scripts/getver.sh: allow conversion between git hash and revision

Add code allowing easy conversion between git commit ids and revisions.

Example:

$ ./scripts/getver.sh
r792
$ ./scripts/getver.sh r123
b7fc892eb56b52d25bc00578af9d1ee058dcf6b3
$ ./scrpts/getver.sh b7fc892eb56b52d25bc00578af9d1ee058dcf6b3
r123

Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com>

diff --git a/scripts/getver.sh b/scripts/getver.sh
index 340ed6862cf7cc566262ea64bfdc33196926fc4d..a60b91ede1390a5fdceccbf9d649460ccea93801 100755 (executable)
--- a/scripts/getver.sh
+++ b/scripts/getver.sh
@@ -3,6 +3,8 @@ export LANG=C
 export LC_ALL=C
 [ -n "$TOPDIR" ] && cd $TOPDIR
 
+GET_REV=$1
+
 try_version() {
        [ -f version ] || return 1
        REV="$(cat version)"
@@ -11,8 +13,22 @@ try_version() {
 
 try_git() {
        git rev-parse --git-dir >/dev/null 2>&1 || return 1
-       REV="$(git rev-list reboot..HEAD --count)"
-       REV="${REV:+r$REV}"
+
+       [ -n "$GET_REV" ] || GET_REV="HEAD"
+
+       case "$GET_REV" in
+       r*)
+               GET_REV="$(echo $GET_REV | tr -d 'r')"
+               BASE_REV="$(git rev-list reboot..HEAD --count)"
+               REV="$(git rev-parse HEAD~$((BASE_REV - GET_REV)))"
+               ;;
+       *)
+
+               REV="$(git rev-list reboot..$GET_REV --count)"
+               REV="${REV:+r$REV}"
+               ;;
+       esac
+
        [ -n "$REV" ]
 }