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1 /***************************************************************************
2  *   Copyright (C) 2007 by Dominic Rath                                    *
3  *   Dominic.Rath@gmx.de                                                   *
4  *                                                                         *
5  *   This program is free software; you can redistribute it and/or modify  *
6  *   it under the terms of the GNU General Public License as published by  *
7  *   the Free Software Foundation; either version 2 of the License, or     *
8  *   (at your option) any later version.                                   *
9  *                                                                         *
10  *   This program is distributed in the hope that it will be useful,       *
11  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
13  *   GNU General Public License for more details.                          *
14  *                                                                         *
15  *   You should have received a copy of the GNU General Public License     *
16  *   along with this program; if not, write to the                         *
17  *   Free Software Foundation, Inc.,                                       *
18  *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
19  ***************************************************************************/
20 #ifdef HAVE_CONFIG_H
21 #include "config.h"
22 #endif
23
24 #include <string.h>
25
26 #include "arm7_9_common.h"
27 #include "etb.h"
28 #include "etm.h"
29
30 #include "log.h"
31 #include "types.h"
32 #include "binarybuffer.h"
33 #include "target.h"
34 #include "register.h"
35 #include "jtag.h"
36
37 #include <stdlib.h>
38
39 char* etb_reg_list[] =
40 {
41         "ETB_identification",
42         "ETB_ram_depth",
43         "ETB_ram_width",
44         "ETB_status",
45         "ETB_ram_data",
46         "ETB_ram_read_pointer",
47         "ETB_ram_write_pointer",
48         "ETB_trigger_counter",
49         "ETB_control",
50 };
51
52 int etb_reg_arch_type = -1;
53
54 int etb_get_reg(reg_t *reg);
55 int etb_set_reg(reg_t *reg, u32 value);
56 int etb_set_reg_w_exec(reg_t *reg, u8 *buf);
57
58 int etb_write_reg(reg_t *reg, u32 value);
59 int etb_read_reg(reg_t *reg);
60
61 int handle_etb_config_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc);
62
63 int etb_set_instr(etb_t *etb, u32 new_instr)
64 {
65         jtag_device_t *device = jtag_get_device(etb->chain_pos);
66         
67         if (buf_get_u32(device->cur_instr, 0, device->ir_length) != new_instr)
68         {
69                 scan_field_t field;
70         
71                 field.device = etb->chain_pos;
72                 field.num_bits = device->ir_length;
73                 field.out_value = calloc(CEIL(field.num_bits, 8), 1);
74                 buf_set_u32(field.out_value, 0, field.num_bits, new_instr);
75                 field.out_mask = NULL;
76                 field.in_value = NULL;
77                 field.in_check_value = NULL;
78                 field.in_check_mask = NULL;
79                 field.in_handler = NULL;
80                 field.in_handler_priv = NULL;
81                                 
82                 jtag_add_ir_scan(1, &field, -1, NULL);
83                 
84                 free(field.out_value);
85         }
86         
87         return ERROR_OK;
88 }
89
90 int etb_scann(etb_t *etb, u32 new_scan_chain)
91 {
92         if(etb->cur_scan_chain != new_scan_chain)
93         {
94                 scan_field_t field;
95                 
96                 field.device = etb->chain_pos;
97                 field.num_bits = 5;
98                 field.out_value = calloc(CEIL(field.num_bits, 8), 1);
