xref: /docs/en/device-dev/subsystems/subsys-boot-init-plugin.md

# Plug-in Management

## Overview
### Basic Concepts

 - Introduction to begetctl

   begetctl is a CLI-based management tool. For details about this functions, see [Description of begetctl Commands](#table14737791480).

 - bootchart plug-in

   The bootchart plug-in is an open source tool used to evaluate system performance during Linux startup. It automatically collects information such as the CPU usage, disk throughput, and process status, and displays the evaluation result in graphics to facilitate system startup optimization.  

 - bootevent plug-in

   bootevent is a plug-in that records key startup events of the init process and each service. The recorded information includes the event name, startup time of the service associated with the event, and event occurrence time. By using the exported file for trace parsing, you can then optimize the system startup process.

### Constraints

bootchart and bootevent are available only for the standard system, and begetctl is available for both the small system and the standard system.

## How to Develop

### Parameters

 **Table 1** Description of begetctl commands<a name="table14737791480"></a>
| Command| Format and Example| Description|
| :----------  |  :----------  |:--------|
| init group test [stage] | init group test | For details about **stage**, see **ServiceStatus**.|
| param ls [-r] [name] | Displays system parameters.<br>Example:<br>begetctl param ls persist.sys.usb   | N/A|
| param get [name] | Obtains system parameter information.<br>Example:<br>begetctl param get or param get| N/A|
| param set name value| Sets system parameters.<br>Example:<br>begetctl param set ohos.servicectrl.display 1 or param set ohos.servicectrl.display 1| N/A|
| param wait name [value] [timeout] | Waits for system parameters.<br>Example:<br>begetctl param wait persist.sys.usb.config hdc or param wait persist.sys.usb.config hdc| The default value of **timeout** is **30**.|
| param dump [verbose] | Dumps system parameter information.<br>Example:<br>begetctl param dump or param dump| N/A|
| param shell [name] | Enters the parameter shell.<br>Example:<br>begetctl param shell or param shell| N/A|
| timer_stop servicename | Stops the service timer.<br>Example:<br>begetctl timer_stop appspawn | The value of **servicename** can contain a maximum of 96 characters.|
| timer_start servicename timeout | Starts the service timer.<br>Example:<br>begetctl timer_start appspawn | The value of **servicename** can contain a maximum of 96 characters. The default value of **timeout** is **10**. |
| start_service servicename | Starts a service.<br>Example:<br>begetctl start_service appspawn or start_service appspawn| N/A|
| stop_service servicename | Stops a service.<br>Example:<br>begetctl stop_service appspawn or stop_service appspawn| N/A|
| service_control start servicename | Starts a service.<br>Example:<br>begetctl service_control start appspawn or service_control start appspawn| N/A|
| service_control stop servicename | Stops a service.<br>Example:<br>begetctl service_control stop appspawn or service_control stop appspawn | N/A|
| misc_daemon --write_logo xxx.rgb | Writes the startup logo.<br>Example:<br>begetctl misc_daemon --write_logo logo.rgb or misc_daemon --write_logo logo.rgb| The maximum size of an RGB file is **1024*2038**. Only Hi3516D V300 is supported.|
| reboot | Restarts the system.<br>Example:<br>begetctl reboot or reboot|N/A|
| reboot shutdown | Shuts down the system.<br>Example:<br>begetctl reboot shutdown or reboot shutdown|N/A|
| reboot suspend | Suspends the system.<br>Example:<br>begetctl reboot suspend or reboot suspend| N/A|
| reboot updater | Restarts the system and enters updater.<br>Example:<br>begetctl reboot updater or reboot updater| N/A|
| reboot updater[:options] | Restarts the system and enters updater.<br>Example:<br>begetctl reboot updater or reboot updater| N/A|
| reboot flashd | Restarts the system and enters flashd.<br>Example:<br>begetctl reboot flashd or reboot flashd| N/A|
| reboot flashd[:options] | Restarts the system and enters flashd.<br>Example:<br>begetctl reboot flashd or reboot flashd| N/A|
| reboot charge | Restarts the system and enters the charge mode.<br>Example:<br>begetctl reboot charge or reboot charge| N/A|
| reboot loader | Restarts the system and enters the burning mode.<br>Example:<br>begetctl reboot loader or reboot loader| N/A|
| bootchart stop | Stops chart analysis.<br>Example:<br>begetctl bootchart stop | Only rk3568 is supported.|
| bootchart start | Starts chart analysis.<br>Example:<br>begetctl bootchart start | N/A|
| bootchart disable | Disables chart analysis.<br>Example:<br>begetctl bootchart disable | N/A|
| bootchart enable | Enables chart analysis.<br>Example:<br>begetctl bootchart enable | N/A|
| sandbox -s service_name | Moves a service into the sandbox.<br>Example:<br>sandbox -s foundation | N/A|
| sandbox -p process_name | Moves a process into the sandbox.<br>Example:<br>sandbox -p /bin/sh | N/A|
| sandbox -n sandbox_name | Enters the configured system or chipset sandbox.<br>Example:<br>sandbox -n system | N/A|
| sandbox -h | sandbox command help | N/A|
| partitionslot getslot | Obtains the current active slot.<br>Example:<br>begetctl partitionslot getslot or partitionslot getslot| N/A| 
| partitionslot getsuffix slot | Obtains the current matching slot.<br>Example:<br>begetctl partitionslot getsuffix 1 or partitionslot getsuffix 1| N/A|
| partitionslot setactive slot | Sets a partition slot as active.<br>Example:<br>begetctl partitionslot setactive 1 or partitionslot setactive 1| N/A|
| partitionslot setunboot slot | Sets a partition slot as inactive.<br>Example:<br>begetctl partitionslot setunboot 1 or partitionslot setunboot 1| N/A|
| modulectl uninstall moduleName | Uninstalls a dynamic plug-in.<br>Example:<br>modulectl uninstall bootchart | N/A|
| modulectl install moduleName | Installs a dynamic plug-in.<br>Example:<br>modulectl install bootchart | N/A|
| modulectl list | Views the list of dynamic plug-ins.<br>Example:<br>begetctl modulectl list | N/A|
| setloglevel level | Sets the log level to **info**.<br>Example:<br>begetctl setloglevel 1 | The log level ranges from **0** to **4**.|
| getloglevel | Obtains the log level of the init process.<br>Example:<br>begetctl getloglevel | N/A|
| bootevent disable | Disables the bootevent plug-in.<br>Example:<br>begetctl bootevent disable| N/A|
| bootevent enable | Enables the bootevent plug-in.<br>Example:<br>begetctl bootevent enable| N/A|
| dump_service parameter_service trigger | Displays information about all triggers.<br>Example:<br>begetctl dump_service parameter_service trigger | N/A|
| dump_service all | Displays information about all services.<br>Example:<br>begetctl dump_service all | N/A|
| dump_service serviceName | Displays information about a single service.<br>Example:<br>begetctl dump_service param_watcher | N/A|
| dump api | Displays information about APIs of the init process.<br>Example:<br>begetctl dump api | N/A|


