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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?

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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.

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thanks! when i partition my hd in MBR mode, it works as expected. however, if i use GPT mode, no matter there is an ESP or not, it just won't boot and gives this error: "Operation System not Found". The error message /w syntax error, is surely from the BIOS itself after I reverse engineered the BIOS rom (not from any bootloader or boot record), so I just can not get the boot control to be passed in GPT mode. –  marstone May 29 '12 at 1:49
    
Some EFI-based systems will only boot in BIOS mode if they detect an MBR partition with its "boot" (aka "active") flag set. On a GPT disk, this requires setting that flag on the 0xEE protective partition in the MBR. You can use a tool like Linux's fdisk to do this (use the "a" option). Do not use parted, GParted, or other libparted-based tools to do this; on a GPT disk, they give you no control over what's in the MBR, and the "boot flag" will be applied to a GPT partition, with the meaning being that it sets the type code to that of an EFI System Partition (ESP). –  Rod Smith Jun 1 '12 at 4:50
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I've just bought a Dell XPS 17 (l702x) and I'm interested in multi-booting a variety of OSes. If what I've understood is correct, the Dell has some form of locked-down Phoenix SecureCore Tiano UEFI 'BIOS'. From what I've read, UEFI isn't directly usable (possibly via a hidden menu etc., which might require a BIOS mod).

It does seem possible to use/access a Phoenix compatible EFI shell, using the open-source (BSD) TianoCore edk2/ShellPkg (source) and edk2/ShellBinPkg (binary) packages (GIT Repo here). Lending from a TianoCore/UEFI post I found:

(TianoCore/EDK) ShellBinPkg offers a "full" UEFI Shell 2.0 (which supports the most commands). A custom shell can be built using the ShellPkg source code (standalone or included in an OVMF package to generate a x64 version).

The [U]EFI shell binary is compiled to run independent of the firmware. This can be tested by putting the shell on a FAT32 file system (USB stick, hard drive partition), renamed as "/efi/boot/bootx64.efi" and then booting to it, from your [UEFI] BIOS.

Help text for the shell is accessed by typing "help utilname". Just using "help" produces a list of all available shell commands.

Also of interest is Arch Linux's take on UEFI, which mentions the following, supporting the use of a shell, as above:

Note: If you are unable to launch UEFI Shell from the firmware directly, create a FAT32 USB pen drive with Shell.efi copied as (USB)/efi/boot/bootx64.efi . This USB should come up in the firmware boot menu. Launching this option will launch the UEFI Shell for you.

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that's great. i bought the same model l702x ;-) i'll try it tomorrow! the hidden menu is still unlockable as far as i know. btw, do u have compiled bootx64.efi and have tested on your xps yet? –  marstone Jul 22 '12 at 16:50
    
ShellBinPkg is a UEFI shell pre-compiled binary, you're supposed to be able just have to rename it and put in the right directory. I tried it, and it didn't work for me, but I don't believe it's the only shell that's available (I'm new to this, also). This post seems to offer a shell download which should work with Phoenix SecureCore Tiano (See the.ridikulus.rat->cfr conversation). Let us know how you get on. –  Big Rich Jul 23 '12 at 16:57
    
I tried put the efi file from the above post to /efi/boot/bootx64.efi, however, my usb disk booted to grub normally(it is bootable already); then i formatted my u-disk to HDD mode, and i got the error "Remove disks or other media ...". I then took a hex search for this string sector by sector in my u-disk, it did not exist. the message must from L702x's Tiano BIOS. anything wrong for my operations? –  marstone Jul 25 '12 at 14:25
    
@marstone, sorry man, but I'm a newbie myself when it comes to this UEFI stuff (I'm just OK with my Google-fu ;-) ). Been occupied elsewhere, as soon as I get some time I'll try this myself and let you know how I get on. Cheers, Rich. –  Big Rich Jul 26 '12 at 20:15
    
Although Dell has now released a UEFI enabled bios (A19), 'capitankasar' over at notebookreview posted 2x modded A18 bioses (uefi, uefi+nvida gpu), they address UEFI, NVidia GPU overclocking and fan speeds etc. (some of these features may also exist in the official Dell release, I haven't confirmed this myself). As always, use at your own risk ;-) –  Big Rich Nov 8 '12 at 11:56
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