Character Driver Unload Fails

Question

I was looking for an inbuilt character driver in Linux, I found the relevant driver in the device (/dev) list, The character device is with Major number 4 (tty), but I'm unable to unload that character driver, I tried using following command

rmmod Modulet1

But when I try this it gives me an error:

Error: Module Modulet1 is not currently loaded

Could someone assist me with this issue?

I was also looking for associated driver code for this module; does anyone have any idea about this?

Answer 1

You can not unload a built-in module. Built in modules are compiled along with the kernel and loaded on kernel boot up. Only loadable module can be insmoded and rmmoded.
Also, lsmod doesn't show you the in-built modules.

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For this particular driver, look into this file: http://lxr.free-electrons.com/source/drivers/tty/tty_io.c

Before you go through that code, you might want to look into the tty driver structure: http://www.linuxjournal.com/article/5896