Instead of adding every possible subsystem which places variables in the C
library memory partition in libc-hooks.h, place those conditions in the
related Kconfig files and simplify the libc-hooks.h to just looking at
CONFIG_NEED_LIBC_MEM_PARTITION.
Signed-off-by: Keith Packard <keithp@keithp.com>
Picolibc dependencies limit ability to use third party minimal
implementations of CPP when enablng PICOLIBC_USE_MODULE.
Signed-off-by: Al Semjonovs <asemjonovs@google.com>
The picolibc kconfigs were tied to ZEPHYR_TOOLCHAIN_VARIANT
and it only supported the Zephyr SDK, which is the only
toolchain having picolibc built-in at the moment. This
commit generalizes that to use TOOLCHAIN_HAS_PICOLIBC
cmake variable the same way as newlib: TOOLCHAIN_HAS_NEWLIB.
This provides the ability for other toolchains to declare
their support for picolibc.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
After commit 9a0aebc5fd,
the exclusion of qemu_x86_tiny is no longer and the "depends on"
option was removed. However, the comment about that remained.
Remove the comment as it is no longer valid.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
It is possible to build with the PICOLIBC_MODULE
with the POSIX arch targets which use the native
simulator as runner.
Update filtering accordingly.
Signed-off-by: Alberto Escolar Piedras <alberto.escolar.piedras@nordicsemi.no>
It is possible to build with STDOUT_CONSOLE with
the embedded C libraries with the POSIX arch.
Narrow down the filtering accordingly.
Signed-off-by: Alberto Escolar Piedras <alberto.escolar.piedras@nordicsemi.no>
So they depend or select on the right NATIVE_BUILD
instead of NATIVE_APPLICATION.
Signed-off-by: Alberto Escolar Piedras <alberto.escolar.piedras@nordicsemi.no>
Enable the common malloc implementation when using picolibc. Support
existing Picolibc configurations by respecting existing PICOLIBC_HEAP_SIZE
settings.
When PICOLIBC_HEAP_SIZE is set to a value other than -2, then
*always* set COMMON_LIBC_MALLOC_ARENA_SIZE to that value.
Signed-off-by: Keith Packard <keithp@keithp.com>
Move the abort implementation into common so its shared among the
libc. As part of this start using the common abort on newlib.
Signed-off-by: Kumar Gala <kumar.gala@intel.com>
Move the strnlen implementation into common so its available to any
libc that may not implement strnlen.
Signed-off-by: Kumar Gala <kumar.gala@intel.com>
Select FULL_LIBC_SUPPORTED when picolibc is available.
Add picolibc as a secondary default C library when REQUIRES_FULL_LIBC is
selected. This is necessary as tests gated on FULL_LIBC_SUPPORTED need to
be sure that a full C library will be selected -- if only picolibc is
available, those tests will need to select that.
This should permit use of a picolibc-only crosstool-ng toolchain in
testing.
Signed-off-by: Keith Packard <keithp@keithp.com>
This symbol is selected when the target has any full libc available. This
allows tests to filter on this condition. It doesn't depend on whether the
application actually selects that library, only whether requesting a full C
library would work.
Signed-off-by: Keith Packard <keithp@keithp.com>
This reflects whether newlib is available in the environment. This
symbol should be used in place of TOOLCHAIN_HAS_NEWLIB.
Signed-off-by: Keith Packard <keithp@keithp.com>
Add a prompt to the Kconfig symbol so that applications can select this in
their configuration to guide C library selection away from the minimal C
library.
Signed-off-by: Keith Packard <keithp@keithp.com>
Add an explicit compiler configuration, COMPILER_FREESTANDING, which
controls whether the compiler should operate in freestanding or hosted mode
(according to the C and C++ language specifications.
This depends on having a C library which conforms with the language
specification, and the minimal C library does not. Have the minimal C
library select COMPILER_FREESTANDING to continue using freestanding mode
with that library.
