Message-Id: <3.0.5.32.19990115132200.00b19da0@ics.u-strasbg.fr>
X-Sender: muller AT ics DOT u-strasbg DOT fr
X-Mailer: QUALCOMM Windows Eudora Pro Version 3.0.5 (32)
Date: Fri, 15 Jan 1999 13:22:00 +0100
To: djgpp-workers AT delorie DOT com
From: Pierre Muller <muller AT cerbere DOT u-strasbg DOT fr>
Subject: Re: dbgcom.c
In-Reply-To: <Pine.A41.4.05.9901130956180.52332-100000@ieva01.lanet.lv>
References: <199901122307 DOT SAA15591 AT envy DOT delorie DOT com>
Mime-Version: 1.0
Content-Type: multipart/mixed; boundary="=====================_916399320==_"
Reply-To: djgpp-workers AT delorie DOT com

--=====================_916399320==_
Content-Type: text/plain; charset="us-ascii"

>> Why can't we just fix the one in libc.a?
>> 
>
>I need to do some fixes there that is only needed for debuggers.
>Also seems I'll have to add additional code there to better support
>keyboard interrupt hooking. I have already some limited support
>of it however debugger still is not getting SIGINT when for example
>Allegro keyboard handler is installed. There is rather easy way how to
>fix this and perhaps exceptn.S is best place where to do this.
>All these changes are not needed for normal programs. Therefore 
>I prefer to have modified version in libdbg.a

  I send you my current version of dbgcom.c

  It has many improvements :

  SIGINT now works correctly on multiple level for me :
   
   gdbpas gdbpas.exe

   run test.exe
  and 
run (running test.exe)

   Crtl-C first stops test.exe so I recieve a message 
  SIGINT in test.exe
  Pressing Ctrl-C again
I come to first level GDB
with SIGINT in gdb.exe !!

  There are several tricks in the file :

  - intercept the changes in app_ds limit
(in particular those with 0xfff limit as they are used in fake exceptions)

  if the limit is 0xfff on an exception I call the app_exception_handler :
  this is needed to reset the forced flags !!

  But I still don't have the fake exception number !!
(it is probably possible to get it from the stack, but this will be 
highly version dependend,

  an easier way would be to store it in a register in djgpp_hw_exception
before calling dpmi function 0008 to set selector limit to 0xfff
but I tried my best not to change exception.S !!


--=====================_916399320==_
Content-Type: text/plain; charset="us-ascii"
Content-Disposition: attachment; filename="Dbgcom.c"

/* $Id: dbgcom.c,v 1.2 1999/01/06 09:30:03 Pierre Exp $ */
/* modified for use with FPC and */
/* exception handling support by Pierre Muller */
/* Copyright (C) 1998 DJ Delorie, see COPYING.DJ for details */
/* Copyright (C) 1997 DJ Delorie, see COPYING.DJ for details */
/* Copyright (C) 1996 DJ Delorie, see COPYING.DJ for details */
/* Copyright (C) 1995 DJ Delorie, see COPYING.DJ for details */
#include <libc/stubs.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <dpmi.h>
#include <crt0.h>
#include <go32.h>
#include <signal.h>
#include <setjmp.h>
#ifndef FPC
#include <debug/dbgcom.h>
#else
#include "dbgcom.h"
#endif /* not FPC */
#include <sys/exceptn.h>
#include <stubinfo.h>
#include <sys/farptr.h>
#include <sys/fsext.h>
#include <io.h>

extern char __libdbg_ident_string[];
static char *id = __libdbg_ident_string;

#define MEM_HANDLE_COUNT	256
#define DESCRIPTOR_COUNT	128
#define DOS_DESCRIPTOR_COUNT	128
#define DPMI_EXCEPTION_COUNT     18
#define DS_SIZE_COUNT           128

#define USE_FSEXT
#define CLOSE_UNREGISTERED_FILES
#define SAVE_FP

#ifdef FPC
#undef CLOSE_UNREGISTERED_FILES
#endif
/* debug splitted into 3 parts */
#define DEBUG_ALL_DBGCOM

#ifdef DEBUG_ALL_DBGCOM
/* general debug infos */
#define DEBUG_DBGCOM
/* files open/close infos */
//#define DEBUG_DBGCOM_FILES
/* exceptions infos */
#define DEBUG_EXCEPTIONS
#endif /* DEBUG_ALL_DBGCOM */

long mem_handles[MEM_HANDLE_COUNT];
unsigned short descriptors[DESCRIPTOR_COUNT];
unsigned short dos_descriptors[DOS_DESCRIPTOR_COUNT];

/* these all need to be static because
  ss can be different from ds in dbgsig !! */
static int excep_stack[1000];
static int errcode,cs,eflags,eip,ss,esp,ret_cs,ret_eip;
static void *cur_pos;
static int child_exception_level;


/* ARGSUSED */
char **
__crt0_glob_function(char *foo)
{
  id = 0;
  return 0;
}

ExternalDebuggerInfo edi;
TSS a_tss;

static jmp_buf jumper;

static int my_ds,my_cs,app_cs,app_exit_cs,app_ds;
static unsigned int app_ds_size[DS_SIZE_COUNT];
static int app_ds_index = 0;
static jmp_buf load_state;

static int nset, breakhandle[4];

static __dpmi_paddr our_handler[DPMI_EXCEPTION_COUNT],app_handler[DPMI_EXCEPTION_COUNT];

#ifdef DEBUG_EXCEPTIONS
typedef
  struct {
   short excp_cs;
   int   excp_eip;
   short excp_nb;
   } texcp_info;

static texcp_info excp_info[20];
static int excp_index;
static int excp_count;
static int redir_excp_count;
#endif

NPX npx;

/* ------------------------------------------------------------------------- */
/* Store the contents of the NPX in the global variable `npx'.  */

#define FPU_PRESENT 0x04

void save_npx (void)
{
#ifdef SAVE_FP
  int i;
  int valid_nb = 0;
  if ((__dpmi_get_coprocessor_status() & FPU_PRESENT) == 0)
    return;
  asm ("inb	$0xa0, %%al
	testb	$0x20, %%al
	jz	1f
	xorb	%%al, %%al
	outb	%%al, $0xf0
	movb	$0x20, %%al
	outb	%%al, $0xa0
	outb	%%al, $0x20
1:
	fnsave	%0
	fwait"
       : "=m" (npx)
       : /* No input */
       : "%eax");
  npx.top = (npx.status & NPX_TOP_MASK) >> NPX_TOP_SHIFT;
  npx.in_mmx_mode = (npx.top == 0);
  for (i=0;i<8;i++)
    {
    /* tag is a array of 8 2 bits that contain info about FPU registers
       st(0) is register(top) and st(1) is register (top+1) ... */
     npx.st_valid[i] = ((npx.tag >> (((npx.top+i) & 7) << 1)) & 3) != 3;
     if (npx.st_valid[i])
       {
        npx.st[i]= * (long double *) &(npx.reg[i]);
        /* On my Pentium II the two last bytes are set to 0xff
           on MMX instructions, but on the Intel docs
           it was only specified that the exponent part
           has all bits set !
           Moreover this are only set if the specific mmx register is used */

        if (npx.reg[i].exponent!=0x7fff)
          if ((npx.tag >> ((((npx.top+i) & 7) << 1)) & 3) == 2)
            npx.in_mmx_mode=0;
       }
     else
       {
        npx.st[i]=0;
        npx.in_mmx_mode=0;
       }
    }
 if (npx.in_mmx_mode)
  for (i=0;i<8;i++)
   {
    npx.mmx[i]= * (long double *) &(npx.reg[i]);
   }
   
