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Thread: ida/disassembly help needed

  1. #1
    Join Date
    Mar 2006
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    ida/disassembly help needed

    hello
    I'm trying to patch some functions
    I'm using IDA to disasm
    replace the functions I need.

    compile the new asm

    but I have a problem in non symblic refs

    e.g
    lui $s0, 0x1111 # Load Upper Immediate
    addiu $s0, $s0, 0x222 # Add Immediate Unsigned

    Address 0x11110222 has been changed

    Any idea how to do it?

    regs

  2. #2
    Join Date
    Mar 2006
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    9
    no single reply!!!!!!!!!!!!

  3. #3
    Join Date
    Jul 2005
    Posts
    507
    The people who would be able to answer your question probably saw the title of the thread and ignored it. This might just be the first time when a title like yours is accurate! Usually a thread with a similar title ends up asking a question like "how can I turn on telnet?"

    Oh and sorry for being unable to help. Have you considered posting the same topic over at the tivocommunity forum underground section?

  4. #4
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    Mar 2006
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    @ciper
    Thanks for reply anyway.

    @Moderators, you may change the topic to whatever you see.

    regs

  5. #5
    Join Date
    Nov 2004
    Posts
    221
    Not sure I understand the question. There really is no re-assembly. Just find the address you want to change, get the new opcodes, hexedit the app and you are done. You can even disassemble the newly edited app and see that your editing was done correctly.

  6. #6
    Join Date
    Mar 2006
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    Quote Originally Posted by mrpenguin View Post
    Not sure I understand the question. There really is no re-assembly. Just find the address you want to change, get the new opcodes, hexedit the app and you are done. You can even disassemble the newly edited app and see that your editing was done correctly.
    @mrpenguin
    thanks for your reply.
    This is a manual process and it's very difficult to modify each and every non symbolic link.

    I want to know how patching is done generally- talking in consideration that the new size is not the same as the original.

    regs

  7. #7
    Join Date
    Aug 2004
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    4,086
    Quote Originally Posted by HNaga View Post
    @mrpenguin
    thanks for your reply.
    This is a manual process and it's very difficult to modify each and every non symbolic link.

    I want to know how patching is done generally- talking in consideration that the new size is not the same as the original.

    regs
    In general, tivoapp patches are done an instruction at a time. There is no size change: it is a one for one replacement of instructions. I don't know anyone who has tried replacing whole functions, though someone might have done it. The closest thing is the "long patch" in the superpatch, where a new function is written on top of an old one that was no longer called. It's all done manually.

  8. #8
    Join Date
    Mar 2006
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    I think I need decompiler not disassembler.
    I don't know if there is one for MIPS BE.

    regs

  9. #9
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    Aug 2004
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    Here's a post with links to available tools. It may be dated. Let us know if you find better tools.

  10. #10
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    Mar 2006
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    Quote Originally Posted by Jamie View Post
    Here's a post with links to available tools. It may be dated. Let us know if you find better tools.
    @Jamie
    Thank you, I'll take a look .

  11. #11
    Join Date
    Mar 2006
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    9
    BTW , any one has used MULTI before?

  12. #12
    Join Date
    Nov 2004
    Posts
    221
    never heard of it, or forgot it.

  13. #13
    Join Date
    Mar 2006
    Posts
    9
    it's green Hills software for MIPS

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