Merge pull request #25 from The412Banner/feat/desktop-gpu

Desktop on the GPU (Vulkan by default), emulator controllers, PC keyboard, PS3 shader fixes
2026-10-14 19:27:09 -04:00 · 2026-09-23 23:16:51 -04:00
commit f6f7470385
@@ -0,0 +1,46 @@
+name: Build wlroots (patched)
+
+# The desktop's wlroots (Arch Linux ARM's wlroots0.20, what the desktop package's labwc links)
+# rebuilt with tools/wlroots/patches: a Vulkan DMA-BUF allocator for the Adreno node, which is not
+# a DRM device, so labwc's vulkan and gles2 renderers can start. Built in an Arch Linux ARM
+# container on an arm64 runner and published as a release asset the apk build fetches
+# (tools/wlroots/release.env names the tag and sha). The hosted desktop package is never changed.
+on:
+  push:
+    paths:
+      - 'tools/wlroots/**'
+      - '.github/workflows/build-wlroots.yml'
+  workflow_dispatch:
+    inputs:
+      tag:
+        description: 'Release tag to publish as (e.g. wlroots-0.20.2-p1); empty = artifact only'
+        required: false
+        default: ''
+
+permissions:
+  contents: write
+
+jobs:
+  build:
+    runs-on: ubuntu-24.04-arm
+    timeout-minutes: 90
+    steps:
+      - uses: actions/checkout@v4
+      - name: Build in Arch Linux ARM
+        run: |
+          set -euo pipefail
+          docker run --rm -v "$PWD:/work" -w /work menci/archlinuxarm:base-devel bash tools/wlroots/build-in-arch.sh
+          sudo chown -R "$(id -u):$(id -g)" .
+      - uses: actions/upload-artifact@v4
+        with:
+          name: wlroots-patched
+          path: |
+            wlroots.tzst
+            wlroots.tzst.sha256
+      - name: Publish
+        if: github.event_name == 'workflow_dispatch' && inputs.tag != ''
+        env:
+          GH_TOKEN: ${{ github.token }}
+        run: |
+          set -euo pipefail
+          gh release create "${{ inputs.tag }}" --title "${{ inputs.tag }}" --notes "wlroots 0.20.2 with tools/wlroots/patches (Vulkan DMA-BUF allocator for non-DRM GPU nodes); staged by the apk at /usr/local/lib/droiddeck-wlroots for the desktop's GPU renderers. sha256 $(cut -d' ' -f1 wlroots.tzst.sha256)" wlroots.tzst wlroots.tzst.sha256 || gh release upload "${{ inputs.tag }}" wlroots.tzst wlroots.tzst.sha256 --clobber
@@ -150,7 +150,7 @@ jobs:
        uses: actions/cache@v4
        with:
          path: app/src/main/assets/linuxfs
-          key: preloads-${{ env.PRELOAD_CACHE_VERSION }}-${{ hashFiles('app/src/main/cpp/fakeinput_steam.cpp', 'tools/linuxfs/preload/*.c', 'tools/linuxfs/overlay/usr/local/bin/*', 'tools/linuxfs/overlay/usr/bin/**', 'tools/linuxfs/desktop/*', 'tools/gamescope/release.env', 'tools/mangoapp/*') }}
+          key: preloads-${{ env.PRELOAD_CACHE_VERSION }}-${{ hashFiles('app/src/main/cpp/fakeinput_steam.cpp', 'tools/linuxfs/preload/*.c', 'tools/linuxfs/overlay/usr/local/bin/*', 'tools/linuxfs/overlay/usr/bin/**', 'tools/linuxfs/desktop/*', 'tools/gamescope/release.env', 'tools/wlroots/release.env', 'tools/mangoapp/*') }}

      - name: Build libfakeinput.so and libblsession.so (glibc aarch64)
        if: steps.preloads.outputs.cache-hit != 'true'
@@ -191,6 +191,15 @@ jobs:
            test -f "$D/usr/local/bin/gamescope"
            rm gamescope.tzst
          fi
+          # The patched wlroots for the desktop's GPU renderers (tools/wlroots), the same way.
+          if [ -f tools/wlroots/release.env ]; then
+            . tools/wlroots/release.env
+            gh release download "${WLROOTS_TAG}" -R "${GITHUB_REPOSITORY}" -p wlroots.tzst -O wlroots.tzst
+            echo "${WLROOTS_SHA256}  wlroots.tzst" | sha256sum -c -
+            tar --use-compress-program=unzstd -xf wlroots.tzst -C "$D"
+            test -f "$D/usr/local/lib/droiddeck-wlroots/libwlroots-0.20.so"
+            rm wlroots.tzst
+          fi
          # Valve's aarch64 mangoapp for Deck mode's performance overlay, plus the five libraries the
          # runtime lacks, pinned by sha256 in tools/mangoapp/packages.txt. Stored under the SONAME
          # each is loaded by, as real files: assets cannot carry symlinks.
@@ -212,6 +221,8 @@ jobs:
          ls -l "$M"
          # And the desktop's launcher and labwc defaults, staged over the desktop package's copies.
          install -Dm644 tools/linuxfs/desktop/droiddeck-desktop "$D/usr/local/bin/droiddeck-desktop"
+          install -Dm644 tools/linuxfs/desktop/droiddeck-gpu "$D/usr/local/bin/droiddeck-gpu"
+          install -Dm644 tools/linuxfs/desktop/droiddeck-desktop-gpu "$D/usr/local/bin/droiddeck-desktop-gpu"
          install -Dm644 tools/linuxfs/desktop/autostart "$D/etc/xdg/labwc/autostart"
          install -Dm644 tools/linuxfs/desktop/rc.xml "$D/etc/xdg/labwc/rc.xml"
          install -Dm644 tools/linuxfs/desktop/panel.conf "$D/etc/xdg/lxqt/panel.conf"
@@ -306,7 +317,7 @@ jobs:
          echo "apk: $APK"
          ls -l "$APK"
          sha256sum "$APK"
-          unzip -l "$APK" | grep -E 'lib/arm64-v8a|assets/linuxfs' | head -30
+          unzip -l "$APK" | grep -E 'lib/arm64-v8a|assets/linuxfs' | awk 'NR <= 30'  # awk reads to the end: head would break the pipe under pipefail

      # Every NEEDED of every library we ship must resolve inside the apk or on the device. The
      # first build shipped libwayland-server.so without libffi.so, and the app died on
@@ -275,6 +275,7 @@ struct surface {
    int sub_x, sub_y, sub_pending_x, sub_pending_y, sub_pending;
    int below_parent;
    int fullscreen;                         /* xdg_toplevel.set_fullscreen: no client decorations */
+    int toplevel_committed;                 /* the toplevel's initial commit was answered */

    char *title;                            /* xdg_toplevel title, for the session log */
    int announced_vulkan;                   /* logged its first dmabuf frame */
@@ -589,6 +590,10 @@ static void map_toplevel(struct surface *s) {
                   s->placed ? "" : " (no desktop position yet)");
    }
    wl_list_insert(g_toplevels.prev, &s->toplevel_link); /* new windows start on top */
+    /* Without a Wine desktop the clients are whole programs (the Linux desktop, a gamescope a
+     * program on it started over it): a window that opens on top takes the keys too, as it would
+     * on any desktop, rather than the one clicked last that is now underneath it. */
+    if (!g_desktop) g_key_target = s;
    apply_zorder();
 }

@@ -884,10 +889,21 @@ static void surface_set_opaque(struct wl_client *c, struct wl_resource *r,
 static void surface_set_input(struct wl_client *c, struct wl_resource *r,
                              struct wl_resource *region) {}

+static void send_toplevel_configure(struct surface *s);
+
 static void surface_commit(struct wl_client *c, struct wl_resource *r) {
    struct surface *s = wl_resource_get_user_data(r);
    struct surface *child;

+    /* xdg-shell: the initial commit of a toplevel is answered with a configure. One is also sent
+     * at get_toplevel, which Wine's driver has always had; a client that waits for the reply to its
+     * commit on a queue of its own (wlroots' Wayland backend - the desktop's labwc) can read that
+     * early one onto the wrong queue and would wait for ever. */
+    if (s->xdg_toplevel && !s->toplevel_committed) {
+        s->toplevel_committed = 1;
+        send_toplevel_configure(s);
+    }
+
    if (s->pending_src_set) {
        s->src_set = s->pending_src[2] > 0;
        memcpy(s->src, s->pending_src, sizeof(s->src));
@@ -1298,6 +1314,7 @@ static void xdg_toplevel_resource_destroy(struct wl_resource *r) {
    struct surface *s = wl_resource_get_user_data(r);
    if (!s) return;
    s->xdg_toplevel = NULL;
+    s->toplevel_committed = 0;
    unmap_toplevel(s);
    s->placed = 0;
    s->hwnd = 0;
@@ -1315,8 +1332,23 @@ static void xdg_surface_get_toplevel(struct wl_client *c, struct wl_resource *r,
    s->xdg_toplevel = tl;
    send_toplevel_configure(s);
 }
+/* A popup is dismissed as soon as it is made (see the positioner below). */
+static void popup_destroy(struct wl_client *c, struct wl_resource *r) { wl_resource_destroy(r); }
+static void popup_grab(struct wl_client *c, struct wl_resource *r, struct wl_resource *seat, uint32_t serial) {}
+static void popup_reposition(struct wl_client *c, struct wl_resource *r, struct wl_resource *positioner,
+                             uint32_t token) {}
+static const struct xdg_popup_interface popup_impl = {
+    .destroy = popup_destroy,
+    .grab = popup_grab,
+    .reposition = popup_reposition,
+};
 static void xdg_surface_get_popup(struct wl_client *c, struct wl_resource *r, uint32_t id,
-                                  struct wl_resource *parent, struct wl_resource *positioner) {}
+                                  struct wl_resource *parent, struct wl_resource *positioner) {
+    struct wl_resource *p = wl_resource_create(c, &xdg_popup_interface, wl_resource_get_version(r), id);
+    if (!p) { wl_client_post_no_memory(c); return; }
+    wl_resource_set_implementation(p, &popup_impl, NULL, NULL);
+    xdg_popup_send_popup_done(p);
+}
 static void xdg_surface_set_geometry(struct wl_client *c, struct wl_resource *r,
                                     int32_t x, int32_t y, int32_t w, int32_t h) {}
 static void xdg_surface_ack_configure(struct wl_client *c, struct wl_resource *r, uint32_t serial) {}
@@ -1333,9 +1365,40 @@ static void xdg_surface_resource_destroy(struct wl_resource *r) {
 }

 static void xdg_wm_base_destroy(struct wl_client *c, struct wl_resource *r) { wl_resource_destroy(r); }
+
+/* Popups are not drawn here, but their requests must still land somewhere: a resource without an
+ * implementation makes libwayland abort on the first request to it - the whole compositor, and the
+ * app with it. A positioner takes every request and keeps nothing; a popup is dismissed at once
+ * (popup_done), which is what a client does with a popup it cannot show. Seen with a gamescope
+ * started from the Linux desktop beside labwc. */
+static void positioner_destroy(struct wl_client *c, struct wl_resource *r) { wl_resource_destroy(r); }
+static void positioner_set_size(struct wl_client *c, struct wl_resource *r, int32_t w, int32_t h) {}
+static void positioner_set_anchor_rect(struct wl_client *c, struct wl_resource *r, int32_t x, int32_t y,
+                                       int32_t w, int32_t h) {}
+static void positioner_set_anchor(struct wl_client *c, struct wl_resource *r, uint32_t a) {}
+static void positioner_set_gravity(struct wl_client *c, struct wl_resource *r, uint32_t g) {}
+static void positioner_set_constraint_adjustment(struct wl_client *c, struct wl_resource *r, uint32_t a) {}
+static void positioner_set_offset(struct wl_client *c, struct wl_resource *r, int32_t x, int32_t y) {}
+static void positioner_set_reactive(struct wl_client *c, struct wl_resource *r) {}
+static void positioner_set_parent_size(struct wl_client *c, struct wl_resource *r, int32_t w, int32_t h) {}
+static void positioner_set_parent_configure(struct wl_client *c, struct wl_resource *r, uint32_t serial) {}
+static const struct xdg_positioner_interface positioner_impl = {
+    .destroy = positioner_destroy,
+    .set_size = positioner_set_size,
+    .set_anchor_rect = positioner_set_anchor_rect,
+    .set_anchor = positioner_set_anchor,
+    .set_gravity = positioner_set_gravity,
+    .set_constraint_adjustment = positioner_set_constraint_adjustment,
+    .set_offset = positioner_set_offset,
+    .set_reactive = positioner_set_reactive,
+    .set_parent_size = positioner_set_parent_size,
+    .set_parent_configure = positioner_set_parent_configure,
+};
+
 static void xdg_wm_base_create_positioner(struct wl_client *c, struct wl_resource *r, uint32_t id) {
    struct wl_resource *p = wl_resource_create(c, &xdg_positioner_interface, wl_resource_get_version(r), id);
-    if (p) wl_resource_set_implementation(p, NULL, NULL, NULL);
+    if (!p) { wl_client_post_no_memory(c); return; }
+    wl_resource_set_implementation(p, &positioner_impl, NULL, NULL);
 }
 static void xdg_wm_base_get_xdg_surface(struct wl_client *c, struct wl_resource *r, uint32_t id,
                                        struct wl_resource *surf) {
@@ -1721,9 +1784,15 @@ static void bind_dmabuf(struct wl_client *c, void *data, uint32_t ver, uint32_t

 /* ------------------------------------------------------------------ wl_output */

+/* wl_output v3+ has a request (release); without an implementation the first client to send it
+ * aborted the compositor. */
+static void output_release(struct wl_client *c, struct wl_resource *r) { wl_resource_destroy(r); }
+static const struct wl_output_interface output_impl = { .release = output_release };
+
 static void bind_output(struct wl_client *c, void *data, uint32_t ver, uint32_t id) {
    struct wl_resource *r = wl_resource_create(c, &wl_output_interface, ver, id);
-    wl_resource_set_implementation(r, NULL, NULL, NULL);
+    if (!r) { wl_client_post_no_memory(c); return; }
+    wl_resource_set_implementation(r, &output_impl, NULL, NULL);
    wl_output_send_geometry(r, 0, 0, 340, 190, WL_OUTPUT_SUBPIXEL_UNKNOWN,
                            "Bannerlator", "Wayland", WL_OUTPUT_TRANSFORM_NORMAL);
    wl_output_send_mode(r, WL_OUTPUT_MODE_CURRENT | WL_OUTPUT_MODE_PREFERRED,
@@ -169,7 +169,7 @@ class MainActivity : ComponentActivity() {
    private var touchMode by mutableStateOf(SessionPrefs.TOUCH_AUTO)
    private var suspendPolicy by mutableStateOf(SessionPrefs.SUSPEND_MANUAL)
    private var oscMode by mutableStateOf(SessionPrefs.OSC_AUTO)
-    private var renderer by mutableStateOf("pixman")
+    private var renderer by mutableStateOf("vulkan")
    private var gameStorage by mutableStateOf("")
    private var storageOptions by mutableStateOf<List<Pair<String, String>>>(emptyList())
    private val pickGameStorage = registerForActivityResult(ActivityResultContracts.StartActivityForResult()) { r ->
@@ -88,6 +88,8 @@ class SessionActivity : ComponentActivity(), SurfaceHolder.Callback {

