Add common function to determin board and variant values.

common.sh

Index: common.sh
diff --git a/common.sh b/common.sh
index 291c112f7730652164e5cf65abb51218831df300..f368e0d6bef0e83fe67945d0865d47fb1694cb32 100644
--- a/common.sh
+++ b/common.sh
@@ -562,3 +562,23 @@ chroot_hacks_from_outside() {
     sudo bash -c "echo root ALL=\(ALL\) ALL >> \"${chroot_dir}/etc/sudoers\""
   fi
 }
+
+# The board and variant command line options can be used in a number of ways
+# to specify the board and variant.  The board can encode both pieces of
+# information separated by underscores.  Or the variant can be passed using
+# the separate variant option.  This function extracts the canonical board and
+# variant information and provides it in the BOARD, VARIANT and BOARD_VARIANT
+# variables.
+get_board_and_variant() {
+  local flags_board="${1}"
+  local flags_variant="${2}"

[kwwaters_gmail.com, 2011/01/24 22:49:59]

These variables are unused.

[robotboy, 2011/01/24 23:17:00]

Ooops, fixed.

+
+  BOARD=$(echo "$FLAGS_board" |cut -d '_' -f 1)

[kwwaters_gmail.com, 2011/01/24 22:49:59]

Spaces around "|".

[robotboy, 2011/01/24 23:17:00]

Done.

+  VARIANT=${FLAGS_variant:-$(echo "$FLAGS_board" |cut -s -d '_' -f 2)}

[kwwaters_gmail.com, 2011/01/24 22:49:59]

Should this be "cut -s -d _ -f 2-"  I'm not sure, but I thought you could have
multiple variants.

[robotboy, 2011/01/24 23:17:00]

Nope, we ensure that the variant and board names do not have _'s in them in the
cros_overlay_list script.  I do not believe that you can specify multiple
variants.

+
+  if [ -n "$VARIANT" ] ; then

[kwwaters_gmail.com, 2011/01/24 22:49:59]

Drop space between "]" and ";".

[robotboy, 2011/01/24 23:17:00]

Done.

+    BOARD_VARIANT="${BOARD}_${VARIANT}"
+  else
+    BOARD_VARIANT="${BOARD}"
+  fi
+}