iM 4,1-14,4 iMac 2011 (see more) UEFI Firmware Mod

[StephN999]

This is a Wiki post with information collected from the entire thread. Before you post, please read this first.



This thread is for supporting iMac 2011 Firmware (BIOS) mods.

Some patches may work on other same era Macs. Look at description inside individual posts for detailed information.

Index of currently available patches:

• Remove eeprom flash protection.
• EnableGOP by @Bmju
• CPU Microcode updates.
• Enable PCIe 64bit address space (aka Windows audio ACPI patch).
• Disable iGPU (IGD).
• Disable DDR3 Memory Frequency Limit.
• native USB3 booting via TB dock or PCI card.
• CPU Turbo Overclocking Enable and Setup

You should be familiar with how to disassemble your system and hardware programming of the eeprom chip. While this patches have been extensively tested, there is always the risk of breaking some hardware parts. PROCEED AT YOUR OWN RISK!

You will need a hardware programmer like CH341A to apply this patches to your system bios eeprom chip.
It is recommended to apply first the patch to remove eeprom flash protection, so from then on you can use software flashing to apply or test other patches.

There is also a github repository where this patches and future ones will be stored.

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Original post by @StephN999


Hello,

As I will soon receive my Ivy Bridge processor and test it on my iMac 2011, I made a simple modification of the intel Microcodes.

Since nothing is that simple (well, who knows), I think I need to make some other modifications.

By the way this code is in duplicate, I'll have to test with only one (capture of an original rom).

I thought it would be nice to see what we can do for that, but not only, make other modifications (see correction?)

I had thought for example to have the boot colors natively black like for a while on the higher machines or even more. 😅



Boot colors natively black mod Ok : Change your GUID 6A504489-884E-4465-A02F-03B248CDEF13,
by the iMac 16,1 GUID 6A504489-884E-4465-A02F-03B248CDEF13 file attached.

Correct the management of the wifi card when it's changed we can't use it directly at boot time.

And who knows other ideas about changes that could help for those who have changed their graphic cards etc...

I really like this kind of research but I know that my skills are very limited.

UEFI ROM (iMac 2011, 21"5 and 27") attachments of a motherboard out of service for those who want.

I count on you, thank you.

Wiki post, don't hesitate to correct my english mistakes.

 

[StephN999]

Hi,

It's not complicated to find out about the Apple Logo and what goes with it (ImageAppleLogo, ProgressBar), but it's complicated to modify it, I don't see it, it's compressed.

I am continuing my research for the rest. 😉
[automerge]1601313814[/automerge]

 

[rodolfo.araujo]

I would be very interested in upgrading CPU on my 2011 27 iMac to a Ivy Bridge 3770K. I even have the chip already

 

[StephN999]

Bonjour,

I explain how to change firmware on the dedicated topic.

I took over all the microcodes of the iMac 2012 rom the last time (I provide you with the updated iMac 2012 rom).

I took a Xeon because I should test the ECC ram, but otherwise it's "exactly" the same processor as you.

Do you have something to flash the ROM of your machine?

In the worst case I do the modification for you (via PM only)

PS: Don't forget that there is duplicate microcodes on the iMac 2011 and according to my research on other Apple machines, so "Apple Microcode Tool" is only for checking, not for editing in our case.

PS2: I would be very interested too in seeing this change in action for as long as we've been talking about it. 😅

 

[rodolfo.araujo]

I have a CH341a flashing tool, a separate computer to run the flash and some basic knowledge

 

[StephN999]

Re-Bonjour,

As I told you, either you do the modification or I do it for you, for the rest don't forget to make one or more backups of your original ROM.

That you can recover with Dosdude's ROMTool, nothing insurmountable, but disassembling the machine, changing the microprocessor, it's already quite a lot of work compared to the re-flashing of the ROM and especially as we are sure of nothing, forcing you to put everything back to the origin would be a real shame, but I can't promise anything.

In short, it's up to you.

Have a nice day.

 

[Ausdauersportler]

Hello!

Have hopefully all the tools and the knowledge how to flash the BIOS again and some UEFI tool experience.

I own a small farm of 2011 iMac all modified with the BCM94360CD/BCM943602CDP cards. The most interesting and most easy part would be to find and replace the WIFI/TFTP client software part from the 2012/2013 iMacs boot rom to get the internet recovery with WIFI working, again.

Have you identified this part so far? I did not spend time in it right now...

Any ideas?

 

[StephN999]

Bonsoir,

I found in the iMac 2011 ROM AtherosWiFi and 80211
and I found in the iMac 2012 ROM BroadcomWirelessDxe and 80211 also

I don't know if it can help you enough. 😉

Otherwise I don't think UEFITool is 100% compatible with all the subtleties of Mac ROMs.

But it's already a great tool!!!!

Edit: By the way it's funny but the bluetooth works very well at startup.

 

[caingraywood]

well thats quite interesting. ivy bridge cpus will enable pcie 3.0 on these 2011 imacs

 

[StephN999]

Bonjour,

No, the chipsets on iMac 2011 does not allow it, so we stay in PCIe 2.0

 

[caingraywood]

Technically, yes. your GPU will get pcie 3.0 x 16, because right now it has pcie 2.0 x 16 directly from CPU(from schematics and boardview: refer PEG_R2D signal).

unless there is limitation inside the EFI itself, saying that ivy bridge cpu should stay in pcie 2.0

 

[StephN999]

Unfortunately the chipsets on the motherboard don't allow it, I'll let you find out why I don't have the link anymore. 😉

 

[USB3foriMac]

Hello StephN999,
I like your enthusiasm about exploring the impossible around the iMac.
As you know, I have updated mine with USB3 (FRESCO FL1100 chip, same as in later (i)Macs). However, they are not bootable on the 2011.
Would you be able to help to get this bootable? I often boot other systems via USB sticks, and it would be great as an upgrade if we could from USB3 for that.
Thanks in advance.

