当我将代码块分成另一个函数时，我的代码不起作用。我一直无法弄清楚问题出在哪里。
工作代码片段如下：
; Filename: bootloader.asm
... code omitted ...
call load_kernel ; Load our kernel
call switch_to_pm ; Note that we never return from here.
jmp $ ; Jump here - infinite loop!
%include "print_string.asm"
%include "gdt.asm"
%include "print_string_pm.asm"
%include "switch_to_pm.asm"
%include "disk_load.asm"
[bits 16]
; load_kernel
load_kernel:
mov si, MSG_LOAD_KERNEL ; Print a message to say we are loading the kernel
call print_string
; This block will be moved into a function called disk_load
mov si, DAPACK ; address of "disk address packet"
mov ah, 0x42 ; AL is unused
mov dl, 0x80 ; drive number 0 (OR the drive # with 0x80)
int 0x13
jc disk_error ; Jump only only if the carry flag was set
ret
... code omitted ...
当我将用于将磁盘扇区加载到另一个功能的代码块分开时，它不起作用。更改如下。
; Filename: bootloader.asm
... code omitted ...
[bits 16]
; load_kernel
load_kernel:
mov si, MSG_LOAD_KERNEL ; Print a message to say we are loading the kernel
call print_string
call disk_load ; Code block moved into disk_load function
ret
... code omitted ...
以下是带有disk_load函数的相关文件：
; filename: disk_load.asm
disk_load:
mov si, DAPACK ; address of "disk address packet"
mov ah, 0x42 ; AL is unused
mov dl, 0x80 ; drive number 0 (OR the drive # with 0x80)
int 0x13
jc disk_error ; Jump only only if the carry flag was set
ret
disk_error:
mov si, DISK_ERROR_MSG
call print_string
DISK_ERROR_MSG:
db 'Disk Read Error',0
DAPACK:
db 0x10
db 0
blkcnt: dw 15 ; int 13 resets this to # of blocks actually read/written
db_add: dw 0x1000 ; memory buffer destination address (0:9dd0h)
dw 0 ; in memory page zero
d_lba: dd 1 ; put the lba to read in this spot
dd 0 ; more storage bytes only for big lba's ( > 4 bytes )