diff --git a/services/java/com/android/server/BootUserInitializer.java b/services/java/com/android/server/BootUserInitializer.java
new file mode 100644
index 0000000000000..46e59a9f10dd2
--- /dev/null
+++ b/services/java/com/android/server/BootUserInitializer.java
@@ -0,0 +1,161 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.android.server;
+
+import android.annotation.UserIdInt;
+import android.content.ContentResolver;
+import android.content.pm.UserInfo;
+import android.os.UserHandle;
+import android.os.UserManager;
+import android.provider.Settings;
+
+import com.android.server.am.ActivityManagerService;
+import com.android.server.pm.UserManagerInternal;
+import com.android.server.utils.Slogf;
+import com.android.server.utils.TimingsTraceAndSlog;
+
+import java.util.List;
+
+/**
+ * Class responsible for booting the device in the proper user on headless system user mode.
+ *
+ */
+// TODO(b/204091126): STOPSHIP - provide proper APIs
+final class BootUserInitializer {
+
+    private static final String TAG = BootUserInitializer.class.getSimpleName();
+
+     // TODO(b/204091126): STOPSHIP - set to false or dynamic value
+    private static final boolean DEBUG = true;
+
+    private final ActivityManagerService mAms;
+    private final ContentResolver mContentResolver;
+
+    BootUserInitializer(ActivityManagerService am, ContentResolver contentResolver) {
+        mAms = am;
+        mContentResolver = contentResolver;
+    }
+
+    public void init(TimingsTraceAndSlog t) {
+        Slogf.i(TAG, "init())");
+
+        // TODO(b/204091126): in the long term, we need to decide who's reponsible for that,
+        // this class or the setup wizard app
+        provisionHeadlessSystemUser();
+
+        UserManagerInternal um = LocalServices.getService(UserManagerInternal.class);
+        t.traceBegin("get-existing-users");
+        List<UserInfo> existingUsers = um.getUsers(/* excludeDying= */ true);
+        t.traceEnd();
+
+        Slogf.d(TAG, "%d existing users", existingUsers.size());
+
+        int initialUserId = UserHandle.USER_NULL;
+
+        for (int i = 0; i < existingUsers.size(); i++) {
+            UserInfo user = existingUsers.get(i);
+            if (DEBUG) {
+                Slogf.d(TAG, "User at position %d: %s", i, user.toFullString());
+            }
+            if (user.id != UserHandle.USER_SYSTEM && user.isFull()) {
+                if (DEBUG) {
+                    Slogf.d(TAG, "Found initial user: %d", user.id);
+                }
+                initialUserId = user.id;
+                break;
+            }
+        }
+
+        if (initialUserId == UserHandle.USER_NULL) {
+            Slogf.d(TAG, "Creating initial user");
+            t.traceBegin("create-initial-user");
+            try {
+                // TODO(b/204091126): proper name for user
+                UserInfo newUser = um.createUserEvenWhenDisallowed("Real User",
+                        UserManager.USER_TYPE_FULL_SECONDARY, UserInfo.FLAG_ADMIN,
+                        /* disallowedPackages= */ null, /* token= */ null);
+                Slogf.i(TAG, "Created initial user: %s", newUser.toFullString());
+                initialUserId = newUser.id;
+            } catch (Exception e) {
+                Slogf.wtf(TAG, "failed to created initial user", e);
+                return;
+            } finally {
+                t.traceEnd(); // create-initial-user
+            }
+        }
+
+        unlockSystemUser(t);
+        switchToInitialUser(initialUserId);
+    }
+
+    private void provisionHeadlessSystemUser() {
+        if (isDeviceProvisioned()) {
+            Slogf.d(TAG, "provisionHeadlessSystemUser(): already provisioned");
+            return;
+        }
+
+        Slogf.i(TAG, "Marking USER_SETUP_COMPLETE for system user");
+        Settings.Secure.putInt(mContentResolver, Settings.Secure.USER_SETUP_COMPLETE, 1);
+        Slogf.i(TAG, "Marking DEVICE_PROVISIONED for system user");
+        Settings.Global.putInt(mContentResolver, Settings.Global.DEVICE_PROVISIONED, 1);
+    }
+
+    private boolean isDeviceProvisioned() {
+        try {
+            return Settings.Global.getInt(mContentResolver,
+                    Settings.Global.DEVICE_PROVISIONED) == 1;
+        } catch (Exception e) {
+            Slogf.wtf(TAG, "DEVICE_PROVISIONED setting not found.", e);
+            return false;
+        }
+    }
+
+    // NOTE: Mostly copied from Automotive's InitialUserSetter
+    private void unlockSystemUser(TimingsTraceAndSlog t) {
+        Slogf.i(TAG, "Unlocking system user");
+        t.traceBegin("unlock-system-user");
+        try {
+            // This is for force changing state into RUNNING_LOCKED. Otherwise unlock does not
+            // update the state and USER_SYSTEM unlock happens twice.
