Remove modem firmware

[aular]

How or where can I remove all the modem firmware from the phone. I know about the exploit in the firmware but that is not my main concern right now. My main goal at this time is to remove all traces and files of the qucell modem and just leave the modem empty. I have other plans for that later. If that modem firmware has dependency issues is there a way to fill those files with empty slots with empty files and garbage to hold up the phone from breaking. Thanks

[alaraajavamma]

Modem firmware lives inside modem.
Modem is separate computer which is attached to Pinephone trough some kind of usb port.

So what you can do? Use the hardware kill switch and then modem and Pinephone does not have any connection and modem is also powered off.

I think in theory you can remove modem firmware but it is kind of same thing like doing "sudo rm -r /*" to Pinephone. So if you are going to use it for something think twice.

[aular]

Thank you, that is what im trying to do is remove firmware without breaking the rest of the phone.
Would removing modem manager remove the whole modem stack and firmware meaning if i try to send calls or texts or event try to set up modem in settings it will be all be void meaning i can do nothing with phone calls or texts at all? I do know that settings is dependent on modem to get settings or vice versa and would like guidence on how to do this so i dont brick the phone and that is why i asked if it is possible to replace the files with blanks or something. thank yoi

My second question is this, would starting from scratch meaning installing the barebones arch not have the modem manager in it so i can avoid the modem manager or the modem in general. Thanks

[alaraajavamma]

Thank you,  that is what im trying to do is remove firmware without breaking the rest of the phone.
Would removing modem manager remove the whole modem stack and firmware meaning if i try to send calls or texts or event try to set up modem in settings it will be all be void meaning i can do nothing with phone calls or texts at all? I do know that settings is dependent on modem to get settings  or vice versa and would like guidence on how to do this so i dont brick the phone and that is why i asked if it is possible to replace the files with blanks or something. thank yoi

My second question is this, would starting from scratch meaning installing the barebones arch not have the modem manager in it so i can avoid the modem manager or the modem in general. Thanks

If you want to remove modem connection from Pinephone just use the killswitch which is located under the back cover.
When you close the modem killswitch you don't have any access to moden even if you want to.
Without modem you can't send SMS, or Call anyone or use mobile network or use GPS.

Read this with thought:
Think Pinephone as a computer. Then think that this Pinephone computer does have USB dongle which is called EG25 modem. This EG25 modem is actually small Android computer and it is connected to Pinephone with some kind of usb. Modem and Pinephone are attached (if you don't use killswitch and kill the connection) but they are separate computers.

What happens when you remove "firmware" (or OS) from your PC? Same thing happens to EG25 if you actually remove firmware from it and because it is not traditional PC changes are quite high that you will brick it completely.

I am not sure what comes "forced" with barebones arch but after installation you can sure remove modemmanager but because of the above this does not affect at all to EG25 firmware because you are removing modemmanager from Pinephone not EG25.

Does this answer to your question?

[aular]

O i do understand what you are saying and yes im trying to remove the EG25 firmware without bricking the device, thats why i asked if, can you, is it possible to place empty folders in place of the folders where the eg25 folders would be as a substitute untill something else can be placed there without bricking the whole device? Thats all im trying to do.

And speaking of the eg25 firmware, may i ask where in the system folders is the firmware located so i can begin planning out how to remove the whole stack without bricking the whole device... thanks

[KC9UDX]

I'd like to stress the point that using the kill switch is no different than physically removing the modem from the device.

Removing your operating system's access to it by deleting parts of it is *less* "secure" than using the kill switch.

Deleting the modem's operating system will (most likely) permanently brick the modem. Your only recourse would be to desolder it and solder in a new one. (You really don't want to do that.)

[alaraajavamma]

And speaking of the eg25 firmware, may i ask where in the system folders is the firmware located so i can begin planning out how to remove the whole stack without bricking the whole device... thanks

Just use the killswitch xD. Read what KC9UDX wrote above

Modem firmware does not live inside Pinephone so you can't find the files or folders inside Pinephone.
To remove modem firmware you need to somehow get "inside" EG25 - which is own computer and not same device as Pinephone - so you can do something in that computer. How? You can have adb access and maybe you can remove the firmware there but the cause of this is most likely not-functional EG25 without any opportunities to recover or use it after the process.

[zetabeta]

some background: i recently erase whole disk in my android device, it also included partitions, so it is permanent brick, super brick. device is in qdl mode now. usually just partitions are erased in android devices. i ... so ... love the destroyer of disks ... i meant command dd. btw this destruction was intentional.

like it was said already, eg25 modem is a device with own memory and files and is connected through usb, which is integrated into a mainboard. so pinephone is sort of independent from eg25, assuming no mobile functions are needed.

eg25 uses similar partitioning than android devices, and uses fastboot, adb and qdl. it means correct partitions need to be flashed. if something is done wrong, then it might result deep brick (for the modem chip).

if eg25's whole internal memory is wiped including partitions, it is deep brick for the modem chip.

i could theorize, if some specific partitions are wiped. it is recoverable. however, i STRONGLY advice not doing this.

there was one security issue with modem, i don't remember name for it, but if i recall correctly, it is fixed in 30.006.30.006 and 30.007.30.007, and also in half-free firmware.

https://github.com/Biktorgj/quectel_eg25...006.30.006

dip switches are mentioned multiple times, i think it is better way to go. technically speaking it does not disconnect usb connection. it disconnects power for eg25 chip.

it is possible to disable software, i think "modemmanager" and/or "eg25manager". but it is not default, i don't know how to change the default. what is the use case, because even pinephone does not communicate with modem chip, modem chip may get power and therefore might do something independently.

[KC9UDX]

Bingo. If you're worried about the modem being compromised, deleting the software for it but leaving it powered up makes for a really good opportunity for compromise.

[dachalife]

As previously stated, just use the dip switches to power off the modem; if your threat level is so high that you have to remove the modem/disable the modem firmware, your opsec has already been compromised by posting this question on a public forum.