Hello Dave,
On Fri, 14 Nov 2014 07:18:58 -0700 (MST), DaveKucharczyk david.kucharczyk@gmail.com wrote:
Hi Albert, Thanks for the great information.
Albert ARIBAUD (U-Boot) wrote
Baaad, bad. The first time you change something in your code, your relocation offset might change and this will make U-Boot crash and burn in interesting ways.
Just define CONFIG_SYS_TEXT_BASE to some low address and let relocation happen. You can find your actual relocation address in the global data structure.
If I set CONFIG_SYS_TEXT_BASE to a low address then I can't run a memory test starting at the lowest address because that's where the U-Boot code will be.
No, that's not where it'll be; it'll relocate as high as it can.
I think the best thing would be to run a memory test on the full 2GB before relocation happens. Is that possible?
Not with U-Boot in DDR. :)
Albert ARIBAUD (U-Boot) wrote
How do you know the lowest address used by your stack during your memory test?
I know the address of the stack pointer from DEBUG message...
So you know it *at a given time*, but you have no assurance that it won't go further down.
I erroneously thought that was the beginning of the stack. The stack expands down form that address, but how much? I don't see a global data stack size variable.
There is none physically, i.e. that's just the size you reserve for it, but it could grow beyond that, although it's not likely. Still, that means you don't test all DDR.
Before, we have #define CONFIG_STACKSIZE (128 * 1024) set in the header file.
Basically what is the best way to run the memory test? If I can run it before relocation then it would make things very simple.
If you happen to have an SPL running from some RAM and not from DDR, then you could perform the full DDR test there.
Amicalement,