esp32-installer

Installs embedded C libraries into an ESP-IDF project, for any ESP32 chip.

A library written for any project has no idea what an ESP-IDF component is. This copies it into your project's components folder and makes it a component: its own CMakeLists.txt, the ESP-IDF components it uses, its settings in menuconfig, and the symbols it needs in sdkconfig.defaults. Then idf.py build picks it up like any other component.

It works with any library that has an installer.yml at the root of its repository. I wrote it for my own NimaLTD libraries, and they all have one, but nothing in it is tied to them: add an installer.yml to yours, as shown below, and it installs the same way. The same file serves stm32-installer, zephyr-installer, arduino-installer and pio-installer, so one library can be installed into an ESP-IDF project, an STM32 project, a Zephyr application, an Arduino sketch and a PlatformIO project alike.

Every command below uses owner/example, the library's GitHub owner and name, such as nimaltd/ee24. Put the real ones in its place.

Installing a library

Install the installer once. This needs internet:

pip install esp32-installer

Then, from your project's folder, the one holding CMakeLists.txt and main/, install a library by its GitHub owner and name. To see it work first, take esp32-installer-example, a library made for trying the installer on:

esp32-installer nimaltd/esp32-installer-example

It builds for any ESP32 chip, with its settings in menuconfig. Its README walks through an install, a setting changed, an option, and an uninstall. Any other library goes in the same way, as esp32-installer owner/example.

Then build as always:

idf.py build

To update it later, pip install --upgrade esp32-installer. To remove it, pip uninstall esp32-installer.

When a newer esp32-installer is out, the last line of a run says so, with that command. It asks PyPI at most once a day, waits no more than two seconds for an answer, and says nothing when there is none. --no-update-check turns it off, and so does INSTALLER_NO_UPDATE_CHECK set to anything. On a build server, where CI is set, it is off already.

It runs from any shell, ESP-IDF's own included: it needs Python and nothing of ESP-IDF's. On Windows, if esp32-installer is not found after installing, pip put it in a folder that is not on your PATH. python -m esp32_installer owner/example runs the same thing.

Every command

Each command with owner/example standing for the library. An update is the install again. Every option is explained under Options.

What happens

Take example, installed into a project called app:

app/
  CMakeLists.txt           not touched, for a library in components/ that
                           adds no lines of its own here
  sdkconfig.defaults       one block added, with the symbols the library needs
  main/
    CMakeLists.txt         example added to PRIV_REQUIRES, when main lists its own
                           or the project builds only what main names
  components/example/
    src/example.h          the library's files, at the paths they have in its repository
    src/example.c
    CMakeLists.txt         written by the installer: idf_component_register()
    Kconfig                written by the installer: the library's settings

ESP-IDF builds every folder of components/ that has a CMakeLists.txt calling idf_component_register(), so the installer writes one, from the library's installer.yml:

idf_component_register(
    SRCS
        "src/example.c"
    INCLUDE_DIRS
        "src"
    REQUIRES
        esp_timer
)

REQUIRES names the ESP-IDF components the library uses, and the libraries it needs, so their headers are on its include path.

The component is named after its folder, example. A component of the project takes the place of one of ESP-IDF's with the same name, so a library called log would replace ESP-IDF's own logging. When ESP-IDF is set up in the shell you run from, so IDF_PATH is set, the installer checks for that before anything is written, and says to install it into a folder of another name:

Requirements
  check   ESP-IDF has a component called log, and this one would take its place
          Install it into a folder of another name, such as --dir components/log_lib.

main

main is special in ESP-IDF: as long as its idf_component_register() lists no REQUIRES or PRIV_REQUIRES of its own, it uses every component of the project by itself, and nothing in it changes. Once it lists its own, it sees only those, so the installer adds the library to them:

idf_component_register(SRCS "main.c"
                       PRIV_REQUIRES example esp_timer)

Into PRIV_REQUIRES when main has one, otherwise REQUIRES.

