VoLTE Implementation For Google Pixel 3a/3a XL

ElliotLurie

I'm willing to help test. I have Verizon, live in the USA, and have VoLTE working on the latest version of LineageOS for MicroG. How can I help?

Also, can I get some elaboration on the super partition problem? It doesn't seem to be an issue for Postmarketos on a mainline kernel.

ElliotLurie

After forking and building myself, I assume these lines have something to do with it?

cp: cannot stat 'partitions/*': No such file or directory
System image: Applying update: halium_halium_arm64.tar.xz
cp: cannot stat 'partitions/*': No such file or directory
System image: Applying update: device_sargo.tar.xz
System image: Applying update: version.tar.xz
cp: cannot stat 'partitions/*': No such file or directory
losetup: /dev/loop0: detach failed: No such device or address

Can these be fixed by tinkering with the build script or the kernel?

mr_growl

@atarilinux I've been using a pixel 3a with volte for several months on lineage with no problems.

Android version: 15
LineageOS version: 22.2-20250607-NIGHTLY-sargo
Phone Version: Sargo
Phone Carrier: Amaysim (Optus)
Country: Australia

atarilinux

@ElliotLurie

I think that's the error. The issue was brought up on the QA call. Please see the link below.

https://m.youtube.com/watch?v=Ox9HLXrOkIg&pp=0gcJCa0JAYcqIYzv

More info on the Ubuntu Touch porting process can be found below.
https://docs.ubports.com/en/latest/porting/introduction/index.html

If the super partition issue can be addressed, I'm assuming the rest will follow as that was the main issue stated on the call. Unfortunately, I'm new to this, so it will take me a while to read up, fiddle with the code, take notes, and make any necessary changes. Any help with this is greatly appreciated!

atarilinux

@mr_growl

Good to know! Thanks so much! The current Ubuntu Touch VoLTE port in development left off on Android 12.1. The current production-ready Ubuntu Touch port (without VoLTE) is based around Android 9. We can certainly use this information as a reference for any new Google Pixel 3a Ubuntu Touch ports!

atarilinux

@ElliotLurie

I have some more info on the error message and the super partition.

On the cannot stat error:
https://stackoverflow.com/questions/34254164/getting-an-error-cp-cannot-stat-when-trying-to-copy-files-from-one-folder-to-an

Postmarket OS has some info on the super partition and dynamic partitions:
https://wiki.postmarketos.org/wiki/Android_dynamic_partitions

From the Android documentation:
https://source.android.com/docs/core/ota/dynamic_partitions/implement

Now we just have to see how we can put this all together for Ubuntu Touch.

atarilinux

I found something else that may be similar on the forums. It is regarding Fairphone 4 though...but there is a partition issue. There may be something we can glean from here.

https://forums.ubports.com/topic/11173/fp4-can-install-android-11-12-13-and-e-os-11-12-13-and-postmarkos-except-ubuntu-touch

atarilinux

Furthermore, Lineage OS has a recent build that should incorporate the retro-fitted super partition changes for the Google Pixel 3a. See below the github page.

https://github.com/orgs/LineageOS/repositories?q=android_device_&type=all&language=&sort=

ikoz

@atarilinux All modern UT devices already work with the super partition. I don't understand what you mean by "implementing" it, the only thing UT has to do is mount them, which is already done.

atarilinux

@ikoz

@fredldotme mentioned having an issue with the retro-fitted super partition for the Google Pixel 3a build on a QA call. He stated that we will need to figure that part out to get it working. When the Google Pixel 3a Android 12-based Ubuntu Touch port was trying to be built, we get the following error messages below, which refernces the partitions. If this has already been worked out on other Ubuntu Touch ports can the fix be applied to this one, or is this a different issue entirely? Any insight is recommended! Thanks!

cp: cannot stat 'partitions/': No such file or directory
System image: Applying update: halium_halium_arm64.tar.xz
cp: cannot stat 'partitions/': No such file or directory
System image: Applying update: device_sargo.tar.xz
System image: Applying update: version.tar.xz
cp: cannot stat 'partitions/*': No such file or directory
losetup: /dev/loop0: detach failed: No such device or address

ikoz

@atarilinux The cp error is normal and happens on all builds, the actual problem is the last one. From my understanding based on an older discussion in the porting telegram group, the retrofitted partition is used for older devices which didn't have the new super partition. However, it shouldn't be impossible to get it working, as others got their device booting, mounting the android partitions is necessary only for getting the android container running.

Anyways, more experienced people are active on the telegram group, so you may want to ask them.

atarilinux

@ikoz

Yes, that is correct. The retro-fitted partition is what the Google Pixel 3a uses. Thanks for helping with reading the error! I'll see what I can find out on this. If you know of anyone who may have some insight, can you let them know this is something we are looking to get resolved?

As we understand it, VoLTE works with a more recent version of Android. We are hoping to make this possible for the Google Pixel 3a on Ubuntu Touch as well. It has been confirmed that other alternative OS's already have VoLTE implemented for the Google Pixel 3a, so I think we have some resources we can potentially pull from if we need to. I'm not entirely sure what is being discussed on Telegram or if people may already be looking this.

mr_growl

@atarilinux No prob. So you know, I've just ordered a Pixel 3a XL for playing around on so if you'd like any specific versions of lineage tested for VoLTE, let me know. I gather that testing with a version based on 12.1 is the one you're most interested in?

atarilinux

@mr_growl

Thanks so much! Yes, that is correct! We are currently looking at Android 12.1 for two reasons:

The unfinished Ubuntu Touch port is based around this version.
This version is supposed to have the VoLTE patch included.

The current struggle seems to be with the retro-fitted super partition, but it seems like this has already been worked out with other Ubuntu Touch ports. If we can get whatever worked for them applied to this port, we may be able to get this working if I understand the recent comments correctly. We may have other issues down the line, but that looks like the first thing we need to address.

atarilinux

Just an added note on trying to troubleshoot the loop error:

Error:
losetup: /dev/loop0: detach failed: No such device or address

Note:
"Loop devices are provided by a kernel module. Therefore, you need special privileges to access them. You also need them to be exposed into your container, or you need to manually create the device files."

I'm not sure if something may have changed between Android 9 and Android 12.1 for this. We would need to investigate this error in addition to the retro-fitted super partition issue.