Extend the bootcontrol HAL to get the active slot

The existing HAL has a setter, but no getter for the active slot for
next boot. The information is useful. For example, clients may need
to figure out which build the device will boot into.

In the resume on reboot case, we want to put the vbmeta digest
together with an encrypted key. And the vbmeta digest is associated
with a set of images (depending on which slot to boot into).

Bug: 173808057
Test: run vts test on cuttlefish
Change-Id: Ia8578926c781eb8e006589f45ab35a95dfe4f9a0

boot/1.1/default/boot_control/include/libboot_control/libboot_control.h

@@ -32,6 +32,7 @@ class BootControl {
   unsigned int GetNumberSlots();
   unsigned int GetCurrentSlot();
   bool MarkBootSuccessful();
+  unsigned int GetActiveBootSlot();
   bool SetActiveBootSlot(unsigned int slot);
   bool SetSlotAsUnbootable(unsigned int slot);
   bool SetSlotBootable(unsigned int slot);

boot/1.1/default/boot_control/libboot_control.cpp

@@ -261,6 +261,24 @@ bool BootControl::MarkBootSuccessful() {
   return UpdateAndSaveBootloaderControl(misc_device_, &bootctrl);
 }
 
+unsigned int BootControl::GetActiveBootSlot() {
+  bootloader_control bootctrl;
+  if (!LoadBootloaderControl(misc_device_, &bootctrl)) return false;
+
+  // Use the current slot by default.
+  unsigned int active_boot_slot = current_slot_;
+  unsigned int max_priority = bootctrl.slot_info[current_slot_].priority;
+  // Find the slot with the highest priority.
+  for (unsigned int i = 0; i < num_slots_; ++i) {
+    if (bootctrl.slot_info[i].priority > max_priority) {
+      max_priority = bootctrl.slot_info[i].priority;
+      active_boot_slot = i;
+    }
+  }
+
+  return active_boot_slot;
+}
+
 bool BootControl::SetActiveBootSlot(unsigned int slot) {
   if (slot >= kMaxNumSlots || slot >= num_slots_) {
     // Invalid slot number.

boot/1.2/Android.bp

@@ -0,0 +1,15 @@
+// This file is autogenerated by hidl-gen -Landroidbp.
+
+hidl_interface {
+    name: "android.hardware.boot@1.2",
+    root: "android.hardware",
+    srcs: [
+        "IBootControl.hal",
+    ],
+    interfaces: [
+        "android.hardware.boot@1.0",
+        "android.hardware.boot@1.1",
+        "android.hidl.base@1.0",
+    ],
+    gen_java: true,
+}

boot/1.2/IBootControl.hal

@@ -0,0 +1,35 @@
+/*
+ * Copyright 2020 The Android Open Source 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.
+ */
+
+package android.hardware.boot@1.2;
+
+import @1.0::IBootControl;
+import @1.0::Slot;
+import @1.1::IBootControl;
+
+interface IBootControl extends @1.1::IBootControl {
+
+  /**
+   * Returns the active slot to boot into on the next boot. If
+   * setActiveBootSlot() has been called, the getter function should return the
+   * same slot as the one provided in the last setActiveBootSlot() call.
+   * The returned value is always guaranteed to be strictly less than the
+   * value returned by getNumberSlots. Slots start at 0 and finish at
+   * getNumberSlots() - 1. For instance, a system with A/B must return 0 or 1.
+   */
+   getActiveBootSlot() generates (Slot slot);
+};
+

