UEFI Booting NVME on x58 Project w/ Tianocore by mrlithium (draft) 4-29-2018 - Round Two

Using a TianoCore DUET USB stick to Boot Windows 10 in EFI mode from NVME SSDs such as Samsung PM961 on Legacy Platform X58 Chipset.

Already confirmed working on Asus Sabertooth X58 motherboard and Intel 750 Series SSDs approx 2 years ago.
Since then, a nice person named AudioCricket has developed a cleaner tutorial, (see AudioCricket blog article on Booting NVME ) which made me want to revise my own process, as he credits me with thanks for knowing it was even possible. You should read his also, its got some good details.

This tutorial is meant to give you bootability on extremely high speed NVME drives. If you are not using a high speed drive, or its in a wrong slot, you may not see much benefit. The whole boot process workaround itself, from the Tianocore DUET USB, takes up a valuable 10-15 seconds at bootup. You will pay a longer price on boot, but your Windows OS will be booted onto this faster drive, and there is no substitute for that. You already could use these drives as secondary storage partitions with no configuration, but thats just boring.
Linux Note: that if you are using Linux, all my info is largely irrelevant. Linux takes entirely another approach to booting.

My Process involves using the TianoCore DUET software and UEFI bootloader to chain boot load EFI Windows from a MBR USB stick.

To redirect your BIOS Boot -> MBR of USB stick -> virtual/emulated UEFI environment (Tianocore DUET) -> load open source NVME driver -> NVME GPT / EFI Windows System boot.
1 USB Stick for TianoCore UDK_X64  (USB 3.0 maybe needs an XHCI driver)
1 USB Stick for Windows 10 Setup ISO
Executing a few commands at the shell prompt
Running the Windows Setup Installer off a 2nd USB stick, using that to lay down new partition information and blank your NVME SSD.
Installing a new copy of Windows to the NVME SSD, with its own EFI partition and GPT layout. This is the best way to get the EFI boot working.
Booting NVME cannot be done without UEFI and booting EFI must be done for Windows (winload.efi). You cannot have Windows boot MBR (winload.exe)
At this point you will have two Windows Installs, and able to dual boot to the new NVME OS drive by inserting the Tianocore USB stick and booting

Boot process summarized: (Thanks to AudioCricket for his excellent description)

1. Computer powers on
2. Legacy BIOS boots / initializes
3. Tianocore DUET boots from the USB stick
4. Tianocore DUET executes UEFI Shell
5. UEFI Shell loads generic NvmExpressDxe-64.efi driver and remaps system block devices
6. UEFI Shell now sees Windows 10 hidden FAT partition DIRECTLY on the NVMe
7. UEFI Shell executes Windows 10 UEFI bootloader from that hidden NVMe FAT partion directly (\EFI\Boot\Bootx64.efi image)
8. Windows 10 is now booting and is in full control of your computer (under UEFI mode, of course)

Tianocore USB Stick Creation:

You will need the TianoCore DUET download package and stuff 

The USB stick needs to be formatted with "HP USB Disk Storage Format Tool" as opposed to Windows, so just download that. There is a reason for needing that stupid program, The MBR and DBR / BPB boot sectors need to be written as if it was a HDD not a removable (floppy) - err don't ask - :) After you reformat it, unplug/replug it.

Start up an administrative command prompt, and cd \tianocore_uefi_duet_installer-master
or, go into the location of CreateUSB.cmd  

Replace J: with the appropriate letter for your USB stick. (double check with HP USB Tool).

.

CreateUSB.cmd J:

Make sure no errors / unsavory messages are shown,
then unplug/replug it, and run this:

CreateUSB.cmd J: UDK_X64

This copies MOST of the files. You still need to manually copy over the file Drivers\NvmExpressDxe-64.efi this can be obtained here: or you can compile your own (coming soon/later)

UEFI Interactive Shell Usage:

From now on, rebooting from the Tianocore USB will launch into a shell. It acts kind of like DOS or Linux does, a simple command shell. Here you can explore and decide what commands to run:
Hit enter after every command. Theres also tab completion. You can use dir to look around.
Green colored files are executable and just typing their name should run them, for example *.efi
FS1: for drives (like C:) and \ for directories.
FS0: should be your booted Tianocore USB drive
FS1: should be the Windows USB stick
FS2: should be the NVME SSD drive (not visible yet)
Run these two important commands:
load \EFI\Drivers\NvmExpressDxe-64.efi  (loads the .efi program for detecting NVME devices - from this root pathname on the current prompts' FS device name)
map -r  (this will make new FS2: alias, etc)
Theres also "BLK" devices that correspond; you can ignore these besides to make sure they do exist for the right USB SATA or PCIe location.

