kernel.bbclass: Add task to export kernel configuration to SPDX

Introduce a new bitbake task do_create_kernel_config_spdx that extracts
the kernel configuration from ${B}/.config and exports it into the
recipe's SPDX document as a separate build_Build object.

The kernel config parameters are stored as SPDX DictionaryEntry objects
and linked to the main kernel build using an ancestorOf relationship.

This enables the kernel build's configuration to be explicitly captured
in the SPDX document for compliance, auditing, and reproducibility.

The task is gated by SPDX_INCLUDE_KERNEL_CONFIG (default = "0").

Reviewed-by: Joshua Watt <JPEWhacker@gmail.com>
(From OE-Core rev: 1fff29a0428778929ffa530482ebf7db95f1e0ae)

Signed-off-by: Kamel Bouhara (Schneider Electric) <kamel.bouhara@bootlin.com>
Signed-off-by: Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
(cherry picked from commit 228a968e7c47d811c06143279bdb0f9c5f374bef)
Signed-off-by: Steve Sakoman <steve@sakoman.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/meta/classes/create-spdx-3.0.bbclass b/meta/classes/create-spdx-3.0.bbclass
index c0a5436ad6..15c31ba9a3 100644
--- a/meta/classes/create-spdx-3.0.bbclass
+++ b/meta/classes/create-spdx-3.0.bbclass
@@ -50,6 +50,12 @@ SPDX_INCLUDE_TIMESTAMPS[doc] = "Include time stamps in SPDX output. This is \
     useful if you want to know when artifacts were produced and when builds \
     occurred, but will result in non-reproducible SPDX output"
 
+SPDX_INCLUDE_KERNEL_CONFIG ??= "0"
+SPDX_INCLUDE_KERNEL_CONFIG[doc] = "If set to '1', the .config file for the kernel will be parsed \
+and each CONFIG_* value will be included in the Build.build_parameter list as DictionaryEntry \
+items. Set to '0' to disable exporting kernel configuration to improve performance or reduce \
+SPDX document size."
+
 SPDX_IMPORTS ??= ""
 SPDX_IMPORTS[doc] = "SPDX_IMPORTS is the base variable that describes how to \
     reference external SPDX ids. Each import is defined as a key in this \