Commit c5bd8af6 authored by Yann E. MORIN's avatar Yann E. MORIN Committed by Thomas Petazzoni
Browse files

system: add options for /bin /sbin and /lib to be symlinks into /usr 

systemd is increasingly expecting things to live in /usr/bin, /usr/sbin
or /usr/lib nad not in /bin, /sbin or /lib. It has inherited those
expectations from a Fedora change:
    https://fedoraproject.org/wiki/Features/UsrMove



Note however, that systemd does support /usr being on a separate
filesystem; it just expects an initramfs to mount it before the final
switchroot over to the actual rootfs.

But the traditional use-case for Buildroot is not to boot with an
initramfs; although that is totally feasible, that's probably not what
is commonly done in the vast majority of cases.

However, a lot of packages still install stuff directly into /bin,
/sbin or /lib, which systemd may need early-on in the boot process,
even before it may have a chance to mount /usr. Even though we can
tell systemd, at configure-time, where it should expect programs to
be at runtime, it does not make sense to go head-first against an
upstream wa^Hill.

Add an option so that /bin, /sbin and /lib be symlinks to /usr/bin
and /usr/sbin. That option is forcibly enabled when the init system
is systemd.

Note: we need not handle /lib32 or /lib64, as they already are symlinks
to /lib, which means they will automatically be redirected to /usr/lib,
as /usr/lib32 and /usr/lib64 already are.

Furthermore, this means we're no longer supporting a split-usr setup, so
the corresponding configure options have been removed as well for
systemd and, when using a merged /usr, for eudev as well.

In Buildroot, we decided (with this patch) not to support a split-usr
when systemd is used as an init system. This is a design decision, not
a systemd issue. Thus the select is with BR2_INIT_SYSTEMD rather than
with BR2_PACKAGE_SYSTEMD.

Signed-off-by: default avatar"Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Arnout Vandecappelle <arnout@mind.be>
Cc: Mike Williams <mike@mikebwilliams.com>
Cc: Vicente Olivert Riera <Vincent.Riera@imgtec.com>
Cc: Baruch Siach <baruch@tkos.co.il>
Tested-by: default avatarMike Williams <mike@mikebwilliams.com>
Signed-off-by: default avatarThomas Petazzoni <thomas.petazzoni@free-electrons.com>
parent 142522ee

package/eudev/eudev.mk

+4 −2
Original line number Diff line number Diff line
@@ -22,16 +22,18 @@ EUDEV_CONF_ENV += LIBS=-lrt 
EUDEV_CONF_OPTS =		\

	--disable-manpages	\

	--sbindir=/sbin		\

	--with-rootlibdir=/lib	\

	--libexecdir=/lib	\

	--with-firmware-path=/lib/firmware	\

	--disable-introspection			\

	--enable-split-usr			\

	--enable-libkmod



EUDEV_DEPENDENCIES = host-gperf host-pkgconf util-linux kmod

EUDEV_PROVIDES = udev



ifeq ($(BR2_ROOTFS_MERGED_USR),)

EUDEV_CONF_OPTS += --with-rootlibdir=/lib --enable-split-usr

endif



ifeq ($(BR2_PACKAGE_EUDEV_RULES_GEN),y)

EUDEV_CONF_OPTS += --enable-rule_generator

endif

package/skeleton/skeleton.mk

+17 −3
Original line number Diff line number Diff line
@@ -19,15 +19,29 @@ else 
SKELETON_PATH = system/skeleton

endif



ifeq ($(BR2_ROOTFS_MERGED_USR),y)