  /* asm("frstor %0" : :"m" (npx)); */
  /* if we do this in mmx mode the fpu will be unusable */
#endif
}
/* ------------------------------------------------------------------------- */
/* Reload the contents of the NPX from the global variable `npx'.  */

void load_npx (void)
{
  int i;
  if ((__dpmi_get_coprocessor_status() & FPU_PRESENT) == 0)
    return;
  if (npx.in_mmx_mode)
   {
    /* change reg to mmx */
    for (i=0;i<8;i++)
     if (npx.mmx[i]!= * (long double *) &(npx.reg[i]))
      {
       memcpy(&(npx.reg[i]),&(npx.mmx[i]),10);
      }
   }
  else
   {
    /* change reg to st */
    for (i=0;i<8;i++)
      {
       if ((npx.st_valid[i]) && (npx.st[i]!= * (long double *) &(npx.reg[i])))
         {
          memcpy(&(npx.reg[i]),&(npx.st[i]),10);
         }
      }
   }
  asm ("frstor %0" : "=m" (npx));
}

static int _DPMIsetBreak(unsigned short sizetype, unsigned vaddr)
{
	int handle;

	asm volatile(						       "\n\
	    movw   %1,%%dx						\n\
	    movl   %2,%%ecx						\n\
	    movl   %%ecx,%%ebx						\n\
	    shrl   $16,%%ebx						\n\
	    movw   $0x0b00,%%ax						\n\
	    int    $0x31						\n\
	    jnc    3f							\n\
	    xorl   %%ebx,%%ebx						\n\
	    decl   %%ebx						\n\
	    jmp    1f							\n\
3:          movzwl %%bx,%%ebx						\n\
1:	    movl   %%ebx,%0						\n\
	    "
	    : "=g" (handle)			/* outputs */
	    : "g" (sizetype), "g"  (vaddr)	/* inputs */
	    : "ax", "bx", "cx", "dx"		/* regs used */
	);
	return handle;
}

static int _DPMIcancelBreak(int handle)
{
	unsigned state;

	asm volatile(						       "\n\
	    movl   %1,%%ebx						\n\
	    movw   $0x0b02,%%ax						\n\
	    int    $0x31						\n\
	    jnc    2f							\n\
	    xorl   %%eax,%%eax                                          \n\
2:	    andl   $1,%%eax						\n\
	    pushl  %%eax						\n\
	    movw   $0x0b01,%%ax						\n\
	    int    $0x31						\n\
	    popl   %0							\n\
	    "
	    : "=g" (state)			/* outputs */
	    : "g"  (handle)			/* inputs */
	    : "ax", "bx"			/* regs used */
	);
	return state;
}

/* Can't be static because called in asm below; -O3 inlines if static */
void _set_break_DPMI(void);
void _set_break_DPMI(void)
{
  int i;
  unsigned extract;
  unsigned short sizetype;
  unsigned long vbase;
  
  if(__dpmi_get_segment_base_address(app_ds, &vbase) == -1)
    return;
  extract = edi.dr[7] >> 16;
  nset = 0;

  for(i=0;i<4;i++)
    if( (edi.dr[7] >> (i*2))&3 ) {		/* enabled? */
      sizetype = (extract >> (i*4)) & 3;    /* extract the type */
      if(sizetype == 3) sizetype = 2;       /* convert for DPMI brain damage */
      sizetype = (sizetype << 8) + ((extract >> (i*4+2)) & 3) + 1; /* & size */
      breakhandle[i] = _DPMIsetBreak(sizetype, edi.dr[i]+vbase);
      if(breakhandle[i] == -1)
        printf("Error allocating DPMI breakpoint at address 0x%08lx\n",edi.dr[i]);
      else
        nset++;
    } else
      breakhandle[i] = -1;
  return;
}

/* Can't be static because called in asm below; -O3 inlines if static */
void _clear_break_DPMI(void);
void _clear_break_DPMI(void)
{
  int i,bt;

  if(!nset) {
    edi.dr[6] = 0;
    return;
  }

  bt = 0;
  for(i=3;i>=0;i--) {
    bt = bt << 1;                             /* Shift for next bit */
    if(breakhandle[i] != -1)
      bt |= _DPMIcancelBreak(breakhandle[i]);  /* Set low bit if active */
  }

  edi.dr[6] = bt;
}

static __dpmi_paddr old_i31,old_i21,user_i31,user_i21;
static int user_int_set = 0;
static __dpmi_paddr my_i9,user_i9,hook_i9,my_i8,user_i8;

static void hook_dpmi(void)
{
  int i;
  __dpmi_paddr new_int;
  extern void i21_hook(void),i31_hook(void),__dbgcom_kbd_hdlr(void);

  __dpmi_get_protected_mode_interrupt_vector(0x21, &old_i21);
  __dpmi_get_protected_mode_interrupt_vector(0x31, &old_i31);
  /* Save our current interrupt vectors for the keyboard and the timer */
  __dpmi_get_protected_mode_interrupt_vector(0x09, &my_i9);
  __dpmi_get_protected_mode_interrupt_vector(0x08, &my_i8);

  for (i=0;i<DPMI_EXCEPTION_COUNT;i++)
    {
      __dpmi_get_processor_exception_handler_vector(i,&our_handler[i]);
    }

  asm("mov %%cs,%0" : "=g" (new_int.selector) );
  new_int.offset32 = (unsigned long)i21_hook;
  __dpmi_set_protected_mode_interrupt_vector(0x21, &new_int);
  new_int.offset32 = (unsigned long)i31_hook;
  __dpmi_set_protected_mode_interrupt_vector(0x31, &new_int);
  /* avoid to set the ds limit to 0xfff twice */
  new_int.offset32 = (unsigned long)__dbgcom_kbd_hdlr;
  __dpmi_set_protected_mode_interrupt_vector(0x09, &new_int);

  /* If we have called already unhook_dpmi, the user interrupt
     vectors for the keyboard and the timer are valid. */
  if (user_int_set)
  {
    if ((user_i9.offset32!=new_int.offset32) || (user_i9.selector!=new_int.selector))
      __dpmi_set_protected_mode_interrupt_vector(0x09, &user_i9);
    __dpmi_set_protected_mode_interrupt_vector(0x08, &user_i8);
    __dpmi_set_protected_mode_interrupt_vector(0x21, &user_i21);
    __dpmi_set_protected_mode_interrupt_vector(0x31, &user_i31);
  }
  /*    DONT DO THIS (PM)
    for (i=0;i<DPMI_EXCEPTION_COUNT;i++)
    {
        if (app_handler[i].offset32 && app_handler[i].selector)
        __dpmi_set_processor_exception_handler_vector(i,&app_handler[i]);
    } */
  load_npx();
  /* Crtl-C renders app code unreadable */
  __djgpp_app_DS = app_ds;
}

/* Set an exception handler */
/* stores it into app_handler if selector is app_cs  */

asm("\n\
        .text                                                           \n\
        .align  2,0x90                                                  \n\
_change_exception_handler:                                              \n\
        pushl   %eax                                                    \n\
        push    %es                                                     \n\
        push    %ds                                                     \n\
        .byte   0x2e                                                    \n\
        movw    _my_ds,%ax                                              \n\
        movw    %ax,%ds                                                 \n\
        movw    %ax,%es                                                 \n\
        movzbl %bl,%eax                                                 \n\
        imull  $8,%eax                                                  \n\
        addl  $_app_handler,%eax  /* only retain handlers */            \n\
        cmpw   _app_cs,%cx /* for the main app     */                   \n\
        jne    _not_in_current_app                                      \n\
        movl  %ecx,4(%eax)                                              \n\
        movl  %edx,(%eax)                                               \n\
_not_in_current_app:                                                    \n\
        subl  $_app_handler,%eax /* allways restore our handler */      \n\
        addl  $_our_handler,%eax                                         \n\
        movl  4(%eax),%ecx                                              \n\
        movl (%eax),%edx                                                \n\
        pop   %ds                                                       \n\
        pop   %es                                                       \n\
        popl  %eax                                                      \n\
        ret                                                             \n"
);

