How to use UEFI - Every other YouTube video is WRONG! - Chris Titus Tech
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Date: 2022-03-20
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Comments and reviews: 10
Varion
Before any GRUB installations haha, how many boot loaders do you think one computer actually needs? Lol..
UEFI is a -boot loader- implemented within the motherboards firmware. Legacy BIOS and its interrupts and data areas etc. all still exists on any PC-AT compatible computer. If it were not than your motherboard would be bricked, and UEFI wouldn't be able to boot. UEFI, unlike legacy BIOS, has actual knowledge of both, how to traverse and search through FAT filesystem partitions, as well as how to utilize any hardware components specifically for the sole purpose of booting.
Given you can use UEFI to boot up to a second stage boot loader like GRUB, with UEFI it seems very wasteful imho. The EFI System Partition, with the recommended FAT16 filesystem type for probabilities sake, lives somewhere within the selected storage device, and has a root directory containing a collection of different drivers, again specifically programmed for the sole purpose of booting and are NOT actually meant to be fully functioning device drivers for the operating system to remain utilizing after the conclusion of the boot up process, something which is actually very similar to 16bit interrupts, except UEFI actually switches you into either 32bit mode or higher.
Aside from any potential drivers contained inside the root directory of this FAT16 EFI System Partition, is also a boot directory containing different executable files with a -[ osKernel ].efi- file extension. This .efi file as well tries remaining portable across implementations by being programmed in some C-like language, and having a file type of PE32+, which is actually a PE32 file with specific header modifications done to allow portability between not only architecture but also in mode (32bit or 64bit doesn't matter they'll both work the same,) and consists of procedures, or functions, which pass things like the PC's configurations and memory-map etc. to the Operating System's Kernel. Which this Operating System Kernel, can now be programmed 100% architecture independent with not a single line of assembly code required to boot it, and is also all loaded as an actual program instead of in pieces. Instead of it being like BIOS -> MBR -> 2nd Stage Bootloader -> Kernel, it's now BIOS -> UEFI -> Kernel.
While at the same time, legacy boot is still supported just in case an Operating System isn't programmed for UEFI standards. In that case, instead of UEFI searching for the EFI System Partition, as a fallback, UEFI emulates legacy boot and attempts to boot the master boot record inside the very first 512bits of the hardware.
Conclusion: UEFI sits on top of BIOS as a boot loader that's implemented within the firmware where it should've belonged to begin with, and no matter what all computers still, whether UEFI or not ARE still BIOS, and UEFI can actually be implemented on old PCs by simply -adding to- their existing firmware the UEFI portion.
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Before any GRUB installations haha, how many boot loaders do you think one computer actually needs? Lol..
UEFI is a -boot loader- implemented within the motherboards firmware. Legacy BIOS and its interrupts and data areas etc. all still exists on any PC-AT compatible computer. If it were not than your motherboard would be bricked, and UEFI wouldn't be able to boot. UEFI, unlike legacy BIOS, has actual knowledge of both, how to traverse and search through FAT filesystem partitions, as well as how to utilize any hardware components specifically for the sole purpose of booting.
Given you can use UEFI to boot up to a second stage boot loader like GRUB, with UEFI it seems very wasteful imho. The EFI System Partition, with the recommended FAT16 filesystem type for probabilities sake, lives somewhere within the selected storage device, and has a root directory containing a collection of different drivers, again specifically programmed for the sole purpose of booting and are NOT actually meant to be fully functioning device drivers for the operating system to remain utilizing after the conclusion of the boot up process, something which is actually very similar to 16bit interrupts, except UEFI actually switches you into either 32bit mode or higher.
Aside from any potential drivers contained inside the root directory of this FAT16 EFI System Partition, is also a boot directory containing different executable files with a -[ osKernel ].efi- file extension. This .efi file as well tries remaining portable across implementations by being programmed in some C-like language, and having a file type of PE32+, which is actually a PE32 file with specific header modifications done to allow portability between not only architecture but also in mode (32bit or 64bit doesn't matter they'll both work the same,) and consists of procedures, or functions, which pass things like the PC's configurations and memory-map etc. to the Operating System's Kernel. Which this Operating System Kernel, can now be programmed 100% architecture independent with not a single line of assembly code required to boot it, and is also all loaded as an actual program instead of in pieces. Instead of it being like BIOS -> MBR -> 2nd Stage Bootloader -> Kernel, it's now BIOS -> UEFI -> Kernel.
While at the same time, legacy boot is still supported just in case an Operating System isn't programmed for UEFI standards. In that case, instead of UEFI searching for the EFI System Partition, as a fallback, UEFI emulates legacy boot and attempts to boot the master boot record inside the very first 512bits of the hardware.
