Wicky Posted January 25, 2006 Share Posted January 25, 2006 Hacking EFI on an Intel Mac can get you a dead Intel Mac click on 'Calender/view the latest entries' ...a resourceful Mac hacker, in an attempt to boot Windows Vista on his iMac Core Duo, worked his way into the machine's EFI menu system. Well, as can be seen in latter comment posts on the user's webpage, some users attempting to hack the EFI are ending up with iMacs that won't boot - at all... ...Therefore, there is no (known) way to reset it to factory defaults to make it ever boot or function again. It becomes a dead system... ...hacking the Intel Mac in this fashion is definitely a "proceed at your own [great] risk" proposition... Looks like we definitely need a CMSF installer for OSX [ January 25, 2006, 09:49 AM: Message edited by: Wicky ] 0 Quote Link to comment Share on other sites More sharing options...
aka_tom_w Posted January 25, 2006 Share Posted January 25, 2006 Full-On Tech GEEK forum about with the latest news on windows boot problems with intel macs First a word of caution. You can leave your system in a state where Mac OS X won't start up again. You can fix it by booting with the install CD (hold down C as you turn on your computer) then using the Start-up Disk utility). Now, on to the instructions. 1. Download the EFI Sample Implementation from Intel. 2. Unzip the file to /efi (or anywhere else, but /efi is what I'll be using) 3. In terminal do 'sudo bless --folder /efi --file /efi/Binary/BIOS32/Bin/GraphicsConsole.efi --setBoot' 4. Reboot your computer. 5. You'll get the familiar chime and gray screen, wait about 10 seconds then hit the spacebar. 6. You're now in EFI! Let's head over to the shell... 1. Select Boot Maintenance Manager 2. Select Boot From File 3. Select the option that begins with "NO FILE SYSTEM INFO", this is your start-up volume 4. Navigate your way to /efi/Binary/BIOS32/SHELLBios32/Shell.efi To get your machine booting Mac OS X again, you have a few options. Probably the easiest is to put the restore CD in the drive, and reboot while holding down C. Once in Installer, go to Utlities, Start-up Disk and select the System folder on your hard drive. Another way to boot back in to OS X from the EFI menu is to follow the same steps as for launching the shell, except navigate to /usr/standalone/i386/boot.efi. Once back in OS X, change your start-up disk back to the system folder on your hard drive using system preferences. Important system recovery instructions: Thanks to a commentor and Dave Schroeder's testing, I am able to give you this information for restoring your iMac should it refuse to power on. Unplug your iMac and wait 10 seconds. Hold down the power button as you plug it back in. You should now be able to boot from the restore DVD. 0 Quote Link to comment Share on other sites More sharing options...
Wicky Posted January 25, 2006 Share Posted January 25, 2006 Tom... from my original linkeroonie: From one of the comments: My EFI-newb 'theory': Because the Intel EFI pre-boot drivers get in the way of Apple's pre-boot code. This in turn disallows ANY APPLE KEYCOMMANDS FROM WORKING. This includes 'Zapping the -NVRAM-', booting in to the Diagnostics/Installer from the 10.4.4 Installer Disc - even EJECTING any disc in the drive. When the Intel Mac gets stuck in this LIMBO MODE, it is unable to do ANYTHING: 1. The screen does not turn on 2. There is NO STARTUP CHIME 3. If a Disc is in the drive it will spin up, but it will not boot 4. If an external Firewire drive is connected, there be brief activity when powered up, but it will not boot (if it has bootable files on it, as mine did) Therefore, there is no (known) way to reset it to factory defaults to make it ever boot or function again. It becomes a dead system, similar to flashing an incorrect/incomplete BIOS. At this stage sounds a risky bit of tinkering. Unless a foolproof repeatable method can be made to boot into Vista or whatever, I'll be steering well clear. http://apple.slashdot.org/article.pl?sid=06/01/24/139218 An anonymous reader writes "The race is on. You can try to get the bounty for booting Windows XP on iMac. At this moment there is $2773 waiting for the winner. However several people have brickified their iMacs when playing with EFI." I imagine those tech support calls are hysterical [ January 25, 2006, 11:41 AM: Message edited by: Wicky ] 0 Quote Link to comment Share on other sites More sharing options...
Diarmud Posted January 28, 2006 Share Posted January 28, 2006 Ah...I wondered when the Cell would come up. Yes, the Cell is a more powerful processor...for those tasks for which it is suited. Cell has only one general purpose processor, with 7 (or 8) specialized cores. If one writes code for which those cores are suitable, then the Cell is a better processor. However, as a general purpose processor, it doesn't have the great advantage that some have claimed.... 0 Quote Link to comment Share on other sites More sharing options...
Pzman Posted January 29, 2006 Share Posted January 29, 2006 I know a few fokes you tried this on their intel based iMacs, no good. 0 Quote Link to comment Share on other sites More sharing options...
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