[Tristan-cx5]

Read ID7 Recovery v2 carefully... "Don’t worry about the error messages and after a minute turn ACC off and on again." ... After pasting in and confirming your command via enter/return, you see the error messages. Afterwards wait about 1-2 minutes, without doing any input. Then the "#" appears I guess. Then it`s done. There is no confirmation about a successful install of ID7v2/autorun. Just prepare a FAT32 formatted usb stick, put any AIO tweak on it and try to install it after a reboot of the CMU/MZD. Thats how it should work. Fingers crossed for you.

 

[Albuyeh]

I have entered this command "rm -rf / mnt / data_persist / dev / bin / *" to delete all the files, but all it does is it starts to fly text and it never stops, I have to start over.

Flying text is good. In your screenshot, there is no flying text so that means you have done something wrong. Please follow Serial Connection very carefully

 

[Tristan-cx5]

Just as info: Working with an external CMU (not in the car): I just connected/did the serial access 31 minutes after the firmware update to .352 ended. Once I tried it several hours later and then the serial access did not work anymore. With a CMU in a car and working just with ACC, the time for starting the serial access after the firmware update is limited to the battery "shutdown" time (see firmware update manual) - e.g. for AT you have to press the brake pedal every 20-25 minutes to prevent an ACC/CMU shutdown.

 

[User Namejoeschmuck]

.337A NA
# LAUNCH DEBUG SHELL HERE
# /usr/bin/rungetty_shell &

/usr/bin/getty_shell

So looking at this code problem where the .up file now contains code which changes the run getty_shell to not execute, is there any way that we could change the code elsewhere to force it to run, of course it would need ot be in the .up file unfortunately. Or is there any other interface we could use?

I'm not foolish to think this is terribly easy for most people (me included), you need to be a serious hacker to pull this off (having the correct tool set and knowing how to use it) but it sounds like we need to change the pound (aka hash) sign to a space " " value. Then magically create a correct sumcheck value and package it up. I use to program in machine code back in the day but then again I had all the reference documentation available to make my job easier. We didn't have graphics either, simple text, the good days. What would be nice to have is a CMU simulator program so we could test code changes.

Even if we could create a separate .up file who's sole purpose is to make the serial port open up, no other code changes, then we could manually adjust the files we desire via the serial port. I'm trying to think of options that are out of the normal box. If we knew the minimum files required to boot up the system, does it need a sumcheck or is that a routine kicked off by the upgrade program, we might be able to bootstrap the CMU with minimal code that we already have access to. I so wish I had a spare CMU to play.

It's nice to dream.

 

[anhnga]

ID7/ID7v2 is not possible at .367. No one can install any tweaks at .367. Unfortunately.
Yes, you can downgrade from .367 to any lower version like .352 and .335 (as far as 59.00.502). At these .352 and .335 then ID7v2 is possible (and at lower versions the ID7 process).
So you can downgrade from .367 and then do the serial access to be able to install AIO tweaks via USB again (I did it myself and can tell you from my own experience).

Hi @Tristan-cx5 !
Did you success on downgrade firmware from .367 to .352 or .335?
Because my friend have CX5 2020 with firmware .367, he try to downgrade to .335 for install AIO tweak, but CMU downgrade fail at 99% and restart over and over on 99%...
I try to use NOR flash with all the way i know (ofcause only with 70.00.100A, because NOR flash not working with all in one .up file), but alway stuck on 99%....
Don't know why...

 

[Tristan-cx5]

As far as I remember, I successfully downgraded from .367 to .352 at my bench. And today I did a successfull downgrade from .367 EU to .335 EU at my bench (not in the car) - just to let you know.

 

[anhnga]

As far as I remember, I successfully downgraded from .367 to .352 at my bench. And today I did a successfull downgrade from .367 EU to .335 EU at my bench (not in the car) - just to let you know.

Hi Tristan-cx5!
May be you successful downgrade firmware version from .367 to .352 or .335 because you done it at your bench... but if you do it on the car with usb hub support Apple carplay port, may be you will have fail while doing downgrade...
I think my friend have fail at downgrade his cmu's firmware version from .367 to .335 because him did it on his car with usb hub suppor apple carplay....

 

[Tristan-cx5]

That`s possible. At my bench I only have an old usb hub with no AA/CP support connected. So, if anyone has a spare AA/CP hub+2 cables and wants to get rid of it, I would be happy to receive it to test other scenarios at my bench ;-)
Thanks anhnga for pointing out this possible different behaviour of different usb hubs. Potentially there are also different behaviours between a CMU in a car and at my bench (with same old usb hub).

