diff --git a/fs_mgr/fs_mgr.cpp b/fs_mgr/fs_mgr.cpp
index 26ce3b2..878dbb3 100644
--- a/fs_mgr/fs_mgr.cpp
+++ b/fs_mgr/fs_mgr.cpp
@@ -1090,6 +1090,13 @@
                 // Skips mounting the device.
                 continue;
             }
+        } else if (!current_entry.avb_key.empty()) {
+            if (AvbHandle::SetUpStandaloneAvbHashtree(&current_entry) == AvbHashtreeResult::kFail) {
+                LERROR << "Failed to set up AVB on standalone partition: "
+                       << current_entry.mount_point << ", skipping!";
+                // Skips mounting the device.
+                continue;
+            }
         } else if ((current_entry.fs_mgr_flags.verify)) {
             int rc = fs_mgr_setup_verity(&current_entry, true);
             if (__android_log_is_debuggable() &&
@@ -1326,6 +1333,13 @@
                 // Skips mounting the device.
                 continue;
             }
+        } else if (!fstab_entry.avb_key.empty()) {
+            if (AvbHandle::SetUpStandaloneAvbHashtree(&fstab_entry) == AvbHashtreeResult::kFail) {
+                LERROR << "Failed to set up AVB on standalone partition: "
+                       << fstab_entry.mount_point << ", skipping!";
+                // Skips mounting the device.
+                continue;
+            }
         } else if (fstab_entry.fs_mgr_flags.verify) {
             int rc = fs_mgr_setup_verity(&fstab_entry, true);
             if (__android_log_is_debuggable() &&
diff --git a/fs_mgr/fs_mgr_fstab.cpp b/fs_mgr/fs_mgr_fstab.cpp
index 0482f6c..7f6145d 100644
--- a/fs_mgr/fs_mgr_fstab.cpp
+++ b/fs_mgr/fs_mgr_fstab.cpp
@@ -338,6 +338,8 @@
         } else if (StartsWith(flag, "zram_backing_dev_path=")) {
             entry->fs_mgr_flags.zram_backing_dev_path = true;
             entry->zram_backing_dev_path = arg;
+        } else if (StartsWith(flag, "avb_key=")) {
+            entry->avb_key = arg;
         } else {
             LWARNING << "Warning: unknown flag: " << flag;
         }
diff --git a/fs_mgr/include_fstab/fstab/fstab.h b/fs_mgr/include_fstab/fstab/fstab.h
index 100e076..a9b386a 100644
--- a/fs_mgr/include_fstab/fstab/fstab.h
+++ b/fs_mgr/include_fstab/fstab/fstab.h
@@ -116,6 +116,7 @@
     std::string zram_loopback_path;
     uint64_t zram_loopback_size = 512 * 1024 * 1024;  // 512MB by default;
     std::string zram_backing_dev_path;
+    std::string avb_key;
 
     // TODO: Remove this union once fstab_rec is deprecated. It only serves as a
     // convenient way to convert between fstab_rec::fs_mgr_flags and these bools.
diff --git a/fs_mgr/libfs_avb/avb_util.cpp b/fs_mgr/libfs_avb/avb_util.cpp
index f57c9d6..945087f 100644
--- a/fs_mgr/libfs_avb/avb_util.cpp
+++ b/fs_mgr/libfs_avb/avb_util.cpp
@@ -27,6 +27,7 @@
 
 #include "util.h"
 
+using android::base::Basename;
 using android::base::StartsWith;
 using android::base::unique_fd;
 
@@ -61,7 +62,7 @@
 // class VBMetaData
 // ----------------
 std::unique_ptr<AvbVBMetaImageHeader> VBMetaData::GetVBMetaHeader(bool update_vbmeta_size) {
-    auto vbmeta_header(std::make_unique<AvbVBMetaImageHeader>());
+    auto vbmeta_header = std::make_unique<AvbVBMetaImageHeader>();
 
     if (!vbmeta_header) return nullptr;
 
@@ -136,7 +137,7 @@
     }
     table.set_readonly(true);
 
-    const std::string mount_point(basename(fstab_entry->mount_point.c_str()));
+    const std::string mount_point(Basename(fstab_entry->mount_point));
     android::dm::DeviceMapper& dm = android::dm::DeviceMapper::Instance();
     if (!dm.CreateDevice(mount_point, table)) {
         LERROR << "Couldn't create verity device!";
@@ -163,12 +164,12 @@
     return true;
 }
 
-bool GetHashtreeDescriptor(const std::string& partition_name,
-                           const std::vector<VBMetaData>& vbmeta_images,
-                           AvbHashtreeDescriptor* out_hashtree_desc, std::string* out_salt,
-                           std::string* out_digest) {
+std::unique_ptr<AvbHashtreeDescriptor> GetHashtreeDescriptor(
+    const std::string& partition_name, const std::vector<VBMetaData>& vbmeta_images,
+    std::string* out_salt, std::string* out_digest) {
     bool found = false;
     const uint8_t* desc_partition_name;
+    auto hashtree_desc = std::make_unique<AvbHashtreeDescriptor>();
 
     for (const auto& vbmeta : vbmeta_images) {
         size_t num_descriptors;
@@ -189,15 +190,15 @@
                 desc_partition_name =
                         (const uint8_t*)descriptors[n] + sizeof(AvbHashtreeDescriptor);
                 if (!avb_hashtree_descriptor_validate_and_byteswap(
-                            (AvbHashtreeDescriptor*)descriptors[n], out_hashtree_desc)) {
+                        (AvbHashtreeDescriptor*)descriptors[n], hashtree_desc.get())) {
                     continue;
                 }
-                if (out_hashtree_desc->partition_name_len != partition_name.length()) {
+                if (hashtree_desc->partition_name_len != partition_name.length()) {
                     continue;
                 }
                 // Notes that desc_partition_name is not NUL-terminated.
                 std::string hashtree_partition_name((const char*)desc_partition_name,
-                                                    out_hashtree_desc->partition_name_len);
+                                                    hashtree_desc->partition_name_len);
                 if (hashtree_partition_name == partition_name) {
                     found = true;
                 }
@@ -209,16 +210,43 @@
 
     if (!found) {
         LERROR << "Partition descriptor not found: " << partition_name.c_str();
+        return nullptr;
+    }
+
+    const uint8_t* desc_salt = desc_partition_name + hashtree_desc->partition_name_len;
+    *out_salt = BytesToHex(desc_salt, hashtree_desc->salt_len);
+
+    const uint8_t* desc_digest = desc_salt + hashtree_desc->salt_len;
+    *out_digest = BytesToHex(desc_digest, hashtree_desc->root_digest_len);
+
+    return hashtree_desc;
+}
+
+bool LoadAvbHashtreeToEnableVerity(FstabEntry* fstab_entry, bool wait_for_verity_dev,
+                                   const std::vector<VBMetaData>& vbmeta_images,
+                                   const std::string& ab_suffix,
+                                   const std::string& ab_other_suffix) {
+    // Derives partition_name from blk_device to query the corresponding AVB HASHTREE descriptor
+    // to setup dm-verity. The partition_names in AVB descriptors are without A/B suffix.
+    std::string partition_name = DeriveAvbPartitionName(*fstab_entry, ab_suffix, ab_other_suffix);
+
+    if (partition_name.empty()) {
+        LERROR << "partition name is empty, cannot lookup AVB descriptors";
         return false;
     }
 
-    const uint8_t* desc_salt = desc_partition_name + out_hashtree_desc->partition_name_len;
-    *out_salt = BytesToHex(desc_salt, out_hashtree_desc->salt_len);
+    std::string salt;
+    std::string root_digest;
+    std::unique_ptr<AvbHashtreeDescriptor> hashtree_descriptor =
+        GetHashtreeDescriptor(partition_name, vbmeta_images, &salt, &root_digest);
+    if (!hashtree_descriptor) {
+        return false;
+    }
 
-    const uint8_t* desc_digest = desc_salt + out_hashtree_desc->salt_len;
-    *out_digest = BytesToHex(desc_digest, out_hashtree_desc->root_digest_len);
-
-    return true;
+    // Converts HASHTREE descriptor to verity table to load into kernel.
+    // When success, the new device path will be returned, e.g., /dev/block/dm-2.
+    return HashtreeDmVeritySetup(fstab_entry, *hashtree_descriptor, salt, root_digest,
+                                 wait_for_verity_dev);
 }
 
 // Converts a AVB partition_name (without A/B suffix) to a device partition name.
@@ -244,6 +272,38 @@
     return sanitized_partition_name + append_suffix;
 }
 
