2 files changed, 52 insertions, 0 deletions
diff --git a/contrib/ChangeLog b/contrib/ChangeLog
index 8f112af5691..c5e4604d6f5 100644
--- a/contrib/ChangeLog
+++ b/contrib/ChangeLog
@@ -1,3 +1,7 @@
+2020-01-22  Richard Earnshaw  <rearnsha@arm.com>
+
+	* git-add-vendor-branch.sh: New file.
+
 2020-01-20  Richard Earnshaw  <rearnsha@arm.com>
 
 	* gcc-git-customization.sh: Check that user-supplied remote
diff --git a/contrib/git-add-vendor-branch.sh b/contrib/git-add-vendor-branch.sh
new file mode 100755
index 00000000000..8fa86682151
--- /dev/null
+++ b/contrib/git-add-vendor-branch.sh
@@ -0,0 +1,48 @@
+#! /bin/sh -e
+
+# Create a new upstream vendor branch.
+
+# Usage:
+#  contrib/git-add-vendor-branch.sh <vendor>/<branch-name> <base>
+
+usage ()
+{
+    echo "Usage:"
+    echo "  $0 <vendor>/<branch-name> <start-point>"
+    echo
+    echo "<vendor> must have already been set up using contrib/git-fetch-vendor.sh"
+    exit 1
+}
+
+if [ $# != 2 ]
+then
+    usage
+fi
+
+vendor=$(echo "$1" | sed -r "s:([^/]*)/.*$:\1:")
+branch=$(echo "$1" | sed -r "s:[^/]*/(.*)$:\1:")
+start=$2
+
+# Sanity check the new branch argument.  If there is no '/', then the
+# vendor will be the same as the entire first argument.
+if [ -z "$vendor" -o -z "$branch" -o ${vendor} = $1 ]
+then
+    usage
+fi
+
+# Check that we know about the vendor
+url=$(git config --get "remote.vendors/${vendor}.url"||true)
+if [ -z "$url" ]
+then
+    echo "Cannot locate remote data for vendor ${vendor}.  Have you set it up?"
+    exit 1
+fi
+
+git branch --no-track ${vendor}/${branch} ${start}
+git push vendors/${vendor} ${vendor}/${branch}:refs/vendors/${vendor}/heads/${branch}
+git fetch -q vendors/${vendor}
+git branch --set-upstream-to=remotes/vendors/${vendor}/${branch} ${vendor}/$branch
+echo "You are now ready to check out ${vendor}/${branch}"
+echo "To push the branch upstream, use:"
+echo
+echo "git push vendors/${vendor} ${vendor}/${branch}"