MP 1,1-5,1 Mac Pro 5,1 only boots into Windows 10 (corrupt firmware?)

[Mac.Apex]

After successfully installing Windows 10 from DVD via Boot Camp on a Mac Pro 5,1, I tried to go back to the High Sierra partition, but the option key would not bring up the Startup Manager, and it booted directly into Windows. When I tried to change the startup disk in the Boot Camp Control Panel, I got the following message: "An error occurred while trying to change the startup disk. You may have not have privileges to change the startup disk. Make sure you have administrative privileges and try again." The Command-Option-P-R combination is not recognized from the Apple keyboard nor from a PC keyboard, both connected directly to the Mac. I tried booting up with other hard drives with multiple partitions on them, and only partitions with Windows 10 on them will boot on this Mac. If a drive only has Mac partitions, I get the following message: "No bootable device - insert boot disk and press any key."

I thought that there was no chance of a legacy install of Windows 10 affecting the firmware of the Mac Pro, but apparently that is not the case. I am afraid somehow it has been corrupted/overwritten by the Windows 10 install or updates. My question is- Am I correct in my assessment, and is there anything I can do to fix it from the Windows 10 side?


Right before I posted this, I was directed to another thread where @tsialex said:

“Even when you have a Windows boot coup that only allows your Mac Pro to boot Windows - resetting the NVRAM won't work for this case - removing the RTC battery completely bypass the NVRAM, so you'll need to install a disk with a fully supported macOS release to boot again. Somethings won't work correctly without the RTC battery, like clock and Wi-Fi, but it's enough to get you started.”

This sounds like my situation. Can removing the battery allow me to work on a fix, or will I still need a BootROM reconstruction service?

 

[Dayo]

Not likely to be firmware related but that you might have used an outdated version of BootCamp, Apple Sanctioned Hackery, and all hackery can go wrong: https://www.rodsbooks.com/gdisk/hybrid.html

Web search says the easiest way to resolve this BootCamp foul up is to create a new user in Windows, make sure that user does not have admin rights, access BootCamp while logged into WIndows as that user and go from there.

Update BootCamp ASAP or better still, use a method that does not involve BootCamp Hackery to install Windows in future: https://forums.macrumors.com/threads/2250317

 

[Macschrauber]

You can also use a bootloader like RefindPlus.

if the firmware has major issues you can check easily with the Dumper (link in the sig).

to get back to MacOs, shut down and pull the Windows drive. If this alone does not boot MacOs, reset the nvram deeply by holding cmd-alt-p-r continuously until the box chimes 3 times.

 

[Mac.Apex]

Not likely to be firmware related but that you might have used an outdated version of BootCamp, Apple Sanctioned Hackery, and all hackery can go wrong: https://www.rodsbooks.com/gdisk/hybrid.html

Web search says the easiest way to resolve this BootCamp foul up is to create a new user in Windows, make sure that user does not have admin rights, access BootCamp while logged into WIndows as that user and go from there.

Update BootCamp ASAP or better still, use a method that does not involve BootCamp Hackery to install Windows in future: https://forums.macrumors.com/threads/2250317

There’s always a little bit of hackery to get things working on these old computers. I used the method in this video, which previously worked for me on a cMP 3,1:
Install Windows 10 via Boot Camp on Older Mac Pro via DVD [Best for Non-EFI GPU]

After creating a new non-admin user in Windows, what would be the next steps? Is there a link that you could share?

I downloaded Boot Camp Support Software 5.1.5621. It is my understanding those drivers are the last that support the cMP 5,1. I'm not certain if I can use any later BC drivers. I want to have High Sierra and Windows 10 on the same SSD, and would be happy to try the alternate method (non-BC) in your post if I can get my 5,1 back to a workable condition.

You can also use a bootloader like RefindPlus.

if the firmware has major issues you can check easily with the Dumper (link in the sig).

to get back to MacOs, shut down and pull the Windows drive. If this alone does not boot MacOs, reset the nvram deeply by holding cmd-alt-p-r continuously until the box chimes 3 times.

I'm a big fan of RefindPlus! I use it on my MacBooks for booting into multiple MacOS partitions. However, I haven't been able to use it on a cMP High Sierra system with multiple monitors and a non-EFI Nvidia GPU. Using only one monitor works great, but when I add more than one, it won't boot and all monitors are black. It works fine with multiple monitors in Yosemite, so something in HS is causing it to have issues. @Dayo has the same avatar as Dakanji, the developer of RefindPlus - is it the same person? If so, perhaps we can discuss this on a separate thread or through private message (sorry to get off-topic).

