I'm not sure whether you meant that you still want to see the patch before I commit it. I've added a few more things to the list anyway.

• When using autotools, be explicit about which features you do and do not want. If you don't specify, autotools will enable features based on which headers/libraries it detects, even if you didn't ask for them. Conversely, if you do request a feature and it doesn't find the needed headers/libraries then it will usually abort with an error, which is better than just continuing the build anyway.


• Put -I include options in CPPFLAGS, not CFLAGS or CXXFLAGS, unless the Makefile doesn't use CPPFLAGS. Almost all autotools-based packages use CPPFLAGS. This will fix these warnings, which you have no doubt seen.
  
  configure: WARNING: foo.h: accepted by the compiler, rejected by the preprocessor!
  configure: WARNING: foo.h: proceeding with the compiler's result


• When using autotools, set CPPFLAGS CFLAGS, CXXFLAGS, and LDFLAGS when running configure, not when running make, and certainly not both. The flags are saved so it doesn't matter if you run make in a fresh environment.

Before:

OPTIMIZE="-O4" ASTCFLAGS="$(ASTERISK_CFLAGS)" ASTLDFLAGS="$(ASTERISK_LDFLAGS)" $(MAKE1) -C $(ASTERISK_DIR) NOISY_BUILD=1 GNU_LD=0



After:

OPTIMIZE="-O4" ASTCFLAGS="$(ASTERISK_CPPFLAGS)" $(MAKE1) -C $(ASTERISK_DIR) NOISY_BUILD=1 GNU_LD=0

Although the points I've mentioned affect almost every package, I've only applied the __BLACKFIN__ and -mfdpic changes across the board so far. The rest have only been applied to Asterisk because it is arguably the most important package. I'll continue my clean up in the near future, along with the raft of other improvements I have planned.

Dimitar, here is the patch. Please let me know if it's good to go.

What I'd actually like to do in the long run is globally define CPPFLAGS and LDFLAGS so that the uClinux-dist paths are always present. It makes sense since these are required by nearly every single package and most (if not all?) of these packages don't need anything else to be added to these variables.

All these changes draw on my years of experience as a Gentoo user, where almost all the packages are built from source in a tightly controlled yet flexible manner. It does make a very good base for other distros (it's the base for Chrome OS!) so I keep having to put off the temptation to start a new embedded VoIP distro with it. I like Switchfin's minimalism though. Stripping Gentoo down to that level would probably be more work.