diff --git a/Android.bp b/Android.bp
index 696a963..03bea5a 100644
--- a/Android.bp
+++ b/Android.bp
@@ -62,6 +62,27 @@
     },
 }
 
+soong_config_module_type {
+    name: "avf_flag_aware_cc_defaults",
+    module_type: "cc_defaults",
+    config_namespace: "ANDROID",
+    bool_variables: [
+        "release_avf_enable_virt_cpufreq",
+    ],
+    properties: [
+        "cflags",
+    ],
+}
+
+avf_flag_aware_cc_defaults {
+    name: "avf_build_flags_cc",
+    soong_config_variables: {
+        release_avf_enable_virt_cpufreq: {
+            cflags: ["-DAVF_ENABLE_VIRT_CPUFREQ=1"],
+        },
+    },
+}
+
 genrule_defaults {
     name: "dts_to_dtb",
     tools: ["dtc"],
diff --git a/apex/canned_fs_config b/apex/canned_fs_config
index a990901..5afd9d6 100644
--- a/apex/canned_fs_config
+++ b/apex/canned_fs_config
@@ -1,3 +1 @@
 /bin/virtualizationservice 0 2000 0755 capabilities=0x1000001  # CAP_CHOWN, CAP_SYS_RESOURCE
-/bin/crosvm 0 3013 0755 capabilities=0x800000 # CAP_SYS_NICE
-/bin/virtmgr 0 3013 0755 capabilities=0x800000 # CAP_SYS_NICE
diff --git a/apex/empty-payload-apk/Android.bp b/apex/empty-payload-apk/Android.bp
index e78daec..72ec392 100644
--- a/apex/empty-payload-apk/Android.bp
+++ b/apex/empty-payload-apk/Android.bp
@@ -18,6 +18,7 @@
 
 cc_library {
     name: "MicrodroidEmptyPayloadJniLib",
+    defaults: ["avf_build_flags_cc"],
     srcs: ["empty_binary.cpp"],
     shared_libs: ["libvm_payload#current"],
     installable: true,
diff --git a/authfs/fd_server/src/aidl.rs b/authfs/fd_server/src/aidl.rs
index ada3ffb..8edd899 100644
--- a/authfs/fd_server/src/aidl.rs
+++ b/authfs/fd_server/src/aidl.rs
@@ -375,6 +375,10 @@
     }
 }
 
+// FFI types like `c_long` vary on 32/64-bit, and the check is only needed on
+// 64-bit conversions. Fixing this lint makes the code less readable.
+#[allow(unknown_lints)]
+#[allow(clippy::unnecessary_fallible_conversions)]
 fn try_into_fs_stat(st: Statvfs) -> Result<FsStat, std::num::TryFromIntError> {
     Ok(FsStat {
         blockSize: st.block_size().try_into()?,
diff --git a/authfs/tests/benchmarks/Android.bp b/authfs/tests/benchmarks/Android.bp
index 5ef01cc..5820cb4 100644
--- a/authfs/tests/benchmarks/Android.bp
+++ b/authfs/tests/benchmarks/Android.bp
@@ -29,6 +29,7 @@
 
 cc_binary {
     name: "measure_io",
+    defaults: ["avf_build_flags_cc"],
     srcs: [
         "src/measure_io.cpp",
     ],
diff --git a/compos/apex/composd.rc b/compos/apex/composd.rc
index aa4b575..55f3737 100644
--- a/compos/apex/composd.rc
+++ b/compos/apex/composd.rc
@@ -19,10 +19,7 @@
     interface aidl android.system.composd
     disabled
     oneshot
-    # Explicitly specify empty capabilities, otherwise composd will inherit all
-    # the capabilities from init.
-    # Note: whether a process can use capabilities is controlled by SELinux, so
-    # inheriting all the capabilities from init is not a security issue.
-    # However, for defense-in-depth and just for the sake of bookkeeping it's
-    # better to explicitly state that composd doesn't need any capabilities.
+    # We need SYS_NICE in order to allow the crosvm child process to use it.
+    # (b/322197421). composd itself never uses it (and isn't allowed to by
+    # SELinux).
     capabilities SYS_NICE
diff --git a/compos/compos_key_helper/Android.bp b/compos/compos_key_helper/Android.bp
index 6b4b61e..7d27525 100644
--- a/compos/compos_key_helper/Android.bp
+++ b/compos/compos_key_helper/Android.bp
@@ -5,6 +5,7 @@
 
 cc_defaults {
     name: "compos_key_defaults",
+    defaults: ["avf_build_flags_cc"],
     apex_available: ["com.android.compos"],
 
     shared_libs: [
diff --git a/compos/verify/native/Android.bp b/compos/verify/native/Android.bp
index 70cb2ab..ac2fcfb 100644
--- a/compos/verify/native/Android.bp
+++ b/compos/verify/native/Android.bp
@@ -25,6 +25,7 @@
 
 cc_library_static {
     name: "libcompos_verify_native_cpp",
+    defaults: ["avf_build_flags_cc"],
     srcs: ["verify_native.cpp"],
     static_libs: ["libcompos_key"],
     shared_libs: [
diff --git a/demo_native/Android.bp b/demo_native/Android.bp
index 7b6967e..facb2bb 100644
--- a/demo_native/Android.bp
+++ b/demo_native/Android.bp
@@ -5,6 +5,7 @@
 
 cc_binary {
     name: "vm_demo_native",
+    defaults: ["avf_build_flags_cc"],
     srcs: ["main.cpp"],
     static_libs: [
         "libbase",
diff --git a/javalib/api/test-current.txt b/javalib/api/test-current.txt
index 958005f..5aff93f 100644
--- a/javalib/api/test-current.txt
+++ b/javalib/api/test-current.txt
@@ -7,12 +7,14 @@
   }
 
   public final class VirtualMachineConfig {
+    method @FlaggedApi("RELEASE_AVF_ENABLE_MULTI_TENANT_MICRODROID_VM") @NonNull public java.util.List<java.lang.String> getExtraApks();
     method @FlaggedApi("RELEASE_AVF_ENABLE_VENDOR_MODULES") @Nullable public String getOs();
     method @Nullable public String getPayloadConfigPath();
     method public boolean isVmConsoleInputSupported();
   }
 
   public static final class VirtualMachineConfig.Builder {
+    method @FlaggedApi("RELEASE_AVF_ENABLE_MULTI_TENANT_MICRODROID_VM") @NonNull public android.system.virtualmachine.VirtualMachineConfig.Builder addExtraApk(@NonNull String);
     method @FlaggedApi("RELEASE_AVF_ENABLE_VENDOR_MODULES") @NonNull public android.system.virtualmachine.VirtualMachineConfig.Builder setOs(@NonNull String);
     method @NonNull @RequiresPermission(android.system.virtualmachine.VirtualMachine.USE_CUSTOM_VIRTUAL_MACHINE_PERMISSION) public android.system.virtualmachine.VirtualMachineConfig.Builder setPayloadConfigPath(@NonNull String);
     method @FlaggedApi("RELEASE_AVF_ENABLE_VENDOR_MODULES") @NonNull @RequiresPermission(android.system.virtualmachine.VirtualMachine.USE_CUSTOM_VIRTUAL_MACHINE_PERMISSION) public android.system.virtualmachine.VirtualMachineConfig.Builder setVendorDiskImage(@NonNull java.io.File);
diff --git a/javalib/jni/Android.bp b/javalib/jni/Android.bp
index 6e2a129..24dece2 100644
--- a/javalib/jni/Android.bp
+++ b/javalib/jni/Android.bp
@@ -5,6 +5,7 @@
 
 cc_library_shared {
     name: "libvirtualizationservice_jni",
+    defaults: ["avf_build_flags_cc"],
     srcs: [
         "android_system_virtualmachine_VirtualizationService.cpp",
     ],
@@ -20,6 +21,7 @@
 
 cc_library_shared {
     name: "libvirtualmachine_jni",
+    defaults: ["avf_build_flags_cc"],
     srcs: [
         "android_system_virtualmachine_VirtualMachine.cpp",
     ],
diff --git a/javalib/src/android/system/virtualmachine/VirtualMachine.java b/javalib/src/android/system/virtualmachine/VirtualMachine.java
index 16f9631..5025e88 100644
--- a/javalib/src/android/system/virtualmachine/VirtualMachine.java
+++ b/javalib/src/android/system/virtualmachine/VirtualMachine.java
@@ -54,6 +54,8 @@
 import android.annotation.WorkerThread;
 import android.content.ComponentCallbacks2;
 import android.content.Context;
+import android.content.pm.ApplicationInfo;
+import android.content.pm.PackageManager;
 import android.content.res.Configuration;
 import android.os.Binder;
 import android.os.IBinder;
@@ -76,7 +78,6 @@
 
 import java.io.File;
 import java.io.FileInputStream;
-import java.io.FileOutputStream;
 import java.io.FileNotFoundException;
 import java.io.FileOutputStream;
 import java.io.IOException;
@@ -807,10 +808,30 @@
                     createVmInputPipes();
                 }
 
+                VirtualMachineConfig vmConfig = getConfig();
                 VirtualMachineAppConfig appConfig =
-                        getConfig().toVsConfig(mContext.getPackageManager());
+                        vmConfig.toVsConfig(mContext.getPackageManager());
                 appConfig.name = mName;
 
+                if (!vmConfig.getExtraApks().isEmpty()) {
+                    // Extra APKs were specified directly, rather than via config file.
+                    // We've already populated the file names for the extra APKs and IDSigs
+                    // (via setupExtraApks). But we also need to open the APK files and add
+                    // fds for them to the payload config.
+                    // This isn't needed when the extra APKs are specified in a config file - then
+                    // Virtualization Manager opens them itself.
+                    List<ParcelFileDescriptor> extraApkFiles = new ArrayList<>(mExtraApks.size());
+                    for (ExtraApkSpec extraApk : mExtraApks) {
+                        try {
+                            extraApkFiles.add(
+                                    ParcelFileDescriptor.open(extraApk.apk, MODE_READ_ONLY));
+                        } catch (FileNotFoundException e) {
+                            throw new VirtualMachineException("Failed to open extra APK", e);
+                        }
+                    }
+                    appConfig.payload.getPayloadConfig().extraApks = extraApkFiles;
+                }
+
                 try {
                     createIdSigs(service, appConfig);
                 } catch (FileNotFoundException e) {
@@ -1239,6 +1260,46 @@
         return result.toString();
     }
 
+    /**
+     * Reads the payload config inside the application, parses extra APK information, and then
+     * creates corresponding idsig file paths.
+     */
+    private static List<ExtraApkSpec> setupExtraApks(
+            @NonNull Context context, @NonNull VirtualMachineConfig config, @NonNull File vmDir)
+            throws VirtualMachineException {
+        String configPath = config.getPayloadConfigPath();
+        List<String> extraApks = config.getExtraApks();
+        if (configPath != null) {
+            return setupExtraApksFromConfigFile(context, vmDir, configPath);
+        } else if (!extraApks.isEmpty()) {
+            return setupExtraApksFromList(context, vmDir, extraApks);
+        } else {
+            return Collections.emptyList();
+        }
+    }
+
+    private static List<ExtraApkSpec> setupExtraApksFromConfigFile(
+            Context context, File vmDir, String configPath) throws VirtualMachineException {
+        try (ZipFile zipFile = new ZipFile(context.getPackageCodePath())) {
+            InputStream inputStream = zipFile.getInputStream(zipFile.getEntry(configPath));
+            List<String> apkList =
+                    parseExtraApkListFromPayloadConfig(
+                            new JsonReader(new InputStreamReader(inputStream)));
+
+            List<ExtraApkSpec> extraApks = new ArrayList<>(apkList.size());
+            for (int i = 0; i < apkList.size(); ++i) {
+                extraApks.add(
+                        new ExtraApkSpec(
+                                new File(apkList.get(i)),
+                                new File(vmDir, EXTRA_IDSIG_FILE_PREFIX + i)));
+            }
+
+            return extraApks;
+        } catch (IOException e) {
+            throw new VirtualMachineException("Couldn't parse extra apks from the vm config", e);
+        }
+    }
+
     private static List<String> parseExtraApkListFromPayloadConfig(JsonReader reader)
             throws VirtualMachineException {
         /*
@@ -1275,36 +1336,28 @@
         }
     }
 
-    /**
-     * Reads the payload config inside the application, parses extra APK information, and then
-     * creates corresponding idsig file paths.
-     */
-    private static List<ExtraApkSpec> setupExtraApks(
-            @NonNull Context context, @NonNull VirtualMachineConfig config, @NonNull File vmDir)
-            throws VirtualMachineException {
-        String configPath = config.getPayloadConfigPath();
-        if (configPath == null) {
-            return Collections.emptyList();
-        }
-        try (ZipFile zipFile = new ZipFile(context.getPackageCodePath())) {
-            InputStream inputStream =
-                    zipFile.getInputStream(zipFile.getEntry(configPath));
-            List<String> apkList =
-                    parseExtraApkListFromPayloadConfig(
-                            new JsonReader(new InputStreamReader(inputStream)));
-
-            List<ExtraApkSpec> extraApks = new ArrayList<>();
-            for (int i = 0; i < apkList.size(); ++i) {
-                extraApks.add(
-                        new ExtraApkSpec(
-                                new File(apkList.get(i)),
-                                new File(vmDir, EXTRA_IDSIG_FILE_PREFIX + i)));
+    private static List<ExtraApkSpec> setupExtraApksFromList(
+            Context context, File vmDir, List<String> extraApkInfo) throws VirtualMachineException {
+        int count = extraApkInfo.size();
+        List<ExtraApkSpec> extraApks = new ArrayList<>(count);
+        for (int i = 0; i < count; i++) {
+            String packageName = extraApkInfo.get(i);
+            ApplicationInfo appInfo;
+            try {
+                appInfo =
+                        context.getPackageManager()
+                                .getApplicationInfo(
+                                        packageName, PackageManager.ApplicationInfoFlags.of(0));
+            } catch (PackageManager.NameNotFoundException e) {
+                throw new VirtualMachineException("Extra APK package not found", e);
             }
 
-            return Collections.unmodifiableList(extraApks);
-        } catch (IOException e) {
-            throw new VirtualMachineException("Couldn't parse extra apks from the vm config", e);
+            extraApks.add(
+                    new ExtraApkSpec(
+                            new File(appInfo.sourceDir),
+                            new File(vmDir, EXTRA_IDSIG_FILE_PREFIX + i)));
         }
+        return extraApks;
     }
 
     private void importInstanceFrom(@NonNull ParcelFileDescriptor instanceFd)
diff --git a/javalib/src/android/system/virtualmachine/VirtualMachineConfig.java b/javalib/src/android/system/virtualmachine/VirtualMachineConfig.java
index e8ef195..9688789 100644
--- a/javalib/src/android/system/virtualmachine/VirtualMachineConfig.java
+++ b/javalib/src/android/system/virtualmachine/VirtualMachineConfig.java
@@ -49,7 +49,10 @@
 import java.io.OutputStream;
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
+import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collections;
+import java.util.List;
 import java.util.Objects;
 import java.util.zip.ZipFile;
 