I have not tried OpenCore yet, it appears to me that it has evolved into a project only to get Mac OS 11+ onto older systems, which I do not want (yet). I currently want 10.13 and W10 for this computer. If I can use OC for that, I would use it as it provides some NVRAM protection.

I can't use the Dumper since I can't boot into MacOS at all, only Windows 10. Do you have a version of the Dumper that runs in Windows?

If I pull the Windows drive and put a Mac-only drive in, I get the message "No bootable device - insert boot disk and press any key." I would love to reset the NVRAM, but startup keypresses (Option or Cmd-Opt-P-R) are ignored. It appears my Bootloader has been corrupted to the point where my 5,1 thinks it's a Windows machine.

I'm wondering if I can remove the battery, boot up from this disc and restore the firmware to its original condition:
Firmware Restoration CD 1.9

 

[tsialex]

I'm wondering if I can remove the battery, boot up from this disc and restore the firmware to its original condition:
Firmware Restoration CD 1.9

Unfortunately, the Firmware Restoration CDs only work if your backplane BootROM is MP51.007F.B03 or an older version - an older EFI can't be applied to a newer one already flashed to the backplane SPI flash memory - Apple efiflasher do not allow downgrades.

If you have a newer release flashed to the Mac Pro, the only way to repair it is via a BootROM reconstruction service.

 

[tsialex]

I can't boot into MacOS at all, only Windows 10.

When you can't boot anything but Windows even after multiple continous NVRAM resets or you can't even reset the NVRAM while at a power on, the only way to get back your Mac Pro working again without de-soldering the SPI flash memory that stores the BootROM is to install Mavericks (Mavericks is the main key to this process, since in fail-safe mode you can't disable SIP) to a spare disk with another working Mac and then:

• power off your Mac Pro, disconnect the PSU power cable,
• remove all disks from your Mac Pro, disconnect all PCIe/FW/USB drives and the DVD (just disconnect the cable),
• remove all PCIe cards,
• install an AppleOEM GPU - any 64bit EFI AppleOEM GPU (MacPro3,1 ATI 2600XT was the first one, MacPro4,1 GT120 is perfect for this) will work,
• install the Mavericks disk to your Mac Pro,
• connect a wired USB mouse/kb directly to the Mac Pro native USB v2.0 ports ( do not use USB hubs, connect to a display and etc),
• remove the RTC battery,
• wait at least five minutes to fully discharge the RTC controller, then reconnect the PSU power cable.

Power on your Mac Pro, without the RTC battery it will enter a fail-safe mode where the NVRAM volume is completely bypassed by the PEI, after two minutes or so it will boot the Mavericks disk.

Be aware that while in the fail-safe mode, several things that depend on time or require NVRAM settings won't work or work very crazily, like Wi-Fi and any BT devices, but the Mac Pro will be working to a point that you can dump your BootROM and later flash a reconstructed BootROM image to it.

 

[Macschrauber]

I can't use the Dumper since I can't boot into MacOS at all, only Windows 10. Do you have a version of the Dumper that runs in Windows?

No, I am absolutely no Windows guy and never had the need to get it working in windows.

If I pull the Windows drive and put a Mac-only drive in, I get the message "No bootable device - insert boot disk and press any key."

Seems you are stuck to Windows booting, assuming BootOrder points first to a Bootvar what is bound to a MBR disk.

I would love to reset the NVRAM, but startup keypresses (Option or Cmd-Opt-P-R) are ignored. It appears my Bootloader has been corrupted to the point where my 5,1 thinks it's a Windows machine.

Try an Apple keyboard connected to a stock USB (not to a PCIe card) port directly, not via a hub, not via some kind of display, no extension cable, etc.

As @tsialex pointed out, booting without the rtc clock battery bypasses the nvram reading out from the firmware chip. This could set you able to bypass BootOrder pointing to Windows.

 

[Mac.Apex]

Unfortunately, the Firmware Restoration CDs only work if your backplane BootROM is MP51.007F.B03 or an older version - an older EFI can't be applied to a newer one already flashed to the backplane SPI flash memory - Apple efiflasher do not allow downgrades.

If you have a newer release flashed to the Mac Pro, the only way to repair it is via a BootROM reconstruction service.

I did not check to see what version of BootROM was on my backplane. Will I be able to tell this after I perform the BootROM dump per the below process?

