[yocto] How do I control what kernel modules are being loaded?
Hi. I have built some custom kernel modules (.ko) using a .bb that inherits from the module.bbclass. There is one main kernel module and the rest are dependent on the first. Building and installing the modules to the rootfs works fine. Next question is how do I control what actual modules are loaded at boot, or actually how do I control this through Yocto? To my surprise one of the kernel module loaded automatically!? How could this happen? I did not have an entry for it in /etc/modules. And what do I need to do to actually add entries to /etc/modules? Or is there some other mechanism that I should use. I tried going through the module.bbclass but must admit I lost it somewhere in the middle ;) Any guidance would be appreciated. Hans ___ yocto mailing list yocto@yoctoproject.org https://lists.yoctoproject.org/listinfo/yocto
Re: [yocto] How do I control what kernel modules are being loaded?
On 13-03-08 07:08 AM, Hans Beckérus wrote: Hi. I have built some custom kernel modules (.ko) using a .bb that inherits from the module.bbclass. There is one main kernel module and the rest are dependent on the first. Building and installing the modules to the rootfs works fine. Next question is how do I control what actual modules are loaded at boot, or actually how do I control this through Yocto? To my surprise one of the kernel module loaded automatically!? How could this happen? I did not have an entry for it in /etc/modules. And what do I need to do to actually add entries to /etc/modules? Or is there some other mechanism that I should use. I tried going through the module.bbclass but must admit I lost it somewhere in the middle ;) Any guidance would be appreciated. module_autoload_module package name, in your module recipe, will trigger the load on boot. Cheers, Bruce Hans ___ yocto mailing list yocto@yoctoproject.org https://lists.yoctoproject.org/listinfo/yocto ___ yocto mailing list yocto@yoctoproject.org https://lists.yoctoproject.org/listinfo/yocto
Re: [yocto] How do I control what kernel modules are being loaded?
8 mar 2013 kl. 18:12 skrev Bruce Ashfield bruce.ashfi...@windriver.com: On 13-03-08 07:08 AM, Hans Beckérus wrote: Hi. I have built some custom kernel modules (.ko) using a .bb that inherits from the module.bbclass. There is one main kernel module and the rest are dependent on the first. Building and installing the modules to the rootfs works fine. Next question is how do I control what actual modules are loaded at boot, or actually how do I control this through Yocto? To my surprise one of the kernel module loaded automatically!? How could this happen? I did not have an entry for it in /etc/modules. And what do I need to do to actually add entries to /etc/modules? Or is there some other mechanism that I should use. I tried going through the module.bbclass but must admit I lost it somewhere in the middle ;) Any guidance would be appreciated. module_autoload_module package name, in your module recipe, will trigger the load on boot. Cheers, Bruce Great! But there must be a catch? My actual module package builds six modules. One mandatory and the rest are optional. How can it know which modules that should actually be loaded? For some to me unknown reason the mandatory one was loaded on boot even though I did nothing to my.bb? Hans Hans ___ yocto mailing list yocto@yoctoproject.org https://lists.yoctoproject.org/listinfo/yocto ___ yocto mailing list yocto@yoctoproject.org https://lists.yoctoproject.org/listinfo/yocto
Re: [yocto] How do I control what kernel modules are being loaded?
On 13-03-08 12:40 PM, Hans Beckérus wrote: 8 mar 2013 kl. 18:12 skrev Bruce Ashfield bruce.ashfi...@windriver.com: On 13-03-08 07:08 AM, Hans Beckérus wrote: Hi. I have built some custom kernel modules (.ko) using a .bb that inherits from the module.bbclass. There is one main kernel module and the rest are dependent on the first. Building and installing the modules to the rootfs works fine. Next question is how do I control what actual modules are loaded at boot, or actually how do I control this through Yocto? To my surprise one of the kernel module loaded automatically!? How could this happen? I did not have an entry for it in /etc/modules. And what do I need to do to actually add entries to /etc/modules? Or is there some other mechanism that I should use. I tried going through the module.bbclass but must admit I lost it somewhere in the middle ;) Any guidance would be appreciated. module_autoload_module package name, in your module recipe, will trigger the load on boot. Cheers, Bruce Great! But there must be a catch? My actual module package builds six modules. One mandatory and the rest are optional. How can it know which modules that should actually be loaded? For some to me unknown reason the mandatory one was loaded on boot even though I did nothing to my.bb? I'd assume that udev or some other kernel - userspace event triggered the load of the required module. If you need more advanced logic than modprobe or udev/systemd can provide, then custom startup scripts for the services would be in order. Cheers, Bruce Hans Hans ___ yocto mailing list yocto@yoctoproject.org https://lists.yoctoproject.org/listinfo/yocto ___ yocto mailing list yocto@yoctoproject.org https://lists.yoctoproject.org/listinfo/yocto
Re: [yocto] How do I control what kernel modules are being loaded?
