USB Boots on Linux, not on 2012 or 2009 Mac Mini. EFI drive shows up TWICE.

[brycenesbitt]

While we find a solution to this, I suggest using MemTest86 5.1 or 6.0 beta 1 as a workaround.

Indeed. Beta 1 works.
And it nailed some defective Corsair RAM with the Hammer Test.
(The computer was rebooting randomly once a week... all other tests showed the
RAM as good).

However, the double icon still appears in the OS X boot menu.

[keith]

Thanks for that.

It looks like the freeze is due to a compatibility issue. With the support of localization in the new 6.0 beta 2 build, MemTest86 attempts to install the localization strings to a database provided by the UEFI platform. However, this database is only available for firmware that support EFI specifications 2.0 and newer. Macs (such as your Mini) that use the older EFI specifications do not support it, which is probably what is causing it to freeze.

While we find a solution to this, I suggest using MemTest86 5.1 or 6.0 beta 1 as a workaround.

[brycenesbitt]

Can you check to see if you have the latest EFI firmware for your Macs:
http://support.apple.com/en-us/HT201518
Also, check to see if a MemTest86.log file is created under EFI\BOOT of your USB drive

Model Identifier: Macmini6,2
Processor Name: Intel Core i7
Processor Speed: 2.3 GHz
Memory: 16 GB
Boot ROM Version: MM61.0106.B03 ( http://support.apple.com/kb/dl1616 )
SMC Version (system): 2.8f0

/Volumes/Untitled/EFI/BOOT/Memtest86.log
2014-12-04 05:03:04 - Attempting to retrieve the root directory of the data partition.
2014-12-04 05:03:04 - Found 5 handles that supported SimpleFileSystem
2014-12-04 05:03:04 - Checking handle 0 (7EAE0790)
2014-12-04 05:03:04 - Checking handle 1 (7EAD9590)
2014-12-04 05:03:04 - Checking handle 2 (7EAD8590)
2014-12-04 05:03:04 - Checking handle 3 (88954B90)
2014-12-04 05:03:05 - HD node found: MBR type(2), Signature type(2), Part #(2), Start LBA(10444, Num Sectors(202719)
2014-12-04 05:03:05 - Self node: MBR type(2), Signature type(2), Part #(1), Start LBA(204, Num Sectors(100353)
2014-12-04 05:03:05 - Checking handle 4 (88953790)
2014-12-04 05:03:05 - Handle is own partition
2014-12-04 05:03:05 - =============================================
2014-12-04 05:03:05 - MemTest86 V6.0 Beta2 Build: 0001 (64-bit)
2014-12-04 05:03:05 - =============================================
2014-12-04 05:03:05 - Console size = 80 x 25
2014-12-04 05:03:05 - Initializing localization strings
2014-12-04 05:10:09 - Successfully opened EFI\BOOT directory.
2014-12-04 05:10:09 - =============================================
2014-12-04 05:10:09 - MemTest86 V6.0 Beta2 Build: 0001 (64-bit)
2014-12-04 05:10:10 - =============================================
2014-12-04 05:10:10 - Console size = 80 x 25
2014-12-04 05:10:10 - Initializing localization strings

# sudo dd if=memtest86-usb.img of=/dev/disk1
# diskutil list
/dev/disk1
#: TYPE NAME SIZE IDENTIFIER
0: GUID_partition_scheme *4.0 GB disk1
1: Microsoft Basic Data 51.4 MB disk1s1
2: EFI 103.8 MB disk1s2

[keith]

Can you check to see if you have the latest EFI firmware for your Macs:

http://support.apple.com/en-us/HT201518

Also, check to see if a MemTest86.log file is created under EFI\BOOT of your USB drive

[brycenesbitt]

I created a v5 USB stick.
On a Linux box it boots and works.
On a 2009 Mini a single "EFI" drive comes up, but it brings up a ? folder icon.
On a 2012 Mini two "EFI" drives come up at boot time, both of which freeze the mouse pointer as soon as they are selected for boot.

I've tried more than one USB port, and there are no devices other than keyboard/mouse/video attached.

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What can I do to get Memtest86 working on these Macs?