Pavel Chromy: performance tweak of gdb_put_packet_inner() removing malloc and avoidin...
[fw/openocd] / src / server / gdb_server.c
index 175e06740e9c75b89bb031116d2fe1dcb19d9e2b..1fac46972a9e4f6c9c3bae36313f396012272421 100644 (file)
 #include "server.h"
 #include "log.h"
 #include "binarybuffer.h"
+#include "jtag.h"
 #include "breakpoints.h"
 #include "flash.h"
 #include "target_request.h"
+#include "configuration.h"
 
-#define __USE_GNU
 #include <string.h>
 #include <errno.h>
 #include <unistd.h>
 #define _DEBUG_GDB_IO_
 #endif
 
+extern int gdb_error(connection_t *connection, int retval);
 static unsigned short gdb_port;
+static const char *DIGITS = "0123456789abcdef";
+
+static void gdb_log_callback(void *priv, const char *file, int line,
+               const char *function, const char *string);
 
 enum gdb_detach_mode
 {
@@ -52,8 +58,18 @@ enum gdb_detach_mode
        GDB_DETACH_NOTHING
 };
 
+/* target behaviour on gdb detach */
 enum gdb_detach_mode detach_mode = GDB_DETACH_RESUME;
 
+/* set if we are sending a memory map to gdb
+ * via qXfer:memory-map:read packet */
+int gdb_use_memory_map = 0;
+int gdb_flash_program = 0;
+
+/* if set, data aborts cause an error to be reported in memory read packets
+ * see the code in gdb_read_memory_packet() for further explanations */
+int gdb_report_data_abort = 0;
+
 int gdb_last_signal(target_t *target)
 {
        switch (target->debug_reason)
@@ -69,15 +85,62 @@ int gdb_last_signal(target_t *target)
                case DBG_REASON_NOTHALTED:
                        return 0x0; /* no signal... shouldn't happen */
                default:
-                       ERROR("BUG: undefined debug reason");
-                       exit(-1);
+                       USER("undefined debug reason %d - target needs reset", target->debug_reason);
+                       return 0x0;
        }
 }
 
+#ifndef _WIN32
+int check_pending(connection_t *connection, int timeout_s, int *got_data)
+{
+       /* a non-blocking socket will block if there is 0 bytes available on the socket,
+        * but return with as many bytes as are available immediately
+        */
+       struct timeval tv;
+       fd_set read_fds;
+       gdb_connection_t *gdb_con = connection->priv;
+       int t;
+       if (got_data==NULL)
+               got_data=&t;
+       *got_data=0;
+
+       if (gdb_con->buf_cnt>0)
+       {
+               *got_data = 1;
+               return ERROR_OK;
+       }
+       
+       FD_ZERO(&read_fds);
+       FD_SET(connection->fd, &read_fds);
+       
+       tv.tv_sec = timeout_s;
+       tv.tv_usec = 0;
+       if (select(connection->fd + 1, &read_fds, NULL, NULL, &tv) == 0)
+       {
+               /* This can typically be because a "monitor" command took too long
+                * before printing any progress messages
+                */
+               if (timeout_s>0)
+               {
+                       return ERROR_GDB_TIMEOUT;
+               } else
+               {
+                       return ERROR_OK;
+               }
+       }
+       *got_data=FD_ISSET(connection->fd, &read_fds)!=0;
+       return ERROR_OK;
+}
+#endif
+
 int gdb_get_char(connection_t *connection, int* next_char)
 {
        gdb_connection_t *gdb_con = connection->priv;
+       int retval=ERROR_OK;
+
+#ifdef _DEBUG_GDB_IO_
        char *debug_buffer;
+#endif
 
        if (gdb_con->buf_cnt-- > 0)
        {
@@ -94,10 +157,23 @@ int gdb_get_char(connection_t *connection, int* next_char)
                return ERROR_OK;
        }
 
-       while ((gdb_con->buf_cnt = read_socket(connection->fd, gdb_con->buffer, GDB_BUFFER_SIZE)) <= 0)
+       for (;;)
        {
+#ifndef _WIN32
+               retval=check_pending(connection, 1, NULL);
+               if (retval!=ERROR_OK)
+                       return retval;
+#endif
+               gdb_con->buf_cnt = read_socket(connection->fd, gdb_con->buffer, GDB_BUFFER_SIZE);
+               if (gdb_con->buf_cnt > 0)
+               {
+                       break;
+               }
                if (gdb_con->buf_cnt == 0)
+               {
+                       gdb_con->closed = 1;
                        return ERROR_SERVER_REMOTE_CLOSED;
+               }
 
 #ifdef _WIN32
                errno = WSAGetLastError();
@@ -108,6 +184,10 @@ int gdb_get_char(connection_t *connection, int* next_char)
                                usleep(1000);
                                break;
                        case WSAECONNABORTED:
+                               gdb_con->closed = 1;
+                               return ERROR_SERVER_REMOTE_CLOSED;
+                       case WSAECONNRESET:
+                               gdb_con->closed = 1;
                                return ERROR_SERVER_REMOTE_CLOSED;
                        default:
                                ERROR("read: %d", errno);
@@ -120,21 +200,26 @@ int gdb_get_char(connection_t *connection, int* next_char)
                                usleep(1000);
                                break;
                        case ECONNABORTED:
+                               gdb_con->closed = 1;
                                return ERROR_SERVER_REMOTE_CLOSED;
                        case ECONNRESET:
+                               gdb_con->closed = 1;
                                return ERROR_SERVER_REMOTE_CLOSED;
                        default:
                                ERROR("read: %s", strerror(errno));
-                               exit(-1);
+                               gdb_con->closed = 1;
+                               return ERROR_SERVER_REMOTE_CLOSED;
                }
 #endif
        }
 
+#ifdef _DEBUG_GDB_IO_
        debug_buffer = malloc(gdb_con->buf_cnt + 1);
        memcpy(debug_buffer, gdb_con->buffer, gdb_con->buf_cnt);
        debug_buffer[gdb_con->buf_cnt] = 0;
        DEBUG("received '%s'", debug_buffer);
        free(debug_buffer);
+#endif
 
        gdb_con->buf_p = gdb_con->buffer;
        gdb_con->buf_cnt--;
@@ -142,12 +227,12 @@ int gdb_get_char(connection_t *connection, int* next_char)
        if (gdb_con->buf_cnt > 0)
                connection->input_pending = 1;
        else
-               connection->input_pending = 0;  
+               connection->input_pending = 0;
 #ifdef _DEBUG_GDB_IO_
        DEBUG("returned char '%c' (0x%2.2x)", *next_char, *next_char);
 #endif
 
-       return ERROR_OK;
+       return retval;
 }
 
 int gdb_putback_char(connection_t *connection, int last_char)
@@ -161,18 +246,36 @@ int gdb_putback_char(connection_t *connection, int last_char)
        }
        else
        {
-               ERROR("BUG: couldn't put character back");      
+               ERROR("BUG: couldn't put character back");
        }
 
        return ERROR_OK;
 }
 
-int gdb_put_packet(connection_t *connection, char *buffer, int len)
+/* The only way we can detect that the socket is closed is the first time
+ * we write to it, we will fail. Subsequent write operations will
+ * succeed. Shudder! */
+int gdb_write(connection_t *connection, void *data, int len)
+{
+       gdb_connection_t *gdb_con = connection->priv;
+       if (gdb_con->closed)
+               return ERROR_SERVER_REMOTE_CLOSED;
+
+       if (write_socket(connection->fd, data, len) == len)
+       {
+               return ERROR_OK;
+       }
+       gdb_con->closed = 1;
+       return ERROR_SERVER_REMOTE_CLOSED;
+}
+
+int gdb_put_packet_inner(connection_t *connection, char *buffer, int len)
 {
        int i;
        unsigned char my_checksum = 0;
-       char checksum[3];
+#ifdef _DEBUG_GDB_IO_
        char *debug_buffer;
+#endif
        int reply;
        int retval;
        gdb_connection_t *gdb_con = connection->priv;
@@ -180,22 +283,59 @@ int gdb_put_packet(connection_t *connection, char *buffer, int len)
        for (i = 0; i < len; i++)
                my_checksum += buffer[i];
 
