Environment variables are used for building the components. On the first time, everything has to be build in the correct order. The first variable is the working directory:

$ cd path/to/working/dir
$ export WD=$(pwd)

• Toolchain (for the kernel and modules)
• Bootloader
• Kernel
• EIM driver
• Root FS
• Toolchain (for applications)

After the first complete build, the environment variables can be set by a script (env.sh):

export WD=/home/userXY/path/to/working/dir
export PATH=$WD/buildroot/output/host/usr/bin:$PATH
export PATH=$WD/u-boot/tools:$PATH
export ARCH=arm
export CROSS_COMPILE=arm-buildroot-linux-uclibcgnueabihf-
export KERNELDIR=$EFS/linux

Source this script to load the variables:

$ . env.sh

A login shell can be accessed through UART A on the Colibri Evaluation board with a null modem cable. The communication settings are: 115200 8N1.

Copy the uImage and the DTB on a FTP server. Turn the evaluation board on and interrupt autoboot by hitting any key. Load and save the uImage from the FTP server:

uboot> tftp $loadaddr colibri_imx6/uImage-v3.10-2613-g667566e-27f54a31

The u-boot variable „serverip“ has to be set for this to work.

Override the existing uImage with the new one:

uboot> fatwrite mmc 0:1 $loadaddr uImage $filesize

Load the DTB:

uboot> tftp $loadaddr colibri_imx6/imx6dl-colibri-efs.dtb-b34079af

Write DTB to flash:

uboot> fatwrite mmc 0:1 $loadaddr imx6dl-colibri-efs.dtb $filesize