From 19de9e560d0372a66879d416435eccbde36333a9 Mon Sep 17 00:00:00 2001
From: Philipp Oppermann <dev@phil-opp.com>
Date: Fri, 25 Jan 2019 12:21:51 +0100
Subject: [PATCH] Add a VGA buffer module

---
 src/main.rs       |  2 ++
 src/vga_buffer.rs | 44 ++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 46 insertions(+)
 create mode 100644 src/vga_buffer.rs

diff --git a/src/main.rs b/src/main.rs
index 0f0eac13..1a4f8b64 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -5,6 +5,8 @@ use core::panic::PanicInfo;
 
 static HELLO: &[u8] = b"Hello World!";
 
+mod vga_buffer;
+
 #[no_mangle]
 pub extern "C" fn _start() -> ! {
     let vga_buffer = 0xb8000 as *mut u8;
diff --git a/src/vga_buffer.rs b/src/vga_buffer.rs
new file mode 100644
index 00000000..2a736b1f
--- /dev/null
+++ b/src/vga_buffer.rs
@@ -0,0 +1,44 @@
+#[allow(dead_code)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+#[repr(u8)]
+pub enum Color {
+    Black = 0,
+    Blue = 1,
+    Green = 2,
+    Cyan = 3,
+    Red = 4,
+    Magenta = 5,
+    Brown = 6,
+    LightGray = 7,
+    DarkGray = 8,
+    LightBlue = 9,
+    LightGreen = 10,
+    LightCyan = 11,
+    LightRed = 12,
+    Pink = 13,
+    Yellow = 14,
+    White = 15,
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+struct ColorCode(u8);
+
+impl ColorCode {
+    fn new(foreground: Color, background: Color) -> ColorCode {
+        ColorCode((background as u8) << 4 | (foreground as u8))
+    }
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+#[repr(C)]
+struct ScreenChar {
+    ascii_character: u8,
+    color_code: ColorCode,
+}
+
+const BUFFER_HEIGHT: usize = 25;
+const BUFFER_WIDTH: usize = 80;
+
+struct Buffer {
+    chars: [[ScreenChar; BUFFER_WIDTH]; BUFFER_HEIGHT],
+}