99                 buf_set_u32(field.out_value, 0, field.num_bits, new_scan_chain);
100                 field.out_mask = NULL;
101                 field.in_value = NULL;
102                 field.in_check_value = NULL;
103                 field.in_check_mask = NULL;
104                 field.in_handler = NULL;
105                 field.in_handler_priv = NULL;
106                 
107                 /* select INTEST instruction */
108                 etb_set_instr(etb, 0x2);
109                 jtag_add_dr_scan(1, &field, -1, NULL);
110                 
111                 etb->cur_scan_chain = new_scan_chain;
112                 
113                 free(field.out_value);
114         }
115
116         return ERROR_OK;
117 }
118
119 reg_cache_t* etb_build_reg_cache(etb_t *etb)
120 {
121         reg_cache_t *reg_cache = malloc(sizeof(reg_cache_t));
122         reg_t *reg_list = NULL;
123         etb_reg_t *arch_info = NULL;
124         int num_regs = 9;
125         int i;
126         
127         /* register a register arch-type for etm registers only once */
128         if (etb_reg_arch_type == -1)
129                 etb_reg_arch_type = register_reg_arch_type(etb_get_reg, etb_set_reg_w_exec);
130         
131         /* the actual registers are kept in two arrays */
132         reg_list = calloc(num_regs, sizeof(reg_t));
133         arch_info = calloc(num_regs, sizeof(etb_reg_t));
134         
135         /* fill in values for the reg cache */
136         reg_cache->name = "etb registers";
137         reg_cache->next = NULL;
138         reg_cache->reg_list = reg_list;
139         reg_cache->num_regs = num_regs;
140         
141         /* set up registers */
142         for (i = 0; i < num_regs; i++)
143         {
144                 reg_list[i].name = etb_reg_list[i];
145                 reg_list[i].size = 32;
146                 reg_list[i].dirty = 0;
147                 reg_list[i].valid = 0;
148                 reg_list[i].bitfield_desc = NULL;
149                 reg_list[i].num_bitfields = 0;
150                 reg_list[i].value = calloc(1, 4);
151                 reg_list[i].arch_info = &arch_info[i];
152                 reg_list[i].arch_type = etb_reg_arch_type;
153                 reg_list[i].size = 32;
154                 arch_info[i].addr = i;
155                 arch_info[i].etb = etb;
156         }
157         
158         return reg_cache;
159 }
160
161 int etb_get_reg(reg_t *reg)
162 {
163         if (etb_read_reg(reg) != ERROR_OK)
164         {
165                 ERROR("BUG: error scheduling etm register read");
166                 exit(-1);
167         }
168         
169         if (jtag_execute_queue() != ERROR_OK)
170         {
171                 ERROR("register read failed");
172         }
173         
174         return ERROR_OK;
175 }
176
177 int etb_read_ram(etb_t *etb, u32 *data, int num_frames)
178 {
179         scan_field_t fields[3];
180         int i;
181         
182         jtag_add_end_state(TAP_RTI);
183         etb_scann(etb, 0x0);
184         etb_set_instr(etb, 0xc);
185         
186         fields[0].device = etb->chain_pos;
187         fields[0].num_bits = 32;
188         fields[0].out_value = NULL;
189         fields[0].out_mask = NULL;
190         fields[0].in_value = NULL;
191         fields[0].in_check_value = NULL;
192         fields[0].in_check_mask = NULL;
193         fields[0].in_handler = NULL;
194         fields[0].in_handler_priv = NULL;
195         
196         fields[1].device = etb->chain_pos;
197         fields[1].num_bits = 7;
198         fields[1].out_value = malloc(1);
199         buf_set_u32(fields[1].out_value, 0, 7, 4);
200         fields[1].out_mask = NULL;
201         fields[1].in_value = NULL;
202         fields[1].in_check_value = NULL;
203         fields[1].in_check_mask = NULL;