/* Get an exception handler */
/* Problem : we must react like the dpmi server */
/* for example win95 refuses call 0x210 so we should also refuse it */
/* otherwise we can get into troubles */
asm("\n\
        .text                                                           \n\
        .align  2,0x90                                                  \n\
_get_exception_handler:                                                 \n\
        pushl   %eax                                                    \n\
	pushf								\n\
	.byte	0x2e							\n\
	lcall	_old_i31						\n\
        popl   %eax                                                     \n\
	jc	Lc31_set_flags_and_iret					\n\
        pushl   %eax                                                    \n\
        push    %es                                                     \n\
        push    %ds                                                     \n\
        .byte   0x2e                                                    \n\
        movw    _my_ds,%ax                                              \n\
        movw    %ax,%ds                                                 \n\
        movw    %ax,%es                                                 \n\
        movzbl %bl,%eax                                                 \n\
        imull  $8,%eax                                                  \n\
        addl  $_app_handler,%eax   /* only retain handlers */           \n\
        cmpw  $0,4(%eax)                                                \n\
        je    _app_exception_not_set /* for the main app */             \n\
        cmpl  $0,(%eax)                                                 \n\
        je    _app_exception_not_set                                    \n\
        movl  (%eax),%edx                                               \n\
        movw  4(%eax),%cx                                               \n\
        pop    %ds                                                      \n\
        pop    %es                                                      \n\
        popl   %eax                                                     \n\
	clc								\n\
        jmp   Lc31_set_flags_and_iret				        \n\
_app_exception_not_set:                                                 \n\
        pop   %ds                                                       \n\
        pop   %es                                                       \n\
        popl  %eax                                                      \n\
        .byte 0x2e                                                      \n\
        ljmp _old_i31                                                   \n\
        ret                                                             \n"
); 

/* Change a handle in the list: EAX is the old handle, EDX is the new */
/* for changing a value, we need our ds, because cs has no write access */
asm(						       			"\n\
	.text								\n\
	.align  2,0x90							\n\
_change_handle:								\n\
	pushl	%ecx							\n\
	xorl	%ecx,%ecx						\n\
CL1:									\n\
	.byte	0x2e 							\n\
	cmpl	%eax,_mem_handles(,%ecx,4)				\n\
	jne	CL2							\n\
	push	%ds							\n\
	.byte	0x2e							\n\
	movw	_my_ds,%ax						\n\
	movw	%ax,%ds							\n\
	movl	%edx,_mem_handles(,%ecx,4)				\n\
	pop	%ds							\n\
	popl	%ecx							\n\
	ret								\n\
CL2:									\n\
	incl	%ecx							\n\
	cmpl	$256,%ecx	/* MEM_HANDLE_COUNT */			\n\
	jl	CL1							\n\
	popl	%ecx							\n\
	ret								\n"
);

/* Change a descriptor in the list: AX is the old, DX is the new */
/* for changing a value, we need our ds, because cs has no write access */
asm(						       			"\n\
	.text								\n\
	.align  2,0x90							\n\
_change_descriptor:							\n\
	pushl	%ecx							\n\
	pushl	%eax							\n\
	xorl	%ecx,%ecx						\n\
CL3:									\n\
	.byte	0x2e 							\n\
	cmpw	%ax,_descriptors(,%ecx,2)				\n\
	jne	CL4							\n\
	push	%ds							\n\
	.byte	0x2e							\n\
	movw	_my_ds,%ax						\n\
	movw	%ax,%ds							\n\
	movw	%dx,_descriptors(,%ecx,2)				\n\
	pop	%ds							\n\
	popl	%eax							\n\
	popl	%ecx							\n\
	ret								\n\
CL4:									\n\
	incl	%ecx							\n\
	cmpl	$128,%ecx	/* DESCRIPTOR_COUNT */			\n\
	jl	CL3							\n\
	popl	%eax							\n\
	popl	%ecx							\n\
	ret								\n"
);

/* Add descriptors to the list: AX is the first, CX is the count */
asm(									"\n\
	.text								\n\
	.align  2,0x90							\n\
_add_descriptors:							\n\
	pushl	%edx							\n\
	pushl	%ecx							\n\
	pushl	%ebx							\n\
	pushl	%eax							\n\
	movw	$0x0003,%ax						\n\
	pushf								\n\
	.byte	0x2e							\n\
	lcall	_old_i31						\n\
	movw	%ax,%bx							\n\
	popl	%eax							\n\
	pushl	%eax							\n\
	movw	%ax,%dx							\n\
	xorw	%ax,%ax							\n\
CL5:									\n\
	call	_change_descriptor					\n\
	addw	%bx,%dx							\n\
	loop	CL5							\n\
	popl	%eax							\n\
	popl	%ebx							\n\
	popl	%ecx							\n\
	popl	%edx							\n\
	ret								\n"
);

/* Change a dos_descriptor in the list: AX is the old, DX is the new */
/* for changing a value, we need our ds, because cs has no write access */
asm(						       			"\n\
	.text								\n\
	.align  2,0x90							\n\
_change_dos_descriptor:							\n\
	pushl	%eax							\n\
	pushl	%ecx							\n\
	xorl	%ecx,%ecx						\n\
CL6:									\n\
	.byte	0x2e 							\n\
	cmpw	%ax,_dos_descriptors(,%ecx,2)				\n\
	jne	CL7							\n\
	push	%ds							\n\
	.byte	0x2e							\n\
	movw	_my_ds,%ax						\n\
	movw	%ax,%ds							\n\
	movw	%dx,_dos_descriptors(,%ecx,2)				\n\
	pop	%ds							\n\
	popl	%ecx							\n\
	popl	%eax							\n\
	ret								\n\
CL7:									\n\
	incl	%ecx							\n\
	cmpl	$128,%ecx	/* DOS_DESCRIPTOR_COUNT */		\n\
	jl	CL6							\n\
	popl	%ecx							\n\
	popl	%eax							\n\
	ret								\n"
);

/* BUGS: We ignore the exception handlers for the child process, so signals
   do not work.  We also disable the hooking of the numeric coprocessor
   HW interrupt. */

/* Watch set selector base, if it is __djgpp_app_DS then reset breakpoints */

/* Watch the following DPMI-functions: (added by RH)  (some by PM)

  0x0000   : __dpmi_allocate_ldt_descriptors
  0x0001   : __dpmi_free_ldt_descriptor
  0x0007   : __dpmi_set_selector_base_address
             hooked because the hardware breakpoints need to be reset
             if we change the base address of __djgpp_app_DS
  0x0008   : __dpmi_set_selector_limit
             hooked for djgpp_hw_exception tracing
  0x000A   : __dpmi_create_alias_descriptor
  
  0x0100   : __dpmi_allocate_dos_memory
  0x0101   : __dpmi_free_dos_memory
  
  0x0202   : __dpmi_get_processor_exception_handler_vector
  0x0203   : __dpmi_set_processor_exception_handler_vector
  0x0205   : __dpmi_set_protected_mode_interrupt
             (int 0x09 and 0x75 rejected)
             Ctrl-C will thus create a SIGINT in the top level
             program but cont will directly return to
             the code before interruption no matter at which level)
             (passing to next would be possible but then we would get a
              interruption in all levels !!)
  0x0210   : __dpmi_get_extended_exception_handler_vector_pm
  0x0212   : __dpmi_set_extended_exception_handler_vector_pm
  
  0x0501   : __dpmi_allocate_memory
  0x0501   : __dpmi_free_memory
  0x0503   : __dpmi_resize_memory
  
