;==============================================================================
; stub.asm: Stub added at the beginning of the patched program.
; 
; $Id: stub.asm,v 1.5 2004/06/07 14:24:06 Olivier Exp $
; 
; - GhostBuster for TI89 Titanium -
; Copyright (C) 2004 Olivier Armand  <ola dot e-ml at wanadoo dot fr>
;                and Kevin Kofler <kevin dot kofler at chello dot at>
; 
; 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.
; 
; 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., 59 Temple
; Place - Suite 330, Boston, MA  02111-1307, USA.
; 
; In addition, as a special exception, Olivier Armand and Kevin Kofler give
; permission to link the code of this program with the ttunpack decompression
; library by the TI-Chess Team, and distribute linked combinations including
; the two. You must obey the GNU General Public License in all respects for
; all of the code used other than the ttunpack decompression library. If you
; modify this program, you may extend this exception to your version of the
; program, but you are not obligated to do so. If you do not wish to do so,
; delete this exception statement from your version.
;
;==============================================================================

	xdef STUB_SIZE
	xdef StubHead
	xdef StubRunPrgm	; to patch the stub of kernel-based programs

; #include "patch.h"

STUB_SIZE	dc.l 	StubTail-StubHead

; This stub is executed before the patched program's code.
; It must not contain any relocation, and must be optimized as much as
; possible because all the patched programs have to carry it.
; The code works both for nostub and kernel-based programs, with a few
; patches. The bsr of the kernel stub code of kernel-based programs should not
; return, so tricks must be used to fool this stub and the loader code if
; instructions have to be executed after the program's execution.
; Note the nostub comments of a patched program won't be seen anymore, but
; only few of these programs have comments.

StubHead:

; <-- Code can be added here -->

StubRunPrgm: ; caution, the offset of the following bsr will be patched in kernel-based programs
	;bra.w 	StubTail ; run the real program
	; Constants are used instead of the assembly instruction to avoid linker-side branches
	; optimization that would convert the bra.w into a bra.s
	dc.w	$6000
	dc.w	StubTail-*

StubTail:
	; The real program follows in nostub programs...