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exception.S revision 1.21
      1 /*	$NetBSD: exception.S,v 1.21 2014/03/05 02:12:24 matt 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 
     50 #include <arm/asm.h>
     51 
     52 #include <arm/locore.h>
     53 
     54 	RCSID("$NetBSD: exception.S,v 1.21 2014/03/05 02:12:24 matt Exp $")
     55 
     56 	.text
     57 	.align	0
     58 
     59 AST_ALIGNMENT_FAULT_LOCALS
     60 
     61 /*
     62  * reset_entry:
     63  *
     64  *	Handler for Reset exception.
     65  */
     66 ARM_ASENTRY_NP(reset_entry)
     67 	adr	r0, .Lreset_panicmsg
     68 	mov	r1, lr
     69 	bl	_C_LABEL(panic)
     70 	/* NOTREACHED */
     71 .Lreset_panicmsg:
     72 	.asciz	"Reset vector called, LR = 0x%08x"
     73 	.balign	4
     74 ASEND(reset_entry)
     75 
     76 /*
     77  * swi_entry
     78  *
     79  *	Handler for the Software Interrupt exception.
     80  */
     81 ARM_ASENTRY_NP(swi_entry)
     82 	PUSHFRAME
     83 	ENABLE_ALIGNMENT_FAULTS
     84 
     85 	mov	r0, sp			/* Pass the frame to any function */
     86 	bl	_C_LABEL(swi_handler)	/* It's a SWI ! */
     87 
     88 	DO_AST_AND_RESTORE_ALIGNMENT_FAULTS
     89 	PULLFRAME
     90 	movs	pc, lr			/* Exit */
     91 ASEND(swi_entry)
     92 
     93 /*
     94  * prefetch_abort_entry:
     95  *
     96  *	Handler for the Prefetch Abort exception.
     97  */
     98 ARM_ASENTRY_NP(prefetch_abort_entry)
     99 #ifdef __XSCALE__
    100 	nop				/* Make absolutely sure any pending */
    101 	nop				/* imprecise aborts have occurred. */
    102 #endif
    103         sub     lr, lr, #0x00000004     /* Adjust the lr */
    104 
    105 	PUSHFRAMEINSVC
    106 	ENABLE_ALIGNMENT_FAULTS
    107 
    108 	ldr	r1, .Lprefetch_abort_handler_address
    109 	adr	lr, .Lexception_exit
    110  	mov	r0, sp			/* pass the stack pointer as r0 */
    111 	ldr	pc, [r1]
    112 
    113 .Labortprefetch:
    114         adr     r0, .Labortprefetchmsg
    115 	b	_C_LABEL(panic)
    116 
    117 .Lprefetch_abort_handler_address:
    118 	.word	_C_LABEL(prefetch_abort_handler_address)
    119 
    120 .Labortprefetchmsg:
    121         .asciz  "abortprefetch"
    122         .align  0
    123 ASEND(prefetch_abort_entry)
    124 
    125 	.data
    126 	.p2align 2
    127 	.global	_C_LABEL(prefetch_abort_handler_address)
    128 _C_LABEL(prefetch_abort_handler_address):
    129 	.word	.Labortprefetch
    130 
    131 /*
    132  * data_abort_entry:
    133  *
    134  *	Handler for the Data Abort exception.
