samsung: hidl: Add fingerprint 2.1 HAL

Change-Id: Ibd1b7fe7e1847ec28b2450fbf44cc740e5f364ef

hidl/fingerprint/.clang-format

@@ -0,0 +1,11 @@
+BasedOnStyle: Google
+AccessModifierOffset: -2
+AllowShortFunctionsOnASingleLine: Inline
+ColumnLimit: 100
+CommentPragmas: NOLINT:.*
+DerivePointerAlignment: false
+IndentWidth: 4
+PointerAlignment: Left
+TabWidth: 4
+UseTab: Never
+PenaltyExcessCharacter: 32

hidl/fingerprint/Android.mk

@@ -0,0 +1,45 @@
+#
+# Copyright (C) 2019 The LineageOS Project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+LOCAL_PATH := $(call my-dir)
+
+include $(CLEAR_VARS)
+
+LOCAL_SRC_FILES := \
+    BiometricsFingerprint.cpp \
+    service.cpp
+
+LOCAL_SHARED_LIBRARIES := \
+    libbase \
+    libhardware \
+    libhidlbase \
+    libhidltransport \
+    liblog \
+    libutils \
+    android.hardware.biometrics.fingerprint@2.1
+
+ifeq ($(TARGET_SEC_FP_USES_PERCENTAGE_SAMPLES),true)
+    LOCAL_CFLAGS += -DUSES_PERCENTAGE_SAMPLES
+endif
+
+LOCAL_MODULE := android.hardware.biometrics.fingerprint@2.1-service.samsung
+LOCAL_INIT_RC := android.hardware.biometrics.fingerprint@2.1-service.samsung.rc
+LOCAL_MODULE_RELATIVE_PATH := hw
+LOCAL_MODULE_TAGS := optional
+LOCAL_MODULE_OWNER := samsung
+LOCAL_VENDOR_MODULE := true
+
+include $(BUILD_EXECUTABLE)

