rtos/hwthread: add hardware-thread pseudo rtos 99/3999/24
authorMatthias Welwarsky <matthias.welwarsky@sysgo.com>
Fri, 17 Feb 2017 15:16:51 +0000 (16:16 +0100)
committerMatthias Welwarsky <matthias@welwarsky.de>
Fri, 8 Mar 2019 12:54:47 +0000 (12:54 +0000)
This patch adds "hwthread", a pseudo rtos that represents cpu cores
in an SMP system as threads to gdb. This allows to debug SMP
system kernels in a more sensible manner and removes the current
atrocities of switching gdb manually between CPU cores to update
the context.

Change-Id: Ib781c6c34097689d21d9e02011e4d74a4a742379
Signed-off-by: Matthias Welwarsky <matthias.welwarsky@sysgo.com>
Reviewed-on: http://openocd.zylin.com/3999
Tested-by: jenkins
Reviewed-by: Tim Newsome <tim@sifive.com>
Reviewed-by: Matthias Welwarsky <matthias@welwarsky.de>
Reviewed-by: Graham Sanderson <graham.sanderson@gmail.com>
doc/openocd.texi
src/rtos/Makefile.am
src/rtos/hwthread.c [new file with mode: 0644]
src/rtos/rtos.c

index 2e04182..bbb9075 100644 (file)
@@ -10199,55 +10199,6 @@ and GDB would require stopping the target to get the prompt back.
 Do not use this mode under an IDE like Eclipse as it caches values of
 previously shown varibles.
 
-@anchor{usingopenocdsmpwithgdb}
-@section Using OpenOCD SMP with GDB
-@cindex SMP
-For SMP support following GDB serial protocol packet have been defined :
-@itemize @bullet
-@item j - smp status request
-@item J - smp set request
-@end itemize
-
-OpenOCD implements :
-@itemize @bullet
-@item @option{jc} packet for reading core id displayed by
-GDB connection. Reply is @option{XXXXXXXX} (8 hex digits giving core id) or
- @option{E01} for target not smp.
-@item @option{JcXXXXXXXX} (8 hex digits) packet for setting core id displayed at next GDB continue
-(core id -1 is reserved for returning to normal resume mode). Reply @option{E01}
-for target not smp or @option{OK} on success.
-@end itemize
-
-Handling of this packet within GDB can be done :
-@itemize @bullet
-@item by the creation of an internal variable (i.e @option{_core}) by mean
-of function allocate_computed_value allowing following GDB command.
-@example
-set $_core 1
-#Jc01 packet is sent
-print $_core
-#jc packet is sent and result is affected in $
-@end example
-
-@item by the usage of GDB maintenance command as described in following example (2 cpus in SMP with
-core id 0 and 1 @pxref{definecputargetsworkinginsmp,,Define CPU targets working in SMP}).
-
-@example
-# toggle0 : force display of coreid 0
-define toggle0
-maint packet Jc0
-continue
-main packet Jc-1
-end
-# toggle1 : force display of coreid 1
-define toggle1
-maint packet Jc1
-continue
-main packet Jc-1
-end
-@end example
-@end itemize
-
 @section RTOS Support
 @cindex RTOS Support
 @anchor{gdbrtossupport}
@@ -10278,12 +10229,11 @@ Currently supported rtos's include:
 @item @option{mqx}
 @item @option{uCOS-III}
 @item @option{nuttx}
+@item @option{hwthread} (This is not an actual RTOS. @xref{usingopenocdsmpwithgdb,,Using OpenOCD SMP with GDB}.)
 @end itemize
 
-@quotation Note
 Before an RTOS can be detected, it must export certain symbols; otherwise, it cannot
 be used by OpenOCD. Below is a list of the required symbols for each supported RTOS.
