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
|
/**************************************************************************
* arch/x86/src/qemu/qemu_fullcontextrestore.S
*
* Copyright (C) 2011 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <spudmonkey@racsa.co.cr>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* 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 THE
* COPYRIGHT OWNER OR CONTRIBUTORS 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.
*
**************************************************************************/
/**************************************************************************
* Conditional Compilation Options
**************************************************************************/
/**************************************************************************
* Included Files
**************************************************************************/
#include <nuttx/config.h>
#include <arch/irq.h>
#include "up_internal.h"
.file "qemu_fullcontextrestore.S"
/**************************************************************************
* Pre-processor Definitions
**************************************************************************/
/**************************************************************************
* Global Variables
**************************************************************************/
/****************************************************************************
* Macros
****************************************************************************/
/* Trace macros, use like trace 'i' to print char to serial port. */
.macro trace, ch
#ifdef CONFIG_DEBUG
mov $0x3f8, %dx
mov $\ch, %al
out %al, %dx
#endif
.endm
/**************************************************************************
* Public Functions
**************************************************************************/
.text
/**************************************************************************
* Name: up_fullcontextrestore
*
* Full C prototype:
* void up_fullcontextrestore(uint32_t *regs) __attribute__ ((noreturn));
*
**************************************************************************/
.globl up_fullcontextrestore
.type up_fullcontextrestore, @function
up_fullcontextrestore:
/* Fetch the pointer to the register save array in EAX. */
movl 4(%esp), %eax
/* Disable interrupts now (the correct EFLAGS will be restored before we
* return
*/
cli
/* We now have everything we need from the old stack. Now get the new
* stack pointer.
*/
movl (4*REG_SP)(%eax), %esp
/* Create an interrupt stack frame for the final iret.
*
* SP Before ->
* SS
* ESP
* EFLAGS
* CS
* SP After -> EIP
*/
mov (4*REG_SS)(%eax), %ebx
push %ebx
movl (4*REG_SP)(%eax), %ebx
push %ebx
movl (4*REG_EFLAGS)(%eax), %ebx
push %ebx
mov (4*REG_CS)(%eax), %ebx
push %ebx
movl (4*REG_EIP)(%eax), %ebx
push %ebx
/* Save the value of EAX on the stack too */
movl (4*REG_EAX)(%eax), %ebx
push %ebx
/* Now restore the remaining registers */
movl (4*REG_ESI)(%eax), %esi
movl (4*REG_EDI)(%eax), %edi
movl (4*REG_EBP)(%eax), %ebp
movl (4*REG_EBX)(%eax), %ebx
movl (4*REG_EDX)(%eax), %edx
movl (4*REG_ECX)(%eax), %ecx
/* Restore the data segment register. I think there is an issue that will
* need to be address here at some time: If the register save area is in
* one data segment and the stack is in another, then the above would not
* work (and, conversely, if they are in the same data segment, the
* following is unnecessary and redundant).
*/
mov (4*REG_DS)(%eax), %ds
/* Restore the correct value of EAX and then return */
popl %eax
iret
.size up_fullcontextrestore, . - up_fullcontextrestore
.end
|
