Add docker container with toolchain and libraries to build aarch64 binary

docker/support/relocate-sdk.sh

@@ -0,0 +1,47 @@
+#!/bin/sh
+#
+if [ "$#" -ne 0 ]; then
+    echo "Run this script to relocate the buildroot SDK at that location"
+    exit 1
+fi
+
+FILEPATH="$(readlink -f "$0")"
+NEWPATH="$(dirname "${FILEPATH}")"
+
+cd "${NEWPATH}"
+LOCFILE="sdk-location"
+if [ ! -r "${LOCFILE}" ]; then
+    echo "Previous location of the buildroot SDK not found!"
+    exit 1
+fi
+OLDPATH="$(cat "${LOCFILE}")"
+
+if [ "${NEWPATH}" = "${OLDPATH}" ]; then
+    echo "This buildroot SDK has already been relocated!"
+    exit 0
+fi
+
+# Check if the path substitution does work properly, e.g.  a tree
+# "/a/b/c" copied into "/a/b/c/a/b/c/" would not be allowed.
+newpath="$(sed -e "s|${OLDPATH}|${NEWPATH}|g" "${LOCFILE}")"
+if [ "${NEWPATH}" != "${newpath}" ]; then
+    echo "Something went wrong with substituting the path!"
+    echo "Please choose another location for your SDK!"
+    exit 1
+fi
+
+echo "Relocating the buildroot SDK from ${OLDPATH} to ${NEWPATH} ..."
+
+# Make sure file uses the right language
+export LC_ALL=C
+# Replace the old path with the new one in all text files
+grep -lr "${OLDPATH}" . | while read -r FILE ; do
+    if file -b --mime-type "${FILE}" | grep -q '^text/' && [ "${FILE}" != "${LOCFILE}" ]
+    then
+        sed -i "s|${OLDPATH}|${NEWPATH}|g" "${FILE}"
+    fi
+done
+
+# At the very end, we update the location file to not break the
+# SDK if this script gets interruted.
+sed -i "s|${OLDPATH}|${NEWPATH}|g" ${LOCFILE}