Hi Raleigh,
On Thu, Jun 30, 2011 at 11:16 AM, Raleigh Boulware r_boulware@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??