Looks the the Maple bus is a direct config bus.  The patch below should
make it behave like a direct config bus in the NetBSD kernel.  I don't
know if this compiles yet (don't have my cross compile environment up),
but you can get the idea about that should happen from the patch.

This, or something like it, should be committed to the tree.

-- 
        -- Jason R. Thorpe <thorpej@zembu.com>

Index: conf/GENERIC
===================================================================
RCS file: /cvsroot/syssrc/sys/arch/dreamcast/conf/GENERIC,v
retrieving revision 1.3
diff -c -r1.3 GENERIC
*** conf/GENERIC	2001/01/16 00:33:50	1.3
--- conf/GENERIC	2001/01/19 20:57:25
***************
*** 115,121 ****
  
  pvr0    at shb?
  
! mkbd*	at maple?
  
  wsdisplay*      at pvr? console ?
  wskbd*          at mkbd? console ?
--- 115,121 ----
  
  pvr0    at shb?
  
! mkbd*	at maple? port ? subunit ?
  
  wsdisplay*      at pvr? console ?
  wskbd*          at mkbd? console ?
Index: conf/files.dreamcast
===================================================================
RCS file: /cvsroot/syssrc/sys/arch/dreamcast/conf/files.dreamcast,v
retrieving revision 1.3
diff -c -r1.3 files.dreamcast
*** conf/files.dreamcast	2001/01/17 00:07:23	1.3
--- conf/files.dreamcast	2001/01/19 20:57:25
***************
*** 18,24 ****
  			BSC_RTCSR_VAL BSC_RTCNT_VAL BSC_RTCOR_VAL BSC_RFCR_VAL
  			BSC_PCR_VAL FRQCR_VAL PFC_SCPCR_VAL
  
! device maple { }
  attach maple at shb
  file	arch/dreamcast/dev/maple/maple.c	maple
  
--- 18,24 ----
  			BSC_RTCSR_VAL BSC_RTCNT_VAL BSC_RTCOR_VAL BSC_RFCR_VAL
  			BSC_PCR_VAL FRQCR_VAL PFC_SCPCR_VAL
  
! device maple { [port = -1], [subunit = -1] }
  attach maple at shb
  file	arch/dreamcast/dev/maple/maple.c	maple
  
Index: dev/maple/maple.c
===================================================================
RCS file: /cvsroot/syssrc/sys/arch/dreamcast/dev/maple/maple.c,v
retrieving revision 1.2
diff -c -r1.2 maple.c
*** dev/maple/maple.c	2001/01/19 20:27:31	1.2
--- dev/maple/maple.c	2001/01/19 20:57:25
***************
*** 62,67 ****
--- 62,68 ----
  static int	maplematch __P((struct device *, struct cfdata *, void *));
  static void	mapleattach __P((struct device *, struct device *, void *));
  static int	mapleprint __P((void *, const char *));
+ static int	maplesubmatch __P((struct device *, struct cfdata *, void *));
  static void	maple_attach_dev __P((struct maple_softc *, int, int));
  static void	maple_begin_txbuf __P((struct maple_softc *));
  static int	maple_end_txbuf __P((struct maple_softc *));
***************
*** 88,95 ****
  	sizeof(struct maple_softc), maplematch, mapleattach
  };
  
- int	maplesearch __P((struct device *, struct cfdata *, void *));
- 
  static int
  maplematch(parent, cf, aux)
  	struct device *parent;
--- 89,94 ----
***************
*** 105,111 ****
  	return (1);
  }
  
- 
  static void
  maple_attach_dev(sc, port, subunit)
  	struct maple_softc *sc;
--- 104,109 ----
***************
*** 113,122 ****
  	int subunit;
  {
  	struct maple_attach_args ma;
  	ma.ma_port = port;
  	ma.ma_subunit = subunit;
  	ma.ma_devinfo = &sc->sc_unit[port][subunit].devinfo;
! 	config_search(maplesearch, &sc->sc_dev, &ma);
  }
  
  static void
--- 111,122 ----
  	int subunit;
  {
  	struct maple_attach_args ma;
+ 
  	ma.ma_port = port;
  	ma.ma_subunit = subunit;
  	ma.ma_devinfo = &sc->sc_unit[port][subunit].devinfo;
! 
! 	(void) config_found_sm(&sc->sc_dev, &ma, mapleprint, maplesubmatch);
  }
  
  static void
***************
*** 394,400 ****
  	uvm_pglistfree(&mlist);
  }
  
- 
  static void
  mapleattach(parent, self, aux)
  	struct device *parent, *self;
--- 394,399 ----
***************
*** 454,479 ****
  	struct maple_attach_args *ma = aux;
  
  	if (pnp != NULL)
! 		printf("%s", pnp);
  
! 	printf(" port %c", ma->ma_port+'A');
  
  	if (ma->ma_subunit != 0)
! 	  printf("%d", ma->ma_subunit);
  
  	return (UNCONF);
  }
  
! int
! maplesearch(parent, cf, aux)
  	struct device *parent;
! 	struct cfdata *cf;
  	void *aux;
  {
! 	if ((*cf->cf_attach->ca_match)(parent, cf, aux) > 0)
! 	  config_attach(parent, cf, aux, mapleprint);
  
! 	return (0);
  }
  
  u_int32_t
--- 453,486 ----
  	struct maple_attach_args *ma = aux;
  
  	if (pnp != NULL)
! 		printf("%s %s at %s", ma->ma_devinfo->di_product_license,
! 		    ma->ma_devinfo->di_product_name, pnp);
  
! 	printf(" port %d", ma->ma_port);
  
  	if (ma->ma_subunit != 0)
! 		printf(" subunit %d", ma->ma_subunit);
  
  	return (UNCONF);
  }
  
! static int
! maplesubmatch(parent, match, aux)
  	struct device *parent;
! 	struct cfdata *match;
  	void *aux;
  {
! 	struct maple_attach_args *ma = aux;
  
! 	if (match->cf_loc[MAPLECF_PORT] != MAPLECF_PORT_DEDFAULT &&
! 	    match->cf_loc[MAPLECF_PORT] != ma->ma_port)
! 		return (0);
! 
! 	if (match->cf_loc[MAPLECF_SUBUNIT] != MAPLECF_SUBUNIT_DEFAULT &&
! 	    match->cf_loc[MAPLECF_SUBUNIT] != ma->ma_subunit)
! 		return (0);
! 
! 	return ((*match->cf_attach->ca_match)(parent, match, aux));
  }
  
  u_int32_t
***************
*** 492,495 ****
  		break;
  	return (0);
  }
- 
--- 499,501 ----