Furthened decomp work

tmp_inspect_regret_debug_patch_sites.py

@@ -0,0 +1,87 @@
+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 selector_to_segment_index(selector):
+    return ((selector - 0x1000) // 8) + 1
+
+
+def get_segment_info(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_to_segment_index(selector)
+    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
+    flags = u16(data, seg_entry_off + 4)
+    seg_file_off = sector << align_shift
+    reloc_off = seg_file_off + seg_len
+    reloc_count = u16(data, reloc_off)
+    return {
+        'selector': selector,
+        'segment_index': seg_index,
+        'segment_file_off': seg_file_off,
+        'segment_len': seg_len,
+        'flags': flags,
+        'reloc_off': reloc_off,
+        'reloc_count': reloc_count,
+    }
+
+
+def read_relocs(data, seg_info):
+    relocs = []
+    pos = seg_info['reloc_off'] + 2
+    for i in range(seg_info['reloc_count']):
+        relocs.append({
+            'index': i,
+            'record_off': pos,
+            'src_type': data[pos],
+            'flags': data[pos + 1],
+            'src_off': u16(data, pos + 2),
+            'b4': data[pos + 4],
+            'b5': data[pos + 5],
+            'target_off': u16(data, pos + 6),
+            'raw': data[pos:pos + 8],
+        })
+        pos += 8
+    return relocs
+
+
+def dump_site(data, seg_info, site, size=16):
+    raw = seg_info['segment_file_off'] + site
+    print(f'site {seg_info["selector"]:04X}:{site:04X} -> file 0x{raw:X}: {data[raw:raw+size].hex(" ")}')
+
+
+def main():
+    path = Path(r'd:\Ghidra\Crusader\REGRET.EXE')
+    data = path.read_bytes()
+
+    for selector in (0x1148, 0x13F8):
+        info = get_segment_info(data, selector)
+        print(f'selector 0x{selector:04X} -> segment index {info["segment_index"]}, file 0x{info["segment_file_off"]:X}, len 0x{info["segment_len"]:X}, reloc@0x{info["reloc_off"]:X}, count={info["reloc_count"]}')
+        relocs = read_relocs(data, info)
+        interesting = []
+        if selector == 0x1148:
+            interesting = [0x3678, 0x36C0, 0x3702, 0x3743]
+        else:
+            interesting = [0x10FA, 0x2040, 0x209F, 0x20B9]
+        for site in interesting:
+            dump_site(data, info, site, 24)
+            local_hits = [r for r in relocs if site <= r['src_off'] <= site + 0x80]
+            for r in local_hits[:20]:
+                print(f'  reloc idx={r["index"]} rec@0x{r["record_off"]:X} src=0x{r["src_off"]:04X} bytes={r["raw"].hex(" ")}')
+        print('')
+
+
+if __name__ == '__main__':
+    main()