allow setting work dir and prefix in the environment

diff --git a/summon-arm-toolchain b/summon-arm-toolchain
index 7cb10a51724bbf2884042e632d1c131d7a89f3ef..7665da6c336dbf687b047ae46ac7174628ef2cdd 100755 (executable)
--- a/summon-arm-toolchain
+++ b/summon-arm-toolchain
@@ -14,7 +14,8 @@ set -e
 # You probably want to customize those
 ##############################################################################
 TARGET=arm-eabi                # Or: TARGET=arm-elf
-PREFIX=${HOME}/arm     # Install location of your final toolchain
+[ -z $PREFIX ] && PREFIX=${HOME}/arm   # Install location of your final toolchain
+[ -z $WORKDIR ] && WORKDIR=$PREFIX/work     #temporary directory
 PARALLEL=                      # Or: PARALLEL="-j 5" for 4 CPUs
 # Set to 'sudo' if you need superuser privileges while installing
 SUDO=''