Merge "Declare example HAL as virtual instance."

    name: "android.hardware.biometrics.fingerprint-service.example",

    vendor: true,

    relative_install_path: "hw",

    init_rc: ["fingerprint-default.rc"],

    vintf_fragments: ["fingerprint-default.xml"],

    init_rc: ["fingerprint-example.rc"],

    vintf_fragments: ["fingerprint-example.xml"],

    local_include_dirs: ["include"],

    srcs: [

        "CancellationSignal.cpp",

# Virtual Fingerprint HAL

This is a virtual HAL implementation that is backed by system properties

instead of actual hardware. It's intended for testing and UI development

on debuggable builds to allow devices to masquerade as alternative device

types and for emulators.

This is a virtual HAL implementation that is backed by system properties instead

of actual hardware. It's intended for testing and UI development on debuggable

builds to allow devices to masquerade as alternative device types and for

emulators.

## Supported Devices

This HAL can be used on emulators, like cuttlefish, or on real devices. Add the

following to your device's `.mk` file to include it:

```

PRODUCT_PACKAGES_DEBUG += android.hardware.biometrics.fingerprint-service.example

```

The virtual HAL will be ignored if a real HAL is also installed on the target

device. Set the `biometric_virtual_enabled` settings and reboot the device to

switch to the virtual HAL. Unset it and reboot again to switch back.

## Getting Started

First, set the type of sensor the device should use, enable the virtual

extensions in the framework, and reboot.

This doesn't work with HIDL and you typically need to have a PIN or password

set for things to work correctly, so this is a good time to set those too.

This doesn't work with HIDL and you typically need to have a PIN or password set

for things to work correctly, so this is a good time to set those too.

```shell

$ adb root

### Enrollments

Next, setup enrollments on the device. This can either be done through

the UI, or via adb. 

Next, setup enrollments on the device. This can either be done through the UI,

or via adb.

#### UI Enrollment

      ```shell

      $ adb shell setprop vendor.fingerprint.virtual.next_enrollment 1:100,100,100:true

      ```

  2. Navigate to `Settings -> Security -> Fingerprint Unlock` and follow the prompts.

2. Navigate to `Settings -> Security -> Fingerprint Unlock` and follow the

   prompts.

3. Verify the enrollments in the UI:

      ```shell

$ adb shell cmd fingerprint sync

```

Note: You may need to do this twice. The templates are checked

as part of some lazy operations, like user switching and startup, which can 

cause the framework to delete the enrollments before the sync operation runs.

Until this is fixed, just run the commands twice as a workaround.

**Note: You may need to do this twice.** The templates are checked as part of

some lazy operations, like user switching and startup, which can cause the

framework to delete the enrollments before the sync operation runs. Until this

is fixed, just run the commands twice as a workaround.

### Authenticate

service vendor.fingerprint-default /vendor/bin/hw/android.hardware.biometrics.fingerprint-service.example

service vendor.fingerprint-example /vendor/bin/hw/android.hardware.biometrics.fingerprint-service.example

    class hal

    user nobody

    group nobody

    <hal format="aidl">

        <name>android.hardware.biometrics.fingerprint</name>

        <version>2</version>

        <fqname>IFingerprint/default</fqname>

        <fqname>IFingerprint/virtual</fqname>

    </hal>

</manifest>

    ABinderProcess_setThreadPoolMaxThreadCount(0);

    std::shared_ptr<Fingerprint> hal = ndk::SharedRefBase::make<Fingerprint>();

    const std::string instance = std::string(Fingerprint::descriptor) + "/default";

    const std::string instance = std::string(Fingerprint::descriptor) + "/virtual";

    binder_status_t status = AServiceManager_addService(hal->asBinder().get(), instance.c_str());

    CHECK_EQ(status, STATUS_OK);