forked from adafruit/Adafruit_nRF52_Bootloader
-
Notifications
You must be signed in to change notification settings - Fork 1
/
SEGGER_RTT.c
1329 lines (1259 loc) · 41.5 KB
/
SEGGER_RTT.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
/*********************************************************************
* SEGGER MICROCONTROLLER GmbH & Co. KG *
* Solutions for real time microcontroller applications *
**********************************************************************
* *
* (c) 2014 - 2016 SEGGER Microcontroller GmbH & Co. KG *
* *
* www.segger.com Support: [email protected] *
* *
**********************************************************************
* *
* SEGGER RTT * Real Time Transfer for embedded targets *
* *
**********************************************************************
* *
* All rights reserved. *
* *
* * This software may in its unmodified form be freely redistributed *
* in source form. *
* * The source code may be modified, provided the source code *
* retains the above copyright notice, this list of conditions and *
* the following disclaimer. *
* * Modified versions of this software in source or linkable form *
* may not be distributed without prior consent of SEGGER. *
* * This software may only be used for communication with SEGGER *
* J-Link debug probes. *
* *
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND *
* CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, *
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF *
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE *
* DISCLAIMED. IN NO EVENT SHALL SEGGER Microcontroller BE LIABLE FOR *
* ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR *
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT *
* OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; *
* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF *
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT *
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE *
* USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH *
* DAMAGE. *
* *
**********************************************************************
* *
* RTT version: 5.12e *
* *
**********************************************************************
---------------------------END-OF-HEADER------------------------------
File : SEGGER_RTT.c
Purpose : Implementation of SEGGER real-time transfer (RTT) which
allows real-time communication on targets which support
debugger memory accesses while the CPU is running.
Additional information:
Type "int" is assumed to be 32-bits in size
H->T Host to target communication
T->H Target to host communication
RTT channel 0 is always present and reserved for Terminal usage.
Name is fixed to "Terminal"
Effective buffer size: SizeOfBuffer - 1
WrOff == RdOff: Buffer is empty
WrOff == (RdOff - 1): Buffer is full
WrOff > RdOff: Free space includes wrap-around
WrOff < RdOff: Used space includes wrap-around
(WrOff == (SizeOfBuffer - 1)) && (RdOff == 0):
Buffer full and wrap-around after next byte
----------------------------------------------------------------------
*/
#include "SEGGER_RTT.h"
#include <string.h> // for memcpy
/*********************************************************************
*
* Configuration, default values
*
**********************************************************************
*/
#ifndef BUFFER_SIZE_UP
#define BUFFER_SIZE_UP 1024 // Size of the buffer for terminal output of target, up to host
#endif
#ifndef BUFFER_SIZE_DOWN
#define BUFFER_SIZE_DOWN 16 // Size of the buffer for terminal input to target from host (Usually keyboard input)
#endif
#ifndef SEGGER_RTT_MAX_NUM_UP_BUFFERS
#define SEGGER_RTT_MAX_NUM_UP_BUFFERS 2 // Number of up-buffers (T->H) available on this target
#endif
#ifndef SEGGER_RTT_MAX_NUM_DOWN_BUFFERS
#define SEGGER_RTT_MAX_NUM_DOWN_BUFFERS 2 // Number of down-buffers (H->T) available on this target
