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Author Topic: How EFI works and how to spot a tech charlatan  (Read 1366 times)
Rominator
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« on: June 07, 2018, 10:31:52 AM »

I've been selling EFI cards for more than 10 years.

I recently had an amazing moment where I read  "low-level programming in EFI C. Nobody will be happy if we rush and your MBP becomes an unbootable brick."

This is baloney.

EFI is a file on peripherals that tells the OS how to use the device.

Only way to turn something into an "unbootable brick" is to write to the bootrom. From 12 years of selling EFI cards this has never been a problem. If you have a USB stick with some EFI code that gets read at boot, BIG DEAL. It won't write to the machine's boot rom.

There is a HD partition with EFI on it, but this is not nearly as important as the EFI in the EEPROM chip soldered onto the logic board. All the peripherals that have EFI are the same as a USB stick, remove them and their EFI doesn't matter.

Darthvader guy and DOSDUDE are offering EFI NVME updates that write to the EEPROM chip on logic board. This could "brick" your machine. They warn you about what this means. But a simple eGPU hack that uses EFI from a file elsewhere poses no risk WHATSOEVER.

Someone who tells you otherwise is a liar and tech charlatan. Don't wander out into the desert following a mindless fool.

EFI from an external source (like GPU or USB stick) is  like a story you read in the newspaper at your breakfast table. You can choose to be moved by it, or set it down and walk away. It has no lasting power unless a specialized program writes it into the system boot rom. Completely harmless, like a butterfly landing on your finger, it has no lasting effect WHATSOEVER.

Don't believe me? Ask the above mentioned folks who know what they are talking about. A USB stick with eGPU EFI is as harmless as junk email you get for mail-order brides or African Prince scams. Only affects you if you buy into  the gibberish.

There is a reason why our EFI eGPU  cards  were called "breakthrough" BEFORE any wannabes posted about EFI. See Barefeats.com for the truth. Or keep reading nonsense in the echo chamber,  your individual choice.
« Last Edit: June 07, 2018, 01:37:04 PM by Rominator » Logged

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DarthnVader
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« Reply #1 on: June 16, 2018, 11:58:04 AM »

What was that about Dave?

Anyone thinking of altering and flashing their logic boards boot rom should use extreme care, all the normal warnings apply, it could brick your Mac, burn your house down, kick your dog, or knock up your teenaged daughter. Grin

Anyway, two completely different targets, obviously  if you are dealing with an add on PCI card that has a ROM chip on it, it's best to just flash that rom chip with a Mac compatible firmware if the device needs to take part in the boot process. However what users have been doing is adding NVME booting to their Boot ROM, because we have no source of M.2 boards with a ROM chip, and I'm not aware any even exists.

There is the hope of the "Holy Grail" of getting cards with GOP roms working with cMPs, but it's just idle talk, no one is really actively working on it, and other than a few reports no one really knows how to do it, or if it will even work.

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Rominator
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« Reply #2 on: June 25, 2018, 06:13:39 PM »

The “definitive source” of black screens has kept up their fine work.

Glad we have working eGPUs here.
« Last Edit: June 25, 2018, 09:51:20 PM by Rominator » Logged

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DarthnVader
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« Reply #3 on: June 30, 2018, 09:29:23 AM »

I recently picked up a MP3,1 on the dirt cheap and resurrected it from it's grave. I figured I'd have a look at GOP boot screens, as one user here once reported they got it to work with Clover and a user at insanelymac made a version of refind that they reported worked on a 3,1 for GOP boot screens.

I had a go at the code used in Clover and rEFInd back last year, but one thing that struck me as odd was there was no code to probe the pci bus and map the GOP rom into memory. Now that I have a Mac Pro, I can say that GOP rommed cards get probed and the GOP module gets mapped into ram, however it reports as invalid.

I was unable to get Clover or rEfind to work with custom changes for GOP, both just boot hang, as does the Next Loader which has some code for GOP. 
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Rominator
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« Reply #4 on: July 03, 2018, 12:30:35 PM »

Good luck with 3,1.

I had another "tech charlatan" encounter.

I have been playing with 2011 iMacs. They are unique in having MXM cards and TB. Flexible as iMacs come. (came?)

Anyhow, I wanted to upgrade from the i5 in one so I did a quick Google for what was best CPU they used.

Found reports that Ivy Bridge i7 3770 might work in these. A guy at MR named "Hacker Wayne" reported it did. He provided screen shots.

I stopped reading and went shopping.

Got a 3770 for $180. Slapped my flashed 780M and the new CPU in. Reassembled. And had a dead iMac. Did a few disassemble/reassemble cycles. Spent a day troubleshooting and finally did some more Googling.

Should have finished reading the MR thread.

Turns out it was a scam. When people started noticing irregularities in screen shots he vanished like a cockroach.

And then a post from some poor SOB who bought a 3770 and spent an afternoon doing what I did.

Why would someone make up an elaborate lie like that? If you have to lie to get attention as a hacker, then you are a fraud and should write fiction instead.

Anyone need a i7 3770?
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DarthnVader
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« Reply #5 on: July 07, 2018, 12:05:30 PM »

We haven't got to the point in firmware hacking that we can add support for CPU's, tho one should be able to ask at the EDK II dev mailing list how OVMF deals with it. Then we could monkey around with virtual machines and have a look to see if we could find the CPU support in Apple's EFI firmwares.

If we could build a virtual machine with a chipset Apple used on an intel mac we should be able to load one of the Apple firmwares on it. Saddly we only have ICH9, and apple never used it.
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