harbour-core/harbour/source/compiler/genobj32.c

/*
 * $Id$
 */

/*
 * Harbour Project source code:
 * Compiler Windows/DOS OBJ32 generation
 *
 * Copyright 1999 Antonio Linares <alinares@fivetech.com>
 * www - http://www.harbour-project.org
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version, with one exception:
 *
 * The exception is that if you link the Harbour Runtime Library (HRL)
 * and/or the Harbour Virtual Machine (HVM) with other files to produce
 * an executable, this does not by itself cause the resulting executable
 * to be covered by the GNU General Public License. Your use of that
 * executable is in no way restricted on account of linking the HRL
 * and/or HVM code into it.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA (or visit
 * their web site at http://www.gnu.org/).
 *
 */

#include "extend.h"
#include "compiler.h"
#include "pcode.h"
#include "hberrors.h"

static ULONG GetSymbolsSize( void );
static PCOMSYMBOL GetFirstSymbol( void );
static char * GetSymbolName( ULONG ulPos );
static ULONG GetPCodesSize( void );
static ULONG GetSymbolsAmount( void );
static BOOL IsExternal( ULONG ulSymbol );
static USHORT GetExternalPos( char * szExternal );
static void GenerateLocalNames( FILE * hObjFile );
static void GenerateSymbolsSegment( FILE * hObjFile );
static void GenerateDataSegment( FILE * hObjFile );
static void GenerateCodeSegment( FILE * hObjFile );
static void GenerateExternals( FILE * hObjFile );
static void putbyte( BYTE b, FILE * hObjFile );
static void putword( USHORT w, FILE * hObjFile );
static void CompiledFileName( FILE * hObjFile, char * szFileName );
static void CompilerVersion( FILE * hObjFile, char * szVersion );
static void LocalNames( FILE * hObjFile, char * szNames[] );
static void ExternalNames( FILE * hObjFile, char * szNames[] );
static void CodeSegment( FILE * hObjFile, BYTE * prgCode, ULONG ulPrgLen, USHORT wFunctions );
static void DataSegment( FILE * hObjFile, BYTE * symbol, USHORT wSymLen, USHORT wSymbols, ULONG ulTotalSize );
static void DefineSegment( FILE * hObjFile, BYTE bName, BYTE bClass, USHORT wLen );
static void PubDef( FILE * hObjFile, char * szName, USHORT wSegment, USHORT wOffset );
static void Fixup( FILE * hObjFile, BYTE bType, USHORT wOffset, BYTE bFlags, BYTE bSymbol );
static void EnumeratedData( FILE * hObjFile, BYTE bSegment, BYTE * pData, USHORT wLen, USHORT wOffset );
static void End( FILE * hObjFile );
static void GroupDef( FILE * hObjFile, BYTE bName, BYTE * aSegs );

static BYTE prgFunction[] = { 0x68, 0x00, 0x00, 0x00, 0x00, 0x68, 0x00, 0x00, 0x00,
                              0x00, 0xE8, 0x00, 0x00, 0x00, 0x00, 0x83, 0xC4, 0x08, 0xC3 };

static char * * externNames = 0;
static USHORT wExternals = 1; /* _hb_vmExecute is always added */

void GenObj32( PHB_FNAME pFileName )
{
  char szFileName[ _POSIX_PATH_MAX ];
  FILE * hObjFile;  /* file handle for OBJ output */

  if( ! pFileName->szExtension )
    pFileName->szExtension =".obj";
  hb_fsFNameMerge( szFileName, pFileName );

  if( ! ( hObjFile = fopen( szFileName, "wb" ) ) )
    {
      GenError( _szCErrors, 'E', ERR_CREATE_OUTPUT, szFileName, NULL );
      return;
    }

  if( ! _bQuiet )
  {
    printf( "\nGenerating Windows/DOS OBJ32 output to \'%s\'... ", szFileName );
    fflush( stdout );
  }

