tools/pyboard.py: Add fast raw-paste mode.

This commit adds support to pyboard.py for the new raw REPL paste mode.

Note that this new pyboard.py is fully backwards compatible with old
devices (it detects if the device supports the new raw REPL paste mode).

Signed-off-by: Damien George <damien@micropython.org>

tools/pyboard.py

@@ -253,6 +253,7 @@ class ProcessPtyToTerminal:
 
 class Pyboard:
     def __init__(self, device, baudrate=115200, user="micro", password="python", wait=0):
+        self.use_raw_paste = True
         if device.startswith("exec:"):
             self.serial = ProcessToSerial(device[len("exec:") :])
         elif device.startswith("execpty:"):
@@ -359,6 +360,41 @@ class Pyboard:
         # return normal and error output
         return data, data_err
 
+    def raw_paste_write(self, command_bytes):
+        # Read initial header, with window size.
+        data = self.serial.read(2)
+        window_size = data[0] | data[1] << 8
+        window_remain = window_size
+
+        # Write out the command_bytes data.
+        i = 0
+        while i < len(command_bytes):
+            while window_remain == 0 or self.serial.inWaiting():
+                data = self.serial.read(1)
+                if data == b"\x01":
+                    # Device indicated that a new window of data can be sent.
+                    window_remain += window_size
+                elif data == b"\x04":
+                    # Device indicated abrupt end.  Acknowledge it and finish.
+                    self.serial.write(b"\x04")
+                    return
+                else:
+                    # Unexpected data from device.
+                    raise PyboardError("unexpected read during raw paste: {}".format(data))
+            # Send out as much data as possible that fits within the allowed window.
+            b = command_bytes[i : min(i + window_remain, len(command_bytes))]
+            self.serial.write(b)
+            window_remain -= len(b)
+            i += len(b)
+
+        # Indicate end of data.
+        self.serial.write(b"\x04")
+
+        # Wait for device to acknowledge end of data.
+        data = self.read_until(1, b"\x04")
+        if not data.endswith(b"\x04"):
+            raise PyboardError("could not complete raw paste: {}".format(data))
+
     def exec_raw_no_follow(self, command):
         if isinstance(command, bytes):
             command_bytes = command
@@ -370,7 +406,26 @@ class Pyboard:
         if not data.endswith(b">"):
             raise PyboardError("could not enter raw repl")
 
-        # write command
+        if self.use_raw_paste:
+            # Try to enter raw-paste mode.
+            self.serial.write(b"\x05A\x01")
+            data = self.serial.read(2)
+            if data == b"R\x00":
+                # Device understood raw-paste command but doesn't support it.
+                pass
+            elif data == b"R\x01":
+                # Device supports raw-paste mode, write out the command using this mode.
+                return self.raw_paste_write(command_bytes)
+            else:
+                # Device doesn't support raw-paste, fall back to normal raw REPL.
+                data = self.read_until(1, b"w REPL; CTRL-B to exit\r\n>")
+                if not data.endswith(b"w REPL; CTRL-B to exit\r\n>"):
+                    print(data)
+                    raise PyboardError("could not enter raw repl")
+            # Don't try to use raw-paste mode again for this connection.
+            self.use_raw_paste = False
+
+        # Write command using standard raw REPL, 256 bytes every 10ms.
         for i in range(0, len(command_bytes), 256):
             self.serial.write(command_bytes[i : min(i + 256, len(command_bytes))])
             time.sleep(0.01)