[PATCH] [POWERPC] Uniformly use memstart_addr variable as the start address of physical memory in powerpc branch

[Paul Mackerras]

Andrew Liu writes:

> You know we can't make sure in future the start address of all incoming 
> boards' RAM is 0, especially, in AMP system, different cpu uses the different RAM area, 
> definitely, the start address of some is not 0.

Any processor that uses ppc_mmu_32.c will have interrupt vectors in
the 0 - 0x3000 region of memory and hence *must* have RAM starting at
zero.  In other words, that file is only used for "classic" 32-bit
PowerPC processors, not for anything based on Book E or Power
architecture v2.04 or later.

Paul.