Merge pull request #14 from zarhus/rpi4-update

docs/supported-targets/targets.md: add rpi4

Author: WiktorG351

docs/getting-started/building.md

@@ -66,6 +66,8 @@ Currently, the following files are present in `meta-zarhus/kas`:
 * `rockchip.yml`: Rockchip-specific target configuration file, should be used
   for Rockchip builds;
 * `webkit.yml`: includes Webkit and some additional functionalities into build.
+* `rpi.yml`: includes a layer necessary for Raspberry Pi boards, as well
+  necessary config.
 
 Then check BSP layers for available target platform (target platforms configs
 are located in `conf/machine` directory of every BSP layer) and choose one.

docs/supported-targets/rpi4.md

@@ -0,0 +1,81 @@
+# Raspberry Pi 4
+
+## Description and Resources
+
+The Raspberry Pi 4 is a versatile single-board computer suitable for a wide
+range of applications. This guide walks through building Zarhus OS using
+`meta-zarhus`, flashing the OS onto an SD card, and accessing the device
+via UART for debugging.
+
+Additional resources for the Raspberry Pi 4:
+
+* [Raspberry Pi Documentation](https://www.raspberrypi.com/documentation/)
+* [Raspberry Pi GPIO Pinout](https://www.raspberrypi.com/documentation/computers/images/GPIO-Pinout-Diagram-2.png?hash=df7d7847c57a1ca6d5b2617695de6d46)
+
+## Zarhus OS Setup
+
+### Build Zarhus OS
+
+1. Clone the `meta-zarhus` repository:
+
+    ```sh
+    git clone https://github.com/zarhus/meta-zarhus
+    ```
+
+2. Follow the instructions in the repository's
+[building guide](../getting-started/building.md) to build Zarhus OS for
+Raspberry Pi 4.
+
+Once built, you can move onto flashing.
+
+### Flash Zarhus OS Image to SD Card
+
+To flash the image to the SD card:
+
+    ```sh
+    cd build/tmp/deploy/images/raspberrypi4
+    sudo bmaptool copy --bmap zarhus-base-image-debug-raspberrypi4.rootfs.wic.bmap zarhus-base-image-debug-raspberrypi4.rootfs.wic.gz /dev/sdc
+    ```
+
+Replace `/dev/sdX` with your SD card device (e.g. `/dev/sdb`).
+Ensure you are writing to the correct device.
+
+## UART Console Access
+
+### Hardware Setup
+
+To connect via UART for debugging:
+
+1. Use a UART-to-USB adapter and connect it to the Raspberry Pi 4 GPIO pins:
+
+    | GPIO Pin | Description  |
+    |----------|--------------|
+    | Pin 6    | GND          |
+    | Pin 8    | UART TXD     |
+    | Pin 10   | UART RXD     |
+
+    Refer to the
+    [Raspberry Pi GPIO Pinout](https://www.raspberrypi.com/documentation/computers/images/GPIO-Pinout-Diagram-2.png?hash=df7d7847c57a1ca6d5b2617695de6d46)
+    for the full pinout.
+
+2. Plug the USB end into your host machine.
+
+### Software Setup
+
+1. Install a terminal program (e.g., `minicom` for Linux).
+
+2. Launch `minicom` on a Linux host to connect to the RPi4:
+
+    ```sh
+    minicom -D /dev/ttyUSBX
+    ```
+
+    Also make sure `Hardware Flow Control` is off (`CTRL-A`, then `Z` to
+    open the menu, then `O` to `Configure minicom`, then choose
+    `Serial port setup`, then (if it's enabled) press `F` to
+    disable `Hardware Flow Control`).
+
+3. You should now see the Zarhus OS boot console.
+
+From this point, you can login (login `root`) to monitor and debug the
+Raspberry Pi 4 running Zarhus OS.

docs/supported-targets/targets.md

@@ -5,3 +5,7 @@ This section contains a list of supported vendors and their targets.
 ## Radxa
 
 * [Radxa CM3 System on Module](./radxa-cm3.md).
+
+## Raspberry Pi
+
+* [Raspberry Pi 4](./rpi4.md)

mkdocs.yml

@@ -73,6 +73,8 @@ nav:
       - 'Targets': supported-targets/targets.md
       - 'Radxa':
           - 'Radxa CM3': supported-targets/radxa-cm3.md
+      - 'Raspberry Pi':
+          - 'Raspberry Pi 4': supported-targets/rpi4.md
   - 'Guides':
       - 'Managing packages': guides/managing-packages.md
       - 'Managing layers': guides/managing-layers.md