Best way to have a port...

[M. Warner Losh]

... that builds part of FreeBSD?

Let me back up...

I'm trying to create a port for gcc and binutils that is configured
for FreeBSD for a given machine.  FreeBSD mips, say.  binutils was
relatively easy (once I ported our mips support forward).  However,
gcc vexes me.  It requires, to build libgcc and friends, a fully
populated include tree.  And it wants to use
/usr/local/freebsd-mips/include instead of /usr/include (which is
good).  However, the former doesn't exist.  I'd like to create a port
for it, but I'm unclear how to even start.  This port should consist
of all files from make includes TARGET_ARCH=mips.

So, some questions: First, how do I know where the FreeBSD source tree
is?  Is there some standard define like SYSDIR that contains this
infomration?

Second, I need to invoke make includes (and a few other things), with
some slightly non-standard args.  is there a stylied way to do this?
I'd like to avoid extracting everything into myport/work/FreeBSD :)

Without solving these problems, the notion that we can use a ports
compiler to build FreeBSD becomes less viable...

Comments?

Warner