Add Display module

src/main.rs

@@ -27,7 +27,7 @@ pub mod arch;
 pub use arch::*;
 pub mod platform;
 
-use platform::uart::MiniUart;
+use platform::{display::Size2d, uart::MiniUart};
 
 // User-facing kernel parts - syscalls and capability invocations.
 // pub mod vesper; -- no mod exported, because available through syscall interface

src/platform/display.rs

@@ -0,0 +1,148 @@
+/* Character cells are 8x8 */
+pub const CHARSIZE_X: u32 = 8;
+pub const CHARSIZE_Y: u32 = 8;
+
+pub struct Size2d {
+    pub x: u32,
+    pub y: u32,
+}
+
+pub struct Color(pub u32);
+
+impl Color {
+    pub fn rgb(r: u8, g: u8, b: u8) -> Color {
+        Color((b as u32) << 16 | (g as u32) << 8 | r as u32)
+    }
+}
+
+#[derive(PartialEq)]
+pub enum PixelOrder {
+    BGR,
+    RGB,
+}
+
+pub struct Display {
+    base: u32,
+    size: u32,
+    pitch: u32,
+    max_x: u32,
+    max_y: u32,
+    width: u32,
+    height: u32,
+    order: PixelOrder,
+}
+
+// https://github.com/david-griffith/rust-bitmap/blob/master/src/lib.rs
+#[rustfmt::skip]
+static CHAR_ARRAY: [u64; 95] = [
+    0x0000_0000_0000_0000,                                                // space
+    0x183c_3c18_1800_1800, 0x3636_0000_0000_0000, 0x3636_7f36_7f36_3600,  // ! " #
+    0x0c3e_031e_301f_0c00, 0x0063_3318_0c66_6300, 0x1c36_1c6e_3b33_6e00,  // $ % &
+    0x0606_0300_0000_0000, 0x180c_0606_060c_1800, 0x060c_1818_180c_0600,  // ' ( )
+    0x0066_3cff_3c66_0000, 0x000c_0c3f_0c0c_0000, 0x0000_0000_000c_0c06,  // * + ,
+    0x0000_003f_0000_0000, 0x0000_0000_000c_0c00, 0x6030_180c_0603_0100,  // - . /
+    0x3e63_737b_6f67_3e00, 0x0c0e_0c0c_0c0c_3f00, 0x1e33_301c_0633_3f00,  // 0 1 2
+    0x1e33_301c_3033_1e00, 0x383c_3633_7f30_7800, 0x3f03_1f30_3033_1e00,  // 3 4 5
+    0x1c06_031f_3333_1e00, 0x3f33_3018_0c0c_0c00, 0x1e33_331e_3333_1e00,  // 6 7 8
+    0x1e33_333e_3018_0e00, 0x000c_0c00_000c_0c00, 0x000c_0c00_000c_0c06,  // 9 : ;
+    0x180c_0603_060c_1800, 0x0000_3f00_003f_0000, 0x060c_1830_180c_0600,  // < = >
+    0x1e33_3018_0c00_0c00, 0x3e63_7b7b_7b03_1e00, 0x0c1e_3333_3f33_3300,  // ? @ A
+    0x3f66_663e_6666_3f00, 0x3c66_0303_0366_3c00, 0x1f36_6666_6636_1f00,  // B C D
+    0x7f46_161e_1646_7f00, 0x7f46_161e_1606_0f00, 0x3c66_0303_7366_7c00,  // E F G
+    0x3333_333f_3333_3300, 0x1e0c_0c0c_0c0c_1e00, 0x7830_3030_3333_1e00,  // H I J
+    0x6766_361e_3666_6700, 0x0f06_0606_4666_7f00, 0x6377_7f7f_6b63_6300,  // K L M
+    0x6367_6f7b_7363_6300, 0x1c36_6363_6336_1c00, 0x3f66_663e_0606_0f00,  // N O P
+    0x1e33_3333_3b1e_3800, 0x3f66_663e_3666_6700, 0x1e33_070e_3833_1e00,  // Q R S
+    0x3f2d_0c0c_0c0c_1e00, 0x3333_3333_3333_3f00, 0x3333_3333_331e_0c00,  // T U V
+    0x6363_636b_7f77_6300, 0x6363_361c_1c36_6300, 0x3333_331e_0c0c_1e00,  // W X Y
+    0x7f63_3118_4c66_7f00, 0x1e06_0606_0606_1e00, 0x0306_0c18_3060_4000,  // Z [ \
+    0x1e18_1818_1818_1e00, 0x081c_3663_0000_0000, 0x0000_0000_0000_00ff,  // ] ^ _
+    0x0c0c_1800_0000_0000, 0x0000_1e30_3e33_6e00, 0x0706_063e_6666_3b00,  // ` a b
+    0x0000_1e33_0333_1e00, 0x3830_303e_3333_6e00, 0x0000_1e33_3f03_1e00,  // c d e
+    0x1c36_060f_0606_0f00, 0x0000_6e33_333e_301f, 0x0706_366e_6666_6700,  // f g h
+    0x0c00_0e0c_0c0c_1e00, 0x3000_3030_3033_331e, 0x0706_6636_1e36_6700,  // i j k
+    0x0e0c_0c0c_0c0c_1e00, 0x0000_337f_7f6b_6300, 0x0000_1f33_3333_3300,  // l m n
+    0x0000_1e33_3333_1e00, 0x0000_3b66_663e_060f, 0x0000_6e33_333e_3078,  // o p q
+    0x0000_3b6e_6606_0f00, 0x0000_3e03_1e30_1f00, 0x080c_3e0c_0c2c_1800,  // r s t
+    0x0000_3333_3333_6e00, 0x0000_3333_331e_0c00, 0x0000_636b_7f7f_3600,  // u v w
+    0x0000_6336_1c36_6300, 0x0000_3333_333e_301f, 0x0000_3f19_0c26_3f00,  // x y z
+    0x380c_0c07_0c0c_3800, 0x1818_1800_1818_1800, 0x070c_0c38_0c0c_0700,  // { | }
+    0x6e3b_0000_0000_0000,                                                // ~
+];
+
+impl Display {
+    pub fn new(
+        base: u32,
+        size: u32,
+        pitch: u32,
+        max_x: u32,
+        max_y: u32,
+        width: u32,
+        height: u32,
+        order: PixelOrder,
+    ) -> Self {
+        Display {
+            base,
+            size,
+            pitch,
+            max_x,
+            max_y,
+            width,
+            height,
+            order,
+        }
+    }
+
+    pub fn putpixel(&mut self, x: u16, y: u16, color: u32) {
+        let c = |chan: u16| {
+            if self.order == PixelOrder::BGR {
+                2 - chan
+            } else {
+                chan
+            }
+        };
+        let f = |v: u32, chan: u16| unsafe {
+            *(self.base as *mut u8)
+                .offset((y as u32 * self.pitch + x as u32 * 3 + c(chan) as u32) as isize) = v as u8;
+        };
+
+        f(color & 0xff, 0);
+        f((color >> 8) & 0xff, 1);
+        f((color >> 16) & 0xff, 2)
+    }
+
+    pub fn rect(&mut self, x1: u16, y1: u16, x2: u16, y2: u16, color: u32) {
+        for y in y1..y2 {
+            for x in x1..x2 {
+                self.putpixel(x, y, color);
+            }
+        }
+    }
+
+    pub fn draw_text(&mut self, x: u16, y: u16, text: &str, color: u32) {
+        for i in 0..8 {
+            let mut char_off = 0;
+            // Take an 8 bit slice from each array value.
+            for my_char in text.as_bytes() {
+                if (*my_char as isize - 0x20 > 95) || (*my_char as isize - 0x20 < 0) {
+                    return; // Err("Character not in font.");
+                }
+
+                let mut myval = CHAR_ARRAY[*my_char as usize - 0x20];
+                myval = myval.swap_bytes();
+                // do initial shr.
+                myval = myval >> (i * 8);
+                for mycount in 0..8 {
+                    if myval & 1 == 1 {
+                        self.putpixel(x + char_off * 8 + mycount, y + i, color);
+                    }
+                    myval = myval >> 1;
+                    if myval == 0 {
+                        break;
+                    }
+                }
+                char_off += 1;
+            }
+        }
+    }
+}

src/platform/mod.rs

@@ -1,3 +1,4 @@
+pub mod display;
 pub mod gpio;
 pub mod rpi3;
 pub mod uart;