Documentation: x86 Enable Serial Output

Document the steps necessary to enable serial output

TEST=None

Change-Id: Ifc0e700d7ef54fb1e28ca9bca34b94cccd3633ac
Signed-off-by: Lee Leahy <leroy.p.leahy@intel.com>
Reviewed-on: https://review.coreboot.org/13444
Tested-by: build bot (Jenkins)
Reviewed-by: Martin Roth <martinroth@google.com>

Documentation/Intel/Board/board.html

@@ -14,6 +14,7 @@
 </p>
 <ol>
   <li><a href="#RequiredFiles">Required Files</a></li>
+  <li>Enable <a href="#SerialOutput">Serial Output</a></li>
 </ol>
 
 
@@ -77,6 +78,30 @@
 </ol>
 
 
+<hr>
+<h1><a name="SerialOutput">Enable Serial Output</a></h1>
+<p>
+  Use the following steps to enable serial output:
+</p>
+<ol>
+  <li>Implement the car_mainboard_pre_console_init routine in the com_init.c
+    file:
+    <ol type="A">
+      <li>Power on and enable the UART controller</li>
+      <li>Connect the UART receive and transmit data lines to the
+        appropriate SoC pins
+      </li>
+    </ol>
+  </li>
+  <li>Add Makefile.inc
+    <ol type="A">
+      <li>Add com_init.c to romstage</li>
+    </ol>
+  </li>
+</ol>
+
+
+
 <hr>
 <p>Modified: 31 January 2016</p>
   </body>

Documentation/Intel/SoC/soc.html

@@ -19,6 +19,11 @@
   <li><a href="#EarlyDebug">Early Debug</a></li>
   <li><a href="#Bootblock">Bootblock</a></li>
   <li><a href="#TempRamInit">TempRamInit</a></li>
+  <li><a href="#Romstage">Romstage</a>
+    <ol type="A">
+      <li>Enable <a href="#SerialOutput">Serial Output"</a></li>
+    </ol>
+  </li>
 </ol>
 
 
@@ -284,6 +289,45 @@ Use the following steps to debug the call to TempRamInit:
 </ol>
 
 
+<hr>
+<h1><a name="Romstage">Romstage</a></h1>
+
+<h2><a name="SerialOutput">Serial Output</a></h2>
+<p>
+  The following steps add the serial output support for romstage:
+</p>
+<ol>
+  <li>Create the romstage subdirectory</li>
+  <li>Add romstage/romstage.c
+    <ol type="A">
+      <li>Program the necessary base addresses</li>
+      <li>Disable the TCO</li>
+    </ol>
+  </li>
+  <li>Add romstage/Makefile.inc
+    <ol type="A">
+      <li>Add romstage.c to romstage</li>
+    </ol>
+  </li>
+  <li>Add gpio configuration support if necessary</li>
+  <li>Add the necessary .h files to support the build</li>
+  <li>Update Makefile.inc
+    <ol type="A">
+      <li>Add the romstage subdirectory</li>
+      <li>Add the gpio configuration support file to romstage</li>
+    </ol>
+  </li>
+  <li>Set the necessary Kconfig values to enable serial output:
+    <ul>
+      <li>CONFIG_DRIVERS_UART_&lt;driver&gt;=y</li>
+      <li>CONFIG_CONSOLE_SERIAL=y</li>
+      <li>CONFIG_UART_FOR_CONSOLE=&lt;port&gt;</li>
+      <li>CONFIG_CONSOLE_SERIAL_115200=y</li>
+    </ul>
+  </li>
+</ol>
+
+
 <hr>
 <p>Modified: 31 January 2016</p>
   </body>

Documentation/Intel/development.html

@@ -71,6 +71,17 @@
   <li><a target="_blank" href="SoC/soc.html#EarlyDebug">Early Debug</a></li>
   <li>Implement and debug the <a target="_blank" href="SoC/soc.html#Bootblock">bootblock</a> code</li>
   <li>Implement and debug the call to <a target="_blank" href="SoC/soc.html#TempRamInit">TempRamInit</a></li>
+  <li>Enable the serial port
+    <ol type="A">
+      <li>Power on, enable and configure GPIOs for the
+        <a target="_blank" href="Board/board.html#SerialOutput">debug serial UART</a>
+      </li>
+      <li>Add the <a target="_blank" href="SoC/soc.html#SerialOutput">serial outupt</a>
+        support to romstage
+      </li>
+    </ol>
+  </li>
+  <li>Enable <a target="_blank" href="fsp1_1.html#corebootFspDebugging">coreboot/FSP</a> debugging</li>
 </ol>
 
 
@@ -106,6 +117,23 @@
       Disable: CONFIG_DISPLAY_MTRRS=y, MTRRs displayed after call to TempRamExit
     </td>
   </tr>
+
+
+  <tr bgcolor="#c0ffc0">
+    <th>Board</th>
+    <th>Where</th>
+    <th>Testing</th>
+  </tr>
+  <tr>
+    <td>Serial Port</td>
+    <td>
+      SoC <a target="_blank" href="SoC/soc.html#SerialOutput">Support</a><br>
+      Enable: src/soc/mainboard/&lt;Board&gt;/com_init.c/<a target="_blank" href="Board/board.html#SerialOutput">car_mainboard_pre_console_init</a>
+    </td>
+    <td>Debug serial output works</td>
+  </tr>
+
+
   <tr bgcolor="#c0ffc0">
     <th>FSP</th>
     <th>Where</th>

Documentation/Intel/fsp1_1.html

@@ -15,6 +15,7 @@
 <ol>
   <li><a href="#RequiredFiles">Required Files</a></li>
   <li>Add the <a href="#FspBinary">FSP Binary File</a> to the coreboot File System</li>
+  <li>Enable <a href="#corebootFspDebugging">coreboot/FSP Debugging</a></li>
 </ol>
 
 <p>
@@ -57,6 +58,19 @@
 </p>
 
 
+<hr>
+<h1><a name="corebootFspDebugging">Enable coreboot/FSP Debugging</a></h1>
+<p>
+  Set the following Kconfig values:
+</p>
+<ul>
+  <li>CONFIG_DISPLAY_FSP_ENTRY_POINTS - Display the FSP entry points in romstage</li>
+  <li>CONFIG_DISPLAY_HOBS - Display and verify the hand-off-blocks (HOBs) returned by MemoryInit</li>
+  <li>CONFIG_DISPLAY_VBT - Display Video BIOS Table (VBT) used for GOP</li>
+  <li>CONFIG_DISPLAY_UPD_DATA - Display the user specified product data passed to MemoryInit and SiliconInit</li>
+</ul>
+
+
 <hr>
 <p>Modified: 31 January 2016</p>
   </body>