5. Advanced - Custom Firmware

1. Overview

Note

This chapter introduces how to develop on the K230 CanMV. If you have no custom requirements, you can skip this chapter.

The K230 CanMV is developed based on the K230 SDK and runs applications using Micropython and OpenMV. Users can flexibly develop by invoking hardware resources through the Python language.

2. Setting Up the Development Environment

Host Environment	Description
Ubuntu 20.04.4 LTS (x86_64)	The K230 CanMV compilation environment is suitable for Ubuntu 20.04 and above.

Currently, K230 CanMV has only been verified to compile in a Linux environment. Other Linux versions have not been tested, so compatibility with other systems cannot be guaranteed.

2.1 Local Build Environment

• Update APT sources (optional)

sudo bash -c 'cp /etc/apt/sources.list /etc/apt/sources_bak.list && \
  sed -i "s/archive.ubuntu.com/mirrors.tuna.tsinghua.edu.cn/g" /etc/apt/sources.list && \
  sed -i "s/security.ubuntu.com/mirrors.tuna.tsinghua.edu.cn/g" /etc/apt/sources.list'

• Install necessary dependencies

# Add support for i386 architecture
sudo bash -c 'dpkg --add-architecture i386 && \
  apt-get clean all && \
  apt-get update && \
  apt-get install -y --fix-broken --fix-missing --no-install-recommends \
    sudo vim wget curl git git-lfs openssh-client net-tools sed tzdata expect mtd-utils inetutils-ping locales \
    sed make cmake binutils build-essential diffutils gcc g++ bash patch gzip bzip2 perl tar cpio unzip rsync \
    file bc findutils dosfstools mtools bison flex autoconf automake python3 python3-pip python3-dev python-is-python3 \
    lib32z1 scons libncurses5-dev kmod fakeroot pigz tree doxygen gawk pkg-config libyaml-dev libconfuse2 libconfuse-dev \
    libssl-dev libc6-dev-i386 libncurses5:i386'

• Update PIP sources (optional)

pip3 config set global.index-url https://pypi.tuna.tsinghua.edu.cn/simple && \
pip3 config set global.extra-index-url "https://mirrors.aliyun.com/pypi/simple https://mirrors.cloud.tencent.com/pypi/simple"

• Install Python dependencies

pip3 install -U pyyaml pycryptodome gmssl

• Install the repo tool

mkdir -p ~/.bin
curl https://storage.googleapis.com/git-repo-downloads/repo > ~/.bin/repo
chmod a+rx ~/.bin/repo
echo 'export PATH="${HOME}/.bin:${PATH}"' >> ~/.bashrc
source ~/.bashrc

3. Compilation Process

3.1 Source Code Download

The source code of CanMV-K230 is hosted on Github. Users can download the source code using the repo tool.

# It's recommended to create a directory in the user's home directory before downloading the code
mkdir -p ~/canmv_k230 && cd ~/canmv_k230

# Download the RT-Smart + CanMV project
repo init -u https://github.com/canmv-k230/manifest -b master --repo-url=https://github.com/canmv-k230/git-repo.git

# Download the pure RT-Smart project
repo init -u https://github.com/canmv-k230/manifest -b master -m rtsmart.xml --repo-url=https://github.com/canmv-k230/git-repo.git

# Synchronize the code
repo sync

3.2 Code Preparation

When compiling for the first time, you need to download the toolchain. The following command only needs to be executed once.

# Download the toolchain when running for the first time
make dl_toolchain

3.3 Compilation

Select the corresponding board configuration file according to actual needs, and then start compiling.

# List available configuration options
make list_def 
# Select the corresponding board configuration file
make xxxx_defconfig 
# Start compilation
time make log

After compilation, the image files will be generated in the ~/canmv_k230/output/xxxx/xxx.img directory.

If you don’t want to compile CanMV, you need to modify the configuration to disable only that module.

make menuconfig

# Disable the CanMV module

4. Code Directory Description

canmv_k230
.
├── boards
├── configs
├── include
├── output
├── src
│   ├── applications
│   ├── canmv
│   ├── opensbi
│   ├── rtsmart
│   └── uboot
└── tools

Directory structure description:

1. boards: Board-related files

2. configs: List of configuration files

3. include: Automatically generated header files

4. output: Compiled files, including images and temporary files

5. src/applications: User applications

6. src/canmv: CanMV-related files

7. src/opensbi: OpenSBI-related files

8. src/rtsmart: RT-Smart and MPP-related files

9. src/uboot: U-Boot-related files

10. scripts: Compilation system-related scripts