disassemble a binary file ecu

[munro]

guys I always wondered, what is this operation, that is, dissasemblare a binary file to an ecu in order to understand exactly the operations provided by the program eprom in the operate via micro..
someone knows something? I understand that the thing is quite complex and more within the reach of a computer scientist/programmer....there is some good pious soul, that could also explain simplifying a lot, what is it?

[munro]

is there any programmer among us who are familiar with the C language/assembly, or the language to ASCII??

[tranky]

Then to explain in the form of "drinking" the composition of a binary file is not readable we have a little step into what I am about to say..
We do realize that you and I (munro) there telefonassimo, between me and you, there is a "tunnel communication" in which transit through my voice messages and your.. if a third of all the contrasts between us 2 can listen quietly to the content of the "tunnel communication".
[I]----[te]
[I]---[and helpful]---[te]
these are the 2 examples as mentioned above.
now let's start with [I] that sending a message is encapsulated behind an algorithm definiamolo XYZ (just to stay in theme with the site, and ecm), which converts the sound into something not understandable to the receiving phase has 2 options:
1) if the sender has the same code as XYZ decrypts the signal and makes it original and "drinking"
2) if the sender or anyone intrude in the transmission does not have a way to listen to the content.
Let's say that this is worth more than the other for communications, but we say that the principle is the same, just the reverse with
[I] = original programming of the ecu
XYZ = the conversion of the file from human readable text (in any language it is expressed formerly always characters and languages must contain)
[tu] = interpreter as winols, ecm, etc, etc
At present I could not tell you with accuracy with which compiler has been created that file, but there are ways to decompile, but it takes time and effort to get the result because the file is in and of itself will be part of a suite alfa/bosch, which will certainly have the source interpreter.
Having that you have the world of tuning between the fingers
I hope I was of help, and especially the clear.. twisted, definitely, but I hope it's clear
Ask me another if you need it

[tranky]

Watch you have my full cooperation and if you want a Sunday morning with calm postane one and start to see the composition and decomposition.
But certainly nothing of drinking seen that each character in the ascii table is linked to a function (either string a single character) from the program that generates these files to the ecu, and with difficulty something maybe results.
Or perhaps it is less complicated as we think..
We test and see what happens

[munro]

thank you very much tranky but you say that it would be for me nearly impossible to learn to read the ASCII??
intato, however, place a small reminder in a way that even those who are less experienced can understand what we're talking about.


The constitution and the operation logic of the electronic control units (ECU)


I want to try to tackle a topic very theoretical and of little practical use, that can help many of us to understand the logic of the functioning and the constitution of the love/hate electronic control units ECU that daily confront us in the diagnosis and repair of the vehicles and in their reprogramming.
My knowledge and skills in this area are rather basic: I am not an expert and I hope that those who have more experience can correct me.
The topic in depth would take a turn very theoretical and abstract fontamentalmente need and do not need it if one has to do is only rimappature, the situation is different in the case of the reprogramming of certain parameters of the micro most of the eprom, so I will try to be as simple as possible by summarising the information that I have in order to understand the reasoning of a control unit.



What is a ecu?
Any it is from the engine to the parking, from the first only appeared for the injection, until those of the last generation, the electronic control units are mainly formed by 5 the physical parts :

-Power supply:
Includes the positive and the negative coming in from the power source which, in the case of cars, is the battery. The control unit has devices that can stabilise the voltage levels, and generate other voltages such as the 5V for the sensors, and filter the potential of mass that is isolated from external noise (ignition systems, spurious radio frequency, electromagnetic interference, etc..)

-The inputs or input (I):
A control unit must have inputs for receiving information from the outside, whether they are "communications" (e.g. CAN) or incoming signals from the sensors; ****llo the physical inputs must be composed of at devices that read the electric signals and transform them into digital information.

-Outputs or output (O):
The outputs are used to convert the digital control signals and power to operate the actuators and / or send information.

-Microprocessor:
It is the operational heart of everything and is able to process the incoming information from the inputs, the access to the memory and the program operation and to control the outputs.

-Memory or eprom's:
It is the home where is "crammed" the information, the famous map and the necessary instructions to manage the processor.




Microprocessors "stupid".
The microprocessor is "stupid" has no possibility of reasoning, but only to execute statements one at a time; a set of instruction of make sense, that they perform a job to the processor that is called a Program example:
- Read the information of a sensor;
- Access to the memory right;
- Compare them with the stored parameters;
- Check the plausibility of the value;
- Manage an eventual exit command.
This set of instructions can be a real "program" what we're interested in.
The special feature of a microprocessor is the speed with which it executes the individual instructions; a speed that can reach even the migliardo operations per second!

