Microhil Yocto Project

This document explains how to clone and set up your Yocto environment with repo, then build an image for Raspberry Pi 5.

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1. Prerequisites

• Operating System: Linux (Ubuntu/Debian recommended).
• Required Packages:

  sudo apt update && sudo apt install -y git repo python3 python3-pip gawk wget diffstat unzip texinfo gcc-multilib build-essential chrpath socat libsdl1.2-dev xterm

• Disk Space: At least 50 GB free.
• Internet Connection: Required to clone layers and download sources.

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2. Clone the Repository with repo

1. Initialize repo:

   repo init -u <repository-git-url> -b <branch> --no-clone-bundle

   Example:

   repo init -u https://github.com/iromzy/microhil-yocto.git -b main --no-clone-bundle

2. Sync Submodules:

   repo sync

3. Layer Structure: After syncing, you will have a directory structure with the required layers, for example:

   microhil-yocto/
   ├── default.xml
   ├── build/
   ├── poky/
   ├── meta-raspberrypi/
   ├── meta-openembedded/
   ├── meta-microhil/
   └── ...
   

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3. Configure the Build Environment

1. Set up the environment with oe-init-build-env:

   source poky/oe-init-build-env build

   This command places you in the build/ directory.

2. Edit bblayers.conf: Ensure all required layers are included in conf/bblayers.conf, for example:

   BBLAYERS ?= " \
       ${TOPDIR}/../poky/meta \
       ${TOPDIR}/../poky/meta-poky \
       ${TOPDIR}/../meta-raspberrypi \
       ${TOPDIR}/../meta-openembedded/meta-networking \
       ${TOPDIR}/../meta-openembedded/meta-python \
       ${TOPDIR}/../meta-microhil \
   "

3. Edit local.conf: Update the build configuration in conf/local.conf:

   • Target Machine:

     MACHINE = "raspberrypi5"

   • Build Parallelization:

     BB_NUMBER_THREADS = "$(nproc)"
     PARALLEL_MAKE = "-j$(nproc)"

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4. Build the Image

1. Start the Build:

   bitbake microhil-image

2. Check the Generated File: After the build completes, the image will be available in:

   build/tmp/deploy/images/raspberrypi5/

   Example generated file:

   core-image-microhil-raspberrypi5.wic.gz
   

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5. Flash the Image to an SD Card

1. Decompress the Image:

   gunzip core-image-microhil-raspberrypi5.wic.gz

2. Flash the SD Card:

   sudo dd if=core-image-microhil-raspberrypi5.wic of=/dev/sdX bs=4M status=progress conv=fsync

   Replace /dev/sdX with the correct path to your SD card (use lsblk to check).

3. Insert the SD Card into your Raspberry Pi and boot it.

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6. Access the Raspberry Pi

1. Connect via Ethernet (mDNS):

   ssh [email protected]

   Default password: changeme (adjust in configuration if needed).

2. Connect via Wi-Fi: Configure the wpa_supplicant.conf file if needed to join a Wi-Fi network.

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