dissect.py

#!/usr/bin/python
#
# usage: python this.py < qca61xx.bin
# unpacks qca61xx.bin files
# creates fw-x.bin files in current work dir (overwrites existing files!)
#
import sys

buf = sys.stdin.read()

head = 'SGMT'
tail = '\xfd\xff\xff\xff\x00\x00\x00\x00\xff\xff\xff\xff'
i = 1

while True:
        start = buf.find(head)
        buf = buf[start:]
        end = buf.find(tail)

        if start == -1 or end == -1:
                break

        end += len(tail)
        fname = 'fw-%d.bin' % i
        i += 1

        print "writing %s (%d bytes)" % (fname, end)
        with open(fname, "wb") as f:
                f.write(buf[:end])
                f.close()

        buf = buf[end:]