BaseTools: Update edksetup.sh to support multiple workspaces

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Liming Gao <liming.gao@intel.com>
Reviewed-by: Wu Hao A <hao.a.wu@intel.com>

git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@18584 6f19259b-4bc3-4df7-8a09-765794883524
diff --git a/edksetup.sh b/edksetup.sh
index 64795c4..57368b5 100755
--- a/edksetup.sh
+++ b/edksetup.sh
@@ -1,5 +1,5 @@
 #
-# Copyright (c) 2006 - 2010, Intel Corporation. All rights reserved.<BR>
+# Copyright (c) 2006 - 2015, Intel Corporation. All rights reserved.<BR>
 # This program and the accompanying materials
 # are licensed and made available under the terms and conditions of the BSD License
 # which accompanies this distribution.  The full text of the license may be found at
@@ -78,10 +78,23 @@
   elif [ -f "$WORKSPACE/BaseTools/BuildEnv" ]
   then
     . $WORKSPACE/BaseTools/BuildEnv $*
+  elif [ -n "$PACKAGES_PATH" ]
+  then 
+    PATH_LIST=$PACKAGES_PATH
+    PATH_LIST=${PATH_LIST//:/ }
+    for DIR in $PATH_LIST
+    do
+      if [ -f "$DIR/BaseTools/BuildEnv" ]
+      then
+        export EDK_TOOLS_PATH=$DIR/BaseTools
+        . $DIR/BaseTools/BuildEnv $*
+        break
+      fi
+    done
   else
     echo BaseTools not found in your tree, and EDK_TOOLS_PATH is not set.
-    echo Please check that WORKSPACE is not set incorrectly in your
-    echo shell, or point EDK_TOOLS_PATH at the directory that contains
+    echo Please check that WORKSPACE or PACKAGES_PATH is not set incorrectly
+    echo in your shell, or point EDK_TOOLS_PATH at the directory that contains
     echo the EDK2 BuildEnv script.
     return 1
   fi