  CompiledFileName( hObjFile, szFileName );
  CompilerVersion( hObjFile, "Harbour" );
  GenerateLocalNames( hObjFile );
  GenerateExternals( hObjFile );
  GenerateCodeSegment( hObjFile );
  GenerateDataSegment( hObjFile );
  GenerateSymbolsSegment( hObjFile );
  End( hObjFile );

  fclose( hObjFile );

  if( ! _bQuiet )
    printf( "Done.\n" );
}

static ULONG GetSymbolsSize( void )
{
  return ( symbols.iCount - ( _bStartProc ? 0: 1 ) ) * sizeof( HB_SYMB );
}

static PCOMSYMBOL GetFirstSymbol( void )
{
  PCOMSYMBOL pSymbol = symbols.pFirst;

  if( ! _bStartProc )
    pSymbol = pSymbol->pNext;

  return pSymbol;
}

static char * GetSymbolName( ULONG ulPos )
{
  PCOMSYMBOL pSymbol = GetFirstSymbol();
  ULONG ul = 0;

  while( pSymbol && ( ul++ < ulPos ) )
    pSymbol = pSymbol->pNext;

  return pSymbol->szName;
}

static ULONG GetPCodesSize( void )
{
  ULONG ulTotal = 0;
  PFUNCTION pFunction = functions.pFirst;

  if( ! _bStartProc )
    pFunction = pFunction->pNext;

  while( pFunction )
    {
      ulTotal += pFunction->lPCodePos + 1; /* HB_P_ENDPROC !!! */
      pFunction = pFunction->pNext;
    }
  return ulTotal;
}

static ULONG GetSymbolsAmount( void )
{
  PCOMSYMBOL pSymbol = GetFirstSymbol();
  ULONG ulAmount = 1;

  while( pSymbol->pNext )
    {
      ulAmount++;
      pSymbol = pSymbol->pNext;
    }
  return ulAmount;
}

static BOOL IsExternal( ULONG ulSymbol )
{
  PCOMSYMBOL pSymbol = GetFirstSymbol();
  ULONG ul = 0;

  while( ul++ < ulSymbol )
    pSymbol = pSymbol->pNext;

  return ! GetFunction( pSymbol->szName );
}

static USHORT GetExternalPos( char * szExternal )
{
  USHORT w = 0;

  while( w < wExternals )
    {
      if( ! strcmp( szExternal, externNames[ w ] ) )
        break;
      w++;
    }

  return w;
}

static void GenerateLocalNames( FILE * hObjFile )
{
  char * localNames[] = { "_TEXT", "CODE", "_DATA", "DATA",
                          "HB_SYMBOLS", "HB_STARTSYMBOLS", "HB_ENDSYMBOLS", "SYMGROUP", 0 };

  LocalNames( hObjFile, localNames );
}

static void GenerateSymbolsSegment( FILE * hObjFile )
{
  BYTE symbolsData[] = { 0, 0, 0, 0, 0, 0 };
  BYTE groupSegments[] = { 3, 4, 5, 0 }; /* segments order for HB_... */

  DefineSegment( hObjFile, 7, 5, 0 ); /* 7 = HB_STARTSYMBOLS, 5 = DATA */
  DefineSegment( hObjFile, 6, /* "HB_SYMBOLS" position + 1 into localNames */
                 5, /* "DATA" position + 1 into localNames */
                 6 ); /* segment length */
  DefineSegment( hObjFile, 8, 5, 0 ); /* 8 = HB_ENDSYMBOLS, 5 = DATA */

  GroupDef( hObjFile, 8, groupSegments ); /* 8 = "SYMGROUP" localNames position */

  * ( USHORT * ) symbolsData = GetSymbolsAmount();

  EnumeratedData( hObjFile, 4, symbolsData, sizeof( symbolsData ), 0 ); /* 4 = HB_SYMBOLS defined segment */

  Fixup( hObjFile, 0xE4, 2, 0x54, 2 ); /* Data: symbols location */
}

static void GenerateDataSegment( FILE * hObjFile )
{
  HB_SYMB symbol;
  ULONG ulSize = GetSymbolsSize();
  PCOMSYMBOL pSymbol = GetFirstSymbol();
  ULONG ulSymbols = GetSymbolsAmount(), ul;

  while( pSymbol )
    {
      ulSize += strlen( pSymbol->szName ) + 1;
      pSymbol = pSymbol->pNext;
    }

  ulSize += GetPCodesSize();