@@ -67,7 +70,7 @@
     private static String[] EMPTY_STRING_ARRAY = {};
 
     // These define the schema of the config file persisted on disk.
-    private static final int VERSION = 7;
+    private static final int VERSION = 8;
     private static final String KEY_VERSION = "version";
     private static final String KEY_PACKAGENAME = "packageName";
     private static final String KEY_APKPATH = "apkPath";
@@ -82,6 +85,7 @@
     private static final String KEY_VM_CONSOLE_INPUT_SUPPORTED = "vmConsoleInputSupported";
     private static final String KEY_VENDOR_DISK_IMAGE_PATH = "vendorDiskImagePath";
     private static final String KEY_OS = "os";
+    private static final String KEY_EXTRA_APKS = "extraApks";
 
     /** @hide */
     @Retention(RetentionPolicy.SOURCE)
@@ -140,6 +144,8 @@
     /** Absolute path to the APK file containing the VM payload. */
     @Nullable private final String mApkPath;
 
+    private final List<String> mExtraApks;
+
     @DebugLevel private final int mDebugLevel;
 
     /**
@@ -181,6 +187,7 @@
     private VirtualMachineConfig(
             @Nullable String packageName,
             @Nullable String apkPath,
+            List<String> extraApks,
             @Nullable String payloadConfigPath,
             @Nullable String payloadBinaryName,
             @DebugLevel int debugLevel,
@@ -195,6 +202,11 @@
         // This is only called from Builder.build(); the builder handles parameter validation.
         mPackageName = packageName;
         mApkPath = apkPath;
+        mExtraApks =
+                extraApks.isEmpty()
+                        ? Collections.emptyList()
+                        : Collections.unmodifiableList(
+                                Arrays.asList(extraApks.toArray(new String[0])));
         mPayloadConfigPath = payloadConfigPath;
         mPayloadBinaryName = payloadBinaryName;
         mDebugLevel = debugLevel;
@@ -292,6 +304,13 @@
             builder.setOs(os);
         }
 
+        String[] extraApks = b.getStringArray(KEY_EXTRA_APKS);
+        if (extraApks != null) {
+            for (String extraApk : extraApks) {
+                builder.addExtraApk(extraApk);
+            }
+        }
+
         return builder.build();
     }
 
@@ -331,6 +350,10 @@
             b.putString(KEY_VENDOR_DISK_IMAGE_PATH, mVendorDiskImage.getAbsolutePath());
         }
         b.putString(KEY_OS, mOs);
+        if (!mExtraApks.isEmpty()) {
+            String[] extraApks = mExtraApks.toArray(new String[0]);
+            b.putStringArray(KEY_EXTRA_APKS, extraApks);
+        }
         b.writeToStream(output);
     }
 
@@ -347,6 +370,19 @@
     }
 
     /**
+     * Returns the package names of any extra APKs that have been requested for the VM. They are
+     * returned in the order in which they were added via {@link Builder#addExtraApk}.
+     *
+     * @hide
+     */
+    @TestApi
+    @FlaggedApi("RELEASE_AVF_ENABLE_MULTI_TENANT_MICRODROID_VM")
+    @NonNull
+    public List<String> getExtraApks() {
+        return mExtraApks;
+    }
+
+    /**
      * Returns the path within the APK to the payload config file that defines software aspects of
      * the VM.
      *
@@ -495,7 +531,8 @@
                 && Objects.equals(this.mPayloadConfigPath, other.mPayloadConfigPath)
                 && Objects.equals(this.mPayloadBinaryName, other.mPayloadBinaryName)
                 && Objects.equals(this.mPackageName, other.mPackageName)
-                && Objects.equals(this.mOs, other.mOs);
+                && Objects.equals(this.mOs, other.mOs)
+                && Objects.equals(this.mExtraApks, other.mExtraApks);
     }
 
     /**
@@ -623,6 +660,7 @@
 
         @Nullable private final String mPackageName;
         @Nullable private String mApkPath;
+        private final List<String> mExtraApks = new ArrayList<>();
         @Nullable private String mPayloadConfigPath;
         @Nullable private String mPayloadBinaryName;
         @DebugLevel private int mDebugLevel = DEBUG_LEVEL_NONE;
@@ -683,6 +721,10 @@
                     throw new IllegalStateException(
                             "setPayloadConfigPath and setOs may not both be called");
                 }
+                if (!mExtraApks.isEmpty()) {
+                    throw new IllegalStateException(
+                            "setPayloadConfigPath and addExtraApk may not both be called");
+                }
             } else {
                 if (mPayloadConfigPath != null) {
                     throw new IllegalStateException(
@@ -710,6 +752,7 @@
             return new VirtualMachineConfig(
                     packageName,
                     apkPath,
+                    mExtraApks,
                     mPayloadConfigPath,
                     mPayloadBinaryName,
                     mDebugLevel,
@@ -742,6 +785,21 @@
         }
 
         /**
+         * Specify the package name of an extra APK to be included in the VM. Each extra APK is
+         * mounted, in unzipped form, inside the VM, allowing access to the code and/or data within
+         * it. The VM entry point must be in the main APK.
+         *
+         * @hide
+         */
+        @TestApi
+        @FlaggedApi("RELEASE_AVF_ENABLE_MULTI_TENANT_MICRODROID_VM")
+        @NonNull
+        public Builder addExtraApk(@NonNull String packageName) {
+            mExtraApks.add(requireNonNull(packageName, "extra APK package name must not be null"));
+            return this;
+        }
+
+        /**
          * Sets the path within the APK to the payload config file that defines software aspects of
          * the VM. The file is a JSON file; see
          * packages/modules/Virtualization/microdroid/payload/config/src/lib.rs for the format.
diff --git a/launcher/Android.bp b/launcher/Android.bp
index c6873ce..9835fc9 100644
--- a/launcher/Android.bp
+++ b/launcher/Android.bp
@@ -5,6 +5,7 @@
 
 cc_binary {
     name: "microdroid_launcher",
+    defaults: ["avf_build_flags_cc"],
     srcs: ["main.cpp"],
     shared_libs: [
         "libbase",
diff --git a/libs/apkmanifest/Android.bp b/libs/apkmanifest/Android.bp
index e6fcbef..54c4f6c 100644
--- a/libs/apkmanifest/Android.bp
+++ b/libs/apkmanifest/Android.bp
@@ -4,6 +4,7 @@
 
 cc_library_shared {
     name: "libapkmanifest_native",
+    defaults: ["avf_build_flags_cc"],
     srcs: ["native/*.cpp"],
     shared_libs: [
         "libandroidfw",
diff --git a/libs/libfdt/src/iterators.rs b/libs/libfdt/src/iterators.rs
index e818c68..cb7afda 100644
--- a/libs/libfdt/src/iterators.rs
+++ b/libs/libfdt/src/iterators.rs
@@ -23,6 +23,8 @@
 use core::marker::PhantomData;
 use core::{mem::size_of, ops::Range, slice::ChunksExact};
 
+use zerocopy::transmute;
+
 /// Iterator over nodes sharing a same compatible string.
 pub struct CompatibleIterator<'a> {
     node: FdtNode<'a>,
@@ -132,12 +134,6 @@
     }
 }
 
-// Converts two cells into bytes of the same size
-fn two_cells_to_bytes(cells: [u32; 2]) -> [u8; 2 * size_of::<u32>()] {
-    // SAFETY: the size of the two arrays are the same
-    unsafe { core::mem::transmute::<[u32; 2], [u8; 2 * size_of::<u32>()]>(cells) }
-}
-
 impl Reg<u64> {
     const NUM_CELLS: usize = 2;
     /// Converts addr and (optional) size to the format that is consumable by libfdt.
@@ -145,14 +141,10 @@
         &self,
     ) -> ([u8; Self::NUM_CELLS * size_of::<u32>()], Option<[u8; Self::NUM_CELLS * size_of::<u32>()]>)
     {
-        let addr =
-            two_cells_to_bytes([((self.addr >> 32) as u32).to_be(), (self.addr as u32).to_be()]);
-        let size = if self.size.is_some() {
-            let size = self.size.unwrap();
-            Some(two_cells_to_bytes([((size >> 32) as u32).to_be(), (size as u32).to_be()]))
-        } else {
-            None
-        };
+        let addr = transmute!([((self.addr >> 32) as u32).to_be(), (self.addr as u32).to_be()]);
+        let size =
+            self.size.map(|sz| transmute!([((sz >> 32) as u32).to_be(), (sz as u32).to_be()]));
+
         (addr, size)
     }
 }
@@ -288,12 +280,8 @@
             ((self.size >> 32) as u32).to_be(),
             (self.size as u32).to_be(),
         ];
-        // SAFETY: the size of the two arrays are the same
-        unsafe {
-            core::mem::transmute::<[u32; Self::SIZE_CELLS], [u8; Self::SIZE_CELLS * size_of::<u32>()]>(
-                buf,
-            )
-        }
+
+        transmute!(buf)
     }
 }
 
diff --git a/libs/libfdt/src/lib.rs b/libs/libfdt/src/lib.rs
index 8a4e251..0249d0d 100644
--- a/libs/libfdt/src/lib.rs
+++ b/libs/libfdt/src/lib.rs
@@ -18,141 +18,22 @@
 #![no_std]
 
 mod iterators;
+mod libfdt;
+mod result;
 
 pub use iterators::{
     AddressRange, CellIterator, CompatibleIterator, DescendantsIterator, MemRegIterator,
     PropertyIterator, RangesIterator, Reg, RegIterator, SubnodeIterator,
 };
+pub use result::{FdtError, Result};
 
-use core::cmp::max;
 use core::ffi::{c_int, c_void, CStr};
-use core::fmt;
-use core::mem;
 use core::ops::Range;
-use core::ptr;
-use core::result;
 use cstr::cstr;
+use result::{fdt_err, fdt_err_expect_zero, fdt_err_or_option};
 use zerocopy::AsBytes as _;
 
-/// Error type corresponding to libfdt error codes.
-#[derive(Clone, Copy, Debug, Eq, PartialEq)]
-pub enum FdtError {
-    /// FDT_ERR_NOTFOUND
-    NotFound,
-    /// FDT_ERR_EXISTS
-    Exists,
-    /// FDT_ERR_NOSPACE
-    NoSpace,
-    /// FDT_ERR_BADOFFSET
-    BadOffset,
-    /// FDT_ERR_BADPATH
-    BadPath,
-    /// FDT_ERR_BADPHANDLE
-    BadPhandle,
-    /// FDT_ERR_BADSTATE
-    BadState,
-    /// FDT_ERR_TRUNCATED
-    Truncated,
-    /// FDT_ERR_BADMAGIC
-    BadMagic,
-    /// FDT_ERR_BADVERSION
-    BadVersion,
-    /// FDT_ERR_BADSTRUCTURE
-    BadStructure,
-    /// FDT_ERR_BADLAYOUT
-    BadLayout,
-    /// FDT_ERR_INTERNAL
-    Internal,
-    /// FDT_ERR_BADNCELLS
-    BadNCells,
-    /// FDT_ERR_BADVALUE
-    BadValue,
-    /// FDT_ERR_BADOVERLAY
-    BadOverlay,
-    /// FDT_ERR_NOPHANDLES
-    NoPhandles,
-    /// FDT_ERR_BADFLAGS
-    BadFlags,
-    /// FDT_ERR_ALIGNMENT
-    Alignment,
-    /// Unexpected error code
-    Unknown(i32),
-}
-
-impl fmt::Display for FdtError {
-    /// Prints error messages from libfdt.h documentation.
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        match self {
-            Self::NotFound => write!(f, "The requested node or property does not exist"),
-            Self::Exists => write!(f, "Attempted to create an existing node or property"),
-            Self::NoSpace => write!(f, "Insufficient buffer space to contain the expanded tree"),
-            Self::BadOffset => write!(f, "Structure block offset is out-of-bounds or invalid"),
-            Self::BadPath => write!(f, "Badly formatted path"),
-            Self::BadPhandle => write!(f, "Invalid phandle length or value"),
-            Self::BadState => write!(f, "Received incomplete device tree"),
-            Self::Truncated => write!(f, "Device tree or sub-block is improperly terminated"),
-            Self::BadMagic => write!(f, "Device tree header missing its magic number"),
-            Self::BadVersion => write!(f, "Device tree has a version which can't be handled"),
-            Self::BadStructure => write!(f, "Device tree has a corrupt structure block"),
-            Self::BadLayout => write!(f, "Device tree sub-blocks in unsupported order"),
-            Self::Internal => write!(f, "libfdt has failed an internal assertion"),
-            Self::BadNCells => write!(f, "Bad format or value of #address-cells or #size-cells"),
-            Self::BadValue => write!(f, "Unexpected property value"),
-            Self::BadOverlay => write!(f, "Overlay cannot be applied"),
-            Self::NoPhandles => write!(f, "Device tree doesn't have any phandle available anymore"),
-            Self::BadFlags => write!(f, "Invalid flag or invalid combination of flags"),
-            Self::Alignment => write!(f, "Device tree base address is not 8-byte aligned"),
-            Self::Unknown(e) => write!(f, "Unknown libfdt error '{e}'"),
-        }
-    }
-}
-
-/// Result type with FdtError enum.
-pub type Result<T> = result::Result<T, FdtError>;
-
-fn fdt_err(val: c_int) -> Result<c_int> {
-    if val >= 0 {
-        Ok(val)
-    } else {
-        Err(match -val as _ {
-            libfdt_bindgen::FDT_ERR_NOTFOUND => FdtError::NotFound,
-            libfdt_bindgen::FDT_ERR_EXISTS => FdtError::Exists,
-            libfdt_bindgen::FDT_ERR_NOSPACE => FdtError::NoSpace,
-            libfdt_bindgen::FDT_ERR_BADOFFSET => FdtError::BadOffset,
-            libfdt_bindgen::FDT_ERR_BADPATH => FdtError::BadPath,
-            libfdt_bindgen::FDT_ERR_BADPHANDLE => FdtError::BadPhandle,
-            libfdt_bindgen::FDT_ERR_BADSTATE => FdtError::BadState,
-            libfdt_bindgen::FDT_ERR_TRUNCATED => FdtError::Truncated,
-            libfdt_bindgen::FDT_ERR_BADMAGIC => FdtError::BadMagic,
-            libfdt_bindgen::FDT_ERR_BADVERSION => FdtError::BadVersion,
-            libfdt_bindgen::FDT_ERR_BADSTRUCTURE => FdtError::BadStructure,
-            libfdt_bindgen::FDT_ERR_BADLAYOUT => FdtError::BadLayout,
-            libfdt_bindgen::FDT_ERR_INTERNAL => FdtError::Internal,
-            libfdt_bindgen::FDT_ERR_BADNCELLS => FdtError::BadNCells,
-            libfdt_bindgen::FDT_ERR_BADVALUE => FdtError::BadValue,
-            libfdt_bindgen::FDT_ERR_BADOVERLAY => FdtError::BadOverlay,
-            libfdt_bindgen::FDT_ERR_NOPHANDLES => FdtError::NoPhandles,
-            libfdt_bindgen::FDT_ERR_BADFLAGS => FdtError::BadFlags,
-            libfdt_bindgen::FDT_ERR_ALIGNMENT => FdtError::Alignment,
-            _ => FdtError::Unknown(val),
-        })
-    }
-}
-
-fn fdt_err_expect_zero(val: c_int) -> Result<()> {
-    match fdt_err(val)? {
-        0 => Ok(()),
-        _ => Err(FdtError::Unknown(val)),
-    }
-}
-
-fn fdt_err_or_option(val: c_int) -> Result<Option<c_int>> {
-    match fdt_err(val) {
-        Ok(val) => Ok(Some(val)),
-        Err(FdtError::NotFound) => Ok(None),
-        Err(e) => Err(e),
-    }
-}
+use crate::libfdt::{Libfdt, LibfdtMut};
 
