Uploaded March 2016 | Updated September 2026, 1 day ago

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I wrote a tutorial about how to implement an untethered iOS Multi-Boot here,
pmbonneau.com/apple/ios/multiboot.php.
It's a testing version, currently only supports iOS 7.1.2 and 6.1.6 on iPhone 4 (N90AP).

For this video, I implemented an untethered iOS 7.1.2 and iOS 6.1.3 dual boot on my iPhone 4 (N90AP). In the video I uploaded last week about a semi-untethered iOS 7.1.2 and iOS 6.1.3 dual boot, an external SSH connection was required to bootstrap an image using kloader. In fact, only on-device Terminal applications causes issues with kloader (I actually don't know why). So, a dedicated application is required to do the untethered boot. I haven't tried, but maybe a dedicated daemon could also works. The iOS 6 bootstrap application I made is only a script launcher. There is a system() call with the command line to execute as argument. Something like system("iOS6Bootstrap.sh"), where iOS6Bootstrap.sh is a script stored in /bin. The script only launches kloader with the unsigned bootloader to bootstrap.

Same as the semi-untethered dual boot, the whole bootchain of a subsequent operating system does chainload untethered when kloader successfully executed the first stage bootloader (LLB).

Kloader tends to crash around one time on two, depending on many factors. In this video, kloader worked four times and it crashed about three times.

When I launch the iOS 6 bootstrap application, the device (should) execute the LLB (Low-Level Bootloader) file set in the script which will execute iBoot (second stage bootloader), which will display the classic apple logo, load the devicetree and boot the kernel with the boot-args (verbose boot, root device and so) set in the appropriate string.

Please note that this video is a demonstration, not really a tutorial. Set up a dual-boot like this one can take few hours, depending on many technological factors.

Special thanks to @xerub, @iH8Sn0w and @JonathanSeals for many advices to help me solve some problems I encountered during the multi-boot implementation.

The soundtrack of this video is a mix made by me with the following tracks :
A) Jim Yosef - Eclipse [NCS Release]
youtube.com/watch?v=1WP_YLn1D1c
B) Different Heaven - Nekozilla [NCS Release], youtube.com/watch?v=6FNHe3kf8_s
C) Jim Yosef - Firefly [NCS Release],
youtube.com/watch?v=x_OwcYTNbHs
D) Unison - Aperture [NCS Release],
youtube.com/watch?v=8VDjPYcL-oU
E) Tobu - Candyland [NCS Release]
youtube.com/watch?v=IIrCDAV3EgI
F) Spektrem - Shine [NCS Release]
youtube.com/watch?v=n4tK7LYFxI0
G) Spektrem - Shine (Gabriel Drew & Bloom Remix) [NCS Release]
youtube.com/watch?v=rWVjht-MIto
H) Itro & Tobu - Cloud 9 [NCS Release]
youtube.com/watch?v=VtKbiyyVZks
I) Spektrem - Shine [NCS Release]
youtube.com/watch?v=n4tK7LYFxI0
J) Ahrix - Nova [NCS Release]
youtube.com/watch?v=FjNdYp2gXRY