Windows 8 AIO x64 and x86 project.

I have abandoned this effort. There is just too many issues that arise from trying to modify the setup files to allow the recovery.
It's fairly easy for normal BIOS booting, but for UEFI booting, it causes a lot of problems.
I spent a few days playing with bcdboot options in the efi\microsoft\boot folder and couldn't get it to boot properly in EFI mode.

I'm not saying it's not possible. I'm just saying that I couldn't figure it out, so I gave up; for now.

 

Indeed they are. x86 bootmgr.efi will not boot an x64 boot.wim and vice versa.
The good news is that you don't actually need to boot x86 UEFI for 99.99% of the systems.
You cannot boot 32-bit UEFI on any processor that is 64-bit.
Typically only some tablets use 32-bit UEFI.

Edit: ahh forgot your issue...
Well... you would copy over the bootmgr.efi and boot\bootx64.efi from an x64 image as well as make a sources folder for the x64 files for upgrades.

Here are my old notes on the issue, though it should be noted that you need to set the efi\boot\bcd to boot from the different x64 boot.wim as well:

Code:

Navigate to \boot\


bcdedit /store bcd /copy {default} /d "x64 Recovery Mode"


This command shall tell you the GUID of the copy made, make a note of it.


Next set the new loader to load the 64 bit PE by executing:


bcdedit /store bcd /set {GUID} device ramdisk=[boot]\sourc64\boot.wim,{7619dcc8-fafe-11d9-b411-000476eba25f}
bcdedit /store bcd /set {GUID} osdevice ramdisk=[boot]\sourc64\boot.wim,{7619dcc8-fafe-11d9-b411-000476eba25f}
(Replace {GUID} with the GUID you noted down, keep the {}s)


Finally, alter the boot timeout by executing:
bcdedit /store bcd /timeout 5


Win8 set legacy mode (may have to do on BOTH boot options. I actually removed x64 upgrade from a win7AIO image using easybcd
then added the new one using this method)
bcdedit /store bcd /set {GUID} bootmenupolicy Legacy


Stage 4: getting upgrade to work
Now, the one problem left is upgrade installs on 64 bit. This involves hex editing files, and so breaks the digital signature, causing the ugly yellow UAC prompt. This is, I am almost ashamed to say, the first of two such cosmetic glitches.


Now first open D:\AIO\DVD\setup64.exe in your hex editor. Search and replace all instances of the unicode string "sources\" with "sourc64\". Although this breaks the signature, it does not break the program, because both strings are the same length.
Now, open D:\AIO\DVD\sourc64\autorun.dll, and replace all instances of the unicode string "sources\setup.exe" with "sourc64\setup.cmd"


Now, create a file in D:\AIO\DVD\sourc64 called setup.cmd containing exactly this:
setup.exe /installfrom:\sources\install.wim


This is the cause of the second cosmetic glitch. A command prompt is briefly visible before setup is launched.


Now, the autorun.inf must be modified so that it runs setup64 on x64 systems. Modify it so it contains:


[Autorun.Amd64]
open=setup64.exe
icon=setup64.exe,0


[Autorun]
open=setup.exe
icon=setup.exe,0

Again, those are old notes, but they should still apply if you modify a few things...

 

In the multi-brand oem project, it has an exe that auto-detects things and sets the key if it finds it in the bios.
You can try playing around with that.