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[/] [or1k/] [trunk/] [rtems-20020807/] [cpukit/] [score/] [cpu/] [sh/] [rtems/] [score/] [cpu.h] - Blame information for rev 1765

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1 1026 ivang
/*
2
 *  This include file contains information pertaining to the Hitachi SH
3
 *  processor.
4
 *
5
 *  Authors: Ralf Corsepius (corsepiu@faw.uni-ulm.de) and
6
 *           Bernd Becker (becker@faw.uni-ulm.de)
7
 *
8
 *  COPYRIGHT (c) 1997-1998, FAW Ulm, Germany
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.
13
 *
14
 *
15
 *  COPYRIGHT (c) 1998-2001.
16
 *  On-Line Applications Research Corporation (OAR).
17
 *
18
 *  The license and distribution terms for this file may be
19
 *  found in the file LICENSE in this distribution or at
20
 *  http://www.OARcorp.com/rtems/license.html.
21
 *
22
 *  cpu.h,v 1.11 2002/04/03 14:06:54 joel Exp
23
 */
24
 
25
#ifndef _SH_CPU_h
26
#define _SH_CPU_h
27
 
28
#ifdef __cplusplus
29
extern "C" {
30
#endif
31
 
32
#include <rtems/score/sh.h>              /* pick up machine definitions */
33
#ifndef ASM
34
#include <rtems/score/types.h>
35
#endif
36
#if 0 && defined(__SH4__)
37
#include <rtems/score/sh4_regs.h>
38
#endif
39
 
40
/* conditional compilation parameters */
41
 
42
/*
43
 *  Should the calls to _Thread_Enable_dispatch be inlined?
44
 *
45
 *  If TRUE, then they are inlined.
46
 *  If FALSE, then a subroutine call is made.
47
 *
48
 *  Basically this is an example of the classic trade-off of size
49
 *  versus speed.  Inlining the call (TRUE) typically increases the
50
 *  size of RTEMS while speeding up the enabling of dispatching.
51
 *  [NOTE: In general, the _Thread_Dispatch_disable_level will
52
 *  only be 0 or 1 unless you are in an interrupt handler and that
53
 *  interrupt handler invokes the executive.]  When not inlined
54
 *  something calls _Thread_Enable_dispatch which in turns calls
55
 *  _Thread_Dispatch.  If the enable dispatch is inlined, then
56
 *  one subroutine call is avoided entirely.]
57
 */
58
 
59
#define CPU_INLINE_ENABLE_DISPATCH       FALSE
60
 
61
/*
62
 *  Should the body of the search loops in _Thread_queue_Enqueue_priority
63
 *  be unrolled one time?  In unrolled each iteration of the loop examines
64
 *  two "nodes" on the chain being searched.  Otherwise, only one node
65
 *  is examined per iteration.
66
 *
67
 *  If TRUE, then the loops are unrolled.
68
 *  If FALSE, then the loops are not unrolled.
69
 *
70
 *  The primary factor in making this decision is the cost of disabling
71
 *  and enabling interrupts (_ISR_Flash) versus the cost of rest of the
72
 *  body of the loop.  On some CPUs, the flash is more expensive than
73
 *  one iteration of the loop body.  In this case, it might be desirable
74
 *  to unroll the loop.  It is important to note that on some CPUs, this
75
 *  code is the longest interrupt disable period in RTEMS.  So it is
76
 *  necessary to strike a balance when setting this parameter.
77
 */
78
 
79
#define CPU_UNROLL_ENQUEUE_PRIORITY      TRUE
80
 
81
/*
82
 *  Does RTEMS manage a dedicated interrupt stack in software?
83
 *
84
 *  If TRUE, then a stack is allocated in _ISR_Handler_initialization.
85
 *  If FALSE, nothing is done.
86
 *
87
 *  If the CPU supports a dedicated interrupt stack in hardware,
88
 *  then it is generally the responsibility of the BSP to allocate it
89
 *  and set it up.
90
 *
91
 *  If the CPU does not support a dedicated interrupt stack, then
92
 *  the porter has two options: (1) execute interrupts on the
93
 *  stack of the interrupted task, and (2) have RTEMS manage a dedicated
94
 *  interrupt stack.
95
 *
96
 *  If this is TRUE, CPU_ALLOCATE_INTERRUPT_STACK should also be TRUE.
97
 *
98
 *  Only one of CPU_HAS_SOFTWARE_INTERRUPT_STACK and
99
 *  CPU_HAS_HARDWARE_INTERRUPT_STACK should be set to TRUE.  It is
100
 *  possible that both are FALSE for a particular CPU.  Although it
101
 *  is unclear what that would imply about the interrupt processing
102
 *  procedure on that CPU.
103
 */
104
 