 /// Value of a #address-cells property.
 #[derive(Copy, Clone, Debug, Eq, PartialEq)]
@@ -162,14 +43,14 @@
     Triple = 3,
 }
 
-impl TryFrom<c_int> for AddrCells {
+impl TryFrom<usize> for AddrCells {
     type Error = FdtError;
 
-    fn try_from(res: c_int) -> Result<Self> {
-        match fdt_err(res)? {
-            x if x == Self::Single as c_int => Ok(Self::Single),
-            x if x == Self::Double as c_int => Ok(Self::Double),
-            x if x == Self::Triple as c_int => Ok(Self::Triple),
+    fn try_from(value: usize) -> Result<Self> {
+        match value {
+            x if x == Self::Single as _ => Ok(Self::Single),
+            x if x == Self::Double as _ => Ok(Self::Double),
+            x if x == Self::Triple as _ => Ok(Self::Triple),
             _ => Err(FdtError::BadNCells),
         }
     }
@@ -183,14 +64,14 @@
     Double = 2,
 }
 
-impl TryFrom<c_int> for SizeCells {
+impl TryFrom<usize> for SizeCells {
     type Error = FdtError;
 
-    fn try_from(res: c_int) -> Result<Self> {
-        match fdt_err(res)? {
-            x if x == Self::None as c_int => Ok(Self::None),
-            x if x == Self::Single as c_int => Ok(Self::Single),
-            x if x == Self::Double as c_int => Ok(Self::Double),
+    fn try_from(value: usize) -> Result<Self> {
+        match value {
+            x if x == Self::None as _ => Ok(Self::None),
+            x if x == Self::Single as _ => Ok(Self::Single),
+            x if x == Self::Double as _ => Ok(Self::Double),
             _ => Err(FdtError::BadNCells),
         }
     }
@@ -201,6 +82,14 @@
 #[derive(Debug)]
 struct FdtPropertyStruct(libfdt_bindgen::fdt_property);
 
+impl AsRef<FdtPropertyStruct> for libfdt_bindgen::fdt_property {
+    fn as_ref(&self) -> &FdtPropertyStruct {
+        let ptr = self as *const _ as *const _;
+        // SAFETY: Types have the same layout (transparent) so the valid reference remains valid.
+        unsafe { &*ptr }
+    }
+}
+
 impl FdtPropertyStruct {
     fn from_offset(fdt: &Fdt, offset: c_int) -> Result<&Self> {
         let mut len = 0;
@@ -212,7 +101,8 @@
             return Err(FdtError::Internal); // shouldn't happen.
         }
         // SAFETY: prop is only returned when it points to valid libfdt_bindgen.
-        Ok(unsafe { &*prop.cast::<FdtPropertyStruct>() })
+        let prop = unsafe { &*prop };
+        Ok(prop.as_ref())
     }
 
     fn name_offset(&self) -> c_int {
@@ -224,7 +114,7 @@
     }
 
     fn data_ptr(&self) -> *const c_void {
-        self.0.data.as_ptr().cast::<_>()
+        self.0.data.as_ptr().cast()
     }
 }
 
@@ -257,7 +147,11 @@
             // SAFETY: Accesses (read-only) are constrained to the DT totalsize.
             unsafe { libfdt_bindgen::fdt_next_property_offset(self.fdt.as_ptr(), self.offset) };
 
-        fdt_err_or_option(ret)?.map(|offset| Self::new(self.fdt, offset)).transpose()
+        if let Some(offset) = fdt_err_or_option(ret)? {
+            Ok(Some(Self::new(self.fdt, offset)?))
+        } else {
+            Ok(None)
+        }
     }
 }
 
@@ -269,31 +163,18 @@
 }
 
 impl<'a> FdtNode<'a> {
-    /// Creates immutable node from a mutable node at the same offset.
-    pub fn from_mut(other: &'a FdtNodeMut) -> Self {
-        FdtNode { fdt: other.fdt, offset: other.offset }
-    }
     /// Returns parent node.
     pub fn parent(&self) -> Result<Self> {
-        // SAFETY: Accesses (read-only) are constrained to the DT totalsize.
-        let ret = unsafe { libfdt_bindgen::fdt_parent_offset(self.fdt.as_ptr(), self.offset) };
+        let offset = self.fdt.parent_offset(self.offset)?;
 
-        Ok(Self { fdt: self.fdt, offset: fdt_err(ret)? })
+        Ok(Self { fdt: self.fdt, offset })
     }
 
     /// Returns supernode with depth. Note that root is at depth 0.
     pub fn supernode_at_depth(&self, depth: usize) -> Result<Self> {
-        // SAFETY: Accesses (read-only) are constrained to the DT totalsize.
-        let ret = unsafe {
-            libfdt_bindgen::fdt_supernode_atdepth_offset(
-                self.fdt.as_ptr(),
-                self.offset,
-                depth.try_into().unwrap(),
-                ptr::null_mut(),
-            )
-        };
+        let offset = self.fdt.supernode_atdepth_offset(self.offset, depth)?;
 
-        Ok(Self { fdt: self.fdt, offset: fdt_err(ret)? })
+        Ok(Self { fdt: self.fdt, offset })
     }
 
     /// Returns the standard (deprecated) device_type <string> property.
@@ -303,9 +184,7 @@
 
     /// Returns the standard reg <prop-encoded-array> property.
     pub fn reg(&self) -> Result<Option<RegIterator<'a>>> {
-        let reg = cstr!("reg");
-
-        if let Some(cells) = self.getprop_cells(reg)? {
+        if let Some(cells) = self.getprop_cells(cstr!("reg"))? {
             let parent = self.parent()?;
 
             let addr_cells = parent.address_cells()?;
@@ -319,8 +198,7 @@
 
     /// Returns the standard ranges property.
     pub fn ranges<A, P, S>(&self) -> Result<Option<RangesIterator<'a, A, P, S>>> {
-        let ranges = cstr!("ranges");
-        if let Some(cells) = self.getprop_cells(ranges)? {
+        if let Some(cells) = self.getprop_cells(cstr!("ranges"))? {
             let parent = self.parent()?;
             let addr_cells = self.address_cells()?;
             let parent_addr_cells = parent.address_cells()?;
@@ -350,12 +228,11 @@
 
     /// Returns the value of a given <string> property.
     pub fn getprop_str(&self, name: &CStr) -> Result<Option<&CStr>> {
-        let value = if let Some(bytes) = self.getprop(name)? {
-            Some(CStr::from_bytes_with_nul(bytes).map_err(|_| FdtError::BadValue)?)
+        if let Some(bytes) = self.getprop(name)? {
+            Ok(Some(CStr::from_bytes_with_nul(bytes).map_err(|_| FdtError::BadValue)?))
         } else {
-            None
-        };
-        Ok(value)
+            Ok(None)
+        }
     }
 
     /// Returns the value of a given property as an array of cells.
@@ -369,22 +246,20 @@
 
     /// Returns the value of a given <u32> property.
     pub fn getprop_u32(&self, name: &CStr) -> Result<Option<u32>> {
-        let value = if let Some(bytes) = self.getprop(name)? {
-            Some(u32::from_be_bytes(bytes.try_into().map_err(|_| FdtError::BadValue)?))
+        if let Some(bytes) = self.getprop(name)? {
+            Ok(Some(u32::from_be_bytes(bytes.try_into().map_err(|_| FdtError::BadValue)?)))
         } else {
-            None
-        };
-        Ok(value)
+            Ok(None)
+        }
     }
 
     /// Returns the value of a given <u64> property.
     pub fn getprop_u64(&self, name: &CStr) -> Result<Option<u64>> {
-        let value = if let Some(bytes) = self.getprop(name)? {
-            Some(u64::from_be_bytes(bytes.try_into().map_err(|_| FdtError::BadValue)?))
+        if let Some(bytes) = self.getprop(name)? {
+            Ok(Some(u64::from_be_bytes(bytes.try_into().map_err(|_| FdtError::BadValue)?)))
         } else {
-            None
-        };
-        Ok(value)
+            Ok(None)
+        }
     }
 
     /// Returns the value of a given property.
@@ -392,7 +267,7 @@
         if let Some((prop, len)) = Self::getprop_internal(self.fdt, self.offset, name)? {
             Ok(Some(self.fdt.get_from_ptr(prop, len)?))
         } else {
-            Ok(None) // property was not found
+            Ok(None)
         }
     }
 
@@ -436,16 +311,9 @@
 
     /// Returns the compatible node of the given name that is next after this node.
     pub fn next_compatible(self, compatible: &CStr) -> Result<Option<Self>> {
-        // SAFETY: Accesses (read-only) are constrained to the DT totalsize.
-        let ret = unsafe {
-            libfdt_bindgen::fdt_node_offset_by_compatible(
-                self.fdt.as_ptr(),
-                self.offset,
-                compatible.as_ptr(),
-            )
-        };
+        let offset = self.fdt.node_offset_by_compatible(self.offset, compatible)?;
 
-        Ok(fdt_err_or_option(ret)?.map(|offset| Self { fdt: self.fdt, offset }))
+        Ok(offset.map(|offset| Self { fdt: self.fdt, offset }))
     }
 
     /// Returns the first range of `reg` in this node.
@@ -454,17 +322,11 @@
     }
 
     fn address_cells(&self) -> Result<AddrCells> {
-        // SAFETY: Accesses are constrained to the DT totalsize (validated by ctor).
-        unsafe { libfdt_bindgen::fdt_address_cells(self.fdt.as_ptr(), self.offset) }
-            .try_into()
-            .map_err(|_| FdtError::Internal)
+        self.fdt.address_cells(self.offset)?.try_into()
     }
 
     fn size_cells(&self) -> Result<SizeCells> {
-        // SAFETY: Accesses are constrained to the DT totalsize (validated by ctor).
-        unsafe { libfdt_bindgen::fdt_size_cells(self.fdt.as_ptr(), self.offset) }
-            .try_into()
-            .map_err(|_| FdtError::Internal)
+        self.fdt.size_cells(self.offset)?.try_into()
     }
 
     /// Returns an iterator of subnodes
@@ -473,17 +335,15 @@
     }
 
     fn first_subnode(&self) -> Result<Option<Self>> {
-        // SAFETY: Accesses (read-only) are constrained to the DT totalsize.
-        let ret = unsafe { libfdt_bindgen::fdt_first_subnode(self.fdt.as_ptr(), self.offset) };
+        let offset = self.fdt.first_subnode(self.offset)?;
 
-        Ok(fdt_err_or_option(ret)?.map(|offset| FdtNode { fdt: self.fdt, offset }))
+        Ok(offset.map(|offset| Self { fdt: self.fdt, offset }))
     }
 
     fn next_subnode(&self) -> Result<Option<Self>> {
-        // SAFETY: Accesses (read-only) are constrained to the DT totalsize.
-        let ret = unsafe { libfdt_bindgen::fdt_next_subnode(self.fdt.as_ptr(), self.offset) };
+        let offset = self.fdt.next_subnode(self.offset)?;
 
-        Ok(fdt_err_or_option(ret)?.map(|offset| FdtNode { fdt: self.fdt, offset }))
+        Ok(offset.map(|offset| Self { fdt: self.fdt, offset }))
     }
 
     /// Returns an iterator of descendants
@@ -492,15 +352,11 @@
     }
 
     fn next_node(&self, depth: usize) -> Result<Option<(Self, usize)>> {
-        let mut next_depth: c_int = depth.try_into().unwrap();
-        // SAFETY: Accesses (read-only) are constrained to the DT totalsize.
-        let ret = unsafe {
-            libfdt_bindgen::fdt_next_node(self.fdt.as_ptr(), self.offset, &mut next_depth)
-        };
-        let Ok(next_depth) = usize::try_from(next_depth) else {
-            return Ok(None);
-        };
-        Ok(fdt_err_or_option(ret)?.map(|offset| (FdtNode { fdt: self.fdt, offset }, next_depth)))
+        if let Some((offset, depth)) = self.fdt.next_node(self.offset, depth)? {
+            Ok(Some((Self { fdt: self.fdt, offset }, depth)))
+        } else {
+            Ok(None)
+        }
     }
 
     /// Returns an iterator of properties
@@ -513,7 +369,11 @@
             // SAFETY: Accesses (read-only) are constrained to the DT totalsize.
             unsafe { libfdt_bindgen::fdt_first_property_offset(self.fdt.as_ptr(), self.offset) };
 
-        fdt_err_or_option(ret)?.map(|offset| FdtProperty::new(self.fdt, offset)).transpose()
+        if let Some(offset) = fdt_err_or_option(ret)? {
+            Ok(Some(FdtProperty::new(self.fdt, offset)?))
+        } else {
+            Ok(None)
+        }
     }
 
     /// Returns the phandle
@@ -530,28 +390,17 @@
 
     /// Returns the subnode of the given name. The name doesn't need to be nul-terminated.
     pub fn subnode(&self, name: &CStr) -> Result<Option<Self>> {
-        let offset = self.subnode_offset(name.to_bytes())?;
+        let name = name.to_bytes();
+        let offset = self.fdt.subnode_offset_namelen(self.offset, name)?;
+
         Ok(offset.map(|offset| Self { fdt: self.fdt, offset }))
     }
 
     /// Returns the subnode of the given name bytes
     pub fn subnode_with_name_bytes(&self, name: &[u8]) -> Result<Option<Self>> {
-        let offset = self.subnode_offset(name)?;
-        Ok(offset.map(|offset| Self { fdt: self.fdt, offset }))
-    }
+        let offset = self.fdt.subnode_offset_namelen(self.offset, name)?;
 
