Ok, seems like this piece is another one with cranky firmware on it. The ROM size you see printed on screen is way too large to be a proper PCI expansion ROM image. The Linux kernel actually tries to allocate this much memory for the expansion ROM(s) in that very early startup and hits the wall. From the figures it looks like - and we have seen the same on that HP x2 210 tablet - ROM size is rather being initialized with some weird pointer instead of the actual size (unsigned integer).
So let’s try something just for the fun of it. 05_bzImage and 06_bzImage (the later without skipping - just in case you’re missing the download link) dereferences the ROM size “pointer”. I have a feeling that this might horribly fail but let’s give it a go.
As well I added 07_bzImage that does not do much printing but only skips the PCI ROM initialization stuff. I have a feeling that maybe the printout might be causing the later hang.
And then there is another heavy debug build in 08_bzImage. So hopefully we’ll see where exactly in exit_boot it does hang.