105
#define CPU_HAS_SOFTWARE_INTERRUPT_STACK TRUE
106
#define CPU_HAS_HARDWARE_INTERRUPT_STACK FALSE
107
 
108
/*
109
 * We define the interrupt stack in the linker script
110
 */
111
#define CPU_ALLOCATE_INTERRUPT_STACK FALSE 
112
 
113
/*
114
 *  Does the RTEMS invoke the user's ISR with the vector number and
115
 *  a pointer to the saved interrupt frame (1) or just the vector
116
 *  number (0)?
117
 */
118
 
119
#define CPU_ISR_PASSES_FRAME_POINTER 0
120
 
121
/*
122
 *  Does the CPU have hardware floating point?
123
 *
124
 *  If TRUE, then the RTEMS_FLOATING_POINT task attribute is supported.
125
 *  If FALSE, then the RTEMS_FLOATING_POINT task attribute is ignored.
126
 *
127
 *  We currently support sh1 only, which has no FPU, other SHes have an FPU
128
 *
129
 *  The macro name "NO_CPU_HAS_FPU" should be made CPU specific.
130
 *  It indicates whether or not this CPU model has FP support.  For
131
 *  example, it would be possible to have an i386_nofp CPU model
132
 *  which set this to false to indicate that you have an i386 without
133
 *  an i387 and wish to leave floating point support out of RTEMS.
134
 */
135
 
136
#if SH_HAS_FPU
137
#define CPU_HARDWARE_FP TRUE
138
#define CPU_SOFTWARE_FP FALSE
139
#else
140
#define CPU_SOFTWARE_FP FALSE
141
#define CPU_HARDWARE_FP FALSE
142
#endif
143
 
144
/*
145
 *  Are all tasks RTEMS_FLOATING_POINT tasks implicitly?
146
 *
147
 *  If TRUE, then the RTEMS_FLOATING_POINT task attribute is assumed.
148
 *  If FALSE, then the RTEMS_FLOATING_POINT task attribute is followed.
149
 *
150
 *  So far, the only CPU in which this option has been used is the
151
 *  HP PA-RISC.  The HP C compiler and gcc both implicitly use the
152
 *  floating point registers to perform integer multiplies.  If
153
 *  a function which you would not think utilize the FP unit DOES,
154
 *  then one can not easily predict which tasks will use the FP hardware.
155
 *  In this case, this option should be TRUE.
156
 *
157
 *  If CPU_HARDWARE_FP is FALSE, then this should be FALSE as well.
158
 */
159
 
160
#if SH_HAS_FPU
161
#define CPU_ALL_TASKS_ARE_FP     TRUE
162
#else
163
#define CPU_ALL_TASKS_ARE_FP     FALSE
164
#endif
165
 
166
/*
167
 *  Should the IDLE task have a floating point context?
168
 *
169
 *  If TRUE, then the IDLE task is created as a RTEMS_FLOATING_POINT task
170
 *  and it has a floating point context which is switched in and out.
171
 *  If FALSE, then the IDLE task does not have a floating point context.
172
 *
173
 *  Setting this to TRUE negatively impacts the time required to preempt
174
 *  the IDLE task from an interrupt because the floating point context
175
 *  must be saved as part of the preemption.
176
 */
177
 
178
#if SH_HAS_FPU
179
#define CPU_IDLE_TASK_IS_FP     TRUE
180
#else
181
#define CPU_IDLE_TASK_IS_FP      FALSE
182
#endif
183
 
184
/*
185
 *  Should the saving of the floating point registers be deferred
186
 *  until a context switch is made to another different floating point
187
 *  task?
188
 *
189
 *  If TRUE, then the floating point context will not be stored until
190
 *  necessary.  It will remain in the floating point registers and not
191
 *  disturned until another floating point task is switched to.
192
 *
193
 *  If FALSE, then the floating point context is saved when a floating
194
 *  point task is switched out and restored when the next floating point
195
 *  task is restored.  The state of the floating point registers between
196
 *  those two operations is not specified.
197
 *
198
 *  If the floating point context does NOT have to be saved as part of
199
 *  interrupt dispatching, then it should be safe to set this to TRUE.
200
 *
201
 *  Setting this flag to TRUE results in using a different algorithm
202
 *  for deciding when to save and restore the floating point context.
203
 *  The deferred FP switch algorithm minimizes the number of times
204
 *  the FP context is saved and restored.  The FP context is not saved
205
 *  until a context switch is made to another, different FP task.
206
 *  Thus in a system with only one FP task, the FP context will never
207
 *  be saved or restored.
208
 */
209
 
210
#if SH_HAS_FPU
211
#define CPU_USE_DEFERRED_FP_SWITCH      FALSE
212
#else
213
#define CPU_USE_DEFERRED_FP_SWITCH      TRUE
214
#endif
215
 
