Support overlay-based filesystem root

src/main/java/li/cil/oc2/common/bus/device/data/FileSystems.java

@@ -36,6 +36,9 @@ public final class FileSystems {
     private static final Logger LOGGER = LogManager.getLogger();
     private static final LayeredFileSystem LAYERED_FILE_SYSTEM = new LayeredFileSystem();
     private static final Map<ResourceLocation, BlockDeviceData> BLOCK_DEVICE_DATA = new HashMap<>();
+    private static final Map<String, BlockDeviceData> blocksByName = new HashMap<>();
+
+    public static ResourceManager _resourceManager = null;
 
     ///////////////////////////////////////////////////////////////////
 
@@ -43,6 +46,10 @@ public final class FileSystems {
         return LAYERED_FILE_SYSTEM;
     }
 
+    public static BlockDeviceData getBlockByName(String name) {
+        return blocksByName.get(name);
+    }
+
     public static ResourceLocation getKeyByValue(BlockDeviceData value) {
         for (Map.Entry<ResourceLocation, BlockDeviceData> entry : BLOCK_DEVICE_DATA.entrySet()) {
             if (Objects.equals(value, entry.getValue())) {
@@ -84,6 +91,7 @@ public final class FileSystems {
     ///////////////////////////////////////////////////////////////////
 
     private static void reload(final ResourceManager resourceManager) {
+        _resourceManager = resourceManager;
         reset();
 
         LOGGER.info("Searching for datapack filesystems...");
@@ -141,6 +149,7 @@ public final class FileSystems {
 
                         LOGGER.info("  Adding block device [{}] with id [{}] and a size of [{}].", name, location, formatSize(data.getBlockDevice().getCapacity()));
                         BLOCK_DEVICE_DATA.put(location, data);
+                        blocksByName.put(name, data);
                     }
                     default -> LOGGER.error("Unsupported file system type [{}].", type);
                 }

src/main/java/li/cil/oc2/common/item/Items.java

@@ -14,6 +14,7 @@ import net.minecraftforge.fml.javafmlmod.FMLJavaModLoadingContext;
 import net.minecraftforge.registries.DeferredRegister;
 import net.minecraftforge.registries.ForgeRegistries;
 import net.minecraftforge.registries.RegistryObject;
+import li.cil.oc2.common.bus.device.data.FileSystems;
 
 import java.util.function.Function;
 import java.util.function.Supplier;
@@ -62,11 +63,12 @@ public final class Items {
     public static final RegistryObject<HardDriveItem> HARD_DRIVE_MEDIUM = register("hard_drive_medium", () ->
         new HardDriveItem(4 * Constants.MEGABYTE, DyeColor.GREEN));
     public static final RegistryObject<HardDriveItem> HARD_DRIVE_LARGE = register("hard_drive_large", () ->
-        new HardDriveItem(8 * Constants.MEGABYTE, DyeColor.CYAN));
+        new HardDriveItem(4 * Constants.MEGABYTE, DyeColor.CYAN));
     public static final RegistryObject<HardDriveItem> HARD_DRIVE_EXTRA_LARGE = register("hard_drive_extra_large", () ->
         new HardDriveItem(16 * Constants.MEGABYTE, DyeColor.YELLOW));
-    public static final RegistryObject<HardDriveWithExternalDataItem> HARD_DRIVE_CUSTOM = register("hard_drive_custom", () ->
-        new HardDriveWithExternalDataItem(BlockDeviceDataRegistry.BUILDROOT.getId(), DyeColor.BROWN));
+    public static final RegistryObject<HardDriveWithExternalDataItem> HARD_DRIVE_CUSTOM = register
+        ("hard_drive_custom", () ->
+         new HardDriveWithExternalDataItem(FileSystems.getKeyByValue(FileSystems.getBlockByName("rootfs")), DyeColor.BROWN));
 
     public static final RegistryObject<CPUItem> CPU_TIER_1 = register("cpu_tier_1", () ->
         new CPUItem(25_000_000));

