Using a MacOS Host to Create a Bootable Device

These steps outline the process for creating a bootable storage device on a macOS* based workstation. Where the .wic image is supplied in a compressed format, it should be expanded prior to this process. For example, a .xz format file can be expanded (uncompressed) using the macOS* built-in Archive Utility application.

Intended usage

A bootable storage device can hold a live operating system that runs entirely from the storage device. Or it can hold an installer package that will, upon booting by the platform, install an Operating System image onto the platform.

Creating the Bootable device

The following steps outline the process to create a bootable microSD card or USB drive with a macOS* based workstation. These steps are a general outline of the best known method. Steps will vary depending on the workstation OS version, developer tool preferences, and other factors outside the scope of this guide.

  1. Open a terminal window, then enter the command:

diskutil list

  1. In the output, identify the disk identifier (not the partition) for your boot device. For example, use disk4, not disk4s1.

  2. To prepare your card for writing, first unmount your boot device by entering the command, where disk# is the disk identifier you found in the step above:

diskutil unmountDisk /dev/disk#

For example:

diskutil unmountDisk /dev/disk4

  1. To copy the data to your boot device, enter the command, where os-image is the name of the Reference Operating System for IoT image file and rdisk# is the disk identifier you found in the step above:

sudo dd bs=1m if=os-image of=/dev/rdisk#

Wait several minutes for the image to copy to your boot device.

  1. When finished, eject the boot device by entering the command:

diskutil eject /dev/disk#

  1. Now that you have created your boot device, disconnect the device from your computer.

Loading an OS image, or an Installer Package, on the Bootable Device

Install the target Live-OS image, or copy the installer package, onto the storage device and configure the targeted files to run at boot. See Acquire Target OS File to Install for instructions.

Connect the bootable device to the platform and configure it as the target boot device, reboot and run or install the operating system from the bootable device.

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