A "startup.nsh" script can also be created, to AutoRun on boot, to automate the above commands in their final form or for anything else special that you may need or want.
Startup.nsh lives at \EFI\Boot\ directory and should just be auto-executed from there.

To boot the Windows Installer on the 2nd USB stick:

FS1:\bootmgr.efi
or
FS1:\efi\boot\bootx64.efi

Follow the Windows Setup, "Install Now" and choose "Custom Upgrade" so you can pick the right drives UnPartitioned Space (If you already attempted this, its best to Delete partition and go back to UnPartitioned Space and then say yes to "Windows may create some additional system Partitions". If it complains they are not in the correct order, "Delete" and hit OK on "UnPartitioned Space" again. The installer's Partitioner should be able to see your NVME drive immediately and without any drivers needing to be loaded.  Installation is seamless from here on out, other than a few reboots. Once the Windows Installer accepts your partition layout, it lays down the EFI partition on your NVME drive,  and starts "Copying Files...".  Meaning, across reboots, you need to reboot it from the NVME drive, not the Windows Install USB stick. While you're still technically doing the Windows Install, everytime the system reboots, this is the command you want to enter at the shell prompt to continue the installation. 

To boot Windows on the NVME drive:

FS2:\EFI\Microsoft\Boot\bootmgfw.efi

FS2 should be the alias for your NVME PCIe SSD drive device, (if not- double check, find it out).
This Runs the Microsoft EFI boot manager - that supports NVME boot.
Then Microsoft takes over, and the rest is magic. Now your system is fully working.
You would want to put this command in "startup.nsh" so its automatic. Keep in mind the FS drive letters numbers may get shifted, even due to just USB sticks.

Possible Secondary Optional or Advanced Steps:

Update Driver ? - replace the Microsoft stornvme.inf driver with a Samsung NVME driver (or whichever one, Intel?).

Using USB 3.0 to boot may require: \EFI\Drivers\XhciDxe-64.efi
Eliminating the need for a permanent USB Stick by copying the partition to any other internal hard drive in your system, and making room for it and also being able to dual boot it.
Not actually installing windows, just laying the boot partition down and then re-copying an Image of windows back over to the new SSD.
Small = ~4 Few megabytes. = Can be downloaded as a Disk Image *.dd, and use RUFUS to restore it back. Should be able to replicate Tianocore USB sticks for backups/disasters.
Editing the Windows BCD to get Dual Boot or Multiple Partitions combined or something else.
Remove un-wanted drive letters of the other system after bootup.

Super Fast NVME PCIe SSD's on Legacy X58 Platform - other Practical Considerations:

*** PCI-e version revision and link width ***
PCI-e 2.0 was the max for X58, and as of today we are up to PCI-e 3.0 which doubles bandwidth by 2x.
Theres also certain slots that are PCI-e 1.0 slots (the bottom slot on Asus Sabertooth is 1.0 and the 2nd GPU x16 slot is the only next best highest speed 2.0 x4 slot :/
Benchmark overall speed drastically improved when switching slots, from around 750-770MB/s over PCI-express 1.0 x4 to 1450-1600MB/s on PCI-express 2.0 x4. (With the Samsung PM961 SSD, and tested under CrystalDiskMark and AS-SSD.)
Note this is nowhere near the drives theoretical maximum, that would requires PCI-e 3.0 and should be hitting somewhere over 2-3000 MB/s.
Also note that most slots are only physically, but not electrically, the full width of PCI-e lanes. Make sure your slot is valid.
It is advised to check in a program like HWInfo64 or AIDA64 at your Motherboard slot DMI information and for sure confirm the devices are detecting at proper revision and width. (CrystalDiskMark will say the link speed for PCI-e devices now so thats handy). If not, Power Management settings could be configured to do Link State Power Management or whatever thats called.