Has the new boot system ever been tried on a 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

Patch to turn off cache at end of message.  Two caveats:

- I don't know what this will do 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.

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

*** SRT0.S.old	Sun Jul  2 20:31:04 1995
--- SRT0.S.nocache	Sun Jul  2 19:36:24 1995
***************
*** 35,40 ****
--- 35,55 ----
  __estack:
  	.globl	start
  start:
+ | Kill cache ASAP
+ 	movc sfc, d1			| save sfc
+ 	moveq #3, d0		| sfc = FC_CONTROL
+ 	movec d0, sfc
+ 	movl #0x40000000, a0			| src addr
+ 	movsb a0@, d0
+ 	movc d1, sfc			| restore sfc
+ 	andb	#0xEF,d0
+ 
+ 	movc dfc, d1			| save dfc
+ 	moveq #3, d2		| dfc = FC_CONTROL
+ 	movc d2, dfc
+ 	movsb d0, a0@			| set byte
+ 	movc d1, dfc			| restore dfc
+ 
  | Check to see if the code is located correctly.
  | This SHOULD do a PC-relative load into a0, but...
  	lea	start, a0	| current location (0x4000)

-- 
David Jones, M.A.Sc student, Electronics Group (VLSI), University of Toronto
           email: dej@eecg.toronto.edu, finger for PGP public key
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