/*
  set up MMU for flash access using mmu.library

  (C) 2022 Henryk Richter

  The F0 area (0xF00000-0xF7ffff) is known to be
  reserved by Commodore for diagnostic ROMs (or
  BootROMs), as well as additional kickstart modules.

  Some configurations of the MMU will mark this
  area as ROM such that write attempts are inhibited
  by the processor itself.

  This code will revert any existing remapping (to
  RAM) and set up useable cache flags such that the
  Flash can be written to.

*/
#define __NOLIBBASE__
#include <proto/mmu.h>
#include <mmu/context.h>
#include <mmu/mmutags.h>
#include "debug.h"
#include "mmustuff.h"


//extern struct Library *MMUBase;
//extern struct DosLibrary *DOSBase;

#define CACHEFLAGS (MAPP_CACHEINHIBIT|MAPP_COPYBACK|MAPP_NONSERIALIZED|MAPP_IMPRECISE)

#define ROMFLAGS  (MAPP_CACHEINHIBIT|MAPP_GLOBAL|MAPP_IO|MAPP_USER0)
#define ROMCFLAGS (MAPP_CACHEINHIBIT|MAPP_COPYBACK|MAPP_NONSERIALIZED|MAPP_IMPRECISE|MAPP_GLOBAL|MAPP_IO|MAPP_WRITEPROTECTED|MAPP_ROM|MAPP_INVALID)

#ifdef __VBCC__
#define BCAST
#else
#define BCAST (ULONG)
#endif


/*
  set up MMU as I/O space from "base", "size" bytes,
  keep flags==0 for now

  the device pointer is used to fetch the MMUbase from it, nothing more
*/
ASM SAVEDS LONG setupMMU( ASMR(a0) void *base    ASMREG(a0),
                          ASMR(d0) LONG size     ASMREG(d0),
			  ASMR(d1) ULONG flags   ASMREG(d1),
		          ASMR(a6) DEVBASEP      ASMREG(a6) )
{
	struct MMUContext *ctx,*sctx;   /* default context, supervisor context */
	ULONG  props;
	struct MinList *ctxl,*sctxl;
	struct TagItem tgs[2] = {{TAG_DONE,0},{TAG_DONE,0} };

	if( !MMUBase )
		return 1;	/* cannot setup MMU without MMULib */

	ctx=DefaultContext();
	sctx=SuperContext(ctx);

	props  = GetPropertiesA(sctx,BCAST base,tgs);
	props |= GetPropertiesA(sctx,BCAST base,tgs);

	D(( (STRPTR)"Current MMU props on 0x%lx area: 0x%lx\n",(ULONG)base,props));

	LockContextList();
	LockMMUContext(ctx);
	LockMMUContext(sctx);

	if( (props & MAPP_REMAPPED) )
	{
		D(( (STRPTR)"Memory was remapped elsewhere, reverting to physical location\n" ));

	        if( (ctxl=GetMapping(ctx)))
		{
        	 if( (sctxl=GetMapping(sctx)))
		 {
		  if( SetPropertiesA(ctx,0,MAPP_REMAPPED|CACHEFLAGS,BCAST base,size,tgs) )
		  {
		   if( SetPropertiesA(sctx,0,MAPP_REMAPPED|CACHEFLAGS,BCAST base,size,tgs) )
		   {
		   }
		  }
		  ReleaseMapping(sctx,sctxl);
		 }
		 ReleaseMapping(ctx,ctxl);
		}
	}

	/* set desired flags */
	SetPropertiesA(ctx,ROMFLAGS,ROMCFLAGS, BCAST base,size,tgs);
	SetPropertiesA(sctx,ROMFLAGS,ROMCFLAGS,BCAST base,size,tgs);

	RebuildTrees(ctx,sctx,NULL); 

        UnlockMMUContext(sctx);
       	UnlockMMUContext(ctx);
       	UnlockContextList();

	props  = GetPropertiesA(sctx,BCAST base,tgs);
	props |= GetPropertiesA(sctx,BCAST base,tgs);
	D(( (STRPTR)"New MMU props on 0x%lx area: 0x%lx\n",(ULONG)base,props));

	return 0;
}