libc/picolibc: Implement fdopen in terms of zvfs APIs #101449
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Two alternatives:
The first is 'more effiicient' as no-one will ever need a wrapper function. The second avoids adding POSIX APIs to the standard Zephyr suite. |
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oops, thanks -- this diff was hanging around after testing with a TI board...
| #ifdef CONFIG_PICOLIBC | ||
| return fileno(file); | ||
| #else |
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This adds a dependency cycle at the API level, so will not work.
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no, this is using fileno from picolibc, not Zephyr. Note that the Zephyr versions of fdopen and fileno should both be disabled by this patch.
| FUNC_ALIAS(close, _close, int); | ||
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| #ifndef CONFIG_PICOLIBC |
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Can this PR be modified to implement POSIX_DEVICE_IO? Picolibc would need to add select TC_PROVIDES_POSIX_DEVICE_IO.
Ideally, this would only be merged after #97855, so that it could be done indpendently of the Zephyr implementation.
The Zephyr implementation should remain untouched, but lib/libc/picolibc/CMakeLists.txt could pull in Zephyr's implementation if it's convenient or simpler.
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All I'm trying to do in this PR is fix the current fdopen/fileno disaster. If you want to take it further, please feel free.
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Please add select TC_PROVIDES_POSIX_DEVICE_IO under config PICOLIBC in lib/libc/Kconfig, implement (or borrow) the rest of POSIX_DEVICE_IO, and remove the layering violation in zvfs.
Use picolibc 'bufio' interfaces to provide a non-POSIX implementation of fdopen. This depends upon CONFIG_ZVFS_FDTABLE as that provides an fd abstraction on top of regular zephyr APIs. Use this API to provide zvfs_fdopen and zvfs_fileno. Signed-off-by: Keith Packard <[email protected]>
There is no layering violation; this removes the layering violation where zvfs provides broken versions of fdopen and fileno. |
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Use picolibc 'bufio' interfaces to provide a non-POSIX implementation of fdopen. This depends upon CONFIG_ZVFS_FDTABLE as that provides an fd abstraction on top of regular zephyr APIs.
Use this API to provide zvfs_fdopen and zvfs_fileno.