Chaining to Grub2 or SysLinux from Windows BCD

Anybody has some good info ???

I'm trying to keep my Super Multiboot USB drive current and have problems loading for example: An extracted MemTestx86_7.50 with syslinux in UEFI...

I would like to keep it with Windows BCD because It permits to completely have MBR and UEFI boot modes separated on only one NTFS partition and a EPS partition.

I'm not as Linux proactive as I would like... But How do you locate boot / kernel file to use in BCD ?

I Have the full working commands with Grub and SysLinux, but still can't make it out to chain from Windows BCD...

The goal is to be able to keep my previous MBR boot manager (who is able to boot "Everything" and I mean it...) and at least have a way / more extensive Way to boot UEFI stuff.

Also the goal is not to redo everything because it takes a couple of days getting there. This setup boots: iso, bin, img, ima, imz, igz, wim, Squash,

The drive currently contains:

Code:

Win10XPE
HBCD_PE
Gena
PHDM14
PHDM15
PW11Tech
UBCD
MEMtest+
MEMTest
Eset SR
NBRT
Win10 Setup
Win11 Setup
Linux Mint
Knoppix
Spinrite
PQPM8
DOS71

At the moment my current BCD is Working perfectly to load in Pure UEFI Everything I Want...But...

I would like to add MEMtest 7.50 And Knoppix 9.1 to the BCD both are already working in MBR and are Extracted (Meaning I'm not loading the ISO file but loading the boot files as ROOT and mapping Virtual disks while using provided boot managers.

As this description is still pretty vague, I can fill in for any questions you may have. But it all boils down to: How to Load an UEFI Linux startup sequence with BCD or chaining to Grub2 or SysLinux.

Any suggestions are welcome.

Thanks @spunk,

Couple of tests demonstrated nothing Linux Boots well in UEFI on something else than Fat32... at least on USB drives.

Sometimes you need to redo... The fact that nearly all are not using the ESP partition makes me laugh...

Then of course the "not enough disk space" popped up later while trying to copy a too large image on the drive... lolll

This is a dead end at the moment... You have to choose between Lin or Win, and I'm not ready to stick a Tux on my keyboard.

So if one day Microsoft decides to load something else than Windows with BCD... Fine... At the moment most utilities creates Bogus entries that are not even related to their Linux counterparts... Their whole concept of Linux UEFI support is... Flawed.

At least on USB booting in what is regarding Ram Drive Loading and Boot Files Mappings... Got to wait some more.