Yocto Build U-Boot from source code

Toolchain installation for out of Yocto builds

To install the toolchain, follow the Yocto Toolchain installation guide.

Build U-Boot out of Yocto tree

Obtain sources:

$ git clone https://github.com/varigit/uboot-imx.git -b imx_v2018.03_4.14.78_1.0.0_ga_var02
$ cd uboot-imx

Configure compilation environment:

$ source /opt/fsl-imx-x11/6.6-scarthgap/environment-setup-cortexa7t2hf-neon-poky-linux-gnueabi

Cleanup everything:

$ make mrproper

Select one of the following configurations:

For booting from SD card/eMMC:
$ make mx6ul_var_dart_mmc_defconfig

For booting from NAND flash:
$ make mx6ul_var_dart_nand_defconfig

Build U-Boot:

$ make -j$(nproc)

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