chiprx
- while (package = call dma_rx with dma[0] is not NULL)
- if GRXF_OVF bit is set in the flags of the frame header
- continue
- if it is no multicast frame or a multicast frame we want
- return package
- free package
- if GRXF_OVF bit is set in the flags of the frame header
- unset I_RI bit in sw intstatus
- call dma_rxfill with dma[0]
- return NULL