following build tools seem to be required to cross-compile
OpenJDK:
- fastjar
- classpath
- gcj
- jamvm
- ecj
Maybe cacao is better, maybe ant is required, too.
... hacking...
STAGING_TARGET_DIR is used for package Makefile's for
include and library search path's. STAGING_DIR is used
for common code in mk/ or Makefile/rules.mk.
STAGING_TARGET_DIR is /usr when native builds are used.