For other C libraries, leave this disabled by default while allowing users
to enable it if they want to go back to the previous configuration.
Signed-off-by: Keith Packard <keithp@keithp.com>
Introduce a place to share implementations of libc functions that
are needed by different libc versions. Place time() in this common
location so it can be shared when building for either minimal libc or
armclang libc.
Signed-off-by: Kumar Gala <kumar.gala@intel.com>
Clang support still work in progress in zephyr. So for now enable only
on gcc based toolchains.
We should enable this back for more toolchains once we have full clang
support and are able to verify.
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
With all of the test suite issues on this board fixed, qemu_x86_tiny should
now be usable with picolibc.
Signed-off-by: Keith Packard <keithp@keithp.com>
Picolibc now supports all of the Zephyr SDK target architectures for C.
qemu_x86_tiny needs fixes to get the libc partition linked
into the right spot. See issue #54148
Signed-off-by: Keith Packard <keithp@keithp.com>
libstdc++ is supported with Picolibc only when the toolchain version of
Picolibc is use -- libstdc++ must be built using a specific Picolibc build
and libstdc++ is included with the toolchain.
Ideally, we'd allow the use of the Picolibc module whenever we weren't
using the GNU libstdc++, including when using the minimal libc++. However,
the obvious dependency settings create a loop:
config PICOLIBC
depends on PICOLIBC_SUPPORTED
config PICOLIBC_SUPPORTED
depends on !(GLIBCXX_LIBCPP && "$(ZEPHYR_TOOCHAIN_VARIANT" = "zephyr")
config GLIBCXX_LIBCPP
depends on NEWLIB_LIBC || PICOLIBC
To break this loop, we replace GLIBCXX_LIBCPP in the second block with
CPP:
config PICOLIBC_SUPPORTED
depends on !(CPP && "$(ZEPHYR_TOOCHAIN_VARIANT" = "zephyr")
This means that picolibc cannot be used with any C++ apps when using the
Zephyr SDK, even when not using the GNU libstdc++. However, Zephyr SDK 0.16
will come with an additional Kconfig file that includes:
config PICOLIBC_SUPPORTED
def_bool y
depends on "$(ZEPHYR_TOOLCHAIN_VARIANT)" = "zephyr"
This will override the Kconfig bits included in Zephyr and allow use of the
Picolibc module with C++ code, including using the minimal libc++ bits.
Signed-off-by: Keith Packard <keithp@keithp.com>
This commit updates the Picolibc configurations to remove any
unnecessary defaults and dependencies and conform to the de-facto
standard convention across the Zephyr repository.
Signed-off-by: Stephanos Ioannidis <stephanos.ioannidis@nordicsemi.no>
This commit relocates the newlib libc configurations under the top-
level libc Kconfig to a new Kconfig under `lib/libc/newlib` for
improved organisation of the libc configurations.
Signed-off-by: Stephanos Ioannidis <stephanos.ioannidis@nordicsemi.no>
This commit relocates the minimal libc configurations under the top-
level libc Kconfig to a new Kconfig under `lib/libc/minimal` for
improved organisation of the libc configurations.
Signed-off-by: Stephanos Ioannidis <stephanos.ioannidis@nordicsemi.no>
The newlib nano variant is currently enabled by default when
`CONFIG_NEWLIB_LIBC=y` and the selected toolchain-architecture
combination includes the newlib nano variant support, even if
`CONFIG_NEWLIB_LIBC_NANO` is not selected by the user.
When `CONFIG_NEWLIB_LIBC=y`, this results in the newlib nano variant
being selected for some architectures (e.g. ARC, ARM and RISC-V), while
the full variant is selected for the rest of the architectures.
The above behaviour is problematic because there exist functional
differences between the newlib full and nano variants (e.g. C99 format
modifiers such as `hh`, `ll`, `z`, `j` and `t` are not available in the
newlib nano variant), and this effectively leads to different level of
C standard support across different architectures when
`CONFIG_NEWLIB_LIBC=y`.
