diff --git a/install.ps1 b/install.ps1
index 46ef83dfa..0b44aa3b4 100644
--- a/install.ps1
+++ b/install.ps1
@@ -16,7 +16,7 @@
     # and Invoke-WebRequest throws on a cut transfer before the hash is read:
     # the site's build rewrites this line there (scripts/sitebootstrap.py).
     $mismatchAdvice = "The download was most likely cut short: try again. Within minutes of an update of this project the two files can come from caches of different ages. Waiting five minutes settles that."
-    $defaultInstallSha256 = "ee24f4f154e68d7d503f12e4816e3f1ff38f80159432093e4c6ed86411783ed7"
+    $defaultInstallSha256 = "bba0f7cd7677fb7f4d767504412843cf3809c03b91808c7c7772f17758893d50"
     $maximumInstallerBytes = 2MB
     $installerExit = 0
     $installer = if ($PSScriptRoot) { Join-Path $PSScriptRoot "install.py" } else { $null }
diff --git a/install.py b/install.py
index 6613a0554..a7a272964 100644
--- a/install.py
+++ b/install.py
@@ -3813,6 +3813,9 @@ def _check_data_directory(entry: object, where: str) -> None:
             raise ValueError(f"{where}.{field} is invalid")
     if entry.get("optional", True) is not True:
         raise ValueError(f"{where}.optional is invalid")
+    cores = entry.get("cores", ["-"])
+    if not isinstance(cores, list) or not cores or not all(isinstance(c, str) and c for c in cores):
+        raise ValueError(f"{where}.cores is invalid")
     files = entry.get("files")
     if not isinstance(files, dict) or not files or len(files) > MAX_MANIFEST_FILES:
         raise ValueError(f"{where}.files is invalid")
@@ -6201,7 +6204,7 @@ _CHOICE_OPTIONS = ("--system", "--core", "--region", "--for-games", "--required-
 # An option not named here comes after them.
 _COMMAND_ORDER = (
     "--manifest", "--from-pack", "--system", "--core", "--emulator", "--region",
-    "--for-games", "--required-only", "--target", "--no-game-data", "--installed-cores", "--cores-dir", "--every-board",
+    "--for-games", "--required-only", "--all-files", "--target", "--no-game-data", "--installed-cores", "--cores-dir", "--every-board",
     "--declared-only", "--standalone-copies", "--save-dir", "--jobs", "--from",
     "--add-app", "--offline", "--check", "--dry-run",
 )
@@ -6238,6 +6241,7 @@ class Invocation:
             options.append(("--for-games", None if games is True else str(games)))
         for flag, on in (
             ("--required-only", getattr(args, "required_only", False)),
+            ("--all-files", getattr(args, "all_files", False)),
             ("--every-board", args.every_board),
             ("--installed-cores", args.installed_cores and not args.cores_dir),
             ("--no-game-data", args.no_game_data),
@@ -7551,13 +7555,20 @@ def _install_data_member(
 
 
 def select_data_directories(manifest: dict, files: list[dict], narrowed: bool,
-                            required_only: bool = False) -> list[dict]:
+                            required_only: bool = False,
+                            games: GamesPlan | None = None) -> list[dict]:
     """The data trees this install keeps: all, or those of a kept system.
     --required-only leaves out a tree every core reading it runs without
     (`optional`): a GBA and a SNES game took FBNeo's cheats and samples,
-    3,472 files no game opened."""
+    3,472 files no game opened. For the games of a card, a tree only cores
+    read (`cores`) is kept when the plan runs one of them, or runs a system
+    of the tree on a core no setup names."""
     entries = [e for e in manifest.get("data_directories") or []
                if not (required_only and e.get("optional"))]
+    if games is not None:
+        entries = [e for e in entries if not e.get("cores")
+                   or set(e["cores"]) & games.profiles
+                   or set(e.get("systems") or []) & games.any_core]
     if not narrowed:
         return entries
     kept = {system for f in files for system in entry_systems(f)}
@@ -8989,7 +9000,8 @@ def _prompt_custom_selection(
         kept = menu_choice(files, omitted, installed, current, False)[0]
         kept_trees = select_data_directories({"data_directories": trees}, kept,
                                              narrowed or current is not None,
-                                             isinstance(current, GamesChoice) and current.required)
+                                             isinstance(current, GamesChoice) and current.required,
+                                             current.plan if isinstance(current, GamesChoice) else None)
         if kept and all_in_place(kept, kept_trees, bios_path):
             # Read before the menu, as the screen reads before it asks: a
             # rerun was offered an install that installs nothing, then told
@@ -9119,7 +9131,8 @@ def _print_menu_head(
     # and PPSSPP were counted for every --system tried.
     kept_trees = select_data_directories({"data_directories": trees}, shown,
                                          narrowed or current is not None,
-                                         isinstance(current, GamesChoice) and current.required)
+                                         isinstance(current, GamesChoice) and current.required,
+                                         current.plan if isinstance(current, GamesChoice) else None)
     data = sum(len(entry.get("files") or {}) for entry in kept_trees)
     data_size = sum(meta.get("size", 0) for entry in kept_trees
                     for meta in (entry.get("files") or {}).values())
@@ -10683,6 +10696,10 @@ class GamesPlan:
         self.required: set[str] = set()
         self.unknown_core: list[str] = []
         self.truncated = False
+        # The cores the games run on (a folder's default and its boards'),
+        # and the systems of a folder no setup names a core for.
