1 files changed, 84 insertions, 1 deletions

diff --git a/tools/pyboard.py b/tools/pyboard.py
index f368455f5e..131634c906 100755
--- a/tools/pyboard.py
+++ b/tools/pyboard.py
@@ -39,6 +39,7 @@ Or:
 
 import sys
 import time
+import os
 
 try:
     stdout = sys.stdout.buffer
@@ -116,9 +117,91 @@ class TelnetToSerial:
         else:
             return n_waiting
 
+
+class ProcessToSerial:
+    "Execute a process and emulate serial connection using its stdin/stdout."
+
+    def __init__(self, cmd):
+        import subprocess
+        self.subp = subprocess.Popen(cmd.split(), bufsize=0, shell=True, preexec_fn=os.setsid,
+            stdin=subprocess.PIPE, stdout=subprocess.PIPE)
+
+        # Initially was implemented with selectors, but that adds Python3
+        # dependency. However, there can be race conditions communicating
+        # with a particular child process (like QEMU), and selectors may
+        # still work better in that case, so left inplace for now.
+        #
+        #import selectors
+        #self.sel = selectors.DefaultSelector()
+        #self.sel.register(self.subp.stdout, selectors.EVENT_READ)
+
+        import select
+        self.poll = select.poll()
+        self.poll.register(self.subp.stdout.fileno())
+
+    def close(self):
+        import signal
+        os.killpg(os.getpgid(self.subp.pid), signal.SIGTERM)
+
+    def read(self, size=1):
+        data = b""
+        while len(data) < size:
+            data += self.subp.stdout.read(size - len(data))
+        return data
+
+    def write(self, data):
+        self.subp.stdin.write(data)
+        return len(data)
+
+    def inWaiting(self):
+        #res = self.sel.select(0)
+        res = self.poll.poll(0)
+        if res:
+            return 1
+        return 0
+
+
+class ProcessPtyToTerminal:
+    """Execute a process which creates a PTY and prints slave PTY as
+    first line of its output, and emulate serial connection using
+    this PTY."""
+
+    def __init__(self, cmd):
+        import subprocess
+        import re
+        import serial
+        self.subp = subprocess.Popen(cmd.split(), bufsize=0, shell=True, preexec_fn=os.setsid,
+            stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+        pty_line = self.subp.stderr.readline().decode("utf-8")
+        m = re.search(r"/dev/pts/[0-9]+", pty_line)
+        if not m:
+            print("Error: unable to find PTY device in startup line:", pty_line)
+            self.close()
+            sys.exit(1)
+        pty = m.group()
+        self.ser = serial.Serial(pty, interCharTimeout=1)
+
+    def close(self):
+        import signal
+        os.killpg(os.getpgid(self.subp.pid), signal.SIGTERM)
+
+    def read(self, size=1):
+        return self.ser.read(size)
+
+    def write(self, data):
+        return self.ser.write(data)
+
+    def inWaiting(self):
+        return self.ser.inWaiting()
+
+
 class Pyboard:
     def __init__(self, device, baudrate=115200, user='micro', password='python', wait=0):
-        if device and device[0].isdigit() and device[-1].isdigit() and device.count('.') == 3:
+        if device.startswith("exec:"):
+            self.serial = ProcessToSerial(device[len("exec:"):])
+        elif device.startswith("execpty:"):
+            self.serial = ProcessPtyToTerminal(device[len("qemupty:"):])
+        elif device and device[0].isdigit() and device[-1].isdigit() and device.count('.') == 3:
             # device looks like an IP address
             self.serial = TelnetToSerial(device, user, password, read_timeout=10)
         else: