I am not lucky enough to have a mac... but my HP servers had this issue and I just disabled ACPI in the BIOS and it fixed the issue.
Let me know if this does not help the issue.
Unfortunately, there is no way to disable ACPI on the Mac that I am aware of. There isn't a traditional BIOS menu on Mac OSX EFI.
However, I did manage to finally get ESXi5.5U2-Patch03 installed and figured I would share my finding in case somebody else has the issue. In my case I had MP61.0116.B04 as my Boot ROM, however there were no EFI updates available to bring it to the supported version for ESXi of MP61.0116.B05. So I opened a case with Apple Engineering and was informed that OS X Yosemite applies an EFI update that is not available any other way than upgrading to Yosemite. So...I installed Yosemite which brought my Boot ROM up to MP61.0116.B07 and ESXi installed without any issues.
- Need Boot ROM MP61.0116.B05 or Higher
- Yosemite Upgrade will get you to MP61.0116.B07 = ESXi Install SUCCESSFUL!
Tangentially to this thread: ESXi cannot function without ACPI. It's been years since ESX could run on a non-ACPI system. If you found a "disable ACPI" option on an HP server and ESXi was able to boot with that selected, it wasn't really disabling ACPI. Who knows what it was really doing.
Great info, thanks. I was helping with ESXi bringup on Mac Pro here, and the Mac I was using had firmware MP61.0116.B05. Probably all the Macs we were working with had that firmware, so we didn't know there was an issue with .B04. (There were some issues with .B05, but we put in workarounds for those.)