Something

void update_cursor()

{
if (u == 0)
{
asm("push %ax\n\t"
"push %bx\n\t"
"push %dx\n\t"
"mov $2, %ah\n\t"
"mov $0, %bh\n\t"
"mov $0, %dh\n\t"
"mov $0, %dl\n\t"
"int $0x10\n\t"
"pop %ax\n\t"
"pop %bx\n\t"
"pop %dx");
u++;
}
}