Re: [Qemu-devel] Re: POST failure (loop) with isapc and seabios

From: Gleb Natapov <gleb@redhat.com>
To: Kevin O'Connor <kevin@koconnor.net>
Cc: qemu-devel@nongnu.org, Sebastian Herbszt <herbszt@gmx.de>
Subject: Re: [Qemu-devel] Re: POST failure (loop) with isapc and seabios
Date: Mon, 23 Nov 2009 13:16:01 +0200	[thread overview]
Message-ID: <20091123111601.GH2999@redhat.com> (raw)
In-Reply-To: <20091122153842.GA13491@morn.localdomain>

On Sun, Nov 22, 2009 at 10:38:42AM -0500, Kevin O'Connor wrote:
> On Sun, Nov 22, 2009 at 05:10:53PM +0200, Gleb Natapov wrote:
> > On Sun, Nov 22, 2009 at 04:07:56PM +0100, Sebastian Herbszt wrote:
> > > Gleb Natapov wrote:
> > > >May be make qemu to map it writable if isapc is specified.
> > > 
> > > I don't think keeping the segment writable after POST is a good idea.
> > > 
> > Isn't it writable now after POST with pcipc? Why this is not a good
> > idea?
> 
> SeaBIOS and bochs bios will make the f-segment readonly at the end of
> post.  See make_bios_readonly() in src/shadow.c.
> 
I see SeaBIOS does this, but I don't see where bochs bios does this.

> SeaBIOS' ram locking requires the same pci access that the unlocking
> needs, so if qemu made the f-segment writable on isa then it would
> remain writable past POST.
> 
> -Kevin

--
			Gleb.