MP 1,1-5,1 5,1 USB EFI windows install - corrupt firmware?

[stuisthebest]

hi,

today i spent the day attempting to install windows onto a spare HD on my 5,1 mac pro (no partition, just using the whole HD), using a USB flash drive which I created NOT with boot camp, but by downloading an ISO from the windows website and using Homebrew to split large files in order to get them copied over.

i eventually managed to install windows but i was experiencing issues - bluetooth not working, losing picture, and eventually I could not even get past a boot loop after a restart. whilst searching for solutions to these issues, i came across this thread

where someone commented,
"Usb efi installs on the 5,1 are a very bad idea, unless bios is protected by open core, windows will write all kinds for stuff to bios, and brick it."

additionally there was a link to this article which says,
"Warning: DO NOT install Windows from a USB flash drive. It has been discovered that Windows when installed in EFI mode is corrupting the Mac Pro’s firmware by signing it with multiple Secure Boot (X.509) certificates."

I formatted the HD that i had used and abandoned the dream, but at this point i had already (semi-)successfully installed windows. i don't know enough to understand what these consequences mean - is it likely that i have done to my firmware what these people say? how might i test this? if so, what are the implications for my mac? it appears to be operating as normal but i'm just worried.

also, as a footnote: when starting up the mac into Startup Manager using the option key, one of my other disks (NOT the one on which i attempted to install windows) is appearing on the list as "windows" even though it is not a bootable drive - in fact if i select it and try to boot from it, it gives me a black screen with some text saying something like, perating system not found". what's that all about?

thanks for your time

Stu

 

[h9826790]

Run "RomDump Macschrauber" which can help you to check if the MS cert is in the firmware now. It's a safe tool and work very automatically for checking this cert.

Healthy NVRAM normal behaviour on 4,1->5,1 machines

Macschrauber's Rom Dump I needed to encrypt the disk image as DropBox has flagged it for containing Flashrom. The password is rom. What's new in the latest versions: Update from 20-2-2024 -> checking Fsys for missing items or wrong order sometimes they get into the wrong order or items...

forums.macrumors.com

 

[tsialex]

Since you installed Windows via UEFI, the Windows UEFI SecureBoot signing already your Mac Pro EFI BootROM - you already known that. The signing happens at the first reboot of Windows while installing and then subsequently, every time you run it with SecureBoot activated.

This will over time brick your Mac Pro corrupting the NVRAM volume or if you are specially unlucky, some conditions can brick it more or less immediately, but it's a rare occurrence that require MP51.0087.B00 being your current BootROM release.

If you saved a backup of your BootROM image previously, time to flash it back to the Mac Pro.

 

[stuisthebest]

Since you installed Windows via UEFI, the Windows UEFI SecureBoot signing already your Mac Pro EFI BootROM - you already known that. The signing happens at the first reboot of Windows while installing and then subsequently, every time you run it with SecureBoot activated.

This will over time brick your Mac Pro corrupting the NVRAM volume or if you are specially unlucky, some conditions can brick it more or less immediately, but it's a rare occurrence that require MP51.0087.B00 being your current BootROM release.

If you saved a backup of your BootROM image previously, time to flash it back to the Mac Pro.

thanks for your reply! i have not saved a backup of my BootROM image. honestly, all this stuff is over my head, i did not flash the mac myself, i just bought it on ebay already upgraded to 5,1 a few years ago. i had no idea it could be so dangerous trying to install windows - there is very little advice about this situation out there, just lots of info on how to do what you apparently should NEVER do!

i have a time machine backup of all my drives and obviously the mac still works for now so i can still get files off it to make extra backups. but it sounds like long-term i'm ****ed. could you tell me the best next step to take? i found the "bootROM thread" started by yourself which talks about replacing parts? apologies for my ignorance - this is all another language to me.

 

[tsialex]

thanks for your reply! i have not saved a backup of my BootROM image. honestly, all this stuff is over my head, i did not flash the mac myself, i just bought it on ebay already upgraded to 5,1 a few years ago.

So, you have a early-2009 Mac Pro cross-flashed to mid-2010, this makes it worse.

i had no idea it could be so dangerous trying to install windows - there is very little advice about this situation out there, just lots of info on how to do what you apparently should NEVER do!

MacPro5,1 is a EFI 1.10 Mac, not a UEFI one, so, you can't follow instructions for a PC or a UEFI Mac (mostly 2013 and newer Macs).

i have a time machine backup of all my drives and obviously the mac still works for now so i can still get files off it to make extra backups. but it sounds like long-term i'm ****ed. could you tell me the best next step to take?

Flash a backup BootROM image, replacing the damaged one, since you don't have it, you gonna need a BootROM reconstruction service, I'll send you a PM.

i found the "bootROM thread" started by yourself which talks about replacing parts? apologies for my ignorance - this is all another language to me.

Right now you just need the BootROM reconstruction service, no need to replace the SPI flash memory (at least, not immediately, but it's an early2009…).

 

[Yebubbleman]

i had no idea it could be so dangerous trying to install windows - there is very little advice about this situation out there, just lots of info on how to do what you apparently should NEVER do!

Installing Windows on a Mac isn't ordinarily anywhere near this dangerous. It doesn't help that pre-UEFI-only Macs will technically boot both a Windows installer in BIOS mode (which thusly installs Windows in BIOS mode) and a Windows installer in EFI mode. Those newer Intel Macs only boot into UEFI mode and it's largely fine. But older Macs HAVE to run Windows in BIOS mode or else squirrelly nonsense like this happens.

 

[mahdif62]

If you already have Opencore legacy patcher installed when you install Windows, will there still be a risk of nvram curroption?

 

[haralds]

I bought a 5,1 system that had a Windows certificate in the boot ROM. Using MacSchrauber and multiple param resets actually were able to remove the bad certificate entries. Perhaps I was lucky.