Managing defs when comparing OFT and non-OFT ROM

[derek1ee]

So I'm using ECUFlash+RR, and do not have an OFT, but I sometime will reference / sanity check the values in OFT image (kudos to OFT for keeping this open source!), and want to see if there's a better way to manage defs.

Here's what I'm doing today.
Both stock and OFT ROM have the same calibration ID (B01C), so the goal here is to make sure stock def is used for stock ROM, and OFT def is used for OFT ROM.

1. Change OFT def's vehicle year value from "2014" to "OFT"
2. In RR, include both defs. Stock def is ranked higher than OFT's
3. Open stock ROM. Verify it shows "2014 BRZ"
4. Move OFT def higher than stock def.
5. Open OFT ROM. Verify it shows "OFT ROM"

I guess another way is to use a different calibration ID for the OFT rom, e.g. B00C, it should be exactly the same, according to OFT, because it's really based on B01C ROM. This way, the defs included will have different calibration ID for stock vs OFT and the right one will always be used.

What's your way managing this?

[Wayno]

Unmolested defs should be prefixed with RR_
OFT defs should be prefixed with OFT_
The problem is openflash don't have any consistent naming scheme.

Just open B01C from openflash and delete the others.
Don't edit definitions, especially the headers if you don't understand what you're doing.

[steve99]

Originally Posted by derek1ee

So I'm using ECUFlash+RR, and do not have an OFT, but I sometime will reference / sanity check the values in OFT image (kudos to OFT for keeping this open source!), and want to see if there's a better way to manage defs.

Here's what I'm doing today.
Both stock and OFT ROM have the same calibration ID (B01C), so the goal here is to make sure stock def is used for stock ROM, and OFT def is used for OFT ROM.

1. Change OFT def's vehicle year value from "2014" to "OFT"
2. In RR, include both defs. Stock def is ranked higher than OFT's
3. Open stock ROM. Verify it shows "2014 BRZ"
4. Move OFT def higher than stock def.
5. Open OFT ROM. Verify it shows "OFT ROM"

I guess another way is to use a different calibration ID for the OFT rom, e.g. B00C, it should be exactly the same, according to OFT, because it's really based on B01C ROM. This way, the defs included will have different calibration ID for stock vs OFT and the right one will always be used.

What's your way managing this?

what your doing is likely bricking your ecu

[derek1ee]

Originally Posted by steve99

what your doing is likely bricking your ecu

Can you explain why?

[steve99]

OFT roms and defs are set up for the OFT system.


ROM are a mixture of program instructions and tables, incorrect defs result in editing of incorrect tables or altering program code instead of tables. this generally results in erratic engine running or bricked ecu.


OFT guys make alterations to the calid in some roms and defs to make them work with the OFT system. these alterations can "fool" other systems like romaider and ecuflash and likely other tune systems and result in a bricked ECU.


In a BRZ/86/FRS rom their are three instances of the calibration ID (calid)


In stock rom and other non OFT roms all three will be the same.


In many OFT roms two of the three calid instances are altered so users of oft can load a different calid rom to their original rom.


The OFT looks at the calid at 0X8000 and 0x100000 to determine if it matches the original calid of the rom storred in the OFT .


The oft then looks at the calid at 0X11EB9C to determine the "real" calid and this is used for logging in oft so it selects the correct ram address for logging .


These alterations are NOT consistent across OFT tune versions eg V1,V2 and now the latest special OFH tunes all have different alterations to roms and defs.


Its extremely important to use matching OFT definitions and tunes that come from SAME tune pack, do not mix and match defs and tunes even if the calibration id on the tune and the def match it means nothing, they MUST come from same tune pack/version. This applies to OFT uses as well.


you need to look at each rom with a hex editor and check the calid.
some oft roms are altered to load later calids and some are altered to load previous calibrations.




The calid are at hex locations


0x8000
0x100000
0X11EB9C


Use the HEX editor to search the ROM for the string "ZA1J"


you should find three instances, compare the calid




Senario 1


All three are the same, you relatively safe but read ROMRAIDER TIPS link below in signature and check tables in rom.


Senario 2


First 2 calid match and third one different.


The first two calid represent the calid that the OFT checks to see if it will load the rom as it compares these to the original rom calid stored in the OFT , if these don't match OFT will not load ROM.


Third calid represent the REAL structure of the ROM it may be a later or earlier calibration.


eg
First two calid are say ZA1JA00C
Third calid is ZA1JB01C


This is actually a B01C rom pretending to be a A00C rom so an OFT user whos original calid was A00C can load a compatible B01C rom into his car.


Romraider and Ecuflash defs will see this as an A00C rom when infact its a B01C. Both these programs only use the calid at 0x8000 to determine the rom calid. This results say in this case that ecuflash will think the rom is an A00C and try to open rom with A00C def and structure, you will likely edit program code instead of tables and result is usually a bricked ECU.