+// Converts fstab_entry.blk_device (with ab_suffix) to a AVB partition name.
+// e.g., "/dev/block/by-name/system_a", slot_select       => "system",
+//       "/dev/block/by-name/system_b", slot_select_other => "system_other".
+//
+// Or for a logical partition (with ab_suffix):
+// e.g., "system_a", slot_select       => "system",
+//       "system_b", slot_select_other => "system_other".
+std::string DeriveAvbPartitionName(const FstabEntry& fstab_entry, const std::string& ab_suffix,
+                                   const std::string& ab_other_suffix) {
+    std::string partition_name;
+    if (fstab_entry.fs_mgr_flags.logical) {
+        partition_name = fstab_entry.logical_partition_name;
+    } else {
+        partition_name = Basename(fstab_entry.blk_device);
+    }
+
+    if (fstab_entry.fs_mgr_flags.slot_select) {
+        auto found = partition_name.rfind(ab_suffix);
+        if (found != std::string::npos) {
+            partition_name.erase(found);  // converts system_a => system
+        }
+    } else if (fstab_entry.fs_mgr_flags.slot_select_other) {
+        auto found = partition_name.rfind(ab_other_suffix);
+        if (found != std::string::npos) {
+            partition_name.erase(found);  // converts system_b => system
+        }
+        partition_name += "_other";  // converts system => system_other
+    }
+
+    return partition_name;
+}
+
 off64_t GetTotalSize(int fd) {
     off64_t saved_current = lseek64(fd, 0, SEEK_CUR);
     if (saved_current == -1) {
@@ -268,19 +328,19 @@
 
 std::unique_ptr<AvbFooter> GetAvbFooter(int fd) {
     std::array<uint8_t, AVB_FOOTER_SIZE> footer_buf;
-    auto footer(std::make_unique<AvbFooter>());
+    auto footer = std::make_unique<AvbFooter>();
 
     off64_t footer_offset = GetTotalSize(fd) - AVB_FOOTER_SIZE;
 
     ssize_t num_read =
             TEMP_FAILURE_RETRY(pread64(fd, footer_buf.data(), AVB_FOOTER_SIZE, footer_offset));
     if (num_read < 0 || num_read != AVB_FOOTER_SIZE) {
-        PERROR << "Failed to read AVB footer";
+        PERROR << "Failed to read AVB footer at offset: " << footer_offset;
         return nullptr;
     }
 
     if (!avb_footer_validate_and_byteswap((const AvbFooter*)footer_buf.data(), footer.get())) {
-        PERROR << "AVB footer verification failed.";
+        PERROR << "AVB footer verification failed at offset " << footer_offset;
         return nullptr;
     }
 
@@ -432,24 +492,22 @@
     return chain_partitions;
 }
 
-VBMetaVerifyResult LoadAndVerifyVbmetaImpl(
-        const std::string& partition_name, const std::string& ab_suffix,
-        const std::string& ab_other_suffix, const std::string& expected_public_key_blob,
-        bool allow_verification_error, bool load_chained_vbmeta, bool rollback_protection,
-        std::function<std::string(const std::string&)> device_path_constructor,
-        bool is_chained_vbmeta, std::vector<VBMetaData>* out_vbmeta_images) {
+// Loads the vbmeta from a given path.
+std::unique_ptr<VBMetaData> LoadAndVerifyVbmetaByPath(
+    const std::string& image_path, const std::string& partition_name,
+    const std::string& expected_public_key_blob, bool allow_verification_error,
+    bool rollback_protection, bool is_chained_vbmeta, bool* out_verification_disabled,
+    VBMetaVerifyResult* out_verify_result) {
     // Ensures the device path (might be a symlink created by init) is ready to access.
-    auto device_path = device_path_constructor(
-            AvbPartitionToDevicePatition(partition_name, ab_suffix, ab_other_suffix));
-    if (!WaitForFile(device_path, 1s)) {
-        PERROR << "No such partition: " << device_path;
-        return VBMetaVerifyResult::kError;
+    if (!WaitForFile(image_path, 1s)) {
+        PERROR << "No such path: " << image_path;
+        return nullptr;
     }
 
-    unique_fd fd(TEMP_FAILURE_RETRY(open(device_path.c_str(), O_RDONLY | O_CLOEXEC)));
+    unique_fd fd(TEMP_FAILURE_RETRY(open(image_path.c_str(), O_RDONLY | O_CLOEXEC)));
     if (fd < 0) {
-        PERROR << "Failed to open: " << device_path;
-        return VBMetaVerifyResult::kError;
+        PERROR << "Failed to open: " << image_path;
+        return nullptr;
     }
 
     VBMetaVerifyResult verify_result;
@@ -457,53 +515,84 @@
             VerifyVBMetaData(fd, partition_name, expected_public_key_blob, &verify_result);
     if (!vbmeta) {
         LERROR << partition_name << ": Failed to load vbmeta, result: " << verify_result;
-        return VBMetaVerifyResult::kError;
+        return nullptr;
     }
+    vbmeta->set_vbmeta_path(image_path);
 
     if (!allow_verification_error && verify_result == VBMetaVerifyResult::kErrorVerification) {
         LERROR << partition_name << ": allow verification error is not allowed";
-        return VBMetaVerifyResult::kError;
+        return nullptr;
     }
 
     std::unique_ptr<AvbVBMetaImageHeader> vbmeta_header =
             vbmeta->GetVBMetaHeader(true /* update_vbmeta_size */);
     if (!vbmeta_header) {
         LERROR << partition_name << ": Failed to get vbmeta header";
-        return VBMetaVerifyResult::kError;
+        return nullptr;
     }
 
     if (rollback_protection && RollbackDetected(partition_name, vbmeta_header->rollback_index)) {
-        return VBMetaVerifyResult::kError;
+        return nullptr;
     }
 
     // vbmeta flags can only be set by the top-level vbmeta image.
     if (is_chained_vbmeta && vbmeta_header->flags != 0) {
         LERROR << partition_name << ": chained vbmeta image has non-zero flags";
-        return VBMetaVerifyResult::kError;
+        return nullptr;
     }
 
+    // Checks if verification has been disabled by setting a bit in the image.
+    if (out_verification_disabled) {
+        if (vbmeta_header->flags & AVB_VBMETA_IMAGE_FLAGS_VERIFICATION_DISABLED) {
+            LWARNING << "VERIFICATION_DISABLED bit is set for partition: " << partition_name;
+            *out_verification_disabled = true;
+        } else {
+            *out_verification_disabled = false;
+        }
+    }
+
+    if (out_verify_result) {
+        *out_verify_result = verify_result;
+    }
+
+    return vbmeta;
+}
+
+VBMetaVerifyResult LoadAndVerifyVbmetaByPartition(
+    const std::string& partition_name, const std::string& ab_suffix,
+    const std::string& ab_other_suffix, const std::string& expected_public_key_blob,
+    bool allow_verification_error, bool load_chained_vbmeta, bool rollback_protection,
+    std::function<std::string(const std::string&)> device_path_constructor, bool is_chained_vbmeta,
+    std::vector<VBMetaData>* out_vbmeta_images) {
+    auto image_path = device_path_constructor(
+        AvbPartitionToDevicePatition(partition_name, ab_suffix, ab_other_suffix));
+
+    bool verification_disabled = false;
+    VBMetaVerifyResult verify_result;
+    auto vbmeta = LoadAndVerifyVbmetaByPath(
+        image_path, partition_name, expected_public_key_blob, allow_verification_error,
+        rollback_protection, is_chained_vbmeta, &verification_disabled, &verify_result);
+
+    if (!vbmeta) {
+        return VBMetaVerifyResult::kError;
+    }
     if (out_vbmeta_images) {
         out_vbmeta_images->emplace_back(std::move(*vbmeta));
     }
 
-    // If verification has been disabled by setting a bit in the image, we're done.
-    if (vbmeta_header->flags & AVB_VBMETA_IMAGE_FLAGS_VERIFICATION_DISABLED) {
-        LWARNING << "VERIFICATION_DISABLED bit is set for partition: " << partition_name;
-        return verify_result;
-    }
-
-    if (load_chained_vbmeta) {
+    // Only loads chained vbmeta if AVB verification is NOT disabled.
+    if (!verification_disabled && load_chained_vbmeta) {
         bool fatal_error = false;
         auto chain_partitions = GetChainPartitionInfo(*out_vbmeta_images->rbegin(), &fatal_error);
         if (fatal_error) {
             return VBMetaVerifyResult::kError;
         }
         for (auto& chain : chain_partitions) {
-            auto sub_ret = LoadAndVerifyVbmetaImpl(
-                    chain.partition_name, ab_suffix, ab_other_suffix, chain.public_key_blob,
-                    allow_verification_error, load_chained_vbmeta, rollback_protection,
-                    device_path_constructor, true, /* is_chained_vbmeta */
-                    out_vbmeta_images);
+            auto sub_ret = LoadAndVerifyVbmetaByPartition(
+                chain.partition_name, ab_suffix, ab_other_suffix, chain.public_key_blob,
+                allow_verification_error, load_chained_vbmeta, rollback_protection,
+                device_path_constructor, true, /* is_chained_vbmeta */
+                out_vbmeta_images);
             if (sub_ret != VBMetaVerifyResult::kSuccess) {
                 verify_result = sub_ret;  // might be 'ERROR' or 'ERROR VERIFICATION'.
                 if (verify_result == VBMetaVerifyResult::kError) {
diff --git a/fs_mgr/libfs_avb/avb_util.h b/fs_mgr/libfs_avb/avb_util.h
index babbfef..14918f2 100644
--- a/fs_mgr/libfs_avb/avb_util.h
+++ b/fs_mgr/libfs_avb/avb_util.h
@@ -46,10 +46,9 @@
 };
 
