1.2. Analyse and Explore a Linux System¶

1.2.1. References¶

man pages

1.2.2. Goals¶

Analyse a Linux system in detail
Understand important concepts regarding Linux

1.2.3. Steps¶

Check which tty the serial port is connected to:
```
user@host: ps -ef | grep tty
```
Check the partition table, their usage and which type of file systems are used:
```
user@host: fdisk -l /dev/sda
```

or:

user@host: lsblk /dev/sda

Check which file systems are mounted:
```
user@host: mount
```

or:

user@host: lsblk -f /dev/sda

Determine the details of the CPU:
```
user@host: cat /proc/cpuinfo
```
Determine the details of the memory:
```
user@host: cat /proc/meminfo
```
Determine which kernel modules are loaded:
```
user@host: lsmod
```
Determine available network interfaces:
```
user@host: ip l
```

1.2.4. Important Concepts¶

Serial port: A UART or RS232 port available to the system which can provide a console/terminal. No need for screen and keyboard for basic terminal support like on desktop systems.
Partition table: Sector on storage medium that describes the physical partioning of the storage memory. Most common schemes are Master Boot Record (MBR) and GUID Partition Table (GPT).
File system: Method that controls how data (files, directories, metadata) is stored and retrieved. It manages the storage memory. Most common file systems are fat and ext4.
Bootloader: Usually collection of software pieces that bootstrap a system. Its most important objective is to load the OS kernel into main memory.
Kernel: Core of the OS which controls and manages everything (hardware, users, processes, protocols, …). It provides an interface to user processes to access resources.
Kernel module: Dynamically loadable object file that can extend the functionality of the running kernel. Modules can implement any feature from device drivers to filesystems to protocols.
Device tree: A data structure that describes the hardware details of a platform. Loaded and used by the kernel to manage those components (CPU, RAM, IO buses, peripherals, …).
Root file system: The file system where the root directory is located. Contains user space programs, kernel modules to be loaded dynamically, mount points for other file systems, …
Init system: The kernel will start only 1 user process at the end of its own initialization. This process is responsible to bootstrap the rest of user space.