  DefineSegment( hObjFile, 4, /* "_DATA" position + 1 into localNames */
                 5, /* "DATA" position + 1 into localNames */
                 ulSize ); /* segment length */

  memset( &symbol, 0, sizeof( symbol ) );
  DataSegment( hObjFile, (BYTE *) &symbol,
               sizeof( symbol ), GetSymbolsAmount(), ulSize );

  pSymbol = GetFirstSymbol();
  for( ul = 0; ul < ulSymbols; ul++ )
    {
      Fixup( hObjFile, 0xE4, ( ul * sizeof( HB_SYMB ) ), 0x54, 2 ); /* Data symbol name location */

      if( IsExternal( ul ) )
        {
          if( ! ( pSymbol->cScope & FS_MESSAGE ) )
            Fixup( hObjFile, 0xE4, ( ul * sizeof( HB_SYMB ) ) + 5, 0x56,
                   GetExternalPos( GetSymbolName( ul ) ) + 1 );
        }
      else
        {
          /* if( ! ( pSymbol->cScope & FS_MESSAGE ) ) */
          Fixup( hObjFile, 0xE4, ( ul * sizeof( HB_SYMB ) ) + 5, 0x54, 1 ); /* function address location */
        }
      pSymbol = pSymbol->pNext;
    }
}

static void GenerateCodeSegment( FILE * hObjFile )
{
  USHORT wFunctions = functions.iCount - ( _bStartProc ? 0: 1 );
  ULONG ulSize    = wFunctions * sizeof( prgFunction );
  PFUNCTION pFunc = ( _bStartProc ? functions.pFirst: functions.pFirst->pNext );
  USHORT w = 0;

  DefineSegment( hObjFile, 2, /* "_TEXT" position + 1 into localNames */
                 3, /* "CODE" position + 1 into localNames */
                 ulSize ); /* segment length */

  while( pFunc )
    {
      if( !( pFunc->cScope & ( FS_STATIC | FS_INIT | FS_EXIT ) ) )
        PubDef( hObjFile, pFunc->szName, 1, w * sizeof( prgFunction ) );
      w++;
      pFunc = pFunc->pNext;
    }

  CodeSegment( hObjFile, prgFunction, sizeof( prgFunction ), wFunctions );

  for( w = 0; w < wFunctions; w++ )
    {
      /* prgFunction fixups */
      Fixup( hObjFile, 0xE4, ( w * sizeof( prgFunction ) ) + 1,
             0x54, 2 ); /* Data: symbols location */

      Fixup( hObjFile, 0xE4, ( w * sizeof( prgFunction ) ) + 6,
             0x54, 2 ); /* Data pcode location */

      Fixup( hObjFile, 0xA4, ( w * sizeof( prgFunction ) ) + 11,
             0x56, 1 ); /* External: _hb_vmExecute */
    }
}

static void GenerateExternals( FILE * hObjFile )
{
  USHORT w;
  PFUNCTION pFunc, pFTemp;

  /* calculate amount of externals */
  pFunc = funcalls.pFirst;
  while( pFunc )
    {
      if( ! ( pFTemp = GetFunction( pFunc->szName ) ) || pFTemp == functions.pFirst )
        wExternals++;
      pFunc = pFunc->pNext;
    }
  if( wExternals )
    {
      externNames = ( char * * ) hb_xgrab( sizeof( char * ) * ( wExternals + 2 ) );
      w = 1;
      externNames[ 0 ] = "_hb_vmExecute";

      pFunc = funcalls.pFirst;
      while( pFunc )
        {
          if( ! ( pFTemp = GetFunction( pFunc->szName ) ) || pFTemp == functions.pFirst )
            externNames[ w++ ] = pFunc->szName;
          pFunc = pFunc->pNext;
        }
      externNames[ w ] = 0;
      ExternalNames( hObjFile, externNames );
    }
}

static void putbyte( BYTE b, FILE * hObjFile )
{
  fputc( b, hObjFile );
}

static void putword( USHORT w, FILE * hObjFile )
{
  putbyte( LOBYTE( w ), hObjFile );
  putbyte( HIBYTE( w ), hObjFile );
}

static void CompiledFileName( FILE * hObjFile, char * szFileName )
{
  USHORT wLen = strlen( szFileName );
  BYTE bChk = 0; /* this is a checksum the linker will check to asure OBJ integrity */
  BYTE bChar;

  putbyte( 0x80, hObjFile );  /* this tells the linker the kind of OBJ record this is */
  bChk += 0x80;

