'Map a number of pages at address `addr` with permissions `permissions`.
:param addr: address to map the pages at
:param length: length in bytes of region to map, will be rounded upwards to the page size
:param permissions: AST of permissions to map, will be a bitvalue representing flags'

def map_region(self, addr, length, permissions, init_zero=False):

    return self.mem.map_region(addr, length, permissions, init_zero=init_zero)
