MP 1,1-5,1 Mac pro 5.1

[DPXLambo]

Mac Pro 5,1 - NVRAM writes fail despite healthy Boot ROM/VSS (Boot ROM 144.0.0.0.0)​

Hello everyone,

I'm hoping someone has seen this before.

Machine​

• Mac Pro 4,1 flashed to 5,1
• Dual Xeon X5690
• Radeon RX 580
• Mojave 10.14.6
• Boot ROM 144.0.0.0.0
• SMC 1.39f5

Problem​

The Mac boots and runs perfectly, but EFI/NVRAM writes fail.


Example:
<span>nvram </span><span>TestVariable</span><span>=</span><span>Hello</span>
returns
<span>nvram: Error setting variable - 'TestVariable': (iokit/common) general error</span>
The variable is never created.

Also:

• bless --setBoot cannot set efi-boot-device.
• OpenCore cannot become the default boot option.
• Software Update does not offer newer macOS installers.

Tests already performed​

• Replaced the CR2032 battery (3.2 V measured).
• Tested two completely different Mojave SSDs.
  • One with OpenCore.
  • One completely without OpenCore.
• Same behaviour on both.
• Disabled SIP from Recovery.
• csrutil status correctly reports disabled on the clean Mojave installation.
• nvram TestVariable=Hello still fails even with SIP disabled.

ROM Dump​

Using Macschrauber's ROM Dump:

• Boot ROM dumped successfully.
• Boot ROM version: 144.0.0.0.0
• VSS1 healthy.
• VSS2 healthy.
• CRC checks OK.
• Free VSS space available.
• No corruption reported by scanvss.

Flashrom reports normal SPI protection (FLOCKDN=1), but the ROM dump and analysis complete successfully.

Question​

Has anyone seen a Mac Pro where:

• the Boot ROM is healthy,
• the VSS store is healthy,
• but EFI runtime variable writes fail (nvram, bless, etc.)?

Is this a known firmware/runtime issue, or is there another diagnostic step I should perform before considering a firmware repair?

Thanks in advance.

 

[tsialex]

Replaced the CR2032 battery (3.2 V measured).

CR2032 is the wrong model of RTC battery, Mac Pros, iMacs and Mac minis all use the BR2032 one, since the internal temperature frequently is over the maximum allowed by the CR2032 chemistry formulation.

MacPro4,1/5,1 RTC battery is exactly below the GPU heatsink, with today's hindsight, one of worst places for it to be located.

[*]Software Update does not offer newer macOS installers.

This is unrelated, with Mojave you don't have any more softwareupdates since 2022, but not being capable of installing the downloaded updates is a classic symptom of failed SPI.

Is this a known firmware/runtime issue,

No.

Seems you have a failing SPI, with spent NAND cells.

or is there another diagnostic step I should perform before considering a firmware repair?

If you can't even bless and the RTC Battery is healthy, you have a hardware issue. You can try to run ASD/AHT and see if there are any errors elsewhere.

Seems you gonna need to replace the SPI flash memory, replace the backplane or buy a MATCard.