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Build U-Boot from source code

Toolchain Installation for Out of Debian Builds

To install the toolchain, follow the Debian Flexbuild Toolchain installation guide.

Build U-Boot Out of Flexbuild Tree

Obtain sources:

git clone https://github.com/varigit/uboot-imx -b lf_v2025.04_6.12.20-2.0.0_var01
cd uboot-imx

Configure compilation environment:

export ARCH=arm64
export CROSS_COMPILE=aarch64-linux-gnu-

Cleanup everything:

make mrproper

Select configuration:

make imx95_var_dart_defconfig

Build U-Boot:

make -j$(nproc)

Download and install Arm-none-eabi cross-compiler required to build OEI and SM

wget https://developer.arm.com/-/media/Files/downloads/gnu/13.2.Rel1/binrel/arm-gnu-toolchain-13.2.Rel1-x86_64-arm-none-eabi.tar.xz
sudo tar -xf arm-gnu-toolchain-13.2.Rel1-x86_64-arm-none-eabi.tar.xz -C /opt

Build Boot Image

The final boot image contains multiple firmware files, as explained by NXP in IMX_LINUX_USERS_GUIDE.pdf (Search for "How to build imx-boot image by using imx-mkimage").

The following procedure builds the final image:

Create imx-boot-tools directory:

mkdir imx-boot-tools
cd imx-boot-tools

Download imx_mkimage:

git clone https://github.com/nxp-imx/imx-mkimage -b lf-6.12.20_2.0.0

Download DDR firmware:

wget https://www.nxp.com/lgfiles/NMG/MAD/YOCTO/firmware-imx-8.26-d4c33ab.bin
chmod +x firmware-imx-8.26-d4c33ab.bin
./firmware-imx-8.26-d4c33ab.bin
rm firmware-imx-8.26-d4c33ab.bin
cp firmware-imx-8.26-d4c33ab/firmware/ddr/synopsys/* imx-mkimage/iMX95

Download ELE firmware:

wget https://www.nxp.com/lgfiles/NMG/MAD/YOCTO/firmware-ele-imx-1.3.0-17945fc.bin
chmod +x firmware-ele-imx-1.3.0-17945fc.bin
./firmware-ele-imx-1.3.0-17945fc.bin
rm firmware-ele-imx-1.3.0-17945fc.bin
cp firmware-ele-imx-1.3.0-17945fc/mx95a0-ahab-container.img imx-mkimage/iMX95

Download and build ATF:

git clone https://github.com/varigit/imx-atf -b f_v2.12_6.12.20-2.0.0_var01
cd imx-atf
source
unset CFLAGS
unset LDFLAGS
unset AS
unset LD
make PLAT=imx95 bl31
cp build/imx95/release/bl31.bin ../imx-mkimage/iMX95
cd ..

Download and build OEI DDR Image and OEI TCM Image:

git clone https://github.com/varigit/imx-oei -b lf-6.12.20-2.0.0_var01
cd imx-oei
export OEI_CROSS_COMPILE=/opt/arm-gnu-toolchain-13.2.Rel1-x86_64-arm-none-eabi/bin/arm-none-eabi-
make really-clean
make board=mx95lp5 DEBUG=1  oei=ddr
cp build/mx95lp5/ddr/oei-m33-ddr.bin ../imx-mkimage/iMX95
make board=mx95lp5 DEBUG=0  oei=tcm
cp build/mx95lp5/tcm/oei-m33-tcm.bin ../imx-mkimage/iMX95
cd ..

Download and build SM:

git clone https://github.com/varigit/imx-sm -b lf-6.12.20-2.0.0_var01
cd imx-sm
export SM_CROSS_COMPILE=/opt/arm-gnu-toolchain-13.2.Rel1-x86_64-arm-none-eabi/bin/arm-none-eabi-
make really-clean
make -j $(nproc --all) config=mx95evk cfg
make -j $(nproc --all) config=mx95evk img
cp build/mx95evk/m33_image.bin ../imx-mkimage/iMX95
cd ..

Copy U-Boot binaries:

cp ../u-boot.bin imx-mkimage/iMX95
cp ../spl/u-boot-spl.bin imx-mkimage/iMX95

Build boot image:

cd imx-mkimage
make clean
make SOC=iMX95 flash_a55 REV=A0 OEI=YES LPDDR_TYPE=lpddr5 LPDDR_FUNC=train
mv iMX95/flash.bin iMX95/flash.bin

Install the Built U-Boot on an SD Card

sudo dd if=iMX95/flash.bin of=/dev/sdX bs=1K seek=32 conv=fsync
(Replace /dev/sdX with the correct device)

If you want to use our recovery SD card to flash the built U-Boot to NAND flash/eMMC, then copy it to the appropriate location in the SD card:

sudo cp iMX95/flash.bin /media/rootfs/opt/images/…

And eject the SD card gracefully from host machine.

Note: If you manually upgrade an existing U-Boot, and you have an old environment saved, it is a good idea to reset your environment to the new default (see Environment handling commands)

Update Your U-Boot Out of Yocto Tree

git pull