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 and are intended to 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 OSs, 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 for both image capture and writing, but is the easiest route when image capture is not needed due to the auto-expansion process.

Note:

It is recommended to use USB drives with solid-state media for this process. Slower USB drives, especially those with spinning media, may take too long to enumerate and the bootloader will not boot the Image Replicator disk. Additionally, the use of 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 named 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. This disk 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 for just image writing, however, in order to ensure full disk space is available it is recommended to write the disk image to a USB drive, boot it on a unit, let the image capture process complete, insert the USB drive in to a workstation, and then remove the captured image files before copying 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 | dd of=/dev/sdX bs=1M conv=fsync

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 performs on other operating systems as well 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 in order to write them to other units.

The image replicator and scripts require a minimum of 50 MB; this plus the size of any target disk images or tarballs to be used dictates 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

It is recommended to use a third party tool, as native Windows archive tools have been observed to not work 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 in to a new folder on the drive as this will not be bootable.