TPLink EAP225-Outdoor V1 revert to factory firmware

[svanheule]

Another user wanted to do the same just last week:

EAP225 v3 flash to stock firmware attempt

Hi everyone, First, I would like to thanks @svanheule for his work on the EAP2X5 series, bringing OpenWRT to these devices. I'm new to OpenWRT, wanted to test it out, and wanted to revert to stock firmware (before reading this comment). I've tried a lot of things, and managed to end up with a serial connection on my device, binwalk and tplink-safeloader binaries to try to modify an openwrt factory firmware, but did not find how to do it. I saw that @wmccann managed to recover his EAP225-Wall …

However, if you are still on the vendor firmware, there is another way. I just realised this from reading the backup instructions on the wiki.

Following the backup instructions, you can extract the two firmware partitions:

• kernel partition (should be mtd3, ca. 1.5MB): will identify as an ELF file, first bytes 0x79 0x7F 'E' 'L' 'F'
• rootfs partition (should be mtd4, ca. 13MB): will identify as a squashfs archive, first bytes "hsqs"

If these two partitions are concatenated, you have effectively created a sysupgrade file you can use from OpenWrt.

Edit: I've added both methods to the wiki page. That should help future users.