The GL-AR750S U-Boot source is not up to date (it does not have any commits that resolve the ARP issue of late last year), which leads me question the GL-AR300M source as well. As a result, I cannot accurately determine if the supplied U-Boot can load and boot a 4 MB kernel.
The sysupgrade part looks robust for the all-NOR and all-NAND cases. It’s ugly for the kernel on NOR and file system on NAND cases.
The AR750S U-Boot source shows a compiled-in limit of 2 MB for the kernel for upload through U-Boot in a couple places. The AR300M doesn’t have a similar limitation that I could find (likely as it doesn’t split the firmware to flash it).
I have yet to determine if the kernel loader will handle in excess of 2 MB for either device. What I see in the public U-Boot sources doesn’t seem to agree with what I see on the serial console. (I am not a U-Boot expert, so I may be mistaken.)
Yep, it’s the split boot targets that might take a hit - that’s why I mentioned “wee-bit ugly”
I’ve got a AR300m sitting on the shelf, might have to bring it online to check out, but I’m thinking the gl-inet devs can check, and it’s their choice whether to migrate to ath79 or not, as they can still support the branch they’re on.
I suspect that ar300m, and the ar750s, they’re in maintenance mode, as shipping code is in place for the 3.x releases on the openwrt branch they’re on.