[PATCH v3 1/2] add new class to add files directly to the rootfs

[Quirin Gylstorff <Quirin.Gylstorff@siemens.com>]

From: Quirin Gylstorff <quirin.gylstorff@siemens.com>

This allows to add files like the installer target directly
to rootfs without compressing the target file. It also reduces
the sstate size.

Signed-off-by: Quirin Gylstorff <quirin.gylstorff@siemens.com>
---
 meta/classes/rootfs-add-files.bbclass | 45 +++++++++++++++++++++++++++
 1 file changed, 45 insertions(+)
 create mode 100644 meta/classes/rootfs-add-files.bbclass

diff --git a/meta/classes/rootfs-add-files.bbclass b/meta/classes/rootfs-add-files.bbclass
new file mode 100644
index 00000000..4125caf5
--- /dev/null
+++ b/meta/classes/rootfs-add-files.bbclass
@@ -0,0 +1,45 @@
+# This software is a part of ISAR.
+# Copyright (C) Siemens AG, 2024
+# This class allows to add a file directly to
+# the rootfs.
+# An example usecase would be an installer which
+# contains an complete rootfs added with multiconfig.
+ROOTFS_INSTALL_COMMAND =+ "rootfs_add_files"
+ROOTFS_ADDITIONAL_FILES ??= ""
+
+# ROOTFS_ADDITIONAL_FILES ??= "installer-target"
+#
+# ROOTFS_ADDITIONAL_FILE_installer-target[source] = \
+# "${DEPLOY_DIR_IMAGE}/${IMG_DATA_FILE}.${IMAGE_DATA_POSTFIX}"
+# ROOTFS_ADDITIONAL_FILE_installer-target[destination] = \
+# "/install/${IMG_DATA_FILE}.${IMAGE_DATA_POSTFIX}"
+
+
+python rootfs_add_files() {
+    import os
+    if d.getVar("SOURCE_DATE_EPOCH") != None:
+        os.environ["SOURCE_DATE_EPOCH"] = d.getVar("SOURCE_DATE_EPOCH")
+
+    postprocess_additional_files = d.getVar('ROOTFS_ADDITIONAL_FILES').split()
+    rootfsdir = d.getVar("ROOTFSDIR")
+
+    for entry in postprocess_additional_files:
+        additional_file_entry = f"ROOTFS_ADDITIONAL_FILE_{entry}"
+        destination = d.getVarFlag(additional_file_entry, "destination") or ""
+        source = d.getVarFlag(additional_file_entry, "source") or ""
+        if os.path.exists(f"{rootfsdir}/{destination}"):
+            bb.process.run([ "/usr/bin/rm", "-f", f"{destination}"])
+
+        dest_dir = os.path.dirname(destination)
+        bb.process.run(["sudo", "-E", "/usr/bin/mkdir", "-p", f"{rootfsdir}/{dest_dir}" ])
+        # empty source creates only an empty destination file
+        if not source:
+            bb.process.run(["sudo", "-E", "/usr/bin/touch", f"{rootfsdir}/{destination}" ])
+            return
+
+        if not os.path.exists(f"{source}"):
+            bb.error(f"{source} does not exists and cannot be copied to the rootfs!")
+        # no recursive copy only single files
+        bb.process.run(["sudo", "-E", "/usr/bin/cp", "-a",  f"{source}", f"{rootfsdir}/{destination}" ])
+}
+ROOTFS_INSTALL_COMMAND += "rootfs_add_files"
-- 
2.43.0