Accessing the Morello console
You can manage the Morello board, including reaching its multiple serial consoles and firmware flash storage, via a USB cable connected to a second computer -- typically a workstation or remote management server. When you plug the USB cable into your workstation, a number of different devices will attach (depending on device drivers on your workstation), including:
- Arm Morello USB debug and trace
- Flash storage used for firmware (an on-board SD card)
- Two 4-port USB-to-serial converters
Each controller has a unique serial number ending in the letter "A" or B". The serial-port converters attach to UARTs associated with:
- The MCC management microcontroller (converter B port 0)
- The PCC management microcontroller (converter B port 1)
- The Morello system console (converter B port 2)
In normal use, only the MCC and Morello system console ports will be used.
You can connect to these using a serial access tool such as cu(1), or a full
terminal emulation environment such as screen(1).
The precise names of the /dev device nodes appearing on the workstation
depend on the operating system being used.
Often access will also require running the terminal command under su(8) or
sudo(8), or adding your user to a dialer or similar group to grant access to
the USB device nodes.
Connecting from FreeBSD
FreeBSD names USB device nodes in the order they probe and attach. Typical command lines to access the MCC and Morello consoles are:
- MCC console:
cu -l /dev/cuaU0 -s 115200 - Morello console:
cu -l /dev/cuaU2 -s 115200
Connecting from Apple macOS
macOS creates /dev/cu.usbserial- device nodes that embed the device
serial number (including A or B) and port number.
Typical command lines to access the MCC and Morello consoles are:
- MCC console:
cu -l /dev/cu.usbserial-00FT41683097B0 -s 115200 - Morello console:
cu -l /dev/cu.usbserial-00FT41683097B2 -s 115200
You will need to substitute the serial numbers of the USB converters in your specific Morello board for these commands to work.