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What is the difference in "Boot with BIOS" and "Boot with UEFI"

Now Windows 8 supports the UEFI bootloader and I have read that its different from the BIOS, but it's unclear to me after many searches on the Google.

Some points in mind are below

• As we all know, BIOS is an important part of accessing boot options. So UEFI will do that now? How?

• How would I know that I'm booting with UEFI not with BIOS?

• So what is the real different in the "boot with BIOS" and "boot with UEFI"?

If I buy a computer with Windows 8 and Secure Boot, will I still be able to install Linux?

I've heard a lot about how Microsoft is implementing UEFI Secure Boot in Windows 8. Apparently it prevents "unauthorized" bootloaders from running on the computer, to prevent malware. There's a campaign by the Free Software Foundation against secure boot, and a lot of people have been saying online that it's a "power grab" by Microsoft to "eliminate free operating systems".

If I get a computer that has Windows 8 and Secure Boot preinstalled, will I still be able to install Linux (or some other OS) later? Or does a computer with Secure Boot only ever work with Windows?

Is a hybrid Linux USB-Stick for UEFI & legacy BIOS possible?

my idea is to create an USB-Boot-Stick with Lubuntu that is able to boot on an older BIOS Laptop and an newer UEFI Systems.

This would be quite easy, when the Stick would be setup as a legacy boot device, but I want it to be an UEFI-able device.

1. Does that make even sense?! Or did I understand the UEFI concept horrobly wrong?
2. If necessary there can be two diffrent Linux installs (one for UEFI, one for legacy but both on the same drive)
3. Boot a GPT Device on legacy Bios - will that work?

I can't see clear, it might be just a better idea to have a seperate legacy Linux boot stick, but I am curious to explore the boundries :)

So, is my idea of a hybrid linux-uefi-boot-usb-stick that would work with legacy bios possible?

(3) seems to be possible for linux with grub http://www.rodsbooks.com/gdisk/booting.html

Further, I do have an EF00 Partition ready on that stick, aside a Swap, Fat32 and two Ext4 partitions.

(1) seems to be possible too http://www.rodsbooks.com/bios2uefi/

This instructions are however from 2012, some time passed since - does anybody have a working example that is easier?

For other researchers of this topic:

Boot of Windows 7 from GPT disk on non EFI motherboard Is there any way to boot Windows 7/8 using BIOS on GPT?

http://www.borncity.com/blog/2012/07/25/uefi-emulation-auf-pcs/

UPDATE:

I have managed to create the UEFI part inlcuding secure Boot setup with rEFInd.

Following the given advice, I have used dd to copy gptmbr.bin to my drive, which now seems to do at least something on a BIOS-System: "This is not a bootable disk"

However, I have followed the advice and set the pmbr flag for the disk and the gpt legacy boot flag - still gettin this error, any ideas?

My ESP partition is the second partition on the disk and is setup with efi files.

The Setup:

• 64GB Space
• GPT Partitiontable
• Disk has pmbr flag set
• 1st Partition starts at 16MiB and is about 45GB, a fat32 primary for data
• 2nd Partition starts around 45GB and is the EFI System(fat32) with a working rEFInd setup
• 3rd - 5th Partition is home (ext4), swap and root(ext4) of my working Lubuntu 14.04.1

Using dd I have copied the gptmbr.bin of my compiled 6.02 Syslinux to the first 440bytes.

Under parted 3.2 I can see that my partition 2 has a boot and legacy_boot flag.

During boot I get No bootable disk found - if I set my 5th instead of the 2nd partition to be legacy_boot I get Missing OS

It's alive!

(As my old Question got deleted http://askubuntu.com/q/516730/319747)

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My guess is, that I have to copy some of the *.c32 and other files to a syslinux folder eighter on my EFI (where?!) or on my root partition (/boot/syslinux?!) to get it to work - am I right? What files are essential?

Further, I guess I will need that syslinucx.cfg file too - right?

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My goal would be at least a direct boot of the lubuntu system on the root ext4 partition.

Update:

Although I have no idea why, I got it working - but not with a manual install.

