source: trunk/hal/generic/hal_context.h @ 500

Last change on this file since 500 was 457, checked in by alain, 6 years ago

This version modifies the exec syscall and fixes a large number of small bugs.
The version number has been updated (0.1)
File size: 8.0 KB
Line 
1/*
2 * hal_context.h - Generic Thread Context Access API definition.
3 *
4 * Author  Alain Greiner    (2016)
5 *
6 * Copyright (c) UPMC Sorbonne Universites
7 *
8 * This file is part of ALMOS-MKH.
9 *
10 * ALMOS-MKH is free software; you can redistribute it and/or modify it
11 * under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; version 2.0 of the License.
13 *
14 * ALMOS-MKH is distributed in the hope that it will be useful, but
15 * WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
17 * General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with ALMOS-MKH; if not, write to the Free Software Foundation,
21 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
22 */
23
24#ifndef  _HAL_CONTEXT_H_
25#define  _HAL_CONTEXT_H_
26
27//////////////////////////////////////////////////////////////////////////////////////////
28//        Generic Thread Context API definition (implementation in hal_context.c)
29//
30// A thread context is defined by the two (core specific) structures hal_cpu_context_t
31// and hal_fpu_context_t, defined in hal_context.c file, that are accessed with generic
32// void* pointers stored in the thread descriptor.
33// - the "hal_context_t" struct is used for the CPU registers values at context switch.
34// - the "hal_fpu_context_t" struct is used for the FPU registers when required.
35//////////////////////////////////////////////////////////////////////////////////////////
36
37/**** Forward declarations ****/
38
39struct thread_s;
40
41/****************************************************************************************
42 * This function allocates memory for a CPU context and links it to the thread
43 * identified by the <thread> argument. The context is not initialised.
44 ****************************************************************************************
45 * @ thread  : pointer on the thread descriptor.
46 * @ return 0 if success / return -1 if failure.
47 ***************************************************************************************/
48error_t hal_cpu_context_alloc( struct thread_s * thread );
49
50/****************************************************************************************
51 * This function initializes a CPU context from scratch.
52 ****************************************************************************************
53 * @ thread  : pointer on the thread descriptor.
54 ***************************************************************************************/
55void hal_cpu_context_init( struct thread_s * thread );
56
57/****************************************************************************************
58 * This function is used to implement the fork() system call.
59 * 1) It saves in a remote (child) thread CPU context the current CPU registers values.
60 *    Three slots are not simple copies of the parent registers values :
61 *    - the thread pointer is set to the child thread local pointer.
62 *    - the stack pointer is set to parrent SP + (child_base - parent_base).
63 *    - the status register is set to kernel mode with IRQ disabled.
64 * 2) It copies the content of the calling (parent) thread kernel_stack,
65 *    to the remote (child) thread kernel_stack.
66 ****************************************************************************************
67 * @ thread_xp  : extended pointer on the remote thread descriptor.
68 ***************************************************************************************/
69void hal_cpu_context_fork( xptr_t    thread_xp );
70
71/****************************************************************************************
72 * This function is used to implement the exec() system call.
73 * 1) It initialize the relevant slots of the the calling thread CPU context.
74 * 2) It call the hal_do_cpu_restore() function to return to user mode and start
75 *    execution of the new process.
76 ****************************************************************************************
77 * @ thread  : pointer on the thread descriptor.
78 ***************************************************************************************/
79void hal_cpu_context_exec( struct thread_s * thread );
80
81/****************************************************************************************
82 * This function display some slots of the CPU context.
83 ****************************************************************************************
84 * @ thread_xp  : extended pointer on the thread descriptor.
85 ***************************************************************************************/
86void hal_cpu_context_display( xptr_t  thread_xp );
87
88/****************************************************************************************
89 * This function releases the physical memory allocated for a thread CPU context.
90 ****************************************************************************************
91 * @ thread  : pointer on the thread descriptor.
92 ***************************************************************************************/
93void hal_cpu_context_destroy( struct thread_s * thread );
94
95
96
97
98
99
100
101/****************************************************************************************
102 * This function allocates memory for a FPU context, reset all entries,
103 * and links it to the thread identified by the <thread> argument.
104 ****************************************************************************************
105 * @ thread  : pointer on the thread descriptor.
106 * @ return 0 if success / return -1 if failure.
107 ***************************************************************************************/
108error_t hal_fpu_context_alloc( struct thread_s * thread );
109
110/****************************************************************************************
111 * This function initializes a FPU context from scratch.
112 ****************************************************************************************
113 * @ thread  : pointer on the thread descriptor.
114 ***************************************************************************************/
115void hal_fpu_context_init( struct thread_s * thread );
116
117/****************************************************************************************
118 * This function copies a FPU context defined by the <src> argument to the FPU context
119 * defined by the <dst> argument. It is used by the fork system call.
120 ****************************************************************************************
121 * @ dst  : pointer on the destination thread descriptor.
122 * @ src  : pointer on the source thread descriptor.
123 ***************************************************************************************/
124void hal_fpu_context_copy( struct thread_s * dst,
125                           struct thread_s * src );
126
127/****************************************************************************************
128 * This function releases the physical memory allocated for a FPU context.
129 ****************************************************************************************
130 * @ thread  : pointer on the thread descriptor.
131 ***************************************************************************************/
132void hal_fpu_context_destroy( struct thread_s * thread );
133
134/****************************************************************************************
135 * This function is used to implement the fork() system call.
136 * It saves in a remote thread FPU context the current FPU registers values.
137 ****************************************************************************************
138 * @ thread_xp  : extended pointer on the remote thread descriptor.
139 ***************************************************************************************/
140void hal_fpu_context_save( xptr_t thread_xp );
141
142/****************************************************************************************
143 * This function restores from the calling thread FPU context the FPU registers values.
144 ****************************************************************************************
145 * @ thread  : pointer on the thread descriptor.
146 ***************************************************************************************/
147void hal_fpu_context_restore( struct thread_s * thread );
148
149#endif  /* _HAL_CONTEXT_H_ */
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