In the default configuration, as shipped, USB in is peripheral mode and a “wall wart” AC adaptor can be used for power. In this mode, it is also possible to connect the development board to a workstation’s USB 3.0+ port (where VBUS can supply up to 900mA) and access a serial console.
In the latest software images, the development board acts as a multifunction composite gadget which provides both serial and networking support.
Connect the board to a workstation using the USB A to USB C cable provided. The haptic motor will sound briefly and the board should appear shortly after as a USB serial device to the workstation:
Bus 001 Device 008: ID 1d6b:0104 Linux Foundation Multifunction Composite Gadget
The bus and device numbers may differ from those shown.
The device will also appear in the
/dev/ directory as a serial port, such as
/dev/ttyACM0, which you can use to access the board’s serial console if
you have permission to read and write to that device:
picocom -b 115200 /dev/ttyACM0
This should produce the output like this:
Debian GNU/Linux buster/sid pureos-test ttyGS0 pureos-test login:
It should be possible to log in using
purism as the user name and
as the password.
Note: You may have trouble accessing the serial device if your user is not
a member of the
dialout group on your workstation. For example, you may get
an error like this:
FATAL: cannot open /dev/ttyACM0: Permission denied
In this case, you can either add your user to the
dialout group or, as a
picocom using the
Alternate Configuration - USB C Host¶
In this configuration, USB host mode is used to allow keyboard, mouse and flash memory sticks to be connected to the development board.
Note: Using the board in this mode means that you will lose access to the USB serial console, so it is important to have set up SSH access via Ethernet before following these steps.
On the target, backup the device tree and copy in the USB host version:cp /boot/dtbs/librem5-evk.dtb /boot/dtbs/librem5-evk.dtb.bak cp /boot/dtbs/librem5-evk-usbhost.dtb /boot/dtbs/librem5-evk.dtb
Attach a USB C hub to the development board.
Attach power to the USB C hub.
Plug in USB devices and they should appear in the output of the
The J5 Create JCA374 USB Type-C Multi-Adapter is known to work as a hub and power the board using USB Power Delivery.