System Development

Yocto Linux

The official development environment is based on yocto and customized by T-head, which could be obtained here: https://gitee.com/thead-yocto/

This section gives a brief introduction of setuping uilding Linux Yocto environment and use it to build the full image able to run on the development board.

Setup Yocto Compilation Environment

Linux SDK uses Yocto to build images, which runs under Ubuntu 18.04. It is recommended to deploy Yocto under Linux with Docker. Yocto could also be deployed under Ubuntu18.04 directly. (Refer to T-Head曳影1520Yocto用户指南.pdf2.2)

This section includes the guide to deploy with Docker only. **It is recommended to reserve 200G disk space and more than 4G memory on the machine. The time cosumed varies because of network situation. Building with a typical Linux configuration (mininal system plus essential basic components) takes about 1.5 hours. (with i5-11400, as only a reference)

• Install docker with official script

  curl -fsSL https://get.docker.com | bash -s docker --mirror Aliyun
  

• Download dockerfile and modify username and ID
  Click here to download linux-dev-master.7z ，enter linux-dev-master after decompressing，open Dockerfile and find following instructions

  ENV DOCKER_USER2 "your the same user name asyour host"`
  ENV USER2_ID "your user id"
  

  Change "your the same user name as your host" to the name of user on host OS, "your user id" to the corresponding password
• Setup Docker image environment

  docker build -t linux-dev-base:base .
  

  Some errors may occur during downloading packages in this step. You could modify Dockerfile and put off downloading to successfully logining. This Docker image is able to build Linux SDKs released by T-Head, such as buildroot, yocto and so on. The default password is 123.
• Startup Docker

  docker run -u thead -dt --name linux-dev-{your_name} -v {your_lock_home}:{your_home} linux-dev-base:base /bin/bash
  

  {your_name} is the name of your container. Remember not to reuse an existing name.
  It is possible mount a directory in host with option -v, which could serve as a way to share files. {your_lock_home} is the local path under host, {your_home} is the path mounted in Docker.
• Check started Docker containers.

  docker ps | grep linux-dev-base
  

then started Docker containers are shown,

• Login Docker

  docker exec -it linux-dev-{your_name} /bin/bash
  

• Download open-source packages (only needed at the first time of building SDK)
  Packages will be downloaded during building the firmware, which could take a long time with a poor network connection. To speed up the process, you could download the packages from Gitee ahead of time.

  cd ~
  git clone https://gitee.com/thead-yocto/yocto-downloads.git
  

• Download Yocto building packages

  git clone https://gitee.com/thead-yocto/xuantie-yocto.git -b Linux_SDK_V1.1.2
  

• Load configuration of targeted device and environment variables (remember to check before building)

  cd xuantie-yocto
  source openembedded-core/oe-init-build-env thead-build/light-fm
  

• Create a softlink to downloaded packages in directory downloads in SDK directory.

  ln -s ~/yocto-downloads ../downloads
  

Now the building environment is ready.

Supported List of Machine/Target

In the step above (load environment variables), following message is shown after successfully setuping.

### Shell environment set up for builds. ###
You can now run 'bitbake <target>'
Common targets are:
    thead-image-linux
    thead-image-multimedia
    thead-image-gui
machines:
    light-beagle
    light-b-product
    light-a-val
    light-lpi4a

Here is the description:
target (List of images supported by the SDK):

machines (Board-level configuration supported by the SDK):

Building images

Building commands are like following:

MACHINE={machine} bitbake {target}

Replace {machine} and {target} with corresponding names in tables above. For example, the command to build a typical Linux image running on LicheePi 4A development board is:

MACHINE=light-lpi4a bitbake thead-image-linux

Problems while building images

• Caused by poor network, downloading may be slow and even fails at this step. Recommend proxies if possible.
• Error message:

  Please use a locale setting which supports utf-8.
  Python can't change the filesystem locale after loading so we need a utf-8 when python starts or things won't work.
  

