1         .code16

     2         .globl code16_start

     3         .globl code16_end

     4 

     5 CS_SEG = 0xf

     6 

     7 code16_start:

     8 

     9         .globl code16_func1

    10 

    11         /* basic test */

    12 code16_func1 = . - code16_start

    13         mov $1, %eax

    14         data32 lret

    15 

    16 /* test push/pop in 16 bit mode */

    17         .globl code16_func2

    18 code16_func2 = . - code16_start

    19         xor %eax, %eax

    20         mov $0x12345678, %ebx

    21         movl %esp, %ecx

    22         push %bx

    23         subl %esp, %ecx

    24         pop %ax

    25         data32 lret

    26 

    27 /* test various jmp opcodes */

    28         .globl code16_func3

    29 code16_func3 = . - code16_start

    30         jmp 1f

    31         nop

    32 1:

    33         mov $4, %eax

    34         mov $0x12345678, %ebx

    35         xor %bx, %bx

    36         jz 2f

    37         add $2, %ax

    38 2:

    39 

    40         call myfunc

    41 

    42         lcall $CS_SEG, $(myfunc2 - code16_start)

    43 

    44         ljmp $CS_SEG, $(myjmp1 - code16_start)

    45 myjmp1_next:

    46 

    47         cs lcall *myfunc2_addr - code16_start

    48 

    49         cs ljmp *myjmp2_addr - code16_start

    50 myjmp2_next:

    51 

    52         data32 lret

    53 

    54 myfunc2_addr:

    55         .short myfunc2 - code16_start

    56         .short CS_SEG

    57 

    58 myjmp2_addr:

    59         .short myjmp2 - code16_start

    60         .short CS_SEG

    61 

    62 myjmp1:

    63         add $8, %ax

    64         jmp myjmp1_next

    65 

    66 myjmp2:

    67         add $16, %ax

    68         jmp myjmp2_next

    69 

    70 myfunc:

    71         add $1, %ax

    72         ret

    73 

    74 myfunc2:

    75         add $4, %ax

    76         lret

    77 

    78 

    79 code16_end: