austinbaccus · Oct 24, 2026 · Oct 24, 2026 · Oct 24, 2026 · Oct 24, 2026 · Oct 24, 2026
diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
@@ -18,6 +18,75 @@ concurrency:
 # when authoring new shaders (offline by the contributor).
 
 jobs:
+  # The boot animation's shaders (theseus/desktop/shaders/xboot/) for D3D11,
+  # the renderer bgfx picks by default on Windows. shaderc hands HLSL to
+  # fxc, which only exists on Windows, so the Linux and macOS jobs cannot
+  # make these. This job builds shaderc, compiles them and checks them
+  # against the .bin files in Data/shaders/dx11/; when they differ the new
+  # ones are in the job's artifact (and in its log, base64) to commit.
+  shaders-dx11:
+    name: Shaders / D3D11
+    runs-on: windows-latest
+    defaults:
+      run:
+        shell: bash
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Checkout bgfx
+        id: bgfx
+        run: |
+          git submodule update --init --depth 1 theseus/third-party/bx theseus/third-party/bimg theseus/third-party/bgfx
+          echo "sha=$(git rev-parse HEAD:theseus/third-party/bgfx)" >> "$GITHUB_OUTPUT"
+
+      - name: Cache shaderc
+        id: cache-shaderc
+        uses: actions/cache@v4
+        with:
+          path: theseus/third-party/bgfx/.build/win64_vs2022/bin/shadercRelease.exe
+          key: shaderc-win64-${{ steps.bgfx.outputs.sha }}
+
+      - uses: microsoft/setup-msbuild@v2
+        if: steps.cache-shaderc.outputs.cache-hit != 'true'
+
+      - name: Build shaderc
+        if: steps.cache-shaderc.outputs.cache-hit != 'true'
+        run: |
+          cd theseus/third-party/bgfx
+          ../bx/tools/bin/windows/genie.exe --with-tools vs2022
+          MSBuild.exe .build/projects/vs2022/shaderc.vcxproj -p:Configuration=Release -p:Platform=x64 -m -v:minimal
+
+      - name: Compile and compare
+        run: |
+          SHADERC=theseus/third-party/bgfx/.build/win64_vs2022/bin/shadercRelease.exe
+          SRC=theseus/desktop/shaders/xboot
+          OUT=out/dx11
+          mkdir -p "$OUT"
+          for SC in "$SRC"/vs_*.sc "$SRC"/fs_*.sc; do
+            NAME=$(basename "$SC" .sc)
+            case $NAME in vs_*) T=v ;; *) T=f ;; esac
+            "$SHADERC" -f "$SC" -o "$OUT/xboot_$NAME.bin" --type $T --platform windows --profile s_5_0 \
+              --varyingdef "$SRC/varying.def.sc" -i theseus/third-party/bgfx/src -i "$SRC"
+          done
+          STALE=0
+          for F in "$OUT"/*.bin; do
+            cmp -s "$F" "Data/shaders/dx11/$(basename "$F")" || { echo "differs: $(basename "$F")"; STALE=1; }
+          done
+          if [ $STALE = 1 ]; then
+            echo "Data/shaders/dx11 is out of date. Commit the job's artifact, or decode this:"
+            tar czf - -C "$OUT" . | base64 -w 0
+            echo
+            exit 1
+          fi
+
+      - name: Upload D3D11 shaders
+        if: always()
+        uses: actions/upload-artifact@v4
+        with:
+          name: xboot-shaders-dx11
+          path: out/dx11/
+          if-no-files-found: ignore
+
   desktop-macos:
     name: Desktop / macOS
     runs-on: macos-latest
@@ -319,7 +388,7 @@ jobs:
           cp -R ~/builds/theseus/desktop-win64/. "$DROP/"
           find "$DROP" -name '*.o' -delete
           find "$DROP" -name '*.d' -delete
-          rm -rf "$DROP/desktop" "$DROP/shared" "$DROP/engine" "$DROP/render" "$DROP/xbox" || true
+          rm -rf "$DROP/desktop" "$DROP/shared" "$DROP/engine" "$DROP/render" "$DROP/xbox" "$DROP/xboot" || true
           ls -la "$DROP"
 