boot/1.2/default/Android.bp

@@ -0,0 +1,50 @@
+cc_library_shared {
+    name: "android.hardware.boot@1.2-impl",
+    stem: "android.hardware.boot@1.0-impl-1.2",
+    defaults: [
+        "hidl_defaults",
+        "libboot_control_defaults",
+    ],
+    relative_install_path: "hw",
+    vendor: true,
+    recovery_available: true,
+    srcs: ["BootControl.cpp"],
+
+    shared_libs: [
+        "liblog",
+        "libhidlbase",
+        "libhardware",
+        "libutils",
+        "android.hardware.boot@1.0",
+        "android.hardware.boot@1.1",
+        "android.hardware.boot@1.2",
+    ],
+    static_libs: [
+        "libboot_control",
+        "libfstab",
+    ],
+}
+
+cc_binary {
+    name: "android.hardware.boot@1.2-service",
+    defaults: ["hidl_defaults"],
+    relative_install_path: "hw",
+    vendor: true,
+    init_rc: ["android.hardware.boot@1.2-service.rc"],
+    srcs: ["service.cpp"],
+
+    vintf_fragments: [
+        "android.hardware.boot@1.2.xml",
+    ],
+
+    shared_libs: [
+        "liblog",
+        "libhardware",
+        "libhidlbase",
+        "libutils",
+        "android.hardware.boot@1.0",
+        "android.hardware.boot@1.1",
+        "android.hardware.boot@1.2",
+    ],
+
+}

boot/1.2/default/BootControl.cpp

@@ -0,0 +1,135 @@
+/*
+ * Copyright (C) 2020 The Android Open Source 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.boot@1.2-impl"
+
+#include <memory>
+
+#include <log/log.h>
+
+#include "BootControl.h"
+
+namespace android {
+namespace hardware {
+namespace boot {
+namespace V1_2 {
+namespace implementation {
+
+using ::android::hardware::boot::V1_0::CommandResult;
+
+bool BootControl::Init() {
+    return impl_.Init();
+}
+
+// Methods from ::android::hardware::boot::V1_0::IBootControl.
+Return<uint32_t> BootControl::getNumberSlots() {
+    return impl_.GetNumberSlots();
+}
+
+Return<uint32_t> BootControl::getCurrentSlot() {
+    return impl_.GetCurrentSlot();
+}
+
+Return<void> BootControl::markBootSuccessful(markBootSuccessful_cb _hidl_cb) {
+    struct CommandResult cr;
+    if (impl_.MarkBootSuccessful()) {
+        cr.success = true;
+        cr.errMsg = "Success";
+    } else {
+        cr.success = false;
+        cr.errMsg = "Operation failed";
+    }
+    _hidl_cb(cr);
+    return Void();
+}
+
+Return<void> BootControl::setActiveBootSlot(uint32_t slot, setActiveBootSlot_cb _hidl_cb) {
+    struct CommandResult cr;
+    if (impl_.SetActiveBootSlot(slot)) {
+        cr.success = true;
+        cr.errMsg = "Success";
+    } else {
+        cr.success = false;
+        cr.errMsg = "Operation failed";
+    }
+    _hidl_cb(cr);
+    return Void();
+}
+
+Return<void> BootControl::setSlotAsUnbootable(uint32_t slot, setSlotAsUnbootable_cb _hidl_cb) {
+    struct CommandResult cr;
+    if (impl_.SetSlotAsUnbootable(slot)) {
+        cr.success = true;
+        cr.errMsg = "Success";
+    } else {
+        cr.success = false;
+        cr.errMsg = "Operation failed";
+    }
+    _hidl_cb(cr);
+    return Void();
+}
+
+Return<BoolResult> BootControl::isSlotBootable(uint32_t slot) {
+    if (!impl_.IsValidSlot(slot)) {
+        return BoolResult::INVALID_SLOT;
+    }
+    return impl_.IsSlotBootable(slot) ? BoolResult::TRUE : BoolResult::FALSE;
+}
+
+Return<BoolResult> BootControl::isSlotMarkedSuccessful(uint32_t slot) {
+    if (!impl_.IsValidSlot(slot)) {
+        return BoolResult::INVALID_SLOT;
+    }
+    return impl_.IsSlotMarkedSuccessful(slot) ? BoolResult::TRUE : BoolResult::FALSE;
+}
+
+Return<void> BootControl::getSuffix(uint32_t slot, getSuffix_cb _hidl_cb) {
+    hidl_string ans;
+    const char* suffix = impl_.GetSuffix(slot);
+    if (suffix) {
+        ans = suffix;
+    }
+    _hidl_cb(ans);
+    return Void();
+}
+
+// Methods from ::android::hardware::boot::V1_1::IBootControl.
+Return<bool> BootControl::setSnapshotMergeStatus(MergeStatus status) {
+    return impl_.SetSnapshotMergeStatus(status);
+}
+
+Return<MergeStatus> BootControl::getSnapshotMergeStatus() {
+    return impl_.GetSnapshotMergeStatus();
+}
+
+// Methods from ::android::hardware::boot::V1_2::IBootControl.
+Return<uint32_t> BootControl::getActiveBootSlot() {
+    return impl_.GetActiveBootSlot();
+}
+
+IBootControl* HIDL_FETCH_IBootControl(const char* /* hal */) {
+    auto module = std::make_unique<BootControl>();
+    if (!module->Init()) {
+        ALOGE("Could not initialize BootControl module");
+        return nullptr;
+    }
+    return module.release();
+}
+
+}  // namespace implementation
+}  // namespace V1_2
+}  // namespace boot
+}  // namespace hardware
+}  // namespace android

