FBNIC_RCD_AL_BUFF_FRAG_MASK
(FBNIC_RCD_AL_BUFF_ID_MASK & ~FBNIC_RCD_AL_BUFF_FRAG_MASK)
pg_off += (FBNIC_RCD_AL_BUFF_FRAG_MASK & rcd) *
hdr_pg_start += (FBNIC_RCD_AL_BUFF_FRAG_MASK & rcd) *