3.9/4.6 bootloader. What the hell?

Discussion in 'Jailbreaks and iOS Hacks' started by Shackler, Mar 15, 2008.

  1. Shackler macrumors 6502a

    Shackler

    Joined:
    Feb 3, 2007
    Location:
    behind you!
    #1
    What is the difference and why is it a big concern?
    Why does iPlus talk so much about this?

    very noob i know but i want a unlocked iphone and want to know everything first and choose best route mainly iPlus vs. ZiPhone.
     
  2. ajl917 macrumors 6502

    Joined:
    Oct 8, 2007
    #2
    I have AT&T, so Ive never unlocked my phone, just from what I hear, iPlus is the best choice. It will downgrade your bootloader to fakeblank, but not only is that fully functional, but also upgradable back to 4.6. Just google around for some more explanation...
     
  3. jav6454 macrumors P6

    jav6454

    Joined:
    Nov 14, 2007
    Location:
    1 Geostationary Tower Plaza
    #3
    Right now there are 4 different Bootloaders, [yes you read right 4]. These are:

    1. Bootloader 3.9
    2. Bootloader 4.6
    3. Bootloader 3.9 Fakeblank
    4. Bootloader 3.8 (Recent appearance)

    Now, I'll explain a bit more on these different bootloaders.

    Bootloader 3.9 was the first bootloader to be used on iPhones that were made on week 45 or earlier in 2007. This Bootloader [3.9] allows the iPhone SimFree (IPSF) paid unlock aswell as GeHot's IPSF-like free unlock. Also, this bootloader allows you to downgrade your Baseband (which controls your Wi-Fi, EDGE and Calls) firmware. Downgrading baseband is useful when you updated by mistake or/and want to go back down to a previous iPhone firmware. Bootloader 3.9 does not allow bootloader update

    Bootloader 4.6 is the current bootloader being placed on iPhones as of Week 45 and later iPhones of 2007 and all 2008 iPhones. This bootloader does not allow your baseband to be downgraded, so once you updated, you are stuck there. Also, this bootloader does not allow the IPSF unlock. As you may remember this bootloader caused many problems when it was reviewed by the Dev-Team to look for a software unlock. Now, thanks to GeoHot, this bootloader [4.6] can be unlocked. One important exploit in this bootloader is that it can allow you to downgrade itself to the earlier 3.9 which is good if you want to downgrade baseband or apply IPSF-like unlock.

    Bootloader 3.9 Fakeblank (BL 3.9FB) is a modified bootloader created by Geohot and the Dev-Team. It has all the capabilites bootloader 3.9 has, but has one great exception. This bootloader, since it's modified, can allow you to updgrade back to bootloader 4.6. One big flaw of it, is that if you downgrade your firmware to 1.1.1 or earlier the bootloader seems to disappear and a new bootloader appears (more on that next).

    Bootloader 3.8 is very, very new. This bootloader is a mistake made by the iPhone when installing firmware 1.1.1 or earlier on a BL 3.9FB. Since, its new not many information is known, but here are some things. This bootloader occurs because 1.1.1 or earlier firmware thinks there is no bootloader (BL 3.9FB makes it look as though there is no actual bootloader). So the strongest suggestion is not to downgrade to 1.1.1 or earlier when using BL 3.9FB until the mistake is corrected. The greatest worry of this Bootloader is the fact it has all the exploits of 3.9, which means no bootloader upgrade. After this info, not much is really known of bootloader 3.8.


    === Hope this helps you inquiries. ===
     
  4. ajl917 macrumors 6502

    Joined:
    Oct 8, 2007
    #4
    Damn, thanks for clarifying everything!
     
  5. twisterplus macrumors newbie

    Joined:
    Mar 26, 2008
    #5
    ?

    Why is it possible to do a software downgrade from 4.6 to 3.9 but not possible to do a software upgrade reversely?! (I have heard of some hardware method for this!!)
     
