diff --git a/Documentation/soc/intel/fsp/index.md b/Documentation/soc/intel/fsp/index.md
index 039a389b46..d7f44c6dee 100644
--- a/Documentation/soc/intel/fsp/index.md
+++ b/Documentation/soc/intel/fsp/index.md
@@ -11,3 +11,7 @@ This section contains documentation about Intel-FSP in public domain.
 * [FSP Specification 1.1](https://www.intel.com/content/dam/www/public/us/en/documents/technical-specifications/fsp-architecture-spec-v1-1.pdf)
 
 * [FSP Specification 2.0](https://www.intel.com/content/dam/www/public/us/en/documents/technical-specifications/fsp-architecture-spec-v2.pdf)
+
+## Additional Features in FSP 2.1 specification
+
+- [PPI](ppi/ppi.md)
diff --git a/Documentation/soc/intel/fsp/ppi/ppi.md b/Documentation/soc/intel/fsp/ppi/ppi.md
new file mode 100644
index 0000000000..66dbf07c16
--- /dev/null
+++ b/Documentation/soc/intel/fsp/ppi/ppi.md
@@ -0,0 +1,9 @@
+# PEIM to PEIM Interface (PPI)
+
+This section is intended to document the purpose of creating PPI service
+inside coreboot space to perform some specific operation related to CPU,
+chipset using Intel FSP. This feature is added into FSP specification 2.1
+where FSP should be able to locate PPI, published by boot firmware and
+able to execute the same in FSP's context.
+
+* [What is PPI](https://www.intel.com/content/dam/www/public/us/en/documents/reference-guides/efi-pei-cis-v09.pdf)