hidl/fingerprint/BiometricsFingerprint.cpp

@@ -0,0 +1,361 @@
+/*
+ * Copyright (C) 2019 The LineageOS Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#define LOG_TAG "android.hardware.biometrics.fingerprint@2.1-service.samsung"
+
+#include <android-base/logging.h>
+
+#include <hardware/hw_auth_token.h>
+
+#include <hardware/fingerprint.h>
+#include <hardware/hardware.h>
+#include "BiometricsFingerprint.h"
+
+#include <dlfcn.h>
+#include <inttypes.h>
+#include <unistd.h>
+
+namespace android {
+namespace hardware {
+namespace biometrics {
+namespace fingerprint {
+namespace V2_1 {
+namespace implementation {
+
+using RequestStatus = android::hardware::biometrics::fingerprint::V2_1::RequestStatus;
+
+BiometricsFingerprint* BiometricsFingerprint::sInstance = nullptr;
+
+BiometricsFingerprint::BiometricsFingerprint() : mClientCallback(nullptr) {
+    sInstance = this;  // keep track of the most recent instance
+    if (!openHal()) {
+        LOG(ERROR) << "Can't open HAL module";
+    }
+}
+
+BiometricsFingerprint::~BiometricsFingerprint() {
+    if (ss_fingerprint_close() != 0) {
+        LOG(ERROR) << "Can't close HAL module";
+    }
+}
+
+Return<RequestStatus> BiometricsFingerprint::ErrorFilter(int32_t error) {
+    switch (error) {
+        case 0:
+            return RequestStatus::SYS_OK;
+        case -2:
+            return RequestStatus::SYS_ENOENT;
+        case -4:
+            return RequestStatus::SYS_EINTR;
+        case -5:
+            return RequestStatus::SYS_EIO;
+        case -11:
+            return RequestStatus::SYS_EAGAIN;
+        case -12:
+            return RequestStatus::SYS_ENOMEM;
+        case -13:
+            return RequestStatus::SYS_EACCES;
+        case -14:
+            return RequestStatus::SYS_EFAULT;
+        case -16:
+            return RequestStatus::SYS_EBUSY;
+        case -22:
+            return RequestStatus::SYS_EINVAL;
+        case -28:
+            return RequestStatus::SYS_ENOSPC;
+        case -110:
+            return RequestStatus::SYS_ETIMEDOUT;
+        default:
+            LOG(ERROR) << "An unknown error returned from fingerprint vendor library: " << error;
+            return RequestStatus::SYS_UNKNOWN;
+    }
+}
+
+// Translate from errors returned by traditional HAL (see fingerprint.h) to
+// HIDL-compliant FingerprintError.
+FingerprintError BiometricsFingerprint::VendorErrorFilter(int32_t error, int32_t* vendorCode) {
+    *vendorCode = 0;
+    switch (error) {
+        case FINGERPRINT_ERROR_HW_UNAVAILABLE:
+            return FingerprintError::ERROR_HW_UNAVAILABLE;
+        case FINGERPRINT_ERROR_UNABLE_TO_PROCESS:
+            return FingerprintError::ERROR_UNABLE_TO_PROCESS;
+        case FINGERPRINT_ERROR_TIMEOUT:
+            return FingerprintError::ERROR_TIMEOUT;
+        case FINGERPRINT_ERROR_NO_SPACE:
+            return FingerprintError::ERROR_NO_SPACE;
+        case FINGERPRINT_ERROR_CANCELED:
+            return FingerprintError::ERROR_CANCELED;
+        case FINGERPRINT_ERROR_UNABLE_TO_REMOVE:
+            return FingerprintError::ERROR_UNABLE_TO_REMOVE;
+        case FINGERPRINT_ERROR_LOCKOUT:
+            return FingerprintError::ERROR_LOCKOUT;
+        default:
+            if (error >= FINGERPRINT_ERROR_VENDOR_BASE) {
+                // vendor specific code.
+                *vendorCode = error - FINGERPRINT_ERROR_VENDOR_BASE;
+                return FingerprintError::ERROR_VENDOR;
+            }
+    }
+    LOG(ERROR) << "Unknown error from fingerprint vendor library: " << error;
+    return FingerprintError::ERROR_UNABLE_TO_PROCESS;
+}
+
+// Translate acquired messages returned by traditional HAL (see fingerprint.h)
+// to HIDL-compliant FingerprintAcquiredInfo.
+FingerprintAcquiredInfo BiometricsFingerprint::VendorAcquiredFilter(int32_t info,
