[U-Boot] more U-boot for Pentium

Raleigh Boulware r_boulware at hotmail.com
Thu Jun 30 03:54:02 CEST 2011



 

> Hi Raleigh,
> 
> On Thu, Jun 30, 2011 at 11:16 AM, Raleigh Boulware
> <r_boulware at hotmail.com> wrote:
> > I have been going through the code and I have stumbled accross a file called
> > sc520_car.S that has something called Cache as ram. I am guessing that this
> > is something special for the sc520 correct? Why was there a need to do this?
> > Why was the Cache used like ram in the boot process?
> 
> Cache-As-RAM allows the CPU cache to be used as regular RAM while U-Boot
> is running from Flash before the onboard SDRAM has been initialised. This
> allows a temporary stack, and therefore C runtime environment to be
> created. This this allows you to write the SDRAM initialisation code in C
> which is a lot easier than assembler.
> 
So this is pnly used if we want to setup the SDRAM controller in C code correct? In this code it is not used because the SDRAM cotroller is pretty much working from power up. So when I port this to my motherboard it looks as if i really do not need this.. Am I correct in this thinking??
 		 	   		  


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