inittodr(9): introduce dedicated flag to enable writes from resettodr(9)

We don't want resettodr(9) to write the RTC until inittodr(9) has
actually run.  Until inittodr(9) calls tc_setclock() the system UTC
clock will contain a meaningless value and there's no sense in
overwriting a good value with a value we know is nonsense.

This is not an uncommon problem if you're debugging a problem in early
boot, e.g. a panic that occurs prior to inittodr(9).

Currently we use the following logic in resettodr(9) to inhibit writes:

	if (time_second == 1)
		return;

... this is too magical.

A better way to accomplish the same thing is to introduce a dedicated
flag set from inittodr(9).  Hence, "inittodr_done".

Suggested by visa@.

ok kettenis@

0 files changed, 0 insertions, 0 deletions