UEFI impacts

[u0206397]

I am a little behind time with regard to UEFI. So bear with me.

I have a few questions regarding UEFI and its impact on OS and drivers, as compared to the old BIOS, which had little limitations and people were free to swap parts, boot drive and OS around.

I had read up a bit on UEFI but I still do not get the full picture.

As a DIY PC/PC tech, I would like to understand now with UEFI, what are the impacts?

1. Does UEFI replace BIOS completely, or is it a second stage of additional firmware that runs after the BIOS i.e. system boot UEFI straight or boot BIOS first then mount the EFI file system to load more codes for GUI and advanced UEFI features?
2. Are there different Windows hardware drivers for BIOS and UEFI mode? Do hardware manufacturers release different driver for the same hardware for system in BIOS and UEFI mode?
3. For Windows 8 and above, is UEFI compulsory?
4. For Windows 8 and above, with UEFI, is the GPT required or just recommended (which users can choose to use MBR)?
5. I presume if I have a Windows 8 and above boot drive, and I swap it into a mainboard with no UEFI support, it won't boot at all.
6. Can I install older Windows on modern mainboard/CPU if I go to BIOS/UEFI and select BIOS mode? Can the mode be switched between BIOS and UEFI in mainboard going into the future?
7. For non-Windows operating systems like Linux, must I switch to BIOS mode to boot? I know a few major distributions like Ubuntu and Red Hat had to get Microsoft to sign their bootloader for them, to allow them to boot in UEFI modes. If not the UEFI won't boot at all. For the other Linux distributions that don't have such agreement with Microsoft, I guess not?
8. With UEFI secure boot, is the Windows OS tied to the mainboard? I heard the Windows product license key is now hardwired and stored in the BIOS/UEFI chip. If I swap in another boot drive with Windows 8 and above from another system, the Windows on the boot drive may not work/boot since the product key on the boot drive and the mainboard UEFI/BIOS will not match?

I am trying to understand the limitations and constraints, in order to understand how to do system and data recovery in case one system fails and I have to swap boot drive etc.

 

[BananaMilkShake]

1. Yes. Its an upgrade
2. No. Old boards cant use new uefi firmwares
3. No. Can upgrade old pc to win 8
4. UEFI will format hdd to gpt format when installing windows 8
5. Yes. But there are ways to bypass it. Just a hassle
6. Yes. Enable CSM
7. IIRC, Linux uses MBR to boot. Just go enable CSM and boot via legacy
8. Only applies for OEMs. Else keys are stored in microsoft servers digitally.

 

[u0206397]

2. No. Old boards cant use new uefi firmwares

I was reading a few years back, when buying graphics card, one needs to be careful. Because it was the transition period, and some graphics cards already out selling in the market were not designed to work with the newer UEFI mainboards. Plug in won't work. Perhaps need to switch to CSM to accept the older non-UEFI hardware. But if the boot drive is already in GPT format for UEFI, now the system won't boot. Solves 1 problem but creates another one.

Likewise, plugging in UEFI ready graphics cards in an old BIOS-only mainboard, I don't know if there is any intelligent backward compability to make it work if it can't find UEFI.

5. Yes. But there are ways to bypass it. Just a hassle

Any article that elaborates on this? Firmware on non-UEFI BIOS mainboard likely no update and no support.

8. Only applies for OEMs. Else keys are stored in microsoft servers digitally.

Which means secure boot in UEFI won't check the DIY PC's mainboard for the Windows product key/serial number and stops booting if it doesn't match. That's good to know. Sometimes for DIY PC, we need to swap parts to test and/or recover data.

 

[yusoffb01]

5. if you install that windows 8 in mbr mode, you can swap to a motherboard without uefi support and it will work

 

[BananaMilkShake]

Any article that elaborates on this? Firmware on non-UEFI BIOS mainboard likely no update and no support.

Cant remember where I used to read the source from. Quite few years back. And cant remember after all the steps whether gotten it to work or not
I didnt try it personally too. So cant assure u. Best is still reformat and use