A project that builds only what main names leaves out every other component, so there main gets a list even when it had none. ESP-IDF's own examples are built that way, hello_world and blink among them, with idf_build_set_property(MINIMAL_BUILD ON) in the project's CMakeLists.txt, and set(COMPONENTS ...) does the same:

idf_component_register(SRCS "main.c"
                    INCLUDE_DIRS "." PRIV_REQUIRES example)

Without it, #include "example.h" in main would not be found. A component of your own that uses the library lists it the same way, by its folder's name.

sdkconfig.defaults

The Kconfig symbols the library needs go into a block at the end of sdkconfig.defaults, created when the project has none:

# >>> esp32-installer: example >>>
# Added by esp32-installer, and written again on every install, so set
# example's symbols below this block rather than in it.
CONFIG_FREERTOS_HZ=1000
# <<< esp32-installer: example <<<

A library that needs no symbol gets no block. A symbol you already set yourself, on or off, is not set again, since the line read last would quietly undo your choice. It is still written in the block, commented out, with the line that set it:

# CONFIG_FREERTOS_HZ=1000  (left out: sdkconfig.defaults sets CONFIG_FREERTOS_HZ=100)

ESP-IDF reads sdkconfig.defaults only for a symbol your sdkconfig does not have yet, and sdkconfig is what it builds with. So the installer also reads your sdkconfig, and names every symbol it holds at another value:

Requirements
  check   sdkconfig has CONFIG_FREERTOS_HZ=100, and example needs 1000
          sdkconfig is what ESP-IDF builds with. Set it in idf.py menuconfig.

Set it in idf.py menuconfig, or delete sdkconfig to start again from sdkconfig.defaults. The installer never edits sdkconfig itself: ESP-IDF writes that file, and it is yours.

Every file is copied aside before it changes, as sdkconfig.defaults.20261016-190827.bak and the like, and the files keep their own line endings. Installing twice changes nothing the second time.

Settings

A library's settings are Kconfig symbols, in idf.py menuconfig under the library's name, from the Kconfig the installer wrote into its component. Set one there, or in sdkconfig.defaults for a fresh sdkconfig:

CONFIG_EXAMPLE_PERIOD_MS=250

The C code reads it as CONFIG_EXAMPLE_PERIOD_MS, from sdkconfig.h.

A folder outside components

Pressed Enter at the folder question, a library goes into components/<name>, where ESP-IDF finds it by itself. Anywhere else, given with --dir or typed as the answer, ESP-IDF has to be told, so a block goes into your project's CMakeLists.txt, above include(project.cmake), which is when ESP-IDF looks:

cmake_minimum_required(VERSION 3.16)

# >>> esp32-installer: example >>>
# Added by esp32-installer, since example is not in the components folder,
# where ESP-IDF looks by itself. Delete this block to drop it from the build.
list(APPEND EXTRA_COMPONENT_DIRS "${CMAKE_CURRENT_SOURCE_DIR}/libs/example")
# <<< esp32-installer: example <<<

include($ENV{IDF_PATH}/tools/cmake/project.cmake)
project(app)

Lines a library adds to your CMakeLists.txt

A library can need lines of CMake in your project's CMakeLists.txt, and then it says so in its installer.yml: above include(project.cmake), for what ESP-IDF reads as the project starts, or at the end of the file, for what needs the project's own targets. The lines of each place go between two lines that name it:

# >>> esp32-installer: example/before-project >>>
# From example's installer.yml, and written again on every install.
list(APPEND SDKCONFIG_DEFAULTS "${CMAKE_CURRENT_SOURCE_DIR}/example.defaults")
# <<< esp32-installer: example/before-project <<<

Every block is written again on every install, so put your own lines outside them. An edit made inside one is noticed on the next install, and the file as it was is in the .bak.

Files that become yours

A library can bring files that belong to your project rather than to the library, such as a version.txt, which ESP-IDF reads the project's version from, or a file of settings: a start, made for you to change. Each is created in your project's folder only when it is not there:

Files
  written components/example/src/example.h
  created version.txt  yours from now on

From then on it is yours. An update never writes over it, and says so with kept version.txt yours. An uninstall leaves it where it is, with kept version.txt yours, not removed. A library can never put such a file over one the installer manages or reads, CMakeLists.txt, main/CMakeLists.txt, sdkconfig and sdkconfig.defaults, nor outside your project's folder.