       - name: Upload Win64 build

diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
@@ -371,7 +371,7 @@ jobs:
           # Zip up; remove the *.o cruft from object subdirs first.
           find "${DROP}" -name '*.o' -delete
           find "${DROP}" -name '*.d' -delete
-          rm -rf "${DROP}/desktop" "${DROP}/shared" "${DROP}/engine" "${DROP}/render" "${DROP}/xbox" || true
+          rm -rf "${DROP}/desktop" "${DROP}/shared" "${DROP}/engine" "${DROP}/render" "${DROP}/xbox" "${DROP}/xboot" || true
           zip -r "${DROP}.zip" "${DROP}"
           echo "ARCHIVE=${DROP}.zip" >> "$GITHUB_ENV"
 

diff --git a/.gitmodules b/.gitmodules
@@ -15,3 +15,7 @@
 	path = theseus/third-party/libdatachannel
 	url = https://github.com/paullouisageneau/libdatachannel.git
 	ignore = untracked
+[submodule "theseus/third-party/xboot"]
+	path = theseus/third-party/xboot
+	url = https://github.com/austinbaccus/re-xbox-boot.git
+	ignore = untracked
diff --git a/Configs/xbox_boot.mp4 b/Configs/xbox_boot.mp4
diff --git a/Data/shaders/dx11/xboot_fs_blob.bin b/Data/shaders/dx11/xboot_fs_blob.bin
diff --git a/Data/shaders/dx11/xboot_fs_depth.bin b/Data/shaders/dx11/xboot_fs_depth.bin
diff --git a/Data/shaders/dx11/xboot_fs_drop.bin b/Data/shaders/dx11/xboot_fs_drop.bin
diff --git a/Data/shaders/dx11/xboot_fs_fixed.bin b/Data/shaders/dx11/xboot_fs_fixed.bin
diff --git a/Data/shaders/dx11/xboot_fs_lightdepth.bin b/Data/shaders/dx11/xboot_fs_lightdepth.bin
diff --git a/Data/shaders/dx11/xboot_fs_logod.bin b/Data/shaders/dx11/xboot_fs_logod.bin
diff --git a/Data/shaders/dx11/xboot_fs_plain.bin b/Data/shaders/dx11/xboot_fs_plain.bin
diff --git a/Data/shaders/dx11/xboot_fs_present.bin b/Data/shaders/dx11/xboot_fs_present.bin
diff --git a/Data/shaders/dx11/xboot_fs_relief.bin b/Data/shaders/dx11/xboot_fs_relief.bin
diff --git a/Data/shaders/dx11/xboot_fs_smooth.bin b/Data/shaders/dx11/xboot_fs_smooth.bin
diff --git a/Data/shaders/dx11/xboot_fs_veil.bin b/Data/shaders/dx11/xboot_fs_veil.bin
diff --git a/Data/shaders/dx11/xboot_vs_blob.bin b/Data/shaders/dx11/xboot_vs_blob.bin
diff --git a/Data/shaders/dx11/xboot_vs_depth.bin b/Data/shaders/dx11/xboot_vs_depth.bin
diff --git a/Data/shaders/dx11/xboot_vs_drop.bin b/Data/shaders/dx11/xboot_vs_drop.bin
diff --git a/Data/shaders/dx11/xboot_vs_fixed.bin b/Data/shaders/dx11/xboot_vs_fixed.bin
diff --git a/Data/shaders/dx11/xboot_vs_lightdepth.bin b/Data/shaders/dx11/xboot_vs_lightdepth.bin
diff --git a/Data/shaders/dx11/xboot_vs_logod.bin b/Data/shaders/dx11/xboot_vs_logod.bin
diff --git a/Data/shaders/dx11/xboot_vs_plain.bin b/Data/shaders/dx11/xboot_vs_plain.bin
diff --git a/Data/shaders/dx11/xboot_vs_present.bin b/Data/shaders/dx11/xboot_vs_present.bin
diff --git a/Data/shaders/dx11/xboot_vs_relief.bin b/Data/shaders/dx11/xboot_vs_relief.bin
diff --git a/Data/shaders/dx11/xboot_vs_smooth.bin b/Data/shaders/dx11/xboot_vs_smooth.bin
