Add VGA palette loader (#203)

* Add VGA palette loader

* Update screenshot

dsk/ini/boot.sh

@@ -1,3 +1,4 @@
+vga set palette /ini/palette.csv
 vga set font /ini/fonts/zap-light-8x16.psf
 read /ini/banner.txt
 user login

dsk/ini/palette.csv

@@ -0,0 +1,18 @@
+# VGA Palette File (Index, Red, Green, Blue)
+# Dark Gruvbox color palette
+0x00, 0x28, 0x28, 0x28 # Black
+0x01, 0x45, 0x85, 0x88 # Blue
+0x02, 0x98, 0x97, 0x1A # Green
+0x03, 0x68, 0x9D, 0x6A # Cyan
+0x04, 0xCC, 0x24, 0x1D # Red
+0x05, 0xB1, 0x62, 0x86 # Magenta
+0x06, 0xD7, 0x99, 0x21 # Brown (Dark Yellow)
+0x07, 0xEB, 0xDB, 0xB2 # Light Gray
+0x08, 0xA8, 0x99, 0x84 # Dark Gray (Gray)
+0x09, 0x83, 0xa5, 0x98 # Light Blue
+0x0A, 0xB8, 0xBB, 0x26 # Light Green
+0x0B, 0x8E, 0xC0, 0x7C # Light Cyan
+0x0C, 0xFB, 0x49, 0x34 # Light Red
+0x0D, 0xD3, 0x86, 0x9B # Pink (Light Magenta)
+0x0E, 0xFA, 0xBD, 0x2F # Yellow (Light Yellow)
+0x0F, 0xFB, 0xF1, 0xF7 # White

src/kernel/vga.rs

@@ -89,6 +89,29 @@ fn color_from_ansi(code: u8) -> Color {
     }
 }
 
+impl Color {
+    fn to_palette_code(&self) -> u8 {
+        match self {
+            Color::Black      => 0x00,
+            Color::Blue       => 0x01,
+            Color::Green      => 0x02,
+            Color::Cyan       => 0x03,
+            Color::Red        => 0x04,
+            Color::Magenta    => 0x05,
+            Color::LightGray  => 0x07,
+            Color::Brown      => 0x14,
+            Color::DarkGray   => 0x38,
+            Color::LightBlue  => 0x39,
+            Color::LightGreen => 0x3A,
+            Color::LightCyan  => 0x3B,
+            Color::LightRed   => 0x3C,
+            Color::Pink       => 0x3D,
+            Color::Yellow     => 0x3E,
+            Color::White      => 0x3F,
+        }
+    }
+}
+
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 #[repr(transparent)]
 struct ColorCode(u8);
@@ -278,6 +301,22 @@ impl Writer {
         }
     }
 
+    pub fn set_palette(&mut self, palette: Palette) {
+        let mut addr: Port<u8> = Port::new(0x03C8); // Address Write Mode Register
+        let mut data: Port<u8> = Port::new(0x03C9); // Data Register
+        for (i, r, g, b) in palette.colors {
+            if i < 16 {
+                let code = COLORS[i as usize].to_palette_code();
+                unsafe {
+                    addr.write(code);
+                    data.write(r >> 2); // Convert 8-bit color to 6-bit color
+                    data.write(g >> 2);
+                    data.write(b >> 2);
+                }
+            }
+        }
+    }
+
 }
 
 /// See https://vt100.net/emu/dec_ansi_parser
@@ -413,25 +452,15 @@ pub fn set_font(font: &Font) {
     })
 }
 
