Image replicator make

Two types of USB Image Replicator images are available for this platform: a tarball and an actual disk image. They both have the same contents yet provide different methods to write the Image Replicator tool to a USB disk.

Disk Image (.dd.xz)

The disk image is easier to write from different workstation OSes, will auto-expand to the full disk length on its first boot, and is intended to be used for image capture (and later image writing) due to its small size and auto-expansion process. We recommend this route for users who may not have access to a Linux workstation or need to capture images from a golden unit first.

Tarball Image (.tar.xz)

The tarball image is easiest to write from a Linux workstation, but requires creating a partition table on the USB disk (if one does not already exist), formatting the filesystem, and unpacking the tarball. It can readily be used for both image capture and writing, but is easiest when image capture is not needed, due to the auto-expansion process.

Note:

This process recommends a solid-state USB drive. Slower USB drives, especially those with spinning media, may take too long to enumerate and the bootloader will not boot the Image Replicator disk. Low quality, damaged, and/or worn out USB drives may cause unexpected errors that appear unrelated to the USB drive itself. If there are issues using the Image Replicator, we recommend first trying a new, fresh, high-quality USB drive from a trusted brand.

Disk Image

This process uses a small disk image that can be written to a USB device. This disk image uses an ext3 filesystem which expands on its first boot to the full length of the disk before beginning the image capture process, and is recommended for users who may not have access to a Linux workstation or who need to capture images from a golden unit.

It is possible to use the disk image only for image writing. However, to ensure that full disk space is available, it is recommended to write the disk image to a USB drive, set the IR_NO_CAPTURE_* Image Replicator Runtime Options, boot it on the target unit, let the system boot and expand to the disk, insert the USB drive back in to a workstation, and then copy in the desired image files for the target unit from the workstation.

Writing Disk Image From a Linux Workstation

The disk image can be written via the command line with the dd command (replace /dev/sdX with the correct USB device node):

xzcat <platform>-usb-image-replicator.dd.xz > /dev/sdX

Graphical tools also exist for this purpose, for example balenaEtcher offers this functionality.

Writing Disk Image From a Windows Workstation

A number of tools exist for writing an image to a USB drive, including (but not limited to) balenaEtcher and Win32DiskImager

Writing Disk Image From a MacOS Workstation

We recommend using a tool such as balenaEtcher to write disk images.

Tarball

This process is easiest on a Linux workstation, but can be performed on other operating systems so long as they can support a compatible filesystem, the xz compression algorithm, as well as the tarball archive format. Note that in many cases, one of our computing platforms running our stock Linux image can be used if a Linux workstation is not available. After writing the tarball to a USB disk, the full length of the USB disk would be available to copy source images, to write them to other units.

The image replicator and scripts require a minimum of 50 MB. Additionally, the size of target disk images or tarballs used also dictate the minimum USB disk size required. The USB drive should have only a single partition, which is formatted ext2 / 3 / 4 or FAT32/vfat Note that other filesystems are not compatible with U-Boot and therefore cannot be used.

Writing Tarball From a Linux Workstation

# This assumes USB drive is /dev/sdc:
sudo mkfs.ext3 /dev/sdc1
sudo mkdir /mnt/usb/
sudo mount /dev/sdc1 /mnt/usb/
sudo tar --numeric-owner -xf /path/to/<platform>-usb-image-replicator-rootfs.tar.xz -C /mnt/usb/
sudo umount /mnt/usb/

Writing Tarball From a Windows Workstation

A third party tool is recommended, as native Windows archive tools have occasionally not worked correctly. Tools such as 7-Zip or PeaZip are known working. (It may also be possible to use Windows Subsystem for Linux following the Linux Workstation instructions above, but this has not been tested.)

Note that some Windows tools may attempt to use the whole disk, rather than create a partition table. A partition table with a single partition is required for U-Boot support.

With a formatted USB disk, the archive can be unpacked to the root folder of the USB disk. Be sure to not unpack the tarball contents into a new folder on the drive, as this will not boot.