diff --git a/components/app_update/CMakeLists.txt b/components/app_update/CMakeLists.txt
index f1d6b11697..74c0d88fed 100644
--- a/components/app_update/CMakeLists.txt
+++ b/components/app_update/CMakeLists.txt
@@ -48,19 +48,32 @@ if(NOT BOOTLOADER_BUILD)
 
         set(otatool_py ${python} ${COMPONENT_DIR}/otatool.py)
 
-        set(esptool_args --esptool-args before=${CONFIG_ESPTOOLPY_BEFORE} after=${CONFIG_ESPTOOLPY_AFTER})
+        set(esptool_args "--esptool-args;before=${CONFIG_ESPTOOLPY_BEFORE};after=${CONFIG_ESPTOOLPY_AFTER}")
+        set(otatool_args "--partition-table-file;${PARTITION_CSV_PATH}"
+                         "--partition-table-offset;${PARTITION_TABLE_OFFSET}")
+        idf_component_get_property(esptool_py_dir esptool_py COMPONENT_DIR)
 
         add_custom_target(read_otadata DEPENDS "${PARTITION_CSV_PATH}"
-                        COMMAND ${otatool_py} ${esptool_args}
-                        --partition-table-file ${PARTITION_CSV_PATH}
-                        --partition-table-offset ${PARTITION_TABLE_OFFSET}
-                        read_otadata)
+            COMMAND ${CMAKE_COMMAND}
+            -D IDF_PATH="${idf_path}"
+            -D SERIAL_TOOL="${otatool_py}"
+            -D SERIAL_TOOL_ARGS="${esptool_args};${otatool_args};read_otadata"
+            -D WORKING_DIRECTORY="${build_dir}"
+            -P ${esptool_py_dir}/run_serial_tool.cmake
+            WORKING_DIRECTORY ${CMAKE_CURRENT_LIST_DIR}
+            USES_TERMINAL
+            )
 
         add_custom_target(erase_otadata DEPENDS "${PARTITION_CSV_PATH}"
-                        COMMAND ${otatool_py} ${esptool_args}
-                        --partition-table-file ${PARTITION_CSV_PATH}
-                        --partition-table-offset ${PARTITION_TABLE_OFFSET}
-                        erase_otadata)
+            COMMAND ${CMAKE_COMMAND}
+            -D IDF_PATH="${idf_path}"
+            -D SERIAL_TOOL="${otatool_py}"
+            -D SERIAL_TOOL_ARGS="${esptool_args};${otatool_args};erase_otadata"
+            -D WORKING_DIRECTORY="${build_dir}"
+            -P ${esptool_py_dir}/run_serial_tool.cmake
+            WORKING_DIRECTORY ${CMAKE_CURRENT_LIST_DIR}
+            USES_TERMINAL
+            )
 
         idf_component_get_property(main_args esptool_py FLASH_ARGS)
         idf_component_get_property(sub_args esptool_py FLASH_SUB_ARGS)
diff --git a/components/app_update/otatool.py b/components/app_update/otatool.py
index 7a087be16d..ca22001015 100755
--- a/components/app_update/otatool.py
+++ b/components/app_update/otatool.py
@@ -63,8 +63,6 @@ class OtatoolTarget():
             self.target.read_partition(OtatoolTarget.OTADATA_PARTITION, temp_file.name)
             with open(temp_file.name, "rb") as f:
                 self.otadata = f.read()
-        except Exception:
-            self.otadata = None
         finally:
             os.unlink(temp_file.name)
 
diff --git a/components/esptool_py/get_port_args.cmake b/components/esptool_py/get_port_args.cmake
index 867094801c..90f5258611 100644
--- a/components/esptool_py/get_port_args.cmake
+++ b/components/esptool_py/get_port_args.cmake
@@ -3,14 +3,15 @@
 # without needing a CMake re-run)
 set(ESPPORT $ENV{ESPPORT})
 if(NOT ESPPORT)
-    message("Note: ${TOOL} will search for a serial port. To specify a port, set the ESPPORT environment variable.")
+    message("Note: ${SERIAL_TOOL} will search for a serial port. "
+            "To specify a port, set the ESPPORT environment variable.")
 else()
     set(port_arg "-p ${ESPPORT}")
 endif()
 
