yocto-poky: Move to import-layers subdir

We are going to import additional layers, so create a subdir to
hold all of the layers that we import with git-subtree.

Change-Id: I6f732153a22be8ca663035c518837e3cc5ec0799
Signed-off-by: Patrick Williams <patrick@stwcx.xyz>

1 files changed, 24 insertions, 0 deletions

diff --git a/import-layers/yocto-poky/meta/classes/fs-uuid.bbclass b/import-layers/yocto-poky/meta/classes/fs-uuid.bbclass
new file mode 100644
index 000000000..bd2613cf1
--- /dev/null
+++ b/import-layers/yocto-poky/meta/classes/fs-uuid.bbclass
@@ -0,0 +1,24 @@
+# Extract UUID from ${ROOTFS}, which must have been built
+# by the time that this function gets called. Only works
+# on ext file systems and depends on tune2fs.
+def get_rootfs_uuid(d):
+    import subprocess
+    rootfs = d.getVar('ROOTFS', True)
+    output = subprocess.check_output(['tune2fs', '-l', rootfs])
+    for line in output.split('\n'):
+        if line.startswith('Filesystem UUID:'):
+            uuid = line.split()[-1]
+            bb.note('UUID of %s: %s' % (rootfs, uuid))
+            return uuid
+    bb.fatal('Could not determine filesystem UUID of %s' % rootfs)
+
+# Replace the special <<uuid-of-rootfs>> inside a string (like the
+# root= APPEND string in a syslinux.cfg or gummiboot entry) with the
+# actual UUID of the rootfs. Does nothing if the special string
+# is not used.
+def replace_rootfs_uuid(d, string):
+    UUID_PLACEHOLDER = '<<uuid-of-rootfs>>'
+    if UUID_PLACEHOLDER in string:
+        uuid = get_rootfs_uuid(d)
+        string = string.replace(UUID_PLACEHOLDER, uuid)
+    return string