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47

One rare possibility could be you triggered some of the infamous UEFI bugs, that already killed some series of Samsung and Lenovo notebooks. It works like this: UEFI specs propose a non volatile memory (nvram or eeprom) that can be accessed by the OS to store settings or debugging information. Linux actually uses this feature in case of a kernel panic: If ...


27

No, it is not possible to destroy the BIOS (legacy or UEFI) in this manner with that command. Even if you somewhat managed to destroy the UEFI partition, core BIOS files will not be affected, as they reside in non-volatile memory (flash-based, mostly) socketed on your motherboard. UEFI partition hosts additional software components (eg: debugger, driver, ...


11

Fantastic. I had this problem with a Fedora 22 Live image on an USB stick created as per UEFI boot of USB sticks using livecd-iso-to-disk --efi --format --reset-mbr Fedora-Live-Xfce-x86_64-22-3.iso /dev/sdX Which gives a bootable GPT-organized disk with a VFAT partition. Then I tried to myy a ZOTAC Nano CI320 using that stick and found myself in a EFI ...


11

The first problem that you write in UNIX style. But the UEFI uses DOS style. So your sequence of commands: map mount blk0 aaa aaa: // !!! change disk in dos stile cd EFI\debian // use backslashes grubx64.efi // run bootloader without "./" The second problem - you have nothing written about the disk partitioning system. You can`t use ...


10

When you say "EFI-only partition table" I suspect you're talking about a GUID Partition Table (GPT). Per Microsoft, Windows 7 and Windows Server 2008 can boot from a GPT, provided you're running an x64 build in a system with UEFI firmware.


10

While fun, rm -rf / can only break a havoc inside its own little jail -- and that is the partition(s) it is given. It cannot mess up disk MBR, nor it cannot magically destroy your computer. Something else is wrong in your case.


8

The other answers seem to agree that wiping the BIOS is probably not your problem, so here's another thought: My computer, when switched into UEFI mode, skips the BIOS screen completely. No manufacturer's logo, no nothing. It just tries to boot and tells me there's no bootable media (or boots). If I remember the key to enter setup, I can whack it as the ...


8

After a good month of going back and forth with Dell and Microsoft I received an "answer" about this error. Here was Microsoft's response: Our escalation engineer has debugged the issue and found this is a by-design behavior on EFI system. We have reproduced this issue on both of the hardware machine & VM. We would like to explain that we can ...


7

CentOS 7 currently does not support running on Hyper-V Generation 2 virtual machines, as can be seen here. You have to recreate the VM and specify Generation 1 as the VM type. Linux Virtual Machines on Hyper-V provides a comprehensive list of which distributions are supported and any limitations associated with them. For a list of the differences between ...


6

You don't need to switch back to a Generation 1 virtual machine. You can use a Generation 2 virtual machine, so long as you disable Secure Boot. To quote from Microsoft: Generation 2 virtual machines have secure boot enabled by default and Generation 2 Linux virtual machines will not boot unless the secure boot option is disabled. You can disable secure ...


6

From my understanding an EFI partition on a Linux server ensures a standard for the disk layout Ah, yeah. So you think laptops are super special? The EFI partition is part of the UEFI standard. Either you have an UEFI bios and use UEFI to boot, or you do not - and Laptop or Server is irrelevant. Let me quote from Wikipedia: It contains the boot ...


6

Firstly you mean GPT vs. MBR, not EFI vs. MBR - one's a firmware, the other a partition type. The only part it plays in your question is that, in general, you need an EFI/UEFI firmware based system (rather than a BIOS based one) to boot from a GPT partition, although that can be worked around sometimes. Anyway a few things, DON'T EVER USE RAID 0, seriously ...


6

There’s a conflict between the architecture types defined in RFC4578 DHCP PXE Options and the IANA registered Processor Architecture Types: the latter notes that x64 UEFI is type 00:07 which seems to be the value used in practice (ref. https://www.syslinux.org/archives/2014-October/022684.html). There's an Errata ID 4624 filed on the RFC. It states that 7 ...


