On Mon, Jan 14, 2002 at 03:25:44PM -0800, Matthew Dharm wrote:
> Thanks for the info. Too bad "MIPS64" and "mips64" sound exactly the
> same on the telephone.
>
> But, I need to be pedantic, just to be clear on a couple of
> questions...
>
> So, the "mips64" kernel can use 64-bits of address, for RAM >4G?
> But, the apps running are always 32-bit?
In theory the kernel has the capability to run 64-bit applications. In
practice that doesn't work due to the lack of 64-bit apps and stuff.
> Does this mean that any individual application can only use 4G of
> memory, tho you could have several applications in physical memory
> doing this? (i.e. multiple applications using 1G of RAM each, but not
> swapping to disk?)
In theory we don't limit the address space of 32-bit applications in 64-bit
mode so they could go and use all memory and syscalls on the 64-bit
address space also. In practice that's just too ugly to be usable so
consider 32-bit apps on the 64-bit kernel as limited to 2gb as they are
currently. You can however run an arbitrary number of these processes.
> Does this mean we could map PCI memory/IO addresses above 4G and have
> it work?
Sure.
Ralf
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