  6. polishmacuser macrumors 6502a

    polishmacuser

    Joined:
    Jan 17, 2007
    Location:
    Los Angeles
    #6
    hey what if you downgrade the bootloader will it be a problem for future updates? i want to unlock for european purposes :D but apple wont let us damn them lol
     
  7. TBi macrumors 68030

    TBi

    Joined:
    Jul 26, 2005
    Location:
    Ireland
    #7
    On this topic, i just got a 1.1.4 iPhone from america (I just need to collect it from my friend who got it).

    If i want to use it here do i have to downgrade to 3.9FB to use my irish SIM card? Or can you unlock phone functionality with 4.6?
     
  8. zetsurin macrumors regular

    Joined:
    Nov 30, 2007
    Location:
    Tokyo, Japan
    #8
    Because the downgrade from 4.6 takes advantage of an exploit found by geohot in 4.6. 3.9 contains no such exploit so the reverse process cannot take place currently.
     
  9. Hudzilla macrumors 6502a

    Hudzilla

    Joined:
    Nov 12, 2007
    Location:
    England
    #9
    I hope someone creates a fix to upgrade from 3.9 , but from what i gather its not a big deal at the moment, and we should be able to upgrade to 2.0 when it comes out when cleared by our differen JB makers (i hope!!!)
     
  10. spinstorm macrumors 65816

    Joined:
    Sep 14, 2007
    #10
    You WILL Be able to upgrade without any issues to the new firmware.

    Ironically enough iPlus/iLiberty users may have issues however!

    Let me explain!

    3.9 came on all original US models - so the 2.0 firmware will work as it does now.

    Obviously if your not on an official iPhone contract then you won't be able to activate the phone unless it is jailbreaked.

    It seems very likely that within hours of it coming out a jailbreak method will be released as the dev teams have already got into the beta.

    However if you used iPlus/iLiberty to UNLOCK (and your phone was 1.1.2 or newer out the box)- then you will have the 3.9FB bootloader. IF Apple includes other bootloader files with the firmware update then there is a chance that it will mess up the phone in someway as is happening with restoring to 1.0.0 and 1.1.1 firmwares now (ie going from 3.9 to 3.8).

    Having said that the beauty of this is that if you have used iPlus/iLiberty that you can go back to 4.6 before you update although you would lose the unlock again so that would only work if you have an official iPhone contract again!

    Of course if there is no older bootloader files in 2.0 then there is no reason why you can't upgrade to 2.0 - although again unless your on an official contract yourl be locked out!

    However this whole argument seems pretty redundant as a news article on iPhone atlas from yesterday seems to suggest you can upgrade and keep your existing unlock if you use the devteam method!

    http://www.iphoneatlas.com/2008/03/26/iphone-os-20-may-leak-publicly-soon/

    I think the point here is that its best to wait for a dev team release before upgrading simply because even if you have an official iPhone contract you may as well jailbreak and unlock if possible at the same time as upgrading! as it seems that the DevTeams are hot on it!
     
  11. Hudzilla macrumors 6502a

    Hudzilla

    Joined:
    Nov 12, 2007
    Location:
    England
    #11
    Sweet, thanks alot for clarifying, if it weren't for these boards and the people that use them I would have no clue what I was doing and have many sleepless nights worrying about stuff I dnt need to LOL!
     
  12. TBi macrumors 68030

    TBi

    Joined:
    Jul 26, 2005
    Location:
    Ireland
    #12
    So you are basically saying that 4.6 cannot be sim-unlocked so I need to downgrade to 3.9 to be able to sim unlock the iPhone?

    That's great to know. Thanks spinstorm, you're a wealth of information!
     
  13. spinstorm macrumors 65816

    Joined:
    Sep 14, 2007
    #13
    Basically your right!

    4.6 can be unlocked but only with the 1.1.2 baseband (the baseband is the phone modem basically) - which means features such as locate me in google maps won't work - in addition to having the wrong baseband for the firmware - which although isn't a huge problem isn't great!

    Independence (on Mac) and iLiberty+ if you DON'T check the bootloader downgrade option can do this for you.

    IF you want the lastest firmware unlocked with the correct baseband then you can ONLY do that if you have bootloader 3.9.