6

Before starting, make sure you have a backup, and make sure to have a linux live boot ready to rescue your system. It's easy to mess this up! Use gdisk to convert the partition table to GPT. gdisk /dev/sda Create the "BIOS boot" partition that GRUB needs. n to create a new partition. Needs to be about 1MB. You can probably squeeze this in from ...


5

If you are getting to the EFI shell you likely already installed Ubuntu in EFI mode. The caveat I have found it that thought the OS installs fine using the grub-efi bootloader, an EFI boot entry for that boot loader is not written into the EFI variables correctly. This means the EFI firmware does not know how to load the boot loader and thus the OS and drops ...


5

I'm exactly at this point now, recording manual installation from PXE netboot to the UEFI VMWare system to extract right answers for preseed with debconf-get-selections --installer. What I see in the resulting file is: partman-auto partman-auto/choose_recipe select /lib/partman/recipes-amd64-efi/30atomic partman-base partman/default_filesystem ...


4

Well, after much searching, experimentation, and general frustration, I have basically come to the conclusion that Hyper-V does not currently support UEFI guests, even if the Hyper-V server is running in UEFI configuration. This seems to be supported by the fact that that recent builds of Windows Blue have what they call "Generation 2" VM's that include ...


4

The general rule is if you don't have a reason to switch back to BIOS, stick with UEFI.


4

This is, in fact, possible: Boot the system using a linux live cd with gdisk on it. I used a CentOS 7 Core installation and used recovery mode. I did this by editing the grub boot options and tacking on rescue to the end. Run gdisk on the disk with Windows installed. See the gdisk docs for more info. Reboot the machine into a Windows installation disk, ...


4

Apparently the card has two pieces of firmware in it: one for the card itself, and another for the system it's installed in. The second one is normally a BIOS extension, but you'd need it to be an UEFI-compatible driver instead. It might be possible to flash the UEFI driver to the card in place of the BIOS extension, or just load it as a separate UEFI ...


3

Hyper-V 2012 R2 generation 2 VM environments have UEFI firmware. See: http://technet.microsoft.com/en-us/library/dn282285.aspx http://blogs.technet.com/b/jhoward/archive/2013/10/24/hyper-v-generation-2-virtual-machines-part-1.aspx


3

Unfortunately you will need to reinstall after changing from uefi to legacy


3

The issue might be that you are not saving configuration. You should click back couple times and at the System Setup click finish and save the changes.


2

I found the answer: No. You cannot restore BIOS firmware backup on to a fresh install on UEFI. GPT/MBR is not the issue. It's a different firmware. Among other things, you will get "inaccessible boot device" blue screen. You will need to backup, do a fresh install on UEFI, install and configure all apps, and restore data.


2

I suspect more recent versions of CentOS will eventually no longer have the issue you faced (see https://bugzilla.redhat.com/show_bug.cgi?id=1192030 for the same issue in Fedora)


2

Just adding more on EFI.. Like TomTom mentioned you either have BIOS or EFI (Extensible Firmware Interface) also called UEFI. When you use EFI based systems you use GPT partitions. GPT partitions can address a disk more than 2TB which MBR can not at the moment. This is one of the major reasons of using GPT partitions in EFI based systems. So when you ...


2

Removed dhcp options 66 and 67 and added ip helper address pointing to wds. additionally had to disable netbios over tcp/ip on the wds server.


2

/sys/firmware/efi/efivars is a special file system containing all EFI variables. If the vendor didn't follow best practices, it's possible that your rm -rf wiped important ones and thus confused the firmware.


2

SEDs (or FDEs) are locked again on power-loss, therefore they should stay unlocked during a reboot. You should be able to boot your PC from a live stick or CD, enter the ATA pw (e.g. with hdparam), remove the live CD and simply reboot the PC. The problem is, that you have to do it every time you start your PC. Note that this current behaviour of SEDs is the ...


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