diff --git a/fs_mgr/libsnapshot/Android.bp b/fs_mgr/libsnapshot/Android.bp
index f8e4b7aec..db50e5824 100644
--- a/fs_mgr/libsnapshot/Android.bp
+++ b/fs_mgr/libsnapshot/Android.bp
@@ -403,3 +403,30 @@ cc_test {
     auto_gen_config: true,
     require_root: false,
 }
+
+cc_binary {
+    name: "make_cow_from_ab_ota",
+    host_supported: true,
+    device_supported: false,
+    static_libs: [
+        "libbase",
+        "libbspatch",
+        "libbrotli",
+        "libbz",
+        "libchrome",
+        "libcrypto",
+        "libgflags",
+        "liblog",
+        "libprotobuf-cpp-lite",
+        "libpuffpatch",
+        "libsnapshot_cow",
+        "libsparse",
+        "libxz",
+        "libz",
+        "libziparchive",
+        "update_metadata-protos",
+    ],
+    srcs: [
+        "make_cow_from_ab_ota.cpp",
+    ],
+}
diff --git a/fs_mgr/libsnapshot/make_cow_from_ab_ota.cpp b/fs_mgr/libsnapshot/make_cow_from_ab_ota.cpp
new file mode 100644
index 000000000..0b40fd60b
--- /dev/null
+++ b/fs_mgr/libsnapshot/make_cow_from_ab_ota.cpp
@@ -0,0 +1,690 @@
+//
+// 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.
+//
+
+#include <arpa/inet.h>
+#include <errno.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <iostream>
+#include <limits>
+#include <string>
+#include <unordered_set>
+
+#include <android-base/file.h>
+#include <android-base/logging.h>
+#include <android-base/unique_fd.h>
+#include <bsdiff/bspatch.h>
+#include <bzlib.h>
+#include <gflags/gflags.h>
+#include <libsnapshot/cow_writer.h>
+#include <puffin/puffpatch.h>
+#include <sparse/sparse.h>
+#include <update_engine/update_metadata.pb.h>
+#include <xz.h>
+#include <ziparchive/zip_archive.h>
+
+namespace android {
+namespace snapshot {
+
+using android::base::borrowed_fd;
+using android::base::unique_fd;
+using chromeos_update_engine::DeltaArchiveManifest;
+using chromeos_update_engine::Extent;
+using chromeos_update_engine::InstallOperation;
+using chromeos_update_engine::PartitionUpdate;
+
+static constexpr uint64_t kBlockSize = 4096;
+
+DEFINE_string(source_tf, "", "Source target files (dir or zip file) for incremental payloads");
+DEFINE_string(compression, "gz", "Compression type to use (none or gz)");
+
+void MyLogger(android::base::LogId, android::base::LogSeverity severity, const char*, const char*,
+              unsigned int, const char* message) {
+    if (severity == android::base::ERROR) {
+        fprintf(stderr, "%s\n", message);
+    } else {
+        fprintf(stdout, "%s\n", message);
+    }
+}
+
+uint64_t ToLittleEndian(uint64_t value) {
+    union {
+        uint64_t u64;
+        char bytes[8];
+    } packed;
+    packed.u64 = value;
+    std::swap(packed.bytes[0], packed.bytes[7]);
+    std::swap(packed.bytes[1], packed.bytes[6]);
+    std::swap(packed.bytes[2], packed.bytes[5]);
+    std::swap(packed.bytes[3], packed.bytes[4]);
+    return packed.u64;
+}
+
+class PayloadConverter final {
+  public:
+    PayloadConverter(const std::string& in_file, const std::string& out_dir)
+        : in_file_(in_file), out_dir_(out_dir), source_tf_zip_(nullptr, &CloseArchive) {}
+
+    bool Run();
+
+  private:
+    bool OpenPayload();
+    bool OpenSourceTargetFiles();
+    bool ProcessPartition(const PartitionUpdate& update);
+    bool ProcessOperation(const InstallOperation& op);
+    bool ProcessZero(const InstallOperation& op);
+    bool ProcessCopy(const InstallOperation& op);
+    bool ProcessReplace(const InstallOperation& op);
+    bool ProcessDiff(const InstallOperation& op);
+    borrowed_fd OpenSourceImage();
+
+    std::string in_file_;
+    std::string out_dir_;
+    unique_fd in_fd_;
+    uint64_t payload_offset_ = 0;
+    DeltaArchiveManifest manifest_;
+    std::unordered_set<std::string> dap_;
+    unique_fd source_tf_fd_;
+    std::unique_ptr<ZipArchive, decltype(&CloseArchive)> source_tf_zip_;
+
+    // Updated during ProcessPartition().
