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gasm与nasm比较

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gasm与nasm比较

gasm: AT&T语法
nasm: Intel语法

原始c文件

note02_21_assembly.c

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#include <stdio.h>
#include <stdlib.h>
int global = 100;
int main(int argc, char const *argv[])  
{
	int stack;
	static int BSS = 100;
	int *p = (int *)malloc(2 * sizeof(int));
	p[1] = 100;
	p[0] = 0;
	printf("Good");
	return 0;
}

gasm汇编c得到s文件

gasm汇编c得到s文件

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dassein@pad:~/nasm_pjt$ gcc -E note02_21_assembly.c > note02_21_assembly.i
dassein@pad:~/nasm_pjt$ gcc -S note02_21_assembly.i
dassein@pad:~/nasm_pjt$ gcc -c note02_21_assembly.s
dassein@pad:~/nasm_pjt$ gcc note02_21_assembly.o -o note02_21_assembly
dassein@pad:~/nasm_pjt$ ./note02_21_assembly

note02_21_assembly.s

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	.file	"note02_21_assembly.c"
	.globl	global
	.data
	.align 4
	.type	global, @object
	.size	global, 4
global:
	.long	100
	.section	.rodata
.LC0:
	.string	"Good"
	.text
	.globl	main
	.type	main, @function
main:
    mov ebp, esp; for correct debugging
    mov rbp, rsp; for correct debugging
    mov ebp, esp; for correct debugging
    movq %rsp, %rbp #for correct debugging
    movl %esp, %ebp #for correct debugging
.LFB2:
	.cfi_startproc
	pushq	%rbp
	.cfi_def_cfa_offset 16
	.cfi_offset 6, -16
	movq	%rsp, %rbp
	.cfi_def_cfa_register 6
	subq	$32, %rsp
	movl	%edi, -20(%rbp)
	movq	%rsi, -32(%rbp)
	movl	$8, %edi
	call	malloc@PLT
	movq	%rax, -8(%rbp)
	movq	-8(%rbp), %rax
	addq	$4, %rax
	movl	$100, (%rax)
	movq	-8(%rbp), %rax
	movl	$0, (%rax)
	leaq	.LC0(%rip), %rdi
	movl	$0, %eax
	call	printf@PLT
	movl	$0, %eax
	leave
	.cfi_def_cfa 7, 8
	ret
	.cfi_endproc
.LFE2:
	.size	main, .-main
	.data
	.align 4
	.type	BSS.2711, @object
	.size	BSS.2711, 4
BSS.2711:
	.long	100
	.ident	"GCC: (Ubuntu 6.2.0-5ubuntu12) 6.2.0 20161005"
	.section	.note.GNU-stack,"",@progbits

nasm反汇编程序文件得到asm文件

先把objconv程序放到/bin中, 供cmd使用obconv
disassemble to NASM syntax .asm file

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objconv -fnasm note02_21_assembly note02_21_assembly.asm

note02_21_assembly.asm

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	.file	"note02_21_assembly.c"
	.intel_syntax noprefix
	.globl	global
	.data
	.align 4
	.type	global, @object
	.size	global, 4
global:
	.long	100
	.section	.rodata
.LC0:
	.string	"Good"
	.text
	.globl	main
	.type	main, @function
main:
.LFB2:
	.cfi_startproc
	push	rbp
	.cfi_def_cfa_offset 16
	.cfi_offset 6, -16
	mov	rbp, rsp
	.cfi_def_cfa_register 6
	sub	rsp, 32
	mov	DWORD PTR -20[rbp], edi
	mov	QWORD PTR -32[rbp], rsi
	mov	edi, 8
	call	malloc@PLT
	mov	QWORD PTR -8[rbp], rax
	mov	rax, QWORD PTR -8[rbp]
	add	rax, 4
	mov	DWORD PTR [rax], 100
	mov	rax, QWORD PTR -8[rbp]
	mov	DWORD PTR [rax], 0
	lea	rdi, .LC0[rip]
	mov	eax, 0
	call	printf@PLT
	mov	eax, 0
	leave
	.cfi_def_cfa 7, 8
	ret
	.cfi_endproc
.LFE2:
	.size	main, .-main
	.data
	.align 4
	.type	BSS.2711, @object
	.size	BSS.2711, 4
BSS.2711:
	.long	100
	.ident	"GCC: (Ubuntu 6.2.0-5ubuntu12) 6.2.0 20161005"
	.section	.note.GNU-stack,"",@progbits

objdump反汇编程序文件

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$objdump -d note02_21_assembly > note02_21_assembly.txt # 简单反汇编, 信息传给note02_21_obj.txt

note02_21_obj.txt
可以看到main段几乎和intel gasm的asm文件完全一致

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note02_21_assembly:     file format elf64-x86-64


