diff --git a/adb/daemon/usb.cpp b/adb/daemon/usb.cpp
index 1abae87..f4aa9fb 100644
--- a/adb/daemon/usb.cpp
+++ b/adb/daemon/usb.cpp
@@ -509,14 +509,16 @@
             }
 
             if (id.direction == TransferDirection::READ) {
-                HandleRead(id, event.res);
+                if (!HandleRead(id, event.res)) {
+                    return;
+                }
             } else {
                 HandleWrite(id);
             }
         }
     }
 
-    void HandleRead(TransferId id, int64_t size) {
+    bool HandleRead(TransferId id, int64_t size) {
         uint64_t read_idx = id.id % kUsbReadQueueDepth;
         IoBlock* block = &read_requests_[read_idx];
         block->pending = false;
@@ -526,7 +528,7 @@
         if (block->id().id != needed_read_id_) {
             LOG(VERBOSE) << "read " << block->id().id << " completed while waiting for "
                          << needed_read_id_;
-            return;
+            return true;
         }
 
         for (uint64_t id = needed_read_id_;; ++id) {
@@ -535,15 +537,22 @@
             if (current_block->pending) {
                 break;
             }
-            ProcessRead(current_block);
+            if (!ProcessRead(current_block)) {
+                return false;
+            }
             ++needed_read_id_;
         }
+
+        return true;
     }
 
-    void ProcessRead(IoBlock* block) {
+    bool ProcessRead(IoBlock* block) {
         if (!block->payload->empty()) {
             if (!incoming_header_.has_value()) {
-                CHECK_EQ(sizeof(amessage), block->payload->size());
+                if (block->payload->size() != sizeof(amessage)) {
+                    HandleError("received packet of unexpected length while reading header");
+                    return false;
+                }
                 amessage msg;
                 memcpy(&msg, block->payload->data(), sizeof(amessage));
                 LOG(DEBUG) << "USB read:" << dump_header(&msg);
@@ -551,7 +560,10 @@
             } else {
                 size_t bytes_left = incoming_header_->data_length - incoming_payload_.size();
                 Block payload = std::move(*block->payload);
-                CHECK_LE(payload.size(), bytes_left);
+                if (block->payload->size() > bytes_left) {
+                    HandleError("received too many bytes while waiting for payload");
+                    return false;
+                }
                 incoming_payload_.append(std::make_unique<Block>(std::move(payload)));
             }
 
@@ -570,6 +582,7 @@
 
         PrepareReadBlock(block, block->id().id + kUsbReadQueueDepth);
         SubmitRead(block);
+        return true;
     }
 
     bool SubmitRead(IoBlock* block) {
diff --git a/init/Android.bp b/init/Android.bp
index fa0a35c..9c1ed15 100644
--- a/init/Android.bp
+++ b/init/Android.bp
@@ -63,6 +63,7 @@
         "libavb",
         "libc++fs",
         "libcgrouprc_format",
+        "libmodprobe",
         "libprotobuf-cpp-lite",
         "libpropertyinfoserializer",
         "libpropertyinfoparser",
diff --git a/init/Android.mk b/init/Android.mk
index 0a3e8c7..b24f757 100644
--- a/init/Android.mk
+++ b/init/Android.mk
@@ -110,6 +110,7 @@
     libdexfile_support \
     libunwindstack \
     libbacktrace \
+    libmodprobe \
 
 LOCAL_SANITIZE := signed-integer-overflow
 # First stage init is weird: it may start without stdout/stderr, and no /proc.
diff --git a/init/README.md b/init/README.md
index 6868378..8179bff 100644
--- a/init/README.md
+++ b/init/README.md
@@ -196,9 +196,9 @@
 
 `interface <interface name> <instance name>`
 > Associates this service with a list of the HIDL services that it provides. The interface name
-  must be a fully-qualified name and not a value name. This is used to allow hwservicemanager to
-  lazily start services. When multiple interfaces are served, this tag should be used multiple
-  times.
+  must be a fully-qualified name and not a value name. For instance, this is used to allow
+  hwservicemanager to lazily start services. When multiple interfaces are served, this tag should
+  be used multiple times.
   For example: interface vendor.foo.bar@1.0::IBaz default
 
 `ioprio <class> <priority>`
diff --git a/init/first_stage_init.cpp b/init/first_stage_init.cpp
index 5d64f41..17387e2 100644
--- a/init/first_stage_init.cpp
+++ b/init/first_stage_init.cpp
@@ -33,6 +33,7 @@
 #include <android-base/chrono_utils.h>
 #include <android-base/file.h>
 #include <android-base/logging.h>
+#include <modprobe/modprobe.h>
 #include <private/android_filesystem_config.h>
 
 #include "debug_ramdisk.h"
@@ -192,6 +193,11 @@
         old_root_dir.reset();
     }
 
+    Modprobe m({"/lib/modules"});
+    if (!m.LoadListedModules()) {
+        LOG(FATAL) << "Failed to load kernel modules";
+    }
+
     if (ForceNormalBoot()) {
         mkdir("/first_stage_ramdisk", 0755);
         // SwitchRoot() must be called with a mount point as the target, so we bind mount the
diff --git a/init/modalias_handler.cpp b/init/modalias_handler.cpp
index a511156..07b05d8 100644
--- a/init/modalias_handler.cpp
+++ b/init/modalias_handler.cpp
@@ -16,147 +16,20 @@
 
 #include "modalias_handler.h"
 
-#include <fnmatch.h>
-#include <sys/syscall.h>
-
-#include <algorithm>
-#include <functional>
 #include <string>
 #include <vector>
 
-#include <android-base/chrono_utils.h>
-#include <android-base/logging.h>
-#include <android-base/unique_fd.h>
-
-#include "parser.h"
+#include <modprobe/modprobe.h>
 
 namespace android {
 namespace init {
 
-Result<void> ModaliasHandler::ParseDepCallback(std::vector<std::string>&& args) {
-    std::vector<std::string> deps;
-
-    // Set first item as our modules path
-    std::string::size_type pos = args[0].find(':');
-    if (pos != std::string::npos) {
-        deps.emplace_back(args[0].substr(0, pos));
-    } else {
-        return Error() << "dependency lines must start with name followed by ':'";
-    }
-
-    // Remaining items are dependencies of our module
-    for (auto arg = args.begin() + 1; arg != args.end(); ++arg) {
-        deps.push_back(*arg);
-    }
-
-    // Key is striped module name to match names in alias file
-    std::size_t start = args[0].find_last_of('/');
-    std::size_t end = args[0].find(".ko:");
-    if ((end - start) <= 1) return Error() << "malformed dependency line";
-    auto mod_name = args[0].substr(start + 1, (end - start) - 1);
-    // module names can have '-', but their file names will have '_'
-    std::replace(mod_name.begin(), mod_name.end(), '-', '_');
-    this->module_deps_[mod_name] = deps;
-
-    return {};
-}
-
-Result<void> ModaliasHandler::ParseAliasCallback(std::vector<std::string>&& args) {
-    auto it = args.begin();
-    const std::string& type = *it++;
-
-    if (type != "alias") {
-        return Error() << "we only handle alias lines, got: " << type;
-    }
-
-    if (args.size() != 3) {
-        return Error() << "alias lines must have 3 entries";
-    }
-
-    std::string& alias = *it++;
-    std::string& module_name = *it++;
-    this->module_aliases_.emplace_back(alias, module_name);
-
-    return {};
-}
-
-ModaliasHandler::ModaliasHandler() {
-    using namespace std::placeholders;
-
-    static const std::string base_paths[] = {
-            "/vendor/lib/modules/",
-            "/lib/modules/",
-            "/odm/lib/modules/",
-    };
-
-    Parser alias_parser;
-    auto alias_callback = std::bind(&ModaliasHandler::ParseAliasCallback, this, _1);
-    alias_parser.AddSingleLineParser("alias", alias_callback);
-    for (const auto& base_path : base_paths) alias_parser.ParseConfig(base_path + "modules.alias");
-
-    Parser dep_parser;
-    auto dep_callback = std::bind(&ModaliasHandler::ParseDepCallback, this, _1);
-    dep_parser.AddSingleLineParser("", dep_callback);
-    for (const auto& base_path : base_paths) dep_parser.ParseConfig(base_path + "modules.dep");
-}
-
-Result<void> ModaliasHandler::Insmod(const std::string& path_name, const std::string& args) {
-    base::unique_fd fd(
-            TEMP_FAILURE_RETRY(open(path_name.c_str(), O_RDONLY | O_NOFOLLOW | O_CLOEXEC)));
-    if (fd == -1) return ErrnoError() << "Could not open module '" << path_name << "'";
-
-    int ret = syscall(__NR_finit_module, fd.get(), args.c_str(), 0);
-    if (ret != 0) {
-        if (errno == EEXIST) {
-            // Module already loaded
-            return {};
-        }
-        return ErrnoError() << "Failed to insmod '" << path_name << "' with args '" << args << "'";
-    }
-
-    LOG(INFO) << "Loaded kernel module " << path_name;
-    return {};
-}
-
-Result<void> ModaliasHandler::InsmodWithDeps(const std::string& module_name,
-                                             const std::string& args) {
-    if (module_name.empty()) {
-        return Error() << "Need valid module name";
-    }
-
-    auto it = module_deps_.find(module_name);
-    if (it == module_deps_.end()) {
-        return Error() << "Module '" << module_name << "' not in dependency file";
-    }
-    auto& dependencies = it->second;
-
-    // load module dependencies in reverse order
-    for (auto dep = dependencies.rbegin(); dep != dependencies.rend() - 1; ++dep) {
-        if (auto result = Insmod(*dep, ""); !result) return result;
-    }
-
-    // load target module itself with args
-    return Insmod(dependencies[0], args);
-}
+ModaliasHandler::ModaliasHandler(const std::vector<std::string>& base_paths)
+    : modprobe_(base_paths) {}
 
