Buildroot Build

Environment Preparation

Prepare an Ubuntu 20.04/22.04 x86_64 host machine.

You can also work inside a virtual machine:

• ubuntu-22.04.5-live-server-amd64 VM with at least 120G of free disk space.

Install Build Dependencies

Host-Linux$

sudo apt update
sudo apt install python2 git rsync gcc g++ make device-tree-compiler bc flex bison lz4 libssl-dev libgmp-dev libmpc-dev expect expect-dev file unzip bzip2 fakeroot bsdmainutils
sudo ln -s /bin/python2 /bin/python

Download the Rockchip Reference SDK

• Baidu Cloud

• MEGA

Extract the SDK

On the Ubuntu host, run the following commands to unpack the SDK:

Host-Linux$

tar -xvzf rk3308_linux5.10_rkr8_sdk.repo.tar.gz
.repo/repo/repo sync -l

Add ROCK Pi S0 Board Support

Use the Radxa-maintained rockchip repository:

Host-Linux$

cd device/rockchip
git remote add radxa https://github.com/radxa/device-rockchip.git
git fetch radxa
git checkout -b rk3308-linux-5.10 remotes/radxa/rk3308-linux-5.10

Use the Radxa-maintained rkbin repository:

Host-Linux$

cd rkbin
git remote add radxa https://github.com/radxa/rkbin.git
git fetch radxa
git checkout -b develop-v2025.04 remotes/radxa/develop-v2025.04

Use the Radxa-maintained kernel repository:

Host-Linux$

cd kernel
git remote add radxa https://github.com/radxa/kernel.git
git fetch radxa
git checkout -b linux-5.10-gen-rkr8-buildroot remotes/radxa/linux-5.10-gen-rkr8-buildroot

Build the SDK

From the root of the SDK run:

Host-Linux$

./build.sh

Then choose the rockchip_rk3308_rock_s0_defconfig configuration file.

After the build finishes, images are produced under the rockdev/ directory. The system image file is update.img.

Flash the Image

Flash the Image to eMMC

On a Linux or macOS host, use upgrade_tool over the 4-pin USB2.0 OTG port to flash the update.img system image into eMMC:

Host-PC$

upgrade_tool uf update.img

On Windows, use RKDevTool via the Type-A flashing port to write update.img into eMMC:

• ①: Put the device into Maskrom mode.
• ②: Choose the Upgrade Firmware option.
• ③: Click Firmware and select the generated update.img.
• ④: Click Upgrade to start flashing the system image.

Flash the Image to a microSD Card

Use SDDiskTool to write the generated image to a microSD card.

SDDiskTool is Rockchip's official SD card flashing tool.

• Download SDDiskTool

  • SDDiskTool currently only has a Windows version, so please use it on a Windows computer.

  • Download link:SDDiskTool_en_v1.74.zip

• Flash SD card

  • We need to flash the corresponding complete image in RK format.

  • Complete image in RK format refers to The update.img image compiled using a series of Linux SDKs released by Rockchip based on Buildroot

  • Open the executable file SD_Firmware_Tool.exe of SDDiskTool and insert the SD card.

    warning

    When multiple storage devices are connected, please ensure you select the correct SD card to flash, otherwise other storage devices may be overwritten.

  • Select the SD card to flash from the removable disk devices, choose SD Boot as the function mode, ensure that the firmware upgrade is a complete image in RK format, and finally click Create to flash the image.

    

  • Please be patient during the flashing process. The image contains many partitions, and if the image is large, the flashing time will be longer.

If you encounter problems clearing the MBR while burning, you need to change the SD card disk label type from dos to gpt.

Windows

• Delete all partitions and convert to gpt using command prompt under windows

  • Press Win + X and select Windows Terminal (Administrator) or Command Prompt (Administrator).

  • Enter the following command and press Enter:

Host-Windows$

diskpart

• Then, enter the following command to list all disks:

Host-Windows$

list disk

• Locate your SD card (assuming it is disk 3) and enter:

Host-Windows$

select disk 3

• (If your SD card has a different disk number, change 3 to the correct number accordingly.)

• Clear all partitions on the disk:

Host-Windows$

clean

• (This deletes all partitions and data on the SD card.)

• Converts a disk to GPT format:

Host-Windows$

convert gpt

• Type exit to exit the diskpart utility.

Linux

• Use the fdisk command to change the label format to gpt on Linux.

  • Find your SD card (assuming it's /dev/sdb) and enter:

Host-Linux$

sudo fdisk /dev/sdb

• Type p and the label format and partition of the current disk will be displayed.

• Then type g to convert the disk to gpt format

• Then just type wq to save and exit.