For now these are just placeholders that execute the syscall.  We will
later optimize them to avoid kernel crossings, but we'd like to have the
VDSO entries from the first released kernel version to make the ABI
simpler.
Signed-off-by: NAndrew Waterman <andrew@sifive.com>
Signed-off-by: NPalmer Dabbelt <palmer@sifive.com>

This patch contains code that is in some way visible to the user:
including via system calls, the VDSO, module loading and signal
handling.  It also contains some generic code that is ABI visible.
Signed-off-by: NPalmer Dabbelt <palmer@dabbelt.com>

This contains the various __init C functions, the initial assembly
kernel entry point, and the code to reset the system.  When a file was
init-related this patch contains the entire file.
Signed-off-by: NPalmer Dabbelt <palmer@dabbelt.com>