more layout work for the VGA Driver

drivers/graphics/vgable/src/main.rs

@@ -3,6 +3,8 @@
 
 use able_graphics_library::display::parse_display_string;
 
+const VGA_ADDRESS: *mut u8 = 0xB8000 as *mut u8;
+
 #[no_mangle]
 fn start() {
     // TODO: Initialize the VGA hardware and configure it to the desired video mode
@@ -14,6 +16,7 @@ fn start() {
         Ok(display) => {
             let (width, height, bpp, fps) = display;
             let vga_mode = VGAMode::get_vga_mode(width, height, bpp).unwrap_or(VGAMode::Mode0);
+            let mut vga_state = VGAState::new(vga_mode);
         }
 
         Err(err) => match err {
@@ -26,20 +29,20 @@ fn start() {
     }
 }
 
-#[derive(Debug)]
+#[derive(Debug, Clone, Copy)]
 enum VGAMode {
-    Mode0,  //: 640x480 pixels, 16 colors
-    Mode1,  //: 640x480 pixels, 256 colors
-    Mode2,  //: 640x480 pixels, 16-bit color
-    Mode3,  //: 800x600 pixels, 16 colors
-    Mode4,  //: 800x600 pixels, 256 colors
-    Mode5,  //: 800x600 pixels, 16-bit color
-    Mode6,  //: 1024x768 pixels, 16 colors
-    Mode7,  //: 1024x768 pixels, 256 colors
-    Mode8,  //: 1024x768 pixels, 16-bit color
-    Mode9,  //: 1280x1024 pixels, 16 colors
-    Mode10, //: 1280x1024 pixels, 256 colors
-    Mode11, //1: 1280x1024 pixels, 16-bit color
+    Mode0 = 0,   //: 640x480 pixels, 16 colors
+    Mode1 = 1,   //: 640x480 pixels, 256 colors
+    Mode2 = 2,   //: 640x480 pixels, 16-bit color
+    Mode3 = 3,   //: 800x600 pixels, 16 colors
+    Mode4 = 4,   //: 800x600 pixels, 256 colors
+    Mode5 = 5,   //: 800x600 pixels, 16-bit color
+    Mode6 = 6,   //: 1024x768 pixels, 16 colors
+    Mode7 = 7,   //: 1024x768 pixels, 256 colors
+    Mode8 = 8,   //: 1024x768 pixels, 16-bit color
+    Mode9 = 9,   //: 1280x1024 pixels, 16 colors
+    Mode10 = 10, //: 1280x1024 pixels, 256 colors
+    Mode11 = 11, //: 1280x1024 pixels, 16-bit color
 }
 impl VGAMode {
     fn get_vga_mode(width: u32, height: u32, bpp: u32) -> Option<VGAMode> {
@@ -60,3 +63,31 @@ impl VGAMode {
         }
     }
 }
+#[allow(dead_code)]
+struct VGAState<'a> {
+    mode: VGAMode,
+    buffer: &'a mut u8,
+}
+#[allow(dead_code)]
+impl<'a> VGAState<'a> {
+    fn new(mode: VGAMode) -> Self {
+        let mut state = Self {
+            mode,
+            buffer: unsafe { &mut *VGA_ADDRESS },
+        };
+        unsafe {
+            state.initialize_hardware();
+        }
+
+        state
+    }
+    unsafe fn set_vga_mode(&mut self, mode: VGAMode) {
+        self.mode = mode;
+        // Set registers here
+    }
+    unsafe fn initialize_hardware(&mut self) {
+        // set vga mode
+        self.set_vga_mode(self.mode)
+        // initalize the graphics lib to be usable
+    }
+}