+        self.profiles: set[str] = set()
+        self.any_core: set[str] = set()
 
     @property
     def fallback(self) -> list[GameFacts]:
@@ -10910,6 +10927,11 @@ def plan_games(plat: str, bios_path: Path, manifest: dict, folder: Path | None =
     cache.save()
     for game_folder, group in read:
         if group:
+            for profile in _folder_profiles(game_folder.row):
+                if profile:
+                    plan.profiles.add(str(profile))
+                else:
+                    plan.any_core.update(str(s) for s in game_folder.row.get("systems") or [])
             arcade = game_folder.row.get("arcade")
             sets = (arcade_index(arcade) or {}).get("support", set()) \
                 if isinstance(arcade, str) else set()
@@ -13514,6 +13536,13 @@ def build_parser() -> argparse.ArgumentParser:
         action="store_true",
         help="with --for-games, only the files the games cannot start without",
     )
+    parser.add_argument(
+        "--all-files",
+        action="store_true",
+        help="install the whole list even when the card holds games. A run that "
+             "asks nothing (--yes, --no-input, --events) otherwise installs only "
+             "what the card's games need, the plan's first choice",
+    )
     parser.add_argument(
         "--no-game-data",
         action="store_true",
@@ -13713,6 +13742,8 @@ def main() -> None:
         parser.error("--quiet applies to an install, not to --check, --dry-run or a listing")
     if args.tui and args.plain:
         parser.error("--tui and --plain ask for two different interfaces")
+    if args.all_files and args.for_games is not None:
+        parser.error("--all-files and --for-games ask for two different lists")
     if args.required_only and args.for_games is None:
         parser.error("--required-only applies to --for-games: the list alone does not "
                      "say which files a game cannot start without")
@@ -15694,8 +15725,18 @@ def _install(args: argparse.Namespace, real_stdout: TextIO) -> None:
         # some, what they need is the menu's first choice, and --for-games
         # narrows the list here, before the systems are counted.
         will_ask = interactive and not args.check and not listing
+        # A run that asks nothing takes the plan's first choice: the games of
+        # the card. `--yes` alone installed 6.4 GB on a dArkOS card holding
+        # two games, while the screen offers what they need first. Not for a
+        # run given its list (the screen's own runs, the choice already
+        # made), nor one narrowed by name.
+        unasked = (not interactive and not args.check and not listing
+                   and not getattr(args, "all_files", False)
+                   and LOCAL.manifest is None and LOCAL.pack is None
+                   and not (args.installed_cores or args.no_game_data or args.system
+                            or args.core or args.region or args.emulator or args.declared_only))
         games_plan = None
-        if args.for_games is not None or (will_ask and not (
+        if args.for_games is not None or unasked or (will_ask and not (
                 args.installed_cores or args.no_game_data or LOCAL.pack is not None)):
             games_plan = read_games(args, plat_name, bios_path, manifest, term, os_type)
         games_applied = False
@@ -15708,6 +15749,9 @@ def _install(args: argparse.Namespace, real_stdout: TextIO) -> None:
             games_applied = True
             print(f"  For the games: {_plural(len(files), 'file')} of the list"
                   + (f", {GAMES_REQUIRED_WORDS}" if args.required_only else ""))
+            if args.for_games is None:
+                print("  The card holds games, so only what they need is installed. "
+                      "--all-files installs the whole list.")
             version_notes += [line.strip() for line in fallback_lines(games_plan)]
         # --no-game-data leaves the game data out once the list is narrowed
         # to the choice: taken out first, its line named the 5099 game data
@@ -15848,7 +15892,8 @@ def _install(args: argparse.Namespace, real_stdout: TextIO) -> None:
             or games_applied
         )
         data_dirs = select_data_directories(manifest, files, narrowed,
-                                            bool(args.required_only))
+                                            bool(args.required_only),
+                                            games_plan if games_applied else None)
         # The kinds as the plan and the menu head say them (parts_words),
         # the data files of the folders kept among them: this head said
         # BIOS files and game data beside a plan of three kinds, neither
diff --git a/install.sh b/install.sh
index d5ee07167..1e47b7f91 100755
--- a/install.sh
+++ b/install.sh
@@ -23,7 +23,7 @@ DEFAULT_INSTALL_URL="https://raw.githubusercontent.com/Abdess/retrobios/main/ins
 # curl or wget stop on a cut transfer before the hash is read: the site's
 # build rewrites this line there (scripts/sitebootstrap.py).
 MISMATCH_ADVICE="The download was most likely cut short: try again. Within minutes of an update of this project the two files can come from caches of different ages. Waiting five minutes settles that."
-DEFAULT_INSTALL_SHA256="ee24f4f154e68d7d503f12e4816e3f1ff38f80159432093e4c6ed86411783ed7"
+DEFAULT_INSTALL_SHA256="bba0f7cd7677fb7f4d767504412843cf3809c03b91808c7c7772f17758893d50"
 MAX_INSTALLER_BYTES=2097152
 
 cleanup() {
diff --git a/install/amberelec.json b/install/amberelec.json
index 71782316f..fb516f651 100644
--- a/install/amberelec.json
+++ b/install/amberelec.json
@@ -63651,7 +63651,10 @@
         }
       },
       "strip_components": 0,
-      "archive_size": 4465709
+      "archive_size": 4465709,
+      "cores": [
+        "bluemsx"
+      ]
     },
     {
       "ref": "fbneo-cheats",
@@ -77382,7 +77385,10 @@
       },