OFT guys produce special defs to suit these alterations.


Ecuflash defs are not set up for these alterations
Tdd did some defs a while back but DONT use these as OFT guys have made more changes in recent tunes and they may not be consistent


This will result in bricked ECU


Hence the reason you MUST use matching OFT roms and defs from same tune release.


And why you must be very carful hi-jacking oft roms for use with other systems.


If your using Tactrix /Ecuflash you need to understand all of this.


If your using OFT all you need to do is just flash the ROMs or if editing use matching rom/def from same tune pack.


If you don't understand this stuff and your using Tactrix/Ecuflash I suggest you Buy an OFT, its cheaper than a new ECU.


note both Ecuflash and Romraider only use the calid at 8000 hex to determine the rom id they don't look at anything else like year/model etc. both will just use the first def they find that matches.

[derek1ee]

Wow lots of info here, thanks a ton! Let me explain what I'm doing and why again.

My ROM is B01C, read via ECUFlash, but editing in RR, with RR B01C definition.
My reference ROM is OFT's B01C ROM, and the matching OFT B01C definition. OFT's B01C is really B01C, where A00C/A01C/B00C are actually B01C.

Now, both ROM are B01C calibration, but OFT's ROM have additional modification (e.g. LC/FS), so when RR create tables, it must use OFT's definition for the OFT ROM.

But the problem is, I'm trying to open two ROMs, both B01C, but need RR to use different definition. I haven't found a way to do this easily, hence my way in OP.

RR will look up matching definitions in the definition lists, from top to bottom, and stop at first match.

So I place stock (td-d's) definition on top, open the stock ROM. Then place OFT's definition on top, open the OFT ROM.

Now I still want to check to make sure RR indeed use the correct definition for each ROM, and I do it in two ways:

1. I changed OFT's definition's "year" from "2014" to "OFT", so that when I look at the left menu of the OFT ROM, the header will show "OFT BRZ", instead of "2014 BRZ", which is shown for the stock ROM, whos definition I did not alter.

2. I then of course looked at some tables, like you documented in other threads (as well as in your scenario 1).

So, am I missing something?

[derek1ee]

Oh, I should also mention, after editing the stock ROM, I then remove OFT's definition from RR's look up list, then open both original ROM and edited ROM, compare and make sure only the table I edited are different.

[Wayno]

You only need one definition. None of the table addresses change.

[Wayno]

All that could have been said in one line. Or found out if you'd done a diff on the 2 def files. That's why we worry about you not knowing what you're doing.

[steve99]

Originally Posted by derek1ee

Wow lots of info here, thanks a ton! Let me explain what I'm doing and why again.

My ROM is B01C, read via ECUFlash, but editing in RR, with RR B01C definition.
My reference ROM is OFT's B01C ROM, and the matching OFT B01C definition. OFT's B01C is really B01C, where A00C/A01C/B00C are actually B01C.

Now, both ROM are B01C calibration, but OFT's ROM have additional modification (e.g. LC/FS), so when RR create tables, it must use OFT's definition for the OFT ROM.

But the problem is, I'm trying to open two ROMs, both B01C, but need RR to use different definition. I haven't found a way to do this easily, hence my way in OP.

RR will look up matching definitions in the definition lists, from top to bottom, and stop at first match.

So I place stock (td-d's) definition on top, open the stock ROM. Then place OFT's definition on top, open the OFT ROM.

Now I still want to check to make sure RR indeed use the correct definition for each ROM, and I do it in two ways:

1. I changed OFT's definition's "year" from "2014" to "OFT", so that when I look at the left menu of the OFT ROM, the header will show "OFT BRZ", instead of "2014 BRZ", which is shown for the stock ROM, whos definition I did not alter.

2. I then of course looked at some tables, like you documented in other threads (as well as in your scenario 1).

So, am I missing something?

Basicly you lucked out as you happend to be using B01C roms and defs and that just happens to be one of the roms\defs that does not get altered by the oft guys, so as @Wayno said you can just use the oft romraider B01C def or wayno,s B01C def with some extra tables defined in it and your even ok with ecuflash B01C for same reasons.

BUT as i said you lucked out has your car been another rom like 700C or even D00C the excercise would likely have ended in tears

I cannot stress this enough you need to break out the hex editor and understand whats going on with the rom and def hacks.

And also the lc\ffs patches

Their been a number of people brick thier ecu or their mates ecu, cause they get lucky the first time ie have a B01C car and eveything works fine.

Then their mate says hey dude can you do mine , so they try their mates car and maybe its a 700C or a D00C and they do the same process and bang car wont start ecu bricked, mate not happy, happened to a guy here about two months ago, $1300 later for new ecu and labour.