• the pmbr flag was bad and prohibited my UEFI system from booting the stick as UEFI
• the legacy_boot flag was necessary for my 5th partition (linux root)
• I had to use extlinux --install /path/to/root/parition
• I had to create a syslinux.cfg in the syslinux folder under boot of my root partition

I did all of this on a second smaller stick, then tried to copy just the syslinux folder, but had no luck - the extlinux --install seems to be mandatory.

Anybody knows what exactly extlinux --install does? Can it be done manually or how else could you install a newer version like 6.02 without installing it on to your system?

Got my stick working with the partitions mentioned on BIOS, UEFI and UEFI SecureBoot, hell of a ride, learned a lot, nearly killed 2TB with parted, be careful and good luck.

How can I repair the Windows 8 EFI Bootloader?

I installed Windows 7 and Windows 8 in EFI mode on a hard disk some days ago. Today, the bootloader got missing/corrupted.

I currently have the Windows 8 installer on a flash drive and tried using the Automatic Repair option to repair the bootloader but it didn't do anything. The Startup Repair option is also missing in the Windows 8 installer.

How I can repair/recreate the EFI bootloader from the Command Prompt?

BCDEDIT returns the following message:

The requested system device cannot be found.

How would I reinstall the grub-efi bootloader on Fedora Linux?

I recently installed Fedora 18 using EFI boot. Like the other current linux distributions, it sets up GRUB2 for me.

I have experience with re-installing the BIOS version of GRUB when things go wrong. I know e.g. how to boot a rescue disc, chroot into the installed system, run grub-install and possibly update-grub / grubby / grub-mkconfig.

How would I reinstall the EFI version of GRUB when things go wrong? (I know things will go wrong: I break them).

Possible to install 64-bit Windows on 32-bit UEFI?

I recently purchased an HP Stream 7, which I was led to believe would have Windows 8.1 64-bit installed. However, it has 32-bit Windows, even though it has a 64-bit processor. Installing 64-bit has been problematic, and I found the reason is the 32-bit UEFI. Is there a way to change it or replace it with a 64-bit UEFI? Are there any other options for installing Windows 8.1 64-bit? Or is this impossible presently?

Thank you.

How can I use TrueCrypt under windows 8.1?

I know that TrueCrypt doesn't support windows 8 because some systems have UEFI enabled. It seems that if UEFI is disabled or Windows 8 is installed on an non UEFI system TrueCrypt just works fine in Full Disk Encryption mode.

Is it possible to deactivate UEFI under Windows 8.1 and use TrueCrypt Full Disk Encryption mode?

Thanks in advance.

How to know if my BIOS supports UEFI?

I recently bought a new Dell notebook for my girlfriend and I want to know if the computer comes with a UEFI BIOS, unfortunately I didnt find any information in the manual or on Windows, is there some way to discover it?

How to reinstall GRUB2 EFI?

After successfully updating my bios, something went wrong and I ended up with a blinking cursor on the top left corner of a black screen. No errors, no nothing. The bios now only listed a SATA: <disc name> boot option in place of the usual UEFI ubuntu one. I'm using a GPT partitioning scheme.

I eventually found that the working solution was to properly reinstall grub-efi-amd64. So, how do I do this ?

PS: Actually, i succeeded to reinstall GRUB2 EFI on my own and will post my answer here as I was unable to find any complete how-to on this.

Asus UEFI/BIOS options - How to boot from DVD?

I just bought a new PC and the default installed OS is Windows 8. I want to install Windows 7 but when I go into the boot options screen I only have one option:

Windows Boot Manager

I can't find my DVD drive. It is plugged in and visible under SATA options. How is it that I don't see it in the boot options menu?

The weirdest thing is that the drive is working perfectly inside Windows. So Windows 8 can detect it but the BIOS can't? I'm stuck with Windows 8... Any ideas?

Is TianoCore+coreboot a true open source UEFI?

There has been a lot of controversy surrounding UEFI, but like it or not, it's becoming the only option when it comes to generally available desktop motherboards. I've been avoiding UEFI mobos for some time, but now it became quite difficult as mobo vendors ship UEFI products with more features than BIOS ones (i.e. support for more RAM). That in mind, I want to be sure that there's at least an option to go open source in the future, and if there isn't, I can bear with less features but more freedom.

