> 1) Is the shutdown hook facility something recent? If so, who is the
>    author of it? What is the reason for the mysterious variable
>    shutdownhooks_done in doshutdownhooks that isn't set anywhere in
>    the kernel?

It was added by cgd in May 1995 and evidently only enabled in the
alpha port because that's probably all Chris needed it for.

I added the doshutdownhooks() call to arch/i386/i386/machdep.c in
August 1995, so it's my fault that it's called incorrectly there.  (It
works fine under normal circumstances, but I should have compared it
to the alpha code more carefully and/or paid more attention.)

> 2) Shouldn't doshutdownhooks() be in boot() in every port, and not
>    just in two of them?

> 3) Should boot() be made machine and port independent, with the only
>    port specificity being a call to a routine that would either call
>    a machine independent "please hit any key to reboot" and loop
>    call, or a machine halt instruction?

Probably (3).