> From: David Jones <dej@eecg.toronto.edu>
> Date: 	Sun, 2 Jul 1995 22:05:17 -0400

> Has the new boot system ever been tried on a 3/260?

Yes. The new netboot works, everywhere I've tried it.
The new ufsboot works only on the desktop machines.
I'm not sure yet why ufsboot fails on the 3/260.

> I ask because I am having real problems.
> 
> First, the cache is enabled at boot, and should be turned off.
> Otherwise you get:
> 
> MEMORY ERROR!  Status C8, DVMA-BIT=1, Context 0,
> Vaddr FF40D10, Paddr 01E80D10, Type 0 at 0x0FEF81B2

Yikes!  My hardware manual says the cache is off at reset,
so your PROM must turn it on.  What prom rev do you have?
If this is true, both the boot programs and the kernel
will have to make sure the cache is off at startup.

> Patch to turn off cache at end of message.  Two caveats:
> 
> - I don't know what this will do on machines without a cache.
The "cache enable" bit is harmless on machines without a cache.

> - There is a comment to the effect that gas got an lea instruction wrong.
>   I have hand inspected the object code produced by my patch and found
>   it to be OK.  YMMV.

Yeah, I'm just paranoid.

> Second, I get the following (with debug turned on):
> 
> bootxx: open...
> disk_open:
> Boot device type: sd: SCSI disk
> prom_iopen: dmaaddr=0xff240f24
> scsi: dma bus error
> prom_iopen: "sd: SCSI disk" error=-1
> bootxx: open failed

I'm not sure why that happens.  I hope that the PROM driver
can be convinced to work after some experimenting with the
initialization code.  If not, someone will have to write a
real stand-alone scsi driver.  It would be nice to have real
stand-alone drivers eventually anyway, but in the mean time
it would be nice if the PROM drivers could be made to work.

Gordon