*/ 
asm(						       			"\n\
	.text								\n\
	.align  2,0x90							\n\
        .globl  _dbgcom_hook_i31                                        \n\
_dbgcom_hook_i31:                                                       \n\
_i31_hook:								\n\
	cmpw	$0x0000,%ax						\n\
	je	Lc31_alloc_descriptors					\n\
	cmpw	$0x0001,%ax						\n\
	je	Lc31_free_descriptor					\n\
	cmpw	$0x0007,%ax						\n\
	je	Lc31_set_selector_base_address				\n\
	cmpw	$0x0008,%ax						\n\
	je	Lc31_set_selector_limit                                 \n\
        cmpw	$0x000A,%ax						\n\
	je	Lc31_create_alias_descriptor				\n\
	cmpw	$0x0100,%ax						\n\
	je	Lc31_allocate_dos_memory				\n\
	cmpw	$0x0101,%ax						\n\
	je	Lc31_free_dos_memory					\n\
        cmpw    $0x0202,%ax                                             \n\
        je      _get_exception_handler                                  \n\
        cmpw    $0x0203,%ax                                             \n\
        je      Lc31_set_exception_handler                              \n\
	cmpw	$0x0205,%ax						\n\
	je	Lc31_set_protected_mode_interrupt			\n\
        cmpw    $0x0210,%ax                                             \n\
        je      _get_exception_handler                                  \n\
        cmpw    $0x0212,%ax                                             \n\
        je      Lc31_set_exception_handler                              \n\
	cmpw	$0x0501,%ax						\n\
	je	Lc31_alloc_mem						\n\
	cmpw	$0x0502,%ax						\n\
	je	Lc31_free_mem						\n\
	cmpw	$0x0503,%ax						\n\
	je	Lc31_resize_mem						\n\
L_jmp_to_old_i31:                                                       \n\
        .byte	0x2e							\n\
	ljmp	_old_i31						\n\
Lc31_set_flags_and_iret:                                                \n\
        pushl	%eax				                        \n\
	pushf								\n\
	popl	%eax		/* store the right flags for iret */	\n\
	movl	%eax,12(%esp)						\n\
	popl	%eax							\n\
Lc31_iret:                                                              \n\
        iret								\n\
Lc31_set_selector_limit:                                                \n\
	.byte	0x2e							\n\
	cmpw	_app_ds,%bx					        \n\
	jne	L_jmp_to_old_i31					\n\
        pushl   %ds                                                     \n\
        pushl   %eax                                                    \n\
        .byte   0x2e                                                    \n\
        movw    _my_ds,%ax                                              \n\
        movw    %ax,%ds                                                 \n\
        movl    _app_ds_index,%eax                                      \n\
        movw    %cx,_app_ds_size+2(,%eax,4)                             \n\
        movw    %dx,_app_ds_size(,%eax,4)                               \n\
        incl    _app_ds_index                                           \n\
        cmpl    $128,_app_ds_index                                      \n\
        jne     Lc31_index_ok                                           \n\
        movl    $0,_app_ds_index                                        \n\
Lc31_index_ok:                                                          \n\
        popl    %eax                                                    \n\
        popl    %ds                                                     \n\
        jmp     L_jmp_to_old_i31                                        \n\
Lc31_set_selector_base_address:                                         \n\
	.byte	0x2e							\n\
	cmpw	_app_ds,%bx					        \n\
	jne	L_jmp_to_old_i31					\n\
	pushf								\n\
	.byte	0x2e							\n\
	lcall	_old_i31						\n\
	call	___djgpp_save_interrupt_regs				\n\
	call	__clear_break_DPMI					\n\
	call	__set_break_DPMI					\n\
	movl	___djgpp_exception_state_ptr,%eax			\n\
	pushl	(%eax)							\n\
	pushl	%eax							\n\
	call	_longjmp						\n\
Lc31_set_protected_mode_interrupt:                                      \n\
	cmpb	$0x75,%bl						\n\
	je	Lc31_iret						\n\
	//cmpb	$0x09,%bl                                             	\n\
	//je	Lc31_iret						\n\
	jmp	L_jmp_to_old_i31					\n\
Lc31_alloc_mem:								\n\
	pushf								\n\
	.byte	0x2e							\n\
	lcall	_old_i31						\n\
	jc	Lc31_set_flags_and_iret					\n\
	pushf								\n\
	pushl	%edx							\n\
	pushw	%si							\n\
	pushw	%di							\n\
	popl	%edx							\n\
	xorl	%eax,%eax						\n\
	call	_change_handle						\n\
	popl	%edx							\n\
	popf								\n\
	clc								\n\
	jmp	Lc31_set_flags_and_iret					\n\
Lc31_free_mem:								\n\
	pushw	%si							\n\
	pushw	%di							\n\
	pushf								\n\
	.byte	0x2e							\n\
	lcall	_old_i31						\n\
	jc	Lc31_resize_mem_error					\n\
	popl	%eax							\n\
	xorl	%edx,%edx						\n\
	call	_change_handle						\n\
	xorl	%eax,%eax						\n\
	jmp	Lc31_set_flags_and_iret					\n\
Lc31_resize_mem:							\n\
	pushw	%si							\n\
	pushw	%di							\n\
	pushf								\n\
	.byte	0x2e							\n\
	lcall	_old_i31						\n\
	jnc	Lc31_resize_mem_ok					\n\
Lc31_resize_mem_error:							\n\
	addl	$4,%esp							\n\
	stc								\n\
	jmp	Lc31_set_flags_and_iret					\n\
Lc31_resize_mem_ok:							\n\
	popl	%eax							\n\
	pushw	%si							\n\
	pushw	%di							\n\
	popl	%edx							\n\
	call	_change_handle						\n\
	xorl	%eax,%eax						\n\
	jmp	Lc31_set_flags_and_iret					\n\
Lc31_alloc_descriptors:							\n\
	pushl	%ecx							\n\
	pushf								\n\
	.byte	0x2e							\n\
	lcall	_old_i31						\n\
	popl	%ecx							\n\
	jc	Lc31_set_flags_and_iret					\n\
	call	_add_descriptors					\n\
	clc								\n\
	jmp	Lc31_set_flags_and_iret					\n\
Lc31_free_descriptor:							\n\
	pushl	%ebx							\n\
	pushf								\n\
	.byte	0x2e							\n\
	lcall	_old_i31						\n\
	popl	%eax							\n\
	jc	Lc31_set_flags_and_iret					\n\
	xorw	%dx,%dx							\n\
	call	_change_descriptor					\n\
	clc								\n\
	jmp	Lc31_set_flags_and_iret					\n\
Lc31_create_alias_descriptor:						\n\
	pushf								\n\
	.byte	0x2e							\n\
	lcall	_old_i31						\n\
	jc	Lc31_set_flags_and_iret					\n\
	pushl	%eax							\n\
	movw	%ax,%dx							\n\
	xorw	%ax,%ax							\n\
	call	_change_descriptor					\n\
	popl	%eax							\n\
	clc								\n\
	jmp	Lc31_set_flags_and_iret					\n\
Lc31_allocate_dos_memory:						\n\
	pushf								\n\
	.byte	0x2e							\n\
	lcall	_old_i31						\n\
	jc	Lc31_set_flags_and_iret					\n\
	pushl	%eax							\n\
	xorl	%eax,%eax						\n\
	call	_change_dos_descriptor					\n\
	popl	%eax							\n\
	clc								\n\
	jmp	Lc31_set_flags_and_iret					\n\
Lc31_free_dos_memory:							\n\
	pushl	%edx							\n\
	pushf								\n\
	.byte	0x2e							\n\
	lcall	_old_i31						\n\
	popl	%eax							\n\
	jc	Lc31_set_flags_and_iret					\n\
	xorw	%dx,%dx							\n\
	call	_change_dos_descriptor					\n\
	clc								\n\
	jmp	Lc31_set_flags_and_iret					\n\
Lc31_set_exception_handler:                                             \n\
        pushl  %eax                                                     \n\
        pushl  %ebx                                                     \n\
        pushl  %ecx                                                     \n\
        pushl  %edx                                                     \n\
        pushf                                                           \n\
        .byte  0x2e                                                     \n\
        lcall   _old_i31                                                \n\
        popl   %edx                                                     \n\
        popl   %ecx                                                     \n\
        popl   %ebx                                                     \n\
        popl   %eax                                                     \n\
        jc   Lc31_set_flags_and_iret                                    \n\
        call   _change_exception_handler                                \n\
        pushf                                                           \n\
        .byte  0x2e                                                     \n\
        lcall   _old_i31                                                \n\
        jmp Lc31_set_flags_and_iret                                     \n\
	.align  2,0x90							\n\
        .globl  _dbgcom_hook_i21                                        \n\
_dbgcom_hook_i21:                                                       \n\
_i21_hook:								\n\
	cmpb	$0x4c,%ah						\n\
	je	Lc21							\n\
Lc21_jmp_to_old:                                                        \n\
        .byte	0x2e							\n\
	ljmp	_old_i21						\n\
Lc21:	push	%eax							\n\
	movl	8(%esp),%eax						\n\
	cs								\n\
	cmpw	_app_exit_cs,%ax					\n\
	je	Lc21_exit                                               \n\
	cs								\n\
	cmpw	_app_cs,%ax					        \n\
	je	Lc21_exit                                               \n\
	pop	%eax							\n\
        jmp     Lc21_jmp_to_old                                         \n\
Lc21_exit:                                                              \n\
	pop	%eax							\n\
	call	___djgpp_save_interrupt_regs				\n\
	movl	___djgpp_exception_state_ptr,%esi			\n\
	movl	$0x21,56(%esi)						\n\
	movl	$_load_state,%edi					\n\
	movl	$43,%ecx						\n\
	rep								\n\
	movsl								\n\
	pushl	$1							\n\
	pushl	$_jumper						\n\
	call	_longjmp						\n\
	"
	);

