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/*

 *  linux/arch/arm/lib/backtrace.S

 *

 *  Copyright (C) 1995, 1996 Russell King

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 as

 * published by the Free Software Foundation.

 */

#include 

#include 

#include 

                .text

@ fp is 0 or stack frame

#define frame   r4

#define next    r5

#define save    r6

#define mask    r7

#define offset  r8

ENTRY(__backtrace)

                mov     r1, #0x10

                mov     r0, fp

ENTRY(c_backtrace)

#ifndef CONFIG_FRAME_POINTER

                mov     pc, lr

#else

                stmfd   sp!, {r4 - r8, lr}      @ Save an extra register so we have a location...

#ifdef CONFIG_CPU_32

                tst     r1, #0x10               @ 26 or 32-bit?

                moveq   mask, #0xfc000003

                movne   mask, #0

#else

                mov     mask, #0xfc000003

#endif

                tst     mask, r0

                movne   r0, #0

                movs    frame, r0

1:              moveq   r0, #-2

                LOADREGS(eqfd, sp!, {r4 - r8, pc})

2:              stmfd   sp!, {pc}               @ calculate offset of PC in STMIA instruction

                ldr     r0, [sp], #4

                adr     r1, 2b - 4

                sub     offset, r0, r1

3:              tst     frame, mask             @ Check for address exceptions...

                bne     1b

1001:           ldr     next, [frame, #-12]     @ get fp

1002:           ldr     r2, [frame, #-4]        @ get lr

1003:           ldr     r3, [frame, #0]         @ get pc

                sub     save, r3, offset        @ Correct PC for prefetching

                bic     save, save, mask

1004:           ldr     r1, [save, #0]          @ get instruction at function

                mov     r1, r1, lsr #10

                ldr     r3, .Ldsi+4

                teq     r1, r3

                subeq   save, save, #4

                adr     r0, .Lfe

                mov     r1, save

                bic     r2, r2, mask

                bl      printk                  @ print pc and link register

                ldr     r0, [frame, #-8]        @ get sp

                sub     r0, r0, #4

1005:           ldr     r1, [save, #4]          @ get instruction at function+4

                mov     r3, r1, lsr #10

                ldr     r2, .Ldsi+4

                teq     r3, r2                  @ Check for stmia sp!, {args}

                addeq   save, save, #4          @ next instruction

                bleq    .Ldumpstm

                sub     r0, frame, #16

1006:           ldr     r1, [save, #4]          @ Get 'stmia sp!, {rlist, fp, ip, lr, pc}' instruction

                mov     r3, r1, lsr #10

                ldr     r2, .Ldsi

                teq     r3, r2

                bleq    .Ldumpstm

                teq     frame, next

                movne   frame, next

                teqne   frame, #0

                bne     3b

                LOADREGS(fd, sp!, {r4 - r8, pc})

/*

 * Fixup for LDMDB

 */

                .section .fixup,"ax"

                .align  0

1007:           ldr     r0, =.Lbad

                mov     r1, frame

                bl      printk

                LOADREGS(fd, sp!, {r4 - r8, pc})

                .ltorg

                .previous

                .section __ex_table,"a"

                .align  3

                .long   1001b, 1007b

                .long   1002b, 1007b

                .long   1003b, 1007b

                .long   1004b, 1007b

                .long   1005b, 1007b

                .long   1006b, 1007b

                .previous

#define instr r4

#define reg   r5

#define stack r6

.Ldumpstm:      stmfd   sp!, {instr, reg, stack, r7, lr}

                mov     stack, r0

                mov     instr, r1

                mov     reg, #9

                mov     r7, #0

1:              mov     r3, #1

                tst     instr, r3, lsl reg

                beq     2f

                add     r7, r7, #1

                teq     r7, #4

                moveq   r7, #0

                moveq   r3, #'\n'

                movne   r3, #' '

                ldr     r2, [stack], #-4

                mov     r1, reg

                adr     r0, .Lfp

                bl      printk

2:              subs    reg, reg, #1

                bpl     1b

                teq     r7, #0

                adrne   r0, .Lcr

                blne    printk

                mov     r0, stack

                LOADREGS(fd, sp!, {instr, reg, stack, r7, pc})

.Lfe:           .asciz  "Function entered at [<%p>] from [<%p>]\n"

.Lfp:           .asciz  " r%d = %08X%c"

.Lcr:           .asciz  "\n"

.Lbad:          .asciz  "Backtrace aborted due to bad frame pointer <%p>\n"

                .align

.Ldsi:          .word   0x00e92dd8 >> 2

                .word   0x00e92d00 >> 2

#endif