1 /* $NetBSD: exception.S,v 1.13 2003/10/31 16:30:15 scw Exp $ */
4 * Copyright (c) 1994-1997 Mark Brinicombe.
5 * Copyright (c) 1994 Brini.
8 * This code is derived from software written for Brini by Mark Brinicombe
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
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.
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
37 * RiscBSD kernel project
41 * Low level handlers for exception vectors
45 * Based on kate/display/abort.s
51 #include <machine/asm.h>
52 #include <machine/armreg.h>
53 #include <machine/asmacros.h>
54 __FBSDID("$FreeBSD$");
64 * Handler for Reset exception.
66 ASENTRY_NP(reset_entry)
67 adr r0, Lreset_panicmsg
71 .asciz "Reset vector called, LR = 0x%08x"
78 * Handler for the Software Interrupt exception.
81 STOP_UNWINDING /* Don't unwind past here */
85 mov r0, sp /* Pass the frame to any function */
86 bl _C_LABEL(swi_handler) /* It's a SWI ! */
90 movs pc, lr /* Exit */
94 * prefetch_abort_entry:
96 * Handler for the Prefetch Abort exception.
98 ASENTRY_NP(prefetch_abort_entry)
100 nop /* Make absolutely sure any pending */
101 nop /* imprecise aborts have occurred. */
103 sub lr, lr, #0x00000004 /* Adjust the lr */
106 ldr r1, Lprefetch_abort_handler_address
107 adr lr, exception_exit
108 mov r0, sp /* pass the stack pointer as r0 */
111 Lprefetch_abort_handler_address:
112 .word _C_LABEL(prefetch_abort_handler_address)
115 .global _C_LABEL(prefetch_abort_handler_address)
117 _C_LABEL(prefetch_abort_handler_address):
122 adr r0, abortprefetchmsg
126 .asciz "abortprefetch"
128 END(prefetch_abort_entry)
133 * Handler for the Data Abort exception.
135 ASENTRY_NP(data_abort_entry)
137 nop /* Make absolutely sure any pending */
138 nop /* imprecise aborts have occurred. */
141 sub lr, lr, #0x00000008 /* Adjust the lr */
142 PUSHFRAMEINSVC /* Push trap frame and switch */
144 ldr r1, Ldata_abort_handler_address
145 adr lr, exception_exit
146 mov r0, sp /* pass the stack pointer as r0 */
148 Ldata_abort_handler_address:
149 .word _C_LABEL(data_abort_handler_address)
152 .global _C_LABEL(data_abort_handler_address)
153 _C_LABEL(data_abort_handler_address):
164 END(data_abort_entry)
167 * address_exception_entry:
169 * Handler for the Address Exception exception.
171 * NOTE: This exception isn't really used on arm32. We
172 * print a warning message to the console and then treat
173 * it like a Data Abort.
175 ASENTRY_NP(address_exception_entry)
179 adr r0, Laddress_exception_msg
180 bl _C_LABEL(printf) /* XXX CLOBBERS LR!! */
182 Laddress_exception_msg:
183 .asciz "Address Exception CPSR=0x%08x SPSR=0x%08x LR=0x%08x\n"
185 END(address_exception_entry)
188 * General exception exit handler
189 * (Placed here to be within range of all the references to it)
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.
196 * This function uses PULLFRAMEFROMSVCANDEXIT and DO_AST and can
197 * only be called if the exception handler used PUSHFRAMEINSVC.
199 * For EABI, don't try to unwind any further than this. This is a
200 * stopgap measure to avoid getting stuck in a loop in the unwinder,
201 * which happens because we don't yet provide the proper unwind info
202 * here that describes which registers are being restored.
205 ASENTRY_NP(exception_exit)
208 PULLFRAMEFROMSVCANDEXIT
214 * Handler for the Undefined Instruction exception.
216 * We indirect the undefined vector via the handler address
217 * in the data area. Entry to the undefined handler must
218 * look like direct entry from the vector.
220 ASENTRY_NP(undefined_entry)
222 ldr r0, Lundefined_handler_indirection
223 ldr r1, [sp], #0x0004
224 str r1, [r0, #0x0000]
225 ldr r1, [sp], #0x0004
226 str r1, [r0, #0x0004]
227 ldmia r0, {r0, r1, pc}
230 Lundefined_handler_indirection:
231 .word Lundefined_handler_indirection_data
235 * assembly bounce code for calling the kernel
236 * undefined instruction handler. This uses
237 * a standard trap frame and is called in SVC mode.
240 ENTRY_NP(undefinedinstruction_bounce)
244 adr lr, exception_exit
245 b _C_LABEL(undefinedinstruction)
252 * 2 words use for preserving r0 and r1
253 * 3rd word contains the undefined handler address.
256 Lundefined_handler_indirection_data:
260 .global _C_LABEL(undefined_handler_address)
261 _C_LABEL(undefined_handler_address):
262 .word _C_LABEL(undefinedinstruction_bounce)
263 END(undefinedinstruction_bounce)