Furthened decomp work

tmp_find_regret_seg13f8_caves.py

@@ -0,0 +1,55 @@
+from pathlib import Path
+
+
+def u16(data, off):
+    return data[off] | (data[off + 1] << 8)
+
+
+def u32(data, off):
+    return u16(data, off) | (u16(data, off + 2) << 16)
+
+
+def get_segment(data, selector):
+    ne_off = u32(data, 0x3C)
+    seg_table_off = ne_off + u16(data, ne_off + 0x22)
+    align_shift = u16(data, ne_off + 0x32)
+    seg_index = ((selector - 0x1000) // 8) + 1
+    seg_entry_off = seg_table_off + (seg_index - 1) * 8
+    sector = u16(data, seg_entry_off)
+    seg_len = u16(data, seg_entry_off + 2)
+    if seg_len == 0:
+        seg_len = 0x10000
+    seg_file_off = sector << align_shift
+    return seg_file_off, seg_len
+
+
+def emit_runs(blob, seg_base, selector, allowed, minimum):
+    start = None
+    for i, byte in enumerate(blob):
+        if byte in allowed:
+            if start is None:
+                start = i
+        elif start is not None:
+            length = i - start
+            if length >= minimum:
+                print(f'{selector:04X}:{start:04X} file=0x{seg_base + start:X} len=0x{length:X} bytes={blob[start:start+min(length,16)].hex(" ")}')
+            start = None
+    if start is not None:
+        length = len(blob) - start
+        if length >= minimum:
+            print(f'{selector:04X}:{start:04X} file=0x{seg_base + start:X} len=0x{length:X} bytes={blob[start:start+min(length,16)].hex(" ")}')
+
+
+def main():
+    data = Path(r'd:\Ghidra\Crusader\REGRET.EXE').read_bytes()
+    seg_base, seg_len = get_segment(data, 0x13F8)
+    blob = data[seg_base:seg_base + seg_len]
+    print(f'segment 13F8 file=0x{seg_base:X} len=0x{seg_len:X}')
+    print('zero runs >= 0x20')
+    emit_runs(blob, seg_base, 0x13F8, {0x00}, 0x20)
+    print('nop/int3 runs >= 0x10')
+    emit_runs(blob, seg_base, 0x13F8, {0x90, 0xCC}, 0x10)
+
+
+if __name__ == '__main__':
+    main()