{****************************************************************************

                     FPK-Pascal -- OS/2 runtime library

                  Copyright (c) 1993,95 by Florian Kl„mpfl
                   Copyright (c) 1997 by Dani‰l Mantione

 FPK-Pascal is distributed under the GNU Public License v2. So is this unit.
 The GNU Public License requires you to distribute the source code of this
 unit with any product that uses it. We grant you an exception to this, and
 that is, when you compile a program with the FPK Pascal compiler, you do not
 need to ship source code with that program, AS LONG AS YOU ARE USING
 UNMODIFIED CODE! If you modify this code, you MUST change the next line:

 <This an official, unmodified FPK Pascal source code file.>

 Send us your modified files, we can work together if you want!

 FPK-Pascal 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
 Library GNU General Public License for more details.

 You should have received a copy of the Library GNU General Public License
 along with FPK-Pascal; see the file COPYING.LIB.  If not, write to
 the Free Software Foundation, 59 Temple Place - Suite 330,
 Boston, MA 02111-1307, USA.

****************************************************************************}

unit sysos2;

{Changelog:

    People:

        DM - Dani‰l Mantione

    Date:           Description of change:              Changed by:

     -              First released version 0.1.         DM

Coding style:

    My coding style is a bit unusual for Pascal. Nevertheless I friendly ask
    you to try to make your changes not look all to different. In general,
    set your IDE to use tab characters, optimal fill on and a tabsize of 4.}

{$I os.inc}

interface

{Link the startup code.}
{$l prt1.oo2}

{$I SYSTEMH.INC}
{$I heaph.inc}

type    Tos=(osDOS,osOS2,osDPMI);

var     os_mode:Tos;
        first_meg:pointer;

type    Psysthreadib=^Tsysthreadib;
        Pthreadinfoblock=^Tthreadinfoblock;
        Pprocessinfoblock=^Tprocessinfoblock;

        Tbytearray=array[0..$ffff] of byte;
        Pbytearray=^Tbytearray;

        Tsysthreadib=record
            tid,
            priority,
            version:longint;
            MCcount,
            MCforceflag:word;
        end;

        Tthreadinfoblock=record
            pexchain,
            stack,
            stacklimit:pointer;
            tib2:Psysthreadib;
            version,
            ordinal:longint;
        end;

        Tprocessinfoblock=record
            pid,
            parentpid,
            hmte:longint;
            cmd,
            env:Pbytearray;
            flstatus,
            ttype:longint;
        end;

const   UnusedHandle=$ffff;
        StdInputHandle=0;
        StdOutputHandle=1;
        StdErrorHandle=2;

implementation

{$I SYSTEM.INC}

procedure dosgetinfoblocks(var Atib:Pthreadinfoblock;
                           var Apib:Pprocessinfoblock);
                           external 'DOSCALLS' index 312;

{This is the correct way to call external assembler procedures.}
procedure syscall;external name '___SYSCALL';

{***************************************************************************

                Runtime error checking related routines.

***************************************************************************}

{$S-}
procedure st1(stack_size:longint);[public,alias: 'STACKCHECK'];

begin
    { called when trying to get local stack }
    { if the compiler directive $S is set   }
    {$ASMMODE DIRECT}
    asm
        movl stack_size,%ebx
        movl %esp,%eax
        subl %ebx,%eax
{$ifdef SYSTEMDEBUG}
        movl U_SYSOS2_LOWESTSTACK,%ebx
        cmpl %eax,%ebx
        jb   Lis_not_lowest
        movl %eax,U_SYSOS2_LOWESTSTACK
    Lis_not_lowest:
{$endif SYSTEMDEBUG}
        cmpb $2,U_SYSOS2_OS_MODE
        jne Lrunning_in_dos
        movl U_SYSOS2_STACKBOTTOM,%ebx
        jmp Lrunning_in_os2
    Lrunning_in_dos:
        movl __heap_brk,%ebx
    Lrunning_in_os2:
        cmpl %eax,%ebx
        jae  Lshort_on_stack
        leave
        ret  $4
    Lshort_on_stack:
    end ['EAX','EBX'];
    {$ASMMODE ATT}
    { this needs a local variable }
    { so the function called itself !! }
    { Writeln('low in stack ');}
    HandleError(202);
end;
{no stack check in system }

{****************************************************************************

                    Miscelleanious related routines.