216
/*
217
 *  Does this port provide a CPU dependent IDLE task implementation?
218
 *
219
 *  If TRUE, then the routine _CPU_Thread_Idle_body
220
 *  must be provided and is the default IDLE thread body instead of
221
 *  _CPU_Thread_Idle_body.
222
 *
223
 *  If FALSE, then use the generic IDLE thread body if the BSP does
224
 *  not provide one.
225
 *
226
 *  This is intended to allow for supporting processors which have
227
 *  a low power or idle mode.  When the IDLE thread is executed, then
228
 *  the CPU can be powered down.
229
 *
230
 *  The order of precedence for selecting the IDLE thread body is:
231
 *
232
 *    1.  BSP provided
233
 *    2.  CPU dependent (if provided)
234
 *    3.  generic (if no BSP and no CPU dependent)
235
 */
236
 
237
#define CPU_PROVIDES_IDLE_THREAD_BODY    TRUE
238
 
239
/*
240
 *  Does the stack grow up (toward higher addresses) or down
241
 *  (toward lower addresses)?
242
 *
243
 *  If TRUE, then the grows upward.
244
 *  If FALSE, then the grows toward smaller addresses.
245
 */
246
 
247
#define CPU_STACK_GROWS_UP               FALSE
248
 
249
/*
250
 *  The following is the variable attribute used to force alignment
251
 *  of critical RTEMS structures.  On some processors it may make
252
 *  sense to have these aligned on tighter boundaries than
253
 *  the minimum requirements of the compiler in order to have as
254
 *  much of the critical data area as possible in a cache line.
255
 *
256
 *  The placement of this macro in the declaration of the variables
257
 *  is based on the syntactically requirements of the GNU C
258
 *  "__attribute__" extension.  For example with GNU C, use
259
 *  the following to force a structures to a 32 byte boundary.
260
 *
261
 *      __attribute__ ((aligned (32)))
262
 *
263
 *  NOTE:  Currently only the Priority Bit Map table uses this feature.
264
 *         To benefit from using this, the data must be heavily
265
 *         used so it will stay in the cache and used frequently enough
266
 *         in the executive to justify turning this on.
267
 */
268
 
269
#define CPU_STRUCTURE_ALIGNMENT __attribute__ ((aligned(16)))
270
 
271
/*
272
 *  Define what is required to specify how the network to host conversion
273
 *  routines are handled.
274
 *
275
 *  NOTE: SHes can be big or little endian, the default is big endian
276
 */
277
 
278
#define CPU_HAS_OWN_HOST_TO_NETWORK_ROUTINES     FALSE
279
 
280
/* __LITTLE_ENDIAN__ is defined if -ml is given to gcc */
281
#if defined(__LITTLE_ENDIAN__)
282
#define CPU_BIG_ENDIAN                           FALSE
283
#define CPU_LITTLE_ENDIAN                        TRUE
284
#else
285
#define CPU_BIG_ENDIAN                           TRUE
286
#define CPU_LITTLE_ENDIAN                        FALSE
287
#endif
288
 
289
/*
290
 *  The following defines the number of bits actually used in the
291
 *  interrupt field of the task mode.  How those bits map to the
292
 *  CPU interrupt levels is defined by the routine _CPU_ISR_Set_level().
293
 */
294
 
295
#define CPU_MODES_INTERRUPT_MASK   0x0000000f
296
 
297
/*
298
 *  Processor defined structures
299
 *
300
 *  Examples structures include the descriptor tables from the i386
301
 *  and the processor control structure on the i960ca.
302
 */
303
 
304
/* may need to put some structures here.  */
305
 
306
/*
307
 * Contexts
308
 *
309
 *  Generally there are 2 types of context to save.
310
 *     1. Interrupt registers to save
311
 *     2. Task level registers to save
312
 *
313
 *  This means we have the following 3 context items:
314
 *     1. task level context stuff::  Context_Control
315
 *     2. floating point task stuff:: Context_Control_fp
316
 *     3. special interrupt level context :: Context_Control_interrupt
317
 *
318
 *  On some processors, it is cost-effective to save only the callee
319
 *  preserved registers during a task context switch.  This means
320
 *  that the ISR code needs to save those registers which do not
321
 *  persist across function calls.  It is not mandatory to make this
322
 *  distinctions between the caller/callee saves registers for the
323
 *  purpose of minimizing context saved during task switch and on interrupts.
324
 *  If the cost of saving extra registers is minimal, simplicity is the
325
 *  choice.  Save the same context on interrupt entry as for tasks in
326
 *  this case.
327
 *
328
 *  Additionally, if gdb is to be made aware of RTEMS tasks for this CPU, then
329
 *  care should be used in designing the context area.
330
 *
331
 *  On some CPUs with hardware floating point support, the Context_Control_fp
332
 *  structure will not be used or it simply consist of an array of a
333
 *  fixed number of bytes.   This is done when the floating point context
334
 *  is dumped by a "FP save context" type instruction and the format
335
 *  is not really defined by the CPU.  In this case, there is no need
336
 *  to figure out the exact format -- only the size.  Of course, although
337
 *  this is enough information for RTEMS, it is probably not enough for
338
 *  a debugger such as gdb.  But that is another problem.
339
 */
340
 
