[coreboot] question: Is it possible for OS to initialize the memory

[Alex G.]

AFAIK, the controller needs to initialise all channels at once. Worse
yet, if you only have two slots, chances are those are on the same
channel, so commands intended for the first dimm will unavoidably reach
the second dimm. You would need to stop the MC for this to happen. You
lose all the tables left by the BIOS in the memory.

That, and there's no reason you'd want to do this. If you had a board
with several sockets, you could theoretically initialize MCs on
application processors independently, but it's too much unnecessary work
IMO.

It's unfeasible and impractical, but if you still want information on
this, the BKDG is your bible.

Alex

On 02/13/2011 10:17 PM, Fengwei Zhang wrote:
> Hi all,
> 
> recently, I am using coreboot for my project. I have two DIMM slots on
> my board and I installed two memory modules on it(each DIMM slot has a
> memory module). Currently, I let coreboot initialize one of them. After
> loading operating system, I would like to use OS to initialize another
> memory module. my question is: Is it feasible for OS to initialize the
> another memory module?
> I looked at the BKDG of my board, I didn't see any documented words
> saying I can do or cannot do this. I would appreciate it if anyone could
> give me some hints or direction of what documents I need to look at.
> 
> Thanks,
> Fengwei
> 
>