So, have you ever seen the Solaris 10 boot process, line by line?
I do not talk about the kernel -m verbose mode, which only shows the particular SMF identifiers.
Have you ever wondered why the boot process has hanged? and what's the cause?

The Wisnios way is as follow.
I've decided to replace the master restarter binary with a shell script.

# mv /lib/svc/bin/svc.startd /lib/svc/bin/svc.startdd
# vi /lib/svc/bin/svc.startd

truss -fa -t exec /lib/svc/bin/svc.startdd

# chmod 555 /lib/svc/bin/svc.startd
# chgrp sys /lib/svc/bin/svc.startd

You could also choose the more verbose mode by adding the -e switch to truss command.
Truss -f option follows all fork/vfork children, -a shows the argument strings within the exec() calls and -e shows the environment variables (for ex. SMF_FMRI).

Other traces are limited by imagination only.