Zero/dev/u-boot
Radxa Zero > Development > U-Boot
Contents
Build U-Boot and flash it on Radxa Zero
This guide describes how to build U-Boot and flash it on Radxa Zero. U-Boot image can be flashed on eMMC or microSD, and it can be sideload from USB as well.
WARNING! Flash bootloader incorrectly could result in unbootable system and loss of data. Do not replace bundled bootloader unless you understand the risk.
Requirement
- Radxa Zero
- USB A to C cable
- A computer running Ubuntu 18.04 or higher
Build U-Boot
Step 1: Get the source code
We use git to fetch source code from internet. If you do not have git installed, try following commands:
sudo apt update sudo apt install git
Once you have git installed, you can download the source code:
git clone -b radxa-zero-v2021.07 https://github.com/radxa/u-boot.git
FIP(Firmware in Package) is a collection of scripts and pre-built binaries (such as first stage loader and so on) for Radxa Zero U-Boot. Get them with following command:
git clone https://github.com/radxa/fip.git
Step 2: Set up build environment
Execute following commands to install build dependencies and the tool chain necessary for building.
sudo apt install bc nano mc build-essential autoconf libtool cmake pkg-config git python python-dev swig libpcre3-dev libnode-dev gawk wget diffstat bison flex device-tree-compiler libncurses5 libncurses5-dev gcc-aarch64-linux-gnu g++-aarch64-linux-gnu binfmt-support qemu-user-static dosfstools libssl-dev mtools wget https://developer.arm.com/-/media/Files/downloads/gnu-a/10.3-2021.07/binrel/gcc-arm-10.3-2021.07-x86_64-aarch64-none-elf.tar.xz sudo tar xvf gcc-arm-10.3-2021.07-x86_64-aarch64-none-elf.tar.xz -C /opt
Step 3: Build U-boot
export CROSS_COMPILE=/opt/gcc-arm-10.3-2021.07-x86_64-aarch64-none-elf/bin/aarch64-none-elf- export ARCH=arm cd u-boot make radxa-zero_defconfig make
You will find u-boot.bin under u-boot folder if everything runs without error.
Step 4: Pack U-boot
cp u-boot.bin ../fip/radxa-zero/bl33.bin cd ../fip/radxa-zero make
This will generate
u-boot.bin u-boot.bin.sd.bin u-boot.bin.usb.bl2 u-boot.bin.usb.tpl
Run U-boot
- Sideloading from USB
When your U-Boot is broken you can sideload a working image to recover an unbootable system. This can also be used to verify the newly generated image is working before flashing it permanently on storage media.
Install the maskrom usb download tool with pip
sudo apt install pip3 sudo pip3 install pyamlboot
Press and hold the USB boot button on the back of Radxa Zero, and connect Zero to your PC.
You should see following device connected to your system:
$ lsusb Bus 002 Device 030: ID 1b8e:c003 Amlogic, Inc. GX-CHIP
Sideloadng u-boot.bin:
boot-g12.py /path/to/fip/radxa-zero/u-boot.bin
If you have serial console attached to Radxa Zero, you will see the boot message from U-Boot.
- Flash U-Boot to microSD
bin=/path/to/fip/radxa-zero/u-boot.bin.sd.bin sudo dd if=$bin of=/dev/sdx conv=fsync,notrunc bs=1 count=444 sudo dd if=$bin of=/dev/sdx conv=fsync,notrunc bs=512 skip=1 seek=1
If your Zero has built-in eMMC, we recommend erase it so the microSD's U-Boot will be used.
- Flash U-Boot to eMMC (ONLY FOR BRANCH 2021.01, DOES NOT WORK WITH ABOVE BUILD)
We use fastboot to flash U-Boot to eMMC. Unplug microSD card from Zero and press & hold the usb boot button, then connect Zero to your PC.
sudo apt install fastboot wget https://dl.radxa.com/zero/images/loader/rz-fastboot-loader.bin boot-g12.py rz-fastboot-loader.bin sudo fastboot flash 0x200 /path/to/fip/radxa-zero/u-boot.bin sudo fastboot reboot
Some forum user also discover a method to flash U-Boot with dd in USB mass storage mode:
curl -L https://dl.radxa.com/zero/images/loader/u-boot.bin | sudo dd of=/dev/sdX bs=512 seek=1 && sync