+#ifdef _DEBUG_GDB_IO_
+       /* 
+        * At this point we should have nothing in the input queue from GDB,
+        * however sometimes '-' is sent even though we've already received
+        * an ACK (+) for everything we've sent off.
+        */
+#ifndef _WIN32
+       int gotdata;
+       for (;;)
+       {
+               if ((retval=check_pending(connection, 0, &gotdata))!=ERROR_OK)
+                       return retval;
+               if (!gotdata)
+                       break;
+               if ((retval = gdb_get_char(connection, &reply)) != ERROR_OK)
+                       return retval;
+               WARNING("Discard unexpected char %c", reply);
+       }
+#endif
+#endif
+
        while (1)
        {
+#ifdef _DEBUG_GDB_IO_
                debug_buffer = malloc(len + 1);
                memcpy(debug_buffer, buffer, len);
                debug_buffer[len] = 0;
                DEBUG("sending packet '$%s#%2.2x'", debug_buffer, my_checksum);
                free(debug_buffer);
+#endif
 
-               write_socket(connection->fd, "$", 1);
-               if (len > 0)
-                       write_socket(connection->fd, buffer, len);
-               write_socket(connection->fd, "#", 1);
-
-               snprintf(checksum, 3, "%2.2x", my_checksum);
-
-               write_socket(connection->fd, checksum, 2);
+               char local_buffer[1024];
+               local_buffer[0] = '$';
+               if (len+4 <= sizeof(local_buffer))
+               {
+                       /* performance gain on smaller packets by only a single call to gdb_write() */
+                       memcpy(local_buffer+1, buffer, len++);
+                       local_buffer[len++] = '#';
+                       local_buffer[len++] = DIGITS[(my_checksum >> 4) & 0xf];
+                       local_buffer[len++] = DIGITS[my_checksum & 0xf];
+                       gdb_write(connection, local_buffer, len);
+               }
+               else
+               {
+                       /* larger packets are transmitted directly from caller supplied buffer
+                          by several calls to gdb_write() to avoid dynamic allocation */
+                       local_buffer[1] = '#';
+                       local_buffer[2] = DIGITS[(my_checksum >> 4) & 0xf];
+                       local_buffer[3] = DIGITS[my_checksum & 0xf];
+                       gdb_write(connection, local_buffer, 1);
+                       gdb_write(connection, buffer, len);
+                       gdb_write(connection, local_buffer+1, 3);
+               }
 
                if ((retval = gdb_get_char(connection, &reply)) != ERROR_OK)
                        return retval;
@@ -203,7 +343,11 @@ int gdb_put_packet(connection_t *connection, char *buffer, int len)
                if (reply == '+')
                        break;
                else if (reply == '-')
+               {
+                       /* Stop sending output packets for now */
+                       log_remove_callback(gdb_log_callback, connection);
                        WARNING("negative reply, retrying");
+               }
                else if (reply == 0x3)
                {
                        gdb_con->ctrl_c = 1;
@@ -212,24 +356,41 @@ int gdb_put_packet(connection_t *connection, char *buffer, int len)
                        if (reply == '+')
                                break;
                        else if (reply == '-')
+                       {
+                               /* Stop sending output packets for now */
+                               log_remove_callback(gdb_log_callback, connection);
                                WARNING("negative reply, retrying");
+                       }
                        else
                        {
                                ERROR("unknown character 0x%2.2x in reply, dropping connection", reply);
+                               gdb_con->closed=1;
                                return ERROR_SERVER_REMOTE_CLOSED;
                        }
                }
                else
                {
                        ERROR("unknown character 0x%2.2x in reply, dropping connection", reply);
+                       gdb_con->closed=1;
                        return ERROR_SERVER_REMOTE_CLOSED;
                }
        }
+       if (gdb_con->closed)
+               return ERROR_SERVER_REMOTE_CLOSED;
 
        return ERROR_OK;
 }
 
-int gdb_get_packet(connection_t *connection, char *buffer, int *len)
+int gdb_put_packet(connection_t *connection, char *buffer, int len)
+{
+       gdb_connection_t *gdb_con = connection->priv;
+       gdb_con->busy = 1;
+       int retval = gdb_put_packet_inner(connection, buffer, len);
+       gdb_con->busy = 0;
+       return retval;
+}
+
+int gdb_get_packet_inner(connection_t *connection, char *buffer, int *len)
 {
        int character;
        int count = 0;
@@ -245,7 +406,9 @@ int gdb_get_packet(connection_t *connection, char *buffer, int *len)
                        if ((retval = gdb_get_char(connection, &character)) != ERROR_OK)
                                return retval;
 
+#ifdef _DEBUG_GDB_IO_
                        DEBUG("character: '%c'", character);
+#endif
 
                        switch (character)
                        {
@@ -269,12 +432,69 @@ int gdb_get_packet(connection_t *connection, char *buffer, int *len)
 
                my_checksum = 0;
 
-               do
+               count = 0;
+               gdb_connection_t *gdb_con = connection->priv;
+               for (;;)
                {
+                       /* The common case is that we have an entire packet with no escape chars.
+                        * We need to leave at least 2 bytes in the buffer to have
+                        * gdb_get_char() update various bits and bobs correctly.
+                        */
+                       if ((gdb_con->buf_cnt > 2) && ((gdb_con->buf_cnt+count) < *len))
+                       {
+                               /* The compiler will struggle a bit with constant propagation and
+                                * aliasing, so we help it by showing that these values do not
+                                * change inside the loop
+                                */
+                               int i;
+                               char *buf = gdb_con->buf_p;
+                               int run = gdb_con->buf_cnt - 2;
+                               i = 0;
+                               int done = 0;
+                               while (i < run)
+                               {
+                                       character = *buf++;
+                                       i++;
+                                       if (character == '#')
+                                       {
+                                               /* Danger! character can be '#' when esc is
+                                                * used so we need an explicit boolean for done here.
+                                                */
+                                               done = 1;
+                                               break;
+                                       }
+
+                                       if (character == '}')
+                                       {
+                                               /* data transmitted in binary mode (X packet)
+                                                * uses 0x7d as escape character */
+                                               my_checksum += character & 0xff;
+                                               character = *buf++;
+                                               i++;
+                                               my_checksum += character & 0xff;
+                                               buffer[count++] = (character ^ 0x20) & 0xff;
+                                       } else
+                                       {
+                                               my_checksum += character & 0xff;
+                                               buffer[count++] = character & 0xff;
+                                       }
+                               }
+                               gdb_con->buf_p += i;
+                               gdb_con->buf_cnt -= i;
+                               if (done)
+                                       break;
+                       }
+                       if (count > *len)
+                       {
+                               ERROR("packet buffer too small");
+                               return ERROR_GDB_BUFFER_TOO_SMALL;
+                       }
+
                        if ((retval = gdb_get_char(connection, &character)) != ERROR_OK)
                                return retval;
 
-                       if (character == '#') break;
+                       if (character == '#')
+                               break;
 
                        if (character == '}')
                        {
@@ -292,12 +512,7 @@ int gdb_get_packet(connection_t *connection, char *buffer, int *len)
                                buffer[count++] = character & 0xff;
                        }
 
-                       if (count > *len)
-                       {
-                               ERROR("packet buffer too small");
-                               return ERROR_GDB_BUFFER_TOO_SMALL;
-                       }
-               } while (1);
+               }
 
                *len = count;
 