#endif
#ifndef SEGGER_RTT_BUFFER_SECTION
#if defined SEGGER_RTT_SECTION
#define SEGGER_RTT_BUFFER_SECTION SEGGER_RTT_SECTION
#endif
#endif
#ifndef SEGGER_RTT_MODE_DEFAULT
#define SEGGER_RTT_MODE_DEFAULT SEGGER_RTT_MODE_NO_BLOCK_SKIP
#endif
#ifndef SEGGER_RTT_LOCK
#define SEGGER_RTT_LOCK()
#endif
#ifndef SEGGER_RTT_UNLOCK
#define SEGGER_RTT_UNLOCK()
#endif
#ifndef STRLEN
#define STRLEN(a) strlen((a))
#endif
#ifndef MEMCPY
#define MEMCPY(pDest, pSrc, NumBytes) memcpy((pDest), (pSrc), (NumBytes))
#endif
#ifndef MIN
#define MIN(a, b) (((a) < (b)) ? (a) : (b))
#endif
#ifndef MAX
#define MAX(a, b) (((a) > (b)) ? (a) : (b))
#endif
//
// For some environments, NULL may not be defined until certain headers are included
//
#ifndef NULL
#define NULL 0
#endif
/*********************************************************************
*
* Static const data
*
**********************************************************************
*/
static unsigned char _aTerminalId[16] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F' };
/*********************************************************************
*
* Static data
*
**********************************************************************
*/
//
// RTT Control Block and allocate buffers for channel 0
//
#ifdef SEGGER_RTT_SECTION
#if (defined __GNUC__)
__attribute__ ((section (SEGGER_RTT_SECTION))) SEGGER_RTT_CB _SEGGER_RTT;
#elif (defined __ICCARM__) || (defined __ICCRX__)
#pragma location=SEGGER_RTT_SECTION
SEGGER_RTT_CB _SEGGER_RTT;
#elif (defined __CC_ARM__)
__attribute__ ((section (SEGGER_RTT_SECTION), zero_init)) SEGGER_RTT_CB _SEGGER_RTT;
#else
SEGGER_RTT_CB _SEGGER_RTT;
#endif
#else
SEGGER_RTT_CB _SEGGER_RTT;
#endif
#ifdef SEGGER_RTT_BUFFER_SECTION
#if (defined __GNUC__)
__attribute__ ((section (SEGGER_RTT_BUFFER_SECTION))) static char _acUpBuffer [BUFFER_SIZE_UP];
__attribute__ ((section (SEGGER_RTT_BUFFER_SECTION))) static char _acDownBuffer[BUFFER_SIZE_DOWN];
#elif (defined __ICCARM__) || (defined __ICCRX__)
#pragma location=SEGGER_RTT_BUFFER_SECTION
static char _acUpBuffer [BUFFER_SIZE_UP];
#pragma location=SEGGER_RTT_BUFFER_SECTION
static char _acDownBuffer[BUFFER_SIZE_DOWN];
#elif (defined __CC_ARM__)
__attribute__ ((section (SEGGER_RTT_BUFFER_SECTION), zero_init)) static char _acUpBuffer [BUFFER_SIZE_UP];
__attribute__ ((section (SEGGER_RTT_BUFFER_SECTION), zero_init)) static char _acDownBuffer[BUFFER_SIZE_DOWN];
#else
static char _acUpBuffer [BUFFER_SIZE_UP];
static char _acDownBuffer[BUFFER_SIZE_DOWN];
#endif
#else
static char _acUpBuffer [BUFFER_SIZE_UP];
static char _acDownBuffer[BUFFER_SIZE_DOWN];
#endif
static char _ActiveTerminal;
/*********************************************************************
*
* Static functions
*
**********************************************************************
*/
/*********************************************************************
*
* _DoInit()
*
* Function description
* Initializes the control block an buffers.
* May only be called via INIT() to avoid overriding settings.
*
*/
#define INIT() do { \
if (_SEGGER_RTT.acID[0] == '\0') { _DoInit(); } \
} while (0)
static void _DoInit(void) {
SEGGER_RTT_CB* p;
//
// Initialize control block
//
p = &_SEGGER_RTT;
p->MaxNumUpBuffers = SEGGER_RTT_MAX_NUM_UP_BUFFERS;
p->MaxNumDownBuffers = SEGGER_RTT_MAX_NUM_DOWN_BUFFERS;
//
// Initialize up buffer 0
//
p->aUp[0].sName = "Terminal";
p->aUp[0].pBuffer = _acUpBuffer;
p->aUp[0].SizeOfBuffer = sizeof(_acUpBuffer);
p->aUp[0].RdOff = 0u;
p->aUp[0].WrOff = 0u;
p->aUp[0].Flags = SEGGER_RTT_MODE_DEFAULT;
//
// Initialize down buffer 0
//
p->aDown[0].sName = "Terminal";
p->aDown[0].pBuffer = _acDownBuffer;
p->aDown[0].SizeOfBuffer = sizeof(_acDownBuffer);
p->aDown[0].RdOff = 0u;
p->aDown[0].WrOff = 0u;
p->aDown[0].Flags = SEGGER_RTT_MODE_DEFAULT;
//
// Finish initialization of the control block.
