[LinuxBIOS] raminit.c

Eric W. Biederman ebiederman at lnxi.com
Thu Mar 22 00:57:43 CET 2007

joe at smittys.pointclark.net writes:

> I hope someone can clarify this for me. The main purpose of the  
> raminit.c file is to:
> a) setup the most minimal northbridge memory registry
> b) detect spd to find memory parimeters
> c) set the spd parimeters in the northbridge memory registry
> d) startup memory
> Is this correct??


> The main question I have is how do I know which of the northbridge  
> memory registers need to be setup on initially?? If they are to use  
> their default values to I even need to include them?? 

Never trust hardware to have default values, if you can help it.
Hardware engineers like to leave registers floating (so they
can take random values) if the don't absolutely have to initialize
them.  Plus there are other cases like reset and very short
power offs where the capacitance in registers can help them hold
a value.

> Or should I just set them all up??
Yes.  If you know a good value for the register to have you should
set it up.

Also carefully test it remembering that people are fallible so the
is probably something missed or slightly incorrect in the documentation.


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