android 音頻加載hal so調試

1. 整個加載流程圖

2. 加載hal so的代碼位置

2.1 在audiopolicymanager中的加載位置

diff --git a/frameworks/av/services/audiopolicy/managerdefault/AudioPolicyManager.cpp b/frameworks/av/services/audiopolicy/managerdefault/AudioPolicyManager.cpp
index 632290a933..54ead728ea 100644
--- a/frameworks/av/services/audiopolicy/managerdefault/AudioPolicyManager.cpp
+++ b/frameworks/av/services/audiopolicy/managerdefault/AudioPolicyManager.cpp
@@ -4110,6 +4110,7 @@ status_t AudioPolicyManager::initialize() {
     audio_devices_t inputDeviceTypes = mAvailableInputDevices.types() & ~AUDIO_DEVICE_BIT_IN;
     for (const auto& hwModule : mHwModulesAll) {
         hwModule->setHandle(mpClientInterface->loadHwModule(hwModule->getName()));
+        ALOGW("===weiqifa=== loadHwModule() %s", hwModule->getName());
         if (hwModule->getHandle() == AUDIO_MODULE_HANDLE_NONE) {
             ALOGW("could not open HW module %s", hwModule->getName());
             continue;

2.2 在audioflinger中加載

AudioFlinger.cpp

audio_module_handle_t AudioFlinger::loadHwModule(const char *name)
{
    if (name == NULL) {
        return AUDIO_MODULE_HANDLE_NONE;
    }
    if (!settingsAllowed()) {
        return AUDIO_MODULE_HANDLE_NONE;
    }
    Mutex::Autolock _l(mLock);
    return loadHwModule_l(name);
}

// loadHwModule_l() must be called with AudioFlinger::mLock held
audio_module_handle_t AudioFlinger::loadHwModule_l(const char *name)
{
    for (size_t i = 0; i < mAudioHwDevs.size(); i++) {
        if (strncmp(mAudioHwDevs.valueAt(i)->moduleName(), name, strlen(name)) == 0) {
            ALOGW("loadHwModule() module %s already loaded", name);
            return mAudioHwDevs.keyAt(i);
        }
    }

    sp<DeviceHalInterface> dev;

    int rc = mDevicesFactoryHal->openDevice(name, &dev);
    if (rc) {
        ALOGE("loadHwModule() error %d loading module %s", rc, name);
        return AUDIO_MODULE_HANDLE_NONE;
    }

    mHardwareStatus = AUDIO_HW_INIT;
    rc = dev->initCheck();
    mHardwareStatus = AUDIO_HW_IDLE;
    if (rc) {
        ALOGE("loadHwModule() init check error %d for module %s", rc, name);
        return AUDIO_MODULE_HANDLE_NONE;
    }

    // Check and cache this HAL's level of support for master mute and master
    // volume.  If this is the first HAL opened, and it supports the get
    // methods, use the initial values provided by the HAL as the current
    // master mute and volume settings.

    AudioHwDevice::Flags flags = static_cast<AudioHwDevice::Flags>(0);
    {  // scope for auto-lock pattern
        AutoMutex lock(mHardwareLock);

        if (0 == mAudioHwDevs.size()) {
            mHardwareStatus = AUDIO_HW_GET_MASTER_VOLUME;
            float mv;
            if (OK == dev->getMasterVolume(&mv)) {
                mMasterVolume = mv;
            }

            mHardwareStatus = AUDIO_HW_GET_MASTER_MUTE;
            bool mm;
            if (OK == dev->getMasterMute(&mm)) {
                mMasterMute = mm;
            }
        }

        mHardwareStatus = AUDIO_HW_SET_MASTER_VOLUME;
        if (OK == dev->setMasterVolume(mMasterVolume)) {
            flags = static_cast<AudioHwDevice::Flags>(flags |
                    AudioHwDevice::AHWD_CAN_SET_MASTER_VOLUME);
        }

        mHardwareStatus = AUDIO_HW_SET_MASTER_MUTE;
        if (OK == dev->setMasterMute(mMasterMute)) {
            flags = static_cast<AudioHwDevice::Flags>(flags |
                    AudioHwDevice::AHWD_CAN_SET_MASTER_MUTE);
        }

        mHardwareStatus = AUDIO_HW_IDLE;
    }

    audio_module_handle_t handle = (audio_module_handle_t) nextUniqueId(AUDIO_UNIQUE_ID_USE_MODULE);
    mAudioHwDevs.add(handle, new AudioHwDevice(handle, name, dev, flags));

    ALOGI("loadHwModule() Loaded %s audio interface, handle %d", name, handle);

    return handle;

}

3. 開機日誌

# logcat |grep loadHwModule
  278   278 I AudioFlinger: loadHwModule() Loaded primary audio interface, handle 10
  278   278 I AudioFlinger: loadHwModule() Loaded a2dp audio interface, handle 18
  278   278 I AudioFlinger: loadHwModule() Loaded r_submix audio interface, handle 26

4. so 在系統的位置

0:/ # find / -iname *primary*.so 2>/dev/nul
/vendor/lib/hw/audio.primary.default.so
/vendor/lib/hw/audio.primary.mt8167.so
/vendor/lib/libaudioprimarydevicehalifclient.so
1|Knowin inSight10:/ #