[Buildroot] [PATCH v2] Add target to create a project directory

[Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>]

Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
---
v2: Removed accidental changes to busybox.config and uClibc.config
---
 Makefile              |   30 ++++++++++++++++++++++++++++++
 Makefile.project.tmpl |   40 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 70 insertions(+)
 create mode 100644 Makefile.project.tmpl

diff --git a/Makefile b/Makefile
index 0e5b28e..a3b88f7 100644
--- a/Makefile
+++ b/Makefile
@@ -698,6 +698,33 @@ endif
 
 cross: $(BASE_TARGETS)
 
+ifneq ($(PROJECT_DIR),)
+ifeq ($(findstring -git,$(BR2_VERSION)),)
+BUILDROOT_VERSION = $(BR2_VERSION)
+else
+BUILDROOT_VERSION = snapshot
+endif
+
+# Write a buildroot config in the project dir, then use that defconfig to
+# re-generate the .config.  This replaces the config file paths with paths
+# pointing into PROJECT_DIR (unless they have been changed from their
+# default values).  The subsequent update-all-config writes all the config
+# files into the PROJECT_DIR.  That last step doesn't need to set PROJECT_DIR
+# or DEFCONFIG anymore, because they're already set in the new .config.
+projectdir:
+	mkdir -p $(PROJECT_DIR)
+	sed s/@BUILDROOT_VERSION@/$(BUILDROOT_VERSION)/g \
+		Makefile.project.tmpl > $(PROJECT_DIR)/Makefile
+	$(MAKE1) $(EXTRAMAKEARGS) \
+		DEFCONFIG=$(PROJECT_DIR)/buildroot.config \
+		savedefconfig
+	$(MAKE1) $(EXTRAMAKEARGS) \
+		PROJECT_DIR=$(PROJECT_DIR) \
+		DEFCONFIG=$(PROJECT_DIR)/buildroot.config \
+		defconfig
+	$(MAKE1) $(EXTRAMAKEARGS) update-all-config
+endif
+
 help:
 	@echo 'Cleaning:'
 	@echo '  clean                  - delete all files created by build'
@@ -756,6 +783,9 @@ endif
 	@echo '  source-check           - check selected packages for valid download URLs'
 	@echo '  external-deps          - list external packages used'
 	@echo '  legal-info             - generate info about license compliance'
+ifneq ($(PROJECT_DIR),)
+	@echo '  projectdir             - Prepare project directory with a Makefile.'
+endif
 	@echo
 	@echo '  make V=0|1             - 0 => quiet build (default), 1 => verbose build'
 	@echo '  make O=dir             - Locate all output files in "dir", including .config'
diff --git a/Makefile.project.tmpl b/Makefile.project.tmpl
new file mode 100644
index 0000000..b41180a
--- /dev/null
+++ b/Makefile.project.tmpl
@@ -0,0 +1,40 @@
+# This Makefile creates a build environment using the directory containing
+# this Makefile as the project directory.
+# If called from a different directory using 'make -f ...', the current
+# directory is used as the output directory.
+
+lastword = $(word $(words $(1)),$(1))
+makedir  = $(dir $(call lastword,$(MAKEFILE_LIST)))
+
+BR2_PROJECT_DIR = $(realpath $(makedir))
+BUILDROOT_DIR   = $(BR2_PROJECT_DIR)/buildroot
+BUILDROOT_VERSION = @BUILDROOT_VERSION@
+BUILDROOT_SITE    = http://buildroot.net/downloads
+BUILDROOT_SOURCE  = buildroot-$(BUILDROOT_VERSION).tar.bz2
+
+ifeq ($(O),)
+ifeq ($(makedir),./)
+# Building in project dir => create output dir
+O = $(CURDIR)/output
+else
+# Building from some other dir => use this dir as output dir
+O = $(CURDIR)
+endif
+endif
+
+.PHONY: all $(MAKECMDGOALS)
+
+all: $(BUILDROOT_DIR)
+	@$(MAKE) -C buildroot O=$(O) BR2_PROJECT_DIR=$(BR2_PROJECT_DIR) $(all)
+
+all     := $(filter-out all,$(MAKECMDGOALS))
+$(all): all
+        @:
+
+$(BUILDROOT_DIR):
+	mkdir -p $@
+	wget -O - $(BUILDROOT_SITE)/$(BUILDROOT_SOURCE) | \
+		tar -xjf - -C $@ --strip-components=1
+	for p in `ls $(makedir)/patches/buildroot/buildroot-* 2>/dev/null`; do \
+		patch -d $@ -p1 -i $$p; \
+	done