// Copy Id string in three steps to make sure "SEGGER RTT" is not found
// in initializer memory (usually flash) by J-Link
//
strcpy(&p->acID[7], "RTT");
strcpy(&p->acID[0], "SEGGER");
p->acID[6] = ' ';
}
/*********************************************************************
*
* _WriteBlocking()
*
* Function description
* Stores a specified number of characters in SEGGER RTT ring buffer
* and updates the associated write pointer which is periodically
* read by the host.
* The caller is responsible for managing the write chunk sizes as
* _WriteBlocking() will block until all data has been posted successfully.
*
* Parameters
* pRing Ring buffer to post to.
* pBuffer Pointer to character array. Does not need to point to a \0 terminated string.
* NumBytes Number of bytes to be stored in the SEGGER RTT control block.
*
* Return value
* >= 0 - Number of bytes written into buffer.
*/
static unsigned _WriteBlocking(SEGGER_RTT_BUFFER_UP* pRing, const char* pBuffer, unsigned NumBytes) {
unsigned NumBytesToWrite;
unsigned NumBytesWritten;
unsigned RdOff;
unsigned WrOff;
//
// Write data to buffer and handle wrap-around if necessary
//
NumBytesWritten = 0u;
WrOff = pRing->WrOff;
do {
RdOff = pRing->RdOff; // May be changed by host (debug probe) in the meantime
if (RdOff > WrOff) {
NumBytesToWrite = RdOff - WrOff - 1u;
} else {
NumBytesToWrite = pRing->SizeOfBuffer - (WrOff - RdOff + 1u);
}
NumBytesToWrite = MIN(NumBytesToWrite, (pRing->SizeOfBuffer - WrOff)); // Number of bytes that can be written until buffer wrap-around
NumBytesToWrite = MIN(NumBytesToWrite, NumBytes);
memcpy(pRing->pBuffer + WrOff, pBuffer, NumBytesToWrite);
NumBytesWritten += NumBytesToWrite;
pBuffer += NumBytesToWrite;
NumBytes -= NumBytesToWrite;
WrOff += NumBytesToWrite;
if (WrOff == pRing->SizeOfBuffer) {
WrOff = 0u;
}
pRing->WrOff = WrOff;
} while (NumBytes);
//
return NumBytesWritten;
}
/*********************************************************************
*
* _WriteNoCheck()
*
* Function description
* Stores a specified number of characters in SEGGER RTT ring buffer
* and updates the associated write pointer which is periodically
* read by the host.
* It is callers responsibility to make sure data actually fits in buffer.
*
* Parameters
* pRing Ring buffer to post to.
* pBuffer Pointer to character array. Does not need to point to a \0 terminated string.
* NumBytes Number of bytes to be stored in the SEGGER RTT control block.
*
* Notes
* (1) If there might not be enough space in the "Up"-buffer, call _WriteBlocking
*/
static void _WriteNoCheck(SEGGER_RTT_BUFFER_UP* pRing, const char* pData, unsigned NumBytes) {
unsigned NumBytesAtOnce;
unsigned WrOff;
unsigned Rem;
WrOff = pRing->WrOff;
Rem = pRing->SizeOfBuffer - WrOff;
if (Rem > NumBytes) {
//
// All data fits before wrap around
//
memcpy(pRing->pBuffer + WrOff, pData, NumBytes);
pRing->WrOff = WrOff + NumBytes;
} else {
//
// We reach the end of the buffer, so need to wrap around
//
NumBytesAtOnce = Rem;
memcpy(pRing->pBuffer + WrOff, pData, NumBytesAtOnce);
NumBytesAtOnce = NumBytes - Rem;
memcpy(pRing->pBuffer, pData + Rem, NumBytesAtOnce);
pRing->WrOff = NumBytesAtOnce;
}
}
/*********************************************************************
*
* _PostTerminalSwitch()
*
* Function description
* Switch terminal to the given terminal ID. It is the caller's
* responsibility to ensure the terminal ID is correct and there is
* enough space in the buffer for this to complete successfully.
