[rescue] Using SCSI2SD on a Sun 3/110

David Brownlee abs at absd.org
Fri May 16 02:05:21 CDT 2014

On 16 May 2014 07:19, Earl Baugh <earl at baugh.org> wrote:

> Another note (keeping this as a separate thread, so as I work on both
> approaches they hopefully don't get too tangled)
> In my attempts to get the Sun 3 to boot, I've also been pursuing setting up
> a disk image directly for the SCSI2SD board.
> Based on comments from various folks, I figured it was worth trying to
> directly build a UFS file system on the SD card that goes into
> the board and give that a whirl.   First things, the latest Mac OS no
> longer has UFS file support (that ended as of 10.5) so I had to come
> up with another approach.
> The best option (at least without another Sun to start from) I've found to
> create a UFS file system was to get the FreeBSD virtual machine
> image (fairly easily to Google and find it... contact me off list if you
> need it) and work from that.
> That I was able to import into Parallels (which involved basically creating
> a new VM, telling it to work from the image you have... it then
> converted it and gets stuff going).  From there, you can mount any standard
> USB SD card reader via the Parallels Devices->USB menu.
> From there it was gpart time. I used gpart to delete any existing
> partitions on the SD card, then re-created the gpart top mapping (gpart
> create)
> and told it to use UFS (BSD is the type).   Then used gpart to add some
> freebsd-ufs partitions to that (I don't know how to add the "c" partition
> which represents the entire disk to the map... was able to make a root,
> swap and 2 general partitions on the SD card.)
> Copying files got a bit tricky.   Since the Mac can't read UFS anymore, I
> had to stay within the FreeBSD image.  But mount_smbfs works to
> mount an Apple share, so did that (after having to enable BRIDGED
> networking for Parallels and rebooting the image) and can bring over files
> from where I have them on the Macs (it's actually from a Windows 7 box that
> acts as my NAS...)  So that lets me move files I want into the
> FreeBSD image, and I can write them directly to the SD card.
> However I'm then at a similar point as I was with netbooting.  What to put
> where....
> Also, with the old boot PROM, there isn't any "probe-scsi" to check to see
> if the Sun 3 even detects the card.
> So, I haven't been able to sort out where any problems are in trying to
> boot from the SCSI2SD.
> If anyone has any suggestions as to how to verify that the card is good,
> cabling is good, termination is good,
> etc. esp on the Sun 3, it would be greatly appreciated.   So far the status
> messages seem to indicate that
> the drive isn't found, not that it's having trouble booting.  I've enabled
> "TERM POWER" on the SCSI2SD card.
> I turned off parity.  And I remembered the weird ID to sd mapping that was
> present in Sun OS (ID 3 is SD 0, ID 0 is SD 3)
> So have been testing both ID's and both sd(0,0,0) and sd(3,0,0) which I
> believe are the correct things to specify
> those two disks.
> I did get confirmation from the SCSI2SD designer that I should be able to
> directly use a disk partition that I've created
> on the SD card on the Mac (via the FreeBSD path) since the card doesn't do
> anything fancy, mapping wise, between
> the SD card and the SCSI interface.   So, if I did have a boot image from a
> Sun 3, I probably could try dd'ing it
> back onto the card as well.   However, that gets back to the original
> chicken-and-egg problem of trying to build
> a boot disk :-)
> So, similar overall problem... how to know what to put where... and make
> the disk bootable...
> Thoughts, comments, ideas all welcome..

The m68k is big endian, unlike x86, so unless you've done something special
the filesystems will all be little endian and unreadable. Also the sun3
PROM/SunOS will only be able to handle FFSv1 rather than the v2 a modern
BSD will create by default. I also suspect the current standard disklabel
may be an issue - number of partitions etc. Then you have bootblocks...

Maybe dd a NetBSD/sun3 image to an SD card and boot from that as an initial

If you build a NetBSD/sun3 cross toolchain it will also come with the tools
to build a sun3 compatible disklabel, filesystems, bootblocks & installboot

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