What is the difference between the DFU and Recovery modes?

This article will explain the differences between the recovery mode (Recovery Mode) and DFU (Device Firmware Update).

The recovery mode uses iBoot (ie the iOS software startup sequence) during restore or update your iPhone, iPad or iPod, while the mode DFU bypasses iBoot and uses the seed material of factory.

Interest Mode DFU is that there is no advanced software control that could prevent a downgrade (downgrade) for example.

iBoot is actually what's called a boot loader (boot loader) on iOS. iBoot is mainly used to verify that you are updating an equal or higher version currently installed version on your iPhone, iPod touch or iPad. If this is not the case, iBoot will prevent the upgrade to continue.

So this is why the downgrade (downgrade) or certain jailbreak and fashion tethered, must be made ​​in DFU.Also, if you try to iTunes to install a version lower than the official version, you will prevent iTunes. For example, you will not be able to pass the 3.0 firmware version 2.2.1 without doing it in DFU mode.

Recovery Mode (Recovery Mode):

The recovery mode is a state that puts iBoot on standby to prepare a for a firmware level (firmware) or a restore. Lorsqu'iBoot is active, it does not allow to change the firmware to a version lower than the one currently installed on the device. It's iBoot that must be mastered in order to flash the firmware.

To enter the recovery mode, simply:

1. Turn off the iPad, iPhone or iPod touch
2. Press the Home button
3. Simultaneously press Home and connect to a computer or dock
3. Keep the Home button until you see the iTunes logo appear: You are in recovery mode!

To exit recovery mode, simply turn off the iPod, iPhone or iPad by pressing for 10 seconds on Home and Power.

Display on the iPhone recovery mode

The DFU (Device Firmware Update)

DFU mode is a special mode where the iPhone, iPad or iPod touch can still communicate with iTunes, but without loading iBoot. The screen is completely black, so that while everyone might believe that the camera is off. As iBoot is not loaded, and the iOS operating system has not launched, it makes possible the injection of any firmware created by a jailbreak tool (sometimes called Pwnage tool, mastering tool ).

To enter DFU mode:

1. Connect your iPhone to computer cutter
2. Turn off the iPod, iPhone or iPad
3. Press Home and Power simultaneously for EXACTLY 10 seconds
4. Release power but keep pressing Home until ordindateur Beep reflecting the USB connection
5. Seconds later, iTunes detects your iPhone, iPod or iPad

If the iTunes logo appears you are in recovery mode, not DFU, you must start over!