Bryan J. Smith 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.
http://marc.theaimsgroup.com/?l=linux-kernel&m=107759901509280&w=2
The Linux option in bios is mentioned here.
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
Yes, that's a modification of the Linux/x86-64 kernel running on a "32- bit" Athlon, because it offers the extended, linear memory addressing and other memory management.
http://marc.theaimsgroup.com/?l=linux-kernel&m=107757492125437&w=2
I think what Bryan here is talking about is called IOMMU by the kernel guys.