Hi,

We know that each OS has it's own installer which takes care of installation process. The first step in any installation process is detecting the system platform architecture and hardwares such as CPU, RAM, VGA, Mouse, Keyboard, Hard Disk,... so it can act based on system configuration and do a clean install, now my question is: "How an installer can do this for the first time?".

I another word: "How lspci/hwinfo/prtconf/kudzu/... can gather those amount of information about hardwares?" (Yes! all of these commands will read some files for gathering those informations! but I need to know who and how created those files)


P.S:
1- Note that, if we have a binary which compiled for a X86 architecture then it won't work on a Sparc system!
2- OpenSolaris can do that!

Thanks you

It is the Linux kernel that detects and initialises the hardware when the system is booted. You can see the results of this in the output of 'dmesg'.
As the kernel boots it builds the /proc and /sys directories. (If you look at these directories in an unmounted file system you will see they are empty.) Tools like 'lspci' get their information from these directories and present them in a more human readable format.
Installer kernels are compiled with support for a wide range of hardware builtin. Once you have completed an install, you can compile a kernel that contains support just for the hardware you have. This makes for a smaller kernel and removes the possibility of some hardware being incorrectly identified. It is also possible to build a kernel with minimal hardware support and have that kernel load modules to support your hardware.

P.S. I do not understand your P.S.

2 members found this post helpful.

Thank you allend,
So you mean: "Kernel does all of this!" (and YES, you are right).

Now I just wanna know, HOW?
I mean: "How kernel detects a hardware?" (The mechanism / which part of the kernel?)
Does it have a Database with signature of all (detectable) hardwares? or there is other ways?


Sorry if I couldn't ask my question brightly, I just couldn't get why Kernel can detect many parts so quick but it's infirm in detecting Dial-UP Modems and many Graphic cards! and if it's the kernel which will take care of hardware detection so, why Ubuntu can detect more hardwares than Fedora!

The detail that you want is within the kernel source code and I must confess that I am not an expert in any way.
Devices that connect to the PCI bus provide a standard structure that can be queried for information such as the vendor and product identification code. The kernel code can read these values and associate appropriate drivers.

The problem with serial line dial-up modems is that they do not provide such standard information. There are also problems with other devices such as graphic cards as they may be generic clones that are not exact copies. Audio chips can have many possible inputs and outputs that can be wired in different ways by manufacturers to suit their board layouts. Newer monitors contain EDID information that can be queried so that the connecting PC can get the monitor capabilities, but older CRT monitors may not have this. Newer widescreen monitors may provide incomplete information on their capabilities in their EDID.

Ubuntu is renowned for being good at supporting hardware. This is partly by design as Ubuntu aims to be a very user friendly distribution. It also has a large user base, so it can widely sample the possible hardware space.
Support for some hardware can involve the use of proprietary drivers. Some distributions take a stricter view of the open source philosophy and do not provide binary code that does not have open source.

2 members found this post helpful.

Thank you very much allend, I got the point.

Does anybody know which parts of the kernel involve in hardware detection?
(Any tips or suggestions would be greatly appreciated, I just need a Clue )