Skip site navigation (1)Skip section navigation (2)
Date:      Sat, 21 Jan 1995 19:15:47 -0500
From:      Garrett Wollman <wollman@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...)
Message-ID:  <9501220015.AA03123@halloran-eldar.lcs.mit.edu>
In-Reply-To: <9501212321.AA00703@cs.weber.edu>
References:  <199501210716.XAA02826@gndrsh.aac.dev.com> <9501212321.AA00703@cs.weber.edu>

next in thread | previous in thread | raw e-mail | index | archive | help
<<On Sat, 21 Jan 95 16:21:05 MST, terry@cs.weber.edu (Terry Lambert) said:

> 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



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?9501220015.AA03123>