mmu.c

RT-Thread是发展中的下一代微内核嵌入式实时操作系统

/*
 * File      : mmu.c
 * This file is part of RT-Thread RTOS
 * COPYRIGHT (C) 2006, RT-Thread Development Team
 *
 * The license and distribution terms for this file may be
 * found in the file LICENSE in this distribution or at
 * http://openlab.rt-thread.com/license/LICENSE
 *
 * Change Logs:
 * Date           Author       Notes
 * 2008-04-25     Yi.qiu       first version
 */

#include <rtthread.h>
#include "s3c2410.h"

#define _MMUTT_STARTADDRESS	 0x30080000
#define DESC_SEC	(0x2|(1<<4))
#define CB		(3<<2)  //cache_on, write_back
#define CNB		(2<<2)  //cache_on, write_through
#define NCB             (1<<2)  //cache_off,WR_BUF on
#define NCNB		(0<<2)  //cache_off,WR_BUF off
#define AP_RW		(3<<10) //supervisor=RW, user=RW
#define AP_RO		(2<<10) //supervisor=RW, user=RO

#define DOMAIN_FAULT	(0x0)
#define DOMAIN_CHK	(0x1)
#define DOMAIN_NOTCHK	(0x3)
#define DOMAIN0		(0x0<<5)
#define DOMAIN1		(0x1<<5)

#define DOMAIN0_ATTR	(DOMAIN_CHK<<0)
#define DOMAIN1_ATTR	(DOMAIN_FAULT<<2)

#define RW_CB		(AP_RW|DOMAIN0|CB|DESC_SEC)
#define RW_CNB		(AP_RW|DOMAIN0|CNB|DESC_SEC)
#define RW_NCNB		(AP_RW|DOMAIN0|NCNB|DESC_SEC)
#define RW_FAULT	(AP_RW|DOMAIN1|NCNB|DESC_SEC)

void rt_hw_mmu_init(void);

void MMU_SetTTBase(register rt_uint32_t i)
{
	asm ("mcr p15, 0, %0, c2, c2, 0": :"r" (i));
}

void MMU_SetDomain(register rt_uint32_t i)
{
	asm ("mcr p15,0, %0, c3, c0,  0": :"r" (i));
}

void MMU_EnableMMU()
{
	register rt_uint32_t i;

	/* read control register */
	asm ("mrc p15, 0, %0, c1, c0, 0":"=r" (i));

	i |= 0x1;

	/* write back to control register */
	asm ("mcr p15, 0, %0, c1, c0, 0": :"r" (i));
}

void MMU_DisableMMU()
{
	register rt_uint32_t i;

	/* read control register */
	asm ("mrc p15, 0, %0, c1, c0, 0":"=r" (i));

	i &= ~0x1;

	/* write back to control register */
	asm ("mcr p15, 0, %0, c1, c0, 0": :"r" (i));
}

void MMU_EnableICache()
{
	register rt_uint32_t i;

	/* read control register */
	asm ("mrc p15, 0, %0, c1, c0, 0":"=r" (i));

	i |= (1 << 12);

	/* write back to control register */
	asm ("mcr p15, 0, %0, c1, c0, 0": :"r" (i));
}

void MMU_EnableDCache()
{
	register rt_uint32_t i;

	/* read control register */
	asm ("mrc p15, 0, %0, c1, c0, 0":"=r" (i));

	i |= (1 << 2);

	/* write back to control register */
	asm ("mcr p15, 0, %0, c1, c0, 0": :"r" (i));
}

void MMU_DisableICache()
{
	register rt_uint32_t i;

	/* read control register */
	asm ("mrc p15, 0, %0, c1, c0, 0":"=r" (i));

	i &= ~(1 << 12);

	/* write back to control register */
	asm ("mcr p15, 0, %0, c1, c0, 0": :"r" (i));
}

void MMU_DisableDCache()
{
	register rt_uint32_t i;

	/* read control register */
	asm ("mrc p15, 0, %0, c1, c0, 0":"=r" (i));

	i &= ~(1 << 2);

	/* write back to control register */
	asm ("mcr p15, 0, %0, c1, c0, 0": :"r" (i));
}

void MMU_EnableAlignFault()
{
	register rt_uint32_t i;

	/* read control register */
	asm ("mrc p15, 0, %0, c1, c0, 0":"=r" (i));

	i |= (1 << 1);

	/* write back to control register */
	asm ("mcr p15, 0, %0, c1, c0, 0": :"r" (i));
}

void MMU_DisableAlignFault()
{
	register rt_uint32_t i;

