2000-11-15 05:05:52

by Barry K. Nathan

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Subject: [BUG?] AMD K5 and 2.4 (was Re: Updated 2.4 TODO List)

(I'm replying to a message from about a month ago, but it's relevant to a
problem I'm having now.)

[email protected] wrote:

> Date: Mon, 09 Oct 2000 20:13:35 +0200
> From: Thomas Sailer <[email protected]>
>
[snip]
> My Asus P55TP4 (i430FX)/AMD K5 PC also crashes after "Booting the
> kernel..."
> and before printing anything else
>
> Are you sure it was compiled with the correct CPU? If you configure the
> CPU incorrectly (686 when you only have a 586, etc.) the kernel *will*
> refuse to boot.

I have a Compaq Presario 425 here, with a K5 upgrade (by Evergreen
Technologies) in it. It reboots immediately after "Booting the kernel..."
with Linux 2.4.0test10 (I haven't tried test11preX on this machine) if the
kernel is compiled for 586/K5/etc. If I compile for 486, then it boots. If
I compile for 586/K5/etc. with 2.2.17, it boots. (This is all with egcs
1.1.2.)

Is this a real bug or just a documentation bug?

-Barry K. Nathan <[email protected]>


2000-11-15 20:28:55

by Barry K. Nathan

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Subject: [BUG?] AMD 5x86 and 2.4 (was Re: [BUG?] AMD K5 and 2.4)

It looks like I was mistaken in my original message. I have an AMD 5x86, not
a K5.

Nevertheless, menuconfig lists the 586 option as "586/K5/5x86/6x86/6x86MX".
But, it fails to boot on my 5x86 and I have to compile for a 486 (for 2.4).
As I mentioned in my previous message, the 586/... option boots with 2.2.

I just noticed that, under both 2.2 and 2.4, uname -a identifies the
machine as an i486.

Should the 486 option be changed to "486/5x86" and the 586/... option
changed to "586/K5/6x86/6x86MX"? Or is there a bug here that needs fixing?
(IIRC, Cyrix and IBM made 5x86's as well - are those more like fast 486's
or slow Pentiums? I don't remember. If they're like Pentiums, perhaps
"486/AMD 5x86" and "586/non-AMD 5x86/6x86/6x86MX"...?)

-Barry K. Nathan <[email protected]>

2000-11-16 15:09:20

by Vojtech Pavlik

[permalink] [raw]
Subject: Re: [BUG?] AMD 5x86 and 2.4 (was Re: [BUG?] AMD K5 and 2.4)

On Wed, Nov 15, 2000 at 11:58:27AM -0800, Barry K. Nathan wrote:
> It looks like I was mistaken in my original message. I have an AMD 5x86, not
> a K5.
>
> Nevertheless, menuconfig lists the 586 option as "586/K5/5x86/6x86/6x86MX".
> But, it fails to boot on my 5x86 and I have to compile for a 486 (for 2.4).
> As I mentioned in my previous message, the 586/... option boots with 2.2.
>
> I just noticed that, under both 2.2 and 2.4, uname -a identifies the
> machine as an i486.
>
> Should the 486 option be changed to "486/5x86" and the 586/... option
> changed to "586/K5/6x86/6x86MX"? Or is there a bug here that needs fixing?
> (IIRC, Cyrix and IBM made 5x86's as well - are those more like fast 486's
> or slow Pentiums? I don't remember. If they're like Pentiums, perhaps
> "486/AMD 5x86" and "586/non-AMD 5x86/6x86/6x86MX"...?)

If I recall correctly:

Am5x86 == AMD X5 == a very fast 486 processor with a big WB cache
Cx5x86 == IBM 5x86 == a slow Pentium-like processor in a 486 socket

So yes, for the AMD 5x86 you have to select '486'.

--
Vojtech Pavlik
SuSE Labs

2000-11-29 19:00:22

by Andreas Eibach

[permalink] [raw]
Subject: Re: [BUG?] AMD 5x86 and 2.4 (was Re: [BUG?] AMD K5 and 2.4)



> It looks like I was mistaken in my original message. I have an AMD 5x86,
not
> a K5.

Careful.

AFAIK, '5x86' (without anything added) is a description for Cyrix/IBM
processors ONLY.
5x86/6x86/6x86MX are _also_ Cyrix names for CPUs.
'MMX' is a registered (!) trademark by Intel Corp., so Cyrix were obliged to
choose another name for the MMX technology (sorta) that they used in their
CPUs. They named it 'MX' and appended this to the name.

Nevertheless, you are right. You do NOT have a K5.

The *correct* name for your processor is 'Am5x86', though, which is a
trademark of AMD, by the way.

Andreas