交叉编译环境下gcc编译汇编文件
1、arm-linux-gcc：
首先编写C程序，假设名字为test.c，保存test.c文件内容：
- #include
- int main()
- {
- printf("hello.world!\n");
- return 0;
- }
在X86架构下的电脑上生成ARM架构的汇编代码有两种方式：
1、使用交叉编译工具链：arm-linux-gcc，指定-S选项可以生成汇编中间文件。
2、使用arm-linux-objdump反汇编arm二进制文件。
1、arm-linux-gcc：
首先编写C程序，假设名字为test.c，保存test.c文件内容：
- #include
- int main()
- {
- printf("hello.world!\n");
- return 0;
- }
使用方法如下：
在使用arm-linux-gcc编译C源文件时，使用-S选项可以将C文件（test.c为例）编译到汇编阶段，生成arm汇编代码，使用方式如下：
arm-linux-gcc -march=armv7-a -mtune=cortex-a9 test.c -S -o test.asm
生成arm汇编文件test.asm。
说明：
-march可以指定目标ARM的架构可选参数见（man gcc）
-mtune（类似于-mcpu）可以具体到ARM处理器类型。
注意：
Specifying both -march= and -mcpu= is redundant, and may not in fact have done what you expected in previous compiler versions (maybe even depending on the order in which the arguments were given). The -march switch selects a "generic" ARMv7-A CPU, and -mcpu selects specifically a Cortex-A8 CPU with tuning specific for that core.
Either use "-march=armv7-a -mtune=cortex-a8", or just use "-mcpu=cortex-a8".
Either use "-march=armv7-a -mtune=cortex-a8", or just use "-mcpu=cortex-a8".
所以只用一个-mcpu=cortex-a9也可以
test.asm内容：
-
- 2 .fpu softvfp
- 3 .eabi_attribute 20, 1
- 4 .eabi_attribute 21, 1
- 5 .eabi_attribute 23, 3
- 6 .eabi_attribute 24, 1
- 7 .eabi_attribute 25, 1
- 8 .eabi_attribute 26, 2
- 9 .eabi_attribute 30, 6
- 10 .eabi_attribute 18, 4
- 11 .file "test.c"
- 12 .section .rodata
- 13 .align 2
- 14 .LC0:
- 15 .ascii "hello.world!\000"
- 16 .text
- 17 .align 2
- 18 .global main
- 19 .type main, %function
- 20 main:
- 21 .fnstart
- 22 .LFB2:
- 23 @ Function supports interworking.
- 24 @ args = 0, pretend = 0, frame = 0
- 25 @ frame_needed = 1, uses_anonymous_args = 0
- 26 stmfd sp!, {fp, lr}
- 27 .save {fp, lr}
- 28 .LCFI0:
- 29 .setfp fp, sp, #4
- 30 add fp, sp, #4
- 31 .LCFI1:
- 32 ldr r0, .L3
- 33 bl puts
- 34 mov r3, #0
- 35 mov r0, r3
- 36 sub sp, fp, #4
-
- 37 ldmfd sp!, {fp, lr}
- 38 bx lr
- 39 .L4:
- 40 .align 2
- 41 .L3:
- 42 .word .LC0
- 43 .LFE2:
- 44 .fnend
- 45 .size main, .-main
- 46 .ident "GCC: (Sourcery G++ Lite 2009q1-176) 4.3.3"
- 47 .section .note.GNU-stack,"",%progbits
另外，使用arm-linux-objdump 反汇编过程如下：
（1）交叉编译：
arm-linux-gcc test.c -o test ,生成test二进制文件（此处可以加入-O2选项优化代码：arm-linux-gcc test.c -O2 -o test）
（2）反汇编：
arm-linux-objdump -alD test > test.txt
生成test.txt文件，内容如下：
- test: file format elf32-littlearm
- test
- Disassembly of section .interp:
- 00008134 <.interp>:
- 8134: 62696c2f rsbvs r6, r9, #12032 ; 0x2f00
- 8138: 2d646c2f stclcs 12, cr6, [r4, #-188]!
- 813c: 756e696c strbvc r6, [lr, #-2412]!
- 8140: 6f732e78 svcvs 0x00732e78
- 8144: Address 0x00008144 is out of bounds.
