Hi Mark,
After all the refactoring work, I got around to re-working the init-program and go words and plugging the new unified ELF loader into the SPARC64 build.
And the result? As of SVN r730, I'm pleased to report that the Solaris kernel starts to execute on my Milax test ISO. After typing "go" to execute the loaded ELF image manually, I see a twirly baton rotating on the console for about 0.5s before the inevitable segfault. So it's a small step, but still a great milestone for the OpenBIOS project :D
Wow! Hats off! Congratulations!