diff --git a/Data/shaders/dx11/xboot_vs_veil.bin b/Data/shaders/dx11/xboot_vs_veil.bin
diff --git a/Data/shaders/essl/xboot_fs_blob.bin b/Data/shaders/essl/xboot_fs_blob.bin
diff --git a/Data/shaders/essl/xboot_fs_depth.bin b/Data/shaders/essl/xboot_fs_depth.bin
diff --git a/Data/shaders/essl/xboot_fs_drop.bin b/Data/shaders/essl/xboot_fs_drop.bin
diff --git a/Data/shaders/essl/xboot_fs_fixed.bin b/Data/shaders/essl/xboot_fs_fixed.bin
diff --git a/Data/shaders/essl/xboot_fs_lightdepth.bin b/Data/shaders/essl/xboot_fs_lightdepth.bin
diff --git a/Data/shaders/essl/xboot_fs_logod.bin b/Data/shaders/essl/xboot_fs_logod.bin
diff --git a/Data/shaders/essl/xboot_fs_plain.bin b/Data/shaders/essl/xboot_fs_plain.bin
diff --git a/Data/shaders/essl/xboot_fs_present.bin b/Data/shaders/essl/xboot_fs_present.bin
diff --git a/Data/shaders/essl/xboot_fs_relief.bin b/Data/shaders/essl/xboot_fs_relief.bin
diff --git a/Data/shaders/essl/xboot_fs_smooth.bin b/Data/shaders/essl/xboot_fs_smooth.bin
diff --git a/Data/shaders/essl/xboot_fs_veil.bin b/Data/shaders/essl/xboot_fs_veil.bin
diff --git a/Data/shaders/essl/xboot_vs_blob.bin b/Data/shaders/essl/xboot_vs_blob.bin
diff --git a/Data/shaders/essl/xboot_vs_depth.bin b/Data/shaders/essl/xboot_vs_depth.bin
diff --git a/Data/shaders/essl/xboot_vs_drop.bin b/Data/shaders/essl/xboot_vs_drop.bin
diff --git a/Data/shaders/essl/xboot_vs_fixed.bin b/Data/shaders/essl/xboot_vs_fixed.bin
diff --git a/Data/shaders/essl/xboot_vs_lightdepth.bin b/Data/shaders/essl/xboot_vs_lightdepth.bin
diff --git a/Data/shaders/essl/xboot_vs_logod.bin b/Data/shaders/essl/xboot_vs_logod.bin
diff --git a/Data/shaders/essl/xboot_vs_plain.bin b/Data/shaders/essl/xboot_vs_plain.bin
diff --git a/Data/shaders/essl/xboot_vs_present.bin b/Data/shaders/essl/xboot_vs_present.bin
diff --git a/Data/shaders/essl/xboot_vs_relief.bin b/Data/shaders/essl/xboot_vs_relief.bin
diff --git a/Data/shaders/essl/xboot_vs_smooth.bin b/Data/shaders/essl/xboot_vs_smooth.bin
diff --git a/Data/shaders/essl/xboot_vs_veil.bin b/Data/shaders/essl/xboot_vs_veil.bin
diff --git a/Data/shaders/glsl/xboot_fs_blob.bin b/Data/shaders/glsl/xboot_fs_blob.bin
diff --git a/Data/shaders/glsl/xboot_fs_depth.bin b/Data/shaders/glsl/xboot_fs_depth.bin
diff --git a/Data/shaders/glsl/xboot_fs_drop.bin b/Data/shaders/glsl/xboot_fs_drop.bin
diff --git a/Data/shaders/glsl/xboot_fs_fixed.bin b/Data/shaders/glsl/xboot_fs_fixed.bin
diff --git a/Data/shaders/glsl/xboot_fs_lightdepth.bin b/Data/shaders/glsl/xboot_fs_lightdepth.bin
diff --git a/Data/shaders/glsl/xboot_fs_logod.bin b/Data/shaders/glsl/xboot_fs_logod.bin
diff --git a/Data/shaders/glsl/xboot_fs_plain.bin b/Data/shaders/glsl/xboot_fs_plain.bin
diff --git a/Data/shaders/glsl/xboot_fs_present.bin b/Data/shaders/glsl/xboot_fs_present.bin
diff --git a/Data/shaders/glsl/xboot_fs_relief.bin b/Data/shaders/glsl/xboot_fs_relief.bin
diff --git a/Data/shaders/glsl/xboot_fs_smooth.bin b/Data/shaders/glsl/xboot_fs_smooth.bin
