rem: mmu_allocate(void *, size_t size)
add: mmu_allocate(void *virtualAddress, size_t size)
context: mmu_allocate(void */*virtualAddress*/, size_t size){	size = (size + B_PAGE_SIZE - 1) / B_PAGE_SIZE;		// get number of pages to map	void *address = (void *)sNextVirtualAddress;	for (uint32 i = 0; i < size; i++) {		map_page(get_next_virtual_page(), get_next_physical_page(), kDefaultPageFlags);	}	return address;}