diff --git a/docs/components/arm-sip-service.rst b/docs/components/arm-sip-service.rst
index 2d58586..01bc04d 100644
--- a/docs/components/arm-sip-service.rst
+++ b/docs/components/arm-sip-service.rst
@@ -17,6 +17,7 @@
 
 -  Performance Measurement Framework (PMF)
 -  Execution State Switching service
+-  DebugFS interface
 
 Source definitions for Arm SiP service are located in the ``arm_sip_svc.h`` header
 file.
@@ -87,6 +88,346 @@
 and 1 populated with the supplied *Cookie hi* and *Cookie lo* values,
 respectively.
 
+DebugFS interface
+-----------------
+
+The optional DebugFS interface is accessed through an SMC SiP service. Refer
+to the component documentation for details.
+
+String parameters are passed through a shared buffer using a specific union:
+
+.. code:: c
+
+    union debugfs_parms {
+        struct {
+            char fname[MAX_PATH_LEN];
+        } open;
+
+        struct mount {
+            char srv[MAX_PATH_LEN];
+            char where[MAX_PATH_LEN];
+            char spec[MAX_PATH_LEN];
+        } mount;
+
+        struct {
+            char path[MAX_PATH_LEN];
+            dir_t dir;
+        } stat;
+
+        struct {
+            char oldpath[MAX_PATH_LEN];
+            char newpath[MAX_PATH_LEN];
+        } bind;
+    };
+
+Format of the dir_t structure as such:
+
+.. code:: c
+
+    typedef struct {
+        char		name[NAMELEN];
+        long		length;
+        unsigned char	mode;
+        unsigned char	index;
+        unsigned char	dev;
+        qid_t		qid;
+    } dir_t;
+
+
+* Identifiers
+
+======================== =============================================
+SMC_OK                   0
+SMC_UNK                  -1
+DEBUGFS_E_INVALID_PARAMS -2
+======================== =============================================
+
+======================== =============================================
+MOUNT                    0
+CREATE                   1
+OPEN                     2
+CLOSE                    3
+READ                     4
+WRITE                    5
+SEEK                     6
+BIND                     7
+STAT                     8
+INIT                     10
+VERSION                  11
+======================== =============================================
+
+MOUNT
+~~~~~
+
+Description
+^^^^^^^^^^^
+This operation mounts a blob of data pointed to by path stored in `src`, at
+filesystem location pointed to by path stored in `where`, using driver pointed
+to by path in `spec`.
+
+Parameters
+^^^^^^^^^^
+======== ============================================================
+uint32_t FunctionID (0x82000030 / 0xC2000030)
+uint32_t ``MOUNT``
+======== ============================================================
+
+Return values
+^^^^^^^^^^^^^
+
+=============== ==========================================================
+int32_t         w0 == SMC_OK on success
+
+                w0 == DEBUGFS_E_INVALID_PARAMS if mount operation failed
+=============== ==========================================================
+
+OPEN
+~~~~
+
+Description
+^^^^^^^^^^^
+This operation opens the file path pointed to by `fname`.
+
+Parameters
+^^^^^^^^^^
+
+======== ============================================================
+uint32_t FunctionID (0x82000030 / 0xC2000030)
+uint32_t ``OPEN``
+uint32_t mode
+======== ============================================================
+
+mode can be one of:
+
+.. code:: c
+
+    enum mode {
+        O_READ   = 1 << 0,
+        O_WRITE  = 1 << 1,
+        O_RDWR   = 1 << 2,
+        O_BIND   = 1 << 3,
+        O_DIR    = 1 << 4,
+        O_STAT   = 1 << 5
+    };
+
+Return values
+^^^^^^^^^^^^^
+
+=============== ==========================================================
+int32_t         w0 == SMC_OK on success
+
+                w0 == DEBUGFS_E_INVALID_PARAMS if open operation failed
+
+uint32_t        w1: file descriptor id on success.
+=============== ==========================================================
+
+CLOSE
+~~~~~
+
+Description
+^^^^^^^^^^^
+
+This operation closes a file described by a file descriptor obtained by a
+previous call to OPEN.
+
+Parameters
+^^^^^^^^^^
+
+======== ============================================================
+uint32_t FunctionID (0x82000030 / 0xC2000030)
+uint32_t ``CLOSE``
+uint32_t File descriptor id returned by OPEN
+======== ============================================================
+
+Return values
+^^^^^^^^^^^^^
+=============== ==========================================================
+int32_t         w0 == SMC_OK on success
+
+                w0 == DEBUGFS_E_INVALID_PARAMS if close operation failed
+=============== ==========================================================
+
+READ
+~~~~
+
+Description
+^^^^^^^^^^^
+
+This operation reads a number of bytes from a file descriptor obtained by
+a previous call to OPEN.
+
+Parameters
+^^^^^^^^^^
+
+======== ============================================================
