Re: Help needed: Devkit header files not upto date with kernel headers

[Denys Dmytriyenko <denys@ti.com>]

Sam,

Please see my last comment - there's a separate recipe for user-space kernel 
headers. The headers need to be properly exported, you cannot just use the 
ones from the kernel directly. Hence they are detached - updating the header 
in the kernel tree does not automatically update exported headers for the user 
space in linux-libc-headers.

-- 
Denys


On Tue, Jul 09, 2013 at 12:00:34PM -0400, Nelson, Sam wrote:
> Understand the user space headers and kernel space headers are different in 
> general. But in this case, I am comparing the files under "uapi" directory. 
> Which I assume is actually meant for user space api. Am I wrong on this? 
> Given that , I expected the header file will be updated in building the 
> devkit.
> 
> For example if we have update on an "uapi" header file , as part of a kernel 
> patch, Don't we expect the corresponding header file in devkit to be 
> updated? Appreciate your comments.
> 
> With regards,
> Sam
> 
> 
> -----Original Message-----
> From: Dmytriyenko, Denys 
> Sent: Tuesday, July 09, 2013 11:40 AM
> To: Nelson, Sam
> Cc: meta-arago@arago-project.org; Karicheri, Muralidharan; Shilimkar, Santosh
> Subject: Re: Help needed: Devkit header files not upto date with kernel headers
> 
> On Tue, Jul 09, 2013 at 11:30:35AM -0400, Nelson, Sam wrote:
> >    Hello all,
> > 
> >    The header files under sysroots/armv7ahf-vfp-neon-oe-linux-gnueabi does
> >    not match the same file from the kernel tree.
> 
> That's normal. There's a difference between kernel and user-space facing headers.
> 
> http://kernelnewbies.org/KernelHeaders
> 
> 
> >    For example
> > 
> >    Comparing the following 2 files, they are different.
> > 
> >    
> > sysroots/armv7ahf-vfp-neon-oe-linux-gnueabi/usr/include/linux/ethtool.
> > h
> > 
> >    and
> > 
> >    
> > sysroots/armv7ahf-vfp-neon-oe-linux-gnueabi/usr/src/kernel/include/uap
> > i/linux/ethtool.h
> > 
> >     
> > 
> >    Looking into some details, the /usr/include/linux/ethtool.h, seems to come
> >    from the libc package.
> 
> Yes, those are different even on my host machine. The first is marked as _LINUX_ETHTOOL_H and the second one as _UAPI_LINUX_ETHTOOL_H
> 
> http://lwn.net/Articles/113349/
> http://lwn.net/Articles/507794/
> 
> 
> >    Any ideas on what can be wrong in the recipes will be helpful.  Is there
> >    any way to update the user space header files to match the kernel header
> >    files?
> 
> There is a special recipe for that - linux-libc-headers.
> 
> --
> Denys