Resolved Flash to 5,1 Not Working, Official Apple EFI 1.5 Link Down

[John Doe 57]

I'm trying to flash my Mac Pro 4,1 to 5,1 but the process is not working.

1. I tried with 10.10 and ran into terminal errors with "bash 3.2#" so none of the csrutil commands were recognized.

2. I updated to 10.11.6 and csrutil commands worked with successful messages indicating that SIP was disabled.

3. I mounted the EFI 1.5 Update DMG, ran the Firmware Tool and was successful in creating the RAM Disk.

4. I shut the computer down and then restarted by holding the power button until the LED flashed rapidly.

5. The computer booted quickly and system profiler showed that I'm still running 4,1.

6. I inserted a new HDD and installed 10.8.5. The csrutil disable command was not recognized.

Perhaps it's worth noting that I had to download the EFI 1.5 update from another site. I was not able to download from Apple's site. When I click on their download link, I'm redirected to a page with this message:

An error occurred while processing your request.
Reference #132.2564d717.1533278807.1fffe44


Specs:
Mac Pro 2009
2 x 2.26GHz Quad-Core
12GB 1066MHz DDR3 ECC
GeForce GT 120
Boot ROM: MP41.0081.B07

 

[Synchro3]

10.8.5 has no SIP. No csrutil disable command needed.

Just mount the MacProEFIUpdate.dmg before you start the 'Mac Pro 2009-2010 Firmware Tool.app'.

The right 5,1 EFI-Update.dmg attached in this post.

 

[bookemdano]

Yeah the process is actually easier if you're on a version earlier than 10.11 (El Capitan) because you don't have to deal with SIP.

 

[John Doe 57]

10.8.5 has no SIP. No csrutil disable command needed.

Just mount the MacProEFIUpdate.dmg before you start the 'Mac Pro 2009-2010 Firmware Tool.app'.

The right 5,1 EFI-Update.dmg attached in this post.

Worked like a charm! Thanks a bunch!!

I also removed the HDD with 10.11.6 just to be safe.