Re: [9fans] loading plan 9 directly from linuxbios

[ron minnich <rminnich@lanl.gov>]

On Wed, 29 Oct 2003, ron minnich wrote:

> On Wed, 29 Oct 2003, David Presotto wrote:
>
> > It's good hygeine but you have to assume something.  Assuming 32 bit mode
> > is already way too much, we're in 16 bit mode when entered from the normal
> > BIOS.
>
> in plan 9? I know that's the way it is in 9load, but in plan 9 it looks to
> me like it assume that 9load enters plan 9 in protected mode. 9load sets
> up protected mode as far as i can see.

foolish me, I misunderstand. Dave, you're taking this further than I
thought about. I'm always ignoring those commercial BIOSen with their
penchant of entering your code in 16-bit mode, possibly I'm blocking out
bad memories.

To start, I'm going to go with the protected-mode assumption as I want to
get the EPIA boards booting Plan 9 direct from flash. Then, later, we can
get into the lovely 16-bit issue. The problem there is Plan 9 loads at
0x100000 and that's a pain to deal with in 16-bit mode. We're going to
need a little hook in the low 640K to set those things up. It starts to
suck at that point.

ron