 // AvbHashtreeDescriptor to dm-verity table setup.
-bool GetHashtreeDescriptor(const std::string& partition_name,
-                           const std::vector<VBMetaData>& vbmeta_images,
-                           AvbHashtreeDescriptor* out_hashtree_desc, std::string* out_salt,
-                           std::string* out_digest);
+std::unique_ptr<AvbHashtreeDescriptor> GetHashtreeDescriptor(
+    const std::string& partition_name, const std::vector<VBMetaData>& vbmeta_images,
+    std::string* out_salt, std::string* out_digest);
 
 bool ConstructVerityTable(const AvbHashtreeDescriptor& hashtree_desc, const std::string& salt,
                           const std::string& root_digest, const std::string& blk_device,
@@ -59,11 +58,20 @@
                            const std::string& salt, const std::string& root_digest,
                            bool wait_for_verity_dev);
 
-// Maps AVB partition name to a device partition name.
+// Searches a Avb hashtree descriptor in vbmeta_images for fstab_entry, to enable dm-verity.
+bool LoadAvbHashtreeToEnableVerity(FstabEntry* fstab_entry, bool wait_for_verity_dev,
+                                   const std::vector<VBMetaData>& vbmeta_images,
+                                   const std::string& ab_suffix, const std::string& ab_other_suffix);
+
+// Converts AVB partition name to a device partition name.
 std::string AvbPartitionToDevicePatition(const std::string& avb_partition_name,
                                          const std::string& ab_suffix,
                                          const std::string& ab_other_suffix);
 
+// Converts by-name symlink to AVB partition name.
+std::string DeriveAvbPartitionName(const FstabEntry& fstab_entry, const std::string& ab_suffix,
+                                   const std::string& ab_other_suffix);
+
 // AvbFooter and AvbMetaImage maninpulations.
 off64_t GetTotalSize(int fd);
 
@@ -84,12 +92,22 @@
 // Extracts chain partition info.
 std::vector<ChainInfo> GetChainPartitionInfo(const VBMetaData& vbmeta, bool* fatal_error);
 
-VBMetaVerifyResult LoadAndVerifyVbmetaImpl(
-        const std::string& partition_name, const std::string& ab_suffix,
-        const std::string& ab_other_suffix, const std::string& expected_public_key_blob,
-        bool allow_verification_error, bool load_chained_vbmeta, bool rollback_protection,
-        std::function<std::string(const std::string&)> device_path_constructor,
-        bool is_chained_vbmeta, std::vector<VBMetaData>* out_vbmeta_images);
+// Loads the single vbmeta from a given path.
+std::unique_ptr<VBMetaData> LoadAndVerifyVbmetaByPath(
+    const std::string& image_path, const std::string& partition_name,
+    const std::string& expected_public_key_blob, bool allow_verification_error,
+    bool rollback_protection, bool is_chained_vbmeta, bool* out_verification_disabled,
+    VBMetaVerifyResult* out_verify_result);
+
+// Loads the top-level vbmeta and all its chained vbmeta images.
+// The actual device path is constructed at runtime by:
+// partition_name, ab_suffix, ab_other_suffix, and device_path_constructor.
+VBMetaVerifyResult LoadAndVerifyVbmetaByPartition(
+    const std::string& partition_name, const std::string& ab_suffix,
+    const std::string& ab_other_suffix, const std::string& expected_public_key_blob,
+    bool allow_verification_error, bool load_chained_vbmeta, bool rollback_protection,
+    std::function<std::string(const std::string&)> device_path_constructor, bool is_chained_vbmeta,
+    std::vector<VBMetaData>* out_vbmeta_images);
 
 }  // namespace fs_mgr
 }  // namespace android
diff --git a/fs_mgr/libfs_avb/fs_avb.cpp b/fs_mgr/libfs_avb/fs_avb.cpp
index 9f8ad53..773baf4 100644
--- a/fs_mgr/libfs_avb/fs_avb.cpp
+++ b/fs_mgr/libfs_avb/fs_avb.cpp
@@ -233,10 +233,10 @@
 
     auto device_path = custom_device_path ? custom_device_path : android_by_name_symlink;
 
-    auto verify_result = LoadAndVerifyVbmetaImpl(
-            partition_name, ab_suffix, ab_other_suffix, expected_key_blob, allow_verification_error,
-            load_chained_vbmeta, rollback_protection, device_path, false,
-            /* is_chained_vbmeta */ &avb_handle->vbmeta_images_);
+    auto verify_result = LoadAndVerifyVbmetaByPartition(
+        partition_name, ab_suffix, ab_other_suffix, expected_key_blob, allow_verification_error,
+        load_chained_vbmeta, rollback_protection, device_path, false,
+        /* is_chained_vbmeta */ &avb_handle->vbmeta_images_);
     switch (verify_result) {
         case VBMetaVerifyResult::kSuccess:
             avb_handle->status_ = AvbHandleStatus::kSuccess;
@@ -245,10 +245,16 @@
             avb_handle->status_ = AvbHandleStatus::kVerificationError;
             break;
         default:
-            LERROR << "LoadAndVerifyVbmetaImpl failed, result: " << verify_result;
+            LERROR << "LoadAndVerifyVbmetaByPartition failed, result: " << verify_result;
             return nullptr;
     }
 
+    // Sanity check here because we have to use vbmeta_images_[0] below.
+    if (avb_handle->vbmeta_images_.size() < 1) {
+        LERROR << "LoadAndVerifyVbmetaByPartition failed, no vbmeta loaded";
+        return nullptr;
+    }
+
     // Sets the MAJOR.MINOR for init to set it into "ro.boot.avb_version".
     avb_handle->avb_version_ = StringPrintf("%d.%d", AVB_VERSION_MAJOR, AVB_VERSION_MINOR);
 
@@ -377,6 +383,54 @@
     return avb_handle;
 }
 
+AvbHashtreeResult AvbHandle::SetUpStandaloneAvbHashtree(FstabEntry* fstab_entry) {
+    if (fstab_entry->avb_key.empty()) {
+        LERROR << "avb_key=/path/to/key is missing for " << fstab_entry->mount_point;
+        return AvbHashtreeResult::kFail;
+    }
+
+    // Binds allow_verification_error and rollback_protection to device unlock state.
+    bool allow_verification_error = IsDeviceUnlocked();
+    bool rollback_protection = !allow_verification_error;
+
+    std::string expected_key_blob;
+    if (!ReadFileToString(fstab_entry->avb_key, &expected_key_blob)) {
+        if (!allow_verification_error) {
+            LERROR << "Failed to load avb_key: " << fstab_entry->avb_key
+                   << " for mount point: " << fstab_entry->mount_point;
+            return AvbHashtreeResult::kFail;
+        }
+        // Use empty key blob, which means no expectation, if allow verification error.
+        expected_key_blob.clear();
+    }
+
+    bool verification_disabled = false;
+    std::unique_ptr<VBMetaData> vbmeta = LoadAndVerifyVbmetaByPath(
+        fstab_entry->blk_device, "" /* partition_name, no need for a standalone path */,
+        expected_key_blob, allow_verification_error, rollback_protection,
+        false /* not is_chained_vbmeta */, &verification_disabled, nullptr /* out_verify_result */);
+
+    if (!vbmeta) {
+        LERROR << "Failed to load vbmeta: " << fstab_entry->blk_device;
+        return AvbHashtreeResult::kFail;
+    }
+
+    if (verification_disabled) {
+        LINFO << "AVB verification disabled on: " << fstab_entry->mount_point;
+        return AvbHashtreeResult::kDisabled;
+    }
+
+    // Puts the vbmeta into a vector, for LoadAvbHashtreeToEnableVerity() to use.
+    std::vector<VBMetaData> vbmeta_images;
+    vbmeta_images.emplace_back(std::move(*vbmeta));
+    if (!LoadAvbHashtreeToEnableVerity(fstab_entry, true /* wait_for_verity_dev */, vbmeta_images,
+                                       fs_mgr_get_slot_suffix(), fs_mgr_get_other_slot_suffix())) {
+        return AvbHashtreeResult::kFail;
+    }
+
+    return AvbHashtreeResult::kSuccess;
+}
+
 AvbHashtreeResult AvbHandle::SetUpAvbHashtree(FstabEntry* fstab_entry, bool wait_for_verity_dev) {
     if (!fstab_entry || status_ == AvbHandleStatus::kUninitialized || vbmeta_images_.size() < 1) {
         return AvbHashtreeResult::kFail;
@@ -388,33 +442,8 @@
         return AvbHashtreeResult::kDisabled;
     }
 
