Kubos Project Configuration

For Kubos projects using C, the project configuration is derived from yotta’s configuration system and module.json files.

If a project’s configuration is changed, the new settings will be incorporated during the next execution of kubos build.



Each Kubos target comes with a set of default configuration options. These options describe things like hardware bus availability and communication settings. The config.json file, which lives in the top level directory of a Kubos project, allows users to override any of these options with a custom value.

Under the covers, the target.json and config.json files are used to generate a yotta_config.h file, which contains #define YOTTA_CFG_{option} statements for each defined option. These YOTTA_CFG_* variables can then be referenced within the Kubos project’s source code.

The current configuration of a project can be seen using the kubos config command. Each configuration option in the output will have a comment showing the origin of the value. Anything marked with “application’s config.json” will have been taken from the project’s config.json file. All other comments will have “*-gcc”, which indicates that that option is a default value taken from the corresponding target.json file.

For example:

$ kubos config

  "system": {
    "initAfterFlash": false, // kubos-linux-gcc
    "initAtBoot": false, // kubos-linux-gcc
    "runLevel": 50, // kubos-linux-gcc
    "destDir": "/home/system/usr/local/bin", // kubos-linux-gcc
    "password": "Kubos123" // kubos-linux-gcc

Custom Settings

Users can add new settings to a config.json file which can then be used within their project. These settings will be generated as #define YOTTA_CFG_{user_option} {value} statements during project compilation time.

For example:

  "TEST": {
    "my_address": "1",
    "target_address": "2",
    "port": "10",
    "uart_bus": "K_UART6",
    "uart_baudrate": "115200",
    "usart": {}

Will generate the following statements:


User-Configurable Included Settings

These are settings which may be changed by the user without compromising the target device, but which will automatically be included in the project without a config.json file present.



Kubos Linux file system properties related to Kubos applications

Object Properties:
  • initAfterFlash (boolean) – (Default: false) Specifies whether the application should be started as a background daemon on the target device immediately after being flashed
  • initAtBoot (boolean) – (Default: true) Specifies whether the application should be started on the target device during system initialization. An init script will be generated with the run level specified by runLevel
  • runLevel (number) – (Default: 50. Range: 10-99) The priority of the generated init script. Scripts with lower values will be run first
  • destDir (string) – (Default: “/home/system/usr/local/bin”) Specifies flashing destination directory for all non-application files
  • password (string) – (Default: “Kubos123”) Specifies the root password to be used by ``kubos flash` to successfully connect to the target device


    "system": {
      "initAfterFlash": true,
      "initAtBoot": true,
      "runLevel": 40,
      "destDir": "/home/myUser/storage",
      "password": "password"


The Kubos project’s module.json file is originally based on yotta’s module.json file

Default Configurations

When you run kubos init -l, a module.json file is created for you with some default values:

    "bin": "./source",
    "license": "Apache-2.0",
    "name": "{your-project-name}",
        "url": "git://<repository_url>",
        "type": "git"
    "version": "0.1.0",
    "homepage": "https://<homepage>",
    "description": "Example app running on Kubos Linux."

Relevant Configuration Options

These are the configuration options which are most likely to be changed for a project. (For all other options, refer to yotta’s documentation.)


The module name, which is also used as the file name of the compiled application binary.

By default, this is the project name, however, it can be changed to anything.

Naming rules:

  • Must start with a letter
  • No uppercase letters
  • Numbers are allowed
  • Hyphens are allowed

Relative path to the project’s source code.


Project library dependencies.

To keep Kubos project binaries small, kubos build will only include libraries which have been specified in this object. As a result, if you want to use a Kubos library, it must be specified here, or must be included with another library you specify.

Object Properties:
  • {component} (string) – Project dependency location and/or version

Available dependency name/value pairs (hierarchy denotes included dependencies. Italics denotes yotta targetDependencies):

  • “ccan-json”: “kubos/ccan-json”

  • “cmocka”: “kubos/cmocka”

  • “kubos-hal”: “kubos/kubos-hal”

    • “kubos-hal-linux”: “kubos/kubos-hal-linux”

      • “kubos-hal” : “kubos/kubos-hal”
  • “isis-iobc-supervisor”: “kubos/isis-iobc-supervisor”