feat(docs): add DPE to RSE desing doc

Signed-off-by: Tamas Ban <tamas.ban@arm.com>
Change-Id: Iec38be8a3eb93a54d9b5bc7db7a7ff8c126920ac
diff --git a/docs/design_documents/measured_boot.rst b/docs/design_documents/measured_boot.rst
index 9dfe494..005903e 100644
--- a/docs/design_documents/measured_boot.rst
+++ b/docs/design_documents/measured_boot.rst
@@ -91,10 +91,10 @@
    and the variable length crypto agile structure called TCG_PCR_EVENT2. Event
    Log driver implemented in TF-A covers later part.
 
-#. RSE
+#. |RSE|
 
-   It is one of physical backend to extend the measurements. Please refer this
-   document :ref:`Runtime Security Engine (RSE)` for more details.
+   It is one of the physical backends to extend the measurements. Please refer
+   this document :ref:`Runtime Security Engine (RSE)` for more details.
 
 Platform Interface
 ------------------
@@ -121,7 +121,7 @@
       void bl2_plat_mboot_init(void);
 
    Initialise all Measured Boot backends supported by the platform
-   (e.g. Event Log buffer, RSE). As these functions do not return any value,
+   (e.g. Event Log buffer, |RSE|). As these functions do not return any value,
    the platform should deal with error management, such as logging the error
    somewhere, or panicking the system if this is considered a fatal error.
 
@@ -147,8 +147,9 @@
 
      - If it is Event Log backend, then record the measurement in TCG Event Log
        format.
-     - If it is a secure crypto-processor (like RSE), then extend the designated
-       PCR (or slot) with the given measurement.
+     - If it is a secure crypto-processor (like |RSE|), then extend the
+       designated PCR (or store it in secure on-chip memory) with the given
+       measurement.
    - This function must return 0 on success, a signed integer error code
      otherwise.
    - On the Arm FVP port, this function measures the given image and then
@@ -223,7 +224,7 @@
    - This function must return 0 on success, a signed integer error code
      otherwise.
    - In TC2 platform, this function is used to calculate the hash of the given
-     key and forward this hash to RSE alongside the measurement of the image
+     key and forward this hash to |RSE| alongside the measurement of the image
      which the key signs.
 
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