+                                                                    int32_t* vendorCode) {
+    *vendorCode = 0;
+    switch (info) {
+        case FINGERPRINT_ACQUIRED_GOOD:
+            return FingerprintAcquiredInfo::ACQUIRED_GOOD;
+        case FINGERPRINT_ACQUIRED_PARTIAL:
+            return FingerprintAcquiredInfo::ACQUIRED_PARTIAL;
+        case FINGERPRINT_ACQUIRED_INSUFFICIENT:
+            return FingerprintAcquiredInfo::ACQUIRED_INSUFFICIENT;
+        case FINGERPRINT_ACQUIRED_IMAGER_DIRTY:
+            return FingerprintAcquiredInfo::ACQUIRED_IMAGER_DIRTY;
+        case FINGERPRINT_ACQUIRED_TOO_SLOW:
+            return FingerprintAcquiredInfo::ACQUIRED_TOO_SLOW;
+        case FINGERPRINT_ACQUIRED_TOO_FAST:
+            return FingerprintAcquiredInfo::ACQUIRED_TOO_FAST;
+        default:
+            if (info >= FINGERPRINT_ACQUIRED_VENDOR_BASE) {
+                // vendor specific code.
+                *vendorCode = info - FINGERPRINT_ACQUIRED_VENDOR_BASE;
+                return FingerprintAcquiredInfo::ACQUIRED_VENDOR;
+            }
+    }
+    LOG(ERROR) << "Unknown acquiredmsg from fingerprint vendor library: " << info;
+    return FingerprintAcquiredInfo::ACQUIRED_INSUFFICIENT;
+}
+
+Return<uint64_t> BiometricsFingerprint::setNotify(
+    const sp<IBiometricsFingerprintClientCallback>& clientCallback) {
+    std::lock_guard<std::mutex> lock(mClientCallbackMutex);
+    mClientCallback = clientCallback;
+    // This is here because HAL 2.1 doesn't have a way to propagate a
+    // unique token for its driver. Subsequent versions should send a unique
+    // token for each call to setNotify(). This is fine as long as there's only
+    // one fingerprint device on the platform.
+    return reinterpret_cast<uint64_t>(this);
+}
+
+Return<uint64_t> BiometricsFingerprint::preEnroll() {
+    return ss_fingerprint_pre_enroll();
+}
+
+Return<RequestStatus> BiometricsFingerprint::enroll(const hidl_array<uint8_t, 69>& hat,
+                                                    uint32_t gid, uint32_t timeoutSec) {
+    const hw_auth_token_t* authToken = reinterpret_cast<const hw_auth_token_t*>(hat.data());
+
+    return ErrorFilter(ss_fingerprint_enroll(authToken, gid, timeoutSec));
+}
+
+Return<RequestStatus> BiometricsFingerprint::postEnroll() {
+    return ErrorFilter(ss_fingerprint_post_enroll());
+}
+
+Return<uint64_t> BiometricsFingerprint::getAuthenticatorId() {
+    return ss_fingerprint_get_auth_id();
+}
+
+Return<RequestStatus> BiometricsFingerprint::cancel() {
+    return ErrorFilter(ss_fingerprint_cancel());
+}
+
+Return<RequestStatus> BiometricsFingerprint::enumerate() {
+    if (ss_fingerprint_enumerate != nullptr) {
+        return ErrorFilter(ss_fingerprint_enumerate());
+    }
+
+    return RequestStatus::SYS_UNKNOWN;
+}
+
+Return<RequestStatus> BiometricsFingerprint::remove(uint32_t gid, uint32_t fid) {
+    return ErrorFilter(ss_fingerprint_remove(gid, fid));
+}
+
+Return<RequestStatus> BiometricsFingerprint::setActiveGroup(uint32_t gid,
+                                                            const hidl_string& storePath) {
+    if (storePath.size() >= PATH_MAX || storePath.size() <= 0) {
+        LOG(ERROR) << "Bad path length: " << storePath.size();
+        return RequestStatus::SYS_EINVAL;
+    }
+
+    if (access(storePath.c_str(), W_OK)) {
+        return RequestStatus::SYS_EINVAL;
+    }
+
+    return ErrorFilter(ss_fingerprint_set_active_group(gid, storePath.c_str()));
+}
+
+Return<RequestStatus> BiometricsFingerprint::authenticate(uint64_t operationId, uint32_t gid) {
+    return ErrorFilter(ss_fingerprint_authenticate(operationId, gid));
+}
+
+IBiometricsFingerprint* BiometricsFingerprint::getInstance() {
+    if (!sInstance) {
+        sInstance = new BiometricsFingerprint();
