Need help trying to patch a driver

[John Toliver]

On Fri, 2007-11-23 at 18:41 -0500, John Dangler wrote:
> On Fri, 2007-11-23 at 12:21 -0500, John Toliver wrote:
> > -----Original Message-----
> > From: John Dangler <jdangler at terremark.com>
> > Reply-To: Ubuntu user technical support, not for general discussions
> > <ubuntu-users at lists.ubuntu.com>
> > To: Ubuntu user technical support, not for general discussions
> > <ubuntu-users at lists.ubuntu.com>
> > Subject: Re: Need help trying to patch a driver
> > Date: Fri, 23 Nov 2007 11:33:10 -0500
> > 
> > On Fri, 2007-11-23 at 10:49 -0500, John Toliver wrote:
> > > This is the first I am hearing of being able to do this.  My T23 has
> > > has
> > > a problem with trackpoint drift for a while and I googled a fix in
> > the
> > > form of a "driver patch"  clicking on the link to me to a document
> > > with
> > > code in it that is all.  I know I need to do something with the code
> > > but
> > > I haven't a clue how to "patch" a driver.  I have googled the
> > subject
> > > and all I get are hits on pages of other driver patches available
> > but
> > > not a howto on how to actually patch your driver.
> > 
> > I'd be interested to see the link.
> > 
> > > My question is:
> > >
> > > 1. is it possible to backup the driver you are going to patch and if
> > > so
> > > how?  Is this as simple as a file copy?
> > Device drivers (I am assuming that this is what you are referring to)
> > are (usually) a mix of 'C' and Assembler code which provide interface
> > instructions between the OS and the particular device.  They should be
> > able to be copied.
> > 
> > > 2. How do you actually patch a driver?
> > Usually, 'patching' a driver would mean replacing the existing code
> > with
> > the updated code, since most people don't write this level of code.
> > If
> > the code you found is meant to be inserted into, or a replacement for
> > certain parts of a particular driver, you'll need the source code for
> > it
> > (which is presumably available with the linux source).
> > 
> > > 3. Once the deed is done, how do you restore it if your system check
> > > out
> > > for a night cap?
> > Since we're speaking of a relatively minor annoyance here, if the
> > pointing devices simply go 'south' after the patch is applied and the
> > system is restarted, going into a text terminal and moving the
> > original
> > back should suffice.
> > 
> > Caution: If the device driver is one that is built into the kernel,
> > this
> > would mean re-compiling the kernel.
> > 
> > > Please correct me if I'm approaching this wrongly.
> > >
> > > Thank you in advance.
> > >
> > >
> > > --
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> > >
> > 
> > I'd be interested to see the link
> >         jt- here it is:
> > http://www.thinkwiki.org/wiki/Patch_to_enable_advanced_trackpoint_configuration#Drift_Correction
> 
> The note on this page says - 
> since 2.6.14-rc5 the patch is included in the mainline kernel
> This leads me to believe that this patch is already included in the
> currently running kernel.
> In Gutsy, my current kernel is _Linux Nebo 2.6.22-14-generic_
> > 
> > Usually, 'patching' a driver would mean replacing the existing code
> > with
> > the updated code, since most people don't write this level of code.
> > If
> > the code you found is meant to be inserted into, or a replacement for
> > certain parts of a particular driver, you'll need the source code for
> > it
> > (which is presumably available with the linux source).
> > 
> >         jt-here is what I think is the assembler and C you are talking
> > about: http://paste.ubuntu-nl.org/45576/  Now is this source code?
> The code looks to be 'C' code (although the code appears to be a header
> file for inclusion in a 'C' program.
> > 
> > Caution: If the device driver is one that is built into the kernel,
> > this
> > would mean re-compiling the kernel.
> > 
> >         jt-how would I determine if the driver I'm using is a part of
> > the kernel or if it's separate?
> Since the code on this page is mentioned as being a part of the kernel,
> I would assume it is built-in.  If it is a module which is loaded
> outside the kernel, there would be a .ko file which would have to be
> either loaded at startup via rc, or it would be modprobe+d when you want
> to load it.
> >        
> > jt-Does a method (other than speaking assembler or C exist to
> > determine if
> > this was malware before I tried to add this to my system?
> Not knowing all of the intricacies of what the default Ubu kernel should
> or should not interface with, you probably wouldn't know on the surface.
> That is a subject left to more knowledgeable minds than mine at the
> moment.
> >        
> >        
> > 
> > 
> > 
> > 
> > 
> > --
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> > https://lists.ubuntu.com/mailman/listinfo/ubuntu-users
> > 
> > 

Thanks for you help.  I'm not going to recompile my kernel to alleviate
trackpoint drift.  I'm OK on the command line but I'l wait a while
before I go there :-)  I appreciate it though.  Are you a programmer?