I'm trying to change our boot configuration from BIOS to UEFI. I've tried to simplify the problem.
I'm booting via BIOS PXE to SCCM task sequence and performing following actions:
- Apply UEFI Secure Boot configuration with BiosConfigUtility (Secure Boot enable, boot order that is ignored anyway...)
- Set disk partition type as GPT
- Create Fat32 partition for EFI boot and NTFS volume for data
- Apply WinPE to NTFS and copy boot files (bcdboot) to Fat32
- Set Fat32 volume as ESP
- Reboot
Now BIOS will not allow me to boot this disk. Disk shows up in "Device configuration" but not in Boot order.
If I boot again to PXE (now in UEFI mode) and check disk contents, all seems in order. If I reapply my script to redo steps 4 and 5 then on following boot the disk will apper in Boot Order and boot.
If before first UEFI attempt I put in a known UEFI bootable disk, the system will not boot it either.
I'm thinking that there's a bug in BIOS.
I've seen something similar with Z620. When applying some config changes to BIOS, system will no longer show valid boot hard drives in Boot Order (that attempt was in BIOS mode). Switching controller emulation to RAID and back to AHCI worked around it then. But this time I'm not changing controller emulation.
Also BiosConfigUtility reports that it has set boot order changes but when reading them back (before or after reboot, they're the same). That's not as important but
BiosConfigUtility 4.0.15.1
BIOS v2.68