+    }
+    return sInstance;
+}
+
+bool BiometricsFingerprint::openHal() {
+    void* handle = dlopen("libbauthserver.so", RTLD_NOW);
+    if (handle) {
+        int err;
+
+        ss_fingerprint_close =
+            reinterpret_cast<typeof(ss_fingerprint_close)>(dlsym(handle, "ss_fingerprint_close"));
+        ss_fingerprint_open =
+            reinterpret_cast<typeof(ss_fingerprint_open)>(dlsym(handle, "ss_fingerprint_open"));
+
+        ss_set_notify_callback = reinterpret_cast<typeof(ss_set_notify_callback)>(
+            dlsym(handle, "ss_set_notify_callback"));
+        ss_fingerprint_pre_enroll = reinterpret_cast<typeof(ss_fingerprint_pre_enroll)>(
+            dlsym(handle, "ss_fingerprint_pre_enroll"));
+        ss_fingerprint_enroll =
+            reinterpret_cast<typeof(ss_fingerprint_enroll)>(dlsym(handle, "ss_fingerprint_enroll"));
+        ss_fingerprint_post_enroll = reinterpret_cast<typeof(ss_fingerprint_post_enroll)>(
+            dlsym(handle, "ss_fingerprint_post_enroll"));
+        ss_fingerprint_get_auth_id = reinterpret_cast<typeof(ss_fingerprint_get_auth_id)>(
+            dlsym(handle, "ss_fingerprint_get_auth_id"));
+        ss_fingerprint_cancel =
+            reinterpret_cast<typeof(ss_fingerprint_cancel)>(dlsym(handle, "ss_fingerprint_cancel"));
+        ss_fingerprint_enumerate = reinterpret_cast<typeof(ss_fingerprint_enumerate)>(
+            dlsym(handle, "ss_fingerprint_enumerate"));
+        ss_fingerprint_remove =
+            reinterpret_cast<typeof(ss_fingerprint_remove)>(dlsym(handle, "ss_fingerprint_remove"));
+        ss_fingerprint_set_active_group = reinterpret_cast<typeof(ss_fingerprint_set_active_group)>(
+            dlsym(handle, "ss_fingerprint_set_active_group"));
+        ss_fingerprint_authenticate = reinterpret_cast<typeof(ss_fingerprint_authenticate)>(
+            dlsym(handle, "ss_fingerprint_authenticate"));
+
+        if ((err = ss_fingerprint_open(nullptr)) != 0) {
+            LOG(ERROR) << "Can't open fingerprint, error: " << err;
+            return false;
+        }
+
+        if ((err = ss_set_notify_callback(BiometricsFingerprint::notify)) != 0) {
+            LOG(ERROR) << "Can't register fingerprint module callback, error: " << err;
+            return false;
+        }
+
+        return true;
+    }
+
+    return false;
+}
+
+void BiometricsFingerprint::notify(const fingerprint_msg_t* msg) {
+    BiometricsFingerprint* thisPtr =
+        static_cast<BiometricsFingerprint*>(BiometricsFingerprint::getInstance());
+    std::lock_guard<std::mutex> lock(thisPtr->mClientCallbackMutex);
+    if (thisPtr == nullptr || thisPtr->mClientCallback == nullptr) {
+        LOG(ERROR) << "Receiving callbacks before the client callback is registered.";
+        return;
+    }
+    const uint64_t devId = 1;
+    switch (msg->type) {
+        case FINGERPRINT_ERROR: {
+            int32_t vendorCode = 0;
+            FingerprintError result = VendorErrorFilter(msg->data.error, &vendorCode);
+            LOG(DEBUG) << "onError(" << static_cast<int>(result) << ")";
+            if (!thisPtr->mClientCallback->onError(devId, result, vendorCode).isOk()) {
+                LOG(ERROR) << "failed to invoke fingerprint onError callback";
+            }
+        } break;
+        case FINGERPRINT_ACQUIRED: {
+            int32_t vendorCode = 0;
+            FingerprintAcquiredInfo result =
+                VendorAcquiredFilter(msg->data.acquired.acquired_info, &vendorCode);
+            LOG(DEBUG) << "onAcquired(" << static_cast<int>(result) << ")";
+            if (!thisPtr->mClientCallback->onAcquired(devId, result, vendorCode).isOk()) {
+                LOG(ERROR) << "failed to invoke fingerprint onAcquired callback";
+            }
+        } break;
