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linux-kernelyoctobitbake

Yocto kernel config propagation

In my Yocto system, I have a layer defining a bunch of patches on the linux kernel, as well as a file "defconfig" containing kernel configuration. When I modify this file, changes are reflected in the image I build.

However, a few changes are being overruled and I have a hard time figuring out how or where. I do find a bunch of defconfig files in other layers, but is there any easy way to figure out which ones are applied and in what order?

Thanks

Solution

  • It is not other defconfigs that overrule your configuration (at least not in an even only remotely sane setup), but configuration fragments (creating fragments). You can find out what happens exactly like that:

    bitbake -e virtual/kernel | less

    (you can of course choose another pager, or redirect to a file for additional processing)

    And look for:

    KERNEL_FEATURES

    --> here you can find a list of kernel configuration fragments in the form of .scc files that are applied to your build

    SRC_URI

    --> this should mention the path to your defconfig file, and no second one.

    Please note that this description only holds entirely true for setups that include a kernel defconfig. If you are working without one, things can be different.