[syslinux] PXE booting WinPE with UEFI architecture

[Michael Brown]

On 30/08/14 02:00, Gene Cumm wrote:
>> And then in the same location, I put this boot.ipxe file and all support
>> files:
>>
>>    #!ipxe
>>    kernel wimboot
>>    initrd bootmgr          bootmgr
>>    initrd boot/bcd         BCD
>>    initrd boot/boot.sdi    boot.sdi
>>    initrd http://<SCCM-server>/boot.wim boot.wim
>>    imgstat
>>    boot
>
> Likely if you transform the above to Syslinux format.
>
> LABEL wimboot
>    LINUX wimboot
>    APPEND initrd=bootmgr,boot/bcd,boot/boot.sdi,http://<sccm-server>/boot.wim

For UEFI, wimboot acts as a UEFI binary and expects to be able to access 
the initrd files via EFI_SIMPLE_FILE_SYSTEM_PROTOCOL.  This allows a 
boot of iPXE->wimboot->WinPE using an iPXE script such as:

   #!ipxe
   kernel wimboot
   initrd bootmgr bootmgr
   initrd EFI/Boot/bootx64.efi bootx64.efi
   initrd Boot/BCD BCD
   initrd Boot/boot.sdi boot.sdi
   initrd sources/boot.wim boot.wim
   boot

Note that the same script (and the same wimboot binary) should work for 
both BIOS and UEFI systems.

For syslinux, I would guess that you could place the bootx64.efi, BCD, 
boot.sdi, and boot.wim files in the same directory as the wimboot 
binary, and then just invoke wimboot as a UEFI binary (_not_ as a Linux 
kernel).  I don't know the configuration file syntax for this, sorry.

Michael