  putbyte( 1 + 1 + wLen, hObjFile ); /* now it comes the total length of this OBJ record */
  bChk += ( 1 + 1 + wLen );
  putbyte( 0, hObjFile );

  putbyte( wLen, hObjFile );     /* szFileName length */
  bChk += wLen;

  while( (bChar = * szFileName++) )
    {
      putbyte( bChar, hObjFile );   /* each of the szFileName characters */
      bChk += bChar;
    }

  putbyte( 256 - bChk, hObjFile ); /* a checksum that will be recalculated by the linker */
}

static void CompilerVersion( FILE * hObjFile, char * szVersion )
{
  USHORT wLen = strlen( szVersion );
  BYTE bChk = 0; /* this is a checksum the linker will check to asure OBJ integrity */
  BYTE bChar;

  putbyte( 0x88, hObjFile );  /* this tells the linker the kind of OBJ record this is */
  bChk += 0x88;

  putword( 3 + wLen, hObjFile ); /* now it comes the total length of this OBJ record */
  bChk += LOBYTE( 3 + wLen );
  bChk += HIBYTE( 3 + wLen );

  putword( 0, hObjFile );

  while( (bChar = * szVersion++) )
    {
      putbyte( bChar, hObjFile );   /* each of the szFileName characters */
      bChk += bChar;
    }

  putbyte( 256 - bChk, hObjFile ); /* a checksum that will be recalculated by the linker */
}

static void LocalNames( FILE * hObjFile, char * szNames[] )
{
  BYTE b = 0, c;
  USHORT wTotalLen = 0;
  BYTE bChk = 0;

  while( szNames[ b ] )
    wTotalLen += strlen( szNames[ b++ ] );
  wTotalLen += 2 + b;

  putbyte( 0x96, hObjFile );
  bChk += 0x96;

  putbyte( LOBYTE( wTotalLen ), hObjFile );
  bChk += LOBYTE( wTotalLen );
  putbyte( HIBYTE( wTotalLen ), hObjFile );
  bChk += HIBYTE( wTotalLen );

  putbyte( 0, hObjFile );

  b = 0;
  while( szNames[ b ] )
    {
      putbyte( strlen( szNames[ b ] ), hObjFile );
      bChk += strlen( szNames[ b ] );

      c = 0;
      while( szNames[ b ][ c ] )
        {
          putbyte( szNames[ b ][ c ], hObjFile );
          bChk += szNames[ b ][ c++ ];
        }
      b++;
    }
  putbyte( 256 - bChk, hObjFile );
}

static void ExternalNames( FILE * hObjFile, char * szNames[] )
{
  BYTE b = 0, c;
  USHORT wTotalLen = 0;
  BYTE bChk = 0;

  while( szNames[ b ] )
    wTotalLen += strlen( szNames[ b++ ] ) + 1;
  wTotalLen += 2 + b - 1;

  putbyte( 0x8C, hObjFile );
  bChk += 0x8C;

  putword( wTotalLen, hObjFile );
  bChk += LOBYTE( wTotalLen );
  bChk += HIBYTE( wTotalLen );

  b = 0;
  while( szNames[ b ] )
    {
      putbyte( strlen( szNames[ b ] ), hObjFile );
      bChk += strlen( szNames[ b ] );

      c = 0;

      while( szNames[ b ][ c ] )
        {
          putbyte( szNames[ b ][ c ], hObjFile );
          bChk += szNames[ b ][ c++ ];
        }
      putbyte( 0, hObjFile );
      b++;
    }
  putbyte( 256 - bChk, hObjFile );
}

static void CodeSegment( FILE * hObjFile, BYTE * prgCode, ULONG ulPrgLen, USHORT wFunctions )
{
  BYTE bCheckSum = 0;
  USHORT y;
  USHORT wTotalLen = ( ulPrgLen * wFunctions ) + 4;
  ULONG ul;
  PFUNCTION pFunction = functions.pFirst;
  ULONG ulPCodeOffset = ( symbols.iCount - ( _bStartProc ? 0: 1 ) ) * sizeof( HB_SYMB );

  if( ! _bStartProc )
    pFunction = pFunction->pNext;

  putbyte( 0xA0, hObjFile );
  bCheckSum += 0xA0;