+        case FINGERPRINT_TEMPLATE_ENROLLING:
+            LOG(DEBUG) << "onEnrollResult(fid=" << msg->data.enroll.finger.fid
+                       << ", gid=" << msg->data.enroll.finger.gid
+                       << ", rem=" << msg->data.enroll.samples_remaining << ")";
+            if (thisPtr->mClientCallback
+                    ->onEnrollResult(devId, msg->data.enroll.finger.fid,
+                                     msg->data.enroll.finger.gid, msg->data.enroll.samples_remaining)
+                    .isOk()) {
+#ifdef USES_PERCENTAGE_SAMPLES
+                fingerprint_msg_t* newMsg = (fingerprint_msg_t*)msg;
+                newMsg->data.enroll.samples_remaining = 100 - msg->data.enroll.samples_remaining;
+                msg = newMsg;
+#endif
+            } else {
+                LOG(ERROR) << "failed to invoke fingerprint onEnrollResult callback";
+            }
+            break;
+        case FINGERPRINT_TEMPLATE_REMOVED:
+            LOG(DEBUG) << "onRemove(fid=" << msg->data.removed.finger.fid
+                       << ", gid=" << msg->data.removed.finger.gid
+                       << ", rem=" << msg->data.removed.remaining_templates << ")";
+            if (!thisPtr->mClientCallback
+                     ->onRemoved(devId, msg->data.removed.finger.fid, msg->data.removed.finger.gid,
+                                 msg->data.removed.remaining_templates)
+                     .isOk()) {
+                LOG(ERROR) << "failed to invoke fingerprint onRemoved callback";
+            }
+            break;
+        case FINGERPRINT_AUTHENTICATED:
+            LOG(DEBUG) << "onAuthenticated(fid=" << msg->data.authenticated.finger.fid
+                       << ", gid=" << msg->data.authenticated.finger.gid << ")";
+            if (msg->data.authenticated.finger.fid != 0) {
+                const uint8_t* hat = reinterpret_cast<const uint8_t*>(&msg->data.authenticated.hat);
+                const hidl_vec<uint8_t> token(
+                    std::vector<uint8_t>(hat, hat + sizeof(msg->data.authenticated.hat)));
+                if (!thisPtr->mClientCallback
+                         ->onAuthenticated(devId, msg->data.authenticated.finger.fid,
+                                           msg->data.authenticated.finger.gid, token)
+                         .isOk()) {
+                    LOG(ERROR) << "failed to invoke fingerprint onAuthenticated callback";
+                }
+            } else {
+                // Not a recognized fingerprint
+                if (!thisPtr->mClientCallback
+                         ->onAuthenticated(devId, msg->data.authenticated.finger.fid,
+                                           msg->data.authenticated.finger.gid, hidl_vec<uint8_t>())
+                         .isOk()) {
+                    LOG(ERROR) << "failed to invoke fingerprint onAuthenticated callback";
+                }
+            }
+            break;
+        case FINGERPRINT_TEMPLATE_ENUMERATING:
+            LOG(DEBUG) << "onEnumerate(fid=" << msg->data.enumerated.finger.fid
+                       << ", gid=" << msg->data.enumerated.finger.gid
+                       << ", rem=" << msg->data.enumerated.remaining_templates << ")";
+            if (!thisPtr->mClientCallback
+                     ->onEnumerate(devId, msg->data.enumerated.finger.fid,
+                                   msg->data.enumerated.finger.gid,
+                                   msg->data.enumerated.remaining_templates)
+                     .isOk()) {
+                LOG(ERROR) << "failed to invoke fingerprint onEnumerate callback";
+            }
+            break;
+    }
+}
+
+}  // namespace implementation
+}  // namespace V2_1
+}  // namespace fingerprint
+}  // namespace biometrics
+}  // namespace hardware
+}  // namespace android

