[syslinux] PXE booting WinPE with UEFI architecture

[Alexandre Blanchette]

With the BIOS architecture, I was used to boot WinPE from PXELINUX. I used
4 different ways:
1- Calling windows' native PXE loader directly from the config file with a
'kernel' line.
2- Calling windows' native PXE loader with pxechn.c32.
3- Loading an ISO with memdisk
4- iPXE project's wimboot, which relies on memdisk

Methods 1 and 2 are slow because loading the bulk of the system is done by
TFTP. Methods 3 and 4 could be adapted to use HTTP.

With the UEFI architecture, memdisk seem to be out of the equation now, so
methods 3 and 4 are out. Although I'd really appreciate if the
functionnality memdisk provided could be ported somehow to the UEFI
architecture.

For option 1, Windows' PXE loader is bootmgfw.efi. The configuration looks
like this:
LABEL WinPE50
  MENU LABEL Windows Boot Manager
  KERNEL \boot\x64\bootmgfw.efi

I then get:
Loading \boot\x64\bootmgfw.efi... failed: Bad file number

How can I load a EFI file?

Lastly for method 2, with the following configuration:
LABEL WinPE50
  MENU LABEL Windows Boot Manager
  COM32 pxechn.c32
  APPEND \boot\x64\bootmgfw.efi

I get:
pxechn.c32: ERROR: Unable to retrieve first packet
Could not unpack packet

Using SYSLINUX 6.02-pre16
I could not use SYSLINUX 6.02-final because of the TFTP port bug.

-- 
Alexandre Blanchette <blanalex at gmail.com>