summaryrefslogtreecommitdiffstats
path: root/cpukit/score/cpu/v850/rtems/score/cpu.h
blob: 6c77f5160c21614fb5b1220b7f55a689291b8d82 (plain)
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
/**
 * @file
 *
 * @brief V850 CPU Department Source
 *
 * This include file contains information pertaining to the v850
 * processor.
 */

/*
 *  COPYRIGHT (c) 1989-2012.
 *  On-Line Applications Research Corporation (OAR).
 *
 *  The license and distribution terms for this file may be
 *  found in the file LICENSE in this distribution or at
 *  http://www.rtems.org/license/LICENSE.
 */

#ifndef _RTEMS_SCORE_CPU_H
#define _RTEMS_SCORE_CPU_H

#ifdef __cplusplus
extern "C" {
#endif

#include <rtems/score/types.h>
#include <rtems/score/v850.h>

/* conditional compilation parameters */

/**
 * Does RTEMS manage a dedicated interrupt stack in software?
 *
 * If TRUE, then a stack is allocated in @ref _ISR_Handler_initialization.
 * If FALSE, nothing is done.
 *
 * If the CPU supports a dedicated interrupt stack in hardware,
 * then it is generally the responsibility of the BSP to allocate it
 * and set it up.
 *
 * If the CPU does not support a dedicated interrupt stack, then
 * the porter has two options: (1) execute interrupts on the
 * stack of the interrupted task, and (2) have RTEMS manage a dedicated
 * interrupt stack.
 *
 * If this is TRUE, @ref CPU_ALLOCATE_INTERRUPT_STACK should also be TRUE.
 *
 * Only one of @ref CPU_HAS_SOFTWARE_INTERRUPT_STACK and
 * @ref CPU_HAS_HARDWARE_INTERRUPT_STACK should be set to TRUE.  It is
 * possible that both are FALSE for a particular CPU.  Although it
 * is unclear what that would imply about the interrupt processing
 * procedure on that CPU.
 *
 * Port Specific Information:
 *
 * The v850 does not have support for a hardware interrupt stack.
 */
#define CPU_HAS_SOFTWARE_INTERRUPT_STACK TRUE

/**
 * Does the CPU follow the simple vectored interrupt model?
 *
 * If TRUE, then RTEMS allocates the vector table it internally manages.
 * If FALSE, then the BSP is assumed to allocate and manage the vector
 * table
 *
 * Port Specific Information:
 *
 * This port uses the Progammable Interrupt Controller interrupt model.
 */
#define CPU_SIMPLE_VECTORED_INTERRUPTS FALSE

/**
 * Does this CPU have hardware support for a dedicated interrupt stack?
 *
 * If TRUE, then it must be installed during initialization.
 * If FALSE, then no installation is performed.
 *
 * If this is TRUE, @ref CPU_ALLOCATE_INTERRUPT_STACK should also be TRUE.
 *
 * Only one of @ref CPU_HAS_SOFTWARE_INTERRUPT_STACK and
 * @ref CPU_HAS_HARDWARE_INTERRUPT_STACK should be set to TRUE.  It is
 * possible that both are FALSE for a particular CPU.  Although it
 * is unclear what that would imply about the interrupt processing
 * procedure on that CPU.
 *
 * Port Specific Information:
 *
 * The v850 does not have support for a hardware interrupt stack.
 */
#define CPU_HAS_HARDWARE_INTERRUPT_STACK FALSE

/**
 * Does RTEMS allocate a dedicated interrupt stack in the Interrupt Manager?
 *
 * If TRUE, then the memory is allocated during initialization.
 * If FALSE, then the memory is allocated during initialization.
 *
 * This should be TRUE is CPU_HAS_SOFTWARE_INTERRUPT_STACK is TRUE.
 *
 * Port Specific Information:
 *
 * XXX document implementation including references if appropriate
 */
#define CPU_ALLOCATE_INTERRUPT_STACK TRUE

