Some very interesting changes in how Windows is installed in Boot Camp on OS X 10.11 “El Capitan”. When you open Boot Camp Assistant on a new Mac that supports Windows 8 or later, you’ll get the new Boot Camp interface.
Notice the ISO image and partitioning are all on a single screen. Prior to El Capitan, you had to insert a USB Flash Drive and Boot Camp Assistant copied the Windows installer from an ISO disk image to the flash drive, and then downloaded and set up the Windows drivers to the correct location in the installer for the Mac hardware. El Capitan makes this a lot simpler. Just select the ISO and how much space you want from Boot Camp, and then you click Install.
How to Create a OS X El Capitan Boot Installer USB Flash Drive. Restart your computer, and keep the Unibeast USB drive plugged in. At the Unibeast boot menu, you'll see an icon for the hard drive where you installed El Capitan. Select it (use the arrow keys on your computer) and press 'Enter'. If everything works properly, then El Capitan will boot. Mission accomplished!
After Boot Camp Assistantd completes, OS X restarts to the Windows installer, and you follow the normal Windows installation.
If you have a spare USB flash drive laying around, you should consider putting it to good use by creating a bootable installation drive for the OS X El Capitan Beta. Creating a bootable drive has many benefits and uses. For starters, it makes it easy to install a fresh copy of whatever operating system you have configured on the drive. Apple allows you to upgrade to the new OS X El Capitan directly from the installed OS X Yosemite, but at least once every couple of years it is recommended to do a “clean” installation. Oct 07, 2015 Mavericks, yosemite and el capitan changed so that just burning the InstallESD.dmg won't give you a bootable dvd. Also, restoring a bootable usb to iso results in a bootable iso, but that iso is useless because booting is ALL it does. Dec 16, 2019 It installs an app named Install OS X El Capitan into your Applications folder.
Behind the Scenes
So how is this possible? Where is the Windows installer if there is no installation media? Boot Camp Assistant doesn’t just create a Boot Camp partition, but also creates an additional partition called “OSXRESERVED” that is FAT32 formatted. It places this partition right after the recovery partition, and before the Boot Camp partition, as shown below.
The command line make this really clear. Partition 1 is the standard EFI partition, partition 2 is the Mac partition, partition 3 is the Recovery partition. All standard stuff. Partition 4 is now the OSXRESERVED partition, and partition 5 is the BOOTCAMP partition. You’ll also notice that disk2 is the Windows install ISO disk image that the Windows install files are copied from.
The OSXRESERVED partition has all the installer files, the Boot Camp drivers for Windows, and the EFI files for booting.
If you are familiar with EFI booting on OS X, you’ll see a familiar setup. The EFI folder on the OSXRESERVED partition is the same one you would normally find on the EFI partition (normally disk0s1). It appears that newer Macs have the ability to detect this partition and present it to Windows as if it were EFI installation media (such as a DVD or USB Flash drive).
So what happens to this partition after you are done installing? During the next boot into OS X, the OSXRESERVED partition is removed and put back into the Core Storage container of the OS X partition:
Note that the Device is disk0s5 since the other partition existed on startup, but then it was deleted. On next reboot, this device will change back to disk0s4, which is the standard device location for a Boot Camp partition.
This setup is not supported on all Macs that run El Capitan. Only hardware that has newer firmware supports this. We did a survey of all the shipping Macs, and here are the ones that support this new slicker setup:
Supported:
- Mac Pro
- MacBook Air 13‑inch
- MacBook Air 11‑inch
- MacBook Pro 13‑inch
- MacBook Pro 15‑inch
Older USB Installation
- iMac 21.5″
- iMac 27″
- MacBook Pro 13‑inch
- USB-C MacBook (surprising)
El Capitan’s Boot Camp-related updates are not just limited to Boot Camp Assistant. There are also changes in how Boot Camp is affected by the new System Integrity Protection (SIP). Tune in tomorrow for the next segment.
Do you have Windows running on your Mac in a Boot Camp partition? Check out Winclone and Boot Runner to backup, migrate, and manage your Boot Camp partition.
Find this article interesting? Let me know what you think by tweeting at me on Twitter: @tperfitt
Created a bootable USB with El Capitan installer
booted from it, erased my MBP (mid 2009), clean install from USB installer
El Capitan Os X
decided to use migration assistant, most apps not working plus all the clutter from pre clean install
decided to do another clean install but MBP won't boot from USB and uses the recovery version instead.
tried to get Maverick back and basically ended up with a non-working MBP that went into a boot loop
did a reinstall from MAS, ended up DLing the entire Installer again, went to bed and in the morning and 'working'
MBP again, plus all the clutter and non working apps.
Made a new bootable USB key using terminal and yes it finished and yes it said bootable at the end as well as in Disk Utilities.
However when trying to boot from USB, start+Option, or start+cmd+r still no sign of the USB stick, which i guess would leave me
with a non clean install again.
Any help, suggestions.....?
Cheers
El Capitan Boot From Usb
Ralf
El Capitan Bootable Usb Download
MacBook Pro (13-inch Mid 2009), OS X El Capitan (10.11)
Posted on Oct 4, 2015 7:57 AM