341
typedef struct {
342
  unsigned32 *r15;      /* stack pointer */
343
 
344
  unsigned32 macl;
345
  unsigned32 mach;
346
  unsigned32 *pr;
347
 
348
  unsigned32 *r14;      /* frame pointer/call saved */
349
 
350
  unsigned32 r13;       /* call saved */
351
  unsigned32 r12;       /* call saved */
352
  unsigned32 r11;       /* call saved */
353
  unsigned32 r10;       /* call saved */
354
  unsigned32 r9;        /* call saved */
355
  unsigned32 r8;        /* call saved */
356
 
357
  unsigned32 *r7;       /* arg in */
358
  unsigned32 *r6;       /* arg in */
359
 
360
#if 0
361
  unsigned32 *r5;       /* arg in */
362
  unsigned32 *r4;       /* arg in */
363
#endif
364
 
365
  unsigned32 *r3;       /* scratch */
366
  unsigned32 *r2;       /* scratch */
367
  unsigned32 *r1;       /* scratch */
368
 
369
  unsigned32 *r0;       /* arg return */
370
 
371
  unsigned32 gbr;
372
  unsigned32 sr;
373
 
374
} Context_Control;
375
 
376
typedef struct {
377
#if SH_HAS_FPU
378
#ifdef SH4_USE_X_REGISTERS
379
  union {
380
    float f[16];
381
    double d[8];
382
  } x;
383
#endif
384
  union {
385
    float f[16];
386
    double d[8];
387
  } r;
388
  float fpul;       /* fp communication register */
389
  unsigned32 fpscr; /* fp control register */
390
#endif /* SH_HAS_FPU */
391
} Context_Control_fp;
392
 
393
typedef struct {
394
} CPU_Interrupt_frame;
395
 
396
 
397
/*
398
 *  The following table contains the information required to configure
399
 *  the SH processor specific parameters.
400
 */
401
 
402
typedef struct {
403
  void       (*pretasking_hook)( void );
404
  void       (*predriver_hook)( void );
405
  void       (*postdriver_hook)( void );
406
  void       (*idle_task)( void );
407
  boolean      do_zero_of_workspace;
408
  unsigned32   idle_task_stack_size;
409
  unsigned32   interrupt_stack_size;
410
  unsigned32   extra_mpci_receive_server_stack;
411
  void *     (*stack_allocate_hook)( unsigned32 );
412
  void       (*stack_free_hook)( void* );
413
  /* end of fields required on all CPUs */
414
  unsigned32    clicks_per_second ; /* cpu frequency in Hz */
415
}   rtems_cpu_table;
416
 
417
/*
418
 *  Macros to access required entires in the CPU Table are in
419
 *  the file rtems/system.h.
420
 */
421
 
422
/*
423
 *  Macros to access SH specific additions to the CPU Table
424
 */
425
 
426
#define rtems_cpu_configuration_get_clicks_per_second() \
427
  (_CPU_Table.clicks_per_second)
428
 
429
/*
430
 *  This variable is optional.  It is used on CPUs on which it is difficult
431
 *  to generate an "uninitialized" FP context.  It is filled in by
432
 *  _CPU_Initialize and copied into the task's FP context area during
433
 *  _CPU_Context_Initialize.
434
 */
435
 
436
#if SH_HAS_FPU
437
SCORE_EXTERN Context_Control_fp  _CPU_Null_fp_context;
438
#endif
439
 
440
/*
441
 *  On some CPUs, RTEMS supports a software managed interrupt stack.
442
 *  This stack is allocated by the Interrupt Manager and the switch
443
 *  is performed in _ISR_Handler.  These variables contain pointers
444
 *  to the lowest and highest addresses in the chunk of memory allocated
445
 *  for the interrupt stack.  Since it is unknown whether the stack
446
 *  grows up or down (in general), this give the CPU dependent
447
 *  code the option of picking the version it wants to use.
448
 *
449
 *  NOTE: These two variables are required if the macro
450
 *        CPU_HAS_SOFTWARE_INTERRUPT_STACK is defined as TRUE.
451
 */
452
 
453
SCORE_EXTERN void               *_CPU_Interrupt_stack_low;
454
SCORE_EXTERN void               *_CPU_Interrupt_stack_high;
455
 