-@end quotation
 
 @table @code
 @item eCos symbols
@@ -10330,6 +10280,72 @@ contrib/rtos-helpers/FreeRTOS-openocd.c
 contrib/rtos-helpers/uCOS-III-openocd.c
 @end table
 
+@anchor{usingopenocdsmpwithgdb}
+@section Using OpenOCD SMP with GDB
+@cindex SMP
+@cindex RTOS
+@cindex hwthread
+OpenOCD includes a pseudo RTOS called @emph{hwthread} that presents CPU cores
+("hardware threads") in an SMP system as threads to GDB. With this extension,
+GDB can be used to inspect the state of an SMP system in a natural way.
+After halting the system, using the GDB command @command{info threads} will
+list the context of each active CPU core in the system. GDB's @command{thread}
+command can be used to switch the view to a different CPU core.
+The @command{step} and @command{stepi} commands can be used to step a specific core
+while other cores are free-running or remain halted, depending on the
+scheduler-locking mode configured in GDB.
+
+@section Legacy SMP core switching support
+@quotation Note
+This method is deprecated in favor of the @emph{hwthread} pseudo RTOS.
+@end quotation
+
+For SMP support following GDB serial protocol packet have been defined :
+@itemize @bullet
+@item j - smp status request
+@item J - smp set request
+@end itemize
+
+OpenOCD implements :
+@itemize @bullet
+@item @option{jc} packet for reading core id displayed by
+GDB connection. Reply is @option{XXXXXXXX} (8 hex digits giving core id) or
+ @option{E01} for target not smp.
+@item @option{JcXXXXXXXX} (8 hex digits) packet for setting core id displayed at next GDB continue
+(core id -1 is reserved for returning to normal resume mode). Reply @option{E01}
+for target not smp or @option{OK} on success.
+@end itemize
+
+Handling of this packet within GDB can be done :
+@itemize @bullet
+@item by the creation of an internal variable (i.e @option{_core}) by mean
+of function allocate_computed_value allowing following GDB command.
+@example
+set $_core 1
+#Jc01 packet is sent
+print $_core
+#jc packet is sent and result is affected in $
+@end example
+
+@item by the usage of GDB maintenance command as described in following example (2 cpus in SMP with
+core id 0 and 1 @pxref{definecputargetsworkinginsmp,,Define CPU targets working in SMP}).
+
+@example
+# toggle0 : force display of coreid 0
+define toggle0
+maint packet Jc0
+continue
+main packet Jc-1
+end
+# toggle1 : force display of coreid 1
+define toggle1
+maint packet Jc1
+continue
+main packet Jc-1
+end
+@end example
+@end itemize
+
 @node Tcl Scripting API
 @chapter Tcl Scripting API
 @cindex Tcl Scripting API
index bbf66a6..38adb6e 100644 (file)
@@ -17,6 +17,7 @@ noinst_LTLIBRARIES += %D%/librtos.la
        %D%/mqx.c \
        %D%/uCOS-III.c \
        %D%/nuttx.c \
+       %D%/hwthread.c \
        %D%/rtos.h \
        %D%/rtos_standard_stackings.h \
        %D%/rtos_ecos_stackings.h \
diff --git a/src/rtos/hwthread.c b/src/rtos/hwthread.c
new file mode 100644 (file)
index 0000000..2d9e42f
--- /dev/null
@@ -0,0 +1,347 @@
+/***************************************************************************
+ *                                                                         *
+ *   This program is free software; you can redistribute it and/or modify  *
+ *   it under the terms of the GNU General Public License as published by  *
+ *   the Free Software Foundation; either version 2 of the License, or     *
+ *   (at your option) any later version.                                   *
+ *                                                                         *
+ *   This program is distributed in the hope that it will be useful,       *
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
+ *   GNU General Public License for more details.                          *
+ *                                                                         *
+ *   You should have received a copy of the GNU General Public License     *
+ *   along with this program.  If not, see <http://www.gnu.org/licenses/>. *
+ ***************************************************************************/
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <helper/time_support.h>
+#include <jtag/jtag.h>
+#include "target/target.h"
+#include "target/target_type.h"
+#include "target/register.h"