       "strip_components": 1,
       "archive_size": 5083767,
-      "optional": true
+      "optional": true,
+      "cores": [
+        "fbneo"
+      ]
     },
     {
       "ref": "fbneo-samples",
@@ -77617,7 +77623,10 @@
       },
       "strip_components": 0,
       "archive_size": 53006540,
-      "optional": true
+      "optional": true,
+      "cores": [
+        "fbneo"
+      ]
     },
     {
       "ref": "freeintv-overlays",
@@ -77991,7 +78000,10 @@
       },
       "strip_components": 1,
       "archive_size": 21311170,
-      "optional": true
+      "optional": true,
+      "cores": [
+        "freeintv"
+      ]
     }
   ]
 }
\ No newline at end of file
diff --git a/install/batocera.json b/install/batocera.json
index 3e8742ea8..d19b0d64e 100644
--- a/install/batocera.json
+++ b/install/batocera.json
@@ -226706,7 +226706,10 @@
       },
       "strip_components": 1,
       "archive_size": 5083767,
-      "optional": true
+      "optional": true,
+      "cores": [
+        "fbneo"
+      ]
     },
     {
       "ref": "fbneo-samples",
@@ -226941,7 +226944,10 @@
       },
       "strip_components": 0,
       "archive_size": 53006540,
-      "optional": true
+      "optional": true,
+      "cores": [
+        "fbneo"
+      ]
     }
   ],
   "save_directory": {
diff --git a/install/emudeck.json b/install/emudeck.json
index ef736b334..88a028ad1 100644
--- a/install/emudeck.json
+++ b/install/emudeck.json
@@ -102220,7 +102220,10 @@
         }
       },
       "strip_components": 0,
-      "archive_size": 4465709
+      "archive_size": 4465709,
+      "cores": [
+        "bluemsx"
+      ]
     },
     {
       "ref": "dinothawr",
@@ -102669,7 +102672,10 @@
         }
       },
       "strip_components": 0,
-      "archive_size": 5752250
+      "archive_size": 5752250,
+      "cores": [
+        "dinothawr"
+      ]
     },
     {
       "ref": "dirksimple",
@@ -102726,7 +102732,10 @@
         }
       },
       "strip_components": 0,
-      "archive_size": 175384
+      "archive_size": 175384,
+      "cores": [
+        "dirksimple"
+      ]
     },
     {
       "ref": "dolphin-sys",
@@ -111403,7 +111412,10 @@
       "exclude": [
         "Themes"
       ],
-      "archive_size": 3197914
+      "archive_size": 3197914,
+      "cores": [
+        "ishiiruka"
+      ]
     },
     {
       "ref": "fbneo-cheats",
@@ -125134,7 +125146,10 @@
       },
       "strip_components": 1,
       "archive_size": 5083767,
-      "optional": true
+      "optional": true,
+      "cores": [
+        "fbneo"
+      ]
     },
     {
       "ref": "fbneo-samples",
@@ -125369,7 +125384,10 @@
       },
       "strip_components": 0,
       "archive_size": 53006540,
-      "optional": true
+      "optional": true,
+      "cores": [
+        "fbneo"
+      ]
     },
     {
       "ref": "freeintv-overlays",
@@ -125743,7 +125761,10 @@
       },
       "strip_components": 1,
       "archive_size": 21311170,
-      "optional": true
+      "optional": true,
+      "cores": [
+        "freeintv"
+      ]
     },
     {
       "ref": "lrps2",
@@ -125760,7 +125781,10 @@
         }
       },
       "strip_components": 0,
-      "archive_size": 318896
+      "archive_size": 318896,
+      "cores": [
+        "lrps2"
+      ]
     },
     {
       "ref": "yaps2-resources",
@@ -126221,7 +126245,10 @@
         }
       },
       "source_path": "yaps2-57ea93c0ce8306063b31fe6658dab6b492bbedfe/bin/resources",
-      "archive_size": 21181421
+      "archive_size": 21181421,
+      "cores": [
+        "yaps2"
+      ]
     }
   ],
   "save_directory": {
diff --git a/install/emuelec.json b/install/emuelec.json
index 3e930db89..3c86a3205 100644
--- a/install/emuelec.json
+++ b/install/emuelec.json
@@ -69460,7 +69460,10 @@
         }
       },
       "strip_components": 0,
-      "archive_size": 4465709
+      "archive_size": 4465709,
+      "cores": [
+        "bluemsx"
+      ]
     },
     {
       "ref": "dinothawr",
@@ -69909,7 +69912,10 @@
         }
       },
       "strip_components": 0,
-      "archive_size": 5752250
+      "archive_size": 5752250,
+      "cores": [
+        "dinothawr"
+      ]
     },
     {
       "ref": "fbneo-cheats",
@@ -83640,7 +83646,10 @@
       },
       "strip_components": 1,
       "archive_size": 5083767,
-      "optional": true
+      "optional": true,
+      "cores": [
+        "fbneo"
+      ]
     },
     {
       "ref": "fbneo-samples",
@@ -83875,7 +83884,10 @@
       },
       "strip_components": 0,
       "archive_size": 53006540,
-      "optional": true
+      "optional": true,
+      "cores": [
+        "fbneo"
+      ]
     },
     {
       "ref": "freeintv-overlays",
@@ -84249,7 +84261,10 @@
       },
       "strip_components": 1,
       "archive_size": 21311170,
-      "optional": true
+      "optional": true,
+      "cores": [
+        "freeintv"
+      ]
     }
   ]
 }
\ No newline at end of file
diff --git a/install/knulli.json b/install/knulli.json
index 803284e04..49e7ebd8f 100644
--- a/install/knulli.json
+++ b/install/knulli.json
@@ -157969,7 +157969,10 @@
       },
       "strip_components": 1,
       "archive_size": 5083767,
-      "optional": true
+      "optional": true,
+      "cores": [
+        "fbneo"
+      ]
     },
     {
       "ref": "fbneo-samples",
@@ -158204,7 +158207,10 @@
       },
       "strip_components": 0,
       "archive_size": 53006540,
-      "optional": true
+      "optional": true,
+      "cores": [
+        "fbneo"
+      ]
     },
     {
       "ref": "lrps2",
@@ -158221,7 +158227,10 @@
         }
       },
       "strip_components": 0,
-      "archive_size": 318896
+      "archive_size": 318896,
+      "cores": [
+        "lrps2"
+      ]
     },
     {
       "ref": "ppsspp-assets",
@@ -158910,7 +158919,10 @@
         }
       },
       "strip_components": 1,
-      "archive_size": 9844388
+      "archive_size": 9844388,
+      "cores": [
+        "ppsspp"
+      ]
     }
   ],
