From 58da5af56ce30e667fd4699d41e7a4a4bc18d2a3 Mon Sep 17 00:00:00 2001
From: shockrah <alejandros714@protonmail.com>
Date: Sun, 1 Dec 2019 02:31:08 -0800
Subject: [PATCH] improvement: kbd_key_read now populates a bit mask containing
 information about state

---
 kbd.c | 18 ++++++++++++++++--
 kbd.h |  8 ++++++++
 2 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/kbd.c b/kbd.c
index 94fa03b..09083c7 100644
--- a/kbd.c
+++ b/kbd.c
@@ -1,6 +1,7 @@
 // US Keyboard layout because 'Murrica
 #include "kbd.h"
 #include "ports.h"
+#include "pit.h"
 #include "serial.h"
 #include "types.h"
 #include "stlio.h"
@@ -49,10 +50,23 @@ unsigned char keymap[128] = {
 
 // Reads one key from the keyboard
 void kbd_read_key(struct cpu_reg_state* cpu) {
-	u32 scancode = serial_read_byte(KBD_PORT);
-	putch(keymap[scancode]);
+	u8 scancode = serial_read_byte(KBD_PORT);
+	if(scancode & 0x80) {
+		// Key released
+		kbd_state &= KBD_RELEASE;
+	}
+	else {
+		// Key pressed
+		kbd_key = keymap[scancode & 0x7f]; // clamp to 127 as the max val(gcc is anoying)
+		kbd_state = kbd_state & !KBD_RELEASE & KBD_PRESS;
+		kbd_time = pit_timer_ticks;
+		putch(kbd_key);
+	}
 }
 
 void kbd_install_keyboard(void) {
 	init_irq_handler(1, kbd_read_key);
+	kbd_key = '\0';
+	kbd_state = 0;
+	kbd_time = 0;
 }
diff --git a/kbd.h b/kbd.h
index 26d9fe4..b1e2039 100644
--- a/kbd.h
+++ b/kbd.h
@@ -5,6 +5,14 @@
 
 #define KBD_PORT 0x60
 
+#define KBD_PRESS 0b00000001
+#define KBD_RELEASE 0b00000010
+#define KBD_SHIFT 0b00000100
+
+char kbd_key;
+u8 kbd_state;
+u8 kbd_time;
+
 void kbd_install_keyboard(void);
 
 void kbd_read_key(struct cpu_reg_state* cpu);