*
* Parameters
* pRing Ring buffer to post to.
* TerminalId Terminal ID to switch to.
*/
static void _PostTerminalSwitch(SEGGER_RTT_BUFFER_UP* pRing, unsigned char TerminalId) {
char ac[2];
ac[0] = 0xFFu;
ac[1] = _aTerminalId[TerminalId]; // Caller made already sure that TerminalId does not exceed our terminal limit
_WriteBlocking(pRing, ac, 2u);
}
/*********************************************************************
*
* _GetAvailWriteSpace()
*
* Function description
* Returns the number of bytes that can be written to the ring
* buffer without blocking.
*
* Parameters
* pRing Ring buffer to check.
*
* Return value
* Number of bytes that are free in the buffer.
*/
static unsigned _GetAvailWriteSpace(SEGGER_RTT_BUFFER_UP* pRing) {
unsigned RdOff;
unsigned WrOff;
unsigned r;
//
// Avoid warnings regarding volatile access order. It's not a problem
// in this case, but dampen compiler enthusiasm.
//
RdOff = pRing->RdOff;
WrOff = pRing->WrOff;
if (RdOff <= WrOff) {
r = pRing->SizeOfBuffer - 1u - WrOff + RdOff;
} else {
r = RdOff - WrOff - 1u;
}
return r;
}
/*********************************************************************
*
* Public code
*
**********************************************************************
*/
/*********************************************************************
*
* SEGGER_RTT_ReadNoLock()
*
* Function description
* Reads characters from SEGGER real-time-terminal control block
* which have been previously stored by the host.
* Do not lock against interrupts and multiple access.
*
* Parameters
* BufferIndex Index of Down-buffer to be used (e.g. 0 for "Terminal").
* pBuffer Pointer to buffer provided by target application, to copy characters from RTT-down-buffer to.
* BufferSize Size of the target application buffer.
*
* Return value
* Number of bytes that have been read.
*/
unsigned SEGGER_RTT_ReadNoLock(unsigned BufferIndex, void* pData, unsigned BufferSize) {
unsigned NumBytesRem;
unsigned NumBytesRead;
unsigned RdOff;
unsigned WrOff;
unsigned char* pBuffer;
SEGGER_RTT_BUFFER_DOWN* pRing;
//
INIT();
pRing = &_SEGGER_RTT.aDown[BufferIndex];
pBuffer = (unsigned char*)pData;
RdOff = pRing->RdOff;
WrOff = pRing->WrOff;
NumBytesRead = 0u;
//
// Read from current read position to wrap-around of buffer, first
//
if (RdOff > WrOff) {
NumBytesRem = pRing->SizeOfBuffer - RdOff;
NumBytesRem = MIN(NumBytesRem, BufferSize);
memcpy(pBuffer, pRing->pBuffer + RdOff, NumBytesRem);
NumBytesRead += NumBytesRem;
pBuffer += NumBytesRem;
BufferSize -= NumBytesRem;
RdOff += NumBytesRem;
//
// Handle wrap-around of buffer
//
if (RdOff == pRing->SizeOfBuffer) {
RdOff = 0u;
}
}
//
// Read remaining items of buffer
//
NumBytesRem = WrOff - RdOff;
NumBytesRem = MIN(NumBytesRem, BufferSize);
if (NumBytesRem > 0u) {
memcpy(pBuffer, pRing->pBuffer + RdOff, NumBytesRem);
NumBytesRead += NumBytesRem;
pBuffer += NumBytesRem;
BufferSize -= NumBytesRem;
RdOff += NumBytesRem;
}
if (NumBytesRead) {
pRing->RdOff = RdOff;
}
//
return NumBytesRead;
}
/*********************************************************************
*
* SEGGER_RTT_Read
*
* Function description
* Reads characters from SEGGER real-time-terminal control block
* which have been previously stored by the host.
*
* Parameters
* BufferIndex Index of Down-buffer to be used (e.g. 0 for "Terminal").