 void ModaliasHandler::HandleUevent(const Uevent& uevent) {
     if (uevent.modalias.empty()) return;
-
-    for (const auto& [alias, module] : module_aliases_) {
-        if (fnmatch(alias.c_str(), uevent.modalias.c_str(), 0) != 0) continue;  // Keep looking
-
-        LOG(DEBUG) << "Loading kernel module '" << module << "' for alias '" << uevent.modalias
-                   << "'";
-
-        if (auto result = InsmodWithDeps(module, ""); !result) {
-            LOG(ERROR) << "Cannot load module: " << result.error();
-            // try another one since there may be another match
-            continue;
-        }
-
-        // loading was successful
-        return;
-    }
+    modprobe_.LoadWithAliases(uevent.modalias, true);
 }
 
 }  // namespace init
diff --git a/init/modalias_handler.h b/init/modalias_handler.h
index 7d0afde..ce89a05 100644
--- a/init/modalias_handler.h
+++ b/init/modalias_handler.h
@@ -17,10 +17,10 @@
 #pragma once
 
 #include <string>
-#include <unordered_map>
 #include <vector>
 
-#include "result.h"
+#include <modprobe/modprobe.h>
+
 #include "uevent.h"
 #include "uevent_handler.h"
 
@@ -29,20 +29,13 @@
 
 class ModaliasHandler : public UeventHandler {
   public:
-    ModaliasHandler();
+    ModaliasHandler(const std::vector<std::string>&);
     virtual ~ModaliasHandler() = default;
 
     void HandleUevent(const Uevent& uevent) override;
 
   private:
-    Result<void> InsmodWithDeps(const std::string& module_name, const std::string& args);
-    Result<void> Insmod(const std::string& path_name, const std::string& args);
-
-    Result<void> ParseDepCallback(std::vector<std::string>&& args);
-    Result<void> ParseAliasCallback(std::vector<std::string>&& args);
-
-    std::vector<std::pair<std::string, std::string>> module_aliases_;
-    std::unordered_map<std::string, std::vector<std::string>> module_deps_;
+    Modprobe modprobe_;
 };
 
 }  // namespace init
diff --git a/init/ueventd.cpp b/init/ueventd.cpp
index d700c46..f550bc2 100644
--- a/init/ueventd.cpp
+++ b/init/ueventd.cpp
@@ -251,7 +251,8 @@
             std::move(ueventd_configuration.firmware_directories)));
 
     if (ueventd_configuration.enable_modalias_handling) {
-        uevent_handlers.emplace_back(std::make_unique<ModaliasHandler>());
+        std::vector<std::string> base_paths = {"/odm/lib/modules", "/vendor/lib/modules"};
+        uevent_handlers.emplace_back(std::make_unique<ModaliasHandler>(base_paths));
     }
     UeventListener uevent_listener(ueventd_configuration.uevent_socket_rcvbuf_size);
 
