Boot Intel Mac From External USB - Without Modifying Host

[WaeV]

http://refit.sourceforge.net/doc/c1s1_install.html says that rEFIt can be installed to and booted from USB drives, provided they are HFS+ format.

As it turns out, I can use Diskutil at school, and I took advantage of that to format a small partition at the front of my USB drive to HFS+. Unfortunately, I couldn't execute the enable.sh without sudo. I am working on getting a release of Darwin running at home so I might execute it. (It can't be run in linux)

Here is what my USB drive looks like at the moment:

50MB HFS+ rEFIt
27GB ext2 Complete Ubuntu Installation
2GB swap


Also, I had an amusing thought today: If I pull this off, it will be a Mac booting rEFIt booting GRUB booting Ubuntu.

[cyberdork33]

http://refit.sourceforge.net/doc/c1s1_install.html says that rEFIt can be installed to and booted from USB drives, provided they are HFS+ format.

Also, I had an amusing thought today: If I pull this off, it will be a Mac booting rEFIt booting GRUB booting Ubuntu.

Feel free to try, but having rEFIt on the USB device has nothing to do with whether or not GRUB will from there. rEFIt is just a GUI for the Mac EFI. The Mac EFI system will not boot "legacy" operating systems from USB.

[WaeV]

If rEFIt is only a GUI for the Mac EFI, how can rEFIt allow people to boot linux off their main drive?

Note that starting with version 0.6, rEFIt can boot legacy OSes directly, without the additional reboot used in 0.5. It also recognizes common Linux and Windows boot sectors and displays the appropriate icon.

Ooh, this could help:

NOTE: It is currently recommended to boot Linux through BIOS compatibility mode (a.k.a. Boot Camp) using LILO or GRUB. Otherwise, the fully accelerated ATI and Intel graphics drivers will not work.

Add a folder inside the “efi” folder. Copy the following files there:

* elilo (called either “elilo.efi” or “e.efi”)
* “vmlinuz”
* “initrd.gz” (if present)
* “elilo.conf” (if present)

Make sure that elilo.conf uses relative paths for the “image=” and “initrd=” options (no leading slash). The folder will show up in the rEFIt menu automatically. You can make as many folders with different configurations as you like.

Edit: nevermind, elilo is for booting from EFI. The following link does assure that Macs can boot to legacy OSes with nothing but rEFIt, however:

http://tubeshards.wordpress.com/2006...osh-usb-drive/

My biggest problem now is getting a copy of OSX or Darwin working so I can run enable.sh on the rEFIt partition (don't know the school sudo password :/)

[senuxis]

This site will help you. Also read the text attachment.

[cyberdork33]

If rEFIt is only a GUI for the Mac EFI, how can rEFIt allow people to boot linux off their main drive?

Because you don't even need rEFIt to boot from the main drive either... You can hold alt on startup of your mac, and it will allow you to boot linux, windows, LiveCDs, etc.

Ooh, this could help:


Edit: nevermind, elilo is for booting from EFI.

using elilo / grub-efi is an option, but there are other limitation doing that, and it is not well supported yet. There are few people here that have messed with it before.
http://grub.enbug.org/TestingOnEFI

The following link does assure that Macs can boot to legacy OSes with nothing but rEFIt, however:

http://tubeshards.wordpress.com/2006...osh-usb-drive/

Yes every once in awhile someone claims to get it working, but then nobody else can. You can read through the "booting from external drives" thread in the FAQ for more examples of that.

Here is a discussion about the inability of Macs to boot Linux from USB.

http://discussions.apple.com/thread....23157&tstart=0

My biggest problem now is getting a copy of OSX or Darwin working so I can run enable.sh on the rEFIt partition (don't know the school sudo password :/)

what you really need is the "bless" command. I don't know if this is on the Darwin CD or not. You can boot a OSX install disc and use bless in the terminal.

[WaeV]

At this point in the process, rEFIt will see all three operating systems and will be able load Mac OS and Windows. Linux, however, needs to have its own partition records updated to properly load.

1. Once the machine is rebooted and on the rEFIt screen, press the arrow keys until you reach the ‘Partitioning Tool’ icon. Press the ‘Enter’ key.

2. When it asks, “May I update the MBR as printed above?”, press the ‘y’ key. rEFIt’s partition records will update.

3. You should now be able to boot into any Operating System.

Ok, I see how that could help, but I don't see how the text attachment is of much use. I am dealing with OSX and Linux only, not Windows. Thanks for your post anyways, but I would need further explanation as to how the attachment is of use.

Edit:

i have tried to use refit by having a small refit partition at the beginning of the usb device. i then boot with the option key and get the mac, windows and refit option.
selecting the refit partition starts refit and lists my linux partition correctly but then cannot boot it giving me the error regarding limited firmware support.

Hmm... this was the next step I was going to take. So the new obstacle to tackle is to discover what is meant by "limited firmware support" and how to either fix it or bypass it. In the meantime, I will work on getting to this point so I can try for myself.

what you really need is the "bless" command. I don't know if this is on the Darwin CD or not. You can boot a OSX install disc and use bless in the terminal.

Getting the OSX disc is the current problem. Maybe I can get a teacher to run the script on their macbook...

[cyberdork33]

Hmm... this was the next step I was going to take. So the new obstacle to tackle is to discover what is meant by "limited firmware support" and how to either fix it or bypass it. In the meantime, I will work on getting to this point so I can try for myself.

That sounds like they didn't update the firmware to enable "bootcamp" stuff. You will probably get a different error because you are not trying to boot from the internal drive.

[WaeV]

While we're on the topic of boot camp, I have heard that there are boot camp drivers for Windows. Are there any such drivers or other modification required for Linux?

The following link does assure that Macs can boot to legacy OSes with nothing but rEFIt, however:

http://tubeshards.wordpress.com/2006...osh-usb-drive/

Yes every once in awhile someone claims to get it working, but then nobody else can. You can read through the "booting from external drives" thread in the FAQ for more examples of that.

There are many comments afterwards claiming success. Differences between that scenario and mine, however, are that they are using Windows, not Linux. (And a specially modified version at that!)

[cyberdork33]

While we're on the topic of boot camp, I have heard that there are boot camp drivers for Windows. Are there any such drivers or other modification required for Linux?

You can check the wiki page for your hardware specifically on direction to get everything working properly. See the "Before You Post" link in my signature to find the right page.

[WaeV]

rEFIt is a user friendly interface to the Mac EFI that will cause a boot menu (to select between OS X/Ubuntu) to appear on every boot. You can make Ubuntu boot by default by uncommenting the 'legacyfirst' option and change the menu timeout in the "refit.conf" file (described on the above website).

Ok, so I need some clarification here. What is actually causing the Mac to recognize and boot legacy OSes here?

http://www.matisse.net/OSX/darwin_commands.html
This website confirms that Darwin can 'bless' drives. Unfortunately, My CD drive is broken and I can't install it. I'll try a virtual machine.