The Linux system calls used by cosmopolitan work fine on Android provided they aren't blocked by seccomp policy. Some of those blocks make sense, others not so much. Yesterday I discovered I could use all the stat variants but not statx.

I believe the features provided by standard C libraries are well covered by the set of allowed system calls.

Android is kind of a special child, it uses custom kernel modules like Binder (IPC framework) and Ashmem (Android's garbage collector/memory manager).