    135  */
    136 ASENTRY_NP(data_abort_entry)
    137 #ifdef __XSCALE__
    138 	nop				/* Make absolutely sure any pending */
    139 	nop				/* imprecise aborts have occurred. */
    140 #endif
    141         sub     lr, lr, #0x00000008     /* Adjust the lr */
    142 
    143 	PUSHFRAMEINSVC			/* Push trap frame and switch */
    144 					/* to SVC32 mode */
    145 	ENABLE_ALIGNMENT_FAULTS
    146 
    147 	ldr	r1, .Ldata_abort_handler_address
    148 	adr	lr, .Lexception_exit
    149 	mov	r0, sp			/* pass the stack pointer as r0 */
    150 	ldr	pc, [r1]
    151 
    152 .Ldata_abort_handler_address:
    153 	.word	_C_LABEL(data_abort_handler_address)
    154 
    155 	.data
    156 	.p2align 2
    157 	.global	_C_LABEL(data_abort_handler_address)
    158 _C_LABEL(data_abort_handler_address):
    159 	.word	.Labortdata
    160 
    161 	.text
    162 .Labortdata:
    163         adr     r0, .Labortdatamsg
    164 	b	_C_LABEL(panic)
    165 
    166 .Labortdatamsg:
    167         .asciz  "abortdata"
    168         .align  0
    169 ASEND(data_abort_entry)
    170 
    171 /*
    172  * address_exception_entry:
    173  *
    174  *	Handler for the Address Exception exception.
    175  *
    176  *	NOTE: This exception isn't really used on arm32.  We
    177  *	print a warning message to the console and then treat
    178  *	it like a Data Abort.
    179  */
    180 ASENTRY_NP(address_exception_entry)
    181 	push	{r0-r3,ip,lr}
    182 	mrs	r1, cpsr
    183 	mrs	r2, spsr
    184 	mov	r3, lr
    185 	adr	r0, .Laddress_exception_msg
    186 	bl	_C_LABEL(printf)	/* XXX CLOBBERS LR!! */
    187 	pop	{r0-r3,ip,lr}
    188 	b	_ASM_LABEL(data_abort_entry)
    189 .Laddress_exception_msg:
    190 	.asciz	"Address Exception CPSR=0x%08x SPSR=0x%08x LR=0x%08x\n"
    191 	.balign	4
    192 
    193 /*
    194  * General exception exit handler
    195  * (Placed here to be within range of all the references to it)
    196  *
    197  * It exits straight away if not returning to USR mode.
    198  * This loops around delivering any pending ASTs.
    199  * Interrupts are disabled at suitable points to avoid ASTs
    200  * being posted between testing and exit to user mode.
    201  *
    202  * This function uses PULLFRAMEFROMSVCANDEXIT and
    203  * DO_AST_AND_RESTORE_ALIGNMENT_FAULTS thus should
    204  * only be called if the exception handler used PUSHFRAMEINSVC
    205  * followed by ENABLE_ALIGNMENT_FAULTS.
    206  */
    207 
    208 .Lexception_exit:
    209 	DO_AST_AND_RESTORE_ALIGNMENT_FAULTS
    210 	PULLFRAMEFROMSVCANDEXIT
    211 ASEND(address_exception_entry)
    212 
    213 /*
    214  * undefined_entry:
    215  *
    216  *	Handler for the Undefined Instruction exception.
    217  *
    218  *	We indirect the undefined vector via the handler address
    219  *	in the data area.  Entry to the undefined handler must
    220  *	look like direct entry from the vector.
    221  */
    222 ASENTRY_NP(undefined_entry)
    223 	stmfd	sp!, {r0, r1}
    224 	GET_CURCPU(r0)
    225 	ldr	r1, [sp], #0x0004
    226 	str	r1, [r0, #CI_UNDEFSAVE]!
    227 	ldr	r1, [sp], #0x0004
    228 	str	r1, [r0, #0x0004]
    229 	ldmia	r0, {r0, r1, pc}
    230 ASEND(undefined_entry)
    231 
    232 /*
    233  * assembly bounce code for calling the kernel
    234  * undefined instruction handler. This uses
    235  * a standard trap frame and is called in SVC mode.
    236  */
    237 
    238 ENTRY_NP(undefinedinstruction_bounce)
    239 	PUSHFRAMEINSVC
    240 	ENABLE_ALIGNMENT_FAULTS
    241 
    242 	mov	r0, sp
    243 	adr	lr, .Lexception_exit
    244 	b	_C_LABEL(undefinedinstruction)
    245 END(undefinedinstruction_bounce)
    246 ASEND(undefined_entry)
    247