Hi, sel4platsupport_new_io_ops is defined in libsel4platsupport/include/sel4platsupport/io.h , it creates a new implementation of the platsupport io_ops interface using a provided simple, vspace and vka, Here is its protocol: /* * @param simple Simple interface for getting the physical frames * @param vspace VSpace interface to use for mapping * @param vka VKA interface for allocating any extra objects or cslots * @param io_ops Interface to fill in * * @return returns 0 on success */ int sel4platsupport_new_io_ops(simple_t simple, vspace_t vspace, vka_t vka, ps_io_ops_t *io_ops); Who can give me a sample program using this function? I guess it will be used in I/O DMA program, but I don't know much about DMA program. Xilong Pei Tongji University 2015/7/1