I am just trying to fill in some more MIPS knowledge here. With a 32-bit
MIPS processor, we are forever limited to a userspace of 2GB in size thanks
to the kuser region. kseg0/1 map the same 512MB of physical memory. kseg2
is 1GB in size and hence it could address another 1GB of RAM. So, is the
maximum amount of RAM for a 32bit MIPS core:
1) 1.5GB = 0.5GB kseg0/1 + 1.0GB kseg2
2) 4.0GB = largest 32-bit address
3) Something larger than 4.0GB by adding fancy external HW logic
Also, for choice #3, while it would be a hit in performance, could you use
the fp registers for 64-bit pointers to address larger than 4.0GB?
Thanks in advance.
Steven J. Hill - Embedded SW Engineer