+    std::string partition_name_;
+    std::unique_ptr<CowWriter> writer_;
+    unique_fd source_image_;
+};
+
+bool PayloadConverter::Run() {
+    if (!OpenPayload()) {
+        return false;
+    }
+
+    if (manifest_.has_dynamic_partition_metadata()) {
+        const auto& dpm = manifest_.dynamic_partition_metadata();
+        for (const auto& group : dpm.groups()) {
+            for (const auto& partition : group.partition_names()) {
+                dap_.emplace(partition);
+            }
+        }
+    }
+
+    if (dap_.empty()) {
+        LOG(ERROR) << "No dynamic partitions found.";
+        return false;
+    }
+
+    if (!OpenSourceTargetFiles()) {
+        return false;
+    }
+
+    for (const auto& update : manifest_.partitions()) {
+        if (!ProcessPartition(update)) {
+            return false;
+        }
+        writer_ = nullptr;
+        source_image_.reset();
+    }
+    return true;
+}
+
+bool PayloadConverter::OpenSourceTargetFiles() {
+    if (FLAGS_source_tf.empty()) {
+        return true;
+    }
+
+    source_tf_fd_.reset(open(FLAGS_source_tf.c_str(), O_RDONLY));
+    if (source_tf_fd_ < 0) {
+        LOG(ERROR) << "open failed: " << FLAGS_source_tf;
+        return false;
+    }
+
+    struct stat s;
+    if (fstat(source_tf_fd_.get(), &s) < 0) {
+        LOG(ERROR) << "fstat failed: " << FLAGS_source_tf;
+        return false;
+    }
+    if (S_ISDIR(s.st_mode)) {
+        return true;
+    }
+
+    // Otherwise, assume it's a zip file.
+    ZipArchiveHandle handle;
+    if (OpenArchiveFd(source_tf_fd_.get(), FLAGS_source_tf.c_str(), &handle, false)) {
+        LOG(ERROR) << "Could not open " << FLAGS_source_tf << " as a zip archive.";
+        return false;
+    }
+    source_tf_zip_.reset(handle);
+    return true;
+}
+
+bool PayloadConverter::ProcessPartition(const PartitionUpdate& update) {
+    auto partition_name = update.partition_name();
+    if (dap_.find(partition_name) == dap_.end()) {
+        // Skip non-DAP partitions.
+        return true;
+    }
+
+    auto path = out_dir_ + "/" + partition_name + ".cow";
+    unique_fd fd(open(path.c_str(), O_RDWR | O_CREAT | O_TRUNC | O_CLOEXEC, 0644));
+    if (fd < 0) {
+        PLOG(ERROR) << "open failed: " << path;
+        return false;
+    }
+
+    CowOptions options;
+    options.block_size = kBlockSize;
+    options.compression = FLAGS_compression;
+
+    writer_ = std::make_unique<CowWriter>(options);
+    if (!writer_->Initialize(std::move(fd))) {
+        LOG(ERROR) << "Unable to initialize COW writer";
+        return false;
+    }
+
+    partition_name_ = partition_name;
+
+    for (const auto& op : update.operations()) {
+        if (!ProcessOperation(op)) {
+            return false;
+        }
+    }
+
+    if (!writer_->Finalize()) {
+        LOG(ERROR) << "Unable to finalize COW for " << partition_name;
+        return false;
+    }
+    return true;
+}
+
+bool PayloadConverter::ProcessOperation(const InstallOperation& op) {
+    switch (op.type()) {
+        case InstallOperation::SOURCE_COPY:
+            return ProcessCopy(op);
+        case InstallOperation::BROTLI_BSDIFF:
+        case InstallOperation::PUFFDIFF:
+            return ProcessDiff(op);
+        case InstallOperation::REPLACE:
+        case InstallOperation::REPLACE_XZ:
+        case InstallOperation::REPLACE_BZ:
+            return ProcessReplace(op);
+        case InstallOperation::ZERO:
+            return ProcessZero(op);
+        default:
+            LOG(ERROR) << "Unsupported op: " << (int)op.type();
+            return false;
+    }
+    return true;
+}
+
+bool PayloadConverter::ProcessZero(const InstallOperation& op) {