- Disassembly of section .note.ABI-tag:
- 00008148 <.note.ABI-tag>:
- 8148: 00000004 .word 0x00000004
- 814c: 00000010 .word 0x00000010
- 8150: 00000001 .word 0x00000001
- 8154: 00554e47 .word 0x00554e47
- 8158: 00000000 .word 0x00000000
- 815c: 00000002 .word 0x00000002
- 8160: 00000006 .word 0x00000006
- 8164: 0000000e .word 0x0000000e
- Disassembly of section .hash:
- 00008168 <.hash>:
- 8168: 00000003 andeq r0, r0, r3
- 816c: 00000008 andeq r0, r0, r8
- 8170: 00000005 andeq r0, r0, r5
- 8174: 00000006 andeq r0, r0, r6
- 8178: 00000007 andeq r0, r0, r7
- ...
- 8188: 00000002 andeq r0, r0, r2
- 818c: 00000000 andeq r0, r0, r0
- 8190: 00000004 andeq r0, r0, r4
- 8194: 00000003 andeq r0, r0, r3
- 8198: 00000001 andeq r0, r0, r1
- Disassembly of section .dynsym:
- 0000819c <.dynsym>:
- ...
- 81ac: 0000006f andeq r0, r0, pc, rrx
- 81b0: 00008354 andeq r8, r0, r4, asr r3
- 81b4: 00000000 andeq r0, r0, r0
- 81b8: 00000012 andeq r0, r0, r2, lsl r0
- 81bc: 00000075 andeq r0, r0, r5, ror r0
- 81c0: 00008360 andeq r8, r0, r0, ror #6
- 81c4: 00000000 andeq r0, r0, r0
- 81c8: 00000012 andeq r0, r0, r2, lsl r0
- 81cc: 0000000f andeq r0, r0, pc
- ...
- 81d8: 00000012 andeq r0, r0, r2, lsl r0
- 81dc: 00000026 andeq r0, r0, r6, lsr #32
- ...
- 81e8: 00000020 andeq r0, r0, r0, lsr #32
- 81ec: 00000035 andeq r0, r0, r5, lsr r0
- ...
- 81f8: 00000020 andeq r0, r0, r0, lsr #32
- 81fc: 0000006a andeq r0, r0, sl, rrx
- 8200: 00008378 andeq r8, r0, r8, ror r3
- 8204: 00000000 andeq r0, r0, r0
- 8208: 00000012 andeq r0, r0, r2, lsl r0
- 820c: 00000049 andeq r0, r0, r9, asr #32
- ...
- 8218: 00000012 andeq r0, r0, r2, lsl r0
- Disassembly of section .dynstr:
- 0000821c <.dynstr>:
- 821c: 62696c00 rsbvs r6, r9, #0 ; 0x0
- 8220: 5f636367 svcpl 0x00636367
- 8224: 6f732e73 svcvs 0x00732e73
- 8228: 5f00312e svcpl 0x0000312e
- 822c: 6165615f cmnvs r5, pc, asr r1
- 8230: 755f6962 ldrbvc r6, [pc, #-2402] ; 78d6 <_init-0xa5a>
- 8234: 6e69776e cdpvs 7, 6, cr7, cr9, cr14, {3}
- 8238: 70635f64 rsbvc r5, r3, r4, ror #30
- 823c: 72705f70 rsbsvc r5, r0, #448 ; 0x1c0
- 8240: 5f5f0030 svcpl 0x005f0030
- 8244: 6e6f6d67 cdpvs 13, 6, cr6, cr15, cr7, {3}
- 8248: 6174735f cmnvs r4, pc, asr r3
- 824c: 5f5f7472 svcpl 0x005f7472
- 8250: 764a5f00 strbvc r5, [sl], -r0, lsl #30
- 8254: 6765525f undefined
- 8258: 65747369 ldrbvs r7, [r4, #-873]!
