RomRaider

I was going to take some screenshots, but my copy of IDA is not working right now. Where exactly do I click? Just on the ROM:00000000, or on line 1, or ??
Also, where would I double click, on the 'data.l,' on the address, or ??

Just on ROM:00000000, doubleclick on value after 'data.l'

You can select the line you want to change the data type on by clicking on the rom address you want to change. ROM:00000000
When you press "d" to cycle through the types you'll notice the bytes start to bunch together and the "data.b" cycles through the types. When you change the type of the first set of bytes in the rom to data.l you can now click on the bytes themselves something like h'B68. That is your link to where you are trying to go. Double click that and when it takes you there press "c" That should change the subroutine you are now looking at into code for you.

Okay, I will try again later when I get IDA to open for me again.

Thank you for posting this thread; there is a lot that is not clear to someone beginning to learn assembly/disassembly. This thread has given me renewed hope in my endeavor.

I have an interest in learning how the machine code in my Motorola MC68376 processor functions. When I began I didn't know anything about assembly language or disassembly. In order to learn assembly (because I did not want to purchase IDA since it is expensive and my lack of knowledge would preclude its effective use), I decided to write my own disassembler. I found documentation for the 68000 and the individual processor's machine instructions and have written a simple script which looks for the first exception table (which shows where the code begins) and linearly translates code from there on (accounting for branching possibilities).

On short examples of code posted online (and in the snippets from this processor/application which others have translated using IDA), I can get a perfect match in disassembly of commands on the first run through the file. Unfortunately, I don't yet know how to handle data types and tables, so these are incorrectly translated into instructions. My end goal is to understand a file with something like a million bytes, so there is a lot of room for error. I'm sure you're all familiar with this.

At first, I was quite disappointed that I could not get the full disassembly with a single pass. After seeing this thread, and realizing that not even IDA can do such a feat, I can adjust my disassembly strategy based upon how you use IDA to disassemble binary files.

I will certainly share more of what I've done if anyone is interested; I would benefit greatly from a conversation about disassembly and how code is organized in memory.

Have you looked at this?
https://support.dce.felk.cvut.cz/nms/cp ... start.html
binutils will make your life much simpler...

Thanks for your reply. Unfortunately, the link you provided leads to a 404 error when trying to download the 68k binutils for MinGW (what I'm most familiar with). I already have the binutils that come with the MinGW implementation of gcc, but I assume that it does not have the m68k instructions built in.

Even still, I'm not sure how to properly use that. I guess I could try to use the objdump to get binutils to disassemble for me, right?

Alternately, I could try to figure out how to use the BDM interface on the board (using the tools in that link).. but I was hoping I would not have to pry off the sealed lid from the ECU.

Yes objdump would provide a disassembly for you. If it's not in the core binutils now I'm sure with some searching you could find what you need in an old version of the tools.

Can anyone offer some guidance on using IDA with a ROM from the 92-95 SVX?
Viewed in Hex I can see many patterns that surely signify tables but determining what they are is another question.
Thanks to Merp I've had some luck in getting the ecu defs to work in Romraider.

See description below from http://www.alcyone.org.uk/

"The ECU is made by JECS and based around the Mitsubishi M37791 CPU (7700 family). There is 32K of ROM and 1280 bytes of RAM. 16-bit values are stored in little-endian form."

I've attached a ROM from a 94 SVX.

Hello, I have a n00b question.

I don't see motorola 6816 in my processors list in Ida Pro. What am I missing? Will one of the processor types I have work as well?

Motorola 6800 should work fine.

For people like my self who are learning ida pro is expensive . Could even be a waste of money if it doesn't pan out right .

Guidra I think its called the file was huge with a lot of content

Hi i have ida now at last .I pressed the G button and a box popped up i put 0x200 in and pressed C then another box popped up. I was presented with the box below . Further up it says in a so many words have a idea of what your looking for .How do i no the start of the table I'm looking for (ie) name of table full address etc? at this moment in time i really would like to no the size of my injectors . and form wjhat i gather the info is in ida. Can some one with more experience please give me a hand or advice please

Are any of the "IDA HOME" licenses relevant to the Subaru ROMs?

You need the version that includes Renesas SH process support.