src/main/java/li/cil/oc2/common/vm/BuiltinDevices.java

@@ -1,6 +1,10 @@
 /* SPDX-License-Identifier: MIT */
 
 package li.cil.oc2.common.vm;
+import li.cil.oc2.api.bus.device.data.BlockDeviceData;
+import java.io.IOException;
+
+import net.minecraft.resources.ResourceLocation;
 
 import li.cil.ceres.api.Serialized;
 import li.cil.oc2.common.bus.device.data.FileSystems;
@@ -12,6 +16,13 @@ import li.cil.sedna.device.rtc.SystemTimeRealTimeCounter;
 import li.cil.sedna.device.serial.UART16550A;
 import li.cil.sedna.device.virtio.VirtIOConsoleDevice;
 import li.cil.sedna.device.virtio.VirtIOFileSystemDevice;
+import li.cil.sedna.device.virtio.VirtIOBlockDevice;
+import li.cil.oc2.common.bus.device.data.ResourceBlockDeviceData;
+import li.cil.sedna.api.device.BlockDevice;
+import li.cil.sedna.buildroot.Buildroot;
+import java.io.InputStream;
+import li.cil.sedna.device.block.ByteBufferBlockDevice;
+
 
 import java.util.function.Function;
 
@@ -21,6 +32,8 @@ public final class BuiltinDevices {
     public static final int RPC_INTERRUPT = 0x3;
     private static final int UART_INTERRUPT = 0x4;
     private static final int VFS_INTERRUPT = 0x5;
+    private static final int BFS_INTERRUPT = 0x6;
+    private static final int RFS_INTERRUPT = 0x7;
 
     ///////////////////////////////////////////////////////////////////
 
@@ -31,6 +44,8 @@ public final class BuiltinDevices {
     @Serialized public final VirtIOConsoleDevice rpcSerialDevice;
     @Serialized public final UART16550A uart;
     @Serialized public final VirtIOFileSystemDevice vfs;
+    @Serialized public VirtIOBlockDevice bfs;
+    @Serialized public VirtIOBlockDevice rfs;
 
     ///////////////////////////////////////////////////////////////////
 
@@ -40,6 +55,21 @@ public final class BuiltinDevices {
         rpcSerialDevice = initialize(context, new VirtIOConsoleDevice(context.getMemoryMap()), RPC_INTERRUPT, VirtIOConsoleDevice::getInterrupt);
         uart = initialize(context, new UART16550A(), UART_INTERRUPT, UART16550A::getInterrupt);
         vfs = initialize(context, new VirtIOFileSystemDevice(context.getMemoryMap(), "builtin", FileSystems.getLayeredFileSystem()), VFS_INTERRUPT, VirtIOFileSystemDevice::getInterrupt);
+        InputStream ris = Buildroot.getRootFilesystem();
+        try {
+            var bfsd = FileSystems.getBlockByName("bootfs");
+            if (bfsd != null) {
+                bfs = initialize(context, new VirtIOBlockDevice(context.getMemoryMap(), bfsd.getBlockDevice()), BFS_INTERRUPT, VirtIOBlockDevice::getInterrupt);
+            }
+            else {
+                bfs = null;
+            }
+            rfs = initialize(context, new VirtIOBlockDevice(context.getMemoryMap(), ByteBufferBlockDevice.createFromStream(ris, true)), RFS_INTERRUPT, VirtIOBlockDevice::getInterrupt);
+        }
+        catch(final IOException e) {
+            System.out.println("Failed to load lower block device");
+        }
+            
     }
 
     ///////////////////////////////////////////////////////////////////

src/main/resources/data/oc2/file_systems/bootfs.json

@@ -0,0 +1,6 @@
+{
+  "name": "bootfs",
+  "type": "block",
+  "order": 1,
+  "location": "oc2:file_systems/bootfs.squashfs"
+}

src/main/resources/data/oc2/file_systems/rootfs.json

@@ -0,0 +1,6 @@
+{
+  "name": "rootfs",
+  "type": "block",
+  "order": 1,
+  "location": "oc2:file_systems/rootfs.dsk"
+}