You can create your env binary and download to flash via MFG tool.
FYI.
mkenvimage: a tool to generate a U-Boot environment binary image
nice tool.
There are also U-boot scripts, quite useful to fetch and execute the same set of instructions in multiple boards. I have not touch this link for a long time, but you may start with this
You can create your env binary and download to flash via MFG tool.
FYI.
mkenvimage: a tool to generate a U-Boot environment binary image