diff --git a/Data/shaders/glsl/xboot_fs_veil.bin b/Data/shaders/glsl/xboot_fs_veil.bin
diff --git a/Data/shaders/glsl/xboot_vs_blob.bin b/Data/shaders/glsl/xboot_vs_blob.bin
diff --git a/Data/shaders/glsl/xboot_vs_depth.bin b/Data/shaders/glsl/xboot_vs_depth.bin
diff --git a/Data/shaders/glsl/xboot_vs_drop.bin b/Data/shaders/glsl/xboot_vs_drop.bin
diff --git a/Data/shaders/glsl/xboot_vs_fixed.bin b/Data/shaders/glsl/xboot_vs_fixed.bin
diff --git a/Data/shaders/glsl/xboot_vs_lightdepth.bin b/Data/shaders/glsl/xboot_vs_lightdepth.bin
diff --git a/Data/shaders/glsl/xboot_vs_logod.bin b/Data/shaders/glsl/xboot_vs_logod.bin
diff --git a/Data/shaders/glsl/xboot_vs_plain.bin b/Data/shaders/glsl/xboot_vs_plain.bin
diff --git a/Data/shaders/glsl/xboot_vs_present.bin b/Data/shaders/glsl/xboot_vs_present.bin
diff --git a/Data/shaders/glsl/xboot_vs_relief.bin b/Data/shaders/glsl/xboot_vs_relief.bin
diff --git a/Data/shaders/glsl/xboot_vs_smooth.bin b/Data/shaders/glsl/xboot_vs_smooth.bin
diff --git a/Data/shaders/glsl/xboot_vs_veil.bin b/Data/shaders/glsl/xboot_vs_veil.bin
diff --git a/Data/shaders/metal/xboot_fs_blob.bin b/Data/shaders/metal/xboot_fs_blob.bin
diff --git a/Data/shaders/metal/xboot_fs_depth.bin b/Data/shaders/metal/xboot_fs_depth.bin
diff --git a/Data/shaders/metal/xboot_fs_drop.bin b/Data/shaders/metal/xboot_fs_drop.bin
diff --git a/Data/shaders/metal/xboot_fs_fixed.bin b/Data/shaders/metal/xboot_fs_fixed.bin
diff --git a/Data/shaders/metal/xboot_fs_lightdepth.bin b/Data/shaders/metal/xboot_fs_lightdepth.bin
diff --git a/Data/shaders/metal/xboot_fs_logod.bin b/Data/shaders/metal/xboot_fs_logod.bin
diff --git a/Data/shaders/metal/xboot_fs_plain.bin b/Data/shaders/metal/xboot_fs_plain.bin
diff --git a/Data/shaders/metal/xboot_fs_present.bin b/Data/shaders/metal/xboot_fs_present.bin
diff --git a/Data/shaders/metal/xboot_fs_relief.bin b/Data/shaders/metal/xboot_fs_relief.bin
diff --git a/Data/shaders/metal/xboot_fs_smooth.bin b/Data/shaders/metal/xboot_fs_smooth.bin
diff --git a/Data/shaders/metal/xboot_fs_veil.bin b/Data/shaders/metal/xboot_fs_veil.bin
diff --git a/Data/shaders/metal/xboot_vs_blob.bin b/Data/shaders/metal/xboot_vs_blob.bin
diff --git a/Data/shaders/metal/xboot_vs_depth.bin b/Data/shaders/metal/xboot_vs_depth.bin
diff --git a/Data/shaders/metal/xboot_vs_drop.bin b/Data/shaders/metal/xboot_vs_drop.bin
diff --git a/Data/shaders/metal/xboot_vs_fixed.bin b/Data/shaders/metal/xboot_vs_fixed.bin
diff --git a/Data/shaders/metal/xboot_vs_lightdepth.bin b/Data/shaders/metal/xboot_vs_lightdepth.bin
diff --git a/Data/shaders/metal/xboot_vs_logod.bin b/Data/shaders/metal/xboot_vs_logod.bin
diff --git a/Data/shaders/metal/xboot_vs_plain.bin b/Data/shaders/metal/xboot_vs_plain.bin
diff --git a/Data/shaders/metal/xboot_vs_present.bin b/Data/shaders/metal/xboot_vs_present.bin
diff --git a/Data/shaders/metal/xboot_vs_relief.bin b/Data/shaders/metal/xboot_vs_relief.bin