 

[Vn11]

My car has fw 70.00.367 A (ADR) preinstalled. I want to downgrade to 70.00.355 or .352 to root, install AIO tweak. Searching the forum, I cannot see the link of the above FWs.
Please share link/up Fw ADR 70.00.355 or. 352.
Thank you

 

[anhnga]

My car has fw 70.00.367 A (ADR) preinstalled. I want to downgrade to 70.00.355 or .352 to root, install AIO tweak. Searching the forum, I cannot see the link of the above FWs.
Please share link/up Fw ADR 70.00.355 or. 352.
Thank you

Hi, you must think carefully about downgrade firmware, if you have fail at downgrade process, your CMU will not possible to recover any more on any way as i've ever done before... because i've try to recover one CMU have bricked on downgrade firmware from .367 to .335 process... I've rescue alot of CMU from all car workshop on Viet Nam... but with CMU bricked on firmware .367, i have no way and no idea to rescue it...

 

[Vn11]

.. if you have fail at downgrade process, your CMU will not possible to recover any more on any way as i've ever done before... because i've try to recover one CMU have bricked on downgrade firmware from .367 to .335 process... I've rescue alot of CMU from all car workshop on Viet Nam... but with CMU bricked on firmware .367, i have no way and no idea to rescue it...

Thank you for your help. So that there is no safe way to downgrade FW from .367 to .335 or .352?

 

[ctve]

Hi, you must think carefully about downgrade firmware, if you have fail at downgrade process, your CMU will not possible to recover any more on any way as i've ever done before... because i've try to recover one CMU have bricked on downgrade firmware from .367 to .335 process... I've rescue alot of CMU from all car workshop on Viet Nam... but with CMU bricked on firmware .367, i have no way and no idea to rescue it...

Hi,
Have you find a solution to unbrick your CMU after you unsuccessfull downgrade ? I wanted to do the same downgrade as yours (from 367 to 335) but your post is a bit frightening.

 

[anhnga]

Hi,
Have you find a solution to unbrick your CMU after you unsuccessfull downgrade ? I wanted to do the same downgrade as yours (from 367 to 335) but your post is a bit frightening.

For now, i have no idea or solution to recover the CMU which bricked in downgrade process...

 

[Nosk89]

@anhnga what about downgrade from 70.00.100 to 59.00.504 is possible to fix that from your experience? I have SPI NOR Clips + CH341A progammer but I've tried a lot of cases without success. I've copied backup.bin from working 70.00.100A EU and even NA version but I can't fix it. If you have any idea how to deal this I can even pay you for the help with remote fix I have all the tools.

 

[JakeStateParm]

Hi,
Have you find a solution to unbrick your CMU after you unsuccessfull downgrade ? I wanted to do the same downgrade as yours (from 367 to 335) but your post is a bit frightening.

Follow this video, worked like a charm for me.

 

[JakeStateParm]

@anhnga what about downgrade from 70.00.100 to 59.00.504 is possible to fix that from your experience? I have SPI NOR Clips + CH341A progammer but I've tried a lot of cases without success. I've copied backup.bin from working 70.00.100A EU and even NA version but I can't fix it. If you have any idea how to deal this I can even pay you for the help with remote fix I have all the tools.

The recovery method shown here should be successful in unbricking any CMU as far as I know. This method essentially gets your CMU to boot into a state where you can reinstall whatever FW you give it.

 

[Tristan-cx5]

@JakeStateParm : For which FW did it work for you like a charm? Please specify. Thanks.

 

[dammy89]

@JakeStateParm are you sure that you did downgrade when the problem accured? Downgrade and upgrade are two different scenarios.

 

[JakeStateParm]

@JakeStateParm are you sure that you did downgrade when the problem accured? Downgrade and upgrade are two different scenarios.

From my understanding, if you brick your CMU doing anything (upgrading or downgrading), following that video should allow you to get your CMU back to a state where you can reinstall whichever version of firmware.

For me specifically, my friend was on some version of 55, and I accidentally rebooted the CMU after the failsafe file (v70.00.100) was installed, which completely bricked the CMU (black screen, only radio worked). I followed the instructions in that video and was able to get the CMU to come back on enough to install v70.100

I don’t see why the steps in that video would be dependent on what you did to brick the CMU. The point is that if you brick it somehow, that video should get your CMU back up and running.

 

[Tristan-cx5]

Whats shown in the video might work for 2 File Firmware (up to/including 70.00.100), but I think anhnga mentioned, that the SPI NOR chip can not be used to fix problems with the 1 File Firmware (70.00.335 and higher).