From 146a06f0e6d505d683fc67d9bffdddd5ba1e1aee Mon Sep 17 00:00:00 2001
From: Mathieu Maret <mathieu.maret@gmail.com>
Date: Wed, 14 Nov 2018 18:03:11 +0100
Subject: [PATCH] wip: add blinking cursor

---
 core/main.c   |  1 +
 drivers/vga.c | 48 ++++++++++++++++++++++++++++++++++--------------
 drivers/vga.h |  3 +++
 3 files changed, 38 insertions(+), 14 deletions(-)

diff --git a/core/main.c b/core/main.c
index 026481e..2ade256 100644
--- a/core/main.c
+++ b/core/main.c
@@ -29,6 +29,7 @@ void kmain(unsigned long magic, unsigned long addr)
 {
     unsigned long upper_mem = 0;
     VGASetup(BLACK, GREEN);
+    cursorEnable(14, 15);
 
     printf("Setting up Interruptions\n");
     gdtSetup();
diff --git a/drivers/vga.c b/drivers/vga.c
index 4043f38..5a0e91a 100644
--- a/drivers/vga.c
+++ b/drivers/vga.c
@@ -34,7 +34,7 @@ void printInt(int integer)
 	if (integer < 0) {
 		printChar('-');
 	}
-	if (integer == 0){
+	if (integer == 0) {
 		num[i++] = 0;
 	}
 	while (integer != 0) {
@@ -57,7 +57,7 @@ void printIntDetails(int integer, uint color, uint bgColor, int startX, int star
 	if (integer < 0) {
 		printCharDetails('-', color, bgColor, x++, startY);
 	}
-	if (integer == 0){
+	if (integer == 0) {
 		num[i++] = 0;
 	}
 	while (integer != 0) {
@@ -111,7 +111,7 @@ void vprintf(const char *format, va_list ap)
 					}
 					case 's': {
 						char *str = va_arg(ap, char *);
-						if(!str)
+						if (!str)
 							str = "[NULL STR]";
 						printString(str);
 						break;
@@ -130,14 +130,14 @@ void vprintf(const char *format, va_list ap)
 	}
 }
 
-void printf(const char *format, ...){
+void printf(const char *format, ...)
+{
 	va_list ap;
 	va_start(ap, format);
 	vprintf(format, ap);
 	va_end(ap);
 }
 
-
 void printString(const char *str)
 {
 	while (*str) {
@@ -154,22 +154,16 @@ void printChar(const char str)
 			vgaScrollUp();
 			line--;
 		}
-	}
-	else if(str == '\r')
-	{
+	} else if (str == '\r') {
 		col = 0;
-	}
-	else if(str == '\b')
-	{
+	} else if (str == '\b') {
 		col--;
 		if (col < 0) {
 			col = VGA_WIDTH - 1;
 			line--;
 		}
 		printCharDetails(' ', vgaColor, vgaBgColor, col, line);
-	}
-	else
-	{
+	} else {
 		printCharDetails(str, vgaColor, vgaBgColor, col++, line);
 		if (col == VGA_WIDTH) {
 			col = 0;
@@ -180,6 +174,7 @@ void printChar(const char str)
 			line--;
 		}
 	}
+	cursorMove(col - 1, line);
 }
 
 void printStringDetails(const char *str, uint color, uint bgColor, int startX, int startY)
@@ -193,3 +188,28 @@ void printStringDetails(const char *str, uint color, uint bgColor, int startX, i
 		i++;
 	}
 }
+
+void cursorEnable(uint8_t cursor_start, uint8_t cursor_end)
+{
+	outb(0x3D4, 0x0A);
+	outb(0x3D5, (inb(0x3D5) & 0xC0) | cursor_start);
+
+	outb(0x3D4, 0x0B);
+	outb(0x3D5, (inb(0x3D5) & 0xE0) | cursor_end);
+}
+
+void cursorDisable(void)
+{
+	outb(0x3D4, 0x0A);
+	outb(0x3D5, 0x20);
+}
+
+void cursorMove(int x, int y)
+{
+	uint16_t pos = y * VGA_WIDTH + x;
+
+	outb(0x3D4, 0x0F);
+	outb(0x3D5, (uint8_t)(pos & 0xFF));
+	outb(0x3D4, 0x0E);
+	outb(0x3D5, (uint8_t)((pos >> 8) & 0xFF));
+}
diff --git a/drivers/vga.h b/drivers/vga.h
index e21969d..19d676e 100644
--- a/drivers/vga.h
+++ b/drivers/vga.h
@@ -27,3 +27,6 @@ void printStringDetails(const char *str, uint color, uint bgColor, int startX, i
 void printString(const char *str);
 void printChar(const char str);
 void vgaScrollUp(void);
+void cursorEnable(uint8_t cursor_start, uint8_t cursor_end);
+void cursorDisable(void);
+void cursorMove(int x, int y);