   "save_directory": {
diff --git a/install/lakka.json b/install/lakka.json
index 047ec53e3..c9b1dd78e 100644
--- a/install/lakka.json
+++ b/install/lakka.json
@@ -116877,7 +116877,10 @@
         }
       },
       "source_path": "Cemu-3310f3b8b184d64a62b89fd59088c799432badf5/bin/gameProfiles/default",
-      "archive_size": 21360579
+      "archive_size": 21360579,
+      "cores": [
+        "cemu"
+      ]
     },
     {
       "ref": "dirksimple",
@@ -116934,7 +116937,10 @@
         }
       },
       "strip_components": 0,
-      "archive_size": 175384
+      "archive_size": 175384,
+      "cores": [
+        "dirksimple"
+      ]
     },
     {
       "ref": "fbneo-cheats",
@@ -130665,7 +130671,10 @@
       },
       "strip_components": 1,
       "archive_size": 5083767,
-      "optional": true
+      "optional": true,
+      "cores": [
+        "fbneo"
+      ]
     },
     {
       "ref": "fbneo-samples",
@@ -130900,7 +130909,10 @@
       },
       "strip_components": 0,
       "archive_size": 53006540,
-      "optional": true
+      "optional": true,
+      "cores": [
+        "fbneo"
+      ]
     },
     {
       "ref": "freeintv-overlays",
@@ -131735,7 +131747,10 @@
         }
       },
       "source_path": "yaps2-57ea93c0ce8306063b31fe6658dab6b492bbedfe/bin/resources",
-      "archive_size": 21181421
+      "archive_size": 21181421,
+      "cores": [
+        "yaps2"
+      ]
     }
   ],
   "save_directory": {
diff --git a/install/launchers/index.json b/install/launchers/index.json
index 44d04c39f..8db6e297a 100644
--- a/install/launchers/index.json
+++ b/install/launchers/index.json
@@ -27,8 +27,8 @@
         {
           "dest": "roms/ports/retrobios/install.py",
           "repo_path": "install.py",
-          "size": 1122422,
-          "sha256": "ee24f4f154e68d7d503f12e4816e3f1ff38f80159432093e4c6ed86411783ed7",
+          "size": 1125268,
+          "sha256": "bba0f7cd7677fb7f4d767504412843cf3809c03b91808c7c7772f17758893d50",
           "executable": false
         },
         {
@@ -71,8 +71,8 @@
     "muos": {
       "archive": {
         "dest": "ARCHIVE/RetroBIOS.muxapp",
-        "size": 1176049,
-        "sha256": "9ac4845d2a448ece2d421db3137c7aea6d636d0ecf6c92ed777630f47dd61021"
+        "size": 1178895,
+        "sha256": "814d80f123e59f5192631842d53a4808bf373599ced857f4622612ffbc25322b"
       },
       "members": [
         {
@@ -92,8 +92,8 @@
         {
           "name": "RetroBIOS/install.py",
           "repo_path": "install.py",
-          "size": 1122422,
-          "sha256": "ee24f4f154e68d7d503f12e4816e3f1ff38f80159432093e4c6ed86411783ed7",
+          "size": 1125268,
+          "sha256": "bba0f7cd7677fb7f4d767504412843cf3809c03b91808c7c7772f17758893d50",
           "executable": false
         },
         {
@@ -166,8 +166,8 @@
         {
           "dest": ".config/modules/retrobios/install.py",
           "repo_path": "install.py",
-          "size": 1122422,
-          "sha256": "ee24f4f154e68d7d503f12e4816e3f1ff38f80159432093e4c6ed86411783ed7",
+          "size": 1125268,
+          "sha256": "bba0f7cd7677fb7f4d767504412843cf3809c03b91808c7c7772f17758893d50",
           "executable": false
         },
         {
diff --git a/install/myminui.json b/install/myminui.json
index 108f1c677..883fc5b48 100644
--- a/install/myminui.json
+++ b/install/myminui.json
@@ -18959,7 +18959,10 @@
       },
       "strip_components": 1,
       "archive_size": 5083767,
-      "optional": true
+      "optional": true,
+      "cores": [
+        "fbneo"
+      ]
     },
     {
       "ref": "fbneo-cheats",
@@ -32690,7 +32693,10 @@
       },
       "strip_components": 1,
       "archive_size": 5083767,
-      "optional": true
+      "optional": true,
+      "cores": [
+        "fbneo"
+      ]
     },
     {
       "ref": "fbneo-samples",
@@ -32925,7 +32931,10 @@
       },
       "strip_components": 0,
       "archive_size": 53006540,
-      "optional": true
+      "optional": true,
+      "cores": [
+        "fbneo"
+      ]
     },
     {
       "ref": "fbneo-samples",
@@ -33160,7 +33169,10 @@
       },
       "strip_components": 0,
       "archive_size": 53006540,
-      "optional": true
+      "optional": true,
+      "cores": [
+        "fbneo"
+      ]
     }
   ]
 }
\ No newline at end of file
diff --git a/install/nextui.json b/install/nextui.json
index 9804f5110..c84614823 100644
--- a/install/nextui.json
+++ b/install/nextui.json
@@ -5636,7 +5636,10 @@
         }
       },
       "strip_components": 0,
-      "archive_size": 4465709
+      "archive_size": 4465709,
+      "cores": [
+        "bluemsx"
+      ]
     },
     {
       "ref": "fbneo-cheats",
@@ -19367,7 +19370,10 @@
       },
       "strip_components": 1,
       "archive_size": 5083767,
-      "optional": true
+      "optional": true,
+      "cores": [
+        "fbneo"
+      ]
     },
     {
       "ref": "fbneo-samples",
@@ -19602,7 +19608,10 @@
       },
       "strip_components": 0,
       "archive_size": 53006540,
-      "optional": true
+      "optional": true,
+      "cores": [
+        "fbneo"
+      ]
     }
   ]
 }
\ No newline at end of file
diff --git a/install/recalbox.json b/install/recalbox.json
index 7bb16ef45..478bfb5c2 100644
--- a/install/recalbox.json
+++ b/install/recalbox.json
@@ -64189,7 +64189,10 @@
       },
       "strip_components": 1,
       "archive_size": 5083767,
-      "optional": true
+      "optional": true,
+      "cores": [
+        "fbneo"
+      ]
     },
     {
       "ref": "fbneo-samples",
@@ -64424,7 +64427,10 @@
       },
       "strip_components": 0,
       "archive_size": 53006540,
-      "optional": true
+      "optional": true,
+      "cores": [
+        "fbneo"
+      ]
     }
   ],
   "save_directory": {
diff --git a/install/retroarch.json b/install/retroarch.json
index 59a748017..1b052c818 100644
--- a/install/retroarch.json
+++ b/install/retroarch.json
@@ -119822,7 +119822,10 @@
         }