/**
 * @def CPU_HARDWARE_FP
 *
 * Does the CPU have hardware floating point?
 *
 * If TRUE, then the RTEMS_FLOATING_POINT task attribute is supported.
 * If FALSE, then the RTEMS_FLOATING_POINT task attribute is ignored.
 *
 * If there is a FP coprocessor such as the i387 or mc68881, then
 * the answer is TRUE.
 *
 * The macro name "V850_HAS_FPU" should be made CPU specific.
 * It indicates whether or not this CPU model has FP support.  For
 * example, it would be possible to have an i386_nofp CPU model
 * which set this to false to indicate that you have an i386 without
 * an i387 and wish to leave floating point support out of RTEMS.
 */

/**
 * @def CPU_SOFTWARE_FP
 *
 * Does the CPU have no hardware floating point and GCC provides a
 * software floating point implementation which must be context
 * switched?
 *
 * This feature conditional is used to indicate whether or not there
 * is software implemented floating point that must be context
 * switched.  The determination of whether or not this applies
 * is very tool specific and the state saved/restored is also
 * compiler specific.
 *
 * Port Specific Information:
 *
 * Some v850 models do have IEEE hardware floating point support but
 * they do not have any special registers to save or bit(s) which
 * determine if the FPU is enabled. In short, there appears to be nothing
 * related to the floating point operations which impact the RTEMS
 * thread context switch. Thus from an RTEMS perspective, there is really
 * no FPU to manage.
 */
#define CPU_HARDWARE_FP     FALSE
#define CPU_SOFTWARE_FP     FALSE

/**
 * Are all tasks RTEMS_FLOATING_POINT tasks implicitly?
 *
 * If TRUE, then the RTEMS_FLOATING_POINT task attribute is assumed.
 * If FALSE, then the RTEMS_FLOATING_POINT task attribute is followed.
 *
 * So far, the only CPUs in which this option has been used are the
 * HP PA-RISC and PowerPC.  On the PA-RISC, The HP C compiler and
 * gcc both implicitly used the floating point registers to perform
 * integer multiplies.  Similarly, the PowerPC port of gcc has been
 * seen to allocate floating point local variables and touch the FPU
 * even when the flow through a subroutine (like vfprintf()) might
 * not use floating point formats.
 *
 * If a function which you would not think utilize the FP unit DOES,
 * then one can not easily predict which tasks will use the FP hardware.
 * In this case, this option should be TRUE.
 *
 * If @ref CPU_HARDWARE_FP is FALSE, then this should be FALSE as well.
 *
 * Port Specific Information:
 *
 * This should be false until it has been demonstrated that gcc for the
 * v850 generates FPU code when it is unexpected. But even this would
 * not matter since there are no FP specific registers or bits which
 * would be corrupted if an FP operation occurred in an integer only
 * thread.
 */
#define CPU_ALL_TASKS_ARE_FP     FALSE

/**
 * Should the IDLE task have a floating point context?
 *
 * If TRUE, then the IDLE task is created as a RTEMS_FLOATING_POINT task
 * and it has a floating point context which is switched in and out.
 * If FALSE, then the IDLE task does not have a floating point context.
 *
 * Setting this to TRUE negatively impacts the time required to preempt
 * the IDLE task from an interrupt because the floating point context
 * must be saved as part of the preemption.
 *
 * Port Specific Information:
 *
 * The IDLE thread should not be using the FPU. Leave this off.
 */
#define CPU_IDLE_TASK_IS_FP      FALSE

/**
 * Should the saving of the floating point registers be deferred
 * until a context switch is made to another different floating point
 * task?
 *
 * If TRUE, then the floating point context will not be stored until
 * necessary.  It will remain in the floating point registers and not
 * disturned until another floating point task is switched to.
 *
 * If FALSE, then the floating point context is saved when a floating
 * point task is switched out and restored when the next floating point
 * task is restored.  The state of the floating point registers between
 * those two operations is not specified.
 *
 * If the floating point context does NOT have to be saved as part of
 * interrupt dispatching, then it should be safe to set this to TRUE.
 *
 * Setting this flag to TRUE results in using a different algorithm
 * for deciding when to save and restore the floating point context.
 * The deferred FP switch algorithm minimizes the number of times
 * the FP context is saved and restored.  The FP context is not saved
 * until a context switch is made to another, different FP task.
 * Thus in a system with only one FP task, the FP context will never
 * be saved or restored.
 *
 * Port Specific Information:
 *
 * See earlier comments. There is no FPU state to manage.
 */
#define CPU_USE_DEFERRED_FP_SWITCH       TRUE

