[coreboot] Intel 8xx northbridge ram init is wrong

Stefan Reinauer stepan at coresystems.de
Tue Jun 2 18:11:42 CEST 2009


>
>
> On Tue, 02 Jun 2009 18:00:53 +0200, Stefan Reinauer <stepan at coresystems.de>
> wrote:
>   
>> On 02.06.2009 17:13 Uhr, Joseph Smith wrote:
>>     
>>> Hello,
>>> Was anyone aware we are doing the do_ram_command() wrong on the i8xx
>>> nothbridges?
>>> We are sending the ram commands to all memory and doing our dummy reads
>>>       
>> at
>>     
>>> the end.
>>> I just found an Intel doc that says we are supposed to do all the ram
>>> commands to each row of memory.
>>>
>>>       
>> ...
>>     
>>> I will work on a patch for the i830, we should probibly fix this on the
>>> other Intle northbridges.
>>>
>>>       
>> Check the i945 code for an example on how to do it... older chipsets
>> might/might not be different...
>>
>>     
> Would it be different for SDRAM vs DDR ?
>
>   

You need a couple more steps (different MRS commands etc) for DDR, but
the loop itself is basically the same. 


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