Updated VGA driver; from NetBSD. Needed for wscons on i386 and alpha. These

files could probably be updated even a bit further (they are from mid-summer).

In addition, I've added support for console scrollback, somewhat inspired by
Linux's vgacon driver. Basically, instead of allocating our own buffer and
doing lots of copies, we take advantage of Video RAM and just modify the VGA
display origin register as appropriate. This approach has a few advantages:
simple to implement, no wasted KVM, it's fast, and after a boot you can now
scroll back all the way to the BIOS messages (assuming your msgbuf is of a
typical length :). Disadvantages are that the VRAM buffer is relatively
small (only 32k) and we do not support raster devices through this method.
(thanks to mickey@ for pointing this out).

The code for this is fairly unobtrusive, so should we come up with a better
approach to console scrollback at a later time (i.e., even more platform
independent) it should be easy to revert this.

We're one step further in porting nice features of PCVT over to wscons.

1 files changed, 161 insertions, 0 deletions

diff --git a/sys/dev/ic/vga_subr.c b/sys/dev/ic/vga_subr.c
new file mode 100644
index 00000000000..0ee1e6f6c98
--- /dev/null
+++ b/sys/dev/ic/vga_subr.c
@@ -0,0 +1,161 @@
+/* $OpenBSD: vga_subr.c,v 1.1 2000/11/15 20:17:38 aaron Exp $ */
+/* $NetBSD: vga_subr.c,v 1.6 2000/01/25 02:44:03 ad Exp $ */
+
+/*
+ * Copyright (c) 1998
+ *	Matthias Drochner.  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.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed for the NetBSD Project
+ *	by Matthias Drochner.
+ * 4. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 THE AUTHOR 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/param.h>
+#include <sys/systm.h>
+#include <sys/device.h>
+#include <sys/queue.h>
+#include <machine/bus.h>
+
+#include <dev/ic/mc6845reg.h>
+#include <dev/ic/pcdisplayvar.h>
+#include <dev/ic/vgareg.h>
+#include <dev/ic/vgavar.h>
+
+#include <dev/wscons/wsdisplayvar.h>
+
+static void fontram __P((struct vga_handle *));
+static void textram __P((struct vga_handle *));
+
+static void
+fontram(vh)
+	struct vga_handle *vh;
+{
+	/* program sequencer to access character generator */
+
+	vga_ts_write(vh, syncreset, 0x01);	/* synchronous reset */
+	vga_ts_write(vh, wrplmask, 0x04);	/* write to map 2 */
+	vga_ts_write(vh, memmode, 0x07);	/* sequential addressing */
+	vga_ts_write(vh, syncreset, 0x03);	/* clear synchronous reset */
+
+	/* program graphics controller to access character generator */
+
+	vga_gdc_write(vh, rdplanesel, 0x02);	/* select map 2 for cpu reads */
+	vga_gdc_write(vh, mode, 0x00);	/* disable odd-even addressing */
+	vga_gdc_write(vh, misc, 0x04);	/* map starts at 0xA000 */
+}
+
+static void
+textram(vh)
+	struct vga_handle *vh;
+{
+	/* program sequencer to access video ram */
+
+	vga_ts_write(vh, syncreset, 0x01);	/* synchronous reset */
+	vga_ts_write(vh, wrplmask, 0x03);	/* write to map 0 & 1 */
+	vga_ts_write(vh, memmode, 0x03);	/* odd-even addressing */
+	vga_ts_write(vh, syncreset, 0x03);	/* clear synchronous reset */
+
+	/* program graphics controller for text mode */
+
+	vga_gdc_write(vh, rdplanesel, 0x00);	/* select map 0 for cpu reads */
+	vga_gdc_write(vh, mode, 0x10);		/* enable odd-even addressing */
+	/* map starts at 0xb800 or 0xb000 (mono) */
+	vga_gdc_write(vh, misc, (vh->vh_mono ? 0x0a : 0x0e));
+}
+
+void
+vga_loadchars(vh, fontset, first, num, lpc, data)
+	struct vga_handle *vh;
+	int fontset, first, num;
+	int lpc;
+	char *data;
+{
+	int offset, i, j, s;
+
+	/* fontset number swizzle done in vga_setfontset() */
+	offset = (fontset << 13) | (first << 5);
+
+	s = splhigh();
+	fontram(vh);
+
+	for (i = 0; i < num; i++)
+		for (j = 0; j < lpc; j++)
+			bus_space_write_1(vh->vh_memt, vh->vh_allmemh,
+					  offset + (i << 5) + j,
+					  data[i * lpc + j]);
+
+	textram(vh);
+	splx(s);
+}
+
+void
+vga_setfontset(vh, fontset1, fontset2)
+	struct vga_handle *vh;
+	int fontset1, fontset2;
+{
+	u_int8_t cmap;
+	static u_int8_t cmaptaba[] = {
+		0x00, 0x10, 0x01, 0x11,
+		0x02, 0x12, 0x03, 0x13
+	};
+	static u_int8_t cmaptabb[] = {
+		0x00, 0x20, 0x04, 0x24,
+		0x08, 0x28, 0x0c, 0x2c
+	};
+
+	/* extended font if fontset1 != fontset2 */
+	cmap = cmaptaba[fontset1] | cmaptabb[fontset2];
+
+	vga_ts_write(vh, fontsel, cmap);
+}
+
+void
+vga_setscreentype(vh, type)
+	struct vga_handle *vh;
+	const struct wsscreen_descr *type;
+{
+	vga_6845_write(vh, maxrow, type->fontheight - 1);
+
+	/* lo byte */
+	vga_6845_write(vh, vde, type->fontheight * type->nrows - 1);
+
+#ifndef PCDISPLAY_SOFTCURSOR
+	/* set cursor to last 2 lines */
+	vga_6845_write(vh, curstart, type->fontheight - 2);
+	vga_6845_write(vh, curend, type->fontheight - 1);
+#endif
+	/*
+	 * disable colour plane 3 if needed for font selection
+	 */
+	if (type->capabilities & WSSCREEN_HILIT) {
+		/*
+		 * these are the screens which don't support
+		 * 512-character fonts
+		 */
+		vga_attr_write(vh, colplen, 0x0f);
+	} else
+		vga_attr_write(vh, colplen, 0x07);
+}