#define CPU_ENABLE_ROBUST_THREAD_DISPATCH FALSE

/**
 * Does this port provide a CPU dependent IDLE task implementation?
 *
 * If TRUE, then the routine @ref _CPU_Thread_Idle_body
 * must be provided and is the default IDLE thread body instead of
 * @ref _CPU_Thread_Idle_body.
 *
 * If FALSE, then use the generic IDLE thread body if the BSP does
 * not provide one.
 *
 * This is intended to allow for supporting processors which have
 * a low power or idle mode.  When the IDLE thread is executed, then
 * the CPU can be powered down.
 *
 * The order of precedence for selecting the IDLE thread body is:
 *
 *   -#  BSP provided
 *   -#  CPU dependent (if provided)
 *   -#  generic (if no BSP and no CPU dependent)
 *
 * Port Specific Information:
 *
 * There does not appear to be a reason for the v850 port itself to provide
 * a special idle task.
 */
#define CPU_PROVIDES_IDLE_THREAD_BODY    FALSE

/**
 * Does the stack grow up (toward higher addresses) or down
 * (toward lower addresses)?
 *
 * If TRUE, then the grows upward.
 * If FALSE, then the grows toward smaller addresses.
 *
 * Port Specific Information:
 *
 * The v850 stack grows from high addresses to low addresses.
 */
#define CPU_STACK_GROWS_UP               FALSE

/* FIXME: Is this the right value? */
#define CPU_CACHE_LINE_BYTES 32

#define CPU_STRUCTURE_ALIGNMENT

/**
 * @ingroup CPUInterrupt
 * The following defines the number of bits actually used in the
 * interrupt field of the task mode.  How those bits map to the
 * CPU interrupt levels is defined by the routine @ref _CPU_ISR_Set_level.
 *
 * Port Specific Information:
 *
 * The v850 only has a single bit in the CPU for interrupt disable/enable.
 */
#define CPU_MODES_INTERRUPT_MASK   0x00000001

#define CPU_MAXIMUM_PROCESSORS 32

/**
 * @defgroup CPUContext Processor Dependent Context Management
 *
 * From the highest level viewpoint, there are 2 types of context to save.
 *
 *    -# Interrupt registers to save
 *    -# Task level registers to save
 *
 * Since RTEMS handles integer and floating point contexts separately, this
 * means we have the following 3 context items:
 *
 *    -# task level context stuff::  Context_Control
 *    -# floating point task stuff:: Context_Control_fp
 *    -# special interrupt level context :: CPU_Interrupt_frame
 *
 * On some processors, it is cost-effective to save only the callee
 * preserved registers during a task context switch.  This means
 * that the ISR code needs to save those registers which do not
 * persist across function calls.  It is not mandatory to make this
 * distinctions between the caller/callee saves registers for the
 * purpose of minimizing context saved during task switch and on interrupts.
 * If the cost of saving extra registers is minimal, simplicity is the
 * choice.  Save the same context on interrupt entry as for tasks in
 * this case.
 *
 * Additionally, if gdb is to be made aware of RTEMS tasks for this CPU, then
 * care should be used in designing the context area.
 *
 * On some CPUs with hardware floating point support, the Context_Control_fp
 * structure will not be used or it simply consist of an array of a
 * fixed number of bytes.   This is done when the floating point context
 * is dumped by a "FP save context" type instruction and the format
 * is not really defined by the CPU.  In this case, there is no need
 * to figure out the exact format -- only the size.  Of course, although
 * this is enough information for RTEMS, it is probably not enough for
 * a debugger such as gdb.  But that is another problem.
 *
 * Port Specific Information:
 *
 * On the v850, this port saves special registers and those that are
 * callee saved.
 */
/**@{**/

