There are three ways new drivers can be put into the kernel
1. Re-linking the Kernel and Rebooting
➡ Explanation:
This method requires manually adding the driver code to the kernel, recompiling it, and then rebooting the system for changes to take effect.
Older UNIX systems (e.g., early versions of Linux and BSD) worked this way.
➡ Advantages:
✔ Ensures tight integration of the driver with the OS.
✔ Can lead to better stability and performance if done correctly.
➡ Disadvantages:
❌ Inconvenient—requires a reboot, causing system downtime.
❌ Complex process—requires technical expertise to compile and configure the kernel.
➡ Example:
If you needed to add a new file system driver in an early UNIX system, you would have to:
1. Add the driver code to the kernel source.
2. Recompile the kernel.
3. Reboot the system for the changes to apply.
---
2. Declaring the Driver in an OS File and Rebooting
➡ Explanation:
In this method, the OS does not require recompiling the kernel. Instead, you make an entry in a configuration file to tell the OS to load the driver during boot.
Windows uses this method, where it detects necessary drivers at startup and loads them automatically.
➡ Advantages:
✔ Easier than recompiling—no need to modify kernel code manually.
✔ More flexible—allows adding or removing drivers without modifying the core system.
➡ Disadvantages:
❌ Still requires a reboot, causing system downtime.
➡ Example:
In Windows, when you install a new graphics card, the OS might detect that a driver is missing and prompt you to install it.
After installation, the system requires a reboot to load the driver properly.
---
3. Loading Drivers On-the-Fly (Without Rebooting)
➡ Explanation:
This is the most modern and flexible method, where the OS allows dynamically loading new drivers while it is running.
The driver is installed and used immediately, without requiring a reboot.
Modern Linux distributions and Windows versions support this method.
➡ Advantages:
✔ No downtime—drivers can be installed, updated, or removed without restarting the system.
✔ More user-friendly—used in plug-and-play devices like USB drives, printers, and external monitors.
➡ Disadvantages:
❌ If a driver is faulty, it may cause system instability without a clean reboot.
➡ Example:
When you plug in a USB device, the OS automatically detects the hardware and loads the required driver without restarting.