diff --git a/Data/shaders/metal/xboot_vs_smooth.bin b/Data/shaders/metal/xboot_vs_smooth.bin
diff --git a/Data/shaders/metal/xboot_vs_veil.bin b/Data/shaders/metal/xboot_vs_veil.bin
diff --git a/Data/shaders/spirv/xboot_fs_blob.bin b/Data/shaders/spirv/xboot_fs_blob.bin
diff --git a/Data/shaders/spirv/xboot_fs_depth.bin b/Data/shaders/spirv/xboot_fs_depth.bin
diff --git a/Data/shaders/spirv/xboot_fs_drop.bin b/Data/shaders/spirv/xboot_fs_drop.bin
diff --git a/Data/shaders/spirv/xboot_fs_fixed.bin b/Data/shaders/spirv/xboot_fs_fixed.bin
diff --git a/Data/shaders/spirv/xboot_fs_lightdepth.bin b/Data/shaders/spirv/xboot_fs_lightdepth.bin
diff --git a/Data/shaders/spirv/xboot_fs_logod.bin b/Data/shaders/spirv/xboot_fs_logod.bin
diff --git a/Data/shaders/spirv/xboot_fs_plain.bin b/Data/shaders/spirv/xboot_fs_plain.bin
diff --git a/Data/shaders/spirv/xboot_fs_present.bin b/Data/shaders/spirv/xboot_fs_present.bin
diff --git a/Data/shaders/spirv/xboot_fs_relief.bin b/Data/shaders/spirv/xboot_fs_relief.bin
diff --git a/Data/shaders/spirv/xboot_fs_smooth.bin b/Data/shaders/spirv/xboot_fs_smooth.bin
diff --git a/Data/shaders/spirv/xboot_fs_veil.bin b/Data/shaders/spirv/xboot_fs_veil.bin
diff --git a/Data/shaders/spirv/xboot_vs_blob.bin b/Data/shaders/spirv/xboot_vs_blob.bin
diff --git a/Data/shaders/spirv/xboot_vs_depth.bin b/Data/shaders/spirv/xboot_vs_depth.bin
diff --git a/Data/shaders/spirv/xboot_vs_drop.bin b/Data/shaders/spirv/xboot_vs_drop.bin
diff --git a/Data/shaders/spirv/xboot_vs_fixed.bin b/Data/shaders/spirv/xboot_vs_fixed.bin
diff --git a/Data/shaders/spirv/xboot_vs_lightdepth.bin b/Data/shaders/spirv/xboot_vs_lightdepth.bin
diff --git a/Data/shaders/spirv/xboot_vs_logod.bin b/Data/shaders/spirv/xboot_vs_logod.bin
diff --git a/Data/shaders/spirv/xboot_vs_plain.bin b/Data/shaders/spirv/xboot_vs_plain.bin
diff --git a/Data/shaders/spirv/xboot_vs_present.bin b/Data/shaders/spirv/xboot_vs_present.bin
diff --git a/Data/shaders/spirv/xboot_vs_relief.bin b/Data/shaders/spirv/xboot_vs_relief.bin
diff --git a/Data/shaders/spirv/xboot_vs_smooth.bin b/Data/shaders/spirv/xboot_vs_smooth.bin
diff --git a/Data/shaders/spirv/xboot_vs_veil.bin b/Data/shaders/spirv/xboot_vs_veil.bin
diff --git a/LICENSE-THIRD-PARTY.md b/LICENSE-THIRD-PARTY.md
@@ -39,9 +39,12 @@ Used by the desktop port:
 | [ImGuiColorTextEdit](https://github.com/BalazsJako/ImGuiColorTextEdit) | MIT | XAP script editor with syntax highlighting |
 | [stb_image](https://github.com/nothings/stb) | Public Domain (or MIT, dual-licensed) | Image loading on the desktop side |
 | [GLEW](https://glew.sourceforge.net/) | Modified BSD / MIT | OpenGL extension loader (Windows desktop build only) |
+| [re-xbox-boot](https://github.com/austinbaccus/re-xbox-boot) (`theseus/third-party/xboot`) | MIT | The boot animation, reconstructed from the BIOS: portable C core, renderer ported to bgfx in `boot_anim.cpp` and `shaders/xboot/` |
 