/**
 * This defines the minimal set of integer and processor state registers
 * that must be saved during a voluntary context switch from one thread
 * to another.
 */
typedef struct {
    uint32_t   r1;
    /** This field is the stack pointer (e.g. r3).  */
    uint32_t   r3_stack_pointer;
    uint32_t   r20;
    uint32_t   r21;
    uint32_t   r22;
    uint32_t   r23;
    uint32_t   r24;
    uint32_t   r25;
    uint32_t   r26;
    uint32_t   r27;
    uint32_t   r28;
    uint32_t   r29;
    uint32_t   r31;
    uint32_t   psw;
} Context_Control;

/**
 * This macro returns the stack pointer associated with @a _context.
 *
 * @param[in] _context is the thread context area to access
 *
 * @return This method returns the stack pointer.
 */
#define _CPU_Context_Get_SP( _context ) \
  (_context)->r3_stack_pointer

/**
 * This defines the complete set of floating point registers that must
 * be saved during any context switch from one thread to another.
 */
typedef struct {
    /** FPU registers are listed here */
    double      some_float_register;
} Context_Control_fp;

/**
 * This defines the set of integer and processor state registers that must
 * be saved during an interrupt.  This set does not include any which are
 * in @ref Context_Control.
 */
typedef struct {
    /** This field is a hint that a port will have a number of integer
     * registers that need to be saved when an interrupt occurs or
     * when a context switch occurs at the end of an ISR.
     */
    uint32_t   special_interrupt_register;
} CPU_Interrupt_frame;

/** @} */

/**
 * @defgroup CPUInterrupt Processor Dependent Interrupt Management
 *
 * On some CPUs, RTEMS supports a software managed interrupt stack.
 * This stack is allocated by the Interrupt Manager and the switch
 * is performed in @ref _ISR_Handler.  These variables contain pointers
 * to the lowest and highest addresses in the chunk of memory allocated
 * for the interrupt stack.  Since it is unknown whether the stack
 * grows up or down (in general), this give the CPU dependent
 * code the option of picking the version it wants to use.
 *
 * @note These two variables are required if the macro
 *       @ref CPU_HAS_SOFTWARE_INTERRUPT_STACK is defined as TRUE.
 *
 * Port Specific Information:
 *
 * XXX document implementation including references if appropriate
 */
/**@{**/

/**
 * @ingroup CPUContext
 * The size of the floating point context area.  On some CPUs this
 * will not be a "sizeof" because the format of the floating point
 * area is not defined -- only the size is.  This is usually on
 * CPUs with a "floating point save context" instruction.
 *
 * Port Specific Information:
 *
 * The v850 does not need a floating point context but this needs to be
 * defined so confdefs.h.
 */
/* #define CPU_CONTEXT_FP_SIZE sizeof( Context_Control_fp ) */
#define CPU_CONTEXT_FP_SIZE 0

/**
 * Amount of extra stack (above minimum stack size) required by
 * MPCI receive server thread.  Remember that in a multiprocessor
 * system this thread must exist and be able to process all directives.
 *
 * Port Specific Information:
 *
 * There is no reason to think the v850 needs extra MPCI receive
 * server stack.
 */
#define CPU_MPCI_RECEIVE_SERVER_EXTRA_STACK 0

/**
 * This is defined if the port has a special way to report the ISR nesting
 * level.  Most ports maintain the variable @a _ISR_Nest_level.
 */
#define CPU_PROVIDES_ISR_IS_IN_PROGRESS FALSE

/** @} */

/**
 * @ingroup CPUContext
 * Should be large enough to run all RTEMS tests.  This ensures
 * that a "reasonable" small application should not have any problems.
 *
 * Port Specific Information:
 *
 * This should be very conservative on the v850.
 */
#define CPU_STACK_MINIMUM_SIZE          (1024*4)

#define CPU_SIZEOF_POINTER 4

/**
 * CPU's worst alignment requirement for data types on a byte boundary.  This
 * alignment does not take into account the requirements for the stack.
 *
 * Port Specific Information:
 *
 * There is no apparent reason why this should be larger than 8.
 */
#define CPU_ALIGNMENT              8

