- the jtag chain is examined and validated after GDB & telnet servers

are up and running. The examination and validation is actually
 "optional" from the point of view of GDB + telnet servers.
 Multiple targets should work fine with this.
- jtag_speed is dropped(divisor is increased), if jtag examination and
 validation fails.
- the chain is validated 10x to catch the worst jtag_speed offences
- added LOG_SILENT that can be used to shut up log. Feeble
 ersatz for try+catch.
- GDB register packets are now always replied in order to make sure
 that GDB connect works. If the target is not halted, then these
 packets contain dummy values.



git-svn-id: svn://svn.berlios.de/openocd/trunk@483 b42882b7-edfa-0310-969c-e2dbd0fdcd60

src/target/target.h

@@ -127,7 +127,15 @@ typedef struct target_type_s
 	int (*soft_reset_halt)(struct target_s *target);
 	int (*prepare_reset_halt)(struct target_s *target);
 	
-	/* target register access for gdb */
+	/* target register access for gdb.
+	 * 
+	 * Danger! this function will succeed even if the target is running
+	 * and return a register list with dummy values.
+	 * 
+	 * The reason is that GDB connection will fail without a valid register
+	 * list, however it is after GDB is connected that monitor commands can
+	 * be run to properly initialize the target
+	 */
 	int (*get_gdb_reg_list)(struct target_s *target, struct reg_s **reg_list[], int *reg_list_size);
 	
 	/* target memory access