--- a/net/minecraft/server/Main.java
+++ b/net/minecraft/server/Main.java
@@ -58,6 +58,12 @@
 import net.minecraft.world.level.storage.WorldInfo;
 import org.slf4j.Logger;
 
+// CraftBukkit start
+import java.util.concurrent.atomic.AtomicReference;
+import net.minecraft.SharedConstants;
+import net.minecraft.world.level.dimension.WorldDimension;
+// CraftBukkit end
+
 public class Main {
 
     private static final Logger LOGGER = LogUtils.getLogger();
@@ -65,8 +71,9 @@
     public Main() {}
 
     @DontObfuscate
-    public static void main(String[] astring) {
+    public static void main(final OptionSet optionset) { // CraftBukkit - replaces main(String[] astring)
         SharedConstants.tryDetectVersion();
+        /* CraftBukkit start - Replace everything
         OptionParser optionparser = new OptionParser();
         OptionSpec<Void> optionspec = optionparser.accepts("nogui");
         OptionSpec<Void> optionspec1 = optionparser.accepts("initSettings", "Initializes 'server.properties' and 'eula.txt', then quits");
@@ -91,9 +98,12 @@
                 optionparser.printHelpOn(System.err);
                 return;
             }
+            */ // CraftBukkit end
+
+        try {
 
             CrashReport.preload();
-            if (optionset.has(optionspec13)) {
+            if (optionset.has("jfrProfile")) { // CraftBukkit
                 JvmProfiler.INSTANCE.start(Environment.SERVER);
             }
 
@@ -101,13 +111,13 @@
             DispenserRegistry.validate();
             SystemUtils.startTimerHackThread();
             Path path = Paths.get("server.properties");
-            DedicatedServerSettings dedicatedserversettings = new DedicatedServerSettings(path);
+            DedicatedServerSettings dedicatedserversettings = new DedicatedServerSettings(optionset); // CraftBukkit - CLI argument support
 
             dedicatedserversettings.forceSave();
             Path path1 = Paths.get("eula.txt");
             EULA eula = new EULA(path1);
 
-            if (optionset.has(optionspec1)) {
+            if (optionset.has("initSettings")) { // CraftBukkit
                 Main.LOGGER.info("Initialized '{}' and '{}'", path.toAbsolutePath(), path1.toAbsolutePath());
                 return;
             }
@@ -117,11 +127,12 @@
                 return;
             }
 
-            File file = new File((String) optionset.valueOf(optionspec9));
+            File file = (File) optionset.valueOf("universe"); // CraftBukkit
             Services services = Services.create(new YggdrasilAuthenticationService(Proxy.NO_PROXY), file);
-            String s = (String) Optional.ofNullable((String) optionset.valueOf(optionspec10)).orElse(dedicatedserversettings.getProperties().levelName);
+            // CraftBukkit start
+            String s = (String) Optional.ofNullable((String) optionset.valueOf("world")).orElse(dedicatedserversettings.getProperties().levelName);
             Convertable convertable = Convertable.createDefault(file.toPath());
-            Convertable.ConversionSession convertable_conversionsession = convertable.createAccess(s);
+            Convertable.ConversionSession convertable_conversionsession = convertable.createAccess(s, WorldDimension.OVERWORLD);
             WorldInfo worldinfo = convertable_conversionsession.getSummary();
 
             if (worldinfo != null) {
@@ -136,13 +147,32 @@
                 }
             }
 
-            boolean flag = optionset.has(optionspec6);
+            boolean flag = optionset.has("safeMode");
 
             if (flag) {
                 Main.LOGGER.warn("Safe mode active, only vanilla datapack will be loaded");
             }
 
             ResourcePackRepository resourcepackrepository = new ResourcePackRepository(EnumResourcePackType.SERVER_DATA, new ResourcePackSource[]{new ResourcePackSourceVanilla(), new ResourcePackSourceFolder(convertable_conversionsession.getLevelPath(SavedFile.DATAPACK_DIR).toFile(), PackSource.WORLD)});
+            // CraftBukkit start
+            File bukkitDataPackFolder = new File(convertable_conversionsession.getLevelPath(SavedFile.DATAPACK_DIR).toFile(), "bukkit");
+            if (!bukkitDataPackFolder.exists()) {
+                bukkitDataPackFolder.mkdirs();
+            }
+            File mcMeta = new File(bukkitDataPackFolder, "pack.mcmeta");
+            try {
+                com.google.common.io.Files.write("{\n"
+                        + "    \"pack\": {\n"
+                        + "        \"description\": \"Data pack for resources provided by Bukkit plugins\",\n"
+                        + "        \"pack_format\": " + SharedConstants.getCurrentVersion().getPackVersion() + "\n"
+                        + "    }\n"
+                        + "}\n", mcMeta, com.google.common.base.Charsets.UTF_8);
+            } catch (java.io.IOException ex) {
+                throw new RuntimeException("Could not initialize Bukkit datapack", ex);
+            }
+            AtomicReference<DataPackConfiguration> config = new AtomicReference<>();
+            AtomicReference<DynamicOps<NBTBase>> ops = new AtomicReference<>();
+            // CraftBukkit end
 
