Device Driver...

[tokool]

Hi All:
I have an elementary question regarding Device Drivers.
It goes something like this:
If i have two Device Drivers installed for the two different hardware, which perform the same tasks. How can i get the system to choose one hardware over the other.
Eg: I have two monitors connected to my system which has two video cards. I want one program to be displayed in the 1st monitor and the second prog to be viewed on the 2nd monitor.
Is it possible and if so, which part of the Kernal manages this.
Thanks,
Preetham.

 

[enigma174]

I dont know about multiple monitors, but i think you need to look in /etc/modules.conf this file defines which services/applications are bound to each kernal module

Kernal Modules are essentially the Linux equivelent of device drivers, you can use the 'lsmod' command to list the currently loaded modules, and modprobe and associated commands to load and unload them - your linux distro will probably have automatically detected them though. With two monitors installed, you can either use modules.conf to manually bind each to a set display, or you can choose not to and have them assigned in the order in which the modules are loaded, from there i think you can just play with the X settings, load two Xclients - one for each display and then refer to them by the display number eg localhost:0 localhost:1 etc

hope that helps
--cb

 

[tokool]

Thanx,
Basically what i want to know is, how does the Kernal know which Device Driver to look into when the UserMode appication requests a device to perform some operation.
Eg: If the user program gives a command to the kernal to draw a circle on the screen, the kernal will locate the device driver for the screen and then call the method that draws on the screen.
There are many Drivers installed, when an operation request arrives, how does it decide which Device Driver to use.