-    fn subnode_offset(&self, name: &[u8]) -> Result<Option<c_int>> {
-        let namelen = name.len().try_into().unwrap();
-        // SAFETY: Accesses are constrained to the DT totalsize (validated by ctor).
-        let ret = unsafe {
-            libfdt_bindgen::fdt_subnode_offset_namelen(
-                self.fdt.as_ptr(),
-                self.offset,
-                name.as_ptr().cast::<_>(),
-                namelen,
-            )
-        };
-        fdt_err_or_option(ret)
+        Ok(offset.map(|offset| Self { fdt: self.fdt, offset }))
     }
 }
 
@@ -753,126 +602,76 @@
     /// Adds new subnodes to the given node.
     pub fn add_subnodes(&mut self, names: &[&CStr]) -> Result<()> {
         for name in names {
-            self.add_subnode_offset(name.to_bytes())?;
+            self.fdt.add_subnode_namelen(self.offset, name.to_bytes())?;
         }
         Ok(())
     }
 
     /// Adds a new subnode to the given node and return it as a FdtNodeMut on success.
     pub fn add_subnode(&'a mut self, name: &CStr) -> Result<Self> {
-        let offset = self.add_subnode_offset(name.to_bytes())?;
+        let name = name.to_bytes();
+        let offset = self.fdt.add_subnode_namelen(self.offset, name)?;
+
         Ok(Self { fdt: self.fdt, offset })
     }
 
     /// Adds a new subnode to the given node with name and namelen, and returns it as a FdtNodeMut
     /// on success.
     pub fn add_subnode_with_namelen(&'a mut self, name: &CStr, namelen: usize) -> Result<Self> {
-        let offset = { self.add_subnode_offset(&name.to_bytes()[..namelen])? };
-        Ok(Self { fdt: self.fdt, offset })
-    }
+        let name = &name.to_bytes()[..namelen];
+        let offset = self.fdt.add_subnode_namelen(self.offset, name)?;
 
-    fn add_subnode_offset(&mut self, name: &[u8]) -> Result<c_int> {
-        let namelen = name.len().try_into().unwrap();
-        // SAFETY: Accesses are constrained to the DT totalsize (validated by ctor).
-        let ret = unsafe {
-            libfdt_bindgen::fdt_add_subnode_namelen(
-                self.fdt.as_mut_ptr(),
-                self.offset,
-                name.as_ptr().cast::<_>(),
-                namelen,
-            )
-        };
-        fdt_err(ret)
+        Ok(Self { fdt: self.fdt, offset })
     }
 
     /// Returns the first subnode of this
     pub fn first_subnode(&'a mut self) -> Result<Option<Self>> {
-        // SAFETY: Accesses (read-only) are constrained to the DT totalsize.
-        let ret = unsafe { libfdt_bindgen::fdt_first_subnode(self.fdt.as_ptr(), self.offset) };
+        let offset = self.fdt.first_subnode(self.offset)?;
 
-        Ok(fdt_err_or_option(ret)?.map(|offset| Self { fdt: self.fdt, offset }))
+        Ok(offset.map(|offset| Self { fdt: self.fdt, offset }))
     }
 
     /// Returns the next subnode that shares the same parent with this
     pub fn next_subnode(self) -> Result<Option<Self>> {
-        // SAFETY: Accesses (read-only) are constrained to the DT totalsize.
-        let ret = unsafe { libfdt_bindgen::fdt_next_subnode(self.fdt.as_ptr(), self.offset) };
+        let offset = self.fdt.next_subnode(self.offset)?;
 
-        Ok(fdt_err_or_option(ret)?.map(|offset| Self { fdt: self.fdt, offset }))
+        Ok(offset.map(|offset| Self { fdt: self.fdt, offset }))
     }
 
     /// Deletes the current node and returns the next subnode
-    pub fn delete_and_next_subnode(mut self) -> Result<Option<Self>> {
-        // SAFETY: Accesses (read-only) are constrained to the DT totalsize.
-        let ret = unsafe { libfdt_bindgen::fdt_next_subnode(self.fdt.as_ptr(), self.offset) };
+    pub fn delete_and_next_subnode(self) -> Result<Option<Self>> {
+        let next_offset = self.fdt.next_subnode(self.offset)?;
 
-        let next_offset = fdt_err_or_option(ret)?;
-
-        if Some(self.offset) == next_offset {
-            return Err(FdtError::Internal);
-        }
-
-        // SAFETY: nop_self() only touches bytes of the self and its properties and subnodes, and
-        // doesn't alter any other blob in the tree. self.fdt and next_offset would remain valid.
-        unsafe { self.nop_self()? };
-
-        Ok(next_offset.map(|offset| Self { fdt: self.fdt, offset }))
-    }
-
-    fn next_node_offset(&self, depth: usize) -> Result<Option<(c_int, usize)>> {
-        let mut next_depth: c_int = depth.try_into().or(Err(FdtError::BadValue))?;
-        // SAFETY: Accesses (read-only) are constrained to the DT totalsize.
-        let ret = unsafe {
-            libfdt_bindgen::fdt_next_node(self.fdt.as_ptr(), self.offset, &mut next_depth)
-        };
-        let Ok(next_depth) = usize::try_from(next_depth) else {
-            return Ok(None);
-        };
-        Ok(fdt_err_or_option(ret)?.map(|offset| (offset, next_depth)))
+        self.delete_and_next(next_offset)
     }
 
     /// Returns the next node
     pub fn next_node(self, depth: usize) -> Result<Option<(Self, usize)>> {
-        Ok(self
-            .next_node_offset(depth)?
-            .map(|(offset, next_depth)| (FdtNodeMut { fdt: self.fdt, offset }, next_depth)))
+        let next = self.fdt.next_node(self.offset, depth)?;
+
+        Ok(next.map(|(offset, depth)| (Self { fdt: self.fdt, offset }, depth)))
     }
 
     /// Deletes this and returns the next node
-    pub fn delete_and_next_node(mut self, depth: usize) -> Result<Option<(Self, usize)>> {
-        // Skip all would-be-removed descendants.
-        let mut iter = self.next_node_offset(depth)?;
-        while let Some((descendant_offset, descendant_depth)) = iter {
-            if descendant_depth <= depth {
-                break;
-            }
-            let descendant = FdtNodeMut { fdt: self.fdt, offset: descendant_offset };
-            iter = descendant.next_node_offset(descendant_depth)?;
+    pub fn delete_and_next_node(self, depth: usize) -> Result<Option<(Self, usize)>> {
+        let next_node = self.fdt.next_node_skip_subnodes(self.offset, depth)?;
+        if let Some((offset, depth)) = next_node {
+            let next_node = self.delete_and_next(Some(offset))?.unwrap();
+            Ok(Some((next_node, depth)))
+        } else {
+            Ok(None)
         }
-        // SAFETY: This consumes self, so invalid node wouldn't be used any further
-        unsafe { self.nop_self()? };
-        Ok(iter.map(|(offset, next_depth)| (FdtNodeMut { fdt: self.fdt, offset }, next_depth)))
     }
 
     fn parent(&'a self) -> Result<FdtNode<'a>> {
-        // SAFETY: Accesses (read-only) are constrained to the DT totalsize.
-        let ret = unsafe { libfdt_bindgen::fdt_parent_offset(self.fdt.as_ptr(), self.offset) };
-
-        Ok(FdtNode { fdt: &*self.fdt, offset: fdt_err(ret)? })
+        self.as_node().parent()
     }
 
     /// Returns the compatible node of the given name that is next after this node.
     pub fn next_compatible(self, compatible: &CStr) -> Result<Option<Self>> {
-        // SAFETY: Accesses (read-only) are constrained to the DT totalsize.
-        let ret = unsafe {
-            libfdt_bindgen::fdt_node_offset_by_compatible(
-                self.fdt.as_ptr(),
-                self.offset,
-                compatible.as_ptr(),
-            )
-        };
+        let offset = self.fdt.node_offset_by_compatible(self.offset, compatible)?;
 
-        Ok(fdt_err_or_option(ret)?.map(|offset| Self { fdt: self.fdt, offset }))
+        Ok(offset.map(|offset| Self { fdt: self.fdt, offset }))
     }
 
     /// Deletes the node effectively by overwriting this node and its subtree with nop tags.
@@ -887,43 +686,25 @@
     // node, and delete the current node, the Rust borrow checker kicks in. The next node has a
     // mutable reference to DT, so we can't use current node (which also has a mutable reference to
     // DT).
-    pub fn delete_and_next_compatible(mut self, compatible: &CStr) -> Result<Option<Self>> {
-        // SAFETY: Accesses (read-only) are constrained to the DT totalsize.
-        let ret = unsafe {
-            libfdt_bindgen::fdt_node_offset_by_compatible(
-                self.fdt.as_ptr(),
-                self.offset,
-                compatible.as_ptr(),
-            )
-        };
-        let next_offset = fdt_err_or_option(ret)?;
+    pub fn delete_and_next_compatible(self, compatible: &CStr) -> Result<Option<Self>> {
+        let next_offset = self.fdt.node_offset_by_compatible(self.offset, compatible)?;
 
+        self.delete_and_next(next_offset)
+    }
+
+    fn delete_and_next(self, next_offset: Option<c_int>) -> Result<Option<Self>> {
         if Some(self.offset) == next_offset {
             return Err(FdtError::Internal);
         }
 
-        // SAFETY: nop_self() only touches bytes of the self and its properties and subnodes, and
-        // doesn't alter any other blob in the tree. self.fdt and next_offset would remain valid.
-        unsafe { self.nop_self()? };
+        self.fdt.nop_node(self.offset)?;
 
         Ok(next_offset.map(|offset| Self { fdt: self.fdt, offset }))
     }
 
     /// Deletes this node effectively from DT, by setting it with FDT_NOP
-    pub fn nop(mut self) -> Result<()> {
-        // SAFETY: This consumes self, so invalid node wouldn't be used any further
-        unsafe { self.nop_self() }
-    }
-
-    /// Deletes this node effectively from DT, by setting it with FDT_NOP.
-    /// This only changes bytes of the node and its properties and subnodes, and doesn't alter or
-    /// move any other part of the tree.
-    /// SAFETY: This node is no longer valid.
-    unsafe fn nop_self(&mut self) -> Result<()> {
-        // SAFETY: Accesses are constrained to the DT totalsize (validated by ctor).
-        let ret = unsafe { libfdt_bindgen::fdt_nop_node(self.fdt.as_mut_ptr(), self.offset) };
-
-        fdt_err_expect_zero(ret)
+    pub fn nop(self) -> Result<()> {
+        self.fdt.nop_node(self.offset)
     }
 }
 
@@ -934,14 +715,31 @@
     buffer: [u8],
 }
 
+// SAFETY: Fdt calls check_full() before safely returning a &Self, making it impossible for trait
+// methods to be called on invalid device trees.
+unsafe impl Libfdt for Fdt {
+    fn as_fdt_slice(&self) -> &[u8] {
+        &self.buffer[..self.totalsize()]
+    }
+}
+
+// SAFETY: Fdt calls check_full() before safely returning a &Self, making it impossible for trait
+// methods to be called on invalid device trees.
+unsafe impl LibfdtMut for Fdt {
+    fn as_fdt_slice_mut(&mut self) -> &mut [u8] {
+        &mut self.buffer
+    }
+}
+
 impl Fdt {
     /// Wraps a slice containing a Flattened Device Tree.
     ///
     /// Fails if the FDT does not pass validation.
     pub fn from_slice(fdt: &[u8]) -> Result<&Self> {
-        // SAFETY: The FDT will be validated before it is returned.
+        libfdt::check_full(fdt)?;
+        // SAFETY: The FDT was validated.
         let fdt = unsafe { Self::unchecked_from_slice(fdt) };
-        fdt.check_full()?;
+
         Ok(fdt)
     }
 
@@ -949,67 +747,58 @@
     ///
     /// Fails if the FDT does not pass validation.
     pub fn from_mut_slice(fdt: &mut [u8]) -> Result<&mut Self> {
-        // SAFETY: The FDT will be validated before it is returned.
+        libfdt::check_full(fdt)?;
+        // SAFETY: The FDT was validated.
         let fdt = unsafe { Self::unchecked_from_mut_slice(fdt) };
-        fdt.check_full()?;
+
         Ok(fdt)
     }
 
     /// Creates an empty Flattened Device Tree with a mutable slice.
     pub fn create_empty_tree(fdt: &mut [u8]) -> Result<&mut Self> {
-        // SAFETY: fdt_create_empty_tree() only write within the specified length,
-        //          and returns error if buffer was insufficient.
-        //          There will be no memory write outside of the given fdt.
-        let ret = unsafe {
-            libfdt_bindgen::fdt_create_empty_tree(
-                fdt.as_mut_ptr().cast::<c_void>(),
-                fdt.len() as i32,
-            )
-        };
-        fdt_err_expect_zero(ret)?;
+        libfdt::create_empty_tree(fdt)?;
 
-        // SAFETY: The FDT will be validated before it is returned.
-        let fdt = unsafe { Self::unchecked_from_mut_slice(fdt) };
-        fdt.check_full()?;
-
-        Ok(fdt)
+        Self::from_mut_slice(fdt)
     }
 
     /// Wraps a slice containing a Flattened Device Tree.
     ///
     /// # Safety
     ///
-    /// The returned FDT might be invalid, only use on slices containing a valid DT.
+    /// It is undefined to call this function on a slice that does not contain a valid device tree.
     pub unsafe fn unchecked_from_slice(fdt: &[u8]) -> &Self {
-        // SAFETY: Fdt is a wrapper around a [u8], so the transmute is valid. The caller is
-        // responsible for ensuring that it is actually a valid FDT.
-        unsafe { mem::transmute::<&[u8], &Self>(fdt) }
+        let self_ptr = fdt as *const _ as *const _;
+        // SAFETY: The pointer is non-null, dereferenceable, and points to allocated memory.
+        unsafe { &*self_ptr }
     }
 
     /// Wraps a mutable slice containing a Flattened Device Tree.
     ///
     /// # Safety
     ///
-    /// The returned FDT might be invalid, only use on slices containing a valid DT.
+    /// It is undefined to call this function on a slice that does not contain a valid device tree.
     pub unsafe fn unchecked_from_mut_slice(fdt: &mut [u8]) -> &mut Self {
-        // SAFETY: Fdt is a wrapper around a [u8], so the transmute is valid. The caller is
-        // responsible for ensuring that it is actually a valid FDT.
-        unsafe { mem::transmute::<&mut [u8], &mut Self>(fdt) }
+        let self_mut_ptr = fdt as *mut _ as *mut _;
+        // SAFETY: The pointer is non-null, dereferenceable, and points to allocated memory.
+        unsafe { &mut *self_mut_ptr }
     }
 
