memory.h

//
//	memory.h
//
//	Definitions for dealing with memory.
//
//
//	$Id: memory.h,v 1.1 2000/09/20 01:50:19 elm Exp elm $

#ifndef	_memory_h_
#define	_memory_h_

// We can read this address in I/O space to figure out how much memory
// is available on the system.
#define	DLX_MEMSIZE_ADDRESS	0xffff0000

// We currently support 64 KB pages.  This is done as 64 KB pages in
// the level 1 page table and no level 2 page table
// These two constants should be set as follows:
// L1_PAGE_SIZE_BITS -> amount mapped by a single entry in the L1 table
// L2_PAGE_SIZE_BITS -> amount mapped by a single entry in the L2 table
//
// For example, if you have 4KB pages and each L2 page table has 512 entries,
// you'd have 2MB per entry in a L1 table.  That would mean L1_BITS=21 and
// L2_BITS=12.
#define	MEMORY_L1_PAGE_SIZE_BITS 16	// each entry in L1 is 64 KB
#define	MEMORY_L2_PAGE_SIZE_BITS 16	// if L1 == L2, there's no L2 tables
#define	MEMORY_PAGE_SIZE	(1 << MEMORY_L2_PAGE_SIZE_BITS)

#define	MEMORY_PAGE_MASK	(MEMORY_PAGE_SIZE-1)
#define	MEMORY_MAX_PAGES	0x10000

// The PTE is valid if this bit is set in the PTE!
#define	MEMORY_PTE_VALID	0x00000001
// The page is dirty if this bit is set in the PTE
#define	MEMORY_PTE_DIRTY	0x00000002
// The page has been referenced if this bit is set in the PTE
#define	MEMORY_PTE_REFERENCED	0x00000004
#define	MEMORY_PTE_MASK		(~(MEMORY_PTE_VALID|MEMORY_PTE_DIRTY|MEMORY_PTE_REFERENCED))

extern int	lastosaddress;		// Defined in an assembly file
extern int	MemoryGetSize ();
extern int	MemoryAllocPage ();
extern void	MemoryFreePage (uint32 page);
extern uint32	MemorySetupPte (uint32 page);
extern void	MemoryFreePte (uint32 pte);
extern uint32	MemoryPteToPage ();
extern void	MemoryModuleInit ();
extern uint32	MemoryTranslateUserToSystem ();
extern int	MemoryCopySystemToUser ();
extern int	MemoryCopyUserToSystem ();

#endif	// _memory_h_