- 825c: 616c4372 smcvs 50226
- 8260: 73657373 cmnvc r5, #-872415231 ; 0xcc000001
- 8264: 615f5f00 cmpvs pc, r0, lsl #30
- 8268: 69626165 stmdbvs r2!, {r0, r2, r5, r6, r8, sp, lr}^
- 826c: 776e755f undefined
- 8270: 5f646e69 svcpl 0x00646e69
- 8274: 5f707063 svcpl 0x00707063
- 8278: 00317270 eorseq r7, r1, r0, ror r2
- 827c: 6362696c cmnvs r2, #1769472 ; 0x1b0000
- 8280: 2e6f732e cdpcs 3, 6, cr7, cr15, cr14, {1}
- 8284: 75700036 ldrbvc r0, [r0, #-54]!
- 8288: 61007374 tstvs r0, r4, ror r3
- 828c: 74726f62 ldrbtvc r6, [r2], #-3938
- 8290: 6c5f5f00 mrrcvs 15, 0, r5, pc, cr0
- 8294: 5f636269 svcpl 0x00636269
- 8298: 72617473 rsbvc r7, r1, #1929379840 ; 0x73000000
- 829c: 616d5f74 smcvs 54772
- 82a0: 47006e69 strmi r6, [r0, -r9, ror #28]
- 82a4: 335f4343 cmpcc pc, #201326593 ; 0xc000001
- 82a8: 4700352e strmi r3, [r0, -lr, lsr #10]
- 82ac: 4342494c movtmi r4, #10572 ; 0x294c
- 82b0: 342e325f strtcc r3, [lr], #-607
- ...
- Disassembly of section .gnu.version:
- 000082b6 <.gnu.version>:
- 82b6: 00020000 andeq r0, r2, r0
- 82ba: 00030002 andeq r0, r3, r2
- 82be: 00000000 andeq r0, r0, r0
- 82c2: 00030002 andeq r0, r3, r2
- Disassembly of section .gnu.version_r:
- 000082c8 <.gnu.version_r>:
- 82c8: 00010001 andeq r0, r1, r1
- 82cc: 00000001 andeq r0, r0, r1
- 82d0: 00000010 andeq r0, r0, r0, lsl r0
- 82d4: 00000020 andeq r0, r0, r0, lsr #32
- 82d8: 0b792655 bleq 1e51c34 <__bss_end__+0x1e415ac>
- 82dc: 00030000 andeq r0, r3, r0
- 82e0: 00000087 andeq r0, r0, r7, lsl #1
- 82e4: 00000000 andeq r0, r0, r0
- 82e8: 00010001 andeq r0, r1, r1
- 82ec: 00000060 andeq r0, r0, r0, rrx
- 82f0: 00000010 andeq r0, r0, r0, lsl r0
- 82f4: 00000000 andeq r0, r0, r0
- 82f8: 0d696914 stcleq 9, cr6, [r9, #-80]!
- 82fc: 00020000 andeq r0, r2, r0
- 8300: 0000008f andeq r0, r0, pc, lsl #1
- 8304: 00000000 andeq r0, r0, r0
- Disassembly of section .rel.dyn:
- 00008308 <.rel.dyn>:
- 8308: 00010678 andeq r0, r1, r8, ror r6
- 830c: 00000415 andeq r0, r0, r5, lsl r4
- Disassembly of section .rel.plt:
- 00008310 <.rel.plt>:
- 8310: 00010668 andeq r0, r1, r8, ror #12
- 8314: 00000116 andeq r0, r0, r6, lsl r1
- 8318: 0001066c andeq r0, r1, ip, ror #12
- 831c: 00000216 andeq r0, r0, r6, lsl r2
- 8320: 00010670 andeq r0, r1, r0, ror r6
- 8324: 00000416 andeq r0, r0, r6, lsl r4
- 8328: 00010674 andeq r0, r1, r4, ror r6
- 832c: 00000616 andeq r0, r0, r6, lsl r6
- Disassembly of section .init:
- 00008330 <_init>:
- _init():
- 8330: e92d4010 push {r4, lr}
- 8334: eb000020 bl 83bc
- 8338: e8bd4010 pop {r4, lr}
- 833c: e12fff1e bx lr
- Disassembly of section .plt:
- 00008340 <.plt>:
- 8340: e52de004 push {lr} ; (str lr, [sp, #-4]!)
- 8344: e59fe004 ldr lr, [pc, #4] ; 8350 <_init+0x20>
- 8348: e08fe00e add lr, pc, lr
- 834c: e5bef008 ldr pc, [lr, #8]!
