Use the calibrated/adjustable i8254 frequency `timer_freq' instead of

TIMER_FREQ.

Fixed missing splx() in scrn_timer().  The bug was harmless because of the
undocumented behaviour that the ipl is automatically restored for timeout
functions (see softclock()).  Perhaps we should depend on this behaviour.

Fixed the ddb fix in rev.1.176.  The in_debugger flag was no use because
it only works when the debugger is entered via the keyboard hotkey.  The
debugger may be entered for breakpoints and traps, and the console putc
routine has no way of knowing when it was, so the console putc routine
must (almost?) always remove the cursor image.

Not fixed: console switching in ddb doesn't work (ISTR it working), and
console 0 shouldn't be switched to for the debugger hotkey unless console
0 is /dev/console.

Fixed side effects from calling add_keyboard_randomness() in the console
getc routine by not calling it.  add_keyboard_randomness() currently
always reenables interrupts on 386's and 486's.  This is very bad if the
console getc routine is called from the debugger and the debugger was
entered with interrupts disabled.

Fixed preservation of initial screen and now-bogus comment about it.  It
was broken by setting the initial scr_buf to `buffer' instead of Crtat.
`buffer' was full of nulls and the first scroll cleared everything above
the things written through syscons.

Submitted by:	bruce (bde@freebsd.org)

3 files changed, 90 insertions, 69 deletions

diff --git a/sys/dev/syscons/syscons.c b/sys/dev/syscons/syscons.c
index ad4e35a..c1579c7 100644
--- a/sys/dev/syscons/syscons.c
+++ b/sys/dev/syscons/syscons.c
@@ -25,7 +25,7 @@
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
- *  $Id: syscons.c,v 1.180 1996/10/18 18:51:36 sos Exp $
+ *  $Id: syscons.c,v 1.181 1996/10/23 07:29:43 pst Exp $
  */
 
 #include "sc.h"
@@ -102,8 +102,7 @@ static  term_stat   	kernel_console;
 static  default_attr    *current_default;
 static  int     	flags = 0;
 static  char        	init_done = COLD;
-static  u_short		buffer[ROW*COL];
-static	char		in_debugger = FALSE;
+static  u_short		sc_buffer[ROW*COL];
 static  char        	switch_in_progress = FALSE;
 static  char        	write_in_progress = FALSE;
 static  char        	blink_in_progress = FALSE;
@@ -172,7 +171,9 @@ static int scprobe(struct isa_device *dev);
 static void scstart(struct tty *tp);
 static void scmousestart(struct tty *tp);
 static void scinit(void);
-static u_int scgetc(int noblock);
+static u_int scgetc(u_int flags);
+#define SCGETC_CN	1
+#define SCGETC_NONBLOCK	2
 static scr_stat *get_scr_stat(dev_t dev);
 static scr_stat *alloc_scp(void);
 static void init_scp(scr_stat *scp);
@@ -392,8 +393,10 @@ scattach(struct isa_device *dev)
 
     scp->scr_buf = (u_short *)malloc(scp->xsize*scp->ysize*sizeof(u_short),
 				     M_DEVBUF, M_NOWAIT);
-    /* copy screen to buffer */
-    bcopyw(buffer, scp->scr_buf, scp->xsize * scp->ysize * sizeof(u_short));
+
+    /* copy temporary buffer to final buffer */
+    bcopyw(sc_buffer, scp->scr_buf, scp->xsize * scp->ysize * sizeof(u_short));
+
     scp->cursor_pos = scp->cursor_oldpos =
 	scp->scr_buf + scp->xpos + scp->ypos * scp->xsize;
     scp->mouse_pos = scp->mouse_oldpos = 
@@ -569,7 +572,7 @@ scintr(int unit)
 	mark_all(cur_console);
     }
 
-    c = scgetc(1);
+    c = scgetc(SCGETC_NONBLOCK);
 
     cur_tty = VIRTUAL_TTY(get_scr_num());
     if (!(cur_tty->t_state & TS_ISOPEN))
@@ -1138,7 +1141,7 @@ scioctl(dev_t dev, int cmd, caddr_t data, int flag, struct proc *p)
     case KIOCSOUND:     	/* make tone (*data) hz */
 	if (scp == cur_console) {
 	    if (*(int*)data) {
-		int pitch = TIMER_FREQ/(*(int*)data);
+		int pitch = timer_freq / *(int*)data;
 