204         fields[1].in_handler = NULL;
205         fields[1].in_handler_priv = NULL;
206
207         fields[2].device = etb->chain_pos;
208         fields[2].num_bits = 1;
209         fields[2].out_value = malloc(1);
210         buf_set_u32(fields[2].out_value, 0, 1, 0);
211         fields[2].out_mask = NULL;
212         fields[2].in_value = NULL;
213         fields[2].in_check_value = NULL;
214         fields[2].in_check_mask = NULL;
215         fields[2].in_handler = NULL;
216         fields[2].in_handler_priv = NULL;
217         
218         jtag_add_dr_scan(3, fields, -1, NULL);
219
220         fields[0].in_handler = buf_to_u32_handler;
221         
222         for (i = 0; i < num_frames; i++)
223         {
224                 /* ensure nR/W reamins set to read */
225                 buf_set_u32(fields[2].out_value, 0, 1, 0);
226                 
227                 /* address remains set to 0x4 (RAM data) until we read the last frame */
228                 if (i < num_frames - 1)
229                         buf_set_u32(fields[1].out_value, 0, 7, 4);
230                 else
231                         buf_set_u32(fields[1].out_value, 0, 7, 0);
232                 
233                 fields[0].in_handler_priv = &data[i];
234                 jtag_add_dr_scan(3, fields, -1, NULL);
235         }
236         
237         jtag_execute_queue();
238         
239         free(fields[1].out_value);
240         free(fields[2].out_value);
241         
242         return ERROR_OK;
243 }
244
245 int etb_read_reg_w_check(reg_t *reg, u8* check_value, u8* check_mask)
246 {
247         etb_reg_t *etb_reg = reg->arch_info;
248         u8 reg_addr = etb_reg->addr & 0x7f;
249         scan_field_t fields[3];
250         
251         DEBUG("%i", etb_reg->addr);
252
253         jtag_add_end_state(TAP_RTI);
254         etb_scann(etb_reg->etb, 0x0);
255         etb_set_instr(etb_reg->etb, 0xc);
256         
257         fields[0].device = etb_reg->etb->chain_pos;
258         fields[0].num_bits = 32;
259         fields[0].out_value = reg->value;
260         fields[0].out_mask = NULL;
261         fields[0].in_value = NULL;
262         fields[0].in_check_value = NULL;
263         fields[0].in_check_mask = NULL;
264         fields[0].in_handler = NULL;
265         fields[0].in_handler_priv = NULL;
266         
267         fields[1].device = etb_reg->etb->chain_pos;
268         fields[1].num_bits = 7;
269         fields[1].out_value = malloc(1);
270         buf_set_u32(fields[1].out_value, 0, 7, reg_addr);
271         fields[1].out_mask = NULL;
272         fields[1].in_value = NULL;
273         fields[1].in_check_value = NULL;
274         fields[1].in_check_mask = NULL;
275         fields[1].in_handler = NULL;
276         fields[1].in_handler_priv = NULL;
277
278         fields[2].device = etb_reg->etb->chain_pos;
279         fields[2].num_bits = 1;
280         fields[2].out_value = malloc(1);
281         buf_set_u32(fields[2].out_value, 0, 1, 0);
282         fields[2].out_mask = NULL;
283         fields[2].in_value = NULL;
284         fields[2].in_check_value = NULL;
285         fields[2].in_check_mask = NULL;
286         fields[2].in_handler = NULL;
287         fields[2].in_handler_priv = NULL;
288         
289         jtag_add_dr_scan(3, fields, -1, NULL);
290         
291         /* read the identification register in the second run, to make sure we
292          * don't read the ETB data register twice, skipping every second entry
293          */
294         buf_set_u32(fields[1].out_value, 0, 7, 0x0);
295         fields[0].in_value = reg->value;
296         fields[0].in_check_value = check_value;
297         fields[0].in_check_mask = check_mask;
298                 
299         jtag_add_dr_scan(3, fields, -1, NULL);
300
301         free(fields[1].out_value);