 All of the above are GPL-3.0-compatible, either by being permissive (MIT, BSD, zlib, public domain) or by being LGPL (linkable from GPL).
 
+The boot animation's data pack is built from `theseus/third-party/xboot/data/`, geometry, samples and tables extracted from the original BIOS. As that repository notes, their content is Microsoft's work; the boot animation itself was created by Pipeworks Software in 2001.
+
 ## Xbox Dashboard Assets (`xboxfs/`)
 
 The XIPs and skin assets in `xboxfs/` are authored by [UIX Lite](https://github.com/OfficialTeamUIX/UIX-Lite) and contain TeamUIX modifications of dashboard scripts present on every retail Xbox console. The `uixdata` directory layout is a convention established by JbOnE's earlier source-level modification, *User.Interface.X* (UIX); Theseus follows that convention so the same content runs on both projects. UIX Lite's modifications are licensed under GPL-3.0-or-later. The underlying script formats and any unmodified original components are referenced for compatibility and preservation; Microsoft retains its rights to its original work. Every Xbox owner already possesses the equivalent original files on their console.

diff --git a/README.md b/README.md
@@ -81,6 +81,7 @@ A drop-in replacement for the stock Xbox dashboard on modded consoles. Same look
 
 The Theseus engine compiled for your computer, with the modern features bolted on. macOS, Linux, Windows, Steam Deck friendly.
 
+- **The original boot animation**, rendered live from the [reverse engineered BIOS animation](https://github.com/austinbaccus/re-xbox-boot) with its synthesized sound, then straight into the dashboard (Settings > Show Boot Animation; Esc, Enter, Space or A/B/Start skips it)
 - **3D launcher** for native PC games, Steam libraries, RetroArch ROMs, and Xbox ISOs via [xemu](https://xemu.app)
 - **xCloud / Game Pass streaming** signs in with your Xbox account and drops your whole cloud library into the games grid, box art and all. Remote play for your own console shows up under "Your Xbox"
 - **Media library** that scans your Movies and TV folders, pulls posters from [TMDB](https://www.themoviedb.org/), and plays back through libmpv. [Plex](https://www.plex.tv/) and [Jellyfin](https://jellyfin.org/) servers browse and stream in the same UI (Jellyfin signs in with Quick Connect)
@@ -196,6 +197,7 @@ manipulation don't translate to a stick. Keyboard equivalents:
 | F4 | Settings |
 | F5 | Xbox HDD browser |
 | F6 | Playlist Maker |
+| F9 | FPS / debug overlay |
 | F10 | Toggle menu bar |
 | F11 | Toggle fullscreen |
 | Ctrl+M | Mute |

diff --git a/art/logo.jpg b/art/logo.jpg
diff --git a/build/Makefile b/build/Makefile
@@ -772,6 +772,41 @@ DESKTOP_ALL_SRCS = \
 	$(DESKTOP_SRCS_IMGUI)
 