diff --git a/libmodprobe/Android.bp b/libmodprobe/Android.bp
new file mode 100644
index 0000000..a2824d1
--- /dev/null
+++ b/libmodprobe/Android.bp
@@ -0,0 +1,30 @@
+cc_library_static {
+    name: "libmodprobe",
+    cflags: [
+        "-Werror",
+    ],
+    recovery_available: true,
+    srcs: [
+        "libmodprobe.cpp",
+        "libmodprobe_ext.cpp",
+    ],
+    shared_libs: [
+        "libbase",
+    ],
+    export_include_dirs: ["include/"],
+}
+
+cc_test {
+    name: "libmodprobe_tests",
+    cflags: ["-Werror"],
+    shared_libs: [
+        "libbase",
+    ],
+    local_include_dirs: ["include/"],
+    srcs: [
+        "libmodprobe_test.cpp",
+        "libmodprobe.cpp",
+        "libmodprobe_ext_test.cpp",
+    ],
+    test_suites: ["device-tests"],
+}
diff --git a/libmodprobe/include/modprobe/modprobe.h b/libmodprobe/include/modprobe/modprobe.h
new file mode 100644
index 0000000..0ec766a
--- /dev/null
+++ b/libmodprobe/include/modprobe/modprobe.h
@@ -0,0 +1,50 @@
+/*
+ * Copyright (C) 2018 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 <string>
+#include <unordered_map>
+#include <vector>
+
+class Modprobe {
+  public:
+    Modprobe(const std::vector<std::string>&);
+
+    bool LoadListedModules();
+    bool LoadWithAliases(const std::string& module_name, bool strict);
+
+  private:
+    std::string MakeCanonical(const std::string& module_path);
+    bool InsmodWithDeps(const std::string& module_name);
+    bool Insmod(const std::string& path_name);
+    std::vector<std::string> GetDependencies(const std::string& module);
+    bool ModuleExists(const std::string& module_name);
+
+    bool ParseDepCallback(const std::string& base_path, const std::vector<std::string>& args);
+    bool ParseAliasCallback(const std::vector<std::string>& args);
+    bool ParseSoftdepCallback(const std::vector<std::string>& args);
+    bool ParseLoadCallback(const std::vector<std::string>& args);
+    bool ParseOptionsCallback(const std::vector<std::string>& args);
+    void ParseCfg(const std::string& cfg, std::function<bool(const std::vector<std::string>&)> f);
+
+    std::vector<std::pair<std::string, std::string>> module_aliases_;
+    std::unordered_map<std::string, std::vector<std::string>> module_deps_;
+    std::vector<std::pair<std::string, std::string>> module_pre_softdep_;
+    std::vector<std::pair<std::string, std::string>> module_post_softdep_;
+    std::vector<std::string> module_load_;
+    std::unordered_map<std::string, std::string> module_options_;
+};
diff --git a/libmodprobe/libmodprobe.cpp b/libmodprobe/libmodprobe.cpp
new file mode 100644
index 0000000..01cf2e3
--- /dev/null
+++ b/libmodprobe/libmodprobe.cpp
@@ -0,0 +1,321 @@
+/*
+ * Copyright (C) 2018 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 <modprobe/modprobe.h>
+
+#include <fnmatch.h>
+#include <sys/stat.h>
+#include <sys/syscall.h>
+
+#include <algorithm>
+#include <set>
+#include <string>
+#include <vector>
+
+#include <android-base/chrono_utils.h>
+#include <android-base/file.h>
+#include <android-base/logging.h>
+#include <android-base/strings.h>
+#include <android-base/unique_fd.h>
+
+std::string Modprobe::MakeCanonical(const std::string& module_path) {
+    auto start = module_path.find_last_of('/');
+    if (start == std::string::npos) {
+        start = 0;
+    } else {
+        start += 1;
+    }
+    auto end = module_path.size();
+    if (android::base::EndsWith(module_path, ".ko")) {
+        end -= 3;
+    }
+    if ((end - start) <= 1) {
+        LOG(ERROR) << "malformed module name: " << module_path;
+        return "";
+    }
+    std::string module_name = module_path.substr(start, end - start);
+    // module names can have '-', but their file names will have '_'
+    std::replace(module_name.begin(), module_name.end(), '-', '_');
+    return module_name;
+}
+
+bool Modprobe::ParseDepCallback(const std::string& base_path,
+                                const std::vector<std::string>& args) {
+    std::vector<std::string> deps;
+    std::string prefix = "";
+
+    // Set first item as our modules path
+    std::string::size_type pos = args[0].find(':');
+    if (args[0][0] != '/') {
+        prefix = base_path + "/";
+    }
+    if (pos != std::string::npos) {
+        deps.emplace_back(prefix + args[0].substr(0, pos));
+    } else {
+        LOG(ERROR) << "dependency lines must start with name followed by ':'";
+    }
+
+    // Remaining items are dependencies of our module
+    for (auto arg = args.begin() + 1; arg != args.end(); ++arg) {
+        if ((*arg)[0] != '/') {
+            prefix = base_path + "/";
+        } else {
+            prefix = "";
+        }
+        deps.push_back(prefix + *arg);
+    }
+
+    std::string canonical_name = MakeCanonical(args[0].substr(0, pos));
+    if (canonical_name.empty()) {
+        return false;
+    }
+    this->module_deps_[canonical_name] = deps;
+
+    return true;
+}
+
+bool Modprobe::ParseAliasCallback(const std::vector<std::string>& args) {
+    auto it = args.begin();
+    const std::string& type = *it++;
+
+    if (type != "alias") {
+        LOG(ERROR) << "non-alias line encountered in modules.alias, found " << type;
+        return false;
+    }
+
+    if (args.size() != 3) {
+        LOG(ERROR) << "alias lines in modules.alias must have 3 entries, not " << args.size();
+        return false;
+    }
+
+    const std::string& alias = *it++;
+    const std::string& module_name = *it++;
+    this->module_aliases_.emplace_back(alias, module_name);
+
+    return true;
+}
+
+bool Modprobe::ParseSoftdepCallback(const std::vector<std::string>& args) {
+    auto it = args.begin();
+    const std::string& type = *it++;
+    std::string state = "";
+
+    if (type != "softdep") {
+        LOG(ERROR) << "non-softdep line encountered in modules.softdep, found " << type;
+        return false;
+    }
+
+    if (args.size() < 4) {
+        LOG(ERROR) << "softdep lines in modules.softdep must have at least 4 entries";
+        return false;
+    }
+
+    const std::string& module = *it++;
+    while (it != args.end()) {
+        const std::string& token = *it++;
+        if (token == "pre:" || token == "post:") {
+            state = token;
+            continue;
+        }
+        if (state == "") {
+            LOG(ERROR) << "malformed modules.softdep at token " << token;
+            return false;
+        }
+        if (state == "pre:") {
+            this->module_pre_softdep_.emplace_back(module, token);
+        } else {
+            this->module_post_softdep_.emplace_back(module, token);
+        }
+    }
+
+    return true;
+}
+
+bool Modprobe::ParseLoadCallback(const std::vector<std::string>& args) {
+    auto it = args.begin();
+    const std::string& module = *it++;
+
+    const std::string& canonical_name = MakeCanonical(module);
+    if (canonical_name.empty()) {
+        return false;
+    }
+    this->module_load_.emplace_back(canonical_name);
+
+    return true;
+}
+
+bool Modprobe::ParseOptionsCallback(const std::vector<std::string>& args) {
+    auto it = args.begin();
+    const std::string& type = *it++;
+
+    if (type != "options") {
+        LOG(ERROR) << "non-options line encountered in modules.options";
+        return false;
+    }
+
+    if (args.size() < 2) {
+        LOG(ERROR) << "lines in modules.options must have at least 2 entries, not " << args.size();
+        return false;
+    }
+
+    const std::string& module = *it++;
+    std::string options = "";
+
+    const std::string& canonical_name = MakeCanonical(module);
+    if (canonical_name.empty()) {
+        return false;
+    }
+
+    while (it != args.end()) {
+        options += *it++;
+        if (it != args.end()) {
+            options += " ";
+        }
+    }
+
+    auto [unused, inserted] = this->module_options_.emplace(canonical_name, options);
+    if (!inserted) {
+        LOG(ERROR) << "multiple options lines present for module " << module;
+        return false;
+    }
+    return true;
+}
+
+void Modprobe::ParseCfg(const std::string& cfg,
+                        std::function<bool(const std::vector<std::string>&)> f) {
+    std::string cfg_contents;
+    if (!android::base::ReadFileToString(cfg, &cfg_contents, false)) {
+        return;
+    }
+
+    std::vector<std::string> lines = android::base::Split(cfg_contents, "\n");
+    for (const std::string line : lines) {
+        if (line.empty() || line[0] == '#') {
+            continue;
+        }
+        const std::vector<std::string> args = android::base::Split(line, " ");
+        if (args.empty()) continue;
+        f(args);
+    }
+    return;
+}
+
+Modprobe::Modprobe(const std::vector<std::string>& base_paths) {
+    using namespace std::placeholders;
+
+    for (const auto& base_path : base_paths) {
+        auto alias_callback = std::bind(&Modprobe::ParseAliasCallback, this, _1);
+        ParseCfg(base_path + "/modules.alias", alias_callback);
+
+        auto dep_callback = std::bind(&Modprobe::ParseDepCallback, this, base_path, _1);
+        ParseCfg(base_path + "/modules.dep", dep_callback);
+
+        auto softdep_callback = std::bind(&Modprobe::ParseSoftdepCallback, this, _1);
+        ParseCfg(base_path + "/modules.softdep", softdep_callback);
+
+        auto load_callback = std::bind(&Modprobe::ParseLoadCallback, this, _1);
+        ParseCfg(base_path + "/modules.load", load_callback);
+
+        auto options_callback = std::bind(&Modprobe::ParseOptionsCallback, this, _1);
+        ParseCfg(base_path + "/modules.options", options_callback);
+    }
+}
+
+std::vector<std::string> Modprobe::GetDependencies(const std::string& module) {
+    auto it = module_deps_.find(module);
+    if (it == module_deps_.end()) {
+        return {};
+    }
+    return it->second;
+}
+
+bool Modprobe::InsmodWithDeps(const std::string& module_name) {
+    if (module_name.empty()) {
+        LOG(ERROR) << "Need valid module name, given: " << module_name;
+        return false;
+    }
+
+    auto dependencies = GetDependencies(module_name);
+    if (dependencies.empty()) {
+        LOG(ERROR) << "Module " << module_name << " not in dependency file";
+        return false;
+    }
+
+    // load module dependencies in reverse order
+    for (auto dep = dependencies.rbegin(); dep != dependencies.rend() - 1; ++dep) {