456
/*
457
 *  With some compilation systems, it is difficult if not impossible to
458
 *  call a high-level language routine from assembly language.  This
459
 *  is especially true of commercial Ada compilers and name mangling
460
 *  C++ ones.  This variable can be optionally defined by the CPU porter
461
 *  and contains the address of the routine _Thread_Dispatch.  This
462
 *  can make it easier to invoke that routine at the end of the interrupt
463
 *  sequence (if a dispatch is necessary).
464
 */
465
 
466
SCORE_EXTERN void           (*_CPU_Thread_dispatch_pointer)();
467
 
468
/*
469
 *  Nothing prevents the porter from declaring more CPU specific variables.
470
 */
471
 
472
/* XXX: if needed, put more variables here */
473
SCORE_EXTERN void CPU_delay( unsigned32 microseconds );
474
 
475
/*
476
 *  The size of the floating point context area.  On some CPUs this
477
 *  will not be a "sizeof" because the format of the floating point
478
 *  area is not defined -- only the size is.  This is usually on
479
 *  CPUs with a "floating point save context" instruction.
480
 */
481
 
482
#define CPU_CONTEXT_FP_SIZE sizeof( Context_Control_fp )
483
 
484
/*
485
 *  Amount of extra stack (above minimum stack size) required by
486
 *  MPCI receive server thread.  Remember that in a multiprocessor
487
 *  system this thread must exist and be able to process all directives.
488
 */
489
 
490
#define CPU_MPCI_RECEIVE_SERVER_EXTRA_STACK 0
491
 
492
/*
493
 *  This defines the number of entries in the ISR_Vector_table managed
494
 *  by RTEMS.
495
 */
496
 
497
#define CPU_INTERRUPT_NUMBER_OF_VECTORS      256
498
#define CPU_INTERRUPT_MAXIMUM_VECTOR_NUMBER  (CPU_INTERRUPT_NUMBER_OF_VECTORS - 1)
499
 
500
/*
501
 *  This is defined if the port has a special way to report the ISR nesting
502
 *  level.  Most ports maintain the variable _ISR_Nest_level.
503
 */
504
 
505
#define CPU_PROVIDES_ISR_IS_IN_PROGRESS FALSE
506
 
507
/*
508
 *  Should be large enough to run all RTEMS tests.  This insures
509
 *  that a "reasonable" small application should not have any problems.
510
 *
511
 *  We have been able to run the sptests with this value, but have not
512
 *  been able to run the tmtest suite.
513
 */
514
 
515
#define CPU_STACK_MINIMUM_SIZE          4096
516
 
517
/*
518
 *  CPU's worst alignment requirement for data types on a byte boundary.  This
519
 *  alignment does not take into account the requirements for the stack.
520
 */
521
#if defined(__SH4__)
522
/* FIXME: sh3 and SH3E? */
523
#define CPU_ALIGNMENT              8
524
#else
525
#define CPU_ALIGNMENT              4
526
#endif
527
 
528
/*
529
 *  This number corresponds to the byte alignment requirement for the
530
 *  heap handler.  This alignment requirement may be stricter than that
531
 *  for the data types alignment specified by CPU_ALIGNMENT.  It is
532
 *  common for the heap to follow the same alignment requirement as
533
 *  CPU_ALIGNMENT.  If the CPU_ALIGNMENT is strict enough for the heap,
534
 *  then this should be set to CPU_ALIGNMENT.
535
 *
536
 *  NOTE:  This does not have to be a power of 2.  It does have to
537
 *         be greater or equal to than CPU_ALIGNMENT.
538
 */
539
 
540
#define CPU_HEAP_ALIGNMENT         CPU_ALIGNMENT
541
 
542
/*
543
 *  This number corresponds to the byte alignment requirement for memory
544
 *  buffers allocated by the partition manager.  This alignment requirement
545
 *  may be stricter than that for the data types alignment specified by
546
 *  CPU_ALIGNMENT.  It is common for the partition to follow the same
547
 *  alignment requirement as CPU_ALIGNMENT.  If the CPU_ALIGNMENT is strict
548
 *  enough for the partition, then this should be set to CPU_ALIGNMENT.
549
 *
550
 *  NOTE:  This does not have to be a power of 2.  It does have to
551
 *         be greater or equal to than CPU_ALIGNMENT.
552
 */
553
 
554
#define CPU_PARTITION_ALIGNMENT    CPU_ALIGNMENT
555
 
556
/*
557
 *  This number corresponds to the byte alignment requirement for the
558
 *  stack.  This alignment requirement may be stricter than that for the
559
 *  data types alignment specified by CPU_ALIGNMENT.  If the CPU_ALIGNMENT
560
 *  is strict enough for the stack, then this should be set to 0.
561
 *
562
 *  NOTE:  This must be a power of 2 either 0 or greater than CPU_ALIGNMENT.
563
 */
564
 