    ZiPhone downgrades it and it can't be put back to 4.6.

    iLiberty+ downgrades it to a hacked version that CAN be put back to 4.6.

    Having said all this if you have not already unlocked your phone wait for PWNED to come out later today (if its not already out when you read this) as it appears that may be a method that makes your bootloader not matter anymore!
     
  14. MuRReC macrumors newbie

    Joined:
    Apr 2, 2008
    #14
    Im getting my iPhone tomorrow and since i don't live in US i have to jailbreak it.
    My question is, if i use iLiberty+ is it possible to use PWNED AFTER that?
    Also, after suing PWNED is it possible to go back to factory or do something else with it???
    Need answer cause i don't want to be stuck.
     
  15. darngooddesign macrumors G3

    Joined:
    Jul 4, 2007
    Location:
    Atlanta, GA
    #15
    Jailbreaking is 3rd party apps
    Unlocking is using any SIM other than ATT.
     
  16. MuRReC macrumors newbie

    Joined:
    Apr 2, 2008
    #16
    Yeah I know that.
    There is:
    Jailbreaking
    Activation
    Unlocking

    But if u se iLiberty+ which is really easy can I later use PWNED?
     
  17. Diatribe macrumors 601

    Diatribe

    Joined:
    Jan 8, 2004
    Location:
    Back in the motherland
    #17
    You cannot unlock it without jailbreaking it first.
     
  18. Ol!ver macrumors 6502a

    Joined:
    Mar 2, 2005
    #18
    What I don't understand is why it is a problem to be on 3.9. I mean, that's what people on legit early iPhones will be on, so it's not like Apple is going to stop anything working with it.
     
  19. MuRReC macrumors newbie

    Joined:
    Apr 2, 2008
    #19
    Yeah I know that.
    There is:
    Jailbreaking
    Activation
    Unlocking

    But if u se iLiberty+ which is really easy can I later use PWNED?
     
  20. spinstorm macrumors 65816

    Joined:
    Sep 14, 2007
    #20
    I explained already if you have a new phone and you use ZiPhone you will get STUCK on 3.9.

    3.9 works perfectly BUT you have voided your warranty because it came with 4.6 and you can't go back so if you ever took it to Apple they wouldn't touch it.

    That is the main point as far as the bootloader goes... on phones that came with firmware 1.0.0-1.0.2-1.1.1 they came as standard with 3.9 bootloader but you didn't and don't have to hack the bootloader to unlock so its easy to restore to factory condition if you needed to take it to Apple.

    iPlus/iLiberty also downgrade the bootloader to 3.9 but its a special hacked version that can be sent back up to 4.6.
     
  21. MuRReC macrumors newbie

    Joined:
    Apr 2, 2008
    #21
    Bare with me. You say here that there is a possiblity that i will be stuck on 1.1.4 if I use iLiberty+, so is your advice yo use PWNED instead?
     
  22. Ol!ver macrumors 6502a

    Joined:
    Mar 2, 2005
    #22
    So you're on 3.9. So what? That's what everyone who bought an iPhone at launch is on.
     
  23. spinstorm macrumors 65816

    Joined:
    Sep 14, 2007
    #23
    No you won't get stuck on 1.1.4 as the bootloader is upgradable which is the whole point of using iPlus/iLiberty!
     
  24. MuRReC macrumors newbie

    Joined:
    Apr 2, 2008
    #24
    This is what worries me, mb i missunderstood.
    So, the worst thing that can happen is that i can't jailbreak/activate/unlock on the newest firmware indepent on what bootloader I have?
     
  25. macluvist macrumors newbie

    Joined:
    Apr 11, 2008
    #25
    Hi all,
    I'm totally clueless about this bootloader thing. I just recently unlock the iphone using iLiberty+ and the phone does seem to be working fine. A check on the bootloader info indicated that it's currently on version 3.9_M3S2.

    Is there a need for me to upgrade it to 4.6 and what's the advantage of doing so? Thanks for your clarification on this.
     

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