 		/* set command for counter 2, 2 byte write */
 		if (acquire_timer2(TIMER_16BIT|TIMER_SQWAVE))
@@ -1370,10 +1373,8 @@ sccnputc(dev_t dev, int c)
 
     scp->term = kernel_console;
     current_default = &kernel_default;
-    if ((scp->scr_buf == buffer || in_debugger) &&
-	!(scp->status & UNKNOWN_MODE)) {
+    if (!(scp->status & UNKNOWN_MODE))
 	remove_cursor_image(scp);
-    }
     buf[0] = c;
     ansi_put(scp, buf, 1);
     kernel_console = scp->term;
@@ -1397,7 +1398,7 @@ int
 sccngetc(dev_t dev)
 {
     int s = spltty();       /* block scintr while we poll */
-    int c = scgetc(0);
+    int c = scgetc(SCGETC_CN);
     splx(s);
     return(c);
 }
@@ -1408,7 +1409,7 @@ sccncheckc(dev_t dev)
     int c, s;
 
     s = spltty();
-    c = scgetc(1);
+    c = scgetc(SCGETC_CN | SCGETC_NONBLOCK);
     splx(s);
     return(c == NOKEY ? -1 : c);	/* c == -1 can't happen */
 }
@@ -1444,6 +1445,7 @@ scrn_timer()
     /* should we just return ? */
     if ((scp->status&UNKNOWN_MODE) || blink_in_progress || switch_in_progress) {
 	timeout((timeout_func_t)scrn_timer, 0, hz/10);
+	splx(s);
 	return;
     }
 
@@ -2300,8 +2302,13 @@ scinit(void)
     current_default = &user_default;
     console[0] = &main_console;
     init_scp(console[0]);
-    console[0]->scr_buf = console[0]->mouse_pos = buffer;
-    console[0]->cursor_pos = console[0]->cursor_oldpos = buffer + hw_cursor;
+
+    /* copy screen to temporary buffer */
+    bcopyw(Crtat, sc_buffer,
+	   console[0]->xsize * console[0]->ysize * sizeof(u_short));
+
+    console[0]->scr_buf = console[0]->mouse_pos = sc_buffer;
+    console[0]->cursor_pos = console[0]->cursor_oldpos = sc_buffer + hw_cursor;
     console[0]->xpos = hw_cursor % COL;
     console[0]->ypos = hw_cursor / COL;
     cur_console = console[0];
@@ -2440,12 +2447,13 @@ history_down_line(scr_stat *scp)
 }
 
 /*
- * scgetc(noblock) - get character from keyboard.
- * If noblock = 0 wait until a key is pressed.
- * Else return NOKEY.
+ * scgetc(flags) - get character from keyboard.
+ * If flags & SCGETC_CN, then avoid harmful side effects.
+ * If flags & SCGETC_NONBLOCK, then wait until a key is pressed, else
+ * return NOKEY if there is nothing there.
  */
 static u_int
-scgetc(int noblock)
+scgetc(u_int flags)
 {
     u_char scancode, keycode;
     u_int state, action;
@@ -2458,13 +2466,14 @@ next_code:
     /* first see if there is something in the keyboard port */
     if (inb(KB_STAT) & KB_BUF_FULL)
 	scancode = inb(KB_DATA);
-    else if (noblock)
+    else if (flags & SCGETC_NONBLOCK)
 	return(NOKEY);
     else
 	goto next_code;
 
     /* do the /dev/random device a favour */
-    add_keyboard_randomness(scancode);
+    if (!(flags & SCGETC_CN))
+	add_keyboard_randomness(scancode);
 
     if (cur_console->status & KBD_RAW_MODE)
 	return scancode;
@@ -2820,9 +2829,7 @@ next_code:
 		if (cur_console->smode.mode == VT_AUTO &&
 		    console[0]->smode.mode == VT_AUTO)
 		    switch_scr(cur_console, 0);
-		in_debugger = TRUE;
 		Debugger("manual escape to debugger");
-		in_debugger = FALSE;
 		return(NOKEY);
 #else
 		printf("No debugger in kernel\n");
diff --git a/sys/i386/isa/syscons.c b/sys/i386/isa/syscons.c
index ad4e35a..c1579c7 100644
--- a/sys/i386/isa/syscons.c
+++ b/sys/i386/isa/syscons.c
@@ -25,7 +25,7 @@
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
- *  $Id: syscons.c,v 1.180 1996/10/18 18:51:36 sos Exp $
+ *  $Id: syscons.c,v 1.181 1996/10/23 07:29:43 pst Exp $
  */
 
