Can anyone recommend a good framework or analysis of the barriers to open-source, general-purpose computing on mobile devices? I have read with interest the var

Can anyone recommend a good framework or analysis of the barriers to open-source, general-purpose computing on mobile devices? I have read with interest the various open-source mobile operating systems posted to HN, but don't feel like I have a good sense of the landscape. Switching to open source feels urgent (mobile has become so important and so privacy-invasive), but it also feels like this is a steep uphill battle; that mobile has been culturally positioned as not-for-open-source. I'd love to see this problem analyzed in terms of layers. My sense is that one barrier is walled-garden apps. I'm happy to give these up. But I also have the sense that there are hard barriers involving firmware (especially cellular modems?), identity (SIM cards are designed to contain secrets you can't access), and connectivity (you can't decouple a phone number from its client as easily as you can with an IP address).