* pBuffer Pointer to buffer provided by target application, to copy characters from RTT-down-buffer to.
* BufferSize Size of the target application buffer.
*
* Return value
* Number of bytes that have been read.
*/
unsigned SEGGER_RTT_Read(unsigned BufferIndex, void* pBuffer, unsigned BufferSize) {
unsigned NumBytesRead;
//
SEGGER_RTT_LOCK();
//
// Call the non-locking read function
//
NumBytesRead = SEGGER_RTT_ReadNoLock(BufferIndex, pBuffer, BufferSize);
//
// Finish up.
//
SEGGER_RTT_UNLOCK();
//
return NumBytesRead;
}
/*********************************************************************
*
* SEGGER_RTT_WriteWithOverwriteNoLock
*
* Function description
* Stores a specified number of characters in SEGGER RTT
* control block.
* SEGGER_RTT_WriteWithOverwriteNoLock does not lock the application
* and overwrites data if the data does not fit into the buffer.
*
* Parameters
* BufferIndex Index of "Up"-buffer to be used (e.g. 0 for "Terminal").
* pBuffer Pointer to character array. Does not need to point to a \0 terminated string.
* NumBytes Number of bytes to be stored in the SEGGER RTT control block.
*
* Notes
* (1) If there is not enough space in the "Up"-buffer, data is overwritten.
* (2) For performance reasons this function does not call Init()
* and may only be called after RTT has been initialized.
* Either by calling SEGGER_RTT_Init() or calling another RTT API function first.
* (3) Do not use SEGGER_RTT_WriteWithOverwriteNoLock if a J-Link
* connection reads RTT data.
*/
void SEGGER_RTT_WriteWithOverwriteNoLock(unsigned BufferIndex, const void* pBuffer, unsigned NumBytes) {
const char* pData;
SEGGER_RTT_BUFFER_UP* pRing;
unsigned Avail;
pData = (const char *)pBuffer;
//
// Get "to-host" ring buffer and copy some elements into local variables.
//
pRing = &_SEGGER_RTT.aUp[BufferIndex];
//
// Check if we will overwrite data and need to adjust the RdOff.
//
if (pRing->WrOff == pRing->RdOff) {
Avail = pRing->SizeOfBuffer - 1u;
} else if ( pRing->WrOff < pRing->RdOff) {
Avail = pRing->RdOff - pRing->WrOff - 1u;
} else {
Avail = pRing->RdOff - pRing->WrOff - 1u + pRing->SizeOfBuffer;
}
if (NumBytes > Avail) {
pRing->RdOff += (NumBytes - Avail);
while (pRing->RdOff >= pRing->SizeOfBuffer) {
pRing->RdOff -= pRing->SizeOfBuffer;
}
}
//
// Write all data, no need to check the RdOff, but possibly handle multiple wrap-arounds
//
Avail = pRing->SizeOfBuffer - pRing->WrOff;
do {
if (Avail > NumBytes) {
//
// Last round
//
#if 1 // memcpy() is good for large amounts of data, but the overhead is too big for small amounts. Use a simple byte loop instead.
char* pDst;
pDst = pRing->pBuffer + pRing->WrOff;
pRing->WrOff += NumBytes;
do {
*pDst++ = *pData++;
} while (--NumBytes);
#else
memcpy(pRing->pBuffer + WrOff, pData, NumBytes);
pRing->WrOff += NumBytes;
#endif
break; //Alternatively: NumBytes = 0;
} else {
//
// Wrap-around necessary, write until wrap-around and reset WrOff
//
memcpy(pRing->pBuffer + pRing->WrOff, pData, Avail);
pData += Avail;
pRing->WrOff = 0;
NumBytes -= Avail;
Avail = (pRing->SizeOfBuffer - 1);
}
} while (NumBytes);
}
/*********************************************************************
*
* SEGGER_RTT_WriteSkipNoLock
*
* Function description
* Stores a specified number of characters in SEGGER RTT
* control block which is then read by the host.
* SEGGER_RTT_WriteSkipNoLock does not lock the application and
* skips all data, if the data does not fit into the buffer.
