Re: Stupid question re: register_cdrom()

[Tony Breeds <tony@bakeyournoodle.com>]

On Mon, Apr 05, 2004 at 04:53:16PM -0400, Calin A. Culianu wrote:
> 
> Let's say I was coding a cdrom emulator in software for kernel 2.4.  I
> am unclear about register_cdrom().  Does register_cdrom() in
> cdrom.c take care of telling the kernel that my kdev_t major/minor
> combination in fact leads to a real driver?  Or do I need to take care of
> that outside of regsiter_cdrom()?
> 
> If not.. how do I tell the kernel data structures that my driver's major
> number does in fact point to a cdrom driver.  Basically, I want my
> driver's major number to show up in /proc/devices..
> 
> This might be a stupid question, but I am not a linux kernel expert...

Neither am I, therefore I hope you get a reply from someone else
refuting or acknowledging my claims.


I looks to me that the code that does the actual registration of the
driver is in drivers/ide/ide-cd.c NOT cdrom.c.  Specifically
ide_cdrom_attach().  Said function eventually calls the register_cdrom()
you ask about.

For writing a cdrom emulator  You may want to look more closely at the
non-IDE/SCSI devices as they seem to register their driver data
themselves  I had a quick read of aztcd.c, I think between cdrom.c and
aztcd.c you should be able to piece together what you want.

Also Try reading http://www.xml.com/ldd/chapter/book/ for details on 2.4
drivers

Yours Tony

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