Add instructions for 32-bit sim build

git-svn-id: https://nuttx.svn.sourceforge.net/svnroot/nuttx/trunk@2814 7fd9a85b-ad96-42d3-883c-3090e2eb8679

nuttx/Documentation/NXGraphicsSubsystem.html

@@ -12,7 +12,7 @@
       <h1><big><font color="#3c34ec">
         <i>NX Graphics Subsystem</i>
       </font></big></h1>
-      <p>Last Updated: April 23, 2010</p>
+      <p>Last Updated: July 27, 2010</p>
     </td>
   </tr>
 </table>
@@ -2746,6 +2746,7 @@ make
         <li>
           The sim target itself is broken under 64-bit Linux.
           This is because the sim target is based upon some assembly language setjmp/longjmp logic that only works on 32-bit systems.
+          <p><small><b>NOTE</b>: There is a workaround in this case; you can build for 32-bit execution on a 64-bit machine by adding <code>-m3</code> to the <code>CFLAGS</code> and <code>-m32 -m elf_i38</code> to the <code>LDFLAGS</code>.</small></p>
         </li>
       </ul>
     </p>

nuttx/TODO

@@ -1,4 +1,4 @@
-NuttX TODO List (Last updated July 19, 2010)
+NuttX TODO List (Last updated July 27, 2010)
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
   (5)  Task/Scheduler (sched/)
@@ -582,7 +582,13 @@ o Linux/Cywgin simulation (arch/sim)
                   to pointers on a 64-bit host.
                2) up_setjmp.S does not build
   Status:      Open
-  Priority:    Medium and increasing (as 32-bit hosts gradually disappear)
+  Priority:    Medium and increasing (as 32-bit hosts gradually disappear).  NOTE
+               is it possible to work-around this limitation by building the sim
+               target for 32-bit operation on a 64-bit platform.  Simply modify the
+               Make.defs file in the appropriate places so that:
+               
+               ARCHCPUFLAGS = -m32 -fno-builtin
+               LDFLAGS += -m32 -m elf_i386
 
 o ARM (arch/arm/)
   ^^^^^^^^^^^^^^^