Disassembly of section .init:

0000000000000570 <_init>:
 570:	48 83 ec 08          	sub    $0x8,%rsp
 574:	48 8b 05 5d 0a 20 00 	mov    0x200a5d(%rip),%rax        # 200fd8 <_GLOBAL_OFFSET_TABLE_+0x30>
 57b:	48 85 c0             	test   %rax,%rax
 57e:	74 02                	je     582 <_init+0x12>
 580:	ff d0                	callq  *%rax
 582:	48 83 c4 08          	add    $0x8,%rsp
 586:	c3                   	retq   

Disassembly of section .plt:

0000000000000590 <.plt>:
 590:	ff 35 1a 0a 20 00    	pushq  0x200a1a(%rip)        # 200fb0 <_GLOBAL_OFFSET_TABLE_+0x8>
 596:	ff 25 1c 0a 20 00    	jmpq   *0x200a1c(%rip)        # 200fb8 <_GLOBAL_OFFSET_TABLE_+0x10>
 59c:	0f 1f 40 00          	nopl   0x0(%rax)

Disassembly of section .plt.got:

00000000000005a0 <.plt.got>:
 5a0:	ff 25 22 0a 20 00    	jmpq   *0x200a22(%rip)        # 200fc8 <_GLOBAL_OFFSET_TABLE_+0x20>
 5a6:	66 90                	xchg   %ax,%ax
 5a8:	ff 25 32 0a 20 00    	jmpq   *0x200a32(%rip)        # 200fe0 <_GLOBAL_OFFSET_TABLE_+0x38>
 5ae:	66 90                	xchg   %ax,%ax
 5b0:	ff 25 42 0a 20 00    	jmpq   *0x200a42(%rip)        # 200ff8 <_GLOBAL_OFFSET_TABLE_+0x50>
 5b6:	66 90                	xchg   %ax,%ax

Disassembly of section .text:

00000000000005c0 <_start>:
 5c0:	31 ed                	xor    %ebp,%ebp
 5c2:	49 89 d1             	mov    %rdx,%r9
 5c5:	5e                   	pop    %rsi
 5c6:	48 89 e2             	mov    %rsp,%rdx
 5c9:	48 83 e4 f0          	and    $0xfffffffffffffff0,%rsp
 5cd:	50                   	push   %rax
 5ce:	54                   	push   %rsp
 5cf:	4c 8d 05 da 01 00 00 	lea    0x1da(%rip),%r8        # 7b0 <__libc_csu_fini>
 5d6:	48 8d 0d 63 01 00 00 	lea    0x163(%rip),%rcx        # 740 <__libc_csu_init>
 5dd:	48 8d 3d 0c 01 00 00 	lea    0x10c(%rip),%rdi        # 6f0 <main>
 5e4:	ff 15 e6 09 20 00    	callq  *0x2009e6(%rip)        # 200fd0 <_GLOBAL_OFFSET_TABLE_+0x28>
 5ea:	f4                   	hlt    
 5eb:	0f 1f 44 00 00       	nopl   0x0(%rax,%rax,1)

00000000000005f0 <deregister_tm_clones>:
 5f0:	48 8d 3d 21 0a 20 00 	lea    0x200a21(%rip),%rdi        # 201018 <__TMC_END__>
 5f7:	48 8d 05 21 0a 20 00 	lea    0x200a21(%rip),%rax        # 20101f <__TMC_END__+0x7>
 5fe:	55                   	push   %rbp
 5ff:	48 29 f8             	sub    %rdi,%rax
 602:	48 89 e5             	mov    %rsp,%rbp
 605:	48 83 f8 0e          	cmp    $0xe,%rax
 609:	76 15                	jbe    620 <deregister_tm_clones+0x30>
 60b:	48 8b 05 ae 09 20 00 	mov    0x2009ae(%rip),%rax        # 200fc0 <_GLOBAL_OFFSET_TABLE_+0x18>
 612:	48 85 c0             	test   %rax,%rax
 615:	74 09                	je     620 <deregister_tm_clones+0x30>
 617:	5d                   	pop    %rbp
 618:	ff e0                	jmpq   *%rax
 61a:	66 0f 1f 44 00 00    	nopw   0x0(%rax,%rax,1)
 620:	5d                   	pop    %rbp
 621:	c3                   	retq   
 622:	0f 1f 40 00          	nopl   0x0(%rax)
 626:	66 2e 0f 1f 84 00 00 	nopw   %cs:0x0(%rax,%rax,1)
 62d:	00 00 00 

