Squashed commit of the following:

Merged in masayuki2009/nuttx.apps/loadable_app (pull request #148)

    loadable app support

    * apps: Introduce a build system for loadable apps for nsh.

        This PR consits of following changes. (NOTE: Changes to each
        application will be provided separately)

        apps/nshlib/Kconfig:
        Add 'option modules' to NSH_FILE_APPS so that a user can change
        an application configuration to tristate (y/n/m)

        apps/Make.defs:
        Override COMPILE and COMPILEXX macros to compile loadable apps.
        To make loadable apps, -DLOADABLE_APP is added to the flags.
        Also, introduce ELFLD to link a lodable app.
        Please note that the variable 'LOADABLE' must be defined in
        each application Makefile if you want to make a loadable app.

        apps/Application.mk:
        Add .build target in case of 'LOADABLE=y' which is used to
        link a final loadable application and install the app to
        apps/bin.

        apps/Makefile:
        Add SYMTABSRC and SYMTABOBJ variables for loadable apps which
        will be generated under the apps directory.
        Add make_symbols target which will be called when all applications
        are installed to generate symtab_app.c which is used for
        nsh to inform symbol information to the NuttX kernel.

        Signed-off-by: Masayuki Ishikawa <Masayuki.Ishikawa@jp.sony.com>

    * apps/examples/hello: Apply changes to support a lodable app.

        Kconfig:
        Change the application state from bool to tristate

        Make.defs:
        Change the condition to build. By default, the application is
        not selected (i.e. 'n'), so if other states (i.e. y/m) are
        selected, the application will be compiled.

        Makefile:
        If the application is specified to 'm', the variable 'LOADABLE'
        must be defined here. Also note that other variables (PRIORITY
        and STACKSIZE) can only be used for built-in apps.

        hello_main.c
        Add LOADABLE_APP condition to main().

        Signed-off-by: Masayuki Ishikawa <Masayuki.Ishikawa@jp.sony.com>

    * apps/examples/helloxx: Apply changes to support a lodable app.

        Kconfig:
        Change the application state from bool to tristate

        Make.defs:
        Change the condition to build. By default, the application is
        not selected (i.e. 'n'), so if other states (i.e. y/m) are
        selected, the application will be compiled.

        Makefile:
        If the application is specified to 'm', the variable 'LOADABLE'
        must be defined here. Also note that other variables (PRIORITY
        and STACKSIZE) can only be used for built-in apps.

        helloxx_main.c
        Add LOADABLE_APP condition to main().

        Signed-off-by: Masayuki Ishikawa <Masayuki.Ishikawa@jp.sony.com>

    Approved-by: GregoryN <gnutt@nuttx.org>

Application.mk

@@ -89,9 +89,16 @@ $(MAINOBJ): %$(OBJEXT): %.c
 	$(call COMPILE, $<, $@)
 endif
 
+ifeq ($(LOADABLE),y)
+.built: $(OBJS)
+	$(call ELFLD, $(APPNAME)_main, $(OBJS), $(APPNAME))
+	$(Q) mkdir -p $(BIN_DIR)
+	$(Q) install $(APPNAME) $(BIN_DIR)$(DELIM)$(APPNAME)
+else
 .built: $(OBJS)
 	$(call ARCHIVE, $(BIN), $(OBJS))
 	$(Q) touch $@
+endif
 
 ifeq ($(CONFIG_BUILD_KERNEL),y)
 $(BIN_DIR)$(DELIM)$(PROGNAME): $(OBJS) $(MAINOBJ)

Make.defs

@@ -56,6 +56,33 @@ define REGISTER
 endef
 endif
 
+# COMPILE - a macro to compile a loadable app in C
+
+ifeq ($(LOADABLE),y)
+define COMPILE
+	@echo "CC) $1"
+	$(Q) $(CC) -c $(CELFFLAGS) -DLOADABLE_APP $1 -o $2
+endef
+endif
+
+# COMPILEXX - a macro to compile a loadable app in C++
+
+ifeq ($(LOADABLE),y)
+define COMPILEXX
+	@echo "CXX: $1"
+	$(Q) $(CXX) -c $(CXXELFFLAGS) -DLOADABLE_APP $1 -o $2
+endef
+endif
+
+# ELFLD - a macro to link loadable app
+# Example: $(call ELFLD, entry point, in-file(s), out-file)
+
+define ELFLD
+	@echo "LD: $3"
+	$(Q) $(LD) $(LDELFFLAGS) $2 -o $3
+	$(Q) chmod +x $3
+endef
+
 # Tools
 #
 # In a normal build, tools will reside in the nuttx/tools sub-directory and

Makefile

@@ -73,6 +73,11 @@ BIN_DIR = $(APPDIR)$(DELIM)bin
 
 BIN = libapps$(LIBEXT)
 
+# Symbol table for loadable apps.
+
+SYMTABSRC = $(APPDIR)$(DELIM)symtab_apps.c
+SYMTABOBJ = $(APPDIR)$(DELIM)symtab_apps.o
+
 # Build targets
 
 all: $(BIN)
@@ -97,7 +102,15 @@ $(foreach SDIR, $(CONFIGURED_APPS), $(eval $(call SDIR_template,$(SDIR),depend))
 $(foreach SDIR, $(CLEANDIRS), $(eval $(call SDIR_template,$(SDIR),clean)))
 $(foreach SDIR, $(CLEANDIRS), $(eval $(call SDIR_template,$(SDIR),distclean)))
 
