Add scrollback support to the pcvt (i386 only) console driver.

Press LEFT_SHIFT+PGUP/PGDN to navigate. Number of buffered pages is currently
only configurable by editing sys/arch/i386/isa/pcvt/pcvt_hdr.h and changing
the SCROLLBACK_PAGES constant.

You must add "option PCVT_SCROLLBACK" to your kernel config file to enable
this support, or uncomment it from sys/arch/i386/conf/GENERIC.

Known issues:
   - Few little buglets when switching line (font) or column modes in scon(1).
   - Can't hold down LEFT_SHIFT+PGUP/PGDN keys. This will be fixed...

Idea from Linux, code by me.

6 files changed, 267 insertions, 9 deletions

diff --git a/sys/arch/i386/conf/GENERIC b/sys/arch/i386/conf/GENERIC
index 550965e35ff..d9e04e5c5b1 100644
--- a/sys/arch/i386/conf/GENERIC
+++ b/sys/arch/i386/conf/GENERIC
@@ -1,4 +1,4 @@
-#	$OpenBSD: GENERIC,v 1.126 1999/08/31 07:55:01 fgsch Exp $
+#	$OpenBSD: GENERIC,v 1.127 1999/09/06 00:12:39 aaron Exp $
 #	$NetBSD: GENERIC,v 1.48 1996/05/20 18:17:23 mrg Exp $
 #
 #	GENERIC -- everything that's currently supported
@@ -31,6 +31,8 @@ option		COMPAT_LINUX	# binary compatibility with Linux
 option		COMPAT_FREEBSD	# binary compatibility with FreeBSD
 option		COMPAT_BSDOS	# binary compatibility with BSD/OS
 
+#option		PCVT_SCROLLBACK	# pcvt console scrollback support
+
 maxusers	32		# estimated number of users
 
 config		bsd	swap generic
diff --git a/sys/arch/i386/isa/pcvt/pcvt_drv.c b/sys/arch/i386/isa/pcvt/pcvt_drv.c
index 33f2adde5e1..1ae909417d9 100644
--- a/sys/arch/i386/isa/pcvt/pcvt_drv.c
+++ b/sys/arch/i386/isa/pcvt/pcvt_drv.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: pcvt_drv.c,v 1.22 1998/11/20 15:57:25 deraadt Exp $	*/
+/*	$OpenBSD: pcvt_drv.c,v 1.23 1999/09/06 00:12:39 aaron Exp $	*/
 
 /*
  * Copyright (c) 1992, 1995 Hellmuth Michaelis and Joerg Wunsch.
@@ -706,7 +706,13 @@ pcstart(register struct tty *tp)
 	 */
 
 	while ((len = q_to_b(&tp->t_outq, buf, PCVT_PCBURST)) != 0)
+	{
+#ifdef PCVT_SCROLLBACK
+		if (vs[minor(tp->t_dev)].scrolling)
+			sgetc(31337);
+#endif
 		sput(&buf[0], 0, len, minor(tp->t_dev));
+	}
 
 	s = spltty();
 
diff --git a/sys/arch/i386/isa/pcvt/pcvt_ext.c b/sys/arch/i386/isa/pcvt/pcvt_ext.c
index c9a89c09bf3..1bb3c492ff1 100644
--- a/sys/arch/i386/isa/pcvt/pcvt_ext.c
+++ b/sys/arch/i386/isa/pcvt/pcvt_ext.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: pcvt_ext.c,v 1.17 1998/09/28 03:00:27 downsj Exp $	*/
+/*	$OpenBSD: pcvt_ext.c,v 1.18 1999/09/06 00:12:40 aaron Exp $	*/
 
