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mirror of https://github.com/RIOT-OS/RIOT.git synced 2025-12-21 20:43:50 +01:00

3 Commits

Author SHA1 Message Date
Marian Buschsieweke
b9b488d6fb
sys/stdio: add printf_long_long
This adds the new `printf_long_long` module that can be used to enable
printing of `long long` and `unsigned long long`.

This has been implemented for `mpaland-printf`. In addition, this module
is a default module for 32-bit and 64-bit systems if `mpaland-printf` is
used, 64 bit support is not too expensive for them. (And on 64-bit
systems support for long long is needed for support of `%p`, which is
pretty basic.)

This is mainly useful for MSP430, where otherwise `mpaland-printf` would
require more memory than newlib's implementation.
2025-04-27 23:37:33 +02:00
Marian Buschsieweke
7caf2066d8
pkg/mpaland-printf: fix overriding printf with printf_float
This makes sure that newlib's printf is correctly overridden by:

1. Adding wrappers for some more obscure printf() variants
2. Forcing a compilation failure when newlib's stdio is still linked in
   while mpaland-printf is used
3. Not adding `-u _printf_float` to the linker flags when mpaland-printf
   is used.
2025-04-26 15:28:17 +02:00
Marian Buschsieweke
6d8233fa24
pkg/mpaland-printf: Add alternative stdio as package
This packs the stdio implementation from [1] as alternative to
what the used standard C lib provides with the intent to provide a
thread-safe, smaller, and more feature-complete alternative on
newlib targets.

Compared to `newlib_nano` this reduces `.text` by a bit more than 200 B
while adding support for standard format specifiers such as `RPIu8`,
`PRIu16`, `PRIu64`, `%z`, and `%t`.

Note that `newlib_nano`'s stdio can be thread-safe in reentrant mode
at the cost of RAM (per thread) and latency. Especially the increase
in latency can be prohibitive when real time requirements need to be
met.

[1]: https://github.com/mpaland/printf
2025-04-24 11:46:09 +02:00