Imx6ul U-boot cmdline
From embeddedTS Manuals
The Linux kernel cmdline can be customized by modifying the cmdline_append variable. If new arguments are added, the existing value should also be included with the new arguments.
env set cmdline_append rw rootwait console=ttymxc0,115200 quiet
env save
The kernel command line can also be modified from from the onboard Linux. From the linux shell prompt run the following commands to install the necessary tools and create the script:
apt-get update && apt-get install u-boot-tools -y
echo "env set cmdline_append rw rootwait console=ttymxc0,115200 quiet" > /boot/boot.scr
mkimage -A arm -T script -C none -n 'tsimx6ul boot script' -d /boot/boot.scr /boot/boot.ub
The boot.scr includes the plain text commands to be run in U-Boot on startup. The mkimage tool adds a checksum and header to this file which can be loaded by U-Boot. The .ub file should not be edited directly.