diff --git a/emulators/ymir.yml b/emulators/ymir.yml
index 07a4abec..29330ed2 100644
--- a/emulators/ymir.yml
+++ b/emulators/ymir.yml
@@ -19,6 +19,20 @@ found_by: {standalone: content}
 systems:
   - sega-saturn
 
+data_root:
+  windows:
+    path: "%APPDATA%/StrikerX3/Ymir"
+    source_ref: "apps/ymir-sdl3/src/app/profile.cpp:29-34, apps/ymir-sdl3/src/app/app.cpp:342-437, apps/ymir-sdl3/CMakeLists.txt:641-642"
+    note: "Portable profile: the current directory, then the folder of the executable, when it holds Ymir.toml. The first launch asks between the two. -p names a folder, -u forces this one"
+  macos:
+    path: "~/Library/Application Support/StrikerX3/Ymir"
+    source_ref: "apps/ymir-sdl3/src/app/profile.cpp:29-34, apps/ymir-sdl3/src/app/app.cpp:342-437, apps/ymir-sdl3/CMakeLists.txt:641-642"
+    note: "Portable profile: the folder of the executable when it holds Ymir.toml. The first launch asks between the two. -p names a folder, -u forces this one"
+  linux:
+    path: "$XDG_DATA_HOME/StrikerX3/Ymir, else ~/.local/share/StrikerX3/Ymir"
+    source_ref: "apps/ymir-sdl3/src/app/profile.cpp:29-34, apps/ymir-sdl3/src/app/app.cpp:342-437, apps/ymir-sdl3/CMakeLists.txt:641-642"
+    note: "Portable profile: the current directory, then the folder of the executable, when it holds Ymir.toml. The first launch asks between the two. -p names a folder, -u forces this one. Always this folder under Flatpak"
+
 notes: |
   Ymir is a Sega Saturn emulator by StrikerX3. The libretro port by
   warmenhoven wraps the shared ymir-core library on the libretro branch of