source: rtems/c/src/exec/score/headers/context.h @ 84b7e72a

4.104.114.84.95
Last change on this file since 84b7e72a was ac7d5ef0, checked in by Joel Sherrill <joel.sherrill@…>, on 05/11/95 at 17:39:37

Initial revision
  • Property mode set to 100644
File size: 3.0 KB
Line 
1/*  context.h
2 *
3 *  This include file contains all information about a context.
4 *
5 *  COPYRIGHT (c) 1989, 1990, 1991, 1992, 1993, 1994.
6 *  On-Line Applications Research Corporation (OAR).
7 *  All rights assigned to U.S. Government, 1994.
8 *
9 *  This material may be reproduced by or for the U.S. Government pursuant
10 *  to the copyright license under the clause at DFARS 252.227-7013.  This
11 *  notice must appear in all copies of this file and its derivatives.
12 *
13 *  $Id$
14 */
15
16#ifndef __RTEMS_CONTEXT_h
17#define __RTEMS_CONTEXT_h
18
19#ifdef __cplusplus
20extern "C" {
21#endif
22
23#include <rtems/cpu.h>
24
25/*
26 *  The following constant defines the number of bytes required
27 *  to store a full floating point context.
28 */
29
30#define CONTEXT_FP_SIZE CPU_CONTEXT_FP_SIZE
31
32/*
33 *  The following variable is set to TRUE when a reschedule operation
34 *  has determined that the processor should be taken away from the
35 *  currently executing thread and given to the heir thread.
36 */
37
38EXTERN boolean _Context_Switch_necessary;
39
40/*
41 *  _Context_Initialize
42 *
43 *  DESCRIPTION:
44 *
45 *  This routine initializes THE_CONTEXT such that the stack
46 *  pointer, interrupt level, and entry point are correct for the
47 *  thread's initial state.
48 */
49
50#define _Context_Initialize( _the_context, _stack, _size, _isr, _entry ) \
51   _CPU_Context_Initialize( _the_context, _stack, _size, _isr, _entry )
52
53/*
54 *  _Context_Switch
55 *
56 *  DESCRIPTION:
57 *
58 *  This routine saves the current context into the EXECUTING
59 *  context record and restores the context specified by HEIR.
60 */
61
62#define _Context_Switch( _executing, _heir ) \
63   _CPU_Context_switch( _executing, _heir )
64
65/*
66 *  _Context_Restart_self
67 *
68 *  DESCRIPTION:
69 *
70 *  This routine restarts the calling thread by restoring its initial
71 *  stack pointer and returning to the thread's entry point.
72 */
73
74#define _Context_Restart_self( _the_context ) \
75   _CPU_Context_Restart_self( _the_context )
76
77/*
78 *  _Context_Fp_start
79 *
80 *  DESCRIPTION:
81 *
82 *  This function returns the starting address of the floating
83 *  point context save area.  It is assumed that the are reserved
84 *  for the floating point save area is large enough.
85 */
86
87#define _Context_Fp_start( _base, _offset ) \
88   _CPU_Context_Fp_start( (_base), (_offset) )
89
90/*
91 *  _Context_Initialize_fp
92 *
93 *  DESCRIPTION:
94 *
95 *  This routine initializes the floating point context save
96 *  area to contain an initial known state.
97 */
98
99#define _Context_Initialize_fp( _fp_area ) \
100   _CPU_Context_Initialize_fp( _fp_area )
101
102/*
103 *  _Context_Restore_fp
104 *
105 *  DESCRIPTION:
106 *
107 *  This routine restores the floating point context contained
108 *  in the FP_CONTEXT area.  It is assumed that the current
109 *  floating point context has been saved by a previous invocation
110 *  of SAVE_FP.
111 */
112
113#define _Context_Restore_fp( _fp ) \
114   _CPU_Context_restore_fp( _fp )
115
116/*
117 *  _Context_Save_fp
118 *
119 *  DESCRIPTION:
120 *
121 *  This routine saves the current floating point context
122 *  in the FP_CONTEXT area.
123 */
124
125#define _Context_Save_fp( _fp ) \
126   _CPU_Context_save_fp( _fp )
127
128#ifdef __cplusplus
129}
130#endif
131
132#endif
133/* end of include file */
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