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From: pl@etana.tut.fi (Pertti Lehtinen)
Newsgroups: comp.sys.amiga.tech
Subject: Re: Patching dos.library
Message-ID: <6587@etana.tut.fi>
Date: 30 Mar 89 09:00:30 GMT
References: <6439@cbmvax.UUCP>
Sender: News@tut.fi
Lines: 36

From article <6439@cbmvax.UUCP>, by andy@cbmvax.UUCP (Andy Finkel):
> In article <11110@well.UUCP> aleks@well.UUCP (Brian J. Witt) writes:
>>
>>The dos.library is not a common library the way Carl would like to see
>>it.  Each vector entry contains code like:
>>        moveq  #9,D0               <--- offset into GlobVec table(?)
>>        bra.s  common_hanlder
>>I told this to Andy Finkel a few years back, and he nope, you're wrong--
>>doesn't even happen.  To patch a function I recommond tracing through
> 
> This is why, after you patch dos.library, your patch will only
> seem to function sometimes.
> 
> BTW, turned out that, according to the Exec manual, any 6 bytes
> will do for a function.  Including functions that aren't even
> jumps, like:
> 
> moveq#0,d0
> rts

	I look exec manual and realized that SetFunction
	does not return anything.

	That seems strange, because I thought that it returns
	address of old function. ( At least i've seen someone
	using t that way)

	I wonder which is true.

					Pertti Lehtinen
					pl@tut.fi

pl@tut.fi				! -------------------------------- !
Pertti Lehtinen				!  Alone at the edge of the world  !
Tampere University of Technology	! -------------------------------- !
Software Systems Laboratory