Import of the watch repository from Pebble

tools/fw_binary_info.py

@@ -0,0 +1,129 @@
+#!/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 binascii import crc32
+import os
+import struct
+
+import stm32_crc
+
+
+class PebbleFirmwareBinaryInfo(object):
+    V1_STRUCT_VERSION = 1
+    V1_STRUCT_DEFINTION = [
+        ('20s', 'build_id'),
+        ('L', 'version_timestamp'),
+        ('32s', 'version_tag'),
+        ('8s', 'version_short'),
+        ('?', 'is_recovery_firmware'),
+        ('B', 'hw_platform'),
+        ('B', 'metadata_version')
+    ]
+    # The platforms which use a legacy defective crc32
+    LEGACY_CRC_PLATFORMS = [
+        0,  # unknown (assume legacy)
+        1,  # OneEV1
+        2,  # OneEV2
+        3,  # OneEV2_3
+        4,  # OneEV2_4
+        5,  # OnePointFive
+        6,  # TwoPointFive
+        7,  # SnowyEVT2
+        8,  # SnowyDVT
+        9,  # SpaldingEVT
+        10,  # BobbyDVT
+        11,  # Spalding
+        0xff,  # OneBigboard
+        0xfe,  # OneBigboard2
+        0xfd,  # SnowyBigboard
+        0xfc,  # SnowyBigboard2
+        0xfb,  # SpaldingBigboard
+    ]
+
+    def get_crc(self):
+        _, ext = os.path.splitext(self.path)
+        assert ext == '.bin', 'Can only calculate crc for .bin files'
+        with open(self.path, 'rb') as f:
+            image = f.read()
+        if self.hw_platform in self.LEGACY_CRC_PLATFORMS:
+            # use the legacy defective crc
+            return stm32_crc.crc32(image)
+        else:
+            # use a regular crc
+            return crc32(image) & 0xFFFFFFFF
+
+    def _get_footer_struct(self):
+        fmt = '<' + reduce(lambda s, t: s + t[0],
+                           PebbleFirmwareBinaryInfo.V1_STRUCT_DEFINTION, '')
+        return struct.Struct(fmt)
+
+    def _get_footer_data_from_elf(self, path):
+        import binutils
+        fw_version_data = binutils.section_bytes(path, '.fw_version')
+        # The GNU Build ID has 16 bytes of header data, strip it off:
+        build_id_data = binutils.section_bytes(path, '.note.gnu.build-id')[16:]
+        return build_id_data + fw_version_data
+
+    def _get_footer_data_from_bin(self, path):
+        with open(path, 'rb') as f:
+            struct_size = self.struct.size
+            f.seek(-struct_size, 2)
+            footer_data = f.read()
+            return footer_data
+
+    def _parse_footer_data(self, footer_data):
+        z = zip(PebbleFirmwareBinaryInfo.V1_STRUCT_DEFINTION,
+                self.struct.unpack(footer_data))
+        return {entry[1]: data for entry, data in z}
+
+    def __init__(self, elf_or_bin_path):
+        self.path = elf_or_bin_path
+        self.struct = self._get_footer_struct()
+        _, ext = os.path.splitext(elf_or_bin_path)
+        if ext == '.elf':
+            footer_data = self._get_footer_data_from_elf(elf_or_bin_path)
+        elif ext == '.bin':
+            footer_data = self._get_footer_data_from_bin(elf_or_bin_path)
+        else:
+            raise ValueError('Unexpected extension. Must be ".bin" or ".elf"')
+        self.info = self._parse_footer_data(footer_data)
+
+        # Trim leading NULLS on the strings:
+        for k in ["version_tag", "version_short"]:
+            self.info[k] = self.info[k].rstrip("\x00")
+
+    def __str__(self):
+        return str(self.info)
+
+    def __repr__(self):
+        return self.info.__repr__()
+
+    def __getattr__(self, name):
+        if name in self.info:
+            return self.info[name]
+        raise AttributeError
+
+
+if __name__ == "__main__":
+    import argparse
+    import pprint
+    parser = argparse.ArgumentParser()
+    parser.add_argument('fw_bin_or_elf_path')
+    args = parser.parse_args()
+
+    fw_bin_info = PebbleFirmwareBinaryInfo(args.fw_bin_or_elf_path)
+
+    pprint.pprint(fw_bin_info)