+#include "rtos.h"
+#include "helper/log.h"
+#include "helper/types.h"
+#include "server/gdb_server.h"
+
+static bool hwthread_detect_rtos(struct target *target);
+static int hwthread_create(struct target *target);
+static int hwthread_update_threads(struct rtos *rtos);
+static int hwthread_get_thread_reg_list(struct rtos *rtos, int64_t thread_id,
+                                       struct rtos_reg **reg_list, int *num_regs);
+static int hwthread_get_symbol_list_to_lookup(symbol_table_elem_t *symbol_list[]);
+static int hwthread_smp_init(struct target *target);
+
+#define HW_THREAD_NAME_STR_SIZE (32)
+
+extern int rtos_thread_packet(struct connection *connection, const char *packet, int packet_size);
+
+static inline threadid_t threadid_from_target(const struct target *target)
+{
+       return target->coreid + 1;
+}
+
+const struct rtos_type hwthread_rtos = {
+       .name = "hwthread",
+       .detect_rtos = hwthread_detect_rtos,
+       .create = hwthread_create,
+       .update_threads = hwthread_update_threads,
+       .get_thread_reg_list = hwthread_get_thread_reg_list,
+       .get_symbol_list_to_lookup = hwthread_get_symbol_list_to_lookup,
+       .smp_init = hwthread_smp_init,
+};
+
+struct hwthread_params {
+       int dummy_param;
+};
+
+static int hwthread_fill_thread(struct rtos *rtos, struct target *curr, int thread_num)
+{
+       char tmp_str[HW_THREAD_NAME_STR_SIZE];
+       threadid_t tid = threadid_from_target(curr);
+
+       memset(tmp_str, 0, HW_THREAD_NAME_STR_SIZE);
+
+       /* thread-id is the core-id of this core inside the SMP group plus 1 */
+       rtos->thread_details[thread_num].threadid = tid;
+       /* create the thread name */
+       rtos->thread_details[thread_num].exists = true;
+       rtos->thread_details[thread_num].thread_name_str = strdup(target_name(curr));
+       snprintf(tmp_str, HW_THREAD_NAME_STR_SIZE-1, "state: %s", debug_reason_name(curr));
+       rtos->thread_details[thread_num].extra_info_str = strdup(tmp_str);
+
+       return ERROR_OK;
+}
+
+static int hwthread_update_threads(struct rtos *rtos)
+{
+       int threads_found = 0;
+       int thread_list_size = 0;
+       struct target_list *head;
+       struct target *target;
+       int64_t current_thread = 0;
+       enum target_debug_reason current_reason = DBG_REASON_UNDEFINED;
+
+       if (rtos == NULL)
+               return -1;
+
+       target = rtos->target;
+
+       /* wipe out previous thread details if any */
+       rtos_free_threadlist(rtos);
+
+       /* determine the number of "threads" */
+       if (target->smp) {
+               for (head = target->head; head != NULL; head = head->next) {
+                       struct target *curr = head->target;
+
+                       if (!target_was_examined(curr))
+                               continue;
+
+                       ++thread_list_size;
+               }
+       } else
+               thread_list_size = 1;
+
+       /* create space for new thread details */
+       rtos->thread_details = malloc(sizeof(struct thread_detail) * thread_list_size);
+
+       if (target->smp) {
+               /* loop over all threads */
+               for (head = target->head; head != NULL; head = head->next) {
+                       struct target *curr = head->target;
+
+                       if (!target_was_examined(curr))
+                               continue;
+
+                       threadid_t tid = threadid_from_target(curr);
+
+                       hwthread_fill_thread(rtos, curr, threads_found);
+
+                       /* find an interesting thread to set as current */
+                       switch (current_reason) {
+                       case DBG_REASON_UNDEFINED:
+                               current_reason = curr->debug_reason;
+                               current_thread = tid;
+                               break;
+                       case DBG_REASON_SINGLESTEP:
+                               /* single-step can only be overridden by itself */
+                               if (curr->debug_reason == DBG_REASON_SINGLESTEP) {
+                                       if (tid == rtos->current_threadid)
+                                               current_thread = tid;
+                               }
