ba8cd58b08
This is no longer required since the functions automatically get
pulled in based on the usage. A quick summary of footprint
comparisions before and after these set of patches is shown below:
Hello-World: (simplified for readability)
old Total image size:~ 104902 bytes (.bin may be padded larger)
old Total image size:~ 105254 bytes (.bin may be padded larger)
Per-archive contributions to ELF file:
Archive File DRAM .data & .bss IRAM Flash code & rodata Total
old libesp32.a 1973 177 4445 3939 2267 12801
new libesp32.a 1973 185 4473 3939 2267 12837
new libnvs_flash.a 0 92 0 274 8 374
new libstdc++.a 0 0 0 24 0 24
For some reason, nvs_flash.a (~400bytes) gets pulled in (particularly
the nvs_flash_init() function).
Power-Save: (simplified for readability)
old Total image size:~ 421347 bytes (.bin may be padded larger)
old Total image size:~ 421235 bytes (.bin may be padded larger)
old libtcpip_adapter.a 0 81 0 1947 115 2143
new libtcpip_adapter.a 0 69 0 1897 115 2081
The size actually shrinks a bit, since the AP interface function
doesn't get pulled in.
Espressif IoT Development Framework
ESP-IDF is the official development framework for the ESP32 chip.
Developing With the ESP-IDF
Setting Up ESP-IDF
See setup guides for detailed instructions to set up the ESP-IDF:
Finding a Project
As well as the esp-idf-template project mentioned in the setup guide, ESP-IDF comes with some example projects in the examples directory.
Once you've found the project you want to work with, change to its directory and you can configure and build it.
Configuring the Project
make menuconfig
- Opens a text-based configuration menu for the project.
- Use up & down arrow keys to navigate the menu.
- Use Enter key to go into a submenu, Escape key to go out or to exit.
- Type
?to see a help screen. Enter key exits the help screen. - Use Space key, or
YandNkeys to enable (Yes) and disable (No) configuration items with checkboxes "[*]" - Pressing
?while highlighting a configuration item displays help about that item. - Type
/to search the configuration items.
Once done configuring, press Escape multiple times to exit and say "Yes" to save the new configuration when prompted.
Compiling the Project
make all
... will compile app, bootloader and generate a partition table based on the config.
Flashing the Project
When make all finishes, it will print a command line to use esptool.py to flash the chip. However you can also do this from make by running:
make flash
This will flash the entire project (app, bootloader and partition table) to a new chip. The settings for serial port flashing can be configured with make menuconfig.
You don't need to run make all before running make flash, make flash will automatically rebuild anything which needs it.
Viewing Serial Output
The make monitor target uses the idf_monitor tool to display serial output from the ESP32. idf_monitor also has a range of features to decode crash output and interact with the device. Check the documentation page for details.
Exit the monitor by typing Ctrl-].
To flash and monitor output in one pass, you can run:
make flash monitor
Compiling & Flashing Just the App
After the initial flash, you may just want to build and flash just your app, not the bootloader and partition table:
make app- build just the app.make app-flash- flash just the app.
make app-flash will automatically rebuild the app if it needs it.
(In normal development there's no downside to reflashing the bootloader and partition table each time, if they haven't changed.)
Parallel Builds
ESP-IDF supports compiling multiple files in parallel, so all of the above commands can be run as make -jN where N is the number of parallel make processes to run (generally N should be equal to or one more than the number of CPU cores in your system.)
Multiple make functions can be combined into one. For example: to build the app & bootloader using 5 jobs in parallel, then flash everything, and then display serial output from the ESP32 run:
make -j5 flash monitor
The Partition Table
Once you've compiled your project, the "build" directory will contain a binary file with a name like "my_app.bin". This is an ESP32 image binary that can be loaded by the bootloader.
A single ESP32's flash can contain multiple apps, as well as many different kinds of data (calibration data, filesystems, parameter storage, etc). For this reason a partition table is flashed to offset 0x8000 in the flash.
Each entry in the partition table has a name (label), type (app, data, or something else), subtype and the offset in flash where the partition is loaded.
The simplest way to use the partition table is to make menuconfig and choose one of the simple predefined partition tables:
- "Single factory app, no OTA"
- "Factory app, two OTA definitions"
In both cases the factory app is flashed at offset 0x10000. If you make partition_table then it will print a summary of the partition table.
For more details about partition tables and how to create custom variations, view the docs/partition-tables.rst file.
Erasing Flash
The make flash target does not erase the entire flash contents. However it is sometimes useful to set the device back to a totally erased state, particularly when making partition table changes or OTA app updates. To erase the entire flash, run make erase_flash.
This can be combined with other targets, ie make erase_flash flash will erase everything and then re-flash the new app, bootloader and partition table.
Resources
-
Documentation for the latest version: http://esp-idf.readthedocs.io/. This documentation is built from the docs directory of this repository.
-
The esp32.com forum is a place to ask questions and find community resources.
-
Check the Issues section on github if you find a bug or have a feature request. Please check existing Issues before opening a new one.
-
If you're interested in contributing to ESP-IDF, please check the Contributions Guide.