Memory must be registered with ERNIC hardware before it is exchanged with remote hosts for doing the RDMA operations (incoming RDMA READ and incoming RDMA WRITE). The following steps are important to register a memory with ERNIC:
1. Allocate physical memory and create a virtual address mapping to it.
2. Create a protection domain number and write to PDPDNUM register at a free slot in the MR table.
3. Write the virtual address of the memory region in VIRTADDRLSB and VIRTADDRMSB registers at the same slot in PD table.
4. Write the physical address of the memory region to BUFBASEADDRLSB and BUFBASEADDRMSB registers.
5. Create an R_KEY and configure it to BUFFERKEY register.
6. Write memory region length to WRRDBUFLEN register and access permission (REMOTE READ or WRITE) to ACCESSDESC registers.