 DESKTOP_OBJS = $(patsubst $(THESEUS_SRC)/%.cpp,$(DESKTOP_DIR)/%.o,$(DESKTOP_ALL_SRCS))
+
+# ------------------------------------------------------------------------
+# Boot animation core (third-party/xboot, the re-xbox-boot repo). Portable
+# C99, compiled with the flags its own build uses (core/build.py) so the
+# numerics stay as the boot repo measured them. Its data pack is built from
+# the repo's data/ by its own tools/pack/pack.py (checked against the
+# SHA-256 it ships) and embedded into the binary as a header, so there is
+# no runtime file to lose. Every desktop target below links these objects;
+# boot_anim.cpp is the only C++ user.
+# ------------------------------------------------------------------------
+XBOOT_ROOT   := $(THESEUS_SRC)/third-party/xboot
+XBOOT_C_SRCS := $(sort $(wildcard $(XBOOT_ROOT)/core/src/*.c))
+XBOOT_PAK    := $(XBOOT_ROOT)/out/pack/xboot.pak
+XBOOT_PAK_H  := $(XBOOT_ROOT)/out/xboot_pak.h
+XBOOT_INC    := -I$(XBOOT_ROOT)/core/include -I$(XBOOT_ROOT)/out
+XBOOT_CFLAGS := -std=c99 $(if $(DEBUG),-g -O0,-O2) -MMD -MP \
+                -ffp-contract=off -fno-fast-math -fno-math-errno \
+                -I$(XBOOT_ROOT)/core/include -I$(XBOOT_ROOT)/core/src
+PYTHON       ?= python3
+
+$(XBOOT_ROOT)/core/include/xboot.h:
+	@echo "xboot submodule not initialized; running git submodule update..."
+	cd $(THESEUS_SRC)/.. && git submodule update --init --depth 1 theseus/third-party/xboot
+
+$(XBOOT_PAK_H): $(XBOOT_ROOT)/core/include/xboot.h $(THESEUS_SRC)/../build/embed_xboot_pak.py
+	$(PYTHON) $(XBOOT_ROOT)/tools/pack/pack.py --check
+	$(PYTHON) $(THESEUS_SRC)/../build/embed_xboot_pak.py $(XBOOT_PAK) $@
+
+DESKTOP_CFLAGS += $(XBOOT_INC)
+DESKTOP_OBJS   += $(patsubst $(XBOOT_ROOT)/core/src/%.c,$(DESKTOP_DIR)/xboot/%.o,$(XBOOT_C_SRCS))
+$(DESKTOP_DIR)/desktop/boot_anim.o: $(XBOOT_PAK_H)
+$(DESKTOP_DIR)/xboot/%.o: $(XBOOT_ROOT)/core/src/%.c
+	@mkdir -p $(dir $@)
+	$(DESKTOP_CC) $(XBOOT_CFLAGS) -c -o $@ $<
+
 DESKTOP_DEPS = $(DESKTOP_OBJS:.o=.d)
 -include $(DESKTOP_DEPS)
 
@@ -914,6 +949,38 @@ shaders-bgfx-dx11:
 	@echo "=== bgfx shaders compiled to $(SHADERS_OUT_DIR)/dx11/ ==="
 
 
+# The boot animation's shaders (theseus/desktop/shaders/xboot/, see
+# boot_anim.cpp) have a varying.def.sc of their own and land next to the
+# others as Data/shaders/<backend>/xboot_<name>.bin. Same tools and
+# profiles as above; dx11 again only on Windows (fxc).
+#   make -C build shaders-xboot          metal, spirv, glsl, essl
+#   make -C build shaders-xboot-dx11     dx11, on Windows
+XBOOT_SHADERS_DIR := $(SHADERS_SRC_DIR)/xboot
+# $(call xboot-shaders,<subdir>,<platform>,<profile>)
+define xboot-shaders
+	@mkdir -p $(SHADERS_OUT_DIR)/$(1)
+	@for SC in $(XBOOT_SHADERS_DIR)/vs_*.sc $(XBOOT_SHADERS_DIR)/fs_*.sc; do \
+		NAME=$$(basename $$SC .sc); \
+		case $$NAME in vs_*) T=v ;; *) T=f ;; esac; \
+		echo "shaderc [$(1)] xboot_$$NAME"; \
+		$(SHADERC) -f $$SC -o $(SHADERS_OUT_DIR)/$(1)/xboot_$$NAME.bin \
+			--type $$T --platform $(2) --profile $(3) \
+			--varyingdef $(XBOOT_SHADERS_DIR)/varying.def.sc \
+			-i $(BGFX_SHADER_INC) -i $(XBOOT_SHADERS_DIR) \
+			|| exit 1; \
+	done
+endef
+
+.PHONY: shaders-xboot shaders-xboot-dx11
+shaders-xboot:
+	$(call xboot-shaders,metal,osx,metal)
+	$(call xboot-shaders,spirv,windows,spirv)
+	$(call xboot-shaders,glsl,linux,150)
+	$(call xboot-shaders,essl,android,300_es)
+
+shaders-xboot-dx11:
+	$(call xboot-shaders,dx11,windows,s_5_0)
+
 desktop: projectm-deps $(DESKTOP_TARGET)
 	@echo "=== desktop build complete: $(DESKTOP_TARGET) ==="
 