Hi Hans, Le Fri, 8 Mar 2013 13:08:21 +0100, Hans Beckérus hans.becke...@gmail.com a écrit : Hi. I have built some custom kernel modules (.ko) using a .bb that inherits from the module.bbclass. There is one main kernel module and the rest are dependent on the first. Building and installing the modules to the rootfs works fine. Next question is how do I control what actual modules are loaded at boot, or actually how do I control this through Yocto? To my surprise one of the kernel module loaded automatically!? How could this happen? I did not have an entry for it in /etc/modules. And what do I need to do to actually add entries to /etc/modules? Or is there some other mechanism that I should use. I tried going through the module.bbclass but must admit I lost it somewhere in the middle ;) Any guidance would be appreciated. when the module is built by the kernel recipe you can use : module_autoload and you can see somme usage examples here : http://cgit.openembedded.org/meta-handheld/tree/conf/machine/palmtx.conf http://cgit.openembedded.org/meta-handheld/tree/conf/machine/include/palm.inc maybe you could get inspiration from kernel.bbclass to do the same thing in your recipe. Eric ___ yocto mailing list yocto@yoctoproject.org https://lists.yoctoproject.org/listinfo/yocto
Re: [yocto] How do I control what kernel modules are being loaded?
On 2013-03-08 7:12, Eric Bénard wrote:
Hi Hans,
Le Fri, 8 Mar 2013 13:08:21 +0100,
Hans Beckérus hans.becke...@gmail.com a écrit :
Hi. I have built some custom kernel modules (.ko) using a .bb that
inherits from the module.bbclass. There is one main kernel module and
the rest are dependent on the first. Building and installing the
modules to the rootfs works fine. Next question is how do I control
what actual modules are loaded at boot, or actually how do I control
this through Yocto? To my surprise one of the kernel module loaded
automatically!? How could this happen? I did not have an entry for it
in /etc/modules. And what do I need to do to actually add entries to
/etc/modules? Or is there some other mechanism that I should use. I
tried going through the module.bbclass but must admit I lost it
somewhere in the middle ;) Any guidance would be appreciated.
when the module is built by the kernel recipe you can use :
module_autoload and you can see somme usage examples here :
http://cgit.openembedded.org/meta-handheld/tree/conf/machine/palmtx.conf
http://cgit.openembedded.org/meta-handheld/tree/conf/machine/include/palm.inc
maybe you could get inspiration from kernel.bbclass to do the same
thing in your recipe.
Eric
Thanks guys for your quick feedback. I can see that using
module_autoload_${PN} seems like a good approach, if a package maps 1:1
to a module.
In my case that is not so. The package/recipe builds six (or even more)
.ko files using one makefile.
I guess one option could be to split each module build in its own
recipe, but that is not supported by the makefile and thus would require
patching from my side in the source tree. I think the only option I have
left is to try to use /etc/modules and add the modules there in a
do_install_append().
But the problem then is, what happens if some other package also add a
/etc/modules.conf to the image folder? Will it be merged or only copied?
In the latter case last package wins which would not work out very well :(
Out of curiosity, what will module_autoload do? Will it add the .ko to
/etc/modules or does it implement some other mechanism to make a module
load automatically at boot?
I do not think that the mandatory module that is loaded originates from
udev. This is a network CM driver that basically hooks into the Linux
network stack. I do not think that udev will ever make this driver load
automatically. But I can not say for sure of course.
Hans
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Re: [yocto] How do I control what kernel modules are being loaded?
On Fri, Mar 8, 2013 at 7:08 AM, Hans Beckérus hans.becke...@gmail.com wrote: I tried going through the module.bbclass but must admit I lost it somewhere in the middle ;) Any guidance would be appreciated. Have you had a chance to look at the Yocto hands-on kernel lab? https://lists.yoctoproject.org/pipermail/yocto/2013-February/014408.html ___ yocto mailing list yocto@yoctoproject.org https://lists.yoctoproject.org/listinfo/yocto
Re: [yocto] How do I control what kernel modules are being loaded?