+    for (const auto& extent : op.dst_extents()) {
+        if (!writer_->AddZeroBlocks(extent.start_block(), extent.num_blocks())) {
+            LOG(ERROR) << "Could not add zero operation";
+            return false;
+        }
+    }
+    return true;
+}
+
+template <typename T>
+static uint64_t SizeOfAllExtents(const T& extents) {
+    uint64_t total = 0;
+    for (const auto& extent : extents) {
+        total += extent.num_blocks() * kBlockSize;
+    }
+    return total;
+}
+
+class PuffInputStream final : public puffin::StreamInterface {
+  public:
+    PuffInputStream(uint8_t* buffer, size_t length) : buffer_(buffer), length_(length) {}
+
+    bool GetSize(uint64_t* size) const override {
+        *size = length_;
+        return true;
+    }
+    bool GetOffset(uint64_t* offset) const override {
+        *offset = pos_;
+        return true;
+    }
+    bool Seek(uint64_t offset) override {
+        if (offset > length_) return false;
+        pos_ = offset;
+        return true;
+    }
+    bool Read(void* buffer, size_t length) override {
+        if (length_ - pos_ < length) return false;
+        memcpy(buffer, buffer_ + pos_, length);
+        pos_ += length;
+        return true;
+    }
+    bool Write(const void*, size_t) override { return false; }
+    bool Close() override { return true; }
+
+  private:
+    uint8_t* buffer_;
+    size_t length_;
+    size_t pos_;
+};
+
+class PuffOutputStream final : public puffin::StreamInterface {
+  public:
+    PuffOutputStream(std::vector<uint8_t>& stream) : stream_(stream), pos_(0) {}
+
+    bool GetSize(uint64_t* size) const override {
+        *size = stream_.size();
+        return true;
+    }
+    bool GetOffset(uint64_t* offset) const override {
+        *offset = pos_;
+        return true;
+    }
+    bool Seek(uint64_t offset) override {
+        if (offset > stream_.size()) {
+            return false;
+        }
+        pos_ = offset;
+        return true;
+    }
+    bool Read(void* buffer, size_t length) override {
+        if (stream_.size() - pos_ < length) {
+            return false;
+        }
+        memcpy(buffer, &stream_[0] + pos_, length);
+        pos_ += length;
+        return true;
+    }
+    bool Write(const void* buffer, size_t length) override {
+        auto remaining = stream_.size() - pos_;
+        if (remaining < length) {
+            stream_.resize(stream_.size() + (length - remaining));
+        }
+        memcpy(&stream_[0] + pos_, buffer, length);
+        pos_ += length;
+        return true;
+    }
+    bool Close() override { return true; }
+
+  private:
+    std::vector<uint8_t>& stream_;
+    size_t pos_;
+};
+
+bool PayloadConverter::ProcessDiff(const InstallOperation& op) {
+    auto source_image = OpenSourceImage();
+    if (source_image < 0) {
+        return false;
+    }
+
+    uint64_t src_length = SizeOfAllExtents(op.src_extents());
+    auto src = std::make_unique<uint8_t[]>(src_length);
+    size_t src_pos = 0;
+
+    // Read source bytes.
+    for (const auto& extent : op.src_extents()) {
+        uint64_t offset = extent.start_block() * kBlockSize;
+        if (lseek(source_image.get(), offset, SEEK_SET) < 0) {
+            PLOG(ERROR) << "lseek source image failed";
+            return false;
+        }
+
+        uint64_t size = extent.num_blocks() * kBlockSize;
+        CHECK(src_length - src_pos >= size);
+        if (!android::base::ReadFully(source_image, src.get() + src_pos, size)) {
+            PLOG(ERROR) << "read source image failed";
+            return false;
+        }
+        src_pos += size;
+    }
+    CHECK(src_pos == src_length);
+
+    // Read patch bytes.
