Firmware Update Procedure – USB method (Mac only) Document No. 480SSD‐SFUSB.A00 09/02/14 Page 4 2. Insert USB drive containing bootable.dmg contents. Hold the “option” key down and power on Mac system. Wait for the “EFI boot” option to appear, release the option key and then select “EFI boot” to continue. EFI Mounter-v2 is developed by com.apple.ScriptEditor.id and is used by 7 users of Mac Informer. The most popular version of this product among our users is unknown. The product will soon be reviewed by our informers. To mount the EFI partition from this app, click on the appropriately-named 'Mount EFI' button in the left column. Then, in the page that comes up, click 'Mount EFI partition.' If you have multiple hard drives, it's the same as with EFI Mounter: choose the hard drive that OS X is currently booting from.
- Efi Mounter For Mac Mojave
- Efi Mounter
- Efi Mounter For Mac High Sierra
- Efi Mounter For Mac Os
- Mount Efi Partition On Usb
- Mount Efi Partition Windows Hackintosh
rEFIt is a boot menu and maintenance toolkit forEFI-basedmachines like theIntel Macs.You can use it to boot multiple operating systems easily,including triple-boot setups with Boot Camp.It also provides an easy way to enter and explorethe EFI pre-boot environment.
On this page:News- Download- Troubleshooting- Resources
Other pages:Documentation- Troubleshooting- Screenshot- Myths and Facts
News
2013-03-29: As you may have noticed, rEFIt is no longer activelymaintained. Please check outrEFInd,a fork that is maintaned and under active development.
2010-03-12: The site has a newtroubleshooting section.Some common problems are also listed below.
Efi Mounter For Mac Mojave
2010-03-07: Version 0.14 was released. This release adds a configurationoption for the default boot choice, fixes the Linux/GRUB detection issue, andfixes Snow Leopard 64-bit issues.
Download
The current release is 0.14.It is available in various forms.Both disk image distributions include the Installer package andcan be burned as a bootable CD as well.All three binary distributions can be used to install rEFIton a USB memory stick or other disk drives.
- rEFIt 0.14 (6.5M Mac disk image)
- rEFIt 0.14 (6.5M ISO disk image)
- rEFIt 0.14 (3.2M .tar.gz)
- rEFIt 0.14 source code (253K .tar.gz)
You can browse the source code online through theViewVC interfaceto the Subversion repository at SourceForge.
Troubleshooting
See the troubleshooting section for a full list.Here are a few common problems:
- I just installed rEFIt, but the menu doesn’t show up.
- It takes two reboots after using the package installer.More...
- I can’t boot Windows/Linux from a USB hard disk.
- This is not well-supported by Apple’s firmware.More...
- I can’t boot Windows/Linux from the second internal hard disk.
- This is not explicitly supported by rEFIt at this time.More...
Resources
This project is hosted by SourceForge.You can use the trackers to submitbug reports,feature requests,and patches.The latest development source code is available from theSubversion repository.Other resources are listed on theproject summary page.
To discuss rEFIt with other people, check out theOnMac Forumsor theDual Boot forum at InsanelyMac.
A friend recently gave me his old Apple iMac (Late 2006) after it began having graphics issues. Before freecycling it, I wanted to try to boot Linux on it, just for kicks. That turned out to be harder than I imagined it would be…
There were two main problems:
- Some Macs of this era had only 32-bit EFI bootloaders; and
- Many Linux distributions are only designed to do 64-bit UEFI boot.
If you want to skip the backstory, jump directly to Booting Linux.
Table of contents:
Booting memtest86
The first thing I wanted to try was memtest86. I downloaded the memtest86 bootable USB image, then used diskutil to find and prepare my USB stick, and dd to copy the memtest86 image to my USB device:
Holding down Option while booting brought up the Startup Manager, which allowed me to select EFI Boot. Worked perfectly! (No memory errors, by the way. ;-)
In fact, there were two EFI Boot entries, which both worked – more on that later.
Examining the memtest86 image
Unlike many of the Linux distribution images, which come as ISO files, memtest86 came already designed for USB booting. Here are some of its properties, information which would later be useful.
Checking the image file itself, notice that it’s actually a hard drive image:
Efi Mounter
At first its partition layout looked pretty odd to me: I did some reading, and discovered that partition type EE is known as a protective MBR, used when the drive is partitioned using the newer GUID Partition Table (GPT) standard.