    // Compose reads these; the activity writes them.
    private var drawerOpen by mutableStateOf(false)
+    /** The on-screen PC keyboard (ui/PcKeyboard): real key presses, Esc and F1 included. */
+    private var pcKeyboardOpen by mutableStateOf(false)
    private var hudOn by mutableStateOf(true)
    private var frameGenLabel by mutableStateOf("Off")
    private var frameGenEngine by mutableStateOf(FrameGen.ENGINE_OFF)
@@ -181,6 +183,13 @@ class SessionActivity : ComponentActivity(), SurfaceHolder.Callback {
                    if (loading.visible) LoadingOverlay(loading.step, loading.percent, loading.elapsed, loading.hint, loading.ended)
                    // Opening the drawer takes the controller away from the game: release its pad.
                    androidx.compose.runtime.LaunchedEffect(drawerOpen) { if (drawerOpen) padBridge?.releaseAll() }
+                    // The PC keyboard takes it too, for moving over the keys; the drawer opens over it.
+                    androidx.compose.runtime.LaunchedEffect(pcKeyboardOpen) { if (pcKeyboardOpen) padBridge?.releaseAll() }
+                    if (pcKeyboardOpen) com.droiddeck.launcher.ui.PcKeyboard(
+                        sendKey = { code, down -> if (CompositorHost.isStarted) WaylandCompositor.nativeSendKey(code, if (down) 1 else 0) },
+                        onAndroidKeyboard = { pcKeyboardOpen = false; keyboard?.toggle() },
+                        onClose = { pcKeyboardOpen = false },
+                    )
                    SessionDrawer(drawerOpen, DrawerActions(
                        steam = SessionState.mode == SessionService.MODE_STEAM,
                        isHomeApp = isHomeApp,
@@ -200,7 +209,8 @@ class SessionActivity : ComponentActivity(), SurfaceHolder.Callback {
                            readPrefs()
                            applyFrameGen()
                        },
-                        onKeyboard = { drawerOpen = false; keyboard?.toggle() },
+                        onKeyboard = { drawerOpen = false; pcKeyboardOpen = false; keyboard?.toggle() },
+                        onHardwareKeyboard = { drawerOpen = false; pcKeyboardOpen = !pcKeyboardOpen },
                        onSteamMenu = if (SessionState.mode == SessionService.MODE_STEAM) ({ sendSteamGuide() }) else null,
                        onQam = if (SessionState.mode == SessionService.MODE_STEAM) ({
                            drawerOpen = false
@@ -247,7 +257,8 @@ class SessionActivity : ComponentActivity(), SurfaceHolder.Callback {
        // from a button a game might also be reading.
        onBackPressedDispatcher.addCallback(this, object : OnBackPressedCallback(true) {
            override fun handleOnBackPressed() {
-                drawerOpen = !drawerOpen
+                // The PC keyboard closes first (B on a controller), then Back is the drawer again.
+                if (pcKeyboardOpen && !drawerOpen) pcKeyboardOpen = false else drawerOpen = !drawerOpen
            }
        })
        watchSession()
@@ -612,7 +623,7 @@ class SessionActivity : ComponentActivity(), SurfaceHolder.Callback {
        // With the drawer open the controller drives the drawer, not the game: Android's own
        // handling moves focus with the d-pad and stick, and its fallbacks make A select and B Back
        // (which closes the drawer) - the same as on the app's main screen.
-        if (drawerOpen && event.device != null && PadBridge.isFromController(event.device)) return super.dispatchKeyEvent(event)
+        if ((drawerOpen || pcKeyboardOpen) && event.device != null && PadBridge.isFromController(event.device)) return super.dispatchKeyEvent(event)
        if (event.keyCode != KeyEvent.KEYCODE_BACK && padBridge?.onKeyEvent(event) == true) return true
        // A hardware keyboard, forwarded to the compositor's wl_keyboard. Back is left to the
        // activity, which opens the drawer.
@@ -654,7 +665,7 @@ class SessionActivity : ComponentActivity(), SurfaceHolder.Callback {
    }

    override fun dispatchGenericMotionEvent(event: MotionEvent): Boolean {
-        if (drawerOpen && event.device != null && PadBridge.isFromController(event.device)) return super.dispatchGenericMotionEvent(event)
+        if ((drawerOpen || pcKeyboardOpen) && event.device != null && PadBridge.isFromController(event.device)) return super.dispatchGenericMotionEvent(event)
        if (padBridge?.onMotionEvent(event) == true) return true
        if (event.isFromSource(android.view.InputDevice.SOURCE_MOUSE) && !drawerOpen && onMouse(event)) return true
        return super.dispatchGenericMotionEvent(event)
@@ -38,6 +38,7 @@ object SessionFiles {
            "usr/local/bin/bannerlator-desktop-games" to "usr/local/bin/bannerlator-desktop-games",
            "usr/local/bin/bannerlator-steam-shim" to "usr/local/bin/bannerlator-steam-shim",
            "usr/local/bin/bannerlator-steam-shortcuts" to "usr/local/bin/bannerlator-steam-shortcuts",
+            "usr/local/bin/bannerlator-pad-defaults" to "usr/local/bin/bannerlator-pad-defaults",
            // The SteamOS helpers the client calls in Deck mode: the two Armada found it needs, plus
            // the three under /usr/bin, all no-ops that answer "nothing to do" (see each file).
            "usr/bin/steamos-update" to "usr/bin/steamos-update",
@@ -56,6 +57,9 @@ object SessionFiles {
        // staging them into a runtime without it would make the desktop look present when it is not.
        val desktop = arrayOf(
            "usr/local/bin/droiddeck-desktop" to "usr/local/bin/droiddeck-desktop",
+            // Games and emulators from the menu, full screen in a gamescope of their own.
+            "usr/local/bin/droiddeck-gpu" to "usr/local/bin/droiddeck-gpu",
+            "usr/local/bin/droiddeck-desktop-gpu" to "usr/local/bin/droiddeck-desktop-gpu",
            "etc/xdg/labwc/autostart" to "etc/xdg/labwc/autostart",
            "etc/xdg/labwc/rc.xml" to "etc/xdg/labwc/rc.xml",
            "etc/xdg/lxqt/panel.conf" to "etc/xdg/lxqt/panel.conf",
@@ -75,9 +79,13 @@ object SessionFiles {
            "usr/local/lib/mangoapp/libtraceevent.so.1",
            "usr/local/lib/mangoapp/libtracefs.so.1",
        ).map { it to it }
+        // The patched wlroots (tools/wlroots) the desktop loads for its vulkan / gles2 renderers.
+        val wlroots = if (File(root, "usr/bin/labwc").isFile) {
+            arrayOf("usr/local/lib/droiddeck-wlroots/libwlroots-0.20.so" to "usr/local/lib/droiddeck-wlroots/libwlroots-0.20.so")
+        } else emptyArray()
        val optional = (arrayOf(
            "usr/local/bin/gamescope" to "usr/local/bin/gamescope",
-        ) + mangoapp).filter { (asset, _) ->
+        ) + wlroots + mangoapp).filter { (asset, _) ->
            val dir = asset.substringBeforeLast('/')
            runCatching { context.assets.list("linuxfs/$dir")?.contains(asset.substringAfterLast('/')) == true }.getOrDefault(false)
        }
@@ -330,14 +330,18 @@ object SessionPrefs {
    }

    /**
-     * What the desktop shell composites with: pixman (software, the default - the Adreno stand-in
-     * is not a DRM render node, so labwc's gbm allocator cannot use it), or gles2 / vulkan for a
-     * device that has a real node. `Download/droiddeck-wlr-renderer` still overrides it.
+     * What the desktop shell composites with: vulkan (the default) or gles2 on the GPU, through the
+     * app's patched wlroots (tools/wlroots) - the Adreno stand-in is not a DRM device and stock
+     * wlroots cannot allocate on it - or pixman in software. A GPU renderer a device cannot start
+     * falls back to pixman by itself (droiddeck-desktop). `Download/droiddeck-wlr-renderer` still
+     * overrides it.
     */
-    fun desktopRenderer(context: Context): String = prefs(context).getString("desktopRenderer", "pixman") ?: "pixman"
+    fun desktopRenderer(context: Context): String = prefs(context).getString("desktopRenderer", "vulkan") ?: "vulkan"

    fun setDesktopRenderer(context: Context, renderer: String) {
        prefs(context).edit().putString("desktopRenderer", renderer).apply()
+        // A choice made again is a retry: forget that a renderer failed to start here before.
+        java.io.File(com.droiddeck.launcher.runtime.LinuxRuntime.rootDir(context), "root/.droiddeck-renderer-failed").delete()
    }

    /**
@@ -280,7 +280,12 @@ class SessionService : Service() {
        // An imported glibc Turnip for this mode, when the user chose one: the session script checks
        // the manifest and its library from inside and points the loader at it with VK_DRIVER_FILES,
        // so the runtime's own driver above stays untouched and is what a bad import falls back to.
-        val linuxDriverId = SessionPrefs.linuxDriver(this, SessionPrefs.prefMode(SessionState.mode))
+        // A program from the rail is one of the desktop's emulators, so it draws with the desktop's
+        // Linux driver, not the Steam session's: the driver's shader cache is keyed on the driver
+        // build, and with two drivers every emulator compiled its shaders twice - once per way of
+        // starting it (RPCS3's 6650 interpreter variants on each first boot).
+        val driverMode = if (SessionState.mode == MODE_RUN) MODE_DESKTOP else SessionPrefs.prefMode(SessionState.mode)
+        val linuxDriverId = SessionPrefs.linuxDriver(this, driverMode)
        LinuxVulkanDriver.resolveIcdPath(this, linuxDriverId)
            ?.let { guest.add(LinuxVulkanDriver.ENV + "=" + it) }
        // Turnip's own debug switches, for the runtime's driver and everything on it. The file in
@@ -321,13 +326,13 @@ class SessionService : Service() {
        // on, even naming every core: it exists to undo the pin Steam applies to its own interface
        // renderer, and the scheduler's default is exactly what that pin takes away. A game's is
        // sent only when it is a real restriction - a game has no pin of its own to undo.
-        if (SessionState.mode == MODE_STEAM) {
-            if (SessionPrefs.clientCpusOverride(this)) {
-                guest.add("BL_CLIENT_CPUS=" + CpuCores.listOrAll(SessionPrefs.clientCpus(this)))
-            }
-            CpuCores.restrictionOrEmpty(SessionPrefs.gameCpus(this))
-                .takeIf { it.isNotEmpty() }?.let { guest.add("BL_GAME_CPUS=$it") }
+        if (SessionState.mode == MODE_STEAM && SessionPrefs.clientCpusOverride(this)) {
+            guest.add("BL_CLIENT_CPUS=" + CpuCores.listOrAll(SessionPrefs.clientCpus(this)))
        }
+        // The game cores also pin the desktop and a program from the rail; without a choice the
+        // session script picks every core but the slowest cluster for those (program_cores).
+        CpuCores.restrictionOrEmpty(SessionPrefs.gameCpus(this))
+            .takeIf { it.isNotEmpty() }?.let { guest.add("BL_GAME_CPUS=$it") }

