Dear Timur Tabi,
In message 4BFECF82.60901@freescale.com you wrote:
Scott pointed out that writing/reading memory to determine how much memory actually exists is dangerous. I'm not convinced that I should be using get_ram_size(). I still believe that I shouldn't.
And I point out that we have been doing this for a decade on tens of different board configurations with millions of devices in the field.
I have not been able to find any other PowerPC system in U-boot that supports more memory than is mapped. If you know of one, please tell me.
The systems I know are the opposite - initially they map more memory than they support, then they determine the real size, then they adjust the mapping to the real size.
My point is that sizeof(phys_addr_t) has got nothing to do with the size of the read/write operation, so I think it's wrong on all platforms.
Actually it will only be wrong on systems where phys_addr_t != ulong, but you are right.
Best regards,
Wolfgang Denk