Steps a library runs

A library can need something made that no file can carry, such as a key, made fresh for each product. It names a step for that, and once its files are in, the installer shows you exactly what will run, and asks:

Run
  make-key     Make the product's key, product.key
               python tools/make_key.py product.key
               Run it? [Y/n]:

Enter runs it, in your project's folder. A Python script runs with the same Python as the installer, so it works the same on every computer. n leaves it, and the output says how to run it later. In a script, where nobody can answer, it is not run.

Nothing in a library's installer.yml can skip the question. Only you can: --run make-key runs that step without asking, --no-run make-key leaves it, and --yes runs every step and takes the offered answer to every other question, for a script or a build server.

A step that makes a file can name it, and when that file is already in your project the step is skipped without a question, so a second install never makes a second key. A step that names no file and ran before is not asked about again either, until the library changes what it runs. When a step fails, what was installed stays installed, and the installer ends with exit code 1, so a script notices.

What you see

A first install from GitHub, into a project whose main lists its own components:

Fetching owner/example ...

example 1.2.0
Driver for the X chip
driver / storage

Requirements
  note    CONFIG_FREERTOS_HZ=1000 goes into sdkconfig.defaults
  note    Needs I2C, 400 kHz
          Set it up in your code, or in idf.py menuconfig.

Folder to install example into [components/example]:

Files
  written components/example/src/example.h
  written components/example/src/example.c

Project
  updated ESP-IDF component  The component example: wrote CMakeLists.txt, Kconfig.
  updated sdkconfig.defaults  Added example to sdkconfig.defaults.
          backup: sdkconfig.defaults.20261016-190827.bak
  updated main/CMakeLists.txt  Added example to PRIV_REQUIRES in main/CMakeLists.txt, since main lists the components it uses.
          backup: CMakeLists.txt.20261016-190827.bak

Done. #include "example.h" and you are away.

The hardware a library uses is yours to set up, which the installer names but does not do.

What to install

The argument can be any of these, and you can give several at once:

A bare name with no owner, like example, is a NimaLTD library, nimaltd/example on GitHub, unless a folder of that name exists where you run it, in which case the folder is used. A path that does not exist is reported as missing rather than looked up on GitHub.

From GitHub, a library comes from its repository's default branch, the one GitHub shows first, whatever the repository calls it. After an @, a tag, a branch or a commit takes exactly that instead, and so does a GitHub address ending in /tree/v2.0.0. Every file comes from one commit, even when the branch moves on while they download, and the record keeps that commit, so you can always tell what you built with.

Options

Updating a library

Run the same command again. Every file of the library is replaced, so an update updates, and the component's CMakeLists.txt and Kconfig are written again from the new installer.yml, so a source file the new version adds is built without you editing anything. A file that did not change is left alone, so the build does not configure again for nothing.

What you wrote between USER CODE BEGIN and USER CODE END in a library's file is kept. Outside those lines, the next install replaces it, and when that would lose something of yours the file is saved beside it first, as a .bak.

The record of what is installed, and where, is .esp32-installer.json in your project's folder. For each library it also keeps where it came from, down to the commit, the blocks written into your files, and the steps that ran. Keep it in version control with the rest.

Uninstalling a library

esp32-installer --uninstall example

From your project's folder, or with --project. Its block goes from sdkconfig.defaults, and its blocks from CMakeLists.txt when it has any, its name goes from main's REQUIRES and PRIV_REQUIRES, and a list left with nothing in it goes too, the files the installer wrote go from its component, and then the library's own files. Installed and then uninstalled, your project's files are back to the byte they were, except the files that became yours, which stay.

What was yours is saved before it goes, as a .bak beside it: any file of the library you wrote in between its USER CODE lines or changed by hand. A file you put in the library's folder yourself is left where it is, and the folder with it.

A setting you set yourself in sdkconfig.defaults is your line, and it stays. The symbol it sets went with the library, though, so the installer names every such line, for you to take out:

  manual  sdkconfig.defaults  sdkconfig.defaults still sets what came with example, which ESP-IDF no longer knows. Take these lines out:
          CONFIG_EXAMPLE_PERIOD_MS=250

Your sdkconfig still has the library's settings too. ESP-IDF drops a symbol it no longer knows the next time it writes sdkconfig, so there is nothing to do there.

