flash: fix retry corruption for compressed writes and cap ESP32 baud rate - #59
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…rate After a timeout during a compressed flash write, the retry's SLIP frame (starting with 0xC0) would terminate the stub's partial frame and then deliver the full retry data in the same write. The stub processed both as separate commands: it emitted a stale error for the truncated frame, then silently decompressed and wrote the retry block then advancing the zlib decompressor state. The host only read the stale error, flushed the real ACK, and retried with the same block, which the decompressor could no longer handle, causing all subsequent retries to hang. Fix by sending a bare 0xC0 to terminate the partial frame as a separate write, then waiting 50ms for the stale error response to arrive before flushing and retrying. This keeps the retry data out of the cleanup sequence and preserves consistent decompressor state. Also: - Add MaxUARTFlashBaud field to chipDef; set to 230400 for ESP32 to prevent UART RX FIFO overflow on USB-UART bridges (CH340, CP2102) - Increase flash block retries from 3 to 5 to provide headroom after the stale-frame cleanup cycle consumes one attempt Signed-off-by: deadprogram <ron@hybridgroup.com>
On Linux, signals such as SIGWINCH (terminal resize) can interrupt write(2) and tcdrain(3) on serial file descriptors, causing them to return EINTR before any bytes are transferred. The go.bug.st/serial library does not retry internally, so the error bubbles up as "interrupted system call" and aborts the flash. Wrap port.Write and port.Drain in sendCommand with EINTR retry loops so transient signal interruptions are handled transparently. Fixes a "send command 0x12: interrupted system call" failure observed during compressed flash download on ESP32-C3 (USB-JTAG/Serial). Signed-off-by: deadprogram <ron@hybridgroup.com>
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After a timeout during a compressed flash write, the retry's SLIP frame (starting with 0xC0) would terminate the stub's partial frame and then deliver the full retry data in the same write. The stub processed both as separate commands: it emitted a stale error for the truncated frame, then silently decompressed and wrote the retry block then advancing the zlib decompressor state. The host only read the stale error, flushed the real ACK, and retried with the same block, which the decompressor could no longer handle, causing all subsequent retries to hang.
Fix by sending a bare 0xC0 to terminate the partial frame as a separate write, then waiting 50ms for the stale error response to arrive before flushing and retrying. This keeps the retry data out of the cleanup sequence and preserves consistent decompressor state.
Also:
UPDATE: added a second commit to handle retry of serial Write and Drain on EINTR to fix a "send command 0x12: interrupted system call" failures observed during compressed flash download on ESP32-C3 (USB-JTAG/Serial).