vga-text.sats

staload "prelude/limits.sats"

absviewt@ype console = @(int, int, int, int, uint8, ptr)

abst@ype colour = int
val black: colour
val blue: colour
val green: colour
val cyan: colour
val red: colour
val magenta: colour
val brown: colour
val white: colour
val grey: colour
val bright_blue: colour
val bright_green: colour
val bright_cyan: colour
val bright_red: colour
val bright_magenta: colour
val bright_yellow: colour
val bright_white: colour

(* Initialise a text console for VRAM at 0xB8000. *)
fun init_B8000
  (con: &console? >> opt (console, success)):<> #[success: bool]
  bool success

fun finit (con: &console >> console?):<> void

fun default_colours (con: &console):<> void
fun set_colour (con: &console, fg: colour):<> void
fun set_background (con: &console, bg: colour):<> void

symintr put

fun put_char (con: &console, ch: c1har):<> void
overload put with put_char

fun put_string {len:Nat}
  (con: &console, len: int len, str: string len):<> void
overload put with put_string