Here's a video tutorial on how to utilise this to boot on an SSD by an awesome small electronics hacker:

https://youtu.be/zVhYvvrGhMU

I'm surprised no one is getting excited for pxe boot.

That's a game changer.

That’s been available on earlier versions of the Pi (2B v1.2, 3B, 3B+).

It was not available at launch for the Pi 4, but was released in beta firmware in late September, and is currently part of the critical firmware update.

It works well, allowing separate boot images for each individual Pi on your network.

> It works well, allowing separate boot images for each individual Pi on your network.

Isn't that a natural capability with PXE implemented at the server keyed off the MAC address?

I’m sure that’s true. I’ve only used this for Rpis, which have it as a neat pull-based capability. Just add a subdirectory with the right name for each one in the tftp root.

That's how it works for other PXE boot as well...

yup, i tried netbooting on the 3b+, with root on nfs and without an sdcard.

> It works well, allowing separate boot images for each individual Pi on your network.

could you elaborate a bit more on that?

Intel should be making an Optane sdcard for embedded use, potentially with a built in power down capacitor to make sure all acknowledged writes make it to Optane.

When using netboot, the boot rom will pull the files it needs from the tftp server. It will first look for them in a subdirectory with the Pi’s serial number as its name.

If you’re netbooting without any sdcard installed, I’d suggest disabling sd polling.

PXE uses the MAC address doesn't it?

It does, but I think what the Pi does is connect to the TFTP server handed out by PXE and then look for a folder named serial-number. If it doesn't exist in the path PXE gave it it just boots whatever is in the tftproot.

Might or might not. It does DHCP request and server-side, you can do decision on what it returns on any tag you want, often client architecture (0x93); you can then point to the right tftp server, or if you have UEFI client, you can also use http.