Yellosn0w: does it modify baseband?

Discussion in 'Jailbreaks and iOS Hacks' started by jmmo20, Jan 2, 2009.

  1. jmmo20 macrumors 65816

    Jun 15, 2006

    I don't think the "official" yellosn0w thread is appropriate for this question since they're only discussing ways to make it work!

    Ok, so I thought the yellowsn0w was just a daemon running on top of your iphone os, right? Like nothing in the baseband was actually modified.

    But one thing made me wonder: before I applied Yellowsn0w for the first time; whenever I inserted a sim from another operator i would get an "invalid sim" error.

    Now, even after I uninstalled yellowsnow (i don't need it for now, it messes with my original sim card so I will only install it when necessary) I no longer get the invalid sim error. I just get the empty signal bar icon.

    So .. either yellowsn0w is not being removed completely, or the hack actually modifies the baseband.

    I'd love to hear from muscle nerd directly but seeing as their blog's comment tool is useless (trying to keep track of threads with 5000+ commments? that's crazy) I thought I would ask here.

    Thanks :)
  2. ppc750fx macrumors 65816

    Aug 20, 2008
    I haven't looked at the source for anything other than 0.90, but from what I can tell it doesn't perform any permanent modifications. That said, it's pretty much uncommented, and although I'm fluent in C I'm not an embedded HW expert, so I can't say for sure.
  3. MikePA macrumors 68020


    Aug 17, 2008
    I imagine they have to put some code in the baseband to get to the yellowsn0w code.
  4. jav6454 macrumors P6


    Nov 14, 2007
    1 Geostationary Tower Plaza
    Looked at the code. I'm semi-fluent in C++, but from what I can read in 0.9.4, the changes are not permanent. They changes are applied each time at boot up. A normal restore clears out yellowsn0w.

    Edit - It's like a mini program running, that allows the usage of other SIM cards.

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