+                               break;
+                       case DBG_REASON_BREAKPOINT:
+                               /* single-step overrides breakpoint */
+                               if (curr->debug_reason == DBG_REASON_SINGLESTEP) {
+                                       current_reason = curr->debug_reason;
+                                       current_thread = tid;
+                               } else
+                               /* multiple breakpoints, prefer gdbs' threadid */
+                               if (curr->debug_reason == DBG_REASON_BREAKPOINT) {
+                                       if (tid == rtos->current_threadid)
+                                               current_thread = tid;
+                               }
+                               break;
+                       case DBG_REASON_WATCHPOINT:
+                               /* breakpoint and single-step override watchpoint */
+                               if (curr->debug_reason == DBG_REASON_SINGLESTEP ||
+                                               curr->debug_reason == DBG_REASON_BREAKPOINT) {
+                                       current_reason = curr->debug_reason;
+                                       current_thread = tid;
+                               }
+                               break;
+                       case DBG_REASON_DBGRQ:
+                               /* all other reasons override debug-request */
+                               if (curr->debug_reason == DBG_REASON_SINGLESTEP ||
+                                               curr->debug_reason == DBG_REASON_WATCHPOINT ||
+                                               curr->debug_reason == DBG_REASON_BREAKPOINT) {
+                                       current_reason = curr->debug_reason;
+                                       current_thread = tid;
+                               } else
+                               if (curr->debug_reason == DBG_REASON_DBGRQ) {
+                                       if (tid == rtos->current_threadid)
+                                               current_thread = tid;
+                               }
+
+                               break;
+
+                       default:
+                               break;
+                       }
+
+                       threads_found++;
+               }
+       } else {
+               hwthread_fill_thread(rtos, target, threads_found);
+               current_thread = threadid_from_target(target);
+               threads_found++;
+       }
+
+       rtos->thread_count = threads_found;
+
+       /* we found an interesting thread, set it as current */
+       if (current_thread != 0)
+               rtos->current_thread = current_thread;
+       else if (rtos->current_threadid != 0)
+               rtos->current_thread = rtos->current_threadid;
+       else
+               rtos->current_thread = threadid_from_target(target);
+
+       LOG_DEBUG("%s current_thread=%i", __func__, (int)rtos->current_thread);
+       return 0;
+}
+
+static int hwthread_smp_init(struct target *target)
+{
+       return hwthread_update_threads(target->rtos);
+}
+
+static int hwthread_get_thread_reg_list(struct rtos *rtos, int64_t thread_id,
+                                       struct rtos_reg **rtos_reg_list, int *num_regs)
+{
+       struct target_list *head;
+       struct target *target;
+       struct target *curr;
+       struct reg **reg_list;
+       int retval;
+
+       if (rtos == NULL)
+               return ERROR_FAIL;
+
+       target = rtos->target;
+
+       /* Find the thread with that thread_id */
+       if (target->smp) {
+               curr = NULL;
+               for (head = target->head; head != NULL; head = head->next) {
+                       curr = head->target;
+
+                       if (thread_id == threadid_from_target(curr))
+                               break;
+               }
+
+               if (head == NULL)
+                       return ERROR_FAIL;
+       } else {
+               curr = target;
+               if (thread_id != threadid_from_target(curr))
+                       return ERROR_FAIL;
+
+       }
+
+       if (!target_was_examined(curr))
+               return ERROR_FAIL;