 set(ESPBAUD $ENV{ESPBAUD})
 if(NOT ESPBAUD)
-    message("Note: ${TOOL} will attempt to set baud rate automatically. "
+    message("Note: ${SERIAL_TOOL} will attempt to set baud rate automatically. "
             "To specify a baud rate, set the ESPBAUD environment variable.")
 else()
     set(baud_arg "-b ${ESPBAUD}")
diff --git a/components/esptool_py/project_include.cmake b/components/esptool_py/project_include.cmake
index cd746a6cda..0297a3a8cd 100644
--- a/components/esptool_py/project_include.cmake
+++ b/components/esptool_py/project_include.cmake
@@ -133,9 +133,9 @@ endif()
 add_custom_target(erase_flash
     COMMAND ${CMAKE_COMMAND}
     -D IDF_PATH="${idf_path}"
-    -D ESPTOOLPY="${ESPTOOLPY}"
-    -D ESPTOOL_ARGS="erase_flash"
-    -P run_esptool.cmake
+    -D SERIAL_TOOL="${ESPTOOLPY}"
+    -D SERIAL_TOOL_ARGS="erase_flash"
+    -P run_serial_tool.cmake
     WORKING_DIRECTORY ${CMAKE_CURRENT_LIST_DIR}
     USES_TERMINAL
     )
@@ -143,10 +143,10 @@ add_custom_target(erase_flash
 add_custom_target(monitor
     COMMAND ${CMAKE_COMMAND}
     -D IDF_PATH="${idf_path}"
-    -D IDF_MONITOR="${idf_path}/tools/idf_monitor.py"
-    -D ELF_FILE="${elf_dir}/${elf}"
+    -D SERIAL_TOOL="${idf_path}/tools/idf_monitor.py"
+    -D SERIAL_TOOL_ARGS="${elf_dir}/${elf}"
     -D WORKING_DIRECTORY="${build_dir}"
-    -P run_idf_monitor.cmake
+    -P run_serial_tool.cmake
     WORKING_DIRECTORY ${CMAKE_CURRENT_LIST_DIR}
     USES_TERMINAL
     )
@@ -332,10 +332,10 @@ function(esptool_py_flash_target target_name main_args sub_args)
     add_custom_target(${target_name}
         COMMAND ${CMAKE_COMMAND}
         -D IDF_PATH="${idf_path}"
-        -D ESPTOOLPY="${ESPTOOLPY}"
-        -D ESPTOOL_ARGS="${main_args};write_flash;@${target_name}_args"
+        -D SERIAL_TOOL="${ESPTOOLPY}"
+        -D SERIAL_TOOL_ARGS="${main_args};write_flash;@${target_name}_args"
         -D WORKING_DIRECTORY="${build_dir}"
-        -P ${esptool_py_dir}/run_esptool.cmake
+        -P ${esptool_py_dir}/run_serial_tool.cmake
         WORKING_DIRECTORY ${CMAKE_CURRENT_LIST_DIR}
         USES_TERMINAL
         )
@@ -373,10 +373,10 @@ $<JOIN:$<TARGET_PROPERTY:${target_name},IMAGES>,\n>")
         add_custom_target(encrypted-${target_name}
             COMMAND ${CMAKE_COMMAND}
             -D IDF_PATH="${idf_path}"
-            -D ESPTOOLPY="${ESPTOOLPY}"
-            -D ESPTOOL_ARGS="${main_args};write_flash;@encrypted_${target_name}_args"
+            -D SERIAL_TOOL="${ESPTOOLPY}"
+            -D SERIAL_TOOL_ARGS="${main_args};write_flash;@encrypted_${target_name}_args"
             -D WORKING_DIRECTORY="${build_dir}"
-            -P ${esptool_py_dir}/run_esptool.cmake
+            -P ${esptool_py_dir}/run_serial_tool.cmake
             WORKING_DIRECTORY ${CMAKE_CURRENT_LIST_DIR}
             USES_TERMINAL
             )
diff --git a/components/esptool_py/run_cmd.cmake b/components/esptool_py/run_cmd.cmake
deleted file mode 100644
index 8eefabbc21..0000000000
--- a/components/esptool_py/run_cmd.cmake
+++ /dev/null
@@ -1,15 +0,0 @@
-if(NOT IDF_PATH)
-    message(FATAL_ERROR "IDF_PATH not set.")
-endif()
-include("${IDF_PATH}/tools/cmake/utilities.cmake")
-spaces2list(CMD)
-
-execute_process(COMMAND ${CMD}
-    WORKING_DIRECTORY "${WORKING_DIRECTORY}"
-    RESULT_VARIABLE result
-    )
-
-if(${result})
-    # No way to have CMake silently fail, unfortunately
-    message(FATAL_ERROR "${TOOL} failed")
-endif()
diff --git a/components/esptool_py/run_esptool.cmake b/components/esptool_py/run_esptool.cmake
deleted file mode 100644
index e632457c36..0000000000
--- a/components/esptool_py/run_esptool.cmake
+++ /dev/null
@@ -1,21 +0,0 @@
-# A CMake script to run esptool commands from within ninja or make
-# or another cmake-based build runner
-#
-# (Needed to expand environment variables, for backwards compatibility.)
