From bb55beef914e7488350ad1d0419d4bc60ad63c99 Mon Sep 17 00:00:00 2001
From: Alex AUVOLAT <alex.auvolat@ens.fr>
Date: Fri, 28 Mar 2014 09:10:23 +0100
Subject: Import code for article1, 2, 3, 4

---
 sos-code-article4/drivers/x86_videomem.c | 128 +++++++++++++++++++++++++++++++
 1 file changed, 128 insertions(+)
 create mode 100644 sos-code-article4/drivers/x86_videomem.c

(limited to 'sos-code-article4/drivers/x86_videomem.c')

diff --git a/sos-code-article4/drivers/x86_videomem.c b/sos-code-article4/drivers/x86_videomem.c
new file mode 100644
index 0000000..cc4b79c
--- /dev/null
+++ b/sos-code-article4/drivers/x86_videomem.c
@@ -0,0 +1,128 @@
+/* Copyright (C) 2004  David Decotigny
+   Copyright (C) 1999  Free Software Foundation, Inc.
+
+   This program 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
+   of the License, or (at your option) any later version.
+   
+   This program 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 02111-1307,
+   USA. 
+*/
+#include <sos/klibc.h>
+#include <hwcore/ioports.h>
+
+#include "x86_videomem.h"
+
+/* The text video memory starts at address 0xB8000. Odd bytes are the
+   ASCII value of the character, even bytes are attribute for the
+   preceding character. */
+#define VIDEO   0xb8000
+
+
+/* Console screen size */
+#define LINES   25
+#define COLUMNS 80
+
+
+/** The structure of a character element in the video memory. @see
+    http://webster.cs.ucr.edu/AoA DOS edition chapter 23 */
+typedef struct {
+  unsigned char character;
+  unsigned char attribute;
+} __attribute__ ((packed)) x86_video_mem[LINES*COLUMNS];
+
+
+
+/** The base pointer for the video memory */
+static volatile x86_video_mem *video = (volatile x86_video_mem*)VIDEO;
+
+sos_ret_t sos_x86_videomem_setup(void)
+{
+  /*
+   * Hide cursor. @see Ralf Brown's interrupt (and port) list
+   * http://www-2.cs.cmu.edu/~ralf/files.html
+   */
+#define CRT_REG_INDEX 0x3d4
+#define CRT_REG_DATA  0x3d5
+
+  /* CRT index port => ask for access to register 0xa ("cursor
+     start") */
+  outb(0x0a, CRT_REG_INDEX);
+
+  /* (RBIL Tables 708 & 654) CRT Register 0xa => bit 5 = cursor OFF */
+  outb(1 << 5, CRT_REG_DATA);
+
+  return SOS_OK;
+}
+
+
+sos_ret_t sos_x86_videomem_cls(unsigned char attribute)
+{
+  /* Clears the screen */
+  int i;
+  for(i = 0 ; i < LINES*COLUMNS ; i++)
+    {
+      (*video)[i].character = 0;
+      (*video)[i].attribute = attribute;
+    }
+
+  return SOS_OK;  
+}
+
+
+sos_ret_t sos_x86_videomem_putstring(unsigned char row, unsigned char col,
+				     unsigned char attribute,
+				     const char *str)
+{
+  unsigned video_offs = row*COLUMNS + col;
+
+  if (video_offs >= LINES*COLUMNS)
+    return -SOS_EINVAL;
+  
+  for ( ; str && *str && (video_offs < LINES*COLUMNS) ; str++, video_offs++)
+    {
+      (*video)[video_offs].character = (unsigned char)*str;
+      (*video)[video_offs].attribute = attribute;
+    }
+
+  return SOS_OK;
+}
+
+
+sos_ret_t sos_x86_videomem_putchar(unsigned char row, unsigned char col,
+				   unsigned char attribute,
+				   unsigned char c)
+{
+  unsigned video_offs = row*COLUMNS + col;
+
+  if (video_offs >= LINES*COLUMNS)
+    return -SOS_EINVAL;
+  
+  (*video)[video_offs].character = c;
+  (*video)[video_offs].attribute = attribute;
+
+  return SOS_OK;
+}
+
+
+sos_ret_t sos_x86_videomem_printf(unsigned char row, unsigned char col,
+				  unsigned char attribute,
+				  const char *format, /* args */...)
+{
+  char buff[256];
+  va_list ap;
+  
+  va_start(ap, format);
+  vsnprintf(buff, sizeof(buff), format, ap);
+  va_end(ap);
+  
+  return sos_x86_videomem_putstring(row, col, attribute, buff);
+}
-- 
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