 /*
  * Copyright (c) 1992, 1995 Hellmuth Michaelis and Joerg Wunsch.
@@ -2552,6 +2552,18 @@ vgapage(int new_screen)
 		{
 			/* we are committed */
 			vt_switch_pending = 0;
+#ifdef PCVT_SCROLLBACK
+			if (vsp->Scrollback)
+			{
+				vsp->scrolling = 0;
+				fillw(user_attr | ' ', (caddr_t)vsp->Scrollback,
+				      vsp->screen_rowsize * vsp->maxcol *
+				      SCROLLBACK_PAGES);
+				bcopy(vsp->Crtat, vsp->Scrollback,
+				      vsp->screen_rows * vsp->maxcol * CHR);
+				vsp->scr_offset = vsp->row - 1;
+			}
+#endif
 		}
 	}
 	return 0;
diff --git a/sys/arch/i386/isa/pcvt/pcvt_hdr.h b/sys/arch/i386/isa/pcvt/pcvt_hdr.h
index c59a577030b..5d3bf399143 100644
--- a/sys/arch/i386/isa/pcvt/pcvt_hdr.h
+++ b/sys/arch/i386/isa/pcvt/pcvt_hdr.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: pcvt_hdr.h,v 1.21 1998/09/06 23:00:03 niklas Exp $	*/
+/*	$OpenBSD: pcvt_hdr.h,v 1.22 1999/09/06 00:12:40 aaron Exp $	*/
 
 /*
  * Copyright (c) 1992, 1995 Hellmuth Michaelis and Joerg Wunsch.
@@ -603,6 +603,13 @@
 #define SYS_FKL		0	/* in hp mode, sys-fkls are active */
 #define USR_FKL		1	/* in hp mode, user-fkls are active */
 
+#ifdef PCVT_SCROLLBACK
+
+/* scrollback buffer size (in pages) */
+#define SCROLLBACK_PAGES	8
+
+#endif
+
 /* variables */
 
 #ifdef EXTERN
@@ -646,6 +653,12 @@ struct rgb {
 typedef struct video_state {
 	u_short	*Crtat;			/* video page start addr */
 	u_short *Memory;		/* malloc'ed memory start address */
+#ifdef PCVT_SCROLLBACK
+	u_short *Scrollback;		/* scrollback buffer */
+	u_short scr_offset;		/* current scrollback offset (lines) */
+	short scrolling;		/* current scrollback page */
+	u_short max_off;		/* maximum scrollback offset */
+#endif
 	struct tty *vs_tty;		/* pointer to this screen's tty */
 	u_char	maxcol;			/* 80 or 132 cols on screen */
 	u_char 	row, col;		/* current cursor position */
@@ -821,6 +834,10 @@ struct tty *pcconsp;		/* ptr to current device, see pcattach() */
 
 u_short *Crtat;			/* screen start address */
 
+#ifdef PCVT_SCROLLBACK
+u_short *Scrollbuffer;		/* scrollback buffer */
+#endif
+
 #if PCVT_EMU_MOUSE
 struct mousestat	mouse = {{0}};
 struct mousedefs	mousedef = {0x3b, 0x3c, 0x3d, 0,     250000};
@@ -978,6 +995,10 @@ extern u_char		vga_family;
 extern u_char		keyboard_is_initialized;
 extern u_char		kbd_polling;
 
+#ifdef PCVT_SCROLLBACK
+extern u_short		*Scrollbuffer;
+#endif
+
 #if PCVT_SHOWKEYS
 extern u_char		keyboard_show;
 #endif /* PCVT_SHOWKEYS */
diff --git a/sys/arch/i386/isa/pcvt/pcvt_kbd.c b/sys/arch/i386/isa/pcvt/pcvt_kbd.c
index 293955e4ef3..369ff540929 100644
--- a/sys/arch/i386/isa/pcvt/pcvt_kbd.c
+++ b/sys/arch/i386/isa/pcvt/pcvt_kbd.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: pcvt_kbd.c,v 1.20 1999/07/06 07:59:54 deraadt Exp $	*/
+/*	$OpenBSD: pcvt_kbd.c,v 1.21 1999/09/06 00:12:40 aaron Exp $	*/
 
 /*
  * Copyright (c) 1992, 1995 Hellmuth Michaelis and Joerg Wunsch.
@@ -115,6 +115,13 @@ static int	tpmrate   = KBD_TPD500|KBD_TPM100;
 static u_char	altkpflag = 0;
 static u_short	altkpval  = 0;
 
+#ifdef PCVT_SCROLLBACK
+static u_short *scrollback_savedscreen = (u_short *)0;
+static size_t scrnsv_size = (size_t)-1;
+static void scrollback_save_screen ( void );
+static void scrollback_restore_screen ( void );
+#endif
+
 extern int kbd_reset;
 
