Re: First cut x86 machine description
On Tue, 15 Sep 1998, Alan Cox wrote:
> Some of it (like page sizes and checking for MMX at run not install time etc
> and the FPU stuff are not I think covered by non Linux documents. Im not
> sure where this text (or the pieces of it diced up) want to go in your document
> itself.
Types:
I've added long long.
Address space:
This is covered in the psABI. IT basically says that there is a
32 bit address space. The OS is allowed to reserve up to 1G at
the top, and it goes on to make some recommendations about where
text/data/stack, etc. should reside.
The psABI states that the page size can vary, and that apps should
use sysconf() to find the actual size.
Processor:
The psABI defines the processor to be a 386 with 387 capabilities.
It also states that no guarantees are make about wether certian
instructions are implemented in HW or Sw, nor does it make any
guarantees about performance.
Procesor Extensions:
I've added some words to say that it is OK to use something greater
than a 386 if you check first.
It would be nice to proved a sysconf() (or at least a library
function) to get the processore type instead of the application
having to do it inline.
Coherency & SMP:
Does an application really need to know about this?
Stuart
Stuart R. Anderson anderson@metrolink.com
Metro Link Incorporated South Carolina Office
4711 North Powerline Road 105 Fox Ridge Run
Fort Lauderdale, Florida 33309 Lexington, SC 29072
voice: 954.938.0283 voice: 803.951.3630
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