From 2503fdb96defd2e096397b5e7d3bf0fa1d2058ab Mon Sep 17 00:00:00 2001
From: Jack Halford <jack@crans.org>
Date: Mon, 12 Feb 2018 16:11:47 +0100
Subject: [PATCH] CONTEXT is instanciated at compile time now

---
 kernel-rs/src/context.rs    | 13 +++++--------
 kernel-rs/src/keyboard.rs   | 27 +++++++++++++--------------
 kernel-rs/src/lib.rs        |  4 +---
 kernel-rs/src/vga/buffer.rs |  2 +-
 4 files changed, 20 insertions(+), 26 deletions(-)

diff --git a/kernel-rs/src/context.rs b/kernel-rs/src/context.rs
index 6eb76626..06ca9bb4 100644
--- a/kernel-rs/src/context.rs
+++ b/kernel-rs/src/context.rs
@@ -2,6 +2,11 @@ extern crate core;
 
 use vga;
 
+pub static mut CONTEXT: Context = Context {
+    current_term: 0,
+    vga1: vga::Writer::new(),
+    vga2: vga::Writer::new(),
+};
 
 pub struct Context {
     pub current_term: u8,
@@ -10,14 +15,6 @@ pub struct Context {
 }
 
 impl Context {
-    pub fn new() -> Context {
-        Context {
-            current_term: 0,
-            vga1: vga::Writer::new(),
-            vga2: vga::Writer::new(),
-        }
-    }
-
     pub fn switch_term(&mut self) {
         self.current_term = {
             if self.current_term == 0 { 1 }
diff --git a/kernel-rs/src/keyboard.rs b/kernel-rs/src/keyboard.rs
index 7cc66263..8ea0148b 100644
--- a/kernel-rs/src/keyboard.rs
+++ b/kernel-rs/src/keyboard.rs
@@ -1,29 +1,28 @@
 extern crate core;
 
 use cpuio;
-use context;
+use context::CONTEXT;
 // use vga::color::{Color, ColorCode};
 
 pub static SCANCODE_TO_ASCII: [u8; 59] = *b"??1234567890-=??qwertyuiop[]\n?asdfghjkl;'`?\\zxcvbnm,./?*? ?"; 
 
-pub fn kbd_callback(context: &mut context::Context) {
+pub fn kbd_callback() {
     // let terminal_two: vga::terminal::Terminal = vga::Screen::new();
     let control = unsafe { cpuio::inb(0x64) };
     if (control & 1) == 1 {
         let scancode = unsafe { cpuio::inb(0x60) };
-        //TODO implement logic to translate scancode->ascii
-        match self::SCANCODE_TO_ASCII.get(scancode as usize) {
-            Some(&b'1') => {
-                context.switch_term();
-                context.current_term().flush();
+        unsafe {
+            match self::SCANCODE_TO_ASCII.get(scancode as usize) {
+                Some(&b'1') => {
+                    CONTEXT.switch_term();
+                    CONTEXT.current_term().flush();
+                }
+                Some(ascii) => {
+                    CONTEXT.current_term().keypress(*ascii);
+                },
+                None =>{},
+                // None => println!("nokey ctrl {:x}", control),
             }
-            Some(ascii) => {
-                let mut terminal = context.current_term();
-                terminal.keypress(*ascii);
-            },
-            None =>{},
-            // None => println!("nokey ctrl {:x}", control),
         }
-        // current_screen.flush();
     }
 }
diff --git a/kernel-rs/src/lib.rs b/kernel-rs/src/lib.rs
index 51bb83a1..77f1d37d 100644
--- a/kernel-rs/src/lib.rs
+++ b/kernel-rs/src/lib.rs
@@ -41,10 +41,8 @@ pub extern fn kmain() -> ! {
     // WRITER.lock().color_code = ColorCode::new(Color::White, Color::Black);
     // println!(">> Kernel startup...");
 
-    let mut context = context::Context::new();
-
     loop {
-        keyboard::kbd_callback(&mut context);
+        keyboard::kbd_callback();
     }
 }
 
diff --git a/kernel-rs/src/vga/buffer.rs b/kernel-rs/src/vga/buffer.rs
index a7765905..eb946ea9 100644
--- a/kernel-rs/src/vga/buffer.rs
+++ b/kernel-rs/src/vga/buffer.rs
@@ -49,7 +49,7 @@ pub struct Writer {
 }
 
 impl Writer {
-    pub fn new() -> Writer {
+    pub const fn new() -> Writer {
         Writer {
             position: 0,
             color_code: ColorCode::new(Color::White, Color::Black),