Android system Native process creation example

1. Android system environment

Qualcomm 865, Android10

2. Implementation method of compiling cpp code to start the process

1. Create a new TestInit module under the vendor, the directory structure is as follows:

2. The standlog.h file in include

#ifndef VCLOG_H
#define VCLOG_H

#include <android/log.h>
#include <stdio.h>
#define LOG_TAG "testinit"

#define filename(x) strrchr(x, '/') ? strrchr(x, '/') + 1 : x

#define LOGI(...)                                                            \
        do                                                                   \
        {                                                                    \
                printf(__VA_ARGS__);                                         \
                printf("\n");                                                \
                __android_log_print(ANDROID_LOG_INFO, LOG_TAG, __VA_ARGS__); \
        } while (0)

#define LOGE(...)                                                             \
        do                                                                    \
        {                                                                     \
                printf(__VA_ARGS__);                                          \
                printf("\n");                                                 \
                __android_log_print(ANDROID_LOG_ERROR, LOG_TAG, __VA_ARGS__); \
        } while (0)

#define LOGD(...)                                                             \
        do                                                                    \
        {                                                                     \
                printf(__VA_ARGS__);                                          \
                printf("\n");                                                 \
                __android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, __VA_ARGS__); \
        } while (0)

#define LOGW(...)                                                            \
        do                                                                   \
        {                                                                    \
                printf(__VA_ARGS__);                                         \
                printf("\n");                                                \
                __android_log_print(ANDROID_LOG_WARN, LOG_TAG, __VA_ARGS__); \
        } while (0)

#define LOGV(...)                                                               \
        do                                                                      \
        {                                                                       \
                printf(__VA_ARGS__);                                            \
                printf("\n");                                                   \
                __android_log_print(ANDROID_LOG_VERBOSE, LOG_TAG, __VA_ARGS__); \
        } while (0)

#endif

3. The main.cpp code is as follows:

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "standlog.h"

 #define filename(x) strrchr(x, '/') ? strrchr(x, '/') + 1 : x

using namespace std;

int main()
{
    LOGI("%s: %s(%d):%s", filename(__FILE__), __FUNCTION__, __LINE__, "start testinit service");
   printf(">>>>>>>>>>>>>>>testinit main");
    while (true)
    {
        sleep(60 * 60);
    }
    return 0;
}

4. Android.mk code is as follows

LOCAL_PATH:= $(call my-dir)

include $(CLEAR_VARS)
LOCAL_MODULE := testinit # 模块的名称
LOCAL_CFLAGS += -Wno-error=date-time
LOCAL_SRC_FILES = src/main.cpp \
# $(call all-cpp-files-under, src) \ #使用宏定义引入src文件夹下所有的cpp文件
                  

LOCAL_MODULE_TAGS := optional
LOCAL_C_INCLUDES := $(LOCAL_PATH)/include
                 
LOCAL_SHARED_LIBRARIES := \
        liblog \
        libcutils

LOCAL_CPPFLAGS += -fexceptions
LOCAL_INIT_RC := testinit.rc #设置init rc
	         
include $(BUILD_EXECUTABLE)

5、testinit.rc

service testinit /system/bin/testinit
class main #main类，属于main的服务会开机被运行，且死掉会重启 如果设置了class main 那么需要把进程设置一个死循环，然后就会无限重启,详细细看main.cpp
   user root
   group root
   disabled


on property:sys.boot_completed=1
   start testinit

6. Add our module to the compiled file of the project 

vendor/qcom/proprietary/prebuilt_HY11/target/product/qssi/prebuilt.mk

7. Configure selinux

(1), add the following code in device/qcom/sepolicy/qva/private/file_contexts

/system/bin/testinit                            u:object_r:testinit_exec:s0

(2), add testinit.te in the device/qcom/sepolicy/qva/private/ directory

typeattribute testinit coredomain;

init_daemon_domain(testinit)

(3), add testinit.te in the device/qcom/sepolicy/qva/public/ directory

type testinit, domain;
type testinit_exec, exec_type, file_type, system_file_type;

8. Compile and refresh the system to verify whether the process exists

 If the process does not exist, you can check whether the testinit binary file exists in the /system/bin/ directory

ls -l /system/bin/testinit

3. Implementation of integrated binary files

1. Create a new TestNative module under the vendor, the directory structure is as follows:

 2. Android.mk code is as follows

LOCAL_PATH:= $(call my-dir)

include $(CLEAR_VARS)
LOCAL_SRC_FILES := testnative
LOCAL_MODULE := testnative
LOCAL_MODULE_CLASS := EXECUTABLES
LOCAL_MODULE_TAGS := optional
LOCAL_MODULE_PATH := $(PRODUCT_OUT)/system/bin
LOCAL_INIT_RC := testnative.rc
include $(BUILD_PREBUILT)

3、testnative.rc

service testnative /system/bin/testnative
   user root
   group root
   disabled

on property:sys.boot_completed=1
   start testnative

4. Add our module to the compiled file of the project 

vendor/qcom/proprietary/prebuilt_HY11/target/product/qssi/prebuilt.mk

 5. Configure selinux

(1), add the following code in device/qcom/sepolicy/qva/private/file_contexts

/system/bin/testnative                          u:object_r:testnative_exec:s0

(2), add testnative.te in the device/qcom/sepolicy/qva/private/ directory

typeattribute testnative coredomain;

init_daemon_domain(testnative)

(3), add testnative.te in the device/qcom/sepolicy/qva/public/ directory

type testnative, domain;
type testnative_exec, exec_type, file_type, system_file_type;

6. Compile and refresh the system to verify whether the process exists