Possible to rewrite (FOSS) software on Prius Prime Multi Media Display?

It most likely runs "Automotive Grade Linux" which has security features to prevent "unauthorized" changes. Probably not possible to do anything. Secure Boot - AGL Documentation

 

never say never...

 

I'm sure it's possible ! Just thinking about it hertz !
extracting the main image, where ever it is, ECU perhaps?
than extracting the images for the other ? ECMs how ever many there are in each different model.
Than parsing the code in whatever programming language(s) are used. And understanding how messages are sent and received on the buses, converting protocols at junctions.
Knowing the crypto, security and magic num / hash types while remembering what the open source various licenses permit and restrict.
Sounds like a fun project for an individual or a small team of exceptional programmers with a large following of users.
Ever edit (without explicit instructions ) or even look at a binary ?

 

Done plenty of that ... just not so much on cryptographically signed ones I don't have the signing key for.

 

I just haven't taken mine out and since a tesla style replacement will go in there I'm not motivated. What id really need is pictures of the circuit boards. in my experience, serial or jtag gets you in to view and from there its like walking and breathing at the same time.

 

Hey if you're up for the adventure, enjoy !
My post was more about the Open Source issues embedded in the control functions if there are any. The open source licensing inclusions might only be for the entertainment features anyways. You know, cameras, usb, bt, radar, sonar, etc; all the good stuff ...
adding ai, vr, ar, xr gets expensive and can be very distracting for those not ready for it.

 

i just need to see pics of the actual system boards inside. It's easy enough most times to locate 3-5 solder points that with some wires can connect to a USB dongle and you are in with putty on the terminal. most things I've gotten into were 3.3v or 5v and a bootloader is bound to appear and you can go from there.

 

Anyone that has already added something to this thread, except the one asking how to get a finished product, is probably already one of these and should take the quiz .
What sort of Bastard are You - Quiz TWO

beware the parent page to the quiz is disclaimed to be not safe for work rated. The quiz might not be work safe bet either.

What I saw was benign enough, I think. Always better to be safe. sorry must resist.

 

Yes, you are right, there are test points for connecting to EMMC via JEDEC protocol.
I have already extracted the image from 2018 and 2021, they are interchangeable when replacing the kernel and kernel modules, since the hardware is slightly different.
A simple software replacement will not do anything, for carplay in 2021, an additional programmable USB HUB is installed.
I extracted the firmware from this USB hub, made a test external device based on this hub, and then carplay started. However, since the touchscreen microcontroller is different in 2021, the carplay system libraries do not support the 2018 hardware, they need deep reverse engineering.

The operating system is a fork of SUSE Linux for the x86 architecture, 32 bits.

If you have software reverse engineering skills in IDA PRO etc., I can share executables and some information.

 

you speak my lanuguage, you might be able to help go the other way around about this all, but it starts with canbus and whats connected behind the headunits is what ive learned.
but...

ding ding ding! this is what I thought and why I didn't bother taking apart my 2017 prime and since general consensuses is swapping in a newer unit I figured why not go for aftermarket tesla style screen which has opened up another can of worms. now that I'm trying to get a Gen 2 with bad mfd going and Im pretty firm on only spending money on replacement unless its some sort of android replacement even if i got to test my theory on the canbus unit thats used across most Toyota's that share the similar bus and a simple a head unit reconfiguration to the canbus adapter gets me a/c controls on the mfd and also the hybrid battery info. just the whole diagnostics screens. I want to be able to take out the two units in the dash and the navigation box under drivers seat and the jbl amp replacing the amp and one unit in dash having the ability to have all ow functionality. then the same for my Gen 3 plugin.. followed by the 2017 prime.

I'm realizing that the wave of android head units coding in hybrid vehicle battery information is upon us and word is, because no Prius in China is why we don't get the support we should so easily... but they are all liking my Prius and my proposals so I'm just gonna keep swimming. Also... if we think far outside the box, we might find that a vehicle Toyota doesn't make in the USA has the same rear connectors as the Prius... thus when you set the canbus to another vehicle the climate controls mysteriously show an android based headunits! I know the Gen 4 Prime things changed like no more additional ECU to control the PHEV, its all built in one yet I say that because thinking through a lot more than just the headunit carplay system libraries... the possibility to "open" them up using code added to the 2021 hardware would be next level yet I don't think most think like us where we know no limit until that wall is on the terminal infront of us saying the hardware is different to stop us... hope the seed I planted grows well.

ahh, easy enough. I still have my reverse engineering hat in the closet still, I took a few Generations step backwards to understand them better which is allowing me to understand the newer better as well and just how much of what can we really modify without causing catastrophe.

in my vision, we are able to swap in the v8 hybrid from the ls600hl.. the AWD cvt as well and combine it with the Gen 3 PHEV ecu and some newer gen high capacity hv cells that work with the PHEV system to build a wonderful Prius V with panoramic roof! The Tesla style screen provides all hv battery and vehicle information without the need for a obd2 dongle. TPMS psi of each tire as well!