- 8350: 0000830c .word 0x0000830c
- 8354: e28fc600 add ip, pc, #0 ; 0x0
- 8358: e28cca08 add ip, ip, #32768 ; 0x8000
- 835c: e5bcf30c ldr pc, [ip, #780]!
- 8360: e28fc600 add ip, pc, #0 ; 0x0
- 8364: e28cca08 add ip, ip, #32768 ; 0x8000
- 8368: e5bcf304 ldr pc, [ip, #772]!
- 836c: e28fc600 add ip, pc, #0 ; 0x0
- 8370: e28cca08 add ip, ip, #32768 ; 0x8000
- 8374: e5bcf2fc ldr pc, [ip, #764]!
- 8378: e28fc600 add ip, pc, #0 ; 0x0
- 837c: e28cca08 add ip, ip, #32768 ; 0x8000
- 8380: e5bcf2f4 ldr pc, [ip, #756]!
- Disassembly of section .text:
- 00008384 <_start>:
- _start():
- 8384: e59fc024 ldr ip, [pc, #36] ; 83b0 <_start+0x2c>
- 8388: e3a0b000 mov fp, #0 ; 0x0
- 838c: e49d1004 pop {r1} ; (ldr r1, [sp], #4)
- 8390: e1a0200d mov r2, sp
- 8394: e52d2004 push {r2} ; (str r2, [sp, #-4]!)
- 8398: e52d0004 push {r0} ; (str r0, [sp, #-4]!)
- 839c: e59f0010 ldr r0, [pc, #16] ; 83b4 <_start+0x30>
- 83a0: e59f3010 ldr r3, [pc, #16] ; 83b8 <_start+0x34>
- 83a4: e52dc004 push {ip} ; (str ip, [sp, #-4]!)
- 83a8: ebffffec bl 8360 <_init+0x30>
- 83ac: ebffffe8 bl 8354 <_init+0x24>
- 83b0: 00008460 .word 0x00008460
- 83b4: 00008438 .word 0x00008438
- 83b8: 00008464 .word 0x00008464
- 000083bc
: - call_gmon_start():
- 83bc: e59f301c ldr r3, [pc, #28] ; 83e0
- 83c0: e59f201c ldr r2, [pc, #28] ; 83e4
- 83c4: e08f3003 add r3, pc, r3
- 83c8: e7931002 ldr r1, [r3, r2]
- 83cc: e3510000 cmp r1, #0 ; 0x0
- 83d0: e92d4010 push {r4, lr}
- 83d4: 1bffffe4 blne 836c <_init+0x3c>
- 83d8: e8bd4010 pop {r4, lr}
- 83dc: e12fff1e bx lr
- 83e0: 00008290 .word 0x00008290
- 83e4: 0000001c .word 0x0000001c
- 000083e8 <__do_global_dtors_aux>:
- __do_global_dtors_aux():
- 83e8: e59f2010 ldr r2, [pc, #16] ; 8400 <__do_global_dtors_aux+0x18>
- 83ec: e5d23000 ldrb r3, [r2]
- 83f0: e3530000 cmp r3, #0 ; 0x0
- 83f4: 03a03001 moveq r3, #1 ; 0x1
- 83f8: 05c23000 strbeq r3, [r2]
- 83fc: e12fff1e bx lr
- 8400: 00010684 .word 0x00010684
- 00008404
: - frame_dummy():
- 8404: e59f0024 ldr r0, [pc, #36] ; 8430
- 8408: e5903000 ldr r3, [r0]
- 840c: e3530000 cmp r3, #0 ; 0x0
- 8410: e92d4010 push {r4, lr}
- 8414: 0a000003 beq 8428
- 8418: e59f3014 ldr r3, [pc, #20] ; 8434
- 841c: e3530000 cmp r3, #0 ; 0x0
- 8420: 11a0e00f movne lr, pc
- 8424: 112fff13 bxne r3
- 8428: e8bd4010 pop {r4, lr}
- 842c: e12fff1e bx lr
- 8430: 00010568 .word 0x00010568
- 8434: 00000000 .word 0x00000000
- 00008438
: - main():
- 8438: e92d4800 push {fp, lr}
- 843c: e28db004 add fp, sp, #4 ; 0x4
- 8440: e59f0014 ldr r0, [pc, #20] ; 845c
- 8444: ebffffcb bl 8378 <_init+0x48>
- 8448: e3a03000 mov r3, #0 ; 0x0
