Add wrapping of HFS disk images into full device images

Required for allowing DingusPPC to boot from disk images. Also allows Saved
HD to be exported to an .hda file that can be used with BlueSCSI and other
software that expects a full device image.

The base device image header was generated by Disk Jockey 2.5.2.2 (it's the
first 0xc000 or 48 KB of an empty device image - the HFS image can be appended
to it and a couple of fields be updated).

Updates #219
Updates #234

scripts/disks.py

@@ -96,6 +96,8 @@ def path(self) -> str:
 
 SYSTEM_711 = Disk(name="System 7.1.1 HD.dsk")
 
+SYSTEM_712 = Disk(name="System 7.1.2 HD.dsk")
+
 SYSTEM_712_DISK_TOOLS = Disk(name="System 7.1.2 Disk Tools FD.dsk")
 
 SYSTEM_75 = Disk(name="System 7.5 HD.dsk")
@@ -173,6 +175,7 @@ def path(self) -> str:
     SYSTEM_70,
     SYSTEM_71,
     SYSTEM_711,
+    SYSTEM_712,
     SYSTEM_712_DISK_TOOLS,
     SYSTEM_75,
     SYSTEM_75_DISK_TOOLS,

src/Mac.tsx

@@ -589,9 +589,9 @@ export default function Mac({
                         );
                         varz.increment("emulator_disk_saver_import");
                     }}
-                    onSaveImage={() => {
+                    onSaveImage={deviceImage => {
                         emulatorRef.current?.restart(() =>
-                            saveDiskSaverImage(SAVED_HD)
+                            saveDiskSaverImage(SAVED_HD, deviceImage)
                         );
                         varz.increment("emulator_disk_saver_save_image");
                     }}

src/MacSettings.tsx

@@ -33,7 +33,7 @@ export function MacSettings({
     onStorageReset: () => void;
     onStorageExport: () => void;
     onStorageImport: () => void;
-    onSaveImage: () => void;
+    onSaveImage: (deviceImage?: boolean) => void;
     onDone: () => void;
 }) {
     const [storagePersistenceStatus, setStoragePersistenceStatus] = useState<
@@ -186,17 +186,22 @@ export function MacSettings({
                             appearance={appearance}
                             visible={saveImageVisible}
                             setVisible={setSaveImageVisible}
-                            title="Save Disk Image"
-                            body="Saving a disk image requires that the Mac be shut down. It will take a little while to generate, and will be downloaded as a .dsk file. Generate the disk image now?"
+                            title="Save Image"
+                            body="Saving a disk image requires that the Mac be shut down. It will take a little while to generate, and will be downloaded as a .dsk or .hda file. Generate the disk image now?"
                             onAccept={() => {
                                 onSaveImage();
                                 onDone();
                             }}
+                            otherLabel="Save Device Image (.hda)"
+                            onOther={() => {
+                                onSaveImage(true);
+                                onDone();
+                            }}
                         />
                         <div className="Dialog-Description">
                             You can also save the contents of Saved HD as a
-                            <code>.dsk</code> file that can be loaded into other
-                            emulators.
+                            <code>.dsk</code> or <code>.hda</code> file that can
+                            be loaded into other emulators.
                         </div>
                     </div>
                     <div className="MacSettings-Row">
@@ -237,13 +242,17 @@ function StorageConfirmDialog({
     title,
     body,
     onAccept,
+    onOther,
+    otherLabel,
     appearance,
 }: {
     visible: boolean;
     setVisible: (visible: boolean) => void;
     title: string;
     body: string;
     onAccept: () => void;
+    onOther?: () => void;
+    otherLabel?: string;
     appearance: Appearance;
 }) {
     if (!visible) {
@@ -257,6 +266,8 @@ function StorageConfirmDialog({
                 onAccept();
             }}
             doneLabel={title}
+            onOther={onOther}
+            otherLabel={otherLabel}
             onCancel={() => setVisible(false)}
             appearance={appearance}>
             <div style={{maxWidth: 400}}>{body}</div>

src/controls/Dialog.css

@@ -89,6 +89,6 @@
     color: #00c;
 }
 
-.Dialog-Cancel {
+.Dialog-Normal-Button {
     font-weight: normal;
 }

src/controls/Dialog.tsx

@@ -11,6 +11,8 @@ export function Dialog({
     onDone,
     doneLabel = "Done",
     doneEnabled = true,
+    onOther,
+    otherLabel,
     onCancel,
     appearance = "Classic",
     className,
@@ -20,6 +22,8 @@ export function Dialog({
     onDone: (e: React.MouseEvent) => void;
     doneLabel?: string;
     doneEnabled?: boolean;
+    onOther?: (e: React.MouseEvent) => void;
+    otherLabel?: string;
     onCancel?: () => void;
     appearance?: Appearance;
     className?: string;
@@ -39,7 +43,7 @@ export function Dialog({
                 <footer>
                     {onCancel && (
                         <Button
-                            className="Dialog-Cancel"
+                            className="Dialog-Normal-Button"
                             appearance={appearance}
                             onClick={e => {
                                 e.preventDefault();
@@ -48,6 +52,17 @@ export function Dialog({
                             Cancel
                         </Button>
                     )}
+                    {onOther && (
+                        <Button
+                            className="Dialog-Normal-Button"
+                            appearance={appearance}
+                            onClick={e => {
+                                e.preventDefault();
+                                onOther(e);
+                            }}>
+                            {otherLabel}
+                        </Button>
+                    )}
                     <Button
                         disabled={!doneEnabled}
                         appearance={appearance}