+
+       retval = target_get_gdb_reg_list(curr, &reg_list, num_regs,
+                       REG_CLASS_GENERAL);
+       if (retval != ERROR_OK)
+               return retval;
+
+       *rtos_reg_list = calloc(*num_regs, sizeof(struct rtos_reg));
+       if (*rtos_reg_list == NULL) {
+               free(reg_list);
+               return ERROR_FAIL;
+       }
+
+       for (int i = 0; i < *num_regs; i++) {
+               (*rtos_reg_list)[i].number = (*reg_list)[i].number;
+               (*rtos_reg_list)[i].size = (*reg_list)[i].size;
+               memcpy((*rtos_reg_list)[i].value, (*reg_list)[i].value,
+                      ((*reg_list)[i].size + 7) / 8);
+       }
+
+       free(reg_list);
+
+       return ERROR_OK;
+
+}
+
+static int hwthread_get_symbol_list_to_lookup(symbol_table_elem_t *symbol_list[])
+{
+       /* return an empty list, we don't have any symbols to look up */
+       *symbol_list = calloc(1, sizeof(symbol_table_elem_t));
+       (*symbol_list)[0].symbol_name = NULL;
+       return 0;
+}
+
+static int hwthread_target_for_threadid(struct connection *connection, int64_t thread_id, struct target **p_target)
+{
+       struct target *target = get_target_from_connection(connection);
+       struct target_list *head;
+       struct target *curr;
+
+       if (target->smp) {
+               /* Find the thread with that thread_id */
+               curr = NULL;
+               for (head = target->head; head != NULL; head = head->next) {
+                       curr = head->target;
+
+                       if (thread_id == threadid_from_target(curr))
+                               break;
+               }
+
+               if (head == NULL)
+                       return ERROR_FAIL;
+       } else {
+               curr = target;
+               if (thread_id != threadid_from_target(curr))
+                       return ERROR_FAIL;
+       }
+
+       *p_target = curr;
+
+       return ERROR_OK;
+}
+
+static bool hwthread_detect_rtos(struct target *target)
+{
+       /* always return 0, avoid auto-detection */
+       return false;
+}
+
+static int hwthread_thread_packet(struct connection *connection, const char *packet, int packet_size)
+{
+       struct target *target = get_target_from_connection(connection);
+
+       struct target *curr = NULL;
+       int64_t current_threadid;
+
+       if (packet[0] == 'H' && packet[1] == 'g') {
+               sscanf(packet, "Hg%16" SCNx64, &current_threadid);
+
+               if (current_threadid > 0) {
+                       if (hwthread_target_for_threadid(connection, current_threadid, &curr) != ERROR_OK) {
+                               LOG_ERROR("hwthread: cannot find thread id %"PRId64, current_threadid);
+                               gdb_put_packet(connection, "E01", 3);
+                               return ERROR_FAIL;
+                       }
+                       target->rtos->current_thread = current_threadid;
+               } else
+               if (current_threadid == 0 || current_threadid == -1)
+                       target->rtos->current_thread = threadid_from_target(target);
+
+               target->rtos->current_threadid = current_threadid;
+
+               gdb_put_packet(connection, "OK", 2);
+               return ERROR_OK;
+       }
+
+       return rtos_thread_packet(connection, packet, packet_size);
+}
+
+static int hwthread_create(struct target *target)
+{
+       LOG_INFO("Hardware thread awareness created");
+
+       target->rtos->rtos_specific_params = NULL;
+       target->rtos->current_thread = 0;
+       target->rtos->thread_details = NULL;
+       target->rtos->gdb_target_for_threadid = hwthread_target_for_threadid;
+       target->rtos->gdb_thread_packet = hwthread_thread_packet;
+       return 0;
+}
index cd2e271..da0a503 100644 (file)
@@ -37,6 +37,7 @@ extern struct rtos_type embKernel_rtos;
 extern struct rtos_type mqx_rtos;
 extern struct rtos_type uCOS_III_rtos;
 extern struct rtos_type nuttx_rtos;
+extern struct rtos_type hwthread_rtos;
 
 static struct rtos_type *rtos_types[] = {
        &ThreadX_rtos,
@@ -49,6 +50,7 @@ static struct rtos_type *rtos_types[] = {
        &mqx_rtos,
        &uCOS_III_rtos,
        &nuttx_rtos,
+       &hwthread_rtos,
        NULL
 };