From owner-freebsd-hackers Sat Jan 21 16:16:01 1995 Return-Path: hackers-owner Received: (from root@localhost) by freefall.cdrom.com (8.6.9/8.6.6) id QAA23022 for hackers-outgoing; Sat, 21 Jan 1995 16:16:01 -0800 Received: from halloran-eldar.lcs.mit.edu (halloran-eldar.lcs.mit.edu [18.26.0.159]) by freefall.cdrom.com (8.6.9/8.6.6) with SMTP id QAA23016 for ; Sat, 21 Jan 1995 16:16:00 -0800 Received: by halloran-eldar.lcs.mit.edu; id AA03123; Sat, 21 Jan 1995 19:15:47 -0500 Date: Sat, 21 Jan 1995 19:15:47 -0500 From: Garrett Wollman Message-Id: <9501220015.AA03123@halloran-eldar.lcs.mit.edu> To: terry@cs.weber.edu (Terry Lambert) Cc: freebsd-hackers@FreeBSD.org Subject: SCSI BIOS (was Re: More serial console stuff...) In-Reply-To: <9501212321.AA00703@cs.weber.edu> References: <199501210716.XAA02826@gndrsh.aac.dev.com> <9501212321.AA00703@cs.weber.edu> Sender: hackers-owner@FreeBSD.org Precedence: bulk < This is not true. There *must* be code to actually *do* something when > you do an int-13 call. Even if this is the *default* code, the int-13 > vector is hooked in order to instantiate the code. It's not ``hooked'', it's always there. No PC since the XT has ever come with a BIOS that did not have built-in INT 13 support for these sorts of controllers. > That you can only have one hook or the other is the whole crux of the > problem. Wrong on both counts. > 2) The INT 13 hook active is *either* the wd0/1 hook *or* the > sd0/1 hook. > 3) In the first case, you can *only* boot from the wd controller > *or* the sd controller. Both BIOS hooks to INT 13 can *not* > be active simultaneously. Of course they can! cmpb %al, (some address) jnb scsi_bios jmp (address of previous INT 13 entry point) -GAWollman -- Garrett A. Wollman | Shashish is simple, it's discreet, it's brief. ... wollman@lcs.mit.edu | Shashish is the bonding of hearts in spite of distance. Opinions not those of| It is a bond more powerful than absence. We like people MIT, LCS, ANA, or NSA| who like Shashish. - Claude McKenzie + Florent Vollant