       },
       "source_path": "Cemu-3310f3b8b184d64a62b89fd59088c799432badf5/bin/gameProfiles/default",
-      "archive_size": 21360579
+      "archive_size": 21360579,
+      "cores": [
+        "cemu"
+      ]
     },
     {
       "ref": "dinothawr",
@@ -120271,7 +120274,10 @@
         }
       },
       "strip_components": 0,
-      "archive_size": 5752250
+      "archive_size": 5752250,
+      "cores": [
+        "dinothawr"
+      ]
     },
     {
       "ref": "dirksimple",
@@ -120328,7 +120334,10 @@
         }
       },
       "strip_components": 0,
-      "archive_size": 175384
+      "archive_size": 175384,
+      "cores": [
+        "dirksimple"
+      ]
     },
     {
       "ref": "dolphin-sys",
@@ -142731,7 +142740,10 @@
       },
       "strip_components": 1,
       "archive_size": 5083767,
-      "optional": true
+      "optional": true,
+      "cores": [
+        "fbneo"
+      ]
     },
     {
       "ref": "fbneo-samples",
@@ -142966,7 +142978,10 @@
       },
       "strip_components": 0,
       "archive_size": 53006540,
-      "optional": true
+      "optional": true,
+      "cores": [
+        "fbneo"
+      ]
     },
     {
       "ref": "freeintv-overlays",
@@ -144490,7 +144505,10 @@
         }
       },
       "source_path": "yaps2-57ea93c0ce8306063b31fe6658dab6b492bbedfe/bin/resources",
-      "archive_size": 21181421
+      "archive_size": 21181421,
+      "cores": [
+        "yaps2"
+      ]
     }
   ],
   "save_directory": {
diff --git a/install/retrobat.json b/install/retrobat.json
index 5a159ad3d..6f7912e0f 100644
--- a/install/retrobat.json
+++ b/install/retrobat.json
@@ -90410,7 +90410,10 @@
       },
       "strip_components": 1,
       "archive_size": 5083767,
-      "optional": true
+      "optional": true,
+      "cores": [
+        "fbneo"
+      ]
     },
     {
       "ref": "fbneo-samples",
@@ -90645,7 +90648,10 @@
       },
       "strip_components": 0,
       "archive_size": 53006540,
-      "optional": true
+      "optional": true,
+      "cores": [
+        "fbneo"
+      ]
     },
     {
       "ref": "freeintv-overlays",
@@ -91019,7 +91025,10 @@
       },
       "strip_components": 1,
       "archive_size": 21311170,
-      "optional": true
+      "optional": true,
+      "cores": [
+        "freeintv"
+      ]
     }
   ],
   "save_directory": {
diff --git a/install/retrodeck.json b/install/retrodeck.json
index caa70af85..cdc184a37 100644
--- a/install/retrodeck.json
+++ b/install/retrodeck.json
@@ -141323,7 +141323,10 @@
         }
       },
       "source_path": "Cemu-3310f3b8b184d64a62b89fd59088c799432badf5/bin/gameProfiles/default",
-      "archive_size": 21360579
+      "archive_size": 21360579,
+      "cores": [
+        "cemu"
+      ]
     },
     {
       "ref": "fbneo-cheats",
@@ -155054,7 +155057,10 @@
       },
       "strip_components": 1,
       "archive_size": 5083767,
-      "optional": true
+      "optional": true,
+      "cores": [
+        "fbneo"
+      ]
     },
     {
       "ref": "fbneo-samples",
@@ -155289,7 +155295,10 @@
       },
       "strip_components": 0,
       "archive_size": 53006540,
-      "optional": true
+      "optional": true,
+      "cores": [
+        "fbneo"
+      ]
     },
     {
       "ref": "freeintv-overlays",
@@ -155663,7 +155672,10 @@
       },
       "strip_components": 1,
       "archive_size": 21311170,
-      "optional": true
+      "optional": true,
+      "cores": [
+        "freeintv"
+      ]
     },
     {
       "ref": "yaps2-resources",
@@ -156128,7 +156140,10 @@
         }
       },
       "source_path": "yaps2-57ea93c0ce8306063b31fe6658dab6b492bbedfe/bin/resources",
-      "archive_size": 21181421
+      "archive_size": 21181421,
+      "cores": [
+        "yaps2"
+      ]
     }
   ],
   "save_directory": {
diff --git a/install/retropie.json b/install/retropie.json
index eb54566d4..a9fab43cd 100644
--- a/install/retropie.json
+++ b/install/retropie.json
@@ -124049,7 +124049,10 @@
         }
       },
       "source_path": "Cemu-3310f3b8b184d64a62b89fd59088c799432badf5/bin/gameProfiles/default",
-      "archive_size": 21360579
+      "archive_size": 21360579,
+      "cores": [
+        "cemu"
+      ]
     },
     {
       "ref": "dolphin-sys",
@@ -146452,7 +146455,10 @@
       },
       "strip_components": 1,
       "archive_size": 5083767,
-      "optional": true
+      "optional": true,
+      "cores": [
+        "fbneo"
+      ]
     },
     {
       "ref": "fbneo-samples",
@@ -146687,7 +146693,10 @@
       },
       "strip_components": 0,
       "archive_size": 53006540,
-      "optional": true
+      "optional": true,
+      "cores": [
+        "fbneo"
+      ]
     },
     {
       "ref": "freeintv-overlays",
@@ -147522,7 +147531,10 @@
         }
       },
       "source_path": "yaps2-57ea93c0ce8306063b31fe6658dab6b492bbedfe/bin/resources",
-      "archive_size": 21181421
+      "archive_size": 21181421,
+      "cores": [
+        "yaps2"
+      ]
     }
   ]
 }
\ No newline at end of file
diff --git a/install/rocknix.json b/install/rocknix.json
index 2fd9be176..6bab702de 100644
--- a/install/rocknix.json
+++ b/install/rocknix.json
@@ -86513,7 +86513,10 @@
         }
       },
       "strip_components": 0,
-      "archive_size": 4465709
+      "archive_size": 4465709,
+      "cores": [
+        "bluemsx"
+      ]
     },
     {
       "ref": "dinothawr",
@@ -86962,7 +86965,10 @@
         }
       },
       "strip_components": 0,
-      "archive_size": 5752250
+      "archive_size": 5752250,
+      "cores": [
+        "dinothawr"
+      ]
     },
     {
       "ref": "dirksimple",
@@ -87019,7 +87025,10 @@
         }
       },
       "strip_components": 0,
-      "archive_size": 175384
+      "archive_size": 175384,
+      "cores": [
+        "dirksimple"
+      ]
     },
     {
       "ref": "dolphin-sys",
@@ -95697,7 +95706,11 @@
       "exclude": [
         "Themes"
       ],
-      "archive_size": 3197914
