fpc/rtl/go32v2/dxeload.pp
2023-07-27 19:04:03 +02:00

95 lines
2.2 KiB
ObjectPascal

{
This file is part of the Free Pascal run time library.
Copyright (c) 1999-2000 by Pierre Muller,
member of the Free Pascal development team.
Unit to Load DXE files for Go32V2
See the file COPYING.FPC, included in this distribution,
for details about the copyright.
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.
**********************************************************************
}
{$IFNDEF FPC_DOTTEDUNITS}
Unit dxeload;
{$ENDIF FPC_DOTTEDUNITS}
interface
function dxe_load(filename : string) : pointer;
implementation
{$IFDEF FPC_DOTTEDUNITS}
uses
DOSApi.dxetype;
{$ELSE FPC_DOTTEDUNITS}
uses
dxetype;
{$ENDIF FPC_DOTTEDUNITS}
function dxe_load(filename : string) : pointer;
{
Copyright (C) 1995 Charles Sandmann (sandmann@clio.rice.edu)
translated to Free Pascal by Pierre Muller
}
type
{ to avoid range check problems }
pointer_array = array[0..maxlongint div sizeof(pointer)-1] of pointer;
tpa = ^pointer_array;
var
dh : dxe_header;
data : PAnsiChar;
f : file;
relocs : tpa;
i : longint;
addr : pcardinal;
begin
dxe_load:=nil;
{ open the file }
assign(f,filename);
{$I-}
reset(f,1);
{$I+}
{ quit if no file !! }
if ioresult<>0 then
exit;
{ load the header }
blockread(f,dh,sizeof(dxe_header),i);
if (i<>sizeof(dxe_header)) or (dh.magic<>DXE_MAGIC) then
begin
close(f);
exit;
end;
{ get memory for code }
getmem(data,dh.element_size);
if data=nil then
exit;
{ get memory for relocations }
getmem(relocs,dh.nrelocs*sizeof(pointer));
if relocs=nil then
begin
freemem(data,dh.element_size);
exit;
end;
{ copy code }
blockread(f,data^,dh.element_size);
blockread(f,relocs^,dh.nrelocs*sizeof(pointer));
close(f);
{ relocate internal references }
for i:=0 to dh.nrelocs-1 do
begin
cardinal(addr):=cardinal(data)+cardinal(relocs^[i]);
addr^:=addr^+cardinal(data);
end;
FreeMem(relocs,dh.nrelocs*sizeof(pointer));
dxe_load:=pointer( dh.symbol_offset + cardinal(data));
end;
end.