I have a DELL machine that use Phoenix SecureCore Tiano as its UEFI/BIOS
However, it is totally not configurable as its UEFI shell & menus are hidden in BIOS Setup.
I'm wondering if there were tools that can modify the UEFI settings(such as Boot Items)
in user mode?
such as "efibootmgr" in linux.
btw, because it is not configurable, I think the boot process is in legacy mode
so that's to say OSes can not detect the UEFI exist, am i right?
so, that's the paradox:
I must be boot in non-legacy mode to enable UEFI tools to modify boot items in user mode?
but I must enable UEFI tools to modify boot items first to enable non-legacy boot?
Best Answer
EFI implementations must provide some way to control the boot mode (EFI vs. BIOS), except of course for EFI-only implementations without BIOS support. Too often, though, the firmware gives the user little or no explicit control of the matter; instead, the firmware attempts to infer the correct boot mode based on the state of the hard disk -- for instance, it might use EFI mode if a GPT is detected and BIOS mode if an MBR is found; or it might use EFI mode if an EFI System Partition (ESP) is found and BIOS mode if not. You may be able to find a clue about what your firmware is doing by reading the manual. If not, you'll just have to experiment.
When booting removable media, the rules may be different, but you can often give it a kick in the right direction by providing just one boot mode. This may require re-mastering a CD or (more easily) carefully selecting a CD. If you're trying to force an EFI-mode boot, my rEFInd, and in particular its bootable CD version, may be helpful; it boots only in EFI mode, and as configured, it will act as a boot manager for other EFI-based boots, but not for BIOS-mode boots.