@@ -311,40 +526,81 @@ int gdb_get_packet(connection_t *connection, char *buffer, int *len)
 
                if (my_checksum == strtoul(checksum, NULL, 16))
                {
-                       write_socket(connection->fd, "+", 1);
+                       gdb_write(connection, "+", 1);
                        break;
                }
 
                WARNING("checksum error, requesting retransmission");
-               write_socket(connection->fd, "-", 1);
+               gdb_write(connection, "-", 1);
        }
+       if (gdb_con->closed)
+               return ERROR_SERVER_REMOTE_CLOSED;
 
        return ERROR_OK;
 }
 
-int gdb_output(struct command_context_s *context, char* line)
+int gdb_get_packet(connection_t *connection, char *buffer, int *len)
+{
+       gdb_connection_t *gdb_con = connection->priv;
+       gdb_con->busy = 1;
+       int retval = gdb_get_packet_inner(connection, buffer, len);
+       gdb_con->busy = 0;
+       return retval;
+}
+
+int gdb_output_con(connection_t *connection, const char* line)
 {
-       connection_t *connection = context->output_handler_priv;
        char *hex_buffer;
        int i, bin_size;
 
        bin_size = strlen(line);
 
-       hex_buffer = malloc(bin_size*2 + 4);
+       hex_buffer = malloc(bin_size*2 + 2);
+       if (hex_buffer == NULL)
+               return ERROR_GDB_BUFFER_TOO_SMALL;
 
        hex_buffer[0] = 'O';
        for (i=0; i<bin_size; i++)
                snprintf(hex_buffer + 1 + i*2, 3, "%2.2x", line[i]);
-       hex_buffer[bin_size*2+1] = '0';
-       hex_buffer[bin_size*2+2] = 'a';
-       hex_buffer[bin_size*2+3] = 0x0;
+       hex_buffer[bin_size*2+1] = 0;
 
-       gdb_put_packet(connection, hex_buffer, bin_size*2 + 3);
+       gdb_put_packet(connection, hex_buffer, bin_size*2 + 1);
 
        free(hex_buffer);
        return ERROR_OK;
 }
 
+int gdb_output(struct command_context_s *context, char* line)
+{
+       /* this will be dumped to the log and also sent as an O packet if possible */
+       USER_N("%s", line);
+       return ERROR_OK;
+}
+
+int gdb_program_handler(struct target_s *target, enum target_event event, void *priv)
+{
+       FILE *script;
+       struct command_context_s *cmd_ctx = priv;
+
+       if (target->gdb_program_script)
+       {
+               script = open_file_from_path(target->gdb_program_script, "r");
+               if (!script)
+               {
+                       ERROR("couldn't open script file %s", target->gdb_program_script);
+                               return ERROR_OK;
+               }
+
+               INFO("executing gdb_program script '%s'", target->gdb_program_script);
+               command_run_file(cmd_ctx, script, COMMAND_EXEC);
+               fclose(script);
+
+               jtag_execute_queue();
+       }
+
+       return ERROR_OK;
+}
+
 int gdb_target_callback_event_handler(struct target_s *target, enum target_event event, void *priv)
 {
        connection_t *connection = priv;
@@ -355,8 +611,20 @@ int gdb_target_callback_event_handler(struct target_s *target, enum target_event
        switch (event)
        {
                case TARGET_EVENT_HALTED:
+                       /* In the GDB protocol when we are stepping or coninuing execution,
+                        * we have a lingering reply. Upon receiving a halted event
+                        * when we have that lingering packet, we reply to the original
+                        * step or continue packet.
+                        *
+                        * Executing monitor commands can bring the target in and
+                        * out of the running state so we'll see lots of TARGET_EVENT_XXX
+                        * that are to be ignored.
+                        */
                        if (gdb_connection->frontend_state == TARGET_RUNNING)
                        {
+                               /* stop forwarding log packets! */
+                               log_remove_callback(gdb_log_callback, connection);
+
                                if (gdb_connection->ctrl_c)
                                {
                                        signal = 0x2;
@@ -372,11 +640,8 @@ int gdb_target_callback_event_handler(struct target_s *target, enum target_event
                                gdb_connection->frontend_state = TARGET_HALTED;
                        }
                        break;
-               case TARGET_EVENT_RESUMED:
-                       if (gdb_connection->frontend_state == TARGET_HALTED)
-                       {
-                               gdb_connection->frontend_state = TARGET_RUNNING;
-                       }
+               case TARGET_EVENT_GDB_PROGRAM:
+                       gdb_program_handler(target, event, connection->cmd_ctx);
                        break;
                default:
                        break;
@@ -385,6 +650,7 @@ int gdb_target_callback_event_handler(struct target_s *target, enum target_event
        return ERROR_OK;
 }
 
+
 int gdb_new_connection(connection_t *connection)
 {
        gdb_connection_t *gdb_connection = malloc(sizeof(gdb_connection_t));
@@ -400,30 +666,39 @@ int gdb_new_connection(connection_t *connection)
        gdb_connection->ctrl_c = 0;
        gdb_connection->frontend_state = TARGET_HALTED;
        gdb_connection->vflash_image = NULL;
+       gdb_connection->closed = 0;
+       gdb_connection->busy = 0;
+       
+       /* send ACK to GDB for debug request */
+       gdb_write(connection, "+", 1);
 
        /* output goes through gdb connection */
        command_set_output_handler(connection->cmd_ctx, gdb_output, connection);
 
        /* register callback to be informed about target events */
-       target_register_event_callback(gdb_target_callback_event_handler, connection);  
-
-       /* a gdb session just attached, put the target in halt mode */
+       target_register_event_callback(gdb_target_callback_event_handler, connection);
+
+       /* a gdb session just attached, try to put the target in halt mode
+        * or alterantively try to issue a reset.
+        *
+        * GDB connection will fail if e.g. register read packets fail,
+        * otherwise resetting/halting the target could have been left to GDB init
+        * scripts
+        */
        if (((retval = gdb_service->target->type->halt(gdb_service->target)) != ERROR_OK) &&
                        (retval != ERROR_TARGET_ALREADY_HALTED))
        {
-               ERROR("error when trying to halt target");
-               exit(-1);
-       }
-
-       while (gdb_service->target->state != TARGET_HALTED)
-       {
-               gdb_service->target->type->poll(gdb_service->target);
+               ERROR("error(%d) when trying to halt target, falling back to \"reset\"", retval);
+               command_run_line(connection->cmd_ctx, "reset");
        }
-
+       
        /* remove the initial ACK from the incoming buffer */
        if ((retval = gdb_get_char(connection, &initial_ack)) != ERROR_OK)
                return retval;
 
+       /* FIX!!!??? would we actually ever receive a + here??? 
+        * Not observed.
+        */
        if (initial_ack != '+')
                gdb_putback_char(connection, initial_ack);
 
@@ -445,13 +720,19 @@ int gdb_connection_closed(connection_t *connection)
 
        /* if this connection registered a debug-message receiver delete it */
        delete_debug_msg_receiver(connection->cmd_ctx, gdb_service->target);
-       
+
        if (connection->priv)
+       {
                free(connection->priv);
+               connection->priv = NULL;
+       }
        else
+       {
                ERROR("BUG: connection->priv == NULL");
+       }
 
        target_unregister_event_callback(gdb_target_callback_event_handler, connection);
+       log_remove_callback(gdb_log_callback, connection);
 
        return ERROR_OK;
 }
@@ -476,32 +757,34 @@ int gdb_last_signal_packet(connection_t *connection, target_t *target, char* pac
        return ERROR_OK;
 }
 
-void gdb_str_to_target(target_t *target, char *str, char *tstr)
+/* Convert register to string of bits. NB! The # of bits in the
+ * register might be non-divisible by 8(a byte), in which
+ * case an entire byte is shown. */
+void gdb_str_to_target(target_t *target, char *tstr, reg_t *reg)
 {
-       int str_len = strlen(str);
        int i;
 