302         free(fields[2].out_value);
303         
304         return ERROR_OK;
305 }
306
307 int etb_read_reg(reg_t *reg)
308 {
309         return etb_read_reg_w_check(reg, NULL, NULL);   
310 }
311
312 int etb_set_reg(reg_t *reg, u32 value)
313 {
314         if (etb_write_reg(reg, value) != ERROR_OK)
315         {
316                 ERROR("BUG: error scheduling etm register write");
317                 exit(-1);
318         }
319         
320         buf_set_u32(reg->value, 0, reg->size, value);
321         reg->valid = 1;
322         reg->dirty = 0;
323         
324         return ERROR_OK;
325 }
326
327 int etb_set_reg_w_exec(reg_t *reg, u8 *buf)
328 {
329         etb_set_reg(reg, buf_get_u32(buf, 0, reg->size));
330         
331         if (jtag_execute_queue() != ERROR_OK)
332         {
333                 ERROR("register write failed");
334                 exit(-1);
335         }
336         return ERROR_OK;
337 }
338
339 int etb_write_reg(reg_t *reg, u32 value)
340 {
341         etb_reg_t *etb_reg = reg->arch_info;
342         u8 reg_addr = etb_reg->addr & 0x7f;
343         scan_field_t fields[3];
344         
345         DEBUG("%i: 0x%8.8x", etb_reg->addr, value);
346         
347         jtag_add_end_state(TAP_RTI);
348         etb_scann(etb_reg->etb, 0x0);
349         etb_set_instr(etb_reg->etb, 0xc);
350         
351         fields[0].device = etb_reg->etb->chain_pos;
352         fields[0].num_bits = 32;
353         fields[0].out_value = malloc(4);
354         buf_set_u32(fields[0].out_value, 0, 32, value);
355         fields[0].out_mask = NULL;
356         fields[0].in_value = NULL;
357         fields[0].in_check_value = NULL;
358         fields[0].in_check_mask = NULL;
359         fields[0].in_handler = NULL;
360         fields[0].in_handler_priv = NULL;
361         
362         fields[1].device = etb_reg->etb->chain_pos;
363         fields[1].num_bits = 7;
364         fields[1].out_value = malloc(1);
365         buf_set_u32(fields[1].out_value, 0, 7, reg_addr);
366         fields[1].out_mask = NULL;
367         fields[1].in_value = NULL;
368         fields[1].in_check_value = NULL;
369         fields[1].in_check_mask = NULL;
370         fields[1].in_handler = NULL;
371         fields[1].in_handler_priv = NULL;
372
373         fields[2].device = etb_reg->etb->chain_pos;
374         fields[2].num_bits = 1;
375         fields[2].out_value = malloc(1);
376         buf_set_u32(fields[2].out_value, 0, 1, 1);
377         fields[2].out_mask = NULL;
378         fields[2].in_value = NULL;
379         fields[2].in_check_value = NULL;
380         fields[2].in_check_mask = NULL;
381         fields[2].in_handler = NULL;
382         fields[2].in_handler_priv = NULL;
383         
384         jtag_add_dr_scan(3, fields, -1, NULL);
385         
386         free(fields[0].out_value);
387         free(fields[1].out_value);
388         free(fields[2].out_value);
389         
390         return ERROR_OK;
391 }
392
393 int etb_store_reg(reg_t *reg)
394 {
395         return etb_write_reg(reg, buf_get_u32(reg->value, 0, reg->size));
396 }
397
398 int etb_register_commands(struct command_context_s *cmd_ctx)
399 {
400         command_t *etb_cmd;
401         
402         etb_cmd = register_command(cmd_ctx, NULL, "etb", NULL, COMMAND_ANY, "Embedded Trace Buffer");
403         
404         register_command(cmd_ctx, etb_cmd, "config", handle_etb_config_command, COMMAND_CONFIG, NULL);
405
406         return ERROR_OK;
407 }
408
409 int handle_etb_config_command(struct command_context_s *cmd_ctx, char *cmd, char **args, int argc)
410 {
411         target_t *target;
412         jtag_device_t *jtag_device;
413         armv4_5_common_t *armv4_5;
414         arm7_9_common_t *arm7_9;
415         
416         if (argc != 2)
417         {