        // PulseAudio always: the client is a native Linux program and has no other way to make a
        // sound - its menus, its music and its voice chat all go through here. DirectAudio is not
@@ -398,7 +403,11 @@ class SessionService : Service() {
            // identity gets the standard layout without the user configuring the pad by hand.
            guest.add("FAKE_EVDEV_IDENTITY=xbox360")
            guest.add("FAKE_EVDEV_VIBRATION=1")
-            guest.add("FAKE_EVDEV_STEAM_VIRTUAL=1")
+            // Steam Input's virtual-gamepad identity is for games the client starts, which are
+            // meant to see that pad. Everywhere else (the desktop, a program from the rail) it
+            // hides the pad: SDL ignores a Steam virtual gamepad unless it runs under Steam, so
+            // every SDL emulator came up with no controller. There it is a plain Xbox 360 pad.
+            if (SessionState.mode == MODE_STEAM) guest.add("FAKE_EVDEV_STEAM_VIRTUAL=1")
            guest.add("SDL_JOYSTICK_DISABLE_UDEV=1")
            guest.add("SDL_HIDAPI_JOYSTICK_DISABLE_UDEV=1")
            guest.add("SDL_JOYSTICK_HIDAPI=0")
@@ -407,12 +416,11 @@ class SessionService : Service() {
            }
            SessionState.fakeInputDir = fakeInputDir
        }
-        // The desktop is wlroots (labwc), and wlroots allocates its buffers through gbm on a real
-        // DRM render node. Ours is a KGSL stand-in that gbm cannot use - labwc dies at "unable to
-        // create allocator" - so the desktop shell is composited by pixman (software, a shm
-        // allocator, no DRM). Accelerated clients on it pay a CPU copy; a 2D emulator does not
-        // notice, a demanding one does. droiddeck-wlr-renderer in Downloads (pixman/vulkan/gles2)
-        // overrides it, for trying acceleration on a device that has a real node.
+        // The desktop is wlroots (labwc). Stock wlroots allocates through gbm on a real DRM render
+        // node, and ours is a KGSL stand-in - labwc died at "unable to create allocator" - so the
+        // default is pixman (software, shm), where a Vulkan program cannot draw at all; those run
+        // through droiddeck-gpu instead. vulkan / gles2 use the app's patched wlroots and fall back
+        // to pixman by themselves. droiddeck-wlr-renderer in Downloads overrides the choice.
        if (SessionState.mode == MODE_DESKTOP) {
            val override = File(Environment.getExternalStorageDirectory(), "Download/droiddeck-wlr-renderer")
                .takeIf { it.isFile }?.let { FileUtils.readString(it)?.trim() }
@@ -322,8 +322,11 @@ fun ModeSettingsPage(s: ModeSettings, a: ModeSettingsActions) {
        if (!steam && s.renderer != null) SettingsGroup("Renderer") {
            ChoiceRow(
                host, "renderer", "Desktop renderer", "Composites the desktop.",
-                listOf("pixman" to "pixman - software", "gles2" to "gles2", "vulkan" to "vulkan"), s.renderer,
-                note = "GLES2 and Vulkan require a DRM render node, unavailable on most devices.", onPick = a.onRenderer,
+                listOf("vulkan" to "vulkan - GPU", "gles2" to "gles2 - GPU (experimental)", "pixman" to "pixman - software"), s.renderer,
+                note = "On Vulkan, programs on the desktop draw with the GPU in their own windows; if it cannot start, " +
+                    "the desktop comes up on pixman. On pixman, games and emulators from the menu open full screen " +
+                    "on the GPU instead (right-click one for a desktop window).",
+                onPick = a.onRenderer,
            )
        }
    }
@@ -0,0 +1,251 @@
+package com.droiddeck.launcher.ui
+
+import android.view.KeyEvent
+import androidx.compose.animation.animateColorAsState
+import androidx.compose.foundation.background
+import androidx.compose.foundation.border
+import androidx.compose.foundation.clickable
+import androidx.compose.foundation.LocalIndication
+import androidx.compose.foundation.focusable
+import androidx.compose.foundation.gestures.awaitEachGesture
+import androidx.compose.foundation.gestures.awaitFirstDown
+import androidx.compose.foundation.gestures.waitForUpOrCancellation
+import androidx.compose.foundation.interaction.MutableInteractionSource
+import androidx.compose.foundation.interaction.collectIsFocusedAsState
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.BoxWithConstraints
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.RowScope
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxHeight
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.width
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateMapOf
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.focus.FocusRequester
+import androidx.compose.ui.focus.focusRequester
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.input.key.nativeKeyCode
+import androidx.compose.ui.input.key.onPreviewKeyEvent
+import androidx.compose.ui.input.key.type
+import androidx.compose.ui.input.key.KeyEventType
+import androidx.compose.ui.input.key.key
+import androidx.compose.ui.input.pointer.pointerInput
+import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.text.style.TextAlign
+import androidx.compose.ui.unit.dp
+import androidx.compose.ui.unit.sp
+
+/**
+ * A PC keyboard on screen: every key is a physical key (a Linux evdev code) pressed and released
+ * on the session's wl_keyboard, as a USB keyboard would - Esc, the function row, Ctrl, Alt, Super,
+ * the arrows and the editing block included, none of which the Android keyboard can send.
+ *
+ * A key goes down when a finger lands on it and up when it lifts, so holding one repeats it the way
+ * the program's own key repeat does. Ctrl, Shift, Alt and Super are sticky: one tap holds the
+ * modifier for the next key, a second tap locks it, a third lets it go. A controller moves over the
+ * keys with the d-pad and presses with A.
+ */
+private data class PcKey(val label: String, val code: Int, val weight: Float = 1f, val shifted: String? = null)
+
+private fun k(label: String, code: Int, weight: Float = 1f, shifted: String? = null) = PcKey(label, code, weight, shifted)
+
+private val ROWS: List<List<PcKey>> = listOf(
+    listOf(
+        k("Esc", 1), k("F1", 59), k("F2", 60), k("F3", 61), k("F4", 62), k("F5", 63), k("F6", 64),
+        k("F7", 65), k("F8", 66), k("F9", 67), k("F10", 68), k("F11", 87), k("F12", 88),
+        k("Ins", 110), k("Del", 111), k("Home", 102), k("End", 107), k("PgUp", 104), k("PgDn", 109),
+    ),
+    listOf(
+        k("`", 41, shifted = "~"), k("1", 2, shifted = "!"), k("2", 3, shifted = "@"), k("3", 4, shifted = "#"),
+        k("4", 5, shifted = "$"), k("5", 6, shifted = "%"), k("6", 7, shifted = "^"), k("7", 8, shifted = "&"),
+        k("8", 9, shifted = "*"), k("9", 10, shifted = "("), k("0", 11, shifted = ")"), k("-", 12, shifted = "_"),
+        k("=", 13, shifted = "+"), k("⌫ Backspace", 14, 2f),
+    ),
+    listOf(
+        k("Tab ⇥", 15, 1.5f), k("q", 16), k("w", 17), k("e", 18), k("r", 19), k("t", 20), k("y", 21),
+        k("u", 22), k("i", 23), k("o", 24), k("p", 25), k("[", 26, shifted = "{"), k("]", 27, shifted = "}"),
+        k("\\", 43, 1.5f, shifted = "|"),
+    ),
+    listOf(
+        k("Caps", 58, 1.75f), k("a", 30), k("s", 31), k("d", 32), k("f", 33), k("g", 34), k("h", 35),
+        k("j", 36), k("k", 37), k("l", 38), k(";", 39, shifted = ":"), k("'", 40, shifted = "\""),
+        k("Enter ⏎", 28, 2.25f),
+    ),
+    listOf(
+        k("⇧ Shift", 42, 2.25f), k("z", 44), k("x", 45), k("c", 46), k("v", 47), k("b", 48), k("n", 49),
+        k("m", 50), k(",", 51, shifted = "<"), k(".", 52, shifted = ">"), k("/", 53, shifted = "?"),
+        k("⇧ Shift", 54, 1.75f), k("↑", 103),
+    ),
+    listOf(
+        k("Ctrl", 29, 1.5f), k("Super", 125, 1.25f), k("Alt", 56, 1.25f), k("Space", 57, 6.25f),
+        k("AltGr", 100, 1.25f), k("Ctrl", 97, 1.25f), k("←", 105), k("↓", 108), k("→", 106),
+    ),
+)
+
+private val MODIFIERS = setOf(42, 54, 29, 97, 56, 100, 125)
+private const val MOD_OFF = 0
+private const val MOD_ONCE = 1
+private const val MOD_LOCKED = 2
+
+@Composable
+fun PcKeyboard(
+    /** evdev code, pressed. */
+    sendKey: (Int, Boolean) -> Unit,
+    onAndroidKeyboard: () -> Unit,
+    onClose: () -> Unit,
+) {
+    val pal = LocalPalette.current
+    val colors = MaterialTheme.colorScheme
+    val mods = remember { mutableStateMapOf<Int, Int>() }
+    var capsOn by remember { mutableStateOf(false) }
+    val firstKey = remember { FocusRequester() }
+    val shifted = (mods[42] ?: MOD_OFF) != MOD_OFF || (mods[54] ?: MOD_OFF) != MOD_OFF
+
+    fun releaseOnceModifiers() {
+        for ((code, state) in mods.toMap()) if (state == MOD_ONCE) { sendKey(code, false); mods[code] = MOD_OFF }
+    }
+    fun press(key: PcKey) {
+        if (key.code in MODIFIERS) {
+            when (mods[key.code] ?: MOD_OFF) {
+                MOD_OFF -> { sendKey(key.code, true); mods[key.code] = MOD_ONCE }
+                MOD_ONCE -> mods[key.code] = MOD_LOCKED
+                else -> { sendKey(key.code, false); mods[key.code] = MOD_OFF }
+            }
+            return
+        }
+        sendKey(key.code, true)
+    }
+    fun release(key: PcKey) {
+        if (key.code in MODIFIERS) return
+        sendKey(key.code, false)
+        if (key.code == 58) capsOn = !capsOn
+        releaseOnceModifiers()
+    }
+    // Nothing is left held when the keyboard goes away.
+    androidx.compose.runtime.DisposableEffect(Unit) {
+        onDispose { for ((code, state) in mods.toMap()) if (state != MOD_OFF) sendKey(code, false) }
+    }
+    LaunchedEffect(Unit) { runCatching { firstKey.requestFocus() } }
+
+    BoxWithConstraints(Modifier.fillMaxSize(), contentAlignment = Alignment.BottomCenter) {
+        // Slightly under half the screen, header included, so the program stays in view above it:
+        // six rows share what is left of 47% after the header, the gaps and the padding.
+        val rowHeight = ((maxHeight * 0.47f - 24.dp - 3.dp * 6 - 10.dp) / 6).coerceIn(24.dp, 44.dp)
+        Box(
+            Modifier.fillMaxWidth()
+                .background(Color(0xE6101418), RoundedCornerShape(topStart = 14.dp, topEnd = 14.dp))
+                .border(1.dp, pal.line2, RoundedCornerShape(topStart = 14.dp, topEnd = 14.dp))
+                // Touches on the keyboard stop here; the program underneath never sees them.
+                .pointerInput(Unit) { awaitEachGesture { awaitFirstDown().consume(); waitForUpOrCancellation()?.consume() } }
+                .padding(horizontal = 8.dp, vertical = 5.dp),
+        ) {
+            Column(verticalArrangement = Arrangement.spacedBy(3.dp)) {
+                Row(verticalAlignment = Alignment.CenterVertically, modifier = Modifier.fillMaxWidth().height(24.dp)) {
+                    Text("PC keyboard", fontSize = 12.sp, fontWeight = FontWeight.SemiBold, color = colors.onSurfaceVariant)
+                    Spacer(Modifier.weight(1f))
+                    HeaderButton("Android keyboard", onAndroidKeyboard)
+                    Spacer(Modifier.width(8.dp))
+                    HeaderButton("Hide  ✕", onClose)
+                }
+                ROWS.forEachIndexed { r, row ->
+                    Row(horizontalArrangement = Arrangement.spacedBy(3.dp), modifier = Modifier.fillMaxWidth().height(rowHeight)) {
+                        row.forEachIndexed { i, key ->
+                            val state = mods[key.code] ?: MOD_OFF
+                            val lit = state != MOD_OFF || (key.code == 58 && capsOn)
+                            val label = when {
+                                shifted && key.shifted != null -> key.shifted
+                                key.label.length == 1 && key.label[0].isLetter() && (shifted xor capsOn) -> key.label.uppercase()
+                                else -> key.label
+                            }
+                            KeyCap(
+                                label, key.weight, lit, locked = state == MOD_LOCKED,
+                                modifier = if (r == 0 && i == 0) Modifier.focusRequester(firstKey) else Modifier,
+                                onDown = { press(key) }, onUp = { release(key) },
+                            )
+                        }
+                    }
+                }
+            }
+        }
+    }
+}
+
+@Composable
+private fun RowScope.KeyCap(
+    label: String, weight: Float, lit: Boolean, locked: Boolean,
+    modifier: Modifier, onDown: () -> Unit, onUp: () -> Unit,
+) {
+    val pal = LocalPalette.current
+    val src = remember { MutableInteractionSource() }
+    val focused by src.collectIsFocusedAsState()
+    var down by remember { mutableStateOf(false) }
+    val fill by animateColorAsState(
+        when {
+            down -> pal.signal.copy(alpha = 0.55f)
+            lit -> pal.signal.copy(alpha = if (locked) 0.45f else 0.28f)
+            else -> Color.White.copy(alpha = 0.07f)
+        }, label = "keyFill",
+    )
+    val edge = if (focused) pal.signal else if (lit) pal.signal.copy(alpha = 0.7f) else Color.White.copy(alpha = 0.12f)
+    Box(
+        contentAlignment = Alignment.Center,
+        modifier = modifier.weight(weight).fillMaxHeight()
+            .background(fill, RoundedCornerShape(7.dp))
+            .border(if (focused) 2.dp else 1.dp, edge, RoundedCornerShape(7.dp))
+            .pointerInput(Unit) {
+                awaitEachGesture {
+                    awaitFirstDown().consume()
+                    down = true; onDown()
+                    waitForUpOrCancellation()?.consume()
+                    down = false; onUp()
+                }
+            }
+            // A controller: A (or the d-pad's centre) is the finger.
+            .onPreviewKeyEvent { e ->
+                val kc = e.key.nativeKeyCode
+                if (kc != KeyEvent.KEYCODE_BUTTON_A && kc != KeyEvent.KEYCODE_DPAD_CENTER && kc != KeyEvent.KEYCODE_ENTER) return@onPreviewKeyEvent false
+                when (e.type) {
+                    KeyEventType.KeyDown -> if (!down) { down = true; onDown() }
+                    KeyEventType.KeyUp -> if (down) { down = false; onUp() }
+                }
+                true
+            }
+            .focusable(interactionSource = src),
+    ) {
+        Text(
+            label, fontSize = if (label.length > 2) 11.sp else 15.sp, fontWeight = FontWeight.SemiBold,
+            color = Color.White, textAlign = TextAlign.Center, maxLines = 1,
+        )
+    }
+}
+
+@Composable
+private fun HeaderButton(text: String, onClick: () -> Unit) {
+    val pal = LocalPalette.current
+    val src = remember { MutableInteractionSource() }
+    val focused by src.collectIsFocusedAsState()
+    Box(
+        contentAlignment = Alignment.Center,
+        modifier = Modifier.fillMaxHeight()
+            .background(Color.White.copy(alpha = 0.08f), RoundedCornerShape(7.dp))
+            .border(if (focused) 2.dp else 1.dp, if (focused) pal.signal else Color.White.copy(alpha = 0.14f), RoundedCornerShape(7.dp))
+            .clickable(interactionSource = src, indication = LocalIndication.current, onClick = onClick)
+            .padding(horizontal = 12.dp),
+    ) { Text(text, fontSize = 12.sp, fontWeight = FontWeight.SemiBold, color = Color.White) }
+}
@@ -158,7 +158,10 @@ class DrawerActions(
    val selectedSecondScreenDisplay: Int,
    val onHud: (Boolean) -> Unit,
    val onFrameGenPick: (engine: String, multiplier: Int) -> Unit,
+    /** The Android keyboard (text, turned into key presses). */
    val onKeyboard: () -> Unit,
+    /** The on-screen PC keyboard: real keys, Esc, F1-F12, Ctrl, Alt... */
+    val onHardwareKeyboard: () -> Unit,
    val onSteamMenu: (() -> Unit)?,
    val onQam: (() -> Unit)?,
    val onOsc: (String) -> Unit,
@@ -320,7 +323,13 @@ fun SessionDrawer(open: Boolean, a: DrawerActions) {
                        listOf(SessionPrefs.OSC_AUTO to "Auto", SessionPrefs.OSC_ALWAYS to "Always", SessionPrefs.OSC_STEAM_QAM to "Steam + QAM", SessionPrefs.OSC_NEVER to "Never"), a.oscMode,
                        onPick = a.onOsc,
                    )
-                    ActionRow("Keyboard", null, "Show") { host.open = null; a.onKeyboard() }
+                    SettingsRow("Keyboard", null) {
+                        Row(verticalAlignment = Alignment.CenterVertically) {
+                            SecondaryButton("Hardware") { host.open = null; a.onHardwareKeyboard() }
+                            Spacer(Modifier.width(8.dp))
+                            SecondaryButton("Android") { host.open = null; a.onKeyboard() }
+                        }
+                    }
                }

