[PATCH V5 09/12] arm: dts: iot2050: Optionally embed OTP programming data into image

Jan Kiszka jan.kiszka at siemens.com
Fri Feb 3 13:26:38 CET 2023

From: Jan Kiszka <jan.kiszka at siemens.com>

Use external blob otpcmd.bin to replace the 0xff filled OTP programming
command block to create a firmware image that provisions the OTP on
first boot. This otpcmd.bin is generated from the customer keys using
steps described in the meta-iot2050 integration layer for the device.

Based on original patch by Baocheng Su.

Signed-off-by: Jan Kiszka <jan.kiszka at siemens.com>
 arch/arm/dts/k3-am65-iot2050-boot-image.dtsi | 8 ++++++++
 board/siemens/iot2050/Kconfig                | 7 +++++++
 doc/board/siemens/iot2050.rst                | 8 ++++++++
 tools/binman/missing-blob-help               | 8 ++++++++
 4 files changed, 31 insertions(+)

diff --git a/arch/arm/dts/k3-am65-iot2050-boot-image.dtsi b/arch/arm/dts/k3-am65-iot2050-boot-image.dtsi
index 9082a79a034..25a22a7b7b8 100644
--- a/arch/arm/dts/k3-am65-iot2050-boot-image.dtsi
+++ b/arch/arm/dts/k3-am65-iot2050-boot-image.dtsi
@@ -111,10 +111,18 @@
 		/* OTP update command block */
+		blob-ext at 0x6c0000 {
+			offset = <0x6c0000>;
+			size   = <0x010000>;
+			filename = "otpcmd.bin";
+			missing-msg = "iot2050-otpcmd";
 		fill at 0x6c0000 {
 			offset = <0x6c0000>;
 			size   = <0x010000>;
 			fill-byte = [ff];
diff --git a/board/siemens/iot2050/Kconfig b/board/siemens/iot2050/Kconfig
index a2b40881d11..e66b2427d95 100644
--- a/board/siemens/iot2050/Kconfig
+++ b/board/siemens/iot2050/Kconfig
@@ -49,4 +49,11 @@ config IOT2050_BOOT_SWITCH
 	bool "Disable eMMC boot via USER button (Advanced version only)"
 	default y
+config IOT2050_EMBED_OTPCMD
+	bool "Embed OTP programming data"
+	help
+	  Embed signed OTP programming data 'otpcmd.bin' into the firmware
+	  image. This data will be evaluated and executed on first boot of the
+	  device.
diff --git a/doc/board/siemens/iot2050.rst b/doc/board/siemens/iot2050.rst
index 4e0925c72c9..cb49a0e36bf 100644
--- a/doc/board/siemens/iot2050.rst
+++ b/doc/board/siemens/iot2050.rst
@@ -27,6 +27,14 @@ The following binaries from that source need to be present in the build folder:
  - seboot_pg1.bin
  - seboot_pg2.bin
+For building an image containing the OTP key provisioning data, below binary
+needs to be present in the build folder:
+ - otpcmd.bin
+Regarding how to generating this otpcmd.bin, please refer to:
diff --git a/tools/binman/missing-blob-help b/tools/binman/missing-blob-help
index 5bb8961ce03..7e88cd03954 100644
--- a/tools/binman/missing-blob-help
+++ b/tools/binman/missing-blob-help
@@ -23,6 +23,14 @@ See the documentation for IOT2050 board. Your image is missing SEBoot
 which is mandatory for board startup. Prebuilt SEBoot located at
+See the documentation for IOT2050 board. Your image is missing OTP command data
+block which is used for provisioning the customer keys to the board.
+Please refer to
+for how to generate this binary. If you are not using secure boot or do not
+intend to provision the keys, disable CONFIG_IOT2050_EMBED_OTPCMD.
 If CONFIG_WDT_K3_RTI_LOAD_FW is enabled, a firmware image is needed for
 the R5F core(s) to trigger the system reset. One possible source is

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