Name
rio_add_outb_message — 
     Add RIO message to an outbound mailbox queue
 
Arguments
- mport
- 
     RIO master port containing the outbound queue
     
- rdev
- 
     RIO device the message is be sent to
     
- mbox
- 
     The outbound mailbox queue
     
- buffer
- 
     Pointer to the message buffer
     
- len
- 
     Length of the message buffer
     
Description
   Adds a RIO message buffer to an outbound mailbox queue for
   transmission. Returns 0 on success.