Newsgroups: comp.sys.transputer
From: tillema@cs.utwente.nl (Henno Tillema)
Subject: network booting problem with iserver
Keywords: iserver, occam toolset
Organization: University of Twente, Dept. of Computer Science
Date: 17 Oct 1994 15:33:03 GMT
Message-ID: <37u5ff$34l@utis084.cs.utwente.nl>


We have a major problem with the iserver booting a network:

Sometimes when we try to boot our transputernetwork the iserver
stops sending the bootfile into the network with the message:
	Error - iserver - unable to write byte # to the boot link
 (# is specific for each bootfile and can even be negative in some cases.)
The error happens at specific bootfiles, always at the same byte
for that bootfile. (bootfile sizes 100-250Kb)

If we add some dummy statements to our source code like
SEQ
  INT i:
  i := 100
the program may boot and run ok. (is that strange or not :-(  )
It's a total guess where to add some statements. The other way around 
a working program may stop booting when we add these lines.


a post-mortem inspection with the debugger shows all transputers
still in an invalid state for the debugger:
-Iptr in Stack area or in Vectorspace, Wdesc is NotProcess
-When comparing memory with intended code the program code is invalid 
-on a lot of nodes. Switching on the 'low level config compare' (shift-z, E) 
-every node shows a 'Config code memory error'

Some extra information:
*we use the Inmos toolset D7205 for Occam:
	iserver : INMOS host file server
	IBM-PC/MS-DOS&B004/B017 version 1.42h of 9th November 1990.
	Copyright (c) INMOS Ltd, 1988.  All Rights Reserved.

	icollect : INMOS toolset collector
	Toolset Version 2.0.30 Jun 25 1991 01:12:46
	(c) Copyright INMOS Limited 1989, 1990, 1991    (etc. ...)

*our transputernetwork has a fixed topology, is a mix from 15 procs
(T8/T2) with memory sizes between 32Kb and 2Mb, connected to a PC.

*programs like check with mtest or ftest show no errors


Any help to solve this problem is very welcome! I don't have 
any idea what to do to overcome this problem and it seems to occur
more often while the program grows.

You may send a reply (yes please) to this newsgroup or directly
by e-mail to tillema@cs.utwente.nl


Thanks, Greetings,

Henno Tillema

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