title: Makefile error when trying to build core-image-minimal with custom DTB
body: <p>I'm new to the Yocto Project and I'm trying to build a simple core-image-minimal image for my custom board based on i.MX6QP/Q/DL SABRE Automotive. Right now I'm only working with the meta-freescale layer.</p>
  
  <p>I have some custom DTS files that I want build and include in a fitImage of the Linux kernel.</p>
  
  <p>This is what I've done so far:</p>
  
  <ol>
  <li><p>I've created a custom layer with a custom machine, and in the <strong>conf/machine.conf</strong> file I have specified the DTBs that I want to use:</p>
  
  <pre><code>KERNEL_DEVICETREE = " \
      imx6qp-g25-protoc-1280x480.dtb \
      ...
  "
  </code></pre></li>
  <li>I've created a <strong>linux-fslc-imx_%.bbappend</strong> file in <strong>/yocto/poky/meta-custom/recipes-kernel/linux/</strong> that references a <strong>.patch</strong> file that contains the git diff like <a href="https://github.com/yoctocookbook/meta-bsp-custom/blob/master/recipes-kernel/linux/linux-wandboard-3.10.17/0001-ARM-dts-Add-wandboard-custom-dts-file.patch" rel="nofollow noreferrer">done here</a>. In the .patch file I've included the required <strong>arch/arm/boot/dts/Makefile</strong> modifications and the DTS files.</li>
  </ol>
  
  <p>Unfortunately, when trying to build core-image-minimal, the DTB building fails with this message:</p>
  
  <blockquote>
    <p>make[3]: <strong>* No rule to make target 'arch/arm/boot/dts/imx6qp-g25-protoc-1280x480.dtb'.  Stop.
    arch/arm/Makefile:322: recipe for target 'imx6qp-g25-protoc-1280x480.dtb' failed
    make[2]: <em></strong> [imx6qp-g25-protoc-1280x480.dtb] Error 2
    Makefile:146: recipe for target 'sub-make' failed
    make[1]: <strong></em> [sub-make] Error 2
    Makefile:24: recipe for target '__sub-make' failed
    make: *</strong> [__sub-make] Error 2
    ERROR: oe_runmake failed
    WARNING: exit code 1 from a shell command.</p>
  </blockquote>
  
  <p>I've checked that the patch is applied, in fact, by looking at the source folder <em>linux-fslc-imx/4.1-2.0.x+gitAUTOINC+6c1ad49339-r0/build/source/arch/arm/boot/dts</em>, the <strong>Makefile</strong> is correct and the <strong>DTS</strong> files are present.</p>