write process accounting
619 	bool "Enable per-task delay accounting"
623 	  Collect information on time spent by a task waiting for system
640 	bool "Enable per-task storage I/O accounting"
653 	  and IO capacity are in the system.
657 	  the share of walltime in which some or all tasks in the system are
679 	  common scheduling-intense workloads in practice (such as
710 	  on-disk kernel.  This information can be extracted from the kernel
711 	  image file with the script scripts/extract-ikconfig and used as
727 	  This option enables access to the in-kernel headers that are generated during
730 	  kheaders.ko is built which can be loaded on-demand to get access to headers.
839 	  the precision of clamping aggregation and tracking at run-time.
845 	  If a second 30% boosted task should be co-scheduled on the same CPU,
856 	  clamp buckets to trade off used memory for run-time tracking
864 # For architectures that want to enable the support for NUMA-affine scheduler
881 	def_bool !$(cc-option,$(m64-flag) -D__SIZEOF_INT128__=0) && 64BIT
885 	default "-Wimplicit-fallthrough=5" if CC_IS_GCC && $(cc-option,-Wimplicit-fallthrough=5)
886 	default "-Wimplicit-fallthrough" if CC_IS_CLANG && $(cc-option,-Wunreachable-code-fallthrough)
888 # Currently, disable gcc-10+ array-bounds globally.
889 # It's still broken in gcc-13, so no upper bound yet.
904 # all cpu-local but of different latencies, such as SuperH.
919 	  This system will be inactive on UMA systems.
937 		- Documentation/scheduler/sched-design-CFS.rst	(CFS)
938 		- Documentation/admin-guide/cgroup-v1/ (features for grouping, isolation
990 	See Documentation/admin-guide/cgroup-v1/blkio-controller.rst for more information.
1020 	  See Documentation/scheduler/sched-bwc.rst for more information.
1029 	  schedule realtime tasks for non-root users until you allocate
1031 	  See Documentation/scheduler/sched-rt-group.rst for more information.
1055 	  specified task-specific clamp value is constrained by the cgroup
1069 	  system to halt without being limited by other cgroup policies. The
1085 	  hierarchy is allowed even if can cross the hierarchy's limit.
1094 	  controller includes important in-kernel memory consumers per default.
1119 	  allow dynamically partitioning a system into sets of CPUs and
1146 	  This option extends the perf per-cpu mode to restrict monitoring
1172 	  Miscellaneous scalar resources are the resources on the host system
1178 	  /Documentation/admin-guide/cgroup-v2.rst.
1215 	  uname() system call
1242 	  user-space use the memory control groups to limit the amount
1292 	bool "Kernel->user space relay support (formerly relayfs)"
1309 	  load modules needed to mount the "real" root file system,
1310 	  etc. See <file:Documentation/admin-guide/initrd.rst> for details.
1328 	  Extra boot config allows system admin to pass a config file as
1332 	  See <file:Documentation/admin-guide/bootconfig.rst> for details.
1342 	  out even when the "bootconfig" kernel-boot parameter is omitted.
1344 	  make the kernel ignore the BOOT_CONFIG-supplied kernel-boot
1355 	  image. But if the system doesn't support initrd, this option will
1383 	bool "Optimize for performance (-O2)"
1386 	  with the "-O2" compiler flag for best performance and most
1387 	  helpful compile-time warnings.
1390 	bool "Optimize for size (-Os)"
1392 	  Choosing this option will pass "-Os" to your compiler resulting
1411 	depends on $(cc-option,-ffunction-sections -fdata-sections)
1412 	depends on $(ld-option,--gc-sections)
1415 	  the linker by compiling with -ffunction-sections -fdata-sections,
1416 	  and linking with --gc-sections.
1418 	  This can reduce on disk and in-memory size of the kernel
1428 	depends on $(ld-option,--orphan-handling=warn)
1429 	depends on $(ld-option,--orphan-handling=error)
1446 	  Enable support for /proc/sys/debug/exception-trace.
1451 	  Enable support for /proc/sys/kernel/ignore-unaligned-usertrap
1458 	  Enable support for /proc/sys/kernel/unaligned-trap
1473 	# Unhide debug options, to make the on-by-default options visible
1478 	  environments which can tolerate a "non-standard" kernel.
1482 	bool "Enable 16-bit UID system calls" if EXPERT
1486 	  This enables the legacy 16-bit UID syscall wrappers.
1492 	  This option enables support for non-root users, groups and
1497 	  system calls related to UIDs, GIDs, and capabilities, such as setuid,
1506 	  sys_sgetmask and sys_ssetmask are obsolete system calls
1516 	  sys_sysfs is an obsolete system call no longer supported in libc.
1529 	  different file system operations. This is useful in implementing
1560 	  very difficult to diagnose system problems, saying N here is
1582 	bool "Enable PC-Speaker support" if EXPERT
1587 	  This option allows to disable the internal PC-Speaker
1592 	bool "Enable full-sized data structures for core" if EXPERT
1606 	  run glibc-based applications correctly.
1618 	  support for epoll family of system calls.
1621 	bool "Enable signalfd() system call" if EXPERT
1624 	  Enable the signalfd() system call that allows to receive signals
1630 	bool "Enable timerfd() system call" if EXPERT
1633 	  Enable the timerfd() system call that allows to receive timer
1639 	bool "Enable eventfd() system call" if EXPERT
1642 	  Enable the eventfd() system call that allows to receive both
1681 	  usage, improving performance. If building an embedded system where no
1686 	bool "Enable membarrier() system call" if EXPERT
1689 	  Enable the membarrier() system call that allows issuing memory
1691 	  the cost of user-space memory barriers asymmetrically by transforming
1714 	  Start self-test automatically after system startup. Suggest executing
1747 	  emit the symbol references in the kallsyms table as 32-bit entries,
1754 	  On 64-bit builds, this reduces the size of the address table by 50%,
1770 	bool "Enable kcmp() system call" if EXPERT
1772 	  Enable the kernel resource comparison system call. It provides
1773 	  user-space with the ability to compare two processes to see if they
1780 	bool "Enable rseq() system call" if EXPERT
1785 	  Enable the restartable sequences system call. It provides a
1786 	  user-space cache for the current CPU number value, which
1787 	  speeds up getting the current CPU number from user-space,
1788 	  as well as an ABI to speed up user-space operations on
1789 	  per-CPU data.
1794 	bool "Enable cachestat() system call" if EXPERT
1797 	  Enable the cachestat system call, which queries the page cache
1805 	bool "Enabled debugging of rseq() system call" if EXPERT
1808 	  Enable extra debugging checks for the rseq system call.
1844 	  Software events are supported either built-in or via the
1850 	  suffered, or branches mis-predicted - without slowing down the
1852 	  when a threshold number of events have passed - and can thus be
1857 	  system call and used by the "perf" utility in tools/perf/. It
1891 	  Provide PKCS#7 message verification using the contents of the system
1915 	  This allows other Rust-related options, like drivers written in Rust,
1928 	default "$(shell,$(RUSTC) --version 2>/dev/null)"
1933 	# The dummy parameter `workaround-for-0.69.0` is required to support 0.69.0
1934 	# (https://github.com/rust-lang/rust-bindgen/pull/2678). It can be removed when
1936 	default "$(shell,$(BINDGEN) --version workaround-for-0.69.0 2>/dev/null)"
2004 # macros for not-implemented syscalls in kernel/sys_ni.c and
2005 # kernel/time/posix-stubs.c. All these overrides need to be available in