[OE-core] [PATCH 0/2] Support for VirtualBox guest additions

Sat Aug 8 01:09:18 UTC 2015

On Fri, Aug 7, 2015 at 6:13 PM, Bystricky, Juro
<juro.bystricky at intel.com> wrote:
> The guest additions basically use standard out-of-tree kernel device driver
> build  (as described http://www.cyberciti.biz/tips/build-linux-kernel-module-against-installed-kernel-source-tree.html)
>
> The build relies on the existence of  "/lib/modules/<kernel-version>/build",  containing (or symlink to) a necessary set
> of  kernel development files. This is not really VirtualBox guest additions specific, it seems to be a common
> packaging/install convention when installing  kernel development files via
>
> apt-get install linux-headers-$(uname -r)
>
> The  actual development files, AFAIK they can be installed in one of two ways:
> 1. Full kernel source tree (over 500MB)
> 2. Subset of the full kernel sources ("kernel-headers" or "linux-headers").
>  These are  basically header files, Makefiles, scripts, .config, firware  and such. About 100MB.
>
> The full set is provided by kernel-devsrc.
> The subset should be provided by kernel-dev (but is not)
>
> At some point kernel-dev provided the symlink , "/lib/modules/<kernel-version>/build".
> The symlink  does not exist anymore. However, kernel.bbclass still contains some references to the
> /lib/modules/${KERNEL_VERSION}/build  in FILES_kernel-dev
>

Can you update the bugzilla that I referenced with the details ? We can use that
bug to tweak our existing packages/recipes (versus adding something new).

