1# Component 2### Configuration Rules 3 4The **bundle.json** file of a component is stored in the root directory of the component source code. The following example shows how to configure the sensor service component of the pan-sensor subsystem: 5 6```shell 7{ 8 "name": "@ohos/sensor_lite", # OpenHarmony Package Manager (HPM) component name, in the "@Organization/Component name" format. 9 "description": "Sensor services", # Description of the component function. 10 "version": "3.1", # Version, which must be the same as the version of OpenHarmony. 11 "license": "MIT", # Component license. 12 "publishAs": "code-segment", # HPM package release mode. The default value is code-segment. 13 "segment": { 14 "destPath": "" 15 }, # Code restoration path (source code path) set when publishAs is code-segment. 16 "dirs": {"base/sensors/sensor_lite"}, # Directory structure of the HPM package. This field is mandatory and can be left empty. 17 "scripts": {}, # Scripts to be executed. This field is mandatory and can be left empty. 18 "licensePath": "COPYING", 19 "readmePath": { 20 "en": "README.rst" 21 }, 22 "component": { # Component attributes. 23 "name": "sensor_lite", # Component name. 24 "subsystem": "", # Subsystem to which the component belongs. 25 "syscap": [], # System capabilities provided by the component for applications. 26 "features": [], # List of external configurable features of the component. Generally, this parameter corresponds to sub_component in build. 27 "adapted_system_type": [], # Types of adapted systems, which can be mini, small, standard, or their combinations. 28 "rom": "92KB", # Component ROM size. 29 "ram": "~200KB", # Component RAM size. 30 "deps": { 31 "components": [ # Other components on which this component depends. 32 "samgr_lite", 33 "ipc_lite" 34 ], 35 "third_party": [ # Third-party open-source software on which this component depends. 36 "bounds_checking_function" 37 ] 38 } 39 "build": { # Build-related configurations. 40 "sub_component": [ 41 ""//base/sensors/sensor_lite/services:sensor_service"", # Component build entry. 42 ], # Component build entry. Configure modules here. 43 "inner_kits": [], # APIs between components. 44 "test": [] # Entry for building the component's test cases. 45 } 46 } 47 } 48``` 49 50>  **NOTE**<br>Existing components on the LiteOS are configured in the JSON file of the corresponding subsystem in the **build/lite/components** directory. The directory is named in the **{Domain}/{Subsystem}/{Component}** format. The component directory structure is as follows: 51 52```shell 53component 54├── interfaces 55│ ├── innerkits # APIs exposed internally among components 56│ └── kits # APIs provided for application developers 57├── frameworks # Framework implementation 58├── services # Service implementation 59├── BUILD.gn # Build script 60``` 61 62You need to configure the component name, source code path, function description, mandatory or not, build target, RAM, ROM, output, adapted kernel, configurable features, and dependencies. 63 64When adding a component, you must add the component definition to the JSON file of the corresponding subsystem. The component configured for a product must have been defined in a subsystem. Otherwise, the verification will fail. 65 66### Adding and Building a Component 67 681. Add a component. 69 70 The following use a custom component as an example to describe how to compile a library, executable file, and configuration file. 71 72 In this example, **partA** consists of **feature1**, **feature2**, and **feature3**, which represent a dynamic library, an executable file, and an etc configuration file, respectively. 73 74 Add **partA** to a subsystem, for example, **subsystem_examples** (defined in the **test/examples/** directory). 75 76 The directory structure of **partA** is as follows: 77 78 ```shell 79 test/examples/partA 80 ├── feature1 81 │ ├── BUILD.gn 82 │ ├── include 83 │ │ └── helloworld1.h 84 │ └── src 85 │ └── helloworld1.cpp 86 ├── feature2 87 │ ├── BUILD.gn 88 │ ├── include 89 │ │ └── helloworld2.h 90 │ └── src 91 │ └── helloworld2.cpp 92 └── feature3 93 ├── BUILD.gn 94 └── src 95 └── config.conf 96 ``` 97 98 (a) Configure **test/examples/partA/feature1/BUILD.gn** for the dynamic library. 99 100 ```shell 101 config("helloworld_lib_config") { 102 include_dirs = [ "include" ] 103 } 104 105 ohos_shared_library("helloworld_lib") { 106 sources = [ 107 "include/helloworld1.h", 108 "src/helloworld1.cpp", 109 ] 110 public_configs = [ ":helloworld_lib_config" ] 111 part_name = "partA" 112 } 113 ``` 114 115 (b) Configure **test/examples/partA/feature2/BUILD.gn** for the executable file. 116 117 ```shell 118 ohos_executable("helloworld_bin") { 119 sources = [ 120 "src/helloworld2.cpp" 121 ] 122 include_dirs = [ "include" ] 123 deps = [ # Dependent modules in the component 124 "../feature1:helloworld_lib" 125 ] 126 external_deps = [ "partB:module1" ] # (Optional) Dependent modules of another component are named in the Component name:Module name format. 127 install_enable = true # By default, executable programs are not installed. Set this parameter to true if an executable program needs to be installed. 128 part_name = "partA" 129 } 130 ``` 131 132 (c) Configure **test/examples/partA/feature3/BUILD.gn** for the etc module. 133 134 ```shell 135 ohos_prebuilt_etc("feature3_etc") { 136 source = "src/config.conf" 137 relative_install_dir = "init" # (Optional) Relative directory for installing the module. The default installation directory is **/system/etc**. 138 part_name = "partA" 139 } 140 ``` 141 142 (d) Add the module configuration **test/examples/bundle.json** to the **bundle.json** file of the component. Each component has a **bundle.json** file in the root directory of the component. For details, see the [component bundle.json file](subsys-build-component.md#configuration-rules). 143 1442. Add the component to **//vendor/{*product_company*}/{*product_name*}/config.json**. 145 146 For example, add "subsystem_examples:partA" to the product **config.json** file. Then, **partA** will be built and packaged into the distribution. 147 1483. Start the build. 149 150 You can start the build by using the [CLI or hb tool](subsys-build-all.md#build-commands). The following uses the CLI as an example: 151 152 You can run '--build-target componentName' to build a component separately. For example, to build the musl component of hispark_taurus_standard, run the following command: 153 154 ``` 155 ./build.sh --product-name hispark_taurus_standard --build-target musl --ccache 156 ``` 157 158 You can also build a product. For example, to build hispark_taurus_standard, run the following command: 159 160 ```shell 161 ./build.sh --product-name hispark_taurus_standard --ccache 162 ``` 163 1644. Obtain the build result. 165 166 You can obtain the generated files from the **out/hispark_taurus/** directory and the image in the **out/hispark_taurus/packages/phone/images/** directory. 167