Efi Mounter For Mac High Sierra
The GPT layout looks like:
The GUIDs have some meaning, which is:| GUID | Purpose |
|---|---|
| EBD0A0A2-B9E5-4433-87C0-68B6B72699C7 | Basic data partition Used for storing the majority of data on the device |
| C12A7328-F81F-11D2-BA4B-00A0C93EC93B | EFI System partition Contains EFI bootloaders, etc |
By default, only the data partition is mounted, but one can mount the EFI System partition also:
Here is a listing of the EFI directory from the data partition:
And here is a listing of the EFI directory from the EFI System partition:
Originally I thought that the two EFI Boot entries were explained by having both BOOTIA32.efi and BOOTX64.efi, but now I know that it is caused by having the EFI bootloader in both partitions.
Summary
For this particular image, we have:
- a protective MBR, within which is
- a GUID Partition Table, which has two partitions:
- a data partition; and
- an EFI System partition
- within each partition is a directory /EFI/BOOT containing EFI bootloaders named
- BOOTIA32.efi (for 32-bit EFI); and
- BOOTX64.efi (64-bit EFI).
32-bit vs 64-bit EFI
One of the first things I checked on this Mac was whether it had a 32-bit or 64-bit processor. The processor is an Intel® Core™2 Duo Processor T7400 which, according to ARK, is 64-bit. So I mistakenly thought that the EFI would be 64-bit, too. Wrong!
EveryMac.com has an excellent list of machines and which processor and EFI they support. There I found that this Mac had a 32-bit EFI.
Another way to find this information is with a command:
Note that you can boot a 64-bit kernel from a 32-bit EFI, provided that the bootloader and kernel support it.
Booting Linux
General procedure
The goal is to get a USB stick with:
- a writeable data partition (so we can, eg, make changes to the grub.cfg file); and
- a 32-bit EFI bootloader in /EFI/BOOT/BOOTIA32.efi
Efi Mounter For Mac Os
What doesn’t work: dding the hybrid ISO directly
Your initial thought might be to use dd to write a hybrid ISO (as most Linux distributions come these days) directly to the USB stick, just as you’d do for a PC. That’s going to fail.
The Ubuntu 15.10 (amd64) ISO looks like this:While you could theoretically modify the EFI System partition, there really isn’t enough space on there to put everything. The data partition is ISO9660 format, which some systems might let you mount read-write, but I couldn’t see how in OS X.
Using UNetbootin
By using UNetbootin, one can prepare the USB key for editing. I won’t go into the operation of UNetbootin since I think it’s fairly self-explanatory. (One tip, though: erase the disk in Disk Utility first.)
The new USB disk looks like:
Adding 32-bit GRUB EFI
Now that you have a read-write partition, you can add the 32-bit GRUB EFI bootloader. I took the one from the Debian netinst (“network install”) CD image. From that image, you need:
- efi/boot/bootia32.efi
- boot/grub/i386-efi/*
Here are the commands I used:
And that’s it! You now have a USB device that will boot on a Mac with 32-bit EFI.
Odds & sods
There are a couple of quirks I found (not related to EFI booting) which I thought I’d include here for reference.
Video modes
I found it was necessary to edit boot/grub/grub.cfg to include the kernel option nomodeset to prevent the console video from being trashed. I changed the original:
linux /casper/vmlinuz.efi file=/cdrom/preseed/ubuntu.seed boot=casper quiet splash ---
Mount Efi Partition On Usb
to:linux /casper/vmlinuz.efi file=/cdrom/preseed/ubuntu.seed boot=casper nomodeset ---
You may find a slightly different command necessary depending on your hardware and kernel release. digium has a good article on their site for this: How to disable the Linux frame buffer if it’s causing problems.
Console-only boots
For somewhat murky reasons, many distributions have switched over to the confusing systemd. On these systems (eg Ubuntu), the text kernel option no longer does what it’s supposed to. (One would think the systemd folks could’ve made it work but I guess they chose not to.)
Anyhow, there is a (much longer and less obvious) option which does work. Add systemd.unit=multi-user.target to your kernel parameters, eg:
linux /casper/vmlinuz.efi file=/cdrom/preseed/ubuntu.seed boot=casper nomodeset systemd.unit=multi-user.target ---
Mount Efi Partition Windows Hackintosh
Typically I’ll have a graphical entry and a text entry so I can decide at boot time without having to remember that particular incantation.
References