1 files changed, 99 insertions, 0 deletions
diff --git a/kernel.soso/screen.c b/kernel.soso/screen.c
new file mode 100644
index 00000000..9613c304
--- /dev/null
+++ b/kernel.soso/screen.c
@@ -0,0 +1,99 @@
+#include "screen.h"
+#include "common.h"
+#include "serial.h"
+
+#define SCREEN_LINE_COUNT 25
+#define SCREEN_COLUMN_COUNT 80
+
+static unsigned char *videoStart = (unsigned char*)0xB8000;
+
+static uint16 gCurrentLine = 0;
+static uint16 gCurrentColumn = 0;
+static uint8 gColor = 0x0A;
+
+void Screen_FlushFromTty(Tty* tty)
+{
+    memcpy(videoStart, tty->buffer, SCREEN_LINE_COUNT * SCREEN_COLUMN_COUNT * 2);
+
+    Screen_MoveCursor(tty->currentLine, tty->currentColumn);
+}
+
+void Screen_Print(int row, int column, const char* text)
+{
+    unsigned char * video = videoStart;
+    
+    video += (row * SCREEN_COLUMN_COUNT + column) * 2;
+    while(*text != 0)
+    {
+        *video++ = *text++;
+        *video++ = gColor;
+    }
+}
+
+void Screen_SetActiveColor(uint8 color)
+{
+    gColor = color;
+}
+
+void Screen_ApplyColor(uint8 color)
+{
+    gColor = color;
+
+    unsigned char * video = videoStart;
+    int i = 0;
+
+    for (i = 0; i < SCREEN_LINE_COUNT * SCREEN_COLUMN_COUNT; ++i)
+    {
+        video++;
+        *video++ = gColor;
+    }
+}
+
+void Screen_Clear()
+{
+	unsigned char * video = videoStart;
+	int i = 0;
+    
+    for (i = 0; i < SCREEN_LINE_COUNT * SCREEN_COLUMN_COUNT; ++i)
+    {
+        *video++ = 0;
+        *video++ = gColor;
+    }
+    
+    gCurrentLine = 0;
+    gCurrentColumn = 0;
+}
+
+void Screen_MoveCursor(uint16 line, uint16 column)
+{
+   // The screen is 80 characters wide...
+   uint16 cursorLocation = line * SCREEN_COLUMN_COUNT + column;
+   outb(0x3D4, 14);                  // Tell the VGA board we are setting the high cursor byte.
+   outb(0x3D5, cursorLocation >> 8); // Send the high cursor byte.
+   outb(0x3D4, 15);                  // Tell the VGA board we are setting the low cursor byte.
+   outb(0x3D5, cursorLocation);      // Send the low cursor byte.
+
+   gCurrentColumn = column;
+   gCurrentLine = line;
+}
+
+void Screen_SetCursorVisible(BOOL visible)
+{
+    uint8 cursor = inb(0x3d5);
+
+    if (visible)
+    {
+        cursor &= ~0x20;//5th bit cleared when cursor visible
+    }
+    else
+    {
+        cursor |= 0x20;//5th bit set when cursor invisible
+    }
+    outb(0x3D5, cursor);
+}
+
+void Screen_GetCursor(uint16* line, uint16* column)
+{
+    *line = gCurrentLine;
+    *column = gCurrentColumn;
+}