freebsd-nq/sys/dev/ofw/ofw_console.c
Peter Wemm 43d7128c14 Expand kdb_alt_break a little, most commonly used with the option
ALT_BREAK_TO_DEBUGGER.  In addition to "Enter ~ ctrl-B" (to enter the
debugger), there is now "Enter ~ ctrl-P" (force panic) and
"Enter ~ ctrl-R" (request clean reboot, ala ctrl-alt-del on syscons).

We've used variations of this at work.  The force panic sequence is
best used with KDB_UNATTENDED for when you just want it to dump and
get on with it.

The reboot request is a safer way of getting into single user than
a power cycle.  eg: you've hosed the ability to log in (pam, rtld, etc).
It gives init the reboot signal, which causes an orderly reboot.

I've taken my best guess at what the !x86 and non-sio code changes
should be.

This also makes sio release its spinlock before calling KDB/DDB.
2008-05-04 23:29:38 +00:00

321 lines
6.6 KiB
C

/*-
* Copyright (C) 2001 Benno Rice.
* All rights reserved.
*
* 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.
* 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.
*
* THIS SOFTWARE IS PROVIDED BY Benno Rice ``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 TOOLS GMBH 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_comconsole.h"
#include "opt_ofw.h"
#include <sys/param.h>
#include <sys/kdb.h>
#include <sys/kernel.h>
#include <sys/priv.h>
#include <sys/systm.h>
#include <sys/types.h>
#include <sys/conf.h>
#include <sys/cons.h>
#include <sys/consio.h>
#include <sys/tty.h>
#include <dev/ofw/openfirm.h>
#include <ddb/ddb.h>
#ifndef OFWCONS_POLL_HZ
#define OFWCONS_POLL_HZ 4 /* 50-100 works best on Ultra2 */
#endif
#define OFBURSTLEN 128 /* max number of bytes to write in one chunk */
static d_open_t ofw_dev_open;
static d_close_t ofw_dev_close;
static struct cdevsw ofw_cdevsw = {
.d_version = D_VERSION,
.d_open = ofw_dev_open,
.d_close = ofw_dev_close,
.d_name = "ofw",
.d_flags = D_TTY | D_NEEDGIANT,
};
static struct tty *ofw_tp = NULL;
static int polltime;
static struct callout_handle ofw_timeouthandle
= CALLOUT_HANDLE_INITIALIZER(&ofw_timeouthandle);
#if defined(KDB) && defined(ALT_BREAK_TO_DEBUGGER)
static int alt_break_state;
#endif
static void ofw_tty_start(struct tty *);
static int ofw_tty_param(struct tty *, struct termios *);
static void ofw_tty_stop(struct tty *, int);
static void ofw_timeout(void *);
static cn_probe_t ofw_cnprobe;
static cn_init_t ofw_cninit;
static cn_term_t ofw_cnterm;
static cn_getc_t ofw_cngetc;
static cn_putc_t ofw_cnputc;
CONSOLE_DRIVER(ofw);
static void
cn_drvinit(void *unused)
{
phandle_t options;
char output[32];
struct cdev *dev;
if (ofw_consdev.cn_pri != CN_DEAD &&
ofw_consdev.cn_name[0] != '\0') {
if ((options = OF_finddevice("/options")) == -1 ||
OF_getprop(options, "output-device", output,
sizeof(output)) == -1)
return;
/*
* XXX: This is a hack and it may result in two /dev/ttya
* XXX: devices on platforms where the sab driver works.
*/
dev = make_dev(&ofw_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600, "%s",
output);
make_dev_alias(dev, "ofwcons");
}
}
SYSINIT(cndev, SI_SUB_CONFIGURE, SI_ORDER_MIDDLE, cn_drvinit, NULL);
static int stdin;
static int stdout;
