Hi DiTBho! I am also very interested on the bootloader side of things, I even tried writing you an email a couple of days ago.
I've been poking around my SL-C1000 and could not figure out how to initialize the SD card reader properly (without booting a full-on kernel). One would think that it should be a trivial task, since there are pretty good Intel developer documents for the PXA27x platform, but there seem to be some very quirky deviations about the SL-C1000 implementation especially.
I have a gentoo kernel booting with the "Frankenstein", but it seems to also suffer from some SD controller handover shenanigans. My debug was somewhat limited though, since I only recently purchased a serial cable that would help immensly on the debugging part of things.
I will write a longer forum post with all the stuff I did and all the info I gathered so far at a later point in time.
P.S. I also found out that the 4.4.8 kexecboot (
https://github.com/LinuxPDA/linux-kexecboot/tree/master/zaurus/kernel-4.4.8) uses the same kernel for both akita and borzoi, but while the kernel runs perfectly fine on the latter it crashes pretty early on the akita. There seems to be a condition race/kernel bug that I haven't been able to fix yet, even though I was able to solve it for the gentoo 5.x kernel, using some rewritten kernel patches (I think the original versions are from greguu if I remember correctly).
Greetings,
btgdelta