565
#define CPU_STACK_ALIGNMENT        CPU_ALIGNMENT
566
 
567
/*
568
 *  ISR handler macros
569
 */
570
 
571
/*
572
 *  Support routine to initialize the RTEMS vector table after it is allocated.
573
 *
574
 *  SH Specific Information: NONE
575
 */
576
 
577
#define _CPU_Initialize_vectors()
578
 
579
/*
580
 *  Disable all interrupts for an RTEMS critical section.  The previous
581
 *  level is returned in _level.
582
 */
583
 
584
#define _CPU_ISR_Disable( _level) \
585
  sh_disable_interrupts( _level )
586
 
587
/*
588
 *  Enable interrupts to the previous level (returned by _CPU_ISR_Disable).
589
 *  This indicates the end of an RTEMS critical section.  The parameter
590
 *  _level is not modified.
591
 */
592
 
593
#define _CPU_ISR_Enable( _level) \
594
   sh_enable_interrupts( _level)
595
 
596
/*
597
 *  This temporarily restores the interrupt to _level before immediately
598
 *  disabling them again.  This is used to divide long RTEMS critical
599
 *  sections into two or more parts.  The parameter _level is not
600
 * modified.
601
 */
602
 
603
#define _CPU_ISR_Flash( _level) \
604
  sh_flash_interrupts( _level)
605
 
606
/*
607
 *  Map interrupt level in task mode onto the hardware that the CPU
608
 *  actually provides.  Currently, interrupt levels which do not
609
 *  map onto the CPU in a generic fashion are undefined.  Someday,
610
 *  it would be nice if these were "mapped" by the application
611
 *  via a callout.  For example, m68k has 8 levels 0 - 7, levels
612
 *  8 - 255 would be available for bsp/application specific meaning.
613
 *  This could be used to manage a programmable interrupt controller
614
 *  via the rtems_task_mode directive.
615
 */
616
 
617
#define _CPU_ISR_Set_level( _newlevel) \
618
  sh_set_interrupt_level(_newlevel)
619
 
620
unsigned32 _CPU_ISR_Get_level( void );
621
 
622
/* end of ISR handler macros */
623
 
624
/* Context handler macros */
625
 
626
/*
627
 *  Initialize the context to a state suitable for starting a
628
 *  task after a context restore operation.  Generally, this
629
 *  involves:
630
 *
631
 *     - setting a starting address
632
 *     - preparing the stack
633
 *     - preparing the stack and frame pointers
634
 *     - setting the proper interrupt level in the context
635
 *     - initializing the floating point context
636
 *
637
 *  This routine generally does not set any unnecessary register
638
 *  in the context.  The state of the "general data" registers is
639
 *  undefined at task start time.
640
 *
641
 *  NOTE: This is_fp parameter is TRUE if the thread is to be a floating
642
 *        point thread.  This is typically only used on CPUs where the
643
 *        FPU may be easily disabled by software such as on the SPARC
644
 *        where the PSR contains an enable FPU bit.
645
 */
646
 
647
/*
648
 * FIXME: defined as a function for debugging - should be a macro
649
 */
650
SCORE_EXTERN void _CPU_Context_Initialize(
651
  Context_Control       *_the_context,
652
  void                  *_stack_base,
653
  unsigned32            _size,
654
  unsigned32            _isr,
655
  void    (*_entry_point)(void),
656
  int                   _is_fp );
657
 
658
/*
659
 *  This routine is responsible for somehow restarting the currently
660
 *  executing task.  If you are lucky, then all that is necessary
661
 *  is restoring the context.  Otherwise, there will need to be
662
 *  a special assembly routine which does something special in this
663
 *  case.  Context_Restore should work most of the time.  It will
664
 *  not work if restarting self conflicts with the stack frame
665
 *  assumptions of restoring a context.
666
 */
667
 
668
#define _CPU_Context_Restart_self( _the_context ) \
669
   _CPU_Context_restore( (_the_context) );
670
 
671
/*
672
 *  The purpose of this macro is to allow the initial pointer into
673
 *  a floating point context area (used to save the floating point
674
 *  context) to be at an arbitrary place in the floating point
675
 *  context area.
676
 *
677
 *  This is necessary because some FP units are designed to have
678
 *  their context saved as a stack which grows into lower addresses.
679
 *  Other FP units can be saved by simply moving registers into offsets
680
 *  from the base of the context area.  Finally some FP units provide
681
 *  a "dump context" instruction which could fill in from high to low
682
 *  or low to high based on the whim of the CPU designers.
683
 */
684
 
