writing device drivers
 

I'm doing a project in writing a network card device driver for RTLinux. Since, I'm new to Linux, I thought it would be better to start off from the basics.

Do I need to know the PCI bus architecture in detail. After mapping, the PCI configuration space to memory( memory mapped i/o) or via port addresses(i/o mapped i/o), what should be done.
I haven't clearly understood what the board initialization part does and also why do we need ioctl().
?? Are there any disadvantages in using pci-dma for a network card in RTLinux

?? Which would be a better option for RTLinux memory mapped or i/o mapped i/o

?? Do I have to allocate memory for the arriving packets or is it buffered in the NIC and sent to some buffer or the NIC sents packets to some allocated portion of memory made to point by the SCB.
?? I read RTLinux dosent create a net_device structure, it uses file_operations. Then, how does it treat a network device.
Also, how does the driver communicate with the protocol modules.


Thanking you
Jess

I don't know specifically the answers to your questions, but the book Linux Device Drivers might help. It's published by O'Reilly and also available legally! online at http://www.xml.com/ldd/chapter/book/ .

Am in the same boat!
 

hi Jess,
Read your message and well mm actually want to do the same stuff i.e. write a device driver for a wireless code to be used a by a RT task.
However I am newbie too and have no idea where to start...
Please let me know how you started ...and how far have you reached..
bye for now
Vishal