> Am 14.01.2015 um 09:43 schrieb Stuart Henderson <s...@spacehopper.org>: > > On 2015-01-13, Patrick Wildt <m...@patrick-wildt.de> wrote: >> Hi, >> >> Yes, it’s kinda possible. I tried that early 2014 or so. You need to have >> some kind of EFI-Grub2 on an sdcard iirc. Then you exit the in-built grub, >> open the EFI shell and have it boot grub2. >> >> Using kopenbsd you can try to load an OpenBSD kernel, but it doesn’t work >> out of the box. >> >> The serial line is not in the ISA(?) space, but memory mapped somewhere >> else, so you do not get serial output. The grub boot options pass the >> actual address to the linux kernel, so that’s where you can find out which >> one it is. >> >> After doing a hack to make that work, I got the following output: >> http://gbpaste.org/Pd5Vv >> >> I fear I do not have the diffs and blobs anymore. > > If you can have grub chain to OpenBSD's boot loader, you can set the port > address > with 'machine comaddr'. >
Yes, that is right. But it does not fix two other issues. First, you need I386_BUS_SPACE_MEM instead of I386_BUS_SPACE_IO. The console is memory mapped and not accessible via outb/inb. Second, registers need to be accessed in 4x space mode. Means, the register you want to access has to be multiplied by 4 before accessing it. All those issues are caused by the console being connected via PCI (puc(4)) as far as I can see.
