Ivan Grokhotkov 3d91e6d993 newlib: implement _fstat_r stub for console ...

When CONFIG_VFS_SUPPORT_IO is disabled, _read_r and _write_r
implementations in syscalls.c are used to provide console I/O via
esp_rom_uart_tx_one_char/esp_rom_uart_rx_one_char.

When newlib opens a (FILE*) stream, it calls fstat to check if the
underlying file is character-oriented. In this case, it configures the
stream to use line buffering. Otherwise (or if fstat fails) the stream
is opened as block buffered.

Since fstat wasn't provided, stdin/stdout/stderr streams got opened in
block buffered mode. For console, we need line buffered output so that
the stream buffer is flushed each time a complete line (ending with
'\n') is sent to stdout or stderr.

Fix by implementing _fstat_r stub, setting st->st_mdoe=S_IFCHR.

2021-12-21 01:25:49 +00:00

5.1 KiB

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