/************************************************
NAME : MMU.C
DESC :
Revision: 2002.2.28 ver 0.0
************************************************/
#include "def.h"
#include "option.h"
#include "2440addr.h"
#include "2440lib.h"
#include "2440slib.h"
#include "mmu.h"
// 1) Only the section table is used.
// 2) The cachable/non-cachable area can be changed by MMT_DEFAULT value.
// The section size is 1MB.
void __ENTRY(void);
//***************************************************************************************
void 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();//禁止数据高速缓存
MMU_DisableICache();//禁止指令高速缓存
//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));//使整个DCache的数据无效
MMU_InvalidateICache();//使无效整个指令Cache
#if 0
//To complete MMU_Init() fast, Icache may be turned on here.为了快速完成MMU_Init()
MMU_EnableICache();
#endif
MMU_DisableMMU();//禁止MMU
MMU_InvalidateTLB();//使快表无效
//MMU_SetMTT(int vaddrStart,int vaddrEnd,int paddrStart,int attr)
// MMU_SetMTT(0x00000000,0x07f00000,0x00000000,RW_NCNB); //bank0
MMU_SetMTT(0x00000000,0x00400000,(U32)__ENTRY,RW_CB); //bank0 when no nor flash, must do this
//!!! Important note, redirect IRQ vector to reset entry !!!
// MMU_SetMTT(0x08000000,0x0ff00000,0x08000000,RW_NCNB); //bank1
MMU_SetMTT(0x08000000,0x0c000000,0x04000000,RW_NCNB); //bank1
// 0x08000000 -> 0x00000000, NCNB
MMU_SetMTT(0x10000000,0x17f00000,0x10000000,RW_NCNB); //bank2
MMU_SetMTT(0x18000000,0x1ff00000,0x18000000,RW_NCNB); //bank3
MMU_SetMTT(0x20000000,0x27f00000,0x20000000,RW_NCNB); //bank4
MMU_SetMTT(0x28000000,0x2ff00000,0x28000000,RW_NCNB); //bank5
MMU_SetMTT(0x30000000,0x30200000,0x30000000,RW_CB); //bank6-1
// MMU_SetMTT(0x30000000,0x30200000,0x30000000,RW_CB); //bank6-1
MMU_SetMTT(0x30200000,0x33e00000,0x30200000,(AP_RO|DOMAIN0|NCNB|DESC_SEC)); //bank6-2
// MMU_SetMTT(0x33f00000,0x33f00000,0x33f00000,RW_CB); //bank6-3
MMU_SetMTT(0x33f00000,0x34000000,0x33f00000,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(0x5b000000,0xfff00000,0x5b000000,RW_FAULT);//not used
MMU_SetTTBase(_MMUTT_STARTADDRESS);//写转换表基地址到C2
MMU_SetDomain(0x55555550|DOMAIN1_ATTR|DOMAIN0_ATTR);
//DOMAIN1: no_access, DOMAIN0,2~15=client(AP is checked)
//写域访问控制位到C3
MMU_SetProcessId(0x0);
MMU_EnableAlignFault();
MMU_EnableMMU();
MMU_EnableICache();
MMU_EnableDCache(); //DCache should be turned on after MMU is turned on.
}
//***************************************************************************************
// attr=RW_CB,RW_CNB,RW_NCNB,RW_FAULT
void ChangeRomCacheStatus(int attr)
{
int i,j;
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();
MMU_DisableMMU();
MMU_InvalidateTLB();
MMU_SetMTT(0x00000000,0x07f00000,0x00000000,attr); //bank0
MMU_SetMTT(0x08000000,0x0ff00000,0x08000000,attr); //bank1
MMU_EnableMMU();
MMU_EnableICache();
MMU_EnableDCache();
}
/****************************************************************************************
设置页表函数:
vaddrStart：虚拟起始地址
vaddrEnd：虚拟结束地址
paddrStart：物理起始地址
attr：访问属性
虚拟存储空间到物理存储空间的映射是以内存块为单位的：分为1M/64Lb/4Kb/1kB
虚拟存储空间中的一块连续的存储空间被映射成物理存储空间中同样大小的一块连续存储空间页表中，
每一个地址变换条目实际上就记录了一个虚拟存储空间的存储块的基地址与物理存储空间相应的一个存储块的基地址的对应关系。
****************************************************************************************/
void MMU_SetMTT(int vaddrStart,int vaddrEnd,int paddrStart,int attr)
{
U32 *pTT;//定义了页表的指针
int i,nSec;
pTT=(U32 *)_MMUTT_STARTADDRESS+(vaddrStart>>20);//由于内存块是1M的，写页表的基地址
nSec=(vaddrEnd>>20)-(vaddrStart>>20);//nSec:段大小
for(i=0;i<=nSec;i++)*pTT++=attr |(((paddrStart>>20)+i)<<20);
//页表存储访问信息和存储块的基地址(((paddrStart>>20)+i)<<20) ：
//对应的物理内存页的地址 attr：访问权限和缓冲属性
}
//*************************************************************************************** |
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