-    /// Updates this FDT from a slice containing another FDT.
-    pub fn copy_from_slice(&mut self, new_fdt: &[u8]) -> Result<()> {
-        if self.buffer.len() < new_fdt.len() {
-            Err(FdtError::NoSpace)
-        } else {
-            let totalsize = self.totalsize();
-            self.buffer[..new_fdt.len()].clone_from_slice(new_fdt);
-            // Zeroize the remaining part. We zeroize up to the size of the original DT because
-            // zeroizing the entire buffer (max 2MB) is not necessary and may increase the VM boot
-            // time.
-            self.buffer[new_fdt.len()..max(new_fdt.len(), totalsize)].fill(0_u8);
-            Ok(())
+    /// Updates this FDT from another FDT.
+    pub fn clone_from(&mut self, other: &Self) -> Result<()> {
+        let new_len = other.buffer.len();
+        if self.buffer.len() < new_len {
+            return Err(FdtError::NoSpace);
         }
+
+        let zeroed_len = self.totalsize().checked_sub(new_len);
+        let (cloned, zeroed) = self.buffer.split_at_mut(new_len);
+
+        cloned.clone_from_slice(&other.buffer);
+        if let Some(len) = zeroed_len {
+            zeroed[..len].fill(0);
+        }
+
+        Ok(())
     }
 
     /// Unpacks the DT to cover the whole slice it is contained in.
@@ -1056,11 +845,8 @@
     ///
     /// NOTE: This does not support individual "/memory@XXXX" banks.
     pub fn memory(&self) -> Result<MemRegIterator> {
-        let memory_node_name = cstr!("/memory");
-        let memory_device_type = cstr!("memory");
-
-        let node = self.node(memory_node_name)?.ok_or(FdtError::NotFound)?;
-        if node.device_type()? != Some(memory_device_type) {
+        let node = self.node(cstr!("/memory"))?.ok_or(FdtError::NotFound)?;
+        if node.device_type()? != Some(cstr!("memory")) {
             return Err(FdtError::BadValue);
         }
         node.reg()?.ok_or(FdtError::BadValue).map(MemRegIterator::new)
@@ -1098,7 +884,9 @@
 
     /// Returns a tree node by its full path.
     pub fn node(&self, path: &CStr) -> Result<Option<FdtNode>> {
-        Ok(self.path_offset(path.to_bytes())?.map(|offset| FdtNode { fdt: self, offset }))
+        let offset = self.path_offset_namelen(path.to_bytes())?;
+
+        Ok(offset.map(|offset| FdtNode { fdt: self, offset }))
     }
 
     /// Iterate over nodes with a given compatible string.
@@ -1141,34 +929,26 @@
 
     /// Returns a mutable tree node by its full path.
     pub fn node_mut(&mut self, path: &CStr) -> Result<Option<FdtNodeMut>> {
-        Ok(self.path_offset(path.to_bytes())?.map(|offset| FdtNodeMut { fdt: self, offset }))
+        let offset = self.path_offset_namelen(path.to_bytes())?;
+
+        Ok(offset.map(|offset| FdtNodeMut { fdt: self, offset }))
+    }
+
+    fn next_node_skip_subnodes(&self, node: c_int, depth: usize) -> Result<Option<(c_int, usize)>> {
+        let mut iter = self.next_node(node, depth)?;
+        while let Some((offset, next_depth)) = iter {
+            if next_depth <= depth {
+                return Ok(Some((offset, next_depth)));
+            }
+            iter = self.next_node(offset, next_depth)?;
+        }
+
+        Ok(None)
     }
 
     /// Returns the device tree as a slice (may be smaller than the containing buffer).
     pub fn as_slice(&self) -> &[u8] {
-        &self.buffer[..self.totalsize()]
-    }
-
-    fn path_offset(&self, path: &[u8]) -> Result<Option<c_int>> {
-        let len = path.len().try_into().map_err(|_| FdtError::BadPath)?;
-        // SAFETY: Accesses are constrained to the DT totalsize (validated by ctor) and the
-        // function respects the passed number of characters.
-        let ret = unsafe {
-            // *_namelen functions don't include the trailing nul terminator in 'len'.
-            libfdt_bindgen::fdt_path_offset_namelen(self.as_ptr(), path.as_ptr().cast::<_>(), len)
-        };
-
-        fdt_err_or_option(ret)
-    }
-
-    fn check_full(&self) -> Result<()> {
-        // SAFETY: Only performs read accesses within the limits of the slice. If successful, this
-        // call guarantees to other unsafe calls that the header contains a valid totalsize (w.r.t.
-        // 'len' i.e. the self.fdt slice) that those C functions can use to perform bounds
-        // checking. The library doesn't maintain an internal state (such as pointers) between
-        // calls as it expects the client code to keep track of the objects (DT, nodes, ...).
-        let ret = unsafe { libfdt_bindgen::fdt_check_full(self.as_ptr(), self.capacity()) };
-        fdt_err_expect_zero(ret)
+        self.as_fdt_slice()
     }
 
     fn get_from_ptr(&self, ptr: *const c_void, len: usize) -> Result<&[u8]> {
@@ -1190,7 +970,7 @@
 
     /// Returns a shared pointer to the device tree.
     pub fn as_ptr(&self) -> *const c_void {
-        self.buffer.as_ptr().cast::<_>()
+        self.buffer.as_ptr().cast()
     }
 
     fn as_mut_ptr(&mut self) -> *mut c_void {
@@ -1202,7 +982,7 @@
     }
 
     fn header(&self) -> &libfdt_bindgen::fdt_header {
-        let p = self.as_ptr().cast::<_>();
+        let p = self.as_ptr().cast();
         // SAFETY: A valid FDT (verified by constructor) must contain a valid fdt_header.
         unsafe { &*p }
     }
diff --git a/libs/libfdt/src/libfdt.rs b/libs/libfdt/src/libfdt.rs
new file mode 100644
index 0000000..7e3b65a
--- /dev/null
+++ b/libs/libfdt/src/libfdt.rs
@@ -0,0 +1,219 @@
+// Copyright 2024, 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.
+
+//! Low-level libfdt_bindgen wrapper, easy to integrate safely in higher-level APIs.
+//!
+//! These traits decouple the safe libfdt C function calls from the representation of those
+//! user-friendly higher-level types, allowing the trait to be shared between different ones,
+//! adapted to their use-cases (e.g. alloc-based userspace or statically allocated no_std).
+
+use core::ffi::{c_int, CStr};
+use core::ptr;
+
+use crate::{fdt_err, fdt_err_expect_zero, fdt_err_or_option, FdtError, Result};
+
+// Function names are the C function names without the `fdt_` prefix.
+
+/// Safe wrapper around `fdt_create_empty_tree()` (C function).
+pub(crate) fn create_empty_tree(fdt: &mut [u8]) -> Result<()> {
+    let len = fdt.len().try_into().unwrap();
+    let fdt = fdt.as_mut_ptr().cast();
+    // SAFETY: fdt_create_empty_tree() only write within the specified length,
+    //          and returns error if buffer was insufficient.
+    //          There will be no memory write outside of the given fdt.
+    let ret = unsafe { libfdt_bindgen::fdt_create_empty_tree(fdt, len) };
+
+    fdt_err_expect_zero(ret)
+}
+
+/// Safe wrapper around `fdt_check_full()` (C function).
+pub(crate) fn check_full(fdt: &[u8]) -> Result<()> {
+    let len = fdt.len();
+    let fdt = fdt.as_ptr().cast();
+    // SAFETY: Only performs read accesses within the limits of the slice. If successful, this
+    // call guarantees to other unsafe calls that the header contains a valid totalsize (w.r.t.
+    // 'len' i.e. the self.fdt slice) that those C functions can use to perform bounds
+    // checking. The library doesn't maintain an internal state (such as pointers) between
+    // calls as it expects the client code to keep track of the objects (DT, nodes, ...).
+    let ret = unsafe { libfdt_bindgen::fdt_check_full(fdt, len) };
+
+    fdt_err_expect_zero(ret)
+}
+
+/// Wrapper for the read-only libfdt.h functions.
+///
+/// # Safety
+///
+/// Implementors must ensure that at any point where a method of this trait is called, the
+/// underlying type returns the bytes of a valid device tree (as validated by `check_full`)
+/// through its `.as_fdt_slice` method.
+pub(crate) unsafe trait Libfdt {
+    /// Provides an immutable slice containing the device tree.
+    ///
+    /// The implementation must ensure that the size of the returned slice and
+    /// `fdt_header::totalsize` match.
+    fn as_fdt_slice(&self) -> &[u8];
+
+    /// Safe wrapper around `fdt_path_offset_namelen()` (C function).
+    fn path_offset_namelen(&self, path: &[u8]) -> Result<Option<c_int>> {
+        let fdt = self.as_fdt_slice().as_ptr().cast();
+        // *_namelen functions don't include the trailing nul terminator in 'len'.
+        let len = path.len().try_into().map_err(|_| FdtError::BadPath)?;
+        let path = path.as_ptr().cast();
+        // SAFETY: Accesses are constrained to the DT totalsize (validated by ctor) and the
+        // function respects the passed number of characters.
+        let ret = unsafe { libfdt_bindgen::fdt_path_offset_namelen(fdt, path, len) };
+
+        fdt_err_or_option(ret)
+    }
+
+    /// Safe wrapper around `fdt_node_offset_by_compatible()` (C function).
+    fn node_offset_by_compatible(&self, prev: c_int, compatible: &CStr) -> Result<Option<c_int>> {
+        let fdt = self.as_fdt_slice().as_ptr().cast();
+        let compatible = compatible.as_ptr();
+        // SAFETY: Accesses (read-only) are constrained to the DT totalsize.
+        let ret = unsafe { libfdt_bindgen::fdt_node_offset_by_compatible(fdt, prev, compatible) };
+
+        fdt_err_or_option(ret)
+    }
+
+    /// Safe wrapper around `fdt_next_node()` (C function).
+    fn next_node(&self, node: c_int, depth: usize) -> Result<Option<(c_int, usize)>> {
+        let fdt = self.as_fdt_slice().as_ptr().cast();
+        let mut depth = depth.try_into().unwrap();
+        // SAFETY: Accesses (read-only) are constrained to the DT totalsize.
+        let ret = unsafe { libfdt_bindgen::fdt_next_node(fdt, node, &mut depth) };
+
+        match fdt_err_or_option(ret)? {
+            Some(offset) if depth >= 0 => {
+                let depth = depth.try_into().unwrap();
+                Ok(Some((offset, depth)))
+            }
+            _ => Ok(None),
+        }
+    }
+
+    /// Safe wrapper around `fdt_parent_offset()` (C function).
+    ///
+    /// Note that this function returns a `Err` when called on a root.
+    fn parent_offset(&self, node: c_int) -> Result<c_int> {
+        let fdt = self.as_fdt_slice().as_ptr().cast();
+        // SAFETY: Accesses (read-only) are constrained to the DT totalsize.
+        let ret = unsafe { libfdt_bindgen::fdt_parent_offset(fdt, node) };
+
+        fdt_err(ret)
+    }
+
+    /// Safe wrapper around `fdt_supernode_atdepth_offset()` (C function).
+    ///
+    /// Note that this function returns a `Err` when called on a node at a depth shallower than
+    /// the provided `depth`.
+    fn supernode_atdepth_offset(&self, node: c_int, depth: usize) -> Result<c_int> {
+        let fdt = self.as_fdt_slice().as_ptr().cast();
+        let depth = depth.try_into().unwrap();
+        let nodedepth = ptr::null_mut();
+        let ret =
+            // SAFETY: Accesses (read-only) are constrained to the DT totalsize.
+            unsafe { libfdt_bindgen::fdt_supernode_atdepth_offset(fdt, node, depth, nodedepth) };
+
+        fdt_err(ret)
+    }
+
+    /// Safe wrapper around `fdt_subnode_offset_namelen()` (C function).
+    fn subnode_offset_namelen(&self, parent: c_int, name: &[u8]) -> Result<Option<c_int>> {
+        let fdt = self.as_fdt_slice().as_ptr().cast();
+        let namelen = name.len().try_into().unwrap();
+        let name = name.as_ptr().cast();
+        // SAFETY: Accesses are constrained to the DT totalsize (validated by ctor).
+        let ret = unsafe { libfdt_bindgen::fdt_subnode_offset_namelen(fdt, parent, name, namelen) };
+
+        fdt_err_or_option(ret)
+    }
+    /// Safe wrapper around `fdt_first_subnode()` (C function).
+    fn first_subnode(&self, node: c_int) -> Result<Option<c_int>> {
+        let fdt = self.as_fdt_slice().as_ptr().cast();
+        // SAFETY: Accesses (read-only) are constrained to the DT totalsize.
+        let ret = unsafe { libfdt_bindgen::fdt_first_subnode(fdt, node) };
+
+        fdt_err_or_option(ret)
+    }
+
+    /// Safe wrapper around `fdt_next_subnode()` (C function).
+    fn next_subnode(&self, node: c_int) -> Result<Option<c_int>> {
+        let fdt = self.as_fdt_slice().as_ptr().cast();
+        // SAFETY: Accesses (read-only) are constrained to the DT totalsize.
+        let ret = unsafe { libfdt_bindgen::fdt_next_subnode(fdt, node) };
+
+        fdt_err_or_option(ret)
+    }
+
+    /// Safe wrapper around `fdt_address_cells()` (C function).
+    fn address_cells(&self, node: c_int) -> Result<usize> {
+        let fdt = self.as_fdt_slice().as_ptr().cast();
+        // SAFETY: Accesses are constrained to the DT totalsize (validated by ctor).
+        let ret = unsafe { libfdt_bindgen::fdt_address_cells(fdt, node) };
+
+        Ok(fdt_err(ret)?.try_into().unwrap())
+    }
+
+    /// Safe wrapper around `fdt_size_cells()` (C function).
+    fn size_cells(&self, node: c_int) -> Result<usize> {
+        let fdt = self.as_fdt_slice().as_ptr().cast();
+        // SAFETY: Accesses are constrained to the DT totalsize (validated by ctor).
+        let ret = unsafe { libfdt_bindgen::fdt_size_cells(fdt, node) };
+
+        Ok(fdt_err(ret)?.try_into().unwrap())
+    }
+}
+
+/// Wrapper for the read-write libfdt.h functions.
+///
+/// # Safety
+///
+/// Implementors must ensure that at any point where a method of this trait is called, the
+/// underlying type returns the bytes of a valid device tree (as validated by `check_full`)
+/// through its `.as_fdt_slice_mut` method.
+///
+/// Some methods may make previously returned values such as node or string offsets or phandles
+/// invalid by modifying the device tree (e.g. by inserting or removing new nodes or properties).
+/// As most methods take or return such values, instead of marking them all as unsafe, this trait
+/// is marked as unsafe as implementors must ensure that methods that modify the validity of those
+/// values are never called while the values are still in use.
+pub(crate) unsafe trait LibfdtMut {
+    /// Provides a mutable pointer to a buffer containing the device tree.
+    ///
+    /// The implementation must ensure that the size of the returned slice is at least
+    /// `fdt_header::totalsize`, to allow for device tree growth.
+    fn as_fdt_slice_mut(&mut self) -> &mut [u8];
+
+    /// Safe wrapper around `fdt_nop_node()` (C function).
+    fn nop_node(&mut self, node: c_int) -> Result<()> {
+        let fdt = self.as_fdt_slice_mut().as_mut_ptr().cast();
+        // SAFETY: Accesses are constrained to the DT totalsize (validated by ctor).
+        let ret = unsafe { libfdt_bindgen::fdt_nop_node(fdt, node) };
+
+        fdt_err_expect_zero(ret)
+    }
+
+    /// Safe wrapper around `fdt_add_subnode_namelen()` (C function).
+    fn add_subnode_namelen(&mut self, node: c_int, name: &[u8]) -> Result<c_int> {
+        let fdt = self.as_fdt_slice_mut().as_mut_ptr().cast();
+        let namelen = name.len().try_into().unwrap();
+        let name = name.as_ptr().cast();
+        // SAFETY: Accesses are constrained to the DT totalsize (validated by ctor).
+        let ret = unsafe { libfdt_bindgen::fdt_add_subnode_namelen(fdt, node, name, namelen) };
+
+        fdt_err(ret)
+    }
+}
diff --git a/libs/libfdt/src/result.rs b/libs/libfdt/src/result.rs
new file mode 100644
index 0000000..9643e1e
--- /dev/null
+++ b/libs/libfdt/src/result.rs
@@ -0,0 +1,139 @@
+// Copyright 2024, 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.
+
+//! Rust types related to the libfdt C integer results.
+
+use core::ffi::c_int;
+use core::fmt;
+use core::result;
+
+/// Error type corresponding to libfdt error codes.
+#[derive(Clone, Copy, Debug, Eq, PartialEq)]
+pub enum FdtError {
+    /// FDT_ERR_NOTFOUND
+    NotFound,
+    /// FDT_ERR_EXISTS
+    Exists,
+    /// FDT_ERR_NOSPACE
+    NoSpace,
+    /// FDT_ERR_BADOFFSET
+    BadOffset,
+    /// FDT_ERR_BADPATH
+    BadPath,
+    /// FDT_ERR_BADPHANDLE
+    BadPhandle,
+    /// FDT_ERR_BADSTATE
+    BadState,
+    /// FDT_ERR_TRUNCATED
+    Truncated,
+    /// FDT_ERR_BADMAGIC
+    BadMagic,
+    /// FDT_ERR_BADVERSION
+    BadVersion,
+    /// FDT_ERR_BADSTRUCTURE
+    BadStructure,
+    /// FDT_ERR_BADLAYOUT
+    BadLayout,
+    /// FDT_ERR_INTERNAL
+    Internal,
+    /// FDT_ERR_BADNCELLS
+    BadNCells,
+    /// FDT_ERR_BADVALUE
+    BadValue,
+    /// FDT_ERR_BADOVERLAY
+    BadOverlay,
+    /// FDT_ERR_NOPHANDLES
+    NoPhandles,
+    /// FDT_ERR_BADFLAGS
+    BadFlags,
+    /// FDT_ERR_ALIGNMENT
+    Alignment,
+    /// Unexpected error code
+    Unknown(i32),
+}
+
+impl fmt::Display for FdtError {
+    /// Prints error messages from libfdt.h documentation.
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match self {
+            Self::NotFound => write!(f, "The requested node or property does not exist"),
+            Self::Exists => write!(f, "Attempted to create an existing node or property"),
+            Self::NoSpace => write!(f, "Insufficient buffer space to contain the expanded tree"),
+            Self::BadOffset => write!(f, "Structure block offset is out-of-bounds or invalid"),
+            Self::BadPath => write!(f, "Badly formatted path"),
+            Self::BadPhandle => write!(f, "Invalid phandle length or value"),
+            Self::BadState => write!(f, "Received incomplete device tree"),
+            Self::Truncated => write!(f, "Device tree or sub-block is improperly terminated"),
+            Self::BadMagic => write!(f, "Device tree header missing its magic number"),
+            Self::BadVersion => write!(f, "Device tree has a version which can't be handled"),
+            Self::BadStructure => write!(f, "Device tree has a corrupt structure block"),
+            Self::BadLayout => write!(f, "Device tree sub-blocks in unsupported order"),
+            Self::Internal => write!(f, "libfdt has failed an internal assertion"),
+            Self::BadNCells => write!(f, "Bad format or value of #address-cells or #size-cells"),
+            Self::BadValue => write!(f, "Unexpected property value"),
+            Self::BadOverlay => write!(f, "Overlay cannot be applied"),
+            Self::NoPhandles => write!(f, "Device tree doesn't have any phandle available anymore"),
+            Self::BadFlags => write!(f, "Invalid flag or invalid combination of flags"),
+            Self::Alignment => write!(f, "Device tree base address is not 8-byte aligned"),
+            Self::Unknown(e) => write!(f, "Unknown libfdt error '{e}'"),
+        }
+    }
+}
+
+/// Result type with FdtError enum.
+pub type Result<T> = result::Result<T, FdtError>;
+
+pub(crate) fn fdt_err(val: c_int) -> Result<c_int> {
+    if val >= 0 {
+        Ok(val)
+    } else {
+        Err(match -val as _ {
+            libfdt_bindgen::FDT_ERR_NOTFOUND => FdtError::NotFound,
+            libfdt_bindgen::FDT_ERR_EXISTS => FdtError::Exists,
+            libfdt_bindgen::FDT_ERR_NOSPACE => FdtError::NoSpace,
+            libfdt_bindgen::FDT_ERR_BADOFFSET => FdtError::BadOffset,
+            libfdt_bindgen::FDT_ERR_BADPATH => FdtError::BadPath,
+            libfdt_bindgen::FDT_ERR_BADPHANDLE => FdtError::BadPhandle,
+            libfdt_bindgen::FDT_ERR_BADSTATE => FdtError::BadState,
+            libfdt_bindgen::FDT_ERR_TRUNCATED => FdtError::Truncated,
+            libfdt_bindgen::FDT_ERR_BADMAGIC => FdtError::BadMagic,
+            libfdt_bindgen::FDT_ERR_BADVERSION => FdtError::BadVersion,
+            libfdt_bindgen::FDT_ERR_BADSTRUCTURE => FdtError::BadStructure,
+            libfdt_bindgen::FDT_ERR_BADLAYOUT => FdtError::BadLayout,
+            libfdt_bindgen::FDT_ERR_INTERNAL => FdtError::Internal,
+            libfdt_bindgen::FDT_ERR_BADNCELLS => FdtError::BadNCells,
+            libfdt_bindgen::FDT_ERR_BADVALUE => FdtError::BadValue,
+            libfdt_bindgen::FDT_ERR_BADOVERLAY => FdtError::BadOverlay,
+            libfdt_bindgen::FDT_ERR_NOPHANDLES => FdtError::NoPhandles,
+            libfdt_bindgen::FDT_ERR_BADFLAGS => FdtError::BadFlags,
+            libfdt_bindgen::FDT_ERR_ALIGNMENT => FdtError::Alignment,
+            _ => FdtError::Unknown(val),
+        })
+    }
+}
+
+pub(crate) fn fdt_err_expect_zero(val: c_int) -> Result<()> {
+    match fdt_err(val)? {
+        0 => Ok(()),
+        _ => Err(FdtError::Unknown(val)),
+    }
+}
+
+pub(crate) fn fdt_err_or_option(val: c_int) -> Result<Option<c_int>> {
+    match fdt_err(val) {
+        Ok(val) => Ok(Some(val)),
+        Err(FdtError::NotFound) => Ok(None),
+        Err(e) => Err(e),
+    }
+}
diff --git a/microdroid/kdump/Android.bp b/microdroid/kdump/Android.bp
index ff73fdb..5d129f4 100644
--- a/microdroid/kdump/Android.bp
+++ b/microdroid/kdump/Android.bp
@@ -5,6 +5,7 @@
 