/* complete code to return from an exception */
asm (  ".text
       .align 2,0x90
       .globl    _dbgcom_exception_return_complete
_dbgcom_exception_return_complete:       /* remove errorcode from stack */
       //* we must also switch stack back !! */
       //* relative to ebp */
       //* 0 previous ebp */
       //* 4 exception number */
       //* 8 return eip */
       //* 12 return cs */
       //* 16 return eflags */
       //* 20 return esp  */
       //* 24 return ss  */
       //* -4 stored ds */
       //* -8 stored eax */
       //* -12 stored esi */
       pushl  %ebp
       movl   %esp,%ebp
       pushl  %ds
       pushl  %eax
       pushl  %esi
       movl   24(%ebp),%eax
       movw   %ax,%ds
       movl   20(%ebp),%esi
       //* ds:esi points now to app stack */
       subl  $28,%esi
       movl  %esi,20(%ebp)
       //* eflags on app stack */
       movl  16(%ebp),%eax
       movl  %eax,%ds:24(%esi)
       //* cs on app stack */
       movl  12(%ebp),%eax
       movl  %eax,%ds:20(%esi)
       //* eip on app stack */
       movl  8(%ebp),%eax
       movl  %eax,%ds:16(%esi)
       //* esi on app stack */
       movl  -12(%ebp),%eax
       movl  %eax,%ds:12(%esi)
       //* eax on app stack */
       movl  -8(%ebp),%eax
       movl  %eax,%ds:8(%esi)
       //* ds on app_stack */
       movl  -4(%ebp),%eax
       movl  %eax,%ds:4(%esi)
       //* ebp on app_stack */
       movl  (%ebp),%eax
       movl  %eax,%ds:(%esi)
       //* switch stack */
       movl  24(%ebp),%eax
       movw  %ax,%ss
       movl  %esi,%esp
       //* now on app stack */
       popl  %ebp
       popl  %eax
       movw  %ax,%ds
       popl  %eax
       popl  %esi
       iret
    ");

static jmp_buf here;

/* simple code to return from an exception */
asm (  ".text
       .align 2,0x90
       .globl    _dbgcom_exception_return
_dbgcom_exception_return:       /* remove errorcode from stack */
        movl    %cs:___djgpp_our_DS,%eax                                \n\
        movw    %ax,%ds                                                 \n\
        movw    %ax,%es                                                 \n\
	pushl	$1							\n\
	pushl	$_here						        \n\
	call	_longjmp						\n\
        ");
        
/*	movw	%cs:__go32_info_block+26, %fs				\n\
	.byte	0x64							\n\
	movw	$0x7021,0xb0f00						\n\ */

/* do not set limit of ds selector two times */
asm (".text
        .global ___dbgcom_kbd_hdlr
___dbgcom_kbd_hdlr:
        ljmp    %cs:___djgpp_old_kbd");
        
    
    
static void unhook_dpmi(void)
{
  int i;
  /* Crtl-C renders debugger code unreadable */
  __djgpp_app_DS = __djgpp_our_DS;
  save_npx();
  /* save app i31 and i21 if changed */
  __dpmi_get_protected_mode_interrupt_vector(0x31, &user_i31);
  __dpmi_get_protected_mode_interrupt_vector(0x21, &user_i21);
  /* restore i31 and i21 */
  __dpmi_set_protected_mode_interrupt_vector(0x31, &old_i31);
  __dpmi_set_protected_mode_interrupt_vector(0x21, &old_i21);

  /* Save the interrupt vectors for the keyboard and the the
     time, because the debuggee may have changed it. */
  __dpmi_get_protected_mode_interrupt_vector(0x09, &user_i9);
  __dpmi_get_protected_mode_interrupt_vector(0x08, &user_i8);

  /* And remember it for hook_dpmi */
  user_int_set = 1;

  /* Now restore our interrupt vectors */
  __dpmi_set_protected_mode_interrupt_vector(0x09, &my_i9);
  __dpmi_set_protected_mode_interrupt_vector(0x08, &my_i8);
  for (i=0;i<DPMI_EXCEPTION_COUNT;i++)
    {
      if (i!=2)
        __dpmi_set_processor_exception_handler_vector(i,&our_handler[i]);
    }

  asm ("sti");   /* This improve stability under Win9X after SIGINT */
		 /* Why? (AP) */
}

static void call_app_exception(int signum, char complete)
    {
    extern void dbgcom_exception_return(void);
    extern void dbgcom_exception_return_complete(void);
#ifdef DEBUG_EXCEPTIONS
    redir_excp_count++;
#endif
    eip = load_state->__eip;
    cs  = load_state->__cs;
    esp = load_state->__esp;
    ss  = load_state->__ss;
    eflags = load_state->__eflags;
    /* reset the debug trace bit */
    /* we don't want to step inside the exception_table code */
    load_state->__eflags &= 0xfffffeff;
    errcode = load_state->__sigmask;
    load_state->__eip=app_handler[signum].offset32;
    load_state->__cs=app_handler[signum].selector;
    /* use our own exception stack */
    child_exception_level++;
    memset(&excep_stack,0xAB,sizeof(excep_stack));
    cur_pos = &excep_stack[1000-40];
    cur_pos -= 8*4;
    load_state->__ss = my_ds;
    load_state->__esp= (int) cur_pos;
    /* where to return */
    ret_cs = my_cs;
    if (complete)
      ret_eip = (int) &dbgcom_exception_return_complete;
    else
      ret_eip = (int) &dbgcom_exception_return;
    memcpy(cur_pos,&ret_eip,4);
    cur_pos+=4;
    memcpy(cur_pos,&ret_cs,4);
    cur_pos+=4;
    memcpy(cur_pos,&errcode,4);
    cur_pos+=4;
    memcpy(cur_pos,&eip,4);
    cur_pos+=4;
    memcpy(cur_pos,&cs,4);
    cur_pos+=4;
    memcpy(cur_pos,&eflags,4);
    cur_pos+=4;
    memcpy(cur_pos,&esp,4);
    cur_pos+=4;
    memcpy(cur_pos,&ss,4);
    cur_pos+=4;
    longjmp(load_state, load_state->__eax);
    }

static void dbgsig(int sig)
{
  unsigned int ds_size;
  int signum =  __djgpp_exception_state->__signum;
  asm ("movl _app_ds,%%eax
        lsl  %%eax,%%eax
        movl %%eax,%0"
        : "=g" (ds_size) );

