I don't really have time to do this properly, but I needed OpenWRT on this box so I've managed to do that in a way that isn't at all elegant. It works, but I'm hoping that someone else can do it properly using what I've done as a start. I've not yet tried to make the LEDs work, but it shouldn't be too hard.
The major problem with this hack is the yaffs support. Essentially, the 750r2 has a nor flash, which causes the standard kernel yaffs to crash. To get around this, I've modified Mikrotik's version of yaffs to compile with the kernel in Barrier Breaker - this obviously causes all sorts of issues and probably breaks other devices. Really, someone needs to mod the kernel's yaffs to work with the rb750r2.
Since the flash is only 16M, I've chosen to make the kernel partition 2M, which may be too small for some configs - but should be ok. Obviously it's wasy enough to change this.
My files are here - the patch is against Barrier Breaker and the 3.10.49 kernel. You will need to:
rm target/linux/generic/patches-3.10/50[^0]*yaffs*
rm target/linux/generic/files/fs/yaffs2/*
untar the Mikrotik-Modded-Yaffs.tar.bz2 file in the target/linux/generic/files/fs/yaffs2/ directory
copy the file 826-MIPS-ath79-add-rb750r2-and-rb2011-rm-support-openwrt.patch to target/linux/ar71xx/patches-3.10/
You'll also need to make the simple changes mentioned in the QCA9533 patch mentioned here
You have to make with "V=s" for some reason ( asks about "new" YAFFS config options. ) Not sure why - I guess that there's a file somewhere that's out of sync.
(Last edited by sidepipe on 17 Jun 2015, 18:32)