diff --git a/ref_app/target.vcxproj b/ref_app/target.vcxproj
index e42c6e18d..51911160c 100644
--- a/ref_app/target.vcxproj
+++ b/ref_app/target.vcxproj
@@ -1071,6 +1071,12 @@
+
+
+
+
+
+
diff --git a/ref_app/target.vcxproj.filters b/ref_app/target.vcxproj.filters
index 371d669d2..8c3bc2cf0 100644
--- a/ref_app/target.vcxproj.filters
+++ b/ref_app/target.vcxproj.filters
@@ -361,6 +361,12 @@
{65c5c603-a019-41d0-8a19-3cadaca7fd3c}
+
+ {78721b7f-e97c-4ac7-906a-a571af4377b1}
+
+
+ {154f1c39-5085-471e-a5c9-444517255025}
+
@@ -813,6 +819,24 @@
micros\esp32p4_riscv_soc\startup\Code\Startup
+
+ micros\esp32p4_riscv_soc\startup\Code\SBL
+
+
+ micros\esp32p4_riscv_soc\startup\Code\SBL\Output
+
+
+ micros\esp32p4_riscv_soc\startup\Code\SBL\Output
+
+
+ micros\esp32p4_riscv_soc\startup\Code\SBL\Output
+
+
+ micros\esp32p4_riscv_soc\startup\Code\SBL\Output
+
+
+ micros\esp32p4_riscv_soc\startup\Code\SBL\Output
+
diff --git a/ref_app/target/micros/esp32p4_riscv_soc/startup/Code/SBL/readme.md b/ref_app/target/micros/esp32p4_riscv_soc/startup/Code/SBL/readme.md
new file mode 100644
index 000000000..386402fea
--- /dev/null
+++ b/ref_app/target/micros/esp32p4_riscv_soc/startup/Code/SBL/readme.md
@@ -0,0 +1,14 @@
+# ESP32-P4 SBL (Secondary Boot Loader)
+
+The SBL (Secondary Boot Loader) is used in combination with the ESP-flash
+tool to boot the multi-core device.
+
+The SBL has been adopted directly from the original work in
+[Chalandi/Baremetal_esp32p4_nosdk](https://github.com/Chalandi/Baremetal_esp32p4_nosdk).
+In that work, the SBL code and build system can be found in the
+[SBL](https://github.com/Chalandi/Baremetal_esp32p4_nosdk/tree/master/Code/SBL) directory.
+
+The original _chalandi_ project has been used locally to build the SBL
+for target `esp32p4_riscv_soc` in the `ref_app`.
+The SBL-Output from that build has been archived and can be found
+in the [Output](./Output) directory.