Starting undionly.efi or snponly.efi from the linux command

[ebruno]

(2018-10-16 07:13)NiKiZe Wrote:  You can use ipxe.lkrn and start that from syslinux or grub in legacy mode yes.
Booting efi binaries from grub seems flaky,
you could put ipxe.efi on the efi partition and add a boot entry to it into the firmware, meaning that it can be selected before grub or any other bootloader.
(You have to remember that Legacy BIOS and EFI boots are different.)
You can not enter efi mode from legacy mode, and you can not enter legacy mode from efi userspace - don't mix this up!

undionly is only usable if there is an existing nic driver that can be used - which in most cases are in the NIC ROM
Same for snp devices.

I was able to build bin-x86_64-efi/ipxe.efi with a custom script and install it on the EFI partition. I made it the first boot option with the command:
sudo efibootmgr -c -w -I \\EFI\\ipxe\ipxe.efi -L "MyTest" -d /dev/sda

BootOrder: 0002,0000,0001
Boot0000* ubuntu
Boot0001* Syslinux
Boot0002* MyTest

The custom ipxe script is as follows:

#!ipxe
set user-class ipxetest
echo ipxe started with user-class ${user-class}
clear ip4
dhcp
echo Chaining to tftp://${next-server}/${filename}
sleep 15
chain tftp://${next-server}/${filename}


I see the echo message. So I know that my ipxe.efi is being invoked, The dhcp command does not see that link is up on net0, tries the other interfaces but is not able bring up the network. The message on the console is:
Waiting for link-up on net0 see http://ipxe.org/38086193
(same message for other interfaces).

Just for testing I added a retry loop on the dhcp 5 times with a 5 second delay.

Same problem from either warm start or a cold boot from a powered down state.

My end goal is to contact a web server on the local network that will generate the final chain command.