****************************************************************************}

procedure halt(errnum:byte);

begin
    asm
        movb $0x4c,%ah
        movb errnum,%al
        call syscall
    end;
end;


{$asmmode direct}
function paramcount:longint;assembler;

asm
    movl _argc,%eax
    decl %eax
end ['EAX'];

function paramstr(l:longint):string;

    function args:pointer;assembler;

    asm
        movl _argv,%eax
    end ['EAX'];

var p:^Pchar;

begin
     if (l>=0) and (l<=paramcount) then
        begin
            p:=args;
            paramstr:=strpas(p[l]);
        end
     else paramstr:='';
end;

{$asmmode att}

procedure randomize;

var hl:longint;

begin
    asm
        movb $0x2c,%ah
        call syscall
        movw %cx,-4(%ebp)
        movw %dx,-2(%ebp)
    end;
    randseed:=hl;
end;

{****************************************************************************

                    Heap management releated routines.

****************************************************************************}


{ this function allows to extend the heap by calling
syscall $7f00 resizes the brk area}

function sbrk(size:longint):longint;

begin
    asm
        movl size,%edx
        movw $0x7f00,%ax
        call syscall
        movl %eax,__RESULT
    end;
end;

{$ASMMODE direct}
function getheapstart:pointer;assembler;

asm
    movl __heap_base,%eax
end ['EAX'];

function getheapsize:longint;assembler;
asm
    movl    HEAPSIZE,%eax
end ['EAX'];
{$ASMMODE ATT}

{$i heap.inc}

{****************************************************************************

                          Low Level File Routines

****************************************************************************}

procedure allowslash(p:Pchar);

{Allow slash as backslash.}

var i:longint;

begin
    for i:=0 to strlen(p) do
        if p[i]='/' then p[i]:='\';
end;

procedure do_close(h:longint);

begin
     asm
        movb $0x3e,%ah
        mov h,%ebx
        call syscall
     end;
end;

procedure do_erase(p:Pchar);

begin
    allowslash(p);
    asm
        movl 8(%ebp),%edx
        movb $0x41,%ah
        call syscall
        jnc .LERASE1
        movw %ax,inoutres;
    .LERASE1:
    end;
end;

procedure do_rename(p1,p2:Pchar);

begin
    allowslash(p1);
    allowslash(p2);
    asm
        movl 8(%ebp),%edx
        movl 12(%ebp),%edi
        movb $0x56,%ah
        call syscall
        jnc .LRENAME1
        movw %ax,inoutres;
    .LRENAME1:
    end;
end;

function do_read(h,addr,len:longint):longint;

begin
    asm
        movl 16(%ebp),%ecx
        movl 12(%ebp),%edx
        movl 8(%ebp),%ebx
        movb $0x3f,%ah
        call syscall
        jnc .LDOSREAD1
        movw %ax,inoutres;
        xorl %eax,%eax
    .LDOSREAD1:
        leave
        ret $12
    end;
end;

function do_write(h,addr,len:longint) : longint;

begin
    asm
        movl 16(%ebp),%ecx
        movl 12(%ebp),%edx
        movl 8(%ebp),%ebx
        movb $0x40,%ah
        call syscall
        jnc .LDOSWRITE1
        movw %ax,inoutres;
    .LDOSWRITE1:
       movl %eax,-4(%ebp)
    end;
end;

function do_filepos(handle:longint):longint;

begin
    asm
        movw $0x4201,%ax
        movl 8(%ebp),%ebx
        xorl %edx,%edx
        call syscall
        jnc .LDOSFILEPOS
        movw %ax,inoutres;
        xorl %eax,%eax
    .LDOSFILEPOS:
        leave
        ret $4
     end;
end;

procedure do_seek(handle,pos:longint);

begin
    asm
        movw $0x4200,%ax
        movl 8(%ebp),%ebx
        movl 12(%ebp),%edx
        call syscall
        jnc .LDOSSEEK1
        movw %ax,inoutres;
    .LDOSSEEK1:
        leave
        ret $8
    end;
end;

function do_seekend(handle:longint):longint;

