Building U Boot

The RetroFW U-Boot is maintained at http://uboot.retrofw.com. The U-Boot is fully open source and easily buildable by anyone with even the slightest interest. Minor knowledge of the Linux command line is required.

Read also the Building the Kernel page to get more detailed Kernel and U-Boot building instructions.

Manual

1. Download the Ingenic GCC 4.12 compiler from Ingenic's website or the toolchain release mirror. e.g.

curl -L -o /tmp/mipseltools-gcc412-glibc261.tar.bz2 https://github.com/retrofw/kernel/releases/download/tools/mipseltools-gcc412-glibc261.tar.bz2

2. Extract the toolchain to the root directory of your Linux system. Make sure you add the toolchain to your PATH so the kernel build can find the compiler. e.g.

tar -xjf /tmp/mipseltools-gcc412-glibc261.tar.bz2 -C /

export PATH="/opt/mipseltools-gcc412-glibc261/bin:$PATH"

3. Create a directory in which you want to work with the U-Boot. e.g.

mkdir -p /opt/retrofw-kernel

4. Clone U-Boot from GitHub into your new working directory. e.g.

cd /opt/retrofw-kernel

git clone https://github.com/retrofw/uboot

5. Clean the U-Boot project and build for the device you're targeting. For ease of use, the project uses the same configuration names as the kernel. The following instructions use the 5B (i.e. IPS) model for the example. Replace the 5B with the appropriate screen/cpu combination for your device.

cd /opt/retrofw-kernel/uboot

make distclean

make RetroFW_5B_defconfig

make all

6. The build process outputs several .bin files. The one we're interested in is u-boot-msc.bin. This needs to be written to the start of the boot image.

dd if=u-boot-msc.bin of=RetroFW.img conv=notrunc bs=512 seek=1

sync

You can then write the RetroFW.img file to an SD Card using a tool like balenaEtcher. Pop the card into your device, and enjoy your new build!