Can I ask as this question has a solution which is for Debian Buster that this thread is removed from the Off Topic section
I have managed to create a live USB of Debian Buster 10.5 which works with Legacy Boot as well as UEFI Secure Boot.
What I am trying to do/learn is if it is possible to run other distros using either their ISO or extracted files from my Live USB.
For example I am able to use it to boot Ubunto ISO's in legacy mode and UEFI ( without Secure Boot ), but when I try to do the same using Secure Boot, I receive a message saying invalid signature for vmlinuz.
Obviously this is because the USB does not have access to the Ubuntu ISO's internal BOOTX64.EFI.
So my question is; is there any way to include those in a way that will allow booting using secure boot.
As a suggestion, I have been trying to find information about fbx64.efi and BOOTX64.CSV which allow defining a fallback BOOTX64, but I dont think that it will work for my use case.
So am I wasting my time? Or is there a way I have not looked at.
Any help/advice would be appreciated.
PS. Once I know what the limitations are I will finish my work and hope to release the steps I followed to create the Live USB in case of it being helpful to other.
Just finished a write up of how I created a Live Debian Buster 10.5 Secure Boot USB
SORRY I REMOVED THE LINK BECAUSE SOMEONE THOUGT I WAS SPAMMING.
PPS. I am not using a live USB to build a live USB. I am building from scratch a live USB using debootstrap and chroot. I end up with a LXDE desktop under 200MB including the latest google chrome browser and include all free and nonfree firmware.
********* SOLVED **************
OK, I know some have said that this was off topic, but having a debian live USB capable of running multiple 3rd part distro is somthing that some may find usful.
I have managed to add multiple BOOTx64.EFI to the USB EFI partition, in the same way as this is done on the HDD. I have also managed to automate the process by using grub keyboard fuctions to run each step.
First for reference, I am using the USB created in the mentioned link above.
I will use Lubuntu as an example 3rd party distro to add to the live USB.
I extracted the grubx64.efi and BOOTx64.EFI from the ISO
mounted the USB EFI partition and created a directory which I used to copy the said files.
You cn repeat this for as many other distro's you want.
Next I modified the main UEFI grub menu and added the following menu entries to allow loading of Ubuntu grub and BOOTx64 EFI entries
menuentry "Debian Buster 10.5 UEFI Secure Mode - Boot 3rd Party Distro (EG : Lubuntu)" {
echo "Debian Buster 10.5 UEFI Secure Mode - Boot 3rd Party Distro (EG : Lubuntu)"
}
menuentry " Step 1 ) Load 3rd Party GrubLoader" {
search --set=root --file /other/grubx64.efi
chainloader ($root)/other/grubx64.efi
boot ($root)/other/grubx64.efi
}
menuentry " Step 2 ) Load 3rd Party BootLoader" {
search --set=root --file /other/grubx64.efi
chainloader ($root)/other/BOOTx64.EFI
}
menuentry " Step 3 ) Enter 3rd Party Grub Menu" {
search --set=root --file /area3/grub.cfg
set prefix=($root)/area3
configfile ($root)/area3/grub.cfg
}
I have automated the process by defining a grub key which run the three menus in turn, so the user will only see the top menu, and once selected the submenus will be run.
For simplicity I have not shown the submenu method as the above is simple to see and understand.
Lastly by adding a exit menu we can return the the Debian grub and bootloader there by allow to run Buster once more.
The only extra work is a small script to extract the files needed from the ISO and updaing the EFI partition.
Thank you again for your input.
PS. Can I ask as this question has a solution which is for Debian Buster that this thread is removed from the Off Topic section.