Hi,<div><br></div><div>It seems that l4_ipc_wait() will always set the sender to zero. I tested it in example at /pkg/examples/sys/ipc/ipc_example.c, in the l4re-2011081207 snapshot.</div><div><br></div><div>Here is the patch I applied to the file (to print out label):</div>
<div><br></div><div><div>--- a/ipc_example.c     2011-08-12 00:20:36.000000000 -0500</div><div>+++ b/ipc_example.c       2012-04-05 17:29:24.844608359 -0500</div><div>@@ -84,6 +84,7 @@</div><div>           continue;</div>
<div>         }</div><div> </div><div>+      printf (&quot;IPC from %lx, %d\n&quot;, label, label == 0);</div><div>       /* So, the IPC was ok, now take the value out of message register 0</div><div>        * of the UTCB and store the square of it back to it. */</div>
<div>       l4_utcb_mr()-&gt;mr[0] = l4_utcb_mr()-&gt;mr[0] * l4_utcb_mr()-&gt;mr[0];</div></div><div><br></div><div>And here is the result I got:</div><div><br></div><div>...</div><div><div>vandroid| Sending:  4</div><div>
vandroid| IPC from 0, 1</div><div>vandroid| Received: 16</div></div><div>...</div><div><br></div><div>So it seems that l4_ipc_wait() doesn&#39;t return the sender.</div><div><br></div><div>I&#39;m writing an OS on top of Fiasco.OC. This information is important for pager because it&#39;ll need it to figure out which page it&#39;ll map in.</div>
<div><br></div><div>Do you have any ideas to fix it, or any idea to work around it (at least L4Linux works)? Your comments are appreciated.</div><div><br></div><div>~Haohui</div>