In article <20050911191322.GB9424@drowsy.duskware.de>
martin@duskware.de wrote:

> On Mon, Sep 12, 2005 at 03:06:15AM +0900, Izumi Tsutsui wrote:
> > (d) On the other hand, the sgimips bootable CD image has an
> >     SGI volume header. If the disk has the header, MD readdisklabel(9)
> >     creates BSD disklabel from values in the volume header, and
> >     d_secsize in struct disklabel is taken from dp.dp_secbytes
> >     in struct sgi_boot_devparms.
> 
> Isn't a simpler aproach to leave sgivol as is (i.e. use 512 byte sectors)
> and have readdisklabel() convert to 2048 byte sector size when creating
> the disklabel from the volume header (and adjusting all offsets/sizes
> accordingly)?

I thought the similar way (ignore dp_secbytes and leave default
b_secsize prepared by each disk driver in readdisklabel(9)),
but I also thought that if MI drivers use p_offset in the
disklabel, b_secsize should be taken from the label too.

It also causes problem that the CD image can't be mounted
via vnd(4) because the default b_secsize of vnd(4) is 512
and it doesn't match with p_offset. But now, I notice
we can specify secsize on vnconfig(8). Hmm.
I haven't tried it, but if it works we could choose this way...
---
Izumi Tsutsui