We have one SONiC Image per ASIC vendor. You can download SONiC Image here.

You can also build SONiC from source and the instructions can be found here.

Once the image is available in your local machine, the image can be installed either by installing using a USB thumb drive or over the network as given in following sub-sections. In case if the device is already preloaded with SONiC image, the device can be booted without the installation process.