VoLTE Implementation For Google Pixel 3a/3a XL

atarilinux

That's great news! Keep us posted how everything goes! Fingers crossed everything works correctly!

mr_growl

Did first attempt at flashing. This is on pixel 3a XL:

flash last stock firmware (android 12.1)
install twrp
boot into twrp and open terminal
umount /dev/block/dm-4 (which was mounted to /data and /sdcard)
mke2fs -t ext4 /dev/block/dm-4
mount /dev/block/dm-4 /data
mount /dev/block/dm-4/sdcard
boot into bootloader
flasboot flash boot boot.img
attempt to reboot into recovery

At this point the device wouldn't boot into recovery. So I'm flashing twrp back on to it.

Any thoughts?

Here's the repo I'm using: https://gitlab.com/mr-growl/ubports-ubuntu-touch-google-bonito-volte
I'm building in a ubuntu server 20.04 vm. I modified the deviceinfo from atarilinux's version slightly which got it building properly for me.

mr_growl

While I was re-flashing twrp a thought occurred. With TWRP on the pixel 3a (compared to the nexus 5 and 4 which I used to use) I have to boot it using "fastboot boot twrp.img" and then use the "flash current twrp" option (taken from the lineage install instructions)... on the older phones it was "fastboot flash recovery twrp.img". Which makes me think this twrp might be writing to the same place as boot.img when I do the "fastboot flash boot boot.img". Any thoughts on that?

ikoz

@mr_growl Why don't you formtat through the built it in option in TWRP or even better via fastboot: fastboot format:ext4 userdata? (the partition name may differ)

Also, when the block device shows up as dm-something it is encrypted.

mr_growl

@ikoz Thanks! I'll give that a go (I'm still new to a lot of this).

I was thinking it was encrypted. Seems to me that encryption is on by default in android 12 / lineage 19.1 and there isn't an option to disable it in the interface. Not sure what to do from this point.

ikoz

@mr_growl If you disable requiring password to login (just swipe to unlock), it will also disable encryption.

But just running the fastboot command will work (if it throws any error, it likely means your fastboot build is broken and you'll have to use the official one from Google).

atarilinux

@mr_growl

I might be off here, but did you use fastbootd? The Google Pixel 3a has retrofitted dynamic partitons in Android 12.1.

https://source.android.com/docs/core/architecture/bootloader/fastbootd

Info on Retrofitted Dynamic Partitions:
https://lucaweiss.eu/post/2023-03-30-retrofit-dynamic-partition/

mr_growl

@atarilinux I did not use or know about fastbootd. I did see it just now as I was flashing it back to stock. I'll have a read up about it.

What would help is if someone could suggest what steps I should take to flash this. Starting with stock android 12 (not even set up, just a fresh flash with all defaults) and a boot.img, system.img, dtbo.img and rootfs.img

I might not have time to test it till the weekend, though. I might try setting up a working build for sargo as well in the mean time. I can only test with bonito and the moment but I gather sargo is the more popular one around here

atarilinux

@mr_growl

That sounds like exactly what was mentioned on the QA call. This was our Step 3 to figure out. I'm assuming we got Step 1 and Step 2 finished. Step 1 was to verify VoLTE was possible. Step 2 was to finish the build (or make a new port). Step 3 was to figure out how to get it on the phone. On Step 3, we were thinking the articles I gave you in the last post would help. Also, keep in mine that Lineage OS, etc. does have some form of install method for Pixel 3a with Android 12. We may be able to pull some information from that project.

Here are my notes from the QA call:

On Android 12 port for the Google Pixel 3a on GitHub:
*Source Material - Not Image (VERIFIED, LOOKING AT NEW PORT)
*Information on image build process, but not how to install it (FIRST IMAGE BUILD COMPLETE)
*Built on top of latest Android 12.1 version for the Google Pixel 3a, but build not completed (FIRST IMAGE BUILD COMPLETE - @mr_growl)

Issues with building/installing: (WHERE WE ARE NOW)
*Issue with getting image on phone
*Has retrofitted system super-partition, this means two partitions act as they are one
*Has not been installed in this type of environment, we would need to figure it out

As far as my phone, I have bonito as well. Unfortunately, I can't test sargo.

mr_growl

@atarilinux Thanks for all that. I'll have a read through those articles hopefully this weekend.

If you have a bonito to test with then I'll stick with that for now. Have you been able to get a build going? Should I find somewhere to host the outputs from my build?

atarilinux

@mr_growl

I haven't gotten a build going. I was still trying to get the process flow, etc. in order. It's all new to me, so any build would take me a long time as I want to know what happens on each step and why.
Initially, I was trying to reverse engineer the original port and figure out what made it incomplete. Once I got to that point, I would complete the port. Doing that on my own is a bit difficult, but I'm detailing things as I come across them. My technical expertise is in a different area than this one, so there is a lot to learn.

If you want to give me the steps and builds, I'd be happy to test further!