New install

JB jb.1234abcd at
Sat Sep 18 16:05:11 UTC 2010

Rod McCown <rodmccown <at>> writes:

> ...


> I just finished with a RedHat class and am trying to run the "Fedora
> 13 desktop" on the only thing that I have left in my office that I can get
> 512 MB of RAM on.
> ...

Yeeees ... :-)

> I just tried on a AMD K6-2 500Mhz machine and it says this is the
> wrong architecture. It says:
> This kernel requires the following features not present on the CPU: cmov
> Unable to boot.    Please use a kernel appropriate for your CPU.

I think you have a point.

Please follow me.
Here are the answers.
The cmov issue is a known problem ...
The problem is that certain CPU's, even though they are "pentium class", lack
the cmov instruction. At some point a few years ago, the default 586/686 build
of the booter (isolinux?) started requiring cmov.
This totally hosed VIA C3 processors and AMD K6/2.

Wow ! Who could be behind it ? :-)
Mr Sherlock Holmes to the rescue ...
                             12                 11
                         constantine         leonidas
Processor Architecture   i686,...            i386,...(Note: actually i586)   
kernel-        28-May-2009 01:26    20M    
kernel-PAE-    28-May-2009 01:26    20M
kernel-        09-Nov-2009 00:18    19M    
kernel-PAE-    09-Nov-2009 00:18    19M
>From F12 onward a processor supporting cmov (amongst others) is required: F12 
Release Notes.
Starting with Fedora 12, it requires an Intel Pentium Pro or better processor
and is optimized for i686 and later processors.

Note: that's march=i686
Note: AMD K6, K6-II and K6-III have an i586 (Pentium) compatible instructions;
      that's march=i586 

... deeper ...
... none here ... deeper ...
The discussion about the changed proposal starts here:
The revised proposal:
- Build all packages for i686 (this requires cmov)
- Optimize for Atom
- We don't really support i586 in any meaningful matter

Mr Sherlock Holmes ? You are ...

switch back to:
My suggestions for the way forward: 
# For F14, reiterate that Geode LX is supported, and accept that it is not
  a 686. Change compiler flags to -march=i586 -mtune=atom and rebuild all
I don't like the suggestion of stating -march=i586, because, if the point is to
*just* support the Geode LX, that then opens the door for a variety of other
CPUs (see the immediate comment about older MediaGX. 
... continue reading ... target arch (march=, mtune=) with i586 vice i686 ...
what we in Fedora should be doing ...
Rather, we should work on broadening support to as many old systems as possible
by compiling for the lowest common denominator (i486 or i586 systems were
probably the oldest ones that would have had enough memory to run mini Fedora
... continue reading ... I think you should read the entire thread.

I checked the current state of supported archs by Linux distros and see that
many support i386, like Red Hat (i386), Debian (i386), Ubuntu (i386), Slackware
(i486 !), openSUSE (i586 !), to name the most important only.
Some may be considered heavy developers/experimenters too, so Fedora's argument
that it is a distro for forward-looking devs and its arch=i686 should reflect
this fact is phony.

There is a post hinting at only marginal benefits of arch i686 over i386:

Clearly, starting with a very popular i586 (equivalent to Pentium) class and
upward, machines with 512 MB RAM are capable of running Fedora with GNOME, not
to mention with LXDE (I do not mention KDE - sorry guys, I do not like what you

I think Fedora excludes too many users and their machines for no good reason.
Perhaps Fedora could change arch to i586 and have a bigger base of users and
testers as a result ? Starting with Fedora 14 ?

Sometimes I think Fedora is getting ahead of itself, as if there were no
yesterday and no tomorrow ...

Mr Sherlock Holmes ? Sir ? Please continue ...
Child in Time 
Deep Purple


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