Yocto Build U-Boot from source code

Toolchain installation for out of Yocto builds

To install the toolchain, follow Yocto Toolchain installation.

Build U-Boot out of Yocto tree

Obtain sources:

$ git clone https://github.com/varigit/uboot-imx.git -b imx_v2015.04_4.1.15_1.1.0_ga_var03
$ cd uboot-imx

Configure compilation environment:

$ source /opt/fslc-x11/2.2.1/environment-setup-armv7at2hf-neon-fslc-linux-gnueabi

Cleanup everything:

$ make mrproper

Select one of the following configurations:

For booting from SD card/eMMC:
$ make mx6var_som_sd_defconfig

For booting from NAND flash:
$ make mx6var_som_nand_defconfig

Build U-Boot:

$ make -j4

{{#ifeq: |imx8|

Build boot image

The final boot image contains multiple firmware files. The following procedure builds the final image.

# Create imx-boot-tools directory
$ mkdir imx-boot-tools
$ cd imx-boot-tools

# Download DDR and HDMI firmware
$ wget /.bin
$ chmod +x .bin
$ ./.bin --auto-accept --force
$ cp /firmware/ddr/synopsys/lpddr4_pmu_train_* .
$ cp /firmware/hdmi/cadence/signed_* .

# Download imx_mkimage
$ git clone /imx-mkimage -b 
$ cp imx-mkimage/iMX8M/*.c imx-mkimage/iMX8M/*.sh  .

# Download and build ATF
$ git clone /imx-atf -b 

$ cd imx-atf
$ source /opt/fslc-x11/2.2.1/environment-setup-armv7at2hf-neon-fslc-linux-gnueabi
$ export LDFLAGS=

$ make PLAT= bl31
$ cp build//release/bl31.bin ..
$ cd ..

# Copy u-boot binaries
$ cp ../tools/mkimage mkimage_uboot
$ cp ../u-boot.bin .

Build boot image

$ make -f soc.mak clean 
$ make -f soc.mak SOC= dtbs= MKIMG=./mkimage_imx8 PAD_IMAGE=./pad_image.sh CC=gcc OUTIMG=u-boot.img-sd flash_evk

Install the built U-Boot on an SD card

$ sudo dd if=SPL of=/dev/sdX bs=1K seek=1; sync
$ sudo dd if=u-boot.img of=/dev/sdX bs=1K seek=69; sync
(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 SPL /media/rootfs/opt/images/... 
$ sudo cp u-boot.img /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