Add missing prototype.
 [rsc] --rw-rw-r-- M 489211 glenda sys 21210 Nov  7 09:55 sys/src/9/pc/trap.c
	/n/sourcesdump/2005/1107/plan9/sys/src/9/pc/trap.c:591,596 - 
	/n/sourcesdump/2005/1108/plan9/sys/src/9/pc/trap.c:591,597
	  	print("unexpected trap %lud; ignoring\n", ureg->trap);
	  }
	  
	+ extern void checkpages(void);
	  static void
	  fault386(Ureg* ureg, void*)
	  {
 [rsc] --rw-rw-r-- M 489211 rsc sys 2396 Nov  7 17:27 sys/src/9/pc/vgavesa.c
	/n/sourcesdump/2005/1107/plan9/sys/src/9/pc/vgavesa.c:23,33 - 
	/n/sourcesdump/2005/1108/plan9/sys/src/9/pc/vgavesa.c:23,36
	  static uchar*
	  vbesetup(Ureg *u, int ax)
	  {
	+ 	ulong pa;
	+ 	
	+ 	pa = PADDR(RMBUF);
	  	memset(u, 0, sizeof *u);
	  	u->ax = ax;
	- 	u->es = (RMBUF>>4)&0xF000;
	- 	u->di = RMBUF&0xFFFF;
	- 	return KADDR(RMBUF);
	+ 	u->es = (pa>>4)&0xF000;
	+ 	u->di = pa&0xFFFF;
	+ 	return (void*)RMBUF;
	  }
	  
	  static void
 [rsc] --rw-rw-r-- M 489211 glenda sys 10255 Nov  7 22:58 sys/src/9/pc/vganeomagic.c
	/n/sourcesdump/2005/1107/plan9/sys/src/9/pc/vganeomagic.c:34,39 - 
	/n/sourcesdump/2005/1108/plan9/sys/src/9/pc/vganeomagic.c:34,41
	  	 * scr->mmio holds the virtual address of the cursor registers
	  	 * in the MMIO space. This may need to change for older chips
	  	 * which have the MMIO space offset in the framebuffer region.
	+ 	 *
	+ 	 * scr->io holds the offset into mmio of the CursorNM struct.
	  	 */
	  	if(scr->mmio)
	  		return;
	/n/sourcesdump/2005/1107/plan9/sys/src/9/pc/vganeomagic.c:88,94 - 
	/n/sourcesdump/2005/1108/plan9/sys/src/9/pc/vganeomagic.c:90,96
	  	 * last 2KB of the framebuffer.
	  	 */
	  	scr->storage = vmsize-2*1024;
	- 	scr->mmio = (ulong*)((uchar*)scr->mmio + curoff);
	+ 	scr->io = curoff;
	  	vgalinearpci(scr);
	  	if(scr->paddr)
	  		addvgaseg("neomagicscreen", scr->paddr, scr->apsize);
	/n/sourcesdump/2005/1107/plan9/sys/src/9/pc/vganeomagic.c:101,107 - 
	/n/sourcesdump/2005/1108/plan9/sys/src/9/pc/vganeomagic.c:103,109
	  
	  	if(scr->mmio == 0)
	  		return;
	- 	cursornm = (void*)scr->mmio;
	+ 	cursornm = (void*)((char*)scr->mmio + scr->io);
	  	cursornm->enable = 0;
	  }
	  
	/n/sourcesdump/2005/1107/plan9/sys/src/9/pc/vganeomagic.c:112,118 - 
	/n/sourcesdump/2005/1108/plan9/sys/src/9/pc/vganeomagic.c:114,120
	  	uint p0, p1;
	  	int x, y;
	  
	- 	p = (uchar*)scr->mmio;
	+ 	p = (uchar*)scr->vaddr;
	  	p += scr->storage + index*1024;
	  
	  	for(y = yo; y < 16; y++){
	/n/sourcesdump/2005/1107/plan9/sys/src/9/pc/vganeomagic.c:156,162 - 
	/n/sourcesdump/2005/1108/plan9/sys/src/9/pc/vganeomagic.c:158,164
	  
	  	if(scr->mmio == 0)
	  		return;
	- 	cursornm = (void*)scr->mmio;
	+ 	cursornm = (void*)((char*)scr->mmio + scr->io);
	  
	  	cursornm->enable = 0;
	  	memmove(&scr->Cursor, curs, sizeof(Cursor));
	/n/sourcesdump/2005/1107/plan9/sys/src/9/pc/vganeomagic.c:172,178 - 
	/n/sourcesdump/2005/1108/plan9/sys/src/9/pc/vganeomagic.c:174,180
	  
	  	if(scr->mmio == 0)
	  		return 1;
	- 	cursornm = (void*)scr->mmio;
	+ 	cursornm = (void*)((char*)scr->mmio + scr->io);
	  
	  	index = 0;
	  	if((x = p.x+scr->offset.x) < 0){
	/n/sourcesdump/2005/1107/plan9/sys/src/9/pc/vganeomagic.c:211,217 - 
	/n/sourcesdump/2005/1108/plan9/sys/src/9/pc/vganeomagic.c:213,219
	  	neomagicenable(scr);
	  	if(scr->mmio == 0)
	  		return;
	- 	cursornm = (void*)scr->mmio;
	+ 	cursornm = (void*)((char*)scr->mmio + scr->io);
	  	cursornm->enable = 0;
	  
	  	/*