Talk on reverse engineering the GBA Link protocol

Discussion in 'User Submitted News' started by Charli, Mar 5, 2019.


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    Last month there was small talk titled Bridging Emulation and the Real World with the Nintendo Game Boy by Or Pinchasof at Microsoft's BlueHat IL conference in Israel.

    upload_2019-3-5_23-12-53.

    In his 40 minute long talk Or Pinchasof explains how he reverse engineered the GBA's link communication protocol from the ground up back in 2005 and which challenges he faced while trying to revive his old project again. The modern USB interface didn't exactly make it easier for him to trade Pokémon between his GBA and the Virtual Boy Advance Emulator.

    Abstract Nintendo's Game Boy Advance is a superb embedded system for homebrew development. It has well documented specifications, is complex enough for some impressive software, and yet is adequately simple enough for people to understand virtually every aspect of it. The field of Game Boy emulation is well established and already has a large body of software written for it. I set to research the system with a specific goal in mind, arising from an actual need - connecting an existing, working, emulator, Visual Boy Advance, to a real-world Game Boy Advance.

    The Game Boy communicates over cable with up to three other systems using several proprietary communication protocols. One such protocol allows loading arbitrary code to the RAM of another Game Boy and booting from it. It has been widely used by the homebrew community for easy development and testing on a real device. Another protocol allows sharing of data for multiplayer gaming in real time. Little research has been focused on this protocol, and its implementation in emulation, which is essential for the emulator-Game Boy link.

    This talk discusses the research methods and tools used to reverse engineer the communication specifications, implement an embedded circuit to perform the necessary data transfer, and integrate it into the emulator, spanning all levels from hardware to software.



    :arrow: Source including the presentation's slides
     
    Discussion (6 replies)
  1. FAST6191

    FAST6191 Techromancer

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    Nov 21, 2005
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    Is this about VBAlinkreal? I shall give it a watch when I get back tomorrow.

    Never heard of this conference either, will have to investigate further.
     
  2. Charli
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    Charli Advanced Member

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    uh, I don't know about VBA Link real, there was no mention of it in the talk. I think it's just the presenter's personal free time project.

    It's a security conference, apparently Microsofts answer to the BlackHat Hacker conference? Had not heard of the conference before either.
    The other talks really are a lot more focused on IT security and malware (e.g. there is one about the recent vulnerabilities in AMD processors), so I was really surprised to see the GBA talk ^^
     
  3. FAST6191

    FAST6191 Techromancer

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    Yeah. Usually we get maybe two console talks a year -- one if the state of things warrants it and another retrospective/walkthrough of the hardware and design philosophy ("the ultimate ??? talk"). Typically at C3 but occasionally a preview/rerun/warmup at the others.

    That said Google's tech talks provided the main discussion of the xbox 360 security system for many years, and still pretty relevant but for the "nothing interesting here" line which ultimately led to many of the hacks we see today.

     
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  4. Charli
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    Charli Advanced Member

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    yeah, I've at least watched the ultimate GameBoy talk :)

    After clicking through the Xbox videos another YT video about the Sega Saturn caught my attention. Seems like it is a very well known project in the Sega scene:



    Really amazing to see what some people are capable of and how much passion they put into their projects.
     
    Last edited by Charli, Mar 9, 2019
  5. pasc

    pasc GBATemps GBA Freak

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    *Visions of GBA Multiplayer via usb-pc linkcable dancing in my head*

    All rose colored ideas aside, the gba's biggest flaw was the way the link protocol worked iIrc...

    Many games have little tolerance for timeout problems.

    This was especially apparant with the Majesco Wireless Link Adapter. Some games work perfect, others don't.

    Sending dummy data to keep the client from shutting the connection down isn't an option either, as it expects specific data.


    All in all a project that seems like it could yield interest, if anyone ever released a product, like this for example.


    Nintendo's Game Boy Advance is a superb embedded system for homebrew development. It has well documented specifications, is complex enough for some impressive software, and yet is adequately simple enough for people to understand virtually every aspect of it.



    Ahh. Pure appreciation xD
     
    Last edited by pasc, Mar 9, 2019
    Charli likes this.
  6. i have heard of it

    — Posts automatically merged - Please don't double post! —

    i dont like your opinion but i respect it so keep it up friend and good luck in life
     
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