1.What's an iPhone?
The iPhone (pronounced /ˈaɪfoʊn/ EYE-fohn) is a line of Internet and multimedia-enabled smartphones designed and marketed by Apple Inc. The first iPhone was introduced on January 9, 2007.
An iPhone functions as a camera phone, including text messaging and visual voicemail, a portable media player, and an Internet client, with e-mail, web browsing, and Wi-Fi connectivity. The user interface is built around the device's multi-touch screen, including a virtual keyboard rather than a physical one. Third-party applications are available from the App Store, which launched in mid-2008 and now has well over 300,000 "apps" approved by Apple. These apps have diverse functionalities, including games, reference, GPS navigation, social networking, and advertising for television shows, films, and celebrities.
There are four generations of iPhone models, and they were accompanied by four major releases of iOS (formerly iPhone OS). The original iPhone established design precedents like screen size and button placement that have persisted through all models. The iPhone 3G added 3G cellular network capabilities and A-GPS location. The iPhone 3GS added a compass, faster processor, and higher resolution camera, including video. The iPhone 4 has two cameras for FaceTime video calling and a higher-resolution display. It was released on June 24, 2010.
2.What's a firmware?
Firmware is the name given to the set of programs that are an integral part of the operation of a computer’s hardware. They enable to hardware to function properly and allow software to run on the hardware.
It is called firmware because it’s not software (i.e., the programs that users run on the computer), but it’s also not hardware (the physical objects that make up the computer).
On the iPhone, firmware is the set of operations and tools that sit between the hardware that the phone uses and the software that runs on the phone. It enables features, fixes bugs, and attends to the functioning of the phone.
Periodically, Apple releases firmware updates to add new functionality to the iPhone, correct problems with it, and close security holes.
3.What's a Baseband?
When hacking the iPhone there are two categories to worry about. The iPhone is essentially a computer with a GSM modem attached to it. So there is the Operating System for the computer half of the phone and the Baseband is like the OS for the Modem half.
When Hackers start to crack the iPhone the first thing they usually hack is the OS, by finding a method to Activate and Jailbreak the phone. All this means is that they've found a way into the OS and gained read/write accesss to the file system. This is fine if all you want to do is use tour iPhone as an iPod Touch. If, however, you want to make and receive calls you must also hack the modem. This requires hacking the Baseband so that it will accept non-AT&T SIM cards, this process is known as unlocking.
4.What's a BootLoader?
A bootloader is some code that is executed when the device is powered on. Two bootloaders
you may have heard of are the baseband bootloader and iBoot. Bootloaders perform integrity checks on data and prevent unsigned, non-apple code from being loaded. They essentially police the iPhone OS, making sure everything is the way Apple want it to be. PwnageTool,WinPwn and QuickPwn patch out integrity checks from the bootloaders (LLB, iBoot) and the kernel, allowing unsigned code to be executed.
In general, this is the code which is run prior to the main firmware and is responsible for loading the main FW and in some cases performs signature checking. Both the baseband and the main iPhone OS have bootloaders, and these are entirely different. PwnageTool and WinPwn allow control over the main OS bootloader, while BootNeuter allows control over the Baseband Bootloader.
5.What's a jailbreak?
Its a way of bypassing the "locked out" features that Apple puts into the phone.
It allows you to install apps that are "not available" from the Apple store.
It essentially Unlocks all the "blinders" that Apple puts on the phone so you can only see what they will allow you to see.'
It's not a bad option if you decide to do it, and congress ruled that it is not illegal for you to do so.
It's just Apples way of "controlling" you.
Screw them....Jail break your phone. I did.
6.What's an activation?
Beginning with the introduction of the original iPhone, users can use iTunes to activate their phone through their mobile carrier. The original plan for the iPhone 3G was to have the carrier authenticate it at the point of sale, either through iTunes or through the carrier's own activation interface.However, a worldwide crash of iTunes' authentication servers on July 11, 2008, the day that the iPhone 3G was released, caused major issues. In some cases, AT&T and Apple Store employees told iPhone buyers to attempt to activate it at home.Also affected were original iPhone users attempting to upgrade to the 2.0 firmware.UK Apple, O2 and Carphone Warehouse stores were further impacted, as carrier O2's contract processing servers (known as Gateway) could not handle the amount of new contracts and upgrades happening on launch day. Some stores reverted to hand written contracts, while others held stock. With the launch of the iPhone 3GS on June 19, 2009, iTunes at home activation was available for people purchasing their iPhone from AT&T and Apple. This allowed them to activate their new iPhone 3G/iPhone 3GS at home when they arrived.
