From: "H. Peter Anvin" <hpa@zytor.com>
To: Ingo Molnar <mingo@elte.hu>
Cc: "Luis R. Rodriguez" <mcgrof@gmail.com>,
linux kernel <linux-kernel@vger.kernel.org>,
"H. Peter Anvin" <hpa@kernel.org>,
Ivan Seskar <Seskar@winlab.rutgers.edu>,
jfm3 <jfm3@winlab.rutgers.edu>, Sujith <m.sujith@gmail.com>
Subject: Re: Bug on 2.6.26 - x86 VIA Nehemiah CentaurHauls processor cannot boot
Date: Tue, 22 Jul 2008 09:24:45 -0400 [thread overview]
Message-ID: <4885DF9D.2090804@zytor.com> (raw)
In-Reply-To: <20080722131408.GA12418@elte.hu>
Ingo Molnar wrote:
>>
>> Not a bug.
>
> it would still be nice to get a nice printk and panic during bootup
> instead of some obscure crash, hm?
>
Yes. The fundamental problem is that Centaur has a set of CPUs which
report family == 6 but don't have the long NOP instructions. We would
need an exact CPUID criterion for these CPUs in order to be able to
report it as an error. An alternative would be to attempt trapping in
the real-mode code (#UD is one of the *very* few CPU exceptions which
can be reliably captured in real mode on a BIOS system), but doing so
would probably mean breaking Loadlin at the very least.
We can't "printk and panic" because we never get that far in the kernel
proper, for obvious reasons: the code is quite littered with these buggers.
-hpa
next prev parent reply other threads:[~2008-07-22 13:25 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-07-21 13:14 Bug on 2.6.26 - x86 VIA Nehemiah CentaurHauls processor cannot boot Luis R. Rodriguez
2008-07-21 13:23 ` H. Peter Anvin
2008-07-21 14:01 ` Luis R. Rodriguez
2008-07-21 23:24 ` H. Peter Anvin
2008-07-22 4:47 ` Luis R. Rodriguez
2008-07-22 13:10 ` H. Peter Anvin
2008-07-22 17:10 ` Jeff Garzik
2008-07-22 18:21 ` H. Peter Anvin
2008-07-22 18:33 ` Jeff Garzik
2008-07-22 18:41 ` H. Peter Anvin
2008-07-22 23:28 ` Jeff Garzik
2008-07-23 0:31 ` H. Peter Anvin
2008-07-22 13:14 ` Ingo Molnar
2008-07-22 13:24 ` H. Peter Anvin [this message]
2008-07-22 13:46 ` Ingo Molnar
2008-07-22 13:54 ` H. Peter Anvin
2008-07-26 18:31 ` Andi Kleen
2008-07-26 18:35 ` H. Peter Anvin
2008-07-26 18:44 ` Andi Kleen
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