When you can't boot anything but Windows even after multiple continous NVRAM resets, the only way to get back your Mac Pro working again without de-soldering the SPI flash memory that stores the BootROM is to install Mavericks to a spare disk with another working Mac and then:

• power off your Mac Pro, disconnect the PSU power cable,
• remove all disks from your Mac Pro, disconnect all PCIe/FW/USB drives and the DVD (just disconnect the cable),
• remove all PCIe cards,
• install an AppleOEM GPU - any 64bit EFI AppleOEM GPU (MacPro3,1 ATI 2600XT was the first one, MacPro4,1 GT120 is perfect for this) will work,
• install the Mavericks disk to your Mac Pro,
• connect a wired USB mouse/kb to the Mac Pro native USB v2.0 ports ( do not use USB hubs, connect to a display and etc),
• remove the RTC battery,
• wait at least five minutes to fully discharge the RTC, then reconnect the PSU power cable.

Power on your Mac Pro, without the RTC battery it will enter a fail-safe mode where the NVRAM volume is bypassed by the PEI and after two minutes or so it will boot the Mavericks disk.

Be aware that several things that depend on time or require NVRAM settings won't work or work crazily, like Wi-Fi and any BT devices, but the Mac Pro will be working to a point that you can dump your BootROM and later flash a reconstructed BootROM image.

Just to clarify, I have been unable to perform even a single NVRAM reset, as the keyboard is not recognized during boot. I have tried this with a known good Mac keyboard and a PC keyboard, and both have been plugged directly into the USB ports of the Mac. Is it possible to somehow reset the NVRAM from the Windows 10 side? I assume not, but just asking...

I have no soldering skills, so the Mavericks method here is perfect and I can certainly do this. Assuming all goes well and I am able to dump the BootROM image, what is the next step? Will I be able to flash a reconstructed image myself?

And the most important question for me is- How did this happen in the first place? I was under the impression that a DVD install of Windows 10 is always a legacy BIOS install, and should not affect the BootROM/EFI/NVRAM in any way. Am I incorrect in this assumption, and if so, how is the best way to prevent this in the future? I have another cMP 5,1 that I would like to configure in the same manner and I certainly don't want to brick it as well.

 

[tsialex]

I did not check to see what version of BootROM was on my backplane. Will I be able to tell this after I perform the BootROM dump per the below process?

Open the dumped BootROM image with HexFiend and search for "BIOS", you will see the EFI version.

Is it possible to somehow reset the NVRAM from the Windows 10 side? I assume not, but just asking...

Not that I know of.

I have no soldering skills, so the Mavericks method here is perfect and I can certainly do this. Assuming all goes well and I am able to dump the BootROM image, what is the next step?

I've sent you a PM (top right corner of the page, letter icon) with the instructions, service fee and turnaround time.

Will I be able to flash a reconstructed image myself?

Sure, it's almost the same process as dumping it.

And the most important question for me is- How did this happen in the first place? I was under the impression that a DVD install of Windows 10 is always a legacy BIOS install, and should not affect the BootROM/EFI/NVRAM in any way.

This is a very wrong assumption. Any and all OS interacts with the NVRAM. Interacting with the NVRAM is part of the normal usage of a EFI/UEFI Mac/PC.

While BIOS/CSM/BootCamp don't sign the NVRAM with SecureBoot and mess everything in a way that you will have a brick in no time, the normal usage of the NVRAM can make it fail over time. MacPro5,1 NVRAM is not resilient by design and definitively wasn't designed to run over a 14 years span.

Am I incorrect in this assumption, and if so, how is the best way to prevent this in the future? I have another cMP 5,1 that I would like to configure in the same manner and I certainly don't want to brick it as well.

Several people had this in the past few years and from what people wrote to me, this seems to happen right after or while doing major Windows Updates, like 21H2 to 22H2.

From the dumps I've had access, seems that the VSS store was failing for some time already and the sudden flow of NVRAM writes to stage the updates was just the straw that broke the camel's back.

From time to time flashing a fully upgraded, reconstructed and never booted BootROM image of your Mac Pro is the best way to avoid a brick.

 

[Mac.Apex]

This is a very wrong assumption. Any and all OS interacts with the NVRAM.

While BIOS/CSM/BootCamp don't sign the NVRAM with SecureBoot and mess everything in a way that you will have a brick in no time, the normal usage of the NVRAM can make it fail overtime. MacPro5,1 NVRAM is not resilient by design.

Right. Poorly worded question. Obviously any OS can write to the NVRAM, for example the Windows Boot Camp Control Panel changing the Startup Disk. What I was trying to confirm is what you mentioned about SecureBoot writing those certificates, which I understood a BootCamp/BIOS mode install from DVD would not do.