 #if PCVT_SHOWKEYS
@@ -1088,6 +1095,13 @@ loop:
 
 #if PCVT_KBD_FIFO
 
+#ifdef PCVT_SCROLLBACK
+	if (noblock == 31337) {
+		vsp->scrolling = 1;
+		goto scroll_reset;
+	}
+#endif
+
 	/* see if there is data from the keyboard available either from */
 	/* the keyboard fifo or from the 8042 keyboard controller	*/
 
@@ -1413,7 +1427,7 @@ no_mouse_event:
 
 #if PCVT_SHOWKEYS
 	showkey (' ', dt);
-#endif	/* PCVT_SHOWKEYS */
+#endif /* PCVT_SHOWKEYS */
 
 	/* lets look what we got */
 	switch(dt)
@@ -1474,6 +1488,98 @@ regular:
 
 	kbd_status.extended = kbd_status.ext1 = 0;
 
+#ifdef PCVT_SCROLLBACK
+	if ((key == 85) && shift_down && kbd_lastkey != 85)
+	{
+		if (vsp->scr_offset >= (vsp->screen_rows - 1))
+		{
+			if (!vsp->scrolling)
+			{
+				vsp->scrolling += vsp->screen_rows - 1;
+				if (vsp->Scrollback)
+				{
+					scrollback_save_screen();
+					if (vsp->scr_offset == vsp->max_off)
+					{
+						bcopy(vsp->Scrollback +
+						      vsp->maxcol,
+						      vsp->Scrollback,
+						      vsp->maxcol *
+						      vsp->max_off * CHR);
+						vsp->scr_offset--;
+					}
+					bcopy(vsp->Crtat + vsp->cur_offset -
+					      vsp->col, vsp->Scrollback +
+				      	      ((vsp->scr_offset + 1) *
+					      vsp->maxcol), vsp->maxcol * CHR);
+				}
+
+				if (vsp->cursor_on)
+					sw_cursor(0);
+			}
+
+			vsp->scrolling += vsp->screen_rows - 1;
+			if (vsp->scrolling > vsp->scr_offset)
+				vsp->scrolling = vsp->scr_offset;
+
+			bcopy(vsp->Scrollback + ((vsp->scr_offset -
+			      vsp->scrolling) * vsp->maxcol), vsp->Crtat,
+			      vsp->screen_rows * vsp->maxcol * CHR);
+		}
+
+		kbd_lastkey = 85;
+		goto loop;
+	}
+	else if ((key == 86) && shift_down && kbd_lastkey != 86)
+	     {
+scroll_reset:
+		if (vsp->scrolling > 0)
+		{
+			vsp->scrolling -= vsp->screen_rows - 1;
+			if (vsp->scrolling < 0)
+				vsp->scrolling = 0;
+
+			if (vsp->scrolling <= vsp->screen_rows)
+			{
+				vsp->scrolling = 0;
+				scrollback_restore_screen();
+			}
+			else
+			{
+				bcopy(vsp->Scrollback + ((vsp->scr_offset -
+			      	      vsp->scrolling) * vsp->maxcol),
+			              vsp->Crtat, vsp->screen_rows *
+				      vsp->maxcol * CHR);
+			}
+		}
+
+		if (vsp->scrolling == 0)
+		{
+			if (vsp->cursor_on)
+			{
+				sw_cursor(1);
+			}
+		}
+
+		if (noblock == 31337)
+			return NULL;
+
+		if (key != 86)
+			goto regular;
+		else
+		{
+			kbd_lastkey = 86;
+			goto loop;
+		}
+	}
+	else if (vsp->scrolling && key != 128 && key != 44 && key != 85 &&
+		 key != 86)
+	     {
+			vsp->scrolling = 1;
+			goto scroll_reset;
+	     }
+#endif
+
 	if(kbd_reset && (key == 76) && ctrl_down && (meta_down||altgr_down)) {
 		printf("\nconsole halt requested: going down.\n");
 		kbd_reset = 0;
@@ -3043,4 +3149,35 @@ cfkey12(void)
 
