rem: int kprintf_xy(int x, int y, const char *fmt, ...)
add: kprintf_xy(int x, int y, const char *fmt, ...)
context: int kprintf_xy(int x, int y, const char *fmt, ...){	int ret = 0;	va_list args;	struct console_op_xy_struct buf;	if(console_fd >= 0) {		va_start(args, fmt);		ret = vsprintf(buf.buf,fmt,args);		va_end(args);			buf.x = x;		buf.y = y;		sys_ioctl(console_fd, CONSOLE_OP_WRITEXY, &buf, ret + sizeof(buf.x) + sizeof(buf.y));	}	return ret;}