+    auto patch = std::make_unique<uint8_t[]>(op.data_length());
+    if (lseek(in_fd_.get(), payload_offset_ + op.data_offset(), SEEK_SET) < 0) {
+        PLOG(ERROR) << "lseek payload failed";
+        return false;
+    }
+    if (!android::base::ReadFully(in_fd_, patch.get(), op.data_length())) {
+        PLOG(ERROR) << "read payload failed";
+        return false;
+    }
+
+    std::vector<uint8_t> dest(SizeOfAllExtents(op.dst_extents()));
+
+    // Apply the diff.
+    if (op.type() == InstallOperation::BROTLI_BSDIFF) {
+        size_t dest_pos = 0;
+        auto sink = [&](const uint8_t* data, size_t length) -> size_t {
+            CHECK(dest.size() - dest_pos >= length);
+            memcpy(&dest[dest_pos], data, length);
+            dest_pos += length;
+            return length;
+        };
+        if (int rv = bsdiff::bspatch(src.get(), src_pos, patch.get(), op.data_length(), sink)) {
+            LOG(ERROR) << "bspatch failed, error code " << rv;
+            return false;
+        }
+    } else if (op.type() == InstallOperation::PUFFDIFF) {
+        auto src_stream = std::make_unique<PuffInputStream>(src.get(), src_length);
+        auto dest_stream = std::make_unique<PuffOutputStream>(dest);
+        bool ok = PuffPatch(std::move(src_stream), std::move(dest_stream), patch.get(),
+                            op.data_length());
+        if (!ok) {
+            LOG(ERROR) << "puffdiff operation failed to apply";
+            return false;
+        }
+    } else {
+        LOG(ERROR) << "unsupported diff operation: " << op.type();
+        return false;
+    }
+
+    // Write the final blocks to the COW.
+    size_t dest_pos = 0;
+    for (const auto& extent : op.dst_extents()) {
+        uint64_t size = extent.num_blocks() * kBlockSize;
+        CHECK(dest.size() - dest_pos >= size);
+
+        if (!writer_->AddRawBlocks(extent.start_block(), &dest[dest_pos], size)) {
+            return false;
+        }
+        dest_pos += size;
+    }
+    return true;
+}
+
+borrowed_fd PayloadConverter::OpenSourceImage() {
+    if (source_image_ >= 0) {
+        return source_image_;
+    }
+
+    unique_fd unzip_fd;
+
+    auto local_path = "IMAGES/" + partition_name_ + ".img";
+    if (source_tf_zip_) {
+        {
+            TemporaryFile tmp;
+            if (tmp.fd < 0) {
+                PLOG(ERROR) << "mkstemp failed";
+                return -1;
+            }
+            unzip_fd.reset(tmp.release());
+        }
+
+        ZipEntry64 entry;
+        if (FindEntry(source_tf_zip_.get(), local_path, &entry)) {
+            LOG(ERROR) << "not found in archive: " << local_path;
+            return -1;
+        }
+        if (ExtractEntryToFile(source_tf_zip_.get(), &entry, unzip_fd.get())) {
+            LOG(ERROR) << "could not extract " << local_path;
+            return -1;
+        }
+        if (lseek(unzip_fd.get(), 0, SEEK_SET) < 0) {
+            PLOG(ERROR) << "lseek failed";
+            return -1;
+        }
+    } else if (source_tf_fd_ >= 0) {
+        unzip_fd.reset(openat(source_tf_fd_.get(), local_path.c_str(), O_RDONLY));
+        if (unzip_fd < 0) {
+            PLOG(ERROR) << "open failed: " << FLAGS_source_tf << "/" << local_path;
+            return -1;
+        }
+    } else {
+        LOG(ERROR) << "No source target files package was specified; need -source_tf";
+        return -1;
+    }
+
+    std::unique_ptr<struct sparse_file, decltype(&sparse_file_destroy)> s(
+            sparse_file_import(unzip_fd.get(), false, false), &sparse_file_destroy);
+    if (s) {
+        TemporaryFile tmp;
+        if (tmp.fd < 0) {
+            PLOG(ERROR) << "mkstemp failed";
+            return -1;
+        }
+        if (sparse_file_write(s.get(), tmp.fd, false, false, false) < 0) {
+            LOG(ERROR) << "sparse_file_write failed";
