SL 6 no cmov support in kernel

[Barry Cisna]

Hello All,

Just wanted to report this somewhat unknown non-available feature in
default kernel in SL6. When trying to boot the Ebox 2300 TC's we have we
receive this when PXE starts to run on the TC and then stops.
"This kernel requires the following features not present on the cpu.
cmov".

I have found several reports somewhat similar in nature only the error
is no PAE support in kernel.

Take Care,
BC

[William Fragakis]

Barry,
Are you sure it's not an i686 issue? Have you tried the F11 kernel for
the client? F11 was the last i386 compliant Fedora version.

http://askubuntu.com/questions/5807/what-is-the-significance-of-the-cmov-cpu-instruction

regards,
William

Date: Wed, 22 Feb 2012 06:19:50 -0600
Subject: [K12OSN] SL 6 no cmov support in kernel
Content-Type: text/plain; charset="UTF-8"
Hello All,
Just wanted to report this somewhat unknown non-available feature in
default kernel in SL6. When trying to boot the Ebox 2300 TC's we have
we
receive this when PXE starts to run on the TC and then stops.
"This kernel requires the following features not present on the cpu.
cmov".
I have found several reports somewhat similar in nature only the error
is no PAE support in kernel.
Take Care,
BC

[Jeff Siddall]

Post by Barry Cisna
Hello All,
Just wanted to report this somewhat unknown non-available feature in
default kernel in SL6. When trying to boot the Ebox 2300 TC's we have we
receive this when PXE starts to run on the TC and then stops.
"This kernel requires the following features not present on the cpu.
cmov".

Actually it is the other way around. The i686 kernel uses the cmov
instruction which the the CPU doesn't have. This means your CPU
probably isn't at least a i686 (ex: old Via Samuel cores etc.)

Old distributions that have old i386 or possibly i586 kernels are
probably your best bet if you need to support the hardware.

Jeff

[Kent Schumacher]

On 02/22/2012 02:52 PM, Support list for open source software in

Post by Barry Cisna
Hello All,
Just wanted to report this somewhat unknown non-available feature in
default kernel in SL6. When trying to boot the Ebox 2300 TC's we have we
receive this when PXE starts to run on the TC and then stops.
"This kernel requires the following features not present on the cpu.
cmov".

Actually it is the other way around. The i686 kernel uses the cmov
instruction which the the CPU doesn't have. This means your CPU probably
isn't at least a i686 (ex: old Via Samuel cores etc.)
Old distributions that have old i386 or possibly i586 kernels are
probably your best bet if you need to support the hardware.
Jeff

ltsp-build-client --release 11 will create an LTSP client setup that can
boot older i386 terminals.

[Barry Cisna]

Jeff,

Yep,You are right. After I posted this I realized I had the fact
reversed.
These little Ebox's are the cat's meow,and I'd like to make these usable
on SL 6.1. This is what i use personally. I have had the same Ebox for
11 years! I would think someone much smarter than I can compile a kmod
module to hang onto the existing running kernel to make the old school
processors seem 'acceptable' to the kernel after the kmod is loaded?

I may delve into running two client chroots( for the older
machines),,although I'd like to stay away from this as I am sure it will
involve behind the scene's snafoos.

Thanks,
Barry

[Jim Kinney]

With old (really old!) hardware, it's not about adding a module, it's about
having a kernel that doesn't require modern hardware. Basically, there are
certain hardware features that are not in your cpu (cmov commands) so you
need a kernel that is older and will not be looking for it. I have not seen
a kernel module that can emulate missing cpu capabilities.

So you will need an _old_ real i386 kernel and that will require all the
supporting libs to be compatible. Thus you'll need two chroots and a
mechanism to point clients appropriately. As you know the MAC addresses,
you can group them in dhcpd.conf and point them to the correct chroots that
way.

Post by Barry Cisna
Jeff,
Yep,You are right. After I posted this I realized I had the fact
reversed.
These little Ebox's are the cat's meow,and I'd like to make these usable
on SL 6.1. This is what i use personally. I have had the same Ebox for
11 years! I would think someone much smarter than I can compile a kmod
module to hang onto the existing running kernel to make the old school
processors seem 'acceptable' to the kernel after the kmod is loaded?
I may delve into running two client chroots( for the older
machines),,although I'd like to stay away from this as I am sure it will
involve behind the scene's snafoos.
Thanks,
Barry
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--
James P. Kinney III

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consumerism or hatred of the vulnerable, then the powerful can do as they
please, and those who survive will be left to contemplate the outcome.
- *2011 Noam Chomsky

http://heretothereideas.blogspot.com/
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