Skip site navigation (1)Skip section navigation (2)
Date:      Mon, 07 Feb 2005 18:23:36 +0000
From:      Ian Dowse <iedowse@maths.tcd.ie>
To:        John Baldwin <jhb@FreeBSD.org>
Cc:        cvs-all@FreeBSD.org
Subject:   Re: cvs commit: src/sys/dev/random probe.c 
Message-ID:  <200502071823.aa13056@salmon.maths.tcd.ie>
In-Reply-To: Your message of "Mon, 07 Feb 2005 10:15:39 EST." <200502071015.39224.jhb@FreeBSD.org> 

next in thread | previous in thread | raw e-mail | index | archive | help
In message <200502071015.39224.jhb@FreeBSD.org>, John Baldwin writes:
>On Sunday 06 February 2005 11:55 am, Ian Dowse wrote:
>>   Check that we have at least a 586-class CPU before calling do_cpuid().
>>   This fixes booting on a number of 486 processors.
>
>This is wrong.  Some 486's do have cpuid, notable the dx4's (I used to have 
>one.)  The correct test is to see if you can flip a bit in %eflags (can't 
>remember which one).  If that flag stays at zero then you don't have cpuid, 
>if the bit follows the value written to it then you do have cpuid.

Indeed - it's just a quick workaround that I'll fix when you find
me a 486 with a Nehemiah random number generator ;-)

Ian



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?200502071823.aa13056>