[CentOS] [OT] Memory Models and Multi/Virtual-Cores -- WAS: 4.0 -> 4.1 update failing

[James Olin Oden]

On 6/24/05, Bryan J. Smith <b.j.smith at ieee.org> wrote:
> On Fri, 2005-06-24 at 07:42 -0500, Bryan J. Smith wrote:
> > I'll find it.  It was from a gentlemen from AMD that discussed it in a
> > thread right after Intel announced EM64T.  Linus & co. were talking
> > about how EM64T is still using a 32-bit platform underneath.  The AMD
> > gentlemen commented how they a few vendors had a BIOS option "Linux" for
> > the memory access, and the Linux kernel could support linear addressing
> > above 4GB.
> 
> Ack, it doesn't appear to be directly in the 2004Feb17 thread:
>  http://kerneltrap.org/node/2466
> 
> There are a few comments on how the Athlon differs from Intel because of
> the Alpha EV6, but not the more technical detail I was referring to.
> 
> Again, to get this "mode" you have to:
> a)  Tell the BIOS to enable a "Linux" memory mode
> b)  Have a Linux kernel (Linux/x86-64 I believe?) that supports it
> 
Any idea what the BIOS actually does to enable "linux" memory mode? 
That is what registers are poked in the MCH (I assume it would be the
MCH)?   Do you think this could be done post bios by say a boot
loader?

Just curious...james