                if (a.steam && a.secondScreenDisplays.isNotEmpty()) SettingsGroup("Second screen") {
@@ -36,3 +36,18 @@ swaybg -m fill -i /usr/share/backgrounds/steamdeck.png &
 run pcmanfm-qt pcmanfm-qt --desktop --profile lxqt
 run lxqt-panel lxqt-panel
 /usr/lib/xdg-desktop-portal-wlr >/dev/null 2>&1 &
+# Remote runs, for driving the desktop from a debugger: with ~/.droiddeck-remote-run present (only
+# the app or root can create it), each script dropped into ~/.cache/droiddeck/run/ is run once,
+# inside the session with its environment, its output tagged into the desktop log.
+if [ -f "$HOME/.droiddeck-remote-run" ]; then
+  mkdir -p "$HOME/.cache/droiddeck/run"
+  (
+    while sleep 1; do
+      for f in "$HOME"/.cache/droiddeck/run/*.sh; do
+        [ -f "$f" ] || continue
+        mv -f "$f" "$f.running" || continue
+        ( echo "[run] $(basename "$f") started"; bash "$f.running" 2>&1 | sed "s/^/[run] /"; echo "[run] $(basename "$f") exited"; rm -f "$f.running" ) &
+      done
+    done
+  ) &
+fi
@@ -14,9 +14,37 @@ export QT_QPA_PLATFORMTHEME=lxqt
 # The prefs for this are only advisory and a profile can override them; the environment is not.
 export MOZ_DISABLE_CONTENT_SANDBOX=1 MOZ_DISABLE_GMP_SANDBOX=1 MOZ_DISABLE_RDD_SANDBOX=1
 export MOZ_DISABLE_SOCKET_PROCESS_SANDBOX=1 MOZ_DISABLE_UTILITY_SANDBOX=1
-# wlroots allocates through gbm on a real DRM node, which the KGSL stand-in is not: pixman
-# (software, shm) is what boots here. BL_WLR_RENDERER=vulkan/gles2 tries acceleration.
-export WLR_RENDERER=${BL_WLR_RENDERER:-pixman}
+# pixman composites in software and gives programs shm buffers only, so a Vulkan program on it
+# fails at its swapchain. vulkan (or gles2) composite on the GPU and give programs DMA-BUFs, but
+# stock wlroots allocates through gbm on a real DRM node and the KGSL stand-in is not one ("unable
+# to create allocator"): they need the app's patched wlroots (tools/wlroots), whose Vulkan
+# allocator exports the buffers instead. BL_WLR_RENDERER picks; see the fallback at the end.
+export WLR_RENDERER=${BL_WLR_RENDERER:-vulkan}
+WLROOTS_DIR=/usr/local/lib/droiddeck-wlroots
+BASE_LD_LIBRARY_PATH=${LD_LIBRARY_PATH:-}
+use_renderer() {
+  export WLR_RENDERER=$1
+  if [ "$1" != pixman ] && [ -f "$WLROOTS_DIR/libwlroots-0.20.so" ]; then
+    export LD_LIBRARY_PATH=$WLROOTS_DIR${BASE_LD_LIBRARY_PATH:+:$BASE_LD_LIBRARY_PATH}
+  elif [ -n "$BASE_LD_LIBRARY_PATH" ]; then
+    export LD_LIBRARY_PATH=$BASE_LD_LIBRARY_PATH
+  else
+    unset LD_LIBRARY_PATH
+  fi
+}
+use_renderer "$WLR_RENDERER"
+# A GPU renderer that failed to start here is not tried again on every desktop start (each try costs
+# up to 20 s): the failure is kept with what it failed on - the renderer, the patched wlroots and the
+# Linux driver - so an app update or a different driver retries, and so does picking a renderer
+# again in the app's settings (which deletes the file).
+FAILED_FILE=$HOME/.droiddeck-renderer-failed
+renderer_key() {
+  echo "$WLR_RENDERER $(md5sum "$WLROOTS_DIR/libwlroots-0.20.so" 2>/dev/null | cut -d' ' -f1) ${BL_VK_DRIVER:-runtime}"
+}
+if [ "$WLR_RENDERER" != pixman ] && [ "$(cat "$FAILED_FILE" 2>/dev/null)" = "$(renderer_key)" ]; then
+  echo "== droiddeck-desktop: $WLR_RENDERER failed to start here before; using pixman (choose a renderer in the settings to retry)"
+  use_renderer pixman
+fi
 # The desktop's own log, beside the session's, so labwc and the programs on it can be read apart
 # from the session that started them. The session log keeps the milestones either way.
 if [ -n "${BL_DEBUG_DIR:-}" ]; then
@@ -85,12 +113,86 @@ export BL_DESKTOP=1
 ln -sf /usr/local/bin/bannerlator-steam-launch /usr/local/bin/steamdeck-steam 2>/dev/null
 ln -sf /usr/local/bin/bannerlator-steam-shim /usr/local/bin/steam 2>/dev/null
 python3 /usr/local/bin/bannerlator-desktop-games 2>&1 | sed 's/^/[games] /'
+# Player 1 on the controller in every emulator that has no profile of its own yet - now, and again
+# every half minute: an emulator started for the first time writes its own config, which is then
+# given the controller for its next start without waiting for the next desktop.
+python3 /usr/local/bin/bannerlator-pad-defaults 2>&1 | sed 's/^/[pads] /'
+( while sleep 30; do python3 /usr/local/bin/bannerlator-pad-defaults 2>&1 | sed 's/^/[pads] /'; done ) &
+# Games and emulators from the menu run through droiddeck-gpu (their own gamescope on the app's
+# compositor) while the desktop is on pixman, where they could not draw with the GPU.
+# BL_DESKTOP_GPU=on/off overrides; each entry keeps "Run in a desktop window" either way.
+gpu_entries() { python3 /usr/local/bin/droiddeck-desktop-gpu 2>&1 | sed 's/^/[gpu] /'; }
+gpu_entries

