Overview

This program will allow you to dump the flash chip on a goTenna connected to your computer. The flash contains the firmware, diagnostic log, configuration, and message queue.

Requires Python 2.7.5+ and pyserial 2. Tested on Fedora 20, and will likely work fine on most any Linux distribution.

Tested against goTenna firmware 00.18.02, 00.21.04, and 0.23.2. All firmware versions work great.

Connect your goTenna

Connect your goTenna to your computer over USB and extend the antenna to turn it on. It will expose a USB serial port. Figure out what serial device it's exposing on your computer.

[jhe@oxcart ~]$ dmesg | grep goTenna -a5
[43446.128944] usb 2-2.1: new full-speed USB device number 20 using uhci_hcd
[43446.234635] usb 2-2.1: New USB device found, idVendor=1fc9, idProduct=2047
[43446.234643] usb 2-2.1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[43446.234647] usb 2-2.1: Product: goTenna
[43446.234656] usb 2-2.1: Manufacturer: goTenna, Inc
[43446.234659] usb 2-2.1: SerialNumber: 123456789ABCDEF
[43446.242217] cdc_acm 2-2.1:1.0: ttyACM0: USB ACM device

Dump the flash

Use the dump-gotenna-flash program to instruct the goTenna to output the flash contents over the serial port. The program achieves this by issuing the read_eflash goTenna cli command. You'll end up with a cli session log containing the contents of the flash, along with several other diagnostic messages.

The version reported may be different than you're expecting as the version displayed in the CLI and the app differ.

[jhe@oxcart gotenna-flash-dumper]$ sudo ./dump-gotenna-flash /dev/ttyACM0 flash.log
Connected to serial port /dev/ttyACM0.
Waiting for idle on the goTenna... Please wait 5 seconds.
Found goTenna running firmware 00.15.04.
The goTenna is available and ready.  Sit back and relax, this will take a bit of time.
Dumping flash.  Do not disconnect or turn the goTenna off!
Saving: 100.00%
Flash read in 0:21:59.210511.

Convert the flash log to a binary

Next, use the flash-log-to-binary program to parse the flash log and output a binary flash file which can then be inspected and/or disassembled.

[jhe@oxcart gotenna-flash-dumper]$ ./flash-log-to-binary flash.log flash.bin 

Break the flash dump into individual blocks

The block-exploder utility can be used to separate the monolithic flash dump in to individual blocks. Useful for looking at one block at a time in a hex editor.

[jhe@oxcart gotenna-flash-dumper]$ mkdir blocks
[jhe@oxcart gotenna-flash-dumper]$ ./block-exploder --skip-empty flash.bin blocks 
[jhe@oxcart gotenna-flash-dumper]$ ls blocks
000.bin  029.bin  058.bin  131.bin  161.bin  227.bin  256.bin  285.bin  314.bin
001.bin  030.bin  059.bin  133.bin  162.bin  228.bin  257.bin  286.bin  315.bin
002.bin  031.bin  060.bin  134.bin  163.bin  229.bin  258.bin  287.bin  316.bin
003.bin  032.bin  061.bin  135.bin  164.bin  230.bin  259.bin  288.bin  317.bin
004.bin  033.bin  062.bin  136.bin  165.bin  231.bin  260.bin  289.bin  318.bin
...