begin
    asm
        movw $0x4202,%ax
        movl 8(%ebp),%ebx
        xorl %edx,%edx
        call syscall
        jnc .Lset_at_end1
        movw %ax,inoutres;
        xorl %eax,%eax
    .Lset_at_end1:
        leave
        ret $4
    end;
end;

function do_filesize(handle:longint):longint;

var aktfilepos:longint;

begin
    aktfilepos:=do_filepos(handle);
    do_filesize:=do_seekend(handle);
    do_seek(handle,aktfilepos);
end;

procedure do_truncate(handle,pos:longint);

begin
    asm
        movl $0x4200,%eax
        movl 8(%ebp),%ebx
        movl 12(%ebp),%edx
        call syscall
        jc .LTruncate1
        movl 8(%ebp),%ebx
        movl 12(%ebp),%edx
        movl %ebp,%edx
        xorl %ecx,%ecx
        movb $0x40,%ah
        call syscall
        jnc .LTruncate2
        .LTruncate1:
        movw %ax,inoutres;
        .LTruncate2:
        leave
        ret $8
    end;
end;

procedure do_open(var f;p:pchar;flags:longint);

{
  filerec and textrec have both handle and mode as the first items so
  they could use the same routine for opening/creating.
  when (flags and $10)   the file will be append
  when (flags and $100)  the file will be truncate/rewritten
  when (flags and $1000) there is no check for close (needed for textfiles)
}

var oflags:byte;

begin
    allowslash(p);
    { close first if opened }
    if ((flags and $1000)=0) then
        begin
            case filerec(f).mode of
                fminput,fmoutput,fminout : Do_Close(filerec(f).handle);
                fmclosed:;
            else
                begin
                    inoutres:=102; {not assigned}
                    exit;
                end;
            end;
       end;
    { reset file handle }
    filerec(f).handle:=high(word);
    oflags:=2;
    { convert filemode to filerec modes }
    case (flags and 3) of
        0 : begin
            filerec(f).mode:=fminput;
            oflags:=0;
        end;
        1 : filerec(f).mode:=fmoutput;
        2 : filerec(f).mode:=fminout;
    end;
    if (flags and $100)<>0 then
        begin
            filerec(f).mode:=fmoutput;
            oflags:=2;
        end
    else
        if (flags and $10)<>0 then
            begin
                filerec(f).mode:=fmoutput;
                oflags:=2;
            end;
    { empty name is special }
    if p[0]=#0 then
        begin
            case filerec(f).mode of
                fminput:filerec(f).handle:=StdInputHandle;
                fmappend,fmoutput : begin
                    filerec(f).handle:=StdOutputHandle;
                    filerec(f).mode:=fmoutput; {fool fmappend}
                end;
            end;
            exit;
        end;
    if (flags and $100)<>0 then
        {Use create function.}
        asm
            movb $0x3c,%ah
            movl p,%edx
            xorw %cx,%cx
            call syscall
            jnc .LOPEN1
            movw %ax,inoutres;
            movw $0xffff,%ax
        .LOPEN1:
            movl f,%edx
            movw %ax,(%edx)
        end
    else
        {Use open function.}
        asm
            movb $0x3d,%ah
            movb oflags,%al
            movl p,%edx
            call syscall
            jnc .LOPEN2
            movw %ax,inoutres;
            movw $0xffff,%ax
        .LOPEN2:
            movl f,%edx
            movw %ax,(%edx)
        end;
    if (flags and $10)<>0 then
        do_seekend(filerec(f).handle);
end;

function do_isdevice(handle:longint):boolean;
begin
  do_isdevice:=(handle<=5);
end;


{*****************************************************************************
                           UnTyped File Handling
*****************************************************************************}

{$i file.inc}

{*****************************************************************************
                           Typed File Handling
*****************************************************************************}

{$i typefile.inc}

{*****************************************************************************
                           Text File Handling
*****************************************************************************}

{$DEFINE EOF_CTRLZ}

{$i text.inc}

{****************************************************************************

                          Directory related routines.

