我正在尝试获得类似的东西
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我已经学会了如何创建一个循环，并多次尝试调整同一代码以使用该循环，但都失败了。以下是我迄今为止写的代码
[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，我在上的行开始时得到了标签或指令
1dot db '*', 13,10,0
3dot db '*',13,10,0
etc..
有人能指导我如何将dotsLoop用于多个实例吗？
1dot db '*',13,10,0 3dot db '*',13,10,0 5dot db '*',13,10,0 7dot db '*',13,10,0 9dot db '*',13,10,0 branchdot1 db '*',13,10,0 branchdot2 db '*',13,10,0
就像Michael Petch在评论中所写的那样，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寄存器将产生您所需要的所有差异
此外，为了在程序中正确操作，您需要从生产线上移除回车和换行对
剩下的就是：
dot db '*', 0
fourSpace db ' ',0 ; For spacing threeSpace db ' ',0 ; For spacing twoSpace db ' ',0 ; For spacing oneSpace db ' ',0 ; For spacing branchThreeSpace1 db ' ',0 ; For spacing branchThreeSpace2 db ' ',0 ; For spacing
这里，你也在重复自己6次！同样重要的是，您没有输出所需数量的空格！每次你写4个空格，这样就不会产生圣诞树。
你所需要的只是：
fourSpace db ' '
threeSpace db ' '
twoSpace db ' '
oneSpace db ' ', 0
threeSpace和branchThreeSpace1或BranchThreeSpace 2之间真的没有区别。它们都应该精确输出3个空格字符。
有人能指导我如何将dotsLoop用于多个实例吗？
将以上内容应用于您的代码，您会发现它会起作用：
...
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
...