  putword( wTotalLen, hObjFile );
  bCheckSum += LOBYTE( wTotalLen );
  bCheckSum += HIBYTE( wTotalLen );

  putbyte( 1, hObjFile ); /* 1 = _TEXT segment */
  bCheckSum += 1;

  putword( 0, hObjFile ); /* 0 = offset */

  for( y = 0; y < wFunctions; y++ )
    {
      * ( ULONG * ) &prgCode[ 6 ] = ulPCodeOffset; /* function pcode offset */
      for( ul = 0; ul < ulPrgLen; ul++ )
        {
          putbyte( * ( prgCode + ul ), hObjFile );
          bCheckSum += * ( prgCode + ul );
        }
      ulPCodeOffset += pFunction->lPCodePos + 1; /* HB_P_ENDPROC !!! */
      pFunction = pFunction->pNext;
    }

  putbyte( 256 - bCheckSum, hObjFile );
}

static void DataSegment( FILE * hObjFile, BYTE * symbol, USHORT wSymLen, USHORT wSymbols,
                         ULONG ulSize )
{
  BYTE bCheckSum = 0;
  USHORT w, y;
  USHORT wTotalLen = 4 + ulSize;
  PCOMSYMBOL pSymbol = GetFirstSymbol();
  PFUNCTION pFunction = functions.pFirst;
  ULONG ulSymbolNameOffset = GetSymbolsSize() + GetPCodesSize();
  ULONG ulFunctionOffset;

  if( ! _bStartProc )
    pFunction = pFunction->pNext;

  putbyte( 0xA0, hObjFile );
  bCheckSum += 0xA0;

  putword( wTotalLen, hObjFile );
  bCheckSum += LOBYTE( wTotalLen );
  bCheckSum += HIBYTE( wTotalLen );

  putbyte( 2, hObjFile ); /* 2 = _DATA segment */
  bCheckSum += 2;

  putword( 0, hObjFile ); /* 0 = offset */

  for( y = 0; y < wSymbols; y++ )
    {
      * ( ULONG * ) symbol = ulSymbolNameOffset;

      if( ! IsExternal( y ) )
        {
          ulFunctionOffset = ( GetFunctionPos( pSymbol->szName ) - 1 ) *
            sizeof( prgFunction );
          * ( ( ULONG * ) &symbol[ 5 ] ) = ulFunctionOffset;
        }
      else
        * ( ( ULONG * ) &symbol[ 5 ] ) = 0;

      if( pSymbol->cScope == FS_MESSAGE )
        symbol[ 4 ] = FS_PUBLIC;
      else
        symbol[ 4 ] = pSymbol->cScope;

      for( w = 0; w < wSymLen; w++ )
        {
          putbyte( * ( symbol + w ), hObjFile );
          bCheckSum += * ( symbol + w );
        }

      ulSymbolNameOffset += strlen( pSymbol->szName ) + 1;
      pSymbol = pSymbol->pNext;
    }

  while( pFunction )
    {
      for( w = 0; w < pFunction->lPCodePos; w++ )
        {
          putbyte( pFunction->pCode[ w ], hObjFile );
          bCheckSum += pFunction->pCode[ w ];
        }
      putbyte( HB_P_ENDPROC, hObjFile );
      bCheckSum += HB_P_ENDPROC;
      pFunction = pFunction->pNext;
    }

  pSymbol = GetFirstSymbol();

  while( pSymbol )
    {
      for( w = 0; w < ( USHORT ) strlen( pSymbol->szName ); w++ )
        {
          putbyte( pSymbol->szName[ w ], hObjFile );
          bCheckSum += pSymbol->szName[ w ];
        }
      putbyte( 0, hObjFile );
      pSymbol = pSymbol->pNext;
    }

  putbyte( 256 - bCheckSum, hObjFile );
}

static void DefineSegment( FILE * hObjFile, BYTE bName, BYTE bClass, USHORT wLen )
{
  BYTE bCheckSum = 0;

  putbyte( 0x98, hObjFile );
  bCheckSum += 0x98;
  putbyte( 7, hObjFile );         /* SegDef records have always this length */
  bCheckSum += 7;
  putbyte( 0, hObjFile );

  putbyte( 0xA9, hObjFile );
  bCheckSum += 0xA9;

  putword( wLen, hObjFile );
  bCheckSum += LOBYTE( wLen );
  bCheckSum += HIBYTE( wLen );