@@ -1195,6 +1262,16 @@ WIN64_SRCS += $(THESEUS_SRC)/desktop/imgui_impl_bgfx.cpp
 
 # Same source list as desktop. the compiler reads the same files.
 WIN64_OBJS = $(patsubst $(THESEUS_SRC)/%.cpp,$(WIN64_DIR)/%.o,$(WIN64_SRCS))
+
+# The boot animation's core, as for the native desktop target.
+WIN64_CC      = x86_64-w64-mingw32-gcc
+WIN64_CFLAGS += $(XBOOT_INC)
+WIN64_OBJS   += $(patsubst $(XBOOT_ROOT)/core/src/%.c,$(WIN64_DIR)/xboot/%.o,$(XBOOT_C_SRCS))
+$(WIN64_DIR)/desktop/boot_anim.o: $(XBOOT_PAK_H)
+$(WIN64_DIR)/xboot/%.o: $(XBOOT_ROOT)/core/src/%.c
+	@mkdir -p $(dir $@)
+	$(WIN64_CC) $(XBOOT_CFLAGS) -c -o $@ $<
+
 WIN64_DEPS = $(WIN64_OBJS:.o=.d)
 -include $(WIN64_DEPS)
 
@@ -1395,6 +1472,16 @@ LINUX_ARM64_LDFLAGS = \
 
 # Same source list as desktop. the compiler reads the same files.
 LINUX_ARM64_OBJS = $(patsubst $(THESEUS_SRC)/%.cpp,$(LINUX_ARM64_DIR)/%.o,$(DESKTOP_ALL_SRCS))
+
+# The boot animation's core, as for the native desktop target.
+LINUX_ARM64_CC      = aarch64-linux-gnu-gcc
+LINUX_ARM64_CFLAGS += $(XBOOT_INC)
+LINUX_ARM64_OBJS   += $(patsubst $(XBOOT_ROOT)/core/src/%.c,$(LINUX_ARM64_DIR)/xboot/%.o,$(XBOOT_C_SRCS))
+$(LINUX_ARM64_DIR)/desktop/boot_anim.o: $(XBOOT_PAK_H)
+$(LINUX_ARM64_DIR)/xboot/%.o: $(XBOOT_ROOT)/core/src/%.c
+	@mkdir -p $(dir $@)
+	$(LINUX_ARM64_CC) $(XBOOT_CFLAGS) -c -o $@ $<
+
 LINUX_ARM64_DEPS = $(LINUX_ARM64_OBJS:.o=.d)
 -include $(LINUX_ARM64_DEPS)
 

diff --git a/build/embed_xboot_pak.py b/build/embed_xboot_pak.py
@@ -0,0 +1,33 @@
+"""Writes the boot animation's data pack as a C++ header.
+
+    python3 build/embed_xboot_pak.py <xboot.pak> <xboot_pak.h>
+
+The pack comes from theseus/third-party/xboot/tools/pack/pack.py (the
+Makefile runs it first). The core reads the pack in place and wants it
+aligned to 16 bytes (XB_ALIGN), so the array is declared that way.
+"""
+
+import sys
+
+
+def main():
+    src, dst = sys.argv[1], sys.argv[2]
+    data = open(src, 'rb').read()
+    lines = [
+        '// Generated by build/embed_xboot_pak.py from %s. Do not edit.' % src.replace('\\', '/').split('/')[-1],
+        '#pragma once',
+        '#include <stddef.h>',
+        '',
+        'alignas(16) static const unsigned char kXbootPak[%d] = {' % len(data),
+    ]
+    for i in range(0, len(data), 16):
+        lines.append('\t' + ', '.join('0x%02x' % b for b in data[i:i + 16]) + ',')
+    lines.append('};')
+    lines.append('static const size_t kXbootPakSize = sizeof(kXbootPak);')
+    lines.append('')
+    with open(dst, 'w', newline='\n') as f:
+        f.write('\n'.join(lines))
+
+
+if __name__ == '__main__':
+    main()