remove dependency on gcc6

We had dependency because we where using an older U-boot version
which only compiled with gcc6. Since we now have updated to a
2018.xx bootloader we no longer have this limitation and we can
use binares in 'gcc-arm-linux-gnueabihf' upstream package

Changelog: Title

Signed-off-by: Mirza Krak <mirza.krak@northern.tech>

Dockerfile

@@ -25,25 +25,16 @@ RUN apt-get update && apt-get install -y \
     dosfstools \
 # to compile U-Boot
     bc \
-# to download gcc toolchain and mender-artifact
+# to download mender-artifact
     wget \
-# to extract gcc toolchain
-    xz-utils \
 # to download mender-convert and U-Boot sources
-    git
+    git \
+# To compile Mender client, U-boot or GRUB
+    gcc-arm-linux-gnueabihf
 
 # Disable sanity checks made by mtools. These checks reject copy/paste operations on converted disk images.
 RUN echo "mtools_skip_check=1" >> $HOME/.mtoolsrc
 
-# Needed while we use older U-Boot version for Raspberry Pi
-# https://tracker.mender.io/browse/MEN-2198
-# Assumes $(pwd) is /
-RUN wget -nc -q http://releases.linaro.org/components/toolchain/binaries/6.3-2017.05/arm-linux-gnueabihf/gcc-linaro-6.3.1-2017.05-x86_64_arm-linux-gnueabihf.tar.xz \
-    && tar -xJf gcc-linaro-6.3.1-2017.05-x86_64_arm-linux-gnueabihf.tar.xz \
-    && rm gcc-linaro-6.3.1-2017.05-x86_64_arm-linux-gnueabihf.tar.xz \
-    && echo export PATH=$PATH:/gcc-linaro-6.3.1-2017.05-x86_64_arm-linux-gnueabihf/bin >> /root/.bashrc
-
-
 RUN wget -q -O /usr/bin/mender-artifact https://d1b0l86ne08fsf.cloudfront.net/mender-artifact/$MENDER_ARTIFACT_VERSION/mender-artifact \
     && chmod +x /usr/bin/mender-artifact
 
@@ -58,7 +49,7 @@ ENV MENDER_CLIENT_VERSION=$mender_client_version
 
 # NOTE: we are assuming generic ARM board here, needs to be extended later
 
-ENV PATH "$PATH:/usr/local/go/bin:/gcc-linaro-6.3.1-2017.05-x86_64_arm-linux-gnueabihf/bin"
+ENV PATH "$PATH:/usr/local/go/bin"
 ENV GOPATH "/root/go"
 
 RUN go get github.com/mendersoftware/mender

rpi-convert-stage-5.sh

@@ -21,16 +21,11 @@ uboot_dir=${output_dir}/uboot-mender
 bin_base_dir=${output_dir}/bin
 bin_dir_pi=${bin_base_dir}/raspberrypi
 sdimg_base_dir=$output_dir/sdimg
-GCC_VERSION="6.3.1"
 build_log=${output_dir}/build.log
 
 declare -a mender_disk_mappings
 declare -a mender_partitions_regular=("boot" "primary" "secondary" "data")
 
-version() {
-  echo "$@" | awk -F. '{ printf("%d%03d%03d\n", $1,$2,$3); }'
-}
-
 # Takes following arguments:
 #
 #  $1 - ARM toolchain
@@ -190,13 +185,6 @@ do_install_bootloader() {
     exit 1
   fi
 
-  local gcc_version=$(${bootloader_toolchain}-gcc -dumpversion)
-
-  if [ $(version $gcc_version) -ne $(version $GCC_VERSION) ]; then
-    log "Error: Invalid ARM GCC version ($gcc_version). Expected $GCC_VERSION. Aborting."
-    exit 1
-  fi
-
   [ ! -f $mender_disk_image ] && \
       { log "$mender_disk_image - file not found. Aborting."; exit 1; }