WIP keyboard driver

assembly/bios/driver_keyboard.asm

@@ -0,0 +1,30 @@
+; Keyboard driver
+; @author Daniele Verducci
+;
+; Requires declaration of following pointers, one for every column of the keys grid:
+; KEYB_A0_REG
+; KEYB_A1_REG
+; KEYB_A2_REG
+; KEYB_A3_REG
+; KEYB_A4_REG
+; These address must be exclusive if a decoder is not present.
+;
+; Example (no decoder):
+; KEYB_A0_REG = 0000001
+; KEYB_A1_REG = 0000010
+; KEYB_A2_REG = 0000100
+; KEYB_A3_REG = 0001000
+; etc...
+;
+; Example (with decoder):
+; KEYB_A0_REG = 0000000
+; KEYB_A1_REG = 0000001
+; KEYB_A2_REG = 0000010
+; KEYB_A3_REG = 0000011
+; etc...
+
+
+; Reads the keyboard
+; @return: a 0-terminated array of keycodes representing the pressed keys
+Keyb_read:
+    in (KEYB_A0_REG),a