Implement scrollback for pcvt based on code submitted by

Aaron Campbell <aaron@cs.dal.ca>.

Use SHIFT-PgUp and SHIFT-PgDn to scroll back and forward.

Aarons original code was enhanced to have a separate scrollbuffer
for every virtual terminal and to preserve the screen contents
when switching screen sizes.

The scrollbuffer size is currently fixed at 8 pages but this
will be made configurable through the use of scon(1) in the
near future.

For pcvt_kbd.h, a longstanding compiler warning was fixed by
using excessive backetizing of the key2ascii[] table.

1 files changed, 68 insertions, 21 deletions

diff --git a/sys/i386/isa/pcvt/pcvt_out.c b/sys/i386/isa/pcvt/pcvt_out.c
index e7ce9e2..2c6d008 100644
--- a/sys/i386/isa/pcvt/pcvt_out.c
+++ b/sys/i386/isa/pcvt/pcvt_out.c
@@ -1,4 +1,6 @@
 /*
+ * Copyright (c) 1999 Hellmuth Michaelis
+ *
  * Copyright (c) 1992, 1995 Hellmuth Michaelis and Joerg Wunsch.
  *
  * Copyright (c) 1992, 1993 Brian Dunford-Shore.
@@ -33,29 +35,16 @@
  * 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.
- *
- *
- * @(#)pcvt_out.c, 3.20, Last Edit-Date: [Mon Apr 19 17:18:58 1999]
- *
  */
 
 /*---------------------------------------------------------------------------*
  *
  *	pcvt_out.c	VT220 Terminal Emulator
  *	---------------------------------------
- *	-hm	------------ Release 3.00 --------------
- *	-hm	integrating NetBSD-current patches
- *	-hm	integrating patch from Thomas Gellekum
- *	-hm	bugfix: clear last line when hpmode 28lines and force 24
- *	-hm	right fkey labels after soft/hard reset
- *	-hm	patch from Joerg for comconsole operation
- *	-hm	patch from Lon Willet to preserve the initial cursor shape
- *	-hm	if FAT_CURSOR is defined, you get the old cursor type back ..
- *	-hm	patch from Lon Willett regarding winsize settings
- *	-hm	applying patch from Joerg fixing Crtat bug, non VGA startup bug
- *	-hm	setting variable color for CGA and MDA/HGC in coldinit
- *	-hm	fixing bug initializing cursor position on startup
- *	-hm	fixing support for EGA boards in vt_coldinit()
+ *
+ *	Last Edit-Date: [Mon Dec 27 14:07:39 1999]
+ *
+ * $FreeBSD$
  *
  *---------------------------------------------------------------------------*/
 
@@ -79,6 +68,7 @@ static void vt_coldinit ( void );
 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 int check_scrollback ( struct video_state *svsp );
 
 /*---------------------------------------------------------------------------*
  *	do character set transformation and write to display memory (inline)
@@ -148,7 +138,8 @@ sput (u_char *s, U_char kernel, int len, int page)
     register struct video_state *svsp;
     u_short	attrib;
     u_short	ch;
-
+    u_short	extra;
+    
     if(page >= PCVT_NSCREENS)		/* failsafe */
 	page = 0;
 
@@ -263,6 +254,18 @@ sput (u_char *s, U_char kernel, int len, int page)
 				case 0x0a:	/* LF */
 				case 0x0b:	/* VT */
 				case 0x0c:	/* FF */
+					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);
+					}
 					if(svsp->lnm)
 					{
 						svsp->cur_offset -= svsp->col;
@@ -343,6 +346,17 @@ sput (u_char *s, U_char kernel, int len, int page)
 					svsp->cur_offset++;
 					svsp->col = 0;
 					svsp->lastchar = 0;
+
+					if (check_scrollback(svsp))
+					{
+						bcopy(svsp->Crtat +
+						      svsp->cur_offset -
+						      svsp->maxcol,
+		      				      svsp->Scrollback +
+						      (svsp->scr_offset *
+						      svsp->maxcol),
+		      				      svsp->maxcol * CHR);
+					}
 					check_scroll(svsp);
 				}
 
@@ -735,6 +749,9 @@ sput (u_char *s, U_char kernel, int len, int page)
 					case 'K':	/* erase line */
 						vt_clreol(svsp);
 						svsp->state = STATE_INIT;
+						if (svsp->scr_offset > 0 &&
+						    svsp == vsp)
+							svsp->scr_offset--;
 						break;
 
 					case 'L':	/* insert line */
@@ -1009,6 +1026,9 @@ vt_coldinit(void)
 	{
 		svsp->Crtat = Crtat;		/* all same until malloc'ed */
 		svsp->Memory = Crtat;		/* until malloc'ed */
+		svsp->Scrollback = 0;		/* until malloc'ed */
+		svsp->scr_offset = 0;		/* scrollback offset (lines) */
+		svsp->scrolling = 0;		/* current scrollback page */
 		svsp->cur_offset = 0;		/* cursor offset */
 		svsp->c_attr = user_attr;	/* non-kernel attributes */
 		svsp->bell_on = 1;		/* enable bell */
@@ -1042,6 +1062,7 @@ vt_coldinit(void)
 #endif /* PCVT_24LINESDEF */
 
 		svsp->screen_rowsize = 25;	/* default 25 rows on screen */
+		svsp->max_off =  svsp->screen_rowsize * SCROLLBACK_PAGES - 1;
 		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 */
@@ -1287,15 +1308,15 @@ vt_coldmalloc(void)
 
 	for(nscr = 0; nscr < PCVT_NSCREENS; nscr++)
 	{
-		if((vs[nscr].Memory =
-		    (u_short *)malloc(screen_max_size * 2, M_DEVBUF, M_WAITOK))
-		   == NULL)
+		if((vs[nscr].Memory = (u_short *)malloc(screen_max_size * 2,
+			 M_DEVBUF, M_WAITOK)) == NULL)
 		{
 			printf("pcvt: screen memory malloc failed, "
 			       "NSCREEN=%d, nscr=%d\n",
 			       PCVT_NSCREENS, nscr);
 			break;
 		}
+		
 		if(nscr != 0)
 		{
 			vs[nscr].Crtat = vs[nscr].Memory;
@@ -1304,6 +1325,10 @@ vt_coldmalloc(void)
 				vs[nscr].maxcol * vs[nscr].screen_rowsize);
 			totalscreens++;
 		}
+
+		vs[nscr].scrollback_pages = SCROLLBACK_PAGES;
+
+		reallocate_scrollbuffer(&(vs[nscr]), vs[nscr].scrollback_pages);
 	}
 }
 
@@ -1347,6 +1372,27 @@ check_scroll(struct video_state *svsp)
         }
 }
 
+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;
+}
+
 /*---------------------------------------------------------------------------*
  *	write to one user function key label
  *---------------------------------------------------------------------------*/
@@ -1831,6 +1877,7 @@ vt_col(struct video_state *svsp, int cols)
 #endif /* PCVT_SIGWINCH */
 	}
 
+	reallocate_scrollbuffer(svsp, svsp->scrollback_pages);
 	return(1);
 }