Booting A Remote OS Image

[obie]

I'm very new to iPXE but have gone through the /docs and /examples to try and build my new iPXE script but am still confused as to how to build this.

I have an OS image created and placed in a cloud storage bucket and I want to be able to boot from that location.
(http://s3.aws.com/my-bucket/my-os-image).

My understanding is that I can create an iPXE script to build an iPXE OS USB image that loads from this bucket location.

along the lines of 'make bin/ipxe.usb EMBED=startup.ipxe' where startup.ipxe is my own custom script.

Is this correct?

Additionally, I'm having trouble writing startup.ipxe itself.

Would it be as simple as:

'
dhcp
imgfetch http://192.168.0.1/img.igz
boot img.igz
'

Please let me know of any examples that are relevant or docs that are useful for what I'm trying to do.

Thanks for your help.