*
* Parameters
* BufferIndex Index of "Up"-buffer to be used (e.g. 0 for "Terminal").
* pBuffer Pointer to character array. Does not need to point to a \0 terminated string.
* NumBytes Number of bytes to be stored in the SEGGER RTT control block.
*
* Return value
* Number of bytes which have been stored in the "Up"-buffer.
*
* Notes
* (1) If there is not enough space in the "Up"-buffer, all data is dropped.
* (2) For performance reasons this function does not call Init()
* and may only be called after RTT has been initialized.
* Either by calling SEGGER_RTT_Init() or calling another RTT API function first.
*/
unsigned SEGGER_RTT_WriteSkipNoLock(unsigned BufferIndex, const void* pBuffer, unsigned NumBytes) {
const char* pData;
SEGGER_RTT_BUFFER_UP* pRing;
unsigned Avail;
unsigned RdOff;
unsigned WrOff;
unsigned Rem;
pData = (const char *)pBuffer;
//
// Get "to-host" ring buffer and copy some elements into local variables.
//
pRing = &_SEGGER_RTT.aUp[BufferIndex];
RdOff = pRing->RdOff;
WrOff = pRing->WrOff;
//
// Handle the most common cases fastest.
// Which is:
// RdOff <= WrOff -> Space until wrap around is free.
// AND
// WrOff + NumBytes < SizeOfBuffer -> No Wrap around necessary.
//
// OR
//
// RdOff > WrOff -> Space until RdOff - 1 is free.
// AND
// WrOff + NumBytes < RdOff -> Data fits into buffer
//
if (RdOff <= WrOff) {
//
// Get space until WrOff will be at wrap around.
//
Avail = pRing->SizeOfBuffer - 1u - WrOff ;
if (Avail >= NumBytes) {
#if 1 // memcpy() is good for large amounts of data, but the overhead is too big for small amounts. Use a simple byte loop instead.
char* pDst;
pDst = pRing->pBuffer + WrOff;
WrOff += NumBytes;
do {
*pDst++ = *pData++;
} while (--NumBytes);
pRing->WrOff = WrOff + NumBytes;
#else
memcpy(pRing->pBuffer + WrOff, pData, NumBytes);
pRing->WrOff = WrOff + NumBytes;
#endif
return 1;
}
//
// If data did not fit into space until wrap around calculate complete space in buffer.
//
Avail += RdOff;
//
// If there is still no space for the whole of this output, don't bother.
//
if (Avail >= NumBytes) {
//
// OK, we have enough space in buffer. Copy in one or 2 chunks
//
Rem = pRing->SizeOfBuffer - WrOff; // Space until end of buffer
if (Rem > NumBytes) {
memcpy(pRing->pBuffer + WrOff, pData, NumBytes);
pRing->WrOff = WrOff + NumBytes;
} else {
//
// We reach the end of the buffer, so need to wrap around
//
memcpy(pRing->pBuffer + WrOff, pData, Rem);
memcpy(pRing->pBuffer, pData + Rem, NumBytes - Rem);
pRing->WrOff = NumBytes - Rem;
}
return 1;
}
} else {
Avail = RdOff - WrOff - 1u;
if (Avail >= NumBytes) {
memcpy(pRing->pBuffer + WrOff, pData, NumBytes);
pRing->WrOff = WrOff + NumBytes;
return 1;
}
}
//
// If we reach this point no data has been written
//
return 0;
}
/*********************************************************************
*
* SEGGER_RTT_WriteNoLock
*
* Function description
* Stores a specified number of characters in SEGGER RTT
* control block which is then read by the host.
* SEGGER_RTT_WriteNoLock does not lock the application.
*
* Parameters
* BufferIndex Index of "Up"-buffer to be used (e.g. 0 for "Terminal").
* pBuffer Pointer to character array. Does not need to point to a \0 terminated string.
* NumBytes Number of bytes to be stored in the SEGGER RTT control block.
*
* Return value
* Number of bytes which have been stored in the "Up"-buffer.
*
* Notes
* (1) If there is not enough space in the "Up"-buffer, remaining characters of pBuffer are dropped.