+            return -1;
+        }
+        source_image_.reset(tmp.release());
+    } else {
+        source_image_ = std::move(unzip_fd);
+    }
+    return source_image_;
+}
+
+template <typename ContainerType>
+class ExtentIter final {
+  public:
+    ExtentIter(const ContainerType& container)
+        : iter_(container.cbegin()), end_(container.cend()) {}
+
+    bool GetNext(uint64_t* block) {
+        while (iter_ != end_) {
+            if (dst_index_ < iter_->num_blocks()) {
+                break;
+            }
+            iter_++;
+            dst_index_ = 0;
+        }
+        if (iter_ == end_) {
+            return false;
+        }
+        *block = iter_->start_block() + dst_index_;
+        dst_index_++;
+        return true;
+    }
+
+  private:
+    typename ContainerType::const_iterator iter_;
+    typename ContainerType::const_iterator end_;
+    uint64_t dst_index_;
+};
+
+bool PayloadConverter::ProcessCopy(const InstallOperation& op) {
+    ExtentIter dst_blocks(op.dst_extents());
+
+    for (const auto& extent : op.src_extents()) {
+        for (uint64_t i = 0; i < extent.num_blocks(); i++) {
+            uint64_t src_block = extent.start_block() + i;
+            uint64_t dst_block;
+            if (!dst_blocks.GetNext(&dst_block)) {
+                LOG(ERROR) << "SOURCE_COPY contained mismatching extents";
+                return false;
+            }
+            if (src_block == dst_block) continue;
+            if (!writer_->AddCopy(dst_block, src_block)) {
+                LOG(ERROR) << "Could not add copy operation";
+                return false;
+            }
+        }
+    }
+    return true;
+}
+
+bool PayloadConverter::ProcessReplace(const InstallOperation& op) {
+    auto buffer_size = op.data_length();
+    auto buffer = std::make_unique<char[]>(buffer_size);
+    uint64_t offs = payload_offset_ + op.data_offset();
+    if (lseek(in_fd_.get(), offs, SEEK_SET) < 0) {
+        PLOG(ERROR) << "lseek " << offs << " failed";
+        return false;
+    }
+    if (!android::base::ReadFully(in_fd_, buffer.get(), buffer_size)) {
+        PLOG(ERROR) << "read " << buffer_size << " bytes from offset " << offs << "failed";
+        return false;
+    }
+
+    uint64_t dst_size = 0;
+    for (const auto& extent : op.dst_extents()) {
+        dst_size += extent.num_blocks() * kBlockSize;
+    }
+
+    if (op.type() == InstallOperation::REPLACE_BZ) {
+        auto tmp = std::make_unique<char[]>(dst_size);
+
+        uint32_t actual_size;
+        if (dst_size > std::numeric_limits<typeof(actual_size)>::max()) {
+            LOG(ERROR) << "too many bytes to decompress: " << dst_size;
+            return false;
+        }
+        actual_size = static_cast<uint32_t>(dst_size);
+
+        auto rv = BZ2_bzBuffToBuffDecompress(tmp.get(), &actual_size, buffer.get(), buffer_size, 0,
+                                             0);
+        if (rv) {
+            LOG(ERROR) << "bz2 decompress failed: " << rv;
+            return false;
+        }
+        if (actual_size != dst_size) {
+            LOG(ERROR) << "bz2 returned " << actual_size << " bytes, expected " << dst_size;
+            return false;
+        }
+        buffer = std::move(tmp);
+        buffer_size = dst_size;
+    } else if (op.type() == InstallOperation::REPLACE_XZ) {
+        constexpr uint32_t kXzMaxDictSize = 64 * 1024 * 1024;
+
+        if (dst_size > std::numeric_limits<size_t>::max()) {
+            LOG(ERROR) << "too many bytes to decompress: " << dst_size;
+            return false;
+        }
+
+        std::unique_ptr<struct xz_dec, decltype(&xz_dec_end)> s(
+                xz_dec_init(XZ_DYNALLOC, kXzMaxDictSize), xz_dec_end);
+        if (!s) {
+            LOG(ERROR) << "xz_dec_init failed";
