[yocto] Setting preferred version of kernel for feature support

Ash Charles ashcharles at gmail.com
Fri Jun 20 07:38:50 PDT 2014


Hi,

In thinking about this a bit more (and struggling with all three
methods), I wonder that creating a separate machine type in much the
same fashion as crownbay and crownbay-noemgd is the way to go.

--Ash

On Tue, Jun 17, 2014 at 8:56 AM, Ash Charles <ashcharles at gmail.com> wrote:
> Hi,
>
> I have two kernels for my device: one is current mainline kernel and
> one is an older kernel that supports magic proprietary hardware
> acceleration blobs.  Some developers want the modern kernel, others
> need the hardware acceleration which means they need the older kernel
> plus a bunch of out-of-tree kernel modules and some additional
> packages included in their image.  What is the best way to give users
> of the meta layer for this device an easy switch?
>
> I came up with three basic ways to do this:
> 1. Create an image recipe or packagegroup.  In this recipe, set the
> PREFERRED_VERSION_<kernel>, add RDEPENDS on the out-of-tree kernel
> modules and pull in any extra recipes to the build.
>
> 2. Describe the dependency information; the user can just choose to
> include one top-level package or not.  The userspace packages depend
> on the out-of-tree modules which would set the preferred version of
> the kernel.  Is setting the preferred version of something as major as
> the kernel in a random recipe okay?
>
> 3. Add a USE_HW_ACCEL type parameter to the machine configuration or
> add a feature to MACHINE_FEATURES and select the packages and versions
> based on this.  Is there any problems adding new features to
> MACHINE_FEATURES?  Does this break the package feeds?
>
> Any suggestions on the best way to achieve this goal or any
> compare-contrast between the methods would be most appreciated.
>
> --Ash



More information about the yocto mailing list