Added .github

.github/scripts/check_boot.py

@@ -0,0 +1,67 @@
+"""QEMU boot check for Nadir CI.
+
+Runs the boot sector headless on a pseudo-terminal with the curses display,
+waits for the boot, then asserts the welcome message reached the screen.
+A garbage image (SeaBIOS "No bootable device") fails this check.
+
+Usage: python3 .github/scripts/check_boot.py   (from the repository root)
+Requires: qemu-system-x86_64 on PATH. Stdlib only.
+"""
+
+import fcntl
+import os
+import pty
+import select
+import struct
+import subprocess
+import sys
+import termios
+import time
+
+IMAGE = "boot.bin"
+NEEDLE = b"Nadir"
+BOOT_WAIT_S = 8
+
+
+def main() -> int:
+    master, slave = pty.openpty()
+    fcntl.ioctl(slave, termios.TIOCSWINSZ, struct.pack("HHHH", 24, 80, 0, 0))
+    env = dict(os.environ, TERM="xterm")
+    proc = subprocess.Popen(
+        ["qemu-system-x86_64", "-display", "curses", "-fda", IMAGE],
+        stdin=slave,
+        stdout=slave,
+        stderr=subprocess.DEVNULL,
+        env=env,
+    )
+    os.close(slave)
+    time.sleep(BOOT_WAIT_S)
+    proc.terminate()
+    try:
+        proc.wait(timeout=10)
+    except subprocess.TimeoutExpired:
+        proc.kill()
+        proc.wait()
+    fcntl.fcntl(master, fcntl.F_SETFL, os.O_NONBLOCK)
+    data = b""
+    while True:
+        ready, _, _ = select.select([master], [], [], 1)
+        if not ready:
+            break
+        try:
+            chunk = os.read(master, 65536)
+        except OSError:
+            break
+        if not chunk:
+            break
+        data += chunk
+    os.close(master)
+    if NEEDLE not in data:
+        print(f"FAIL: {NEEDLE!r} not found on the QEMU screen")
+        return 1
+    print("OK: QEMU booted and printed the welcome message")
+    return 0
+
+
+if __name__ == "__main__":
+    sys.exit(main())