- 844c: e1a00003 mov r0, r3
- 8450: e24bd004 sub sp, fp, #4 ; 0x4
- 8454: e8bd4800 pop {fp, lr}
- 8458: e12fff1e bx lr
- 845c: 000084e8 .word 0x000084e8
- 00008460 <__libc_csu_fini>:
- __libc_csu_fini():
- 8460: e12fff1e bx lr
- 00008464 <__libc_csu_init>:
- __libc_csu_init():
- 8464: e92d47f0 push {r4, r5, r6, r7, r8, r9, sl, lr}
- 8468: e1a08001 mov r8, r1
- 846c: e1a07002 mov r7, r2
- 8470: e1a0a000 mov sl, r0
- 8474: ebffffad bl 8330 <_init>
- 8478: e59f104c ldr r1, [pc, #76] ; 84cc <__libc_csu_init+0x68>
- 847c: e59f304c ldr r3, [pc, #76] ; 84d0 <__libc_csu_init+0x6c>
- 8480: e59f204c ldr r2, [pc, #76] ; 84d4 <__libc_csu_init+0x70>
- 8484: e0613003 rsb r3, r1, r3
- 8488: e08f2002 add r2, pc, r2
- 848c: e1b05143 asrs r5, r3, #2
- 8490: e0822001 add r2, r2, r1
- 8494: 0a00000a beq 84c4 <__libc_csu_init+0x60>
- 8498: e1a06002 mov r6, r2
- 849c: e3a04000 mov r4, #0 ; 0x0
- 84a0: e1a0000a mov r0, sl
- 84a4: e1a01008 mov r1, r8
- 84a8: e1a02007 mov r2, r7
- 84ac: e796c104 ldr ip, [r6, r4, lsl #2]
- 84b0: e1a0e00f mov lr, pc
- 84b4: e12fff1c bx ip
- 84b8: e2844001 add r4, r4, #1 ; 0x1
- 84bc: e1540005 cmp r4, r5
- 84c0: 3afffff6 bcc 84a0 <__libc_csu_init+0x3c>
- 84c4: e8bd47f0 pop {r4, r5, r6, r7, r8, r9, sl, lr}
- 84c8: e12fff1e bx lr
- 84cc: ffffff04 .word 0xffffff04
- 84d0: ffffff08 .word 0xffffff08
- 84d4: 000081cc .word 0x000081cc
- Disassembly of section .fini:
- 000084d8 <_fini>:
- _fini():
- 84d8: e92d4010 push {r4, lr}
- 84dc: e8bd4010 pop {r4, lr}
- 84e0: e12fff1e bx lr
- Disassembly of section .rodata:
- 000084e4 <_IO_stdin_used>:
- 84e4: 00020001 .word 0x00020001
- 84e8: 6c6c6568 .word 0x6c6c6568
- 84ec: 6f772e6f .word 0x6f772e6f
- 84f0: 21646c72 .word 0x21646c72
- 84f4: 00000000 .word 0x00000000
- Disassembly of section .ARM.extab:
- 000084f8 <.ARM.extab>:
- 84f8: 81019b40 .word 0x81019b40
- 84fc: 8480b0b0 .word 0x8480b0b0
- 8500: 00000000 .word 0x00000000
- Disassembly of section .ARM.exidx:
- 00008504 <.ARM.exidx>:
- 8504: 7fff7afc .word 0x7fff7afc
- 8508: 80b0b0b0 .word 0x80b0b0b0
- 850c: 7ffffe34 .word 0x7ffffe34
- 8510: 00000001 .word 0x00000001
- 8514: 7ffffea8 .word 0x7ffffea8
- 8518: 80a8b0b0 .word 0x80a8b0b0
- 851c: 7ffffecc .word 0x7ffffecc
- 8520: 80b0b0b0 .word 0x80b0b0b0
- 8524: 7ffffee0 .word 0x7ffffee0
- 8528: 80a8b0b0 .word 0x80a8b0b0
- 852c: 7fffff0c .word 0x7fffff0c
- 8530: 7fffffc8 .word 0x7fffffc8
- 8534: 7fffff2c .word 0x7fffff2c
- 8538: 80b0b0b0 .word 0x80b0b0b0
- 853c: 7fffff28 .word 0x7fffff28
- 8540: 80aeb0b0 .word 0x80aeb0b0
- 8544: 7fffff94 .word 0x7fffff94
