Init.rc file to launch C + + program, through JNI call Java implementation

Function: The mobile phone after the boot to write a flag bit.

There is an implementation, that is, after receiving the power-on broadcast, the startup service reads the flag bits in BP (Java code waits for Ril to be ready),
And write this flag bit to the AP (Java code calls C + +).

Problems encountered later: In practice, it was found that receiving a boot broadcast waits longer and requires writing to the AP time ahead.

Solution:
Start the C + + program in the Init.rc file and invoke the Java implementation via JNI.

The refinement code is as follows:
C + + program code:

#define LOG_TAG "Testmain" #define Log_ndebug 0#include <dlfcn.h> #include <cutils/log.h> #include <utils /log.h> #include <jni.h>using namespace android;void wirtepscalivaltokernel (); int main (int argc, char * argv[])    {Alogi ("Start C");    Wirtepscalivaltokernel ();    Alogi ("Start C End"); return 0;}    void Wirtepscalivaltokernel () {javavm* vm;    jnienv* env;    Start a VM Javavminitargs args;    Javavmoption opt;    opt.optionstring = "-agentlib:jdwp=transport=dt_android_adb,suspend=n,server=y";    Args.version = jni_version_1_4;    Args.options = &opt;    Args.noptions = 1;    args.ignoreunrecognized = Jni_false;    void* Libdvm_dso = Dlopen ("libdvm.so", Rtld_now);    Aloge_if (!libdvm_dso, "Ddmconnection:%s", Dlerror ());    void* Libandroid_runtime_dso = Dlopen ("libandroid_runtime.so", Rtld_now);    Aloge_if (!libandroid_runtime_dso, "Ddmconnection:%s", Dlerror ());    if (!libdvm_dso | |!libandroid_runtime_dso) {GOTO error;  }  Jint (*JNI_CREATEJAVAVM) (javavm** p_vm, jnienv** p_env, void* Vm_args);    JNI_CREATEJAVAVM = (typeof jni_createjavavm) Dlsym (Libdvm_dso, "JNI_CREATEJAVAVM"); ALOGE_IF (!    JNI_CREATEJAVAVM, "Ddmconnection:%s", Dlerror ());    Jint (*registernatives) (jnienv* env, Jclass clazz); Registernatives = (typeof registernatives) Dlsym (Libandroid_runtime_dso, "Java_com_android_internal_util_withframew    Ork_registernatives ");    Aloge_if (!registernatives, "Ddmconnection:%s", Dlerror ()); if (! JNI_CREATEJAVAVM | |    !registernatives) {goto error;        } if (JNI_CREATEJAVAVM (&AMP;VM, &env, &args) = = 0) {Jclass startclass;        Jmethodid Readpsmeth; Register native code if (registernatives (env, 0) = = 0) {Startclass = Env->findclass ("Android/hard            Ware/camera ");                if (startclass) {Alogi ("Startclass is OK");   Readpsmeth = Env->getstaticmethodid (Startclass, "Getcurrentfocusposition", "(I) V");             Readpsmeth = Env->getmethodid (Startclass, "Getcurrentfocusposition", "() I");                int result =-1;                    if (Readpsmeth) {Alogi ("Readpsmeth is OK, result =%d", result);                    result = Env->callstaticintmethod (Startclass, Readpsmeth);                Alogi ("Readpsmeth is OK end, result =%d", result);                }else{aloge ("-->> Readpsmeth is fail");            }}else{Aloge ("Startclass is Fail");    }}} return;error:if (LIBANDROID_RUNTIME_DSO) {dlclose (LIBANDROID_RUNTIME_DSO);    } if (LIBDVM_DSO) {dlclose (LIBDVM_DSO); }}

ANDROID.MK:

Local_path:= $ (call My-dir) include $ (clear_vars) local_module:= testmainlocal_src_files:=         testmain.cpplocal_c_ Includes: =local_module_tags: = optional Englocal_shared_libraries + = Libcutils libutils                              liblog                              Libandroid_runtime                           libnativehelper                           LIBDL include $ (build_executable)

Init.rc Modification:

The class value is main when the boot starts automatically

Service Testmain/system/bin/testmainclass Mainuser Rootoneshot

End

Init.rc file to launch C + + program, through JNI call Java implementation