+            return false;
+        }
+
+        auto tmp = std::make_unique<char[]>(dst_size);
+
+        struct xz_buf args;
+        args.in = reinterpret_cast<const uint8_t*>(buffer.get());
+        args.in_pos = 0;
+        args.in_size = buffer_size;
+        args.out = reinterpret_cast<uint8_t*>(tmp.get());
+        args.out_pos = 0;
+        args.out_size = dst_size;
+
+        auto rv = xz_dec_run(s.get(), &args);
+        if (rv != XZ_STREAM_END) {
+            LOG(ERROR) << "xz decompress failed: " << (int)rv;
+            return false;
+        }
+        buffer = std::move(tmp);
+        buffer_size = dst_size;
+    }
+
+    uint64_t buffer_pos = 0;
+    for (const auto& extent : op.dst_extents()) {
+        uint64_t extent_size = extent.num_blocks() * kBlockSize;
+        if (buffer_size - buffer_pos < extent_size) {
+            LOG(ERROR) << "replace op ran out of input buffer";
+            return false;
+        }
+        if (!writer_->AddRawBlocks(extent.start_block(), buffer.get() + buffer_pos, extent_size)) {
+            LOG(ERROR) << "failed to add raw blocks from replace op";
+            return false;
+        }
+        buffer_pos += extent_size;
+    }
+    return true;
+}
+
+bool PayloadConverter::OpenPayload() {
+    in_fd_.reset(open(in_file_.c_str(), O_RDONLY));
+    if (in_fd_ < 0) {
+        PLOG(ERROR) << "open " << in_file_;
+        return false;
+    }
+
+    char magic[4];
+    if (!android::base::ReadFully(in_fd_, magic, sizeof(magic))) {
+        PLOG(ERROR) << "read magic";
+        return false;
+    }
+    if (std::string(magic, sizeof(magic)) != "CrAU") {
+        LOG(ERROR) << "Invalid magic in " << in_file_;
+        return false;
+    }
+
+    uint64_t version;
+    uint64_t manifest_size;
+    uint32_t manifest_signature_size = 0;
+    if (!android::base::ReadFully(in_fd_, &version, sizeof(version))) {
+        PLOG(ERROR) << "read version";
+        return false;
+    }
+    version = ToLittleEndian(version);
+    if (version < 2) {
+        LOG(ERROR) << "Only payload version 2 or higher is supported.";
+        return false;
+    }
+
+    if (!android::base::ReadFully(in_fd_, &manifest_size, sizeof(manifest_size))) {
+        PLOG(ERROR) << "read manifest_size";
+        return false;
+    }
+    manifest_size = ToLittleEndian(manifest_size);
+    if (!android::base::ReadFully(in_fd_, &manifest_signature_size,
+                                  sizeof(manifest_signature_size))) {
+        PLOG(ERROR) << "read manifest_signature_size";
+        return false;
+    }
+    manifest_signature_size = ntohl(manifest_signature_size);
+
+    auto manifest = std::make_unique<uint8_t[]>(manifest_size);
+    if (!android::base::ReadFully(in_fd_, manifest.get(), manifest_size)) {
+        PLOG(ERROR) << "read manifest";
+        return false;
+    }
+
+    // Skip past manifest signature.
+    auto offs = lseek(in_fd_, manifest_signature_size, SEEK_CUR);
+    if (offs < 0) {
+        PLOG(ERROR) << "lseek failed";
+        return false;
+    }
+    payload_offset_ = offs;
+
+    if (!manifest_.ParseFromArray(manifest.get(), manifest_size)) {
+        LOG(ERROR) << "could not parse manifest";
+        return false;
+    }
+    return true;
+}
+
+}  // namespace snapshot
+}  // namespace android
+
+int main(int argc, char** argv) {
+    android::base::InitLogging(argv, android::snapshot::MyLogger);
+    gflags::SetUsageMessage("Convert OTA payload to a Virtual A/B COW");
+    int arg_start = gflags::ParseCommandLineFlags(&argc, &argv, false);
+
+    xz_crc32_init();
+
+    if (argc - arg_start != 2) {
+        std::cerr << "Usage: [options] <payload.bin> <out-dir>\n";
+        return 1;
+    }
+
+    android::snapshot::PayloadConverter pc(argv[arg_start], argv[arg_start + 1]);
+    return pc.Run() ? 0 : 1;
+}