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/*

**      Called as start(argc, argv, envp)

*/

/*      gs:edx points to prog_info structure.  All other registers are OBSOLETE

**      but included for backwards compatibility

*/

/* These symbols are for global constructors and destructors */

#if 0

        .section        .ctor

        .globl          ___go32_first_ctor

___go32_first_ctor:

        .section        .dtor

        .globl          ___go32_last_ctor

___go32_last_ctor:

        .globl          ___go32_first_dtor

___go32_first_dtor:

        .data

        .globl          ___go32_last_dtor

___go32_last_dtor:

#endif

        .text

        .globl  _start

_start:

        .globl  start

start:

#ifdef EMU387

        pusha

        push    %gs

#endif

        movl    %eax,__hard_master

        movl    %esi,___pid

        movl    %edi,___transfer_buffer

        movl    %ebx,_ScreenPrimary

        movl    %ebp,_ScreenSecondary

        cmpl    $0, %edx

        je      Lcopy_none

        movw    %gs,%cx

        movw    %ds,%ax

        cmpw    %cx,%ax

        je      Lcopy_none

        movl    %gs:(%edx), %ecx

        cmpl    __go32_info_block, %ecx

        jbe     Lcopy_less

        movl    __go32_info_block, %ecx

Lcopy_less:

        movl    $__go32_info_block, %edi

        addl    $3, %ecx

        andl    $0xfffffffc, %ecx

        movl    %ecx, (%edi)

        addl    $4, %edi

        addl    $4, %edx

        subl    $4, %ecx

Lcopy_more:

        movl    %gs:(%edx), %eax

        movl    %eax, (%edi)

        addl    $4, %edx

        addl    $4, %edi

        subl    $4, %ecx

        jnz     Lcopy_more

        movl    __go32_info_block+4, %eax

        movl    %eax, _ScreenPrimary

        movl    __go32_info_block+8, %eax

        movl    %eax, _ScreenSecondary

/* Backward compatibility - do not copy this one!

**      movl    __go32_info_block+12, %eax

**      movl    %eax, ___transfer_buffer

*/

        movl    __go32_info_block+20, %eax

        movl    %eax, ___pid

        movl    __go32_info_block+24, %eax

        movl    %eax, __hard_master

        jmp     Lcopy_done

Lcopy_none:

        movl    %ebx,__go32_info_block+4

        movl    %ebp,__go32_info_block+8

        movl    %edi,__go32_info_block+12

        movl    $4096,__go32_info_block+16

        movl    %esi,__go32_info_block+20

        movl    %eax,__go32_info_block+24

        movl    $28, __go32_info_block

Lcopy_done:

#ifndef EMU387

        call    __setstack

#endif

        xorl    %esi,%esi

        xorl    %edi,%edi

        xorl    %ebp,%ebp

        xorl    %ebx,%ebx

        movl    %esp,%ebx

#ifdef MAKE_GCRT0

        call    mcount_init /* initialize the profiler */

#endif

        movl    8(%ebx),%eax

        pushl   %eax

        movl    %eax,_environ

        pushl   4(%ebx)

        pushl   (%ebx)

        call    ___main

        call    _main

        addl    $12,%esp

#ifdef EMU387

        pop     %gs

        popa

#else

        pushl   %eax

        call    _exit

exit_again:

        movl    $0x4c00,%eax

        int     $0x21

        jmp     exit_again

#endif

        ret

#ifdef MAKE_GCRT0

        .globl  __exit

__exit:

        call    mcount_write /* make sure we dump the output */

exit_again2:

        movb    4(%esp),%al

        movb    $0x4c,%ah

        int     $0x21

        jmp     exit_again2

/* Here is where we initialize the timer interrupt - specific to go32 */

/* In this case, the timer calls mcount_isr */

        .globl  mcount_isr_init

mcount_isr_init:

        movw    __go32_info_block+36, %ax       /* run mode */

        cmp     $1,%ax

        jb      skip_mcount

        cmp     $3,%ax

        ja      skip_mcount

        movw    $16,%ax

        movw    %ax,%gs

        movzbl  __hard_master,%eax      /* timer is on irq 0 */

        shll    $3,%eax /* times 8 bpv */

/*      movl    $960,%eax          vector 0x78 * 8 bpv */

        movw    %gs:(%eax),%cx

        movw    %cx,mc_chain

        movw    %gs:6(%eax),%cx

        movw    %cx,mc_chain_hi

        movw    %gs:2(%eax),%cx

        movw    %cx,mc_chain_sel

        movl    $mcount_isr,%ecx

        movw    %cx,%gs:(%eax)

        movw    $0xd8,%gs:2(%eax)       /* selector 27 == 32-bit code */

        movw    $0x8f00,%gs:4(%eax)

        rorl    $16,%ecx

        movw    %cx,%gs:6(%eax)

        movw    %ds,%ax

        movw    %ax,%gs

skip_mcount:

        movl    mcount_histogram,%eax

        movl    $1,(%eax)

        ret

/* Obtain the PC where we interrupted, and bump the histogram.  We should  */

/* do error checking here, but we don't.  This routine is specific to go32 */

/* in some spots */

mcount_isr:

        pushl   %eax

        cmpl    $1,mcount_skip

        je      L0

        movl    4(%esp),%eax /* get the PC */

        subl    $0x1020,%eax /* to fit in low..high */

        andl    $0xfffffffc,%eax

        shrl    $1,%eax /* now points to one 4-byte entry */

        addl    mcount_histogram,%eax

        incw    (%eax)

L0:

        popl    %eax

        ljmp    mc_chain /* chain to the next timer vector */

        iret

#endif

        .data

        .globl  _environ

_environ:

        .long   0

        .globl  ___pid

___pid:

        .long   42

        .globl  ___transfer_buffer

___transfer_buffer:

        .long   0

        .globl  _ScreenPrimary

_ScreenPrimary:

        .long   0

        .globl  _ScreenSecondary

_ScreenSecondary:

        .long   0

        .globl  __hard_master

        .globl  __hard_slave

        .globl  __core_select

__hard_master:

        .byte   0

__hard_slave:

        .byte   0

__core_select:

        .short  0

#ifdef MAKE_GCRT0

mc_chain:

        .short  0

mc_chain_hi:

        .short  0

mc_chain_sel:

        .short  0

#endif