environment generation: Fix dependencies

The dependencies for generating the environment do not work properly:

- If files are removed from the defaultenv, a subsequent make will not
  update the default environment.
- If CONFIG_DEFAULT_ENVIRONMENT_PATH changes, the default environment
  also will not be regenerated.

This patch fixes this by introducing a cmd_env which has the content of
$(ENV_FILES) in the command so that the if_changed mechanism recognizes
a change when $(ENV_FILE) changes. This also results in a nice "  ENV "
string in the build process.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

3 files changed, 32 insertions, 15 deletions

diff --git a/Makefile b/Makefile
index c6264d3404..4e50c9f766 100644
--- a/Makefile
+++ b/Makefile
@@ -1007,7 +1007,7 @@ endif # CONFIG_MODULES
 CLEAN_DIRS  += $(MODVERDIR)
 CLEAN_FILES +=	barebox System.map include/generated/barebox_default_env.h \
                 .tmp_version .tmp_barebox* barebox.bin barebox.map barebox.S \
-		.tmp_kallsyms* barebox_default_env* barebox.ldr \
+		.tmp_kallsyms* common/barebox_default_env* barebox.ldr \
 		scripts/bareboxenv-target barebox-flash-image \
 		Doxyfile.version barebox.srec barebox.s5p
 
diff --git a/common/Makefile b/common/Makefile
index 88580a235d..c091b7350c 100644
--- a/common/Makefile
+++ b/common/Makefile
@@ -38,6 +38,7 @@ obj-$(CONFIG_PASSWORD) += password.o
 obj-$(CONFIG_MODULES) += module.o
 obj-$(CONFIG_FLEXIBLE_BOOTARGS) += bootargs.o
 extra-$(CONFIG_MODULES) += module.lds
+extra-y += barebox_default_env
 
 ifdef CONFIG_DEFAULT_ENVIRONMENT
 $(obj)/startup.o: include/generated/barebox_default_env.h
@@ -62,8 +63,19 @@ ENV_FILES := $(shell cd $(srctree); for i in $(DEFAULT_ENVIRONMENT_PATH); do fin
 
 endif # ifdef CONFIG_DEFAULT_ENVIRONMENT
 
-barebox_default_env: $(ENV_FILES)
-	$(Q)$(srctree)/scripts/genenv $(srctree) $(objtree) $(DEFAULT_ENVIRONMENT_PATH)
+#
+# Generate a barebox envfs image.
+#
+# echo $(ENV_FILES) > /dev/null is just for letting if_changed
+# recognize that something has changed when the environment has
+# other files,
+#
+quiet_cmd_env = ENV     $@
+cmd_env = ($(srctree)/scripts/genenv $(srctree) $(objtree) $@ $(DEFAULT_ENVIRONMENT_PATH)) || \
+	(echo $(ENV_FILES) > /dev/null; rm -f $@ ; false)
+
+$(obj)/barebox_default_env: $(ENV_FILES) FORCE
+	$(call if_changed,env)
 
 barebox_default_env_comp =
 ifeq ($(CONFIG_DEFAULT_ENVIRONMENT_COMPRESSED_GZIP),y)
@@ -76,18 +88,18 @@ ifeq ($(CONFIG_DEFAULT_ENVIRONMENT_COMPRESSED_LZO),y)
 barebox_default_env_comp = .lzo
 endif
 
-barebox_default_env.gz: barebox_default_env
+$(obj)/barebox_default_env.gz: $(obj)/barebox_default_env
 	$(call if_changed,gzip)
 
-barebox_default_env.bz2: barebox_default_env
+$(obj)/barebox_default_env.bz2: $(obj)/barebox_default_env
 	$(call if_changed,bzip2)
 
-barebox_default_env.lzo: barebox_default_env
+$(obj)/barebox_default_env.lzo: $(obj)/barebox_default_env
 	$(call if_changed,lzo)
 
-include/generated/barebox_default_env.h: barebox_default_env$(barebox_default_env_comp)
-	$(Q)cat $< | $(objtree)/scripts/bin2c default_environment > $@
-	$(Q)echo "const int default_environment_uncompress_size=`stat -c%s barebox_default_env`;" >> $@
+include/generated/barebox_default_env.h: $(obj)/barebox_default_env$(barebox_default_env_comp)
+	$(Q)cat $< | (cd $(obj) && $(objtree)/scripts/bin2c default_environment) > $@
+	$(Q)echo "const int default_environment_uncompress_size=`stat -c%s $(obj)/barebox_default_env`;" >> $@
 
 # dependencies on generated files need to be listed explicitly
 $(obj)/version.o: include/generated/compile.h
diff --git a/scripts/genenv b/scripts/genenv
index c84af0c015..834ea594dd 100755
--- a/scripts/genenv
+++ b/scripts/genenv
@@ -1,22 +1,27 @@
 #!/bin/bash
 
 # Generate the default environment file from a list of directories
-# usage: genenv <basedir> <objdir> <dir>...
+# usage: genenv <basedir> <objdir> <target> <dir>...
 # where <basedir> is the base directory for relative pathes in <dir>
 # where <objdir> is the base directory for relative pathes for result
+# and <target> is the resulting binary environment
 objtree=$2
-cd $1 || exit 1
-shift 2
+basedir=$1
+target=$3
+shift 3
 
-tempdir=$(mktemp -d tmp.XXXXXX)
+tempdir="$objtree/.barebox_default_env"
 
+mkdir -p "$tempdir"
+
+(cd $basedir
 for i in $*; do
 	cp -r $i/* $tempdir
 done
+)
 
 find $tempdir -name '.svn' -o -name '*~' | xargs --no-run-if-empty rm -r
 
-$objtree/scripts/bareboxenv -s $tempdir $objtree/barebox_default_env
+$objtree/scripts/bareboxenv -s $tempdir $target
 
 rm -r $tempdir
-