Package index specification

Introduced in Arduino IDE 1.6.4, Boards Manager makes it easy to install and update Arduino platforms. In order toprovide Boards Manager installation support for a platform, a JSON formatted index file must be published. This is thespecification for that file.

Boards Manager functionality is provided byArduino CLI andArduino IDE.

Naming of the JSON index file¶

Many different index files coming from different vendors may be in use, so each vendor should name their own index filein a way that won't conflict with others. The file must be named as follows:

package_YOURNAME_PACKAGENAME_index.json

The prefixpackage_ and the postfix_index.json aremandatory (otherwise the index file is not recognised by theArduino development software) while the choice ofYOURNAME_PACKAGENAME is left to the packager. We suggest using adomain name owned by the packager. For example:

package_arduino.cc_index.json

or

package_example.com_avr_boards_index.json

The index URL is periodically checked for updates, so expect a constant flow of downloads (proportional to the number ofactive users).

JSON Index file contents¶

The root of the JSON index is an array ofpackages:

{"packages":[PACKAGE_XXXX]}

3rd party vendors should use a singlePACKAGE_XXXX that is a dictionary map with the vendor's metadata, a list ofPLATFORMS and a list ofTOOLS. For example:

{"name":"arduino","maintainer":"Arduino LLC","websiteURL":"http://www.arduino.cc/","email":"packages@arduino.cc","platforms":[PLATFORM_AVR,PLATFORM_ARM,PLATFORM_XXXXX,PLATFORM_YYYYY],"tools":[TOOLS_COMPILER_AVR,TOOLS_UPLOADER_AVR,TOOLS_COMPILER_ARM,TOOLS_XXXXXXX,TOOLS_YYYYYYY]}

The metadata fields are:

• name: the folder used for the installed cores. Thevendor folder name of the installed package is determined by this field
  • The value must not contain any characters other than the lettersA-Z anda-z, numbers (0-9), underscores (_), dashes (-), and dots (.).
• maintainer: the extended name of the vendor that is displayed on the Arduino IDE Boards Manager GUI
• websiteURL: the URL to the vendor's website, appears on the Arduino IDE Boards Manager as a "More info" link
• email: the email of the vendor/maintainer

Now, before looking atPLATFORMS, let's explore first howTOOLS are made.

Tools definitions¶

Each tool describes a binary distribution of a command line tool. A tool can be:

• a compiler toolchain
• an uploader
• a file preprocessor
• a debugger
• a program that performs a firmware upgrade
• apluggable discovery
• apluggable monitor

basically anything that can run on the user's host PC and do something useful.

For example, Arduino uses two command line tools for the AVR boards: avr-gcc (the compiler) and avrdude (the uploader).

Tools are mapped as JSON in this way:

{"name":"avr-gcc","version":"7.3.0-atmel3.6.1-arduino7","systems":[{"size":"34683056","checksum":"SHA-256:3903553d035da59e33cff9941b857c3cb379cb0638105dfdf69c97f0acc8e7b5","host":"arm-linux-gnueabihf","archiveFileName":"avr-gcc-7.3.0-atmel3.6.1-arduino7-arm-linux-gnueabihf.tar.bz2","url":"http://downloads.arduino.cc/tools/avr-gcc-7.3.0-atmel3.6.1-arduino7-arm-linux-gnueabihf.tar.bz2"},{"size":"38045723","checksum":"SHA-256:03d322b9df6da17289e9e7c6233c34a8535d9c645c19efc772ba19e56914f339","host":"aarch64-linux-gnu","archiveFileName":"avr-gcc-7.3.0-atmel3.6.1-arduino7-aarch64-pc-linux-gnu.tar.bz2","url":"http://downloads.arduino.cc/tools/avr-gcc-7.3.0-atmel3.6.1-arduino7-aarch64-pc-linux-gnu.tar.bz2"},{"size":"36684546","checksum":"SHA-256:f6ed2346953fcf88df223469088633eb86de997fa27ece117fd1ef170d69c1f8","host":"x86_64-apple-darwin14","archiveFileName":"avr-gcc-7.3.0-atmel3.6.1-arduino7-x86_64-apple-darwin14.tar.bz2","url":"http://downloads.arduino.cc/tools/avr-gcc-7.3.0-atmel3.6.1-arduino7-x86_64-apple-darwin14.tar.bz2"},{"size":"52519412","checksum":"SHA-256:a54f64755fff4cb792a1495e5defdd789902a2a3503982e81b898299cf39800e","host":"i686-mingw32","archiveFileName":"avr-gcc-7.3.0-atmel3.6.1-arduino7-i686-w64-mingw32.zip","url":"http://downloads.arduino.cc/tools/avr-gcc-7.3.0-atmel3.6.1-arduino7-i686-w64-mingw32.zip"},{"size":"37176991","checksum":"SHA-256:954bbffb33545bcdcd473af993da2980bf32e8461ff55a18e0eebc7b2ef69a4c","host":"i686-linux-gnu","archiveFileName":"avr-gcc-7.3.0-atmel3.6.1-arduino7-i686-pc-linux-gnu.tar.bz2","url":"http://downloads.arduino.cc/tools/avr-gcc-7.3.0-atmel3.6.1-arduino7-i686-pc-linux-gnu.tar.bz2"},{"size":"37630618","checksum":"SHA-256:bd8c37f6952a2130ac9ee32c53f6a660feb79bee8353c8e289eb60fdcefed91e","host":"x86_64-linux-gnu","archiveFileName":"avr-gcc-7.3.0-atmel3.6.1-arduino7-x86_64-pc-linux-gnu.tar.bz2","url":"http://downloads.arduino.cc/tools/avr-gcc-7.3.0-atmel3.6.1-arduino7-x86_64-pc-linux-gnu.tar.bz2"}]},