-echo "== droiddeck-desktop: labwc ($WLR_RENDERER) on $WAYLAND_DISPLAY"
-# ~/.droiddeck-desktop-debug: labwc's own debug log (views and layer surfaces mapping) too.
-DEBUG=; [ -f "$HOME/.droiddeck-desktop-debug" ] && DEBUG=-d
-# A session bus: the panel's menus, the file manager and the portal all expect one.
-if command -v dbus-run-session >/dev/null 2>&1; then
-  exec dbus-run-session -- labwc $DEBUG -C "$HOME/.config/labwc"
+# ~/.droiddeck-desktop-debug: labwc's own debug log (views and layer surfaces mapping) too. The GPU
+# renderers are experimental and always log in full, so a desktop that does not come up says why.
+DEBUG=; { [ -f "$HOME/.droiddeck-desktop-debug" ] || [ "$WLR_RENDERER" != pixman ]; } && DEBUG=-d
+run_labwc() {
+  echo "== droiddeck-desktop: labwc ($WLR_RENDERER${LD_LIBRARY_PATH:+, wlroots from $WLROOTS_DIR}) on $WAYLAND_DISPLAY"
+  # A session bus: the panel's menus, the file manager and the portal all expect one.
+  if command -v dbus-run-session >/dev/null 2>&1; then
+    dbus-run-session -- labwc $DEBUG -C "$HOME/.config/labwc"
+  else
+    labwc $DEBUG -C "$HOME/.config/labwc"
+  fi
+}
+pids_named() {
+  local p
+  for p in /proc/[0-9]*; do
+    [ "$(cat "$p/comm" 2>/dev/null)" = "$1" ] && echo "${p#/proc/}"
+  done
+}
+# labwc answers on its own socket (the one beside the app's wayland-0) once its event loop runs; a
+# labwc stuck on the GPU never does.
+labwc_answers() {
+  local sock
+  for sock in "$XDG_RUNTIME_DIR"/wayland-*; do
+    case $sock in *.lock|*/wayland-0) continue ;; esac
+    [ -S "$sock" ] || continue
+    WAYLAND_DISPLAY=${sock##*/} timeout 3 wayland-info >/dev/null 2>&1 && return 0
+  done
+  return 1
+}
+if [ "$WLR_RENDERER" = pixman ]; then
+  run_labwc
+  exit $?
 fi
-exec labwc $DEBUG -C "$HOME/.config/labwc"
+# A GPU renderer this device cannot start either ends the desktop at once or leaves it hanging on
+# the loading screen. Either way the desktop comes up on pixman instead, and the log says why.
+started=$(date +%s)
+run_labwc &
+labwc_job=$!
+answered=
+while kill -0 "$labwc_job" 2>/dev/null; do
+  if labwc_answers; then answered=1; break; fi
+  [ $(( $(date +%s) - started )) -ge 20 ] && break
+  sleep 1
+done
+if [ -n "$answered" ]; then
+  echo "== droiddeck-desktop: labwc on $WLR_RENDERER is up after $(( $(date +%s) - started )) s"
+  wait "$labwc_job"
+  exit $?
+fi
+if kill -0 "$labwc_job" 2>/dev/null; then
+  echo "== droiddeck-desktop: labwc on $WLR_RENDERER did not answer in 20 s; stopping it"
+  kill -TERM $(pids_named labwc) 2>/dev/null
+  sleep 2
+  kill -KILL $(pids_named labwc) 2>/dev/null
+  for prog in lxqt-panel pcmanfm-qt swaybg Xwayland; do kill -KILL $(pids_named "$prog") 2>/dev/null; done
+  wait "$labwc_job" 2>/dev/null
+  rc=124
+else
+  wait "$labwc_job"
+  rc=$?
+fi
+if [ "$rc" -ne 0 ] && [ $(( $(date +%s) - started )) -lt 40 ]; then
+  echo "== droiddeck-desktop: labwc on $WLR_RENDERER failed at start (exit $rc); starting on pixman instead"
+  renderer_key > "$FAILED_FILE"
+  use_renderer pixman
+  DEBUG=; [ -f "$HOME/.droiddeck-desktop-debug" ] && DEBUG=-d
+  find "$XDG_RUNTIME_DIR" -mindepth 1 -maxdepth 1 ! -name 'wayland-0*' ! -name 'keymap.xkb' -exec rm -rf {} + 2>/dev/null
+  gpu_entries
+  run_labwc
+  rc=$?
+fi
+exit $rc
@@ -0,0 +1,123 @@
+#!/usr/bin/python3
+# The desktop's games and emulators, started on the GPU. Every menu entry whose categories say
+# Game or Emulator gets a copy of its own in ~/.local/share/applications (which wins over
+# /usr/share/applications) whose Exec runs it through droiddeck-gpu: full screen on the app's
+# compositor, where Vulkan and OpenGL work. The entry keeps the old way as a second action, "Run in
+# a desktop window". Run at every desktop start; copies whose original is gone, or all of them when
+# the switch is off, are removed.
+#
+#   BL_DESKTOP_GPU=auto (default: on while the desktop is composited by pixman) | on | off
+import os
+import re
+
+HOME = os.environ.get("HOME", "/root")
+SYSTEM_DIR = "/usr/share/applications"
+USER_DIR = os.path.join(HOME, ".local/share/applications")
+MARK = "X-DroidDeck-GPU=1"
+# The client and its games already hand themselves to the app (bannerlator-steam-launch).
+SKIP = re.compile(r"^(steam|droiddeck-game-|droiddeck-steam|steamdeck-)", re.I)
+
+
+def enabled():
+    mode = os.environ.get("BL_DESKTOP_GPU", "auto").strip().lower()
+    if mode in ("on", "1", "yes", "true"):
+        return True
+    if mode in ("off", "0", "no", "false"):
+        return False
+    return os.environ.get("WLR_RENDERER", "pixman") == "pixman"
+
+
+def main_group(text):
+    """The [Desktop Entry] group's lines, and everything after it."""
+    lines = text.splitlines()
+    start = next((i for i, l in enumerate(lines) if l.strip() == "[Desktop Entry]"), None)
+    if start is None:
+        return None, None, None
+    end = next((i for i in range(start + 1, len(lines)) if lines[i].startswith("[")), len(lines))
+    return lines[:start + 1], lines[start + 1:end], lines[end:]
+
+
+def wrap(text):
+    head, group, rest = main_group(text)
+    if group is None:
+        return None
+    keys = {}
+    for l in group:
+        if "=" in l and not l.lstrip().startswith("#"):
+            k, v = l.split("=", 1)
+            keys.setdefault(k.strip(), v)
+    cats = set(filter(None, keys.get("Categories", "").split(";")))
+    if not cats & {"Game", "Emulator"}:
+        return None
+    if keys.get("Type", "Application") != "Application" or keys.get("NoDisplay", "").lower() == "true":
+        return None
+    exec_line = keys.get("Exec", "").strip()
+    if not exec_line or exec_line.startswith("droiddeck-gpu "):
+        return None
+    out_group = []
+    actions = keys.get("Actions", "")
+    for l in group:
+        k = l.split("=", 1)[0].strip() if "=" in l else None
+        if k == "Exec":
+            out_group.append("Exec=droiddeck-gpu " + exec_line)
+        elif k == "Actions":
+            continue
+        else:
+            out_group.append(l)
+    while out_group and not out_group[-1].strip():
+        out_group.pop()
+    out_group.append("Actions=" + ("droiddeck-window;" + actions if actions else "droiddeck-window;"))
+    out_group.append(MARK)
+    window = ["", "[Desktop Action droiddeck-window]", "Name=Run in a desktop window", "Exec=" + exec_line]
+    # The entry's own actions (new window, a different mode...) run on the GPU as well.
+    wrapped_rest = []
+    for l in rest:
+        if l.startswith("Exec=") and not l[5:].startswith("droiddeck-gpu "):
+            l = "Exec=droiddeck-gpu " + l[5:]
+        wrapped_rest.append(l)
+    if wrapped_rest and wrapped_rest[0].strip():
+        wrapped_rest.insert(0, "")
+    return "\n".join(head + out_group + window + wrapped_rest) + "\n"
+
+
+def ours(path):
+    try:
+        with open(path, encoding="utf-8", errors="replace") as f:
+            return MARK in f.read()
+    except OSError:
+        return False
+
+
+def main():
+    on = enabled()
+    os.makedirs(USER_DIR, exist_ok=True)
+    written = set()
+    if on and os.path.isdir(SYSTEM_DIR):
+        for name in sorted(os.listdir(SYSTEM_DIR)):
+            if not name.endswith(".desktop") or SKIP.match(name):
+                continue
+            target = os.path.join(USER_DIR, name)
+            # A copy the user made or edited themselves is theirs.
+            if os.path.exists(target) and not ours(target):
+                continue
+            try:
+                with open(os.path.join(SYSTEM_DIR, name), encoding="utf-8", errors="replace") as f:
+                    text = wrap(f.read())
+            except OSError:
+                continue
+            if text is None:
+                continue
+            with open(target + ".tmp", "w", encoding="utf-8") as f:
+                f.write(text)
+            os.replace(target + ".tmp", target)
+            written.add(name)
+    removed = 0
+    for name in os.listdir(USER_DIR):
+        path = os.path.join(USER_DIR, name)
+        if name.endswith(".desktop") and name not in written and ours(path):
+            os.remove(path)
+            removed += 1
+    print(f"droiddeck-desktop-gpu: {'on' if on else 'off'}, {len(written)} entries on the GPU, {removed} removed")
+
+
+main()
@@ -0,0 +1,32 @@
+#!/bin/bash
+# Runs a program from the desktop on the GPU: in a gamescope of its own that draws straight into
+# the app's compositor (wayland-0), not inside labwc. The desktop is composited by pixman, and
+# pixman gives its windows no DMA-BUFs - a Vulkan program there fails at its swapchain
+# (VK_ERROR_SURFACE_LOST, RPCS3's error). Here it gets the same path as a program started from the
+# app's rail: full screen over the desktop until it exits, then the desktop is back.
+#   droiddeck-gpu <program> [args...]
+set -u
+[ $# -gt 0 ] || { echo "usage: droiddeck-gpu <program> [args...]" >&2; exit 64; }
+if [ -n "${BL_DEBUG_DIR:-}" ]; then
+  exec >>"$BL_DEBUG_DIR/desktop.log" 2>&1
+fi
+width=${BL_WIDTH:-1280}
+height=${BL_HEIGHT:-720}
+args=(--backend wayland --expose-wayland -f -W "$width" -H "$height" -w "$width" -h "$height")
+if [ "${BL_FPS:-0}" -gt 0 ]; then
+  args+=(-r "$BL_FPS")
+elif [ "${BL_REFRESH:-0}" -gt 0 ]; then
+  args+=(-r "$BL_REFRESH")
+fi
+[ "${BL_HDR:-0}" = 1 ] && args+=(--hdr-enabled)
+echo "== droiddeck-gpu $(date -u +%H:%M:%S): $* (gamescope ${width}x${height} on wayland-0)"
+# gamescope is a client of the app's compositor, beside labwc; the program inside it reaches it
+# through gamescope's own Xwayland, as in a Steam session.
+export WAYLAND_DISPLAY=wayland-0
+export GDK_BACKEND=x11 QT_QPA_PLATFORM=xcb SDL_VIDEODRIVER=x11
+# AppImages cannot mount under proot; the menu entries already say so, a hand-typed one may not.
+export APPIMAGE_EXTRACT_AND_RUN=1
+gamescope "${args[@]}" -- "$@"
+rc=$?
+echo "== droiddeck-gpu $(date -u +%H:%M:%S): exited $rc"
+exit $rc
@@ -0,0 +1,457 @@
+#!/usr/bin/python3
+# Player 1 on the session's controller, for every emulator that would otherwise start on the
+# keyboard. The session's pad is an Xbox 360 controller (libfakeinput's identity outside Steam) that
+# SDL maps by itself; what an emulator lacks is a profile that points Player 1 at it. One is
+# written only where the emulator has none yet - a profile the user made is never touched.
+# Run at every desktop start and before every program from the rail.
+import os
+
+HOME = os.environ.get("HOME", "/root")
+CONFIG = os.environ.get("XDG_CONFIG_HOME", os.path.join(HOME, ".config"))
+
+
+def seed(path, text, what, done="Player 1 on the controller"):
+    if os.path.exists(path):
+        return False
+    os.makedirs(os.path.dirname(path), exist_ok=True)
+    with open(path + ".tmp", "w", encoding="utf-8") as f:
+        f.write(text)
+    os.replace(path + ".tmp", path)
+    print(f"bannerlator-pad-defaults: {what}: {done} ({path})")
+    return True
+
+
+# RPCS3: its global input configuration (rpcs3::utils::get_input_config_dir() + "Default.yml").
+# Without one it adds the keyboard pad handler (pad_config.cpp, cfg_input::load). SDL handler
+# names from rpcs3/Input/sdl_pad_handler.cpp (button_list, init_config); the device is
+# "<SDL gamepad name> <n>" (sdl_pad_handler::enumerate_devices).
+RPCS3_PLAYER1 = """Player 1 Input:
+  Handler: SDL
+  Device: Xbox 360 Controller 1
+  Config:
+    Left Stick Left: LS X-
+    Left Stick Down: LS Y-
+    Left Stick Right: LS X+
+    Left Stick Up: LS Y+
+    Right Stick Left: RS X-
+    Right Stick Down: RS Y-
+    Right Stick Right: RS X+
+    Right Stick Up: RS Y+
+    Start: Start
+    Select: Back
+    PS Button: Guide
+    Square: West
+    Cross: South
+    Circle: East
+    Triangle: North
+    Left: Left
+    Down: Down
+    Right: Right
+    Up: Up
+    R1: RB
+    R2: RT
+    R3: RS
+    L1: LB
+    L2: LT
+    L3: LS
+    Left Stick Deadzone: 8000
+    Right Stick Deadzone: 8000
+    Left Stick Anti-Deadzone: 4259
+    Right Stick Anti-Deadzone: 4259
+    Left Trigger Threshold: 0
+    Right Trigger Threshold: 0
+    Color Value B: 20
+    LED battery indicator brightness: 10
+  Buddy Device: ""
+"""
+
+
+def rpcs3():
+    seed(os.path.join(CONFIG, "rpcs3/input_configs/global/Default.yml"), RPCS3_PLAYER1, "RPCS3")
+    rpcs3_shader_mode()
+
+
+# RPCS3's default shader mode (Async Recompiler with Shader Interpreter) builds 6650 interpreter
+# pipelines at the start of every boot, minutes on an Adreno. The async recompiler compiles only
+# what a game draws, in the background, once. A new install starts with it (a config.yml that
+# holds only this is merged over RPCS3's defaults); an existing one still on the default is moved
+# once, and a marker keeps any later choice the user makes in RPCS3's own settings.
+RPCS3_INTERPRETER = "Async Recompiler with Shader Interpreter"
+RPCS3_RECOMPILER = "Async Recompiler (multi-threaded)"  # the GUI says "Async Shader Recompiler"; this is the value (system_config_types.cpp)
