Re: Fwd: memory probing

[alfred hitch <alfred.hitch@gmail.com>]

Hi Stefan,

thanks for your reply, 
but I am still not very clear on how this is done by say bios on x86
plattforms, ?
can u please expain in more detail abt this north bridge , south
bridge thing .. ?

I would like to try and recreate the same way of probing for our set
up, may be its not that portable , but atleast works on our series of
products ..

What registers are these ? 

Cheers,
Alfred

On 5/10/05, Stefan Reinauer <stepan@openbios.org> wrote:
> * alfred hitch <alfred.hitch@gmail.com> [050510 12:23]:
> > anyways, how can u get this from processor also ?
> 
> The processor has little to nothing to do with this.. it's dependent on
> the northbridge and southbridge.
> 
> > I vaguely remember see'ing some code where someone on a i386 based
> > plattform but WITHOUT bios, used smbus protocol to talk to a device
> > across PIIX4 to get the info.
> 
> Which might work on one motherboard and fail on another. Even if they
> both have a PIIX4.
> 
> > I am not familiar with PC architecture, so can someone tell me if
> > there is some standard chip  (memory controller? ?) where one can read
> > this on PC type arch. atleast ?
> 
> No. Not in a portable way. That's why BIOS provides the e820 table.
> 
> > I am on  a IXDP425 plattform, and so far I cannot see any such
> > register on the data sheets ..
> 
> They are usually not disclosed in publically available datasheets.
> 
>   Stefan
> 
> 
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