switching mode text/graphics, text is distorted

2 files changed, 45 insertions, 7 deletions

diff --git a/src/drivers/video/vga.c b/src/drivers/video/vga.c
index 1ec7829..cf1157c 100644
--- a/src/drivers/video/vga.c
+++ b/src/drivers/video/vga.c
@@ -112,10 +112,30 @@ vga_mode_t vga_make_mode( const int x, const int y, const int color_depth )
 	return mode;
 }
 	
-
+// from http://files.osdev.org/mirrors/geezer/osd/graphics/modes.c
 static vga_mode_t modes[] = {
+	{ 640, 480, 4,
+		{ 
+		/* MISC */
+			0x67,
+		/* SEQ */
+			0x03, 0x00, 0x03, 0x00, 0x02,
+		/* CRTC */
+			0x5F, 0x4F, 0x50, 0x82, 0x55, 0x81, 0xBF, 0x1F,
+			0x00, 0x4F, 0x0D, 0x0E, 0x00, 0x00, 0x00, 0x50,
+			0x9C, 0x0E, 0x8F, 0x28, 0x1F, 0x96, 0xB9, 0xA3,
+			0xFF,
+		/* GC */
+			0x00, 0x00, 0x00, 0x00, 0x00, 0x10, 0x0E, 0x00,
+			0xFF,
+		/* AC */
+			0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x14, 0x07,
+			0x38, 0x39, 0x3A, 0x3B, 0x3C, 0x3D, 0x3E, 0x3F,
+			0x0C, 0x00, 0x0F, 0x08, 0x00
+		},
+		NULL
+	},
 	{ 320, 200, 8,
-		// from http://files.osdev.org/mirrors/geezer/osd/graphics/modes.c
 		{
 		/* MISC */
 			0x63,
diff --git a/src/kernel/kernel.c b/src/kernel/kernel.c
index 19cf8e6..6342a26 100644
--- a/src/kernel/kernel.c
+++ b/src/kernel/kernel.c
@@ -27,10 +27,16 @@ static void handle_mouse_event( mouse_event_t *event, void *context );
 
 static bool terminate = false;
 
+typedef enum {
+	MODE_TEXT,
+	MODE_GRAPHICS
+} mode_t;
+
 typedef struct {
 	vga_text_t vga_text;
 	driver_manager_t driver_manager;
 	vga_t vga;
+	mode_t mode;
 } global_context_t;
 
 static global_context_t global_context;
@@ -39,6 +45,8 @@ static global_context_t global_context;
 // the boot loader expects the entry point to be here!
 void kernel_main( void )
 {	
+	global_context.mode = MODE_TEXT;
+
 	serial_t serial;
 	serial_init( &serial );
 
@@ -181,12 +189,22 @@ static void handle_keyboard_event( keyboard_event_t *event, void *context )
 				} else if( strcmp( buf, "mode" ) == 0 ) {
 					// TODO: move mode switches to and from graphics/text mode here,
 					// for now when we enter the graphics mode we remain there
-					if( vga_set_mode( vga, vga_make_mode( 320, 200, 8 ) ) ) {
-						vga_clear_screen( vga, vga_make_RGB( 0x00, 0x00, 0xA8 ) );
-						vga_draw_char( vga, 'A', 100, 100, vga_make_RGB( 0x00, 0x00, 0xA8 ),
-							vga_make_RGB( 0xFF, 0xFF, 0xFF ) );
+					switch( global_context->mode ) {
+						case MODE_TEXT:
+							if( vga_set_mode( vga, vga_make_mode( 320, 200, 8 ) ) ) {
+								vga_clear_screen( vga, vga_make_RGB( 0x00, 0x00, 0xA8 ) );
+								vga_draw_char( vga, 'A', 100, 100, vga_make_RGB( 0x00, 0x00, 0xA8 ),
+									vga_make_RGB( 0xFF, 0xFF, 0xFF ) );
+							}
+							global_context->mode = MODE_GRAPHICS;
+							break;
+
+						case MODE_GRAPHICS:
+							if( vga_set_mode( vga, vga_make_mode( 640, 480, 4 ) ) ) {
+							}
+							global_context->mode = MODE_TEXT;
+							break;
 					}
-
 				} else {
 					printf( "ERR: Unknown pre-boot command '%s'\n", buf );
 				}