Rebuilding the Kernel

[Dan Williams]

On Wed, 2008-01-23 at 11:24 -0500, Tom Hoffman wrote:
> Hi all,
> 
> I'm trying to get a USB2VGA adapter working.  Step 1 would appear to
> be compiling the SISUSBVGA module in the standard kernel tree and
> getting it onto my XO.
> 
> So I've been trying http://wiki.laptop.org/go/Rebuilding_OLPC_kernel
> 
> And rpmbuild bombs out the same way whether I use a SRPM or git:
> 
> ++ /usr/bin/id -u
> + '[' 500 = 0 ']'
> + /bin/chmod -Rf a+rX,u+w,g-w,o-w .
> + mv linux-2.6. vanilla
> mv: cannot stat `linux-2.6.': No such file or directory
> error: Bad exit status from /var/tmp/rpm-tmp.57150 (%prep)
> 
> 
> RPM build errors:
>     Bad exit status from /var/tmp/rpm-tmp.57150 (%prep)
> 
> This is on Fedora 8.
> 
> Anyone have any helpful advice?  I'll update the wiki if you do.

You don't need to rebuild the kernel itself.  All you need is to install
the kernel-devel package for the kernel you want to build against.

Then cd into your usb2vga driver directory.  Run:

make -C /lib/modules/<kernel version>/build SUBDIRS=`pwd` modules

And it'll spit out a .ko you can load if usb2vga has a makefile in the
appropriate form (which should be quite simple).

If you want to build it for the XO, find out the version of the kernel
running on the XO, and get the matching kernel-devel package from
Andres' site at http://dev.laptop.org/~dilinger/stable/

And do the same:

make -C /lib/modules/<olpc kernel version>/build SUBDIRS=`pwd` modules

Many times, the module (like madwifi, some out-of-tree v4l2 drivers, or
others) will include the right makefile magic for you to just type
'make' and it'll handle this all for you.

Dan