first commit

README.md

@@ -0,0 +1,42 @@
+# 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
+
+```bash
+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
+
+```bash
+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/
+```