contrib/rpc_examples: add example for python3

Halt, resume, memory read/write are used in various ways.

Change-Id: Ia6727678bfc19cc764f822b739bddaae56e9dc70
Signed-off-by: Andreas Ortmann <ortmann@finf.uni-hannover.de>
Reviewed-on: http://openocd.zylin.com/2000
Tested-by: jenkins
Reviewed-by: Paul Fertser <fercerpav@gmail.com>

diff --git a/contrib/rpc_examples/ocd_rpc_example.py b/contrib/rpc_examples/ocd_rpc_example.py
new file mode 100755 (executable)
index 0000000..6c8529c
--- /dev/null
+++ b/contrib/rpc_examples/ocd_rpc_example.py
@@ -0,0 +1,145 @@
+#!/usr/bin/env python3
+"""
+OpenOCD RPC example, covered by GNU GPLv3 or later
+Copyright (C) 2014 Andreas Ortmann (ortmann@finf.uni-hannover.de)
+
+
+Example output:
+./ocd_rpc_example.py
+echo says hi!
+
+target state: halted
+target halted due to debug-request, current mode: Thread
+xPSR: 0x01000000 pc: 0x00000188 msp: 0x10000fd8
+
+variable @ 0x10000000: 0x01c9c380
+
+variable @ 0x10000000: 0xdeadc0de
+
+memory (before): ['0xdeadc0de', '0x00000011', '0xaaaaaaaa', '0x00000023',
+'0x00000042', '0x0000ffff']
+
+memory (after): ['0x00000001', '0x00000000', '0xaaaaaaaa', '0x00000023',
+'0x00000042', '0x0000ffff']
+"""
+
+import socket
+import itertools
+
+def strToHex(data):
+    return map(strToHex, data) if isinstance(data, list) else int(data, 16)
+
+def hexify(data):
+    return "<None>" if data is None else ("0x%08x" % data)
+
+def compareData(a, b):
+    for i, j, num in zip(a, b, itertools.count(0)):
+        if i != j:
+            print("difference at %d: %s != %s" % (num, hexify(i), hexify(j)))
+
+
+class OpenOcd:
+    COMMAND_TOKEN = '\x1a'
+    def __init__(self, verbose=False):
+        self.verbose = verbose
+        self.tclRpcIp       = "127.0.0.1"
+        self.tclRpcPort     = 6666
+        self.bufferSize     = 4096
+
+        self.sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+
+    def __enter__(self):
+        self.sock.connect((self.tclRpcIp, self.tclRpcPort))
+        return self
+
+    def __exit__(self, type, value, traceback):
+        try:
+            self.send("exit")
+        finally:
+            self.sock.close()
+
+    def send(self, cmd):
+        """Send a command string to TCL RPC. Return the result that was read."""
+        data = (cmd + OpenOcd.COMMAND_TOKEN).encode("utf-8")
+        if self.verbose:
+            print("<- ", data)
+
+        self.sock.send(data)
+        return self._recv()
+
+    def _recv(self):
+        """Read from the stream until the token (\x1a) was received."""
+        data = bytes()
+        while True:
+            chunk = self.sock.recv(self.bufferSize)
+            data += chunk
+            if bytes(OpenOcd.COMMAND_TOKEN, encoding="utf-8") in chunk:
+                break
+
+        if self.verbose:
+            print("-> ", data)
+
+        data = data.decode("utf-8").strip()
+        data = data[:-1] # strip trailing \x1a
+
+        return data
+
+    def readVariable(self, address):
+        raw = self.send("ocd_mdw 0x%x" % address).split(": ")
+        return None if (len(raw) < 2) else strToHex(raw[1])
+
+    def readMemory(self, wordLen, address, n):
+        self.send("array unset output") # better to clear the array before
+        self.send("mem2array output %d 0x%x %d" % (wordLen, address, n))
+
+        output = self.send("ocd_echo $output").split(" ")
+
+        return [int(output[2*i+1]) for i in range(len(output)//2)]
+
+    def writeVariable(self, address, value):
+        assert value is not None
+        self.send("mww 0x%x 0x%x" % (address, value))
+
+    def writeMemory(self, wordLen, address, n, data):
+        array = " ".join(["%d 0x%x" % (a, b) for a, b in enumerate(data)])
+
+        self.send("array unset 1986ве1т") # better to clear the array before
+        self.send("array set 1986ве1т { %s }" % array)
+        self.send("array2mem 1986ве1т 0x%x %s %d" % (wordLen, address, n))
+
+if __name__ == "__main__":
+
+    def show(*args):
+        print(*args, end="\n\n")
+
+    with OpenOcd() as ocd:
+        ocd.send("reset")
+
+        show(ocd.send("ocd_echo \"echo says hi!\"")[:-1])
+        show(ocd.send("capture \"ocd_halt\"")[:-1])
+
+        # Read the first few words at the RAM region (put starting adress of RAM
+        # region into 'addr')
+        addr = 0x10000000
+
+        value = ocd.readVariable(addr)
+        show("variable @ %s: %s" % (hexify(addr), hexify(value)))
+
+        ocd.writeVariable(addr, 0xdeadc0de)
+        show("variable @ %s: %s" % (hexify(addr), hexify(ocd.readVariable(addr))))
+
+        data = [1, 0, 0xaaaaaaaa, 0x23, 0x42, 0xffff]
+        wordlen = 32
+        n = len(data)
+
+        read = ocd.readMemory(wordlen, addr, n)
+        show("memory (before):", list(map(hexify, read)))
+
+        ocd.writeMemory(wordlen, addr, n, data)
+
+        read = ocd.readMemory(wordlen, addr, n)
+        show("memory  (after):", list(map(hexify, read)))
+
+        compareData(read, data)
+
+        ocd.send("resume")