sanity checks for commands

git-svn-id: https://svn.spreadspace.org/pic/trunk@22 a09c6847-51d9-44de-8ef2-e725cf50f3c7

1 files changed, 67 insertions, 4 deletions

diff --git a/downloader/downloader.py b/downloader/downloader.py
index cc1c97c..5380b4d 100755
--- a/downloader/downloader.py
+++ b/downloader/downloader.py
@@ -23,13 +23,16 @@
 
 '''spreadspace simple pic downloader.'''
 
-VERSION = '0.1'
+VERSION_MAJ = 0
+VERSION_MIN = 1
 
 def open_serial(device, baud):
     import os
     import tty
     import termios
 
+    print "opening %s (%s Baud)" % (device, baud)
+
     baudrates = { 50: termios.B50, 75: termios.B75, 110: termios.B110, 134: termios.B134,
                   150: termios.B150, 200: termios.B200, 300: termios.B300, 600: termios.B600,
                   1200: termios.B1200, 1800: termios.B1800, 2400: termios.B2400, 4800: termios.B4800,
@@ -61,8 +64,6 @@ def open_serial(device, baud):
 
 
 def load_hex(file):
-    import os
-
     fin = file
     if fin == '-':
         fin = sys.stdin
@@ -82,10 +83,70 @@ def load_hex(file):
 
     return data
 
+def calc_csum(str):
+    cs = 0
+    for c in str:
+        cs ^= ord(c)
+    return chr(cs)
+
+
+def exec_command(dev, cmd, answer):
+    import struct
+
+    return_codes = { 0: "OK", 1: "invalid command", 2: "bad checksum",
+                     3: "not implemented", 4: "flash write error",
+                     5: "address invalid", 6: "address prohibited" }
+
+    answer = "=cB" + answer + "B"
+    answer_len = struct.calcsize(answer)
+
+    cstr = cmd + calc_csum(cmd)
+    os.write(dev, cstr)
+
+    astr = ""
+    while len(astr) < answer_len:
+        astr += os.read(dev, answer_len - len(astr))
+    data = list(struct.unpack(answer, astr))
+    code = data.pop(0)
+    ret = data.pop(1)
+    checksum = data.pop()
+    if code != cmd[0]:
+        print "ERROR: bootloader returned wrong command code"
+        sys.exit(4)
+    if ret != 0:
+        rstr = "invalid return code"
+        try:
+            rstr = return_codes[ret]
+        except KeyError:
+            pass
+        print "ERROR: bootloader returned %d: %s" % (ret, rstr)
+        sys.exit(4)
+    if 0 != calc_csum(astr):
+        print "ERROR: checksum error"
+        sys.exit(4)
+
+    return data
+
+### commands
+
+def identify(dev):
+    data = exec_command(dev, "i", "BB10sHBB")
+    id = { 'ver_maj': data[0], 'ver_min': data[1], 'name': data[2], 'devid': data[3], 'fss': data[4], 'supported': data[5] }
+
+    if id['ver_maj'] != VERSION_MAJ:
+        print "Incomaptible protocol version, expected: %d, got: %d" % (VERSION_MAJ, id['ver_maj'])
+        sys.exit(4)
+
+    print "connected with Bootloader '%s', (ID=%04X, FSS=%d)" % (id['name'], id['devid'], id['fss'])
+    return id
+
+
+### main
 
 if __name__ == '__main__':
     import getopt
     import sys
+    import os
 
     from intelhex import IntelHex
 
@@ -116,7 +177,7 @@ Options:
                 print(usage)
                 sys.exit(0)
             elif o in ("-v", "--version"):
-                print(VERSION)
+                print("Version %d.%d" % (VERSION_MAJ, VERSION_MIN))
                 sys.exit(0)
             elif o in ("--device"):
                 device = a
@@ -141,3 +202,5 @@ Options:
     addrs.sort()
     for a in addrs:
         print "%05d: %04X" % (a, data[a])
+
+    id = identify(dev)