[linux-yocto] EXTERNAL: Re: Missing Kernel Modules (GPU folder and radeon.ko)

Bruce Ashfield bruce.ashfield at windriver.com
Wed Jun 24 06:46:17 PDT 2015

On 2015-06-24 8:03 AM, Chen, Simon wrote:
> Hi Bruce,
> Thanks for the response. I was able to get this running by creating a .bbappend to the kernel recipe and link a .cfg to change the kernel configurations, and it worked! I see what you're saying though. When doing the menuconfig, I would probably have to do a separate "$bitbake kernel-modules" before I do a "$bitbake linux-yocto" or whatever core-image I'm

My wiggle answer is "it depends", that's why I was wondering how you
built them ? You can't bitbake kernel-modules, since it is a package not
a recipe, but the concept is the same. You need to go through the
compile_kernel_modules task, and have the package splits happen (the
dynamically created per kernel module class, and then the updates to the
meta package).

>   using? However, I believe the use of a .cfg means that the Yocto environment is smart enough to update and auto-build the kernel-modules meta package... is that correct?

This is the solution I would have recommended. The fragment is pulled into
the main build of the kernel, so that configuration is available during the
first pass through the build. As a result, your new configuration (and 
are pulled in like any of the options and modules that were part of the



> -Simon
> -----Original Message-----
> From: Bruce Ashfield [mailto:bruce.ashfield at windriver.com]
> Sent: Tuesday, June 23, 2015 4:17 PM
> To: Chen, Simon; linux-yocto at yoctoproject.org
> Subject: EXTERNAL: Re: [linux-yocto] Missing Kernel Modules (GPU folder and radeon.ko)
> On 2015-06-23 11:27 AM, Chen, Simon wrote:
>> Hi all,
>> I am trying to integrate the AMD Radeon E8860 graphics card on to a
>> Yocto (poky-dizzy-12.0.1) embedded machine. Ialready have the open
>> source xf86-video-ati driver (7.4.0) installed into my Yocto image.
>> The problem is that the kernel module radeon.ko, and all of its
>> dependencies under the GPU and I2C folders seems to be missing from the kernel.
>> Without these .ko files, Yocto cannot recognize the external graphics
>> card, and udev cannot generate an appropriate device node
>> (/dev/dri/card0) for Xorg to use.
>> I've already tried adding the following line to my local.conf:
>> CORE_IMAGE_EXTRA_INSTALL_append = "kernel-modules"
> How are you invoking the rebuild of the kernel modules after you've added them via menuconfig ?
> kernel-modules is a meta package that has embedded RDEPENDS on individual kernel module packages. If you are rebuilding the kernel, but not re-building and repacking the kernel modules then any additions won't be in the RDEPENDS and hence won't make it to the image.
> Bruce
>> This populates the file system with .ko's but none seem to be the ones
>> I need for my graphics card to run, which are radeon.ko, drm.ko,
>> drm_kms_helper.ko, ttm.ko, and i2c_algo_bit.ko. I am missing the
>> entire lib/modules/<KERNEL_VERSION>/kernel/drivers/gpu folder and also
>> most of the contents in lib/modules/<KERNEL_VERSION/kernel/drivers/i2c.
>> I wondered if it was just a matter of implementing the .config file
>> correctly. But I've already executed "$bitbake linux-yocto -c menconfig"
>> and enabled the appropriate configuration flags for each of these
>> modules. Perhaps this just a matter of appending to the kernel.bbclass
>> file which is responsible for executing the kernel Makefiles, and
>> building these .ko's?
>> Can you guys please check your own lib/modules/<KERNEL_VERSION>/kernel
>> directory to see that these .ko's exist? I'd like to know if there is
>> something else that isn't enabled or included into the build, or if
>> it's something I need to hardcode in order to fix this issue.
>> Thanks,
>> Simon

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