A library another one needs stays, and the installer says which needs it. Name them all, in any order, and each goes after what needs it: esp32-installer --uninstall osal ee24. When the library you took out brought another with it that nothing left needs, the last line names it, with the command that takes it out too.

A library that needs another

You install only the one you want, and what it needs goes in first, each as a component of its own, and the one that needs it lists it in its REQUIRES. It comes from the release the library names for it, or else from its default branch. One already in the project at a version that will do is left alone. Everything is fetched before anything is installed, so when a library cannot be had, your project is left as it was.

Without internet

On a machine that has internet, pip download esp32-installer saves one file, the installer, which needs nothing else. Download the library too, from the green Code button, Download ZIP. Then, on the machine with no internet:

pip install esp32_installer-1.0.0-py3-none-any.whl
esp32-installer D:/Downloads/example-main.zip

If the library needs another, give that zip on the same line. Behind a proxy, set HTTPS_PROXY to its address.

A private repository

A library in a private repository installs the same way, given a GitHub token that can read it. Make one once:

1. Open github.com/settings/personal-access-tokens and click Generate new token.

2. Give it a name and an expiry. Under Resource owner, pick the account or the organisation that owns the repository.

3. Under Repository access, choose Only select repositories and pick the library's repository.

4. Under Permissions, set Contents to Read-only:

   • Older layout: open Repository permissions and change Contents from No access to Read-only.
   • Newer layout: click + Add permissions, tick Contents, then set its access to Read-only.

   Metadata comes with it by itself. Contents is the one that matters: without it the token can see the repository but not read a file of it.

5. Click Generate token, and copy it. GitHub shows it only once.

Then give it with --key:

esp32-installer owner/example --key github_pat_...

Or put it in GITHUB_TOKEN once, and install by name as usual. That keeps it out of your shell's history, where --key leaves it:

Windows, PowerShell:

$env:GITHUB_TOKEN = "github_pat_..."
esp32-installer owner/example

Windows, Command Prompt:

set GITHUB_TOKEN=github_pat_...
esp32-installer owner/example

Linux and macOS:

export GITHUB_TOKEN=github_pat_...
esp32-installer owner/example

--key comes first when both are there. GH_TOKEN works as well, and if you use the gh command, gh auth token prints the token you are signed in with. Whichever way it comes, the token is sent to GitHub and nowhere else.

When the token cannot read the library, the installer says which of these it is:

• It can see the repository, but cannot read its files. The token has no Contents permission, only Metadata. Edit the token, and its value stays the same, so the command you ran keeps working: open the tokens page, click the token's name, click Edit, set Contents to Read-only as in step 4, and click Update at the bottom of the page. Then run the same command again.
• It cannot see the repository. The repository is not in the token's Repository access. Edit the token as above and add it.
• GitHub did not accept the token. It has expired, been revoked, or was copied with a character missing. Make a new one.

A repository of an organisation can need one more step: an organisation that asks for fine-grained tokens to be approved shows the token nothing of its repositories until an owner of the organisation approves it, under its settings, Personal access tokens, Pending requests.

For someone writing a library

Put an installer.yml at the root of the repository. Any library can have one, whoever wrote it, and the one file serves esp32-installer and the other installers alike: each reads its own keys and leaves the others' alone.

Every key esp32-installer reads is below, each with what it does, as a manifest asking for 2.1.0 writes it. Only name and its headers or sources are required; leave out what your library does not need. What changed in 2.1.0, and how a manifest from before reads, is under Paths, from 2.1.0. For a working one to copy, see esp32-installer-example.