 #include "sc.h"
@@ -102,8 +102,7 @@ static  term_stat   	kernel_console;
 static  default_attr    *current_default;
 static  int     	flags = 0;
 static  char        	init_done = COLD;
-static  u_short		buffer[ROW*COL];
-static	char		in_debugger = FALSE;
+static  u_short		sc_buffer[ROW*COL];
 static  char        	switch_in_progress = FALSE;
 static  char        	write_in_progress = FALSE;
 static  char        	blink_in_progress = FALSE;
@@ -172,7 +171,9 @@ static int scprobe(struct isa_device *dev);
 static void scstart(struct tty *tp);
 static void scmousestart(struct tty *tp);
 static void scinit(void);
-static u_int scgetc(int noblock);
+static u_int scgetc(u_int flags);
+#define SCGETC_CN	1
+#define SCGETC_NONBLOCK	2
 static scr_stat *get_scr_stat(dev_t dev);
 static scr_stat *alloc_scp(void);
 static void init_scp(scr_stat *scp);
@@ -392,8 +393,10 @@ scattach(struct isa_device *dev)
 
     scp->scr_buf = (u_short *)malloc(scp->xsize*scp->ysize*sizeof(u_short),
 				     M_DEVBUF, M_NOWAIT);
-    /* copy screen to buffer */
-    bcopyw(buffer, scp->scr_buf, scp->xsize * scp->ysize * sizeof(u_short));
+
+    /* copy temporary buffer to final buffer */
+    bcopyw(sc_buffer, scp->scr_buf, scp->xsize * scp->ysize * sizeof(u_short));
+
     scp->cursor_pos = scp->cursor_oldpos =
 	scp->scr_buf + scp->xpos + scp->ypos * scp->xsize;
     scp->mouse_pos = scp->mouse_oldpos = 
@@ -569,7 +572,7 @@ scintr(int unit)
 	mark_all(cur_console);
     }
 
-    c = scgetc(1);
+    c = scgetc(SCGETC_NONBLOCK);
 
     cur_tty = VIRTUAL_TTY(get_scr_num());
     if (!(cur_tty->t_state & TS_ISOPEN))
@@ -1138,7 +1141,7 @@ scioctl(dev_t dev, int cmd, caddr_t data, int flag, struct proc *p)
     case KIOCSOUND:     	/* make tone (*data) hz */
 	if (scp == cur_console) {
 	    if (*(int*)data) {
-		int pitch = TIMER_FREQ/(*(int*)data);
+		int pitch = timer_freq / *(int*)data;
 
 		/* set command for counter 2, 2 byte write */
 		if (acquire_timer2(TIMER_16BIT|TIMER_SQWAVE))
@@ -1370,10 +1373,8 @@ sccnputc(dev_t dev, int c)
 
     scp->term = kernel_console;
     current_default = &kernel_default;
-    if ((scp->scr_buf == buffer || in_debugger) &&
-	!(scp->status & UNKNOWN_MODE)) {
+    if (!(scp->status & UNKNOWN_MODE))
 	remove_cursor_image(scp);
-    }
     buf[0] = c;
     ansi_put(scp, buf, 1);
     kernel_console = scp->term;
@@ -1397,7 +1398,7 @@ int
 sccngetc(dev_t dev)
 {
     int s = spltty();       /* block scintr while we poll */
-    int c = scgetc(0);
+    int c = scgetc(SCGETC_CN);
     splx(s);
     return(c);
 }
@@ -1408,7 +1409,7 @@ sccncheckc(dev_t dev)
     int c, s;
 
     s = spltty();
-    c = scgetc(1);
+    c = scgetc(SCGETC_CN | SCGETC_NONBLOCK);
     splx(s);
     return(c == NOKEY ? -1 : c);	/* c == -1 can't happen */
 }
@@ -1444,6 +1445,7 @@ scrn_timer()
     /* should we just return ? */
     if ((scp->status&UNKNOWN_MODE) || blink_in_progress || switch_in_progress) {
 	timeout((timeout_func_t)scrn_timer, 0, hz/10);
+	splx(s);
 	return;
     }
 
@@ -2300,8 +2302,13 @@ scinit(void)
     current_default = &user_default;
     console[0] = &main_console;
     init_scp(console[0]);
-    console[0]->scr_buf = console[0]->mouse_pos = buffer;
-    console[0]->cursor_pos = console[0]->cursor_oldpos = buffer + hw_cursor;
+
+    /* copy screen to temporary buffer */
+    bcopyw(Crtat, sc_buffer,
+	   console[0]->xsize * console[0]->ysize * sizeof(u_short));
+
+    console[0]->scr_buf = console[0]->mouse_pos = sc_buffer;
+    console[0]->cursor_pos = console[0]->cursor_oldpos = sc_buffer + hw_cursor;
     console[0]->xpos = hw_cursor % COL;
     console[0]->ypos = hw_cursor / COL;
     cur_console = console[0];
@@ -2440,12 +2447,13 @@ history_down_line(scr_stat *scp)
 }
 
