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Pentax (Fujitsu FR) hacking
  • I am trying to start reverse engineering the Pentax firmware. I have already got some clue but i have questions which you probably may help me with.

    1) Does there exist any FR-V instruction manual at all? I could find "disassemble" command in Softune manual but I cannot find any programming manual for FR-V at all, even for FR400 board which seems to be FR-V based. Even if I can disassemble code, I will stugle to read it.

    2) Can I disassemble FR-V code with IDA Pro (5.0)? It seems to me that I can't.

    3) How do I know entry point without any processor user manual? I do not know how an entry point looks like. - My guess is: I probably should convert all data into code and check out all positions which do not accept any jumps.

    4) How do I know base address in RAM? - My guess is: I probably should count occurencies of all bytes in every alignes uint32_t (assuming that there might be addresses stored somewhere) and plot them ti see any fluctuations.

    5) Does IDA 5.0 Pro Free has scripting support?

    6) Which firmware should have bigger size: for DSP or for CPU? Which firmware should contain strings: one for DSP or one for CPU? I have dumped firmware using debug mode but the bigger file has "DSP" in it and also contains strings.

  • 7 Replies sorted by
  • Before asking such question you always need to do your homework

    For 1 - yes, use Google.

    For 2 -

    For 3 - you use your brain, such tool existing in some individuals, now can be rare

    For 4- same as 3.

    For 5 - What scripting exactly?

    For 6 - It all depends.

    What kind of reversing experience do you have?

  • I have read many information written by you and I have found many useful tools on Pentax Hacks.

    1) Google did not help me here. Query - nothing useful past some PR overviews.

    2) But isn't FR-V different from FR?

    5) Like that mentioned above - scripting which would interact with IDA and use it's features.

    What kind of reversing experience do you have?

    I am very familiar with many computing and hardware problems but I never did any reversing.

  • Well, start with some Windows software and IDA Books, it'll help.

    As you'll be handy and will have few thousands hours free, return to Pentax reversing.

  • I have found short assembler reference derived from open-source project. I searched for pages containing several commands from those mentioned in the reference and found other open-source projects only (many of which were written by RedHat). It makes me think that there is no publicly available documentation for FR-V processors. I guess that no reading of IDA books and studying Windows software would fix it.

    I have few thousands hours of free time easily.

    This is not a personal message asking about help and I surely am not the single person wondering about all of that.

  • Sure I found it even before I wrote here. But it does not relate to FR-V, does it?

  • Start reading and doing things.