src/disks.ts

@@ -326,13 +326,15 @@ const SYSTEM_7_1_1: SystemDiskDef = {
     generatedSpec: () => import("./Data/System 7.1.1 HD.dsk.json"),
 };
 
-const SYSTEM_7_1_2: PlaceholderDiskDef = {
-    type: "placeholder",
+const SYSTEM_7_1_2: SystemDiskDef = {
     displayName: "System 7.1.2",
     description:
-        "Initial system software for the Power Macintosh computers. Does not run under emulation.",
+        "Initial system software for the first Power Macintosh computers.",
     releaseDate: [1994, 3, 14],
-    machines: [POWER_MACINTOSH_9500],
+    prefetchChunks: [0, 1, 2],
+    machines: [POWER_MACINTOSH_6100],
+    isUnstable: true,
+    generatedSpec: () => import("./Data/System 7.1.2 HD.dsk.json"),
 };
 
 const SYSTEM_7_1_2_DISK_TOOLS: SystemDiskDef = {

src/emulator/emulator-common-device-image.ts

@@ -0,0 +1,27 @@
+const BLOCK_SIZE = 512;
+
+export function generateDeviceImageHeader(
+    baseHeader: ArrayBuffer,
+    hfsPartitionSize: number
+): ArrayBuffer {
+    const headerSize = baseHeader.byteLength;
+    if (headerSize !== 0xc000) {
+        console.warn(
+            "Expected base header to be 0xc000 bytes, got 0x" +
+                headerSize.toString(16) +
+                " bytes, results may be unpredictable"
+        );
+    }
+    const header = baseHeader.slice(0);
+    const headerView = new DataView(header);
+
+    const totalSize = hfsPartitionSize + headerSize;
+    const totalBlocks = totalSize / BLOCK_SIZE;
+    headerView.setInt32(0x4, totalBlocks); // sbBlkCount
+
+    const hfsBlocks = hfsPartitionSize / BLOCK_SIZE;
+    headerView.setInt32(0x060c, hfsBlocks); // pmPartBlkCnt?
+    headerView.setInt32(0x0654, hfsBlocks); // pmDataCnt?
+
+    return header;
+}

src/emulator/emulator-common-emulators.ts

@@ -46,6 +46,10 @@ export function emulatorSupportsDownloadsFolder(type: EmulatorType): boolean {
     return type === "BasiliskII" || type === "SheepShaver";
 }
 
+export function emulatorNeedsDeviceImage(type: EmulatorType): boolean {
+    return type === "DingusPPC";
+}
+
 export function emulatorCpuId(
     type: EmulatorType,
     cpu: EmulatorCpu

src/emulator/emulator-common.ts

@@ -124,6 +124,7 @@ export type EmulatorWorkerConfig = {
     wasmUrl: string;
     disks: EmulatorChunkedFileSpec[];
     delayedDisks?: EmulatorChunkedFileSpec[];
+    deviceImageHeader: ArrayBuffer;
     cdroms: EmulatorCDROM[];
     useCDROM: boolean;
     autoloadFiles: {[name: string]: ArrayBuffer};

src/emulator/emulator-ui-disk-saver.ts

@@ -3,6 +3,8 @@ import {saveAs} from "file-saver";
 import {type EmulatorDiskDef} from "../disks";
 import {dirtyChunksFileName, dataFileName} from "./emulator-common-disk-saver";
 import {generateChunkUrl} from "./emulator-common";
+import deviceImageHeaderPath from "../Data/Device Image Header.hda";
+import {generateDeviceImageHeader} from "./emulator-common-device-image";
 
 export async function resetDiskSaver(disk: EmulatorDiskDef) {
     const spec = (await disk.generatedSpec()).default;
@@ -91,7 +93,10 @@ function pickDiskSaverFile() {
     });
 }
 
-export async function saveDiskSaverImage(disk: EmulatorDiskDef) {
+export async function saveDiskSaverImage(
+    disk: EmulatorDiskDef,
+    deviceImage?: boolean
+) {
     const spec = (await disk.generatedSpec()).default;
     const opfsRoot = await navigator.storage.getDirectory();
 
@@ -136,5 +141,17 @@ export async function saveDiskSaverImage(disk: EmulatorDiskDef) {
         image.set(new Uint8Array(chunk), chunkIndex * spec.chunkSize);
     }
 