hidl/fingerprint/BiometricsFingerprint.h

@@ -0,0 +1,97 @@
+/*
+ * Copyright (C) 2019 The LineageOS Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ANDROID_HARDWARE_BIOMETRICS_FINGERPRINT_V2_1_BIOMETRICSFINGERPRINT_H
+#define ANDROID_HARDWARE_BIOMETRICS_FINGERPRINT_V2_1_BIOMETRICSFINGERPRINT_H
+
+#include <android/hardware/biometrics/fingerprint/2.1/IBiometricsFingerprint.h>
+#include <hardware/fingerprint.h>
+#include <hardware/hardware.h>
+#include <hidl/MQDescriptor.h>
+#include <hidl/Status.h>
+
+namespace android {
+namespace hardware {
+namespace biometrics {
+namespace fingerprint {
+namespace V2_1 {
+namespace implementation {
+
+using ::android::sp;
+using ::android::hardware::hidl_string;
+using ::android::hardware::hidl_vec;
+using ::android::hardware::Return;
+using ::android::hardware::Void;
+using ::android::hardware::biometrics::fingerprint::V2_1::IBiometricsFingerprint;
+using ::android::hardware::biometrics::fingerprint::V2_1::IBiometricsFingerprintClientCallback;
+using ::android::hardware::biometrics::fingerprint::V2_1::RequestStatus;
+
+struct BiometricsFingerprint : public IBiometricsFingerprint {
+    BiometricsFingerprint();
+    ~BiometricsFingerprint();
+
+    // Method to wrap legacy HAL with BiometricsFingerprint class
+    static IBiometricsFingerprint* getInstance();
+
+    // Methods from ::android::hardware::biometrics::fingerprint::V2_1::IBiometricsFingerprint follow.
+    Return<uint64_t> setNotify(
+        const sp<IBiometricsFingerprintClientCallback>& clientCallback) override;
+    Return<uint64_t> preEnroll() override;
+    Return<RequestStatus> enroll(const hidl_array<uint8_t, 69>& hat, uint32_t gid,
+                                 uint32_t timeoutSec) override;
+    Return<RequestStatus> postEnroll() override;
+    Return<uint64_t> getAuthenticatorId() override;
+    Return<RequestStatus> cancel() override;
+    Return<RequestStatus> enumerate() override;
+    Return<RequestStatus> remove(uint32_t gid, uint32_t fid) override;
+    Return<RequestStatus> setActiveGroup(uint32_t gid, const hidl_string& storePath) override;
+    Return<RequestStatus> authenticate(uint64_t operationId, uint32_t gid) override;
+
+  private:
+    bool openHal();
+    static void notify(
+        const fingerprint_msg_t* msg); /* Static callback for legacy HAL implementation */
+    static Return<RequestStatus> ErrorFilter(int32_t error);
+    static FingerprintError VendorErrorFilter(int32_t error, int32_t* vendorCode);
+    static FingerprintAcquiredInfo VendorAcquiredFilter(int32_t error, int32_t* vendorCode);
+    static BiometricsFingerprint* sInstance;
+
+    std::mutex mClientCallbackMutex;
+    sp<IBiometricsFingerprintClientCallback> mClientCallback;
+
+    int (*ss_fingerprint_close)();
+    int (*ss_fingerprint_open)(const char* id);
+
+    int (*ss_set_notify_callback)(fingerprint_notify_t notify);
+    uint64_t (*ss_fingerprint_pre_enroll)();
+    int (*ss_fingerprint_enroll)(const hw_auth_token_t* hat, uint32_t gid, uint32_t timeout_sec);
+    int (*ss_fingerprint_post_enroll)();
+    uint64_t (*ss_fingerprint_get_auth_id)();
+    int (*ss_fingerprint_cancel)();
+    int (*ss_fingerprint_enumerate)();
+    int (*ss_fingerprint_remove)(uint32_t gid, uint32_t fid);
+    int (*ss_fingerprint_set_active_group)(uint32_t gid, const char* store_path);
+    int (*ss_fingerprint_authenticate)(uint64_t operation_id, uint32_t gid);
+};
+
+}  // namespace implementation
+}  // namespace V2_1
+}  // namespace fingerprint
+}  // namespace biometrics
+}  // namespace hardware
+}  // namespace android
+
+#endif  // ANDROID_HARDWARE_BIOMETRICS_FINGERPRINT_V2_1_BIOMETRICSFINGERPRINT_H

hidl/fingerprint/android.hardware.biometrics.fingerprint@2.1-service.samsung.rc

@@ -0,0 +1,8 @@
+service vendor.fps_hal /vendor/bin/hw/android.hardware.biometrics.fingerprint@2.1-service.samsung
+    # "class hal" causes a race condition on some devices due to files created
+    # in /data. As a workaround, postpone startup until later in boot once
+    # /data is mounted.
+    class late_start
+    user system
+    group system input
+    writepid /dev/cpuset/system-background/tasks

hidl/fingerprint/service.cpp

@@ -0,0 +1,51 @@
+/*
+ * Copyright (C) 2019 The LineageOS Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#define LOG_TAG "android.hardware.biometrics.fingerprint@2.1-service.samsung"
+
+#include <android-base/logging.h>
+#include <hidl/HidlTransportSupport.h>
+#include <utils/Errors.h>
+
+#include "BiometricsFingerprint.h"
+
+using android::hardware::configureRpcThreadpool;
+using android::hardware::joinRpcThreadpool;
+
+using android::hardware::biometrics::fingerprint::V2_1::IBiometricsFingerprint;
+using android::hardware::biometrics::fingerprint::V2_1::implementation::BiometricsFingerprint;
+
+using android::OK;
+using android::sp;
+
+int main() {
+    android::sp<IBiometricsFingerprint> bio = BiometricsFingerprint::getInstance();
+
+    configureRpcThreadpool(1, true);
+
+    if (bio == nullptr || bio->registerAsService() != OK) {
+        LOG(ERROR) << "Could not register service for Fingerprint HAL";
+        goto shutdown;
+    }
+
+    LOG(INFO) << "Fingerprint HAL service is Ready.";
+    joinRpcThreadpool();
+
+shutdown:
+    // In normal operation, we don't expect the thread pool to shutdown
+    LOG(ERROR) << "Fingerprint HAL failed to join thread pool.";
+    return 1;
+}