685
#define _CPU_Context_Fp_start( _base, _offset ) \
686
   ( (void *) _Addresses_Add_offset( (_base), (_offset) ) )
687
 
688
/*
689
 *  This routine initializes the FP context area passed to it to.
690
 *  There are a few standard ways in which to initialize the
691
 *  floating point context.  The code included for this macro assumes
692
 *  that this is a CPU in which a "initial" FP context was saved into
693
 *  _CPU_Null_fp_context and it simply copies it to the destination
694
 *  context passed to it.
695
 *
696
 *  Other models include (1) not doing anything, and (2) putting
697
 *  a "null FP status word" in the correct place in the FP context.
698
 *  SH1, SH2, SH3 have no FPU, but the SH3e and SH4 have.
699
 */
700
 
701
#if SH_HAS_FPU
702
#define _CPU_Context_Initialize_fp( _destination ) \
703
  do { \
704
     *((Context_Control_fp *) *((void **) _destination)) = _CPU_Null_fp_context;\
705
  } while(0)
706
#else
707
#define _CPU_Context_Initialize_fp( _destination ) \
708
  {  }
709
#endif
710
 
711
/* end of Context handler macros */
712
 
713
/* Fatal Error manager macros */
714
 
715
/*
716
 * FIXME: Trap32 ???
717
 *
718
 *  This routine copies _error into a known place -- typically a stack
719
 *  location or a register, optionally disables interrupts, and
720
 *  invokes a Trap32 Instruction which returns to the breakpoint
721
 *  routine of cmon.
722
 */
723
 
724
#ifdef BSP_FATAL_HALT
725
  /* we manage the fatal error in the board support package */
726
  void bsp_fatal_halt( unsigned32 _error);
727
#define _CPU_Fatal_halt( _error ) bsp_fatal_halt( _error)
728
#else
729
#define _CPU_Fatal_halt( _error)\
730
{ \
731
  asm volatile("mov.l %0,r0"::"m" (_error)); \
732
  asm volatile("mov #1, r4"); \
733
  asm volatile("trapa #34"); \
734
}
735
#endif
736
 
737
/* end of Fatal Error manager macros */
738
 
739
/* Bitfield handler macros */
740
 
741
/*
742
 *  This routine sets _output to the bit number of the first bit
743
 *  set in _value.  _value is of CPU dependent type Priority_Bit_map_control.
744
 *  This type may be either 16 or 32 bits wide although only the 16
745
 *  least significant bits will be used.
746
 *
747
 *  There are a number of variables in using a "find first bit" type
748
 *  instruction.
749
 *
750
 *    (1) What happens when run on a value of zero?
751
 *    (2) Bits may be numbered from MSB to LSB or vice-versa.
752
 *    (3) The numbering may be zero or one based.
753
 *    (4) The "find first bit" instruction may search from MSB or LSB.
754
 *
755
 *  RTEMS guarantees that (1) will never happen so it is not a concern.
756
 *  (2),(3), (4) are handled by the macros _CPU_Priority_mask() and
757
 *  _CPU_Priority_bits_index().  These three form a set of routines
758
 *  which must logically operate together.  Bits in the _value are
759
 *  set and cleared based on masks built by _CPU_Priority_mask().
760
 *  The basic major and minor values calculated by _Priority_Major()
761
 *  and _Priority_Minor() are "massaged" by _CPU_Priority_bits_index()
762
 *  to properly range between the values returned by the "find first bit"
763
 *  instruction.  This makes it possible for _Priority_Get_highest() to
764
 *  calculate the major and directly index into the minor table.
765
 *  This mapping is necessary to ensure that 0 (a high priority major/minor)
766
 *  is the first bit found.
767
 *
768
 *  This entire "find first bit" and mapping process depends heavily
769
 *  on the manner in which a priority is broken into a major and minor
770
 *  components with the major being the 4 MSB of a priority and minor
771
 *  the 4 LSB.  Thus (0 << 4) + 0 corresponds to priority 0 -- the highest
772
 *  priority.  And (15 << 4) + 14 corresponds to priority 254 -- the next
773
 *  to the lowest priority.
774
 *
775
 *  If your CPU does not have a "find first bit" instruction, then
776
 *  there are ways to make do without it.  Here are a handful of ways
777
 *  to implement this in software:
778
 *
779
 *    - a series of 16 bit test instructions
780
 *    - a "binary search using if's"
781
 *    - _number = 0
782
 *      if _value > 0x00ff
783
 *        _value >>=8
784
 *        _number = 8;
785
 *
786
 *      if _value > 0x0000f
787
 *        _value >=8
788
 *        _number += 4
789
 *
790
 *      _number += bit_set_table[ _value ]
791
 *
792
 *    where bit_set_table[ 16 ] has values which indicate the first
793
 *      bit set
794
 */
795
 