 /*
- * scgetc(noblock) - get character from keyboard.
- * If noblock = 0 wait until a key is pressed.
- * Else return NOKEY.
+ * scgetc(flags) - get character from keyboard.
+ * If flags & SCGETC_CN, then avoid harmful side effects.
+ * If flags & SCGETC_NONBLOCK, then wait until a key is pressed, else
+ * return NOKEY if there is nothing there.
  */
 static u_int
-scgetc(int noblock)
+scgetc(u_int flags)
 {
     u_char scancode, keycode;
     u_int state, action;
@@ -2458,13 +2466,14 @@ next_code:
     /* first see if there is something in the keyboard port */
     if (inb(KB_STAT) & KB_BUF_FULL)
 	scancode = inb(KB_DATA);
-    else if (noblock)
+    else if (flags & SCGETC_NONBLOCK)
 	return(NOKEY);
     else
 	goto next_code;
 
     /* do the /dev/random device a favour */
-    add_keyboard_randomness(scancode);
+    if (!(flags & SCGETC_CN))
+	add_keyboard_randomness(scancode);
 
     if (cur_console->status & KBD_RAW_MODE)
 	return scancode;
@@ -2820,9 +2829,7 @@ next_code:
 		if (cur_console->smode.mode == VT_AUTO &&
 		    console[0]->smode.mode == VT_AUTO)
 		    switch_scr(cur_console, 0);
-		in_debugger = TRUE;
 		Debugger("manual escape to debugger");
-		in_debugger = FALSE;
 		return(NOKEY);
 #else
 		printf("No debugger in kernel\n");
diff --git a/sys/isa/syscons.c b/sys/isa/syscons.c
index ad4e35a..c1579c7 100644
--- a/sys/isa/syscons.c
+++ b/sys/isa/syscons.c
@@ -25,7 +25,7 @@
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
- *  $Id: syscons.c,v 1.180 1996/10/18 18:51:36 sos Exp $
+ *  $Id: syscons.c,v 1.181 1996/10/23 07:29:43 pst Exp $
  */
 
 #include "sc.h"
@@ -102,8 +102,7 @@ static  term_stat   	kernel_console;
 static  default_attr    *current_default;
 static  int     	flags = 0;
 static  char        	init_done = COLD;
-static  u_short		buffer[ROW*COL];
-static	char		in_debugger = FALSE;
+static  u_short		sc_buffer[ROW*COL];
 static  char        	switch_in_progress = FALSE;
 static  char        	write_in_progress = FALSE;
 static  char        	blink_in_progress = FALSE;
@@ -172,7 +171,9 @@ static int scprobe(struct isa_device *dev);
 static void scstart(struct tty *tp);
 static void scmousestart(struct tty *tp);
 static void scinit(void);
-static u_int scgetc(int noblock);
+static u_int scgetc(u_int flags);
+#define SCGETC_CN	1
+#define SCGETC_NONBLOCK	2
 static scr_stat *get_scr_stat(dev_t dev);
 static scr_stat *alloc_scp(void);
 static void init_scp(scr_stat *scp);
@@ -392,8 +393,10 @@ scattach(struct isa_device *dev)
 
     scp->scr_buf = (u_short *)malloc(scp->xsize*scp->ysize*sizeof(u_short),
 				     M_DEVBUF, M_NOWAIT);
-    /* copy screen to buffer */
-    bcopyw(buffer, scp->scr_buf, scp->xsize * scp->ysize * sizeof(u_short));
+
+    /* copy temporary buffer to final buffer */
+    bcopyw(sc_buffer, scp->scr_buf, scp->xsize * scp->ysize * sizeof(u_short));
+
     scp->cursor_pos = scp->cursor_oldpos =
 	scp->scr_buf + scp->xpos + scp->ypos * scp->xsize;
     scp->mouse_pos = scp->mouse_oldpos = 
@@ -569,7 +572,7 @@ scintr(int unit)
 	mark_all(cur_console);
     }
 