- 8548: 00000001 .word 0x00000001
- 854c: 7fff7ab4 .word 0x7fff7ab4
- 8550: 80b0b0b0 .word 0x80b0b0b0
- 8554: 7fffff90 .word 0x7fffff90
- 8558: 00000001 .word 0x00000001
- Disassembly of section .eh_frame:
- 0000855c <__FRAME_END__>:
- 855c: 00000000 .word 0x00000000
- Disassembly of section .init_array:
- 00010560 <__frame_dummy_init_array_entry>:
- __init_array_start():
- 10560: 00008404 .word 0x00008404
- Disassembly of section .fini_array:
- 00010564 <__do_global_dtors_aux_fini_array_entry>:
- 10564: 000083e8 .word 0x000083e8
- Disassembly of section .jcr:
- 00010568 <__JCR_END__>:
- 10568: 00000000 .word 0x00000000
- Disassembly of section .dynamic:
- 0001056c <_DYNAMIC>:
- 1056c: 00000001 andeq r0, r0, r1
- 10570: 00000001 andeq r0, r0, r1
- 10574: 00000001 andeq r0, r0, r1
- 10578: 00000060 andeq r0, r0, r0, rrx
- 1057c: 0000000c andeq r0, r0, ip
- 10580: 00008330 andeq r8, r0, r0, lsr r3
- 10584: 0000000d andeq r0, r0, sp
- 10588: 000084d8 ldrdeq r8, [r0], -r8
- 1058c: 00000019 andeq r0, r0, r9, lsl r0
- 10590: 00010560 andeq r0, r1, r0, ror #10
- 10594: 0000001b andeq r0, r0, fp, lsl r0
- 10598: 00000004 andeq r0, r0, r4
- 1059c: 0000001a andeq r0, r0, sl, lsl r0
- 105a0: 00010564 andeq r0, r1, r4, ror #10
- 105a4: 0000001c andeq r0, r0, ip, lsl r0
- 105a8: 00000004 andeq r0, r0, r4
- 105ac: 00000004 andeq r0, r0, r4
- 105b0: 00008168 andeq r8, r0, r8, ror #2
- 105b4: 00000005 andeq r0, r0, r5
- 105b8: 0000821c andeq r8, r0, ip, lsl r2
- 105bc: 00000006 andeq r0, r0, r6
- 105c0: 0000819c muleq r0, ip, r1
- 105c4: 0000000a andeq r0, r0, sl
- 105c8: 00000099 muleq r0, r9, r0
- 105cc: 0000000b andeq r0, r0, fp
- 105d0: 00000010 andeq r0, r0, r0, lsl r0
- 105d4: 00000015 andeq r0, r0, r5, lsl r0
- 105d8: 00000000 andeq r0, r0, r0
- 105dc: 00000003 andeq r0, r0, r3
- 105e0: 0001065c andeq r0, r1, ip, asr r6
- 105e4: 00000002 andeq r0, r0, r2
- 105e8: 00000020 andeq r0, r0, r0, lsr #32
- 105ec: 00000014 andeq r0, r0, r4, lsl r0
- 105f0: 00000011 andeq r0, r0, r1, lsl r0
- 105f4: 00000017 andeq r0, r0, r7, lsl r0
- 105f8: 00008310 andeq r8, r0, r0, lsl r3
- 105fc: 00000011 andeq r0, r0, r1, lsl r0
- 10600: 00008308 andeq r8, r0, r8, lsl #6
- 10604: 00000012 andeq r0, r0, r2, lsl r0
- 10608: 00000008 andeq r0, r0, r8
- 1060c: 00000013 andeq r0, r0, r3, lsl r0
- 10610: 00000008 andeq r0, r0, r8
- 10614: 6ffffffe svcvs 0x00fffffe
- 10618: 000082c8 andeq r8, r0, r8, asr #5
- 1061c: 6fffffff svcvs 0x00ffffff
- 10620: 00000002 andeq r0, r0, r2
- 10624: 6ffffff0 svcvs 0x00fffff0
- 10628: 000082b6 strheq r8, [r0], -r6
- ...