boot/1.2/default/BootControl.h

@@ -0,0 +1,66 @@
+/*
+ * Copyright (C) 2020 The Android Open Source 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.
+ */
+
+#pragma once
+
+#include <android/hardware/boot/1.2/IBootControl.h>
+#include <hidl/MQDescriptor.h>
+#include <hidl/Status.h>
+#include <libboot_control/libboot_control.h>
+
+namespace android {
+namespace hardware {
+namespace boot {
+namespace V1_2 {
+namespace implementation {
+using ::android::hardware::Return;
+using ::android::hardware::Void;
+using ::android::hardware::boot::V1_0::BoolResult;
+using ::android::hardware::boot::V1_1::MergeStatus;
+using ::android::hardware::boot::V1_2::IBootControl;
+
+class BootControl : public IBootControl {
+  public:
+    bool Init();
+
+    // Methods from ::android::hardware::boot::V1_0::IBootControl.
+    Return<uint32_t> getNumberSlots() override;
+    Return<uint32_t> getCurrentSlot() override;
+    Return<void> markBootSuccessful(markBootSuccessful_cb _hidl_cb) override;
+    Return<void> setActiveBootSlot(uint32_t slot, setActiveBootSlot_cb _hidl_cb) override;
+    Return<void> setSlotAsUnbootable(uint32_t slot, setSlotAsUnbootable_cb _hidl_cb) override;
+    Return<BoolResult> isSlotBootable(uint32_t slot) override;
+    Return<BoolResult> isSlotMarkedSuccessful(uint32_t slot) override;
+    Return<void> getSuffix(uint32_t slot, getSuffix_cb _hidl_cb) override;
+
+    // Methods from ::android::hardware::boot::V1_1::IBootControl.
+    Return<bool> setSnapshotMergeStatus(MergeStatus status) override;
+    Return<MergeStatus> getSnapshotMergeStatus() override;
+
+    // Methods from ::android::hardware::boot::V1_2::IBootControl.
+    Return<uint32_t> getActiveBootSlot() override;
+
+  private:
+    android::bootable::BootControl impl_;
+};
+
+extern "C" IBootControl* HIDL_FETCH_IBootControl(const char* name);
+
+}  // namespace implementation
+}  // namespace V1_2
+}  // namespace boot
+}  // namespace hardware
+}  // namespace android

boot/1.2/default/android.hardware.boot@1.2-service.rc

@@ -0,0 +1,7 @@
+service vendor.boot-hal-1-2 /vendor/bin/hw/android.hardware.boot@1.2-service
+    interface android.hardware.boot@1.0::IBootControl default
+    interface android.hardware.boot@1.1::IBootControl default
+    interface android.hardware.boot@1.2::IBootControl default
+    class early_hal
+    user root
+    group root

boot/1.2/default/android.hardware.boot@1.2.xml

@@ -0,0 +1,7 @@
+<manifest version="1.0" type="device">
+    <hal format="hidl">
+        <name>android.hardware.boot</name>
+        <transport>hwbinder</transport>
+        <fqname>@1.2::IBootControl/default</fqname>
+    </hal>
+</manifest>

