kernel/user mode

[rohit]

can any one please let me know the difference between a module running in kernel mode and the normal user mode.

what and what can not be achieved if we run the program/module in kernel/normal mode(s)

best regards
rohit

[starX]

Refferencing Linux Device Druvers (Rubini & Corbet, Oreilly, 2001) page 45:


The advantages of user-space drivers can be surmised as follows:

* The full C Library can be linked in. the driver can perform many exotic tasks without resorting to other programs...

* The programmer can run a conventional debugger on the driver code without having to go through the contortions to debug a running kernel.

* If a user-space driver hangs, you can simply kill it...

*User memory is swappable, unlike kernel memory...

*A well-designed driver program can still allow concurrent access to the device.



Hope this helps,

starX
www.axisoftime.com