static int
ofw_dev_open(struct cdev *dev, int flag, int mode, struct thread *td)
{
struct tty *tp;
int unit;
int error, setuptimeout;
error = 0;
setuptimeout = 0;
unit = minor(dev);
/*
* XXX: BAD, should happen at attach time
*/
if (dev->si_tty == NULL) {
ofw_tp = ttyalloc();
dev->si_tty = ofw_tp;
ofw_tp->t_dev = dev;
}
tp = dev->si_tty;
tp->t_oproc = ofw_tty_start;
tp->t_param = ofw_tty_param;
tp->t_stop = ofw_tty_stop;
tp->t_dev = dev;
if ((tp->t_state & TS_ISOPEN) == 0) {
tp->t_state |= TS_CARR_ON;
ttyconsolemode(tp, 0);
setuptimeout = 1;
} else if ((tp->t_state & TS_XCLUDE) &&
priv_check(td, PRIV_TTY_EXCLUSIVE)) {
return (EBUSY);
}
error = ttyld_open(tp, dev);
if (error == 0 && setuptimeout) {
polltime = hz / OFWCONS_POLL_HZ;
if (polltime < 1) {
polltime = 1;
}
ofw_timeouthandle = timeout(ofw_timeout, tp, polltime);
}
return (error);
}
static int
ofw_dev_close(struct cdev *dev, int flag, int mode, struct thread *td)
{
int unit;
struct tty *tp;
unit = minor(dev);
tp = dev->si_tty;
if (unit != 0) {
return (ENXIO);
}
/* XXX Should be replaced with callout_stop(9) */
untimeout(ofw_timeout, tp, ofw_timeouthandle);
ttyld_close(tp, flag);
tty_close(tp);
return (0);
}
static int
ofw_tty_param(struct tty *tp, struct termios *t)
{
return (0);
}
static void
ofw_tty_start(struct tty *tp)
{
struct clist *cl;
int len;
u_char buf[OFBURSTLEN];
if (tp->t_state & (TS_TIMEOUT | TS_BUSY | TS_TTSTOP))
return;
tp->t_state |= TS_BUSY;
cl = &tp->t_outq;
len = q_to_b(cl, buf, OFBURSTLEN);
OF_write(stdout, buf, len);
tp->t_state &= ~TS_BUSY;
ttwwakeup(tp);
}
static void
ofw_tty_stop(struct tty *tp, int flag)
{
if (tp->t_state & TS_BUSY) {
if ((tp->t_state & TS_TTSTOP) == 0) {
tp->t_state |= TS_FLUSH;
}
}
}
static void
ofw_timeout(void *v)
{
struct tty *tp;
int c;
tp = (struct tty *)v;
while ((c = ofw_cngetc(NULL)) != -1) {
if (tp->t_state & TS_ISOPEN) {
ttyld_rint(tp, c);
}
}
ofw_timeouthandle = timeout(ofw_timeout, tp, polltime);
}
static void
ofw_cnprobe(struct consdev *cp)
{
int chosen;
if ((chosen = OF_finddevice("/chosen")) == -1) {
cp->cn_pri = CN_DEAD;
return;
}
if (OF_getprop(chosen, "stdin", &stdin, sizeof(stdin)) == -1) {
cp->cn_pri = CN_DEAD;
return;
}
if (OF_getprop(chosen, "stdout", &stdout, sizeof(stdout)) == -1) {
cp->cn_pri = CN_DEAD;
return;
}
cp->cn_pri = CN_LOW;
}
static void
ofw_cninit(struct consdev *cp)
{
/* XXX: This is the alias, but that should be good enough */
sprintf(cp->cn_name, "ofwcons");
cp->cn_tp = ofw_tp;
}
static void
ofw_cnterm(struct consdev *cp)
{
}
static int
ofw_cngetc(struct consdev *cp)
{
unsigned char ch;
if (OF_read(stdin, &ch, 1) > 0) {
#if defined(KDB) && defined(ALT_BREAK_TO_DEBUGGER)
int kdb_brk;
if ((kdb_brk = kdb_alt_break(ch, &alt_break_state)) != 0) {
switch (kdb_brk) {
case KDB_REQ_DEBUGGER:
kdb_enter(KDB_WHY_BREAK,
"Break sequence on console");
break;
case KDB_REQ_PANIC:
kdb_panic("Panic sequence on console");
break;
case KDB_REQ_REBOOT:
kdb_reboot();
break;
}
}
#endif
return (ch);
}
return (-1);
}
static void
ofw_cnputc(struct consdev *cp, int c)
{
char cbuf;
if (c == '\n') {
cbuf = '\r';
OF_write(stdout, &cbuf, 1);
}
cbuf = c;
OF_write(stdout, &cbuf, 1);
}