crosstool-ng/config/libc/picolibc.in
Keith Packard c15de32ec6 Add picolibc support [v2]
This adds support for using picolibc instead of newlib on embedded
systems.

Signed-off-by: Keith Packard <keithp@keithp.com>

v2:
	Add check for meson and ninja
	Sync option default values with current picolibc defaults
	Remove xtensa sys header file install as those aren't in picolibc
2020-09-01 09:42:53 -07:00

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# picolibc options
## depends on BARE_METAL && CONFIGURE_has_meson && CONFIGURE_has_ninja
## select LIBC_SUPPORT_THREADS_NATIVE
## select CC_CORE_PASSES_NEEDED if CANADIAN
## select CC_CORE_PASS_2_NEEDED if ! CANADIAN
## help Picolibc is a C library intended for use on embedded systems. It is a
## help conglomeration of several library parts, all under BSD-compatible software
## help licenses that make them easily usable on embedded products. Picolibc
## help is only available in source form. It can be compiled for a wide
## help array of processors, and will usually work on any architecture with
## help the addition of a few low-level routines.
config PICOLIBC_CXA_ATEXIT
def_bool y
select LIBC_PROVIDES_CXA_ATEXIT
config LIBC_PICOLIBC_TARGET_CFLAGS
string
prompt "Target CFLAGS for picolibc"
default ""
help
Used to add specific options when compiling the target libraries
(eg. -ffunction-sections -fdata-sections), which can't be defined
in global TARGET_CFLAGS, because they shall be not used for the
gcc target libraries.
Note: Both TARGET_CFLAGS and LIBC_PICOLIBC_TARGET_CFLAGS are used
to compile the libraries.
Leave blank if you don't know better.
config LIBC_PICOLIBC_IO_C99FMT
bool
prompt "Enable IOs on C99 formats"
default y
help
Enable support for IOs on C99 formats.
config LIBC_PICOLIBC_REGISTER_FINI
bool
prompt "Enable finalization function registration using atexit"
help
Enable finalization function registration using atexit.
config LIBC_PICOLIBC_ATEXIT_DYNAMIC_ALLOC
bool
prompt "Enable dynamic allocation of atexit entries"
help
Enable dynamic allocation of atexit entries.
config LIBC_PICOLIBC_GLOBAL_ATEXIT
bool
prompt "Enable atexit data structure as global variable"
help
Enable atexit data structure as global variable, instead
of being thread-local.
config LIBC_PICOLIBC_LITE_EXIT
bool
prompt "Enable lite exit"
default y
help
Enable lite exit, a size-reduced implementation of exit that doesn't
invoke clean-up functions such as _fini or global destructors.
config LIBC_PICOLIBC_MULTITHREAD
bool
prompt "Enable support for multiple threads"
default y
help
Enable support for multiple threads.
config LIBC_PICOLIBC_RETARGETABLE_LOCKING
bool
prompt "Enable retargetable locking"
help
Enable retargetable locking to allow the operating system to override
the dummy lock functions defined within picolibc.
config LIBC_PICOLIBC_EXTRA_SECTIONS
bool
prompt "Place each function & data element in their own section"
help
Place each function & data symbol in their own section. This allows
the linker to garbage collect unused symbols at link time.
config LIBC_PICOLIBC_ENABLE_TARGET_OPTSPACE
bool
prompt "Optimize picolibc for size"
default y
help
Pass --enable-target-optspace to picolibc configure.
This will compile picolibc with -Os.
config LIBC_PICOLIBC_LTO
bool
prompt "Enable Link Time Optimization"
depends on CC_GCC_USE_LTO
help
Builds the libraries with -flto to enable more aggressive link time
optimization. You will need to add -flto-partition=one to your
application's link line to keep the RETURN assembler macro together
with it's consumers.
config LIBC_PICOLIBC_NANO_MALLOC
bool
prompt "Enable Nano Malloc"
default y
help
PICOLIBC has two implementations of malloc family's functions, one in
`mallocr.c' and the other one in `nano-mallocr.c'. This options
enables the nano-malloc implementation, which is for small systems
with very limited memory. Note that this implementation does not
support `--enable-malloc-debugging' any more.
config LIBC_PICOLIBC_EXTRA_CONFIG_ARRAY
string
prompt "Extra config for picolibc"
default ""
help
Extra flags to pass to meson when configuring picolibc.