-    c = scgetc(1);
+    c = scgetc(SCGETC_NONBLOCK);
 
     cur_tty = VIRTUAL_TTY(get_scr_num());
     if (!(cur_tty->t_state & TS_ISOPEN))
@@ -1138,7 +1141,7 @@ scioctl(dev_t dev, int cmd, caddr_t data, int flag, struct proc *p)
     case KIOCSOUND:     	/* make tone (*data) hz */
 	if (scp == cur_console) {
 	    if (*(int*)data) {
-		int pitch = TIMER_FREQ/(*(int*)data);
+		int pitch = timer_freq / *(int*)data;
 
 		/* set command for counter 2, 2 byte write */
 		if (acquire_timer2(TIMER_16BIT|TIMER_SQWAVE))
@@ -1370,10 +1373,8 @@ sccnputc(dev_t dev, int c)
 
     scp->term = kernel_console;
     current_default = &kernel_default;
-    if ((scp->scr_buf == buffer || in_debugger) &&
-	!(scp->status & UNKNOWN_MODE)) {
+    if (!(scp->status & UNKNOWN_MODE))
 	remove_cursor_image(scp);
-    }
     buf[0] = c;
     ansi_put(scp, buf, 1);
     kernel_console = scp->term;
@@ -1397,7 +1398,7 @@ int
 sccngetc(dev_t dev)
 {
     int s = spltty();       /* block scintr while we poll */
-    int c = scgetc(0);
+    int c = scgetc(SCGETC_CN);
     splx(s);
     return(c);
 }
@@ -1408,7 +1409,7 @@ sccncheckc(dev_t dev)
     int c, s;
 
     s = spltty();
-    c = scgetc(1);
+    c = scgetc(SCGETC_CN | SCGETC_NONBLOCK);
     splx(s);
     return(c == NOKEY ? -1 : c);	/* c == -1 can't happen */
 }
@@ -1444,6 +1445,7 @@ scrn_timer()
     /* should we just return ? */
     if ((scp->status&UNKNOWN_MODE) || blink_in_progress || switch_in_progress) {
 	timeout((timeout_func_t)scrn_timer, 0, hz/10);
+	splx(s);
 	return;
     }
 
@@ -2300,8 +2302,13 @@ scinit(void)
     current_default = &user_default;
     console[0] = &main_console;
     init_scp(console[0]);
-    console[0]->scr_buf = console[0]->mouse_pos = buffer;
-    console[0]->cursor_pos = console[0]->cursor_oldpos = buffer + hw_cursor;
+
+    /* copy screen to temporary buffer */
+    bcopyw(Crtat, sc_buffer,
+	   console[0]->xsize * console[0]->ysize * sizeof(u_short));
+
+    console[0]->scr_buf = console[0]->mouse_pos = sc_buffer;
+    console[0]->cursor_pos = console[0]->cursor_oldpos = sc_buffer + hw_cursor;
     console[0]->xpos = hw_cursor % COL;
     console[0]->ypos = hw_cursor / COL;
     cur_console = console[0];
@@ -2440,12 +2447,13 @@ history_down_line(scr_stat *scp)
 }
 
 /*
- * scgetc(noblock) - get character from keyboard.
- * If noblock = 0 wait until a key is pressed.
- * Else return NOKEY.
+ * scgetc(flags) - get character from keyboard.
+ * If flags & SCGETC_CN, then avoid harmful side effects.
+ * If flags & SCGETC_NONBLOCK, then wait until a key is pressed, else
+ * return NOKEY if there is nothing there.
  */
 static u_int
-scgetc(int noblock)
+scgetc(u_int flags)
 {
     u_char scancode, keycode;
     u_int state, action;
@@ -2458,13 +2466,14 @@ next_code:
     /* first see if there is something in the keyboard port */
     if (inb(KB_STAT) & KB_BUF_FULL)
 	scancode = inb(KB_DATA);
-    else if (noblock)
+    else if (flags & SCGETC_NONBLOCK)
 	return(NOKEY);
     else
 	goto next_code;
 
     /* do the /dev/random device a favour */
-    add_keyboard_randomness(scancode);
+    if (!(flags & SCGETC_CN))
+	add_keyboard_randomness(scancode);
 
     if (cur_console->status & KBD_RAW_MODE)
 	return scancode;
@@ -2820,9 +2829,7 @@ next_code:
 		if (cur_console->smode.mode == VT_AUTO &&
 		    console[0]->smode.mode == VT_AUTO)
 		    switch_scr(cur_console, 0);
-		in_debugger = TRUE;
 		Debugger("manual escape to debugger");
-		in_debugger = FALSE;
 		return(NOKEY);
 #else
 		printf("No debugger in kernel\n");