add hacky yuzu2ryujinx script

scripts/yuzu2ryujinx.py

@@ -0,0 +1,56 @@
+#!/usr/bin/env nix-shell
+#!nix-shell -i python3 -p python3
+
+'''
+Convert Yuzu saves to Ryujinx by putting them in profile 0 (RyuPlayer)
+Note that this is rather destructive and won't deal well with multiple profiles,
+so back saves up before trying it
+
+(if anyone wants to modify it, it's CC0)
+'''
+
+from pathlib import Path
+import os
+import shutil
+import struct
+import typing
+
+RYUJINX_DIR = Path.home() / ".config" / "Ryujinx"
+YUZU_DIR = Path.home() / ".local" / "share" / "yuzu"
+
+def get_yuzu_save_dir():
+    profile_path = YUZU_DIR / "nand" / "system" / "save" / "8000000000000010" / "su" / "avators" / "profiles.dat"
+    with open(profile_path, "rb") as f:
+        # Just go with profile 0
+        uid_low, uid_high = struct.unpack("<QQ", f.read(0x20)[0x10:])
+    return YUZU_DIR / "nand" / "user" / "save" / "0000000000000000" / f"{uid_high:016X}{uid_low:016X}"
+
+RYUJINX_SAVE_DIR = RYUJINX_DIR / "bis" / "user" / "save"
+YUZU_SAVE_DIR = get_yuzu_save_dir()
+
+
+titles: typing.Dict[str, Path] = dict()
+
+# The first 8 bytes of ExtraData0 are the program ID, next 16 are user ID.
+# NOTE: if you try to do multiple profiles, ryujinx doesn't seem to update uid in ExtraData1
+# https://github.com/Thealexbarney/LibHac/blob/master/src/LibHac/Fs/Common/SaveDataTypes.cs#L97
+# https://github.com/Thealexbarney/LibHac/blob/master/src/LibHac/Fs/Common/SaveDataTypes.cs#L131
+for child in RYUJINX_SAVE_DIR.iterdir():
+    with open(child / "ExtraData0", "rb") as extra:
+        data = extra.read(24)
+        title_id, *uid = struct.unpack("<QQQ", data)
+    if uid not in ([0, 0], [1, 0]):
+        # Always use default profile
+        print("Found and ignored save for user {:016X}{:016X} ({:016X})".format(*uid, title_id))
+        continue
+    titles[f"{title_id:016X}"] = child / "0"
+
+for title_id, ryujinx_dir in titles.items():
+    yuzu_dir = YUZU_SAVE_DIR / title_id
+    if not yuzu_dir.exists():
+        continue
+    
+    print(yuzu_dir, ryujinx_dir)
+
+    shutil.rmtree(ryujinx_dir)
+    shutil.copytree(yuzu_dir, ryujinx_dir)