+        const std::string& canonical_name = MakeCanonical(*dep);
+        if (canonical_name.empty()) {
+            return false;
+        }
+        if (!LoadWithAliases(canonical_name, true)) {
+            return false;
+        }
+    }
+
+    // try to load soft pre-dependencies
+    for (const auto& [module, softdep] : module_pre_softdep_) {
+        if (module_name == module) {
+            LoadWithAliases(softdep, false);
+        }
+    }
+
+    // load target module itself with args
+    if (!Insmod(dependencies[0])) {
+        return false;
+    }
+
+    // try to load soft post-dependencies
+    for (const auto& [module, softdep] : module_post_softdep_) {
+        if (module_name == module) {
+            LoadWithAliases(softdep, false);
+        }
+    }
+
+    return true;
+}
+
+bool Modprobe::LoadWithAliases(const std::string& module_name, bool strict) {
+    std::set<std::string> modules_to_load = {module_name};
+    bool module_loaded = false;
+
+    // use aliases to expand list of modules to load (multiple modules
+    // may alias themselves to the requested name)
+    for (const auto& [alias, aliased_module] : module_aliases_) {
+        if (fnmatch(alias.c_str(), module_name.c_str(), 0) != 0) continue;
+        modules_to_load.emplace(aliased_module);
+    }
+
+    // attempt to load all modules aliased to this name
+    for (const auto& module : modules_to_load) {
+        if (!ModuleExists(module)) continue;
+        if (InsmodWithDeps(module)) module_loaded = true;
+    }
+
+    if (strict && !module_loaded) {
+        LOG(ERROR) << "LoadWithAliases did not find a module for " << module_name;
+        return false;
+    }
+    return true;
+}
+
+bool Modprobe::LoadListedModules() {
+    for (const auto& module : module_load_) {
+        if (!LoadWithAliases(module, true)) {
+            return false;
+        }
+    }
+    return true;
+}
diff --git a/libmodprobe/libmodprobe_ext.cpp b/libmodprobe/libmodprobe_ext.cpp
new file mode 100644
index 0000000..5f3a04d
--- /dev/null
+++ b/libmodprobe/libmodprobe_ext.cpp
@@ -0,0 +1,68 @@
+/*
+ * Copyright (C) 2018 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 <sys/stat.h>
+#include <sys/syscall.h>
+
+#include <android-base/logging.h>
+#include <android-base/unique_fd.h>
+
+#include <modprobe/modprobe.h>
+
+bool Modprobe::Insmod(const std::string& path_name) {
+    android::base::unique_fd fd(
+            TEMP_FAILURE_RETRY(open(path_name.c_str(), O_RDONLY | O_NOFOLLOW | O_CLOEXEC)));
+    if (fd == -1) {
+        LOG(ERROR) << "Could not open module '" << path_name << "'";
+        return false;
+    }
+
+    std::string options = "";
+    auto options_iter = module_options_.find(MakeCanonical(path_name));
+    if (options_iter != module_options_.end()) {
+        options = options_iter->second;
+    }
+
+    LOG(INFO) << "Loading module " << path_name << " with args \"" << options << "\"";
+    int ret = syscall(__NR_finit_module, fd.get(), options.c_str(), 0);
+    if (ret != 0) {
+        if (errno == EEXIST) {
+            // Module already loaded
+            return true;
+        }
+        LOG(ERROR) << "Failed to insmod '" << path_name << "' with args '" << options << "'";
+        return false;
+    }
+
+    LOG(INFO) << "Loaded kernel module " << path_name;
+    return true;
+}
+
+bool Modprobe::ModuleExists(const std::string& module_name) {
+    struct stat fileStat;
+    auto deps = GetDependencies(module_name);
+    if (deps.empty()) {
+        // missing deps can happen in the case of an alias
+        return false;
+    }
+    if (stat(deps.front().c_str(), &fileStat)) {
+        return false;
+    }
+    if (!S_ISREG(fileStat.st_mode)) {
+        return false;
+    }
+    return true;
+}
diff --git a/libmodprobe/libmodprobe_ext_test.cpp b/libmodprobe/libmodprobe_ext_test.cpp
new file mode 100644
index 0000000..0f073cb
--- /dev/null
+++ b/libmodprobe/libmodprobe_ext_test.cpp
@@ -0,0 +1,61 @@
+/*
+ * Copyright (C) 2019 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 <sys/stat.h>
+#include <sys/syscall.h>
+
+#include <string>
+#include <vector>
+
+#include <android-base/logging.h>
+#include <android-base/strings.h>
+#include <android-base/unique_fd.h>
+#include <gtest/gtest.h>
+
+#include <modprobe/modprobe.h>
+
+#include "libmodprobe_test.h"
+
+bool Modprobe::Insmod(const std::string& path_name) {
+    auto deps = GetDependencies(MakeCanonical(path_name));
+    if (deps.empty()) {
+        return false;
+    }
+    if (std::find(test_modules.begin(), test_modules.end(), deps.front()) == test_modules.end()) {
+        return false;
+    }
+    for (auto it = modules_loaded.begin(); it != modules_loaded.end(); ++it) {
+        if (android::base::StartsWith(*it, path_name)) {
+            return true;
+        }
+    }
+    std::string options;
+    auto options_iter = module_options_.find(MakeCanonical(path_name));
+    if (options_iter != module_options_.end()) {
+        options = " " + options_iter->second;
+    }
+    modules_loaded.emplace_back(path_name + options);
+    return true;
+}
+
+bool Modprobe::ModuleExists(const std::string& module_name) {
+    auto deps = GetDependencies(module_name);
+    if (deps.empty()) {
+        // missing deps can happen in the case of an alias
+        return false;
+    }
+    return std::find(test_modules.begin(), test_modules.end(), deps.front()) != test_modules.end();
+}
diff --git a/libmodprobe/libmodprobe_test.cpp b/libmodprobe/libmodprobe_test.cpp
new file mode 100644
index 0000000..481658d
--- /dev/null
+++ b/libmodprobe/libmodprobe_test.cpp
@@ -0,0 +1,134 @@
+/*
+ * Copyright (C) 2019 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 <functional>
+
+#include <android-base/file.h>
+#include <android-base/macros.h>
+#include <android-base/unique_fd.h>
+#include <gtest/gtest.h>
+
+#include <modprobe/modprobe.h>
+
+#include "libmodprobe_test.h"
+
+// Used by libmodprobe_ext_test to check if requested modules are present.
+std::vector<std::string> test_modules;
+
+// Used by libmodprobe_ext_test to report which modules would have been loaded.
+std::vector<std::string> modules_loaded;
+
+TEST(libmodprobe, Test) {
+    test_modules = {
+            "/test1.ko",  "/test2.ko",  "/test3.ko",  "/test4.ko",  "/test5.ko",
+            "/test6.ko",  "/test7.ko",  "/test8.ko",  "/test9.ko",  "/test10.ko",
+            "/test11.ko", "/test12.ko", "/test13.ko", "/test14.ko", "/test15.ko",
+    };
+
+    std::vector<std::string> expected_modules_loaded = {
+            "/test14.ko",
+            "/test15.ko",
+            "/test3.ko",
+            "/test4.ko",
+            "/test1.ko",
+            "/test6.ko",
+            "/test2.ko",
+            "/test5.ko",
+            "/test8.ko",
+            "/test7.ko param1=4",
+            "/test9.ko param_x=1 param_y=2 param_z=3",
+            "/test10.ko",
+            "/test12.ko",
+            "/test11.ko",
+            "/test13.ko",
+    };
+
+    const std::string modules_dep =
+            "test1.ko:\n"
+            "test2.ko:\n"
+            "test3.ko:\n"
+            "test4.ko: test3.ko\n"
+            "test5.ko: test2.ko test6.ko\n"
+            "test6.ko:\n"
+            "test7.ko:\n"
+            "test8.ko:\n"
+            "test9.ko:\n"
+            "test10.ko:\n"
+            "test11.ko:\n"
+            "test12.ko:\n"
+            "test13.ko:\n"
+            "test14.ko:\n"
+            "test15.ko:\n";
+
+    const std::string modules_softdep =
+            "softdep test7 pre: test8\n"
+            "softdep test9 post: test10\n"
+            "softdep test11 pre: test12 post: test13\n"
+            "softdep test3 pre: test141516\n";
+
+    const std::string modules_alias =
+            "# Aliases extracted from modules themselves.\n"
+            "\n"
+            "alias test141516 test14\n"
+            "alias test141516 test15\n"
+            "alias test141516 test16\n";
+
+    const std::string modules_options =
+            "options test7.ko param1=4\n"
+            "options test9.ko param_x=1 param_y=2 param_z=3\n"
+            "options test100.ko param_1=1\n";
+
+    const std::string modules_load =
+            "test4.ko\n"
+            "test1.ko\n"
+            "test3.ko\n"
+            "test5.ko\n"
+            "test7.ko\n"
+            "test9.ko\n"
+            "test11.ko\n";
+
+    TemporaryDir dir;
+    ASSERT_TRUE(android::base::WriteStringToFile(
+            modules_alias, std::string(dir.path) + "/modules.alias", 0600, getuid(), getgid()));
+
+    ASSERT_TRUE(android::base::WriteStringToFile(
+            modules_dep, std::string(dir.path) + "/modules.dep", 0600, getuid(), getgid()));
+    ASSERT_TRUE(android::base::WriteStringToFile(
+            modules_softdep, std::string(dir.path) + "/modules.softdep", 0600, getuid(), getgid()));
+    ASSERT_TRUE(android::base::WriteStringToFile(
+            modules_options, std::string(dir.path) + "/modules.options", 0600, getuid(), getgid()));
+    ASSERT_TRUE(android::base::WriteStringToFile(
+            modules_load, std::string(dir.path) + "/modules.load", 0600, getuid(), getgid()));
+
+    for (auto i = test_modules.begin(); i != test_modules.end(); ++i) {
+        *i = dir.path + *i;
+    }
+
+    Modprobe m({dir.path});
+    EXPECT_TRUE(m.LoadListedModules());
+
+    GTEST_LOG_(INFO) << "Expected modules loaded (in order):";
+    for (auto i = expected_modules_loaded.begin(); i != expected_modules_loaded.end(); ++i) {
+        *i = dir.path + *i;
+        GTEST_LOG_(INFO) << "\"" << *i << "\"";
+    }
+    GTEST_LOG_(INFO) << "Actual modules loaded (in order):";
+    for (auto i = modules_loaded.begin(); i != modules_loaded.end(); ++i) {
+        GTEST_LOG_(INFO) << "\"" << *i << "\"";
+    }
+
+    EXPECT_TRUE(modules_loaded == expected_modules_loaded);
+}
diff --git a/mkbootimg/mkbootimg_dummy.cpp b/libmodprobe/libmodprobe_test.h
similarity index 70%
rename from mkbootimg/mkbootimg_dummy.cpp
rename to libmodprobe/libmodprobe_test.h
index 410d379..a001b69 100644
--- a/mkbootimg/mkbootimg_dummy.cpp
+++ b/libmodprobe/libmodprobe_test.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2018 The Android Open Source Project
+ * Copyright (C) 2019 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.
@@ -14,11 +14,10 @@
  * limitations under the License.
  */
 
