1

我的引导加载程序有以下代码：

[org 0x7c00]
KERN_OFFSET equ 0x1000
mov bx, BOOTLOADER_MSG
call print_string
mov [BOOTDISK], dl
mov dl, 0x0 ;0 is for floppy-disk
mov ah, 0x2 ;Read function for the interrupt
mov al, 0x15 ;Read 15 sectors conating kernel
mov ch, 0x0 ;Use cylinder 0
mov cl, 0x2 ;Start from the second sector which contains kernel
mov dh, 0x0 ;Read head 0 
mov bx, KERN_OFFSET
int 0x13
jc disk_error
cmp al, 0x15
jne disk_error
jmp $

disk_error:
mov bx, DISK_ERROR_MSG 
call print_string
jmp $

%include "print_string.asm"

DISK_ERROR_MSG:
db 'Disk Read Error',0

BOOTLOADER_MSG:
db 'Reading Kernel from sector 2',0

BOOTDISK: db 0

times 510-($-$$) db 0
dw 0xaa55

print_string.asm 文件是：

print_string:
pusha
mov ah, 0xe
sub bx, 0x1
print:
add bx, 0x1
mov al, [bx]
int 0x10
cmp al, 0x0
jne print
popa
ret

该程序可以使用 nasm 命令很好地组装，但如果我尝试使用 as86，它会显示很多错误：

00001                                           [org 0x7c00]
00024                                           %include     "print_string.asm"
00027 003B                        44            db 'Disk Read Error',0
***** junk after operands............................^
00030 003C                        52            db 'Reading Kernel   from sector 2',0
***** junk after operands............................^
00034                       0000003E>           times 510-($-$$) db 0
***** illegal label...................................^
00001                                           [org 0x7c00]
00004 0004           E8         0000            call print_string
***** unbound label..................................^
***** relocation impossible......................................^
00017 0030           EB           00            jmp $
***** relocation impossible..........................^
00021 0036           E8         0000            call print_string
***** unbound label..................................^
***** relocation impossible......................................^
00022 0039           EB           00            jmp $
***** relocation impossible..........................^
00024                                           %include   "print_string.asm"
00027 003B                        44            db 'Disk Read Error',0
***** junk after operands............................^
00030 003C                        52            db 'Reading Kernel    from sector 2',0
***** junk after operands............................^
00034                       0000003E>           times 510-($-$$) db 0
***** illegal label...................................^

我想用 16 位机器语言组装这段代码。我可以对这段代码使用 nasm 吗？
另外，为什么这段代码不能用 as86 汇编？

4

0 回答 0