Conclusion: UEFI sits on top of BIOS as a boot loader that's implemented within the firmware where it should've belonged to begin with, and no matter what all computers still, whether UEFI or not ARE still BIOS, and UEFI can actually be implemented on old PCs by simply -adding to- their existing firmware the UEFI portion.
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Linosh
Here's the thing
Windows 7/8/8.1/10 REQUIRES that your disk be formatted in GPT partitioning for UEFI Boot
Meaning if you have MBR disk you are forced to legacy boot.
So to put it simply in Windows
UEFI Boot = GPT Disk formatting
Legacy Boot = MBR Disk formatting
No mix and match is possible
Also in the case of Windows 7, your BIOS must be set to UEFI Hybrid or UEFI with CSM Support to boot into UEFI since Windows 7 still uses a 16 bit mode INT10H call during booting even in UEFI
Windows 11 has dropped Legacy boot support completely and will not boot from MBR disks or Legacy boot mode (Workarounds have been found, but none fully functional)
Linux can have mixed and matched boot modes, such as GPT with Legacy boot and MBR with UEFI Boot
reply
Here's the thing
Windows 7/8/8.1/10 REQUIRES that your disk be formatted in GPT partitioning for UEFI Boot
Meaning if you have MBR disk you are forced to legacy boot.
So to put it simply in Windows
UEFI Boot = GPT Disk formatting
Legacy Boot = MBR Disk formatting
No mix and match is possible
Also in the case of Windows 7, your BIOS must be set to UEFI Hybrid or UEFI with CSM Support to boot into UEFI since Windows 7 still uses a 16 bit mode INT10H call during booting even in UEFI
Windows 11 has dropped Legacy boot support completely and will not boot from MBR disks or Legacy boot mode (Workarounds have been found, but none fully functional)
Linux can have mixed and matched boot modes, such as GPT with Legacy boot and MBR with UEFI Boot
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coegj
Question for you CTT, I have a Thinkpad t530 uefi only bios locked laptop ( bought used that way ) and installed MX Linux 19.2 on it with a Rufus GPT usb installer. Worked fine all is good, now I want to add a Msata in the wwan slot with Linux Mint as a second OS, would I need to install ( efibootmgr ) you talked about in this video before or after to the existing OS Mx Linux before I try to install the Mint to the Msata drive, so the ufibootmgr will see and show the Mint OS ready to boot. Any reply would be appreciated. I have been using Linux/Ubuntu for a decade or more but always had Legacy boot mode to deal with, the uefi only is really new and tricky for me to deal with. Again any reply appreciated.
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Question for you CTT, I have a Thinkpad t530 uefi only bios locked laptop ( bought used that way ) and installed MX Linux 19.2 on it with a Rufus GPT usb installer. Worked fine all is good, now I want to add a Msata in the wwan slot with Linux Mint as a second OS, would I need to install ( efibootmgr ) you talked about in this video before or after to the existing OS Mx Linux before I try to install the Mint to the Msata drive, so the ufibootmgr will see and show the Mint OS ready to boot. Any reply would be appreciated. I have been using Linux/Ubuntu for a decade or more but always had Legacy boot mode to deal with, the uefi only is really new and tricky for me to deal with. Again any reply appreciated.
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Just
I have a weird setup on my computer. I dual-boot, and to boot into Windows 10 (yuck...but sometimes I still have to at this stage, though rarely) I have to have my BIOS set to UEFI, and to boot into Linux (I use Lubuntu on this machine), I switch over to legacy. I am sure there are other ways to configure it, but that was the easiest way to get it done on my main machine, which is a desktop. Windows 10 does not seem to like to play nice with Linux. The last time I had a dual-boot system was when XP was the latest version of Windows, and I just threw GRUB on it and was good to go. Seems to be more complex now.
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I have a weird setup on my computer. I dual-boot, and to boot into Windows 10 (yuck...but sometimes I still have to at this stage, though rarely) I have to have my BIOS set to UEFI, and to boot into Linux (I use Lubuntu on this machine), I switch over to legacy. I am sure there are other ways to configure it, but that was the easiest way to get it done on my main machine, which is a desktop. Windows 10 does not seem to like to play nice with Linux. The last time I had a dual-boot system was when XP was the latest version of Windows, and I just threw GRUB on it and was good to go. Seems to be more complex now.
