Probing Unfamilar Devices ​

When working with embedded linux devices where you only have command line access, there are still several ways that you can gain basic information about the system. This can be important to understand how to interact with it and its processes.

System & Architecture ​

uname -a

• Provides info on system hardware, kernel, and hostname

lscpu

• CPU info and architecture

lshw -short

• Lists info about system hardware
• Pro tip: The standrd lshw command is very verbose. Redirect output to html and view it with sudo lshw -html > hwinfo.html && firefox hwinfo.html

Processes & Services ​

top or htop

• Shows the processes that are running and the command that spawned them (among other things)

  • Often embedded devices don't run too many processes because they're specialized for specific tasks

systemctl list-unit-files

• These files are located in /lib/systemd/system and are the raw text files that encode info about the associated service, socket, etc.

systemctl list-units

• Lists all current units (eg. services, sockets, devices) in memory

• Tips:

  • To search a for a service use systemctl list-unit-files | grep <search-string>. You can then manage that service as discussed in no-bs-systemd

Network ​

ip a

• Display information about currently configured IP addresses, MAChine addresses, and network connections

ip r

• Display the IP of your gateway/router

[sudo] nmap -sn <subnet>

• Conduct a ping scan on the specified subnet (eg. nmap -sn 192.168.1.0/24)

Devices ​

lsblk

• Lists info on block storage devices (eg. hard drives, partitions, flash drives)

lsusb -t

• Lists info on USB devices with a tree-like structure

lsmod

• Lists info on loadable kernel modules