Date: Thu, 27 Mar 1997 16:20:03 -0800 (PST) From: Kazutaka YOKOTA <yokota@zodiac.mech.utsunomiya-u.ac.jp> To: freebsd-bugs Subject: Re: i386/3124: BOOT_PROBE_KEYBOARD hangs system in bootblocks Message-ID: <199703280020.QAA05847@freefall.freebsd.org>
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The following reply was made to PR i386/3124; it has been noted by GNATS.
From: Kazutaka YOKOTA <yokota@zodiac.mech.utsunomiya-u.ac.jp>
To: nsayer@quack.kfu.com
Cc: FreeBSD-gnats-submit@freebsd.org, yokota@zodiac.mech.utsunomiya-u.ac.jp
Subject: Re: i386/3124: BOOT_PROBE_KEYBOARD hangs system in bootblocks
Date: Fri, 28 Mar 1997 09:23:28 +0900
>>Number: 3124
>>Category: i386
>>Synopsis: BOOT_PROBE_KEYBOARD hangs system in bootblocks
>>Confidential: no
>>Severity: serious
>>Priority: high
>>Responsible: freebsd-bugs
>>State: open
>>Class: sw-bug
>>Submitter-Id: current-users
>>Arrival-Date: Thu Mar 27 11:00:04 PST 1997
>>Last-Modified:
>>Originator: Nick Sayer
>>Organization:
>Just me
>>Release: FreeBSD 2.2-RELEASE i386
>>Environment:
>
>Award BIOS, 486, no keyboard
>
>>Description:
>
>If you set BOOT_PROBE_KEYBOARD=true in /etc/make.conf and rebuild and
>install the resulting boot blocks, the system will hang on reboot.
>If you plug in a keyboard while it is hanging, it will instantly
>start booting as if a keyboard was plugged in. The probe is obviously
>hanging when no keyboard is present.
AFAIK, BOOT_PROBE_KEYBOARD didn't work well in the past and nobody is
actively working on it nowadays. That's why it is currently an option.
The problem is that probe_keyboard() (in
/sys/i386/boot/biosboot/probe_keyboard.c) doesn't work as expected in
some systems.
I once wrote a replacement routine. It worked in my systems, but I
abandoned the project because I had other, more urgent code to work
on.
I don't know if it is good for you, but if you are interested, here
goes. Save the following code as probe_keyboard.c (of course you had
better save the original copy of probe_keyboard.c somewhere), and
rebuild the boot block.
Please remember that I don't guarantee anything; this code may or may
not work in your system. To test the boot block, you had better have
the `install' and `fixit' floppy handy; a broken boot block and an
unbootable system are too bad.
Kazu
----8<---8<---8<---8<---8<---8<---8<---8<---8<---8<---8<---8<---8<---
/*-
* $Id:$
*/
#ifdef PROBE_KEYBOARD
#include <i386/include/cpufunc.h>
#include <i386/isa/isa.h>
#include <i386/isa/ic/i8042.h>
#include <i386/isa/kbdio.h>
#include "boot.h"
#define PROBE_MAXRETRY 5
#define PROBE_MAXWAIT 500
#define IO_DUMMY 0x84
/* 7 microsec delay necessary for some keyboard controllers */
static void
delay7(void)
{
/*
* I know this is broken, but no timer is avaiable yet at this stage...
* See also comments in `delay1ms()' in `io.c'.
*/
inb(IO_DUMMY); inb(IO_DUMMY);
inb(IO_DUMMY); inb(IO_DUMMY);
inb(IO_DUMMY); inb(IO_DUMMY);
}
/*
* Perform a simple test on the keyboard; issue the ECHO command and see
* if the right answer is returned. We don't do anything as drastic as
* full keyboard reset; it will be too troublesome and take too much time.
*/
int
probe_keyboard(void)
{
int retry = PROBE_MAXRETRY;
int wait;
int i;
while (--retry >= 0) {
/* flush any noise */
while (inb(IO_KBD + KBD_STATUS_PORT) & KBDS_ANY_BUFFER_FULL) {
delay7();
inb(IO_KBD + KBD_DATA_PORT);
delay1ms();
}
/* wait until the controller can accept a command */
for (wait = PROBE_MAXWAIT; wait > 0; --wait) {
if (((i = inb(IO_KBD + KBD_STATUS_PORT))
& (KBDS_INPUT_BUFFER_FULL | KBDS_ANY_BUFFER_FULL)) == 0)
break;
if (i & KBDS_ANY_BUFFER_FULL) {
delay7();
inb(IO_KBD + KBD_DATA_PORT);
}
delay1ms();
}
if (wait <= 0)
continue;
/* ECHO command */
outb(IO_KBD + KBD_DATA_PORT, KBDC_ECHO);
/* wait for a response */
for (wait = PROBE_MAXWAIT; wait > 0; --wait) {
if (inb(IO_KBD + KBD_STATUS_PORT) & KBDS_ANY_BUFFER_FULL)
break;
delay1ms();
}
if (wait <= 0)
continue;
delay7();
i = inb(IO_KBD + KBD_DATA_PORT);
#ifdef PROBE_KBD_BEBUG
printf("probe_keyboard: got 0x%x.\n", i);
#endif
if (i == KBD_ECHO) {
/* got the right answer */
#ifdef PROBE_KBD_BEBUG
printf("probe_keyboard: succeeded.\n");
#endif
return (0);
}
}
#ifdef PROBE_KBD_BEBUG
printf("probe_keyboard: failed.\n");
#endif
return (1);
}
#endif /* PROBE_KEYBOARD */
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