I am sorry to keep bringing this up... but I have still not heard any
authoritative answer to my question. It seems very likely that
the newer Intel ia32e chips do indeed support W^X.
By newer I mean since early 2005. Right now the AMD64 page
says:
"It also runs on the Intel ia32e processors (...) but since Intel
left out support for the page table NXE bit (No-EXecute)
there is no W^X support on the Intel CPUs."
If indeed this is supported (and the dmesg for my Core 2
on 4.1 does have NXE next to the processor) this really should
be changed. I understand that there is a lot of unhappiness with
Intel's Core architecture... however there are P4s that appear
to have support for NXE.
I understand that updates to the webpages could take a bit and
that people might be very busy with development. I do feel that
of the pages people look at when considering OpenBSD... the
platform pages are very important. When I built my most recent
computer... I very carefully checked various motherboards with
those pages to make sure that things would run smoothly.
If I am being unreasonable or am incorrect... please let me know.
So far I have only heard from one person who seems to be
knowledgeable but didn't really give me a clear answer on whether
I should feel comfortable running AMD64 on my chip. A few other
people replied but they did not seem to really know the answer.
Could someone higher up comment or let me know if the page
is planned to be changed one day in the future?
----- Original Message -----
From: <[EMAIL PROTECTED]>
To: <misc@openbsd.org>
Sent: Thursday, September 20, 2007 6:21 PM
Subject: Re: Is AMD64 page out of date about W^X?
I am not so sure of that.If you go here:
http://processorfinder.intel.com/Default.aspx and then select Core 2 Duo or
some such... then filter by "Execute Disable Bit" under supported
features... you will see a bunch of Core 2s.
The Core 2 is ia32e. It is not EM64T. According to some sites... if anyone
really cares I will find the links... Intel started putting ia32e chips
out in late 2004.. this includes some Pentium 4's. I believe Theo was
expressing his disappointment around Feb of 2004.
Anyway... the page does seem to be updated semi-regularly.. if the date at
the bottom is accurate.. it was last changed on 2007/08/10
If Intel did indeed start including it on chips in early 2005... it would
be nice to know that instead of a blanket statement that Intel does not
support the NXE bit at all. It is important when making purchasing
decisions and architecture choices.
---- Darren Spruell <[EMAIL PROTECTED]> wrote:
On 9/20/07, [EMAIL PROTECTED] <[EMAIL PROTECTED]> wrote:
> According to:
> http://www.openbsd.org/amd64.html
> W^X will not work on Intel's 64 bit chips. I for one chose to go with
> i386 on my Core 2 because of this fact alone.
Intel produces 2 families of 64-bit processors; the EM64T and an AMD64
family chip. You're probably misinterpreting what is meant to indicate
the former.
http://en.wikipedia.org/wiki/64-bit#Current_64-bit_microprocessor_architectures
http://www.xbitlabs.com/news/cpu/display/20040310223922.html
DS