-       if (str_len % 2)
-       {
-               ERROR("BUG: gdb value with uneven number of characters encountered: %s", str);
-               exit(-1);
-       }
+       u8 *buf;
+       int buf_len;
+       buf = reg->value;
+       buf_len = CEIL(reg->size, 8);
 
        if (target->endianness == TARGET_LITTLE_ENDIAN)
        {
-               for (i = 0; i < str_len; i+=2)
+               for (i = 0; i < buf_len; i++)
                {
-                       tstr[str_len - i - 1] = str[i + 1];
-                       tstr[str_len - i - 2] = str[i];
+                       tstr[i*2]   = DIGITS[(buf[i]>>4) & 0xf];
+                       tstr[i*2+1] = DIGITS[buf[i]&0xf];
                }
        }
        else
        {
-               for (i = 0; i < str_len; i++)
+               for (i = 0; i < buf_len; i++)
                {
-                       tstr[i] = str[i];
+                       tstr[(buf_len-1-i)*2]   = DIGITS[(buf[i]>>4)&0xf];
+                       tstr[(buf_len-1-i)*2+1] = DIGITS[buf[i]&0xf];
                }
-       }       
+       }
 }
 
 void gdb_target_to_str(target_t *target, char *tstr, char *str)
@@ -529,7 +812,7 @@ void gdb_target_to_str(target_t *target, char *tstr, char *str)
                {
                        str[i] = tstr[i];
                }
-       }       
+       }
 }
 
 int gdb_get_registers_packet(connection_t *connection, target_t *target, char* packet, int packet_size)
@@ -542,20 +825,13 @@ int gdb_get_registers_packet(connection_t *connection, target_t *target, char* p
        char *reg_packet_p;
        int i;
 
+#ifdef _DEBUG_GDB_IO_
        DEBUG("-");
+#endif
 
        if ((retval = target->type->get_gdb_reg_list(target, &reg_list, &reg_list_size)) != ERROR_OK)
        {
-               switch (retval)
-               {
-                       case ERROR_TARGET_NOT_HALTED:
-                               ERROR("gdb requested registers but we're not halted, dropping connection");
-                               return ERROR_SERVER_REMOTE_CLOSED;
-                       default:
-                               /* this is a bug condition - get_gdb_reg_list() may not return any other error */
-                               ERROR("BUG: unexpected error returned by get_gdb_reg_list()");
-                               exit(-1);
-               }
+               return gdb_error(connection, retval);
        }
 
        for (i = 0; i < reg_list_size; i++)
@@ -568,16 +844,18 @@ int gdb_get_registers_packet(connection_t *connection, target_t *target, char* p
 
        for (i = 0; i < reg_list_size; i++)
        {
-               char *hex_buf = buf_to_str(reg_list[i]->value, reg_list[i]->size, 16);
-               DEBUG("hex_buf: %s", hex_buf);
-               gdb_str_to_target(target, hex_buf, reg_packet_p);
+               gdb_str_to_target(target, reg_packet_p, reg_list[i]);
                reg_packet_p += CEIL(reg_list[i]->size, 8) * 2;
-               free(hex_buf);
        }
 
-       reg_packet_p = strndup(reg_packet, CEIL(reg_packet_size, 8) * 2);
-       DEBUG("reg_packet: %s", reg_packet_p);
-       free(reg_packet_p);
+#ifdef _DEBUG_GDB_IO_
+       {
+               char *reg_packet_p;
+               reg_packet_p = strndup(reg_packet, CEIL(reg_packet_size, 8) * 2);
+               DEBUG("reg_packet: %s", reg_packet_p);
+               free(reg_packet_p);
+       }
+#endif
 
        gdb_put_packet(connection, reg_packet, CEIL(reg_packet_size, 8) * 2);
        free(reg_packet);
@@ -595,7 +873,9 @@ int gdb_set_registers_packet(connection_t *connection, target_t *target, char *p
        int retval;
        char *packet_p;
 
+#ifdef _DEBUG_GDB_IO_
        DEBUG("-");
+#endif
 
        /* skip command character */
        packet++;
@@ -609,16 +889,7 @@ int gdb_set_registers_packet(connection_t *connection, target_t *target, char *p
 
        if ((retval = target->type->get_gdb_reg_list(target, &reg_list, &reg_list_size)) != ERROR_OK)
        {
-               switch (retval)
-               {
-                       case ERROR_TARGET_NOT_HALTED:
-                               ERROR("gdb tried to registers but we're not halted, dropping connection");
-                               return ERROR_SERVER_REMOTE_CLOSED;
-                       default:
-                               /* this is a bug condition - get_gdb_reg_list() may not return any other error */
-                               ERROR("BUG: unexpected error returned by get_gdb_reg_list()");
-                               exit(-1);
-               }
+               return gdb_error(connection, retval);
        }
 
        packet_p = packet;
@@ -636,7 +907,7 @@ int gdb_set_registers_packet(connection_t *connection, target_t *target, char *p
                bin_buf = malloc(CEIL(reg_list[i]->size, 8));
                str_to_buf(hex_buf, CEIL(reg_list[i]->size, 8) * 2, bin_buf, reg_list[i]->size, 16);
 
-               /* get register arch_type, and call set method */       
+               /* get register arch_type, and call set method */
                arch_type = register_get_arch_type(reg_list[i]->arch_type);
                if (arch_type == NULL)
                {
@@ -645,14 +916,14 @@ int gdb_set_registers_packet(connection_t *connection, target_t *target, char *p
                }
                arch_type->set(reg_list[i], bin_buf);
 
-               /* advance packet pointer */            
+               /* advance packet pointer */
                packet_p += (CEIL(reg_list[i]->size, 8) * 2);
 
                free(bin_buf);
                free(hex_buf);
        }
 
-       /* free reg_t *reg_list[] array allocated by get_gdb_reg_list */ 
+       /* free reg_t *reg_list[] array allocated by get_gdb_reg_list */
        free(reg_list);
 
        gdb_put_packet(connection, "OK", 2);
@@ -667,22 +938,14 @@ int gdb_get_register_packet(connection_t *connection, target_t *target, char *pa
        reg_t **reg_list;
        int reg_list_size;
        int retval;
-       char *hex_buf;
 
+#ifdef _DEBUG_GDB_IO_
        DEBUG("-");
+#endif
 
        if ((retval = target->type->get_gdb_reg_list(target, &reg_list, &reg_list_size)) != ERROR_OK)
        {
-               switch (retval)
-               {
-                       case ERROR_TARGET_NOT_HALTED:
-                               ERROR("gdb requested registers but we're not halted, dropping connection");
-                               return ERROR_SERVER_REMOTE_CLOSED;
-                       default:
-                               /* this is a bug condition - get_gdb_reg_list() may not return any other error */
-                               ERROR("BUG: unexpected error returned by get_gdb_reg_list()");
-                               exit(-1);
-               }
+               return gdb_error(connection, retval);
        }
 
        if (reg_list_size <= reg_num)
@@ -693,15 +956,12 @@ int gdb_get_register_packet(connection_t *connection, target_t *target, char *pa
 
        reg_packet = malloc(CEIL(reg_list[reg_num]->size, 8) * 2);
 
