PAE with dragonfly

David Rhodus sdrhodus at
Wed Jun 8 12:49:52 PDT 2005

On 6/8/05, Craig Dooley <xlnxminusx at xxxxxxxxx> wrote:
> PAE lets you address 36 bits (although like you said, only 32 at a
> time), but it makes the paging structures 64bits long, and AMD64 long

That's not exactly what I said.  With PAE on a ia32 machine you still
only allocate 4Gig of memory per-process.

> mode is built off the same structures.  The AMD64 manuals say you need
> to enable PAE before enabling long mode.  Granted this would probably

This is just setting a control register bit on the processor, not
actually doing the page table hacks one would have to do on ia32.

> mean only setting up a small page table before jumping to long mode,
> but wouldn't the infrastructure for PAE on x86 make it easier to
> implement AMD64?

Not really because most of the infrastructural changes needed to
support PAE are machine dependent.

                                            Steven David Rhodus
                                            <drhodus at xxxxxxxxxxx>

More information about the Kernel mailing list