Wrote script to fix checksums

2026-06-19 01:16:26 -07:00 · 2021-06-11 01:14:18 -05:00
parent 3cf8c10588
commit f16317428e
6 changed files with 94 additions and 2 deletions
@@ -0,0 +1,75 @@
+import re
+import os
+import sys
+
+from file_util import FileUtil
+
+VERSION = sys.argv[1]
+
+BUILD_DIR = 'build/' + VERSION
+MAP_FILEPATH = BUILD_DIR + '/dkr.map'
+ROM_FILEPATH = BUILD_DIR + '/dkr.z64'
+
+FUNCTIONS_TO_CALC = [
+    ('func_8003B4BC', 'D_800DCDD0'),
+    ('func_80068158', 'D_800DD320'),
+    ('D_80024D54', 'D_800DCEA0')
+]
+
+def getMatches(string, regex):
+    out = []
+    matches = re.finditer(regex, string, re.MULTILINE)
+    for matchNum, match in enumerate(matches, start=1):
+        start = match.start()
+        end = match.end()
+        out.append((string[start:end], match.groups(), (start, end)))
+    return out
+    
+rom = FileUtil.get_bytes_from_file(ROM_FILEPATH)
+mapFile = {}
+RAM_TO_ROM = None
+
+def write_checksum_to_rom(romOffset, value):
+    global rom
+    rom[romOffset + 0] = (value >> 24) & 0xFF
+    rom[romOffset + 1] = (value >> 16) & 0xFF
+    rom[romOffset + 2] = (value >> 8) & 0xFF
+    rom[romOffset + 3] = value & 0xFF
+    
+def calculate_checksum_for_function(funcLabel, varLabel):
+    if funcLabel not in mapFile:
+        raise Exception('Label "' + funcLabel + '" does not exist in the map file!')
+    if varLabel not in mapFile:
+        raise Exception('Label "' + varLabel + '" does not exist in the map file!')
+    funcEntry = mapFile[funcLabel]
+    funcAddress = funcEntry['value']
+    funcLength = funcEntry['length']
+    funcRomOffset = funcAddress - RAM_TO_ROM
+    count = 0
+    for i in range(0, funcLength):
+        count += rom[funcRomOffset + i]
+    varEntry = mapFile[varLabel]
+    varAddress = varEntry['value']
+    varRomOffset = varAddress - RAM_TO_ROM
+    write_checksum_to_rom(varRomOffset, count)
+    # print('The checksum count for "' + funcLabel + '" is: ' + hex(count))
+
+def calculate_matches():
+    global mapFile, RAM_TO_ROM
+    REGEX_MAP_GET_LABEL = r"[ ]*0x[0-9A-Fa-f]{8}([0-9A-Fa-f]{8})[ ]*([_A-Za-z0-9]+)"
+    mapMatches = getMatches(FileUtil.get_text_from_file(MAP_FILEPATH), REGEX_MAP_GET_LABEL)
+    for i in range(0, len(mapMatches) - 1):
+        match = mapMatches[i]
+        labelValue = match[1]
+        value = int(labelValue[0], 16)
+        length = int(mapMatches[i + 1][1][0], 16) - value
+        mapFile[labelValue[1]] = { "value": value, "length": length }
+    RAM_TO_ROM = mapFile['__RAM_TO_ROM']['value']
+
+def main():
+    calculate_matches()
+    for entry in FUNCTIONS_TO_CALC:
+        calculate_checksum_for_function(entry[0], entry[1])
+    FileUtil.write_bytes_to_file(ROM_FILEPATH, rom)
+
+main()