  /* correct ds limit here */
  if ((ds_size==0xfff) && (signum==0xc || signum==0xd))
    {
      if (app_ds_index>1)
        {
          /* set the limt correctly */
          __dpmi_set_segment_limit(app_ds,app_ds_size[app_ds_index-2]);
        }
     /* let app restore the ds selector */
     if (!setjmp(here))
      {
       *load_state = *__djgpp_exception_state;     /* exception was in other process */
       load_state->__eip = here->__eip;
       load_state->__esp = here->__esp;
       load_state->__cs = here->__cs;
       load_state->__ss = here->__ss;
       /* do use ss stack
       load_state->__signum = 0xd;
       /* longjmp returns eax value */
       load_state->__eax = 1;
       call_app_exception(__djgpp_exception_state->__signum,0);
      }
     /* I still have no idea how to get the exception number back */
     /* just keep the fake exception value */
     signum=0x1B;
     __djgpp_exception_state->__signum=signum;
    }
  
#ifdef DEBUG_EXCEPTIONS
    excp_info[excp_index].excp_eip=__djgpp_exception_state->__eip;
    excp_info[excp_index].excp_cs=__djgpp_exception_state->__cs;
    excp_info[excp_index].excp_nb=signum;
    excp_index++;
    excp_count++;
    if (excp_index==20)
      excp_index=0;
#endif
  if(__djgpp_exception_state->__cs == app_cs)
     /* || sig == SIGTRAP) */
  {
    *load_state = *__djgpp_exception_state;	/* exception was in other process */
    longjmp(jumper, 1);
  }
  else
  {
    extern int invalid_sel_addr(short sel, unsigned a, unsigned len, char for_write);
    
  if ((signum<DPMI_EXCEPTION_COUNT) &&
     (app_handler[signum].offset32) &&
     (app_handler[signum].selector) &&
      !invalid_sel_addr(app_handler[signum].selector,
        app_handler[signum].offset32,1,0) &&
     ((app_handler[signum].offset32 !=
      our_handler[signum].offset32) ||
     (app_handler[signum].selector !=
      our_handler[signum].selector)))
    {
     *load_state = *__djgpp_exception_state;     /* exception was in other process */
     call_app_exception(signum,1);
    }
   /*  else
     {
      *load_state = *__djgpp_exception_state;
      longjmp(jumper, 1);
     }  */
  }
}

void run_child(void)
{
  /* we should call the exception handlers if an exception is on */
  /* Question : how distinguish exception zero ? */
  load_state->__cs = a_tss.tss_cs;
  load_state->__ss = a_tss.tss_ss;
  load_state->__ds = a_tss.tss_ds;
  load_state->__es = a_tss.tss_es;
  load_state->__fs = a_tss.tss_fs;
  load_state->__gs = a_tss.tss_gs;
  load_state->__eip = a_tss.tss_eip;
  load_state->__eflags = a_tss.tss_eflags;
  load_state->__eax = a_tss.tss_eax;
  load_state->__ebx = a_tss.tss_ebx;
  load_state->__ecx = a_tss.tss_ecx;
  load_state->__edx = a_tss.tss_edx;
  load_state->__esp = a_tss.tss_esp;
  load_state->__ebp = a_tss.tss_ebp;
  load_state->__esi = a_tss.tss_esi;
  load_state->__edi = a_tss.tss_edi;
  if(!setjmp(jumper)){
    extern int invalid_sel_addr(short sel, unsigned a, unsigned len, char for_write);
    /* jump to tss */
    _set_break_DPMI();
    hook_dpmi();
    if ((a_tss.tss_trap == 0xffff) &&
     (a_tss.tss_irqn<DPMI_EXCEPTION_COUNT) &&
     (app_handler[a_tss.tss_irqn].offset32) &&
     (app_handler[a_tss.tss_irqn].selector) &&
      !invalid_sel_addr(app_handler[a_tss.tss_irqn].selector,
        app_handler[a_tss.tss_irqn].offset32,1,0))
      {
       call_app_exception(a_tss.tss_irqn,1);
      }
    else
      longjmp(load_state, load_state->__eax);
    /* we never return here, execption routine will longjump */
  }
  /* exception routine:  save state, copy to tss, return */
  a_tss.tss_cs = load_state->__cs;
  a_tss.tss_ss = load_state->__ss;
  a_tss.tss_ds = load_state->__ds;
  a_tss.tss_es = load_state->__es;
  a_tss.tss_fs = load_state->__fs;
  a_tss.tss_gs = load_state->__gs;
  a_tss.tss_eip = load_state->__eip;
  a_tss.tss_esp = load_state->__esp;
  a_tss.tss_eflags = load_state->__eflags;
  a_tss.tss_eax = load_state->__eax;
  a_tss.tss_ebx = load_state->__ebx;
  a_tss.tss_ecx = load_state->__ecx;
  a_tss.tss_edx = load_state->__edx;
  a_tss.tss_esi = load_state->__esi;
  a_tss.tss_edi = load_state->__edi;
  a_tss.tss_ebp = load_state->__ebp;
  a_tss.tss_irqn = load_state->__signum;
  a_tss.tss_error = load_state->__sigmask;
  a_tss.tss_trap = 0;
  unhook_dpmi();
  _clear_break_DPMI();
}

static int invalid_addr(unsigned a, unsigned len)
{
  /* Here we assume expand up writable code.  We could check the rights to
     be sure, but that's a waste unless *_child routines fixed to know about
     different selectors. */

  unsigned limit;
  limit = __dpmi_get_segment_limit(app_ds);
  if(4096 <= a             /* First page is used for NULL pointer detection. */
  && a <= limit            /* To guard against limit < len. */
  && a - 1 <= limit - len  /* To guard against limit <= a + len - 1. */
     )
    return 0;
/*  printf("Invalid access to child, address %#x length %#x  limit: %#x\n", a, len, limit);
  if (can_longjmp)
    longjmp(debugger_jmpbuf, 1); */
  return 1;
}

int read_child(unsigned child_addr, void *buf, unsigned len)
{
  if (invalid_addr(child_addr, len))
    return 1;
  movedata(app_ds, child_addr, my_ds, (int)buf, len);
  return 0;
}

int write_child(unsigned child_addr, void *buf, unsigned len)
{
  if (invalid_addr(child_addr, len))
    return 1;
  movedata(my_ds, (int)buf, app_ds, child_addr, len);
  return 0;
}

int invalid_sel_addr(short sel, unsigned a, unsigned len, char for_write)
{
  /* Here we assume expand up writable code.  We could check the rights to
     be sure, but that's a waste unless *_child routines fixed to know about
     different selectors. */

  unsigned limit;
  char read_allowed = 0;
  char write_allowed = 0;
  
  asm("
      movw  %2,%%ax
      verr  %%ax
      jnz   .Ldoes_not_has_read_right
      movb  $1,%0
.Ldoes_not_has_read_right:
      verrw %%ax
      jnz   .Ldoes_not_has_write_right
      movb  $1,%1
.Ldoes_not_has_write_right: "
     : "=g" (read_allowed), "=g" (write_allowed)
     : "g" (sel)
     );
  if (for_write)
    {
     if (!write_allowed)
       return 1;
    }
  else
    if (!read_allowed)
      return 1;
      
