[SeaBIOS] BEV and bootorder

[Gleb Natapov]

On Sun, Apr 15, 2012 at 02:39:45PM +0200, Fred . wrote:
> 2012/4/15 Gleb Natapov <gleb at redhat.com>:
> > On Sun, Apr 15, 2012 at 02:24:05PM +0200, Fred . wrote:
> >> Why would anyone want to define some devices as unbootable?
> >>
> > Because he does not want to boot from them.
> 
> Then the partition should not be flagged as a boot partition, and it
> won't be booted from.
> Then it proceeds to try to boot from the next device.
Adding flag to qemu is easier then modifying partitions. In reality all
partitions are marked as boot partition during format. And there are
other bootable devices besides HDs.

> >
> >> On Sun, Apr 15, 2012 at 8:57 AM, Gleb Natapov <gleb at redhat.com> wrote:
> >> > On Sat, Apr 14, 2012 at 11:19:31PM -0400, Kevin O'Connor wrote:
> >> >> On Thu, Apr 12, 2012 at 01:30:36PM -0600, Steve Goodrich wrote:
> >> >> > I'm working towards a goal of having specific devices be bootable, and
> >> >> > *only* those devices.  For example, if my bootorder file specifies SATA
> >> >> > drive 3, I do not want it to try SATA drives 0, 1, and 2, nor any other HDD
> >> >> > or floppy that it finds.
> >> >> >
> >> >> > My first question is: how do I do this?
> >> >>
> >> >> There is no current way to do this.  I suppose one could code support
> >> >> for a "stop boot" option to the boot order file - so that if it was
> >> >> listed in the file the boot would stop after trying all options prior
> >> >> to it.
> >> >>
> >> > I thought to add skipboot file. If device is in skipboot file it is not
> >> > considered for booting from.
> >> >
> >> >> > If that can't be answered, can someone explain to me the relationship
> >> >> > between the bootorder file and the BEV (Boot Execution Vector) configured in
> >> >> > boot.c?
> >> >>
> >> >> All possible boot options (both BEV and BCV) are assembled in a sorted
> >> >> list pointed to by boot.c:BootList.  The bootorder file alters the
> >> >> default sort order of that list.  During the latter parts of the POST
> >> >> phase, the BCVs are executed and only BEVs remain.  The list of BEVs
> >> >> is generated from the BootList.  So, in a nutshell, the bootorder file
> >> >> determines the order of the BEVs that SeaBIOS will attempt to boot
> >> >> from.
> >> >>
> >> >> -Kevin
> >> >>
> >> >> _______________________________________________
> >> >> SeaBIOS mailing list
> >> >> SeaBIOS at seabios.org
> >> >> http://www.seabios.org/mailman/listinfo/seabios
> >> >
> >> > --
> >> >                        Gleb.
> >> >
> >> > _______________________________________________
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> >
> > --
> >                        Gleb.

--
			Gleb.