Fw: Single Stepping for TX3912

["TAKEMURA Shin" <takemura@netbsd.org>]

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----- Original Message ----- 
From: "Robert Smith" <roberts@transpond.co.uk>
To: <takemura@netbsd.org>
Cc: "'Chris Bacon'" <chrisb@transpond.co.uk>
Sent: Wednesday, June 13, 2001 2:07 AM
Subject: Single Stepping for TX3912


> Dear Sir
> 
> We have been developing a hpcmips / NetBSD port for
> our TX3912 based MIPS platform.  The port is up and running
> and I have been working on the development environment, which
> is based on GDB.  I have hit a problem with single stepping, and 
> in tracking it down realised that by default, the single step 
> operation invoked via the ptrace() function is disabled (that is,
> the definition of the macro PT_STEP in sys/arch/mips/include/ptrace.h
> is commented out).  I have "enabling" this definition, 
> and although the code goes through the process of
> inserting a break instruction when attempting to 
> single step via ptrace(...), it in fact does not seem to 
> generate the associated software exception and so 
> single stepping fails.
> 
> Is this a known issue?
> If so, is there a workaround?
> 
> Kind regards - Robert Smith