配置文件设计

配置文件

1. 自动生成：src/ohos_config.json 指定 产品的配置文件路径

{
"root_path": "D:\\DevEco-Device-Tool\\Projects\\hi3861\\src",
"board": "hispark_pegasus",
"kernel": "liteos_m",
"product": "wifiiot_hispark_pegasus",
"product_path": "D:\\DevEco-Device-Tool\\Projects\\hi3861\\src\\vendor\\hisilicon\\hispark_pegasus",
"device_path": "D:\\DevEco-Device-Tool\\Projects\\hi3861\\src\\device\\hisilicon\\hispark_pegasus\\sdk_liteos"
}

2. 产品的配置文件： "product_path"

• 配置好各个子系统和对应的部件
• 误导人的：src\build\subsystem_config.json 根本没有被编译进去

{
"product_name": "wifiiot_hispark_pegasus",
    "ohos_version": "OpenHarmony 1.0",
    "device_company": "hisilicon",
    "board": "hispark_pegasus",
    "kernel_type": "liteos_m",
    "kernel_version": "",

    "subsystems": [
      {
        "subsystem": "applications",
        "components": [
          { "component": "app_wifi-iot_sample", "features":[] },
          { "component": "mqtt", "features":[]}
        ]
      }
      ...
  ]
}

3. 各子系统的配饰文件：src\build\lite\components

{
  "components": [
	{
	  "component": "app_wifi-iot_sample",
	  "description": "Wifi iot samples.",
	  "optional": "true",
	  "dirs": [
		"applications/sample/wifi-iot/app"       # 路径
	  ],
	  "targets": [
		"//applications/sample/wifi-iot/app:app"
	  ],
	  "rom": "",
	  "ram": "",
	  "output": [],
	  "adapted_board": [ "hi3861v100" ],
	  "adapted_kernel": [ "liteos_m" ],
	  "features": [],
	  "deps": {
		  "components": [
			"utils_base"      # 依赖组件
		]
	  }
	},
	...
]

{
      "component": "utils_base",
      "description": "Basic macro and type definitions",
      "optional": "true",
      "dirs": [
        "utils/native/lite/include"
      ],
      "targets": [],
      "rom": "0KB",
      "ram": "0KB",
      "output": [ ],
      "adapted_kernel": [
        "liteos_a",
        "liteos_m",
        "linux"
      ],
      "features": [],
      "deps": {}
    },

4. 部件下的 json 文件：

• 不知道有什么用

{
    "name": "@ohos/applications_sample_wifi_iot",
    "version": "",
    "description": "供开发者参考的代码示例。",
    "homePage": "https://gitee.com/openharmony",
    "license": "Apache V2",
    "repository": "https://gitee.com/openharmony/applications_sample_wifi_iot/tree/OpenHarmony-v3.0-LTS",
    "domain": "os",
    "language": "",
    "publishAs": "code-segment",
    "segment": {
        "destPath": "applications/sample/wifi-iot"
    },
    "private": false,
    "scripts": {},
    "tags": [
        "applications"
    ],
    "keywords": [
        "applications",
        "sample",
        "wifi",
        "iot"
    ],

    "envs": [],
    "dirs": [],

    "component": {
        "name": "111",
        "subsystem": "111",
        "syscap": [],
        "features": [],
        "adapted_system_type": [
            "standard",
            "mini",
            "standard"
        ],
        "rom": "",
        "ram": "",
        "deps": {
            "components": [],
            "third_party": []
        },
        "build": {
            "sub_component": [],
            "inner_kits": [],
            "test": []
        }
    }
}

5. 部件下的 gn 文件：

import("//build/lite/config/component/lite_component.gni")

lite_component("app") {
    features = [
       "00_thread:thread_demo",
       "14_pwmbeer:pwm_beer_demo",
	]
}

6. 编译成功的提示

[OHOS INFO] wifiiot_hispark_pegasus build success
[OHOS INFO] cost time: 0:00:13

BUILD.gn 文件

目录：src\build\lite\BUILD.gn

1. Read product configuration profile.（读产品的配置文件）
2. Loop subsystems configured by product.（遍历文件中的子系统）
3. Read OS subsystems profile.（读子系统的配置文件）
4. Loop components configured by product.（遍历系统的配置文件中的部件配置）
5. Check whether the component configured by product is exist.（检查是否存在）
6. Skip component which not configured by product.（跳过那些没有在产品配置文件中写的部件）

3861 中定义模板的位置 src\build\lite\config\BUILDCONFIG.gn

1. executable
2. static_library
3. shared_library
4. source_set
5. action
6. action_foreach

src\build\lite\config\component\lite_component.gni

1. lite_component
2. lite_library
3. build_ext_component
4. ohos_tools
5. generate_notice_file

补充 gn 语法

GN 提供了 gn build 命令从根目录递归构建。

# 根目录的 BUILD.gn 文件
deps = [
    "//module1",  # 引用子目录
    "//module2",
]

# module1/BUILD.gn 文件
static_library("module1_lib") {
    sources = [ "module1.cpp" ]
}

常见的目标类型

# 定义目标（如可执行文件、静态库）
executable("my_app") {
    sources = [ "main.cpp" ]
    deps = [ ":utils_lib" ]  # 依赖其他目标
}

# 自定义模板
template("custom_library") {
    sources = defined_sources
    static_library(target_name) {
        sources = sources
    }
}

变量

# 字符串变量
output_dir = "out/my_app"

# 列表变量
source_files = [ "main.cpp", "utils.cpp" ]

# 布尔值
enable_feature = true

内置变量

1. foreach(product_configed_subsystem, product_cfg.subsystems) 是 GN 中的循环语法，表示对 product_cfg.subsystems 中的每个元素进行遍历，并将当前元素赋值给 product_configed_subsystem