The iPhone is locked, meaning that it can only be used on AT&T’s network, a move that has caused substantial criticism from some users.
However, a number of third-party programmers have found ways to unlock the iPhone through both hardware and software. Few of these techniques have been widely released and the iPhone seems only to work on T-Mobile and AT&T for now.
8.What's DFU Mode?
Development Firmware Upgrade：is not the same as restore mode. DFU mode bypasses the current OS installed and allows you to upgrade or downgrade your OS. If you are getting errors trying to restore in iTunes, DFU mode is very likely for you.
This is how to achieve DFU mode. You can do it on every phone:
* Attach the phone to the pc
* Turn the phone off
* Hold power and home together for *exactly* 10 seconds
* Release power but keep holding home until the pc beeps as a USB device is recognized.
* At no point will the display come on. Now your restore should work.
9.What is Difference Between Recovery Mode and DFU Mode?
The Main difference between the Recovery mode and DFU mode is iBoot. Recovery mode uses iBoot during restoring or upgrading your iPhone while DFU mode bypasses the iBoot so you can downgrade the current firmware because there is no iBoot agent during the DFU mode. About iBoot, iBoot is the bootloader on iPhone OS devices. iBoot acts on restore while iPhone is in Recovery Mode, iBoot makes sure that you are flashing a firmware version greater than or equal to a current one. If you are not, iBoot will not allow the restore to proceed. Because of this, firmware downgrading must be done in DFU mode.This means if you need to restore your iPhone to current version simply put the iPhone in recovery mode and iTunes takes care of the rest but if you need to downgrade your current firmware to lower one you need to put your iPhone in DFU mode. For example you can’t downgrade Firmware 3.0 to Firmware 2.2.1 without entering in to DFU Mode.
Recovery Mode : Recovery Mode is a state of iBoot that is used during standard upgrades and restores. As iBoot is active, it does not allow you to downgrade your device’s software. Also, unless it is ‘pwned,’ it will not allow custom firmware to be flashed.
DFU Mode : DFU Mode is a special mode where the device can still interface with iTunes, yet it does not load the iBoot. The screen will appear totally black in DFU mode, so you can’t guess whether the device is in DFU or powered down from simply looking at the screen. Because iBoot and the OS are not loaded this exploit makes us able to downgrade your iPhone firmware or upgrade with a custom firmware created by Pwnage tool.
How to put your iPhone in recovery mode :
- Turn the device completely off and disconnect it from cable/dock.
- Hold down the home button.
- While holding down the home button connect to a computer with a cable (easiest) or dock.
- Keep holding down the home button until you see a connect-to-itunes screen You are now in recovery mode.
To escape Recovery Mode and power the phone off simply hold down power and home buttons for ten seconds.
How to put your iPhone in DFU mode :
- Connect your iPhone to your computer.
- Turn iPhone off.
- Hold power and home together for 10 seconds (exactly).
- Release power but keep holding home until the computers beeps (observed on a PC) as a USB device is recognized.
- A few seconds later iTunes should detect your iPhone.
- If the Restore Logo is present on the screen, you are in Recovery Mode, not DFU.
PwnageTool is an iPhone jailbreaking application for Mac OS X that creates custom iOS firmware images to user-defined specifications. These firmware images often contain the Apt interface Cydia as well as additional Apt packages.
redsn0w is a utility to jailbreak iOS devices. It does so by reading the stock firmware that you can download from iTunes or from various locations on the internet (as iTunes will detect and delete old firmwares), and then running a payload directly on the device in the form of a ramdisk. When jailbreaking, the device will also enter into Device Firmware Upgrade mode. It allows users to install Cydia, the popular 3rd party app installer. This allows the user access to tweaks, homebrew applications, and the root directory and file system.
yellowsn0w&ultrasn0w are the software designed to unlock your iphone.