Start X on Raspberry Pi, lazzer style

Signed-off-by: Joachim Wiberg <[email protected]>

Author: troglobit

Dockerfile

@@ -13,6 +13,11 @@ RUN apk add --no-cache \
     libxmp \
     mesa-dri-gallium \
     mesa-gbm \
+    xorg-server \
+    xf86-video-fbdev \
+    xf86-input-evdev \
+    xdpyinfo \
+    xinit \
     gcc \
     musl-dev \
     make \
@@ -24,8 +29,53 @@ COPY demo.c Makefile topaz-8.otf *.png music.mod* ./
 
 RUN make
 
-# Default to X11, but can be overridden for framebuffer
+# Create minimal X config for framebuffer
+RUN mkdir -p /etc/X11 && cat > /etc/X11/xorg.conf << 'EOF'
+Section "ServerFlags"
+    Option "DontVTSwitch" "true"
+    Option "BlankTime" "0"
+    Option "StandbyTime" "0"
+    Option "SuspendTime" "0"
+    Option "OffTime" "0"
+EndSection
+
+Section "Device"
+    Identifier "Card0"
+    Driver "fbdev"
+    Option "fbdev" "/dev/fb0"
+EndSection
+
+Section "Screen"
+    Identifier "Screen0"
+    Device "Card0"
+EndSection
+EOF
+
+# Create startup script
+RUN cat > /app/start.sh << 'EOF'
+#!/bin/sh
+# Smart startup: use existing X or start our own
+
+# Check if X server is already available
+if xdpyinfo -display "${DISPLAY:-:0}" >/dev/null 2>&1; then
+    echo "Using existing X server on $DISPLAY"
+    exec ./demo "$@"
+else
+    echo "No X server found, starting embedded X server..."
+    # Start X server in background and run demo
+    Xorg -noreset +extension GLX +extension RANDR +extension RENDER -logfile /tmp/xorg.log -config /etc/X11/xorg.conf :0 &
+    XPID=$!
+    sleep 2
+    DISPLAY=:0 ./demo "$@"
+    EXITCODE=$?
+    kill $XPID 2>/dev/null
+    wait $XPID 2>/dev/null
+    exit $EXITCODE
+fi
+EOF
+
+RUN chmod +x /app/start.sh
+
 ENV DISPLAY=:0
-ENV SDL_VIDEODRIVER=x11
 
-CMD ["./demo"]
+CMD ["/app/start.sh", "-f"]

README.md

@@ -70,13 +70,17 @@ No installation required! The AppImage bundles all dependencies.
 
 ### Run with Docker
 
-**Pull and run the latest image:**
+The container image automatically detects whether X11 is available and adapts accordingly.
+
+#### On Desktop Systems (with X11)
+
+**Basic run:**
 
 ```bash
 # Allow X11 connections (run once per session)
 xhost +local:docker
 
-# Run the demo (video only)
+# Run the demo
 docker run --rm -it \
   -e DISPLAY=$DISPLAY \
   -v /tmp/.X11-unix:/tmp/.X11-unix \
@@ -107,65 +111,47 @@ docker run --rm -it \
   -e PULSE_SERVER=unix:${XDG_RUNTIME_DIR}/pulse/native \
   -v ${XDG_RUNTIME_DIR}/pulse/native:${XDG_RUNTIME_DIR}/pulse/native \
   ghcr.io/kernelkit/demo:latest \
-  ./demo -w 1920x1080
-```
-
-**Or use docker-compose:**
-
-```bash
-docker compose up
+  /app/start.sh -w 1920x1080
 ```
 
-### Run without X11 (Direct Framebuffer)
+#### On Embedded Systems (without X11)
 
-For embedded systems or headless setups without X11 (e.g., Raspberry Pi, embedded Linux):
+For embedded systems like Raspberry Pi or Infix OS, the container starts its own X server:
 
-**Using KMS/DRM (recommended for modern systems):**
+**Raspberry Pi 4 / Embedded Linux (fullscreen):**
 
 ```bash
-# Requires access to DRI and input devices
 docker run --rm -it \
   --privileged \
-  -v /dev/dri:/dev/dri \
-  -v /dev/input:/dev/input \
-  -e SDL_VIDEODRIVER=kmsdrm \
-  -e SDL_AUDIODRIVER=alsa \
+  -v /dev/fb0:/dev/fb0 \
+  -v /dev/tty1:/dev/tty1 \
   ghcr.io/kernelkit/demo:latest
 ```
 
-**Using legacy framebuffer:**
+**With custom demo options:**
 
 ```bash
+# Example: 30 seconds per scene, show scenes 0, 2, and 6
 docker run --rm -it \
   --privileged \
   -v /dev/fb0:/dev/fb0 \
-  -v /dev/input:/dev/input \
-  -e SDL_VIDEODRIVER=fbcon \
-  -e SDL_FBDEV=/dev/fb0 \
-  -e SDL_AUDIODRIVER=alsa \
-  ghcr.io/kernelkit/demo:latest
+  -v /dev/tty1:/dev/tty1 \
+  ghcr.io/kernelkit/demo:latest \
+  /app/start.sh -d 30 0 2 6
 ```
 
-**On Raspberry Pi 4:**
+#### Using docker-compose
 
 ```bash
-# KMS/DRM mode (best performance)
-docker run --rm -it \
-  --privileged \
-  -v /dev/dri:/dev/dri \
-  -v /dev/input:/dev/input \
-  -e SDL_VIDEODRIVER=kmsdrm \
-  -e SDL_AUDIODRIVER=alsa \
-  ghcr.io/kernelkit/demo:latest \
-  ./demo -f
+docker compose up
 ```
 
 **Notes:**
-- `SDL_VIDEODRIVER=kmsdrm` uses kernel mode setting (modern, hardware accelerated)
-- `SDL_VIDEODRIVER=fbcon` uses legacy framebuffer (fallback)
-- `--privileged` gives access to GPU and input devices
-- `-f` flag runs in fullscreen mode (recommended for framebuffer)
-- For audio without PulseAudio, use `SDL_AUDIODRIVER=alsa` or omit for no audio
+- The container automatically detects if X11 is available via `xdpyinfo`
+- With X11: Uses the host's X server
+- Without X11: Starts embedded X server using framebuffer
+- `--privileged` needed for framebuffer/TTY access on embedded systems
+- Default runs fullscreen (`-f` flag) when using embedded X server
 
 ## Building from Source