implemented stdin methods for reading a string (async) and reading keystrokes (sync + async). added a very basic shell on top of it for debugging

libk/src/drivers/io/ascii/mod.rs

@@ -29,9 +29,6 @@ pub struct Writer {
 
     fg_color: Colour,
     bg_color: Colour,
-
-    offset1: usize,
-    offset2: usize,
 }
 
 impl Default for Writer {
@@ -54,8 +51,6 @@ impl Writer {
                 text_col: 0,
                 fg_color: Colour::White,
                 bg_color: Colour::Black,
-                offset1: 16,
-                offset2: 0,
             },
         )
     }
@@ -65,10 +60,10 @@ impl Writer {
     }
 
     /// This is sent when the user types a backspace.
-    const BACKSPACE: u16 = 8;
+    const BACKSPACE: u8 = 8;
 
-    pub fn write_glyph(&mut self, c: u16) {
-        if c == b'\n' as u16 {
+    pub fn write_glyph(&mut self, c: u8) {
+        if c == b'\n' {
             self.newline();
             return;
         } else if c == Self::BACKSPACE {
@@ -104,11 +99,6 @@ impl Writer {
         }
     }
 
-    pub const fn set_offset(&mut self, offset1: usize, offset2: usize) {
-        self.offset1 = offset1;
-        self.offset2 = offset2;
-    }
-
     pub const fn dimensions(&self) -> (u32, u32) {
         (self.screen_width, self.screen_height)
     }
@@ -133,14 +123,14 @@ impl Writer {
         if self.text_col > 0 {
             self.text_col -= 1;
             // Blank out the previous char.
-            self.write_glyph(' ' as u16);
+            self.write_glyph(b' ');
             self.text_col -= 1;
         }
     }
 
     pub fn write_string(&mut self, s: &str) {
         for c in s.chars() {
-            self.write_glyph(c as u16);
+            self.write_glyph(c as u8);
         }
     }
 
@@ -203,6 +193,14 @@ pub fn clear_screen() {
     });
 }
 
+pub fn reset_cursor() {
+    interrupts::without_interrupts(|| {
+        let mut writer = WRITER.lock();
+        writer.text_line = 0;
+        writer.text_col = 0;
+    });
+}
+
 #[macro_export]
 macro_rules! println_log {
 	() => ($crate::print_log!("\n"));