Subj : Re: Quest: Rebuilding c0t.obj for 16-bit BC++ OS loader...
To   : borland.public.cpp.borlandcpp
From : "lewi" <bj7lewis@willapabay.org>
Date : Sat Jul 19 2003 06:50 pm

Ok an update now...

I was able to get the code below to work(by using org 100h and using opcode
asm defines) but I know it isn't what I did a year ago and also I only can
make a jump to _main not call it through opcode asm defines and later when I
add the entering PMode code to the asm I need to have returned from _main
and start after the call to _main...

Also a near call _main opcode will be better than a far call...

The asm code...

extrn _main

..model tiny

..code

org 100h
_startup:
 mov ax, cs
 mov ds, ax
 DB 0EAh   ; far jump
 DD _main  ; 32-bit offset
 DW 2000
 jmp short $

;Continue on adding 0 to fill rest of the sector.
 ;db 246 dup (0)

end _startup

The C code [Note: if you dont know this will reset video mode and write
"..." to the top left of screen...]...

extern "C" void main()
{
  _asm {
  mov ax, 0x0003
  int 0x10

  mov ah, 0x0e
  mov al, '.'
  mov bx, 0x004f
  int 0x10
  int 0x10
  int 0x10
 }

 for(;;);
}

The cmdlines...
c:\bc31\bin\tasm.exe /la /q c0Start.asm, c0tStart.obj
c:\bc31\bin\bcc.exe -c -mt -oOSLoad.obj OSLoad.cpp
c:\bc31\bin\tlink.exe /n /3 /m /s /t c0tStart.obj OSLoad.obj, OSLoad.com

Any more help...

.