This commit fixes this problem by making the `CONFIG_NEWLIB_LIBC_NANO`
not `default y` and requiring its user to explicitly set this symbol to
`y` when they want to use the newlib nano variant.
Signed-off-by: Stephanos Ioannidis <stephanos.ioannidis@nordicsemi.no>
Currently picolib isn't compatible with ARC MWDT toolchain,
so don't try to build picolib tests in case of ARC MWDT toolchain
usage.
Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Evgeniy Paltsev <PaltsevEvgeniy@gmail.com>
If the architecture has TLS support, but the toolchain doesn't, then
don't enable Zephyr TLS support when selecting picolibc.
Closes: #47275.
Signed-off-by: Keith Packard <keithp@keithp.com>
For targets without thread local storage, we need to use the builtin
per-thread errno support provided by Zephyr as the multi-thread errno
support provided in picolibc relies on TLS.
Signed-off-by: Keith Packard <keithp@keithp.com>
Picolibc is a fork of newlib designed and tested on embedded systems. It
offers a smaller memory footprint (both ROM and RAM), and native TLS
support, which uses the Zephyr TLS support.
By default, the full printf version is included in the executable, which
includes exact floating point and long long input and output. A
configuration option has been added to switch to the integer-only
version (which also omits long long support).
Here are some size comparisons using qemu-cortex-m3 and this application
(parameters passed to printf to avoid GCC optimizing it into puts):
void main(void)
{
printf("Hello World! %s %d\n", CONFIG_BOARD, 12);
}
FLASH SRAM
minimal 8696 3952
picolibc int 7600 3960
picolibc float 12304 3960
newlib-nano int 11696 4128
newlib-nano float 30516 4496
newlib 34800 6112
---
v2:
Include picolibc-tls.ld
v3:
Document usage in guides/c_library.rst and
getting_started/toolchain_other_x_compilers.rst
v4:
Lost the lib/libc/picolibc directory somehow!
v5:
Add PICOLIBC_ALIGNED_HEAP_SIZE configuration option.
Delete PICOLIBC_SEMIHOST option support code
v6:
Don't allocate static RAM for TLS values; TLS
values only need to be allocated for each thread.
v7:
Use arm coprocessor for TLS pointer storage where supported for
compatibility with the -mtp=cp15 compiler option (or when the
target cpu type selects this option)
Add a bunch of tests
Round TLS segment up to stack alignment so that overall stack
remains correctly aligned
Add aarch64 support
Rebase to upstream head
v8:
Share NEWLIB, NEWLIB_NANO and PICOLIBC library configuration
variables in a single LIBC_PARTITIONS variable instead of
having separate PICOLIBC_PART and NEWLIB_PART variables.
v9:
Update docs to reference pending sdk-ng support for picolibc
v10:
Support memory protection by creating a partition for
picolibc shared data and any pre-defined picolibc heap.
v11:
Fix formatting in arch/arm/core/aarch64/switch.S
v12:
Remove TLS support from this patch now that TLS is upstream
Require THREAD_LOCAL_STORAGE when using PICOLIBC for architectures
that support it.
v13:
Merge errno changes as they're only needed for picolibc.
Adapt cmake changes suggested by Torsten Tejlmand Rasmussen
v14:
Update to picolibc 1.7 and newer (new stdin/stdout/stderr ABI)
v15:
Respond to comments from dcpleung:
* switch kernel/errno to use CONFIG_LIBC_ERRNO instead of
CONFIG_PICOLIBC
* Add comment to test/lib/sprintf as to why the %n test
was disabled for picolibc.
v16:
Switch picolibc to a module built with Zephyr. This eliminates
toolchain dependencies and allows compiler settings for Zephyr
to also be applied to picolibc.
v17:
Provide Zephyr-specific 'abort' implementation.