-       hex_buf = buf_to_str(reg_list[reg_num]->value, reg_list[reg_num]->size, 16);
-
-       gdb_str_to_target(target, hex_buf, reg_packet);
+       gdb_str_to_target(target, reg_packet, reg_list[reg_num]);
 
        gdb_put_packet(connection, reg_packet, CEIL(reg_list[reg_num]->size, 8) * 2);
 
        free(reg_list);
        free(reg_packet);
-       free(hex_buf);
 
        return ERROR_OK;
 }
@@ -721,22 +981,13 @@ int gdb_set_register_packet(connection_t *connection, target_t *target, char *pa
 
        if ((retval = target->type->get_gdb_reg_list(target, &reg_list, &reg_list_size)) != ERROR_OK)
        {
-               switch (retval)
-               {
-                       case ERROR_TARGET_NOT_HALTED:
-                               ERROR("gdb tried to set a register but we're not halted, dropping connection");
-                               return ERROR_SERVER_REMOTE_CLOSED;
-                       default:
-                               /* this is a bug condition - get_gdb_reg_list() may not return any other error */
-                               ERROR("BUG: unexpected error returned by get_gdb_reg_list()");
-                               exit(-1);
-               }
+               return gdb_error(connection, retval);
        }
 
        if (reg_list_size < reg_num)
        {
                ERROR("gdb requested a non-existing register");
-               return ERROR_SERVER_REMOTE_CLOSED;
+               return ERROR_SERVER_REMOTE_CLOSED;      
        }
 
        if (*separator != '=')
@@ -753,7 +1004,7 @@ int gdb_set_register_packet(connection_t *connection, target_t *target, char *pa
        bin_buf = malloc(CEIL(reg_list[reg_num]->size, 8));
        str_to_buf(hex_buf, CEIL(reg_list[reg_num]->size, 8) * 2, bin_buf, reg_list[reg_num]->size, 16);
 
-       /* get register arch_type, and call set method */       
+       /* get register arch_type, and call set method */
        arch_type = register_get_arch_type(reg_list[reg_num]->arch_type);
        if (arch_type == NULL)
        {
@@ -771,14 +1022,10 @@ int gdb_set_register_packet(connection_t *connection, target_t *target, char *pa
        return ERROR_OK;
 }
 
-int gdb_memory_packet_error(connection_t *connection, int retval)
+int gdb_error(connection_t *connection, int retval)
 {
        switch (retval)
        {
-               case ERROR_TARGET_NOT_HALTED:
-                       ERROR("gdb tried to read memory but we're not halted, dropping connection");
-                       return ERROR_SERVER_REMOTE_CLOSED;
-                       break;
                case ERROR_TARGET_DATA_ABORT:
                        gdb_send_error(connection, EIO);
                        break;
@@ -788,14 +1035,24 @@ int gdb_memory_packet_error(connection_t *connection, int retval)
                case ERROR_TARGET_UNALIGNED_ACCESS:
                        gdb_send_error(connection, EFAULT);
                        break;
+               case ERROR_TARGET_NOT_HALTED:
+                       gdb_send_error(connection, EFAULT);
+                       break;
                default:
-                       ERROR("BUG: unexpected error %i", retval);
-                       exit(-1);
+                       /* This could be that the target reset itself. */
+                       ERROR("unexpected error %i", retval);
+                       gdb_send_error(connection, EFAULT);
+                       break;
        }
 
        return ERROR_OK;
 }
 
+/* We don't have to worry about the default 2 second timeout for GDB packets,
+ * because GDB breaks up large memory reads into smaller reads.
+ *
+ * 8191 bytes by the looks of it. Why 8191 bytes instead of 8192?????
+ */
 int gdb_read_memory_packet(connection_t *connection, target_t *target, char *packet, int packet_size)
 {
        char *separator;
@@ -805,8 +1062,7 @@ int gdb_read_memory_packet(connection_t *connection, target_t *target, char *pac
        u8 *buffer;
        char *hex_buffer;
 
-       int i;
-       int retval;
+       int retval = ERROR_OK;
 
        /* skip command character */
        packet++;
@@ -825,33 +1081,37 @@ int gdb_read_memory_packet(connection_t *connection, target_t *target, char *pac
 
        DEBUG("addr: 0x%8.8x, len: 0x%8.8x", addr, len);
 
-       switch (len)
+       retval = target_read_buffer(target, addr, len, buffer);
+
+       if ((retval == ERROR_TARGET_DATA_ABORT) && (!gdb_report_data_abort))
        {
-               case 4:
-                       if ((addr % 4) == 0)
-                               retval = target->type->read_memory(target, addr, 4, 1, buffer);
-                       else
-                               retval = target->type->read_memory(target, addr, 1, len, buffer);
-                       break;
-               case 2:
-                       if ((addr % 2) == 0)
-                               retval = target->type->read_memory(target, addr, 2, 1, buffer);
-                       else
-                               retval = target->type->read_memory(target, addr, 1, len, buffer);
-                       break;
-               default:
-                       if (((addr % 4) == 0) && ((len % 4) == 0))
-                               retval = target->type->read_memory(target, addr, 4, len / 4, buffer);
-                       else
-                               retval = target->type->read_memory(target, addr, 1, len, buffer);
+               /* TODO : Here we have to lie and send back all zero's lest stack traces won't work.
+                * At some point this might be fixed in GDB, in which case this code can be removed.
+                *
+                * OpenOCD developers are acutely aware of this problem, but there is nothing
+                * gained by involving the user in this problem that hopefully will get resolved
+                * eventually
+                *
+                * http://sourceware.org/cgi-bin/gnatsweb.pl?cmd=view%20audit-trail&database=gdb&pr=2395
+                *
+                * For now, the default is to fix up things to make current GDB versions work.
+                * This can be overwritten using the gdb_report_data_abort <'enable'|'disable'> command.
+                */
+               memset(buffer, 0, len);
+               retval = ERROR_OK;
        }
 
        if (retval == ERROR_OK)
        {
                hex_buffer = malloc(len * 2 + 1);
 
-               for (i=0; i<len; i++)
-                       snprintf(hex_buffer + 2*i, 3, "%2.2x", buffer[i]);
+               int i;
+               for (i = 0; i < len; i++)
+               {
+                       u8 t = buffer[i];
+                       hex_buffer[2 * i] = DIGITS[(t >> 4) & 0xf];
+                       hex_buffer[2 * i + 1] = DIGITS[t & 0xf];
+               }
 
                gdb_put_packet(connection, hex_buffer, len * 2);
 
@@ -859,13 +1119,12 @@ int gdb_read_memory_packet(connection_t *connection, target_t *target, char *pac
        }
        else
        {
-               if ((retval = gdb_memory_packet_error(connection, retval)) != ERROR_OK)
-                       return retval; 
+               retval = gdb_error(connection, retval);
        }
 
        free(buffer);
 
-       return ERROR_OK;
+       return retval;
 }
 
 int gdb_write_memory_packet(connection_t *connection, target_t *target, char *packet, int packet_size)
@@ -909,31 +1168,7 @@ int gdb_write_memory_packet(connection_t *connection, target_t *target, char *pa
                buffer[i] = tmp;
        }
 
-       retval = ERROR_OK;
-       switch (len)
-       {
-               /* handle sized writes */
-               case 4:
-                       if ((addr % 4) == 0)
-                               retval = target->type->write_memory(target, addr, 4, 1, buffer);
-                       else
-                               retval = target->type->write_memory(target, addr, 1, len, buffer);
-                       break;
-               case 2:
-                       if ((addr % 2) == 0)
-                               retval = target->type->write_memory(target, addr, 2, 1, buffer);
-                       else
-                               retval = target->type->write_memory(target, addr, 1, len, buffer);
-                       break;
-               case 3:
-               case 1:
-                       retval = target->type->write_memory(target, addr, 1, len, buffer);
-                       break;
-                       /* handle bulk writes */
-               default:
-                       retval = target_write_buffer(target, addr, len, buffer);
-                       break;
-       }
+       retval = target_write_buffer(target, addr, len, buffer);
 
        if (retval == ERROR_OK)
        {
@@ -941,8 +1176,8 @@ int gdb_write_memory_packet(connection_t *connection, target_t *target, char *pa
        }
        else
        {
-               if ((retval = gdb_memory_packet_error(connection, retval)) != ERROR_OK)
-                       return retval; 
+               if ((retval = gdb_error(connection, retval)) != ERROR_OK)
+                       return retval;
        }
 
        free(buffer);
@@ -956,7 +1191,6 @@ int gdb_write_memory_binary_packet(connection_t *connection, target_t *target, c
        u32 addr = 0;
        u32 len = 0;
 