/**
 * This number corresponds to the byte alignment requirement for the
 * heap handler.  This alignment requirement may be stricter than that
 * for the data types alignment specified by @ref CPU_ALIGNMENT.  It is
 * common for the heap to follow the same alignment requirement as
 * @ref CPU_ALIGNMENT.  If the @ref CPU_ALIGNMENT is strict enough for
 * the heap, then this should be set to @ref CPU_ALIGNMENT.
 *
 * @note  This does not have to be a power of 2 although it should be
 *        a multiple of 2 greater than or equal to 2.  The requirement
 *        to be a multiple of 2 is because the heap uses the least
 *        significant field of the front and back flags to indicate
 *        that a block is in use or free.  So you do not want any odd
 *        length blocks really putting length data in that bit.
 *
 *        On byte oriented architectures, @ref CPU_HEAP_ALIGNMENT normally will
 *        have to be greater or equal to than @ref CPU_ALIGNMENT to ensure that
 *        elements allocated from the heap meet all restrictions.
 *
 * Port Specific Information:
 *
 * There is no apparent reason why this should be larger than CPU_ALIGNMENT.
 */
#define CPU_HEAP_ALIGNMENT         CPU_ALIGNMENT

/**
 * This number corresponds to the byte alignment requirement for memory
 * buffers allocated by the partition manager.  This alignment requirement
 * may be stricter than that for the data types alignment specified by
 * @ref CPU_ALIGNMENT.  It is common for the partition to follow the same
 * alignment requirement as @ref CPU_ALIGNMENT.  If the @ref CPU_ALIGNMENT is
 * strict enough for the partition, then this should be set to
 * @ref CPU_ALIGNMENT.
 *
 * @note  This does not have to be a power of 2.  It does have to
 *        be greater or equal to than @ref CPU_ALIGNMENT.
 *
 * Port Specific Information:
 *
 * There is no apparent reason why this should be larger than CPU_ALIGNMENT.
 */
#define CPU_PARTITION_ALIGNMENT    CPU_ALIGNMENT

/**
 * This number corresponds to the byte alignment requirement for the
 * stack.  This alignment requirement may be stricter than that for the
 * data types alignment specified by @ref CPU_ALIGNMENT.  If the
 * @ref CPU_ALIGNMENT is strict enough for the stack, then this should be
 * set to 0.
 *
 * @note This must be a power of 2 either 0 or greater than @ref CPU_ALIGNMENT.
 *
 * Port Specific Information:
 *
 * The v850 has enough RAM where alignment to 16 may be desirable depending
 * on the cache properties. But this remains to be demonstrated.
 */
#define CPU_STACK_ALIGNMENT        4

/*
 *  ISR handler macros
 */

/**
 * @addtogroup CPUInterrupt
 */
/**@{**/

/**
 * Disable all interrupts for an RTEMS critical section.  The previous
 * level is returned in @a _isr_cookie.
 *
 * @param[out] _isr_cookie will contain the previous level cookie
 *
 * Port Specific Information:
 *
 * On the v850, we need to save the PSW and use "di" to disable interrupts.
 */
#define _CPU_ISR_Disable( _isr_cookie ) \
  do { \
    unsigned int _psw; \
    \
    v850_get_psw( _psw ); \
    __asm__ __volatile__( "di" ); \
    _isr_cookie = _psw; \
  } while (0)

/**
 * Enable interrupts to the previous level (returned by _CPU_ISR_Disable).
 * This indicates the end of an RTEMS critical section.  The parameter
 * @a _isr_cookie is not modified.
 *
 * @param[in] _isr_cookie contain the previous level cookie
 *
 * Port Specific Information:
 *
 * On the v850, we simply need to restore the PSW.
 */
#define _CPU_ISR_Enable( _isr_cookie )  \
  do { \
    unsigned int _psw = (_isr_cookie); \
    \
    v850_set_psw( _psw ); \
  } while (0)

