It appeara that uboot can be compiled for this model right from mainline,. Did anyone try this uboot, if so, can you post a boot log? Is it possible to mod it for other QCA atheros models?
While I get the wish for mainline u-boot support, from a functionality point of view you're probably better suited by (which works nicely on the tl-wdr4300):
I've seen this too some time ago and compiled a binary with the default defconfig for wdr4300...
I've never flashed it because the compiled binary was very large (>300kb) and also removing some features helped not to shrink it enought to fit in the default mtd partition layout...
I think it makes only sense if you need all the extra functionality and boot from network or an external storage device instead of the limited 8mb nor flash.
So at least you have to change the partition layout, but i see no improvement with a more feature rich bl over tje great u-boot_mod from @pepe2k
Anybody tried yet? While I like pepe's mod; it's also based on an ancient U-Boot.
I think the most important difference would be that you could be that the mod offers web-server support. I'm surprised that's still not upstream ... or I don't recall it being upstream.