What? Could you actually respond to my point rather than just make nonsensical posts? And aren't you the one who's been making post after post saying that the switch to 64-bit has nothing to do with addressing more memory?
It doesn't need to be. Google Play Services will update automatically OTA on anything running 2.2 or later, and the majority of new APIs are available in the support library. Google's apps have been decoupled from the OS, so they're updated independently. Kinda frustrating how we have to keep repeating this on here. The OS version number is a lot less important than it used to be.
Nor does it need to. That's the benefit of their VM-based approach - it isolates app developers from the underlying hardware, so OEMs can choose the best processor for a particular device. Dalvik already runs on 32-bit ARM, x86, and MIPS. While some future devices will benefit from 64-bit CPUs, there's no need for every device to be 64-bit.
I'm not sure Dalvik needs to be 64-bit. Android uses a separate Dalvik VM instance for each app, and it's unlikely an individual app will need more than 4 GB of memory. For x86, I'd think Google would use the new x32 ABI. That has the architectural improvements of x64 (more registers, faster syscalls, faster dynamic linking, etc), without the pointer bloat. As for ARM, I agree -- drivers will be stumbling block.
That's just wrong. Android compiles and runs on multiple ARM platforms (ARM11, ARMv7, ARMv8), x86, and MIPS. Intel is actively working on x32 and x64. For example, here are two patches from Intel for multi-arch support:x86_64/x32: Add arch/bionic and arch/include/machine Extend x86 to have different arch variantsThese were picked just by looking at today's AOSP Gerrit front page. Further, APK files support multiple architectures. The installer extracts the appropriate...
You missed the part of my post where I said that APKs already support multiple architectures. You only need multi-APK if you run into a size limit. The new Gradle build system in Android Studio makes supporting multi-APKs easier.
Android already has fat binary support; the APK format allows multiple architectures. If you run into the APK size limits, you can use the multiple-APK support Google rolled out last year. But this shouldn't be an issue for most apps which use Dalvik because it's platform-independent
The Linux kernel has run on multiple 64-bit architectures for years, since the 2.6 days at least. Of course, there will be some work involved in porting to ARMv8, but Linaro has already started on that. The first bit of support was merged into Linux 3.7 almost a year ago. Many of the low-level user-space libraries on Android are shared with common Linux distributions and already support 64-bit. I suspect the only real sticking points would be bionic (Android's libc) and...