From The Apple Wiki

DownBB is a tool that allows the user to downgrade the iPhone 3G Baseband from 02.30.03 to 02.28.00 with the Baseband Bootloader 5.8.


This tool will not work with any X-Gold 608 devices with Baseband Bootloader 5.9 or later.


Exploit: Geohot and iPhone Dev Team
Patch Implementation: Geohot
Bash Script: EvilPenguin|
Help: pH and DHowett - Thanks guys..


DownBB - by James. (a.k.a. EvilPenguin|).

How To

To run DownBB, you must first put my repo/source in cydia sources: [Archived 2009-04-20 at the Wayback Machine]

          soon to be on bigbosses as well

Download "DownBB"

          Open MobileTerminal
          type "DownBB"    -without the ""

BootLoader Check

To check your bootloader version, install minicom and run at+xgendata (see Baseband Commands for more info)


Install Download

    Place the DownBB.deb /var/mobile/
    ssh root@XXX.XXX.XXX.XXX
    dpkg -i DownBB.deb
    Then follow the How To's