Multiboot - PXE Network Boot

PXE Boot multiboot requires you to install iPXE package. The idea is that it transfers the full control to iPXE for executing PXE network booting.

Install iPXE Package

First of all, you need to install the iPXE Package via your distribution channel. For example, on Debian or dpkg manager:

$ sudo apt install ipxe

This package will setup:

1. A grub configuration entry containing the menuetry at: /etc/grub.d/20_ipxe.
2. The iPXE executable, installed into your /boot directory, specifically /boot/ipxe.lkrn.

Once done, that's all about it.

Explanation

The package automatically adds the following entry:

menuentry 'Linux NetBoot Environment' {

        set root='(hd0,1)'

        ...

        <More, less important options>

        ...

        linux16 /boot/ipxe.lkrn

}

This means the GRUB is transferring the full control to /boot/ipxe.lkrn, similar to memtest entry for memory testing.

That's all about multi-booting to PXE boot.