Casting from rman_res_t to a pointer results in "cast to pointer from integer of different size" warnings with base gcc on i386, so use an intermediate cast to uintptr_t to suppress it. In this case, the I/O port range is effectively limited to the range of 0..65535. Reviewed by: imp MFC after: 3 days Differential Revision: https://reviews.freebsd.org/D15746