[Open-graphics] 64 bit segmented architecture

[Hamie]

On Thursday 12 April 2007 12:26, Rogelio Serrano wrote:
> On 4/12/07, Hamie <hamish at travellingkiwi.com> wrote:
> > On Thursday 12 April 2007 10:12, Rogelio Serrano wrote:
> > > sorry to ask but i dont know where to go.
> > >
> > > im looking for a 64 bit processor with segmented memory support. im
> > > working on a no kernel os and the prototype is running on a 32 bit
> > > processor. the problem is there is not enough memory space to have
> > > very strong address randomization. unfortunately the x86_64 arch does
> > > not have segmentation in long mode.
> > >
> > > maybe the only option is an fpga based processor.
> >
> > Why do you want segmented specifically?
>
> i use segmentation to protect shared data and code from other
> processes. this allows service calls without using traps. and it makes
> zero copy io and ipc very easy.

Hmm... The only problem with that is it doesn't tend to scale very well... IBM 
used to do this extensively with AIX on the Power (And later PowerII, PowerPC 
etc) architecture for shared memory and shared lib access. But each process 
was limited to just 16 segments of 256MB each.

What's wrong with using pages for this? 

Hamish.
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