diff --git a/tools/dev/flash.sh b/tools/dev/flash.sh
index 5134e7a1f..c81fa0089 100644
--- a/tools/dev/flash.sh
+++ b/tools/dev/flash.sh
@@ -25,13 +25,14 @@ set -e
 : "${FLASH_SERIAL_PORT:=/dev/ttyUSB0}"
 : "${FLASH_OFFSET:=0x210000}"
 
-if [ -z "${IDF_PATH}" ]; then
-    echo "ERROR!  IDF_PATH must be set to root of IDF-SDK to pick up esptool."
+ESP_TOOL=`which esptool.py`
+if [ -z ${ESP_TOOL} ]; then
+    echo "ERROR!  esptool.py not found! IDF_PATH must be set to root of IDF-SDK to pick up esptool. Or install the standalone tool."
     exit -1
 fi
 
 usage() {
-    echo "Usage: $0 [-p <port>] [-b <baud>] <avm_file>"
+    echo "Usage: $ ${0} [-p <port>] [-b <baud>] [-o <offset>] [-l :: flash given .avm file to lib.avm partition] <avm_file>"
 }
 
 if [[ $# -lt 1 ]]; then
@@ -39,7 +40,7 @@ if [[ $# -lt 1 ]]; then
     exit -1
 fi
 
-while getopts 'p:b:h' arg; do
+while getopts 'p:b:o:lh' arg; do
     case ${arg} in
         p)
             FLASH_SERIAL_PORT=${OPTARG}
@@ -47,6 +48,12 @@ while getopts 'p:b:h' arg; do
         b)
             FLASH_BAUD_RATE=${OPTARG}
             ;;
+        o)
+            FLASH_OFFSET=${OPTARG}
+            ;;
+        l)
+            FLASH_OFFSET="0x1D0000"
+            ;;
         h)
             usage
             exit 0
@@ -69,6 +76,7 @@ echo "%%"
 echo "%% Flashing ${1} (size=${filesize}k)"
 echo "%%"
 
+
 exec `which esptool.py` \
     --chip auto \
     --port "${FLASH_SERIAL_PORT}" \