ramips: missing mikrotik bootloader check in `platform.sh`

Describe the bug

Mikrotik devices running v7 of the bootloader utilize a separate sysupgrade-v7 image (example) for upgrades.

When using Attended Sysupgrade or owut, it seems the wrong image is being used:

root@OpenWrt:/tmp# owut check --verbose
owut - OpenWrt Upgrade Tool 2026.01.13~2526d84b-r1 (/usr/bin/owut)
ASU-Server     https://sysupgrade.openwrt.org
Upstream       https://downloads.openwrt.org
Target         ramips/mt7621
Profile        mikrotik_routerboard-750gr3
Package-arch   mipsel_24kc
Root-FS-type   squashfs
Sys-type       sysupgrade
Version-from   25.12.0 r32713-f919e7899d (kernel 6.12.71)
Version-to     25.12.2 r32802-f505120278 (kernel 6.12.74)
Build-commit   https://git.openwrt.org/?p=openwrt/openwrt.git;a=shortlog;h=f505120278
Build-FS-type  squashfs
Build-at       2026-03-25T20:09:53Z (~28 days ago)
Image-prefix   openwrt-25.12.2-ramips-mt7621-mikrotik_routerboard-750gr3
Image-URL      https://downloads.openwrt.org/releases/25.12.2/targets/ramips/mt7621
Image-file     openwrt-25.12.2-ramips-mt7621-mikrotik_routerboard-750gr3-squashfs-sysupgrade.bin
Installed      163 packages
Top-level      131 packages
Default         29 packages
User-installed 103 packages (top-level only)

Image-file above should be openwrt-25.12.2-ramips-mt7621-mikrotik_routerboard-750gr3-squashfs-sysupgrade-v7.bin (note the -v7).

I'm not sure what the full set of changes are to fix this, but from what I've found:

• The Mikrotik bootloader check is done for ath79 devices, found here, and some further upgrade logic is found here. None of this logic seems to be included for ramips devices (here).

I hope this provides enough information to at least get started. Let me know if I can provide any further info.

OpenWrt version

r32713-f919e7899d

OpenWrt release

25.12.0

OpenWrt target/subtarget

ramips/mt7621

Device

MikroTik RouterBOARD 750Gr3

Image kind

Official downloaded image

Steps to reproduce

No response

Actual behaviour

No response

Expected behaviour

No response

Additional info

No response

Diffconfig

Terms

• I am reporting an issue for OpenWrt, not an unsupported fork.