makefile cleanup

Moved nuttx specific make rules to files in makefiles/nuttx.

All target specific makefiles are in their target sub directories.

To minimize file duplication, targets that share rules include a
common file. For example the posix and posix-arm targets both use
makefiles/posix/posix_elf.mk

Signed-off-by: Mark Charlebois <charlebm@gmail.com>

makefiles/nuttx/nuttx.mk

@@ -0,0 +1,85 @@
+#
+#   Copyright (C) 2012 PX4 Development Team. All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+#
+# 1. Redistributions of source code must retain the above copyright
+#    notice, this list of conditions and the following disclaimer.
+# 2. Redistributions in binary form must reproduce the above copyright
+#    notice, this list of conditions and the following disclaimer in
+#    the documentation and/or other materials provided with the
+#    distribution.
+# 3. Neither the name PX4 nor the names of its contributors may be
+#    used to endorse or promote products derived from this software
+#    without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+# FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+# COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+# BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+# OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+# AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+# ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+# POSSIBILITY OF SUCH DAMAGE.
+#
+
+#
+# Rules and definitions related to handling the NuttX export archives when
+# building firmware.
+#
+
+MODULES += platforms/nuttx/px4_layer platforms/common
+
+#
+# Check that the NuttX archive for the selected board is available.
+#
+NUTTX_ARCHIVE		:= $(wildcard $(ARCHIVE_DIR)$(BOARD).export)
+ifeq ($(NUTTX_ARCHIVE),)
+$(error The NuttX export archive for $(BOARD) is missing from $(ARCHIVE_DIR) - try 'make archives' in $(PX4_BASE))
+endif
+
+#
+# The NuttX config header should always be present in the NuttX archive, and
+# if it changes, everything should be rebuilt. So, use it as the trigger to
+# unpack the NuttX archive.
+#
+NUTTX_EXPORT_DIR	 = $(WORK_DIR)nuttx-export/
+NUTTX_CONFIG_HEADER	 = $(NUTTX_EXPORT_DIR)include/nuttx/config.h
+$(info %  NUTTX_EXPORT_DIR    = $(NUTTX_EXPORT_DIR))
+$(info %  NUTTX_CONFIG_HEADER = $(NUTTX_CONFIG_HEADER))
+
+
+GLOBAL_DEPS		+= $(NUTTX_CONFIG_HEADER)
+
+#
+# Use the linker script from the NuttX export
+#
+LDSCRIPT		+= $(NUTTX_EXPORT_DIR)build/ld.script
+
+#
+# Add directories from the NuttX export to the relevant search paths
+#
+INCLUDE_DIRS		+= $(NUTTX_EXPORT_DIR)include \
+			   $(NUTTX_EXPORT_DIR)include/cxx \
+			   $(NUTTX_EXPORT_DIR)arch/chip \
+			   $(NUTTX_EXPORT_DIR)arch/common
+
+LIB_DIRS		+= $(NUTTX_EXPORT_DIR)libs
+LIBS			+= -lapps -lnuttx
+NUTTX_LIBS		 = $(NUTTX_EXPORT_DIR)libs/libapps.a \
+			   $(NUTTX_EXPORT_DIR)libs/libnuttx.a
+LINK_DEPS		+= $(NUTTX_LIBS)
+
+$(NUTTX_CONFIG_HEADER):	$(NUTTX_ARCHIVE)
+	@$(ECHO) %% Unpacking $(NUTTX_ARCHIVE)
+	$(Q) $(UNZIP_CMD) -q -o -d $(WORK_DIR) $(NUTTX_ARCHIVE)
+	$(Q) $(TOUCH) $@
+
+ $(LDSCRIPT): $(NUTTX_CONFIG_HEADER)
+ $(NUTTX_LIBS): $(NUTTX_CONFIG_HEADER)