TianoCore is Intel's open source implementation of UEFI interfaces and Wikipedia has this to say about it:

TianoCore lacks the specialized drivers that initialize chipset functions, which are instead provided by Coreboot, of which TianoCore is one of many payload options. The development of Coreboot requires cooperation from chipset manufacturers to provide the specifications needed to develop initialization drivers.

My question is, do these drivers provided by coreboot still require some kind of binary blobs from chipset vendors? Also, Ronald G. Minnich has this to say about EFI:

Accesses to IDE I/O addresses, or certain memory addresses, can be trapped to EFI code and potentially examined and modified or aborted. Many see this as an effort to build a "DRM BIOS".

In a TianoCore+coreboot setup, are parts that could potentially do that open source or binary firmware provided by hardware vendor?

Preinstalled Windows 8 and Linux UEFI dual boot on a laptop

I am trying to set up Windows 8 and Arch Linux on a new Sony Vaio E14 with preinstalled windows 8.

So far:

• installed W8 to my new SSD (switched for the original HDD) using Recovery Media
• shrunk the W8 partition, deleted recovery partition, disabled swap
• confirmed W8 booting just fine

On to Arch:

• disabled Secure Boot in bios
• confirmed W8 booting just fine
• Booted Arch off the CD and installed everything to 4th and 5th partition
• set up rEFInd for EFIstub kernel bootloader

After that it got worse. I was unable to boot anything else than Windows 8 (although I was glad that they at least kept working just fine).

Tried:

• creating EFI\refind\ and putting the .efi there (as per Arch manual
• overwriting EFI\boot\bootx64.efi
• overwriting EFI\Microsoft\Boot\bootmgr.efi
• overwriting EFI\Microsoft\Boot\bootmgfw.efi --- YAY rEFInd shown up!

So far, so good. I've kept the whole W8 Boot\ directory in EFI\windows8 and set up a boot menuentry for it; and it booted just fine.

But, upon restart, everything was wrong -- 'Operating system not found' instead of any bootloader (refind or w8).

Booted back into Arch using the live CD to find out that the EFI partition had erroneous FAT table. fsck.vfat fixed it, and I've found that EFI\Microsoft\Boot was back to it's original state (all refind files deleted and replaced with W8 bootloaders). I've overwritten them again and got back to rEFInd showing up correctly and Arch being perfectly bootable.

After that I've tried only renaming EFI\Microsoft\Boot\bootmgfw.efi to bootmgfw.001.efi (then copying refind's .efi to bootmgfw.efi and keeping EVERY OTHER file as it was), but with exactly the same result. Tried marking the GPT EFI partition as read-only, same result.

Now I'm kinda out of luck. Arch boots fine, so does W8 but it destroys the EFI partition in the process.

Thanks for any ideas, Googling brought me this far and I can't find any better.

PS -- windows 8 MAYBE destroys the partition upon shutdown -- when I order a shutdown in W8, it takes unusually long (about half a minute instead of ~5 seconds). So in theory I could solve this by hard-resetting the laptop instead of a normal shutdown, but that's just not nice.

What are the advantages to install Windows 7 with UEFI?

I just received a Dell Precision M4600 and looking at firmware it seems it has UEFI support but it is disabled.

So due to the fact that I need to reinstall Windows 7 from scratch, do you suggest to enable UEFI boot? What are the advantages? Are there any disadvantages?

Is it possible to update BIOS to UEFI?

I just ran the Windows 8 Upgrade Assistant on an older machine (just for fun) and was informed that due to lack of UEFI firmware, Secure Boot would not be supported.

Is it possible for motherboard manufacturers, if they so choose (obviously they won't), to release a firmware flash that would update the BIOS to UEFI (or maybe UEFI+BIOS which some systems have)? Does UEFI require actual hardware support or is it entirely a matter of low-level software?

Do I need to re-install windows 8 to enable UEFI?

I know that UEFI provides for much faster boot up speeds, but as of right now it is disabled in my BIOS. Should I enable it and it'll switch over auto-magically?