anchor.diff:  # build kernels without patches.
   COPY / /
   
  +RUN mkdir -p /out/src
  +
   # Download and verify kernel
   # PGP keys: 589DA6B1 (greg@kroah.com) & 6092693E (autosigner@kernel.org) & 00411886 (torvalds@linux-foundation.org)
   RUN KERNEL_MAJOR=$(echo ${KERNEL_VERSION} | cut -d . -f 1) && \
  
positive.code:     xz -d linux-${KERNEL_VERSION}.tar.xz && \
      curl -fsSLO ${KERNEL_PGP2_SIGN} && \
      gpg2 --verify linux-${KERNEL_VERSION}.tar.sign linux-${KERNEL_VERSION}.tar && \
      cat linux-${KERNEL_VERSION}.tar | tar --absolute-names -x && mv /linux-${KERNEL_VERSION} /linux
  
  
  RUN mkdir -p /out/src
  
  WORKDIR /tmp
  # Download Intel ucode, create a CPIO archive for it, and keep it in the build context
  
negative.code:         done; \
      fi
  
  # Save kernel source
  RUN tar cJf /out/src/linux.tar.xz /linux
  
  