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The
Hey Chris. I'm currently on a -Legacy- computer (Dell Precision T1700) and want to make my SSD with Windows boot on the newer -UEFI- computer (Dell Precision 3670) I already used Rufus to make a UEFI Windows iso USB thumbdrive...I think. I did this on the Precision as my Inspiron will not load windows. Do you know what my next step would be? Insert the USB on the newer computer, change BIOS to turn off all legacy and secure boot, and then F12 and try to start windows?? Im sorry if this is not the place to ask this.
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Hey Chris. I'm currently on a -Legacy- computer (Dell Precision T1700) and want to make my SSD with Windows boot on the newer -UEFI- computer (Dell Precision 3670) I already used Rufus to make a UEFI Windows iso USB thumbdrive...I think. I did this on the Precision as my Inspiron will not load windows. Do you know what my next step would be? Insert the USB on the newer computer, change BIOS to turn off all legacy and secure boot, and then F12 and try to start windows?? Im sorry if this is not the place to ask this.
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Myszka
4:45 suggested method by M$, in command prompt: reg query HKLM\System\CurrentControlSet\Control /v PEFirmwareType (return code: 0x1 -> BIOS; if 0x2 -> UEFI). Another way is check output of bcdedit (Vista+) command...
9:44 in theory yes, MBR partition entries has relative sector and number of sectors so you can reach size -4 TiB (512B sectors) but this is very risky and could cause data corruption by software with internal 32-bit calculations.
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4:45 suggested method by M$, in command prompt: reg query HKLM\System\CurrentControlSet\Control /v PEFirmwareType (return code: 0x1 -> BIOS; if 0x2 -> UEFI). Another way is check output of bcdedit (Vista+) command...
9:44 in theory yes, MBR partition entries has relative sector and number of sectors so you can reach size -4 TiB (512B sectors) but this is very risky and could cause data corruption by software with internal 32-bit calculations.
reply
Daniel
I think Twilight Spakle (a few comments below) may be on to something. I am still so confused. Furthermore, I am smart enough and more than capable of understanding this stuff. I started my life by changing MFM Partition tables in DOS Debug with Hex Codes. But I just upgraded from my old Win 7 rig to a NEW Dell laptop. Now I find out I can't duel boot my Win 7 because of UEFI. Still looking for a solution!
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I think Twilight Spakle (a few comments below) may be on to something. I am still so confused. Furthermore, I am smart enough and more than capable of understanding this stuff. I started my life by changing MFM Partition tables in DOS Debug with Hex Codes. But I just upgraded from my old Win 7 rig to a NEW Dell laptop. Now I find out I can't duel boot my Win 7 because of UEFI. Still looking for a solution!
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Dark
Hey Chris I don't whether you will read this or not but I ran in to a problem
Yesterday I coupled my windows laptop with a hard disk which was already having Ubuntu installed in it , to surprise it didn't show the drives where the Ubuntu was installed or was showing that they were empty, also while using bcd software it gave me warning that my system was using efi so it can't do that grup repair
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Hey Chris I don't whether you will read this or not but I ran in to a problem
Yesterday I coupled my windows laptop with a hard disk which was already having Ubuntu installed in it , to surprise it didn't show the drives where the Ubuntu was installed or was showing that they were empty, also while using bcd software it gave me warning that my system was using efi so it can't do that grup repair
reply
Alejandro
So, we could say UEFI and Legacy are ONLY different ways of present the BIOS interface and capabilities for managing the BOOT, because it is controlled from the firmware only? With that being said, we also could add that it doesn't anything to do with size partitioning on disks, since MBR and GPT are different forms of how the files (sectors) are presented in the secondary memory.
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So, we could say UEFI and Legacy are ONLY different ways of present the BIOS interface and capabilities for managing the BOOT, because it is controlled from the firmware only? With that being said, we also could add that it doesn't anything to do with size partitioning on disks, since MBR and GPT are different forms of how the files (sectors) are presented in the secondary memory.
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Retro
Do I want GPT, UEFI=FAT32 or do I JUST WANT THE MOTHERBOARD TO DETECT MY GOSH DARN USB AS UEFI BOOTABLE! Only Legacy pops up as an option for the USB. Why is my PC's UEFI system inherently having this problem in the first place? I've made the perfect NVMe Windows 7 USB drive and I find my PC is having DETECTING BOOT PROBLEMS!
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Do I want GPT, UEFI=FAT32 or do I JUST WANT THE MOTHERBOARD TO DETECT MY GOSH DARN USB AS UEFI BOOTABLE! Only Legacy pops up as an option for the USB. Why is my PC's UEFI system inherently having this problem in the first place? I've made the perfect NVMe Windows 7 USB drive and I find my PC is having DETECTING BOOT PROBLEMS!
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