 cc_binary {
     name: "microdroid_kexec",
+    defaults: ["avf_build_flags_cc"],
     stem: "kexec_load",
     srcs: ["kexec.c"],
     installable: false,
@@ -14,6 +15,7 @@
 
 cc_binary {
     name: "microdroid_crashdump",
+    defaults: ["avf_build_flags_cc"],
     stem: "crashdump",
     srcs: ["crashdump.c"],
     static_executable: true,
diff --git a/microdroid/payload/Android.bp b/microdroid/payload/Android.bp
index 7e11de3..e67a6d5 100644
--- a/microdroid/payload/Android.bp
+++ b/microdroid/payload/Android.bp
@@ -5,6 +5,7 @@
 
 cc_defaults {
     name: "microdroid_metadata_default",
+    defaults: ["avf_build_flags_cc"],
     host_supported: true,
     srcs: [
         "metadata.proto",
diff --git a/pvmfw/Android.bp b/pvmfw/Android.bp
index ee77f14..110d46a 100644
--- a/pvmfw/Android.bp
+++ b/pvmfw/Android.bp
@@ -295,6 +295,7 @@
 // numbers defined in the ARM DT binding headers
 cc_object {
     name: "pvmfw_platform.dts.preprocessed",
+    defaults: ["avf_build_flags_cc"],
     header_libs: ["arm_dt_bindings_headers"],
     host_supported: true,
     srcs: [":pvmfw_platform.dts.renamed"],
diff --git a/pvmfw/src/fdt.rs b/pvmfw/src/fdt.rs
index d2aad61..ac52be9 100644
--- a/pvmfw/src/fdt.rs
+++ b/pvmfw/src/fdt.rs
@@ -35,12 +35,12 @@
 use libfdt::CellIterator;
 use libfdt::Fdt;
 use libfdt::FdtError;
-use libfdt::FdtNode;
 use libfdt::FdtNodeMut;
 use log::debug;
 use log::error;
 use log::info;
 use log::warn;
+use static_assertions::const_assert;
 use tinyvec::ArrayVec;
 use vmbase::fdt::SwiotlbInfo;
 use vmbase::layout::{crosvm::MEM_START, MAX_VIRT_ADDR};
@@ -172,33 +172,40 @@
         .setprop_inplace(cstr!("reg"), [addr.to_be(), size.to_be()].as_bytes())
 }
 
-/// Read the number of CPUs from DT
-fn read_num_cpus_from(fdt: &Fdt) -> libfdt::Result<usize> {
-    Ok(fdt.compatible_nodes(cstr!("arm,arm-v8"))?.count())
-}
+#[derive(Debug, Default)]
+struct CpuInfo {}
 
-/// Validate number of CPUs
-fn validate_num_cpus(num_cpus: usize) -> Result<(), FdtValidationError> {
-    if num_cpus == 0 || DeviceTreeInfo::gic_patched_size(num_cpus).is_none() {
-        Err(FdtValidationError::InvalidCpuCount(num_cpus))
-    } else {
-        Ok(())
+fn read_cpu_info_from(fdt: &Fdt) -> libfdt::Result<ArrayVec<[CpuInfo; DeviceTreeInfo::MAX_CPUS]>> {
+    let mut cpus = ArrayVec::new();
+
+    let mut cpu_nodes = fdt.compatible_nodes(cstr!("arm,arm-v8"))?;
+    for _cpu in cpu_nodes.by_ref().take(cpus.capacity()) {
+        let info = CpuInfo {};
+        cpus.push(info);
     }
+    if cpu_nodes.next().is_some() {
+        warn!("DT has more than {} CPU nodes: discarding extra nodes.", cpus.capacity());
+    }
+
+    Ok(cpus)
 }
 
-/// Patch DT by keeping `num_cpus` number of arm,arm-v8 compatible nodes, and pruning the rest.
-fn patch_num_cpus(fdt: &mut Fdt, num_cpus: usize) -> libfdt::Result<()> {
-    let cpu = cstr!("arm,arm-v8");
-    let mut next = fdt.root_mut()?.next_compatible(cpu)?;
-    for _ in 0..num_cpus {
-        next = if let Some(current) = next {
-            current.next_compatible(cpu)?
-        } else {
-            return Err(FdtError::NoSpace);
-        };
+fn validate_cpu_info(cpus: &[CpuInfo]) -> Result<(), FdtValidationError> {
+    if cpus.is_empty() {
+        return Err(FdtValidationError::InvalidCpuCount(0));
+    }
+
+    Ok(())
+}
+
+fn patch_cpus(fdt: &mut Fdt, cpus: &[CpuInfo]) -> libfdt::Result<()> {
+    const COMPAT: &CStr = cstr!("arm,arm-v8");
+    let mut next = fdt.root_mut()?.next_compatible(COMPAT)?;
+    for _cpu in cpus {
+        next = next.ok_or(FdtError::NoSpace)?.next_compatible(COMPAT)?;
     }
     while let Some(current) = next {
-        next = current.delete_and_next_compatible(cpu)?;
+        next = current.delete_and_next_compatible(COMPAT)?;
     }
     Ok(())
 }
@@ -507,11 +514,8 @@
     let name = cstr!("ns16550a");
     let mut next = fdt.root_mut()?.next_compatible(name);
     while let Some(current) = next? {
-        let reg = FdtNode::from_mut(&current)
-            .reg()?
-            .ok_or(FdtError::NotFound)?
-            .next()
-            .ok_or(FdtError::NotFound)?;
+        let reg =
+            current.as_node().reg()?.ok_or(FdtError::NotFound)?.next().ok_or(FdtError::NotFound)?;
         next = if !serial_info.addrs.contains(&reg.addr) {
             current.delete_and_next_compatible(name)
         } else {
@@ -582,7 +586,8 @@
     let mut range1 = ranges.next().ok_or(FdtError::NotFound)?;
 
     let addr = range0.addr;
-    // `validate_num_cpus()` checked that this wouldn't panic
+    // `read_cpu_info_from()` guarantees that we have at most MAX_CPUS.
+    const_assert!(DeviceTreeInfo::gic_patched_size(DeviceTreeInfo::MAX_CPUS).is_some());
     let size = u64::try_from(DeviceTreeInfo::gic_patched_size(num_cpus).unwrap()).unwrap();
 
     // range1 is just below range0
@@ -628,7 +633,7 @@
     pub initrd_range: Option<Range<usize>>,
     pub memory_range: Range<usize>,
     bootargs: Option<CString>,
-    num_cpus: usize,
+    cpus: ArrayVec<[CpuInfo; DeviceTreeInfo::MAX_CPUS]>,
     pci_info: PciInfo,
     serial_info: SerialInfo,
     pub swiotlb_info: SwiotlbInfo,
@@ -637,7 +642,9 @@
 }
 
 impl DeviceTreeInfo {
-    fn gic_patched_size(num_cpus: usize) -> Option<usize> {
+    const MAX_CPUS: usize = 16;
+
+    const fn gic_patched_size(num_cpus: usize) -> Option<usize> {
         const GIC_REDIST_SIZE_PER_CPU: usize = 32 * SIZE_4KB;
 
         GIC_REDIST_SIZE_PER_CPU.checked_mul(num_cpus)
@@ -664,7 +671,9 @@
 
     let info = parse_device_tree(fdt, vm_dtbo.as_deref())?;
 
