SceSblSsSmComm

SceSblSsSmComm is a kernel module that is primary responsible for sending F00D commands.

sceSblSmCommStartSm2
Priority is binary: 1 = low, 0 = high. Running a high priority SM module while a low priority one is currently running will suspend it.

sceSblSmCommCallFunc
sm_comm_context is described more here

f00d_resp comes from Request Buffer from offset 0x08

gc_param is generated by game card and has value 0x01