name: example                      # the library's name, its component and its folder
description: Driver for the X chip # one line, shown while installing and in menuconfig
repository: https://github.com/owner/example  # where it comes from
license: Apache-2.0                # the licence's SPDX name
version: 1.0.0                     # only when the first header has no @version tag

kind: driver                       # driver, middleware, rtos, protocol, filesystem,
                                   # utility or bsp
category: storage                  # sensor, storage, display, communication, wireless,
                                   # rtos, timing, power, input, math or system
provides: []                       # what it gives other libraries: [rtos] for an RTOS

requires:
  esp32_installer: 2.1.0           # the oldest esp32-installer that reads this file
  libraries:                       # other libraries, installed first when missing
    - osal >= 1.0.0                # no owner means nimaltd; >= the oldest that will do
    - owner/lib                    # anyone else's, as owner/name
    - owner/lib@v1.2.0             # a tag, branch or commit, not its default branch
    - source: owner/other@v2.9.3   # a repository with no installer.yml of its own,
      manifest: manifests/other.yml  # with one this library carries for it
      minimum: 2.9.0               # the oldest version that will do
  kconfig:                         # symbols it needs, set in sdkconfig.defaults
    - FREERTOS_HZ=1000             # SYMBOL=value: y, n, a number, 0x.. or "text"
    - SPI_MASTER_IN_IRAM           # a symbol alone is set to y
  peripherals:                     # hardware it uses, named to the user
    - type: i2c                    # what it is
      count: 1                     # how many
      note: 400 kHz                # how to set it up

install:
  include_dirs: [src]              # include folders, only when the guess is wrong
  defines:                         # given to the library and every component using it,
    - EXAMPLE_FAST                 # NAME or NAME=value

headers:                           # .h files; the first is the one to #include
  - src/example.h                  # every file keeps its path: components/example/src/example.h
  - src/port/*.h                   # a wildcard, matched the way a shell would:
                                   # * inside one folder, ** across any number of them
sources:                           # .c files, the component's SRCS
  - src/example.c
  - from: src/port/spi.c           # a file that goes somewhere of its own,
    to: port/spi.c                 # in the library's folder

options:                           # parts the user chooses at install
  littlefs:                        # the name typed after --with
    description: LittleFS file system on the flash  # the question asked
    libraries:                     # libraries this part needs, installed first
      - littlefs >= 2.11.0
    sources:                       # its files, written like headers and sources above
      - src/example_lfs.c

extras:                            # copied as they are, never compiled
  - LICENSE.md                     # LICENSE.md and NOTICE are the default,
  - NOTICE                         # so leave this out if that is all
  - README.md                      # in the library's folder: components/example/README.md
  - root: tools                    # 2.1.0: tools/ into the project's folder instead, as
                                   # the library's own, written again on every install

once:                              # the project's own files: made when missing,
                                   # then the user's, never replaced or removed
  - version.txt                    # 2.1.0: a path alone lands at that path: version.txt
  - from: config/example.defaults  # to: another place in the project
    to: example.defaults

run:                               # steps run once the files are in, each asked about first
  - label: make-key                # the name typed after --run
    description: Make the product's key, product.key  # shown with the question
    script: tools/make_key.py      # Python, run with the installer's own Python, from the
                                   # project's folder, or {library}/... in the library's
    args: [product.key]            # or command: [program, arguments], with no shell
    unless: product.key            # skipped when this file is in the project already

esp32:                             # read by esp32-installer only
  requires:                        # ESP-IDF components the code uses: its REQUIRES
    - esp_timer
    - esp_driver_i2c
  cmake:                           # lines of CMake, under the place they go:
    component:                     # the component's CMakeLists.txt
      - target_link_libraries(${COMPONENT_LIB} PRIVATE m)
    before-project:                # the project's, above include(project.cmake)
      - list(APPEND EXTRA_COMPONENT_DIRS "{library}/extra")
    after-project: []              # the project's, at its end
  settings:                        # Kconfig symbols for menuconfig, CONFIG_<name> in the code
    - name: EXAMPLE_POLL_CHUNK     # the symbol, best started with the library's name
      type: int                    # bool, int, hex or string
      default: 32                  # required: true or false, a number, 0x.. or text
      range: [1, 32768]            # int and hex only: [smallest, largest]
      prompt: Bytes read per call  # one line, shown in menuconfig
      help: |                      # as many lines as it takes, shown in menuconfig
        A read by polling moves at most this many bytes per call.