-    // Derives partition_name from blk_device to query the corresponding AVB HASHTREE descriptor
-    // to setup dm-verity. The partition_names in AVB descriptors are without A/B suffix.
-    std::string partition_name;
-    if (fstab_entry->fs_mgr_flags.logical) {
-        partition_name = fstab_entry->logical_partition_name;
-    } else {
-        partition_name = Basename(fstab_entry->blk_device);
-    }
-
-    if (fstab_entry->fs_mgr_flags.slot_select) {
-        auto ab_suffix = partition_name.rfind(fs_mgr_get_slot_suffix());
-        if (ab_suffix != std::string::npos) {
-            partition_name.erase(ab_suffix);
-        }
-    }
-
-    AvbHashtreeDescriptor hashtree_descriptor;
-    std::string salt;
-    std::string root_digest;
-    if (!GetHashtreeDescriptor(partition_name, vbmeta_images_, &hashtree_descriptor, &salt,
-                               &root_digest)) {
-        return AvbHashtreeResult::kFail;
-    }
-
-    // Converts HASHTREE descriptor to verity_table_params.
-    if (!HashtreeDmVeritySetup(fstab_entry, hashtree_descriptor, salt, root_digest,
-                               wait_for_verity_dev)) {
+    if (!LoadAvbHashtreeToEnableVerity(fstab_entry, wait_for_verity_dev, vbmeta_images_,
+                                       fs_mgr_get_slot_suffix(), fs_mgr_get_other_slot_suffix())) {
         return AvbHashtreeResult::kFail;
     }
 
diff --git a/fs_mgr/libfs_avb/include/fs_avb/fs_avb.h b/fs_mgr/libfs_avb/include/fs_avb/fs_avb.h
index 7af3c7e..55a320e 100644
--- a/fs_mgr/libfs_avb/include/fs_avb/fs_avb.h
+++ b/fs_mgr/libfs_avb/include/fs_avb/fs_avb.h
@@ -81,8 +81,15 @@
     // true to update vbmeta_size_ to the actual size with valid content.
     std::unique_ptr<AvbVBMetaImageHeader> GetVBMetaHeader(bool update_vbmeta_size = false);
 
+    // Sets the vbmeta_path where we load the vbmeta data. Could be a partition or a file.
+    // e.g.,
+    // - /dev/block/by-name/system_a
+    // - /path/to/system_other.img.
+    void set_vbmeta_path(std::string vbmeta_path) { vbmeta_path_ = std::move(vbmeta_path); }
+
     // Get methods for each data member.
     const std::string& partition() const { return partition_name_; }
+    const std::string& vbmeta_path() const { return vbmeta_path_; }
     uint8_t* data() const { return vbmeta_ptr_.get(); }
     const size_t& size() const { return vbmeta_size_; }
 
@@ -93,6 +100,7 @@
     std::unique_ptr<uint8_t[]> vbmeta_ptr_;
     size_t vbmeta_size_;
     std::string partition_name_;
+    std::string vbmeta_path_;
 };
 
 class FsManagerAvbOps;
@@ -160,6 +168,9 @@
     //   - kDisabled: hashtree is disabled.
     AvbHashtreeResult SetUpAvbHashtree(FstabEntry* fstab_entry, bool wait_for_verity_dev);
 
+    // Similar to above, but loads the offline vbmeta from the end of fstab_entry->blk_device.
+    static AvbHashtreeResult SetUpStandaloneAvbHashtree(FstabEntry* fstab_entry);
+
     const std::string& avb_version() const { return avb_version_; }
     const VBMetaInfo& vbmeta_info() const { return vbmeta_info_; }
     AvbHandleStatus status() const { return status_; }
diff --git a/fs_mgr/libfs_avb/tests/avb_util_test.cpp b/fs_mgr/libfs_avb/tests/avb_util_test.cpp
index 26b3294..23faffc 100644
--- a/fs_mgr/libfs_avb/tests/avb_util_test.cpp
+++ b/fs_mgr/libfs_avb/tests/avb_util_test.cpp
@@ -14,20 +14,25 @@
  * limitations under the License.
  */
 
+#include <endian.h>
+
 #include <android-base/unique_fd.h>
 #include <base/files/file_util.h>
 #include <base/rand_util.h>
 #include <base/strings/string_util.h>
+#include <libavb/libavb.h>
 
 #include "avb_util.h"
 #include "fs_avb_test_util.h"
 
 // Target classes or functions to test:
 using android::fs_mgr::AvbPartitionToDevicePatition;
+using android::fs_mgr::DeriveAvbPartitionName;
 using android::fs_mgr::GetAvbFooter;
 using android::fs_mgr::GetChainPartitionInfo;
 using android::fs_mgr::GetTotalSize;
-using android::fs_mgr::LoadAndVerifyVbmetaImpl;
+using android::fs_mgr::LoadAndVerifyVbmetaByPartition;
+using android::fs_mgr::LoadAndVerifyVbmetaByPath;
 using android::fs_mgr::VBMetaData;
 using android::fs_mgr::VBMetaVerifyResult;
 using android::fs_mgr::VerifyPublicKeyBlob;
@@ -52,8 +57,34 @@
 
     // Loads the content of avb_image_path and comparies it with the content of vbmeta.
     bool CompareVBMeta(const base::FilePath& avb_image_path, const VBMetaData& expected_vbmeta);
+
+    // Sets the flas in vbmeta header, the image_path could be a vbmeta.img or a system.img.
+    void SetVBMetaFlags(const base::FilePath& image_path, uint32_t flags);
 };
 
+void AvbUtilTest::SetVBMetaFlags(const base::FilePath& image_path, uint32_t flags) {
+    if (!base::PathExists(image_path)) return;
+
+    std::string image_file_name = image_path.RemoveExtension().BaseName().value();
+    bool is_vbmeta_partition =
+        base::StartsWith(image_file_name, "vbmeta", base::CompareCase::INSENSITIVE_ASCII);
+
+    android::base::unique_fd fd(open(image_path.value().c_str(), O_RDWR | O_CLOEXEC));
+    EXPECT_TRUE(fd > 0);
+
+    uint64_t vbmeta_offset = 0;  // for vbmeta.img
+    if (!is_vbmeta_partition) {
+        std::unique_ptr<AvbFooter> footer = GetAvbFooter(fd);
+        EXPECT_NE(nullptr, footer);
+        vbmeta_offset = footer->vbmeta_offset;
+    }
+
+    auto flags_offset = vbmeta_offset + offsetof(AvbVBMetaImageHeader, flags);
+    uint32_t flags_data = htobe32(flags);
+    EXPECT_EQ(flags_offset, lseek64(fd, flags_offset, SEEK_SET));
+    EXPECT_EQ(sizeof flags_data, write(fd, &flags_data, sizeof flags_data));
+}
+
 TEST_F(AvbUtilTest, AvbPartitionToDevicePatition) {
     EXPECT_EQ("system", AvbPartitionToDevicePatition("system", "", ""));
     EXPECT_EQ("system", AvbPartitionToDevicePatition("system", "", "_b"));
@@ -65,6 +96,63 @@
     EXPECT_EQ("system_b", AvbPartitionToDevicePatition("system_other", "_a", "_b"));
 }
 
+TEST_F(AvbUtilTest, DeriveAvbPartitionName) {
+    // The fstab_entry to test.
+    FstabEntry fstab_entry = {
+        .blk_device = "/dev/block/dm-1",  // a dm-linear device (logical)
+        .mount_point = "/system",
+        .fs_type = "ext4",
+        .logical_partition_name = "system",
+    };
+
+    // Logical partitions.
+    // non-A/B
+    fstab_entry.fs_mgr_flags.logical = true;
+    EXPECT_EQ("system", DeriveAvbPartitionName(fstab_entry, "_dont_care", "_dont_care"));
+    EXPECT_EQ("system", DeriveAvbPartitionName(fstab_entry, "_a", "_b"));
+    EXPECT_EQ("system", DeriveAvbPartitionName(fstab_entry, "", ""));
+    // Active slot.
+    fstab_entry.fs_mgr_flags.slot_select = true;
+    fstab_entry.logical_partition_name = "system_a";
+    EXPECT_EQ("system", DeriveAvbPartitionName(fstab_entry, "_a", "_dont_care"));
+    EXPECT_EQ("system", DeriveAvbPartitionName(fstab_entry, "_a", "_b"));
+    EXPECT_EQ("system", DeriveAvbPartitionName(fstab_entry, "_a", ""));
+    EXPECT_EQ("system_a", DeriveAvbPartitionName(fstab_entry, "_wont_erase_a", "_dont_care"));
+    // The other slot.
+    fstab_entry.fs_mgr_flags.slot_select = false;
+    fstab_entry.fs_mgr_flags.slot_select_other = true;
+    fstab_entry.logical_partition_name = "system_b";
+    EXPECT_EQ("system_other", DeriveAvbPartitionName(fstab_entry, "_dont_care", "_b"));
+    EXPECT_EQ("system_other", DeriveAvbPartitionName(fstab_entry, "_a", "_b"));
+    EXPECT_EQ("system_other", DeriveAvbPartitionName(fstab_entry, "", "_b"));
+    EXPECT_EQ("system_b_other", DeriveAvbPartitionName(fstab_entry, "_dont_care", "_wont_erase_b"));
+
+    // Non-logical partitions.
+    // non-A/B.
+    fstab_entry.fs_mgr_flags.logical = false;
+    fstab_entry.fs_mgr_flags.slot_select = false;
+    fstab_entry.fs_mgr_flags.slot_select_other = false;
+    fstab_entry.blk_device = "/dev/block/by-name/system";
+    EXPECT_EQ("system", DeriveAvbPartitionName(fstab_entry, "_dont_care", "_dont_care"));
+    EXPECT_EQ("system", DeriveAvbPartitionName(fstab_entry, "_a", "_b"));
+    EXPECT_EQ("system", DeriveAvbPartitionName(fstab_entry, "", ""));
+    // Active slot _a.
+    fstab_entry.fs_mgr_flags.slot_select = true;
+    fstab_entry.blk_device = "/dev/block/by-name/system_a";
+    EXPECT_EQ("system", DeriveAvbPartitionName(fstab_entry, "_a", "_dont_care"));
+    EXPECT_EQ("system", DeriveAvbPartitionName(fstab_entry, "_a", "_b"));
+    EXPECT_EQ("system", DeriveAvbPartitionName(fstab_entry, "_a", ""));
+    EXPECT_EQ("system_a", DeriveAvbPartitionName(fstab_entry, "_wont_erase_a", "_dont_care"));
+    // Inactive slot _b.
+    fstab_entry.fs_mgr_flags.slot_select = false;
+    fstab_entry.fs_mgr_flags.slot_select_other = true;
+    fstab_entry.blk_device = "/dev/block/by-name/system_b";
+    EXPECT_EQ("system_other", DeriveAvbPartitionName(fstab_entry, "dont_care", "_b"));
+    EXPECT_EQ("system_other", DeriveAvbPartitionName(fstab_entry, "_a", "_b"));
+    EXPECT_EQ("system_other", DeriveAvbPartitionName(fstab_entry, "", "_b"));
+    EXPECT_EQ("system_b_other", DeriveAvbPartitionName(fstab_entry, "dont_care", "_wont_erase_b"));
+}
+
 TEST_F(AvbUtilTest, GetFdTotalSize) {
     // Generates a raw test.img via BaseFsAvbTest.
     const size_t image_size = 5 * 1024 * 1024;
@@ -751,7 +839,213 @@
     EXPECT_EQ(false, fatal_error);
 }
 
