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Format Assembler (NASM Linux64) (#863)

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Thomas Voss 2020-11-06 22:09:48 +01:00 committed by GitHub
parent 3505651409
commit d0586af01e
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1 changed files with 14 additions and 17 deletions
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a/assembler_nasm_linux64.asm
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@ -1,20 +1,17 @@
section .rodata
msg db "Hello World", 0xA ; String to print
len equ $- msg ; Length of string
section .text
global _start ;must be declared for linker (ld)
global _start ; Specify entry point to linker
_start: ;tell linker entry point
_start:
mov eax, 1 ; System call ID (sys_write)
mov edi, eax ; File descriptor (stdout)
mov esi, msg ; Text to print
mov edx, len ; Length of text to print
syscall ; Call kernel
xor eax,eax ;eax:=0
lea edx,[rax+len] ;message length
mov al,1 ;system call number (sys_write)
mov esi,msg ;message to write
mov edi,eax ;file descriptor (stdout)
syscall ;call kernel
xor edi, edi ;return 0 (EXIT_SUCCESS)
lea eax,[rdi+60] ;system call number (sys_exit)
syscall ;call kernel
section .rodata
msg db 'Hello, world!',0xa ;our string
len equ $ - msg ;length of our string
mov eax, 60 ; System call ID (sys_exit)
xor edi, edi ; Error code (EXIT_SUCCESS)
syscall ; Call kernel