Overview

This document describes how to use Yocto Project to quickly build
board-level images for the RockChip platform. Mainly describe the
basic construction method of meta-rochip layer and Yocto Project.

The Yocto Project is an open source collaborative project focused on
embedded Linux® operating system development that provides a flexible
toolset and development environment that allows embedded device
developers worldwide to share technologies, software stacks,
configurations and tools for creating these customizations Best
Practices for Linux Imaging Collaboration. For more information about
the Yocto Project, please refer to the official Yocto Project website:

www.yoctoproject.org/

. The Yocto Project home page has the

Yocto Project Reference Manual

 and the

Yocto Project Overview

 and other related documents describe in detail how to build the
system.

The Yocer Project support provided by firefly is as follows:

Manifests repository: https://gitlab.com/firefly-
linux/manifests/-/tree/master/yocto

Introduction to Yocto Project Release layer

Get SDK

   repo init --no-clone-bundle --repo-url https://gitlab.com/firefly-linux/git-repo.git -u https://gitlab.com/firefly-linux/manifests.git -b master -m yocto_release.xml
   .repo/repo/repo sync -c

compile

Select core-image-minimal image

The Yocto project provides some images that can be used without
layers. The following table lists currently supported build images and
associated recipes.

Build image

Select board configuration file

There are many board-level configuration files under

<yocto SDK>/build/conf

, select the corresponding configuration file by generating local.conf
soft link.

Take the firefly-rk3399 board as an example:

       # Go to yocto SDK
       cd build/conf

       # Select the configuration file and find the configuration file corresponding to the firefly-rk3399 board
       firefly-rk3399.conf进行软连接
       ln -fs rk3399/firefly-rk3399.conf local.conf

Note

: Different boards have different configuration files, the above is
just for reference

The process of building with the bitbake command needs to ensure that
the network connection is normal. If it is a customer in inland China,
you need to ensure that it can ping the external network

Enter the directory <path/to/yocto> and execute the following commands
in sequence    # Install the required environment packages   # sudo
apt install zstd   source oe-init-build-env   bitbake core-image-
minimal

The above command is to compile the complete core-image-minimal
recipes. If you want to compile some recipes separately, you can refer
to the following:    # kernel   bitbake linux-rockchip    # u-boot
bitbake u-boot    # rkmpp   bitbake rockchip-mpp    # rockchip-librga
bitbake rockchip-librga    # 参看更多编译对象   bitbake -s

More bitbake options

Fundamentally, BitBake is a generic task execution engine that allows
shell and Python tasks to be run efficiently and in parallel while
working within complex inter-task dependency constraints. One of
BitBake’s main users, OpenEmbedded, takes this core and builds
embedded Linux software stacks using a task-oriented approach.For more
detailed usage, please check

《bitbake-user-manual》

。

       bitbake <target> <paramater>
       # e.g
       bitbake u-boot -c clean
       bitbake u-boot

Flash image

The compiled firmware is located in the directory
"<path/to/yocto>/build/tmp/deploy/<board>/", the files to be
downloaded are .wic and update.img, and after entering the loader
mode, execute the following commands :

   $ sudo upgrade_tool wl 0 <IMAGE NAME>.wic
   $ sudo upgrade_tool uf update.img

   # The default core-image-minimal login account password is: root

If customers develop on Windows PC, they can also use RKdevtool to
directly burn update.img