@"Memory Management"
@(parent := kernel_feature)
def memory_subsystem():
    """ Config the memory subsystem """

    @"Physical Memory"
    def physical_mm():
        """ Physical memory manager  """

        @flag
        def pmalloc_method_simple() -> bool:
            return pmalloc_method.val == "simple"
        
        @flag
        def pmalloc_method_buddy() -> bool:
            return pmalloc_method.val == "buddy"
        
        @flag
        def pmalloc_method_ncontig() -> bool:
            return pmalloc_method.val == "ncontig"

        @"Allocation policy"
        def pmalloc_method() -> "simple" | "buddy" | "ncontig":
            """ Allocation policy for phiscal memory  """
            
            return "simple"

        @"PMalloc Thresholds"
        def pmalloc_simple_po_thresholds():

            require(pmalloc_method_simple)
            
            @"Maximum cached order-0 free pages"
            def pmalloc_simple_max_po0() -> int:
                """ free list capacity for order-0 pages  """
                
                return 4096

            @"Maximum cached order-1 free pages"
            def pmalloc_simple_max_po1() -> int:
                """ free list capacity for order-1 pages  """

                return 2048
            
            @"Maximum cached order-2 free pages"
            def pmalloc_simple_max_po2() -> int:
                """ free list capacity for order-2 pages  """

                return 2048
            
            @"Maximum cached order-3 free pages"
            def pmalloc_simple_max_po3() -> int:
                """ free list capacity for order-3 pages  """
                
                return 2048
            
            @"Maximum cached order-4 free pages"
            def pmalloc_simple_max_po4() -> int:
                """ free list capacity for order-4 pages  """

                return 512
            
            @"Maximum cached order-5 free pages"
            def pmalloc_simple_max_po5() -> int:
                """ free list capacity for order-5 pages  """

                return 512
            
            @"Maximum cached order-6 free pages"
            def pmalloc_simple_max_po6() -> int:
                """ free list capacity for order-6 pages  """

                return 128
            
            @"Maximum cached order-7 free pages"
            def pmalloc_simple_max_po7() -> int:
                """ free list capacity for order-7 pages  """

                return 128
            
            @"Maximum cached order-8 free pages"
            def pmalloc_simple_max_po8() -> int:
                """ free list capacity for order-8 pages  """

                return 64
            
            @"Maximum cached order-9 free pages"
            def pmalloc_simple_max_po9() -> int:
                """ free list capacity for order-9 pages  """

                return 32