796
#define CPU_USE_GENERIC_BITFIELD_CODE TRUE
797
#define CPU_USE_GENERIC_BITFIELD_DATA TRUE
798
 
799
#if (CPU_USE_GENERIC_BITFIELD_CODE == FALSE)
800
 
801
extern unsigned8 _bit_set_table[];
802
 
803
#define _CPU_Bitfield_Find_first_bit( _value, _output ) \
804
  { \
805
      _output = 0;\
806
      if(_value > 0x00ff) \
807
      { _value >>= 8; _output = 8; } \
808
      if(_value > 0x000f) \
809
        { _output += 4; _value >>= 4; } \
810
      _output += _bit_set_table[ _value]; }
811
 
812
#endif
813
 
814
/* end of Bitfield handler macros */
815
 
816
/*
817
 *  This routine builds the mask which corresponds to the bit fields
818
 *  as searched by _CPU_Bitfield_Find_first_bit().  See the discussion
819
 *  for that routine.
820
 */
821
 
822
#if (CPU_USE_GENERIC_BITFIELD_CODE == FALSE)
823
 
824
#define _CPU_Priority_Mask( _bit_number ) \
825
  ( 1 << (_bit_number) )
826
 
827
#endif
828
 
829
/*
830
 *  This routine translates the bit numbers returned by
831
 *  _CPU_Bitfield_Find_first_bit() into something suitable for use as
832
 *  a major or minor component of a priority.  See the discussion
833
 *  for that routine.
834
 */
835
 
836
#if (CPU_USE_GENERIC_BITFIELD_CODE == FALSE)
837
 
838
#define _CPU_Priority_bits_index( _priority ) \
839
  (_priority)
840
 
841
#endif
842
 
843
/* end of Priority handler macros */
844
 
845
/* functions */
846
 
847
/*
848
 *  _CPU_Initialize
849
 *
850
 *  This routine performs CPU dependent initialization.
851
 */
852
 
853
void _CPU_Initialize(
854
  rtems_cpu_table  *cpu_table,
855
  void      (*thread_dispatch)
856
);
857
 
858
/*
859
 *  _CPU_ISR_install_raw_handler
860
 *
861
 *  This routine installs a "raw" interrupt handler directly into the
862
 *  processor's vector table.
863
 */
864
 
865
void _CPU_ISR_install_raw_handler(
866
  unsigned32  vector,
867
  proc_ptr    new_handler,
868
  proc_ptr   *old_handler
869
);
870
 
871
/*
872
 *  _CPU_ISR_install_vector
873
 *
874
 *  This routine installs an interrupt vector.
875
 */
876
 
877
void _CPU_ISR_install_vector(
878
  unsigned32  vector,
879
  proc_ptr    new_handler,
880
  proc_ptr   *old_handler
881
);
882
 
883
/*
884
 *  _CPU_Install_interrupt_stack
885
 *
886
 *  This routine installs the hardware interrupt stack pointer.
887
 *
888
 *  NOTE:  It needs only be provided if CPU_HAS_HARDWARE_INTERRUPT_STACK
889
 *         is TRUE.
890
 */
891
 
892
void _CPU_Install_interrupt_stack( void );
893
 
894
/*
895
 *  _CPU_Thread_Idle_body
896
 *
897
 *  This routine is the CPU dependent IDLE thread body.
898
 *
899
 *  NOTE:  It need only be provided if CPU_PROVIDES_IDLE_THREAD_BODY
900
 *         is TRUE.
901
 */
902
 
903
void _CPU_Thread_Idle_body( void );
904
 
905
/*
906
 *  _CPU_Context_switch
907
 *
908
 *  This routine switches from the run context to the heir context.
909
 */
910
 
911
void _CPU_Context_switch(
912
  Context_Control  *run,
913
  Context_Control  *heir
914
);
915
 
916
/*
917
 *  _CPU_Context_restore
918
 *
919
 *  This routine is generally used only to restart self in an
920
 *  efficient manner.  It may simply be a label in _CPU_Context_switch.
921
 */
922
 
923
void _CPU_Context_restore(
924
  Context_Control *new_context
925
);
926
 
927
/*
928
 *  _CPU_Context_save_fp
929
 *
930
 *  This routine saves the floating point context passed to it.
931
 */
932
 
933
void _CPU_Context_save_fp(
934
  void **fp_context_ptr
935
);
936
 
937
/*
938
 *  _CPU_Context_restore_fp
939
 *
940
 *  This routine restores the floating point context passed to it.
941
 */
942
 
943
void _CPU_Context_restore_fp(
944
  void **fp_context_ptr
945
);
946
 
947
 
948
#ifdef __cplusplus
949
}
950
#endif
951
 
952
#endif

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