/**
 * This temporarily restores the interrupt to @a _isr_cookie before immediately
 * disabling them again.  This is used to divide long RTEMS critical
 * sections into two or more parts.  The parameter @a _isr_cookie is not
 * modified.
 *
 * @param[in] _isr_cookie contain the previous level cookie
 *
 * Port Specific Information:
 *
 * This saves at least one instruction over using enable/disable back to back.
 */
#define _CPU_ISR_Flash( _isr_cookie ) \
  do { \
    unsigned int _psw = (_isr_cookie); \
    v850_set_psw( _psw ); \
    __asm__ __volatile__( "di" ); \
  } while (0)

RTEMS_INLINE_ROUTINE bool _CPU_ISR_Is_enabled( uint32_t level )
{
  return ( level & V850_PSW_INTERRUPT_DISABLE_MASK )
    != V850_PSW_INTERRUPT_DISABLE;
}

/**
 * This routine and @ref _CPU_ISR_Get_level
 * Map the interrupt level in task mode onto the hardware that the CPU
 * actually provides.  Currently, interrupt levels which do not
 * map onto the CPU in a generic fashion are undefined.  Someday,
 * it would be nice if these were "mapped" by the application
 * via a callout.  For example, m68k has 8 levels 0 - 7, levels
 * 8 - 255 would be available for bsp/application specific meaning.
 * This could be used to manage a programmable interrupt controller
 * via the rtems_task_mode directive.
 *
 * Port Specific Information:
 *
 * On the v850, level 0 is enabled. Non-zero is disabled.
 */
#define _CPU_ISR_Set_level( new_level ) \
  do { \
    if ( new_level ) \
      __asm__ __volatile__( "di" ); \
    else \
      __asm__ __volatile__( "ei" ); \
  } while (0)

/**
 * Return the current interrupt disable level for this task in
 * the format used by the interrupt level portion of the task mode.
 *
 * @note This routine usually must be implemented as a subroutine.
 *
 * Port Specific Information:
 *
 * This method is implemented in C on the v850.
 */
uint32_t   _CPU_ISR_Get_level( void );

/* end of ISR handler macros */

/** @} */

/* Context handler macros */

/**
 * @ingroup CPUContext
 * Initialize the context to a state suitable for starting a
 * task after a context restore operation.  Generally, this
 * involves:
 *
 *    - setting a starting address
 *    - preparing the stack
 *    - preparing the stack and frame pointers
 *    - setting the proper interrupt level in the context
 *    - initializing the floating point context
 *
 * This routine generally does not set any unnecessary register
 * in the context.  The state of the "general data" registers is
 * undefined at task start time.
 *
 * @param[in] _the_context is the context structure to be initialized
 * @param[in] _stack_base is the lowest physical address of this task's stack
 * @param[in] _size is the size of this task's stack
 * @param[in] _isr is the interrupt disable level
 * @param[in] _entry_point is the thread's entry point.  This is
 *        always @a _Thread_Handler
 * @param[in] _is_fp is TRUE if the thread is to be a floating
 *       point thread.  This is typically only used on CPUs where the
 *       FPU may be easily disabled by software such as on the SPARC
 *       where the PSR contains an enable FPU bit.
 * @param[in] tls_area is the thread-local storage (TLS) area
 *
 * Port Specific Information:
 *
 * This method is implemented in C on the v850.
 */
void _CPU_Context_Initialize(
  Context_Control  *the_context,
  uint32_t         *stack_base,
  uint32_t          size,
  uint32_t          new_level,
  void             *entry_point,
  bool              is_fp,
  void             *tls_area
);

/**
 * This routine is responsible for somehow restarting the currently
 * executing task.  If you are lucky, then all that is necessary
 * is restoring the context.  Otherwise, there will need to be
 * a special assembly routine which does something special in this
 * case.  For many ports, simply adding a label to the restore path
 * of @ref _CPU_Context_switch will work.  On other ports, it may be
 * possibly to load a few arguments and jump to the restore path. It will
 * not work if restarting self conflicts with the stack frame
 * assumptions of restoring a context.
 *
 * Port Specific Information:
 *
 * On the v850, we require a special entry point to restart a task.
 */
#define _CPU_Context_Restart_self( _the_context ) \
   _CPU_Context_restore( (_the_context) );

