Custom device tree for Toradex Easy Installer


We would like to use Toradex Easy Installer to update the operating system in the field, by using a memory stick. The update works well, but the colors on the screen are wrong during the update. We are using a 800x480 RGB LCD with 24 bits. Therefore, I made a customized boot script with the following additional line:

setenv bootargs console=ttymxc0,115200 quiet video=mxcfb0:dev=lcd,800x480M@60,if=RGB24,bpp=32 fbmem=8M rootfstype=squashfs root=/dev/ram autoinstall fullscreen ${teziargs}

Even with this parameter, the colors are wrong. I assume, that the device tree of the TEZI image is made for 18bit displays, since 18bit is the standard for Colibri modules. Is it possible, to use a customized device tree for the TEZI image, so that we can use it with 24bit displays?

Best regards,

You can unpack the FIT image and replace the device tree in it. You need to have U-Boot utilities, hence make sure to have a U-Boot build tree ready. Then you can unpack the FIT image using this commands:

./tools/dumpimage -T flat_dt -i tezi.itb -p 0 zImage
./tools/dumpimage -T flat_dt -i tezi.itb -p 1 tezi-run-colibri-imx6.squashfs
./tools/dumpimage -T flat_dt -i tezi.itb -p 2 zImage-imx6dl-colibri-eval-v3.dtb

Instead of zImage-imx6dl-colibri-eval-v3.dtb use the customized device tree for your Linux image, then repack using the tezi.its file for Colibri iMX6.

./tools/mkimage -f tezi.its tezi-new.itb

Make sure you use a customized device tree which matches the kernel version used by the Toradex Easy Installer (see linux-toradex_4.1-2.0.x.bbappend).