### How to Develop
  Add a plug-in. The following uses bootchart as an example:

1. Install the **.so** file and define an independent file to implement the following functions:
      ```c
      static int bootchartEarlyHook(int stage, int prio, void *cookie)
      {
          char enable[4] = {}; // 4 enable size
          uint32_t size = sizeof(enable);
          SystemReadParam("persist.init.bootchart.enabled", enable, &size);
          if (strcmp(enable, "1") != 0) {
              PLUGIN_LOGI("bootchart disabled.");
              return 0;
          }
          InitModuleMgrInstall("libbootchart");
          PLUGIN_LOGI("bootchart enabled.");
          return 0;
      }
      
      MODULE_CONSTRUCTOR(void)
      {
          // Depends on parameter service
          InitAddPostPersistParamLoadHook(0, bootchartEarlyHook);
      }
      ```     
2. Compile the static library **libbootchart\_static** and add it to the **static\_modules** group.
      ```
      group("static_modules") {
        if (!defined(ohos_lite)) {
          deps = [ ":libbootchart_static" ]
        }
      }
      ```
      
3. Initialize the bootchart plug-in.
      ```c
      static int BootchartInit(void)
      {
          if (g_executorId == -1) {
              g_executorId = AddCmdExecutor("bootchart", DoBootchartCmd);
              PLUGIN_LOGI("BootchartInit executorId %d", g_executorId);
          }
          return 0;
      }
      
      MODULE_CONSTRUCTOR(void)
      {
          PLUGIN_LOGI("DoBootchartStart now ...");
          BootchartInit();
      }
      ```
4. Exit the bootchart plug-in.
      ```c
      MODULE_DESTRUCTOR(void)
      {
          PLUGIN_LOGI("DoBootchartStop now ...");
          DoBootchartStop();
          BootchartExit();
      }
      ```
5. Run the bootchart command.
    ```c
    static int DoBootchartCmd(int id, const char *name, int argc, const char **argv)
    {
        PLUGIN_LOGI("DoBootchartCmd argc %d %s", argc, name);
        ...
        return 0;
    }
    ```

### Development Example

#### Bootchart

  Prerequisites

  1. Prepare the bootchart test environment. Specifically, install Python and pycairo by running **pip install pycairo** on Linux.
  2. Decompress **bootchart-master.tar**.

     tar -zxvf  bootchart-master.tar

  Procedure

  1. Start the system.
  2. Run the **begetctl bootchart enable** command.
  3. Restart the system.
  4. Run the **begetctl bootchart stop** command.
  5. Run the **begetctl bootchart disable** command.
  6. Export the following files from the **/data/service/el0/startup/init/** directory and save them to the **bootchart** folder:<br>
        header<br>
        proc_diskstats.log<br>
        proc_ps.log<br>
        proc_stat.log<br>
  7. Run the **tar -zcvf bootchart.tgz *** command to compress the **bootchart.tgz** file (available only for Linux) and copy the compressed file to the **linux:bootchart-master** directory.
  8. Run the following command in the **bootchart-master** directory:
      ```
      python3 pybootchartgui.py -f pdf bootchart.tgz
      ```

  Expected result:

  A **bootchart.pdf** file is generated in the **bootchart-master** directory.

#### bootevent

1. Configure one or more boot events in the **.cfg** file.

    Configure a single boot event.
    ```json
    bootevents : "bootevent.xxxbootevent",
    ```
    Configure multiple boot events.
    ```json
    bootevents : ["bootevent.xxxbootevent1", "bootevent.xxxbootevent2.xxx"],
    ```
> **NOTE**
> 
> The configured event must start with **bootevent**.

2. Send the boot events.

    Call the **SetParameter** API provided by init process to send the boot events. For example, to send the XXXbootevent1 event configured in the previous step, use the following code:
    ```c
    SetParameter("bootevent.XXXbootevent1", "true");
    ```
3. Enable the bootevent function by running the **begetctl bootevent enable** command.

   To disable the bootevent function, run the **begetctl bootevent disable** command and restart the system.

4. Use the exported bootevent file for trace analysis.

    - The exported bootevent file is stored in the **/data/service/el0/startup/init/** directory.
    - It is named in the format of *timestamp***.bootevent**.
    - You can import the file to the trace analysis tool for visual analysis.