418                 ERROR("incomplete 'etb config <target> <chain_pos>' command");
419                 exit(-1);
420         }
421         
422         target = get_target_by_num(strtoul(args[0], NULL, 0));
423         
424         if (!target)
425         {
426                 ERROR("target number '%s' not defined", args[0]);
427                 exit(-1);
428         }
429         
430         if (arm7_9_get_arch_pointers(target, &armv4_5, &arm7_9) != ERROR_OK)
431         {
432                 command_print(cmd_ctx, "current target isn't an ARM7/ARM9 target");
433                 return ERROR_OK;
434         }
435         
436         jtag_device = jtag_get_device(strtoul(args[1], NULL, 0));
437         
438         if (!jtag_device)
439         {
440                 ERROR("jtag device number '%s' not defined", args[1]);
441                 exit(-1);
442         }
443         
444         if (arm7_9->etm_ctx)
445         {
446                 etb_t *etb = malloc(sizeof(etb_t));
447                 
448                 arm7_9->etm_ctx->capture_driver_priv = etb;
449                 
450                 etb->chain_pos = strtoul(args[1], NULL, 0);
451                 etb->cur_scan_chain = -1;
452                 etb->reg_cache = NULL;
453                 etb->ram_width = 0;
454                 etb->ram_depth = 0;
455         }
456         else
457         {
458                 ERROR("target has no ETM defined, ETB left unconfigured");
459         }
460
461         return ERROR_OK;
462 }
463
464 int etb_init(etm_context_t *etm_ctx)
465 {
466         etb_t *etb = etm_ctx->capture_driver_priv;
467         
468         etb->etm_ctx = etm_ctx;
469         
470         /* identify ETB RAM depth and width */
471         etb_read_reg(&etb->reg_cache->reg_list[ETB_RAM_DEPTH]);
472         etb_read_reg(&etb->reg_cache->reg_list[ETB_RAM_WIDTH]);
473         jtag_execute_queue();
474
475         etb->ram_depth = buf_get_u32(etb->reg_cache->reg_list[ETB_RAM_DEPTH].value, 0, 32);
476         etb->ram_width = buf_get_u32(etb->reg_cache->reg_list[ETB_RAM_WIDTH].value, 0, 32);
477         
478         return ERROR_OK;
479 }
480
481 trace_status_t etb_status(etm_context_t *etm_ctx)
482 {
483         etb_t *etb = etm_ctx->capture_driver_priv;
484         
485         etb->etm_ctx = etm_ctx;
486         
487         /* if tracing is currently idle, return this information */
488         if (etm_ctx->capture_status == TRACE_IDLE)
489         {
490                 return etm_ctx->capture_status;
491         }
492         else if (etm_ctx->capture_status & TRACE_RUNNING)
493         {
494                 reg_t *etb_status_reg = &etb->reg_cache->reg_list[ETB_STATUS];
495                 int etb_timeout = 100;
496                 
497                 /* trace is running, check the ETB status flags */
498                 etb_get_reg(etb_status_reg);
499         
500                 /* check Full bit to identify an overflow */
501                 if (buf_get_u32(etb_status_reg->value, 0, 1) == 1)
502                         etm_ctx->capture_status |= TRACE_OVERFLOWED;
503
504                 /* check Triggered bit to identify trigger condition */
505                 if (buf_get_u32(etb_status_reg->value, 1, 1) == 1)
506                         etm_ctx->capture_status |= TRACE_TRIGGERED;
507
508                 /* check AcqComp to identify trace completion */
509                 if (buf_get_u32(etb_status_reg->value, 2, 1) == 1)
510                 {
511                         while (etb_timeout-- && (buf_get_u32(etb_status_reg->value, 3, 1) == 0))
512                         {
513                                 /* wait for data formatter idle */
514                                 etb_get_reg(etb_status_reg);
515                         }
