Re: NetBSD 8.10 does not boot on 7043-140

Howdy Uli,
my guess would be to turn on the DDB or KGDB option in the _COM version 
of the kernel (compile) and try to debug it that way.
http://www.netbsd.org/docs/kernel/kgdb.html

I have recently tried to compile with the KGDB kernel option enabled, 
but it fails without a few workarounds (I will be making a separate post 
on this shortly). For this _COM issue, it might be best (once KGDB is 
fully working) to setup the 7043 to boot from network BOOTP/TFTP and use 
a separate (more powerful) machine for KGDB REMOTE, cross-compiling, and 
TFTP/BOOTP server. This should allow you to cross-compile the kernel on 
the REMOTE machine and push it to the 7043 by simply copying the 
cross-compiled kernel to the /tftp directory on the same machine. The 
kernel source would also be on the same machine for KGDB to use, so it 
seems like this is probably an ideal setup for a physical machine. 
There's probably a way to do it through QEMU, but I don't really have 
any experience with it.

I've only seen this problem with the _COM versions of the kernel, so 
when you setup KGDB, you might want to have it use COM1 and have TERM on 
COM0 to see what's going on.

Like you, I don't have much experience with the kernel (other than 
compiling), so much of the actual debugging is new to me.

On 5/31/19 5:36 AM, Ulrich Teichert wrote:
> Hi,
>
> as others have already observed, NetBSD is broken on the IBM 7043-140:
>
> https://mail-index.netbsd.org/port-prep/2017/04/02/msg000109.html [1]
> https://mail-index.netbsd.org/port-prep/2017/06/27/msg000119.html [2]
> https://mail-index.netbsd.org/port-prep/2018/08/27/msg000131.html [3]
>
> Artyom Tarasenkos guess was that the breakage exists since 3.99.22,
> but his quick fix (from [1]) does not work anymore.
>
> The bootup of my 7043 (on a serial console) looks similar to [2]:
>
>>> NetBSD/prep BOOT, Revision 1.9 (Tue Jul 17 14:59:51 UTC 2018)
> INTRF
> phase mismatch without command
> selection timeout without command
> unhandled scsi interrupt, sist=0xffff sstat1=0xff DSA=0xffffffff DSP=0x7f7e8fff
> XXXXX: fatal error, need reset the bus...
> INTRF
> phase mismatch without command
> selection timeout without command
> unhandled scsi interrupt, sist=0xffff sstat1=0xff DSA=0xffffffff DSP=0x7f7e8fff
> XXXXX: fatal error, need reset the bus...
> INTRF
>
> ... And so on until you'll switch off power. I am pretty sure that this
> is not a hardware fault, as the same machine boots Linux just fine and
> the other boot failures are looking very similar, ever the one under qemu.
>
> Can somebody point me in the right direction where to start digging?
> I mean, the INTRF and "phase mismatch without command" prints are most
> probably from sys/arch/prep/stand/boot/siop.c, function siop_intr, but
> as this is my first look into the NetBSD kernel tree, I'd be glad for
> every help ;-)
>
> TIA,
> Uli