for forking the traditional UNIX init(8) and it does the Mach port naming
service. We need mach_init for the naming service, but unfortunately, it
will only act as such if its PID is 1. We introduce a sysctl
(emul.darwin.init_pid) to fool a given process into thinking its PID is 1.
That way we can get mach_init into behaving as the name server.
Typical use:
/sbin/sysctl -w emul.darwin.init_pid=$$ ; exec /emul/darwin/sbin/mach_init
two ways:
- the child gets its pid as retval[0] (userland stub will turn it into a 0),
retval[1] is 1 and it is 0 in the parent.
- in the child, the fork syscall is successful, hence we must skip the next
instruction.
compat/common, so that they can be shared by several emulations, and use
them for Darwin.
This removes the ugly dependance on FreeBSD freebsd_file.c for COMPAT_DARWIN