516                         
517                         if (etb_timeout == 0)
518                         {
519                                 ERROR("AcqComp set but DFEmpty won't go high, ETB status: 0x%x",
520                                         buf_get_u32(etb_status_reg->value, 0, etb_status_reg->size));
521                         }
522                         
523                         if (!(etm_ctx->capture_status && TRACE_TRIGGERED))
524                         {
525                                 ERROR("trace completed, but no trigger condition detected");
526                         }
527                         
528                         etm_ctx->capture_status &= ~TRACE_RUNNING;
529                         etm_ctx->capture_status |= TRACE_COMPLETED;
530                 }
531         }
532         
533         return etm_ctx->capture_status;
534 }
535
536 int etb_read_trace(etm_context_t *etm_ctx)
537 {
538         etb_t *etb = etm_ctx->capture_driver_priv;
539         int first_frame = 0;
540         int num_frames = etb->ram_depth;
541         u32 *trace_data = NULL;
542         int i, j;
543         
544         etb_read_reg(&etb->reg_cache->reg_list[ETB_STATUS]);
545         etb_read_reg(&etb->reg_cache->reg_list[ETB_RAM_WRITE_POINTER]);
546         jtag_execute_queue();
547         
548         /* check if we overflowed, and adjust first frame of the trace accordingly
549          * if we didn't overflow, read only up to the frame that would be written next,
550          * i.e. don't read invalid entries
551          */
552         if (buf_get_u32(etb->reg_cache->reg_list[ETB_STATUS].value, 0, 1))
553         {
554                 first_frame = buf_get_u32(etb->reg_cache->reg_list[ETB_RAM_WRITE_POINTER].value, 0, 32);
555         }
556         else
557         {
558                 num_frames = buf_get_u32(etb->reg_cache->reg_list[ETB_RAM_WRITE_POINTER].value, 0, 32);
559         }
560         
561         etb_write_reg(&etb->reg_cache->reg_list[ETB_RAM_READ_POINTER], first_frame);
562
563         /* read data into temporary array for unpacking */      
564         trace_data = malloc(sizeof(u32) * num_frames);
565         etb_read_ram(etb, trace_data, num_frames);
566
567         if (etm_ctx->trace_depth > 0)
568         {
569                 free(etm_ctx->trace_data);
570         }
571         
572         if ((etm_ctx->portmode & ETM_PORT_MODE_MASK) == ETM_PORT_DEMUXED)
573                 etm_ctx->trace_depth = num_frames * 2;
574         else
575                 etm_ctx->trace_depth = num_frames;
576
577         etm_ctx->trace_data= malloc(sizeof(etmv1_trace_data_t) * etm_ctx->trace_depth);
578         
579         for (i = 0, j = 0; i < num_frames; i++)
580         {
581                 if ((etm_ctx->portmode & ETM_PORT_MODE_MASK) == ETM_PORT_DEMUXED)
582                 {
583                         etm_ctx->trace_data[j].pipestat = trace_data[i] & 0x7;
584                         etm_ctx->trace_data[j].packet = (trace_data[i] & 0x7f8) >> 3;
585                         etm_ctx->trace_data[j].flags = 0;
586                         if ((trace_data[i] & 0x800) >> 11)
587                         {
588                                 etm_ctx->trace_data[j].flags |= ETMV1_TRACESYNC_CYCLE;
589                         }
590                         if (etm_ctx->trace_data[j].pipestat == STAT_TR)
591                         {
592                                 etm_ctx->trace_data[j].pipestat = etm_ctx->trace_data[j].packet & 0x7;
593                                 etm_ctx->trace_data[j].flags |= ETMV1_TRIGGER_CYCLE;
594                         }
595
596                         etm_ctx->trace_data[j+1].pipestat = (trace_data[i] & 0x7000) >> 12;
597                         etm_ctx->trace_data[j+1].packet = (trace_data[i] & 0x7f8000) >> 15;