-#
-# It is recommended to NOT USE this CMake script if you have the option of
-# running esptool.py directly. This script exists only for use inside CMake builds.
-#
-cmake_minimum_required(VERSION 3.5)
-
-set(TOOL "esptool.py")
-
-if(NOT ESPTOOLPY OR NOT ESPTOOL_ARGS)
-    message(FATAL_ERROR "ESPTOOLPY and ESPTOOL_ARGS must "
-        "be specified on the CMake command line. For direct execution, it is "
-        "strongly recommended to run ${TOOL} directly.")
-endif()
-
-include("${CMAKE_CURRENT_LIST_DIR}/get_port_args.cmake")
-set(CMD "${ESPTOOLPY} ${port_arg} ${baud_arg} ${ESPTOOL_ARGS}")
-include("${CMAKE_CURRENT_LIST_DIR}/run_cmd.cmake")
diff --git a/components/esptool_py/run_idf_monitor.cmake b/components/esptool_py/run_idf_monitor.cmake
deleted file mode 100644
index 56b58de3da..0000000000
--- a/components/esptool_py/run_idf_monitor.cmake
+++ /dev/null
@@ -1,21 +0,0 @@
-# A CMake script to run idf_monitor from within ninja or make
-# or another cmake-based build runner
-#
-# (Needed to expand environment variables, for backwards compatibility.)
-#
-# It is recommended to NOT USE this CMake script if you have the option of
-# running idf_monitor.py directly. This script exists only for use inside CMake builds.
-#
-cmake_minimum_required(VERSION 3.5)
-
-set(TOOL "idf_monitor.py")
-
-if(NOT IDF_MONITOR OR NOT ELF_FILE)
-    message(FATAL_ERROR "IDF_MONITOR and ELF_FILE must "
-        "be specified on the CMake command line. For direct execution, it is "
-        "strongly recommended to run ${TOOL} directly.")
-endif()
-
-include("${CMAKE_CURRENT_LIST_DIR}/get_port_args.cmake")
-set(CMD "${IDF_MONITOR} ${port_arg} ${baud_arg} ${ELF_FILE}")
-include("${CMAKE_CURRENT_LIST_DIR}/run_cmd.cmake")
diff --git a/components/esptool_py/run_serial_tool.cmake b/components/esptool_py/run_serial_tool.cmake
new file mode 100644
index 0000000000..ce8bf93d98
--- /dev/null
+++ b/components/esptool_py/run_serial_tool.cmake
@@ -0,0 +1,51 @@
+# A CMake script to run serial tool commands supporting ESPPORT and
+# ESPBAUD environment variables from within ninja or make or another
+# cmake-based build runner.
+#
+# It is recommended to NOT USE this CMake script if you have the option of
+# running the tool directly. This script exists only for use inside CMake builds.
+cmake_minimum_required(VERSION 3.5)
+
+if(NOT IDF_PATH)
+    message(FATAL_ERROR "IDF_PATH not set.")
+endif()
+
+if(NOT SERIAL_TOOL OR NOT SERIAL_TOOL_ARGS)
+    message(FATAL_ERROR "SERIAL_TOOL and SERIAL_TOOL_ARGS must "
+        "be specified on the CMake command line. For direct execution, it is "
+        "strongly recommended to run ${SERIAL_TOOL} directly.")
+endif()
+
+# Main purpose of this script: we can't expand these environment variables in the main IDF CMake build,
+# because we want to expand them at flashing time not at CMake runtime (so they can change
+# without needing a CMake re-run)
+set(ESPPORT $ENV{ESPPORT})
+if(NOT ESPPORT)
+    message("Note: ${SERIAL_TOOL} will search for a serial port. "
+            "To specify a port, set the ESPPORT environment variable.")
+else()
+    set(port_arg "-p ${ESPPORT}")
+endif()
+
+set(ESPBAUD $ENV{ESPBAUD})
+if(NOT ESPBAUD)
+    message("Note: ${SERIAL_TOOL} will attempt to set baud rate automatically. "
+            "To specify a baud rate, set the ESPBAUD environment variable.")
+else()
+    set(baud_arg "-b ${ESPBAUD}")
+endif()
+
+set(serial_tool_cmd "${SERIAL_TOOL} ${port_arg} ${baud_arg} ${SERIAL_TOOL_ARGS}")
+
+include("${IDF_PATH}/tools/cmake/utilities.cmake")
+spaces2list(serial_tool_cmd)
+
+execute_process(COMMAND ${serial_tool_cmd}
+    WORKING_DIRECTORY "${WORKING_DIRECTORY}"
+    RESULT_VARIABLE result
+    )
+
+if(${result})
+    # No way to have CMake silently fail, unfortunately
+    message(FATAL_ERROR "${SERIAL_TOOL} failed")
+endif()