Re: [X86] Re: x86 SIG / Dropping PAE support

On 09/19/2017 08:08 PM, Stephen John Smoogen wrote:
> Argh. This is an oversight on my part when bringing this as an option
> from the kernel team. I was not aware that the NX was dependent on
> PAE. The primary hardware that people were wanting all seemed to be
> below 4 GB so having PAE didn't seem to be worth the overhead. I am
> not sure if the OLPC desktops even have support for either NX or PAE.
> The people with P-III or no SSE2 definitely don't have PAE.

PAE is *way* older than NX/XD, but as you said, it does not matter for 
the old hardware because of RAM sizes and lack of NX/XD support.

There used to be an approximation to NX/XD based on segment register 
limits, but the art of writing userspace applications to make use of 
that may have been lost (and I don't know if the corresponding kernel 
code bits still exist and are being maintained).

Thanks,
Florian