screen: implement cursorhome terminal command

Makefile

@@ -58,6 +58,9 @@ iso:
 test-cdrom:
 	qemu-system-i386 -cdrom boot.iso -m 4096M -d int
 
+cdrom:
+	qemu-system-i386 -cdrom boot.iso -m 4096M
+
 debug-cdrom:
 	qemu-system-i386 -s -S -cdrom boot.iso -m 4096M -monitor stdio
 

src/drivers/screen.c

@@ -7,6 +7,12 @@ static size_t terminal_column;
 static uint8_t terminal_color;
 static uint16_t* terminal_buffer;
 
+static enum {
+	STATE_NORMAL,
+	STATE_ESCAPE,
+	STATE_BRACKET,
+} terminal_state = STATE_NORMAL;
+
 inline uint8_t vga_entry_color(enum vga_color fg, enum vga_color bg) 
 {
         return fg | bg << 4;
@@ -66,24 +72,43 @@ void terminal_scroll(void)
 
 void terminal_putchar(char c)
 {
-	if(c != '\n')
+	if (terminal_state == STATE_ESCAPE) {
+		if (c == '[') {
+			terminal_state = STATE_BRACKET;
+		} else {
+			terminal_state = STATE_NORMAL;
+		}
+		return;
+	} else if (terminal_state == STATE_BRACKET) {
+		if (c == 'H') {
+			terminal_row = 0;
+			terminal_column = 0;
+		}
+		terminal_state = STATE_NORMAL;
+		return;
+	}
+
+	if (c == '\033') {//ESC
+		terminal_state = STATE_ESCAPE;
+		return;
+	}
+
+	if (c == '\n') {
+		terminal_column = 0;
+		terminal_row++;
+	} else {
 		terminal_putentryat(c, terminal_color, terminal_column, terminal_row);
-
-	if (++terminal_column >= VGA_WIDTH){
-                terminal_column = 0;
-        	if (++terminal_row >= VGA_HEIGHT)
-                	terminal_scroll();
-	}
-	if(terminal_row >= VGA_HEIGHT){
-		terminal_scroll();
+		terminal_column++;
 	}
 
-	if(c == '\n')
-	{
+	if (terminal_column > VGA_WIDTH) {
 		terminal_column = 0;
 		terminal_row++;
 	}
 
+	if (terminal_row >= VGA_HEIGHT) {
+		terminal_scroll();
+	}
 }
 
 void terminal_write(const char* data, size_t size) 

src/utils/stdio.c

@@ -4,21 +4,15 @@
 #include <stddef.h>
 #include "../include/string.h"
 
-#ifdef __is_katauos
 #include "../include/screen.h"
-#endif
 
 int puts(const char* string) {
 	return printf("%s\n", string);
 }
 
 int putchar(int ic) {
-#if defined(__is_katauos)
 	char c = (char) ic;
 	terminal_write(&c, sizeof(c));
-#else
-	// TODO: Implement stdio and the write system call.
-#endif
 	return ic;
 }