From 20dd72e40dc2728d3c5335d860e4b8ab8da14fcc Mon Sep 17 00:00:00 2001
From: Aleksa Vučković <aleksav013@gmail.com>
Date: Mon, 25 Oct 2021 00:36:33 +0200
Subject: Changing build system to recursive make

---
 src/c/keyboard.c | 110 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 110 insertions(+)
 create mode 100644 src/c/keyboard.c

(limited to 'src/c/keyboard.c')

diff --git a/src/c/keyboard.c b/src/c/keyboard.c
new file mode 100644
index 0000000..548cdda
--- /dev/null
+++ b/src/c/keyboard.c
@@ -0,0 +1,110 @@
+#include"../include/types.h"
+#include"../include/asm.h"
+#include"../include/stdio.h"
+
+#define BUFFER_SIZE 200
+char buffer[BUFFER_SIZE];
+size_t buffer_index=0;
+
+#define PIC1_COMMAND_PORT 0x20
+#define PIC1_DATA_PORT 0x21
+#define PIC2_COMMAND_PORT 0xA0
+#define PIC2_DATA_PORT 0xA1
+// IO Ports for Keyboard
+#define KEYBOARD_DATA_PORT 0x60
+#define KEYBOARD_STATUS_PORT 0x64
+
+void previous_field(void);
+void terminal_putchar(char c);
+void tty(char *buffer);
+void prompt(void);
+void clear();
+void us_en(char keymap[]);
+
+char charcode[256];
+bool ispressed[128];
+
+void init_keyboard()
+{
+    // 0xFD = 1111 1101 in binary. enables only IRQ1
+    // Why IRQ1? Remember, IRQ0 exists, it's 0-based
+    ioport_out(PIC1_DATA_PORT, 0xFD);
+    us_en(charcode);
+}
+
+void backspace()
+{
+    if(buffer_index<=0) return;
+
+    previous_field();
+    printf(" ");
+    previous_field();
+    buffer[--buffer_index]='\0';
+    return;
+}
+
+void enter()
+{
+    printf("\n");
+    if(buffer_index>0)
+    {
+	tty(buffer);
+	for(int i=0;i<BUFFER_SIZE;i++) buffer[i]='\0';
+	buffer_index=0;
+    }
+    prompt();
+    return;
+}
+
+void space()
+{
+    buffer[buffer_index++]=' ';
+    printf(" ");
+}
+#define lshift ispressed[0x2A]
+#define lctrl ispressed[0x1D]
+
+void handle_keyboard_interrupt()
+{
+    ioport_out(PIC1_COMMAND_PORT, 0x20);
+    uint8_t status = ioport_in(KEYBOARD_STATUS_PORT);
+
+    if (status & 0x1)
+    {
+	uint8_t keycode = ioport_in(KEYBOARD_DATA_PORT);
+	if(keycode<0x80)
+	{
+	    ispressed[keycode]=1;
+	    if(keycode==0x0E) backspace();
+	    else if(keycode==0x1C) enter();
+	    else if(keycode==0x39) space();
+	    else
+	    {
+		char c=charcode[keycode];
+		if(c!=' ')
+		{
+		    if(lshift)
+		    {
+			if(c>='a'&&c<='z') c-=32;
+		    }
+		    if(lctrl)
+		    {
+			if(c=='l')
+			{
+			    clear();
+			    prompt();
+			    return;
+			}
+		    }
+		    buffer[buffer_index++]=c;
+		    printf("%c",c);
+		}
+	    }
+	}
+	else
+	{
+	    ispressed[keycode-0x80]=0;
+	}
+
+    }
+}
-- 
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