feat: run retrodeck dual-mode cores as libretro

README.md

@@ -120,7 +120,7 @@ Full list with per-file details: **[https://abdess.github.io/retrobios/](https:/
 | Recalbox | 351/351 | 2,762/2,933 | MD5 hash |
 | RetroArch | 526/526 | 7,691/7,733 | file presence |
 | RetroBat | 348/348 | 4,752/9,218 | MD5 hash |
-| RetroDECK | 2,007/2,008 | 6,287/6,547 | MD5 hash |
+| RetroDECK | 2,007/2,008 | 6,480/6,741 | MD5 hash |
 | RetroPie * | 532/532 | 7,858/12,489 | file presence |
 | RomM | 383/383 | 83/860 | MD5 hash |
 
@@ -209,4 +209,4 @@ The scripts and tooling are released under the [MIT License](LICENSE).
 The BIOS and firmware files are not covered by that license: they are third-party system software, preserved and provided for personal backup, archival, and interoperability with emulation software. [NOTICE](NOTICE) sets out their status and how to ask for a file to be removed.
 The reasoning, and where it is weakest, is in [the project's legal position](https://abdess.github.io/retrobios/wiki/legal/).
 
-*Auto-generated on 2026-10-22T19:15:47Z*
+*Auto-generated on 2026-10-22T20:58:47Z*

platforms/retrodeck.yml

@@ -44,6 +44,14 @@ standalone_cores:
 - vita3k
 - xemu
 - xroar
+dual_mode_cores:
+- azahar
+- cemu
+- dolphin
+- mame
+- melonds
+- pcsx2
+- ppsspp
 systems:
   triforce:
     files:

scripts/scraper/retrodeck_scraper.py

@@ -96,6 +96,25 @@ def es_systems_libretro_systems(text: str) -> dict[str, list[str]]:
             if match:
                 found.setdefault(match.group(1), set()).add(folder)
     return {core: sorted(folders) for core, folders in sorted(found.items())}
+
+
+def component_modes(
+    components: list[str], libretro_systems: dict[str, list[str]]
+) -> tuple[list[str], list[str]]:
+    """(standalone_cores, dual_mode_cores) of RetroDECK's emulator components.
+
+    Every component but retroarch is an emulator RetroDECK launches on its
+    own (its component_launcher.sh execs the emulator's binary). One whose name
+    is also a core an ES-DE command loads through RetroArch is offered both
+    ways: es_systems.xml lists "Azahar (Standalone)" and "Azahar"
+    (azahar_libretro.so) for n3ds. The core itself ships, RetroArch's cores
+    coming whole from the buildbot's nightly RetroArch_cores.7z
+    (retroarch/component_recipe.json:250-262 at components fcd0d729).
+    """
+    standalone = [c for c in components if c != "retroarch"]
+    return standalone, [c for c in standalone if c in libretro_systems]
+
+
 NON_EMULATOR_COMPONENTS = {
     "framework",
     "es-de",
@@ -533,6 +552,9 @@ class Scraper(BaseScraper):
             sys_entry["files"].append(requirement_entry(req))
 
         version = fetch_github_latest_version("RetroDECK/RetroDECK")
+        # The ROM folders each libretro core runs for: its save folders.
+        libretro_systems = self._fetch_libretro_systems()
+        standalone, dual = component_modes(cores, libretro_systems)
 
         return {
             "platform": "RetroDECK",
@@ -547,12 +569,10 @@ class Scraper(BaseScraper):
             "hash_type": "md5",
             "verification_mode": "md5",
             "cores": cores,
-            # Each component is one emulator RetroDECK ships and launches on
-            # its own, and retroarch is the one that runs cores.
-            "standalone_cores": [c for c in cores if c != "retroarch"],
+            "standalone_cores": standalone,
+            **({"dual_mode_cores": dual} if dual else {}),
             "systems": systems,
-            # The ROM folders each libretro core runs for: its save folders.
-            "libretro_systems": self._fetch_libretro_systems(),
+            "libretro_systems": libretro_systems,
             "launchers": extract_launchers(cores, self.component_file),
         }
 

tests/test_scraper_contract.py

@@ -472,6 +472,78 @@ class RetroDeckCoresAreItsComponents(unittest.TestCase):
         self.assertNotIn("cores", registry["platforms"]["retrodeck"])
 
