Assembly I'；我正在尝试创建一个引导加载程序，其中圣诞树由星号组成，但我可以'；我不知道如何使用相同的循环打印

我想得到这样的东西

    *
   ***
  *****
 *******
*********
   ***
   ***

我已经学会了如何创建一个循环，并尝试调整相同的代码以多次使用循环，但失败了。下面是到目前为止我编写的代码

[BITS 16] 
[ORG 0x7C00] 
top: 
    ;; Put 0 into ds (data segment) 
    ;; Can't do it directly 
    mov ax,0x0000 
    mov ds,ax 
    ;; si is the location relative to the data segment of the 
    ;; string/char to display 
    mov si, fourSpace
    call writeString
    mov ch, 1 ; mov 1 into the register ch
    call dotsLoop
    mov si, threeSpace
    call writeString
    mov ch, 3 ; mov 3 into the register ch
    call dotsLoop
    mov si, twoSpace
    call writeString
    mov ch, 5 ; mov 5 into the register ch
    call dotsLoop
    mov si, oneSpace
    call writeString
    mov ch, 7 ; mov 7 into the register ch
    call dotsLoop
    mov ch, 9 ; mov 9 into the register ch
    call dotsLoop
    mov si, branchThreeSpace1
    call writeString
    mov ch, 3 ; mov 3 into the register ch
    call dotsLoop
    mov si, branchThreeSpace2
    call writeString
    mov ch, 3 ; mov 3 into the register ch
    call dotsLoop
 
    jmp $ ; Spin 
    
dotsLoop:
    mov si, dot ; print the dot
    call writeString ; See below 
    dec ch ; reduce what is in ch by 1
    cmp ch, 0 ; compare to see if what is store in ch is 0
    jne dotsLoop ; if ch does not contain 0 call dotsLoop again.
    mov si, cr ; print the newline code
    call writeString ; See below 
    ret ; when ch contains 0 return back to main code 
    
    
writeString: 
    mov ah,0x0E ; Display a chacter (as before) 
    mov bh,0x00 
    mov bl,0x07 
nextchar: 
    Lodsb ; Loads [SI] into AL and increases SI by one 
    ;; Effectively "pumps" the string through AL 
    cmp al,0 ; End of the string? 
    jz done 
    int 0x10 ; BIOS interrupt 
    jmp nextchar 
done: 
    ret 
    fourSpace db '    ',0 ; For spacing
    1dot db '*', 13,10,0
    threeSpace db '    ',0 ; For spacing
    3dot db '*',13,10,0
    twoSpace db '    ',0 ; For spacing
    5dot db '*',13,10,0
    oneSpace db '    ',0 ; For spacing
    7dot db '*',13,10,0
    9dot db '*',13,10,0
    branchThreeSpace1 db '    ',0 ; For spacing
    branchdot1 db '*',13,10,0
    branchThreeSpace2 db '    ',0 ; For spacing
    branchdot2 db '*',13,10,0
    times 510-($-$$) db 0
    dw 0xAA55

但是，正如预期的那样，我在这些行的开头得到了预期的标签或指令

1dot db '*', 13,10,0
3dot db '*',13,10,0
etc..

有人能指导我如何在多个实例中使用dotsLoop吗

正如迈克尔·佩奇在评论中所说，NASM标签不能以数字0-9开头。
接下来，因为所有这些行都有相同的内容，所以您不需要重复7次。

CH

寄存器将产生您需要的所有差异。
此外，为了在程序中正确操作，您需要从行中删除回车和换行符对。
剩下的是：

dot db '*', 0

---

在这里，你也重复自己6次！同样重要的是，您没有输出所需的空间数！每次你写4个空格，这样就不会产生圣诞树

您所需要的只是：

fourSpace  db ' '
threeSpace db ' '
twoSpace   db ' '
oneSpace   db ' ', 0

threeSpace和BranchThrespace1或BranchThrespace2之间实际上没有区别。它们都应该精确地输出3个空格字符

---

有人能指导我如何在多个实例中使用dotsLoop吗

将以上内容应用到代码中，您将看到它将起作用：

...
mov  si, fourSpace
call writeString
mov  ch, 1
call dotsLoop
mov  si, threeSpace
call writeString
mov  ch, 3
call dotsLoop
mov  si, twoSpace
call writeString
mov  ch, 5
call dotsLoop
mov  si, oneSpace
call writeString
mov  ch, 7
call dotsLoop
mov  ch, 9
call dotsLoop
mov  si, threeSpace
call writeString
mov  ch, 3
call dotsLoop
mov  si, threeSpace
call writeString
mov  ch, 3
call dotsLoop
jmp  $ 
dotsLoop:
...
writeString: 
...
dot        db '*', 0
fourSpace  db ' '
threeSpace db ' '
twoSpace   db ' '
oneSpace   db ' ', 0
cr         db 13, 10, 0
...

---

不清楚您对循环的要求是什么，但您得到的错误是因为NASM标签不能以数字0-9开头。

cr

字符串缺少其

db

指令。@ecm感谢您报告此错误。更正。

fourSpace  db ' '
threeSpace db ' '
twoSpace   db ' '
oneSpace   db ' ', 0

...
mov  si, fourSpace
call writeString
mov  ch, 1
call dotsLoop
mov  si, threeSpace
call writeString
mov  ch, 3
call dotsLoop
mov  si, twoSpace
call writeString
mov  ch, 5
call dotsLoop
mov  si, oneSpace
call writeString
mov  ch, 7
call dotsLoop
mov  ch, 9
call dotsLoop
mov  si, threeSpace
call writeString
mov  ch, 3
call dotsLoop
mov  si, threeSpace
call writeString
mov  ch, 3
call dotsLoop
jmp  $ 
dotsLoop:
...
writeString: 
...
dot        db '*', 0
fourSpace  db ' '
threeSpace db ' '
twoSpace   db ' '
oneSpace   db ' ', 0
cr         db 13, 10, 0
...