diff --git a/docs/api-guides/build-system.rst b/docs/api-guides/build-system.rst
index ea4925f74..aa4a67032 100644
--- a/docs/api-guides/build-system.rst
+++ b/docs/api-guides/build-system.rst
@@ -506,3 +506,22 @@ For example projects or other projects where you don't want to specify a full sd
 
 To override the name of this file, set the ``SDKCONFIG_DEFAULTS`` environment variable.
 
+
+Save flash arguments
+-------------------------
+
+There're some scenarios that we want to flash the target board without IDF. For this case we want to save the built binaries, esptool.py and esptool write_flash arguments. It's simple to write a script to save binaries and esptool.py. For flash arguments, we can add the following code to application project makefile:
+::
+    print_flash_cmd:
+        echo $(ESPTOOL_WRITE_FLASH_OPTIONS) $(ESPTOOL_ALL_FLASH_ARGS) | sed -e 's:'$(PWD)/build/'::g'
+    
+the original ESPTOOL_ALL_FLASH_ARGS are absolute file name. Usually we want to save relative file name so we can move the bin folder to somewhere else. For this case we can use ``sed`` to convert to relative file name, like what we did in the example above.
+
+When running ``make print_flash_cmd``, it will print the flash arguments:
+::
+    --flash_mode dio --flash_freq 40m --flash_size detect 0x1000 bootloader/bootloader.bin 0x10000 example_app.bin 0x8000 partition_table_unit_test_app.bin
+
+Then use flash arguments as the arguemnts for esptool write_flash arguments:
+::
+    python esptool.py --chip esp32 --port /dev/ttyUSB0 --baud 921600 --before default_reset --after hard_reset write_flash -z --flash_mode dio --flash_freq 40m --flash_size detect 0x1000 bootloader/bootloader.bin 0x10000 example_app.bin 0x8000 partition_table_unit_test_app.bin
+