haiku/headers/private/kernel/arch/arm/arm_mmu.h

#ifndef _ARCH_ARM_ARM_MMU_H
#define _ARCH_ARM_ARM_MMU_H

/*
 * generic arm mmu definitions
 */


/*
 * defines for the page directory (aka Master/Section Table)
 */

#define MMU_L1_TYPE_COARSEPAGETABLE 0x1
	//only type used in Haiku by now (4k pages)

// coarse pagetable entry :
//
// 31                    10 9 8      5 432 10
// | page table address    |?| domain |000|01
//
// the domain is not used so and the ? is implementation specified... have not
// found it in the cortex A8 reference... so I set t to 0
// page table must obviously be on multiple of 1KB

#define MMU_L1_TYPE_SECTION 0x2
	//map 1MB directly instead of using a page table (not used)
#define MMU_L1_TYPE_FINEEPAGETABLE 0x3
	//map 1kb pages (not used and not supported on newer ARMs)

/*
 * L2-Page descriptors... now things get really complicated...
 * there are three different types of pages large pages (64KB) and small(4KB)
 * and "small extended".
 * only small extende is used by now....
 * and there is a new and a old format of page table entries
 * I will use the old format...
 */

#define MMU_L2_TYPE_SMALLEXT 0x3
/* for new format entries (cortex-a8) */
#define MMU_L2_TYPE_SMALLNEW 0x2

// for B C and TEX see ARM arm B4-11
#define MMU_L2_FLAG_B 0x4
#define MMU_L2_FLAG_C 0x8
#define MMU_L2_FLAG_TEX 0	// use 0b000 as TEX
#define MMU_L2_FLAG_AP_RW 0x30	// allow read and write for user and system
// #define MMU_L2_FLAG_AP_


#define MMU_L1_TABLE_SIZE (4096 * 4)
	//4096 entries (one entry per MB) -> 16KB
#define MMU_L2_COARSE_TABLE_SIZE (256 * 4)
	//256 entries (one entry per 4KB) -> 1KB


/*
 * definitions for CP15 r1
 */

#define CR_R1_MMU 0x1		// enable MMU
#define CP_R1_XP 0x800000	// if XP=0 then use backwards comaptible
				// translation tables

#define VADDR_TO_PDENT(va)	((va) >> 20)
#define VADDR_TO_PTENT(va)	(((va) & 0xff000) >> 12)
#define VADDR_TO_PGOFF(va)	((va) & 0x0fff)

#define ARM_PDE_ADDRESS_MASK	0xfffffc00
#define ARM_PTE_ADDRESS_MASK	0xfffff000

#endif /* _ARCH_ARM_ARM_MMU_H */