Add up/down cursor support to PS/2 driver

Author: Ian Seyler

src/drivers/ps2.asm

@@ -109,6 +109,10 @@ ps2_keyboard_interrupt:
 	in al, PS2_DATA			; Get the scan code from the keyboard
 	cmp al, 0x01
 	je keyboard_escape
+	cmp al, 0x48
+	je keyboard_up
+	cmp al, 0x50
+	je keyboard_down
 	cmp al, 0x4B
 	je keyboard_left
 	cmp al, 0x4D
@@ -160,6 +164,14 @@ keyboard_right:
 	mov byte [key], 0x02
 	jmp keyboard_done
 
+keyboard_up:
+	mov byte [key], 0x04
+	jmp keyboard_done
+
+keyboard_down:
+	mov byte [key], 0x05
+	jmp keyboard_done
+
 keyboard_control:
 	mov byte [key_control], 0x01
 	jmp keyboard_done