screen: implement cursor positioning

include/screen.h

@@ -39,5 +39,6 @@ void terminal_putentryat(char c, uint8_t color, size_t x, size_t y);
 void terminal_putchar(char c);
 void terminal_write(const char* data, size_t size);
 void terminal_writestring(const char* data);
+void update_cursor(int x, int y);
 
 #endif

src/drivers/screen.c

@@ -1,6 +1,7 @@
 // screen.c
 #include "../include/screen.h"
 #include "../include/string.h"
+#include "../include/utils.h"
 
 static size_t terminal_row;
 static size_t terminal_column;
@@ -83,6 +84,7 @@ void terminal_putchar(char c)
 		if (c == 'H') {
 			terminal_row = 0;
 			terminal_column = 0;
+			update_cursor(0, 0);
 		}
 		terminal_state = STATE_NORMAL;
 		return;
@@ -109,6 +111,7 @@ void terminal_putchar(char c)
 	if (terminal_row >= VGA_HEIGHT) {
 		terminal_scroll();
 	}
+	update_cursor(terminal_column, terminal_row);
 }
 
 void terminal_write(const char* data, size_t size) 
@@ -121,3 +124,13 @@ void terminal_writestring(const char* data)
 {
         terminal_write(data, strlen(data));
 }
+
+void update_cursor(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));
+}