-       u8 *buffer;
        int retval;
 
        /* skip command character */
@@ -979,38 +1213,11 @@ int gdb_write_memory_binary_packet(connection_t *connection, target_t *target, c
        }
 
        retval = ERROR_OK;
-       if( len ) {
-
-               buffer = malloc(len);
-
+       if (len)
+       {
                DEBUG("addr: 0x%8.8x, len: 0x%8.8x", addr, len);
 
-               memcpy( buffer, separator, len );
-
-               switch (len)
-               {
-                       case 4:
-                               if ((addr % 4) == 0)
-                                       retval = target->type->write_memory(target, addr, 4, 1, buffer);
-                               else
-                                       retval = target->type->write_memory(target, addr, 1, len, buffer);
-                               break;
-                       case 2:
-                               if ((addr % 2) == 0)
-                                       retval = target->type->write_memory(target, addr, 2, 1, buffer);
-                               else
-                                       retval = target->type->write_memory(target, addr, 1, len, buffer);
-                               break;
-                       case 3:
-                       case 1:
-                               retval = target->type->write_memory(target, addr, 1, len, buffer);
-                               break;
-                       default:
-                               retval = target_write_buffer(target, addr, len, buffer);
-                               break;
-               }
-
-               free(buffer);
+               retval = target_write_buffer(target, addr, len, (u8*)separator);
        }
 
        if (retval == ERROR_OK)
@@ -1019,8 +1226,8 @@ int gdb_write_memory_binary_packet(connection_t *connection, target_t *target, c
        }
        else
        {
-               if ((retval = gdb_memory_packet_error(connection, retval)) != ERROR_OK)
-                       return retval; 
+               if ((retval = gdb_error(connection, retval)) != ERROR_OK)
+                       return retval;
        }
 
        return ERROR_OK;
@@ -1055,25 +1262,6 @@ void gdb_step_continue_packet(connection_t *connection, target_t *target, char *
        }
 }
 
-int gdb_bp_wp_packet_error(connection_t *connection, int retval)
-{
-       switch (retval)
-       {
-               case ERROR_TARGET_NOT_HALTED:
-                       ERROR("gdb tried to set a breakpoint but we're not halted, dropping connection");
-                       return ERROR_SERVER_REMOTE_CLOSED;
-                       break;
-               case ERROR_TARGET_RESOURCE_NOT_AVAILABLE:
-                       gdb_send_error(connection, EBUSY);
-                       break;
-               default:
-                       ERROR("BUG: unexpected error %i", retval);
-                       exit(-1);
-       }
-
-       return ERROR_OK;
-}
-
 int gdb_breakpoint_watchpoint_packet(connection_t *connection, target_t *target, char *packet, int packet_size)
 {
        int type;
@@ -1123,7 +1311,7 @@ int gdb_breakpoint_watchpoint_packet(connection_t *connection, target_t *target,
                        {
                                if ((retval = breakpoint_add(target, address, size, bp_type)) != ERROR_OK)
                                {
-                                       if ((retval = gdb_bp_wp_packet_error(connection, retval)) != ERROR_OK)
+                                       if ((retval = gdb_error(connection, retval)) != ERROR_OK)
                                                return retval;
                                }
                                else
@@ -1145,7 +1333,7 @@ int gdb_breakpoint_watchpoint_packet(connection_t *connection, target_t *target,
                        {
                                if ((retval = watchpoint_add(target, address, size, type-2, 0, 0xffffffffu)) != ERROR_OK)
                                {
-                                       if ((retval = gdb_bp_wp_packet_error(connection, retval)) != ERROR_OK)
+                                       if ((retval = gdb_error(connection, retval)) != ERROR_OK)
                                                return retval;
                                }
                                else
@@ -1167,6 +1355,90 @@ int gdb_breakpoint_watchpoint_packet(connection_t *connection, target_t *target,
        return ERROR_OK;
 }
 