0000000000000630 <register_tm_clones>:
 630:	48 8d 3d e1 09 20 00 	lea    0x2009e1(%rip),%rdi        # 201018 <__TMC_END__>
 637:	48 8d 35 da 09 20 00 	lea    0x2009da(%rip),%rsi        # 201018 <__TMC_END__>
 63e:	55                   	push   %rbp
 63f:	48 29 fe             	sub    %rdi,%rsi
 642:	48 89 e5             	mov    %rsp,%rbp
 645:	48 c1 fe 03          	sar    $0x3,%rsi
 649:	48 89 f0             	mov    %rsi,%rax
 64c:	48 c1 e8 3f          	shr    $0x3f,%rax
 650:	48 01 c6             	add    %rax,%rsi
 653:	48 d1 fe             	sar    %rsi
 656:	74 18                	je     670 <register_tm_clones+0x40>
 658:	48 8b 05 91 09 20 00 	mov    0x200991(%rip),%rax        # 200ff0 <_GLOBAL_OFFSET_TABLE_+0x48>
 65f:	48 85 c0             	test   %rax,%rax
 662:	74 0c                	je     670 <register_tm_clones+0x40>
 664:	5d                   	pop    %rbp
 665:	ff e0                	jmpq   *%rax
 667:	66 0f 1f 84 00 00 00 	nopw   0x0(%rax,%rax,1)
 66e:	00 00 
 670:	5d                   	pop    %rbp
 671:	c3                   	retq   
 672:	0f 1f 40 00          	nopl   0x0(%rax)
 676:	66 2e 0f 1f 84 00 00 	nopw   %cs:0x0(%rax,%rax,1)
 67d:	00 00 00 

0000000000000680 <__do_global_dtors_aux>:
 680:	80 3d 91 09 20 00 00 	cmpb   $0x0,0x200991(%rip)        # 201018 <__TMC_END__>
 687:	75 27                	jne    6b0 <__do_global_dtors_aux+0x30>
 689:	48 83 3d 67 09 20 00 	cmpq   $0x0,0x200967(%rip)        # 200ff8 <_GLOBAL_OFFSET_TABLE_+0x50>
 690:	00 
 691:	55                   	push   %rbp
 692:	48 89 e5             	mov    %rsp,%rbp
 695:	74 0c                	je     6a3 <__do_global_dtors_aux+0x23>
 697:	48 8b 3d 6a 09 20 00 	mov    0x20096a(%rip),%rdi        # 201008 <__dso_handle>
 69e:	e8 0d ff ff ff       	callq  5b0 <_init+0x40>
 6a3:	e8 48 ff ff ff       	callq  5f0 <deregister_tm_clones>
 6a8:	5d                   	pop    %rbp
 6a9:	c6 05 68 09 20 00 01 	movb   $0x1,0x200968(%rip)        # 201018 <__TMC_END__>
 6b0:	f3 c3                	repz retq 
 6b2:	0f 1f 40 00          	nopl   0x0(%rax)
 6b6:	66 2e 0f 1f 84 00 00 	nopw   %cs:0x0(%rax,%rax,1)
 6bd:	00 00 00 

00000000000006c0 <frame_dummy>:
 6c0:	48 8d 3d 19 07 20 00 	lea    0x200719(%rip),%rdi        # 200de0 <__JCR_END__>
 6c7:	48 83 3f 00          	cmpq   $0x0,(%rdi)
 6cb:	75 0b                	jne    6d8 <frame_dummy+0x18>
 6cd:	e9 5e ff ff ff       	jmpq   630 <register_tm_clones>
 6d2:	66 0f 1f 44 00 00    	nopw   0x0(%rax,%rax,1)
 6d8:	48 8b 05 09 09 20 00 	mov    0x200909(%rip),%rax        # 200fe8 <_GLOBAL_OFFSET_TABLE_+0x40>
 6df:	48 85 c0             	test   %rax,%rax
 6e2:	74 e9                	je     6cd <frame_dummy+0xd>
 6e4:	55                   	push   %rbp
 6e5:	48 89 e5             	mov    %rsp,%rbp
 6e8:	ff d0                	callq  *%rax
 6ea:	5d                   	pop    %rbp
 6eb:	e9 40 ff ff ff       	jmpq   630 <register_tm_clones>