+uint32_t FunctionID (0x82000030 / 0xC2000030)
+uint32_t ``READ``
+uint32_t File descriptor id returned by OPEN
+uint32_t Number of bytes to read
+======== ============================================================
+
+Return values
+^^^^^^^^^^^^^
+
+On success, the read data is retrieved from the shared buffer after the
+operation.
+
+=============== ==========================================================
+int32_t         w0 == SMC_OK on success
+
+                w0 == DEBUGFS_E_INVALID_PARAMS if read operation failed
+
+uint32_t        w1: number of bytes read on success.
+=============== ==========================================================
+
+SEEK
+~~~~
+
+Description
+^^^^^^^^^^^
+
+Move file pointer for file described by given `file descriptor` of given
+`offset` related to `whence`.
+
+Parameters
+^^^^^^^^^^
+
+======== ============================================================
+uint32_t FunctionID (0x82000030 / 0xC2000030)
+uint32_t ``SEEK``
+uint32_t File descriptor id returned by OPEN
+sint32_t offset in the file relative to whence
+uint32_t whence
+======== ============================================================
+
+whence can be one of:
+
+========= ============================================================
+KSEEK_SET 0
+KSEEK_CUR 1
+KSEEK_END 2
+========= ============================================================
+
+Return values
+^^^^^^^^^^^^^
+
+=============== ==========================================================
+int32_t         w0 == SMC_OK on success
+
+                w0 == DEBUGFS_E_INVALID_PARAMS if seek operation failed
+=============== ==========================================================
+
+BIND
+~~~~
+
+Description
+^^^^^^^^^^^
+
+Create a link from `oldpath` to `newpath`.
+
+Parameters
+^^^^^^^^^^
+
+======== ============================================================
+uint32_t FunctionID (0x82000030 / 0xC2000030)
+uint32_t ``BIND``
+======== ============================================================
+
+Return values
+^^^^^^^^^^^^^
+
+=============== ==========================================================
+int32_t         w0 == SMC_OK on success
+
+                w0 == DEBUGFS_E_INVALID_PARAMS if bind operation failed
+=============== ==========================================================
+
+STAT
+~~~~
+
+Description
+^^^^^^^^^^^
+
+Perform a stat operation on provided file `name` and returns the directory
+entry statistics into `dir`.
+
+Parameters
+^^^^^^^^^^
+
+======== ============================================================
+uint32_t FunctionID (0x82000030 / 0xC2000030)
+uint32_t ``STAT``
+======== ============================================================
+
+Return values
+^^^^^^^^^^^^^
+
+=============== ==========================================================
+int32_t         w0 == SMC_OK on success
+
+                w0 == DEBUGFS_E_INVALID_PARAMS if stat operation failed
+=============== ==========================================================
+
+INIT
+~~~~
+
+Description
+^^^^^^^^^^^
+Initial call to setup the shared exchange buffer. Notice if successful once,
+subsequent calls fail after a first initialization. The caller maps the same
+page frame in its virtual space and uses this buffer to exchange string
+parameters with filesystem primitives.
+
+Parameters
+^^^^^^^^^^
+
+======== ============================================================
+uint32_t FunctionID (0x82000030 / 0xC2000030)
+uint32_t ``INIT``
+uint64_t Physical address of the shared buffer.
+======== ============================================================
+
+Return values
+^^^^^^^^^^^^^
+
+=============== ======================================================
+int32_t         w0 == SMC_OK on success
+
+                w0 == DEBUGFS_E_INVALID_PARAMS if already initialized,
+                or internal error occurred.
+=============== ======================================================
+
+VERSION
+~~~~~~~
+
+Description
+^^^^^^^^^^^
+Returns the debugfs interface version if implemented in TF-A.
+
+Parameters
+^^^^^^^^^^
+
+======== ============================================================
+uint32_t FunctionID (0x82000030 / 0xC2000030)
+uint32_t ``VERSION``
+======== ============================================================
+
+Return values
+^^^^^^^^^^^^^
+
+=============== ======================================================
+int32_t         w0 == SMC_OK on success
+
+                w0 == SMC_UNK if interface is not implemented
+
+uint32_t        w1: On success, debugfs interface version, 32 bits
+                value with major version number in upper 16 bits and
+                minor version in lower 16 bits.
+=============== ======================================================
+
+* CREATE(1) and WRITE (5) command identifiers are unimplemented and
+  return `SMC_UNK`.
+
 --------------
 
 *Copyright (c) 2017-2019, Arm Limited and Contributors. All rights reserved.*