Initial check-in.

1 files changed, 139 insertions, 0 deletions

diff --git a/laden/output-vga.c b/laden/output-vga.c
new file mode 100644
index 0000000..251316d
--- /dev/null
+++ b/laden/output-vga.c
@@ -0,0 +1,139 @@
+/* output-vga.c - A VGA output driver.
+   Copyright (C) 2003 Free Software Foundation, Inc.
+   Written by Marcus Brinkmann.
+
+   This file is part of the GNU Hurd.
+
+   The GNU Hurd is free software; you can redistribute it and/or
+   modify it under the terms of the GNU General Public License as
+   published by the Free Software Foundation; either version 2, or (at
+   your option) any later version.
+
+   The GNU Hurd is distributed in the hope that it will be useful, but
+   WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA. */
+
+#include "laden.h"
+
+#include <sys/io.h>
+
+#define VGA_VIDEO_MEM_BASE_ADDR	0x0B8000
+#define VGA_VIDEO_MEM_LENGTH	0x004000
+
+/* The default attribute is light grey on black.  */
+#define VGA_DEF_ATTRIBUTE	7
+
+#define VGA_COLUMNS	       	80
+#define VGA_ROWS	       	25
+
+/* The CRTC Registers.  XXX Depends on the I/O Address Select field.
+   However, the only need to use the other values is for compatibility
+   with monochrome adapters.  */
+#define VGA_CRT_ADDR_REG	0x3d4
+#define VGA_CRT_DATA_REG	0x3d5
+
+/* The cursor position subregisters.  */
+#define VGA_CRT_CURSOR_HIGH	0x0e
+#define VGA_CRT_CURSOR_LOW	0x0f
+
+
+/* Set the cursor position to POS, which is (x_pos + y_pos * width).  */
+static void
+vga_set_cursor_pos (unsigned int pos)
+{
+  outb (VGA_CRT_CURSOR_HIGH, VGA_CRT_ADDR_REG);
+  outb (pos >> 8, VGA_CRT_DATA_REG);
+  outb (VGA_CRT_CURSOR_LOW, VGA_CRT_ADDR_REG);
+  outb (pos & 0xff, VGA_CRT_DATA_REG);
+}
+
+
+/* Set the cursor position to POS, which is (x_pos + y_pos * width).  */
+static unsigned int
+vga_get_cursor_pos (void)
+{
+  unsigned int pos;
+
+  outb (VGA_CRT_CURSOR_HIGH, VGA_CRT_ADDR_REG);
+  pos = inb (VGA_CRT_DATA_REG) << 8;
+  outb (VGA_CRT_CURSOR_LOW, VGA_CRT_ADDR_REG);
+  pos |= inb (VGA_CRT_DATA_REG) & 0xff;
+
+  return pos;
+}
+
+
+/* Global variables.  */
+
+static int col;
+static int row;
+static char *video;
+
+
+static void
+vga_init (void)
+{
+  unsigned int pos = vga_get_cursor_pos ();
+  col = pos % VGA_COLUMNS;
+  row = pos / VGA_COLUMNS;
+  video = (char *) VGA_VIDEO_MEM_BASE_ADDR;
+}
+
+
+static void
+vga_putchar (int chr)
+{
+  unsigned int pos;
+
+  if (chr == '\n')
+    {
+      col = 0;
+      row++;
+    }
+  else
+    {
+      pos = row * VGA_COLUMNS + col;
+      video[2 * pos] = chr & 0xff;
+      video[2 * pos + 1] = VGA_DEF_ATTRIBUTE;
+      col++;
+      if (col == VGA_COLUMNS)
+	{
+	  col = 0;
+	  row++;
+	}
+    }
+
+  if (row == VGA_ROWS)
+    {
+      int i;
+
+      row--;
+      for (i = 0; i < VGA_COLUMNS * row; i++)
+	{
+	  video[2 * i] = video[2 * (i + VGA_COLUMNS)];
+	  video[2 * i + 1] = video[2 * (i + VGA_COLUMNS) + 1];
+	}
+      for (i = VGA_COLUMNS * row; i < VGA_COLUMNS * VGA_ROWS; i++)
+	{
+	  video[2 * i] = ' ';
+	  video[2 * i + 1] = VGA_DEF_ATTRIBUTE;
+	}
+    }
+
+  pos = row * VGA_COLUMNS + col;
+  vga_set_cursor_pos (pos);
+}
+
+
+struct output_driver vga_output =
+  {
+    "vga",
+    vga_init,
+    0,		/* deinit */
+    vga_putchar
+  };