pcduino3 network issues

Trying to get a stable network on pcduino3 nano, but I'm experiencing many issues.
Short question: which parameters would result in a working solution?

My setup: I've built a 11.0 kernel with KERNCONF=PCDUINO3 where conffile (/usr/src/sys/arm/conf/PCDUINO3 is a copy of ALLWINNER except for a line
makeoptions     FDT_DTS_FILE=pcduino3nano.dts
and /boot/dtb/pcduino3nano.dtb is constructed from /usr/src/sys/gnu/dts/arm/sun7i-a20-pcduino3-nano.dts
For network tests I've connected pcduino's rj45 with a cross-cable directly into another systems network interface (test end).

- 1000baseTX does not work - link is established but no packets are either sent or received by the pcduino (tested with tcpdump on both systems); however yellow tx/rx led does flash on pcduino both for send and recieve.
- 100basetx can only brought into working mode if pcduino is set with ifconfig dwc0 media auto and test host is forced into 100basetx half-duplex and then disconnect/reconnect the cable to have the pcduino do an autodetect.
- 10baseT mode always looses network traffic (~15%)
- 100basetx mode cannot be set into full duplex. ifconfig dwc0 media 100basetx mediaopt full-duplex results in:
ifconfig dwc0
        media: Ethernet 100baseTX <full-duplex> (100baseTX <half-duplex>)
if the test end is in full-duplex, or
ifconfig dwc0
        media: Ethernet 100baseTX <full-duplex>
if the test end is in testend# ifconfig bge0 media auto but then there is massive packet loss.
- In the 100basetx half-duplex mode that seems to, almost, work a test setup with spray towards the pcduino start dropping packets when more then ~400 packets are sent. But strangely, from time to time io seems to stall for ~15 seconds.

Any suggestions are appreciated.