[U-Boot-Users] PPC: How to access RAM location 0x0 (unmapped) ?

[KokHow Teh]

Hi;
      In MIPS I can access RAM localtion 0x0 unmapped with 0x8000_0000
(cached) and 0xA000_0000(uncached). I guess this is not possible in PPC?
      I ask because I would like to call get_ram_size() during the bootup
to determine the size of my SDRAM before it is mapped. Anyway, I need to
know the size of SDRAM in order to map it.

Thanks & Regards,
TEH