-#include <abi_check/mkbootimg_abi_check.h>
+#pragma once
 
-void mkbootimg_dummy(boot_img_hdr* hdr) {
-    // TODO: Hack to trigger abi checks, remove this.
-    if (hdr) {
-        hdr--;
-    }
-}
+#include <string>
+#include <vector>
+
+extern std::vector<std::string> test_modules;
+extern std::vector<std::string> modules_loaded;
diff --git a/libprocessgroup/cgroup_map.cpp b/libprocessgroup/cgroup_map.cpp
index 92fcd1e..9797d76 100644
--- a/libprocessgroup/cgroup_map.cpp
+++ b/libprocessgroup/cgroup_map.cpp
@@ -70,8 +70,8 @@
 bool CgroupController::IsUsable() const {
     if (!HasValue()) return false;
 
-    uint32_t flags = ACgroupController_getFlags(controller_);
-    return (flags & CGROUPRC_CONTROLLER_FLAG_MOUNTED) != 0;
+    static bool enabled = (access(GetProcsFilePath("", 0, 0).c_str(), F_OK) == 0);
+    return enabled;
 }
 
 std::string CgroupController::GetTasksFilePath(const std::string& rel_path) const {
@@ -160,7 +160,6 @@
         const ACgroupController* controller = ACgroupFile_getController(i);
         LOG(INFO) << "\t" << ACgroupController_getName(controller) << " ver "
                   << ACgroupController_getVersion(controller) << " path "
-                  << ACgroupController_getFlags(controller) << " flags "
                   << ACgroupController_getPath(controller);
     }
 }
diff --git a/libprocessgroup/cgrouprc/cgroup_controller.cpp b/libprocessgroup/cgrouprc/cgroup_controller.cpp
index 5a326e5..d064d31 100644
--- a/libprocessgroup/cgrouprc/cgroup_controller.cpp
+++ b/libprocessgroup/cgrouprc/cgroup_controller.cpp
@@ -27,11 +27,6 @@
     return controller->version();
 }
 
-uint32_t ACgroupController_getFlags(const ACgroupController* controller) {
-    CHECK(controller != nullptr);
-    return controller->flags();
-}
-
 const char* ACgroupController_getName(const ACgroupController* controller) {
     CHECK(controller != nullptr);
     return controller->name();
diff --git a/libprocessgroup/cgrouprc/include/android/cgrouprc.h b/libprocessgroup/cgrouprc/include/android/cgrouprc.h
index ffc9f0b..0f6a9cd 100644
--- a/libprocessgroup/cgrouprc/include/android/cgrouprc.h
+++ b/libprocessgroup/cgrouprc/include/android/cgrouprc.h
@@ -66,18 +66,11 @@
         __INTRODUCED_IN(29);
 
 /**
- * Flag bitmask used in ACgroupController_getFlags
+ * Flag bitmask to be used when ACgroupController_getFlags can be exported
  */
 #define CGROUPRC_CONTROLLER_FLAG_MOUNTED 0x1
 
