Re: Kernel virtual memory?

Stephen Williams (steve@icarus.icarus.com)
Thu, 07 Aug 1997 21:20:08 +0800

davem@jenolan.rutgers.edu said:
> sun4c gives you the full address space (cpu's tlb is used as iommu)
> sun4m can give you up to 3.5GB (full address space - 0.5GB) sun4u can
> give you up to 4GB (full virtual range of SBUS on Ultra's)

I must be remembering sun4 (pre-c). It HAS been a while, I'm glad you're
the one doing the SPARC port, given the failure of my memory:-)

In practice, though, it seems like you just mapped the VDMA map 1-to-1 to
physical memory. I think I had used it to do scatter-gather directly into
the user's buffers.

-- 
Steve Williams
steve@icarus.com
steve@picturel.com


"The woods are lovely, dark and deep.  But I have promises to keep,
And lines to code before I sleep, And lines to code before I sleep."