[PATCH 1/4] build: fix that defaultenv is always rebuilt

[Sam Ravnborg]

>From fcffd0176b3394cc664d9bf5b31b053253323bfb Mon Sep 17 00:00:00 2001
From: Sam Ravnborg <sam at ravnborg.org>
Date: Tue, 26 Dec 2017 16:47:16 +0100
Subject: [PATCH 1/4] build: fix that defaultenv is always rebuilt

Using following pattern:

	target: prerequisite FORCE
		$(call cmd,foo)

is almost always wrong. Due to FORCE target will be rebuilt
using cmd_foo no mater the timestamps.

The following pattern:

	target: prerequisite FORCE
        	$(call if_changed,foo)

Will call cmd_foo only if:
- target is not updated
- or command to built target has changed

But to make this work target must be added to the
list af targets built.
This can be done by assigning target to extra-y or targets.

Use the latter pattern for defaultenv to avoid rebuilding
the environmentt for each build.

Signed-off-by: Sam Ravnborg <sam at ravnborg.org>
---
 defaultenv/Makefile | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/defaultenv/Makefile b/defaultenv/Makefile
index 33e0eceef..f313b04e8 100644
--- a/defaultenv/Makefile
+++ b/defaultenv/Makefile
@@ -14,7 +14,7 @@ quiet_cmd_env_default = ENV     $@
 cmd_env_default = ($(srctree)/scripts/genenv $(srctree) $(objtree) $@ $(CONFIG_DEFAULT_ENVIRONMENT_PATH))
 
 $(obj)/barebox_default_env: FORCE
-	$(call cmd,env_default)
+	$(call if_changed,env_default)
 
 quiet_cmd_env_h = ENVH    $@
 cmd_env_h = cat $< | (cd $(obj) && $(objtree)/scripts/bin2c "__aligned(4) default_environment") > $@; \
@@ -27,4 +27,4 @@ quiet_cmd_env_zero = ENVZ    $@
 cmd_env_zero = ($(objtree)/scripts/bareboxenv -z $(CONFIG_DEFAULT_ENVIRONMENT_PATH) $@)
 
 $(obj)/barebox_zero_env: FORCE
-	$(call cmd,env_zero)
+	$(call if_changed,env_zero)
-- 
2.12.0