 #endif	/* NVT > 0 */
 
+#ifdef PCVT_SCROLLBACK
+static void
+scrollback_save_screen(void)
+{
+	int x = spltty();
+	register size_t s;
+
+	s = sizeof(u_short) * vsp->screen_rowsize * vsp->maxcol;
+
+	if (scrollback_savedscreen)
+		free(scrollback_savedscreen, M_TEMP);
+
+	scrnsv_size = s;
+
+	if (!(scrollback_savedscreen = (u_short *)malloc(s, M_TEMP, M_NOWAIT)))
+	{
+		splx(x);
+		return;
+	}
+	bcopy(vsp->Crtat, scrollback_savedscreen, scrnsv_size);
+	splx(x);
+}
+
+static void
+scrollback_restore_screen(void)
+{
+	if (scrollback_savedscreen)
+		bcopy(scrollback_savedscreen, vsp->Crtat, scrnsv_size);
+}
+#endif
+
 /* ------------------------------- EOF -------------------------------------*/
diff --git a/sys/arch/i386/isa/pcvt/pcvt_out.c b/sys/arch/i386/isa/pcvt/pcvt_out.c
index e6e9d232d20..734e19f2426 100644
--- a/sys/arch/i386/isa/pcvt/pcvt_out.c
+++ b/sys/arch/i386/isa/pcvt/pcvt_out.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: pcvt_out.c,v 1.7 1999/01/13 07:26:02 niklas Exp $	*/
+/*	$OpenBSD: pcvt_out.c,v 1.8 1999/09/06 00:12:40 aaron Exp $	*/
 
 /*
  * Copyright (c) 1992, 1995 Hellmuth Michaelis and Joerg Wunsch.
@@ -80,6 +80,9 @@ static void wrfkl ( int num, u_char *string, struct video_state *svsp );
 static void writefkl ( int num, u_char *string, struct video_state *svsp );
 static __inline void write_char (struct	video_state *, u_short, u_short ch);
 
+#ifdef PCVT_SCROLLBACK
+static int check_scrollback ( struct video_state *svsp );
+#endif
 
 /*---------------------------------------------------------------------------*
  *	do character set transformation and write to display memory (inline)
@@ -147,6 +150,9 @@ void
 sput (u_char *s, U_char kernel, int len, int page)
 {
     register struct video_state *svsp;
+#ifdef PCVT_SCROLLBACK
+    int		extra;
+#endif
     u_short	attrib;
     u_short	ch;
 
@@ -269,6 +275,20 @@ sput (u_char *s, U_char kernel, int len, int page)
 				case 0x0a:	/* LF */
 				case 0x0b:	/* VT */
 				case 0x0c:	/* FF */
+#ifdef PCVT_SCROLLBACK
+					if (check_scrollback(svsp))
+					{
+						extra = (svsp->cur_offset %
+							svsp->maxcol) ?
+							svsp->col : 0;
+						bcopy(svsp->Crtat +
+						      svsp->cur_offset - extra,
+						      svsp->Scrollback +
+					              (svsp->scr_offset *
+						      svsp->maxcol),
+						      svsp->maxcol * CHR);
+					}
+#endif
 					if(svsp->lnm)
 					{
 						svsp->cur_offset -= svsp->col;
@@ -421,6 +441,18 @@ sput (u_char *s, U_char kernel, int len, int page)
 					svsp->cur_offset++;
 					svsp->col = 0;
 					svsp->lastchar = 0;
+#ifdef PCVT_SCROLLBACK
+					if (check_scrollback(svsp))
+					{
+						bcopy(svsp->Crtat +
+						      svsp->cur_offset -
+						      svsp->maxcol,
+		      				      svsp->Scrollback +
+						      (svsp->scr_offset *
+						      svsp->maxcol),
+		      				      svsp->maxcol * CHR);
+					}
+#endif
 					check_scroll(svsp);
 				}
 
