U-boot environment
From embeddedTS Manuals
The eMMC flash contains both the U-Boot executable binary and U-Boot environment. Our default build has 2MiB of environment space which can be used for variables and boot scripts. The following commands are examples of how to manipulate the U-Boot environment:
# Print all environment variables
env print -a
# Sets the variable bootdelay to 5 seconds
env set bootdelay 5;
# Variables can also contain commands
env set hellocmd 'led red on; echo Hello world; led green on;'
# Execute commands saved in a variable
env run hellocmd;
# Commit env changes to the spi flash
# Otherwise changes are lost
env save
# Restore env to default
env default -a
# Remove a variable
env delete emmcboot