Support systems with MMU
v18:
Allow use of toolchain picolibc version.
v19:
Use zephyr/ for zephyr headers
v20:
Add locking
Use explicit commit for picolibc module
v21:
Create PICOLIBC_SUPPORTED config param. Set on arc, arm, arm64,
mips and riscv architectures.
Signed-off-by: Keith Packard <keithp@keithp.com>
The gmtime() function returns a global result variable, and this
variable must be placed in the `z_libc_partition` when userspace is
enabled.
Since gmtime() makes use of a global variable and this results in a
footprint increase, this commit makes the time functions optional by
introducing `CONFIG_MINIMAL_LIBC_TIME` Kconfig and making them only
available when this option is enabled.
Signed-off-by: Stephanos Ioannidis <root@stephanos.io>
This commit introduces a new configuration called
`CONFIG_MINIMAL_LIBC_NON_REENTRANT_FUNCTIONS`, which enables the
traditional non-reentrant (i.e. not thread-safe) version of the C
standard library functions such as rand() and gmtime() when the
respective configs are enabled.
The non-reentrant functions make use of the globals and require an
additional memory partition (MPU region), which is scarce on low-end
devices, when CONFIG_USERSPACE=y.
The purpose of this option is to classify the MPU resource intensive
functions as a separate category and only enable them when there is a
demand for such.
Signed-off-by: Stephanos Ioannidis <root@stephanos.io>
According to Kconfig guidelines, boolean prompts must not start with
"Enable...". The following command has been used to automate the changes
in this patch:
sed -i "s/bool \"[Ee]nables\? \(\w\)/bool \"\U\1/g" **/Kconfig*
Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no>
* add generic heap event listener module that can be used
for notifying an application of heap-related events
* use the listener module in newlib libc hooks
* add a unit test
Signed-off-by: Damian Krolik <damian.krolik@nordicsemi.no>
Support for ARM Compiler C library.
This commit add support for the ARM Compiler C libary in:
- Kconfig
- libc/armstdc
A new Kconfig symbol is added to allow a toolchain to specify if they
support linking with the minimal C library.
Also the CMake variable `TOOLCHAIN_HAS_NEWLIB` is exported to Kconfig
so that CONFIG_NEWLIB_LIBS can only be enabled if the toolchain has
newlib.
The armclang toolchain selects the CMake scatter file generator and
disables support for the LD linker template which is not supported by
armlink.
For the ARM Compiler C library, a corresponding lib/libc/armstc/ folder
with a minimal implementation to work with the ARM Compiler C library
is added.
Signed-off-by: Torsten Rasmussen <Torsten.Rasmussen@nordicsemi.no>
rand() and srand() are pseudo-random number generator functions
defined in ISO C. This implementation uses the Linear Congruential
Generator (LCG) algorithm with the following parameters, which are the
same as used in GNU Libc "TYPE_0" algorithm.
Modulus 2^31
Multiplier 1103515245
Increment 12345
Output Bits 30..0
Note that the default algorithm used by GNU Libc is not TYPE_0, and
TYPE_0 should be selected first by an initstate() call as shown below.
All global variables in a C library must be routed to a memory
partition in order to be used by user-mode applications when
CONFIG_USERSPACE is enabled. Thus, srand_seed is marked as
such. z_libc_partition is originally used by the Newlib C library but
it's generic enough to be used by either the minimal libc or the
newlib.
All other functions in the Minimal C library, however, don't require
global variables/states. Unconditionally using z_libc_partition with
the minimal libc might be a problem for applications utilizing many
custom memory partitions on platforms with a limited number of MPU
regions (eg. Cortex M0/M3). This commit introduces a kconfig option
CONFIG_MINIMAL_LIBC_RAND so that applications can enable the
functions if needed. The option is disabled by default.
Because this commit _does_ implement rand() and srand(), our coding
guideline check on GitHub Action finds it as a violation.
Error: lib/libc/minimal/include/stdlib.h:45:WARNING: Violation to
rule 21.2 (Should not used a reserved identifier) - srand
But this is false positive.
