Bug 55067

Summary:	Installer kernel won't boot on P60: machine check exception
Product:	[Retired] Red Hat Linux	Reporter:	ckulesa
Component:	kernel	Assignee:	Arjan van de Ven <arjanv>
Status:	CLOSED ERRATA	QA Contact:	Brock Organ <borgan>
Severity:	medium	Docs Contact:
Priority:	medium
Version:	7.2	CC:	ckulesa
Target Milestone:	---
Target Release:	---
Hardware:	i586
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2001-10-25 10:32:47 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description ckulesa 2001-10-25 02:59:22 UTC

Description of Problem:
AST Bravo 8060P (Pentium 60) w/48MB will not boot the stock kernel
(2.4.7-BOOT) on the Redhat 7.2 boot.img image.  Redhat 7.1 installs and works fine.

How Reproducible:
Insert Redhat 7.2 CD, boot floppy w/boot.img, turn on machine to install Redhat 7.2.  

First, the usual kernel messages before init takes hold... then after:
"Pentium detected w/ F00F bug"
which is followed by repeated:
"CPU#0: Machine Check Exception 0x 10CDE0  (type 0x     9)."

Solution!!!  At the boot prompt: 'linux nomce' is the trick that
allows the system to boot and install 7.2 correctly. 

This could stand to be documented.  Is this a bug or a feature? 
I vote for the former, as this machine has worked flawlessly for years.  

Will test against the updated 2.4.9-RH kernel when the machine is ready.

Comment 1 Arjan van de Ven 2001-10-25 10:32:42 UTC

It's sort of both a bug and a feature. Recent kernels support the Intel Machine
Check Exception mechanism, a way for the CPU to let the OS know that it has
detected a (fatal) problem in itself or the chipset. In order for the cpu to
know if the chipset has a problem, the CPU has a pin which should be wired to
the chipset pin for this; unfortionatly a number of pentium motherboards have
this pin wired to the 5 Volts line ;(

For the next kernel Red Hat will release I'll disable the MCE on pentium class
machines so "nomce" is then no longer needed.

Comment 2 Arjan van de Ven 2001-11-03 17:51:02 UTC

This should be fixed in the new errata kernels we released yesterday. Thanks for
the report!