-$(BIN): $(foreach SDIR, $(CONFIGURED_APPS), $(SDIR)_all)
+make_symbols:
+ifeq ($(CONFIG_EXAMPLES_NSH_SYMTAB),y)
+	mkdir -p $(BIN_DIR)
+	$(Q) $(APPDIR)$(DELIM)tools$(DELIM)mksymtab.sh $(BIN_DIR) $(SYMTABSRC)
+	$(call COMPILE, $(SYMTABSRC), $(SYMTABOBJ))
+	$(call ARCHIVE, $(APPDIR)$(DELIM)$(BIN), $(SYMTABOBJ))
+endif
+
+$(BIN): $(foreach SDIR, $(CONFIGURED_APPS), $(SDIR)_all) make_symbols
 
 .install: $(foreach SDIR, $(CONFIGURED_APPS), $(SDIR)_install)
 
@@ -143,6 +156,7 @@ clean_context:
 	$(Q) $(MAKE) -C platform clean_context TOPDIR="$(TOPDIR)" APPDIR="$(APPDIR)"
 
 clean: $(foreach SDIR, $(CLEANDIRS), $(SDIR)_clean)
+	$(call DELFILE, $(SYMTABSRC))
 	$(call DELFILE, $(BIN))
 	$(call DELFILE, Kconfig)
 	$(call DELDIR, $(BIN_DIR))
@@ -164,6 +178,7 @@ else
 	)
 endif
 	$(call DELFILE, .depend)
+	$(call DELFILE, $(SYMTABSRC))
 	$(call DELFILE, $(BIN))
 	$(call DELFILE, Kconfig)
 	$(call DELDIR, $(BIN_DIR))

examples/hello/Kconfig

@@ -4,7 +4,7 @@
 #
 
 config EXAMPLES_HELLO
-	bool "\"Hello, World!\" example"
+	tristate "\"Hello, World!\" example"
 	default n
 	---help---
 		Enable the \"Hello, World!\" example

examples/hello/Make.defs

@@ -34,6 +34,6 @@
 #
 ############################################################################
 
-ifeq ($(CONFIG_EXAMPLES_HELLO),y)
+ifneq ($(CONFIG_EXAMPLES_HELLO),)
 CONFIGURED_APPS += examples/hello
 endif

examples/hello/Makefile

@@ -41,8 +41,13 @@ CONFIG_EXAMPLES_HELLO_PRIORITY ?= SCHED_PRIORITY_DEFAULT
 CONFIG_EXAMPLES_HELLO_STACKSIZE ?= 2048
 
 APPNAME = hello
-PRIORITY = $(CONFIG_EXAMPLES_HELLO_PRIORITY)
+
+ifeq ($(CONFIG_EXAMPLES_HELLO),m)
+LOADABLE  = y
+else
+PRIORITY  = $(CONFIG_EXAMPLES_HELLO_PRIORITY)
 STACKSIZE = $(CONFIG_EXAMPLES_HELLO_STACKSIZE)
+endif
 
 # Hello, World! Example
 

examples/hello/hello_main.c

@@ -48,7 +48,7 @@
  * hello_main
  ****************************************************************************/
 
-#ifdef CONFIG_BUILD_KERNEL
+#if defined (CONFIG_BUILD_KERNEL) || defined (LOADABLE_APP)
 int main(int argc, FAR char *argv[])
 #else
 int hello_main(int argc, char *argv[])

examples/helloxx/Kconfig

@@ -4,7 +4,7 @@
 #
 
 config EXAMPLES_HELLOXX
-	bool "\"Hello, World!\" C++ example"
+	tristate "\"Hello, World!\" C++ example"
 	default n
 	depends on HAVE_CXX
 	---help---

examples/helloxx/Make.defs

@@ -34,6 +34,6 @@
 #
 ############################################################################
 
-ifeq ($(CONFIG_EXAMPLES_HELLOXX),y)
+ifneq ($(CONFIG_EXAMPLES_HELLOXX),)
 CONFIGURED_APPS += examples/helloxx
 endif

examples/helloxx/Makefile

@@ -48,7 +48,12 @@ PROGNAME = $(CONFIG_EXAMPLES_HELLOXX_PROGNAME)
 # helloxx built-in application info
 
 APPNAME = helloxx
+
+ifeq ($(CONFIG_EXAMPLES_HELLOXX),m)
+LOADABLE  = y
+else
 PRIORITY = SCHED_PRIORITY_DEFAULT
 STACKSIZE = 2048
+endif
 
 include $(APPDIR)/Application.mk

examples/helloxx/helloxx_main.cxx

@@ -127,7 +127,7 @@ static CHelloWorld g_HelloWorld;
 
 extern "C"
 {
-#ifdef CONFIG_BUILD_KERNEL
+#if defined (CONFIG_BUILD_KERNEL) || defined (LOADABLE_APP)
   int main(int argc, FAR char *argv[])
 #else
   int helloxx_main(int argc, char *argv[])

nshlib/Kconfig

@@ -182,6 +182,7 @@ config NSH_BUILTIN_APPS
 
 config NSH_FILE_APPS
 	bool "Enable execution of program files"
+	option modules
 	default n
 	depends on LIBC_EXECFUNCS
 	---help---