The following is a simple test program for LCG with GNU Libc.
#include <stdio.h>
#include <stdlib.h>
int main()
{
static char state[8];
/* Switch GLIBC to use LCG/TYPE_0 generator type. */
initstate(0, state, sizeof(state));
srand(1); /* Or any other value. */
printf("%d\n", rand());
printf("%d\n", rand());
return 0;
}
See initstate(3p) for more detail about how to use LCG in GLIBC.
Signed-off-by: Yasushi SHOJI <yashi@spacecubics.com>
The current implementations of memcpy and memset are optimized for
performance and use a word based loop before the byte based loop.
Add a config option that skips the word based loop. This saves 120
bytes on the Cortex-M0+ which is worthwhile on small apps like a
bootloader.
Enable by default if SIZE_OPTIMIZATIONS is set.
Signed-off-by: Michael Hope <mlhx@google.com>
This commit adds a new `CONFIG_NEWLIB_MIN_REQUIRED_HEAP_SIZE` config
that allows user to specify the minimum required heap size for the
newlib heap, and makes `malloc_prepare` validate that the memory space
available for the newlib heap is greater than this value.
The default minimum required heap size values were empiricially
determined, so as to allow the basic standard C functions such as
`printf` and `scanf` to work properly.
Signed-off-by: Stephanos Ioannidis <root@stephanos.io>
Previously, newlib claimed all free physical memory in the
system.
Now, the kernel manages this, allowing for memory to be
used via k_mem_map() calls.
Establish an upper bound to how much newlib will try to
claim on system startup, instead of trying to take all
of it, allowing other parts of the system to also map
anonymous memory.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Previously, newlib claimed all free physical memory in the
system.
Now, the kernel manages this, allowing for memory to be
used via k_mem_map() calls.
Establish an upper bound to how much newlib will try to
claim on system startup, instead of trying to take all
of it, allowing other parts of the system to also map
anonymous memory.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
The z_libc_partition was only enabled when newlib is being used,
and/or stack canaries are needed. This adds a hidden option
where this partition can be enabled if needed, regardless of
whether newlib is used or stack canaries are needed.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
I think people might be reading differences into 'if' and 'depends on'
that aren't there, like maybe 'if' being needed to "hide" a symbol,
while 'depends on' just adds a dependency.
There are no differences between 'if' and 'depends on'. 'if' is just a
shorthand for 'depends on'. They work the same when it comes to creating
implicit menus too.
The way symbols get "hidden" is through their dependencies not being
satisfied ('if'/'depends on' get copied up as a dependency on the
prompt).
Since 'if' and 'depends on' are the same, an 'if' with just a single
symbol in it can be replaced with a 'depends on'. IMO, it's best to
avoid 'if' there as a style choice too, because it confuses people into
thinking there's deep Kconfig magic going on that requires 'if'.
Going for 'depends on' can also remove some nested 'if's, which
generates nicer symbol information and docs, because nested 'if's really
are so simple/dumb that they just add the dependencies from both 'if's
to all symbols within.
Replace a bunch of single-symbol 'if's with 'depends on' to despam the
Kconfig files a bit and make it clearer how things work. Also do some
other minor related dependency refactoring.
The replacement isn't complete. Will fix up the rest later. Splitting it
a bit to make it more manageable.
(Everything above is true for choices, menus, and comments as well.)
Detected by tweaking the Kconfiglib parsing code. It's impossible to
detect after parsing, because 'if' turns into 'depends on'.
Signed-off-by: Ulf Magnusson <Ulf.Magnusson@nordicsemi.no>
Introduce HAS_NEWLIB_LIBC_NANO Kconfig option that the toolchain
specific Kconfig (gnuarmemb & zephyr 0.11) can select to convey that the
feature is supported.
This removes the need to if protect the NEWLIB_LIBC_NANO Kconfig with:
if "$(ZEPHYR_TOOLCHAIN_VARIANT)" = "gnuarmemb"
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