Keys only the other installers read, such as requires.stm32_installer, requires.hal_modules and zephyr, can stay in the same file. This installer skips them.

Leave version out. The installer reads the version from the @version tag in the file comment of the first header listed, so it is written in the code and nowhere else.

requires.esp32_installer is the oldest esp32-installer that reads the file correctly. It is checked before anything else in the file is read, so an older installer stops with a message saying to update, rather than read the file wrongly. Write it as three numbers, 1.0.0: unquoted, YAML reads 1.10 as the decimal number 1.1, and that is refused.

A library that uses anything 2.0.0 brings says requires.esp32_installer: 2.0.0: once files in the project's folder, run, groups under esp32.cmake, or a library it needs given with an @ or a manifest. The version also decides where once files go. A manifest asking for 2.0.0 or newer puts them in the project's folder, and one asking for less keeps the meaning it was written for, the library's own folder, so a release tagged before 2.0.0 still installs and builds as it did.

Paths, from 2.1.0

A manifest asking for requires.esp32_installer: 2.1.0 has one rule for every path that names a place in the project's folder: it starts at the project's folder. {library} at its start names the library's own folder instead, wherever --dir put it. A path that names a file of the library, under headers, sources, extras or once, or as a from, is a path in the repository, as always.

And every file is copied to the path it has, unchanged, unless a to says otherwise, so a path alone is all an entry needs: src/example.c lands at src/example.c in the library's folder, so install.layout is gone, flat is refused and mirror says nothing new. A once file lands at its own path in the project's folder: - config/partitions.csv at config/partitions.csv, where before 2.1.0 it was written - from: config/partitions.csv and took only its name. And headers and sources need no files around them; files still reads, but not both at once.

A to gives a file another place, where its list puts files. Under headers, sources and extras that is the library's folder, so - from: src/example.h, to: example.h lands at the top of it, and the include path follows. Under once it is the project's folder, where every once file lands. A root puts an extra in the project's folder instead of the library's: - root: tools takes the library's tools/ to the project's tools/. Code has no root, since it is built in the library's folder, and a once file needs none. Wherever a from would be the same path as its to or root, leave it out: - root: tools is - from: tools, root: tools.

And esp32.cmake gives its lines under the places they go, with no label, where or lines: see More CMake for a library.

An extra with a root lands in the project's folder, as the library's own: a file at root itself, the files of a folder under it with their path below it, those a wildcard matches under it with their names; an extra's to places them the same way in the library's folder. It is written again on every install, a file of it the new version no longer ships is removed, and an uninstall takes it out. A file already there that the installer did not put there is the user's, and is never written over: the install stops and says so.

In every manifest, a wildcard matches the whole path, the way a shell does, and the same whether the library comes from GitHub or a folder: * and ? stay inside one folder, ** crosses any number of them, none included, and [ab] is one of a set. So *.c is the .c files at the top, src/*.c those in src, and src/**/*.c every one below src, however deep. And two files of the code that would land in one place, such as two util.c that flat put side by side, are refused when the manifest is read, where the second used to replace the first without a word.

extras:
  - root: tools                    # tools/keygen.py and tools/keygen.md, into the project's folder
run:
  - label: signing-key
    script: tools/keygen.py        # from the project's folder
    unless: sign_key.pem

A step's script has to be one the install puts in place, an extra with a root or a once file, or with {library}, a file of the library's folder; anything else is refused when the manifest is read. A manifest asking for less than 2.1.0 keeps the meaning it was written for: its script is found in the library as it was fetched, and {library} is left as it is written.