****************************************************************************}

{*****************************************************************************
                           Directory Handling
*****************************************************************************}

procedure dosdir(func:byte;const s:string);

var buffer:array[0..255] of char;

begin
    move(s[1],buffer,length(s));
    buffer[length(s)]:=#0;
    allowslash(Pchar(@buffer));
    asm
        leal buffer,%edx
        movb 8(%ebp),%ah
        call syscall
        jnc  .LDOS_DIRS1
        movw %ax,inoutres;
    .LDOS_DIRS1:
    end;
end;


procedure mkdir(const s : string);

begin
    DosDir($39,s);
end;


procedure rmdir(const s : string);

begin
    DosDir($3a,s);
end;

procedure chdir(const s : string);

begin
    DosDir($3b,s);
end;

procedure getdir(drivenr : byte;var dir : shortstring);

{Written by Michael Van Canneyt.}

var temp:array[0..255] of char;
    sof:Pchar;
    i:byte;

begin
    sof:=pchar(@dir[4]);
    { dir[1..3] will contain '[drivenr]:\', but is not }
    { supplied by DOS, so we let dos string start at   }
    { dir[4]                                           }
    { Get dir from drivenr : 0=default, 1=A etc... }
    asm
        movb drivenr,%dl
        movl sof,%esi
        mov  $0x47,%ah
        call syscall
    end;
    { Now Dir should be filled with directory in ASCIIZ, }
    { starting from dir[4]                               }
    dir[0]:=#3;
    dir[2]:=':';
    dir[3]:='\';
    i:=4;
    {Conversion to Pascal string }
    while (dir[i]<>#0) do
        begin
            { convert path name to DOS }
            if dir[i]='/' then
            dir[i]:='\';
            dir[0]:=char(i);
            inc(i);
        end;
    { upcase the string (FPKPascal function) }
    dir:=upcase(dir);
    if drivenr<>0 then   { Drive was supplied. We know it }
        dir[1]:=char(65+drivenr-1)
    else
        begin
            { We need to get the current drive from DOS function 19H  }
            { because the drive was the default, which can be unknown }
            asm
                movb $0x19,%ah
                call syscall
                addb $65,%al
                movb %al,i
            end;
            dir[1]:=char(i);
        end;
end;



{****************************************************************************

                        System unit initialization.

****************************************************************************}

var pib:Pprocessinfoblock;
    tib:Pthreadinfoblock;

begin
    {Determine the operating system we are running on.}
    asm
        movw $0x7f0a,%ax
        call syscall
        testw $512,%bx         {Bit 9 is OS/2 flag.}
        setnzl os_mode
        testw $4096,%bx
        jz .LnoRSX
        movl $2,os_mode
    .LnoRSX:
    end;

    {$ASMMODE DIRECT}
    {Enable the brk area by initializing it with the initial heap size.}
    asm
        movw $0x7f01,%ax
        movl HEAPSIZE,%edx
        addl __heap_base,%edx
        call ___SYSCALL
        cmpl $-1,%eax
        jnz Lheapok
        pushl $204
        {call RUNERROR$$WORD}
    Lheapok:
    end;
    {$ASMMODE ATT}

    {Now request, if we are running under DOS,
     read-access to the first meg. of memory.}
    if os_mode in [osDOS,osDPMI] then
        asm
            movw $0x7f13,%ax
            xorl %ebx,%ebx
            movl $0xfff,%ecx
            xorl %edx,%edx
            call syscall
            movl %eax,first_meg
        end
    else
        first_meg:=nil;
    {At 0.9.2, case for enumeration does not work.}
    case os_mode of
        osDOS:
            stackbottom:=0;     {In DOS mode, heap_brk is also the
                                 stack bottom.}
        osOS2:
            begin
                dosgetinfoblocks(tib,pib);
                stackbottom:=longint(tib^.stack);
            end;
        osDPMI:
            stackbottom:=0;     {Not sure how to get it, but seems to be
                                 always zero.}
    end;
    exitproc:=nil;

    {Initialize the heap.}
    initheap;

    { to test stack depth }
    loweststack:=maxlongint;

    OpenStdIO(Input,fmInput,StdInputHandle);
    OpenStdIO(Output,fmOutput,StdOutputHandle);
    OpenStdIO(StdOut,fmOutput,StdOutputHandle);
    OpenStdIO(StdErr,fmOutput,StdErrorHandle);

    { kein Ein- Ausgabefehler }
    inoutres:=0;
end.