On 2013-03-08 7:12, Eric Bénard wrote: Hi Hans, Le Fri, 8 Mar 2013 13:08:21 +0100, Hans Beckérus hans.becke...@gmail.com a écrit : Hi. I have built some custom kernel modules (.ko) using a .bb that inherits from the module.bbclass. There is one main kernel module and the rest are dependent on the first. Building and installing the modules to the rootfs works fine. Next question is how do I control what actual modules are loaded at boot, or actually how do I control this through Yocto? To my surprise one of the kernel module loaded automatically!? How could this happen? I did not have an entry for it in /etc/modules. And what do I need to do to actually add entries to /etc/modules? Or is there some other mechanism that I should use. I tried going through the module.bbclass but must admit I lost it somewhere in the middle ;) Any guidance would be appreciated. when the module is built by the kernel recipe you can use : module_autoload and you can see somme usage examples here : http://cgit.openembedded.org/meta-handheld/tree/conf/machine/palmtx.conf http://cgit.openembedded.org/meta-handheld/tree/conf/machine/include/palm.inc maybe you could get inspiration from kernel.bbclass to do the same thing in your recipe. Eric Coming to think about it, module_autoload should actually specify module, not package right? That would work then. But is this only supported in a machine.conf? Can it not be used also in e.g. the image.bb or a distro.conf? The reason is that I do not have a machine.conf in my highest layer! My layer is a simple distro that does not have any real knowledge of what hardware it is running on. My local.conf points out the actual MACHINE. The kernel modules are not hardware dependent either since they are pure network extensions so it would be wrong to have them in the machine.conf. Hans ___ yocto mailing list yocto@yoctoproject.org https://lists.yoctoproject.org/listinfo/yocto
Re: [yocto] How do I control what kernel modules are being loaded?
On 13-03-08 2:00 PM, Hans Beckerus wrote:
On 2013-03-08 7:12, Eric Bénard wrote:
Hi Hans,
Le Fri, 8 Mar 2013 13:08:21 +0100,
Hans Beckérus hans.becke...@gmail.com a écrit :
Hi. I have built some custom kernel modules (.ko) using a .bb that
inherits from the module.bbclass. There is one main kernel module and
the rest are dependent on the first. Building and installing the
modules to the rootfs works fine. Next question is how do I control
what actual modules are loaded at boot, or actually how do I control
this through Yocto? To my surprise one of the kernel module loaded
automatically!? How could this happen? I did not have an entry for it
in /etc/modules. And what do I need to do to actually add entries to
/etc/modules? Or is there some other mechanism that I should use. I
tried going through the module.bbclass but must admit I lost it
somewhere in the middle ;) Any guidance would be appreciated.
when the module is built by the kernel recipe you can use :
module_autoload and you can see somme usage examples here :
http://cgit.openembedded.org/meta-handheld/tree/conf/machine/palmtx.conf
http://cgit.openembedded.org/meta-handheld/tree/conf/machine/include/palm.inc
maybe you could get inspiration from kernel.bbclass to do the same
thing in your recipe.
Eric
Thanks guys for your quick feedback. I can see that using
module_autoload_${PN} seems like a good approach, if a package maps 1:1
to a module.
In my case that is not so. The package/recipe builds six (or even more)
.ko files using one makefile.
I guess one option could be to split each module build in its own
recipe, but that is not supported by the makefile and thus would require
patching from my side in the source tree. I think the only option I have
left is to try to use /etc/modules and add the modules there in a
do_install_append().
But the problem then is, what happens if some other package also add a
/etc/modules.conf to the image folder? Will it be merged or only copied?
In the latter case last package wins which would not work out very well :(
Out of curiosity, what will module_autoload do? Will it add the .ko to
/etc/modules or does it implement some other mechanism to make a module
load automatically at boot?
It depends on what release you are using. In yocto 1.3 and before the
autoload variables translated to mod-util loading, using just what you'd
think. In yocto 1.4 and kmod in the picture:
# If autoloading is requested, output
/etc/modules-load.d/name.conf and append
# appropriate modprobe commands to the postinst
autoload = d.getVar('module_autoload_%s' % basename, True)
if autoload:
name = '%s/etc/modules-load.d/%s.conf' % (dvar, basename)
f = open(name, 'w')
for m in autoload.split():
f.write('%s\n' % m)
f.close()
postinst = d.getVar('pkg_postinst_%s' % pkg, True)
if not postinst:
bb.fatal(pkg_postinst_%s not defined % pkg)
postinst += d.getVar('autoload_postinst_fragment', True) %
autoload
d.setVar('pkg_postinst_%s' % pkg, postinst)
# Write out any modconf fragment
modconf = d.getVar('module_conf_%s' % basename, True)
if modconf:
name = '%s/etc/modprobe.d/%s.conf' % (dvar, basename)
f = open(name, 'w')
f.write(%s\n % modconf)
f.close()
Cheers,
Bruce
I do not think that the mandatory module that is loaded originates from
udev. This is a network CM driver that basically hooks into the Linux
network stack. I do not think that udev will ever make this driver load
automatically. But I can not say for sure of course.
Hans
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