+      "archive_size": 3197914,
+      "cores": [
+        "dolphin",
+        "ishiiruka"
+      ]
     },
     {
       "ref": "fbneo-cheats",
@@ -109428,7 +109441,10 @@
       },
       "strip_components": 1,
       "archive_size": 5083767,
-      "optional": true
+      "optional": true,
+      "cores": [
+        "fbneo"
+      ]
     },
     {
       "ref": "fbneo-samples",
@@ -109663,7 +109679,10 @@
       },
       "strip_components": 0,
       "archive_size": 53006540,
-      "optional": true
+      "optional": true,
+      "cores": [
+        "fbneo"
+      ]
     },
     {
       "ref": "freeintv-overlays",
@@ -110037,7 +110056,10 @@
       },
       "strip_components": 1,
       "archive_size": 21311170,
-      "optional": true
+      "optional": true,
+      "cores": [
+        "freeintv"
+      ]
     },
     {
       "ref": "lrps2",
@@ -110054,7 +110076,10 @@
         }
       },
       "strip_components": 0,
-      "archive_size": 318896
+      "archive_size": 318896,
+      "cores": [
+        "lrps2"
+      ]
     },
     {
       "ref": "ppsspp-assets",
@@ -110743,7 +110768,10 @@
         }
       },
       "strip_components": 1,
-      "archive_size": 9844388
+      "archive_size": 9844388,
+      "cores": [
+        "ppsspp"
+      ]
     },
     {
       "ref": "yaps2-resources",
@@ -111204,7 +111232,10 @@
         }
       },
       "source_path": "yaps2-57ea93c0ce8306063b31fe6658dab6b492bbedfe/bin/resources",
-      "archive_size": 21181421
+      "archive_size": 21181421,
+      "cores": [
+        "yaps2"
+      ]
     }
   ]
 }
\ No newline at end of file
diff --git a/schemas/install-manifest.schema.json b/schemas/install-manifest.schema.json
index a72245722..0dbcecd40 100644
--- a/schemas/install-manifest.schema.json
+++ b/schemas/install-manifest.schema.json
@@ -457,6 +457,14 @@
             "const": true,
             "description": "Every core reading the tree runs without it (required: false in its profile): --required-only leaves it out."
           },
+          "cores": {
+            "type": "array",
+            "items": {
+              "type": "string"
+            },
+            "minItems": 1,
+            "description": "The cores that read the tree, when no platform system declares it: an install for the games of a card keeps it only when its plan runs one of them."
+          },
           "files": {
             "type": "object",
             "additionalProperties": {
diff --git a/scripts/generate_pack.py b/scripts/generate_pack.py
index 4b4c4f726..25b9f97ca 100644
--- a/scripts/generate_pack.py
+++ b/scripts/generate_pack.py
@@ -448,7 +448,7 @@ def core_data_trees(
     # the trees go there as the core extras do.
     root = declared_root(config)
     trees: list[dict] = []
-    seen: set[tuple[str, str]] = set()
+    seen: dict[tuple[str, str], int] = {}
     for core in sorted(_platform_cores(config, profiles, target_cores)):
         profile = profiles[core]
         if all(standalone for _view, standalone in platform_layouts(core, profile, handed)):
@@ -473,13 +473,19 @@ def core_data_trees(
                     if part.strip("/")
                 ), root) or root
                 if (ref, destination) in seen:
+                    # One tree, read by a second core: the manifest says both
+                    # (tree_readers), the pack writes it once.
+                    first = trees[seen[(ref, destination)]]
+                    if core not in first["readers"]:
+                        first["readers"].append(core)
                     continue
-                seen.add((ref, destination))
+                seen[(ref, destination)] = len(trees)
                 trees.append({
                     "ref": ref,
                     "destination": destination,
                     "required": tree.get("required"),
                     "core": core,
+                    "readers": [core],
                     "source_systems": entry_system_ids(tree, profile),
                 })
     return trees
@@ -5086,16 +5092,14 @@ def generate_manifest(
     # whose hash the list below records, the same tree the pack carries.
     data_refs: dict[str, tuple[str, tuple[str, ...], str, bool]] = {}
     reclaim = {full: path for full, (path, _size) in cache_held.items()}
+    core_trees = ([] if source == "platform"
+                  else core_data_trees(config, emu_profiles, platform_name, data_registry,
+                                       target_cores))
     data_members = list(_data_directory_members(
         pack_systems, data_registry, platform_name, base_dest,
         case_insensitive, seen_destinations, seen_lower, seen_parents,
         data_refs, required_only=required_only,
-        core_trees=(
-            [] if source == "platform"
-            else core_data_trees(
-                config, emu_profiles, platform_name, data_registry, target_cores
-            )
-        ),
+        core_trees=core_trees,
         reclaim=reclaim,
     ))
     # A platform entry found in a tree the pack carries is that tree's member:
@@ -5108,7 +5112,8 @@ def generate_manifest(
             omitted_by_destination.pop(full_dest, None)
     data_sizes = pack_only_sizes + [os.path.getsize(src) for src, _dest in data_members]
     data_directories = _manifest_data_directories(
-        data_members, data_refs, data_registry or {}, base_dest
+        data_members, data_refs, data_registry or {}, base_dest,
+        tree_readers(pack_systems, core_trees),
     )
 
     now = _build_timestamp(db)
@@ -5192,11 +5197,28 @@ def generate_manifest(
     return result
 
 
+def tree_readers(pack_systems: dict, core_trees: Iterable[dict]) -> dict[str, list[str]]:
+    """The cores that read each tree, for a tree only cores read. A tree a
+    platform system declares is the system's, whatever core runs it, and
+    gets no entry. Every reference counts: two cores reading one tree yield
+    its files once."""
