pre-built kernels -- the gentoo way?

[adsmith]

I manage many machines with nearly identical gentoo installations. I use distcc to build once quickly, and then I use tbz2 binary packages and "emerge -k" to install everywhere -- basically I have my own little binary distribution.

There is only one thing lacking:
Is there a "gentoo way" (or at least a "sane way") to use a pre-built kernel?

I have considered using "make targz-pkg" in /usr/src/linux and manually un-tarring it on all machines, but this seems a little hackish somehow, especially since installed third-party modules may not build correctly, since the /usr/src/linux on each client would not contain the right config, headers, et cetera. (kernel gurus, am I right about this?)

Is there a better method than this?

I am also somewhat loathe to write a new ebuild for each kernel version, but I suppose I could...

[NeddySeagoon]

adsmith,

For a binary kernel, you need only /lib/modules/`uname -r`/ and the bzImage file.
You want the bzImage under its name in boot.
If the kernel is monolithic, you don't need /lib/modules/`uname -r`/ as its empty.

How about tarring them up into a single tarball and writing a kernel-bin ebuild to untar them ?
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

[Hu]

The kernel Makefile supports the INSTALL_PATH and INSTALL_MOD_PATH variables to install the files into a temporary location, which may make it easier to install the files into a temporary location, so that you can tar them all up with a simple tar -c -f mykernel.tar -C /my/kernel/staging/area ..

[adsmith]

Both,
Yes, that was generally my original though. I was hoping there was a better way.

What both you outline is exactly what "make targz-pkg" does in the standard kernel Makefile -- it just tars up everything that would come out of "make install" and "make modules_install", namely /boot/vmlinuz, /boot/config, /boot/System-map, and /lib/modules/ (all of these with version extensions)


So it looks like I do indeed have to write a kernel-bin ebuild to unpack the binary, and keep it up-to-date with my kernel version.



NeddySeagoon,

That is technically correct, but I think (?) just the vmlinuz and modules are not enough for some purposes. What if I were to do something like "emerge nvidia-drivers lirc madwifi", where it builds/installs kernel modules and need to check that dependencies are set properly in /usr/src/linux/.config (really /lib/modules/$(uname)/build)? Based on my (possibly false) recollection, it will fail unless the .config is OK.
Since the goal is to never really touch the /usr/src/linux directories on any client, such emerges may fail?

Maybe I'm just being too picky, and I should make sure ALL potential 3rd party modules are pre-built on the build master.

[dsd]

genkernel might be able to help you here
_________________
http://dev.gentoo.org/~dsd

[adsmith]

I thought genkernel still builds locally?

[NeddySeagoon]

adsmith,

If you use any 3rd party kernel modules, they are still put into /lib/modules/`uname -r`/....
After you have the binararies, the sources are no longer required.

You will have to do your own tarring to pick up the binaray 3rd party modules because make targz-pkg will only pick up offical kernel tree things.
As a minimum you need bzImage and /lib/modules/`uname -r`/ after all the 3rd party suff is installed.
System.Map is only needed for debugging

You may need /etc/modules.d/ as nvidia-drivers puts things there.
I'm not sure if you can make a binary package of nvidia-drivers that you can later use with emerge -K but I don't see why not.
That may be another option. Use make targz-pkg on the kernel and build binary packages of any 3rd party kernel additions.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

[adsmith]

OK, so something like this should do it