fpc/rtl/msxdos/si_prc.pp
2020-06-13 09:36:18 +00:00

70 lines
1.5 KiB
ObjectPascal

{
This file is part of the Free Pascal run time library.
Copyright (c) 2020 by Free Pascal development team
This file contains startup code for the ZX Spectrum
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.
**********************************************************************}
unit si_prc;
{$SMARTLINK OFF}
{$GOTO ON}
interface
implementation
var
stktop: word; external name '__stktop';
procedure PascalMain; external name 'PASCALMAIN';
{ this *must* always remain the first procedure with code in this unit }
procedure _start; assembler; nostackframe; public name 'start';
label
bstart, bend, loop;
asm
{ first init BSS }
ld bc, offset bstart
ld hl, offset bend
scf
ccf
sbc hl, bc
ld a, 0
loop:
ld (bc), a
inc bc
dec hl
cp a, l
jr NZ, loop
cp a, h
jr NZ, loop
{ now we can store the top of the stack }
ld (stktop), sp
jp PASCALMAIN
{ When using the SDCC-SDLDZ80 linker, the first object module defines the
order of areas (sections). Since this module contains the startup code,
it is loaded first, so we define all the sections we use in the proper
order. }
area '_DATA'
area '_BSS'
bstart:
area '_BSSEND'
bend:
area '_HEAP'
area '_STACK'
area '_CODE'
end;
end.