Import of the watch repository from Pebble

src/fw/util/legacy_checksum_crc_table.py

@@ -0,0 +1,38 @@
+#!/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 = 0x04C11DB7
+CRC_WIDTH = 32
+
+
+def precompute_table(bits):
+    lookup_table = []
+    for i in xrange(2**bits):
+        rr = i << (CRC_WIDTH - bits)
+        for x in xrange(bits):
+            if rr & 0x80000000:
+                rr = (rr << 1) ^ CRC_POLY
+            else:
+                rr <<= 1
+        lookup_table.append(rr & 0xffffffff)
+    return lookup_table
+
+print('static const uint32_t s_lookup_table[] = {')
+for entry in precompute_table(4):
+    print('  0x{:08x},'.format(entry))
+print('};')