From 1816cefb47bb4575af2a01c6b1c11fff02780ac1 Mon Sep 17 00:00:00 2001
From: Arnau478 <arnauxabia@gmail.com>
Date: Fri, 17 Jun 2022 12:47:57 +0200
Subject: [PATCH]  VGA set_cursor() and get_cursor()

---
 src/kernel/drivers/vga.c | 16 ++++++++++++++++
 src/kernel/drivers/vga.h |  5 +++++
 src/kernel/main.c        |  1 +
 3 files changed, 22 insertions(+)

diff --git a/src/kernel/drivers/vga.c b/src/kernel/drivers/vga.c
index 2ed09f0..9046610 100644
--- a/src/kernel/drivers/vga.c
+++ b/src/kernel/drivers/vga.c
@@ -1,4 +1,5 @@
 #include "vga.h"
+#include "../arch/i686/io.h"
 
 void set_char(int x, int y, char c){
     VGA_MEMORY[(x+y*VGA_WIDTH)*2] = c;
@@ -7,3 +8,18 @@ void set_char(int x, int y, char c){
 void set_color(int x, int y, uint8_t color){
     VGA_MEMORY[(x+y*VGA_WIDTH)*2+1] = color;
 }
+
+void set_cursor(int offset){
+    i686_outb(VGA_PORT_CTRL, 14);
+    i686_outb(VGA_PORT_DATA, (uint8_t)(offset >> 8));
+    i686_outb(VGA_PORT_CTRL, 15);
+    i686_outb(VGA_PORT_DATA, (uint8_t)(offset & 0xff));
+}
+
+int get_cursor(){
+    i686_outb(VGA_PORT_CTRL, 14);
+    int offset = i686_inb(VGA_PORT_DATA) << 8; // High byte
+    i686_outb(VGA_PORT_CTRL, 15);
+    offset += i686_inb(VGA_PORT_DATA); // Low byte
+    return offset;
+}
diff --git a/src/kernel/drivers/vga.h b/src/kernel/drivers/vga.h
index 212ad6b..3fdecde 100644
--- a/src/kernel/drivers/vga.h
+++ b/src/kernel/drivers/vga.h
@@ -41,5 +41,10 @@
 #define VGA_WIDTH 80
 #define VGA_HEIGHT 25
 
+#define VGA_PORT_CTRL 0x3D4
+#define VGA_PORT_DATA 0x3D5
+
 void set_char(int x, int y, char c);
 void set_color(int x, int y, uint8_t color);
+void set_cursor(int offset);
+int get_cursor();
diff --git a/src/kernel/main.c b/src/kernel/main.c
index 92b2867..6c3af3a 100644
--- a/src/kernel/main.c
+++ b/src/kernel/main.c
@@ -5,5 +5,6 @@ void __attribute__((cdecl)) kmain(uint64_t magic, uint64_t addr){
     // Print a light cyan 'X' over green on the top left corner
     set_char(0, 0, 'X');
     set_color(0, 0, VGA_COLOR_BG_GREEN | VGA_COLOR_FG_LIGHT_CYAN);
+    set_cursor(1);
     for(;;); // Halt here 
 }