/* XXX this should be possible to remove */
#if 0
/**
 * @ingroup CPUContext
 * The purpose of this macro is to allow the initial pointer into
 * a floating point context area (used to save the floating point
 * context) to be at an arbitrary place in the floating point
 * context area.
 *
 * This is necessary because some FP units are designed to have
 * their context saved as a stack which grows into lower addresses.
 * Other FP units can be saved by simply moving registers into offsets
 * from the base of the context area.  Finally some FP units provide
 * a "dump context" instruction which could fill in from high to low
 * or low to high based on the whim of the CPU designers.
 *
 * @param[in] _base is the lowest physical address of the floating point
 *        context area
 * @param[in] _offset is the offset into the floating point area
 *
 * Port Specific Information:
 *
 * XXX document implementation including references if appropriate
 */
#define _CPU_Context_Fp_start( _base, _offset ) \
   ( (void *) _Addresses_Add_offset( (_base), (_offset) ) )
#endif

/* XXX this should be possible to remove */
#if 0
/**
 * This routine initializes the FP context area passed to it to.
 * There are a few standard ways in which to initialize the
 * floating point context.  The code included for this macro assumes
 * that this is a CPU in which a "initial" FP context was saved into
 * @a _CPU_Null_fp_context and it simply copies it to the destination
 * context passed to it.
 *
 * Other floating point context save/restore models include:
 *   -# not doing anything, and
 *   -# putting a "null FP status word" in the correct place in the FP context.
 *
 * @param[in] _destination is the floating point context area
 *
 * Port Specific Information:
 *
 * XXX document implementation including references if appropriate
 */
#define _CPU_Context_Initialize_fp( _destination ) \
  { \
  }
#endif

/* end of Context handler macros */

/* Fatal Error manager macros */

/**
 * This routine copies _error into a known place -- typically a stack
 * location or a register, optionally disables interrupts, and
 * halts/stops the CPU.
 *
 * Port Specific Information:
 *
 * Move the error code into r10, disable interrupts and halt.
 */
#define _CPU_Fatal_halt( _source, _error ) \
  do { \
    __asm__ __volatile__ ( "di" ); \
    __asm__ __volatile__ ( "mov %0, r10; " : "=r" ((_error)) ); \
    __asm__ __volatile__ ( "halt" ); \
  } while (0)

/* end of Fatal Error manager macros */

#define CPU_USE_GENERIC_BITFIELD_CODE TRUE

/* functions */

/**
 * @brief CPU initialize.
 * This routine performs CPU dependent initialization.
 *
 * Port Specific Information:
 *
 * This is implemented in C.
 *
 * v850 CPU Dependent Source
 */
void _CPU_Initialize(void);

/**
 * @addtogroup CPUContext
 */
/**@{**/

/**
 * This routine switches from the run context to the heir context.
 *
 * @param[in] run points to the context of the currently executing task
 * @param[in] heir points to the context of the heir task
 *
 * Port Specific Information:
 *
 * This is implemented in assembly on the v850.
 */
void _CPU_Context_switch(
  Context_Control  *run,
  Context_Control  *heir
);

/**
 * This routine is generally used only to restart self in an
 * efficient manner.  It may simply be a label in @ref _CPU_Context_switch.
 *
 * @param[in] new_context points to the context to be restored.
 *
 * @note May be unnecessary to reload some registers.
 *
 * Port Specific Information:
 *
 * This is implemented in assembly on the v850.
 */
void _CPU_Context_restore(
  Context_Control *new_context
) RTEMS_NO_RETURN;

/* XXX this should be possible to remove */
#if 0
/**
 * This routine saves the floating point context passed to it.
 *
 * @param[in] fp_context_ptr is a pointer to a pointer to a floating
 * point context area
 *
 * @return on output @a *fp_context_ptr will contain the address that
 * should be used with @ref _CPU_Context_restore_fp to restore this context.
 *
 * Port Specific Information:
 *
 * XXX document implementation including references if appropriate
 */
void _CPU_Context_save_fp(
  Context_Control_fp **fp_context_ptr
);
#endif

