.init: 08048520 <_init>: 8048520: 53 push %ebx 8048521: 83 ec 08 sub $0x8,%esp 8048524: e8 f7 00 00 00 call 8048620 <__x86.get_pc_thunk.bx> 8048529: 81 c3 d7 1a 00 00 add $0x1ad7,%ebx 804852f: 8b 83 fc ff ff ff mov -0x4(%ebx),%eax 8048535: 85 c0 test %eax,%eax 8048537: 74 05 je 804853e <_init+0x1e> 8048539: e8 42 00 00 00 call 8048580 <__gmon_start__@plt> 804853e: 83 c4 08 add $0x8,%esp 8048541: 5b pop %ebx 8048542: c3 ret Disassembly of section .plt: 08048550 <_ZNSolsEi@plt-0x10>: 8048550: ff 35 04 a0 04 08 pushl 0x804a004 8048556: ff 25 08 a0 04 08 jmp *0x804a008 804855c: 00 00 add %al,(%eax) ... 08048560 <_ZNSolsEi@plt>: 8048560: ff 25 0c a0 04 08 jmp *0x804a00c 8048566: 68 00 00 00 00 push $0x0 804856b: e9 e0 ff ff ff jmp 8048550 <_init+0x30> 08048570 <__cxa_atexit@plt>: 8048570: ff 25 10 a0 04 08 jmp *0x804a010 8048576: 68 08 00 00 00 push $0x8 804857b: e9 d0 ff ff ff jmp 8048550 <_init+0x30> 08048580 <__gmon_start__@plt>: 8048580: ff 25 14 a0 04 08 jmp *0x804a014 8048586: 68 10 00 00 00 push $0x10 804858b: e9 c0 ff ff ff jmp 8048550 <_init+0x30> 08048590 <_ZNSt8ios_base4InitC1Ev@plt>: 8048590: ff 25 18 a0 04 08 jmp *0x804a018 8048596: 68 18 00 00 00 push $0x18 804859b: e9 b0 ff ff ff jmp 8048550 <_init+0x30> 080485a0 <__libc_start_main@plt>: 80485a0: ff 25 1c a0 04 08 jmp *0x804a01c 80485a6: 68 20 00 00 00 push $0x20 80485ab: e9 a0 ff ff ff jmp 8048550 <_init+0x30> 080485b0 <_ZNSt8ios_base4InitD1Ev@plt>: 80485b0: ff 25 20 a0 04 08 jmp *0x804a020 80485b6: 68 28 00 00 00 push $0x28 80485bb: e9 90 ff ff ff jmp 8048550 <_init+0x30> 080485c0 <_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc@plt>: 80485c0: ff 25 24 a0 04 08 jmp *0x804a024 80485c6: 68 30 00 00 00 push $0x30 80485cb: e9 80 ff ff ff jmp 8048550 <_init+0x30> 080485d0 <_ZNSolsEPFRSoS_E@plt>: 80485d0: ff 25 28 a0 04 08 jmp *0x804a028 80485d6: 68 38 00 00 00 push $0x38 80485db: e9 70 ff ff ff jmp 8048550 <_init+0x30> 080485e0 <_ZSt4endlIcSt11char_traitsIcEERSt13basic_ostreamIT_T0_ES6_@plt>: 80485e0: ff 25 2c a0 04 08 jmp *0x804a02c 80485e6: 68 40 00 00 00 push $0x40 80485eb: e9 60 ff ff ff jmp 8048550 <_init+0x30> Disassembly of section .text: 080485f0 <_start>: 80485f0: 31 ed xor %ebp,%ebp 80485f2: 5e pop %esi 80485f3: 89 e1 mov %esp,%ecx 80485f5: 83 e4 f0 and $0xfffffff0,%esp 80485f8: 50 push %eax 80485f9: 54 push %esp 80485fa: 52 push %edx 80485fb: 68 50 88 04 08 push $0x8048850 8048600: 68 e0 87 04 08 push $0x80487e0 8048605: 51 push %ecx 8048606: 56 push %esi 8048607: 68 65 87 04 08 push $0x8048765 804860c: e8 8f ff ff ff call 80485a0 <__libc_start_main@plt> 8048611: f4 hlt 8048612: 66 90 xchg %ax,%ax 8048614: 66 90 xchg %ax,%ax 8048616: 66 90 xchg %ax,%ax 8048618: 66 90 xchg %ax,%ax 804861a: 66 90 xchg %ax,%ax 804861c: 66 90 xchg %ax,%ax 804861e: 66 90 xchg %ax,%ax 08048620 <__x86.get_pc_thunk.bx>: 8048620: 8b 1c 24 mov (%esp),%ebx 8048623: c3 ret 8048624: 66 90 xchg %ax,%ax 8048626: 66 90 xchg %ax,%ax 8048628: 66 90 xchg %ax,%ax 804862a: 66 90 xchg %ax,%ax 804862c: 66 90 xchg %ax,%ax 804862e: 66 90 xchg %ax,%ax 08048630 <deregister_tm_clones>: 8048630: b8 3b a0 04 08 mov $0x804a03b,%eax 8048635: 2d 38 a0 04 08 sub $0x804a038,%eax 804863a: 83 f8 06 cmp $0x6,%eax 804863d: 77 01 ja 8048640 <deregister_tm_clones+0x10> 804863f: c3 ret 8048640: b8 00 00 00 00 mov $0x0,%eax 8048645: 85 c0 test %eax,%eax 8048647: 74 f6 je 804863f <deregister_tm_clones+0xf> 8048649: 55 push %ebp 804864a: 89 e5 mov %esp,%ebp 804864c: 83 ec 18 sub $0x18,%esp 804864f: c7 04 24 38 a0 04 08 movl $0x804a038,(%esp) 8048656: ff d0 call *%eax 8048658: c9 leave 8048659: c3 ret 804865a: 8d b6 00 00 00 00 lea 0x0(%esi),%esi 08048660 <register_tm_clones>: 8048660: b8 38 a0 04 08 mov $0x804a038,%eax 8048665: 2d 38 a0 04 08 sub $0x804a038,%eax 804866a: c1 f8 02 sar $0x2,%eax 804866d: 89 c2 mov %eax,%edx 804866f: c1 ea 1f shr $0x1f,%edx 8048672: 01 d0 add %edx,%eax 8048674: d1 f8 sar %eax 8048676: 75 01 jne 8048679 <register_tm_clones+0x19> 8048678: c3 ret 8048679: ba 00 00 00 00 mov $0x0,%edx 804867e: 85 d2 test %edx,%edx 8048680: 74 f6 je 8048678 <register_tm_clones+0x18> 8048682: 55 push %ebp 8048683: 89 e5 mov %esp,%ebp 8048685: 83 ec 18 sub $0x18,%esp 8048688: 89 44 24 04 mov %eax,0x4(%esp) 804868c: c7 04 24 38 a0 04 08 movl $0x804a038,(%esp) 8048693: ff d2 call *%edx 8048695: c9 leave 8048696: c3 ret 8048697: 89 f6 mov %esi,%esi 8048699: 8d bc 27 00 00 00 00 lea 0x0(%edi,%eiz,1),%edi 080486a0 <__do_global_dtors_aux>: 80486a0: 80 3d cc a0 04 08 00 cmpb $0x0,0x804a0cc 80486a7: 75 13 jne 80486bc <__do_global_dtors_aux+0x1c> 80486a9: 55 push %ebp 80486aa: 89 e5 mov %esp,%ebp 80486ac: 83 ec 08 sub $0x8,%esp 80486af: e8 7c ff ff ff call 8048630 <deregister_tm_clones> 80486b4: c6 05 cc a0 04 08 01 movb $0x1,0x804a0cc 80486bb: c9 leave 80486bc: f3 c3 repz ret 80486be: 66 90 xchg %ax,%ax 080486c0 <frame_dummy>: 80486c0: a1 08 9f 04 08 mov 0x8049f08,%eax 80486c5: 85 c0 test %eax,%eax 80486c7: 74 1f je 80486e8 <frame_dummy+0x28> 80486c9: b8 00 00 00 00 mov $0x0,%eax 80486ce: 85 c0 test %eax,%eax 80486d0: 74 16 je 80486e8 <frame_dummy+0x28> 80486d2: 55 push %ebp 80486d3: 89 e5 mov %esp,%ebp 80486d5: 83 ec 18 sub $0x18,%esp 80486d8: c7 04 24 08 9f 04 08 movl $0x8049f08,(%esp) 80486df: ff d0 call *%eax 80486e1: c9 leave 80486e2: e9 79 ff ff ff jmp 8048660 <register_tm_clones> 80486e7: 90 nop 80486e8: e9 73 ff ff ff jmp 8048660 <register_tm_clones> 080486ed <_Z9whatDoIDov>: 80486ed: 55 push %ebp 80486ee: 89 e5 mov %esp,%ebp 80486f0: 83 ec 38 sub $0x38,%esp 80486f3: c7 45 e0 01 00 00 00 movl $0x1,-0x20(%ebp) 80486fa: c7 45 e4 02 00 00 00 movl $0x2,-0x1c(%ebp) 8048701: c7 45 e8 03 00 00 00 movl $0x3,-0x18(%ebp) 8048708: c7 45 ec 04 00 00 00 movl $0x4,-0x14(%ebp) 804870f: c7 45 f0 05 00 00 00 movl $0x5,-0x10(%ebp) 8048716: 8b 45 e4 mov -0x1c(%ebp),%eax 8048719: 8b 55 e0 mov -0x20(%ebp),%edx 804871c: 01 c2 add %eax,%edx 804871e: 8b 45 e8 mov -0x18(%ebp),%eax 8048721: 01 c2 add %eax,%edx 8048723: 8b 45 ec mov -0x14(%ebp),%eax 8048726: 01 c2 add %eax,%edx 8048728: 8b 45 f0 mov -0x10(%ebp),%eax 804872b: 01 d0 add %edx,%eax 804872d: 89 45 f4 mov %eax,-0xc(%ebp) 8048730: c7 44 24 04 70 88 04 movl $0x8048870,0x4(%esp) 8048737: 08 8048738: c7 04 24 40 a0 04 08 movl $0x804a040,(%esp) 804873f: e8 7c fe ff ff call 80485c0 <_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc@plt> 8048744: 8b 55 f4 mov -0xc(%ebp),%edx 8048747: 89 54 24 04 mov %edx,0x4(%esp) 804874b: 89 04 24 mov %eax,(%esp) 804874e: e8 0d fe ff ff call 8048560 <_ZNSolsEi@plt> 8048753: c7 44 24 04 e0 85 04 movl $0x80485e0,0x4(%esp) 804875a: 08 804875b: 89 04 24 mov %eax,(%esp) 804875e: e8 6d fe ff ff call 80485d0 <_ZNSolsEPFRSoS_E@plt> 8048763: c9 leave 8048764: c3 ret 08048765 <main>: 8048765: 55 push %ebp 8048766: 89 e5 mov %esp,%ebp 8048768: 83 e4 f0 and $0xfffffff0,%esp 804876b: e8 7d ff ff ff call 80486ed <_Z9whatDoIDov> 8048770: b8 00 00 00 00 mov $0x0,%eax 8048775: c9 leave 8048776: c3 ret 08048777 <_Z41__static_initialization_and_destruction_0ii>: 8048777: 55 push %ebp 8048778: 89 e5 mov %esp,%ebp 804877a: 83 ec 18 sub $0x18,%esp 804877d: 83 7d 08 01 cmpl $0x1,0x8(%ebp) 8048781: 75 31 jne 80487b4 <_Z41__static_initialization_and_destruction_0ii+0x3d> 8048783: 81 7d 0c ff ff 00 00 cmpl $0xffff,0xc(%ebp) 804878a: 75 28 jne 80487b4 <_Z41__static_initialization_and_destruction_0ii+0x3d> 804878c: c7 04 24 cd a0 04 08 movl $0x804a0cd,(%esp) 8048793: e8 f8 fd ff ff call 8048590 <_ZNSt8ios_base4InitC1Ev@plt> 8048798: c7 44 24 08 34 a0 04 movl $0x804a034,0x8(%esp) 804879f: 08 80487a0: c7 44 24 04 cd a0 04 movl $0x804a0cd,0x4(%esp) 80487a7: 08 80487a8: c7 04 24 b0 85 04 08 movl $0x80485b0,(%esp) 80487af: e8 bc fd ff ff call 8048570 <__cxa_atexit@plt> 80487b4: c9 leave 80487b5: c3 ret 080487b6 <_GLOBAL__sub_I__Z9whatDoIDov>: 80487b6: 55 push %ebp 80487b7: 89 e5 mov %esp,%ebp 80487b9: 83 ec 18 sub $0x18,%esp 80487bc: c7 44 24 04 ff ff 00 movl $0xffff,0x4(%esp) 80487c3: 00 80487c4: c7 04 24 01 00 00 00 movl $0x1,(%esp) 80487cb: e8 a7 ff ff ff call 8048777 <_Z41__static_initialization_and_destruction_0ii> 80487d0: c9 leave 80487d1: c3 ret 80487d2: 66 90 xchg %ax,%ax 80487d4: 66 90 xchg %ax,%ax 80487d6: 66 90 xchg %ax,%ax 80487d8: 66 90 xchg %ax,%ax 80487da: 66 90 xchg %ax,%ax 80487dc: 66 90 xchg %ax,%ax 80487de: 66 90 xchg %ax,%ax 080487e0 <__libc_csu_init>: 80487e0: 55 push %ebp 80487e1: 57 push %edi 80487e2: 31 ff xor %edi,%edi 80487e4: 56 push %esi 80487e5: 53 push %ebx 80487e6: e8 35 fe ff ff call 8048620 <__x86.get_pc_thunk.bx> 80487eb: 81 c3 15 18 00 00 add $0x1815,%ebx 80487f1: 83 ec 1c sub $0x1c,%esp 80487f4: 8b 6c 24 30 mov 0x30(%esp),%ebp 80487f8: 8d b3 04 ff ff ff lea -0xfc(%ebx),%esi 80487fe: e8 1d fd ff ff call 8048520 <_init> 8048803: 8d 83 fc fe ff ff lea -0x104(%ebx),%eax 8048809: 29 c6 sub %eax,%esi 804880b: c1 fe 02 sar $0x2,%esi 804880e: 85 f6 test %esi,%esi 8048810: 74 27 je 8048839 <__libc_csu_init+0x59> 8048812: 8d b6 00 00 00 00 lea 0x0(%esi),%esi 8048818: 8b 44 24 38 mov 0x38(%esp),%eax 804881c: 89 2c 24 mov %ebp,(%esp) 804881f: 89 44 24 08 mov %eax,0x8(%esp) 8048823: 8b 44 24 34 mov 0x34(%esp),%eax 8048827: 89 44 24 04 mov %eax,0x4(%esp) 804882b: ff 94 bb fc fe ff ff call *-0x104(%ebx,%edi,4) 8048832: 83 c7 01 add $0x1,%edi 8048835: 39 f7 cmp %esi,%edi 8048837: 75 df jne 8048818 <__libc_csu_init+0x38> 8048839: 83 c4 1c add $0x1c,%esp 804883c: 5b pop %ebx 804883d: 5e pop %esi 804883e: 5f pop %edi 804883f: 5d pop %ebp 8048840: c3 ret 8048841: eb 0d jmp 8048850 <__libc_csu_fini> 8048843: 90 nop 8048844: 90 nop 8048845: 90 nop 8048846: 90 nop 8048847: 90 nop 8048848: 90 nop 8048849: 90 nop 804884a: 90 nop 804884b: 90 nop 804884c: 90 nop 804884d: 90 nop 804884e: 90 nop 804884f: 90 nop 08048850 <__libc_csu_fini>: 8048850: f3 c3 repz ret Disassembly of section .fini: 08048854 <_fini>: 8048854: 53 push %ebx 8048855: 83 ec 08 sub $0x8,%esp 8048858: e8 c3 fd ff ff call 8048620 <__x86.get_pc_thunk.bx> 804885d: 81 c3 a3 17 00 00 add $0x17a3,%ebx 8048863: 83 c4 08 add $0x8,%esp 8048866: 5b pop %ebx 8048867: c3 ret
Write, Run & Share Assembly code online using OneCompiler's Assembly online compiler for free. It's one of the robust, feature-rich online compilers for Assembly language. Getting started with the OneCompiler's Assembly compiler is simple and pretty fast. The editor shows sample boilerplate code when you choose language as Assembly and start coding.
Assembly language(asm) is a low-level programming language, where the language instructions will be more similar to machine code instructions.
Every assembler may have it's own assembly language designed for a specific computers or an operating system.
Assembly language requires less execution time and memory. It is more helful for direct hardware manipulation, real-time critical applications. It is used in device drivers, low-level embedded systems etc.
Assembly language usually consists of three sections,
Data section
To initialize variables and constants, buffer size these values doesn't change at runtime.
bss section
To declare variables
text section
_start specifies the starting of this section where the actually code is written.
There are various define directives to allocate space for variables for both initialized and uninitialized data.
variable-name define-directive initial-value
| Define Directive | Description | Allocated Space |
|---|---|---|
| DB | Define Byte | 1 byte |
| DW | Define Word | 2 bytes |
| DD | Define Doubleword | 4 bytes |
| DQ | Define Quadword | 8 bytes |
| DT | Define Ten Bytes | 10 bytes |
| Define Directive | Description |
|---|---|
| RESB | Reserve a Byte |
| RESW | Reserve a Word |
| RESD | Reserve a Doubleword |
| RESQ | Reserve a Quadword |
| REST | Reserve a Ten Bytes |
Constants can be defined using
CONSTANT_NAME EQU regular-exp or value
%assign constant_name value
%define constant_name value
Loops are used to iterate a set of statements for a specific number of times.
mov ECX,n
L1:
;<loop body>
loop L1
where n specifies the no of times loops should iterate.
Procedure is a sub-routine which contains set of statements. Usually procedures are written when multiple calls are required to same set of statements which increases re-usuability and modularity.
procedure_name:
;procedure body
ret