+
+
+def rpcs3_shader_mode():
+    d = os.path.join(CONFIG, "rpcs3")
+    marker = os.path.join(d, ".droiddeck-shader-mode")
+    if os.path.exists(marker):
+        return
+    cfg = os.path.join(d, "config.yml")
+    if not os.path.isfile(cfg):
+        if seed(cfg, f"Video:\n  Shader Mode: {RPCS3_RECOMPILER}\n", "RPCS3", f"shader mode {RPCS3_RECOMPILER}"):
+            open(marker, "w").close()
+        return
+    with open(cfg, encoding="utf-8", errors="replace") as f:
+        text = f.read()
+    if f"Shader Mode: {RPCS3_INTERPRETER}" in text:
+        text = text.replace(f"Shader Mode: {RPCS3_INTERPRETER}", f"Shader Mode: {RPCS3_RECOMPILER}", 1)
+        with open(cfg + ".tmp", "w", encoding="utf-8") as f:
+            f.write(text)
+        os.replace(cfg + ".tmp", cfg)
+        print(f"bannerlator-pad-defaults: RPCS3: shader mode {RPCS3_RECOMPILER} ({cfg})")
+    open(marker, "w").close()
+
+
+# ---- ini helpers (DuckStation and PCSX2 share one ini dialect, keys may repeat) -------------
+
+def ini_section(lines, name):
+    """(start, end) line indices of [name]'s body, or None."""
+    start = None
+    for i, l in enumerate(lines):
+        t = l.strip()
+        if t.startswith("[") and t.endswith("]"):
+            if start is not None:
+                return start, i
+            if t[1:-1].strip() == name:
+                start = i + 1
+    return (start, len(lines)) if start is not None else None
+
+
+def patch_ini_section(path, section, body, what, needle="SDL-", require=None):
+    """Add body's lines to [section] of an ini the emulator wrote itself, unless the section
+    already binds a controller (needle). Missing file: nothing - the emulator writes its own
+    defaults on first run and this runs again."""
+    if not os.path.isfile(path):
+        return
+    with open(path, encoding="utf-8", errors="replace") as f:
+        text = f.read()
+    if require and require not in text:
+        return
+    lines = text.splitlines()
+    span = ini_section(lines, section)
+    if span and any(needle in l for l in lines[span[0]:span[1]]):
+        return
+    new = body.strip("\n").splitlines()
+    if span:
+        # The controller type the emulator already wrote stays; only bindings are added.
+        have = {l.split("=", 1)[0].strip() for l in lines[span[0]:span[1]] if "=" in l}
+        new = [l for l in new if not (l.split("=", 1)[0].strip() == "Type" and "Type" in have)]
+        end = span[1]
+        while end > span[0] and not lines[end - 1].strip():
+            end -= 1
+        lines[end:end] = new
+    else:
+        lines += ["", f"[{section}]"] + new
+    with open(path + ".tmp", "w", encoding="utf-8") as f:
+        f.write("\n".join(lines) + "\n")
+    os.replace(path + ".tmp", path)
+    print(f"bannerlator-pad-defaults: {what}: Player 1 on the controller ({path})")
+
+
+# DuckStation: SDL-<n>/<name>, axes signed (src/util/sdl_input_source.cpp); Pad1 keys from
+# src/core/analog_controller.cpp. Its defaults bind the keyboard only (settings.cpp).
+DUCKSTATION_PAD1 = """Type = AnalogController
+Up = SDL-0/DPadUp
+Down = SDL-0/DPadDown
+Left = SDL-0/DPadLeft
+Right = SDL-0/DPadRight
+Cross = SDL-0/A
+Circle = SDL-0/B
+Square = SDL-0/X
+Triangle = SDL-0/Y
+Select = SDL-0/Back
+Start = SDL-0/Start
+Analog = SDL-0/Guide
+L1 = SDL-0/LeftShoulder
+R1 = SDL-0/RightShoulder
+L2 = SDL-0/+LeftTrigger
+R2 = SDL-0/+RightTrigger
+L3 = SDL-0/LeftStick
+R3 = SDL-0/RightStick
+LLeft = SDL-0/-LeftX
+LRight = SDL-0/+LeftX
+LUp = SDL-0/-LeftY
+LDown = SDL-0/+LeftY
+RLeft = SDL-0/-RightX
+RRight = SDL-0/+RightX
+RUp = SDL-0/-RightY
+RDown = SDL-0/+RightY
+LargeMotor = SDL-0/LargeMotor
+SmallMotor = SDL-0/SmallMotor
+"""
+
+
+def duckstation():
+    for d in (os.path.join(CONFIG, "duckstation"), os.path.join(HOME, ".local/share/duckstation")):
+        patch_ini_section(os.path.join(d, "settings.ini"), "Pad1", DUCKSTATION_PAD1, "DuckStation")
+
+
+# PCSX2: FaceSouth/... names (pcsx2/Input/SDLInputSource.cpp), keys from SIO/Pad/PadDualshock2.cpp.
+# An ini without [UI] SettingsVersion is thrown away and rebuilt, so only a complete one is patched.
+PCSX2_PAD1 = """Type = DualShock2
+Up = SDL-0/DPadUp
+Right = SDL-0/DPadRight
+Down = SDL-0/DPadDown
+Left = SDL-0/DPadLeft
+Triangle = SDL-0/FaceNorth
+Circle = SDL-0/FaceEast
+Cross = SDL-0/FaceSouth
+Square = SDL-0/FaceWest
+Select = SDL-0/Back
+Start = SDL-0/Start
+L1 = SDL-0/LeftShoulder
+R1 = SDL-0/RightShoulder
+L2 = SDL-0/+LeftTrigger
+R2 = SDL-0/+RightTrigger
+L3 = SDL-0/LeftStick
+R3 = SDL-0/RightStick
+Analog = SDL-0/Guide
+LUp = SDL-0/-LeftY
+LRight = SDL-0/+LeftX
+LDown = SDL-0/+LeftY
+LLeft = SDL-0/-LeftX
+RUp = SDL-0/-RightY
+RRight = SDL-0/+RightX
+RDown = SDL-0/+RightY
+RLeft = SDL-0/-RightX
+LargeMotor = SDL-0/LargeMotor
+SmallMotor = SDL-0/SmallMotor
+"""
+
+
+def pcsx2():
+    patch_ini_section(os.path.join(CONFIG, "PCSX2/inis/PCSX2.ini"), "Pad1", PCSX2_PAD1, "PCSX2",
+                      require="SettingsVersion")
+
+
+# Dolphin: SDL/<id>/<SDL gamepad name>; control names from InputCommon/.../SDL/SDLGamepad.h (Left Y+
+# is up). A section that exists is taken whole - keys it lacks are unbound - so both are complete.
+DOLPHIN_GC = """[GCPad1]
+Device = SDL/0/Xbox 360 Controller
+Buttons/A = `Button S`
+Buttons/B = `Button W`
+Buttons/X = `Button E`
+Buttons/Y = `Button N`
+Buttons/Z = `Shoulder R`
+Buttons/Start = `Start`
+Main Stick/Up = `Left Y+`
+Main Stick/Down = `Left Y-`
+Main Stick/Left = `Left X-`
+Main Stick/Right = `Left X+`
+C-Stick/Up = `Right Y+`
+C-Stick/Down = `Right Y-`
+C-Stick/Left = `Right X-`
+C-Stick/Right = `Right X+`
+Triggers/L = `Trigger L`
+Triggers/R = `Trigger R`
+Triggers/L-Analog = `Trigger L`
+Triggers/R-Analog = `Trigger R`
+D-Pad/Up = `Pad N`
+D-Pad/Down = `Pad S`
+D-Pad/Left = `Pad W`
+D-Pad/Right = `Pad E`
+Rumble/Motor = `Motor`
+"""
+DOLPHIN_WII = """[Wiimote1]
+Device = SDL/0/Xbox 360 Controller
+Source = 1
+Buttons/A = `Button S`
+Buttons/B = `Trigger R`
+Buttons/1 = `Button W`
+Buttons/2 = `Button N`
+Buttons/- = `Back`
+Buttons/+ = `Start`
+Buttons/Home = `Guide`
+D-Pad/Up = `Pad N`
+D-Pad/Down = `Pad S`
+D-Pad/Left = `Pad W`
+D-Pad/Right = `Pad E`
+IR/Up = `Right Y+`
+IR/Down = `Right Y-`
+IR/Left = `Right X-`
+IR/Right = `Right X+`
+Shake/X = `Button E`
+Shake/Y = `Button E`
+Shake/Z = `Button E`
+Rumble/Motor = `Motor`
+Extension = Nunchuk
+Nunchuk/Buttons/C = `Shoulder L`
+Nunchuk/Buttons/Z = `Trigger L`
+Nunchuk/Stick/Up = `Left Y+`
+Nunchuk/Stick/Down = `Left Y-`
+Nunchuk/Stick/Left = `Left X-`
+Nunchuk/Stick/Right = `Left X+`
+"""
+
+
+def dolphin():
+    d = os.path.join(CONFIG, "dolphin-emu")
+    seed(os.path.join(d, "GCPadNew.ini"), DOLPHIN_GC, "Dolphin (GameCube)")
+    seed(os.path.join(d, "WiimoteNew.ini"), DOLPHIN_WII, "Dolphin (Wii)")
+
+
+# Cemu: an SDLController profile for the GamePad. The uuid is "<index>_<SDL GUID>" and SDL's GUID
+# carries a CRC of the device name; this is the one SDL reports for the session's pad
+# ("Xbox 360 Controller (0)", 045e:028e - read from RPCS3's SDL log on the device). Mapping ids
+# from VPADController.h, values from Controller.h, Cemu's own SDL default layout plus Home.
+CEMU_MAP = [(1, 1), (2, 0), (3, 3), (4, 2), (5, 9), (6, 10), (7, 42), (8, 43), (9, 6), (10, 4),
+            (11, 11), (12, 12), (13, 13), (14, 14), (15, 7), (16, 8), (17, 45), (18, 39), (19, 44),
+            (20, 38), (21, 47), (22, 41), (23, 46), (24, 40), (27, 5)]
+CEMU_XML = """<?xml version="1.0" encoding="UTF-8"?>
+<emulated_controller>
+\t<type>Wii U GamePad</type>
+\t<toggle_display>0</toggle_display>
+\t<controller>
+\t\t<api>SDLController</api>
+\t\t<uuid>0_03005e615e0400008e02000010010000</uuid>
+\t\t<display_name>Xbox 360 Controller</display_name>
+\t\t<rumble>0.5</rumble>
+\t\t<mappings>
+""" + "".join(f"\t\t\t<entry>\n\t\t\t\t<mapping>{m}</mapping>\n\t\t\t\t<button>{b}</button>\n\t\t\t</entry>\n" for m, b in CEMU_MAP) + """\t\t</mappings>
+\t</controller>
+</emulated_controller>
+"""
+
+
+def cemu():
+    seed(os.path.join(CONFIG, "Cemu/controllerProfiles/controller0.xml"), CEMU_XML, "Cemu")
+
+
+# melonDS 1.x: raw SDL joystick indices. The session's pad has the kernel's Xbox 360 layout
+# (buttons A B X Y LB RB Back Start Guide LS RS = 0..10, hat 0 for the d-pad); the d-pad values
+# also take the left stick (EmuInstanceInput.cpp; encoding InputConfig/MapButton.h).
+MELONDS_JOY = """[Instance0.Joystick]
+A = 1
+B = 0
+X = 3
+Y = 2
+L = 4
+R = 5
+Select = 6
+Start = 7
+Up = 17891585
+Down = 16843012
+Left = 1114376
+Right = 65794
+"""
+
+
+def melonds():
+    path = os.path.join(CONFIG, "melonDS/melonDS.toml")
+    if not os.path.isfile(path):
+        seed(path, "[Instance0]\nJoystickID = 0\n\n" + MELONDS_JOY, "melonDS")
+        return
+    with open(path, encoding="utf-8", errors="replace") as f:
+        text = f.read()
+    try:
+        import tomllib
+        joy = tomllib.loads(text).get("Instance0", {}).get("Joystick", {})
+    except Exception:
+        return
+    if any(isinstance(v, int) and v != -1 for v in joy.values()):
+        return  # something is bound already
+    # Replace melonDS's own all-unbound table with ours (a TOML table can be defined only once).
+    out, skipping = [], False
+    for line in text.splitlines():
+        t = line.strip()
+        if t.startswith("["):
+            skipping = t == "[Instance0.Joystick]"
+        if not skipping:
+            out.append(line)
+    with open(path + ".tmp", "w", encoding="utf-8") as f:
+        f.write("\n".join(out).rstrip("\n") + "\n\n" + MELONDS_JOY)
+    os.replace(path + ".tmp", path)
+    print(f"bannerlator-pad-defaults: melonDS: Player 1 on the controller ({path})")
+
+
+# PPSSPP (SDL): its pad defaults leave the shoulders, the right stick and the triggers unbound on
+# SDL builds (SDLJoystick.cpp codes vs KeyMapDefaults.cpp); a [ControlMapping] that exists replaces
+# every default, so this one is complete, keyboard included (device 1 keyboard, 10 pad).
+PPSSPP_CONTROLS = """[ControlMapping]
+Up = 1-19,10-19
+Down = 1-20,10-20
+Left = 1-21,10-21
+Right = 1-22,10-22
+Cross = 1-54,10-189
+Circle = 1-52,10-190
+Square = 1-29,10-191
+Triangle = 1-47,10-188
+Start = 1-62,10-197
+Select = 1-66,10-196
+L = 1-45,10-193
+R = 1-51,10-192
+An.Up = 1-37,10-4003
+An.Down = 1-39,10-4002
+An.Left = 1-38,10-4001
+An.Right = 1-40,10-4000
+RightAn.Up = 10-4007
+RightAn.Down = 10-4006
+RightAn.Left = 10-4005
+RightAn.Right = 10-4004
+Pause = 1-111,10-4
+"""
+
+
+def ppsspp():
+    seed(os.path.join(CONFIG, "ppsspp/PSP/SYSTEM/controls.ini"), PPSSPP_CONTROLS, "PPSSPP")
+
+
+# RetroArch: the udev joypad driver finds nothing here (no udev database in the runtime); sdl2
+# does, and matches this profile by vendor/product (task_autodetect.c).
+RETROARCH_PROFILE = """input_driver = "sdl2"
+input_device = "Xbox 360 Controller"
+input_vendor_id = "1118"
+input_product_id = "654"
+input_b_btn = "0"
+input_a_btn = "1"
+input_y_btn = "2"
+input_x_btn = "3"
+input_select_btn = "4"
+input_menu_toggle_btn = "5"
+input_start_btn = "6"
+input_l3_btn = "7"
+input_r3_btn = "8"
+input_l_btn = "9"
+input_r_btn = "10"
+input_up_btn = "11"
+input_down_btn = "12"
+input_left_btn = "13"
+input_right_btn = "14"
+input_l2_axis = "+4"
+input_r2_axis = "+5"
+input_l_x_plus_axis = "+0"
+input_l_x_minus_axis = "-0"
+input_l_y_plus_axis = "+1"
+input_l_y_minus_axis = "-1"
+input_r_x_plus_axis = "+2"
+input_r_x_minus_axis = "-2"
+input_r_y_plus_axis = "+3"
+input_r_y_minus_axis = "-3"
+"""
+
+
+def retroarch():
+    d = os.path.join(CONFIG, "retroarch")
+    seed(os.path.join(d, "autoconfig/sdl2/Xbox 360 Controller.cfg"), RETROARCH_PROFILE, "RetroArch (profile)")
+    cfg = os.path.join(d, "retroarch.cfg")
+    if not os.path.isfile(cfg):
+        seed(cfg, 'input_joypad_driver = "sdl2"\ninput_autodetect_enable = "true"\n', "RetroArch")
+        return
+    with open(cfg, encoding="utf-8", errors="replace") as f:
+        lines = f.read().splitlines()
+    changed = False
+    for i, l in enumerate(lines):
+        if l.replace(" ", "").startswith('input_joypad_driver="udev"'):
+            lines[i] = 'input_joypad_driver = "sdl2"'
+            changed = True
+    if changed:
+        with open(cfg + ".tmp", "w", encoding="utf-8") as f:
+            f.write("\n".join(lines) + "\n")
+        os.replace(cfg + ".tmp", cfg)
+        print(f"bannerlator-pad-defaults: RetroArch: joypad driver udev -> sdl2 ({cfg})")
+
+
+for step in (rpcs3, duckstation, pcsx2, dolphin, cemu, melonds, ppsspp, retroarch):
+    try:
+        step()
+    except Exception as e:
+        print(f"bannerlator-pad-defaults: {step.__name__}: {e}")
@@ -79,6 +79,28 @@ export XDG_CONFIG_HOME=${XDG_CONFIG_HOME:-$HOME/.config}
 export XDG_CACHE_HOME=${XDG_CACHE_HOME:-$HOME/.cache}
 mkdir -p "$XDG_DATA_HOME" "$XDG_CONFIG_HOME" "$XDG_CACHE_HOME"

