...

grub.cfg

@@ -2,3 +2,6 @@ menuentry "nub-os" {
     multiboot2 /boot/kernel
     boot
 }
+
+set default="nub-os"
+set timeout=0

src/kernel.c

@@ -2,6 +2,6 @@
 
 void kernel_main(void)
 {
-    vga_reset();
+    vga_clear();
     vga_print("Welcome to nub OS\n");
 }

src/vga.c

@@ -23,7 +23,7 @@ vga_char vga_char_at(uint8_t row, uint8_t col)
     return vga_buffer[COLUMNS * row + col];
 }
 
-void vga_reset(void)
+void vga_clear(void)
 {
     for (uint8_t row = 0; row < ROWS; row++)
     {
@@ -83,7 +83,7 @@ void vga_print_char(char character, vga_color_t color)
         {
             for (uint8_t col = 0; col < COLUMNS; col++)
             {
-                vga_set_char(row, col, vga_char_at(row - 1, col));
+                vga_set_char(row - 1, col, vga_char_at(row, col));
             }
         }
 

src/vga.h

@@ -21,7 +21,7 @@
 
 typedef uint8_t vga_color_t;
 
-void vga_reset(void);
+void vga_clear(void);
 void vga_set_cursor_position(uint8_t row, uint8_t col);
 
 void vga_print_colored(const char* string, vga_color_t color);