[PATCH v5 3/3] doc/buildman: describe using fragments

[Heinrich Schuchardt]

Describe the new --fragments parameter

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt at canonical.com>
---
v5:
	Fix typo comma-separated
v4:
	Describe the invocation of merge_config.sh
v3:
	no change
v2:
	new patch
---
 tools/buildman/buildman.rst | 28 ++++++++++++----------------
 1 file changed, 12 insertions(+), 16 deletions(-)

diff --git a/tools/buildman/buildman.rst b/tools/buildman/buildman.rst
index 07ecc5c110c..0729f15f2b5 100644
--- a/tools/buildman/buildman.rst
+++ b/tools/buildman/buildman.rst
@@ -1126,27 +1126,23 @@ later comparison.
 defconfig fragments
 -------------------
 
-Buildman provides some initial support for configuration fragments. It can scan
-these when present in defconfig files and handle the resuiting Kconfig
-correctly. Thus it is possible to build a board which has a ``#include`` in the
-defconfig file.
+A comma-separated list of configuration fragments can be added via the
+--fragments parameter to all processed defconfig files, e.g.
 
-For now, Buildman simply includes the files to produce a single output file,
-using the C preprocessor. It does not call the ``merge_config.sh`` script. The
-redefined/redundant logic in that script could fairly easily be repeated in
-Buildman, to detect potential problems. For now it is not clear that this is
-useful.
+.. code-block:: bash
 
-To specify the C preprocessor to use, set the ``CPP`` environment variable. The
-default is ``cpp``.
+    buildman -k qemu-riscv64_smode --fragments acpi.config
 
-Note that Buildman does not support adding fragments to existing boards, e.g.
-like::
+Buildman invokes ``make`` passing the defconfig file and the fragment files as
+target arguments. In ``scripts/kconfig/Makefile`` the script ``merge_config.sh``
+is called for each fragment file to add it to the configuration.
 
-    make qemu_riscv64_defconfig acpi.config
+Buildman also supports configuration fragments that are included in defconfig
+files via an ``#include`` statement. It can scan these and handle the resulting
+Kconfig correctly.
 
-This is partly because there is no way for Buildman to know which fragments are
-valid on which boards.
+To specify the C preprocessor to use, set the ``CPP`` environment variable. The
+default is ``cpp``.
 
 Building with clang
 -------------------
-- 
2.48.1