a question about ipxe boot for imac a1419

[robinsmidsrod]

If you downloaded ipxe.iso from boot.ipxe.org it should contain all drivers supported by iPXE. Most likely your iMac is using an unsupported network card. If you could figure out the PCI vendor/device ID for the card we might be able to figure out if it is trivial or very complicated to add support for your card. You can figure out these numbers using the lspci command in Linux.