 /**
- * Returns the flags bitmask of the given controller.
- * If the given controller is null, return 0.
- */
-__attribute__((warn_unused_result)) uint32_t ACgroupController_getFlags(const ACgroupController*)
-        __INTRODUCED_IN(29);
-
-/**
  * Returns the name of the given controller.
  * If the given controller is null, return nullptr.
  */
diff --git a/libprocessgroup/cgrouprc/libcgrouprc.llndk.txt b/libprocessgroup/cgrouprc/libcgrouprc.llndk.txt
index ea3df33..91df392 100644
--- a/libprocessgroup/cgrouprc/libcgrouprc.llndk.txt
+++ b/libprocessgroup/cgrouprc/libcgrouprc.llndk.txt
@@ -4,7 +4,6 @@
     ACgroupFile_getControllerCount;
     ACgroupFile_getController;
     ACgroupController_getVersion;
-    ACgroupController_getFlags;
     ACgroupController_getName;
     ACgroupController_getPath;
   local:
diff --git a/mkbootimg/Android.bp b/mkbootimg/Android.bp
deleted file mode 100644
index c3cf746..0000000
--- a/mkbootimg/Android.bp
+++ /dev/null
@@ -1,64 +0,0 @@
-// Copyright 2012 The Android Open Source Project
-
-cc_library_headers {
-    name: "libmkbootimg_abi_headers",
-    vendor_available: true,
-    export_include_dirs: ["include"],
-}
-
-cc_library_headers {
-    name: "bootimg_headers",
-    vendor_available: true,
-    recovery_available: true,
-    export_include_dirs: ["include/bootimg"],
-    host_supported: true,
-    target: {
-        windows: {
-            enabled: true,
-        },
-    },
-}
-
-cc_library {
-    name: "libmkbootimg_abi_check",
-    vendor_available: true,
-    vndk: {
-        enabled: true,
-    },
-    srcs: [
-        "mkbootimg_dummy.cpp",
-    ],
-    header_libs: ["libmkbootimg_abi_headers"],
-    export_header_lib_headers: ["libmkbootimg_abi_headers"],
-}
-
-python_defaults {
-    name: "mkbootimg_defaults",
-
-    version: {
-        py2: {
-            enabled: true,
-            embedded_launcher: true,
-        },
-        py3: {
-            enabled: false,
-            embedded_launcher: false,
-        },
-    },
-}
-
-python_binary_host {
-    name: "mkbootimg",
-    defaults: ["mkbootimg_defaults"],
-    srcs: [
-        "mkbootimg.py",
-    ],
-}
-
-python_binary_host {
-    name: "unpack_bootimg",
-    defaults: ["mkbootimg_defaults"],
-    srcs: [
-        "unpack_bootimg.py",
-    ],
-}
diff --git a/mkbootimg/OWNERS b/mkbootimg/OWNERS
deleted file mode 100644
index 3a00860..0000000
--- a/mkbootimg/OWNERS
+++ /dev/null
@@ -1,2 +0,0 @@
-hridya@google.com
-tbao@google.com
diff --git a/mkbootimg/include/abi_check/mkbootimg_abi_check.h b/mkbootimg/include/abi_check/mkbootimg_abi_check.h
deleted file mode 100644
index d478aba..0000000
--- a/mkbootimg/include/abi_check/mkbootimg_abi_check.h
+++ /dev/null
@@ -1,28 +0,0 @@
-/*
- * Copyright (C) 2018 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 <bootimg/bootimg.h>
-
-// This header has been created for the following reaons:
-//    1) In order for a change in a user defined type to be classified as API /
-//       ABI breaking, it needs to be referenced by an 'exported interface'
-//       (in this case the function mkbootimg_dummy).
-//    2) Since 'mkbootimg_dummy' needs to be exported, we need to have it
-//       exposed through a public header.
-//    3) It is desirable not to pollute bootimg.h with interfaces which are not
-//       'used' in reality by on device binaries. Furthermore, bootimg.h might
-//       be exported by a library in the future, so we must avoid polluting it.
-void mkbootimg_dummy(boot_img_hdr*);
diff --git a/mkbootimg/include/bootimg/bootimg.h b/mkbootimg/include/bootimg/bootimg.h
deleted file mode 100644
index 9ee7869..0000000
--- a/mkbootimg/include/bootimg/bootimg.h
+++ /dev/null
@@ -1,160 +0,0 @@
-/*
- * Copyright (C) 2007 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 <stdint.h>
-
-#define BOOT_MAGIC "ANDROID!"
-#define BOOT_MAGIC_SIZE 8
-#define BOOT_NAME_SIZE 16
-#define BOOT_ARGS_SIZE 512
-#define BOOT_EXTRA_ARGS_SIZE 1024
-
-// The bootloader expects the structure of boot_img_hdr with header
-// version 0 to be as follows:
-struct boot_img_hdr_v0 {
-    // Must be BOOT_MAGIC.
-    uint8_t magic[BOOT_MAGIC_SIZE];
-
-    uint32_t kernel_size; /* size in bytes */
-    uint32_t kernel_addr; /* physical load addr */
-
-    uint32_t ramdisk_size; /* size in bytes */
-    uint32_t ramdisk_addr; /* physical load addr */
-
-    uint32_t second_size; /* size in bytes */
-    uint32_t second_addr; /* physical load addr */
-
-    uint32_t tags_addr; /* physical addr for kernel tags */
-    uint32_t page_size; /* flash page size we assume */
-
-    // Version of the boot image header.
-    uint32_t header_version;
-
-    // Operating system version and security patch level.
-    // For version "A.B.C" and patch level "Y-M-D":
-    //   (7 bits for each of A, B, C; 7 bits for (Y-2000), 4 bits for M)
-    //   os_version = A[31:25] B[24:18] C[17:11] (Y-2000)[10:4] M[3:0]
-    uint32_t os_version;
-
-#if __cplusplus
-    void SetOsVersion(unsigned major, unsigned minor, unsigned patch) {
-        os_version &= ((1 << 11) - 1);
-        os_version |= (((major & 0x7f) << 25) | ((minor & 0x7f) << 18) | ((patch & 0x7f) << 11));
-    }
-
-    void SetOsPatchLevel(unsigned year, unsigned month) {
-        os_version &= ~((1 << 11) - 1);
-        os_version |= (((year - 2000) & 0x7f) << 4) | ((month & 0xf) << 0);
-    }
-#endif
-
-    uint8_t name[BOOT_NAME_SIZE]; /* asciiz product name */
-
-    uint8_t cmdline[BOOT_ARGS_SIZE];
-
-    uint32_t id[8]; /* timestamp / checksum / sha1 / etc */
-
-    // Supplemental command line data; kept here to maintain
-    // binary compatibility with older versions of mkbootimg.
-    uint8_t extra_cmdline[BOOT_EXTRA_ARGS_SIZE];
-} __attribute__((packed));
-
-/*
- * It is expected that callers would explicitly specify which version of the
- * boot image header they need to use.
- */
-typedef struct boot_img_hdr_v0 boot_img_hdr;
-
-/* When a boot header is of version 0, the structure of boot image is as
- * follows:
- *
- * +-----------------+
- * | boot header     | 1 page
- * +-----------------+
- * | kernel          | n pages
- * +-----------------+
- * | ramdisk         | m pages
- * +-----------------+
- * | second stage    | o pages
- * +-----------------+
- *
- * n = (kernel_size + page_size - 1) / page_size
- * m = (ramdisk_size + page_size - 1) / page_size
- * o = (second_size + page_size - 1) / page_size
- *
- * 0. all entities are page_size aligned in flash
- * 1. kernel and ramdisk are required (size != 0)
- * 2. second is optional (second_size == 0 -> no second)
- * 3. load each element (kernel, ramdisk, second) at
- *    the specified physical address (kernel_addr, etc)
- * 4. prepare tags at tag_addr.  kernel_args[] is
- *    appended to the kernel commandline in the tags.
- * 5. r0 = 0, r1 = MACHINE_TYPE, r2 = tags_addr
- * 6. if second_size != 0: jump to second_addr
- *    else: jump to kernel_addr
- */
-
-struct boot_img_hdr_v1 : public boot_img_hdr_v0 {
-    uint32_t recovery_dtbo_size;   /* size in bytes for recovery DTBO/ACPIO image */
-    uint64_t recovery_dtbo_offset; /* offset to recovery dtbo/acpio in boot image */
-    uint32_t header_size;
-} __attribute__((packed));
-
-/* When the boot image header has a version of 2, the structure of the boot
- * image is as follows:
- *
- * +---------------------+
- * | boot header         | 1 page
- * +---------------------+
- * | kernel              | n pages
- * +---------------------+
- * | ramdisk             | m pages
- * +---------------------+
- * | second stage        | o pages
- * +---------------------+
- * | recovery dtbo/acpio | p pages
- * +---------------------+
- * | dtb                 | q pages
- * +---------------------+
-
- * n = (kernel_size + page_size - 1) / page_size
- * m = (ramdisk_size + page_size - 1) / page_size
- * o = (second_size + page_size - 1) / page_size
- * p = (recovery_dtbo_size + page_size - 1) / page_size
- * q = (dtb_size + page_size - 1) / page_size
- *
- * 0. all entities are page_size aligned in flash
- * 1. kernel, ramdisk and DTB are required (size != 0)
- * 2. recovery_dtbo/recovery_acpio is required for recovery.img in non-A/B
- *    devices(recovery_dtbo_size != 0)
- * 3. second is optional (second_size == 0 -> no second)
- * 4. load each element (kernel, ramdisk, second, dtb) at