-TEST_F(AvbUtilTest, LoadAndVerifyVbmetaImpl) {
+TEST_F(AvbUtilTest, LoadAndVerifyVbmetaByPath) {
+    // Generates a raw system_other.img, use a smaller size to speed-up unit test.
+    const size_t system_image_size = 10 * 1024 * 1024;
+    const size_t system_partition_size = 15 * 1024 * 1024;
+    base::FilePath system_path = GenerateImage("system_other.img", system_image_size);
+
+    // Adds AVB Hashtree Footer.
+    AddAvbFooter(system_path, "hashtree", "system_other", system_partition_size, "SHA512_RSA4096",
+                 20, data_dir_.Append("testkey_rsa4096.pem"), "d00df00d",
+                 "--internal_release_string \"unit test\"");
+
+    base::FilePath rsa4096_public_key =
+        ExtractPublicKeyAvb(data_dir_.Append("testkey_rsa4096.pem"));
+
+    std::string expected_key_blob_4096;
+    EXPECT_TRUE(base::ReadFileToString(rsa4096_public_key, &expected_key_blob_4096));
+
+    bool verification_disabled;
+    VBMetaVerifyResult verify_result;
+    std::unique_ptr<VBMetaData> vbmeta = LoadAndVerifyVbmetaByPath(
+        system_path.value(), "system_other", expected_key_blob_4096,
+        false /* allow_verification_error */, false /* rollback_protection */,
+        false /* is_chained_vbmeta */, &verification_disabled, &verify_result);
+
+    EXPECT_NE(nullptr, vbmeta);
+    EXPECT_EQ(VBMetaVerifyResult::kSuccess, verify_result);
+    EXPECT_EQ(false, verification_disabled);
+
+    EXPECT_EQ(2112UL, vbmeta->size());
+    EXPECT_EQ(system_path.value(), vbmeta->vbmeta_path());
+    EXPECT_EQ("system_other", vbmeta->partition());
+    EXPECT_TRUE(CompareVBMeta(system_path, *vbmeta));
+}
+
+TEST_F(AvbUtilTest, LoadAndVerifyVbmetaByPathErrorVerification) {
+    // Generates a raw system_other.img, use a smaller size to speed-up unit test.
+    const size_t system_image_size = 10 * 1024 * 1024;
+    const size_t system_partition_size = 15 * 1024 * 1024;
+    base::FilePath system_path = GenerateImage("system_other.img", system_image_size);
+
+    // Adds AVB Hashtree Footer.
+    AddAvbFooter(system_path, "hashtree", "system_other", system_partition_size, "SHA512_RSA4096",
+                 20, data_dir_.Append("testkey_rsa4096.pem"), "d00df00d",
+                 "--internal_release_string \"unit test\"");
+
+    base::FilePath rsa4096_public_key =
+        ExtractPublicKeyAvb(data_dir_.Append("testkey_rsa4096.pem"));
+
+    std::string expected_key_blob_4096;
+    EXPECT_TRUE(base::ReadFileToString(rsa4096_public_key, &expected_key_blob_4096));
+
+    // Modifies the auxiliary data of system_other.img
+    auto fd = OpenUniqueReadFd(system_path);
+    auto system_footer = GetAvbFooter(fd);
+    auto system_vbmeta = ExtractAndLoadVBMetaData(system_path, "system_other-vbmeta.img");
+    auto system_header = system_vbmeta.GetVBMetaHeader(true /* update_vbmeta_size */);
+    size_t header_block_offset = 0;
+    size_t authentication_block_offset = header_block_offset + sizeof(AvbVBMetaImageHeader);
+    size_t auxiliary_block_offset =
+        authentication_block_offset + system_header->authentication_data_block_size;
+
+    // Modifies the hash.
+    ModifyFile(
+        system_path,
+        (system_footer->vbmeta_offset + authentication_block_offset + system_header->hash_offset),
+        system_header->hash_size);
+
+    VBMetaVerifyResult verify_result;
+    // Not allow verification error.
+    std::unique_ptr<VBMetaData> vbmeta = LoadAndVerifyVbmetaByPath(
+        system_path.value(), "system_other", expected_key_blob_4096,
+        false /* allow_verification_error */, false /* rollback_protection */,
+        false /* is_chained_vbmeta */, nullptr /* verification_disabled */, &verify_result);
+    EXPECT_EQ(nullptr, vbmeta);
+
+    // Allow verification error.
+    vbmeta = LoadAndVerifyVbmetaByPath(
+        system_path.value(), "system_other", expected_key_blob_4096,
+        true /* allow_verification_error */, false /* rollback_protection */,
+        false /* is_chained_vbmeta */, nullptr /* verification_disabled */, &verify_result);
+    EXPECT_NE(nullptr, vbmeta);
+    EXPECT_EQ(VBMetaVerifyResult::kErrorVerification, verify_result);
+
+    EXPECT_EQ(2112UL, vbmeta->size());
+    EXPECT_EQ(system_path.value(), vbmeta->vbmeta_path());
+    EXPECT_EQ("system_other", vbmeta->partition());
+    EXPECT_TRUE(CompareVBMeta(system_path, *vbmeta));
+
+    // Modifies the auxiliary data block.
+    ModifyFile(system_path, system_footer->vbmeta_offset + auxiliary_block_offset,
+               system_header->auxiliary_data_block_size);
+
+    // Not allow verification error.
+    vbmeta = LoadAndVerifyVbmetaByPath(
+        system_path.value(), "system_other", expected_key_blob_4096,
+        false /* allow_verification_error */, false /* rollback_protection */,
+        false /* is_chained_vbmeta */, nullptr /* verification_disabled */, &verify_result);
+    EXPECT_EQ(nullptr, vbmeta);
+
+    // Allow verification error.
+    vbmeta = LoadAndVerifyVbmetaByPath(
+        system_path.value(), "system_other", expected_key_blob_4096,
+        true /* allow_verification_error */, false /* rollback_protection */,
+        false /* is_chained_vbmeta */, nullptr /* verification_disabled */, &verify_result);
+    EXPECT_NE(nullptr, vbmeta);
+    EXPECT_EQ(VBMetaVerifyResult::kErrorVerification, verify_result);
+}
+
+TEST_F(AvbUtilTest, LoadAndVerifyVbmetaByPathUnexpectedPublicKey) {
+    // Generates a raw system_other.img, use a smaller size to speed-up unit test.
+    const size_t system_image_size = 10 * 1024 * 1024;
+    const size_t system_partition_size = 15 * 1024 * 1024;
+    base::FilePath system_path = GenerateImage("system_other.img", system_image_size);
+
+    // Adds AVB Hashtree Footer.
+    AddAvbFooter(system_path, "hashtree", "system_other", system_partition_size, "SHA512_RSA4096",
+                 20, data_dir_.Append("testkey_rsa4096.pem"), "d00df00d",
+                 "--internal_release_string \"unit test\"");
+
+    base::FilePath rsa2048_public_key =
+        ExtractPublicKeyAvb(data_dir_.Append("testkey_rsa2048.pem"));
+    base::FilePath rsa4096_public_key =
+        ExtractPublicKeyAvb(data_dir_.Append("testkey_rsa4096.pem"));
+
+    std::string expected_key_blob_4096;
+    EXPECT_TRUE(base::ReadFileToString(rsa4096_public_key, &expected_key_blob_4096));
+    std::string unexpected_key_blob_2048;
+    EXPECT_TRUE(base::ReadFileToString(rsa2048_public_key, &unexpected_key_blob_2048));
+
+    // Uses the correct expected public key.
+    VBMetaVerifyResult verify_result;
+    std::unique_ptr<VBMetaData> vbmeta = LoadAndVerifyVbmetaByPath(
+        system_path.value(), "system_other", expected_key_blob_4096,
+        false /* allow_verification_error */, false /* rollback_protection */,
+        false /* is_chained_vbmeta */, nullptr /* verification_disabled */, &verify_result);
+    EXPECT_NE(nullptr, vbmeta);
+    EXPECT_EQ(verify_result, VBMetaVerifyResult::kSuccess);
+    EXPECT_EQ(2112UL, vbmeta->size());
+    EXPECT_EQ(system_path.value(), vbmeta->vbmeta_path());
+    EXPECT_EQ("system_other", vbmeta->partition());
+    EXPECT_TRUE(CompareVBMeta(system_path, *vbmeta));
+
+    // Uses the wrong expected public key with allow_verification_error set to false.
+    vbmeta = LoadAndVerifyVbmetaByPath(
+        system_path.value(), "system_other", unexpected_key_blob_2048,
+        false /* allow_verification_error */, false /* rollback_protection */,
+        false /* is_chained_vbmeta */, nullptr /* verification_disabled */, &verify_result);
+    EXPECT_EQ(nullptr, vbmeta);
+
+    // Uses the wrong expected public key with allow_verification_error set to true.
+    vbmeta = LoadAndVerifyVbmetaByPath(
+        system_path.value(), "system_other", unexpected_key_blob_2048,
+        true /* allow_verification_error */, false /* rollback_protection */,
+        false /* is_chained_vbmeta */, nullptr /* verification_disabled */, &verify_result);
+    EXPECT_NE(nullptr, vbmeta);
+    EXPECT_EQ(verify_result, VBMetaVerifyResult::kErrorVerification);
+    EXPECT_EQ(2112UL, vbmeta->size());
+    EXPECT_EQ(system_path.value(), vbmeta->vbmeta_path());
+    EXPECT_EQ("system_other", vbmeta->partition());
+    EXPECT_TRUE(CompareVBMeta(system_path, *vbmeta));
+}
+
+TEST_F(AvbUtilTest, LoadAndVerifyVbmetaByPathVerificationDisabled) {
+    // Generates a raw system_other.img, use a smaller size to speed-up unit test.
+    const size_t system_image_size = 10 * 1024 * 1024;
+    const size_t system_partition_size = 15 * 1024 * 1024;
+    base::FilePath system_path = GenerateImage("system_other.img", system_image_size);
+
+    // Adds AVB Hashtree Footer.
+    AddAvbFooter(system_path, "hashtree", "system_other", system_partition_size, "SHA512_RSA4096",
+                 20, data_dir_.Append("testkey_rsa4096.pem"), "d00df00d",
+                 "--internal_release_string \"unit test\"");
+
+    base::FilePath rsa4096_public_key =
+        ExtractPublicKeyAvb(data_dir_.Append("testkey_rsa4096.pem"));
+
+    std::string expected_key_blob_4096;
+    EXPECT_TRUE(base::ReadFileToString(rsa4096_public_key, &expected_key_blob_4096));
+
+    // Sets disabled flag and expect the returned verification_disabled is true.
+    SetVBMetaFlags(system_path, AVB_VBMETA_IMAGE_FLAGS_VERIFICATION_DISABLED);
+    bool verification_disabled;
+    VBMetaVerifyResult verify_result;
+    std::unique_ptr<VBMetaData> vbmeta = LoadAndVerifyVbmetaByPath(
+        system_path.value(), "system_other", expected_key_blob_4096,
+        true /* allow_verification_error */, false /* rollback_protection */,
+        false /* is_chained_vbmeta */, &verification_disabled, &verify_result);
+
+    EXPECT_NE(nullptr, vbmeta);
+    EXPECT_EQ(VBMetaVerifyResult::kErrorVerification, verify_result);
+    EXPECT_EQ(true, verification_disabled);  // should be true.
+
+    EXPECT_EQ(2112UL, vbmeta->size());
+    EXPECT_EQ(system_path.value(), vbmeta->vbmeta_path());
+    EXPECT_EQ("system_other", vbmeta->partition());
+    EXPECT_TRUE(CompareVBMeta(system_path, *vbmeta));
+
+    // Since the vbmeta flags is modified, vbmeta will be nullptr
+    // if verification error isn't allowed.
+    vbmeta = LoadAndVerifyVbmetaByPath(
+        system_path.value(), "system_other", expected_key_blob_4096,
+        false /* allow_verification_error */, false /* rollback_protection */,
+        false /* is_chained_vbmeta */, &verification_disabled, &verify_result);
+    EXPECT_EQ(nullptr, vbmeta);
+}
+
+TEST_F(AvbUtilTest, LoadAndVerifyVbmetaByPartition) {
     // Generates a raw boot.img
     const size_t boot_image_size = 5 * 1024 * 1024;
     const size_t boot_partition_size = 10 * 1024 * 1024;
@@ -795,18 +1089,18 @@
     EXPECT_EQ("6f4bf815a651aa35ec7102a88b7906b91aef284bc5e20d0bf527c7d460da3266",
               CalcVBMetaDigest("vbmeta.img", "sha256"));
 
