Hello, im tried this firmware on R770 (S3 Classic), here is some feedback
Seems that Google Fit is not working , it means that HRM is not working at all.
Vibration is very low
Poor battery life when bluetooth is connected
In general performance is at high level, very smooth
In theory SM-R770 Classic will work too. They use same kernel and hardware.
Reply my comment pleaseAll Galaxy watches have combination firmware and kernel sources. If Samsung has not added some new security things to these watches, yes it can be ported. Just need to give it a try. Exynos 9110 shares the same GPU with 7270. So display part will be easier to work. I am not sure about 2G because LTE version of these watches are not selling in where I live. Also I do not have any Galaxy Watch.
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