exception.S revision 1.16.34.1 1 /* $NetBSD: exception.S,v 1.16.34.1 2012/10/30 17:18:57 yamt Exp $ */
2
3 /*
4 * Copyright (c) 1994-1997 Mark Brinicombe.
5 * Copyright (c) 1994 Brini.
6 * All rights reserved.
7 *
8 * This code is derived from software written for Brini by Mark Brinicombe
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. All advertising materials mentioning features or use of this software
19 * must display the following acknowledgement:
20 * This product includes software developed by Brini.
21 * 4. The name of the company nor the name of the author may be used to
22 * endorse or promote products derived from this software without specific
23 * prior written permission.
24 *
25 * THIS SOFTWARE IS PROVIDED BY BRINI ``AS IS'' AND ANY EXPRESS OR IMPLIED
26 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
27 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
28 * IN NO EVENT SHALL BRINI OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
29 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
30 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
31 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35 * SUCH DAMAGE.
36 *
37 * RiscBSD kernel project
38 *
39 * exception.S
40 *
41 * Low level handlers for exception vectors
42 *
43 * Created : 24/09/94
44 *
45 * Based on kate/display/abort.s
46 */
47
48 #include "assym.h"
49 #include <machine/asm.h>
50 #include <machine/cpu.h>
51 #include <machine/frame.h>
52
53 RCSID("$NetBSD: exception.S,v 1.16.34.1 2012/10/30 17:18:57 yamt Exp $")
54
55 .text
56 .align 0
57
58 AST_ALIGNMENT_FAULT_LOCALS
59
60 /*
61 * reset_entry:
62 *
63 * Handler for Reset exception.
64 */
65 ASENTRY_NP(reset_entry)
66 adr r0, Lreset_panicmsg
67 mov r1, lr
68 bl _C_LABEL(panic)
69 /* NOTREACHED */
70 Lreset_panicmsg:
71 .asciz "Reset vector called, LR = 0x%08x"
72 .balign 4
73
74 /*
75 * swi_entry
76 *
77 * Handler for the Software Interrupt exception.
78 */
79 ASENTRY_NP(swi_entry)
80 PUSHFRAME
81 ENABLE_ALIGNMENT_FAULTS
82
83 mov r0, sp /* Pass the frame to any function */
84 bl _C_LABEL(swi_handler) /* It's a SWI ! */
85
86 DO_AST_AND_RESTORE_ALIGNMENT_FAULTS
87 PULLFRAME
88 movs pc, lr /* Exit */
89
90 /*
91 * prefetch_abort_entry:
92 *
93 * Handler for the Prefetch Abort exception.
94 */
95 ASENTRY_NP(prefetch_abort_entry)
96 #ifdef __XSCALE__
97 nop /* Make absolutely sure any pending */
98 nop /* imprecise aborts have occurred. */
99 #endif
100 sub lr, lr, #0x00000004 /* Adjust the lr */
101
102 PUSHFRAMEINSVC
103 ENABLE_ALIGNMENT_FAULTS
104
105 ldr r1, Lprefetch_abort_handler_address
106 adr lr, exception_exit
107 mov r0, sp /* pass the stack pointer as r0 */
108 ldr pc, [r1]
109
110 Lprefetch_abort_handler_address:
111 .word _C_LABEL(prefetch_abort_handler_address)
112
113 .data
114 .p2align 2
115 .global _C_LABEL(prefetch_abort_handler_address)
116 _C_LABEL(prefetch_abort_handler_address):
117 .word abortprefetch
118
119 .text
120 abortprefetch:
121 adr r0, abortprefetchmsg
122 b _C_LABEL(panic)
123
124 abortprefetchmsg:
125 .asciz "abortprefetch"
126 .align 0
127
128 /*
129 * data_abort_entry:
130 *
131 * Handler for the Data Abort exception.
132 */
133 ASENTRY_NP(data_abort_entry)
134 #ifdef __XSCALE__
135 nop /* Make absolutely sure any pending */
136 nop /* imprecise aborts have occurred. */
137 #endif
138 sub lr, lr, #0x00000008 /* Adjust the lr */
139
140 PUSHFRAMEINSVC /* Push trap frame and switch */
141 /* to SVC32 mode */
142 ENABLE_ALIGNMENT_FAULTS
143
144 ldr r1, Ldata_abort_handler_address
145 adr lr, exception_exit
146 mov r0, sp /* pass the stack pointer as r0 */
147 ldr pc, [r1]
148
149 Ldata_abort_handler_address:
150 .word _C_LABEL(data_abort_handler_address)
151
152 .data
153 .p2align 2
154 .global _C_LABEL(data_abort_handler_address)
155 _C_LABEL(data_abort_handler_address):
156 .word abortdata
157
158 .text
159 abortdata:
160 adr r0, abortdatamsg
161 b _C_LABEL(panic)
162
163 abortdatamsg:
164 .asciz "abortdata"
165 .align 0
166
167 /*
168 * address_exception_entry:
169 *
170 * Handler for the Address Exception exception.
171 *
172 * NOTE: This exception isn't really used on arm32. We
173 * print a warning message to the console and then treat
174 * it like a Data Abort.
175 */
176 ASENTRY_NP(address_exception_entry)
177 mrs r1, cpsr_all
178 mrs r2, spsr_all
179 mov r3, lr
180 adr r0, Laddress_exception_msg
181 bl _C_LABEL(printf) /* XXX CLOBBERS LR!! */
182 b data_abort_entry
183 Laddress_exception_msg:
184 .asciz "Address Exception CPSR=0x%08x SPSR=0x%08x LR=0x%08x\n"
185 .balign 4
186
187 /*
188 * General exception exit handler
189 * (Placed here to be within range of all the references to it)
190 *
191 * It exits straight away if not returning to USR mode.
192 * This loops around delivering any pending ASTs.
193 * Interrupts are disabled at suitable points to avoid ASTs
194 * being posted between testing and exit to user mode.
195 *
196 * This function uses PULLFRAMEFROMSVCANDEXIT and
197 * DO_AST_AND_RESTORE_ALIGNMENT_FAULTS thus should
198 * only be called if the exception handler used PUSHFRAMEINSVC
199 * followed by ENABLE_ALIGNMENT_FAULTS.
200 */
201
202 exception_exit:
203 DO_AST_AND_RESTORE_ALIGNMENT_FAULTS
204 PULLFRAMEFROMSVCANDEXIT
205
206 /*
207 * undefined_entry:
208 *
209 * Handler for the Undefined Instruction exception.
210 *
211 * We indirect the undefined vector via the handler address
212 * in the data area. Entry to the undefined handler must
213 * look like direct entry from the vector.
214 */
215 ASENTRY_NP(undefined_entry)
216 stmfd sp!, {r0, r1}
217 GET_CURCPU(r0)
218 ldr r1, [sp], #0x0004
219 str r1, [r0, #CI_UNDEFSAVE]!
220 ldr r1, [sp], #0x0004
221 str r1, [r0, #0x0004]
222 ldmia r0, {r0, r1, pc}
223
224 /*
225 * assembly bounce code for calling the kernel
226 * undefined instruction handler. This uses
227 * a standard trap frame and is called in SVC mode.
228 */
229
230 ENTRY_NP(undefinedinstruction_bounce)
231 PUSHFRAMEINSVC
232 ENABLE_ALIGNMENT_FAULTS
233
234 mov r0, sp
235 adr lr, exception_exit
236 b _C_LABEL(undefinedinstruction)
237