@@ -813,6 +845,11 @@ sput (u_char *s, U_char kernel, int len, int page)
 					case 'K':	/* erase line */
 						vt_clreol(svsp);
 						svsp->state = STATE_INIT;
+#ifdef PCVT_SCROLLBACK
+						if (svsp->scr_offset > 0 &&
+						    svsp == vsp)
+							svsp->scr_offset--;
+#endif
 						break;
 
 					case 'L':	/* insert line */
@@ -1094,6 +1131,11 @@ vt_coldinit(void)
 	{
 		svsp->Crtat = Crtat;		/* all same until malloc'ed */
 		svsp->Memory = Crtat;		/* until malloc'ed */
+#ifdef PCVT_SCROLLBACK
+		svsp->Scrollback = 0;		/* until malloc'ed */
+		svsp->scr_offset = 0;		/* scrollback offset (lines) */
+		svsp->scrolling = 0;		/* current scrollback page */
+#endif
 		svsp->cur_offset = 0;		/* cursor offset */
 		svsp->c_attr = user_attr;	/* non-kernel attributes */
 		svsp->bell_on = 1;		/* enable bell */
@@ -1128,6 +1170,9 @@ vt_coldinit(void)
 #endif /* PCVT_24LINESDEF */
 
 		svsp->screen_rowsize = 25;	/* default 25 rows on screen */
+#ifdef PCVT_SCROLLBACK
+		svsp->max_off =  svsp->screen_rowsize * SCROLLBACK_PAGES - 1;
+#endif
 		svsp->scrr_beg = 0;		/* scrolling region begin row*/
 		svsp->scrr_len = svsp->screen_rows; /* scrolling region length*/
 		svsp->scrr_end = svsp->scrr_len - 1;/* scrolling region end */
@@ -1361,6 +1406,15 @@ vt_coldmalloc(void)
 					MAXROW_VGA * MAXCOL_VGA * CHR;
 	}
 
+#ifdef PCVT_SCROLLBACK
+	if ((Scrollbuffer = (u_short *)malloc(vs[0].maxcol *
+	     vs[0].screen_rowsize * SCROLLBACK_PAGES * CHR * 2, M_DEVBUF,
+	     M_WAITOK)) == NULL)
+	{
+		printf("pcvt: scrollback memory malloc failed\n");
+	}
+#endif
+
 	for(nscr = 0; nscr < PCVT_NSCREENS; nscr++)
 	{
 		if((vs[nscr].Memory =
@@ -1372,6 +1426,9 @@ vt_coldmalloc(void)
 			       PCVT_NSCREENS, nscr);
 			break;
 		}
+#ifdef PCVT_SCROLLBACK
+		vs[nscr].Scrollback = Scrollbuffer;
+#endif
 		if(nscr != 0)
 		{
 			vs[nscr].Crtat = vs[nscr].Memory;
@@ -1423,6 +1480,29 @@ check_scroll(struct video_state *svsp)
 	}
 }
 
+#ifdef PCVT_SCROLLBACK
+static int
+check_scrollback(struct video_state *svsp)
+{
+	/* still waiting for scrollback memory or not on current page */
+	if (!svsp->Scrollback || svsp != vsp)
+		return 0;
+
+	/* remove first line of scrollback buffer to make room for new line */
+	if (svsp->scr_offset == svsp->max_off)
+	{
+		bcopy(svsp->Scrollback + svsp->maxcol, svsp->Scrollback,
+		      svsp->maxcol * svsp->max_off * CHR);
+	}
+	else
+	{
+		/* still room left, increase scroll offset (lines) */
+		svsp->scr_offset++;
+	}
+	return 1;
+}
+#endif
+
 /*---------------------------------------------------------------------------*
  *	write to one user function key label
  *---------------------------------------------------------------------------*/
@@ -1877,8 +1957,8 @@ vt_col(struct video_state *svsp, int cols)
 
 	clr_parms(svsp);		/* escape parameter init */
 	svsp->state = STATE_INIT;	/* initial state */
-	svsp->col = 0;			/* init row */
-	svsp->row = 0;			/* init col */
+	svsp->col = 0;			/* init col */
+	svsp->row = 0;			/* init row */
 	svsp->cur_offset = 0;		/* cursor offset init */
 	svsp->sc_flag = 0;		/* invalidate saved cursor position */
 	svsp->scrr_beg = 0;		/* reset scrolling region */