-// Dark Gruvbox color palette
-const PALETTE: [(u8, u8, u8, u8); 16] = [
-    (0x00, 0x28, 0x28, 0x28), // Black
-    (0x01, 0x45, 0x85, 0x88), // Blue
-    (0x02, 0x98, 0x97, 0x1A), // Green
-    (0x03, 0x68, 0x9D, 0x6A), // Cyan
-    (0x04, 0xCC, 0x24, 0x1D), // Red
-    (0x05, 0xB1, 0x62, 0x86), // Magenta
-    (0x07, 0xEB, 0xDB, 0xB2), // Light Gray
-    (0x14, 0xD7, 0x99, 0x21), // Brown (Dark Yellow)
-    (0x38, 0xA8, 0x99, 0x84), // Gray (Dark Gray)
-    (0x39, 0x83, 0xa5, 0x98), // Light Blue
-    (0x3A, 0xB8, 0xBB, 0x26), // Light Green
-    (0x3B, 0x8E, 0xC0, 0x7C), // Light Cyan
-    (0x3C, 0xFB, 0x49, 0x34), // Light Red
-    (0x3D, 0xD3, 0x86, 0x9B), // Pink (Light Magenta)
-    (0x3E, 0xFA, 0xBD, 0x2F), // Yellow (Light Yellow)
-    (0x3F, 0xFB, 0xF1, 0xF7), // White
-];
+pub fn set_palette(palette: Palette) {
+    interrupts::without_interrupts(|| {
+        WRITER.lock().set_palette(palette)
+    })
+}
+
+pub struct Palette {
+    pub colors: [(u8, u8, u8, u8); 16]
+}
 
 pub fn init() {
     let mut isr: Port<u8> = Port::new(0x03DA); // Input Status Register
@@ -445,17 +474,4 @@ pub fn init() {
         let value = adrr.read(); // Read attribute mode control register
         aadr.write(value & !0x08); // Use `value | 0x08` to enable and `value ^ 0x08` to toggle
     }
-
-
-    // Load color palette
-    let mut addr: Port<u8> = Port::new(0x03C8); // Address Write Mode Register
-    let mut data: Port<u8> = Port::new(0x03C9); // Data Register
-    for (i, r, g, b) in &PALETTE {
-        unsafe {
-            addr.write(*i);
-            data.write(*r >> 2); // Convert 8-bit color to 6-bit color
-            data.write(*g >> 2);
-            data.write(*b >> 2);
-        }
-    }
 }

src/user/install.rs

@@ -41,6 +41,7 @@ pub fn main(_args: &[&str]) -> user::shell::ExitCode {
         copy_file("/ini/boot.sh", include_bytes!("../../dsk/ini/boot.sh"));
         copy_file("/ini/banner.txt", include_bytes!("../../dsk/ini/banner.txt"));
         copy_file("/ini/version.txt", include_bytes!("../../dsk/ini/version.txt"));
+        copy_file("/ini/palette.csv", include_bytes!("../../dsk/ini/palette.csv"));
         copy_file("/tmp/alice.txt", include_bytes!("../../dsk/tmp/alice.txt"));
 
         create_dir("/ini/fonts");

src/user/vga.rs

@@ -1,5 +1,7 @@
 use crate::{kernel, print, user};
+use crate::kernel::vga::Palette;
 use alloc::vec::Vec;
+use core::convert::TryInto;
 
 pub fn main(args: &[&str]) -> user::shell::ExitCode {
     if args.len() == 1 {
@@ -21,6 +23,29 @@ pub fn main(args: &[&str]) -> user::shell::ExitCode {
                         return user::shell::ExitCode::CommandError;
                     }
                 }
+            } else if args.len() == 4 && args[2] == "palette" {
+                if let Some(file) = kernel::fs::File::open(args[3]) {
+                    let mut colors = Vec::with_capacity(16);
+                    for line in file.read_to_string().split("\n") {
+                        let line = line.split("#").next().unwrap();
+                        let color: Vec<u8> = line.split(",").filter_map(|value| {
+                            let radix = if value.contains("0x") { 16 } else { 10 };
+                            let value = value.trim().trim_start_matches("0x");
+                            u8::from_str_radix(value, radix).ok()
+                        }).collect();
+                        if color.len() == 4 {
+                            colors.push((color[0], color[1], color[2], color[3]));
+                        }
+                    }
+                    if let Ok(colors) = colors.try_into() {
+                        let palette = Palette { colors };
+                        kernel::vga::set_palette(palette);
+                    } else {
+                        print!("Could not parse palette file\n");
+                        return user::shell::ExitCode::CommandError;
+                    }
+                }
+
             } else {
                 print!("Invalid command\n");
                 return user::shell::ExitCode::CommandError;