- *    the specified physical address (kernel_addr, etc)
- * 5. If booting to recovery mode in a non-A/B device, extract recovery
- *    dtbo/acpio and apply the correct set of overlays on the base device tree
- *    depending on the hardware/product revision.
- * 6. prepare tags at tag_addr.  kernel_args[] is
- *    appended to the kernel commandline in the tags.
- * 7. r0 = 0, r1 = MACHINE_TYPE, r2 = tags_addr
- * 8. if second_size != 0: jump to second_addr
- *    else: jump to kernel_addr
- */
-struct boot_img_hdr_v2 : public boot_img_hdr_v1 {
-    uint32_t dtb_size; /* size in bytes for DTB image */
-    uint64_t dtb_addr; /* physical load address for DTB image */
-} __attribute__((packed));
diff --git a/mkbootimg/mkbootimg.py b/mkbootimg/mkbootimg.py
deleted file mode 100644
index 934f28e..0000000
--- a/mkbootimg/mkbootimg.py
+++ /dev/null
@@ -1,236 +0,0 @@
-#!/usr/bin/env python
-# Copyright 2015, 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.
-
-from __future__ import print_function
-from sys import argv, exit, stderr
-from argparse import ArgumentParser, FileType, Action
-from os import fstat
-from struct import pack
-from hashlib import sha1
-import sys
-import re
-
-def filesize(f):
-    if f is None:
-        return 0
-    try:
-        return fstat(f.fileno()).st_size
-    except OSError:
-        return 0
-
-
-def update_sha(sha, f):
-    if f:
-        sha.update(f.read())
-        f.seek(0)
-        sha.update(pack('I', filesize(f)))
-    else:
-        sha.update(pack('I', 0))
-
-
-def pad_file(f, padding):
-    pad = (padding - (f.tell() & (padding - 1))) & (padding - 1)
-    f.write(pack(str(pad) + 'x'))
-
-
-def get_number_of_pages(image_size, page_size):
-    """calculates the number of pages required for the image"""
-    return (image_size + page_size - 1) / page_size
-
-
-def get_recovery_dtbo_offset(args):
-    """calculates the offset of recovery_dtbo image in the boot image"""
-    num_header_pages = 1 # header occupies a page
-    num_kernel_pages = get_number_of_pages(filesize(args.kernel), args.pagesize)
-    num_ramdisk_pages = get_number_of_pages(filesize(args.ramdisk), args.pagesize)
-    num_second_pages = get_number_of_pages(filesize(args.second), args.pagesize)
-    dtbo_offset = args.pagesize * (num_header_pages + num_kernel_pages +
-                                   num_ramdisk_pages + num_second_pages)
-    return dtbo_offset
-
-
-def write_header(args):
-    BOOT_IMAGE_HEADER_V1_SIZE = 1648
-    BOOT_IMAGE_HEADER_V2_SIZE = 1660
-    BOOT_MAGIC = 'ANDROID!'.encode()
-
-    if (args.header_version > 2):
-        raise ValueError('Boot header version %d not supported' % args.header_version)
-
-    args.output.write(pack('8s', BOOT_MAGIC))
-    args.output.write(pack('10I',
-        filesize(args.kernel),                          # size in bytes
-        args.base + args.kernel_offset,                 # physical load addr
-        filesize(args.ramdisk),                         # size in bytes
-        args.base + args.ramdisk_offset,                # physical load addr
-        filesize(args.second),                          # size in bytes
-        args.base + args.second_offset,                 # physical load addr
-        args.base + args.tags_offset,                   # physical addr for kernel tags
-        args.pagesize,                                  # flash page size we assume
-        args.header_version,                            # version of bootimage header
-        (args.os_version << 11) | args.os_patch_level)) # os version and patch level
-    args.output.write(pack('16s', args.board.encode())) # asciiz product name
-    args.output.write(pack('512s', args.cmdline[:512].encode()))
-
-    sha = sha1()
-    update_sha(sha, args.kernel)
-    update_sha(sha, args.ramdisk)
-    update_sha(sha, args.second)
-
-    if args.header_version > 0:
-        update_sha(sha, args.recovery_dtbo)
-    if args.header_version > 1:
-        update_sha(sha, args.dtb)
-
-    img_id = pack('32s', sha.digest())
-
-    args.output.write(img_id)
-    args.output.write(pack('1024s', args.cmdline[512:].encode()))
-
-    if args.header_version > 0:
-        args.output.write(pack('I', filesize(args.recovery_dtbo)))   # size in bytes
-        if args.recovery_dtbo:
-            args.output.write(pack('Q', get_recovery_dtbo_offset(args))) # recovery dtbo offset
-        else:
-            args.output.write(pack('Q', 0)) # Will be set to 0 for devices without a recovery dtbo
-
-    # Populate boot image header size for header versions 1 and 2.
-    if args.header_version == 1:
-        args.output.write(pack('I', BOOT_IMAGE_HEADER_V1_SIZE))
-    elif args.header_version == 2:
-        args.output.write(pack('I', BOOT_IMAGE_HEADER_V2_SIZE))
-
-    if args.header_version > 1:
-
-        if filesize(args.dtb) == 0:
-            raise ValueError("DTB image must not be empty.")
-
-        args.output.write(pack('I', filesize(args.dtb)))   # size in bytes
-        args.output.write(pack('Q', args.base + args.dtb_offset)) # dtb physical load address
-    pad_file(args.output, args.pagesize)
-    return img_id
-
-
-class ValidateStrLenAction(Action):
-    def __init__(self, option_strings, dest, nargs=None, **kwargs):
-        if 'maxlen' not in kwargs:
-            raise ValueError('maxlen must be set')
-        self.maxlen = int(kwargs['maxlen'])
-        del kwargs['maxlen']
-        super(ValidateStrLenAction, self).__init__(option_strings, dest, **kwargs)
-
-    def __call__(self, parser, namespace, values, option_string=None):
-        if len(values) > self.maxlen:
-            raise ValueError('String argument too long: max {0:d}, got {1:d}'.
-                format(self.maxlen, len(values)))
-        setattr(namespace, self.dest, values)
-
-
-def write_padded_file(f_out, f_in, padding):
-    if f_in is None:
-        return
-    f_out.write(f_in.read())
-    pad_file(f_out, padding)
-
-
-def parse_int(x):
-    return int(x, 0)
-
-def parse_os_version(x):
-    match = re.search(r'^(\d{1,3})(?:\.(\d{1,3})(?:\.(\d{1,3}))?)?', x)
-    if match:
-        a = int(match.group(1))
-        b = c = 0
-        if match.lastindex >= 2:
-            b = int(match.group(2))
-        if match.lastindex == 3:
-            c = int(match.group(3))
-        # 7 bits allocated for each field
-        assert a < 128
-        assert b < 128
-        assert c < 128
-        return (a << 14) | (b << 7) | c
-    return 0
-
-def parse_os_patch_level(x):
-    match = re.search(r'^(\d{4})-(\d{2})-(\d{2})', x)
-    if match:
-        y = int(match.group(1)) - 2000
-        m = int(match.group(2))
-        # 7 bits allocated for the year, 4 bits for the month
-        assert y >= 0 and y < 128
-        assert m > 0 and m <= 12
-        return (y << 4) | m
-    return 0
-
-def parse_cmdline():
-    parser = ArgumentParser()
-    parser.add_argument('--kernel', help='path to the kernel', type=FileType('rb'),
-                        required=True)
-    parser.add_argument('--ramdisk', help='path to the ramdisk', type=FileType('rb'))
-    parser.add_argument('--second', help='path to the 2nd bootloader', type=FileType('rb'))
-    parser.add_argument('--dtb', help='path to dtb', type=FileType('rb'))
-    recovery_dtbo_group = parser.add_mutually_exclusive_group()
-    recovery_dtbo_group.add_argument('--recovery_dtbo', help='path to the recovery DTBO', type=FileType('rb'))
-    recovery_dtbo_group.add_argument('--recovery_acpio', help='path to the recovery ACPIO',
-                                     type=FileType('rb'), metavar='RECOVERY_ACPIO', dest='recovery_dtbo')
-    parser.add_argument('--cmdline', help='extra arguments to be passed on the '
-                        'kernel command line', default='', action=ValidateStrLenAction, maxlen=1536)
-    parser.add_argument('--base', help='base address', type=parse_int, default=0x10000000)
-    parser.add_argument('--kernel_offset', help='kernel offset', type=parse_int, default=0x00008000)
-    parser.add_argument('--ramdisk_offset', help='ramdisk offset', type=parse_int, default=0x01000000)
-    parser.add_argument('--second_offset', help='2nd bootloader offset', type=parse_int,
-                        default=0x00f00000)
-    parser.add_argument('--dtb_offset', help='dtb offset', type=parse_int, default=0x01f00000)
-
