| This hierarchy supports Linux systems using the new |
| asm-generic/unistd.h, which removes many familiar old syscalls. For |
| example, to implement open(), newer Linux architectures require glibc |
| to invoke the __NR_openat syscall with AT_FDCWD. This hierarchy |
| provides all those implementations. |
| |
| It also provides support for 32-bit platforms using the 64-bit kernel |
| syscall APIs, as the 32-bit ones are no longer provided. Note that |
| newer ILP32 environments (x32 or AArch64:ILP32, for example) are |
| converting to use more 64-bit types in kernel syscalls, so that aspect |
| of this support is in more flux as of this writing. |
