Which cars have the motorola chip in their PCM?

[okidedrak]

I have a 97 Grand prix GTP, i assume i have the intel AB28F400BX is that right?

is the intel compatible with the motorola?
I have the IDA pro disassembler, how do i use it to disassemble the .bin from my pcm? I know it has an option to select the motorola chip but not the intel.

any replies would be apreciated
Thanks!

[Keith@HPTuners]

Welcome to the forum,

The data (.bin) is stored on that Intel Flash chip. It just acts as a hard drive, that's all..

The data is executed by the processor however, a motorola CPU32 68332.

When you disassemble a file, you want to select what type of processor it is run on. Even though the data is stored on an intel chip, that is irrelevant, you would want to select a motorola 68332 processor. If a 68332 process is not present, maybe a previous model is such as a 68331 or 68330. It won't be perfect but it should get you started.

Hope this helps.

[RoboGeek]

It seems confusing since with PC's you normally think of Intel (WinTel) and Motorola (Apple) as competitors, and that they have incompatible hardware. But like Magnus said, the Intel chip is just holding the program thats compiled for the Motorola processor.

And I'm jealous.. IDA Pro is too expensive for a poor boy like me..

[okidedrak]

that makes sense, i guess i need more schooling

thanks Keith

Now anyone go to play around with teh IDA program and can provide more info on how to disassemble teh code properly?

i dont know assembly language but i do know c++ and others and i intent to learn this one too..i'll do anything to be able to tune my pcm

[Keith@HPTuners]

You find your reset vector at location $004... go to that location and hit C.. it may be around $500 or $540 area (hex).

That disasembles your main routine, then near the bottom is a jump to a address stores in the binary, you have to find that address (called right above the jump), and hit C again.

[okidedrak]

thats exactly what i was about to ask "where is/are teh entry point(s)?"

cool

also which processor has similar instructions to the 68332 the 68330 or the 68K?

[Keith@HPTuners]

I would think the 68330 but I'm not exactly sure.

[Chris@HPTuners]

check the 68332 user manuals - links on this site somewhere.

set your processor to 68330 and also create a RAM segment as well. I just do ff0000 to ffffff for the ram seg. you can start with the CPU registers and such that are documented.

you will find that heaps of the code is ref'd by jump tables both local and remote. heaps of subs have local jmp's referenced by tables stored at $7Cxxx'ish.

search for things like jmp (a2).

Also, i posted a thread here somewhere on what the 3dlookup routines look like. to find them is easy just do a global search for "tbl" and look for 3 lookups very close to each other. that will be a 3dlookup routine.

next step is to find the DTC routines, which has also been posted here someplace. Then the long task of mapping out the variables begins.

the main loops are not that hard to find and just a matter of working your way thru each routine looking at the vars and DTC info to work out what each does.

to make it easy for you, everything from $8000-$1FFFF is the cal. Everything else is code, jump tables, DTC tables etc. 99% of the code is butted up against each other so if disassembly stops just move down and hit the "C" key.

you can write a little script to look at a jump table and auto the code, but be careful as sometimes the jump table is a long way from, look for bounds checking before the jmp calls.

hope that helps.

[okidedrak]

gameover , good info thanks

btw on what pcm(car) you workign on?

did you find any concrete stuff in yr search yet?

also i have the files of an original tech2 flash card
for a GMC Sonoma 2001. there are a couple of bins, most of them small sizes only one is 400k and a .tbl file

i also have the vin for which they are intended
so if one goes here http://calid.gm.com/vci/ and inputs the vin 1GTCT19W618109633
it shows all the calibration files that i have right here and also specifies what each is for

would this stuff in teh right hands help us in any way?

[Chris@HPTuners]

most of the good stuff is in the operating system not the cal files.

cal is just tables, constants and flags etc.

[qs9999]

IDA is very expensive but i did find this freeware version at http://www.themel.com/ida.html. I am very new at this and don't know if this program will do what we want. but I will play with it and hopefully learn from it.

Ken

[okidedrak]

Gameover what do you mean when you refer to good stuff?
and what o/s you talkign about?

[Chris@HPTuners]

okay so the image on the flash files consists of two main things:
1. the operating system (or segment 1 as most people call it). This contains all the code, algorithms and procedures the PCM uses to do it's job. Everything from calculating the right spark timing, knock learn etc. to outputting diagnostic information.
2. the calibration section. This is broken up into 7 smaller segments related to each engine/trans function. There is no code stored here. Just flags, bit fields, 2D tables, 3D tables and the like. The code refernces this section to determine how the engine will operate. ie. if you don't have "electronic traction control" system fitted to your car then the calibration will tell the operating system to skip that part of the routine. Another example is if you have a supercharger fitted then the calibration will tell the operating system to run the supercharger related stuff.

The operating system generally contains lots of features, a subset of which is used on each different car/truck application.