Add a new mechanism, cndbctl(), to tell the console driver that

ddb is entered.  Don't refer to `in_Debugger' to see if we
are in the debugger.  (The variable used to be static in Debugger()
and wasn't updated if ddb is entered via traps and panic anyway.)

- Don't refer to `in_Debugger'.
- Add `db_active' to i386/i386/db_interface.d (as in
  alpha/alpha/db_interface.c).
- Remove cnpollc() stub from ddb/db_input.c.
- Add the dbctl function to syscons, pcvt, and sio. (The function for
  pcvt and sio is noop at the moment.)

Jointly developed by: bde and me

(The final version was tweaked by me and not reviewed by bde.  Thus,
if there is any error in this commit, that is entirely of mine, not
his.)

Some changes were obtained from: NetBSD

1 files changed, 28 insertions, 27 deletions

diff --git a/sys/dev/syscons/syscons.c b/sys/dev/syscons/syscons.c
index 822d42b..64ecd73 100644
--- a/sys/dev/syscons/syscons.c
+++ b/sys/dev/syscons/syscons.c
@@ -124,15 +124,7 @@ SYSCTL_INT(_machdep, OID_AUTO, enable_panic_key, CTLFLAG_RW, &enable_panic_key,
 
 #define VIRTUAL_TTY(sc, x) (SC_DEV((sc), (x))->si_tty)
 
-#define debugger	FALSE
-
-#ifdef __i386__
-#ifdef DDB
-extern int		in_Debugger;
-#undef debugger
-#define debugger	in_Debugger
-#endif /* DDB */
-#endif /* __i386__ */
+static	int		debugger;
 
 /* prototypes */
 static int scvidprobe(int unit, int flags, int cons);
@@ -199,13 +191,15 @@ static cn_init_t	sccninit;
 static cn_getc_t	sccngetc;
 static cn_checkc_t	sccncheckc;
 static cn_putc_t	sccnputc;
+static cn_dbctl_t	sccndbctl;
 static cn_term_t	sccnterm;
 
 #if __alpha__
 void sccnattach(void);
 #endif
 
-CONS_DRIVER(sc, sccnprobe, sccninit, sccnterm, sccngetc, sccncheckc, sccnputc);
+CONS_DRIVER(sc, sccnprobe, sccninit, sccnterm, sccngetc, sccncheckc, sccnputc,
+	    sccndbctl);
 
 static	d_open_t	scopen;
 static	d_close_t	scclose;
@@ -1474,6 +1468,28 @@ sccncheckc(dev_t dev)
     return sccngetch(SCGETC_NONBLOCK);
 }
 
+static void
+sccndbctl(dev_t dev, int on)
+{
+    /* try to switch to the kernel console screen */
+    if (on && debugger == 0) {
+	/*
+	 * TRY to make sure the screen saver is stopped, 
+	 * and the screen is updated before switching to 
+	 * the vty0.
+	 */
+	scrn_timer(NULL);
+	if (!cold
+	    && sc_console->sc->cur_scp->smode.mode == VT_AUTO
+	    && sc_console->smode.mode == VT_AUTO)
+	    switch_scr(sc_console->sc, sc_console->index);
+    }
+    if (on)
+	++debugger;
+    else
+	--debugger;
+}
+
 static int
 sccngetch(int flags)
 {
@@ -1553,7 +1569,7 @@ sccnupdate(scr_stat *scp)
     if (scp->sc->font_loading_in_progress || scp->sc->videoio_in_progress)
 	return;
 
-    if (debugger || panicstr || shutdown_in_progress) {
+    if (debugger > 0 || panicstr || shutdown_in_progress) {
 	sc_touch_scrn_saver();
     } else if (scp != scp->sc->cur_scp) {
 	return;
@@ -1626,7 +1642,7 @@ scrn_timer(void *arg)
 
     /* should we stop the screen saver? */
     getmicrouptime(&tv);
-    if (debugger || panicstr || shutdown_in_progress)
+    if (debugger > 0 || panicstr || shutdown_in_progress)
 	sc_touch_scrn_saver();
     if (run_scrn_saver) {
 	if (tv.tv_sec > sc->scrn_time_stamp + scrn_blank_time)
@@ -3720,21 +3736,6 @@ next_code:
 	    case DBG:
 #ifndef SC_DISABLE_DDBKEY
 #ifdef DDB
-		if (debugger)
-		    break;
-		/* try to switch to the kernel console screen */
-		if (sc_console) {
-		    /*
-		     * TRY to make sure the screen saver is stopped, 
-		     * and the screen is updated before switching to 
-		     * the vty0.
-		     */
-		    scrn_timer(NULL);
-		    if (!cold
-			&& sc_console->sc->cur_scp->smode.mode == VT_AUTO
-			&& sc_console->smode.mode == VT_AUTO)
-			switch_scr(sc_console->sc, sc_console->index);
-		}
 		Debugger("manual escape to debugger");
 #else
 		printf("No debugger in kernel\n");