+/* print out a string and allocate more space as needed, mainly used for XML at this point */
+void xml_printf(int *retval, char **xml, int *pos, int *size, const char *fmt, ...)
+{
+       if (*retval != ERROR_OK)
+       {
+               return;
+       }
+       int first = 1;
+
+       for (;;)
+       {
+               if ((*xml == NULL) || (!first))
+               {
+                       /* start by 0 to exercise all the code paths.
+                        * Need minimum 2 bytes to fit 1 char and 0 terminator. */
+
+                       *size = *size * 2 + 2;
+                       char *t = *xml;
+                       *xml = realloc(*xml, *size);
+                       if (*xml == NULL)
+                       {
+                               if (t)
+                                       free(t);
+                               *retval = ERROR_SERVER_REMOTE_CLOSED;
+                               return;
+                       }
+               }
+
+               va_list ap;
+               int ret;
+               va_start(ap, fmt);
+               ret = vsnprintf(*xml + *pos, *size - *pos, fmt, ap);
+               va_end(ap);
+               if ((ret > 0) && ((ret + 1) < *size - *pos))
+               {
+                       *pos += ret;
+                       return;
+               }
+               /* there was just enough or not enough space, allocate more. */
+               first = 0;
+       }
+}
+
+static int decode_xfer_read(char *buf, char **annex, int *ofs, unsigned int *len)
+{
+       char *separator;
+
+       /* Extract and NUL-terminate the annex. */
+       *annex = buf;
+       while (*buf && *buf != ':')
+               buf++;
+       if (*buf == '\0')
+               return -1;
+       *buf++ = 0;
+
+       /* After the read marker and annex, qXfer looks like a
+        * traditional 'm' packet. */
+
+       *ofs = strtoul(buf, &separator, 16);
+
+       if (*separator != ',')
+               return -1;
+
+       *len = strtoul(separator+1, NULL, 16);
+
+       return 0;
+}
+
+int gdb_calc_blocksize(flash_bank_t *bank)
+{
+       int i;
+       int block_size = 0xffffffff;
+
+       /* loop through all sectors and return smallest sector size */
+
+       for (i = 0; i < bank->num_sectors; i++)
+       {
+               if (bank->sectors[i].size < block_size)
+                       block_size = bank->sectors[i].size;
+       }
+
+       return block_size;
+}
+
 int gdb_query_packet(connection_t *connection, target_t *target, char *packet, int packet_size)
 {
        command_context_t *cmd_ctx = connection->cmd_ctx;
@@ -1185,54 +1457,188 @@ int gdb_query_packet(connection_t *connection, target_t *target, char *packet, i
                                cmd[i] = tmp;
                        }
                        cmd[(packet_size - 6)/2] = 0x0;
+
+                       /* We want to print all debug output to GDB connection */
+                       log_add_callback(gdb_log_callback, connection);
+                       target_call_timer_callbacks();
                        command_run_line(cmd_ctx, cmd);
+                       log_remove_callback(gdb_log_callback, connection);
                        free(cmd);
                }
                gdb_put_packet(connection, "OK", 2);
                return ERROR_OK;
        }
-
-       if (strstr(packet, "qCRC:"))
+       else if (strstr(packet, "qCRC:"))
        {
                if (packet_size > 5)
                {
                        int retval;
-                       u8 gdb_reply[9];
+                       char gdb_reply[10];
                        char *separator;
                        u32 checksum;
                        u32 addr = 0;
                        u32 len = 0;
-                       
+
                        /* skip command character */
                        packet += 5;
-                       
+
                        addr = strtoul(packet, &separator, 16);
-                       
+
                        if (*separator != ',')
                        {
                                ERROR("incomplete read memory packet received, dropping connection");
                                return ERROR_SERVER_REMOTE_CLOSED;
                        }
-                       
-                       len = strtoul(separator+1, NULL, 16);
-                       
+
+                       len = strtoul(separator + 1, NULL, 16);
+
                        retval = target_checksum_memory(target, addr, len, &checksum);
-                       
+
                        if (retval == ERROR_OK)
                        {
-                               snprintf(gdb_reply, 9, "C%2.2x", checksum);
+                               snprintf(gdb_reply, 10, "C%8.8x", checksum);
                                gdb_put_packet(connection, gdb_reply, 9);
                        }
                        else
                        {
-                               if ((retval = gdb_memory_packet_error(connection, retval)) != ERROR_OK)
-                                       return retval; 
+                               if ((retval = gdb_error(connection, retval)) != ERROR_OK)
+                                       return retval;
                        }
-                       
+
                        return ERROR_OK;
                }
        }
-       
+       else if (strstr(packet, "qSupported"))
+       {
+               /* we currently support packet size and qXfer:memory-map:read (if enabled)
+                * disable qXfer:features:read for the moment */
+               int retval = ERROR_OK;
+               char *buffer = NULL;
+               int pos = 0;
+               int size = 0;
+
+               xml_printf(&retval, &buffer, &pos, &size,
+                               "PacketSize=%x;qXfer:memory-map:read%c;qXfer:features:read-",
+                               (GDB_BUFFER_SIZE - 1), gdb_use_memory_map == 1 ? '+' : '-');
+
+               if (retval != ERROR_OK)
+               {
+                       gdb_send_error(connection, 01);
+                       return ERROR_OK;
+               }
+
+               gdb_put_packet(connection, buffer, strlen(buffer));
+               free(buffer);
+
+               return ERROR_OK;
+       }
+       else if (strstr(packet, "qXfer:memory-map:read::"))
+       {
+               /* We get away with only specifying flash here. Regions that are not
+                * specified are treated as if we provided no memory map(if not we
+                * could detect the holes and mark them as RAM).
+                * Normally we only execute this code once, but no big deal if we
+                * have to regenerate it a couple of times. */
+
+               flash_bank_t *p;
+               char *xml = NULL;
+               int size = 0;
+               int pos = 0;
+               int retval = ERROR_OK;
+
+               int offset;
+               int length;
+               char *separator;
+               int blocksize;
+
+               /* skip command character */
+               packet += 23;
+
+               offset = strtoul(packet, &separator, 16);
+               length = strtoul(separator + 1, &separator, 16);
+
+               xml_printf(&retval, &xml, &pos, &size, "<memory-map>\n");
+
+               int i;
+               for (i=0; i<flash_get_bank_count(); i++)
+               {
+                       p = get_flash_bank_by_num(i);
+                       if (p == NULL)
+                               break;
+
+                       /* if device has uneven sector sizes, eg. str7, lpc
+                        * we pass the smallest sector size to gdb memory map */
+                       blocksize = gdb_calc_blocksize(p);
+
+                       xml_printf(&retval, &xml, &pos, &size, "<memory type=\"flash\" start=\"0x%x\" length=\"0x%x\">\n" \
+                               "<property name=\"blocksize\">0x%x</property>\n" \
+                               "</memory>\n", \
+                               p->base, p->size, blocksize);
+               }
+
+               xml_printf(&retval, &xml, &pos, &size, "</memory-map>\n");
+
+               if (retval != ERROR_OK)
+               {
+                       gdb_send_error(connection, retval);
+                       return retval;
+               }
+
+               if (offset + length > pos)
+               {
+                       length = pos - offset;
+               }
+
+               char *t = malloc(length + 1);
+               t[0] = 'l';
+               memcpy(t + 1, xml + offset, length);
+               gdb_put_packet(connection, t, length + 1);
+
+               free(t);
+               free(xml);
+               return ERROR_OK;
+       }
+       else if (strstr(packet, "qXfer:features:read:"))
+       {
+               char *xml = NULL;
+               int size = 0;
+               int pos = 0;
+               int retval = ERROR_OK;
+
+               int offset;
+               unsigned int length;
+               char *annex;
+
+               /* skip command character */
+               packet += 20;
+
+               if (decode_xfer_read(packet, &annex, &offset, &length) < 0)
+               {
+                       gdb_send_error(connection, 01);
+                       return ERROR_OK;
+               }
+
+               if (strcmp(annex, "target.xml") != 0)
+               {
+                       gdb_send_error(connection, 01);
+                       return ERROR_OK;
+               }
+
+               xml_printf(&retval, &xml, &pos, &size, \
+                       "l<target version=\"1.0\">\n<architecture>arm</architecture>\n</target>\n");
+
+               if (retval != ERROR_OK)
+               {
+                       gdb_send_error(connection, retval);
+                       return retval;
+               }
+
+               gdb_put_packet(connection, xml, strlen(xml) + 1);
+
+               free(xml);
+               return ERROR_OK;
+       }
+
        gdb_put_packet(connection, "", 0);
        return ERROR_OK;
 }
@@ -1243,10 +1649,19 @@ int gdb_v_packet(connection_t *connection, target_t *target, char *packet, int p
        gdb_service_t *gdb_service = connection->service->priv;
        int result;
 
+       /* if flash programming disabled - send a empty reply */
+
+       if (gdb_flash_program == 0)
+       {
+               gdb_put_packet(connection, "", 0);
+               return ERROR_OK;
+       }
+
        if (strstr(packet, "vFlashErase:"))
        {
                unsigned long addr;
                unsigned long length;
+
                char *parse = packet + 12;
                if (*parse == '\0')
                {
@@ -1270,8 +1685,15 @@ int gdb_v_packet(connection_t *connection, target_t *target, char *packet, int p
                        return ERROR_SERVER_REMOTE_CLOSED;
                }
 
+               /* assume all sectors need erasing - stops any problems
+                * when flash_write is called multiple times */
+               flash_set_dirty();
+
+               /* perform any target specific operations before the erase */
+               target_call_event_callbacks(gdb_service->target, TARGET_EVENT_GDB_PROGRAM);
+
                /* perform erase */
-               if ((result = flash_erase(gdb_service->target, addr, length)) != ERROR_OK)
+               if ((result = flash_erase_address_range(gdb_service->target, addr, length)) != ERROR_OK)
                {
                        /* GDB doesn't evaluate the actual error number returned,
                         * treat a failed erase as an I/O error
@@ -1303,7 +1725,7 @@ int gdb_v_packet(connection_t *connection, target_t *target, char *packet, int p
                        return ERROR_SERVER_REMOTE_CLOSED;
                }
                length = packet_size - (parse - packet);
-               
+
                /* create a new image if there isn't already one */
                if (gdb_connection->vflash_image == NULL)
                {
@@ -1322,28 +1744,22 @@ int gdb_v_packet(connection_t *connection, target_t *target, char *packet, int p
        if (!strcmp(packet, "vFlashDone"))
        {
                u32 written;
-               char *error_str;
 
-               /* process the flashing buffer */
-               if ((result = flash_write(gdb_service->target, gdb_connection->vflash_image, &written, &error_str, NULL, 0)) != ERROR_OK)
+               /* process the flashing buffer. No need to erase as GDB
+                * always issues a vFlashErase first. */
+               if ((result = flash_write(gdb_service->target, gdb_connection->vflash_image, &written, 0)) != ERROR_OK)
                {
                        if (result == ERROR_FLASH_DST_OUT_OF_BANK)
                                gdb_put_packet(connection, "E.memtype", 9);
                        else
                                gdb_send_error(connection, EIO);
-                       
-                       if (error_str)
-                       {
-                               ERROR("flash writing failed: %s", error_str);
-                               free(error_str);
                        }
-               }
                else
                {
                        DEBUG("wrote %u bytes from vFlash image to flash", written);
                        gdb_put_packet(connection, "OK", 2);
                }
-               
+
                image_close(gdb_connection->vflash_image);
                free(gdb_connection->vflash_image);
                gdb_connection->vflash_image = NULL;
@@ -1362,25 +1778,40 @@ int gdb_detach(connection_t *connection, target_t *target)
                case GDB_DETACH_RESUME:
                        target->type->resume(target, 1, 0, 1, 0);
                        break;
-               
+
                case GDB_DETACH_RESET:
                        target_process_reset(connection->cmd_ctx);
                        break;
-               
+
                case GDB_DETACH_HALT:
                        target->type->halt(target);
                        break;
-               
+
                case GDB_DETACH_NOTHING:
                        break;
        }
-       
+
        gdb_put_packet(connection, "OK", 2);
-       
+
        return ERROR_OK;
 }
 
