Subversion Repositories HelenOS

Rev

Details | Last modification | View Log | RSS feed

Rev Author Line No. Line
4666 pillai 1
#
2
# Copyright (c) 2009 Vineeth Pillai
3
# All rights reserved.
4
#
5
# Redistribution and use in source and binary forms, with or without
6
# modification, are permitted provided that the following conditions
7
# are met:
8
#
9
# - Redistributions of source code must retain the above copyright
10
#   notice, this list of conditions and the following disclaimer.
11
# - Redistributions in binary form must reproduce the above copyright
12
#   notice, this list of conditions and the following disclaimer in the
13
#   documentation and/or other materials provided with the distribution.
14
# - The name of the author may not be used to endorse or promote products
15
#   derived from this software without specific prior written permission.
16
#
17
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18
# IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19
# OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20
# IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21
# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22
# NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23
# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24
# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26
# THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27
#
28
 
29
.text   
30
 
31
.global irq_exception_entry
32
.global fiq_exception_entry
33
.global data_abort_exception_entry
34
.global prefetch_abort_exception_entry
35
.global undef_instr_exception_entry
36
.global swi_exception_entry
37
.global reset_exception_entry
38
 
39
 
40
# Switches to kernel stack and saves all registers there.
41
#
42
#  The stack frame created by the function looks like:
43
#
44
#              |_________________|
45
#              |                 |
46
#              |     SPSR        |
47
#              |                 |
48
#              |_________________|
49
#              | Stack Pointer   |
50
#              |      of         |
51
#              | Previous Mode   |
52
#              |_________________|
53
#              | Return address  |
54
#              |      of         |
55
#              | Previous Mode   |
56
#              |_________________|
57
#              |   R0  - R12     |
58
#              |      of         |
59
#              | Previous Mode   |
60
#              |_________________|
61
#              | Return address  |
62
#              |     from        |
63
#              |Exception Handler|
64
#              |_________________|
65
#              |                 |
66
#
67
#
68
 
69
.macro SAVE_REGS_TO_STACK
70
	stmfd r13!, {r0-r3}
71
	mov r3, sp
72
	add sp, sp, #16
73
	mrs r1, cpsr
74
	bic r1, r1, #0x1f
75
	mrs r2, spsr
76
	and r0, r2, #0x1f
77
	cmp r0, #0x10
78
	bne 1f
79
 
80
	# prev mode was usermode
81
	mov r0, lr
82
 
83
	# Switch to supervisor mode
84
	orr r1, r1, #0x13
85
	msr cpsr_c, r1
86
 
87
	# Load sp with [supervisor_sp]
88
	ldr r13, =supervisor_sp
89
	ldr r13, [r13]
90
 
91
	# Populate the stack frame
92
	msr spsr, r2
93
	mov lr, r0
94
	stmfd r13!, {lr}
95
	stmfd r13!, {r4-r12}
96
	ldmfd r3!, {r4-r7}
97
	stmfd r13!, {r4-r7}
98
	stmfd r13!, {r13, lr}^
99
	stmfd r13!, {r2}
100
	b 2f
101
 
102
	# mode was not usermode
103
1:
104
	# Switch to previous mode which is undoubtedly the supervisor mode
105
	orr r1, r1, r0
106
	mov r0, lr
107
	msr cpsr_c, r1
108
 
109
	# Populate the stack frame
110
	mov r1, sp
111
	stmfd r13!, {r0}
112
	stmfd r13!, {r4-r12}
113
 
114
	# Store r0-r3 in r4-r7 and then push it on to stack
115
	ldmfd r3!, {r4-r7}
116
	stmfd r13!, {r4-r7}
117
 
118
	# Push return address and stack pointer on to stack
119
	stmfd r13!, {lr}
120
	stmfd r13!, {r1}
121
	mov lr, r0
122
	msr spsr, r2
123
	stmfd r13!, {r2}
124
2:
125
.endm
126
 
127
.macro LOAD_REGS_FROM_STACK
128
	ldmfd r13!, {r0}
129
	msr spsr, r0
130
	and r0, r0, #0x1f
131
	cmp r0, #0x10
132
	bne 1f
133
 
134
	# return to user mode
135
	ldmfd r13!, {r13, lr}^
136
	b 2f
137
 
138
	# return to non-user mode
139
1:
140
	ldmfd r13!, {r1, lr}
141
 
142
2:
143
	ldmfd r13!, {r0-r12, pc}^
144
.endm
145
 
146
reset_exception_entry:
147
	SAVE_REGS_TO_STACK
148
	mov r0, #0
149
	mov r1, r13
150
	bl exc_dispatch
151
	LOAD_REGS_FROM_STACK
152
 
153
irq_exception_entry:
154
	sub lr, lr, #4
155
	SAVE_REGS_TO_STACK
156
	mov r0, #5
157
	mov r1, r13
158
	bl exc_dispatch
159
	LOAD_REGS_FROM_STACK
160
 
161
fiq_exception_entry:
162
	sub lr, lr, #4
163
	SAVE_REGS_TO_STACK
164
	mov r0, #6
165
	mov r1, r13
166
	bl exc_dispatch
167
	LOAD_REGS_FROM_STACK
168
 
169
undef_instr_exception_entry:
170
	SAVE_REGS_TO_STACK
171
	mov r0, #1
172
	mov r1, r13
173
	bl exc_dispatch
174
	LOAD_REGS_FROM_STACK
175
 
176
prefetch_abort_exception_entry:
177
	sub lr, lr, #4
178
	SAVE_REGS_TO_STACK
179
	mov r0, #3
180
	mov r1, r13
181
	bl exc_dispatch
182
	LOAD_REGS_FROM_STACK
183
 
184
data_abort_exception_entry:
185
	sub lr, lr, #8
186
	SAVE_REGS_TO_STACK
187
	mov r0, #4
188
	mov r1, r13
189
	bl exc_dispatch
190
	LOAD_REGS_FROM_STACK
191
 
192
swi_exception_entry:
193
	ldr r13, =exc_stack
194
	SAVE_REGS_TO_STACK
195
	mov r0, #2
196
	mov r1, r13
197
	bl exc_dispatch
198
	LOAD_REGS_FROM_STACK
199