	/* read control register */
	asm ("mrc p15, 0, %0, c1, c0, 0":"=r" (i));

	i &= ~(1 << 1);

	/* write back to control register */
	asm ("mcr p15, 0, %0, c1, c0, 0": :"r" (i));
}

void MMU_CleanInvalidateDCacheIndex(int index)
{
	asm ("mcr p15, 0, %0, c7, c14, 2": :"r" (index));
}

void MMU_InvalidateTLB()
{
	asm ("mcr p15, 0, %0, c8, c7, 0": :"r" (0));
}

void MMU_InvalidateICache()
{
	asm ("mcr p15, 0, %0, c7, c5, 0": :"r" (0));
}

void MMU_SetMTT(int vaddrStart,int vaddrEnd,int paddrStart,int attr)
{
    volatile rt_uint32_t *pTT;
    volatile int i,nSec;
    pTT=(rt_uint32_t *)_MMUTT_STARTADDRESS+(vaddrStart>>20);
    nSec=(vaddrEnd>>20)-(vaddrStart>>20);
    for(i=0;i<=nSec;i++)
    {
		*pTT = attr |(((paddrStart>>20)+i)<<20);
		pTT++;
    }
}

void rt_hw_mmu_init(void)
{
    int i,j;
    //========================== IMPORTANT NOTE =========================
    //The current stack and code area can't be re-mapped in this routine.
    //If you want memory map mapped freely, your own sophiscated MMU
    //initialization code is needed.
    //===================================================================

    MMU_DisableDCache();
    MMU_DisableICache();

    //If write-back is used,the DCache should be cleared.
    for(i=0;i<64;i++)
    	for(j=0;j<8;j++)
    	    MMU_CleanInvalidateDCacheIndex((i<<26)|(j<<5));
    
    MMU_InvalidateICache();

    //To complete MMU_Init() fast, Icache may be turned on here.
    MMU_EnableICache();

    MMU_DisableMMU();
    MMU_InvalidateTLB();

    //MMU_SetMTT(int vaddrStart,int vaddrEnd,int paddrStart,int attr);
    MMU_SetMTT(0x00000000,0x07f00000,0x00000000,RW_CNB);  //bank0
	MMU_SetMTT(0x00000000,0x03f00000,(int)0x30000000,RW_CB);  //bank0
    MMU_SetMTT(0x04000000,0x07f00000,0,RW_NCNB);  			//bank0
    MMU_SetMTT(0x08000000,0x0ff00000,0x08000000,RW_CNB);  //bank1
    MMU_SetMTT(0x10000000,0x17f00000,0x10000000,RW_NCNB); //bank2
    MMU_SetMTT(0x18000000,0x1ff00000,0x18000000,RW_NCNB); //bank3
    //MMU_SetMTT(0x20000000,0x27f00000,0x20000000,RW_CB); //bank4
    MMU_SetMTT(0x20000000,0x27f00000,0x20000000,RW_CNB); //bank4 for STRATA Flash
    MMU_SetMTT(0x28000000,0x2ff00000,0x28000000,RW_NCNB); //bank5
    //30f00000->30100000, 31000000->30200000
    MMU_SetMTT(0x30000000,0x30100000,0x30000000,RW_CB);	  //bank6-1
    MMU_SetMTT(0x30200000,0x33e00000,0x30200000,RW_NCNB); //bank6-2
 
    MMU_SetMTT(0x33f00000,0x33f00000,0x33f00000,RW_CB);   //bank6-3
    MMU_SetMTT(0x38000000,0x3ff00000,0x38000000,RW_NCNB); //bank7

    MMU_SetMTT(0x40000000,0x47f00000,0x40000000,RW_NCNB); //SFR
    MMU_SetMTT(0x48000000,0x5af00000,0x48000000,RW_NCNB); //SFR
    MMU_SetMTT(0x5b000000,0x5b000000,0x5b000000,RW_NCNB); //SFR
    MMU_SetMTT(0x5b100000,0xfff00000,0x5b100000,RW_FAULT);//not used

    MMU_SetTTBase(_MMUTT_STARTADDRESS);

	/* DOMAIN1: no_access, DOMAIN0,2~15=client(AP is checked) */
    MMU_SetDomain(0x55555550|DOMAIN1_ATTR|DOMAIN0_ATTR);
    	
    //MMU_SetProcessId(0x0);
    MMU_EnableAlignFault();

    MMU_EnableMMU();
    MMU_EnableICache();

	/* DCache should be turned on after MMU is turned on. */
    MMU_EnableDCache(); 	
}