  putbyte( bName, hObjFile );
  bCheckSum += bName;
  putbyte( bClass, hObjFile );
  bCheckSum += bClass;
  putbyte( 0, hObjFile );

  putbyte( 256 - bCheckSum, hObjFile );
}

static void PubDef( FILE * hObjFile, char * szName, USHORT wSegment, USHORT wOffset )
{
  BYTE bChk = 0;
  BYTE bChar;
  USHORT wLen = 2 + 2 + strlen( szName ) + 2 + 1;

  putbyte( 0x90, hObjFile );
  bChk += 0x90;

  putword( wLen, hObjFile );
  bChk += LOBYTE( wLen );
  bChk += HIBYTE( wLen );

  putbyte( 0x00, hObjFile );
  putbyte( wSegment, hObjFile );
  bChk += wSegment;

  putbyte( strlen( szName ), hObjFile );
  bChk += strlen( szName );

  while( (bChar = * szName++) )
    {
      putbyte( bChar, hObjFile );
      bChk += bChar;
    }

  putword( wOffset, hObjFile);
  bChk += LOBYTE( wOffset );
  bChk += HIBYTE( wOffset );
  putbyte( 0x00, hObjFile );

  putbyte( 256 - bChk, hObjFile );
}

static void Fixup( FILE * hObjFile, BYTE bType, USHORT wOffset, BYTE bFlags, BYTE bSymbol )
{
  BYTE bCheckSum = 0;

  putbyte( 0x9D, hObjFile ); bCheckSum += 0x9D;

  putword( 5, hObjFile ); bCheckSum += 5;

  putbyte( bType + HIBYTE( wOffset ), hObjFile );
  bCheckSum += bType + HIBYTE( wOffset );

  putbyte( LOBYTE( wOffset ), hObjFile );
  bCheckSum += LOBYTE( wOffset );

  putbyte( bFlags, hObjFile );  bCheckSum += bFlags;
  putbyte( bSymbol, hObjFile ); bCheckSum += bSymbol;

  putbyte( 256 - bCheckSum, hObjFile );
}

static void EnumeratedData( FILE * hObjFile, BYTE bSegment, BYTE * pData, USHORT wLen, USHORT wOffset )
{
  BYTE bCheckSum = 0;
  USHORT w;

  putbyte( 0xA0, hObjFile );
  bCheckSum += 0xA0;

  putword( ( USHORT ) ( wLen + 4 ), hObjFile );
  bCheckSum += LOBYTE( wLen + 4 );
  bCheckSum += HIBYTE( wLen + 4 );

  putbyte( bSegment, hObjFile );
  bCheckSum += bSegment;

  putword( wOffset, hObjFile );
  bCheckSum += wOffset;

  for( w = 0; w < wLen; w++ )
    {
      putbyte( * ( pData + w ), hObjFile );
      bCheckSum += * ( pData + w );
    }

  putbyte( 256 - bCheckSum, hObjFile );
}

static void End( FILE * hObjFile )
{
  BYTE bChk = 0;

  putbyte( 0x8A, hObjFile );  bChk += 0x8A;

  putbyte( 0x02, hObjFile );   bChk += 0x02;
  putbyte( 0x00, hObjFile );

  putbyte( 0x00, hObjFile );    bChk += 0x00;

  putbyte( 256 - bChk, hObjFile );
}

static void GroupDef( FILE * hObjFile, BYTE bName, BYTE * aSegs )
{
  BYTE bCheckSum = 0;
  USHORT wRecLen   = 2;
  USHORT w         = 0;

  while( aSegs[ w++ ] )
    wRecLen += 2;

  putbyte( 0x9A, hObjFile );
  bCheckSum += 0x9A;

  putword( wRecLen, hObjFile );
  bCheckSum += LOBYTE( wRecLen );
  bCheckSum += HIBYTE( wRecLen );

  putbyte( bName + 1, hObjFile );
  bCheckSum += bName + 1;

  w = 0;
  while( aSegs[ w ] )
    {
      putbyte( 0xFF, hObjFile );
      bCheckSum += 0xFF;
      putbyte( aSegs[ w ], hObjFile );
      bCheckSum += aSegs[ w ];
      w++;
    }

  putbyte( 256 - bCheckSum, hObjFile );
}