freebsd-dev/sys/i386/boot/biosboot/probe_keyboard.c
Joerg Wunsch 9c6e0c69be . Make Poul's boot2 overflow warning less noisy in case the blocks
do fit, and beeping in case of an overflow.

.  Drop a comment about the ``FORCE_COMCONSOLE'' option into
   README.serial.

.  Increase the name buffer for the root directory from 100 bytes
   to 8 KB;  this is in no way ideal, but (IMHO) the best that can
   be done by now.  People did encounter problems with their root
   dir name listing overflowing the allocated buffer space.  Once
   we've got the three-stage boot, we should implement some basic
   malloc().  Swap space is already getting tight now, perhaps the
   swap should go into another 64 KB segment instead.

.  Make the keyboard probe less paranoid.  It should not give up in
   case of a keyboard that's continuously demanding RESEND's.  Even
   though the keyboard reset apparently has not been reported to be
   complete, it's at the very least proven that there IS something
   like a keyboard available.

   This solves problems with the ``Gateway-2000 AllKey programmable''
   (sp?) keyboard, that experienced a total hang with the previous
   probe.

   Thanks goes to Scott Blachowicz <scott@statsci.com> for his
   extensive testing of my various interim (debugging) bootblocks
   to get this working.
1995-04-20 23:15:10 +00:00

121 lines
3.6 KiB
C

/*-
* Copyright (c) 1992-1995 Søren Schmidt
* Copyright (c) 1990 The Regents of the University of California.
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* William Jolitz and Don Ahn.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer
* in this position and unchanged.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* This is a modified version of the keyboard reset code used in syscons.
* If the keyboard reset fails, we assume that the keyboard has been
* unplugged and we use a serial port (COM1) as the console instead.
* Returns 1 on failure (no keyboard), 0 on success (keyboard attached).
*
* This grody hack brought to you by Bill Paul (wpaul@ctr.columbia.edu)
*
* $Id: probe_keyboard.c,v 1.4 1995/04/14 21:26:52 joerg Exp $
*/
#ifndef FORCE_COMCONSOLE
#include <machine/console.h>
#include <machine/cpufunc.h>
#include "boot.h"
int
probe_keyboard(void)
{
int i, retries = 5;
unsigned char val;
/* flush any noise in the buffer */
while (inb(KB_STAT) & KB_BUF_FULL) {
delay1ms();
(void) inb(KB_DATA);
}
/* Try to reset keyboard hardware */
again:
while (--retries) {
#ifdef DEBUG
printf("%d ", retries);
#endif
while ((inb(KB_STAT) & KB_READY) == KB_READY) delay1ms();
outb(KB_DATA, KB_RESET);
for (i=0; i<1000; i++) {
delay1ms();
val = inb(KB_DATA);
if (val == KB_ACK || val == KB_ECHO)
goto gotres;
if (val == KB_RESEND)
break;
}
}
gotres:
#ifdef DEBUG
printf("gotres\n");
#endif
if (!retries) {
if (val == KB_RESEND) {
#ifdef DEBUG
printf("gave up\n");
#endif
return(0);
}
return(1);
}
gotack:
delay1ms();
while ((inb(KB_STAT) & KB_BUF_FULL) == 0) delay1ms();
delay1ms();
#ifdef DEBUG
printf("ACK ");
#endif
val = inb(KB_DATA);
if (val == KB_ACK)
goto gotack;
if (val == KB_RESEND)
goto again;
if (val != KB_RESET_DONE) {
#ifdef DEBUG
printf("stray val %d\n", val);
#endif
return(0);
}
#ifdef DEBUG
printf("ok\n");
#endif
return(0);
}
#endif /* !FORCE_COMCONSOLE */