The fieldname andversion are respectively the name and version of the tool. Each tool is uniquely identified bythe triple (packager,name,version).packager (AKA "vendor") is defined by thename value of the tool'spackage. There can be many different versions of the same tool available at the same time, for example:

• (arduino,avr-gcc,5.4.0-atmel3.6.1-arduino2)
• (arduino,avr-gcc,7.3.0-atmel3.6.1-arduino5)
• (arduino,avr-gcc,7.3.0-atmel3.6.1-arduino7)
• (arduino,avrdude,5.11)
• (arduino,avrdude,6.0)
• (arduino,avrdude,6.1)
• .....

Thesystems field lists all availableTools Flavours.

The other fields are:

• url: the download URL of the tool's archive
• archiveFileName: the name of the file saved to disk after the download (some web servers don't provide the filename through the HTTP request)
• size: the size of the archive in bytes
• checksum: the checksum of the archive, used to check if the file has been corrupted. The format isALGORITHM:CHECKSUM, currentlyMD5,SHA-1,SHA-256 algorithm are supported, we recommendSHA-256. On *nix or macOS you can use the commandshasum -a 256 filename to generate SHA-256 checksums. There are free options for Windows, including md5deep. There are also online utilities for generating checksums.

Tools flavours (available builds made for different OS)¶

Each tool version may come in different build flavours for different OS. Each flavour is listed under thesystemsarray. The IDE will take care to install the right flavour for the user's OS by matching thehost value with thefollowing table or fail if a needed flavour is missing.

Thehost value is matched with the regexp, this means that a more specific value for thehost field is allowed (forexample you may writex86_64-apple-darwin14.1 for MacOSX instead of the suggestedx86_64-apple-darwin), by the way,we recommend to keep it simple and stick to the suggested value in the table.

Some OS allows to run different flavours:

This is taken into account when the tools are downloaded (for example if we are on a Windows 64 machine and the neededtool is available only for the Windows 32 flavour, then the Windows 32 flavour will be downloaded and used).

For completeness, the previous exampleavr-gcc comes with builds for:

• ARM Linux 32 (arm-linux-gnueabihf),
• ARM Linux 64 (aarch64-linux-gnu),
• MacOSX 64 (x86_64-apple-darwin14),
• Windows 32 (i686-mingw32),
• Linux 32 (i686-linux-gnu),
• Linux 64 (x86_64-linux-gnu)
• MacOSX Arm64 will use the MacOSX 64 flavour
• Windows 64 will use the Windows 32 flavour
• Windows Arm64 will use the Windows 32 flavour

Note: this information is not used to select the toolchain during compilation. If you want a specific version to beused, you should use the notation{runtime.tools.TOOLNAME-VERSION.path} in the platform.txt.

Platforms definitions¶

Finally, let's see howPLATFORMS are made.

