There was Dalvik VM at one point but now it’s just the Android Runtime.
Some folks like the termux rebels, occasionally find out there is a sherif in town.
> As documented in the Android N behavioral changes, to protect Android users and apps from unforeseen crashes, Android N will restrict which libraries your C/C++ code can link against at runtime. As a result, if your app uses any private symbols from platform libraries, you will need to update it to either use the public NDK APIs or to include its own copy of those libraries. Some libraries are public: the NDK exposes libandroid, libc, libcamera2ndk, libdl, libGLES, libjnigraphics, liblog, libm, libmediandk, libOpenMAXAL, libOpenSLES, libstdc++, libvulkan, and libz as part of the NDK API. Other libraries are private, and Android N only allows access to them for platform HALs, system daemons, and the like. If you aren’t sure whether your app uses private libraries, you can immediately check it for warnings on the N Developer Preview.
https://android-developers.googleblog.com/2016/06/improving-...
These stable APIs,
That said, newer Androids use seccomp to restrict which syscalls you can use, basically to what bionic exposes anyway. This doesn't seem to affect Termux and friends, which can apparently run full X11 applications without root.
(edit) Notably, splice() is still callable, so maybe the POC needs to be tweaked...
As for termux,
Someone can statically build a freestanding executable/so targetting arm64 linux (specifically the right android linux kernel version) and it will run fine on Android. The syscall interface, process model, file descriptors, signals, memory mapping, all of this is Linux, this is what people mean when they say Android is just Linux.
Also some obligatory Linux vs GNU/Linux comment. (and it's not like GNU/Linux doesn't ever change under your feet - see the glibc DT_HASH debacle)
Google relies on Linux LTS kernels. When the Linux LTS team dropped support from 6 years down to 2 years, Google stepped in to cover the 4-year gap.
It is Linux. It's basically a distro.
- Is totally Linux