TODO:
- - fix transmit overflows
+ - Rx block size is limited to < 2048, hardware bug?
+ - Group size is limited to < page size, kernel alloc/mmap API issues
+ - fix/workaround cache issues in circular buffer header
+ - test whether Tx is transmitting data from provided buffers
+ - handle device unplug case
+ - handle temperature above threshold
+ - use bus address instead of physical address for DMA
+ - support for snapshot mode
- audit userspace interfaces
- get reserved major/minor if needed