[LinuxBIOS] 440BX progress.

ron minnich rminnich at gmail.com
Sun Dec 3 19:33:40 CET 2006

On 12/3/06, Segher Boessenkool <segher at kernel.crashing.org> wrote:

> Yes, if you set up the DRBs so that no DRAM ranks are overlapping,
> you can program them all separately.  This is the kind of thing
> people do if they cannot read the SPDs or just don't want to for
> some reason (many fuctory BIOSes do).

yes, this was very common on lots of V1 boards, even in SPD cases.

The reason was that some dram setup could be done in assembly, but
doing DRB in C was simpler.

> At some later stage you'll have to program the DRBs properly; and

ah well some things you can. DRB is one of them.

Of course, given an OS that can handle non-contiguous ram, there would
never be a need to anything BUT size the DRB to max size. But that was
not the case in 1999.

> If you use the SPDs properly (or at all!), you really don't have
> to fall back to tricks like this.

certain tricks are ok if they simplify assembly.  This was one of them
in some cases IIRC.


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