[PATCH v2 1/9] MIPS: Kconfig: Allow user selection of BUILTIN_DTB with description

["H. Nikolaus Schaller" <hns@goldelico.com>]

Make CONFIG_BUILTIN_DTB visible in Kconfig by adding a prompt and a
detailed help text.

Previously, BUILTIN_DTB was a silent option forcefully selected by
certain machine types (such as MACH_INGENIC) whenever appended DTB
support was disabled. This prevented modern setups from turning off the
built-in DTB fallback when the bootloader is fully capable of passing a
dynamic DTB.

By adding a prompt, users can now explicitly toggle this behavior. The
added help text clarifies the distinction between MIPS_NO_APPENDED_DTB
(which controls image appending) and BUILTIN_DTB (which controls the
compiled-in fallback data and code path via get_fdt()), as well as its
relationship to BUILTIN_DTB_NAME.

Suggested-by: Paul Cercueil <paul@crapouillou.net>
Signed-off-by: H. Nikolaus Schaller <hns@goldelico.com>
---

Notes:
    Help text and commit message generated by public Google AI.

 arch/mips/Kconfig | 24 +++++++++++++++++++++++-
 1 file changed, 23 insertions(+), 1 deletion(-)

diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index dac3ec5120a34..92bca520cd5ae 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -2924,7 +2924,29 @@ config UHI_BOOT
 	bool
 
 config BUILTIN_DTB
-	bool
+	bool "Enable builtin DTB fallback support"
+	depends on USE_OF
+	help
+	  Compiles a Device Tree Blob (DTB) directly into the kernel image
+	  and enables the kernel to use it as a fallback during boot.
+
+	  This option:
+	  a) Links the DTB specified by BUILTIN_DTB_NAME into the
+	     kernel binary.
+	  b) Instructs the boot code (get_fdt()) to return this internal
+	     DTB if no dynamic DTB from the bootloader or appended DTB
+	     image data is detected.
+
+	  Note on MIPS boot strategy:
+	  MIPS kernels check for a DTB in the following order inside get_fdt():
+	  1. An appended DTB image (if CONFIG_MIPS_*_APPENDED_DTB is set).
+	  2. The built-in DTB fallback controlled by this option.
+
+	  If your bootloader provides a valid DTB dynamically and you do not
+	  rely on appended or built-in DTBs, you should enable
+	  MIPS_NO_APPENDED_DTB and disable BUILTIN_DTB.
+
+	  If unsure, say Y.
 
 choice
 	prompt "Kernel appended dtb support"
-- 
2.56.0