mini_desktop — GEC6818 Desktop System

800×480 framebuffer + touch desktop with photo album and IR remote control.

Architecture

desktop → album     (swipe photo browser)
        → ir_app    (learn / send / receive IR codes)

Non-blocking I/O pattern

All I/O uses O_NONBLOCK + drain-events-into-cache. Never block on read().

Touch events are drained per-frame via ts_read() — after the while(ts_read > 0) loop exits (no more events), remaining logic (serial polling, etc.) runs once, then the outer loop repeats. This keeps the UI responsive to both touch and serial.

Do NOT let ts_read() return 1 with stale data

ts_read() uses a static int has_new flag. It MUST be reset to 0 at the top of every call. If you forget this, has_new sticks at 1 after the first touch, every ts_read() call returns 1 forever, and while (ts_read(...) > 0) loops spin endlessly — code after the loop is never reached. This bit us when page_learn() could never read from the IR serial port.

Build

docker run --platform linux/amd64 --rm \
  -v /path/to/toolchain:/opt/gec6818-toolchain:ro \
  -v /path/to/mini_desktop:/work -w /work \
  gec6818-dev:ubuntu18 bash -c 'make static'

Deploy

ssh root@192.168.1.88 'killall mini_desktop 2>/dev/null; sleep 1'
scp -O mini_desktop root@192.168.1.88:/home/cyy/