Probes update

developer_guides/debugability/probes/index.rst

@@ -65,6 +65,28 @@ Firmware side
 
 	 make menuconfig
 
+  The following options available
+
+  Required for audio probes:
+
+  .. code-block:: bash
+
+	CONFIG_PROBE=y			# enable probes
+	CONFIG_PROBE_POINTS_MAX=16	# max probepoints
+
+  Required for logging through probes interface:
+
+  .. code-block:: bash
+
+	CONFIG_LOG_BACKEND_SOF_PROBE=y
+	CONFIG_ZEPHYR_LOG=y
+
+  This option enables the probes logging automatically when probes extraction DMA is started:
+
+  .. code-block:: bash
+
+	CONFIG_LOG_BACKEND_SOF_PROBE_OUTPUT_AUTO_ENABLE=y
+
 - Refer to **Step 3 Build firmware binaries** in :ref:`Build SOF from Scratch <build-from-scratch>` for reference.
 
 Note that you do not need to modify the audio topology file.
@@ -101,7 +123,8 @@ the last stage of extraction.
      - Pause the playback stream. (optional)
      - Add probe points via the ``debugfs`` "probe_points" entry in ``/sys/kernel/debug/sof``
 
-   For example, to add a buffer with 7 probe points:
+
+   For example, to add buffer 7 with a probe point (IPC3):
 
    .. code-block:: bash
 
@@ -138,6 +161,52 @@ the last stage of extraction.
 			strnlen(tw->sname, SNDRV_CTL_ELEM_ID_NAME_MAXLEN) > 0
 				? tw->sname : "none");
 
+   For IPC4 system, the above example looks like this:
+
+   .. code-block:: bash
+
+	  echo 2,0,0 > probe_points
+
+  The semantics of the buffer_id are quite different on IPC4 system:
+
+  .. code-block:: c
+
+		typedef union probe_point_id {
+			uint32_t full_id;
+			struct {
+				uint32_t  module_id   : 16;	/**< Target module ID */
+				uint32_t  instance_id : 8;	/**< Target module instance ID */
+				uint32_t  type        : 2;	/**< Probe point type as specified by ProbeType enumeration */
+				uint32_t  index       : 6;	/**< Queue index inside target module */
+			} fields;
+		} __attribute__((packed, aligned(4))) probe_point_id_t;
+
+  .. code-block:: c
+
+		/**
+		 * Description of probe point
+		 */
+		struct probe_point {
+			probe_point_id_t buffer_id;	/**< ID of buffer to which probe is attached */
+			uint32_t purpose;	/**< PROBE_PURPOSE_xxx */
+			uint32_t stream_tag;	/**< Stream tag of DMA via which data will be provided for injection.
+						 *   For extraction purposes, stream tag is ignored when received,
+						 *   but returned actual extraction stream tag via INFO function.
+						 */
+		} __attribute__((packed, aligned(4)));
+
+Enabling the log in IPC3 system (in case auto enable is not on):
+
+   .. code-block:: bash
+
+	  echo 0,1,0 > probe_points
+
+And on IPC4 system:
+
+   .. code-block:: bash
+
+	  echo 0,0,0 > probe_points
+
 2. Unpause the playback stream. (optional)
 #. Close the playback stream when done.
 #. Close the crecord tool.
@@ -159,4 +228,14 @@ Usage and ouput:
    sof-probes:	 done
 
 As a result, ``buffer_7.wav`` is generated in the *tools/build_tools/probes* folder. The wave file can then be examined with your tool of choice
-such as ``Audacity``.
+such as ``Audacity``.
+
+
+Simple logging case
+*******************
+
+With the crecord and sof-probes in path, probes logging backend with auto enable option it is possible to get the firmware logs to stdout with this command combination:
+
+.. code-block:: bash
+
+	crecord -c3 -d0 -b8192 -f4 -FS32_LE -R48000 -C4 | sof-probes -l