Board are shipped with serial bootlaoder for AVR109 protocol. This makes it possible to upgrade and reflash firmware via the TTL-USB cable. When RESET button is pushed bootloader waits for 3 Sec for programming commands. The red LED is lit while waiting in bootloader. After wait firmware is booted. BAUD is 38400. avrdude program can be used to flash the firmware. The Unix example below flashes beta-2.6.hex having the mote on /dev/ttyUSB0 avrdude -p m128rfa1 -c avr109 -P /dev/ttyUSB0 -b 38400 -e -U flash:w:beta-2.6.hex Use your appropriate USB-device. Note! If you program the board with ISP-programmer the bootloader will be overwritten and MCU Fuses might be inconsistent. FYI. For the custom firmware the upgrade-sm.sh script can be used to avoid the manual RESET of the MCU. Bifrost/Linux has a x86-package for avrdude. That should run on most x86 linuxes. http://ftp.sunet.se/pub/os/Linux/distributions/bifrost/download/opt/