             WorldStem worldstem;
 
@@ -155,6 +185,12 @@
                     return WorldStem.load(worldloader_a, (iresourcemanager, datapackconfiguration1) -> {
                         IRegistryCustom.e iregistrycustom_e = IRegistryCustom.builtinCopy();
                         DynamicOps<NBTBase> dynamicops = RegistryOps.createAndLoad(DynamicOpsNBT.INSTANCE, iregistrycustom_e, iresourcemanager);
+                        // CraftBukkit start
+                        config.set(datapackconfiguration1);
+                        ops.set(dynamicops);
+                        return Pair.of(null, iregistrycustom_e.freeze());
+                        // CraftBukkit end
+                        /*
                         SaveData savedata = convertable_conversionsession.getDataTag(dynamicops, datapackconfiguration1, iregistrycustom_e.allElementsLifecycle());
 
                         if (savedata != null) {
@@ -177,6 +213,7 @@
 
                             return Pair.of(worlddataserver, iregistrycustom_e.freeze());
                         }
+                         */
                     }, SystemUtils.backgroundExecutor(), executor);
                 }).get();
             } catch (Exception exception) {
@@ -184,6 +221,7 @@
                 return;
             }
 
+            /*
             IRegistryCustom.Dimension iregistrycustom_dimension = worldstem.registryAccess();
 
             dedicatedserversettings.getProperties().getWorldGenSettings(iregistrycustom_dimension);
@@ -196,21 +234,32 @@
             }
 
             convertable_conversionsession.saveDataTag(iregistrycustom_dimension, savedata);
+            */
             final DedicatedServer dedicatedserver = (DedicatedServer) MinecraftServer.spin((thread) -> {
-                DedicatedServer dedicatedserver1 = new DedicatedServer(thread, convertable_conversionsession, resourcepackrepository, worldstem, dedicatedserversettings, DataConverterRegistry.getDataFixer(), services, WorldLoadListenerLogger::new);
+                DedicatedServer dedicatedserver1 = new DedicatedServer(optionset, config.get(), ops.get(), thread, convertable_conversionsession, resourcepackrepository, worldstem, dedicatedserversettings, DataConverterRegistry.getDataFixer(), services, WorldLoadListenerLogger::new);
 
+                /*
                 dedicatedserver1.setSingleplayerProfile(optionset.has(optionspec8) ? new GameProfile((UUID) null, (String) optionset.valueOf(optionspec8)) : null);
                 dedicatedserver1.setPort((Integer) optionset.valueOf(optionspec11));
                 dedicatedserver1.setDemo(optionset.has(optionspec2));
                 dedicatedserver1.setId((String) optionset.valueOf(optionspec12));
-                boolean flag1 = !optionset.has(optionspec) && !optionset.valuesOf(nonoptionargumentspec).contains("nogui");
+                */
+                boolean flag1 = !optionset.has("nogui") && !optionset.nonOptionArguments().contains("nogui");
 
                 if (flag1 && !GraphicsEnvironment.isHeadless()) {
                     dedicatedserver1.showGui();
                 }
 
+                if (optionset.has("port")) {
+                    int port = (Integer) optionset.valueOf("port");
+                    if (port > 0) {
+                        dedicatedserver1.setPort(port);
+                    }
+                }
+
                 return dedicatedserver1;
             });
+            /* CraftBukkit start
             Thread thread = new Thread("Server Shutdown Thread") {
                 public void run() {
                     dedicatedserver.halt(true);
@@ -219,6 +268,7 @@
 
             thread.setUncaughtExceptionHandler(new DefaultUncaughtExceptionHandler(Main.LOGGER));
             Runtime.getRuntime().addShutdownHook(thread);
+            */ // CraftBukkit end
         } catch (Exception exception1) {
             Main.LOGGER.error(LogUtils.FATAL_MARKER, "Failed to start the minecraft server", exception1);
         }
@@ -226,7 +276,7 @@
     }
 
     public static void forceUpgrade(Convertable.ConversionSession convertable_conversionsession, DataFixer datafixer, boolean flag, BooleanSupplier booleansupplier, GeneratorSettings generatorsettings) {
-        Main.LOGGER.info("Forcing world upgrade!");
+        Main.LOGGER.info("Forcing world upgrade! {}", convertable_conversionsession.getLevelId()); // CraftBukkit
         WorldUpgrader worldupgrader = new WorldUpgrader(convertable_conversionsession, datafixer, generatorsettings, flag);
         IChatBaseComponent ichatbasecomponent = null;