How do you manage the information?
The Processor of any control unit being an electronic component can only reason with electrical signals: hence, there exists the need to convert all signals will be adequate.
The speech of the conversion is the basis of my discussion: the information undergo many transformations in the time that they reach the control unit, and for now leave it, the complexity is in the follow them all.

Bits,Bytes, hex, and ASCII
All this names represent the "formats", and the languages used by the control units (and the PC) to process the data, but let's start from the base.
The bits:
The only thing that knows how to make an electronic component is to recognize the voltages (with a multimeter), that, behold, hence the need to turn everything into electric signals, where a low voltage almost equal to zero will be recognized as a "0", while a higher voltage (for example 5V) will be recognized as "1", these two parameters are the bit, or the letters of the alphabet electronic.
By making all the combinations of 1 and 0 we can create an alphabet, and then words or instructions example 00000001 means "the beginning of the text," you have to think that a processor does not need a quantity of words as a human being, but only instructions to execute.
8-bit consecutive make up a Byte.
HEX CODE:
To simplify the work programme and who manages this fleet of 1's and 0's have created another language that simplifies everything is the "language, hexadecimal" or "HEX" or a system with base 16 which transforms the data into bytes, a code more short example 00111111 you can write 1F (translated means separator or N°31).
It seems difficult, but in the end it is just a different way of representing the same information, in the HEX code also appears that the letters (A B C D E F). Usually the ecus and the PC this code (in HEX) is used to represent the addresses of the memories, or the address from where to take or where to write the information, this need arises from the fact that a processor needs to know where to go to look for the data that they need otherwise they can find.
ASCII CODE
The ASCII code is an additional code to transform the Bytes of letters or sentences in order to understand something about us human beings is to program is to interface, for example, the diagnosis (P0300 means misfire).

To sum it up:
the management programs are written in ASCII code, the addresses in the HEX code and everything is translated by the program itself in Bytes (8bit) or the only language that the processor can understand, the practical side if we use an oscilloscope to, and observe what passes on the pin of the processor, we see electrical signals similar to square waves that represent the bits 1 and 0:




If, however, the programs which is affixed to, for example, those of remapping, we look for something in the memories we use addresses in HEX




If we make the diagnosis or plan we use the ASCII code, and ragionandoci you understand why there are so many languages, bits are inleggibili, the HEX are complex and used in rimappature only from "eyes" experts, while the ASCII code is for all the workers so to speak, is a bit like if we were to read japanese, translate in English and then in Italian.



Turns that you turn the control unit through the use of specific electrical signals (instructions) stored in the memory, operates with the other electrical signals by enabling or not the outputs, all at a speed ininmaginabile and without committing any errors, the errors if there are any, have been made by those who made the programs.
The unit for work, it must have the right supplies, the right input signals, and must operate in the correct manner, always speaking of voltages, currents and reaction times, while inside the memories need to contain the programs and the processor must control everything.

Clearly most the control unit is complex, and most operations must manage and the harder it is to analyze from our side, but with the knowledge bases described we can tackle any kind from a window automatically with a EDC17, clearly with the proper proportions.

The remapping on the part of the word is to vary some parameters "motor" inserted in the memory and taken as a reference by the processor, occupy a small part of the whole program and the protections of the anti-processing.

I hope I have not made confusion, I tried to sum up everything and make it as simple as possible in order to help to understand the logic of operation of a control unit, in order to have fewer doubts,on the other hand, luck or misfortune of these units there are and there is nothing you can do, if not get past them friends and improve our work.

[tranky]

Ask and you shall receive!
I'm not really a programmer certificate, but I coddato a lot in various programming languages.
You have to realize?

[tranky]

doing a summary: to have XYZ is equivalent to having a driver/damos interpreter of the file only encodes that the damos/driver interprets the ID, the"XYZ" would play the entire composition of the file.ecu

[munro]

Ask and you shall receive!
I'm not really a programmer certificate, but I coddato a lot in various programming languages.
You have to realize?

the idea and implement in the micro and eprom new functions not provided by the manufacturer, see, for example, multimappa,launch control with als,system bang-bang,etc. this could be done in theory by changing the code strings in the eprom so that the micro in the reading of his routine program implements these functions.

[munro]

ok but if we do not have "xyz" how can we decipher the contents of a micro or eprom?
I seem to have read somewhere that you use the language ASCII...

[tranky]

It is the ASCII you see in fact, from the code on the hex dump.
Should I see some files of the EPROM and see the composition.
As soon as I have time I'll take a look.