I used to be an Android device developer back in the Lollipop days. I compiled the various images myself, including the bootloader, recovery, and the Android OS. I can say with 100% certainty that at least back in the Lollipop days, and at least on the vast, vast majority of devices (a device could theoretically change this, and I don’t know everything about every device ever released), the battery percentage that shows up when the phone is off is part of the bootloader, not Android. It’s a separate image entirely.
I’ve rooted many android phones including modern ones. Flashing the bootloader/recovery without the OS always changed the charging animation in the off state in my experience. Can’t say this is how all Androids work, but I’ve never encountered one that didn’t behave this way.
You most likely are flashing the bootloader, recovery, and OS all in one step. They can be combined into one image and all flashed at once. I doubt the Android bootloader would be able to boot Linux, but tbh, that’s not my area of expertise, so I could be wrong.
I know how it is. Used to work on phone chipsets. That being said, I have no idea how pixel 8 is doing this, but likely the Bluetooth chipset has a mode it can go into to behave like AirTags and just pulse out a BTLE beacon occasionally with both the main OS and sub-OSes turned off and power just being trickled to VCC on the BT chip.
Edit: apologies, didn’t mean to sound so curt. Tl;dr: I know how bootloaders run to allow battery charge while off, not sure how pixel 8 is doing their magic-to-be but have a good theory.
Actually I don’t believe it is. That part of the system is part of the OS image. I believe its how google tracks the Pixel 8
I used to be an Android device developer back in the Lollipop days. I compiled the various images myself, including the bootloader, recovery, and the Android OS. I can say with 100% certainty that at least back in the Lollipop days, and at least on the vast, vast majority of devices (a device could theoretically change this, and I don’t know everything about every device ever released), the battery percentage that shows up when the phone is off is part of the bootloader, not Android. It’s a separate image entirely.
I’ve rooted many android phones including modern ones. Flashing the bootloader/recovery without the OS always changed the charging animation in the off state in my experience. Can’t say this is how all Androids work, but I’ve never encountered one that didn’t behave this way.
I just know that when I flash anything Linux the offline charging indicator stops working
You most likely are flashing the bootloader, recovery, and OS all in one step. They can be combined into one image and all flashed at once. I doubt the Android bootloader would be able to boot Linux, but tbh, that’s not my area of expertise, so I could be wrong.
I know how it is. Used to work on phone chipsets. That being said, I have no idea how pixel 8 is doing this, but likely the Bluetooth chipset has a mode it can go into to behave like AirTags and just pulse out a BTLE beacon occasionally with both the main OS and sub-OSes turned off and power just being trickled to VCC on the BT chip.
Edit: apologies, didn’t mean to sound so curt. Tl;dr: I know how bootloaders run to allow battery charge while off, not sure how pixel 8 is doing their magic-to-be but have a good theory.