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From: John Baldwin <jhb@freebsd.org>
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 sbruno@freebsd.org
Date: Mon, 5 Mar 2012 12:22:45 -0500
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Cc: 
Subject: Re: [patch] Disable bios probe if acpi is enabled
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On Friday, March 02, 2012 3:38:44 pm Sean Bruno wrote:
> I'm noting that newer machines are completely hosed if we attempt to
> probe for bios values.  I'm proposing this change.

Hmm, perhaps better than this is tying it into some device as a child of 
legacy0.  That is possibly cleaner than checking for acpi0.

I think your patch will break booting on a system that doesn't have ACPI 
(certainly it won't be able to find PCI anymore).

> -bash-4.2$ p4 diff -du //depot/yahoo/ybsd_7/src/sys/i386/i386/bios.c
> --- //depot/yahoo/ybsd_7/src/sys/i386/i386/bios.c       2011-09-16
> 22:47:30.000000000 0000
> +++ /home/seanbru/ybsd_7/src/sys/i386/i386/bios.c       2011-09-16
> 22:47:30.000000000 0000
> @@ -84,6 +84,12 @@
>      char                       *p;
>      
>      /*
> +     * Don't do bios probing if acpi is enabled, its
> +     * pointless and breaks on newer systems
> +     */
> +    if (!resource_disabled("acpi", 0))
> +       return;
> +    /*
>       * BIOS32 Service Directory, PCI BIOS
>       */
> 
> 

-- 
John Baldwin