docker: prepare SD card images, update README.md

Closes #1

Author: manio

Dockerfile

@@ -1,15 +1,27 @@
+# syntax=docker/dockerfile:1-labs
 FROM rust:latest AS stage-rust
-
 # crosscompile stuff
 RUN apt update && apt upgrade -y
 RUN apt install -y gcc-arm-linux-gnueabihf
 RUN rustup target add arm-unknown-linux-gnueabihf
-
 # cloning and building
 WORKDIR /usr/src/app
 RUN git clone https://github.com/manio/aa-proxy-rs .
 RUN cargo build --release
 
+# injecting aa-proxy-rs into all SD card images
+FROM alpine AS stage-sdcards
+RUN apk --no-cache add xz
+WORKDIR /root
+COPY --from=stage-rust /usr/src/app/target/arm-unknown-linux-gnueabihf/release/aa-proxy-rs .
+ADD contrib/injector.sh .
+ADD contrib/S93aa-proxy-rs .
+RUN --security=insecure ./injector.sh
+
 # copy the resulting binary out of container to local dir
 FROM scratch AS custom-exporter
 COPY --from=stage-rust /usr/src/app/target/arm-unknown-linux-gnueabihf/release/aa-proxy-rs .
+COPY --from=stage-sdcards /root/raspberrypi0w-sdcard.img.xz .
+COPY --from=stage-sdcards /root/raspberrypi3a-sdcard.img.xz .
+COPY --from=stage-sdcards /root/raspberrypi4-sdcard.img.xz .
+COPY --from=stage-sdcards /root/raspberrypizero2w-sdcard.img.xz .

README.md

@@ -64,7 +64,7 @@ not ready with USB connection then we can't send data to the phone and Android w
 ## Demo
 [![asciicast](https://asciinema.org/a/686949.svg)](https://asciinema.org/a/686949)
 
-## Building and installing
+## Building
 `rpi02w` binaries build by [WirelessAndroidAutoDongle](https://github.com/nisargjhaveri/WirelessAndroidAutoDongle) are for `arm-unknown-linux-gnueabihf` 32-bit architecture, probably
 because of usb-gadget module [incompatibility](https://github.com/nisargjhaveri/WirelessAndroidAutoDongle/pull/129).
 To be able to properly crosscompile output binary I provided `.cargo/config.toml` with target set for this specific arch.
@@ -79,17 +79,31 @@ arm-unknown-linux-gnueabihf (installed)
 ```
 Besides a `gcc-arm-linux-gnueabihf` package is needed on Debian. This is distro-depended so I recommend to RTFM.
 
-After building you need to transfer the binary to the target filesystem (I am using ssh/scp for this) and start it.
-For permanent solution I also modified startup scripts - but how to do it is out of scope of this document.
-
 ## Building using Docker
 To build with Docker you need to have a [buildx](https://github.com/docker/buildx) and [BuildKit](https://github.com/moby/buildkit).<br>
-Then you can e.g. create some output dir and build the binary like this:
+Docker container is also preparing an SD card images based on [@nisargjhaveri](https://github.com/nisargjhaveri)'s [latests assets](https://github.com/nisargjhaveri/WirelessAndroidAutoDongle/releases).
+It has to loop-mount that images, thus an insecure builder is [needed](https://docs.docker.com/reference/cli/docker/buildx/build/#allow).
+To sum it up - the following commands are needed when building for the first time:
 ```
 mkdir out
-DOCKER_BUILDKIT=1 docker build --output out .
+docker buildx create --use --name insecure-builder --buildkitd-flags '--allow-insecure-entitlement security.insecure'
+docker buildx build --builder insecure-builder --allow security.insecure --output out .
 ```
-After successful execution the resulting `aa-proxy-rs` will be in `out` directory.
+After successful execution the resulting `aa-proxy-rs` and SD card images will be in `out` directory.
+
+## Installing into target
+If you currently using a Raspberry Pi with working _WirelessAndroidAutoDongle_, then you can also manually install `aa-proxy-rs`:
+
+You need to transfer the resulting output binary to the target filesystem and start it. I am using ssh/scp for this, but it should be also possible with `wget`.
+You can also do it "offline" by making a changes directly on the SD card: mounting system partition and make necessary changes.
+Sample [startup script](https://raw.githubusercontent.com/manio/aa-proxy-rs/refs/heads/main/contrib/S93aa-proxy-rs) is provided for convenience.
+
+Example steps:
+- put `aa-proxy-rs` into /usr/bin
+- put `S93aa-proxy-rs` into /etc/init.d
+- remove or disable /etc/init.d/S93aawgd
+
+Startup parameters (see below) are defined [here](https://github.com/manio/aa-proxy-rs/blob/main/contrib/S93aa-proxy-rs#L10).
 
 ## Usage
 ```

contrib/injector.sh

@@ -0,0 +1,25 @@
+#!/bin/sh
+
+# download official images
+for pi in 0w 3a 4 zero2w; do
+	wget https://github.com/nisargjhaveri/WirelessAndroidAutoDongle/releases/latest/download/raspberrypi${pi}-sdcard.img.xz
+done
+
+# unpack
+for filename in *xz; do
+	echo ">>> unpacking $filename..."
+	unxz $filename
+done
+
+# process each image and place an aa-proxy-rs
+for filename in *img; do
+	echo ">>> processing $filename..."
+	mount -o loop,offset=33554944 $filename /mnt
+	rm /mnt/etc/init.d/S93aawgd
+	cp /root/S93aa-proxy-rs /mnt/etc/init.d
+	cp /root/aa-proxy-rs /mnt/usr/bin
+	umount /mnt
+
+	echo ">>> compressing $filename..."
+	xz $filename
+done