read_flash_segment works now

added timeout for responses from bootloader


git-svn-id: https://svn.spreadspace.org/pic/trunk@43 a09c6847-51d9-44de-8ef2-e725cf50f3c7

1 files changed, 12 insertions, 2 deletions

diff --git a/downloader/downloader.py b/downloader/downloader.py
index 8da13cf..9efb30e 100755
--- a/downloader/downloader.py
+++ b/downloader/downloader.py
@@ -85,7 +85,7 @@ def open_serial(device, baud):
     print "opening %s (%s Baud)" % (device, baud)
 
     try:
-        dev = serial.Serial(port=device, baudrate=baud)
+        dev = serial.Serial(port=device, baudrate=baud, timeout=3)
         dev.flushInput()
         dev.flushOutput()
         return dev
@@ -114,6 +114,9 @@ def exec_command(dev, cmd, answer):
 
     astr = bytearray()
     astr += dev.read(3)
+    if len(astr) < 3:
+        print "ERROR: timeout while reading response header"
+        sys.exit(4)
 
     if astr[0] != cstr[0]:
         print "ERROR: bootloader returned wrong command code"
@@ -130,7 +133,14 @@ def exec_command(dev, cmd, answer):
         sys.exit(4)
 
     answer_len = struct.calcsize(answer)
-    astr += dev.read(answer_len)
+    if answer_len > 0:
+        tmp = bytearray()
+        tmp += dev.read(answer_len)
+        if len(tmp) < answer_len:
+            print "ERROR: timeout while reading response"
+            sys.exit(4)
+
+        astr += tmp
 
     if 0 != calc_csum(astr):
         print "ERROR: checksum error"