Flashing Linksys MR75MS Partitioned BIOS

bork · June 21, 2026, 6:10am

My Linksys MR75MS appears to have the infamous partitioned 1/2 BIOS system, so when I flash it normally it just auto-recovers the old Linksys image. It unfortunately has no device page, and I can't find any installation instructions for this particular router either.

Per the sysinfo.cgi:

fw_printenv bootcmd: bootcmd=if test $auto_recovery = no; then bootipq; elif test $boot_part = 1; then run bootpart1; else run bootpart2; fi
fw_printenv boot_part: boot_part=2
fw_printenv auto_recovery: auto_recovery=yes

I think this means it's currently on partition 2? And if that's true, I would need to switch to part 1 and flash that one instead? I have no idea. If someone could help, it would be much appreciated.

frollic · June 21, 2026, 6:12am

What are you flashing it with ?

bork · June 21, 2026, 6:13am

I'm using openwrt-25.12.0-qualcommax-ipq60xx-linksys_mr7500-squashfs-factory.bin

frollic · June 21, 2026, 6:14am

And you know those two are the same ?

https://github.com/openwrt/openwrt/pull/17428.

EDIT: based on FCC ID they seem to be the same.

bork · June 21, 2026, 6:18am

Thank you, I'll take a look! Yes, at least per the OpenWRT hardware table it is the same device:

Update: Looking at the non-serial flash instructions, that's what I've been following. No mention is made of the BIOS partitions, which makes me wonder if there is a version of this router that doesn't use them