  limit = __dpmi_get_segment_limit(sel);
  /* some selectors don't have zero page protection
     like the protected interrupt stack */
  if(/*a >= 4096 && */ (a+len-1) <= limit)
    return 0;
/*  printf("Invalid access to child, address %#x length %#x  limit: %#x\n", a, len, limit);
  if (can_longjmp)
    longjmp(debugger_jmpbuf, 1); */
  return 1;
}

int read_sel_addr(unsigned child_addr, void *buf, unsigned len, unsigned sel)
{
  /* first clear memory */
  memcpy(buf,0,len);
  if (invalid_sel_addr(sel, child_addr, len, 0))
    return 1;
  movedata(sel, child_addr, my_ds, (int)buf, len);
  return 0;
}

int write_sel_addr(unsigned sel, unsigned child_addr, void *buf, unsigned len)
{
  if (invalid_sel_addr(sel, child_addr, len, 1))
    return 1;
  movedata(my_ds, (int)buf, sel, child_addr, len);
  return 0;
}

static _GO32_StubInfo si;

static void (*oldTRAP)(int);
static void (*oldSEGV)(int);
static void (*oldFPE)(int);
static void (*oldINT)(int);
static void (*oldILL)(int);

void edi_init(jmp_buf start_state)
{
  int i;
  my_ds = 0;
  asm("mov %%ds,%0" : "=g" (my_ds) );
  my_cs = 0;
  asm("mov %%cs,%0" : "=g" (my_cs) );

  for (i=0;i<DPMI_EXCEPTION_COUNT;i++)
    {
      app_handler[i].offset32 = 0;
      app_handler[i].selector = 0;
    }
  *load_state = *start_state;
  a_tss.tss_cs = load_state->__cs;
  a_tss.tss_ss = load_state->__ss;
  a_tss.tss_ds = load_state->__ds;
  a_tss.tss_es = load_state->__es;
  a_tss.tss_fs = load_state->__fs;
  a_tss.tss_gs = load_state->__gs;
  a_tss.tss_eip = load_state->__eip;
  a_tss.tss_esp = load_state->__esp;
  a_tss.tss_eflags = load_state->__eflags;
  a_tss.tss_trap = 0;

  app_ds = a_tss.tss_ds;
  app_cs = a_tss.tss_cs;
  edi.app_base = 0;
  memset(&npx,0,sizeof(npx));
  /* Save all the changed signal handlers */
  oldTRAP = signal(SIGTRAP, dbgsig);
  oldSEGV = signal(SIGSEGV, dbgsig);
  oldFPE = signal(SIGFPE, dbgsig);
  oldINT = signal(SIGINT, dbgsig);
  oldILL = signal(SIGILL, dbgsig);
  movedata(a_tss.tss_fs,0,my_ds,(unsigned)&si,sizeof(si));
  memset(mem_handles,0,sizeof(mem_handles));
  mem_handles[0] = si.memory_handle;
  memset(descriptors,0,sizeof(descriptors));
  descriptors[0] = si.cs_selector;
  descriptors[1] = si.ds_selector;
  descriptors[2] = app_ds;
  descriptors[3] = app_cs; 
  app_exit_cs=si.cs_selector;
  memset(dos_descriptors,0,sizeof(dos_descriptors));
  dos_descriptors[0] = _farpeekw(si.psp_selector,0x2c);
  dos_descriptors[1] = si.psp_selector; 
}

static void close_handles(void); /* Forward declaration */

void cleanup_client(void)
{
  int i;

  /* restore __djgpp_app_DS for Ctrl-C !! */
  __djgpp_app_DS = __djgpp_our_DS;
#ifdef DEBUG_EXCEPTIONS
    fprintf(stderr,"excp_count = %d\n",excp_count);
    fprintf(stderr,"redir_excp_count = %d\n",redir_excp_count);
    fprintf(stderr,"excp_index = %d\n",excp_index);
    fprintf(stderr,"app_cs %04x\tapp_ds %04x\n",app_cs,app_ds);
    fprintf(stderr,"my_cs %04x\tmy_ds %04x\n",my_cs,my_ds);
    for (i=0;i<excp_count;i++)
      {
       fprintf(stderr," excep %04x:%08x\tsignal %08x\n",
         excp_info[i].excp_cs,
         excp_info[i].excp_eip,
         excp_info[i].excp_nb);
         excp_info[i].excp_eip=0;
         excp_info[i].excp_cs=0;
         excp_info[i].excp_nb=0;
      }
    for (i=0;i<DS_SIZE_COUNT;i++)
      {
       if (app_ds_size[i])
         {
          fprintf(stderr," ds size %08x\n",app_ds_size[i]);
          app_ds_size[i] = 0;
         }
      }
    excp_count=0;
    redir_excp_count=0;
    excp_index=0;
  for (i=0;i<DPMI_EXCEPTION_COUNT;i++)
    {
      fprintf(stderr," app %d handler = %04x:%08lx\n",
              i,app_handler[i].selector,app_handler[i].offset32);
    }
  for (i=0;i<DESCRIPTOR_COUNT;i++)
  {
    if (descriptors[i])
    {
      fprintf(stderr,"used descriptor: %08x\n",descriptors[i]);
    }
  }
#endif
  for (i=0;i<DPMI_EXCEPTION_COUNT;i++)
    {
      app_handler[i].offset32 = 0;
      app_handler[i].selector = 0;
    }
  /* Set the flag, that the user interrupt vectors are no longer valid */
  user_int_set = 0;

  memset(&npx,0,sizeof(npx));
  /* Close all handles, which may be left open */
  close_handles();
  for (i=0;i<DOS_DESCRIPTOR_COUNT;i++)
  {
    if (dos_descriptors[i])
    {
#ifdef DEBUG_DBGCOM
      fprintf(stderr,"free dos memory: %08x\n",dos_descriptors[i]);
#endif
      __dpmi_free_dos_memory(dos_descriptors[i]);
    }
  }
  for (i=0;i<MEM_HANDLE_COUNT;i++)
  {
    if (mem_handles[i])
    {
#ifdef DEBUG_DBGCOM
      fprintf(stderr,"free mem : %08lx\n",mem_handles[i]);
#endif
      __dpmi_free_memory(mem_handles[i]);
    }
  }
  for (i=0;i<DESCRIPTOR_COUNT;i++)
  {
    if (descriptors[i])
    {
#ifdef DEBUG_DBGCOM
      fprintf(stderr,"free descriptor: %08x\n",descriptors[i]);
#endif
      __dpmi_free_ldt_descriptor(descriptors[i]);
    }
  }
  /* Restore all changed signal handlers */
  signal(SIGTRAP, oldTRAP);
  signal(SIGSEGV, oldSEGV);
  signal(SIGFPE, oldFPE);
  signal(SIGINT, oldINT);
  signal(SIGILL, oldILL);
}

#ifndef USE_FSEXT

static void close_handles(void)
{
}

#else /* USE_FSEXT */
/*
   Now the FSEXT function for watching files being opened. This is needed,
   because the debuggee can open files which are not closed and if you
   do this multiple times, the limit of max opened files is reached.

   The watching is done by the FSEXT function by hooking the _open(),
   _creat() and _close() calls from the libc functions. The only things
   which are added is recording files which are opened (and closed) by
   the debugger. When cleanup_client() is called, this list is compared
   with actual open files and every file, which was not seen by dbg_fsext()
   is closed.

