If you wish to access root on Tessel 2 and explore its Linux filesystem, you have a few options.
The simplest option is t2 root, which gives SSH access to a Tessel 2 you are authorized with.
However, while you're building tools for Tessel, you may need to access Tessel in ways not exposed by the CLI. Here are two options:
If you can connect to your Tessel 2 over LAN, SSH or t2 root are your best options.
Make sure your Tessel is online. Check that it shows up on LAN with t2 list.
Run t2 provision to authorize your computer with your Tessel.
Use the command ssh root@<tesselname>.local -i ~/.tessel/id_rsa.
The -i command lets you specify the filepath to the RSA keys written by t2 provision.
When you need out, type exit.
Dterm lets you talk to Tessel over USB.
Unfortunately, dterm isn't supported on El Capitan and later. You may be able to use screen instead.
Install dterm with brew install dterm.
Figure out what USB port your Tessel is plugged into by typing ls /dev/tty.usbmodem – see whether it auto-completes to e.g. /dev/tty.usbmodem1412 or a different number.
Download and build dterm from http://www.knossos.net.nz/resources/free-software/dterm/, or use screen, which comes with most Linux distros.
The path to the serial port is /dev/ttyACM0 or /dev/serial/by-id/usb-Technical_Machine_Tessel_2_<serial number>-if01 - find out by typing ls for those locations.
Not sure, sorry... if you know how to access serial on Windows, please PR.
Run dterm /dev/tty.usbmodem1412 (or a different port number).
You will have to press enter twice.
If you're going to do this a lot, it might be a good idea to alias the command: alias v2="dterm /dev/tty.usbmodem1412".
If you need your ip address (for example if you'd like to ssh in next time), you can run ifconfig to get it.
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