Using the dfu-programmer with MCUZone UC3B-CPU board

Finally I got dfu-programmer working:

$ sudo dfu-programmer at32uc3b0256 get
Bootloader Version: 0x02 (2)

$ sudo dfu-programmer at32uc3b0256 erase

$ sudo dfu-programmer at32uc3b0256 getfuse
Locked regions: 0xffff (65535)

I flashed my nuttx.hex this way:

sudo dfu-programmer at32uc3b0256 flash nuttx.hex

I can start the program running dfu-programmer start:

$ sudo dfu-programmer at32uc3b0256 start

Thanks Raman Gopalan for help!
Also this post helped me a lot: https://hofmeyr.de/avr32%20hello%20world/