-    // Starts to test LoadAndVerifyVbmetaImpl.
+    // Starts to test LoadAndVerifyVbmetaByPartition.
     std::vector<VBMetaData> vbmeta_images;
     auto vbmeta_image_path = [this](const std::string& partition_name) {
         return test_dir_.Append(partition_name + ".img").value();
     };
 
     EXPECT_EQ(VBMetaVerifyResult::kSuccess,
-              LoadAndVerifyVbmetaImpl(
-                      "vbmeta" /* partition_name */, "" /* ab_suffix */, "" /* other_suffix */,
-                      "" /* expected_public_key_blob*/, false /* allow_verification_error */,
-                      true /* load_chained_vbmeta */, true /* rollback_protection */,
-                      vbmeta_image_path, false /* is_chained_vbmeta*/, &vbmeta_images));
+              LoadAndVerifyVbmetaByPartition(
+                  "vbmeta" /* partition_name */, "" /* ab_suffix */, "" /* other_suffix */,
+                  "" /* expected_public_key_blob*/, false /* allow_verification_error */,
+                  true /* load_chained_vbmeta */, true /* rollback_protection */, vbmeta_image_path,
+                  false /* is_chained_vbmeta*/, &vbmeta_images));
 
     EXPECT_EQ(4UL, vbmeta_images.size());  // vbmeta, boot, vbmeta_system and system
     // Binary comparison for each vbmeta image.
@@ -818,17 +1112,17 @@
     // Skip loading chained vbmeta images.
     vbmeta_images.clear();
     EXPECT_EQ(VBMetaVerifyResult::kSuccess,
-              LoadAndVerifyVbmetaImpl(
-                      "vbmeta" /* partition_name */, "" /* ab_suffix */, "" /* other_suffix */,
-                      "" /* expected_public_key_blob*/, false /* allow_verification_error */,
-                      false /* load_chained_vbmeta */, true /* rollback_protection */,
-                      vbmeta_image_path, false /* is_chained_vbmeta*/, &vbmeta_images));
+              LoadAndVerifyVbmetaByPartition(
+                  "vbmeta" /* partition_name */, "" /* ab_suffix */, "" /* other_suffix */,
+                  "" /* expected_public_key_blob*/, false /* allow_verification_error */,
+                  false /* load_chained_vbmeta */, true /* rollback_protection */,
+                  vbmeta_image_path, false /* is_chained_vbmeta*/, &vbmeta_images));
     // Only vbmeta is loaded.
     EXPECT_EQ(1UL, vbmeta_images.size());
     EXPECT_TRUE(CompareVBMeta(vbmeta_path, vbmeta_images[0]));
 }
 
-TEST_F(AvbUtilTest, LoadAndVerifyVbmetaImplWithSuffixes) {
+TEST_F(AvbUtilTest, LoadAndVerifyVbmetaByPartitionWithSuffixes) {
     // Tests the following chained partitions.
     // vbmeta_a.img
     // |--> boot_b.img (boot_other)
@@ -874,18 +1168,18 @@
              {"vbmeta_system_other", 2, rsa4096_public_key}},
             "--internal_release_string \"unit test\"");
 
-    // Starts to test LoadAndVerifyVbmetaImpl with ab_suffix and ab_other_suffix.
+    // Starts to test LoadAndVerifyVbmetaByPartition with ab_suffix and ab_other_suffix.
     auto vbmeta_image_path = [this](const std::string& partition_name) {
         return test_dir_.Append(partition_name + ".img").value();
     };
 
     std::vector<VBMetaData> vbmeta_images;
     EXPECT_EQ(VBMetaVerifyResult::kSuccess,
-              LoadAndVerifyVbmetaImpl(
-                      "vbmeta" /* partition_name */, "_a" /* ab_suffix */, "_b" /* other_suffix */,
-                      "" /* expected_public_key_blob*/, false /* allow_verification_error */,
-                      true /* load_chained_vbmeta */, true /* rollback_protection */,
-                      vbmeta_image_path, false /* is_chained_vbmeta*/, &vbmeta_images));
+              LoadAndVerifyVbmetaByPartition(
+                  "vbmeta" /* partition_name */, "_a" /* ab_suffix */, "_b" /* other_suffix */,
+                  "" /* expected_public_key_blob*/, false /* allow_verification_error */,
+                  true /* load_chained_vbmeta */, true /* rollback_protection */, vbmeta_image_path,
+                  false /* is_chained_vbmeta*/, &vbmeta_images));
 
