Date: Sat, 03 Apr 1999 12:38:51 -0500 From: Dennis <dennis@etinc.com> To: Alfred Perlstein <bright@rush.net> Cc: hackers@freebsd.org Subject: Re: What does the "s" in insl and insw mean? Message-ID: <199904031744.MAA26618@etinc.com> In-Reply-To: <Pine.BSF.3.96.990403113649.4169P-100000@cygnus.rush.net> References: <Pine.SOL.L3.93.990403110237.13968B-100000@bingsun1>
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At 11:39 AM 4/3/99 -0500, you wrote: >On Sat, 3 Apr 1999, zhihuizhang wrote: > >> >> The instructions insl() and insw() should read a long word (l) or a word >> (w) from a specified I/O port. But what does the "s" in both instructions >> stand for? I can not find it in the Info files. > >in from port string operation > >it grabs a byte/word from the port, stores it into DS:DI and increments >DI, (that's in x86 real mode) afaik in prot mode it prolly just stores >to the segemtn pointed to DS and uses EDI. > >The opcodes without 's' use al/ax/eax for the destination. Its important to note that is a string read in that it will read multiple words (count of CX) ....of REP fame for memory copies. If you have an IO mapped card (rather than a memory mapped on) ins? functions can simulate a memory copy from IO space. DB To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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