minicom script generator for dumping firmware

dumpscript-gen.py

#!/usr/bin/python2
#
# script to generate a minicom script that dumps entire flash
# problem is the stub seems to read all data into RAM first,
# so you can only do in batches
#
# 2019.10.24

# inc needs to be low enough to complete within `expect` timeout
inc  = 0x20000
end  = 0x1000000
addr = 0

prompt = 'flash> '
dump_cmd = r'dump -p /dev/mtdblock0 -r 0x{addr:08x} -l 0x{len:08x} -4\n'

print r"""#
# dump firmware answer file, generated by dumpscript-gen.py
#

timeout 86400  # one day ought to be enough

# test it works
sleep 2
send "\n\n"
expect {{
	"{prompt}" break
	timeout 5 goto end
}}

""".format(prompt=prompt)

while addr < end: 
    l = min(end - addr, inc)

    cmd = dump_cmd.format(addr=addr, len=l)
    print 'send "{cmd}"\nexpect "{prompt}"'.format(cmd=cmd, prompt=prompt)
    addr += inc

print """
end:
print "dumpscript done."
"""