Bruce

>
>
>
>
>
>> -----Original Message-----
>> From: Khem Raj [mailto:raj.khem at gmail.com]
>> Sent: Wednesday, August 5, 2015 7:20 PM
>> To: Bystricky, Juro
>> Cc: Bruce Ashfield; Hatle, Mark G (Wind River); Purdie, Richard;
>> jurobystricky at hotmail.com; openembedded-
>> core at lists.openembedded.org
>> Subject: Re: [OE-core] [PATCH 0/2] Support for VirtualBox guest additions
>>
>> On Wed, Aug 5, 2015 at 3:02 PM, Bystricky, Juro <juro.bystricky at intel.com>
>> wrote:
>> > Thanks for the link. My new understanding is that kernel-dev package
>> > should already have essentially the same functionality as the
>> > kernel-headers package, which makes kernel-headers package redundant.
>> >  I tried it, but it did not work.
>> > To be specific, I expected to see the folder "/usr/lib/modules/3.19.5-yocto-
>> standard/build"
>> > however, it is missing . Looking at kernel.bbclass it seems it used to
>> > exist, but succumbed to some bitrot.
>> >
>>
>> have you thought of looking at the guest additions package and see if it could
>> be doing something that can be fixed ? what you need here is kernel
>> development files on target I assume, that should be easier than cross-build
>> scenario which we have not fixed completely. I think this additional headers
>> package is redundant.
>> you could get by fixing the existing kernel-headers package ( for
>> target) if anything is missing.
>>
>> How is guest additions compiled ? is it during build or dynamically on target ?
>>
>> > Just to make sure  we are on the same page, this is what I would like to
>> accomplish:
>> > http://www.cyberciti.biz/tips/build-linux-kernel-module-against-instal
>> > led-kernel-source-tree.html
>> >
>> > Juro
>> >
>> >> -----Original Message-----
>> >> From: Bruce Ashfield [mailto:bruce.ashfield at gmail.com]
>> >> Sent: Tuesday, August 4, 2015 7:49 PM
>> >> To: Hatle, Mark G (Wind River)
>> >> Cc: Bystricky, Juro; openembedded-core at lists.openembedded.org;
>> >> jurobystricky at hotmail.com; Purdie, Richard
>> >> Subject: Re: [OE-core] [PATCH 0/2] Support for VirtualBox guest
>> >> additions
>> >>
>> >> On Tue, Aug 4, 2015 at 11:43 PM, Bruce Ashfield
>> >> <bruce.ashfield at gmail.com>
>> >> wrote:
>> >> > On Tue, Aug 4, 2015 at 2:32 PM, Mark Hatle
>> >> > <mark.hatle at windriver.com>
>> >> wrote:
>> >> >> On 8/4/15 12:25 PM, Bystricky, Juro wrote:
>> >> >>> I agree, the name "kernel-headers" may not be the most fortunate,
>> >> "linux-headers"
>> >> >>> is probably more fitting.  The recipe installs the files in a
>> >> >>> similar fashion that is done by
>> >> >>>
>> >> >>> apt-get install linux-headers-$(uname -r)
>> >> >>>
>> >> >>> Typical contents can be viewed for example here:
>> >> >>> https://www.archlinux.org/packages/core/i686/linux-headers/
>> >> >>>
>> >> >>> These files are needed to allow building  of kernel drivers
>> >> >>> against the running Linux kernel. In a way, it is a subset of
>> >> >>> kernel-devsrc, but including  ".config" file used for the actual running
>> kernel.
>> >> >>
>> >> >> Again this is part of the purpose of the existing kernel-devsrc
>> >> >> package.  So what is missing preventing this from working.  It
>> >> >> likely needs to be added to the kernel-devsrc package instead (or
>> >> >> a sub package that is created by the kernel-devsrc recipe.)
>> >> >
>> >> > Peeking in on vacation.
>> >> >
>> >> > At a minimum, we need to figure out why the existing package wasn't
>> >> > able to build the use case in question here .. I've built pretty
>> >> > much everything against it at one point .. so I'd like to learn more.
>> >> >
>> >> > And yes, what we don't need is more sets of rules that copy and
>> >> > package parts of the kernel build. We are already doing that in our
>> >> > do_shared_workdir and that is pretty much the minimum to build
>> >> > against the kernel. If that directory structure needs more for this
>> >> > purpose (or less),
>> >> then update it.
>> >> >
>> >> > But we need to do all of this in the existing classes, to keep
>> >> > everything in one place, not more recipes that are grabbing chunks
>> >> > of the same source tree.
>> >>
>> >> FYI: exiting thoughts are here:
>> >>
>> >> https://bugzilla.yoctoproject.org/show_bug.cgi?id=7095
>> >>
>> >> So as you can see, we aren't offended by a 'headers' package, but it
>> >> has to make sense with the existing packages, and needs to be
