pebble/src/fw/util/crc32_lut.py
2025-01-27 11:38:16 -08:00

37 lines
1.1 KiB
Python
Executable file

#!/usr/bin/env python
# Copyright 2024 Google LLC
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from __future__ import print_function
CRC_POLY = 0xEDB88320
def crc_table(bits):
lookup_table = []
for i in xrange(2**bits):
rr = i * 16
for x in xrange(8):
rr = (rr >> 1) ^ (-(rr & 1) & CRC_POLY)
lookup_table.append(rr & 0xffffffff)
return lookup_table
table = ['0x{:08x},'.format(entry) for entry in crc_table(4)]
chunks = zip(*[iter(table)]*4)
print('static const uint32_t s_lookup_table[] = {')
for chunk in chunks:
print(' ' + ' '.join(chunk))
print('};')