[Buildroot] [PATCH v2 1/1] Makefile: add target to clean targetfs

Emeric Vigier emeric.vigier at savoirfairelinux.com
Tue Mar 10 19:28:08 UTC 2015

If you had some files added to the targetfs (fs-overlay, new packages,
...) and you no longer need them, buildroot does not offer a simple way
to remove these items from the output/target directory. The rule added
by this commit allows you to clean the targetfs. Issuing 'make'
afterward will generate a new and clean targetfs.

A section in the documentation is also added. It describes few examples
when developers could need it. 'make help' is also updated accordingly.

Signed-off-by: Emeric Vigier <emeric.vigier at savoirfairelinux.com>
Changes v1 -> v2
  - remove non-existent .built and deprecated .stamp_installed
    references (suggested by Baruch Siach)
  - mention the new target in 'make help'
 Makefile                                |  5 +++++
 docs/manual/advanced.txt                |  2 ++
 docs/manual/clean-target-filesystem.txt | 37 +++++++++++++++++++++++++++++++++
 3 files changed, 44 insertions(+)
 create mode 100644 docs/manual/clean-target-filesystem.txt

diff --git a/Makefile b/Makefile
index af043a3..45ad2aa 100644
--- a/Makefile
+++ b/Makefile
@@ -679,6 +679,10 @@ graph-depends: graph-depends-requirements
 	|tee $(BASE_DIR)/graphs/$(@).dot \
 	|dot $(BR2_GRAPH_DOT_OPTS) -T$(BR_GRAPH_OUT) -o $(BASE_DIR)/graphs/$(@).$(BR_GRAPH_OUT)
+	rm -rf $(TARGET_DIR) $(STAGING_DIR) $(BUILD_DIR)/.root \
+		$(BUILD_DIR)/*/.stamp_target_installed $(BUILD_DIR)/*/.stamp_staging_installed
 else # ifeq ($(BR2_HAVE_DOT_CONFIG),y)
 all: menuconfig
@@ -849,6 +853,7 @@ help:
 	@echo 'Cleaning:'
 	@echo '  clean                  - delete all files created by build'
 	@echo '  distclean              - delete all non-source files (including .config)'
+	@echo '  clean-target           - delete targetfs, issuing make again will recreate it'
 	@echo 'Build:'
 	@echo '  all                    - make world'
diff --git a/docs/manual/advanced.txt b/docs/manual/advanced.txt
index b7bfc49..1cf0427 100644
--- a/docs/manual/advanced.txt
+++ b/docs/manual/advanced.txt
@@ -14,3 +14,5 @@ include::download-location.txt[]
diff --git a/docs/manual/clean-target-filesystem.txt b/docs/manual/clean-target-filesystem.txt
new file mode 100644
index 0000000..0274474
--- /dev/null
+++ b/docs/manual/clean-target-filesystem.txt
@@ -0,0 +1,37 @@
+// -*- mode:doc; -*-
+// vim: set syntax=asciidoc:
+==== Clean target filesystem
+There are various cases where you would like to clean the target
+filesystem. Especially once you understood that buildroot build system
+is kept simple, and does not allow to uninstall files. Let's take some
+1. You enabled +PACKAGE_OPENSSH+ to have a SSH server running on your
+   board. But you figure out that +sshd+ does not run well on your
+   target's architecture. Thus you decide to disable +PACKAGE_OPENSSH+
+   and enable +PACKAGE_DROPBEAR+ instead. You run +make+, +openssh+
+   gets built and installed. Problem: +openssh+ files are still present
+   in +output/target+!
+2. You enabled +PACKAGE_NTPD+ and set the local timezone to
+   +America/Montreal+ with +BR2_TARGET_LOCALTIME+ config. Then you find
+   out that +Montreal+ local has been replaced by +Toronto+ (French
+   looks like a rogue language). You enter +make menuconfig+, make the
+   change, save, and run +make+ again. Problem:
+   +output/target/etc/timezone+ still has +America/Montreal+ content!
+Solution to this is either to identify which package to reconfigure, or
+remove files manually, or destroy the target filesystem and recreate it.
+This latter option is convenient: you don't have to care about which
+packages to rebuild, and it is fast. Here is how to recreate your
+target filesystem, and get rid of filesystem _stains_:
+make clean-target
++clean-target+ removes +output/target+, tells buildroot to recreate the
+target skeleton, and install each package again.

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