   This technique does not work correctly when the debugger uses the lowest
   routines for opening/creating/closing files which are
   _dos_open(), _dos_creat(), _dos_creatnew() and _dos_close().
*/

static unsigned char handles[256];
static int in_dbg_fsext = 0;

static void close_handles(void)
{
  __dpmi_regs r;
  int psp_la;
  int jft_ofs;
  int jft_count;
  int handle;

  /* Get our PSP address.  */
  r.x.ax = 0x6200;
  __dpmi_int (0x21, &r);
  psp_la = ( (int)r.x.bx ) << 4;

  /* Get the offset of the JFT table by (seg << 4) + offset */
  jft_ofs = (_farpeekw(_dos_ds, psp_la + 0x36) << 4) +
            _farpeekw(_dos_ds, psp_la + 0x34);

  /* Number of used entries in the JFT table */
  jft_count = _farpeekw(_dos_ds, psp_la + 0x32);

  /* Disable the fsext function */
  in_dbg_fsext++;

  for (handle=0;handle<jft_count;handle++)
  {
    if (_farpeekb(_dos_ds,jft_ofs++) != 0xff /* it is an opened handle */
        && handles[handle] == 0xff /* but not recorded by the fsext function */
       )
    { /* it was opened by the debuggee */
#ifdef CLOSE_UNREGISTERED_FILES
#ifdef DEBUG_DBGCOM_FILES
      fprintf(stderr,"closing %d\n",handle);
#endif
      _close(handle);
#else  /* not CLOSE_UNREGISTERED_FILES */
#ifdef DEBUG_DBGCOM_FILES
      fprintf(stderr,"unknown open file %d\n",handle);
#endif
#endif /* CLOSE_UNREGISTERED_FILES */
    }
  }

  /* Enable the fsext function */
  in_dbg_fsext--;
}


static int dbg_fsext(__FSEXT_Fnumber _function_number,
                      int *_rv, va_list _args)
{
  int attrib,oflag,retval = 0,handle;
  const char *filename;
  /* We are called from this function */
  if (in_dbg_fsext) return 0;
  switch (_function_number)
  {
    default:
      return 0;
    case __FSEXT_creat:
      filename = va_arg(_args,const char *);
      attrib = va_arg(_args,int);
      in_dbg_fsext++;
      retval = _creat(filename,attrib);
#ifdef DEBUG_DBGCOM_FILES
      fprintf(stderr,"_creat(%s) => %d\n",filename,retval);
#endif
      in_dbg_fsext--;
      if (retval != -1)
      {
        handles[retval] = retval;
        __FSEXT_set_function(retval,dbg_fsext);
      }
      break;
    case __FSEXT_open:
      filename = va_arg(_args,const char *);
      oflag = va_arg(_args,int);
      in_dbg_fsext++;
      retval = _open(filename,oflag);
#ifdef DEBUG_DBGCOM_FILES
      fprintf(stderr,"_open(%s) => %d\n",filename,retval);
#endif
      in_dbg_fsext--;
      if (retval != -1)
      {
        handles[retval] = retval;
        __FSEXT_set_function(retval,dbg_fsext);
      }
      break;
    case __FSEXT_close:
      handle = va_arg(_args,int);
      in_dbg_fsext++;
#ifdef DEBUG_DBGCOM_FILES
      fprintf(stderr,"_close(%d)\n",handle);
#endif
      retval = _close(handle);
      in_dbg_fsext--;
      if (retval == 0)
      {
        handles[handle] = 0xff;
        __FSEXT_set_function(handle,NULL);
      }
      break;
  }
  *_rv = retval;
  return 1;
}

/* With attribute constructor to be called automaticaly before main */

static void __attribute__((__constructor__))
_init_dbg_fsext(void)
{
  __dpmi_regs r;
  int psp_la;
  int jft_ofs;
  int jft_count;

  /* Get our PSP address.  */
  r.x.ax = 0x6200;
  __dpmi_int (0x21, &r);
  psp_la = ( (int)r.x.bx ) << 4;

  /* Get the offset of the JFT table by (seg << 4) + offset */
  jft_ofs = (_farpeekw(_dos_ds, psp_la + 0x36) << 4) +
            _farpeekw(_dos_ds, psp_la + 0x34);

  /* Number of used entries in the JFT table */
  jft_count = _farpeekw(_dos_ds, psp_la + 0x32);

  /* Add the handler for opening/creating files */
  __FSEXT_add_open_handler(dbg_fsext);

  /* Initialize all the handles to 0xff */
  memset(handles,0xff,sizeof(handles));

  /* Get a copy of all already opened handles */
  movedata(_dos_ds,jft_ofs,_my_ds(),(int)handles,jft_count);

  /* enable the fsext function */
  in_dbg_fsext = 0;
}
#endif /* def USE_FSEXT */

/* 
  $Log: dbgcom.c,v $
  Revision 1.2  1999/01/06 09:30:03  Pierre
  FPU and MMX add-on

  Revision 1.3  1998/12/21 11:03:01  pierre
   * problems of FSEXT_dbg solved
 
*/

--=====================_916399320==_
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/* Copyright (C) 1996 DJ Delorie, see COPYING.DJ for details */
/* Copyright (C) 1995 DJ Delorie, see COPYING.DJ for details */
#ifndef __dj_include_debug_dbgcom_h_
#define __dj_include_debug_dbgcom_h_

#ifdef __cplusplus
extern "C" {
#endif

#ifndef __dj_ENFORCE_ANSI_FREESTANDING

#ifndef __STRICT_ANSI__

#ifndef _POSIX_SOURCE

#include <setjmp.h>
#include <debug/tss.h>

typedef struct {
  unsigned long app_base;	/* linear base address of application */
  unsigned long dr[8];		/* debug registers, set when a_tss runs */
} ExternalDebuggerInfo;

extern ExternalDebuggerInfo edi;

/* structure of FPU state                       */
/* 14 bytes for FPU env                         */
/* plus 8*10 bytes from the FPU stack           */
/* r[8] is the array as defined in intel docs   */
/* st0 is r[top]                                */

#define NPX_TOP_MASK 0x3800
#define NPX_TOP_SHIFT 11

typedef struct {
  unsigned short sig0;
  unsigned short sig1;
  unsigned short sig2;
  unsigned short sig3;
  unsigned short exponent:15;
  unsigned short sign:1;
} NPXREG;

typedef struct {
  unsigned int control;
  unsigned int status;
  unsigned int tag;
  unsigned int eip;
  unsigned int cs;
  unsigned int dataptr;
  unsigned int datasel;
  NPXREG reg[8];
  long double st[8];
  char st_valid[8];
  long double mmx[8];
  char in_mmx_mode;
  char top;
} NPX;

extern NPX npx;

void save_npx (void); /* Save the FPU of the debugged program */
void load_npx (void); /* Restore the FPU of the debugged program */

void run_child(void);
int read_child(unsigned child_addr, void *buf, unsigned len);
int write_child(unsigned child_addr, void *buf, unsigned len);
void edi_init(jmp_buf start_state);
void cleanup_client(void);

#endif /* !_POSIX_SOURCE */
#endif /* !__STRICT_ANSI__ */
#endif /* !__dj_ENFORCE_ANSI_FREESTANDING */

#ifndef __dj_ENFORCE_FUNCTION_CALLS
#endif /* !__dj_ENFORCE_FUNCTION_CALLS */

#ifdef __cplusplus
}
#endif

#endif /* !__dj_include_debug_dbgcom_h_ */

--=====================_916399320==_
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|\  Pierre Muller    
|/  Institut Charles Sadron  6, rue Boussingault
|\  F 67083 STRASBOURG CEDEX
|/  Phone : (33)(0)3-88-41-40-07  Fax : (33)(0)3-88-41-40-99
|\  e-mail : muller AT ics DOT u-strasbg DOT fr
--=====================_916399320==_--