boot/1.2/default/service.cpp

@@ -0,0 +1,27 @@
+/*
+ * Copyright (C) 2020 The Android Open Source 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.boot@1.2-service"
+
+#include <android/hardware/boot/1.2/IBootControl.h>
+#include <hidl/LegacySupport.h>
+
+using android::hardware::defaultPassthroughServiceImplementation;
+using IBootControl_V1_0 = android::hardware::boot::V1_0::IBootControl;
+using IBootControl_V1_2 = android::hardware::boot::V1_2::IBootControl;
+
+int main(int /* argc */, char* /* argv */[]) {
+    return defaultPassthroughServiceImplementation<IBootControl_V1_0, IBootControl_V1_2>();
+}

boot/1.2/vts/functional/Android.bp

@@ -0,0 +1,31 @@
+//
+// Copyright (C) 2020 The Android Open Source 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.
+//
+
+cc_test {
+    name: "VtsHalBootV1_2TargetTest",
+    defaults: ["VtsHalTargetTestDefaults"],
+    srcs: ["VtsHalBootV1_2TargetTest.cpp"],
+    static_libs: [
+        "android.hardware.boot@1.0",
+        "android.hardware.boot@1.1",
+        "android.hardware.boot@1.2",
+        "libgmock",
+    ],
+    test_suites: [
+        "device-tests",
+        "vts",
+    ],
+}

boot/1.2/vts/functional/VtsHalBootV1_2TargetTest.cpp

@@ -0,0 +1,72 @@
+/*
+ * Copyright (C) 2020 The Android Open Source 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 "boot_hidl_hal_test"
+
+#include <android-base/logging.h>
+#include <android/hardware/boot/1.2/IBootControl.h>
+#include <gmock/gmock.h>
+#include <gtest/gtest.h>
+#include <hidl/GtestPrinter.h>
+#include <hidl/ServiceManagement.h>
+
+#include <unistd.h>
+
+using ::android::sp;
+using ::android::hardware::Return;
+using ::android::hardware::Void;
+using ::android::hardware::boot::V1_0::CommandResult;
+using ::android::hardware::boot::V1_0::Slot;
+using ::android::hardware::boot::V1_2::IBootControl;
+
+class BootHidlTest : public testing::TestWithParam<std::string> {
+  public:
+    virtual void SetUp() override {
+        boot = IBootControl::getService(GetParam());
+        ASSERT_NE(boot, nullptr);
+
+        LOG(INFO) << "Test is remote " << boot->isRemote();
+    }
+
+    sp<IBootControl> boot;
+};
+
+auto generate_callback(CommandResult* dest) {
+    return [=](CommandResult cr) { *dest = cr; };
+}
+
+TEST_P(BootHidlTest, GetActiveBootSlot) {
+    Slot curSlot = boot->getCurrentSlot();
+    Slot otherSlot = curSlot ? 0 : 1;
+
+    // Set the active slot, then check if the getter returns the correct slot.
+    CommandResult cr;
+    Return<void> result = boot->setActiveBootSlot(otherSlot, generate_callback(&cr));
+    EXPECT_TRUE(result.isOk());
+    Slot activeSlot = boot->getActiveBootSlot();
+    EXPECT_EQ(otherSlot, activeSlot);
+
+    result = boot->setActiveBootSlot(curSlot, generate_callback(&cr));
+    EXPECT_TRUE(result.isOk());
+    activeSlot = boot->getActiveBootSlot();
+    EXPECT_EQ(curSlot, activeSlot);
+}
+
+GTEST_ALLOW_UNINSTANTIATED_PARAMETERIZED_TEST(BootHidlTest);
+INSTANTIATE_TEST_SUITE_P(
+        PerInstance, BootHidlTest,
+        testing::ValuesIn(android::hardware::getAllHalInstanceNames(IBootControl::descriptor)),
+        android::hardware::PrintInstanceNameToString);

compatibility_matrices/compatibility_matrix.current.xml

@@ -122,7 +122,7 @@
     </hal>
     <hal format="hidl" optional="true">
         <name>android.hardware.boot</name>
-        <version>1.1</version>
+        <version>1.2</version>
         <interface>
             <name>IBootControl</name>
             <instance>default</instance>