* (2) For performance reasons this function does not call Init()
* and may only be called after RTT has been initialized.
* Either by calling SEGGER_RTT_Init() or calling another RTT API function first.
*/
unsigned SEGGER_RTT_WriteNoLock(unsigned BufferIndex, const void* pBuffer, unsigned NumBytes) {
unsigned Status;
unsigned Avail;
const char* pData;
SEGGER_RTT_BUFFER_UP* pRing;
pData = (const char *)pBuffer;
//
// Get "to-host" ring buffer.
//
pRing = &_SEGGER_RTT.aUp[BufferIndex];
//
// How we output depends upon the mode...
//
switch (pRing->Flags) {
case SEGGER_RTT_MODE_NO_BLOCK_SKIP:
//
// If we are in skip mode and there is no space for the whole
// of this output, don't bother.
//
Avail = _GetAvailWriteSpace(pRing);
if (Avail < NumBytes) {
Status = 0u;
} else {
Status = NumBytes;
_WriteNoCheck(pRing, pData, NumBytes);
}
break;
case SEGGER_RTT_MODE_NO_BLOCK_TRIM:
//
// If we are in trim mode, trim to what we can output without blocking.
//
Avail = _GetAvailWriteSpace(pRing);
Status = Avail < NumBytes ? Avail : NumBytes;
_WriteNoCheck(pRing, pData, Status);
break;
case SEGGER_RTT_MODE_BLOCK_IF_FIFO_FULL:
//
// If we are in blocking mode, output everything.
//
Status = _WriteBlocking(pRing, pData, NumBytes);
break;
default:
Status = 0u;
break;
}
//
// Finish up.
//
return Status;
}
/*********************************************************************
*
* SEGGER_RTT_Write
*
* Function description
* Stores a specified number of characters in SEGGER RTT
* control block which is then read by the host.
*
* Parameters
* BufferIndex Index of "Up"-buffer to be used (e.g. 0 for "Terminal").
* pBuffer Pointer to character array. Does not need to point to a \0 terminated string.
* NumBytes Number of bytes to be stored in the SEGGER RTT control block.
*
* Return value
* Number of bytes which have been stored in the "Up"-buffer.
*
* Notes
* (1) If there is not enough space in the "Up"-buffer, remaining characters of pBuffer are dropped.
*/
unsigned SEGGER_RTT_Write(unsigned BufferIndex, const void* pBuffer, unsigned NumBytes) {
unsigned Status;
//
INIT();
SEGGER_RTT_LOCK();
//
// Call the non-locking write function
//
Status = SEGGER_RTT_WriteNoLock(BufferIndex, pBuffer, NumBytes);
//
// Finish up.
//
SEGGER_RTT_UNLOCK();
//
return Status;
}
/*********************************************************************
*
* SEGGER_RTT_WriteString
*
* Function description
* Stores string in SEGGER RTT control block.
* This data is read by the host.
*
* Parameters
* BufferIndex Index of "Up"-buffer to be used (e.g. 0 for "Terminal").
* s Pointer to string.
*
* Return value
* Number of bytes which have been stored in the "Up"-buffer.
*
* Notes
* (1) If there is not enough space in the "Up"-buffer, depending on configuration,
* remaining characters may be dropped or RTT module waits until there is more space in the buffer.
* (2) String passed to this function has to be \0 terminated
* (3) \0 termination character is *not* stored in RTT buffer
*/
unsigned SEGGER_RTT_WriteString(unsigned BufferIndex, const char* s) {
unsigned Len;
Len = STRLEN(s);
return SEGGER_RTT_Write(BufferIndex, s, Len);
}
/*********************************************************************
*
* SEGGER_RTT_GetKey
*
* Function description
* Reads one character from the SEGGER RTT buffer.
* Host has previously stored data there.
*
* Return value
* < 0 - No character available (buffer empty).
* >= 0 - Character which has been read. (Possible values: 0 - 255)
*
* Notes
* (1) This function is only specified for accesses to RTT buffer 0.
