Here is a good way to start initramfs from USB pendrive .
AW1000 will boot normally when there is no USB with initramfs , and will start from USB initramfs when plugged...
https://eko.one.pl/forum/viewtopic.php?pid=299428#p299428
You can set this uBoot env's from running system via command fw_setenv , but device have to be not bricked... If the system don't start ,then you have to connect to serial console anyway.
It is good to set it and have some spare usbe pendrive with initramfs just in case.