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Modern hardware requires proper configuration before and after installing an operating system. In this guide, you’ll learn how to configure firmware settings (BIOS/UEFI), detect hardware in Linux, inspect devices on PCI and USB buses, manage kernel modules, and explore kernel information in /proc and /sys.

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1. Firmware Configuration: BIOS vs UEFI

Computers use firmware interfaces to initialize hardware and start the boot process. Legacy systems rely on BIOS (Basic Input/Output System), while most modern machines use UEFI (Unified Extensible Firmware Interface).
FeatureBIOSUEFI
InitializationLegacy MBR bootGPT support, faster boot
Configuration interfaceText-based menuGraphical menu, mouse support
Firmware updatesManufacturer-specific flasher toolsBuilt-in update utilities
Hardware testing & configBasic POST (Power-On Self-Test)Extended diagnostics, secure boot, variable storage
The image is a diagram explaining the acronyms BIOS, UEFI, and POST, with their full forms: Basic Input/Output System, Unified Extensible Firmware Interface, and Power-On Self-Test.
During POST, your firmware checks CPU, memory, and motherboard health. To enter the setup utility, press the key shown on-screen (often F2, Delete, or F12). Inside you can:
  • Set the hardware clock’s date and time
  • Enable/disable onboard peripherals (LAN, audio)
  • Configure RAM error protection (ECC)
  • Adjust IRQ and DMA channels
  • Define boot device priority
  • Enable performance features (XMP, virtualization)
  • Disable unused hardware for security or power saving
Changing firmware settings can affect system stability. Always document original values before modifying.

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2. Detecting Hardware in Linux

Once Linux boots, it discovers and initializes hardware. Missing devices usually indicate a faulty component or port; detected but non-functional devices often need the correct kernel module (driver).
Here are the primary inspection tools:
ToolPurposeExample
lspciList PCI/PCIe devicessudo lspci
lsusbList USB devicessudo lsusb
lsmodShow loaded kernel moduleslsmod
modinfoDisplay module detailsmodinfo snd

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2.1 Inspecting PCI Devices with lspci

The lspci utility enumerates PCI/PCIe devices: 
sudo lspci
Sample output: 
00:00.0 Host bridge: Intel Corporation 440FX - 82441FX PMC [Natoma] (rev 02)
00:03.0 Ethernet controller: Intel Corporation 82540EM Gigabit Ethernet Controller (rev 02)
00:0c.0 USB controller: Intel Corporation 7 Series/C210 Series Chipset Family USB xHCI
To get verbose details for a specific device (e.g., 00:03.0): 
sudo lspci -s 00:03.0 -v
Show only kernel driver info: 
sudo lspci -s 00:03.0 -k

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2.2 Inspecting USB Devices with lsusb

List all USB devices: 
sudo lsusb
For a tree-view with drivers and speeds: 
sudo lsusb -t
Query a specific device by bus and device number: 
sudo lsusb -s 01:20

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3. Managing Kernel Modules

Kernel modules enable Linux to communicate with hardware. 
# List loaded modules
lsmod

# Filter for sound-related modules
lsmod | fgrep -i snd
Unload (remove) a module: 
sudo modprobe -r snd_hda_intel
Unloading critical modules (e.g., storage or network drivers) can render your system unbootable. Proceed with caution.
View detailed information about a module: 
modinfo snd
List only parameters: 
modinfo snd -p

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3.1 Persistent Module Configuration

To apply module parameters at boot or blacklist unwanted modules, use files in /etc/modprobe.d/:
Config FilePurpose
/etc/modprobe.d/<module>.confSet parameters for a module
/etc/modprobe.d/blacklist.confPrevent modules from loading
/etc/modprobe.confLegacy configuration file
Example: blacklisting the snd driver: 
blacklist snd

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4. Kernel Information Files (/proc and /sys)

Linux exposes hardware and process information via two virtual filesystems:
  • /proc: Process and kernel data (e.g., /proc/cpuinfo)
  • /sys: Device and driver attributes (e.g., /sys/class/net)
The image is a slide titled "Information and Device Files," describing the /proc and /sys directories as special directories in RAM used by the kernel to store information on running processes.
Since /proc and /sys reside in volatile memory, their contents reset on reboot.
Continue to the quiz to test your understanding of Linux hardware configuration and inspection.

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