*/
int SEGGER_RTT_GetKey(void) {
char c;
int r;
r = (int)SEGGER_RTT_Read(0u, &c, 1u);
if (r == 1) {
r = (int)(unsigned char)c;
} else {
r = -1;
}
return r;
}
/*********************************************************************
*
* SEGGER_RTT_WaitKey
*
* Function description
* Waits until at least one character is avaible in the SEGGER RTT buffer.
* Once a character is available, it is read and this function returns.
*
* Return value
* >=0 - Character which has been read.
*
* Notes
* (1) This function is only specified for accesses to RTT buffer 0
* (2) This function is blocking if no character is present in RTT buffer
*/
int SEGGER_RTT_WaitKey(void) {
int r;
do {
r = SEGGER_RTT_GetKey();
} while (r < 0);
return r;
}
/*********************************************************************
*
* SEGGER_RTT_HasKey
*
* Function description
* Checks if at least one character for reading is available in the SEGGER RTT buffer.
*
* Return value
* == 0 - No characters are available to read.
* == 1 - At least one character is available.
*
* Notes
* (1) This function is only specified for accesses to RTT buffer 0
*/
int SEGGER_RTT_HasKey(void) {
unsigned RdOff;
int r;
INIT();
RdOff = _SEGGER_RTT.aDown[0].RdOff;
if (RdOff != _SEGGER_RTT.aDown[0].WrOff) {
r = 1;
} else {
r = 0;
}
return r;
}
/*********************************************************************
*
* SEGGER_RTT_HasData
*
* Function description
* Check if there is data from the host in the given buffer.
*
* Return value:
* ==0: No data
* !=0: Data in buffer
*
*/
unsigned SEGGER_RTT_HasData(unsigned BufferIndex) {
SEGGER_RTT_BUFFER_DOWN* pRing;
unsigned v;
pRing = &_SEGGER_RTT.aDown[BufferIndex];
v = pRing->WrOff;
return v - pRing->RdOff;
}
/*********************************************************************
*
* SEGGER_RTT_AllocDownBuffer
*
* Function description
* Run-time configuration of the next down-buffer (H->T).
* The next buffer, which is not used yet is configured.
* This includes: Buffer address, size, name, flags, ...
*
* Parameters
* sName Pointer to a constant name string.
* pBuffer Pointer to a buffer to be used.
* BufferSize Size of the buffer.
* Flags Operating modes. Define behavior if buffer is full (not enough space for entire message).
*
* Return value
* >= 0 - O.K. Buffer Index
* < 0 - Error
*/
int SEGGER_RTT_AllocDownBuffer(const char* sName, void* pBuffer, unsigned BufferSize, unsigned Flags) {
int BufferIndex;
INIT();
SEGGER_RTT_LOCK();
BufferIndex = 0;
do {
if (_SEGGER_RTT.aDown[BufferIndex].pBuffer == NULL) {
break;
}
BufferIndex++;
} while (BufferIndex < _SEGGER_RTT.MaxNumDownBuffers);
if (BufferIndex < _SEGGER_RTT.MaxNumDownBuffers) {
_SEGGER_RTT.aDown[BufferIndex].sName = sName;
_SEGGER_RTT.aDown[BufferIndex].pBuffer = pBuffer;
_SEGGER_RTT.aDown[BufferIndex].SizeOfBuffer = BufferSize;
_SEGGER_RTT.aDown[BufferIndex].RdOff = 0u;
_SEGGER_RTT.aDown[BufferIndex].WrOff = 0u;
_SEGGER_RTT.aDown[BufferIndex].Flags = Flags;
} else {
BufferIndex = -1;
}
SEGGER_RTT_UNLOCK();
return BufferIndex;
}
/*********************************************************************
*
* SEGGER_RTT_AllocUpBuffer
*
* Function description
* Run-time configuration of the next up-buffer (T->H).
* The next buffer, which is not used yet is configured.
* This includes: Buffer address, size, name, flags, ...
*
* Parameters
* sName Pointer to a constant name string.
* pBuffer Pointer to a buffer to be used.
* BufferSize Size of the buffer.
* Flags Operating modes. Define behavior if buffer is full (not enough space for entire message).
*
* Return value