Netgear WAC510 repair “can’t create ‘/var/config’: No space left on device”

Hello. I recently purchased a used Netgear WAC510 AP with a boot problem. I opened up the AP and connected the UART header to a PL-2303HX TTL-USB adapter. Now I can interface with ipq40xx and SDK as root.

I grabbed the bootlog from the WAC510 and compared it to the OEM bootlog (see link and diff output, below).

I think I can see what the problem is: I get a “cp: can't create '/var/config': No space left on device” error which leads to a slew of “No such file or directory” errors.

So I checked the available space:

[root@SDK ~]# df -a
Filesystem                Size      Used Available Use% Mounted on
mtd:ubi_rootfs           24.5M     24.5M         0 100% /
proc                         0         0         0   0% /proc
tmpfs                   120.9M    100.0K    120.8M   0% /tmp
devpts                       0         0         0   0% /dev/pts
none                    120.9M      2.4M    118.5M   2% /etc
none                         0         0         0   0% /sys
/dev/mtdblock11          15.0M     14.8M    248.0K  98% /var

/var is 98% full! I don't know what went wrong. But I’d like to try and clear the memory and attempt a clean boot to factory condition and hopefully sidestep having to flash new firmware over TFTP. But I don’t know what commands to use to wipe the memory. Can anyone point me in the right direction? Thank you!

• Netgear WAC510 specs, OEM firmware, UART pinouts, OEM bootlog: https://openwrt.org/toh/netgear/wac510
• Here is the output of a 'diff -aw bootlog0.txt bootlog1.txt' command comparing bootlog0 (OEM) to bootlog1 (mine): https://pastebin.com/31nEy6hu
• My full bootlog with all errors: https://pastebin.com/hA0NbJ5t