Several people had this in the past few years and from what people wrote to me, this seems to happen right after or while doing major Windows Updates, like 21H2 to 22H2.

From the dumps I've had access, seems that the VSS store was failing for some time already and the sudden flow of NVRAM writes to stage the updates was just the straw that broke the camel's back.

My Windows 10 DVD is version 1903, so it has a lot of updates to get to 22H2, and I noticed the computer rebooted many times during the update process. So I can see exactly what you are referring to and I assume that happened in my case.

From time to time flashing a fully upgraded, reconstructed and never booted BootROM image of your Mac Pro is the best way to avoid a brick.

So just to confirm, would the proper procedure be to flash a never booted BootROM image after the Windows 10 install but before the massive updates to 22H2? Or just anytime before the Windows 10 install?

I've sent you a PM

Got it, I'll get to work on the Mavericks procedure to see where I stand and get back to you. Thanks!!!

 

[tsialex]

So just to confirm, would the proper procedure be to flash a never booted BootROM image after the Windows 10 install but before the massive updates to 22H2? Or just anytime before the Windows 10 install?

I usually flash the never booted BootROM image right before installing a OS, after the install is complete I do a shutdown and then a multiple NVRAM reset at power on before running all the software updates, then after everything software update wise is fully completed, sometimes is a very lengthy process, a new deep NVRAM reset.

Doing this way you minimize NVRAM volume corruption.

 

[Dayo]

@Mac.Apex
Raise an issue on Github if you have problems with RefindPlus.
On the BootCamp thing, run BootCamp from the new non-privileged user to get back into MacOS.
Avoid using BootCamp to install Windows on other other unit. Mixing OS Types on a single disk is often problematic.

 

[Dayo]

I was under the impression that a DVD install of Windows 10 is always a legacy BIOS install, and should not affect the BootROM/EFI/NVRAM in any way. Am I incorrect in this assumption

Legacy Windows itself does not interact with your nvRAM in any shape or form but BootCamp does however to allow booting back to MacOS. When you use it to set things to boot into Windows in MacOS, it writes something into the nvRAM but when it then refuses to run in Windows, you are stuck with the nvRAM setting to always boot into Windows.

As said though, your issue is not likely to be firmware related but from a BootCamp issue where it can bizarrely not work because the user permissions are "too high". Using a non-privileged user to run it gets around the issue until you either get offered a BootCamp update (seems the issue affected some older versions) or you can rid yourself of the instance.

 

[tsialex]

Legacy Windows itself does not interact with your nvRAM in any shape or form but BootCamp does however.

As said though, your issue is not likely to be firmware related but from a BootCamp issue where it can bizarrely not work because the user permissions are "too high". Using a non-privileged user to run it gets around the issue until you either get offered a BootCamp update (seems the issue affected some older versions) or you can rid yourself of the instance.

If was just a misconfigured BootCamp issue as you are suggesting, the OP could just reset the NVRAM at power up and all is good again.

He can't even use the keyboard at POST…

 

[Dayo]

It might well be something else but note that he is able to boot into Windows and it that is Legacy Windows.

He should try the non-privileged user or a tool such as EasyUEFI to reset the boot order from within Windows: https://www.easyuefi.com/index-us.html.

If that fails, then there is something else going on but there is apparently a problem with some versions of BootCamp that show the symptoms he has.

 

[tsialex]

OP should try all the suggestions here, but when the NVRAM volume is corrupted and in read-only mode nothing can write to it.

Not being able to reset it at power on is a sign that the NVRAM is read-only mode and only a NOR sector erase and re-flash will get it working again.

 

[Dayo]

There is always the chance that a person that thinks they are installing/running Legacy Windows is in fact installing/running UEFI Windows.

 

[Mac.Apex]

There is always the chance that a person that thinks they are installing/running Legacy Windows is in fact installing/running UEFI Windows.

How can I tell if I have installed Legacy or UEFI Windows? I thought the DVD install method was always Legacy.

 

[Mac.Apex]

To answer my own question, I checked the System Information app in Windows to verify that I had installed Legacy BIOS Windows:

However, I also noticed the BIOS Version/Date which I underlined in red. Does this mean that this 5,1 only was updated through the first public firmware update as shown below?

