create

Create a CheerpX DataDevice instance to store temporary data in memory.

namespace CheerpX {
  class DataDevice {
    static async create(): Promise<DataDevice>;
  }
}

Parameters

None

Returns

CheerpX.DataDevice.create returns a Promise that resolves to a DataDevice instance. You can use this instance to create a temporary in-memory filesystem in your CheerpX environment.

Example

Create a DataDevice instance for in-memory storage.

// Create a read-only block device for a disk image stored on the HTTP server
const blockDevice = await CheerpX.HttpBytesDevice.create("/cheerpXImage.ext2");
// Make the block device read-write using a persistent IndexedDB overlay
const idbDevice = await CheerpX.IDBDevice.create("block_idbDevice");
const overlayDevice = await CheerpX.OverlayDevice.create(
  blockDevice,
  idbDevice
);
// Add a device to expose JavaScript data in the VM
const dataDevice = await CheerpX.DataDevice.create();
// Initialize the CheerpX environment
const mountPoints = [
  // Use the disk image as the filesystem root
  { type: "ext2", path: "/", dev: overlayDevice },
  // Add the DataDevice to a known location
  { type: "dir", path: "/data", dev: dataDevice },
];
const cx = await CheerpX.Linux.create({
  mounts: mountPoints,
});

In this example, the DataDevice is created using CheerpX.DataDevice.create() and mounted at /data in the Linux environment inside the CheerpX system.

If you’d like to learn more about related topics, check out these guides:

Files and filesystems – Managing files and storage in CheerpX.
Custom disk images – Creating and using custom disk images.
Input and output – Handling data flow in your environment.