-    fdt.copy_from_slice(pvmfw_fdt_template::RAW).map_err(|e| {
+    // SAFETY: We trust that the template (hardcoded in our RO data) is a valid DT.
+    let fdt_template = unsafe { Fdt::unchecked_from_slice(pvmfw_fdt_template::RAW) };
+    fdt.clone_from(fdt_template).map_err(|e| {
         error!("Failed to instantiate FDT from the template DT: {e}");
         RebootReason::InvalidFdt
     })?;
@@ -733,12 +742,12 @@
         RebootReason::InvalidFdt
     })?;
 
-    let num_cpus = read_num_cpus_from(fdt).map_err(|e| {
-        error!("Failed to read num cpus from DT: {e}");
+    let cpus = read_cpu_info_from(fdt).map_err(|e| {
+        error!("Failed to read CPU info from DT: {e}");
         RebootReason::InvalidFdt
     })?;
-    validate_num_cpus(num_cpus).map_err(|e| {
-        error!("Failed to validate num cpus from DT: {e}");
+    validate_cpu_info(&cpus).map_err(|e| {
+        error!("Failed to validate CPU info from DT: {e}");
         RebootReason::InvalidFdt
     })?;
 
@@ -786,7 +795,7 @@
         initrd_range,
         memory_range,
         bootargs,
-        num_cpus,
+        cpus,
         pci_info,
         serial_info,
         swiotlb_info,
@@ -812,7 +821,7 @@
             RebootReason::InvalidFdt
         })?;
     }
-    patch_num_cpus(fdt, info.num_cpus).map_err(|e| {
+    patch_cpus(fdt, &info.cpus).map_err(|e| {
         error!("Failed to patch cpus to DT: {e}");
         RebootReason::InvalidFdt
     })?;
@@ -828,11 +837,11 @@
         error!("Failed to patch swiotlb info to DT: {e}");
         RebootReason::InvalidFdt
     })?;
-    patch_gic(fdt, info.num_cpus).map_err(|e| {
+    patch_gic(fdt, info.cpus.len()).map_err(|e| {
         error!("Failed to patch gic info to DT: {e}");
         RebootReason::InvalidFdt
     })?;
-    patch_timer(fdt, info.num_cpus).map_err(|e| {
+    patch_timer(fdt, info.cpus.len()).map_err(|e| {
         error!("Failed to patch timer info to DT: {e}");
         RebootReason::InvalidFdt
     })?;
@@ -938,7 +947,7 @@
     // SAFETY: on failure, the corrupted DT is restored using the backup.
     if let Err(e) = unsafe { fdt.apply_overlay(overlay) } {
         warn!("Failed to apply debug policy: {e}. Recovering...");
-        fdt.copy_from_slice(backup_fdt.as_slice())?;
+        fdt.clone_from(backup_fdt)?;
         // A successful restoration is considered success because an invalid debug policy
         // shouldn't DOS the pvmfw
         Ok(false)
diff --git a/rialto/src/main.rs b/rialto/src/main.rs
index e705562..ad9b776 100644
--- a/rialto/src/main.rs
+++ b/rialto/src/main.rs
@@ -37,7 +37,7 @@
 use hyp::{get_mem_sharer, get_mmio_guard};
 use libfdt::FdtError;
 use log::{debug, error, info};
-use service_vm_comm::{RequestProcessingError, Response, ServiceVmRequest, VmType};
+use service_vm_comm::{ServiceVmRequest, VmType};
 use service_vm_fake_chain::service_vm;
 use service_vm_requests::process_request;
 use virtio_drivers::{
@@ -177,15 +177,7 @@
 
     let mut vsock_stream = VsockStream::new(socket_device, host_addr())?;
     while let ServiceVmRequest::Process(req) = vsock_stream.read_request()? {
-        let mut response = process_request(req, bcc_handover.as_ref());
-        // TODO(b/185878400): We don't want to issue a certificate to pVM when the client VM
-        // attestation is unfinished. The following code should be removed once the
-        // verification is completed.
-        if vm_type() == VmType::ProtectedVm
-            && matches!(response, Response::RequestClientVmAttestation(_))
-        {
-            response = Response::Err(RequestProcessingError::OperationUnimplemented);
-        }
+        let response = process_request(req, bcc_handover.as_ref());
         vsock_stream.write_response(&response)?;
         vsock_stream.flush()?;
     }
diff --git a/service_vm/test_apk/Android.bp b/service_vm/demo_apk/Android.bp
similarity index 69%
rename from service_vm/test_apk/Android.bp
rename to service_vm/demo_apk/Android.bp
index 681f4e8..5644819 100644
--- a/service_vm/test_apk/Android.bp
+++ b/service_vm/demo_apk/Android.bp
@@ -4,9 +4,9 @@
 }
 
 android_app {
-    name: "ServiceVmClientTestApp",
+    name: "VmAttestationDemoApp",
     installable: true,
-    jni_libs: ["libservice_vm_client"],
+    jni_libs: ["libvm_attestation_payload"],
     jni_uses_platform_apis: true,
     use_embedded_native_libs: true,
     sdk_version: "system_current",
@@ -15,8 +15,8 @@
 }
 
 rust_defaults {
-    name: "service_vm_client_defaults",
-    crate_name: "service_vm_client",
+    name: "vm_attestation_payload_defaults",
+    crate_name: "vm_attestation_payload",
     defaults: ["avf_build_flags_rust"],
     srcs: ["src/main.rs"],
     prefer_rlib: true,
@@ -29,6 +29,6 @@
 }
 
 rust_ffi {
-    name: "libservice_vm_client",
-    defaults: ["service_vm_client_defaults"],
+    name: "libvm_attestation_payload",
+    defaults: ["vm_attestation_payload_defaults"],
 }
diff --git a/service_vm/test_apk/AndroidManifest.xml b/service_vm/demo_apk/AndroidManifest.xml
similarity index 94%
rename from service_vm/test_apk/AndroidManifest.xml
rename to service_vm/demo_apk/AndroidManifest.xml
index b3598fc..228195d 100644
--- a/service_vm/test_apk/AndroidManifest.xml
+++ b/service_vm/demo_apk/AndroidManifest.xml
@@ -13,7 +13,7 @@
      limitations under the License.
 -->
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
-      package="com.android.virt.service_vm.client">
+      package="com.android.virt.vm_attestation.demo">
      <uses-permission android:name="android.permission.MANAGE_VIRTUAL_MACHINE" />
      <uses-permission android:name="android.permission.USE_CUSTOM_VIRTUAL_MACHINE" />
 
diff --git a/service_vm/demo_apk/README.md b/service_vm/demo_apk/README.md
new file mode 100644
index 0000000..551d47b
--- /dev/null
+++ b/service_vm/demo_apk/README.md
@@ -0,0 +1,53 @@
+# VmAttestationDemoApp
+
+## Overview
+
+The *VmAttestationDemoApp* is an Android application that provides a practical
+demonstration of how to interact with the VM Attestation APIs. This app focuses
+on the payload of the Android app and the payload performs two main tasks:
+requesting attestation and validating the attestation result.
+
+## Building
+
+To build the VmAttestationDemoApp, use the following command:
+
+```
+m VmAttestationDemoApp
+```
+
+## Installing
+
+To install the app on your device, execute the following command:
+
+```
+adb install $ANDROID_PRODUCT_OUT/system/app/VmAttestationDemoApp/VmAttestationDemoApp.apk
+```
+
+## Running
+
+Before running the app, make sure that the device has an internet connection and
+that the remote provisioning host is not empty. You can use the following
+command to check the remote provisioning host:
+
+```
+$ adb shell getprop remote_provisioning.hostname
+remoteprovisioning.googleapis.com
+```
+
+Once you have confirmed the remote provisioning host, you can run the app using
+the following command:
+
+```
+TEST_ROOT=/data/local/tmp/virt && adb shell /apex/com.android.virt/bin/vm run-app \
+  --config-path assets/config.json --debug full \
+  $(adb shell pm path com.android.virt.vm_attestation.demo | cut -c 9-) \
+  $TEST_ROOT/VmAttestationDemoApp.apk.idsig \
+  $TEST_ROOT/instance.vm_attestation.debug.img --protected
+```
+
+Please note that remote attestation is only available for protected VMs.
+Therefore, ensure that the VM is launched in protected mode using the
+`--protected` flag.
+
+If everything is set up correctly, you should be able to see the attestation
+result printed out in the VM logs.
diff --git a/service_vm/test_apk/assets/config.json b/service_vm/demo_apk/assets/config.json
similarity index 74%
rename from service_vm/test_apk/assets/config.json
rename to service_vm/demo_apk/assets/config.json
index 02749fe..1684696 100644
--- a/service_vm/test_apk/assets/config.json
+++ b/service_vm/demo_apk/assets/config.json
@@ -4,7 +4,7 @@
     },
     "task": {
       "type": "microdroid_launcher",
-      "command": "libservice_vm_client.so"
+      "command": "libvm_attestation_payload.so"
     },
     "export_tombstones": true
   }
\ No newline at end of file
diff --git a/service_vm/test_apk/src/main.rs b/service_vm/demo_apk/src/main.rs
similarity index 99%
rename from service_vm/test_apk/src/main.rs
rename to service_vm/demo_apk/src/main.rs
index df60325..0d1efb0 100644
--- a/service_vm/test_apk/src/main.rs
+++ b/service_vm/demo_apk/src/main.rs
@@ -224,6 +224,6 @@
     // static string.
     let message = unsafe { AVmAttestationResult_resultToString(status) };
     // SAFETY: The pointer returned by `AVmAttestationResult_resultToString` is guaranteed to
-    // point to a valid C String.
+    // point to a valid C String that lives forever.
     unsafe { CStr::from_ptr(message) }
 }
diff --git a/tests/benchmark/Android.bp b/tests/benchmark/Android.bp
index 31fe0f6..c31c929 100644
--- a/tests/benchmark/Android.bp
+++ b/tests/benchmark/Android.bp
@@ -34,6 +34,7 @@
 
 cc_library_shared {
     name: "MicrodroidBenchmarkNativeLib",
+    defaults: ["avf_build_flags_cc"],
     srcs: ["src/native/*.cpp"],
     local_include_dirs: ["src/native/include"],
     static_libs: [
diff --git a/tests/benchmark/src/jni/Android.bp b/tests/benchmark/src/jni/Android.bp
index c2e1b7c..06de3e5 100644
--- a/tests/benchmark/src/jni/Android.bp
+++ b/tests/benchmark/src/jni/Android.bp
@@ -5,6 +5,7 @@
 
 cc_library_shared {
     name: "libiovsock_host_jni",
+    defaults: ["avf_build_flags_cc"],
     srcs: ["io_vsock_host_jni.cpp"],
     header_libs: ["jni_headers"],
     shared_libs: ["libbase"],
diff --git a/tests/testapk/Android.bp b/tests/testapk/Android.bp
index 10bbfb4..86172b0 100644
--- a/tests/testapk/Android.bp
+++ b/tests/testapk/Android.bp
@@ -68,6 +68,7 @@
 // (MicrodroidTestApp) can start a payload defined in the another app (MicrodroidVmShareApp).
 cc_defaults {
     name: "MicrodroidTestNativeLibDefaults",
+    defaults: ["avf_build_flags_cc"],
     srcs: ["src/native/testbinary.cpp"],
     stl: "libc++_static",
     header_libs: ["vm_payload_restricted_headers"],
@@ -99,12 +100,14 @@
 
 cc_library_shared {
     name: "MicrodroidTestNativeLibSub",
+    defaults: ["avf_build_flags_cc"],
     srcs: ["src/native/testlib.cpp"],
     stl: "libc++_static",
 }
 
 cc_library_shared {
     name: "MicrodroidIdleNativeLib",
+    defaults: ["avf_build_flags_cc"],
     srcs: ["src/native/idlebinary.cpp"],
     header_libs: ["vm_payload_headers"],
     stl: "libc++_static",
@@ -113,6 +116,7 @@
 // An empty payload missing AVmPayload_main
 cc_library_shared {
     name: "MicrodroidEmptyNativeLib",
+    defaults: ["avf_build_flags_cc"],
     srcs: ["src/native/emptybinary.cpp"],
     stl: "none",
 }
@@ -120,6 +124,7 @@
 // A payload that exits immediately on start
 cc_library_shared {
     name: "MicrodroidExitNativeLib",
+    defaults: ["avf_build_flags_cc"],
     srcs: ["src/native/exitbinary.cpp"],
     header_libs: ["vm_payload_headers"],
     stl: "libc++_static",
@@ -128,6 +133,7 @@
 // A payload which tries to link against libselinux, one of private libraries
 cc_library_shared {
     name: "MicrodroidPrivateLinkingNativeLib",
+    defaults: ["avf_build_flags_cc"],
     srcs: ["src/native/idlebinary.cpp"],
     header_libs: ["vm_payload_headers"],
     // HACK: linking against "libselinux" will embed libselinux.so into the apk
@@ -139,6 +145,7 @@
 // A payload that crashes immediately on start
 cc_library_shared {
     name: "MicrodroidCrashNativeLib",
+    defaults: ["avf_build_flags_cc"],
     srcs: ["src/native/crashbinary.cpp"],
     header_libs: ["vm_payload_headers"],
     stl: "libc++_static",
diff --git a/tests/testapk/src/java/com/android/microdroid/test/MicrodroidTests.java b/tests/testapk/src/java/com/android/microdroid/test/MicrodroidTests.java
index 25dab0e..1dd0309 100644
--- a/tests/testapk/src/java/com/android/microdroid/test/MicrodroidTests.java
+++ b/tests/testapk/src/java/com/android/microdroid/test/MicrodroidTests.java
@@ -453,29 +453,32 @@
         // Minimal has as little as specified as possible; everything that can be is defaulted.
         VirtualMachineConfig.Builder minimalBuilder =
                 new VirtualMachineConfig.Builder(getContext())
-                        .setPayloadBinaryName("binary.so")
+                        .setPayloadConfigPath("config/path")
                         .setProtectedVm(isProtectedVm());
         VirtualMachineConfig minimal = minimalBuilder.build();
 
         assertThat(minimal.getApkPath()).isNull();
+        assertThat(minimal.getExtraApks()).isEmpty();
         assertThat(minimal.getDebugLevel()).isEqualTo(DEBUG_LEVEL_NONE);
         assertThat(minimal.getMemoryBytes()).isEqualTo(0);
         assertThat(minimal.getCpuTopology()).isEqualTo(CPU_TOPOLOGY_ONE_CPU);
-        assertThat(minimal.getPayloadBinaryName()).isEqualTo("binary.so");
-        assertThat(minimal.getPayloadConfigPath()).isNull();
+        assertThat(minimal.getPayloadBinaryName()).isNull();
+        assertThat(minimal.getPayloadConfigPath()).isEqualTo("config/path");
         assertThat(minimal.isProtectedVm()).isEqualTo(isProtectedVm());
         assertThat(minimal.isEncryptedStorageEnabled()).isFalse();
         assertThat(minimal.getEncryptedStorageBytes()).isEqualTo(0);
         assertThat(minimal.isVmOutputCaptured()).isEqualTo(false);
-        assertThat(minimal.getOs()).isEqualTo("microdroid");
+        assertThat(minimal.getOs()).isNull();
 
