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I have had Lion for a 2, 3 months on the iMac 27 inch purchased last October (2011). Last night I chose to update the system, and deselected iMoves update because it was 1GB, and chose only 4 updates, including iTunes, Safari (i think)... But the update says error, and ask to restart the system (it won't restart itself, so I waited 30 minutes, and then pressed the Power button for 10 seconds, to let it power down, and press Power again to power it up).

However, after that, the system failed to boot up, showing a

panic(cpu 0 caller .....)" "Unable to finder driver for 
    this platform: \"ACPI\". ... xnu-1699.26.8/iokit/Kernel/IOPlatformExpert.cpp:1504

This is not typical of the upgrade process. So I searched the Internet for IOPlatformExpert.cpp:1504 and some people said it is a hard drive error, but then I powered down and pressed Options when booting up, and was able to boot to Windows 7 (bootcamp)... and was able to boot to the "Recovery", which let me choose

  1. Restore from Time Machine Backup
  2. Reinstall Mac OS X
  3. Get Help Online
  4. Disk Utility

what should I do now to fix it so that it can boot again?

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I'll guess an answer - but read up here and make sure you have a backup before trying to reinstall Lion.… – bmike Jun 12 '12 at 15:25
up vote 1 down vote accepted

You likely ran into a problem with the Thunderbolt Update 1.2 - it's not clear how often this is causing problems (or if the problem was pre-existing and the update process just surfaced it or if the update itself has a problem).

Your best bet for up to date service information is contacting Apple support - especially if you are covered and it's a free request.

Next would be some of the long time Apple blogs like Tidbits that has some very good reporting on this so far.

You might booting from an external drive (or reinstalling to an external drive and reapplying the combo update 10.7.4 to the failed drive while booted from another install of Lion) to see if you can avoid total reinstallation.

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Apple support went into details that they will need to charge me $49 for a support of 30 days, or I can purchase Apple Care because it is within a year... or I can pack the computer and bring to the Genius Bar... I told them about it might be related to Thunderbolt update and they still insisted on $49 – 太極者無極而生 Jun 12 '12 at 15:37
That's a tough one - if they gave free support, then it's not fair to people that paid for support. But, it looks like their update could be at cause. At least you have options and can make a decision how much your time is worth and get help that makes sense (or spend time learning and then fixing it yourself if you prefer that self-learning journey). – bmike Jun 12 '12 at 19:37
So it is not fair to them huh? It is fair to me losing two days of work? Salary in Silicon Valley is $400 to $500 per day... so causing me to lose $800 to $1000, that's fair, right? – 太極者無極而生 Jun 13 '12 at 12:49
If they want money, then you are out of your "free support window". I'm not sure I understand your money loss comment - seems like you'd plan for support or just pay for AppleCare (or JointVenture) if you stand to lose two days work to restore from a backup when that much money is on the line. – bmike Jun 13 '12 at 13:24

Tried clearing your PRAM? Hold down Option + Command + P + R before turning the mac on, keep holding them until the mac makes the startup chime again (twice in total). Apart from that, boot off the recovery partition and reinstall over the top of your hdd. Your data won't be changed, the OS will just be repaired.

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Lion CD's are self baked - so I'd guess someone with the knowledge to make one wouln't be asking this (except perhaps to alert everyone of a problem??). Did you mean to say to boot from the Recovery HD to attempt the normal repairs and reinstall? – bmike Jun 12 '12 at 15:29
Edited and updated answer. – TheIrishGuy Jun 12 '12 at 15:32
yeah I was told that before the .dmg goes away, there is an opportunity to burn that to a DVD-R, but otherwise it would have been deleted upon installation of Lion – 太極者無極而生 Jun 12 '12 at 15:35
So I pressed and hold Option + Command + P + R and released it on the second chime, and it would show the same screen of the IOPlatformExpert.cpp:1504 – 太極者無極而生 Jun 12 '12 at 15:36
Or what about Recover from the Time Machine Backup instead of reinstalling OS X? – 太極者無極而生 Jun 12 '12 at 15:45

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