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Resolved i7-940 and kernel panic
- Thread starter Zeke D
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It's inside FirmwareUpdate.pkg, you need to extract it first then reopen it on Pacifist. Then somewhere on that file is 0085.
I've downgraded several times, but I have the means to replace the SPI flash/reprogram it externally.
Like I said, it's risky and you shouldn't do this.
Yikes. Will your cMP not boot now? There have been several reports of this, but I'm not sure any common thread was identified (and on the ones whose flash chip was damaged I think that the firmware update process got stuck and they had to manually power off).
Zeke I would say if your cMP actually still boots then you should just replace your CPU and forget about trying to downgrade firmware. It seems too risky!
Zeke I would say if your cMP actually still boots then you should just replace your CPU and forget about trying to downgrade firmware. It seems too risky!
Yeah. I put the Xeon back in it. The 4,1 is my spare (my spare has a spare cMP3,1.) I hate to waste $15, but I also would hate bricking my 4,1 even more. Maybe if I get a nice royalty check next month, I'll spring for a 6-core i7.
If you really want to try, downgrade to 0087 then to 0085. Do this by baby steps since the LOCKED.fd file don't contain the complete BootROM. Do a backup before, using ROMTool.
Yes, definitely the right call. I know some people have been able to downgrade at least one version back, but sounds like it's best avoided.
same steps? find 87, rename it to 90, then rename 85 to 92 or something?
Should I be worried like bookemdano?
LOL well my worry came from tsialex. If he's worried then I'm worried, because he knows a hell of a lot more about this stuff than I do. 
Also, I don't have 10.13.5 saved anywhere so I can't help you find 0087. Maybe someone else has it.
Also, I don't have 10.13.5 saved anywhere so I can't help you find 0087. Maybe someone else has it.
1) Do a full BootROM dump with dosdude1 ROMTool
2) rename 0087 to 0090, then "upgrade" it to the previous version
3) rename 0085 to 0088, then "upgrade" it to the previous version
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Board.
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The problem is that the LOCKED.fd file it's a unpersonalised one. You can boot with a SPI flash restored to it, but you will loose iCloud/Facetime/iMessage.LOL well my worry came from tsialex. If he's worried then I'm worried, because he knows a hell of a lot more about this stuff than I do.
Also, I don't have 10.13.5 saved anywhere so I can't help you find 0087. Maybe someone else has it.
To personalize it again, you will need the SystemSerialNumer (label next to the video card port, behind the Mac), LogicBoardSerial number (it's on a label next to the CPU tray conector) and the SalesOrderNumber ( sometimes you can use the SKU for a retail bought Mac, but on a Refurb or on a BTO/CTO, only Apple has it). Next you will need to carefully edit the LOCKED.fd file with the needed information, on the correct places that don't exist on the unpersonalised one.
It's a royal pain in the _ss to get the SON on a Mac that don't use the SKU as the SON. So, I recommend to everyone do a full BootROM dump and save more than one backup.
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Yes, sorry.
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I'm running 10.13.3 right now, but I doubt I can get just 10.13.5 either.LOL well my worry came from tsialex. If he's worried then I'm worried, because he knows a hell of a lot more about this stuff than I do.
Also, I don't have 10.13.5 saved anywhere so I can't help you find 0087. Maybe someone else has it.
You can get it hidden on the 10.13.5 ComboUpdate. Extract RecoveryHDMeta.dmg, then re-open it on Pacifist, on the Firmware folder you will have the MP51.0087.B00.LOCKED.fd file.
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If you overwrite your personalised by Apple BootROM with the LOCKED.fd file you will loose access to iCloud/Facetime/iMessage. Read again my previous post about it.
with no way to re-add it?
[doublepost=1533437193][/doublepost]I could temporarily use the LOCKED vie dosdude to verify that the i7 works again, then use the dump to restore cloud/face/message.
[doublepost=1533437259][/doublepost]I've got the 10.13.5 combo, plus pacifist 3.6, so I guess when you're off youriPhone, you can walk me through it.
Without knowing what to add, what to remove, what to overwrite on the LOCKED.fd file, no.
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RecoveryHDMeta.DMG, extract it, reopen it on Pacifist, go to the Firmware folder, extract the LOCKED.fd file.
I had to downgrade mine from 0087 to 0085 using @tsialex ’s method described above. For me it went perfectly. Then when 0089 came out and fixed the microcode problem, I flashed to that without issue.
You need to think it all out, and get a firm understanding of what’s taking place, and run through it in your head or on paper the first time. You personally may not need to do all that, but this isn’t the time for mistakes.
I just flashed mine again today with modified firmware for NVMe boot support. It went well, but I cringed a bit myself. Sigh of relief when I saw that it all went well.
Good luck, I wish you success.
You need to think it all out, and get a firm understanding of what’s taking place, and run through it in your head or on paper the first time. You personally may not need to do all that, but this isn’t the time for mistakes.
I just flashed mine again today with modified firmware for NVMe boot support. It went well, but I cringed a bit myself. Sigh of relief when I saw that it all went well.
Good luck, I wish you success.