kumquat-buildroot/fs/common.mk
Thomas Petazzoni 9226a9907c Warn the user about the usage of output/target as the root filesystem
A very common mistake done by our users is that they use
output/target/ directory as their root filesystem. Even though this is
loudly documented in our Buildroot manual, people don't read
documentation, so it is not sufficient.

This patch adds a text file named
output/target/THIS_IS_NOT_YOUR_ROOT_FILESYSTEM which explains why
output/target isn't appropriate to use as the root filesystem. The
process is:

 * At the beginning of the build, right after the skeleton has been
   copied, support/misc/target-dir-warning.txt is copied to
   output/target/THIS_IS_NOT_YOUR_ROOT_FILESYSTEM

 * In the filesystem images creation code, this file is removed before
   launching fakeroot, and restored right after that, so that this
   file is not present in the generated root filesystem images.

Note that the file has not been added to the default skeleton for two
reasons:

 * It would have annoying to have in our source tree a file named in
   capital letters inside system/skeleton/

 * The proposed way works even if the user uses a custom skeleton.

[Peter: fixed typo]
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Juha Lumme <juha.lumme@gmail.com>
Acked-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
2012-11-17 17:12:49 +01:00

89 lines
3.2 KiB
Makefile

#
# Macro that builds the needed Makefile target to create a root
# filesystem image.
#
# The following variable must be defined before calling this macro
#
# ROOTFS_$(FSTYPE)_CMD, the command that generates the root
# filesystem image. A single command is allowed. The filename of the
# filesystem image that it must generate is $$@.
#
# The following variables can optionaly be defined
#
# ROOTFS_$(FSTYPE)_DEPENDENCIES, the list of dependencies needed to
# build the root filesystem (usually host tools)
#
# ROOTFS_$(FSTYPE)_PRE_GEN_HOOKS, a list of hooks to call before
# generating the filesystem image
#
# ROOTFS_$(FSTYPE)_POST_GEN_HOOKS, a list of hooks to call after
# generating the filesystem image
#
# ROOTFS_$(FSTYPE)_POST_TARGETS, the list of targets that should be
# run after running the main filesystem target. This is useful for
# initramfs, to rebuild the kernel once the initramfs is generated.
#
# In terms of configuration option, this macro assumes that the
# BR2_TARGET_ROOTFS_$(FSTYPE) config option allows to enable/disable
# the generation of a filesystem image of a particular type. If
# configura options BR2_TARGET_ROOTFS_$(FSTYPE)_GZIP,
# BR2_TARGET_ROOTFS_$(FSTYPE)_BZIP2 or
# BR2_TARGET_ROOTFS_$(FSTYPE)_LZMA exist and are enabled, then the
# macro will automatically generate a compressed filesystem image.
FAKEROOT_SCRIPT = $(BUILD_DIR)/_fakeroot.fs
FULL_DEVICE_TABLE = $(BUILD_DIR)/_device_table.txt
ROOTFS_DEVICE_TABLES = $(call qstrip,$(BR2_ROOTFS_DEVICE_TABLE)) \
$(call qstrip,$(BR2_ROOTFS_STATIC_DEVICE_TABLE))
define ROOTFS_TARGET_INTERNAL
# extra deps
$(eval ROOTFS_$(2)_DEPENDENCIES += host-fakeroot host-makedevs $(if $(BR2_TARGET_ROOTFS_$(2)_LZMA),host-lzma))
$(BINARIES_DIR)/rootfs.$(1): $(ROOTFS_$(2)_DEPENDENCIES)
@$(call MESSAGE,"Generating root filesystem image rootfs.$(1)")
$(foreach hook,$(ROOTFS_$(2)_PRE_GEN_HOOKS),$(call $(hook))$(sep))
rm -f $(FAKEROOT_SCRIPT)
rm -f $(TARGET_DIR_WARNING_FILE)
echo "chown -R 0:0 $(TARGET_DIR)" >> $(FAKEROOT_SCRIPT)
ifneq ($(ROOTFS_DEVICE_TABLES),)
cat $(ROOTFS_DEVICE_TABLES) > $(FULL_DEVICE_TABLE)
ifeq ($(BR2_ROOTFS_DEVICE_CREATION_STATIC),y)
printf '$(subst $(sep),\n,$(PACKAGES_DEVICES_TABLE))' >> $(FULL_DEVICE_TABLE)
endif
printf '$(subst $(sep),\n,$(PACKAGES_PERMISSIONS_TABLE))' >> $(FULL_DEVICE_TABLE)
echo "$(HOST_DIR)/usr/bin/makedevs -d $(FULL_DEVICE_TABLE) $(TARGET_DIR)" >> $(FAKEROOT_SCRIPT)
endif
echo "$(ROOTFS_$(2)_CMD)" >> $(FAKEROOT_SCRIPT)
chmod a+x $(FAKEROOT_SCRIPT)
$(HOST_DIR)/usr/bin/fakeroot -- $(FAKEROOT_SCRIPT)
cp support/misc/target-dir-warning.txt $(TARGET_DIR_WARNING_FILE)
-@rm -f $(FAKEROOT_SCRIPT) $(FULL_DEVICE_TABLE)
$(foreach hook,$(ROOTFS_$(2)_POST_GEN_HOOKS),$(call $(hook))$(sep))
ifeq ($$(BR2_TARGET_ROOTFS_$(2)_GZIP),y)
gzip -9 -c $$@ > $$@.gz
endif
ifeq ($$(BR2_TARGET_ROOTFS_$(2)_BZIP2),y)
bzip2 -9 -c $$@ > $$@.bz2
endif
ifeq ($$(BR2_TARGET_ROOTFS_$(2)_LZMA),y)
$(LZMA) -9 -c $$@ > $$@.lzma
endif
rootfs-$(1)-show-depends:
@echo $(ROOTFS_$(2)_DEPENDENCIES)
rootfs-$(1): $(BINARIES_DIR)/rootfs.$(1) $(ROOTFS_$(2)_POST_TARGETS)
ifeq ($$(BR2_TARGET_ROOTFS_$(2)),y)
TARGETS += rootfs-$(1)
endif
endef
define ROOTFS_TARGET
$(call ROOTFS_TARGET_INTERNAL,$(1),$(call UPPERCASE,$(1)))
endef
include fs/*/*.mk