Possible to rip patch from pre-patched ROM?

Discussion in 'NDS - ROM Hacking and Translations' started by gumbyx84, Jul 7, 2010.

  1. gumbyx84
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    gumbyx84 GBAtemp Advanced Fan

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    I know this is an odd question, but is it possible to rip the patch out of a patched ROM? I ask this because some ROM hacks (the HG/SS hacks for example) can only be batched using specific Windows tools. That leave people like me who use have a Mac out in the cold. There is a patching tool for OS X that works with basic patch files (like translation patches). I basically want to rip a hack/patch out of a pre-patched ROM (patching under windows) into a "standard" patch file that can be used with the OS X patching app.

    So, is it possible?
     
  2. evandixon

    evandixon PMD Researcher

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    Well, you would have to have a clean ROM, then just find the binary difference between the clean one and the patched one (basically how patches are made in the first place).
     
  3. gumbyx84
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    gumbyx84 GBAtemp Advanced Fan

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    I understand that. I guess my question is if a app already exists that does this already.
     
  4. FAST6191

    FAST6191 Techromancer

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    The key is in the bracketed text- any patching tool will do, they are not usually that specialised and any file is just that which leaves it up to the end user to choose what to feed it.
    http://gbatemp.net/index.php?showtopic=180142 might help and http://bsdiff.darwinports.com/ should be good too. Those are the big two patching methods on the DS and work well enough with it (more on such things here: http://gbatemp.net/t99814-ds-patcher?view=...t&p=1332416 ).

    On the other hand I have experimented with use of data recovery algorithms/methods (mainly par2) and several things in the GBA era had lists of every rom and variation thereof (usually caused by/as a side effect of intros and removal/bypass methods). Somewhat cumbersome though so unless you are truly at a loss (or do not care about online distribution) but par2 is far more widely supported being closely associated with modern usenet.
     
  5. gumbyx84
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    gumbyx84 GBAtemp Advanced Fan

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    I had a feeling it wouldn't be as easy as putting dropping the patched and fresh ROM in an app. Sucks though.

    Does anyone know the type of patch the HG/SS mods are? The OS X patch app doesn't seem to work with them.
     
  6. rastsan

    rastsan 8 baller, Death Wizard,

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    Any program that does a file compare most likely does a patch too. Ultra compoare has a hex viewer. so if you can find a mac os file comparer that does patches too you will be fine, since you seem to have access to both patched and unpatched it won't take you that long.
     
  7. Necron

    Necron Lurking~

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    You could use xDelta. Have the clean rom, the patched rom, and then make the patch with the program. It will create a .patch file (which you can rename later). The program is included inside the patch in my signature.
     
  8. gumbyx84
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    gumbyx84 GBAtemp Advanced Fan

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    Wait wait wait. FAST6191 made it sound like it was impossible. So I can use xDelta to do it?
     
  9. Necron

    Necron Lurking~

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    Yes. How do you think normal people makes patches? (like me xD) They modify the rom and then make a .patch file so everyone can use it. Give it a try!
     
  10. gumbyx84
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    gumbyx84 GBAtemp Advanced Fan

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    Oh I will be. I'll boot up my windows laptop and do a test with the HG/SS mods. Thanks for the heads up on this Necron. Appreciate it.