00000000000006f0 <main>:
 6f0:	55                   	push   %rbp
 6f1:	48 89 e5             	mov    %rsp,%rbp
 6f4:	48 83 ec 20          	sub    $0x20,%rsp
 6f8:	89 7d ec             	mov    %edi,-0x14(%rbp)
 6fb:	48 89 75 e0          	mov    %rsi,-0x20(%rbp)
 6ff:	bf 08 00 00 00       	mov    $0x8,%edi
 704:	e8 9f fe ff ff       	callq  5a8 <_init+0x38>
 709:	48 89 45 f8          	mov    %rax,-0x8(%rbp)
 70d:	48 8b 45 f8          	mov    -0x8(%rbp),%rax
 711:	48 83 c0 04          	add    $0x4,%rax
 715:	c7 00 64 00 00 00    	movl   $0x64,(%rax)
 71b:	48 8b 45 f8          	mov    -0x8(%rbp),%rax
 71f:	c7 00 00 00 00 00    	movl   $0x0,(%rax)
 725:	48 8d 3d 98 00 00 00 	lea    0x98(%rip),%rdi        # 7c4 <_IO_stdin_used+0x4>
 72c:	b8 00 00 00 00       	mov    $0x0,%eax
 731:	e8 6a fe ff ff       	callq  5a0 <_init+0x30>
 736:	b8 00 00 00 00       	mov    $0x0,%eax
 73b:	c9                   	leaveq 
 73c:	c3                   	retq   
 73d:	0f 1f 00             	nopl   (%rax)

0000000000000740 <__libc_csu_init>:
 740:	41 57                	push   %r15
 742:	41 56                	push   %r14
 744:	41 89 ff             	mov    %edi,%r15d
 747:	41 55                	push   %r13
 749:	41 54                	push   %r12
 74b:	4c 8d 25 7e 06 20 00 	lea    0x20067e(%rip),%r12        # 200dd0 <__frame_dummy_init_array_entry>
 752:	55                   	push   %rbp
 753:	48 8d 2d 7e 06 20 00 	lea    0x20067e(%rip),%rbp        # 200dd8 <__init_array_end>
 75a:	53                   	push   %rbx
 75b:	49 89 f6             	mov    %rsi,%r14
 75e:	49 89 d5             	mov    %rdx,%r13
 761:	4c 29 e5             	sub    %r12,%rbp
 764:	48 83 ec 08          	sub    $0x8,%rsp
 768:	48 c1 fd 03          	sar    $0x3,%rbp
 76c:	e8 ff fd ff ff       	callq  570 <_init>
 771:	48 85 ed             	test   %rbp,%rbp
 774:	74 20                	je     796 <__libc_csu_init+0x56>
 776:	31 db                	xor    %ebx,%ebx
 778:	0f 1f 84 00 00 00 00 	nopl   0x0(%rax,%rax,1)
 77f:	00 
 780:	4c 89 ea             	mov    %r13,%rdx
 783:	4c 89 f6             	mov    %r14,%rsi
 786:	44 89 ff             	mov    %r15d,%edi
 789:	41 ff 14 dc          	callq  *(%r12,%rbx,8)
 78d:	48 83 c3 01          	add    $0x1,%rbx
 791:	48 39 dd             	cmp    %rbx,%rbp
 794:	75 ea                	jne    780 <__libc_csu_init+0x40>
 796:	48 83 c4 08          	add    $0x8,%rsp
 79a:	5b                   	pop    %rbx
 79b:	5d                   	pop    %rbp
 79c:	41 5c                	pop    %r12
 79e:	41 5d                	pop    %r13
 7a0:	41 5e                	pop    %r14
 7a2:	41 5f                	pop    %r15
 7a4:	c3                   	retq   
 7a5:	90                   	nop
 7a6:	66 2e 0f 1f 84 00 00 	nopw   %cs:0x0(%rax,%rax,1)
 7ad:	00 00 00 

00000000000007b0 <__libc_csu_fini>:
 7b0:	f3 c3                	repz retq 

Disassembly of section .fini:

00000000000007b4 <_fini>:
 7b4:	48 83 ec 08          	sub    $0x8,%rsp
 7b8:	48 83 c4 08          	add    $0x8,%rsp
 7bc:	c3                   	retq