Question

i am very new to assembly although i have lots of c and c++ experience. my assembly code is supposed to print hello world like all first programs in a new language. it prints out hello world but also prints out some extra text:

hello world!
.shstrtab.text.data

我的集会方案:

section .text
    global _start       ;for the linker
    
_start:
    mov edx, length     ; message length
    mov ecx, message    ; message to write
    mov ebx, 1      ; file descriptor stdout
    mov eax, 4      ; system call number
    int 0x80    ; call kernel
    
    mov eax, 1  ;system call number for sys_exit to exit program
    int 0x80    ; call kernel
    
section .data
message db "hello world!"
length DD 10

if you know how to fix this also explain why is this happening. thanks.

extra info: i am using nasm assembler with ld linker

Answer 1

因此,问题在于增加篇幅,因为它能够处理长度变量,而不是价值。回答是使用<条码>除代号,[宽]。感谢杰斯特指出:

Answer 2

长度(美元)——信息——时间长度(10天)

Answer 3

我给你正确的法典并作解释。然而,我没有经验告诉你,你的法典为什么不工作。

这里正确的法典:

section .text
    global _start       ;for the linker
    
_start:
    mov edx, length     ; message length
    mov ecx, message    ; message to write
    mov ebx, 1      ; file descriptor stdout
    mov eax, 4      ; system call number
    int 0x80    ; call kernel
    
    mov eax, 1  ;system call number for sys_exit to exit program
    int 0x80    ; call kernel
    
section .data
message db "hello world!"
length equ $-message

在<代码>mesage db “hello universe/code>-<<>>>上,是贴上“hello world>起始地址的标签。

<代码>db系指define byte,用于为标签message分配1个按位次位。

www.un.org/Depts/DGACM/index_spanish.htm TWO VERY CRUCIALTHINGS TO REMEMBER:

Instructions are fetched, decoded and executed 1 AFTER ANOTHER.
Data and Instructions are stored in the same memory.

这就是说,每一封“世界”信都写进了1 AFTER ANOTHER。

页: 1

接着,请上<<>tong>next memory Address,该length equ message。

In length equ $-message - The $ represents the current address. So, you are subtracting the start of string (message) from end of string ($).

这给你留下了长处,甚至不必人工计算或写。

我在你的法典中发现了一个错误,你写道:length DD 10。如今,<代码>length 本应保持<代码>message的长度。

然而,<代码>hello World!12 not 10. 另一件事是<条码>d,意思是<条码>define Double , 通常为4英明,储存时间所需的记忆空间要多得多。您可参考指南。

我希望这一帮助,有一天?

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