52 lines
1.7 KiB
Python
Executable File
52 lines
1.7 KiB
Python
Executable File
#!/usr/bin/env python2
|
|
#
|
|
# Compute and insert the vector table checksum required for booting the
|
|
# LPC43xx and some other NXP ARM microcontrollers.
|
|
#
|
|
# usage: lpcvtcksum firmware.bin
|
|
#
|
|
# This file is part of the libopencm3 project.
|
|
#
|
|
# Copyright (C) 2012 Michael Ossmann <mike@ossmann.com>
|
|
#
|
|
# This library is free software: you can redistribute it and/or modify
|
|
# it under the terms of the GNU Lesser General Public License as published by
|
|
# the Free Software Foundation, either version 3 of the License, or
|
|
# (at your option) any later version.
|
|
#
|
|
# This library is distributed in the hope that it will be useful,
|
|
# but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
# GNU Lesser General Public License for more details.
|
|
#
|
|
# You should have received a copy of the GNU Lesser General Public License
|
|
# along with this library. If not, see <http://www.gnu.org/licenses/>.
|
|
|
|
import sys, struct
|
|
|
|
binfile = open(sys.argv[1], 'r+b')
|
|
rawvectors = binfile.read(32)
|
|
vectors = list(struct.unpack('<IIIIIIII', rawvectors))
|
|
|
|
# compute vector table checksum
|
|
sum = 0
|
|
for i in range(7):
|
|
sum += vectors[i]
|
|
vectors[7] = 1 + (0xffffffff ^ (0xffffffff & sum))
|
|
|
|
print "computed vector table checksum: 0x%08x" % vectors[7]
|
|
|
|
rawremainder = binfile.read()
|
|
remainder = list(struct.unpack('B' * len(rawremainder), rawremainder))
|
|
numbytes = len(remainder) + 32
|
|
|
|
# pad to multiple of 4096 bytes to make GoodFET happy
|
|
if (numbytes % 4096):
|
|
remainder.extend([0] * (4096 - numbytes % 4096))
|
|
|
|
# rewrite file with checksum and padding
|
|
data = vectors
|
|
data.extend(remainder)
|
|
binfile.seek(0)
|
|
binfile.write(struct.pack('<IIIIIIII' + 'B' * len(remainder), *data))
|