[OE-core] [PATCH v2 24/25] image: create symlinks needed for merged /usr

[Amarnath Valluri]

Prepare the symlinks required for merged /usr at the time of rootfs creation.

The links created in rootfs are:
/bin --> /usr/sbin
/sbin --> /usr/sbin
/lib --> /usr/lib
/lib64 --> /usr/lib64

We cannot make these symlinks as part of 'base-files' or some other package.
Because at rootfs creation, installation of the package(say kernel) that depends
on these root folders/links fails, if package manager installs this package
prior to base-files.

These symbolic links in top level folder should present as long as
 - kerenl tools use /lib/{module,firmware}
 - shell scripts uses "#!/bin/sh"

Signed-off-by: Amarnath Valluri <amarnath.valluri at intel.com>
---
 meta/classes/image.bbclass | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/meta/classes/image.bbclass b/meta/classes/image.bbclass
index 127e62d..4a9b40e 100644
--- a/meta/classes/image.bbclass
+++ b/meta/classes/image.bbclass
@@ -617,3 +617,26 @@ do_bundle_initramfs () {
 	:
 }
 addtask bundle_initramfs after do_image_complete
+
+# Prepare the root links to point to the /usr counterparts.
+create_merged_usr_symlinks() {
+    install -m 0755 -d ${IMAGE_ROOTFS}/${base_bindir}
+    install -m 0755 -d ${IMAGE_ROOTFS}/${base_sbindir}
+    install -m 0755 -d ${IMAGE_ROOTFS}/${base_libdir}
+    lnr ${IMAGE_ROOTFS}${base_bindir} ${IMAGE_ROOTFS}/bin
+    lnr ${IMAGE_ROOTFS}${base_sbindir} ${IMAGE_ROOTFS}/sbin
+    lnr ${IMAGE_ROOTFS}${base_libdir} ${IMAGE_ROOTFS}/${baselib}
+
+    if [ "${nonarch_base_libdir}" != "${base_libdir}" ]; then
+       install -m 0755 -d ${IMAGE_ROOTFS}/${nonarch_base_libdir}
+       lnr ${IMAGE_ROOTFS}${nonarch_base_libdir} ${IMAGE_ROOTFS}/lib
+    fi
+
+    # create base links for multilibs
+    multi_libdirs="${@d.getVar('MULTILIB_VARIANTS')}"
+    for d in $multi_libdirs; do
+        install -m 0755 -d ${IMAGE_ROOTFS}/${exec_prefix}/$d
+        lnr ${IMAGE_ROOTFS}/${exec_prefix}/$d ${IMAGE_ROOTFS}/$d
+    done
+}
+ROOTFS_PREPROCESS_COMMAND += "${@bb.utils.contains('DISTRO_FEATURES', 'usrmerge', 'create_merged_usr_symlinks; ', '',d)}"
-- 
2.7.4