Zero/dev/u-boot

2022-10-18T13:18:43Z

Timbo: Changed compiler flag to match installed libraries. Added warning as fastboot flashing does not work for current image (as long as nobody figures out the 'magic number' to U-Boot)

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[[zero | Radxa Zero]] > [[zero/dev | Development]] > [[zero/dev/u-boot | U-Boot]]

=== 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.

<font color="#FF0000">WARNING!</font> 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 <code>u-boot.bin</code> under <code>u-boot</code> 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 [https://wiki.radxa.com/mw/images/e/e2/Radxa_zero_ports.jpg 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 [[Zero/install/eMMC_erase | 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 [https://wiki.radxa.com/mw/images/e/e2/Radxa_zero_ports.jpg 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 [https://forum.radxa.com/t/install-os-direct-to-emmc-with-ubuntu/7435 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

Radxa Wiki - User contributions [en]

Zero/dev/u-boot