598                         etm_ctx->trace_data[j+1].flags = 0;
599                         if ((trace_data[i] & 0x800000) >> 23)
600                         {
601                                 etm_ctx->trace_data[j+1].flags |= ETMV1_TRACESYNC_CYCLE;
602                         }
603                         if (etm_ctx->trace_data[j+1].pipestat == STAT_TR)
604                         {
605                                 etm_ctx->trace_data[j+1].pipestat = etm_ctx->trace_data[j+1].packet & 0x7;
606                                 etm_ctx->trace_data[j+1].flags |= ETMV1_TRIGGER_CYCLE;
607                         }
608                         
609                         j += 2;
610                 }
611                 else
612                 {
613                         etm_ctx->trace_data[j].pipestat = trace_data[i] & 0x7;
614                         etm_ctx->trace_data[j].packet = (trace_data[i] & 0x7fff8) >> 3;
615                         etm_ctx->trace_data[j].flags = 0;
616                         if ((trace_data[i] & 0x80000) >> 19)
617                         {
618                                 etm_ctx->trace_data[j].flags |= ETMV1_TRACESYNC_CYCLE;
619                         }
620                         if (etm_ctx->trace_data[j].pipestat == STAT_TR)
621                         {
622                                 etm_ctx->trace_data[j].pipestat = etm_ctx->trace_data[j].packet & 0x7;
623                                 etm_ctx->trace_data[j].flags |= ETMV1_TRIGGER_CYCLE;
624                         }
625                         
626                         j += 1;
627                 }
628         }
629         
630         free(trace_data);
631         
632         return ERROR_OK;
633 }
634
635 int etb_start_capture(etm_context_t *etm_ctx)
636 {
637         etb_t *etb = etm_ctx->capture_driver_priv;
638         u32 etb_ctrl_value = 0x1;
639
640         if ((etm_ctx->portmode & ETM_PORT_MODE_MASK) == ETM_PORT_DEMUXED)
641         {
642                 if ((etm_ctx->portmode & ETM_PORT_WIDTH_MASK) == ETM_PORT_16BIT)
643                 {
644                         DEBUG("ETB can't run in demultiplexed mode with a 16-bit port");
645                         return ERROR_ETM_PORTMODE_NOT_SUPPORTED;
646                 }
647                 etb_ctrl_value |= 0x2;
648         }
649         
650         if ((etm_ctx->portmode & ETM_PORT_MODE_MASK) == ETM_PORT_MUXED)
651                 return ERROR_ETM_PORTMODE_NOT_SUPPORTED;
652         
653         etb_write_reg(&etb->reg_cache->reg_list[ETB_TRIGGER_COUNTER], 0x600);
654         etb_write_reg(&etb->reg_cache->reg_list[ETB_RAM_WRITE_POINTER], 0x0);
655         etb_write_reg(&etb->reg_cache->reg_list[ETB_CTRL], etb_ctrl_value);
656         jtag_execute_queue();
657         
658         /* we're starting a new trace, initialize capture status */
659         etm_ctx->capture_status = TRACE_RUNNING;
660         
661         return ERROR_OK; 
662 }
663
664 int etb_stop_capture(etm_context_t *etm_ctx)
665 {
666         etb_t *etb = etm_ctx->capture_driver_priv;
667         reg_t *etb_ctrl_reg = &etb->reg_cache->reg_list[ETB_CTRL];
668
669         etb_write_reg(etb_ctrl_reg, 0x0);
670         jtag_execute_queue();
671         
672         /* trace stopped, just clear running flag, but preserve others */ 
673         etm_ctx->capture_status &= ~TRACE_RUNNING;
674         
675         return ERROR_OK;
676 }
677
678 etm_capture_driver_t etb_capture_driver =
679 {
680         .name = "etb",
681         .register_commands = etb_register_commands,
682         .init = etb_init,
683         .status = etb_status,
684         .start_capture = etb_start_capture,
685         .stop_capture = etb_stop_capture,
686         .read_trace = etb_read_trace,
687 };