Safecom technologies, a manufacturer that also uses the AR7WRD platform has a very interesting instruction you might be interested in.

This company instructs it's end-users to upgrade the bootloader themselves with these commands and then flash a new firmware.

cd /var/tmp
wget ftp://192.168.1.20/psbl-4-marvell.bin
cp psbl-4-marvell.bin /dev/mtdblock/2/
reboot

Now I know this is possible, but it is the first time I see any manufacturer instructing it's users to do this.

Link to this instructions
http://safecom.cn/code/sub/driversmanua … subcatid=1

download PC TOOLS  and iside you will find the instructions in PDF format.

it is usual for almost all devices, not only based on AR7. But if Intel flash chips are used, some regions of memory can be protected. In addition, flash support can be broken in some linux kernels, so flash will be erased instead of rewriting.

updated my adam2 0.22.02 to 022.03 based on the instructions and had no problems.