More CMake for a library

A library that needs more than its files and its defines, a library linked in, an option for its compiler, or a line in the project's own CMakeLists.txt, lists the lines under esp32.cmake, under the place each goes:

esp32:
  cmake:
    component:
      - target_link_libraries(${COMPONENT_LIB} PRIVATE m)
      - target_compile_options(${COMPONENT_LIB} PRIVATE -O2)
    before-project:
      - list(APPEND SDKCONFIG_DEFAULTS "${CMAKE_CURRENT_SOURCE_DIR}/example.defaults")
    after-project:
      - idf_component_get_property(main_lib main COMPONENT_LIB)
      - target_compile_definitions(${main_lib} PRIVATE EXAMPLE_IN_MAIN)

The lines of each place are written as one block, between two lines that name the library and the place, # >>> esp32-installer: example/before-project >>> and its pair, in the manifest's order. Every install writes them again: a place whose lines changed is updated, and one the manifest no longer has is taken out. A line keeps the spaces it starts with, so the body of an if() can be indented. {library} in a line names the library's folder, as ${CMAKE_CURRENT_SOURCE_DIR}/components/example in the project's file and ${COMPONENT_DIR} in the component's, wherever --dir put it; anything else in a line is CMake's own, written as it stands. A line holding a colon, as message() often does, goes in quotes, or YAML reads it as a mapping.

An option brings lines of its own under options.<name>.esp32.cmake, the same way, written while it is chosen and taken out by the update that turns it off. Its blocks are named after it and the place, example/littlefs-component, so they never meet the library's.

One thing about SDKCONFIG_DEFAULTS: once it is set, ESP-IDF reads only the files it lists, and no longer sdkconfig.defaults by itself. A group that adds a file to it names sdkconfig.defaults first, when the project has one and nothing set the list yet:

if(NOT SDKCONFIG_DEFAULTS AND EXISTS "${CMAKE_CURRENT_SOURCE_DIR}/sdkconfig.defaults")
    set(SDKCONFIG_DEFAULTS "${CMAKE_CURRENT_SOURCE_DIR}/sdkconfig.defaults")
endif()
list(APPEND SDKCONFIG_DEFAULTS "${CMAKE_CURRENT_SOURCE_DIR}/example.defaults")

A component of headers alone is an interface library, so its lines use INTERFACE where one with sources uses PRIVATE or PUBLIC. The lines run when the user configures the build, the same as a CMakeLists.txt the library ships itself would, so they are the library's to answer for.

The forms from before 2.1.0 still install. A list of groups, each with a label, a where, component when left out, and its lines, writes each group as a block named after its label, example/<label>; a manifest moving to places has its old blocks taken out on the next install, and the new ones written. The form from before 2.0.0, a plain list of lines, is one group in component, written as it always was.

The user has a place in the component's file too. Its last lines are a USER CODE section, empty to start with, and every install keeps what is written in it, the way a configuration header keeps settings:

# USER CODE BEGIN EXAMPLE_CMAKE
target_compile_definitions(${COMPONENT_LIB} PRIVATE EXAMPLE_DEBUG=1)
# USER CODE END EXAMPLE_CMAKE

On an uninstall, a section with something in it is saved as a .bak before the file goes.

Files of the project's own

A file that belongs to the project rather than to the library goes under once: a version.txt, which ESP-IDF reads the project's version from, a file of settings for SDKCONFIG_DEFAULTS, a partition table. It is created in the project's folder when it is missing, and is the user's from then on: never replaced by an update, never removed by an uninstall.

once:
  - version.txt                        # lands at version.txt, its own path
  - from: config/partitions.csv
    to: partitions.csv                 # a place of its own

From 2.1.0 a path alone is a file of the library's repository, landing at the same path in the project, so a repository that keeps these files where the project keeps them needs nothing more. A file that goes somewhere else names it with from, the file in the repository, and to, its place from the project's folder. Before 2.1.0 each entry is a mapping with a from, and a to left out meant the file's name alone, at the top. A once file has no root: it always lands in the project's folder. A folder inside the project is fine.

Each is checked before anything is written. to stays inside the project, names none of the files the installer manages or reads, CMakeLists.txt, main/CMakeLists.txt, sdkconfig, sdkconfig.defaults and the record, and does not point into the library's own folder, which every install replaces. Two entries with one to are refused. And from, like every file a manifest names, stays inside the library: no .., no absolute path, no link leading out of it.

What the user changes in their settings belongs in USER CODE sections of the library's own files, or in menuconfig, not in once, which is for files outside the library.