+# The cores a program runs on outside Steam (the desktop and everything started from it, a
+# program from the rail): the user's game cores when set (BL_GAME_CPUS), else every core but the
+# slowest cluster - Android is free to park an emulator's threads on the little cores, and those
+# are what compile shaders and recompile PPU/SPU code. BL_PIN_CORES=0 leaves the scheduler alone.
+program_cores() {
+  [ "${BL_PIN_CORES:-1}" = 0 ] && return 0
+  command -v taskset >/dev/null 2>&1 || return 0
+  if [ -n "${BL_GAME_CPUS:-}" ]; then echo "$BL_GAME_CPUS"; return 0; fi
+  local f n max min= list=
+  for f in /sys/devices/system/cpu/cpu[0-9]*/cpufreq/cpuinfo_max_freq; do
+    max=$(cat "$f" 2>/dev/null) || continue
+    [ -z "$min" ] || [ "$max" -lt "$min" ] && min=$max
+  done
+  [ -n "$min" ] || return 0
+  for f in /sys/devices/system/cpu/cpu[0-9]*/cpufreq/cpuinfo_max_freq; do
+    max=$(cat "$f" 2>/dev/null) || continue
+    n=${f#/sys/devices/system/cpu/cpu}; n=${n%%/*}
+    [ "$max" -gt "$min" ] && list="$list${list:+,}$n"
+  done
+  echo "$list"
+}
+
 if [ -z "${BL_INSIDE:-}" ]; then
  # The compositor may still be starting, and a socket left by an earlier session is not
  # a compositor: probe until a connection succeeds.
@@ -91,6 +113,11 @@ if [ -z "${BL_INSIDE:-}" ]; then
  if [ "$mode" = lxqt ]; then
    step "starting the desktop"
    [ -x /usr/local/bin/droiddeck-desktop ] || { echo "== the desktop package is not installed"; exit 66; }
+    cores=$(program_cores)
+    if [ -n "$cores" ]; then
+      echo "== desktop cores: $cores (the desktop and every program started from it)"
+      exec taskset -c "$cores" /usr/local/bin/droiddeck-desktop
+    fi
    exec /usr/local/bin/droiddeck-desktop
  fi
  width=${BL_WIDTH:-1280}
@@ -162,6 +189,13 @@ case $mode in
  run)
    target=${1:?program path}
    shift
+    cores=$(program_cores)
+    if [ -n "$cores" ]; then
+      echo "== program cores: $cores"
+      taskset -cp "$cores" $$ >/dev/null 2>&1 || true
+    fi
+    # Player 1 on the controller in an emulator that has no profile of its own yet.
+    python3 /usr/local/bin/bannerlator-pad-defaults 2>&1 || true
    case ${target,,} in
      *.appimage)
        export APPIMAGE_EXTRACT_AND_RUN=1
@@ -0,0 +1,58 @@
+#!/usr/bin/bash
+# Runs INSIDE an Arch Linux ARM container (menci/archlinuxarm:base-devel) on an arm64 runner.
+# Builds Arch's own wlroots0.20 package - the wlroots the desktop package's labwc links - with the
+# patches in ./patches added, keeps only the library, and packs it as wlroots.tzst
+# (usr/local/lib/droiddeck-wlroots/libwlroots-0.20.so) for the apk to stage. The desktop launcher
+# puts that directory first on labwc's library path for the GPU renderers only.
+set -euxo pipefail
+VERSION=${WLROOTS_VERSION:-0.20.2}
+WORK=/work
+cd "$WORK"
+# Same container workarounds as tools/gamescope/build-in-arch.sh.
+grep -q '^DisableSandbox' /etc/pacman.conf || sed -i 's/^\[options\]/[options]\nDisableSandbox/' /etc/pacman.conf
+{ for m in https://ca.us.mirror.archlinuxarm.org https://fl.us.mirror.archlinuxarm.org https://de3.mirror.archlinuxarm.org https://nl.mirror.archlinuxarm.org; do echo "Server = $m/\$arch/\$repo"; done; cat /etc/pacman.d/mirrorlist; } > /etc/pacman.d/mirrorlist.new
+mv /etc/pacman.d/mirrorlist.new /etc/pacman.d/mirrorlist
+pacman -Syu --noconfirm --needed git sudo zstd binutils
+id builder >/dev/null 2>&1 || useradd -m builder
+echo 'builder ALL=(ALL) NOPASSWD: ALL' > /etc/sudoers.d/builder
+rm -rf pkg && mkdir pkg && cp -r tools/wlroots/patches pkg/ && chown -R builder pkg
+sudo -u builder bash -c "
+set -euxo pipefail
+cd pkg
+for rel in 1 2 3 4; do
+  if git clone -q --depth 1 --branch ${VERSION}-\$rel https://gitlab.archlinux.org/archlinux/packaging/packages/wlroots0.20.git arch 2>/dev/null; then break; fi
+done
+test -f arch/PKGBUILD
+cd arch
+grep -q '^pkgver=${VERSION}$' PKGBUILD
+cp ../patches/*.patch .
+PATCHES=\$(ls *.patch | sort)
+{ echo; echo 'source+=('; for p in \$PATCHES; do echo \"  \$p\"; done; echo ')'; for p in \$PATCHES; do echo \"sha256sums+=('SKIP')\"; done; } >> PKGBUILD
+# Arch's PKGBUILD has no prepare(); ours applies the patches to the checkout.
+cat >> PKGBUILD <<'PREP'
+
+prepare() {
+  cd \"\$srcdir/\$pkgname\"
+  for p in \$(ls \"\$srcdir\"/*.patch | sort); do
+    echo \"applying \$(basename \"\$p\")\"
+    patch -p1 --no-backup-if-mismatch < \"\$p\"
+  done
+}
+PREP
+makepkg -A -s --noconfirm --skipchecksums --skippgpcheck
+ls -l *.pkg.tar.*
+"
+cd "$WORK"
+rm -rf out && mkdir -p out/usr/local/lib/droiddeck-wlroots
+PKG=$(ls pkg/arch/wlroots0.20-*.pkg.tar.* | grep -v -- '-debug-' | head -1)
+mkdir -p x && tar --use-compress-program=unzstd -xf "$PKG" -C x
+SO=x/usr/lib/libwlroots-0.20.so
+test -f "$SO"
+cp -L "$SO" out/usr/local/lib/droiddeck-wlroots/libwlroots-0.20.so
+strip --strip-unneeded out/usr/local/lib/droiddeck-wlroots/libwlroots-0.20.so || true
+# The patch is in: the allocator's symbol and its log line.
+grep -q 'Created Vulkan DMA-BUF allocator' out/usr/local/lib/droiddeck-wlroots/libwlroots-0.20.so
+readelf -d out/usr/local/lib/droiddeck-wlroots/libwlroots-0.20.so | grep -E 'NEEDED|SONAME'
+(cd out && tar --use-compress-program='zstd -19' -cf ../wlroots.tzst usr)
+sha256sum wlroots.tzst | tee wlroots.tzst.sha256
+ls -l wlroots.tzst out/usr/local/lib/droiddeck-wlroots/
@@ -0,0 +1,549 @@
+diff --git a/include/render/vulkan.h b/include/render/vulkan.h
+index f96619f2..9f945f87 100644
+--- a/include/render/vulkan.h
+++ b/include/render/vulkan.h
+@@ -461,6 +461,10 @@ struct wlr_vk_descriptor_pool *vulkan_alloc_blend_ds(
+ // Frees the given descriptor set from the pool its pool.
+ void vulkan_free_ds(struct wlr_vk_renderer *renderer,
+ 	struct wlr_vk_descriptor_pool *pool, VkDescriptorSet ds);
+// A DMA-BUF allocator on a Vulkan device of its own, for a DRM fd gbm cannot use (see
+// render/vulkan/allocator.c).
+struct wlr_allocator *vulkan_allocator_create(int drm_fd);
+
+ struct wlr_vk_format_props *vulkan_format_props_from_drm(
+ 	struct wlr_vk_device *dev, uint32_t drm_format);
+ struct wlr_vk_renderer *vulkan_get_renderer(struct wlr_renderer *r);
+diff --git a/render/allocator/allocator.c b/render/allocator/allocator.c
+index b7dbf3d6..f3162d47 100644
+--- a/render/allocator/allocator.c
+++ b/render/allocator/allocator.c
+@@ -1,6 +1,7 @@
+ #include <assert.h>
+ #include <fcntl.h>
+ #include <stdlib.h>
+#include <string.h>
+ #include <unistd.h>
+ #include <wlr/backend.h>
+ #include <wlr/config.h>
+@@ -13,6 +14,10 @@
+ #include "render/allocator/shm.h"
+ #include "render/wlr_renderer.h"
+ 
+#if WLR_HAS_VULKAN_RENDERER
+#include "render/vulkan.h"
+#endif
+
+ #if WLR_HAS_GBM_ALLOCATOR
+ #include "render/allocator/gbm.h"
+ #endif
+@@ -32,6 +37,29 @@ void wlr_allocator_init(struct wlr_allocator *alloc,
+ 	wl_signal_init(&alloc->events.destroy);
+ }
+ 
+/* Whether the fd is a DRM device at all. The GPU node on Android (KGSL, for Adreno) stands in for
+ * a render node so that Vulkan and libdrm's device lookup can name the GPU, but it answers no DRM
+ * ioctl: drmIsMaster() takes that for mastership, and gbm cannot allocate on it. */
+static bool is_drm_device(int fd) {
+	drmVersion *version = drmGetVersion(fd);
+	if (version == NULL) {
+		return false;
+	}
+	drmFreeVersion(version);
+	return true;
+}
+
+#if WLR_HAS_VULKAN_RENDERER
+static struct wlr_allocator *try_vulkan_allocator(int drm_fd) {
+	wlr_log(WLR_DEBUG, "Trying to create Vulkan allocator");
+	struct wlr_allocator *alloc = vulkan_allocator_create(drm_fd);
+	if (alloc == NULL) {
+		wlr_log(WLR_DEBUG, "Failed to create Vulkan allocator");
+	}
+	return alloc;
+}
+#endif
+
+ /* Re-open the DRM node to avoid GEM handle ref'counting issues. See:
+  * https://gitlab.freedesktop.org/mesa/drm/-/merge_requests/110
+  */
+@@ -109,8 +137,20 @@ struct wlr_allocator *wlr_allocator_autocreate(struct wlr_backend *backend,
+ 	struct wlr_allocator *alloc = NULL;
+ 
+ 	uint32_t gbm_caps = WLR_BUFFER_CAP_DMABUF;
+	bool drm_device = drm_fd >= 0 && is_drm_device(drm_fd);
+	const char *forced = getenv("WLR_ALLOCATOR");
+	bool vk_first = forced != NULL && strcmp(forced, "vulkan") == 0;
+#if WLR_HAS_VULKAN_RENDERER
+	// A GPU node that is not a DRM device (and WLR_ALLOCATOR=vulkan): buffers come from Vulkan.
+	if ((backend_caps & gbm_caps) && (renderer_caps & gbm_caps) && drm_fd >= 0
+			&& (vk_first || !drm_device)) {
+		if ((alloc = try_vulkan_allocator(drm_fd)) != NULL) {
+			return alloc;
+		}
+	}
+#endif
+ 	if ((backend_caps & gbm_caps) && (renderer_caps & gbm_caps)
+-			&& drm_fd >= 0) {
+			&& drm_fd >= 0 && drm_device) {
+ #if WLR_HAS_GBM_ALLOCATOR
+ 		wlr_log(WLR_DEBUG, "Trying to create gbm allocator");
+ 		int gbm_fd = reopen_drm_node(drm_fd, true);
+@@ -124,6 +164,11 @@ struct wlr_allocator *wlr_allocator_autocreate(struct wlr_backend *backend,
+ 		wlr_log(WLR_DEBUG, "Failed to create gbm allocator");
+ #else
+ 		wlr_log(WLR_DEBUG, "Skipping gbm allocator: disabled at compile-time");
+#endif
+#if WLR_HAS_VULKAN_RENDERER
+		if (!vk_first && (alloc = try_vulkan_allocator(drm_fd)) != NULL) {
+			return alloc;
+		}
+ #endif
+ 	}
+ 
+@@ -138,7 +183,7 @@ struct wlr_allocator *wlr_allocator_autocreate(struct wlr_backend *backend,
+ 
+ 	uint32_t drm_caps = WLR_BUFFER_CAP_DMABUF | WLR_BUFFER_CAP_DATA_PTR;
+ 	if ((backend_caps & drm_caps) && (renderer_caps & drm_caps)
+-			&& drm_fd >= 0 && drmIsMaster(drm_fd)) {
+			&& drm_fd >= 0 && drm_device && drmIsMaster(drm_fd)) {
+ 		wlr_log(WLR_DEBUG, "Trying to create drm dumb allocator");
+ 		int dumb_fd = reopen_drm_node(drm_fd, false);
+ 		if (dumb_fd < 0) {
+diff --git a/render/vulkan/allocator.c b/render/vulkan/allocator.c
+new file mode 100644
+index 00000000..4c00d361
+--- /dev/null
+++ b/render/vulkan/allocator.c
+@@ -0,0 +1,392 @@
+#include <assert.h>
+#include <drm_fourcc.h>
+#include <fcntl.h>
+#include <inttypes.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <wlr/interfaces/wlr_buffer.h>
+#include <wlr/render/allocator.h>
+#include <wlr/render/drm_format_set.h>
+#include <wlr/util/log.h>
+#include "render/vulkan.h"
+
+/*
+ * DMA-BUFs allocated by Vulkan, for a GPU whose device node is not a DRM device and so cannot be
+ * given to gbm - Adreno through KGSL on Android, where the node Turnip opens stands in for a
+ * render node. Each buffer is an exportable image with an explicit DRM format modifier, created
+ * the way vulkan_import_dmabuf() imports one for rendering, so the renderer and the parent
+ * compositor see the same layout. The device is our own, on the physical device the DRM fd names:
+ * this works under the gles2 renderer too, as long as its EGL can import the result.
+ */
+
+struct wlr_vk_allocator {
+	struct wlr_allocator base;
+	struct wlr_vk_device *dev;
+	PFN_vkGetMemoryFdKHR get_memory_fd;
+	PFN_vkGetImageDrmFormatModifierPropertiesEXT get_modifier_props;
+	struct wl_list buffers; // wlr_vk_allocator_buffer.link
+};
+
+struct wlr_vk_allocator_buffer {
+	struct wlr_buffer base;
+	struct wlr_vk_allocator *alloc; // NULL once the allocator is gone
+	struct wl_list link;
+	VkImage image;
+	VkDeviceMemory memory;
+	struct wlr_dmabuf_attributes dmabuf;
+};
+
+static const struct wlr_buffer_impl buffer_impl;
+
+static struct wlr_vk_allocator_buffer *buffer_from_buffer(struct wlr_buffer *wlr_buffer) {
+	assert(wlr_buffer->impl == &buffer_impl);
+	struct wlr_vk_allocator_buffer *buffer = wl_container_of(wlr_buffer, buffer, base);
+	return buffer;
+}
+
+static void buffer_release_vk(struct wlr_vk_allocator_buffer *buffer) {
+	if (buffer->alloc == NULL) {
+		return;
+	}
+	VkDevice dev = buffer->alloc->dev->dev;
+	// The exported DMA-BUF keeps the memory alive for whoever imported it.
+	if (buffer->image != VK_NULL_HANDLE) {
+		vkDestroyImage(dev, buffer->image, NULL);
+	}
+	if (buffer->memory != VK_NULL_HANDLE) {
+		vkFreeMemory(dev, buffer->memory, NULL);
+	}
+	buffer->image = VK_NULL_HANDLE;
+	buffer->memory = VK_NULL_HANDLE;
+	wl_list_remove(&buffer->link);
+	buffer->alloc = NULL;
+}
+
+static void buffer_destroy(struct wlr_buffer *wlr_buffer) {
+	struct wlr_vk_allocator_buffer *buffer = buffer_from_buffer(wlr_buffer);
+	wlr_buffer_finish(wlr_buffer);
+	buffer_release_vk(buffer);
+	wlr_dmabuf_attributes_finish(&buffer->dmabuf);
+	free(buffer);
+}
+
+static bool buffer_get_dmabuf(struct wlr_buffer *wlr_buffer,
+		struct wlr_dmabuf_attributes *dmabuf) {
+	struct wlr_vk_allocator_buffer *buffer = buffer_from_buffer(wlr_buffer);
+	*dmabuf = buffer->dmabuf;
+	return true;
+}
+
+static const struct wlr_buffer_impl buffer_impl = {
+	.destroy = buffer_destroy,