>> >> generating from our existing bits of the system.
>> >>
>> >> Cheers,
>> >>
>> >> Bruce
>> >>
>> >> >
>> >> > Bruce
>> >> >
>> >> >
>> >> >>
>> >> >>> Having these files installed, it is possible  to compile
>> >> >>> additional kernel drivers that are not part of the kernel-devsrc .
>> >> >>>  VirtualBox compiles some of their own drivers this way, others as
>> well.
>> >> >>> There are many other scenarios where you may want to add a new
>> >> >>> kernel driver to an already installed Linux kernel.
>> >> >>
>> >> >> Yes, this was part of the design behind the kernel-devsrc, make
>> >> >> sure the sources and components used to build the running kernel
>> >> >> were made available to the target so that out-of-tree/external
>> >> >> kernel modules could be built to match the running system -- as
>> >> >> well as the ability to reconfigure and rebuild the kernel itself.
>> >> >>
>> >> >> Bruce is on vacation this week and may not be around to respond,
>> >> >> but adding yet another package is not the right answer here.  Lets
>> >> >> fix what may be broken in what we have.
>> >> >>
>> >> >> --Mark
>> >> >>
>> >> >>> Juro
>> >> >>>
>> >> >>>
>> >> >>>
>> >> >>>> -----Original Message-----
>> >> >>>> From: Mark Hatle [mailto:mark.hatle at windriver.com]
>> >> >>>> Sent: Tuesday, August 4, 2015 9:20 AM
>> >> >>>> To: Bystricky, Juro; openembedded-core at lists.openembedded.org;
>> >> >>>> jurobystricky at hotmail.com
>> >> >>>> Cc: Purdie, Richard
>> >> >>>> Subject: Re: [OE-core] [PATCH 0/2] Support for VirtualBox guest
>> >> >>>> additions
>> >> >>>>
>> >> >>>> On 8/3/15 3:35 PM, Juro Bystricky wrote:
>> >> >>>>> In order to support VirtualBox guest additions, kernel headers
>> >> >>>>> need to be present in the VM. I am aware we already have two
>> >> >>>>> packages/recipes that are somewhat similar (kernel-devsrc.bb,
>> >> >>>>> linux-libc-headers), but none
>> >> >>>> of them is suitable for this purpose.
>> >> >>>>> Besides the kernel headers, some additional files (scripts,
>> >> >>>>> Makefiles, .config, etc) are also required.
>> >> >>>>
>> >> >>>> linux-libc-headers is only for building applications.
>> >> >>>> kernel-devsrc is for building modules on the target.
>> >> >>>>
>> >> >>>> What do these specific modules need that are not present in
>> >> >>>> kernel-
>> >> devsrc?
>> >> >>>> (I really don't want 'yet another' confusing package added to
>> >> >>>> the
>> >> >>>> system.)
>> >> >>>>
>> >> >>>>> The new recipe "kernel-headers.bb" can in principle be used by
>> >> >>>>> other
>> >> >>>> images as well.
>> >> >>>>> It is not limited to the Build Appliance and hence is not a
>> >> >>>>> part of the Build Appliance recipe.
>> >> >>>>
>> >> >>>> I think kernel-headers is a bad name for a package.  It could be
>> >> confusing.
>> >> >>>>
>> >> >>>> --Mark
>> >> >>>>
>> >> >>>>> Juro Bystricky (2):
>> >> >>>>>   kernel-headers: linux kernel headers
>> >> >>>>>   build-appliance-image: support for VirtualBox guest addtions
>> >> >>>>>
>> >> >>>>>  .../README_vbox_guest_additions.txt                | 78
>> >> >>>> ++++++++++++++++++++++
>> >> >>>>>  .../images/build-appliance-image_12.0.1.bb         |  4 +-
>> >> >>>>>  meta/recipes-kernel/linux/kernel-headers.bb        | 66
>> >> >>>> ++++++++++++++++++
>> >> >>>>>  3 files changed, 147 insertions(+), 1 deletion(-)  create mode
>> >> >>>>> 100644
>> >> >>>>> meta/recipes-core/images/build-appliance-
>> >> >>>> image/README_vbox_guest_addit
>> >> >>>>> ions.txt  create mode 100644
>> >> >>>>> meta/recipes-kernel/linux/kernel-headers.bb
>> >> >>>>>
>> >> >>>
>> >> >>
>> >> >> --
>> >> >> _______________________________________________
>> >> >> Openembedded-core mailing list
>> >> >> Openembedded-core at lists.openembedded.org
>> >> >> http://lists.openembedded.org/mailman/listinfo/openembedded-
>> core
>> >> >
>> >> >
>> >> >
>> >> > --
>> >> > "Thou shalt not follow the NULL pointer, for chaos and madness
>> >> > await thee at its end"
>> >>
>> >>
>> >>
>> >> --
>> >> "Thou shalt not follow the NULL pointer, for chaos and madness await
>> >> thee at its end"
>> > --
>> > _______________________________________________
>> > Openembedded-core mailing list
>> > Openembedded-core at lists.openembedded.org
>> > http://lists.openembedded.org/mailman/listinfo/openembedded-core

-- 
"Thou shalt not follow the NULL pointer, for chaos and madness await
thee at its end"