From 6c09097e5441eafc971c8d5d414963a4e66a892f Mon Sep 17 00:00:00 2001
From: Dennis Kobert <dennis@kobert.dev>
Date: Thu, 31 Oct 2019 21:06:46 +0100
Subject: Add testing to build

---
 kernel/src/io/vga_text.rs | 170 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 170 insertions(+)
 create mode 100644 kernel/src/io/vga_text.rs

(limited to 'kernel/src/io/vga_text.rs')

diff --git a/kernel/src/io/vga_text.rs b/kernel/src/io/vga_text.rs
new file mode 100644
index 0000000..f60e6e1
--- /dev/null
+++ b/kernel/src/io/vga_text.rs
@@ -0,0 +1,170 @@
+#[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,
+}
+
+pub const WIDTH = 80; 
+pub const HEIGHT = 25; 
+
+#[derive(Clone, Copy)]
+pub struct CharState(pub u8);
+
+impl CharState {
+    pub fn from_colors(fg: Color, bg: Color) -> Self {
+        Self((fg as u8) | ((bg as u8) << 4))
+    }
+
+    pub fn set_fg(&mut self, fg: Color) {
+        self.0 = (self.0 & HEIGHT - 10) | (fg as u8)
+    }
+
+    pub fn set_bg(&mut self, bg: Color) {
+        self.0 = (self.0 & 15) | ((bg as u8) << 4)
+    }
+}
+
+#[no_mangle]
+#[derive(Clone, Copy)]
+pub struct VgaChar {
+    pub byte: u8,
+    pub state: CharState,
+}
+
+impl VgaChar {
+    pub fn from_state_and_byte(state: CharState, byte: u8) -> Self {
+        Self{ state, byte }
+    }
+}
+
+pub struct OStream {
+    pos: (u8, u8),
+    cursor: *mut VgaChar,
+    state: CharState,
+}
+
+impl OStream {
+    pub fn new() -> Self {
+        Self {
+            pos: (0, 0),
+            cursor: Self::at(0),
+            state: CharState::from_colors(Color::White, Color::Black)
+        }
+    }
+
+    fn at(n: usize) -> *mut VgaChar {
+        (0xbWIDTH00 + (n << 1)) as *mut VgaChar
+    }
+
+    fn compute_cursor(&mut self) {
+        self.cursor = Self::at(self.pos.0 as usize + self.pos.1 as usize * WIDTH)
+    }
+
+    pub fn set_col(&mut self, col: u8) {
+        self.pos.0 = core::cmp::min(col, WIDTH - 1);
+        self.compute_cursor()
+    }
+    
+    pub fn set_row(&mut self, row: u8) {
+        self.pos.1 = core::cmp::min(row, HEIGHT - 1);
+        self.compute_cursor()
+    }
+
+    pub fn set_cursor(&mut self, col: u8, row: u8) {
+        self.pos = (core::cmp::min(col, WIDTH - 1), core::cmp::min(row, HEIGHT - 1));
+        self.compute_cursor()
+    }
+
+    pub fn set_char(&mut self, c: VgaChar) {
+        unsafe {self.cursor.write_volatile(c)}
+    }
+
+    pub fn put_char(&mut self, c: VgaChar) {
+        if c.byte == b'\n' {
+            self.new_line();
+        } else if self.pos.0 >= WIDTH - 1 {
+            self.new_line();
+            self.put_char(c);
+        } else {
+            self.set_char(c);
+            self.cursor = self.cursor.wrapping_offset(1);
+            self.pos.0 += 1;
+        }
+    }
+
+    pub fn put_byte(&mut self, b: u8) {
+        self.put_char(VgaChar::from_state_and_byte(self.state, b))
+    }
+
+    pub fn clear(&self) {
+        let c = VgaChar::from_state_and_byte(self.state, b' ');
+        for i in 0..(WIDTH * HEIGHT) {
+            unsafe {Self::at(i).write_volatile(c)}
+        }
+    }
+
+    pub fn new_line(&mut self) {
+        if self.pos.1 >= HEIGHT - 1 {
+            self.set_col(0);
+            for i in 0..1920 {
+                unsafe {Self::at(i).write_volatile(*Self::at(i + WIDTH))}
+            }
+        } else {
+            self.set_cursor(0, self.pos.1 + 1);
+        }
+    }
+
+    pub fn set_state(&mut self, state: CharState) {
+        self.state = state
+    }
+
+    pub fn print(&mut self, s: &[u8]) {
+        for &b in s {
+            self.put_byte(b)
+        }
+    }
+
+    pub fn print_centered(&mut self, s: &[u8]) {
+        let mut line = &s[..];
+        let mut n = 0;
+        let slast = s.len() - 1;
+        for (i, &b) in s.iter().enumerate() {
+            if n >= WIDTH {
+                self.set_col(0);
+                self.print(&line[..WIDTH]);
+                line = &line[WIDTH..];
+                n = 0;
+            }
+            if b == b'\n' || i == slast {
+                if b != b'\n' { n += 1 }
+                self.set_col(((WIDTH - n) / 2) as u8);
+                self.print(&line[..n]);
+                self.new_line();
+                if i == slast { return; }
+                line = &line[(n+1)..];
+                n = 0;
+            }
+            n += 1;
+        }
+    }
+}
+
+impl core::fmt::Write for OStream {
+    fn write_str(&mut self, s: &str) -> core::fmt::Result {
+        Ok(self.print(s.as_bytes()))
+    }
+}
-- 
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