define SKELETON_USR_SYMLINKS_OR_DIRS

	ln -snf usr/bin $(TARGET_DIR)/bin

	ln -snf usr/sbin $(TARGET_DIR)/sbin

	ln -snf usr/lib $(TARGET_DIR)/lib

endef

else

define SKELETON_USR_SYMLINKS_OR_DIRS

	$(INSTALL) -d -m 0755 $(TARGET_DIR)/bin

	$(INSTALL) -d -m 0755 $(TARGET_DIR)/sbin

	$(INSTALL) -d -m 0755 $(TARGET_DIR)/lib

endef

endif



define SKELETON_INSTALL_TARGET_CMDS

	rsync -a --ignore-times $(SYNC_VCS_EXCLUSIONS) \

		--chmod=u=rwX,go=rX --exclude .empty --exclude '*~' \

		$(SKELETON_PATH)/ $(TARGET_DIR)/

	$(INSTALL) -m 0644 support/misc/target-dir-warning.txt \

		$(TARGET_DIR_WARNING_FILE)

	$(SKELETON_USR_SYMLINKS_OR_DIRS)

	ln -snf lib $(TARGET_DIR)/$(LIB_SYMLINK)

	mkdir -p $(TARGET_DIR)/usr

	ln -snf lib $(TARGET_DIR)/usr/$(LIB_SYMLINK)

	$(INSTALL) -m 0644 support/misc/target-dir-warning.txt \

		$(TARGET_DIR_WARNING_FILE)

endef



SKELETON_TARGET_GENERIC_HOSTNAME = $(call qstrip,$(BR2_TARGET_GENERIC_HOSTNAME))

package/systemd/systemd.mk

+0 −2
Original line number Diff line number Diff line
@@ -27,7 +27,6 @@ endif 


SYSTEMD_CONF_OPTS += \

	--with-rootprefix= \

	--with-rootlibdir=/lib \

	--enable-static=no \

	--disable-manpages \

	--disable-selinux \
@@ -36,7 +35,6 @@ SYSTEMD_CONF_OPTS += \ 
	--with-dbuspolicydir=/etc/dbus-1/system.d \

	--with-dbussessionservicedir=/usr/share/dbus-1/services \

	--with-dbussystemservicedir=/usr/share/dbus-1/system-services \

	--enable-split-usr \

	--disable-efi \

	--disable-gnuefi \

	--disable-tests \

system/Config.in

+17 −0
Original line number Diff line number Diff line
@@ -78,6 +78,10 @@ config BR2_INIT_SYSV 
	select BR2_PACKAGE_INITSCRIPTS

	select BR2_PACKAGE_SYSVINIT



# In Buildroot, we decided not to support a split-usr when systemd is

# used as an init system. This is a design decision, not a systemd

# issue. Thus the select is with BR2_INIT_SYSTEMD (below) rather than

# with BR2_PACKAGE_SYSTEMD.

config BR2_INIT_SYSTEMD

	bool "systemd"

	depends on BR2_PACKAGE_SYSTEMD_ARCH_SUPPORTS
@@ -88,6 +92,7 @@ config BR2_INIT_SYSTEMD 
	depends on BR2_USE_MMU

	depends on !BR2_STATIC_LIBS

	depends on BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_10

	select BR2_ROOTFS_MERGED_USR

	select BR2_PACKAGE_SYSTEMD



comment "systemd needs (e)glibc toolchain, headers >= 3.10"
@@ -178,6 +183,18 @@ endif 


if BR2_ROOTFS_SKELETON_DEFAULT



config BR2_ROOTFS_MERGED_USR

	bool "Use symlinks to /usr for /bin, /sbin and /lib"

	help

	  If you say 'n' here, then /bin, /sbin and /lib and their

	  counterparts in /usr will be separate directories. This

	  is the historical UNIX way. In this case, /usr can be a

	  filesystem on a partition separate from / .



	  If you say 'y' here, then /bin, /sbin and /lib will be symlinks

	  to their counterparts in /usr. In this case, /usr can not be a

	  separate filesystem.



config BR2_TARGET_ENABLE_ROOT_LOGIN

	bool "Enable root login with password"

	default y

system/skeleton/bin/.empty

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+0 −0

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