/* XXX this should be possible to remove */
#if 0
/**
 * This routine restores the floating point context passed to it.
 *
 * @param[in] fp_context_ptr is a pointer to a pointer to a floating
 * point context area to restore
 *
 * @return on output @a *fp_context_ptr will contain the address that
 * should be used with @ref _CPU_Context_save_fp to save this context.
 *
 * Port Specific Information:
 *
 * XXX document implementation including references if appropriate
 */
void _CPU_Context_restore_fp(
  Context_Control_fp **fp_context_ptr
);
#endif

static inline void _CPU_Context_volatile_clobber( uintptr_t pattern )
{
  /* TODO */
}

static inline void _CPU_Context_validate( uintptr_t pattern )
{
  while (1) {
    /* TODO */
  }
}

/** @} */

/* FIXME */
typedef CPU_Interrupt_frame CPU_Exception_frame;

void _CPU_Exception_frame_print( const CPU_Exception_frame *frame );

/**
 * @ingroup CPUEndian
 * The following routine swaps the endian format of an unsigned int.
 * It must be static because it is referenced indirectly.
 *
 * This version will work on any processor, but if there is a better
 * way for your CPU PLEASE use it.  The most common way to do this is to:
 *
 *    swap least significant two bytes with 16-bit rotate
 *    swap upper and lower 16-bits
 *    swap most significant two bytes with 16-bit rotate
 *
 * Some CPUs have special instructions which swap a 32-bit quantity in
 * a single instruction (e.g. i486).  It is probably best to avoid
 * an "endian swapping control bit" in the CPU.  One good reason is
 * that interrupts would probably have to be disabled to ensure that
 * an interrupt does not try to access the same "chunk" with the wrong
 * endian.  Another good reason is that on some CPUs, the endian bit
 * endianness for ALL fetches -- both code and data -- so the code
 * will be fetched incorrectly.
 *
 * @param[in] value is the value to be swapped
 * @return the value after being endian swapped
 *
 * Port Specific Information:
 *
 * The v850 has a single instruction to swap endianness on a 32 bit quantity.
 */
static inline uint32_t CPU_swap_u32(
  uint32_t value
)
{
  unsigned int swapped;

  #if (V850_HAS_BYTE_SWAP_INSTRUCTION == 1)
    unsigned int v;

    v = value;
    __asm__ __volatile__ ("bsw %0, %1" : "=r" (v), "=&r" (swapped) );
  #else
    uint32_t byte1, byte2, byte3, byte4;

    byte4 = (value >> 24) & 0xff;
    byte3 = (value >> 16) & 0xff;
    byte2 = (value >> 8)  & 0xff;
    byte1 =  value        & 0xff;

    swapped = (byte1 << 24) | (byte2 << 16) | (byte3 << 8) | byte4;
  #endif
  return swapped;
}

/**
 * @ingroup CPUEndian
 * This routine swaps a 16 bir quantity.
 *
 * @param[in] value is the value to be swapped
 * @return the value after being endian swapped
 *
 * Port Specific Information:
 *
 * The v850 has a single instruction to swap endianness on a 16 bit quantity.
 */
static inline uint16_t CPU_swap_u16( uint16_t value )
{
  unsigned int swapped;

  #if (V850_HAS_BYTE_SWAP_INSTRUCTION == 1)
    unsigned int v;

    v = value;
    __asm__ __volatile__ ("bsh %0, %1" : "=r" (v), "=&r" (swapped) );
  #else
    swapped = ((value & 0xff) << 8) | ((value >> 8) & 0xff);
  #endif
  return swapped;
}

typedef uint32_t CPU_Counter_ticks;

CPU_Counter_ticks _CPU_Counter_read( void );

static inline CPU_Counter_ticks _CPU_Counter_difference(
  CPU_Counter_ticks second,
  CPU_Counter_ticks first
)
{
  return second - first;
}

#ifdef __cplusplus
}
#endif

#endif