Problems making and booting ISOs in qemu-system-x86_32

[Rhialto <rhialto%falu.nl@localhost>]

I am trying to make my own bootable install ISO from files in the NetBSD
4.0 distribution. I have always used a script that allows booting by
Alpha and (either i386 or amd64 (they conflict)). I am now running into
the following problems, because for amd64 there is no boot floppy image
any more:

1. Name conflicts. Amd64 boots want /boot and /netbsd.gz in the
   filesystem (and amd64's /usr/mdec/bootxx_cd9660 is added as El Torito
   boot image apparently).  Alpha wants /boot and /netbsd.alpha.gz in
   the ISO image (and alpha's /usr/mdec/bootxx_cd9660 is added with
   installboot).
   
   Obviously /boot conflicts, and /netbsd.gz for amd64 ought to be
   /netbsd.amd64.gz too.

   Why don't the bootxx* first stage booters look for /boot.alpha resp.
   /boot.amd64 (before looking for /boot)? And why does the Alpha /boot
   look for /netbsd.alpha.gz but the amd64 /boot not look for
   /netbsd.amd64.gz?

2. Boot problems. These occur with the supplied 4.0 .iso file too,
   so they are not caused by my iso creation process.

   The symptom is that if I start the .iso file in qemu

    qemu-system-x86_64 -serial stdio -cdrom amd64/installation/cdrom/boot.iso

   then it panics when it is about to create the mfs /dev. The last
   lines of output are

    warning: no /dev/console
    panic: cnopen: no console device
    syncing disks... done

    dump to dev 17,1 not possible
    rebooting...

   If I use boot-com.iso instead, it works:

    warning: no /dev/console
    init: Creating mfs /dev (487 blocks, 1280 inodes)

   (and then it proceeds as normal)

   The file i386/installation/cdrom/boot.iso starts fine too (in qemu and
   on a real machine).

   So would this problem also occur on a real amd64 machine, or is it a
   qemu problem? I haven't brought my server down to try it yet.

I realise I can update my amd64 server by simply copying an install
kernel to / and booting it, but I really want a known working bootable
install cd for emergencies too, so I always update by using such a cd.

-Olaf.
-- 
___ Olaf 'Rhialto' Seibert      -- You author it, and I'll reader it.
\X/ rhialto/at/xs4all.nl        -- Cetero censeo "authored" delendum esse.