+    cores: dict[str, set[str]] = {}
+    declared: set[str] = set()
+    for _systems, dd in _tree_references(pack_systems, core_trees):
+        ref = str(dd.get("ref") or "")
+        if dd.get("core"):
+            cores.setdefault(ref, set()).update(str(core) for core in dd.get("readers") or [dd["core"]])
+        else:
+            declared.add(ref)
+    return {ref: sorted(names) for ref, names in cores.items() if ref not in declared}
+
+
 def _manifest_data_directories(
     members: list[tuple[str, str]],
     refs: dict[str, tuple[str, tuple[str, ...], str, bool]],
     registry: dict,
     base_dest: str,
+    readers: dict[str, list[str]] | None = None,
 ) -> list[dict]:
     """Each data directory the pack carries, as the installer rebuilds it.
 
@@ -5209,7 +5231,9 @@ def _manifest_data_directories(
     the tree costs: a tarball whose tree is 10 KB is a download of 21 MB.
     ``optional`` marks a tree every core reading it runs without
     (``required: false``): install.py --required-only leaves it out, as the
-    pack built with --required-only does.
+    pack built with --required-only does. ``cores`` names the cores that
+    read a tree no platform system declares (``readers``): an install for
+    the games of a card keeps it only when its plan runs one of them.
     """
     grouped: dict[tuple[str, str], dict] = {}
     versions: dict[str, dict[str, dict]] = {}
@@ -5259,6 +5283,8 @@ def _manifest_data_directories(
         group = grouped[key]
         if not group.pop("needed", False):
             group["optional"] = True
+        if readers and group["ref"] in readers:
+            group["cores"] = readers[group["ref"]]
         trees.append(group)
     return trees
 
diff --git a/scripts/siteagents.py b/scripts/siteagents.py
index ffed73260..1776cb992 100644
--- a/scripts/siteagents.py
+++ b/scripts/siteagents.py
@@ -82,8 +82,8 @@ def llms_txt(platforms: list[tuple[str, str]]) -> str:
         "Most people want to play now, with the fewest files. The installer does that in one "
         "command: it finds the setup and its BIOS folder, reads the games on the card, and with "
         "`--for-games --required-only` installs only the files those games cannot start "
-        "without. Without these two options it installs every file of the setup's list "
-        "(gigabytes), even with `--yes`.",
+        "without. `--yes` alone installs what the card's games need, optional files "
+        "included, and `--all-files` the setup's whole list (gigabytes).",
         "",
         f"1. Preview, nothing written: `{SH} --for-games --required-only --dry-run`",
         f"2. Install, no questions: `{SH} --for-games --required-only --yes`",
diff --git a/scripts/sitediagrams.py b/scripts/sitediagrams.py
index d552657b3..dc75524d6 100644
--- a/scripts/sitediagrams.py
+++ b/scripts/sitediagrams.py
@@ -899,7 +899,7 @@ GLANCE_HEADING = "## Options at a glance"
 GLANCE_GROUPS: tuple[tuple[str, tuple[str, ...]], ...] = (
     ("Where and for what", ("--platform", "--dest", "--target", "--every-board", "--save-dir",
                             "--romm-firmware", "--standalone-copies", "--add-app")),
-    ("Fewer files", ("--for-games", "--required-only", "--system", "--core", "--emulator",
+    ("Fewer files", ("--for-games", "--required-only", "--all-files", "--system", "--core", "--emulator",
                      "--region", "--no-game-data", "--declared-only", "--installed-cores",
                      "--cores-dir")),
     ("Look first", ("--check", "--dry-run", "--list-platforms", "--list-targets",
diff --git a/tests/test_core_data_trees.py b/tests/test_core_data_trees.py
index 2fb6e7f3e..6d352552b 100644
--- a/tests/test_core_data_trees.py
+++ b/tests/test_core_data_trees.py
@@ -87,6 +87,24 @@ class CoreDataTreesTest(unittest.TestCase):
     def test_standalone_build_brings_no_tree(self) -> None:
         self.assertNotIn("solo", {t["core"] for t in self.trees("other")})
 
+    def test_every_reader_of_a_shared_tree_is_recorded(self) -> None:
+        """The second core reading a tree was dropped with the duplicate, and an
+        install for its games would have lost the tree."""
+        twin = {**PROFILES["demo"], "emulator": "Twin", "cores": ["twin"]}
+        profiles = {**PROFILES, "twin": twin}
+        config = {**CONFIG, "cores": ["demo", "solo", "twin"]}
+        trees = builder.core_data_trees(config, profiles, "plat", REGISTRY)
+        shared = [t for t in trees if t["ref"] == "shared"]
+        self.assertEqual(len(shared), 1)
+        self.assertEqual(shared[0]["readers"], ["demo", "twin"])
+        self.assertEqual(builder.tree_readers({}, trees)["shared"], ["demo", "twin"])
+
+    def test_a_tree_a_system_declares_names_no_core(self) -> None:
+        trees = self.trees()
+        declared = {"demo-system": {"data_directories": [{"ref": "shared"}]}}
+        self.assertNotIn("shared", builder.tree_readers(declared, trees))
+        self.assertIn("shared", builder.tree_readers({}, trees))
+
     def test_tree_below_the_declared_bios_folder(self) -> None:
         config = {
             **CONFIG,
diff --git a/tests/test_install_games.py b/tests/test_install_games.py
index 8388202d0..829f5da1e 100644
--- a/tests/test_install_games.py
+++ b/tests/test_install_games.py
@@ -912,6 +912,78 @@ class CommandLine(unittest.TestCase):
         self.assertTrue((self.card.cache / install.GAMES_SCAN_FILE).is_file())
 
 
+class ARunThatAsksNothing(unittest.TestCase):
+    """`--yes` alone installed the whole list (6.4 GB on a dArkOS card that
+    held two games), while the screen offers what the games need first."""
