patch to add semihosting control for remote arm targets

[Vadim Lebedev <vadim at 7chips dot com>]

When debugging remote arm targets using  devices such as JEENI  from epitools 
the semihosting function slows execution by the target of SWI instruction 
nearly 100-fold.  This is especially annoying when you try to debug  linux 
kernel on the target as it uses SWI to implement system calls.  
The attached patch adds a set rdisemihosting {on/off/1/0/true/false} command 
to the gdb which allows one to enable or disable semihosting suppport.
the command shoud be executed before target rdi ....  command
The patch is against gdb 5.3 but i think will apply to older versions cleanly 
too.




Chang log entry

 Wed Mar 12 13:00:00 2003  Vadim Lebedev  (vadim at 7chips.com)

	* remote-rdi.c 		add set rdisemihosting command



--- remote-rdi.c.orig	Wed Mar 12 11:59:55 2003
+++ remote-rdi.c	Wed Mar 12 12:02:23 2003
@@ -118,6 +118,10 @@ static int rdi_heartbeat = 0;
 /* Target has ROM at address 0. */
 static int rom_at_zero = 0;
 
+
+/* target has semihosting enabled */
+static int rdi_semihosting = 1;
+
 /* Enable logging? */
 static int log_enable = 0;
 
@@ -319,10 +323,19 @@ device is attached to the remote system 
 
   rslt = angel_RDI_info (RDIVector_Catch, &arg1, &arg2);
   if (rslt != RDIError_NoError)
-    {
-      printf_filtered ("RDI_info: %s\n", rdi_error_message (rslt));
-    }
+  {
+	  printf_filtered ("RDI_info: %s\n", rdi_error_message (rslt));
+  }
+
+  arg1 = rdi_semihosting ? 1 : 0;
+  
+  rslt = angel_RDI_info(RDISemiHosting_SetState,  &arg1, &arg2);
+  if (rslt != RDIError_NoError)
+  {
+	  printf_filtered ("RDI_info: %s\n", rdi_error_message (rslt));
+  }
 
+  
   arg1 = (unsigned long) "";
   rslt = angel_RDI_info (RDISet_Cmdline, &arg1, &arg2);
   if (rslt != RDIError_NoError)
@@ -1051,14 +1064,24 @@ _initialize_remote_rdi (void)
      &setlist, &showlist);
 
   add_setshow_boolean_cmd
-    ("rdiheartbeat", no_class, &rdi_heartbeat,
-     "Set enable for ADP heartbeat packets.\n"
-     "I don't know why you would want this. If you enable them,\n"
-     "it will confuse ARM and EPI JTAG interface boxes as well\n"
-     "as the Angel Monitor.\n",
-     "Show enable for ADP heartbeat packets.\n",
-     NULL, NULL,
-     &setlist, &showlist);
+		  ("rdiheartbeat", no_class, &rdi_heartbeat,
+		   "Set enable for ADP heartbeat packets.\n"
+		   "I don't know why you would want this. If you enable them,\n"
+		   "it will confuse ARM and EPI JTAG interface boxes as well\n"
+		   "as the Angel Monitor.\n",
+		   "Show enable for ADP heartbeat packets.\n",
+		   NULL, NULL,
+		   &setlist, &showlist);
+
+  add_setshow_boolean_cmd
+		  ("rdisemihosting", no_class, &rdi_semihosting,
+		   "Set semihosting support.\n"
+		   "A true value activates semihosting false value deactivates it.\n",
+		   "Show enable for semihosting.\n",
+		   NULL, NULL,
+		   &setlist, &showlist);
+
+  
 }
 
 /* A little dummy to make linking with the library succeed. */