Re: [coreboot] I've turned on paging as a test

[Jonathan A. Kollasch]

On Mon, Mar 10, 2014 at 02:43:45PM -0700, ron minnich wrote:
> Now you've just made me sad.
>
> OK, given that in the beginning times we never supplied this little tidbit,
> who or what needs it? It looks like another memory turd whose time has gone.

Put it this way, any payload that presents a BIOS or CSM is going to need
to populate the BDA where software expects to find it (at 0x400).

I've not actually looked in to why coreboot itself cares about the BDA.

Perhaps the BDA can be passed to the payload.

Jonathan Kollasch

I've turned on paging as a test

[ron minnich]

On Mon, Mar 10, 2014 at 3:12 PM, Jonathan A. Kollasch <[e-mail]
> wrote:
> Put it this way, any payload that presents a BIOS or CSM is going to need
> to populate the BDA where software expects to find it (at 0x400).

OK, but ... I've been finding platforms lately which don't have lots of
these tables, including ones which no longer have _MP_. They all count on
ACPI. I'm not yet convinced we need the BDA -- yes, yes, for compliance, I
understand we do; but I wonder how many OSes can survive with it's not
there. So much of the information in there is what we used to call "legacy
crap.". I know that we did not set up BDA for the first six years or so of
this project, in part because I kept trying to avoid inheriting all this
historical gunk.

So I'm curious to see what would happen were it not there. That said, I do
turn off paging before I jump to payload, so it might
be possible to work around this nonsense.

So many little tables. What a mess!

ron