Since the MR44 has not yet been added to the Table of Hardware, I am willing to send two of my three devices to a developer who has the time and resources to try to make Open-WRT work on them. I'd love to be able to give the third one to my sister as a Christmas gift to extend her network range in her basement. I just need some guidance on how to get Open-WRT installed.
Please contact me here if you are interested in working on opening the Meraki MR44.
I also got two MR74 devices which I plan to use for my own needs, since most of my devices still only use WiFi 5.
(P.S. If the MR44 has already been deemed un-openable for whatever reason, I'd appreciate a heads-up so I can take these to my local recycler.)
These indeed do appear to have secure boot enabled from what I can gather. (And a locked-down u-boot image that does not accept xyzzy nor is vulnerable to environment changes)
However, it's not without implementation bugs it appears, since apparently you can just change it's product id byte (with a programmer) and the u-boot image will just skip image verification. Hilarious. (Assuming that they haven't shipped a new u-boot image AND haven't enabled rollback protection)
Only problem being is that without a vulnerability in the stock firmware, you'd have to program the many many pin nand part in addition to the smaller eeprom in order to place a compiled u-boot image to chainload.