- Disassembly of section .got:
- 0001065c <_GLOBAL_OFFSET_TABLE_>:
- 1065c: 0001056c andeq r0, r1, ip, ror #10
- ...
- 10668: 00008340 andeq r8, r0, r0, asr #6
- 1066c: 00008340 andeq r8, r0, r0, asr #6
- 10670: 00008340 andeq r8, r0, r0, asr #6
- 10674: 00008340 andeq r8, r0, r0, asr #6
- 10678: 00000000 andeq r0, r0, r0
- Disassembly of section .data:
- 0001067c <__data_start>:
- __data_start():
- 1067c: 00000000 .word 0x00000000
- 00010680 <__dso_handle>:
- 10680: 00000000 .word 0x00000000
- Disassembly of section .bss:
- 00010684
: - 10684: 00000000 andeq r0, r0, r0
- Disassembly of section .ARM.attributes:
- 00000000 <.ARM.attributes>:
- 0: 00002541 andeq r2, r0, r1, asr #10
- 4: 61656100 cmnvs r5, r0, lsl #2
- 8: 01006962 tsteq r0, r2, ror #18
- c: 0000001b andeq r0, r0, fp, lsl r0
- 10: 00543405 subseq r3, r4, r5, lsl #8
- 14: 01080206 tsteq r8, r6, lsl #4
- 18: 04120109 ldreq r0, [r2], #-265
- 1c: 01150114 tsteq r5, r4, lsl r1
- 20: 01180317 tsteq r8, r7, lsl r3
- 24: Address 0x00000024 is out of bounds.
- Disassembly of section .comment:
- 00000000 <.comment>:
- 0: 43434700 movtmi r4, #14080 ; 0x3700
- 4: 5328203a teqpl r8, #58 ; 0x3a
- 8: 6372756f cmnvs r2, #465567744 ; 0x1bc00000
- c: 20797265 rsbscs r7, r9, r5, ror #4
- 10: 202b2b47 eorcs r2, fp, r7, asr #22
- 14: 6574694c ldrbvs r6, [r4, #-2380]!
- 18: 30303220 eorscc r3, r0, r0, lsr #4
- 1c: 2d317139 ldfcss f7, [r1, #-228]!
- 20: 29363731 ldmdbcs r6!, {r0, r4, r5, r8, r9, sl, ip, sp}
- 24: 332e3420 teqcc lr, #536870912 ; 0x20000000
- 28: Address 0x00000028 is out of bounds.
- Disassembly of section .debug_frame:
- 00000000 <.debug_frame>:
- 0: 0000000c andeq r0, r0, ip
- 4: ffffffff undefined instruction 0xffffffff
- 8: 7c010001 stcvc 0, cr0, [r1], {1}
- c: 000d0c0e andeq r0, sp, lr, lsl #24
- 10: 0000000c andeq r0, r0, ip
- 14: 00000000 andeq r0, r0, r0
- 18: 00008460 andeq r8, r0, r0, ror #8
- 1c: 00000004 andeq r0, r0, r4
- 20: 00000020 andeq r0, r0, r0, lsr #32
- 24: 00000000 andeq r0, r0, r0
- 28: 00008464 andeq r8, r0, r4, ror #8
- 2c: 00000074 andeq r0, r0, r4, ror r0
- 30: 8e200e44 cdphi 14, 2, cr0, cr0, cr4, {2}
- 34: 89028a01 stmdbhi r2, {r0, r9, fp, pc}
- 38: 87048803 strhi r8, [r4, -r3, lsl #16]
- 3c: 85068605 strhi r8, [r6, #-1541]
- 40: 00088407 andeq r8, r8, r7, lsl #8
对比使用-S选项生成的test.asm和反汇编生成的test.txt的区别为：
（1）反汇编可以生成ARM指令操作码，-S生成的汇编没有指令码
（2）反汇编的代码是经过编译器优化过的。
（3）反汇编代码量很大。