Re: [Etherboot-developers] Tagged Test Image

[<ke...@us...>]

>(1) could be an error in the trampoline that mknbi uses, but with
>FreeDOS and the ROM image it should be just straight jumps into 16-bit
>code; Etherboot is supposed to just call xstart16. Which makes me
>suspect that the 16-bit registers are messed up in RELOCATE mode. Or
>maybe it's something to do with A20 routines? Any theories, Eric?

Eric, at lines 133 onward in tagged_loader.c there is:

					gateA20_unset();
					xstart16(tctx.img.execaddr, 
						tctx.img.u.location, 
						virt_to_phys(BOOTP_DATA_ADDR));

But if A20 is unset, the relocated Etherboot may be unmapped (depending
on whether it's in an odd or even megabyte), and then there's no way to
execute xstart16. Am I wrong? Wasn't this discussed last year?

Perhaps what's needed is an xstart16 that does the A20 unset as well (in
16-bit mode).

I'm going to comment out the gateA20_unset and see what happens.