mbv: now with functioning timer interrupts!

And a few other nice things.
The bootloader now has an embedded wozmon!
If you know its offset, you can jump to it from the app.

mbv/prog.py

@@ -1,6 +1,8 @@
+import argparse
 import serial
 import struct
 import sys
+import threading
 import time
 
 offset = 0x80000000
@@ -29,28 +31,46 @@ def write(s, offset, dat):
 
 def jump(s, offset):
         cmd = struct.pack('<cI', b'j', offset)
+        print(f'Jumping to 0x{offset:04x}')
         s.write(cmd)
 
 
+def stream_logs(s):
+    while True:
+        dat = s.read()
+        if not dat:
+            continue
+        sys.stdout.buffer.write(dat.replace(b'\r', b''))
+        sys.stdout.buffer.flush()
+
+
+def parse_args():
+    parser = argparse.ArgumentParser()
+    parser.add_argument("binary")
+    parser.add_argument("--monitor", action="store_true",
+                        help="wait for and display program serial output")
+    return parser.parse_args()
+
 def main():
-    binfile = sys.argv[1]
-    with open(binfile, 'rb') as f:
+    args = parse_args()
+
+    with open(args.binary, 'rb') as f:
         dat = f.read()
 
     s = serial.Serial(tty, baud, timeout=1)
     write(s, offset, dat)
     jump(s, offset)
-    last_dat = time.time()
 
-    while True:
-        dat = s.read()
-        if not dat:
-            if time.time() - last_dat > 1.0:
-                print('Data timeout')
-                break
-            continue
-        last_dat = time.time()
-        sys.stdout.buffer.write(dat)
+    if args.monitor:
+        t = threading.Thread(target=lambda: stream_logs(s), daemon=True)
+        t.start()
+
+        try:
+            while True:
+                dat = input("") + '\r'
+                s.write(dat.encode())
+        except KeyboardInterrupt:
+            print("Bye.")
 
 
 if __name__ == "__main__":