Re: VAXstation 3100/30 KA420 SCSI DMA problem on netboot (and fix)

[Izumi Tsutsui <tsutsui%ceres.dti.ne.jp@localhost>]

kwellsch@ wrote:

> On Sun, Feb 18, 2024 at 03:39:18AM +0900, Izumi Tsutsui wrote:
 :
> > Ok, if you can try netboot (via mopd(8) etc.) on your M76,
> >  http://www.netbsd.org/docs/network/netboot/intro.vax.html
> > could you try to boot the following debug kernel to check a
> > region around KA420_STC_MODE?
 :
> So, for what it is worth, this is a disk boot (an install CD image I built
> with your patch, served from a SCSI emulator card):
> 
> >>> boot DKA500
 :
> [   1.0000000] VAXstation 3100/m76
> 
> 	...
> 
> [   1.0000000] si0 at vsbus0 csr 0x200c0080 vec 770 ipl 17 maskbit 1
> [   1.0000000] Dumping KA420_SCD region
> [   1.0000000] 0x200C00A0: 00 08 00 00 FF FF FF FF FF FF FF FF FF FF FF FF
> [   1.0000000] 0x200C00B0: 00 00 00 00 FF FF FF FF FF FF FF FF FF FF FF FF
> [   1.0000000] 0x200C00C0: 00 00 00 00 01 00 00 00 FF FF FF FF FF FF FF FF
> [   1.0000000] 0x200C00D0: FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
> [   1.0000000] 0x200C00E0: FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
> [   1.0000000] 0x200C00F0: FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
> [   1.0000000] si0: NCR5380, SCSI ID 6
> [   1.0000000] scsibus0 at si0: 8 targets, 8 luns per target

Ok, this indicates:
- No valid register at 200C00E0 (KA420_STC_MODE for KA420 to switch DMA size)
- KA43_SC1_DADR/KA420_SCD_DADR (200C00A0),
  KA43_SC1_DCNT/KA420_SCD_DCNT (200C00C0), and
  KA43_SC1_DDIR/KA420_SCD_DDIR (200C00C4) are also available as KA420
- There is some register is at 200C00B0
  (no info at least in <machine/ka43.h>)

So at least it's confirmed that we don't have to manage KA420_STC_MODE
on KA430.

Thanks,
---
Izumi Tsutsui