/****************************************************************************
   
    OS/A65 Version 2.0.0
    Multitasking Operating System for 6502 Computers

    Copyright (C) 1989-1998 Andre Fachat 

    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., 675 Mass Ave, Cambridge, MA 02139, USA.

****************************************************************************/


/*
 * this little program starts the gecko when its CPU is replaced by
 * the 40 pin connection to the CSA emulator board.
 * The gecko must be setup for internal CPU.
 *
 * The ROM is mapped from pages 4-c. The RAM is mapped from the
 * Gecko card itself.
 *
 * The I/O is mapped from the gecko obviously,
 * i.e. we set ioinh on the BIOS board.
 *
 * As the I/O is mapped from the gecko, the whole page $exxx must
 * not have any data/code in it, as it is remapped from the original
 * gecko ROM, not from the pages 4-c like the rest of the ROM!
 */

#define	GSEGMENT	$20

#include  "kdefs.i65"
#include  "kernel.i65"
#include  "../../csa65/csa65.i65"	; we boot from a csa system

          .word $400
          *=$400
          
l1        =$0
			 	; exit all devices
          lda #0
          sta l1
l2        ldx l1
          lda #DC_EXIT
          jsr DEVCMD
          inc l1
          lda l1
          cmp #16
          bcc l2
				; disable timer interrupt
          lda SYSPORT
          and #$ff-SYS_IRQEN
          sta SYSPORT

          sei			; remap MMU pages 8-15 with values from 
          ldx #8		; 4 to c
l3        lda $eff4,x
          sta $eff8,x
          dex
          bpl l3

          ldx #1		; map pages 1-7 from gecko
l4        txa
	  ora #GSEGMENT
          sta $eff0,x
          inx
          cpx #$8
          bcc l4

          ldx #0		; copy program to valid RAM
l5        lda data,x
          sta $1000,x
          inx
          bne l5
          
          jmp $1000		; and jump there
          
data      
	  lda #GSEGMENT		; remap page 0
          sta $eff0

	  lda #$0b		; extio is on page $0b000
	  sta $eff7		; map I/O to $07000 for ext. I/O
	  lda #GSEGMENT + $e	; gecko I/O page
	  sta $effe
	  lda SYSPORT
	  ora #%00100000	; ioinh
	  and #%11101111	; extio
	  sta SYSPORT

	lda $7fe0
	eor #%00001000
	sta $7fe0

	ldx #0
	ldy #0
x0	dey
	bne x0
	dex
	bne x0
	
	lda $7fe0
	eor #%00001000
	sta $7fe0

	ldx #0
	ldy #0
x1	dey
	bne x1
	dex
	bne x1

;lda #$0f
;sta $7fff
;lda #%00100000
;sta $7fe0

          jmp RESET