  Run following commands first

  sudo apt-get install locales
  sudo dpkg-reconfigure locales 
  

  Then find en\_US.UTF8 in the printed list (approximately the 158th). Type its ID and then press enter. Select this option also in the next step.
  Then run following commands (it is worth adding to .bashrc in Docker)

  sudo locale-gen en_US.UTF-8
  sudo update-locale LC_ALL=en_US.UTF-8 LANG=en_US.UTF-8
  export LANG=en_US.UTF-8
  

  After finishing, there will not be errors during building.
• Error message:

  please install them in order to proceed: lz4c pzstd zstd
  

  Simply install corrsponding dependencies.

  sudo apt update && sudo apt install -y zstd liblz4-tool
  

Packaging images

This repository light_deploy_images contains serveral pre-released images. sdk.sh in the repository is suitable to package new-built images.
Enter light-fm directory in the built image and move sdk.sh here. Run it with ./sdk.sh and the corresponding image is generated after packaging. For file paths and directory structure of the image, refer to repository light_deploy_images.
Finally, copy the built image and related files to the shared directory mounted with option -v and the file could be used for burning.
Now we have finished building and packaging, resulting with an image able to burn into and run in the development board.

Build Separately

How to build official components released by T-head separately

• OpenSBI

• Uboot

  git clone https://gitee.com/thead-yocto/u-boot
  cd u-boot
  make CROSS_COMPILE=riscv64-unknown-linux-gnu- ARCH=riscv light_lpi4a_defconfig
  make CROSS_COMPILE=riscv64-unknown-linux-gnu- ARCH=riscv
  

  The generated firmware is u-boot-with-spl.bin, which could be burnt with fastboot.

• Kernel

Device Tree Analysis

TODO

Other References

light_deploy_images Repository：

• Includes pre-built and burnable Linux images, packaging scripts and other reletive tools. Refer to the repository for more information.
• Repository Address: https://gitee.com/thead-yocto/light_deploy_images

documents Repository:

• Includes all released documentation related to SDK
• Repository Address: https://gitee.com/thead-yocto/documents

Mainline

How to build mainline version (under developing)

OpenSBI

• Download and build

  git clone https://github.com/riscv-software-src/opensbi
  cd opensbi
  make CROSS_COMPILE=riscv64-unknown-linux-gnu- PLATFORM=generic
  

  Generated firmware is build/platform/generic/firmware/fw_dynamic.bin. Copy it to /boot

U-boot

• Download and build

  git clone -b th1520 https://github.com/dlan17/u-boot.git
  cd u-boot
  make CROSS_COMPILE=riscv64-unknown-linux-gnu- ARCH=riscv light_lpi4a_defconfig
  make CROSS_COMPILE=riscv64-unknown-linux-gnu- ARCH=riscv
  

  Generated firmware is u-boot-dtb.bin. Copy it to /boot

• Boot mainline U-boot (under developing) with on-board U-boot
  Pre-burnt U-boot has supported Ethernet already, which makes it possible to obtain new U-boot image through tftp protocol.

  Startup a tftp instance on the developing machine. Taking Alpine for example, install package tftp-hpa and enable corresponding service.

  apk add tftp-hpa
  rc-update add in.tftp
  rc-service in.tftp start
  

  By default tftp uses /var/tftpboot as the root directory, so copy the new-built U-boot u-boot-dbt.bin to /var/tftpboot.

  Connect UART and Ethernet on LicheePi 4A development board, power it and press any key when following message is shown in serial

  Press any key to stop autoboot
  

  to enter U-boot shell.

  Type dhcp to configure Ethernet card with DHCP protocol. Mainline U-boot is expected to be loaded at 0x1c00000, so type

  tftp 0x1c00000 TFTP_SERVER_IP:u-boot-dtb.bin
  go 0x1c00000
  

  in U-boot shell to load the new-built U-boot into 0x1c00000 and jump to it.

Linux

OpenWRT

TODO

Andriod

TODO

OpenHarmony

TODO

Others

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