Steps run after the install

Something no file can carry, such as a key made fresh for each product, is made by a step under run. It runs once the library's files are in, in the project's folder:

extras:
  - root: tools                        # tools/make_key.py, into the project's folder
run:
  - label: make-key
    description: Make the product's key, product.key
    script: tools/make_key.py          # the project's tools/make_key.py
    args: [product.key]
    unless: product.key

• label names the step, typed after --run, in lower case letters, digits, _ and -.
• description is shown with the question.
• script is a Python file, run with the installer's own Python, so it works on every computer the installer does. From 2.1.0 it is a path from the project's folder, where an extra with a root or a once file put it, or {library}/... in the library's folder, see Paths, from 2.1.0; before, it is a file of the library's repository. Or command, a program and its arguments as a list, [openssl, rand, -out, product.key, "32"], run as it is, with no shell. One of the two, never both.
• args are added after either.
• unless names a file the step makes, from the project's folder. When it is there, the step is skipped without a question.

The step sees where things are in its environment: INSTALLER_PROJECT, the project's folder, INSTALLER_LIBRARY, the library's folder in it, INSTALLER_NAME and INSTALLER_VERSION, the library's, and INSTALLER, esp32-installer.

The user is always asked, and is shown exactly what will run. Nothing in the manifest can turn that off, only the user, with --run or --yes. A step with no unless that ran before is not asked about again until what it runs changes, so make it safe to run twice anyway. A step that fails leaves the install as it is and ends the run with exit code 1.

A library it needs

requires.libraries lists the libraries yours needs, each installed first when it is missing or older than the version given:

requires:
  libraries:
    - osal >= 1.0.0                    # no owner means nimaltd: github.com/nimaltd/osal
    - someone/lib                      # anyone else's, by owner and name
    - someone/lib@v1.2.0               # exactly this tag, branch or commit
    - source: littlefs-project/littlefs@v2.11.0
      manifest: manifests/littlefs.yml # an installer.yml for a repository without one
      minimum: 2.11.0

Without an @, a library comes from its repository's default branch. The last form installs a library whose repository has no installer.yml of its own: yours carries one for it, at the path given, written as if it sat at the root of that repository.

Settings in the code

ESP-IDF writes every setting into sdkconfig.h, so the library's code reads it as a macro once it includes that. One header can serve ESP-IDF and any other project, taking the setting from Kconfig when it is there:

#if __has_include("sdkconfig.h")
#include "sdkconfig.h"
#endif

#ifdef CONFIG_EXAMPLE_POLL_CHUNK
#define EXAMPLE_POLL_CHUNK          CONFIG_EXAMPLE_POLL_CHUNK
#endif

#ifndef EXAMPLE_POLL_CHUNK
#define EXAMPLE_POLL_CHUNK          32U
#endif

A bool setting that is off is not defined at all, which is how Kconfig does it, so test it with #ifdef. A string arrives in quotes, ready for C.

Each setting is checked at install, since all of it is written into a Kconfig file: a default of the wrong type, one outside its range, or a name Kconfig would refuse stops the install with the reason, before anything is written.

A library with its own component

A library that ships a CMakeLists.txt of its own, listed under extras or files so it is installed, knows its build better than the installer does. It is used as it is: nothing is written into its folder, and only the project's own files get what they need.

Running the tests

The shared core, core-installer, is a git submodule in src/core, so clone with it:

git clone --recursive https://github.com/nimaltd/esp32-installer.git

In a clone made without --recursive, git submodule update --init fetches it. Then:

python test/run_tests.py

CI also installs two small libraries from test/e2e/ into a project with the installer it just built, one of them with everything 2.0.0 brings: files made once and groups of CMake lines in all three places. It builds the project with ESP-IDF for the linux target, runs it, and checks what it prints, then builds it again for the esp32, and last takes that library out and checks nothing of it is left in the project's files. So every release is known to build with real ESP-IDF.

Support

I write these tools and libraries in my own time and give them away, because good tools should be easy to get. If this one saved you an afternoon, there are two things that genuinely help:

Star the repo. It costs you one click, it helps other engineers find the tool, and it is the main reason I keep going.

Buy me a coffee on Ko-fi. Any amount is a real motivation to keep writing, documenting and maintaining this work.

License

Apache License 2.0. See LICENSE.