+            t.traceBegin("am.startUser");
+            boolean started = mAms.startUserInBackgroundWithListener(UserHandle.USER_SYSTEM,
+                            /* listener= */ null);
+            t.traceEnd();
+            if (!started) {
+                Slogf.w(TAG, "could not restart system user in background; trying unlock instead");
+                t.traceBegin("am.unlockUser");
+                boolean unlocked = mAms.unlockUser(UserHandle.USER_SYSTEM, /* token= */ null,
+                        /* secret= */ null, /* listener= */ null);
+                t.traceEnd();
+                if (!unlocked) {
+                    Slogf.w(TAG, "could not unlock system user either");
+                    return;
+                }
+            }
+        } finally {
+            t.traceEnd();
+        }
+    }
+
+    private void switchToInitialUser(@UserIdInt int initialUserId) {
+        Slogf.i(TAG, "Switching to initial user %d", initialUserId);
+        boolean started = mAms.startUserInForegroundWithListener(initialUserId,
+                /* unlockListener= */ null);
+        if (!started) {
+            Slogf.wtf(TAG, "Failed to start user %d in foreground", initialUserId);
+        }
+    }
+}
diff --git a/services/java/com/android/server/SystemServer.java b/services/java/com/android/server/SystemServer.java
index 8c414b9330066..b44b692bce129 100644
--- a/services/java/com/android/server/SystemServer.java
+++ b/services/java/com/android/server/SystemServer.java
@@ -73,6 +73,7 @@ import android.os.StrictMode;
 import android.os.SystemClock;
 import android.os.SystemProperties;
 import android.os.UserHandle;
+import android.os.UserManager;
 import android.os.storage.IStorageManager;
 import android.provider.DeviceConfig;
 import android.provider.Settings;
@@ -2768,7 +2769,9 @@ public final class SystemServer implements Dumpable {
                 }, WEBVIEW_PREPARATION);
             }
 
-            if (mPackageManager.hasSystemFeature(PackageManager.FEATURE_AUTOMOTIVE)) {
+            boolean isAutomotive = mPackageManager
+                    .hasSystemFeature(PackageManager.FEATURE_AUTOMOTIVE);
+            if (isAutomotive) {
                 t.traceBegin("StartCarServiceHelperService");
                 final SystemService cshs = mSystemServiceManager
                         .startService(CAR_SERVICE_HELPER_SERVICE_CLASS);
@@ -2877,6 +2880,13 @@ public final class SystemServer implements Dumpable {
             mSystemServiceManager.startBootPhase(t, SystemService.PHASE_THIRD_PARTY_APPS_CAN_START);
             t.traceEnd();
 
+            if (UserManager.isHeadlessSystemUserMode() && !isAutomotive) {
+                // TODO(b/204091126): remove isAutomotive check once the workflow is finalized
+                t.traceBegin("BootUserInitializer");
+                new BootUserInitializer(mActivityManagerService, mContentResolver).init(t);
+                t.traceEnd();
+            }
+
             t.traceBegin("StartNetworkStack");
             try {
                 // Note : the network stack is creating on-demand objects that need to send