+	.get_dmabuf = buffer_get_dmabuf,
+};
+
+// One vkCreateImage over the modifiers that share the same mutable-sRGB setting, the one thing
+// in the import that depends on the modifier. The driver picks the modifier.
+static VkImage create_image(struct wlr_vk_allocator *alloc,
+		const struct wlr_vk_format_props *props, int width, int height,
+		const uint64_t *mods, uint32_t mods_len, bool mutable_srgb) {
+	VkImageCreateInfo img_info = {
+		.sType = VK_STRUCTURE_TYPE_IMAGE_CREATE_INFO,
+		.imageType = VK_IMAGE_TYPE_2D,
+		.format = props->format.vk,
+		.mipLevels = 1,
+		.arrayLayers = 1,
+		.samples = VK_SAMPLE_COUNT_1_BIT,
+		.sharingMode = VK_SHARING_MODE_EXCLUSIVE,
+		.initialLayout = VK_IMAGE_LAYOUT_UNDEFINED,
+		.extent = (VkExtent3D){ width, height, 1 },
+		.usage = vulkan_render_usage,
+		.tiling = VK_IMAGE_TILING_DRM_FORMAT_MODIFIER_EXT,
+	};
+	if (mutable_srgb) {
+		img_info.flags |= VK_IMAGE_CREATE_MUTABLE_FORMAT_BIT;
+	}
+
+	VkExternalMemoryImageCreateInfo eimg = {
+		.sType = VK_STRUCTURE_TYPE_EXTERNAL_MEMORY_IMAGE_CREATE_INFO,
+		.handleTypes = VK_EXTERNAL_MEMORY_HANDLE_TYPE_DMA_BUF_BIT_EXT,
+	};
+	img_info.pNext = &eimg;
+
+	VkImageDrmFormatModifierListCreateInfoEXT mod_list = {
+		.sType = VK_STRUCTURE_TYPE_IMAGE_DRM_FORMAT_MODIFIER_LIST_CREATE_INFO_EXT,
+		.drmFormatModifierCount = mods_len,
+		.pDrmFormatModifiers = mods,
+	};
+	eimg.pNext = &mod_list;
+
+	VkFormat view_formats[] = {
+		props->format.vk,
+		props->format.vk_srgb,
+	};
+	VkImageFormatListCreateInfoKHR list_info = {
+		.sType = VK_STRUCTURE_TYPE_IMAGE_FORMAT_LIST_CREATE_INFO_KHR,
+		.pViewFormats = view_formats,
+		.viewFormatCount = sizeof(view_formats) / sizeof(view_formats[0]),
+	};
+	if (mutable_srgb) {
+		mod_list.pNext = &list_info;
+	}
+
+	VkImage image = VK_NULL_HANDLE;
+	VkResult res = vkCreateImage(alloc->dev->dev, &img_info, NULL, &image);
+	if (res != VK_SUCCESS) {
+		wlr_vk_error("vkCreateImage", res);
+		return VK_NULL_HANDLE;
+	}
+	return image;
+}
+
+static struct wlr_buffer *allocator_create_buffer(struct wlr_allocator *wlr_allocator,
+		int width, int height, const struct wlr_drm_format *format) {
+	struct wlr_vk_allocator *alloc = wl_container_of(wlr_allocator, alloc, base);
+	VkDevice dev = alloc->dev->dev;
+
+	const struct wlr_vk_format_props *props =
+		vulkan_format_props_from_drm(alloc->dev, format->format);
+	if (props == NULL) {
+		wlr_log(WLR_ERROR, "Vulkan allocator: format 0x%08"PRIX32" not supported",
+			format->format);
+		return NULL;
+	}
+
+	// The modifiers asked for that this device can render to at this size, split by whether the
+	// import will make the image mutable-format. INVALID (implicit) is not something Vulkan can
+	// allocate; LINEAR stands in for it when it is all there is.
+	uint64_t *mutable_mods = calloc(format->len + 1, sizeof(uint64_t));
+	uint64_t *plain_mods = calloc(format->len + 1, sizeof(uint64_t));
+	if (mutable_mods == NULL || plain_mods == NULL) {
+		free(mutable_mods);
+		free(plain_mods);
+		return NULL;
+	}
+	uint32_t mutable_len = 0, plain_len = 0;
+	bool implicit_only = format->len > 0;
+	for (size_t i = 0; i <= format->len; i++) {
+		uint64_t mod;
+		if (i < format->len) {
+			mod = format->modifiers[i];
+			if (mod == DRM_FORMAT_MOD_INVALID) {
+				continue;
+			}
+			implicit_only = false;
+		} else if (implicit_only) {
+			mod = DRM_FORMAT_MOD_LINEAR;
+		} else {
+			break;
+		}
+		const struct wlr_vk_format_modifier_props *mp =
+			vulkan_format_props_find_modifier(props, mod, true);
+		if (mp == NULL || (uint32_t)width > mp->max_extent.width ||
+				(uint32_t)height > mp->max_extent.height) {
+			continue;
+		}
+		if (mp->has_mutable_srgb) {
+			mutable_mods[mutable_len++] = mod;
+		} else {
+			plain_mods[plain_len++] = mod;
+		}
+	}
+
+	VkImage image = VK_NULL_HANDLE;
+	if (mutable_len > 0) {
+		image = create_image(alloc, props, width, height, mutable_mods, mutable_len, true);
+	}
+	if (image == VK_NULL_HANDLE && plain_len > 0) {
+		image = create_image(alloc, props, width, height, plain_mods, plain_len, false);
+	}
+	free(mutable_mods);
+	free(plain_mods);
+	if (image == VK_NULL_HANDLE) {
+		wlr_log(WLR_ERROR, "Vulkan allocator: no usable modifier for %dx%d format 0x%08"PRIX32,
+			width, height, format->format);
+		return NULL;
+	}
+
+	struct wlr_vk_allocator_buffer *buffer = calloc(1, sizeof(*buffer));
+	if (buffer == NULL) {
+		vkDestroyImage(dev, image, NULL);
+		return NULL;
+	}
+	wlr_buffer_init(&buffer->base, &buffer_impl, width, height);
+	buffer->alloc = alloc;
+	buffer->image = image;
+	wl_list_insert(&alloc->buffers, &buffer->link);
+	for (int i = 0; i < WLR_DMABUF_MAX_PLANES; i++) {
+		buffer->dmabuf.fd[i] = -1;
+	}
+
+	VkMemoryRequirements reqs;
+	vkGetImageMemoryRequirements(dev, image, &reqs);
+	int mem_type = vulkan_find_mem_type(alloc->dev,
+		VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT, reqs.memoryTypeBits);
+	if (mem_type < 0) {
+		mem_type = vulkan_find_mem_type(alloc->dev, 0, reqs.memoryTypeBits);
+	}
+	if (mem_type < 0) {
+		wlr_log(WLR_ERROR, "Vulkan allocator: no memory type for the image");
+		goto error;
+	}
+
+	VkMemoryDedicatedAllocateInfo dedicated = {
+		.sType = VK_STRUCTURE_TYPE_MEMORY_DEDICATED_ALLOCATE_INFO,
+		.image = image,
+	};
+	VkExportMemoryAllocateInfo export = {
+		.sType = VK_STRUCTURE_TYPE_EXPORT_MEMORY_ALLOCATE_INFO,
+		.pNext = &dedicated,
+		.handleTypes = VK_EXTERNAL_MEMORY_HANDLE_TYPE_DMA_BUF_BIT_EXT,
+	};
+	VkMemoryAllocateInfo mem_info = {
+		.sType = VK_STRUCTURE_TYPE_MEMORY_ALLOCATE_INFO,
+		.pNext = &export,
+		.allocationSize = reqs.size,
+		.memoryTypeIndex = mem_type,
+	};
+	VkResult res = vkAllocateMemory(dev, &mem_info, NULL, &buffer->memory);
+	if (res != VK_SUCCESS) {
+		wlr_vk_error("vkAllocateMemory", res);
+		goto error;
+	}
+	res = vkBindImageMemory(dev, image, buffer->memory, 0);
+	if (res != VK_SUCCESS) {
+		wlr_vk_error("vkBindImageMemory", res);
+		goto error;
+	}
+
+	VkImageDrmFormatModifierPropertiesEXT mod_props = {
+		.sType = VK_STRUCTURE_TYPE_IMAGE_DRM_FORMAT_MODIFIER_PROPERTIES_EXT,
+	};
+	res = alloc->get_modifier_props(dev, image, &mod_props);
+	if (res != VK_SUCCESS) {
+		wlr_vk_error("vkGetImageDrmFormatModifierPropertiesEXT", res);
+		goto error;
+	}
+	const struct wlr_vk_format_modifier_props *mp =
+		vulkan_format_props_find_modifier(props, mod_props.drmFormatModifier, true);
+	if (mp == NULL) {
+		wlr_log(WLR_ERROR, "Vulkan allocator: driver chose modifier 0x%016"PRIX64
+			" which it cannot render to", mod_props.drmFormatModifier);
+		goto error;
+	}
+	uint32_t n_planes = mp->props.drmFormatModifierPlaneCount;
+	if (n_planes == 0 || n_planes > WLR_DMABUF_MAX_PLANES) {
+		wlr_log(WLR_ERROR, "Vulkan allocator: %"PRIu32" memory planes", n_planes);
+		goto error;
+	}
+
+	VkMemoryGetFdInfoKHR fd_info = {
+		.sType = VK_STRUCTURE_TYPE_MEMORY_GET_FD_INFO_KHR,
+		.memory = buffer->memory,
+		.handleType = VK_EXTERNAL_MEMORY_HANDLE_TYPE_DMA_BUF_BIT_EXT,
+	};
+	int fd = -1;
+	res = alloc->get_memory_fd(dev, &fd_info, &fd);
+	if (res != VK_SUCCESS || fd < 0) {
+		wlr_vk_error("vkGetMemoryFdKHR", res);
+		goto error;
+	}
+
+	buffer->dmabuf = (struct wlr_dmabuf_attributes){
+		.width = width,
+		.height = height,
+		.format = format->format,
+		.modifier = mod_props.drmFormatModifier,
+		.n_planes = n_planes,
+	};
+	for (int i = 0; i < WLR_DMABUF_MAX_PLANES; i++) {
+		buffer->dmabuf.fd[i] = -1;
+	}
+	static const VkImageAspectFlagBits plane_aspects[] = {
+		VK_IMAGE_ASPECT_MEMORY_PLANE_0_BIT_EXT,
+		VK_IMAGE_ASPECT_MEMORY_PLANE_1_BIT_EXT,
+		VK_IMAGE_ASPECT_MEMORY_PLANE_2_BIT_EXT,
+		VK_IMAGE_ASPECT_MEMORY_PLANE_3_BIT_EXT,
+	};
+	for (uint32_t i = 0; i < n_planes; i++) {
+		VkImageSubresource sub = { .aspectMask = plane_aspects[i] };
+		VkSubresourceLayout layout;
+		vkGetImageSubresourceLayout(dev, image, &sub, &layout);
+		buffer->dmabuf.offset[i] = layout.offset;
+		buffer->dmabuf.stride[i] = layout.rowPitch;
+		// Every plane lives in the one allocation; each gets its own fd, as
+		// wlr_dmabuf_attributes_finish() closes them one by one.
+		buffer->dmabuf.fd[i] = i == 0 ? fd : fcntl(fd, F_DUPFD_CLOEXEC, 0);
+		if (buffer->dmabuf.fd[i] < 0) {
+			wlr_log_errno(WLR_ERROR, "Vulkan allocator: dup failed");
+			goto error;
+		}
+	}
+
+	wlr_log(WLR_DEBUG, "Vulkan allocator: %dx%d format 0x%08"PRIX32" modifier 0x%016"PRIX64
+		", %"PRIu32" plane(s)", width, height, format->format, mod_props.drmFormatModifier, n_planes);
+	return &buffer->base;
+
+error:
+	buffer_destroy(&buffer->base);
+	return NULL;
+}
+
+static void allocator_destroy(struct wlr_allocator *wlr_allocator) {
+	struct wlr_vk_allocator *alloc = wl_container_of(wlr_allocator, alloc, base);
+	// Buffers may outlive their allocator; their DMA-BUF fds stay valid without the device.
+	struct wlr_vk_allocator_buffer *buffer, *tmp;
+	wl_list_for_each_safe(buffer, tmp, &alloc->buffers, link) {
+		buffer_release_vk(buffer);
+	}
+	struct wlr_vk_instance *ini = alloc->dev->instance;
+	vulkan_device_destroy(alloc->dev);
+	vulkan_instance_destroy(ini);
+	free(alloc);
+}
+
+static const struct wlr_allocator_interface allocator_impl = {
+	.destroy = allocator_destroy,
+	.create_buffer = allocator_create_buffer,
+};
+
+struct wlr_allocator *vulkan_allocator_create(int drm_fd) {
+	struct wlr_vk_instance *ini = vulkan_instance_create(false);
+	if (ini == NULL) {
+		wlr_log(WLR_ERROR, "Vulkan allocator: could not create an instance");
+		return NULL;
+	}
+	VkPhysicalDevice phdev = vulkan_find_drm_phdev(ini, drm_fd);
+	if (phdev == VK_NULL_HANDLE) {
+		wlr_log(WLR_ERROR, "Vulkan allocator: no Vulkan device for the DRM fd");
+		vulkan_instance_destroy(ini);
+		return NULL;
+	}
+	struct wlr_vk_device *dev = vulkan_device_create(ini, phdev);
+	if (dev == NULL) {
+		wlr_log(WLR_ERROR, "Vulkan allocator: could not create a device");
+		vulkan_instance_destroy(ini);
+		return NULL;
+	}
+
+	struct wlr_vk_allocator *alloc = calloc(1, sizeof(*alloc));
+	if (alloc == NULL) {
+		vulkan_device_destroy(dev);
+		vulkan_instance_destroy(ini);
+		return NULL;
+	}
+	alloc->dev = dev;
+	wl_list_init(&alloc->buffers);
+	alloc->get_memory_fd = (PFN_vkGetMemoryFdKHR)
+		vkGetDeviceProcAddr(dev->dev, "vkGetMemoryFdKHR");
+	alloc->get_modifier_props = (PFN_vkGetImageDrmFormatModifierPropertiesEXT)
+		vkGetDeviceProcAddr(dev->dev, "vkGetImageDrmFormatModifierPropertiesEXT");
+	if (alloc->get_memory_fd == NULL || alloc->get_modifier_props == NULL) {
+		wlr_log(WLR_ERROR, "Vulkan allocator: the device lacks DMA-BUF export");
+		free(alloc);
+		vulkan_device_destroy(dev);
+		vulkan_instance_destroy(ini);
+		return NULL;
+	}
+
+	wlr_allocator_init(&alloc->base, &allocator_impl, WLR_BUFFER_CAP_DMABUF);
+	wlr_log(WLR_INFO, "Created Vulkan DMA-BUF allocator");
+	return &alloc->base;
+}
+diff --git a/render/vulkan/meson.build b/render/vulkan/meson.build
+index 36a822f9..abeb5337 100644
+--- a/render/vulkan/meson.build
+++ b/render/vulkan/meson.build
+@@ -37,6 +37,7 @@ glslang_version_info = run_command(glslang, '--version', check: true).stdout()
+ glslang_version = glslang_version_info.split('\n')[0].split(':')[-1]
+ 
+ wlr_files += files(
+	'allocator.c',
+ 	'pass.c',
+ 	'renderer.c',
+ 	'texture.c',
+diff --git a/types/wlr_linux_dmabuf_v1.c b/types/wlr_linux_dmabuf_v1.c
+index 3165e880..a7fe060c 100644
+--- a/types/wlr_linux_dmabuf_v1.c
+++ b/types/wlr_linux_dmabuf_v1.c
+@@ -901,11 +901,22 @@ static bool set_default_feedback(struct wlr_linux_dmabuf_v1 *linux_dmabuf,
+ 	if (device->available_nodes & (1 << DRM_NODE_RENDER)) {
+ 		const char *name = device->nodes[DRM_NODE_RENDER];
+ 		main_device_fd = open(name, O_RDWR | O_CLOEXEC);
+-		drmFreeDevice(&device);
+ 		if (main_device_fd < 0) {
+ 			wlr_log_errno(WLR_ERROR, "Failed to open DRM device %s", name);
+			drmFreeDevice(&device);
+ 			goto error_compiled;
+ 		}
+		// A GPU node that stands in for a render node without being a DRM device (KGSL on
+		// Android) cannot import a buffer as a GEM handle; every client's would be refused.
+		drmVersion *version = drmGetVersion(main_device_fd);
+		if (version == NULL) {
+			wlr_log(WLR_INFO, "%s is not a DRM device, skipping DMA-BUF import checks", name);
+			close(main_device_fd);
+			main_device_fd = -1;
+		} else {
+			drmFreeVersion(version);
+		}
+		drmFreeDevice(&device);
+ 	} else {
+ 		// Likely a split display/render setup. Unfortunately we have no way to
+ 		// get back the proper render node used by the renderer under-the-hood.
@@ -0,0 +1,2 @@
+WLROOTS_TAG=wlroots-0.20.2-p1
+WLROOTS_SHA256=b4dcb08b46e69dbfaa004597844e843cdf938591ba5dbc7079b91626cdd4591d