Subject: Re: creating new ioctls
To: Jeremy Cooper <>
From: Bill Studenmund <>
List: tech-kern
Date: 08/05/1997 16:46:36
> On Tue, 5 Aug 1997, Colin Wood wrote:
> > > Also, there is a 'u' hierarchy which is dedicated to whatever the
> > > driver wants to do.
> > 
> > Would you mind explaining just exactly what you mean by this last
> > sentence?
> I think he means that the rest of the kernel has explicitly avoided
> creating ioctls that use the 'U' character as a begining identifier.
> This leaves a clear path for drivers to use 'U' ioctls for their own
> special purposes.

Exactly. Except that as all the characters are case sensitive, the
'u' hierarchy is clearly wide open. As I've not seen anything use
upper-case letters, I bet 'U' is also open. :-)

Take care,