-    parser.add_argument('--os_version', help='operating system version', type=parse_os_version,
-                        default=0)
-    parser.add_argument('--os_patch_level', help='operating system patch level',
-                        type=parse_os_patch_level, default=0)
-    parser.add_argument('--tags_offset', help='tags offset', type=parse_int, default=0x00000100)
-    parser.add_argument('--board', help='board name', default='', action=ValidateStrLenAction,
-                        maxlen=16)
-    parser.add_argument('--pagesize', help='page size', type=parse_int,
-                        choices=[2**i for i in range(11,15)], default=2048)
-    parser.add_argument('--id', help='print the image ID on standard output',
-                        action='store_true')
-    parser.add_argument('--header_version', help='boot image header version', type=parse_int, default=0)
-    parser.add_argument('-o', '--output', help='output file name', type=FileType('wb'),
-                        required=True)
-    return parser.parse_args()
-
-
-def write_data(args):
-    write_padded_file(args.output, args.kernel, args.pagesize)
-    write_padded_file(args.output, args.ramdisk, args.pagesize)
-    write_padded_file(args.output, args.second, args.pagesize)
-
-    if args.header_version > 0:
-        write_padded_file(args.output, args.recovery_dtbo, args.pagesize)
-    if args.header_version > 1:
-        write_padded_file(args.output, args.dtb, args.pagesize)
-
-def main():
-    args = parse_cmdline()
-    img_id = write_header(args)
-    write_data(args)
-    if args.id:
-        if isinstance(img_id, str):
-            # Python 2's struct.pack returns a string, but py3 returns bytes.
-            img_id = [ord(x) for x in img_id]
-        print('0x' + ''.join('{:02x}'.format(c) for c in img_id))
-
-if __name__ == '__main__':
-    main()
diff --git a/mkbootimg/unpack_bootimg.py b/mkbootimg/unpack_bootimg.py
deleted file mode 100755
index 789bf5e..0000000
--- a/mkbootimg/unpack_bootimg.py
+++ /dev/null
@@ -1,152 +0,0 @@
-#!/usr/bin/env python
-# Copyright 2018, 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.
-
-"""unpacks the bootimage.
-
-Extracts the kernel, ramdisk, second bootloader, dtb and recovery dtbo images.
-"""
-
-from __future__ import print_function
-from argparse import ArgumentParser, FileType
-from struct import unpack
-import os
-
-
-def create_out_dir(dir_path):
-    """creates a directory 'dir_path' if it does not exist"""
-    if not os.path.exists(dir_path):
-        os.makedirs(dir_path)
-
-
-def extract_image(offset, size, bootimage, extracted_image_name):
-    """extracts an image from the bootimage"""
-    bootimage.seek(offset)
-    with open(extracted_image_name, 'wb') as file_out:
-        file_out.write(bootimage.read(size))
-
-
-def get_number_of_pages(image_size, page_size):
-    """calculates the number of pages required for the image"""
-    return (image_size + page_size - 1) / page_size
-
-
-def unpack_bootimage(args):
-    """extracts kernel, ramdisk, second bootloader and recovery dtbo"""
-    boot_magic = unpack('8s', args.boot_img.read(8))
-    print('boot_magic: %s' % boot_magic)
-    kernel_ramdisk_second_info = unpack('10I', args.boot_img.read(10 * 4))
-    print('kernel_size: %s' % kernel_ramdisk_second_info[0])
-    print('kernel load address: %#x' % kernel_ramdisk_second_info[1])
-    print('ramdisk size: %s' % kernel_ramdisk_second_info[2])
-    print('ramdisk load address: %#x' % kernel_ramdisk_second_info[3])
-    print('second bootloader size: %s' % kernel_ramdisk_second_info[4])
-    print('second bootloader load address: %#x' % kernel_ramdisk_second_info[5])
-    print('kernel tags load address: %#x' % kernel_ramdisk_second_info[6])
-    print('page size: %s' % kernel_ramdisk_second_info[7])
-    print('boot image header version: %s' % kernel_ramdisk_second_info[8])
-    print('os version and patch level: %s' % kernel_ramdisk_second_info[9])
-
-    product_name = unpack('16s', args.boot_img.read(16))
-    print('product name: %s' % product_name)
-    cmdline = unpack('512s', args.boot_img.read(512))
-    print('command line args: %s' % cmdline)
-
-    args.boot_img.read(32)  # ignore SHA
-
-    extra_cmdline = unpack('1024s', args.boot_img.read(1024))
-    print('additional command line args: %s' % extra_cmdline)
-
-    kernel_size = kernel_ramdisk_second_info[0]
-    ramdisk_size = kernel_ramdisk_second_info[2]
-    second_size = kernel_ramdisk_second_info[4]
-    page_size = kernel_ramdisk_second_info[7]
-    version = kernel_ramdisk_second_info[8]
-    if version > 0:
-        recovery_dtbo_size = unpack('I', args.boot_img.read(1 * 4))[0]
-        print('recovery dtbo size: %s' % recovery_dtbo_size)
-        recovery_dtbo_offset = unpack('Q', args.boot_img.read(8))[0]
-        print('recovery dtbo offset: %#x' % recovery_dtbo_offset)
-        boot_header_size = unpack('I', args.boot_img.read(4))[0]
-        print('boot header size: %s' % boot_header_size)
-    else:
-        recovery_dtbo_size = 0
-    if version > 1:
-        dtb_size = unpack('I', args.boot_img.read(4))[0]
-        print('dtb size: %s' % dtb_size)
-        dtb_load_address = unpack('Q', args.boot_img.read(8))[0]
-        print('dtb address: %#x' % dtb_load_address)
-    else:
-        dtb_size = 0
-
-
-    # The first page contains the boot header
-    num_header_pages = 1
-
-    num_kernel_pages = get_number_of_pages(kernel_size, page_size)
-    kernel_offset = page_size * num_header_pages  # header occupies a page
-    image_info_list = [(kernel_offset, kernel_size, 'kernel')]
-
-    num_ramdisk_pages = get_number_of_pages(ramdisk_size, page_size)
-    ramdisk_offset = page_size * (num_header_pages + num_kernel_pages
-                                 ) # header + kernel
-    image_info_list.append((ramdisk_offset, ramdisk_size, 'ramdisk'))
-
-    if second_size > 0:
-        second_offset = page_size * (
-                num_header_pages + num_kernel_pages + num_ramdisk_pages
-                )  # header + kernel + ramdisk
-        image_info_list.append((second_offset, second_size, 'second'))
-
-    if recovery_dtbo_size > 0:
-        image_info_list.append((recovery_dtbo_offset, recovery_dtbo_size,
-                                'recovery_dtbo'))
-    if dtb_size > 0:
-        num_second_pages = get_number_of_pages(second_size, page_size)
-        num_recovery_dtbo_pages = get_number_of_pages(recovery_dtbo_size, page_size)
-        dtb_offset = page_size * (
-            num_header_pages + num_kernel_pages + num_ramdisk_pages + num_second_pages +
-            num_recovery_dtbo_pages
-        )
-
-        image_info_list.append((dtb_offset, dtb_size, 'dtb'))
-
-    for image_info in image_info_list:
-        extract_image(image_info[0], image_info[1], args.boot_img,
-                      os.path.join(args.out, image_info[2]))
-
-
-def parse_cmdline():
-    """parse command line arguments"""
-    parser = ArgumentParser(
-        description='Unpacks boot.img/recovery.img, extracts the kernel,'
-        'ramdisk, second bootloader, recovery dtbo and dtb')
-    parser.add_argument(
-        '--boot_img',
-        help='path to boot image',
-        type=FileType('rb'),
-        required=True)
-    parser.add_argument('--out', help='path to out binaries', default='out')
-    return parser.parse_args()
-
-
-def main():
-    """parse arguments and unpack boot image"""
-    args = parse_cmdline()
-    create_out_dir(args.out)
-    unpack_bootimage(args)
-
-
-if __name__ == '__main__':
-    main()
diff --git a/rootdir/init.rc b/rootdir/init.rc
index 7cb0f66..3acf301 100644
--- a/rootdir/init.rc
+++ b/rootdir/init.rc
@@ -345,8 +345,11 @@
     trigger early-boot
     trigger boot
 
-on post-fs
+on early-fs
+    # Once metadata has been mounted, we'll need vold to deal with userdata checkpointing
     start vold
+
+on post-fs
     exec - system system -- /system/bin/vdc checkpoint markBootAttempt
 
     # Once everything is setup, no need to modify /.
@@ -442,6 +445,7 @@
     mkdir /data/apex 0750 root system
     mkdir /data/apex/active 0750 root system
     mkdir /data/apex/backup 0700 root system
+    mkdir /data/apex/hashtree 0700 root system
     mkdir /data/apex/sessions 0700 root system
     mkdir /data/app-staging 0750 system system
     start apexd