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From: "Vladimir 'φ-coder/phcoder' Serbinenko" <phcoder@gmail.com>
To: The development of GNU GRUB <grub-devel@gnu.org>
Cc: Iain Barker <IBarker@acmepacket.com>
Subject: Re: HP root-caues analysis for GRUB "Red screen of death" on	DL120/DL360 G7 servers
Date: Thu, 08 Dec 2011 21:16:25 +0100	[thread overview]
Message-ID: <4EE11B19.6000300@gmail.com> (raw)
In-Reply-To: <6F28EE1C9AAED6468989841A3FB66CB44980B21C@Mail2.acmepacket.com>


> 1) Grub installs its own INT13 handler
> 2) Near the end of the chain loading process, Grub loads an image of the Linux kernel into memory which wipes out their Int13 handler.
> 3) Right before grub transfers control to the kernel to boot, grub makes a call to a function to turn off the floppy drive.
> 4) The call to the floppy code then makes an Int13 call to the handler which has been overwritten by the kernel and thereby results in the red screen.
>
This text seems to be contradictory. INT13 handler is installed if 
drivemap is useful only with chainload. But then it mentions Linux 
loading. Also the call to stop floppy doesn't call BIOS:
static inline void
grub_stop_floppy (void)
{
   grub_outb (0, GRUB_FLOPPY_REG_DIGITAL_OUTPUT);
}
May I see the configfile in question?
Also GRUB does calculate the safe place based on memory layout, looking 
at code I see the problem that it's calculated before installing 
drivemap hook. While this should be fixed, I see no reason to use 
drivemap with Linux.
> _end quoted text_
>
> Regards,
> Iain Barker - Platform Engineering, Acme Packet.
> [yoshac@member.fsf.org]
>
>
> _______________________________________________
> Grub-devel mailing list
> Grub-devel@gnu.org
> https://lists.gnu.org/mailman/listinfo/grub-devel
>


-- 
Regards
Vladimir 'φ-coder/phcoder' Serbinenko



  reply	other threads:[~2011-12-08 20:16 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-12-08 19:39 HP root-caues analysis for GRUB "Red screen of death" on DL120/DL360 G7 servers Iain Barker
2011-12-08 20:16 ` Vladimir 'φ-coder/phcoder' Serbinenko [this message]
2011-12-08 20:23   ` Seth Goldberg
2011-12-08 20:42     ` Vladimir 'φ-coder/phcoder' Serbinenko
  -- strict thread matches above, loose matches on Subject: below --
2011-12-08 15:36 Iain Barker

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