2bad1dd594
build system: General refactoring The original goal here was to support setting different COMPONENT_INCLUDEDIRS/COMPONENT_LDFLAGS based on sdkconfig. It's turned into a general refactor. * The `get_variable` target & associated macros have been replaced with a target that generates a makefile snippet for each component (inside the build directory), and includes these in the project make pass. This improves build speed ( "no-op" `make all` on my system is down from 1.43s (wall) / 0.55s (CPU) to 0.49s (wall) / 0.23s (CPU) due to not forking as many processes) and also makes the builds more debuggable, as you can go and look at the component_project_vars.mk files in the build directory to see what paths are being added where. * Including component_common.mk from component.mk is no longer necessary (and prints a deprecation warning). Instead, component.mk is included from inside a wrapper makefile. This allows default variables and project configuration to be loaded before component.mk begins, and removes the need to split makefile statements arbitrarily between "before including component_common" and "after including component_common", with which goes where depending on internals of the build system. Part-fix for TW#8017. * Rewrote build system docs to reflect these details and also clarify some other points, add more ReST structure. Fixes other issues raised in TW#8017. * Should be backwards compatible with existing components. The only difference I know is the deprecation warning when including component_common.mk. Adds one new failure case: because some paths are encoded in the generated component_project_vars.mk files then reorganising the component directory structure (but not modifying any other files or menuconfig) may cause a partial build to fail and require a `make clean`. Moving the whole project directory, whole build directory, or whole ESP-IDF directory will not trigger this. This failure case should only ever cause a build error, not incorrect build output. See merge request !188
Using Espressif IoT Development Framework with the ESP32
Setting Up ESP-IDF
In the docs directory you will find per-platform setup guides:
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 your project
make menuconfig
Compiling your project
make all
... will compile app, bootloader and generate a partition table based on the config.
Flashing your 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.
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.
(There's no downside to reflashing the bootloader and partition table each time, if they haven't changed.)
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 0x4000 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.
Resources
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The docs directory of the esp-idf repository contains source of esp-idf documentation.
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The esp32.com forum is a place to ask questions and find community resources.
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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.
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If you're interested in contributing to esp-idf, please check the Contributions Guide.