On Thu, Jul 21, 2011 at 6:23 AM, Marc Jones marcj303@gmail.com wrote:
Why would you exclude romstage? What will setup the RAM? bootblock? i suspect that the stuff you are doing in bootblock should be done in romstage.
Yes. I setup the RAM in the bootblock. 1. It is much easier setting up RAM than that on X86. We can do it in the bootblock. 2. We don't have romcc for ARM, so if we want to run the code written in C and compiled by GCC, we should have a stack. I use the RAM as a temp stack just as cache_as_ram. 3. If we boot from NAND Flash, most CPUs do like this: It copies the first sector of Nand Flash to its internal SRAM and passes control to it. The internal SRAM is too small to hold the whole romfile, even the bootblock+romstage. So we need to set up the RAM ASAP. U-boot does like this,too.