title: modifying kernel config in Yocto
body: <p>I am trying to modify the kernel config without luck.</p>
  <p>There is a BSP in meta-xxx-yyy/ with <code>recipes-kernel/linux/linux_git.bb</code>.
  I try to override the kernel config in my layer named meta-xxx-mylayer where I have
  <code>recipes-kernel/linux/linux_git.bbappend and recipes-kernel/linux/files/frag.cfg</code></p>
  <p>frag.cfg:</p>
  <pre><code># CONFIG_NETFILTER is not set
  CONFIG_AUTOFS4_FS=y 
  </code></pre>
  <p>linux_git.bbappend:</p>
  <pre><code>COMPATIBLE_MACHINE_my_mach = &quot;my_mach&quot;
  FILESEXTRAPATHS_prepend := &quot;${THISDIR}/files:&quot;
  SRC_URI += &quot;file://frag.cfg&quot;
  </code></pre>
  <p>linux_git.bb: (just a part of the file)</p>
  <pre><code>KERNEL_RELEASE = &quot;3.10&quot;
  PV = &quot;3.10&quot;
  PR = &quot;r10&quot;
  S = &quot;${WORKDIR}/git&quot;
  COMPATIBLE_MACHINE = &quot;(my_mach)&quot;
  </code></pre>
  <p>meta-xxx-yyy/conf/machine/my_mach.conf:
  (there is no meta-xxx-mylayer/conf/machine/my_mach.conf)</p>
  <pre><code>PREFERRED_PROVIDER_virtual/kernel = &quot;linux&quot;
  UBOOT_MACHINE = &quot;socfpga_cyclone5_config&quot;
  KERNEL_MACHINE = &quot;socfpga&quot;
  </code></pre>
  <p>Build commands:</p>
  <pre><code>bitbake linux -c cleansstate -f
  bitbake linux -c configure -f
  bitbake linux -c compile -f
  bitbake linux -c deploy -f
  </code></pre>
  <p>Everything builds, but when I inspect <code>/proc/config.gz</code>, I can see that <code>CONFIG_AUTOFS4_FS</code> is not enabled.</p>
  <p>I have another recipe in the meta-xxx-mylayer layer which builds and installs into rootfs just fine so I know that the layer is enabled.</p>
  <p>The frag.cfg file is copied to <code>./tmp/work/my_mach-poky-linux-gnueabi/linux/3.10-r10/</code> during build, while the rest of the files are in <code>./tmp/work/my_mach-poky-linux-gnueabi/linux/3.10-r10/git/</code>. Is that a problem?</p>