{"name":"Arduino AVR Boards","architecture":"avr","version":"1.6.6","category":"Arduino","help":{"online":"http://www.arduino.cc/en/Reference/HomePage"},"url":"http://downloads.arduino.cc/cores/avr-1.6.6.tar.bz2","archiveFileName":"avr-1.6.6.tar.bz2","checksum":"SHA-256:08ad5db4978ebea22344edc5d77dce0923d8a644da7a14dc8072e883c76058d8","size":"4876916","boards":[{"name":"Arduino Yún"},{"name":"Arduino Uno"},{"name":"Arduino Diecimila"},{"name":"Arduino Nano"},{"name":"Arduino Mega"},{"name":"Arduino MegaADK"},{"name":"Arduino Leonardo"},],"toolsDependencies":[{"packager":"arduino","name":"avr-gcc","version":"4.8.1-arduino5"},{"packager":"arduino","name":"avrdude","version":"6.0.1-arduino5"}],"discoveryDependencies":[{"packager":"arduino","name":"serial-discovery"},{"packager":"arduino","name":"mdns-discovery"}],"monitorDependencies":[{"packager":"arduino","name":"serial-monitor"}]},

Each PLATFORM describes a core for a specific architecture. The fields needed are:

• name: the extended name of the platform that is displayed on the Boards Manager GUI
• architecture: is the architecture of the platform (avr, sam, etc...). It must match the architecture of the core as explained in theArduino platform specification
  • The value must not contain any characters other than the lettersA-Z anda-z, numbers (0-9), underscores (_), dashes (-), and dots (.).
• version: the version of the platform.
• deprecated: (optional) setting totrue causes the platform to be moved to the bottom of all Boards Manager andarduino-cli core listings and marked "DEPRECATED".
• category: this field is reserved, a 3rd party core must set it toContributed
• help/online: is a URL that is displayed on the Arduino IDE's Boards Manager as an "Online Help" link
• url,archiveFileName,size andchecksum: metadata of the core archive file. The meaning is the same as for the TOOLS
• boards: the list of boards supported (note: just the names to display on the Arduino IDE's Boards Manager GUI! the real boards definitions are insideboards.txt inside the core archive file)
• toolsDependencies: the tools needed by this platform. They will be installed by Boards Manager along with the platform. Each tool is referenced by the triple (packager,name,version) as previously said. Note that you can reference tools available in other packages as well, even if no platform of that package is installed.
• discoveryDependencies: the Pluggable Discoveries needed by this platform. These aretools, defined exactly like the ones referenced intoolsDependencies. UnliketoolsDependencies, discoveries are referenced by the pair (packager,name). Theversion is not specified because the latest installed discovery tool will always be used. LiketoolsDependencies they will be installed by Boards Manager along with the platform and can reference tools available in other packages as well, even if no platform of that package is installed.
• monitorDependencies: the Pluggable Monitors needed by this platform. These aretools, defined exactly like the ones referenced intoolsDependencies. UnliketoolsDependencies, monitors are referenced by the pair (packager,name). Theversion is not specified because the latest installed monitor tool will always be used. LiketoolsDependencies they will be installed by Boards Manager along with the platform and can reference tools available in other packages as well, even if no platform of that package is installed.

Theversion field is validated by both Arduino IDE andJSemVer. Here are therules Arduino IDE follows for parsing versions(source):

• Split the version at the- character and continue with the first part.
• If there are no dots (.), parseversion as an integer and form a Version from that integer usingVersion.forIntegers
• If there is one dot, splitversion into two, parse each part as an integer, and form a Version from those integers usingVersion.forIntegers
• Otherwise, simply parseversion into a Version usingVersion.valueOf

Note: if you miss a bracket in the JSON index, then add the URL to your Preferences, and open Boards Manager it cancause the Arduino IDE to no longer load until you have deleted the file from your arduino15 folder.

How a tool's path is determined in platform.txt¶

When the IDE needs a tool, it downloads the corresponding archive file and unpacks the content into a private folderthat can be referenced fromplatform.txt using one of the following properties:

• {runtime.tools.TOOLNAME-VERSION.path}
• {runtime.tools.TOOLNAME.path}

For example, to obtain the avr-gcc 4.8.1 folder we can use{runtime.tools.avr-gcc-4.8.1.path} or{runtime.tools.avr-gcc.path}.