     EXPECT_EQ(4UL, vbmeta_images.size());  // vbmeta, boot_other, vbmeta_system_other and system
     // Binary comparison for each vbmeta image.
@@ -897,26 +1191,26 @@
     // Skips loading chained vbmeta images.
     vbmeta_images.clear();
     EXPECT_EQ(VBMetaVerifyResult::kSuccess,
-              LoadAndVerifyVbmetaImpl(
-                      "vbmeta" /* partition_name */, "_a" /* ab_suffix */, "_b" /* other_suffix */,
-                      "" /* expected_public_key_blob*/, false /* allow_verification_error */,
-                      false /* load_chained_vbmeta */, true /* rollback_protection */,
-                      vbmeta_image_path, false /* is_chained_vbmeta*/, &vbmeta_images));
+              LoadAndVerifyVbmetaByPartition(
+                  "vbmeta" /* partition_name */, "_a" /* ab_suffix */, "_b" /* other_suffix */,
+                  "" /* expected_public_key_blob*/, false /* allow_verification_error */,
+                  false /* load_chained_vbmeta */, true /* rollback_protection */,
+                  vbmeta_image_path, false /* is_chained_vbmeta*/, &vbmeta_images));
     // Only vbmeta is loaded.
     EXPECT_EQ(1UL, vbmeta_images.size());
     EXPECT_TRUE(CompareVBMeta(vbmeta_path, vbmeta_images[0]));
 
     // Using an invalid suffix for 'other' slot, checks it returns error.
     EXPECT_EQ(VBMetaVerifyResult::kError,
-              LoadAndVerifyVbmetaImpl(
-                      "vbmeta" /* partition_name */, "_a" /* ab_suffix */,
-                      "_invalid_suffix" /* other_suffix */, "" /* expected_public_key_blob*/,
-                      false /* allow_verification_error */, true /* load_chained_vbmeta */,
-                      true /* rollback_protection */, vbmeta_image_path,
-                      false /* is_chained_vbmeta*/, &vbmeta_images));
+              LoadAndVerifyVbmetaByPartition(
+                  "vbmeta" /* partition_name */, "_a" /* ab_suffix */,
+                  "_invalid_suffix" /* other_suffix */, "" /* expected_public_key_blob*/,
+                  false /* allow_verification_error */, true /* load_chained_vbmeta */,
+                  true /* rollback_protection */, vbmeta_image_path, false /* is_chained_vbmeta*/,
+                  &vbmeta_images));
 }
 
-TEST_F(AvbUtilTest, LoadAndVerifyVbmetaImplErrorVerification) {
+TEST_F(AvbUtilTest, LoadAndVerifyVbmetaByPartitionErrorVerification) {
     // Generates a raw boot.img
     const size_t boot_image_size = 5 * 1024 * 1024;
     const size_t boot_partition_size = 10 * 1024 * 1024;
@@ -964,27 +1258,27 @@
     // Modifies the hash.
     ModifyFile(vbmeta_path, authentication_block_offset + header->hash_offset, header->hash_size);
 
-    // Starts to test LoadAndVerifyVbmetaImpl.
+    // Starts to test LoadAndVerifyVbmetaByPartition.
     std::vector<VBMetaData> vbmeta_images;
     auto vbmeta_image_path = [this](const std::string& partition_name) {
         return test_dir_.Append(partition_name + ".img").value();
     };
     EXPECT_EQ(VBMetaVerifyResult::kError,
-              LoadAndVerifyVbmetaImpl(
-                      "vbmeta" /* partition_name */, "" /* ab_suffix */, "" /* other_suffix */,
-                      "" /* expected_public_key_blob*/, false /* allow_verification_error */,
-                      true /* load_chained_vbmeta */, true /* rollback_protection */,
-                      vbmeta_image_path, false /* is_chained_vbmeta*/, &vbmeta_images));
+              LoadAndVerifyVbmetaByPartition(
+                  "vbmeta" /* partition_name */, "" /* ab_suffix */, "" /* other_suffix */,
+                  "" /* expected_public_key_blob*/, false /* allow_verification_error */,
+                  true /* load_chained_vbmeta */, true /* rollback_protection */, vbmeta_image_path,
+                  false /* is_chained_vbmeta*/, &vbmeta_images));
     // Stops to load vbmeta because the top-level vbmeta has verification error.
     EXPECT_EQ(0UL, vbmeta_images.size());
 
     // Tries again with verification error allowed.
     EXPECT_EQ(VBMetaVerifyResult::kErrorVerification,
-              LoadAndVerifyVbmetaImpl(
-                      "vbmeta" /* partition_name */, "" /* ab_suffix */, "", /* other_suffix */
-                      "" /* expected_public_key_blob*/, true /* allow_verification_error */,
-                      true /* load_chained_vbmeta */, true /* rollback_protection */,
-                      vbmeta_image_path, false /* is_chained_vbmeta*/, &vbmeta_images));
+              LoadAndVerifyVbmetaByPartition(
+                  "vbmeta" /* partition_name */, "" /* ab_suffix */, "", /* other_suffix */
+                  "" /* expected_public_key_blob*/, true /* allow_verification_error */,
+                  true /* load_chained_vbmeta */, true /* rollback_protection */, vbmeta_image_path,
+                  false /* is_chained_vbmeta*/, &vbmeta_images));
 
     EXPECT_EQ(3UL, vbmeta_images.size());  // vbmeta, boot, and system
     // Binary comparison for each vbmeta image.
@@ -1008,11 +1302,11 @@
                system_header->auxiliary_data_block_size);
     vbmeta_images.clear();
     EXPECT_EQ(VBMetaVerifyResult::kError,
-              LoadAndVerifyVbmetaImpl(
-                      "vbmeta" /* partition_name */, "" /* ab_suffix */, "" /* other_suffix */,
-                      "" /* expected_public_key_blob*/, false /* allow_verification_error */,
-                      true /* load_chained_vbmeta */, true /* rollback_protection */,
-                      vbmeta_image_path, false /* is_chained_vbmeta*/, &vbmeta_images));
+              LoadAndVerifyVbmetaByPartition(
+                  "vbmeta" /* partition_name */, "" /* ab_suffix */, "" /* other_suffix */,
+                  "" /* expected_public_key_blob*/, false /* allow_verification_error */,
+                  true /* load_chained_vbmeta */, true /* rollback_protection */, vbmeta_image_path,
+                  false /* is_chained_vbmeta*/, &vbmeta_images));
     // 'vbmeta', 'boot' but no 'system', because of verification error.
     EXPECT_EQ(2UL, vbmeta_images.size());
     // Binary comparison for the loaded 'vbmeta' and 'boot'.
@@ -1020,20 +1314,113 @@
     EXPECT_TRUE(CompareVBMeta(boot_path, vbmeta_images[1]));
 
     // Resets the modification of the auxiliary data.
-    ModifyFile(vbmeta_path, 0 /* offset */, -1 /* length */);
+    ModifyFile(system_path, 0 /* offset */, -1 /* length */);
 
     // Sets the vbmeta header flags on a chained partition, which introduces an error.
     ModifyFile(system_path, system_footer->vbmeta_offset + offsetof(AvbVBMetaImageHeader, flags),
                sizeof(uint32_t));
     EXPECT_EQ(VBMetaVerifyResult::kError,
-              LoadAndVerifyVbmetaImpl(
-                      "vbmeta" /* partition_name */, "" /* ab_suffix */, "" /* other_suffix */,
-                      "" /* expected_public_key_blob*/, true /* allow_verification_error */,
-                      true /* load_chained_vbmeta */, true /* rollback_protection */,
-                      vbmeta_image_path, false /* is_chained_vbmeta*/, &vbmeta_images));
+              LoadAndVerifyVbmetaByPartition(
+                  "vbmeta" /* partition_name */, "" /* ab_suffix */, "" /* other_suffix */,
+                  "" /* expected_public_key_blob*/, true /* allow_verification_error */,
+                  true /* load_chained_vbmeta */, true /* rollback_protection */, vbmeta_image_path,
+                  false /* is_chained_vbmeta*/, &vbmeta_images));
 }
 