 

[Ausdauersportler]

Hi @StephN999!

Have you seen this post?

 

[StephN999]

Bonjour,

@USB3foriMac, I'm not at this level, so I'm asking for help, I hope someone will find this kind of solution.


@Ausdauersportler, For the moment my graphic card is down, so I have less time to look at the new posts, yes I just saw it, I said it quite a few times, Apple Microcode Tool changes only half of the microcodes.

I don't know why, but there are many Apple machines, not just iMacs that have duplicate microcodes.

Bonne journée.

 

[Pascal Baillargeau]

Bonjour,

@USB3foriMac, I'm not at this level, so I'm asking for help, I hope someone will find this kind of solution.


@Ausdauersportler, For the moment my graphic card is down, so I have less time to look at the new posts, yes I just saw it, I said it quite a few times, Apple Microcode Tool changes only half of the microcodes.

I don't know why, but there are many Apple machines, not just iMacs that have duplicate microcodes.

Bonne journée.

Hey Steph, did you made any progress on your project?
Cheers from Chelles.

 

[StephN999]

Yo,

Friday if amazon delivers me on time (I ran out of thermal paste and my replacement pliers were defective...).😄

 

[StephN999]

@ALL> My mod not working, no beep, no boot, just full ventilation after some secondes.
We'll have to look into other firmware modifications...😟

 

[StephN999]

Bonjour,

I will try to see and understand the firmware structure of the iMac 13.1, I also hope for help and advice, because besides promising that I would test an Ivy Bridge processor, I have a personal reason to succeed with this hack.

Edit: I was thinking of asking for help on the win-raid forum, as they are more specialized on bios/UEFI PCs I don't know if they will be able to help me.

Edit2: I found "CpuInitDxe" that seems to be useful for something, I will test it later today.

Edit3: Replaced "CpuInitDxe" no change everythink.
I registered on win-raid.com and I'm just waiting for an answer/track.

Edit4: CpuInitPei and PeiCore seem to be changing as well, I would see that as well.

Have a nice day.

 

[StephN999]

Bonjour,

I changed CpuInitDxe, CpuIoDxe, PeiCore, CpuInitPei, the machine seems to reboot (still no beep), I put back my old microprocessor and my original firmware to reassure myself, everything works! phew!

I thought of asking @dosdude1 but I imagine he is very busy, if anyone has a contact with him and can ask him for advice?

Thank you for that!

Otherwise I would have tried some tricks concerning Correct the management of the wifi card on boot but without a graphic card I can't...

 

[StephN999]

Bonjour,

I continue my research, I go from time to time, so that it doesn't become an obsession, I'm already depressed enough, I'm not going to make myself sicker.

So still running, I'll be more help when I get a graphics card again, if it can help me with every test.

I keep asking questions about win-raid otherwise.

Bonne journée.

 

[StephN999]

Bonjour,

I went through the firmware of my machine again, I think it would be better if I had a complete firmware of the iMac 2012 to compare completely.

In order for our machines to boot with an Ivy Bridge, in addition to other modifications, we need to update the Intel ME from version 7 to 8 (Intel Management Engine).

DxeMainDxe
CpuIoDxe
CpuInitDxe
PchInitDxe
PchS3Peim ?
AppleMemoryTest ?
PowerMgmtDxe
PowerManagementAcpiTables2 ?
PeiCore
PeiCpuIoPei
CpuInitPei
MemoryInit
PchInitPeim
S3ResumePei ?
CpuS3Pei ?

I have installed Ubuntu on the computer I have at my disposal, I started my installation and research with CoreBoot, I still don't know if it's very complicated, if it allows a boot even only under Linux it will already be a step.

Bonne journée.

 

[StephN999]

Hi,

CoreBoot KO

IME 7 to IME 8 Ok

Test later!

 

[StephN999]

Bonjour,

I replaced as planned :

CpuIoDxe BAE7599F-3C6B-43B7-BDF0-9CE07AA91AA6
CpuInitDxe 62D171CB-78CD-4480-8678-C6A2A797A8DE
PchInitDxe DE23ACEE-CF55-4FB6-AA77-984AB53DE823
PchS3Peim 271DD6F2-54CB-45E6-8585-8C923C1AC706
AppleMemoryTest 60A14F6F-55B9-47A3-B067-01A93027F3FE
PowerMgmtDxe F7731B4C-58A2-4DF4-8980-5645D39ECE58
CpuInitPei x2 01359D99-9446-456D-ADA4-50A711C03ADA
MemoryInit x2 3B42EF57-16D3-44CB-8632-9FDB06B41451
PchInitPeim x2 FD236AE7-0791-48C4-B29E-29BDEEE1A838
S3ResumePei x2 8BCEDDD7-E285-4168-9B3F-09AF66C93FFE
CpuS3Pei x2 C866BD71-7C79-4BF1-A93B-066B830D8F9A

I still don't know if I should add AppleIvyBridgeGop?

Still no Boot.

I'm still hoping for CoreBoot but I'll need people with a working 21.5" with Linux installed.

Clearly I can't do better without help from either side (Mods & CoreBoot).

Bonne journée.

 

[StephN999]

I'm always looking for information and I stumbled upon this, I don't know if it can be useful, everything is good to take, I thought it could be useful for Xeon microprocessor hibernate problems with or without iGPU!?

Utility to patch UEFI BIOS PowerManagement modules to be compatible with MacOS X SpeedStep implementation.

Edit: In my memory the hibernation problem also concerned Windows.