         // Maximal has everything that can be set to some non-default value. (And has different
         // values than minimal for the required fields.)
         VirtualMachineConfig.Builder maximalBuilder =
                 new VirtualMachineConfig.Builder(getContext())
                         .setProtectedVm(mProtectedVm)
-                        .setPayloadConfigPath("config/path")
+                        .setPayloadBinaryName("binary.so")
                         .setApkPath("/apk/path")
+                        .addExtraApk("package.name1:split")
+                        .addExtraApk("package.name2")
                         .setDebugLevel(DEBUG_LEVEL_FULL)
                         .setMemoryBytes(42)
                         .setCpuTopology(CPU_TOPOLOGY_MATCH_HOST)
@@ -484,25 +487,28 @@
         VirtualMachineConfig maximal = maximalBuilder.build();
 
         assertThat(maximal.getApkPath()).isEqualTo("/apk/path");
+        assertThat(maximal.getExtraApks())
+                .containsExactly("package.name1:split", "package.name2")
+                .inOrder();
         assertThat(maximal.getDebugLevel()).isEqualTo(DEBUG_LEVEL_FULL);
         assertThat(maximal.getMemoryBytes()).isEqualTo(42);
         assertThat(maximal.getCpuTopology()).isEqualTo(CPU_TOPOLOGY_MATCH_HOST);
-        assertThat(maximal.getPayloadBinaryName()).isNull();
-        assertThat(maximal.getPayloadConfigPath()).isEqualTo("config/path");
+        assertThat(maximal.getPayloadBinaryName()).isEqualTo("binary.so");
+        assertThat(maximal.getPayloadConfigPath()).isNull();
         assertThat(maximal.isProtectedVm()).isEqualTo(isProtectedVm());
         assertThat(maximal.isEncryptedStorageEnabled()).isTrue();
         assertThat(maximal.getEncryptedStorageBytes()).isEqualTo(1_000_000);
         assertThat(maximal.isVmOutputCaptured()).isEqualTo(true);
-        assertThat(maximal.getOs()).isNull();
+        assertThat(maximal.getOs()).isEqualTo("microdroid");
 
         assertThat(minimal.isCompatibleWith(maximal)).isFalse();
         assertThat(minimal.isCompatibleWith(minimal)).isTrue();
         assertThat(maximal.isCompatibleWith(maximal)).isTrue();
 
-        VirtualMachineConfig os = minimalBuilder.setOs("microdroid_gki-android14-6.1").build();
+        VirtualMachineConfig os = maximalBuilder.setOs("microdroid_gki-android14-6.1").build();
         assertThat(os.getPayloadBinaryName()).isEqualTo("binary.so");
         assertThat(os.getOs()).isEqualTo("microdroid_gki-android14-6.1");
-        assertThat(os.isCompatibleWith(minimal)).isFalse();
+        assertThat(os.isCompatibleWith(maximal)).isFalse();
     }
 
     @Test
@@ -514,6 +520,7 @@
         // All your null are belong to me.
         assertThrows(NullPointerException.class, () -> new VirtualMachineConfig.Builder(null));
         assertThrows(NullPointerException.class, () -> builder.setApkPath(null));
+        assertThrows(NullPointerException.class, () -> builder.addExtraApk(null));
         assertThrows(NullPointerException.class, () -> builder.setPayloadConfigPath(null));
         assertThrows(NullPointerException.class, () -> builder.setPayloadBinaryName(null));
         assertThrows(NullPointerException.class, () -> builder.setVendorDiskImage(null));
@@ -579,6 +586,7 @@
                 .isTrue();
 
         // Changes that must be incompatible, since they must change the VM identity.
+        assertConfigCompatible(baseline, newBaselineBuilder().addExtraApk("foo")).isFalse();
         assertConfigCompatible(baseline, newBaselineBuilder().setDebugLevel(DEBUG_LEVEL_FULL))
                 .isFalse();
         assertConfigCompatible(baseline, newBaselineBuilder().setPayloadBinaryName("different"))
@@ -903,7 +911,34 @@
                         vm,
                         (ts, tr) -> {
                             tr.mExtraApkTestProp =
-                                    ts.readProperty("debug.microdroid.test.extra_apk");
+                                    ts.readProperty(
+                                            "debug.microdroid.test.extra_apk_build_manifest");
+                        });
+        assertThat(testResults.mExtraApkTestProp).isEqualTo("PASS");
+    }
+
+    @Test
+    @CddTest(requirements = {"9.17/C-1-1", "9.17/C-2-1"})
+    public void extraApkInVmConfig() throws Exception {
+        assumeSupportedDevice();
+        assumeFeatureEnabled(VirtualMachineManager.FEATURE_MULTI_TENANT);
+
+        grantPermission(VirtualMachine.USE_CUSTOM_VIRTUAL_MACHINE_PERMISSION);
+        VirtualMachineConfig config =
+                newVmConfigBuilderWithPayloadBinary("MicrodroidTestNativeLib.so")
+                        .setMemoryBytes(minMemoryRequired())
+                        .setDebugLevel(DEBUG_LEVEL_FULL)
+                        .addExtraApk(VM_SHARE_APP_PACKAGE_NAME)
+                        .build();
+        VirtualMachine vm = forceCreateNewVirtualMachine("test_vm_extra_apk", config);
+
+        TestResults testResults =
+                runVmTestService(
+                        TAG,
+                        vm,
+                        (ts, tr) -> {
+                            tr.mExtraApkTestProp =
+                                    ts.readProperty("debug.microdroid.test.extra_apk_vm_share");
                         });
         assertThat(testResults.mExtraApkTestProp).isEqualTo("PASS");
     }
diff --git a/tests/testapk/src/native/testbinary.cpp b/tests/testapk/src/native/testbinary.cpp
index c9b5e3a..1a75102 100644
--- a/tests/testapk/src/native/testbinary.cpp
+++ b/tests/testapk/src/native/testbinary.cpp
@@ -349,7 +349,7 @@
     return {};
 }
 
-Result<void> verify_apk() {
+Result<void> verify_build_manifest() {
     const char* path = "/mnt/extra-apk/0/assets/build_manifest.pb";
 
     std::string str;
@@ -364,6 +364,17 @@
     return {};
 }
 
+Result<void> verify_vm_share() {
+    const char* path = "/mnt/extra-apk/0/assets/vmshareapp.txt";
+
+    std::string str;
+    if (!android::base::ReadFileToString(path, &str)) {
+        return ErrnoError() << "failed to read vmshareapp.txt";
+    }
+
+    return {};
+}
+
 } // Anonymous namespace
 
 extern "C" int AVmPayload_main() {
@@ -372,8 +383,10 @@
     // Make sure we can call into other shared libraries.
     testlib_sub();
 
-    // Extra apks may be missing; this is not a fatal error
-    report_test("extra_apk", verify_apk());
+    // Report various things that aren't always fatal - these are checked in MicrodroidTests as
+    // appropriate.
+    report_test("extra_apk_build_manifest", verify_build_manifest());
+    report_test("extra_apk_vm_share", verify_vm_share());
 
     __system_property_set("debug.microdroid.app.run", "true");
 
diff --git a/tests/vmshareapp/assets/vmshareapp.txt b/tests/vmshareapp/assets/vmshareapp.txt
new file mode 100644
index 0000000..02fdd71
--- /dev/null
+++ b/tests/vmshareapp/assets/vmshareapp.txt
@@ -0,0 +1 @@
+Marker file for the vmshareapp APK
diff --git a/virtualizationmanager/fsfdt/Android.bp b/virtualizationmanager/fsfdt/Android.bp
index 0aa2ef0..7199485 100644
--- a/virtualizationmanager/fsfdt/Android.bp
+++ b/virtualizationmanager/fsfdt/Android.bp
@@ -18,8 +18,8 @@
     ],
 }
 
-rust_library_rlib {
-    name: "libfsfdt",
+rust_defaults {
+    name: "libfsfdt_default",
     crate_name: "fsfdt",
     defaults: ["avf_build_flags_rust"],
     edition: "2021",
@@ -31,3 +31,17 @@
     ],
     apex_available: ["com.android.virt"],
 }
+
+rust_library_rlib {
+    name: "libfsfdt",
+    defaults: ["libfsfdt_default"],
+}
+
+rust_test {
+    name: "libfsfdt_test",
+    defaults: ["libfsfdt_default"],
+    data: ["testdata/**/*"],
+    data_bins: ["dtc_static"],
+    rustlibs: ["libtempfile"],
+    compile_multilib: "first",
+}
diff --git a/virtualizationmanager/fsfdt/src/lib.rs b/virtualizationmanager/fsfdt/src/lib.rs
index a2ca519..549df04 100644
--- a/virtualizationmanager/fsfdt/src/lib.rs
+++ b/virtualizationmanager/fsfdt/src/lib.rs
@@ -98,3 +98,56 @@
         Ok(())
     }
 }
+
+#[cfg(test)]
+mod test {
+    use super::*;
+    use std::io::Write;
+    use std::process::Command;
+    use tempfile::NamedTempFile;
+
+    const TEST_FS_FDT_ROOT_PATH: &str = "testdata/fs";
+    const BUF_SIZE_MAX: usize = 1024;
+
+    fn dts_from_fs(path: &Path) -> String {
+        let path = path.to_str().unwrap();
+        let res = Command::new("./dtc_static")
+            .args(["-f", "-s", "-I", "fs", "-O", "dts", path])
+            .output()
+            .unwrap();
+        assert!(res.status.success(), "{res:?}");
+        String::from_utf8(res.stdout).unwrap()
+    }
+
+    fn dts_from_dtb(path: &Path) -> String {
+        let path = path.to_str().unwrap();
+        let res = Command::new("./dtc_static")
+            .args(["-f", "-s", "-I", "dtb", "-O", "dts", path])
+            .output()
+            .unwrap();
+        assert!(res.status.success(), "{res:?}");
+        String::from_utf8(res.stdout).unwrap()
+    }
+
+    fn to_temp_file(fdt: &Fdt) -> Result<NamedTempFile> {
+        let mut file = NamedTempFile::new()?;
+        file.as_file_mut().write_all(fdt.as_slice())?;
+        file.as_file_mut().sync_all()?;
+
+        Ok(file)
+    }
+
+    #[test]
+    fn test_from_fs() {
+        let fs_path = Path::new(TEST_FS_FDT_ROOT_PATH);
+
+        let mut data = vec![0_u8; BUF_SIZE_MAX];
+        let fdt = Fdt::from_fs(fs_path, &mut data).unwrap();
+        let file = to_temp_file(fdt).unwrap();
+
+        let expected = dts_from_fs(fs_path);
+        let actual = dts_from_dtb(file.path());
+
+        assert_eq!(&expected, &actual);
+    }
+}
diff --git a/virtualizationmanager/fsfdt/testdata/fs/avf/reference/oem/stub b/virtualizationmanager/fsfdt/testdata/fs/avf/reference/oem/stub
new file mode 100644
index 0000000..2e73f18
--- /dev/null
+++ b/virtualizationmanager/fsfdt/testdata/fs/avf/reference/oem/stub
Binary files differ
diff --git a/virtualizationmanager/fsfdt/testdata/fs/avf/reference/vendor/empty b/virtualizationmanager/fsfdt/testdata/fs/avf/reference/vendor/empty
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/virtualizationmanager/fsfdt/testdata/fs/avf/reference/vendor/empty
diff --git a/virtualizationmanager/fsfdt/testdata/fs/avf/reference/vendor/vendor_extra_node/flag b/virtualizationmanager/fsfdt/testdata/fs/avf/reference/vendor/vendor_extra_node/flag
new file mode 100644
index 0000000..accba00
--- /dev/null
+++ b/virtualizationmanager/fsfdt/testdata/fs/avf/reference/vendor/vendor_extra_node/flag
Binary files differ
diff --git a/virtualizationmanager/fsfdt/testdata/fs/avf/reference/vendor_hashtree_descriptor_root_digest b/virtualizationmanager/fsfdt/testdata/fs/avf/reference/vendor_hashtree_descriptor_root_digest
new file mode 100644
index 0000000..e901bb1
--- /dev/null
+++ b/virtualizationmanager/fsfdt/testdata/fs/avf/reference/vendor_hashtree_descriptor_root_digest
Binary files differ
diff --git a/virtualizationmanager/fsfdt/testdata/fs/avf/reference/vendor_image_key b/virtualizationmanager/fsfdt/testdata/fs/avf/reference/vendor_image_key
new file mode 100644
index 0000000..4d02944
--- /dev/null
+++ b/virtualizationmanager/fsfdt/testdata/fs/avf/reference/vendor_image_key
Binary files differ
diff --git a/vm_payload/Android.bp b/vm_payload/Android.bp
index 286612c..a745fd6 100644
--- a/vm_payload/Android.bp
+++ b/vm_payload/Android.bp
@@ -53,7 +53,7 @@
     ],
     visibility: [
         "//packages/modules/Virtualization/compos",
-        "//packages/modules/Virtualization/service_vm/test_apk",
+        "//packages/modules/Virtualization/service_vm:__subpackages__",
     ],
     shared_libs: [
         "libvm_payload#current",
@@ -63,6 +63,7 @@
 // Shared library for clients to link against.
 cc_library_shared {
     name: "libvm_payload",
+    defaults: ["avf_build_flags_cc"],
     shared_libs: [
         "libbinder_ndk",
         "libbinder_rpc_unstable",
@@ -84,6 +85,7 @@
 // declaration of AVmPayload_main().
 cc_library_headers {
     name: "vm_payload_headers",
+    defaults: ["avf_build_flags_cc"],
     apex_available: ["com.android.compos"],
     export_include_dirs: ["include"],
 }
@@ -91,6 +93,7 @@
 // Restricted headers for use by internal clients & associated tests.
 cc_library_headers {
     name: "vm_payload_restricted_headers",
+    defaults: ["avf_build_flags_cc"],
     header_libs: ["vm_payload_headers"],
     export_header_lib_headers: ["vm_payload_headers"],
     export_include_dirs: ["include-restricted"],
diff --git a/vmbase/Android.bp b/vmbase/Android.bp
index e682773..07e1b4c 100644
--- a/vmbase/Android.bp
+++ b/vmbase/Android.bp
@@ -41,6 +41,7 @@
 // Used by extra cc_library_static linked into the final ELF.
 cc_defaults {
     name: "vmbase_cc_defaults",
+    defaults: ["avf_build_flags_cc"],
     nocrt: true,
     no_libcrt: true,
     system_shared_libs: [],