MacPro5,1 BootROM releases, from the oldest EFI update to the newest:​

BootROM Version	Released with:	Type:	Note:
MP51.007F.B03	Mac Pro EFI Firmware Update 1.5	General release	First public released Mac Pro 5,1 firmware update, BootPicker improvements, microcodes vulnerable to Spectre and Meltdown

Could I then use the Firmware Restoration CD as I previously suggested?

Unfortunately, the Firmware Restoration CDs only work if your backplane BootROM is MP51.007F.B03 or an older version - an older EFI can't be applied to a newer one already flashed to the backplane SPI flash memory - Apple efiflasher do not allow downgrades.

If you have a newer release flashed to the Mac Pro, the only way to repair it is via a BootROM reconstruction service.

Would using this CD keep me at Firmware MP51.007F.B03, or update it to a later version?

 

[Dayo]

Forget about the Firmware Restoration CD and the like IMO.

Your firmware is either corrupted and you need a reconstruction, or the issue is simply down to a BootCamp misconfiguration. To explain the responses you got:

1. Create a non privileged user and run BootCamp via that user. If the issue is down to Bootcamp, this will resolve the issue and you will be able to boot back into Mac OS.
2. If that does not fix things, remove the coin battery, install something like Mavericks and get Alex to reconstruct the firmware for you once you can boot back into Mac OS

Get on with Item 1 and then Item 2 if needed or go to Item 2 directly. You might still want a reconstruction to update to a current firmware version even if Item 1 works btw. In terms of the CD, I suppose you could run it if you want to experiment and contribute to cMP science.

 

[Mac.Apex]

Create a non privileged user and run BootCamp via that user. If the issue is down to Bootcamp, this will resolve the issue and you will be able to boot back into Mac OS.

Under the non privileged user, the Boot Camp Control Panel will not even open (likely due to lack of privileges, as UAC asks for permission to run even under the Admin account). Choosing 'Restart in OS X' still just reboots Windows 10.

If that does not fix things, remove the coin battery, install something like Mavericks and get Alex to reconstruct the firmware for you once you can boot back into Mac OS

That is definitely Plan A!

In terms of the CD, I suppose you could run it if you want to experiment and contribute to cMP science.

I would certainly be curious to try, but I don't want to corrupt things to the point where they can't be fixed.

 

[Dayo]

I would certainly be curious to try, but I don't want to corrupt things to the point where they can't be fixed.

The coin battery removal procedure is to bypass the entire nvRAM.
Whether it is "just a little" corrupted or a bit more corrupted makes no difference.

Thing to note though is that your firmware needs an update.
Easiest/Best way is via a reconstruction.

PS: Don't mix OS types on same disks afterwards

 

[tsialex]

Could I then use the Firmware Restoration CD as I previously suggested?

Don't waste your time with that, you problem is within the NVRAM volume and not in the EFI firmware, or you wouldn't even boot Windows.

Firmware Restoration CD only touches the EFI area, while the NVRAM is completely ignored.

 

[Dayo]

Choosing 'Restart in OS X' still just reboots Windows 10.

You presumably did not get the previous error message when using the non privileged user. If so, it would seem BootCamp somehow managed to hose the nvRAM or pushed a tottering one over the edge.

Going back to your earlier statement that hackery is always needed for our old units, this is true but must remember that there is a difference between applying hacks created to make stuff work on the old units when they are already old as compared to taking hacks derived to make then current stuff such as Windows 7/8 work on then relatively new units and applying those to different relatively new stuff such as Windows 10 on now old units.

I wouldn't expect that userspace apps such as BootCamp are supposed to access the nvRAM on Legacy Windows. Not sure what hackery BootCamp uses to pull it off if so, but clearly a potential problem point if that is the case. Especially if running a version that has not been tweaked for Windows 10 ... at least on a cMP. Speculation though but I just avoid avoid the damn thing myself.

Ensure you keep the Mavericks and rebuilt firmware safe when you get them, since running that BootCamp instance from Mac OS may foul things up again. Good luck!

 

[osxfr33k]

Unfortunately, the Firmware Restoration CDs only work if your backplane BootROM is MP51.007F.B03 or an older version - an older EFI can't be applied to a newer one already flashed to the backplane SPI flash memory - Apple efiflasher do not allow downgrades.

If you have a newer release flashed to the Mac Pro, the only way to repair it is via a BootROM reconstruction service.

I know this is an old thread but why can't you somehow put your newly backup or newly restored bootrom copy onto the restoration CD or image then burn that CD? If this would work then there would be no need to de-solder and re-flash the chip or flash the newer chip from a flash programmer. Is it possible to place that copy onto the extracted CD image and replace the bootrom that is in the image?