In general the same tool may be provided by different packagers (for example the Arduino packager may provide anarduino:avr-gcc and another 3rd party packager may provide their own3rdparty:avr-gcc). The rules to disambiguateare as follows:

• The property{runtime.tools.TOOLNAME.path} points, in order of priority, to:
  1. the tool, version and packager specified viatoolsDependencies in thepackage_index.json
  2. the highest version of the tool provided by the packager of the current platform
  3. the highest version of the tool provided by the packager of the referenced platform used for compile (see"Referencing another core, variant or tool" for more info)
  4. the highest version of the tool provided by any other packager (in case of tie, the first packager in alphabetical order wins)

• The property{runtime.tools.TOOLNAME-VERSION.path} points, in order of priority, to:
  1. the tool and version provided by the packager of the current platform
  2. the tool and version provided by the packager of the referenced platform used for compile (see"Referencing another core, variant or tool" for more info)
  3. the tool and version provided by any other packager (in case of tie, the first packager in alphabetical order wins)

Example JSON index file¶

{"packages":[{"name":"myboard","maintainer":"Jane Developer","websiteURL":"https://github.com/janedeveloper/myboard","email":"jane@janedeveloper.org","help":{"online":"http://janedeveloper.org/forum/myboard"},"platforms":[{"name":"My Board","architecture":"avr","version":"1.0.0","category":"Contributed","help":{"online":"http://janedeveloper.org/forum/myboard"},"url":"https://janedeveloper.github.io/myboard/myboard-1.0.0.zip","archiveFileName":"myboard-1.0.0.zip","checksum":"SHA-256:ec3ff8a1dc96d3ba6f432b9b837a35fd4174a34b3d2927de1d51010e8b94f9f1","size":"15005","boards":[{"name":"My Board"},{"name":"My Board Pro"}],"toolsDependencies":[{"packager":"arduino","name":"avr-gcc","version":"4.8.1-arduino5"},{"packager":"arduino","name":"avrdude","version":"6.0.1-arduino5"}]},{"name":"My Board","architecture":"avr","version":"1.0.1","category":"Contributed","help":{"online":"http://janedeveloper.org/forum/myboard"},"url":"https://janedeveloper.github.io/myboard/myboard-1.0.1.zip","archiveFileName":"myboard-1.0.1.zip","checksum":"SHA-256:9c86ee28a7ce9fe33e8b07ec643316131e0031b0d22e63bb398902a5fdadbca9","size":"15125","boards":[{"name":"My Board"},{"name":"My Board Pro"}],"toolsDependencies":[{"packager":"arduino","name":"avr-gcc","version":"4.8.1-arduino5"},{"packager":"arduino","name":"avrdude","version":"6.0.1-arduino5"}]}],"tools":[]}]}

In the example there is onePACKAGE, My Board. The package is compatible with the AVR architecture. There are twoversions of thePACKAGE, 1.0.0 and 1.0.1. NoTOOLS needed to be installed so that section was left empty.

Here is the Boards Manager entry created by the example:

Archive structure¶

It must contain a single folder in the root. All files and__MACOSX folder present in the root will be ignored.

Valid structure

.└── avr/    ├── bootloaders    ├── cores    ├── firmwares    ├── libraries    ├── variants    ├── boards.txt    ├── platform.txt    └── programmers.txt

Invalid structure:

.├── avr/│   ├── ...│   ├── boards.txt│   ├── platform.txt│   └── programmers.txt├── folder2└── folder3

Note: the folder structure of the core archive is slightly different from the standard manually installed ArduinoIDE 1.5+ compatible hardware folder structure. You must remove the architecture folder(e.g.,avr orarm), moving allthe files and folders within the architecture folder up a level.

Installation¶

The installation archives contain the Board support files.

Supported formats are.zip,.tar.bz2, and.tar.gz. Starting from Arduino CLI >=0.30.0 support for.tar.xz, and.tar.zst has been added, by the way, if you want to keep compatibility with older versions of Arduino IDE and ArduinoCLI we recommend using one of the older formats.

The folder structure of the core archive is slightly different from the standard manually installed Arduino IDE 1.5+compatible hardware folder structure. You must remove the architecture folder(e.g.,avr orarm), moving all thefiles and folders within the architecture folder up a level.

After adding Boards Manager support for your boards, please share the JSON index file URL on theUnofficial list of 3rd party boards support urls.