-TEST_F(AvbUtilTest, LoadAndVerifyVbmetaImplUnexpectedPublicKey) {
+TEST_F(AvbUtilTest, LoadAndVerifyVbmetaByPartitionVerificationDisabled) {
+    // Generates a raw boot.img
+    const size_t boot_image_size = 5 * 1024 * 1024;
+    const size_t boot_partition_size = 10 * 1024 * 1024;
+    base::FilePath boot_path = GenerateImage("boot.img", boot_image_size);
+
+    // Adds AVB Hash Footer.
+    AddAvbFooter(boot_path, "hash", "boot", boot_partition_size, "SHA256_RSA2048", 10,
+                 data_dir_.Append("testkey_rsa2048.pem"), "d00df00d",
+                 "--internal_release_string \"unit test\"");
+
+    // Generates a raw system.img, use a smaller size to speed-up unit test.
+    const size_t system_image_size = 10 * 1024 * 1024;
+    const size_t system_partition_size = 15 * 1024 * 1024;
+    base::FilePath system_path = GenerateImage("system.img", system_image_size);
+    // Adds AVB Hashtree Footer.
+    AddAvbFooter(system_path, "hashtree", "system", system_partition_size, "SHA512_RSA4096", 20,
+                 data_dir_.Append("testkey_rsa4096.pem"), "d00df00d",
+                 "--internal_release_string \"unit test\"");
+
+    // Generates chain partition descriptors.
+    base::FilePath rsa2048_public_key =
+        ExtractPublicKeyAvb(data_dir_.Append("testkey_rsa2048.pem"));
+    base::FilePath rsa4096_public_key =
+        ExtractPublicKeyAvb(data_dir_.Append("testkey_rsa4096.pem"));
+    // Makes a vbmeta_system.img including the 'system' chained descriptor.
+    auto vbmeta_system_path = GenerateVBMetaImage(
+        "vbmeta_system.img", "SHA256_RSA4096", 0, data_dir_.Append("testkey_rsa4096.pem"),
+        {},                                  /* include_descriptor_image_paths */
+        {{"system", 3, rsa4096_public_key}}, /* chain_partitions */
+        "--internal_release_string \"unit test\"");
+
+    // Makes a vbmeta image includeing 'boot' and 'vbmeta_system' chained descriptors.
+    auto vbmeta_path = GenerateVBMetaImage("vbmeta.img", "SHA256_RSA8192", 0,
+                                           data_dir_.Append("testkey_rsa8192.pem"),
+                                           {}, /* include_descriptor_image_paths */
+                                           {{"boot", 1, rsa2048_public_key}, /* chain_partitions */
+                                            {"vbmeta_system", 2, rsa4096_public_key}},
+                                           "--internal_release_string \"unit test\"");
+
+    // Calculates the digest of all chained partitions, to ensure the chained is formed properly.
+    EXPECT_EQ("6f4bf815a651aa35ec7102a88b7906b91aef284bc5e20d0bf527c7d460da3266",
+              CalcVBMetaDigest("vbmeta.img", "sha256"));
+
+    // Starts to test LoadAndVerifyVbmetaByPartition.
+    std::vector<VBMetaData> vbmeta_images;
+    auto vbmeta_image_path = [this](const std::string& partition_name) {
+        return test_dir_.Append(partition_name + ".img").value();
+    };
+
+    EXPECT_EQ(VBMetaVerifyResult::kSuccess,
+              LoadAndVerifyVbmetaByPartition(
+                  "vbmeta" /* partition_name */, "" /* ab_suffix */, "" /* other_suffix */,
+                  "" /* expected_public_key_blob*/, false /* allow_verification_error */,
+                  true /* load_chained_vbmeta */, true /* rollback_protection */, vbmeta_image_path,
+                  false /* is_chained_vbmeta*/, &vbmeta_images));
+
+    EXPECT_EQ(4UL, vbmeta_images.size());  // vbmeta, boot, vbmeta_system and system
+    // Binary comparison for each vbmeta image.
+    EXPECT_TRUE(CompareVBMeta(vbmeta_path, vbmeta_images[0]));
+    EXPECT_TRUE(CompareVBMeta(boot_path, vbmeta_images[1]));
+    EXPECT_TRUE(CompareVBMeta(vbmeta_system_path, vbmeta_images[2]));
+    EXPECT_TRUE(CompareVBMeta(system_path, vbmeta_images[3]));
+
+    // Sets VERIFICATION_DISABLED to the top-level vbmeta.img
+    SetVBMetaFlags(vbmeta_path, AVB_VBMETA_IMAGE_FLAGS_VERIFICATION_DISABLED);
+    vbmeta_images.clear();
+    EXPECT_EQ(VBMetaVerifyResult::kErrorVerification,
+              LoadAndVerifyVbmetaByPartition(
+                  "vbmeta" /* partition_name */, "" /* ab_suffix */, "" /* other_suffix */,
+                  "" /* expected_public_key_blob*/, true /* allow_verification_error */,
+                  true /* load_chained_vbmeta */, true /* rollback_protection */, vbmeta_image_path,
+                  false /* is_chained_vbmeta*/, &vbmeta_images));
+    EXPECT_EQ(1UL, vbmeta_images.size());  // Only vbmeta is loaded
+    EXPECT_TRUE(CompareVBMeta(vbmeta_path, vbmeta_images[0]));
+
+    // HASHTREE_DISABLED still loads the chained vbmeta.
+    SetVBMetaFlags(vbmeta_path, AVB_VBMETA_IMAGE_FLAGS_HASHTREE_DISABLED);
+    vbmeta_images.clear();
+    EXPECT_EQ(VBMetaVerifyResult::kErrorVerification,
+              LoadAndVerifyVbmetaByPartition(
+                  "vbmeta" /* partition_name */, "" /* ab_suffix */, "" /* other_suffix */,
+                  "" /* expected_public_key_blob*/, true /* allow_verification_error */,
+                  true /* load_chained_vbmeta */, true /* rollback_protection */, vbmeta_image_path,
+                  false /* is_chained_vbmeta*/, &vbmeta_images));
+    EXPECT_EQ(4UL, vbmeta_images.size());  // vbmeta, boot, vbmeta_system and system
+    // Binary comparison for each vbmeta image.
+    EXPECT_TRUE(CompareVBMeta(vbmeta_path, vbmeta_images[0]));
+    EXPECT_TRUE(CompareVBMeta(boot_path, vbmeta_images[1]));
+    EXPECT_TRUE(CompareVBMeta(vbmeta_system_path, vbmeta_images[2]));
+    EXPECT_TRUE(CompareVBMeta(system_path, vbmeta_images[3]));
+}
+
+TEST_F(AvbUtilTest, LoadAndVerifyVbmetaByPartitionUnexpectedPublicKey) {
     // Generates chain partition descriptors.
     base::FilePath rsa2048_public_key =
             ExtractPublicKeyAvb(data_dir_.Append("testkey_rsa2048.pem"));
@@ -1060,29 +1447,29 @@
     std::vector<VBMetaData> vbmeta_images;
     // Uses the correct expected public key.
     EXPECT_EQ(VBMetaVerifyResult::kSuccess,
-              LoadAndVerifyVbmetaImpl(
-                      "vbmeta" /* partition_name */, "" /* ab_suffix */, "" /* other_suffix */,
-                      expected_key_blob_8192, true /* allow_verification_error */,
-                      false /* load_chained_vbmeta */, true /* rollback_protection */,
-                      vbmeta_image_path, false /* is_chained_vbmeta*/, &vbmeta_images));
+              LoadAndVerifyVbmetaByPartition(
+                  "vbmeta" /* partition_name */, "" /* ab_suffix */, "" /* other_suffix */,
+                  expected_key_blob_8192, true /* allow_verification_error */,
+                  false /* load_chained_vbmeta */, true /* rollback_protection */,
+                  vbmeta_image_path, false /* is_chained_vbmeta*/, &vbmeta_images));
 
     // Uses the wrong expected public key with allow_verification_error set to true.
     vbmeta_images.clear();
     EXPECT_EQ(VBMetaVerifyResult::kErrorVerification,
-              LoadAndVerifyVbmetaImpl(
-                      "vbmeta" /* partition_name */, "" /* ab_suffix */, "" /* other_suffix */,
-                      expected_key_blob_4096, true /* allow_verification_error */,
-                      false /* load_chained_vbmeta */, true /* rollback_protection */,
-                      vbmeta_image_path, false /* is_chained_vbmeta*/, &vbmeta_images));
+              LoadAndVerifyVbmetaByPartition(
+                  "vbmeta" /* partition_name */, "" /* ab_suffix */, "" /* other_suffix */,
+                  expected_key_blob_4096, true /* allow_verification_error */,
+                  false /* load_chained_vbmeta */, true /* rollback_protection */,
+                  vbmeta_image_path, false /* is_chained_vbmeta*/, &vbmeta_images));
 
     // Uses the wrong expected public key with allow_verification_error set to false.
     vbmeta_images.clear();
     EXPECT_EQ(VBMetaVerifyResult::kError,
-              LoadAndVerifyVbmetaImpl(
-                      "vbmeta" /* partition_name */, "" /* ab_suffix */, "" /* other_suffix */,
-                      expected_key_blob_4096, false /* allow_verification_error */,
-                      false /* load_chained_vbmeta */, true /* rollback_protection */,
-                      vbmeta_image_path, false /* is_chained_vbmeta*/, &vbmeta_images));
+              LoadAndVerifyVbmetaByPartition(
+                  "vbmeta" /* partition_name */, "" /* ab_suffix */, "" /* other_suffix */,
+                  expected_key_blob_4096, false /* allow_verification_error */,
+                  false /* load_chained_vbmeta */, true /* rollback_protection */,
+                  vbmeta_image_path, false /* is_chained_vbmeta*/, &vbmeta_images));
 }
 
 }  // namespace fs_avb_host_test