 
+class RetroDeckComponentModes(unittest.TestCase):
+    """Every RetroDECK component was written standalone only: Azahar, whose
+    ES-DE system also loads azahar_libretro.so, never got its libretro
+    files, which the core reads below its save folder."""
+
+    # Commands as RetroDECK/ES-DE 15e1b236 writes them in
+    # resources/systems/linux/es_systems.xml (n3ds at 1379-1383, psx at
+    # 1843 and 1847). The commented-out DuckStation core is the fixture's own.
+    ES_SYSTEMS = """\
+<?xml version="1.0"?>
+<systemList>
+  <system><name>n3ds</name><path>%ROMPATH%/n3ds</path>
+    <command label="Azahar (Standalone)">%EMULATOR_AZAHAR% %ROM%</command>
+    <command label="Azahar">%EMULATOR_RETROARCH% -L %CORE_RETROARCH%/azahar_libretro.so %ROM%</command>
+    <command label="Citra">%EMULATOR_RETROARCH% -L %CORE_RETROARCH%/citra_libretro.so %ROM%</command>
+  </system>
+  <system><name>psx</name><path>%ROMPATH%/psx</path>
+    <command label="SwanStation">%EMULATOR_RETROARCH% -L %CORE_RETROARCH%/swanstation_libretro.so %ROM%</command>
+    <!-- <command label="DuckStation">%EMULATOR_RETROARCH% -L %CORE_RETROARCH%/duckstation_libretro.so %ROM%</command> -->
+    <command label="DuckStation (Legacy) (Standalone)">%EMULATOR_DUCKSTATION% -batch %ROM%</command>
+  </system>
+</systemList>
+"""
+
+    def _config(self) -> dict:
+        from scraper import retrodeck_scraper as rd
+
+        with tempfile.TemporaryDirectory() as tmp:
+            for component in ("azahar", "duckstation", "es-de", "retroarch"):
+                (Path(tmp) / component).mkdir()
+                (Path(tmp) / component / "component_manifest.json").write_text(
+                    json.dumps({component: {"system": component}})
+                )
+            scraper = rd.Scraper(manifests_dir=tmp)
+            systems = rd.es_systems_libretro_systems(self.ES_SYSTEMS)
+            with mock.patch.object(rd, "fetch_github_latest_version", return_value="0.10.10b"), \
+                    mock.patch.object(rd, "extract_launchers", return_value=[]), \
+                    mock.patch.object(rd.Scraper, "_fetch_libretro_systems", return_value=systems):
+                return scraper.generate_platform_yaml()
+
+    def test_a_component_es_de_also_runs_as_a_core_is_dual_mode(self):
+        config = self._config()
+        self.assertEqual(config["cores"], ["azahar", "duckstation", "retroarch"])
+        self.assertEqual(config["standalone_cores"], ["azahar", "duckstation"])
+        self.assertEqual(config["dual_mode_cores"], ["azahar"])
+
+    def test_a_commented_out_core_command_offers_nothing(self):
+        """duckstation_libretro.so sits in a comment: DuckStation runs standalone only."""
+        config = self._config()
+        self.assertNotIn("duckstation", config["dual_mode_cores"])
+        self.assertNotIn("duckstation", config["libretro_systems"])
+
+    def test_a_core_without_a_component_is_not_a_component(self):
+        """citra_libretro.so runs through RetroArch, and RetroDECK ships no citra build."""
+        from scraper.retrodeck_scraper import component_modes
+
+        standalone, dual = component_modes(
+            ["azahar", "retroarch"], {"azahar": ["n3ds"], "citra": ["n3ds"]}
+        )
+        self.assertEqual((standalone, dual), (["azahar"], ["azahar"]))
+
+    def test_the_platform_file_carries_the_modes(self):
+        import yaml
+
+        root = Path(__file__).resolve().parents[1]
+        platform = yaml.safe_load((root / "platforms" / "retrodeck.yml").read_text())
+        dual = set(platform.get("dual_mode_cores") or [])
+        self.assertIn("azahar", dual)
+        self.assertLessEqual(dual, set(platform["standalone_cores"]))
+        self.assertLessEqual(dual, set(platform["libretro_systems"]))
+
+
 class BizHawkRunsAresForN64Only(unittest.TestCase):
     """BizHawk embeds ares as Ares64, its N64 core. Mapping it to the ares
     profile claimed thirty systems and accused FirmwareDatabase.cs of a