+
+    def install(self, *options: str) -> tuple[list[str], str]:
+        card = Card()
+        self.addCleanup(card.close)
+        card.game("SEGACD", "sonic.iso", mcd_iso(100))
+        card.game("MD", "eu.md", MD_EU)
+        root = card.root / "repo"
+        (root / "install").mkdir(parents=True)
+        shutil.copytree(card.lists / "games", root / "install" / "games")
+        listed = manifest()
+        (root / "bios").mkdir()
+        for entry in listed["files"]:
+            payload = entry["dest"].encode().ljust(entry["size"], b".")[:entry["size"]]
+            (root / entry["repo_path"]).write_bytes(payload)
+        (root / "install" / "retroarch.json").write_text(json.dumps(listed))
+        handler = functools.partial(_Quiet, directory=str(root))
+        server = http.server.ThreadingHTTPServer(("127.0.0.1", 0), handler)
+        threading.Thread(target=server.serve_forever, daemon=True).start()
+        self.addCleanup(server.server_close)
+        self.addCleanup(server.shutdown)
+        proc = run_cli(card, *options, offline=False,
+                       base=f"http://127.0.0.1:{server.server_address[1]}")
+        self.assertEqual(proc.returncode, 0, proc.stdout + proc.stderr)
+        return sorted(p.relative_to(card.bios).as_posix()
+                      for p in card.bios.rglob("*") if p.is_file()), proc.stdout
+
+    def test_it_installs_what_the_games_need(self):
+        unasked, said = self.install("--yes")
+        self.assertEqual(unasked, self.install("--for-games", "--yes")[0])
+        self.assertIn("--all-files installs the whole list", said)
+
+    def test_all_files_installs_the_whole_list(self):
+        everything, said = self.install("--all-files", "--yes")
+        self.assertEqual(everything, sorted(entry["dest"] for entry in manifest()["files"]))
+        self.assertNotIn("For the games", said)
+
+    def test_all_files_and_for_games_are_refused_together(self):
+        card = Card()
+        self.addCleanup(card.close)
+        proc = run_cli(card, "--all-files", "--for-games", "--check")
+        self.assertEqual(proc.returncode, 2)
+        self.assertIn("--all-files and --for-games ask for two different lists", proc.stderr)
+
+
+class DataTreesFollowTheGamesCores(unittest.TestCase):
+    """One GBA and one SNES game took FBNeo's cheats and samples: a tree
+    only cores read is kept when the plan runs one of them."""
+
+    def test_a_tree_of_a_core_the_plan_does_not_run_is_left_out(self):
+        plan = install.GamesPlan(Path("card"), True)
+        plan.profiles = {"snes9x"}
+        fbneo = {"ref": "fbneo-cheats", "systems": ["nintendo-snes"], "cores": ["fbneo"]}
+        dolphin = {"ref": "dolphin-sys", "systems": ["nintendo-snes"]}
+        trees = {"data_directories": [fbneo, dolphin]}
+        files = [{"dest": "a.bin", "systems": ["nintendo-snes"]}]
+        self.assertEqual(install.select_data_directories(trees, files, True, games=plan), [dolphin])
+        plan.profiles.add("fbneo")
+        self.assertEqual(install.select_data_directories(trees, files, True, games=plan),
+                         [fbneo, dolphin])
+
+    def test_a_system_with_no_named_core_keeps_every_cores_tree(self):
+        plan = install.GamesPlan(Path("card"), True)
+        plan.any_core = {"nintendo-gba"}
+        fbneo = {"ref": "fbneo-cheats", "systems": ["nintendo-gba"], "cores": ["fbneo"]}
+        self.assertEqual(install.select_data_directories(
+            {"data_directories": [fbneo]}, [{"systems": ["nintendo-gba"]}], True, games=plan),
+            [fbneo])
+
+
 class _Quiet(http.server.SimpleHTTPRequestHandler):
     def log_message(self, format, *args):  # noqa: A002 - stdlib signature
         return
diff --git a/wiki/installer.md b/wiki/installer.md
index 0ecd328ec..894674a5d 100644
--- a/wiki/installer.md
+++ b/wiki/installer.md
@@ -866,7 +866,10 @@ games on this card: yes**, and Install takes only what those games need. One
 press on the row installs everything instead. Line mode asks the same: Enter
 installs for the games, `e` everything, `r` only what starts. On the command
 line it is `--for-games`, and `--for-games FOLDER` reads a games folder on a
-computer, one subfolder per system.
+computer, one subfolder per system. A run that asks nothing (`--yes`,
+`--no-input`, `--events`) takes the same first choice when it finds games on
+the card, and says so. `--all-files` installs the whole list instead, as does
+a run narrowed by name (`--system`, `--core`, `--region`, `--emulator`).
 
 The rule is that every game must start. Per system, the run keeps what the
 system's default core reads. One region is kept only where the game's own
@@ -983,6 +986,7 @@ what the options name, everything by default.
 | <span id="option-region"></span>`--region LIST` | Preferred regions, best first (`us,eu,jp`): keep one BIOS per region where a system has several. Accepts the names and aliases of `generate_pack.py --region` |
 | <span id="option-for-games"></span>`--for-games FOLDER` | Install only what the games on the card need. See [For the games on this card](#for-the-games-on-this-card) |
 | <span id="option-required-only"></span>`--required-only` | With `--for-games`, only the files the games cannot start without |
+| <span id="option-all-files"></span>`--all-files` | The whole list, even when the card holds games. A run that asks nothing (`--yes`, `--no-input`, `--events`) otherwise installs what the card's games need, the plan's first choice. See [For the games on this card](#for-the-games-on-this-card) |
 | <span id="option-no-game-data"></span>`--no-game-data` | Leave out game data (a game's own files, not firmware) and install the firmware only. What it leaves out is named. See [Firmware without game data](#firmware-without-game-data) |
 | <span id="option-declared-only"></span>`--declared-only` | Keep only the files the platform's own list names (`cores: null` in the manifest), not the extra files cores load. With `--check`, the answer is about the list the platform itself checks. Refused with `--core`, the listings it does not change, `--standalone-copies` and `--tui` |
 | <span id="option-list-systems"></span>`--list-systems` | Print a platform's systems with the files and size each holds, the files other systems share too counted apart. `--system`, `--core`, `--region`, `--target` and `--installed-cores` narrow it, as they narrow an install. A run prints one list: two listing options are refused |