Re: port-xen/59350: PVHVM kernel cannot access cd unless vdev=hdc

[Manuel Bouyer <bouyer%antioche.eu.org@localhost>]

On Thu, Apr 24, 2025 at 08:20:00AM +0000, netbsd%precedence.co.uk@localhost wrote:
> [...[
> If the CD device is hdb (or hdd) it will be mis-detected as a hard-disk and so the CD will not be usable:
> 
> wdc0 at isa0 port 0x1f0-0x1f7 irq 14
> atabus0 at wdc0 channel 0
> wd0 at atabus0 drive 0
> wd0: 
> wd0: drive supports 1-sector PIO transfers, chs addressing
> wd0: 69632 KB, 1024 cyl, 8 head, 17 sec, 512 bytes/sect x 139264 sectors

this is probably because in this case, the CD device appears as a slave
IDE device, without master. In the ATA/ATAPI spec this is not a
supported configuration, although with some hardware configuration it may
work.

-- 
Manuel Bouyer <bouyer%antioche.eu.org@localhost>
     NetBSD: 26 ans d'experience feront toujours la difference
--