# Section (.data .text .bss)

## 在Nasm檔案中分為三個區塊。

會用以下來區分。

```
section .data
.....

section .text
.....

section .bss
....
```

### .data

此區塊主要用來定義常數與初始化的值

```
section .data

  filename db "this.txt"
```

### .bss

可用來保存變數。

```
section .bss

  variable: resb 4
```

> 上面這段代表宣告了一個變數名為variable，含有4 bytes。

之後可以用類似如下方法，把某個暫存器的值移到該變數。

```
mov [variable], eax
```

或是將變數移回暫存器

```
mov eax, [variable]
```

<https://stackoverflow.com/a/8145374>

### .text

此區段為主要的程式碼區塊。

```
section.text
   global _start
_start:
 .....
```

## 註解

使用分號來代表註解。

```
add eax, ebx   ; 分號後面是註解 adds ebx to eax
```


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