A way to boot with dead radio module

ahahahhahaha

Hey guys,
Is there a way to boot a phone (first start after installing/reseting OS) with airplane mode being already turned on?
I need phone to be completely radio silent for my application, "you can turn it off really quickly" sadly won't work for me.
Please only suggest software ideas.
I will not remove my radio module, nor does faraday's cage fit my need.
Thank you.

teezeh

ahahahhahaha I need phone to be completely radio silent for my application

Why and what for?

DeletedUser237

ahahahhahaha Please only suggest software ideas.

Not possible. Especially for new system before first setup

Watermelon

ahahahhahaha Boot up the phone as normal, wait for the Google logo, when you see the Google logo immediately start holding down the volume down button and continue to hold it until you feel three vibrations (two quick ones and then another long vibration). This will boot GrapheneOS into Safe Mode, before any network/cellular connections are made and before any user-installed apps are loaded, which automatically enables Airplane Mode and disables all user-installed apps until the next reboot. To exit Safe Mode you can just do a normal reboot, no need to press anything special or disable anything beforehand while you're still in Safe Mode. The Airplane Mode setting should (from my experience) persist between boots so you can just do a normal reboot immediately after you reach the lockscreen in Safe Mode, which would start your phone in Airplane Mode and all user-installed apps working as usual. (Safe Mode is a feature that GrapheneOS inherits from Android. It's also possible to enter it by long pressing the Restart button in the power menu, but that'd require you to already have the OS booted.)

Carlos-Anso

ahahahhahaha Is there a way to boot a phone (first start after installing/resetting OS) with airplane mode being already turned on?

We purposely did not implement this in software when we created the new OS setup wizard as we could not be certain that devices would not make broadcasts on first boot before the OS had an opportunity to connect to the broadband to set airplane mode on.

We did not want to give users the impression that devices do not make any transmissions without knowing for sure that they do not.

Would need thorough testing with radio equipment to see what actually happens. We dont currently have equipment or people available to do this testing. Also could potentially be different for different broadband hardware or firmware versions.

It is possible that the state of airplane mode when the phone was last active will influence the possibility of RF leaks, before the OS is fully booted, when booting after a new OS is installed or a factory reset is performed.

avaluedcustomer

What about removing the SIM card?

DeletedUser237

avaluedcustomer does not work like that. Radio is still operational and pings towers for emergency calls, you need to physically disable radio or go into airplane mode. Latter can't be done before booting.

roamer4223

Not possible if you don't allow those suggestions you listed.

If you were to use a Faraday cage while being deep underground or something but you have outlined that Faraday cages won't work for you

secrec

teezeh Why and what for?

@ahahahhahaha -- to clarify the reason why @teezeh asks this question, knowing the "big picture" could help us to potentially think of other ways to approach your problem with hopefully more feasible solutions.

roamer4223

Watermelon Wow impressive! I have no need to test myself but I believe you, that sounds like a solution. You better get a thank you from OP for that beast of an answer. Bravo!

I was far too pessimistic with my answer!

rustybird

Watermelon There's an AOSP comment saying that Safe Mode "may" enable Airplane Mode too late:

// Enable airplane mode in safe mode. setAirplaneMode() cannot be called
// earlier as it sends broadcasts to other services.
// TODO: This may actually be too late if radio firmware already started leaking
// RF before the respective services start. However, fixing this requires changes
// to radio firmware and interfaces.

No idea if this applies to Pixels.

Watermelon

rustybird Thank you for the finding!

GrapheneOS

rustybird That may not be relevant to the Pixel 6 or later since the cellular radio is far different than earlier devices. Pixel 6 and later very likely don't require changes to the radio firmware to keep it disabled before the OS is booted, but the OS needs to do things in a particular way to make sure it works from early boot of the OS when it enables the cellular radio.