From 37755ffdb63164e768745369a98f06c5ec9d476d Mon Sep 17 00:00:00 2001 From: oharboe Date: Thu, 24 Sep 2009 06:34:23 +0000 Subject: [PATCH] When attaching GDB to OpenOCD, the target state is no longer affected. Added gdb_sync feature that allows GDB to sync up to target state. Issue "monitor gdb_sync" and the next stepi, will return immediately with updated register values to GDB. git-svn-id: svn://svn.berlios.de/openocd/trunk@2754 b42882b7-edfa-0310-969c-e2dbd0fdcd60 --- src/server/gdb_server.c | 92 ++++++++++++++++++++++++++++------------- src/server/gdb_server.h | 4 ++ 2 files changed, 68 insertions(+), 28 deletions(-) diff --git a/src/server/gdb_server.c b/src/server/gdb_server.c index dc14b75c83..44d9de8381 100644 --- a/src/server/gdb_server.c +++ b/src/server/gdb_server.c @@ -40,6 +40,8 @@ #define _DEBUG_GDB_IO_ #endif +static gdb_connection_t *current_gdb_connection; + static int gdb_breakpoint_override; static enum breakpoint_type gdb_breakpoint_override_type; @@ -750,6 +752,7 @@ int gdb_new_connection(connection_t *connection) gdb_connection->closed = 0; gdb_connection->busy = 0; gdb_connection->noack_mode = 0; + gdb_connection->sync = true; /* send ACK to GDB for debug request */ gdb_write(connection, "+", 1); @@ -767,30 +770,6 @@ int gdb_new_connection(connection_t *connection) /* register callback to be informed about target events */ target_register_event_callback(gdb_target_callback_event_handler, connection); - /* a gdb session just attached, try to put the target in halt mode. - * - * DANGER!!!! - * - * If the halt fails(e.g. target needs a reset, JTAG communication not - * working, etc.), then the GDB connect will succeed as - * the get_gdb_reg_list() will lie and return a register list with - * dummy values. - * - * This allows GDB monitor commands to be run from a GDB init script to - * initialize the target - * - * Also, since the halt() is asynchronous target connect will be - * instantaneous and thus avoiding annoying timeout problems during - * connect. - */ - target_halt(gdb_service->target); - /* FIX!!!! could extended-remote work better here? - * - * wait a tiny bit for halted state or we just continue. The - * GDB register packet will then contain garbage - */ - target_wait_state(gdb_service->target, TARGET_HALTED, 500); - /* remove the initial ACK from the incoming buffer */ if ((retval = gdb_get_char(connection, &initial_ack)) != ERROR_OK) return retval; @@ -1609,7 +1588,11 @@ int gdb_query_packet(connection_t *connection, target_t *target, char *packet, i /* We want to print all debug output to GDB connection */ log_add_callback(gdb_log_callback, connection); target_call_timer_callbacks_now(); + /* some commands need to know the GDB connection, make note of current + * GDB connection. */ + current_gdb_connection = gdb_connection; command_run_line(cmd_ctx, cmd); + current_gdb_connection = NULL; target_call_timer_callbacks_now(); log_remove_callback(gdb_log_callback, connection); free(cmd); @@ -2107,20 +2090,52 @@ int gdb_input_inner(connection_t *connection) case 'c': case 's': { - if (target->state != TARGET_HALTED) + int retval = ERROR_OK; + + gdb_connection_t *gdb_con = connection->priv; + log_add_callback(gdb_log_callback, connection); + + bool nostep = false; + if (target->state == TARGET_RUNNING) + { + LOG_WARNING("The target is already running. Halt target before stepi/continue."); + retval = target_halt(target); + if (retval == ERROR_OK) + retval = target_wait_state(target, TARGET_HALTED, 100); + } else if (target->state != TARGET_HALTED) + { + LOG_WARNING("The target is not in the halted nor running stated, stepi/continue ignored."); + nostep = true; + } else if ((packet[0] == 's') && gdb_con->sync) + { + /* Hmm..... when you issue a continue in GDB, then a "stepi" is + * sent by GDB first to OpenOCD, thus defeating the check to + * make only the single stepping have the sync feature... + */ + nostep = true; + LOG_WARNING("stepi ignored. GDB will now fetch the register state from the target."); + } + gdb_con->sync = false; + + if ((retval!=ERROR_OK) || nostep) { - /* If the target isn't in the halted state, then we can't + /* Either the target isn't in the halted state, then we can't * step/continue. This might be early setup, etc. + * + * Or we want to allow GDB to pick up a fresh set of + * register values without modifying the target state. + * */ gdb_sig_halted(connection); + + /* stop forwarding log packets! */ + log_remove_callback(gdb_log_callback, connection); } else { /* 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); target_call_event_callbacks(target, TARGET_EVENT_GDB_START); int retval = gdb_step_continue_packet(connection, target, packet, packet_size); if (retval != ERROR_OK) @@ -2255,6 +2270,25 @@ int gdb_init(void) return ERROR_OK; } +int handle_gdb_sync_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc) +{ + if (argc != 0) + { + return ERROR_COMMAND_SYNTAX_ERROR; + } + + if (current_gdb_connection == NULL) + { + command_print(cmd_ctx, + "gdb_sync command can only be run from within gdb using \"monitor gdb_sync\""); + return ERROR_FAIL; + } + + current_gdb_connection->sync = true; + + return ERROR_OK; +} + /* daemon configuration command gdb_port */ int handle_gdb_port_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc) { @@ -2399,6 +2433,8 @@ int handle_gdb_breakpoint_override_command(struct command_context_s *cmd_ctx, ch int gdb_register_commands(command_context_t *command_context) { + register_command(command_context, NULL, "gdb_sync", handle_gdb_sync_command, + COMMAND_ANY, "next stepi will return immediately allowing GDB fetch register state without affecting target state"); register_command(command_context, NULL, "gdb_port", handle_gdb_port_command, COMMAND_ANY, "daemon configuration command gdb_port"); register_command(command_context, NULL, "gdb_detach", handle_gdb_detach_command, diff --git a/src/server/gdb_server.h b/src/server/gdb_server.h index fb4cdbab6b..ea981f3164 100644 --- a/src/server/gdb_server.h +++ b/src/server/gdb_server.h @@ -43,6 +43,10 @@ typedef struct gdb_connection_s int closed; int busy; int noack_mode; + bool sync; /* set flag to true if you want the next stepi to return immediately. + allowing GDB to pick up a fresh set of register values from the target + without modifying the target state. */ + } gdb_connection_t; typedef struct gdb_service_s -- 2.30.2