How to connect to Debian 9.2 console of VisionSOM-6ULL on Linux (UART/USB and SSH)

How to connect to Debian 9.2 console of VisionSOM-6ULL on Linux (UART/USB and SSH)

---

Prerequisites

• PC with Ubuntu 16.04 operating system and USB port (for USB-UART converter connection) or local network connection (for SSH connection)
• VisionCB-STD board with VisionSOM-6ULL and micro-SD card with Debian 9.2 image installed (Debian 9.2 SD card installation manual for Windows and Linux are available)
• Micro-USB cable

Connecting to Debian console through UART-USB converter

VisionCB-STD has built-in UART-USB converter, it lets you connect to Debian console via virtual COM port. First of all you need to determine what is the VisionCB-STD virtual COM number on your Linux system. To do that connect VisionCB-STD board to your PC with micro-USB cable and list your terminal devices:

ls /dev/ttyUSB*
/dev/ttyUSB0

If there is only one device then it is the terminal you are looking for (/dev/ttyUSB0 in the example above), if there are more /dev/ttyUSB* terminal then disconnect and reconnect your board to find proper one.

Now install minicom:

sudo apt install minicom

Start minicom:

sudo minicom -b 115200 -D /dev/ttyUSB0 -s

Enter Serial port setup, press F to disable hardware flow control, press Enter, choose Exit, now you can log in. Default login is root, password is blank (do NOT enter blank, just press Enter). Now you are logged in. It is strongly recommended to change root password, to do that enter passwd command, you will be prompted to enter password twice:

root@somlabs:~# passwd
Enter new UNIX password:
Retype new UNIX password:
passwd: password updated successfully
root@somlabs:~#

To exit minicom press Ctrl+A, Z, X, then confirm by pressing Enter.

Connecting to Debian console via SSH client

Connecting as root - not recommended

By default Debian root user has blank password, you have to change it before connecting via SSH. Please refer Connecting to Debian console through UART-USB converter section on how to change root password. Once you have changed root password (still via UART-USB connection) you need to modify /etc/ssh/sshd_config file:

nano /etc/ssh/sshd_config

Add line:

PermitRootLogin yes

Restart SSH service:

service sshd restart

Now you can log in as root via SSH, you only need ip address of VisionSOM-6ULL Ethernet (eth0) interface, to get it enter ip a:

root@somlabs:~# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether a6:e3:1c:a0:3d:b0 brd ff:ff:ff:ff:ff:ff
    inet 192.168.0.25/24 brd 192.168.0.255 scope global eth0
       valid_lft forever preferred_lft forever
    inet6 2a02:a310:813c:d700:a4e3:1cff:fea0:3db0/64 scope global mngtmpaddr dynamic
       valid_lft 974055sec preferred_lft 369255sec
    inet6 fe80::a4e3:1cff:fea0:3db0/64 scope link
       valid_lft forever preferred_lft forever
3: sit0@NONE: <NOARP> mtu 1480 qdisc noop state DOWN group default
    link/sit 0.0.0.0 brd 0.0.0.0

In this case Ethernet the interface IP is 192.168.0.25, now you can connect to VisionSOM-6ULL with SSH client:

ssh root@192.168.0.25

Connecting as regular user

To connect as a regular user you need to create new account. Login as root through USB-UART converter or SSH, then add new account and set password:

root@somlabs:~# useradd tom
root@somlabs:~# passwd tom
Enter new UNIX password:
Retype new UNIX password:
passwd: password updated successfully
root@somlabs:~#

By default new user has no home directory and his shell is /bin/sh. To create home directory enter:

root@somlabs:~# mkdir /home/tom

To change shell to bash enter:

root@somlabs:~# chsh -s /bin/bash tom

Now you can log in as tom with SSH client.