From owner-freebsd-hackers Sat Apr 3 9:47: 6 1999 Delivered-To: freebsd-hackers@freebsd.org Received: from etinc.com (et-gw.etinc.com [207.252.1.2]) by hub.freebsd.org (Postfix) with ESMTP id 6333814C90 for ; Sat, 3 Apr 1999 09:47:00 -0800 (PST) (envelope-from dennis@etinc.com) Received: from dbsys (dbsys.etinc.com [207.252.1.18]) by etinc.com (8.8.8/8.6.9) with SMTP id MAA26618; Sat, 3 Apr 1999 12:44:33 -0500 (EST) Message-Id: <199904031744.MAA26618@etinc.com> X-Sender: dennis@etinc.com X-Mailer: QUALCOMM Windows Eudora Pro Version 4.0 Date: Sat, 03 Apr 1999 12:38:51 -0500 To: Alfred Perlstein From: Dennis Subject: Re: What does the "s" in insl and insw mean? Cc: hackers@freebsd.org In-Reply-To: References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG 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