将下面代码排列成正确格式 org 0x7c00start: jmp main ;跳过开头的指令，进入main函数;清屏函数clear_screen: xor ax, axmov es, axmov di, 0mov cx, 80 * 25mov ax, 0x0720rep stoswret ;打印字符串函数print_string: mov ah, 0x0eprint_loop: lodsbcmp al, 0je print_endint 0x10jmp print_loopprint_end: ret ;计算ASCII码总和calculate_sum: xor cx, cxmov si, stringsum_loop: lodsbcmp al, 0je sum_endadd cx, axjmp sum_loopsum_end: ret ;显示ASCII码总和print_sum: mov bx, 10xor cx, cxdiv bxpush axcmp ax, 0jz print_sum_endcall print_sumprint_sum_end: pop axadd al, '0' mov ah, 0x0eint 0x10ret ;主函数main: mov ax, csmov ds, axmov es, axcall clear_screenmov si, stringcall print_stringcall calculate_sumcall print_sum;计算结束，无限循环clihltjmp $ string db "21210929周何昊然", 0times 510-($-$$) db 0dw 0xaa55

下面是正确格式的代码：

org 0x7c00

start:
    jmp main ;跳过开头的指令，进入main函数

;清屏函数
clear_screen:
    xor ax, ax
    mov es, ax
    mov di, 0
    mov cx, 80 * 25
    mov ax, 0x0720
    rep stosw
    ret

;打印字符串函数
print_string:
    mov ah, 0x0e
print_loop:
    lodsb
    cmp al, 0
    je print_end
    int 0x10
    jmp print_loop
print_end:
    ret

;计算ASCII码总和
calculate_sum:
    xor cx, cx
    mov si, string
sum_loop:
    lodsb
    cmp al, 0
    je sum_end
    add cx, ax
    jmp sum_loop
sum_end:
    ret

;显示ASCII码总和
print_sum:
    mov bx, 10
    xor cx, cx
div_loop:
    div bx
    push ax
    cmp ax, 0
    jz print_sum_end
    call print_sum
print_sum_end:
    pop ax
    add al, '0'
    mov ah, 0x0e
    int 0x10
    ret

;主函数
main:
    mov ax, cs
    mov ds, ax
    mov es, ax
    call clear_screen
    mov si, string
    call print_string
    call calculate_sum
    call print_sum

    ;计算结束，无限循环
    cli
    hlt
    jmp $

string db "21210929周何昊然", 0
times 510-($-$$) db 0
dw 0xaa55