-int gdb_input(connection_t *connection)
+static void gdb_log_callback(void *priv, const char *file, int line,
+               const char *function, const char *string)
+{
+       connection_t *connection = priv;
+       gdb_connection_t *gdb_con = connection->priv;
+
+       if (gdb_con->busy)
+       {
+               /* do not reply this using the O packet */
+               return;
+       }
+
+       gdb_output_con(connection, string);
+}
+
+int gdb_input_inner(connection_t *connection)
 {
        gdb_service_t *gdb_service = connection->service->priv;
        target_t *target = gdb_service->target;
@@ -1388,6 +1819,7 @@ int gdb_input(connection_t *connection)
        int packet_size;
        int retval;
        gdb_connection_t *gdb_con = connection->priv;
+       static int extended_protocol = 0;
 
        /* drain input buffer */
        do
@@ -1395,23 +1827,13 @@ int gdb_input(connection_t *connection)
                packet_size = GDB_BUFFER_SIZE-1;
                if ((retval = gdb_get_packet(connection, packet, &packet_size)) != ERROR_OK)
                {
-                       switch (retval)
-                       {
-                               case ERROR_GDB_BUFFER_TOO_SMALL:
-                                       ERROR("BUG: buffer supplied for gdb packet was too small");
-                                       exit(-1);
-                               case ERROR_SERVER_REMOTE_CLOSED:
-                                       return ERROR_SERVER_REMOTE_CLOSED;
-                               default:
-                                       ERROR("BUG: unexpected error");
-                                       exit(-1);
-                       }
+                       return retval;
                }
 
                /* terminate with zero */
                packet[packet_size] = 0;
 
-               DEBUG("recevied packet: '%s'", packet);
+               DEBUG("received packet: '%s'", packet);
 
                if (packet_size > 0)
                {
@@ -1419,7 +1841,7 @@ int gdb_input(connection_t *connection)
                        switch (packet[0])
                        {
                                case 'H':
-                                       /* Hct... -- set thread 
+                                       /* Hct... -- set thread
                                         * we don't have threads, send empty reply */
                                        gdb_put_packet(connection, NULL, 0);
                                        break;
@@ -1453,21 +1875,40 @@ int gdb_input(connection_t *connection)
                                        break;
                                case 'c':
                                case 's':
-                                       gdb_step_continue_packet(connection, target, packet, packet_size);
+                                       {
+                                       /* We're running/stepping, in which case we can
+                                        * forward log output until the target is halted */
+                                               gdb_connection_t *gdb_con = connection->priv;
+                                               gdb_con->frontend_state = TARGET_RUNNING;
+                                               log_add_callback(gdb_log_callback, connection);
+                                               gdb_step_continue_packet(connection, target, packet, packet_size);
+                                       }
                                        break;
                                case 'v':
                                        retval = gdb_v_packet(connection, target, packet, packet_size);
                                        break;
                                case 'D':
                                        retval = gdb_detach(connection, target);
+                                       extended_protocol = 0;
                                        break;
                                case 'X':
                                        if ((retval = gdb_write_memory_binary_packet(connection, target, packet, packet_size)) != ERROR_OK)
                                                return retval;
                                        break;
                                case 'k':
+                                       if (extended_protocol != 0)
+                                               break;
                                        gdb_put_packet(connection, "OK", 2);
                                        return ERROR_SERVER_REMOTE_CLOSED;
+                               case '!':
+                                       /* handle extended remote protocol */
+                                       extended_protocol = 1;
+                                       gdb_put_packet(connection, "OK", 2);
+                                       break;
+                               case 'R':
+                                       /* handle extended restart packet */
+                                       target_process_reset(connection->cmd_ctx);
+                                       break;
                                default:
                                        /* ignore unkown packets */
                                        DEBUG("ignoring 0x%2.2x packet", packet[0]);
@@ -1494,6 +1935,21 @@ int gdb_input(connection_t *connection)
        return ERROR_OK;
 }
 
+int gdb_input(connection_t *connection)
+{
+       int retval = gdb_input_inner(connection);
+       gdb_connection_t *gdb_con = connection->priv;
+       if (retval == ERROR_SERVER_REMOTE_CLOSED)
+               return retval;
+
+       /* logging does not propagate the error, yet can set th gdb_con->closed flag */
+       if (gdb_con->closed)
+               return ERROR_SERVER_REMOTE_CLOSED;
+       
+       /* we'll recover from any other errors(e.g. temporary timeouts, etc.) */
+       return ERROR_OK;
+}
+
 int gdb_init()
 {
        gdb_service_t *gdb_service;
@@ -1570,17 +2026,82 @@ int handle_gdb_detach_command(struct command_context_s *cmd_ctx, char *cmd, char
                        return ERROR_OK;
                }
        }
-       
+
        WARNING("invalid gdb_detach configuration directive: %s", args[0]);
        return ERROR_OK;
 }
 
+int handle_gdb_memory_map_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
+{
+       if (argc == 1)
+       {
+               if (strcmp(args[0], "enable") == 0)
+               {
+                       gdb_use_memory_map = 1;
+                       return ERROR_OK;
+               }
+               else if (strcmp(args[0], "disable") == 0)
+               {
+                       gdb_use_memory_map = 0;
+                       return ERROR_OK;
+               }
+       }
+
+       WARNING("invalid gdb_memory_map configuration directive: %s", args[0]);
+       return ERROR_OK;
+}
+
+int handle_gdb_flash_program_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
+{
+       if (argc == 1)
+       {
+               if (strcmp(args[0], "enable") == 0)
+               {
+                       gdb_flash_program = 1;
+                       return ERROR_OK;
+               }
+               else if (strcmp(args[0], "disable") == 0)
+               {
+                       gdb_flash_program = 0;
+                       return ERROR_OK;
+               }
+       }
+
+       WARNING("invalid gdb_memory_map configuration directive: %s", args[0]);
+       return ERROR_OK;
+}
+
+int handle_gdb_report_data_abort_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
+{
+       if (argc == 1)
+       {
+               if (strcmp(args[0], "enable") == 0)
+               {
+                       gdb_report_data_abort = 1;
+                       return ERROR_OK;
+               }
+               else if (strcmp(args[0], "disable") == 0)
+               {
+                       gdb_report_data_abort = 0;
+                       return ERROR_OK;
+               }
+       }
+
+       WARNING("invalid gdb_report_data_abort configuration directive: %s", args[0]);
+       return ERROR_OK;
+}
+
 int gdb_register_commands(command_context_t *command_context)
 {
        register_command(command_context, NULL, "gdb_port", handle_gdb_port_command,
                        COMMAND_CONFIG, "");
        register_command(command_context, NULL, "gdb_detach", handle_gdb_detach_command,
                        COMMAND_CONFIG, "");
-       
+       register_command(command_context, NULL, "gdb_memory_map", handle_gdb_memory_map_command,
+                       COMMAND_CONFIG, "");
+       register_command(command_context, NULL, "gdb_flash_program", handle_gdb_flash_program_command,
+                       COMMAND_CONFIG, "");
+       register_command(command_context, NULL, "gdb_report_data_abort", handle_gdb_report_data_abort_command,
+                       COMMAND_CONFIG, "");
        return ERROR_OK;
 }