very first test of CI

.gitlab-ci.yml

+stages:
+  - build
+
+build-kernel:
+  image: ubuntu:bionic
+  stage: build
+  script:
+    - apt-get update
+    - apt-get install -y build-essential
+    - cd kernel; ./scripts/compile.bash
+  tags:
+  - highmem

kernel/compile.bash

+#!/bin/bash
+
+# get current kernel and realtime patch version
+
+FILE=`curl -s https://mirrors.edge.kernel.org/pub/linux/kernel/projects/rt/5.4/`
+KERNEL=`echo $FILE | sed -n 's/.*patch-5.4.\(.*\)-rt.*.patch.gz.*/\1/p'`
+RTPATCH=`echo $FILE | sed -n 's/.*patch-5.4..*-rt\(.*\).patch.gz.*/\1/p'`
+echo "using kernel 5.4.$KERNEL with realtime patch $RTPATCH"
+
+# get kernel file names and location
+
+KERNELURL=https://www.kernel.org/pub/linux/kernel/v5.x/
+KERNELNAME=linux-5.4.${KERNEL}
+KERNELFILE=linux-5.4.${KERNEL}.tar
+KERNELFILEXZ=linux-5.4.${KERNEL}.tar.xz
+KERNELSIGN=linux-5.4.${KERNEL}.tar.sign
+PATCHURL=https://www.kernel.org/pub/linux/kernel/projects/rt/5.4/
+PATCHFILE=patch-5.4.${KERNEL}-rt${RTPATCH}.patch
+PATCHFILEXZ=patch-5.4.${KERNEL}-rt${RTPATCH}.patch.xz
+PATCHSIGN=patch-5.4.${KERNEL}-rt${RTPATCH}.patch.sign
+
+# download kernel
+
+echo "downloading kernel from ${PATCHURL}${PATCHFILE}"
+curl -SLO ${KERNELURL}${KERNELFILEXZ}
+curl -SLO ${KERNELURL}${KERNELSIGN}
+echo "downloading patch from ${PATCHURL}${PATCHSIGN}"
+curl -sLO ${PATCHURL}${PATCHFILEXZ}
+curl -sLO ${PATCHURL}${PATCHSIGN}
+
+# unzip kernel (required for verification)
+
+xz -d $KERNELFILEXZ
+xz -d $PATCHFILEXZ
+
+# verify the kernel
+
+gpg --verify --keyserver hkp://keys.gnupg.net --auto-key-retrieve $KERNELSIGN
+gpg --verify --keyserver hkp://keys.gnupg.net --auto-key-retrieve $PATCHSIGN
+
+# unpack kernel
+
+tar xf $KERNELFILE
+cd $KERNELNAME
+patch -p1 < ../${PATCHFILE}
+
+# build the kernel
+
+# use the kernel config build on a normal ubuntu 18.4
+cp ../config .config
+# update config with defaults if new options have been added
+make olddefconfig
+make deb-pkg