gdb: enable target description support by default

This enables gdb target description support by default, it will check that
this is supported by the active target.

Change-Id: Iea5a5b94c5e373af30dacb780020b79536caa1e3
Signed-off-by: Spencer Oliver <spen@spen-soft.co.uk>
Reviewed-on: http://openocd.zylin.com/1618
Tested-by: jenkins
Reviewed-by: Andreas Fritiofson <andreas.fritiofson@gmail.com>

diff --git a/src/server/gdb_server.c b/src/server/gdb_server.c
index a9681c79716ea36f6c91d80b8ce0841e6f4c1ab7..a930ec4106b845603b722afcafa1012769fc3c6f 100644 (file)
--- a/src/server/gdb_server.c
+++ b/src/server/gdb_server.c
@@ -122,8 +122,8 @@ static int gdb_report_data_abort;
 
 /* set if we are sending target descriptions to gdb
  * via qXfer:features:read packet */
-/* disabled by default */
-static int gdb_use_target_description;
+/* enabled by default */
+static int gdb_use_target_description = 1;
 
 /* current processing free-run type, used by file-I/O */
 static char gdb_running_type;
@@ -2154,6 +2154,50 @@ static int gdb_get_target_description_chunk(struct target *target, char **chunk,
        return ERROR_OK;
 }
 
+static int gdb_target_description_supported(struct target *target, int *supported)
+{
+       int retval = ERROR_OK;
+       struct reg **reg_list = NULL;
+       int reg_list_size = 0;
+       int feature_list_size = 0;
+
+       retval = target_get_gdb_reg_list(target, &reg_list,
+                       &reg_list_size, REG_CLASS_ALL);
+       if (retval != ERROR_OK) {
+               LOG_ERROR("get register list failed");
+               goto error;
+       }
+
+       if (reg_list_size <= 0) {
+               retval = ERROR_FAIL;
+               goto error;
+       }
+
+       char **features = NULL;
+       /* Get a list of available target registers features */
+       retval = get_reg_features_list(target, &features, &feature_list_size, reg_list, reg_list_size);
+       if (retval != ERROR_OK) {
+               LOG_ERROR("Can't get the registers feature list");
+               goto error;
+       }
+
+       if (supported) {
+               if (feature_list_size)
+                       *supported = 1;
+               else
+                       *supported = 0;
+       }
+
+error:
+       if (reg_list != NULL)
+               free(reg_list);
+
+       if (features != NULL)
+               free(features);
+
+       return retval;
+}
+
 static int gdb_query_packet(struct connection *connection,
                char *packet, int packet_size)
 {
@@ -2218,11 +2262,26 @@ static int gdb_query_packet(struct connection *connection,
                }
        } else if (strncmp(packet, "qSupported", 10) == 0) {
                /* we currently support packet size and qXfer:memory-map:read (if enabled)
-                * disable qXfer:features:read for the moment */
+                * qXfer:features:read is supported for some targets */
                int retval = ERROR_OK;
                char *buffer = NULL;
                int pos = 0;
                int size = 0;
+               int gdb_target_desc_supported = 0;
+
+               /* we need to test that the target supports target descriptions */
+               retval = gdb_target_description_supported(target, &gdb_target_desc_supported);
+               if (retval != ERROR_OK) {
+                       LOG_INFO("Failed detecting Target Description Support, disabling");
+                       gdb_target_desc_supported = 0;
+               }
+
+               /* support may be disabled globally */
+               if (gdb_use_target_description == 0) {
+                       if (gdb_target_desc_supported)
+                               LOG_WARNING("Target Descriptions Supported, but disabled");
+                       gdb_target_desc_supported = 0;
+               }
 
                xml_printf(&retval,
                        &buffer,
@@ -2231,7 +2290,7 @@ static int gdb_query_packet(struct connection *connection,
                        "PacketSize=%x;qXfer:memory-map:read%c;qXfer:features:read%c;QStartNoAckMode+",
                        (GDB_BUFFER_SIZE - 1),
                        ((gdb_use_memory_map == 1) && (flash_get_bank_count() > 0)) ? '+' : '-',
-                       (gdb_use_target_description == 1) ? '+' : '-');
+                       (gdb_target_desc_supported == 1) ? '+' : '-');
 
                if (retval != ERROR_OK) {
                        gdb_send_error(connection, 01);