+    if (deviceImage) {
+        const baseDeviceImageHeader = await (
+            await fetch(deviceImageHeaderPath)
+        ).arrayBuffer();
+        const deviceImageHeader = generateDeviceImageHeader(
+            baseDeviceImageHeader,
+            spec.totalSize
+        );
+        saveAs(new Blob([deviceImageHeader, image]), spec.name + ".hda");
+        return;
+    }
+
     saveAs(new Blob([image]), spec.name + ".dsk");
 }

src/emulator/emulator-ui.ts

@@ -63,6 +63,7 @@ import {
 } from "./emulator-ui-clipboard";
 import {type MachineDefRAMSize, type MachineDef} from "../machines";
 import {type EmulatorDiskDef} from "../disks";
+import deviceImageHeaderPath from "../Data/Device Image Header.hda";
 
 export type EmulatorConfig = {
     machine: MachineDef;
@@ -276,9 +277,13 @@ export class Emulator {
         // Fetch all of the dependent files ourselves, to avoid a waterfall
         // if we let Emscripten handle it (it would first load the JS, and
         // then that would load the WASM and data files).
-        const [[wasmBlobUrl], [rom, basePrefs]] = await load(
+        const [[wasmBlobUrl], [rom, basePrefs, deviceImageHeader]] = await load(
             [emulatorWasmPath],
-            [this.#config.machine.romPath, this.#config.machine.prefsPath],
+            [
+                this.#config.machine.romPath,
+                this.#config.machine.prefsPath,
+                deviceImageHeaderPath,
+            ],
             (total, left) => {
                 this.#delegate?.emulatorDidMakeLoadingProgress?.(
                     this,
@@ -333,6 +338,7 @@ export class Emulator {
             wasmUrl: wasmBlobUrl,
             disks,
             delayedDisks,
+            deviceImageHeader,
             cdroms: this.#config.cdroms,
             useCDROM: emulatorUsesCDROMDrive(emulatorType),
             autoloadFiles: {
@@ -364,6 +370,7 @@ export class Emulator {
         }
         this.#worker.postMessage({type: "start", config}, [
             rom,
+            deviceImageHeader,
             ...(prefsBuffer ? [prefsBuffer] : []),
         ]);
     }
@@ -897,7 +904,21 @@ function configToEmulatorArgs(
     if (config.debugLog) {
         args.push("--log-to-stderr", "--log-to-stderr-verbose");
     }
+    let addedHardDisk = false;
+    let addedFloppy = false;
     for (const spec of disks) {
+        // TODO: support more than one disk in DingusPPC
+        if (spec.isFloppy) {
+            if (addedFloppy) {
+                continue;
+            }
+            addedFloppy = true;
+        } else {
+            if (addedHardDisk) {
+                continue;
+            }
+            addedHardDisk = true;
+        }
         args.push(spec.isFloppy ? "--fdd_img" : "--hdd_img", spec.name);
     }
     for (const spec of config.cdroms) {

src/emulator/emulator-worker-device-image-disk.ts

@@ -0,0 +1,58 @@
+import {generateDeviceImageHeader} from "./emulator-common-device-image";
+import {type EmulatorWorkerDisk} from "./emulator-worker-disks";
+
+export class EmulatorWorkerDeviceImageDisk implements EmulatorWorkerDisk {
+    #disk: EmulatorWorkerDisk;
+    #deviceHeader: ArrayBuffer;
+
+    constructor(disk: EmulatorWorkerDisk, baseDeviceHeader: ArrayBuffer) {
+        this.#disk = disk;
+        this.#deviceHeader = generateDeviceImageHeader(
+            baseDeviceHeader,
+            disk.size
+        );
+    }
+
+    get name(): string {
+        return this.#disk.name;
+    }
+
+    get size(): number {
+        return this.#disk.size + this.#deviceHeader.byteLength;
+    }
+
+    read(buffer: Uint8Array, offset: number, length: number): number {
+        if (offset < this.#deviceHeader.byteLength) {
+            if (offset + length > this.#deviceHeader.byteLength) {
+                throw new Error(
+                    "Cannot read from both device header and disk in one op"
+                );
+            }
+            buffer.set(new Uint8Array(this.#deviceHeader, offset, length));
+            return length;
+        }
+        const diskOffset = offset - this.#deviceHeader.byteLength;
+        return this.#disk.read(buffer, diskOffset, length);
+    }
+
+    write(buffer: Uint8Array, offset: number, length: number): number {
+        if (offset < this.#deviceHeader.byteLength) {
+            if (offset + length > this.#deviceHeader.byteLength) {
+                throw new Error(
+                    "Cannot write to both device header and disk in one op"
+                );
+            }
+
+            new Uint8Array(this.#deviceHeader, offset).set(
+                buffer.subarray(0, length)
+            );
+            return length;
+        }
+        const diskOffset = offset - this.#deviceHeader.byteLength;
+        return this.#disk.write(buffer, diskOffset, length);
+    }
+
+    validate?(): void {
+        this.#disk.validate?.();
+    }
+}