diff options
| -rw-r--r-- | kernel/src/terminal.rs | 33 | 
1 files changed, 15 insertions, 18 deletions
diff --git a/kernel/src/terminal.rs b/kernel/src/terminal.rs index d532ccc..c64188c 100644 --- a/kernel/src/terminal.rs +++ b/kernel/src/terminal.rs @@ -3,13 +3,13 @@ use compiler_builtins::mem::memcpy;  const VGA_BUFFER_POINTER: *mut u8 = 0xb8000 as *mut u8;  const VGA_BUFFER_SIZE: u16 = 4000; -const ROW_COUNT: u8 = 25; -const COL_COUNT: u8 = 80; -const VALUE_SIZE: u8 = 2; +const ROW_COUNT: u16 = 25; +const COL_COUNT: u16 = 80; +const VALUE_SIZE: u16 = 2;  pub(crate) struct Terminal { -    current_row: u8, -    current_col: u8, +    current_row: u16, +    current_col: u16,  }  impl Terminal { @@ -39,11 +39,10 @@ impl Terminal {              return;          } -        /// Safety: This is safe because VGA_BUFFER_POINTER points toward the VGA character buffer +        // Safety: This is safe because VGA_BUFFER_POINTER points toward the VGA character buffer          unsafe {              *VGA_BUFFER_POINTER.offset( -                ((self.current_col as isize + self.current_row as isize * COL_COUNT as isize) -                    * VALUE_SIZE as isize), +                ((self.current_col + self.current_row * COL_COUNT) * VALUE_SIZE) as isize,              ) = c;          }          self.compute_current_position(); @@ -68,25 +67,23 @@ impl Terminal {          // The end pointer isn't past the VGA character buffer pointer          // The offset doesn't overflow isize          // The offset doesn't rely on wrapping around the address space -        let src = unsafe { VGA_BUFFER_POINTER.offset(COL_COUNT as isize * VALUE_SIZE as isize) }; +        let src = unsafe { VGA_BUFFER_POINTER.offset((COL_COUNT * VALUE_SIZE) as isize) };          let dest = VGA_BUFFER_POINTER; -        let size = (VGA_BUFFER_SIZE as usize - COL_COUNT as usize) * VALUE_SIZE as usize; +        let size = (VGA_BUFFER_SIZE - COL_COUNT) * VALUE_SIZE;          // Safety:          // dest and src are valid pointer to the same object being the VGA character buffer          // This copy will not go  past the VGA character buffer -        unsafe { memcpy(dest, src, size) }; - +        unsafe { memcpy(dest, src, size as usize) };          self.clear_line(ROW_COUNT - 1);      } -    pub fn put_char_at(&mut self, c: u8, row: u8, col: u8) { +    pub fn put_char_at(&mut self, c: u8, row: u16, col: u16) {          self.current_row = row;          self.current_col = col;          unsafe {              *VGA_BUFFER_POINTER.offset( -                (self.current_col as isize + self.current_row as isize * COL_COUNT as isize) -                    * VALUE_SIZE as isize, +                ((self.current_col + self.current_row * COL_COUNT) * VALUE_SIZE) as isize,              ) = c;          }      } @@ -99,7 +96,7 @@ impl Terminal {          self.current_row = 0;      } -    fn clear_line(&mut self, row: u8) { +    fn clear_line(&mut self, row: u16) {          for col in 0..COL_COUNT {              self.put_char_at(b' ', row, col);          } @@ -108,8 +105,8 @@ impl Terminal {          self.current_col = 0;      } -    pub fn set_cursor_position(&mut self, row: u8, col: u8) { -        let cursor_position: u16 = (row * COL_COUNT + col) as u16; +    pub fn set_cursor_position(&mut self, row: u16, col: u16) { +        let cursor_position = row * COL_COUNT + col;          let address_register = 0x3D4;          let data_register = 0x3D5;          unsafe {  | 
