Yocto 3.1 support for RPI 3B+ - 2020 - M12

Introduction

This manual describes the rdk-generic-broadband-image build procedure for Yocto 3.1 builds. This will upgrade the default build system used in RDKB, from morty(2.2) to dunfell(3.1). In addition to upgrades to opensource packages, Yocto 3.1 also contain Long term Support release feature. The current version lacks the variety of features available in the dunfell. The upgraded build tools will be used to generate rdk-generic-broadband-image for Raspberrypi reference platform. 

Yocto 3.1 Upgradation support the following:

• Yocto BSP layer for meta-raspberrypi.
• OpenEmbedded and Yocto Dunfell.
• Linux kernel 5.4.72.
• Version upgrades for bitbake, and other oe/python recipes.

Each component in RDK is a standalone repository with its own individual build tools producing a library or set of binaries. When we upgrade the OE layers to the newer versions, we need to make necessary changes in the RDK layers which use these components, to avoid build failures.

Host Setup

The OpenEmbedded build system should be able to run on Ubuntu 18.04 distribution/other compatible linux distribution with the following versions for Git, tar, and Python.

• Git 1.8.3.1 or greater
• tar 1.27 or greater
• Python 3.4.0 or greater
• Coreutils(E.g realpath)

Note: You should also have about 50 Gbytes of free disk space for building images.

The essential packages you need for a supported Ubuntu or Debian distribution are shown in the following command:

$ sudo apt-get install gawk wget git-core diffstat unzip texinfo gcc-multilib \
  build-essential chrpath socat cpio python python3 python3-pip python3-pexpect \
  xz-utils debianutils iputils-ping python3-git python3-jinja2 libegl1-mesa libsdl1.2-dev \
  pylint3 xterm bmap-tools

Repo Setup

In order to use Yocto build system, the repo tool must be properly installed on the machine.

To install Repo make sure you have a /bin directory in your home directory and that it is included in your path

$ mkdir ~/bin
$ PATH=~/bin:$PATH
Download the repo tool and ensure that it is executable
$ curl http://commondatastorage.googleapis.com/git-repo-downloads/repo > ~/bin/repo
$ chmod a+x ~/bin/repo

Note: it is also recommended to put credentials in ~/.netrc when interacting with repo.

A sample ~/.netrc file is illustrated below

machine code.rdkcentral.com
login YOUR_USERNAME
password YOUR_PASSWORD

Executing System

Yocto Build Steps

To build, follow below instructions

$ mkdir <workspace dir>
$ cd <workspace dir>
$ repo init -u https://code.rdkcentral.com/r/manifests -b yocto-dunfell-upgrade -m rdkv-asp-nosrc.xml
$ repo sync -j4 --no-clone-bundle
$ MACHINE=raspberrypi-rdk-mc source meta-cmf-raspberrypi/setup-environment
$ bitbake rdk-generic-mediaclient-image

Flashing Procedure

Following command can be used to flash the RPI image to sd card using linux machine . bmap tool should be available in linux

bzip2 -d <path to ImageName.wic.bz2>
sudo -E bmaptool copy --nobmap <path to ImageName.wic> <path to SD card space>

Example:

$ bzip2 -d rdk-generic-broadband-image-raspberrypi-rdk-broadband.wic.bz2
$ sudo -E bmaptool copy --nobmap rdk-generic-broadband-image-raspberrypi-rdk-broadband.wic /dev/sdb

Known Issues and Limitations