MMU.rar_mmu_s3c2440 mmu

/******************************************************** *init.c:进行一些初始化，在steppingstone中进行 *他和head.S同属第一部分程序，此时MMU未启动，使用物理地址 *********************************************************/ #define WTCON (*(volatile unsigned long *)0x53000000) #define MEM_CTL_BASE 0x48000000 void disable_watch_dog(void){ WTCON=0; } void memsetup(void){ unsigned long const mem_cfg_val[]={ 0x22011110, //BWSCON 0X00000700, //BANKCON0 0X00000700, //BANKCON1 0X00000700, //BANKCON2 0X00000700, //BANKCON3 0X00000700, //BANKCON4 0X00000700, //BANKCON5 0X00180005, //BANKCON6 0X00180005, //BANKCON7 0X008C07A3, //REFRESH 0X000000B1, //BANKSIZE 0X00000030, //MRSRB6 0X00000030, //MRSRB7 }; int i=0; volatile unsigned long *p=(volatile unsigned long *)MEM_CTL_BASE; for(;i<13;i++) p[i]=mem_cfg_val[i]; } void copy_2_sdram(void){ /******************* *复制代码到SDRAM ********************/ unsigned int *pdwSrc=(unsigned int *)2048; unsigned int *pdwDest=(unsigned int *)0x30004000; while (pdwSrc<(unsigned int *)4096){ *pdwDest=*pdwSrc; pdwDest++; pdwSrc++; } } void create_page_table(void){ /***************************** *设置页表 ******************************/ #define MMU_FULL_ACCESS (3<<10) //访问权限 #define MMU_DOMAIN (0<<5) //属于哪个域 #define MMU_SPECIAL (1<<4) //必须是1 #define MMU_CACHEABLE (1<<3) #define MMU_BUFERABLE (1<<2) #define MMU_SECTION (2) //表示为段描述符 #define MMU_SECDESC (MMU_FULL_ACCESS|MMU_DOMAIN|MMU_SPECIAL|MMU_SECTION #define MMU_SECDESC_WB (MMU_FULL_ACCESS|MMU_DOMAIN|MMU_SPECIAL|MMU_CACHEABLE|MMU_BUFERABLE|MMU_SECTION #define MMU_SECTION_SIZE 0x00100000 unsigned long virtuladdr,physicaladdr; unsigned long *mmu_tlb_base=(unsigned long *)0x30000000; virtuladdr=0; physicaladdr=0; *(mmu_tlb_base+(virtuladdr>>20))=(physicaladdr&0xfff00000)|MMU_SECDESC_WB; virtuladdr=0xa0000000; physicaladdr=0x56000040; *(mmu_tlb_base+(virtuladdr>>20))=(physicaladdr&0xfff00000)|MMU_SECDESC; virtuladdr=0xb0000000; physicaladdr=0x30000000; while(virtuladdr<0xb4000000){ *(mmu_tlb_base+(virtuladdr>>20))=(physicaladdr&0xfff00000)|MMU_SECDESC_WB; virtuladdr+=0x100000; physicaladdr+=0x100000; } } void mmu_init(void){ /************************** ******启动mmu************* ***************************/ unsigned long ttb=0x30000000; __asm__( "mov r0,#0\n" "mcr p15,0,r0,c7,c7,0\n" /*使无效ICaches和DCaches*/ "mcr p15,0,r0,c7,c10,4\n" /*drain write buffer on v4*/ "mcr p15,0,r0,c8,c7,0\n" /*使无效指令、数据TLB*/ "mov r4,%0\n" /*r4=页表基址*/ "mcr p15,0,r0,c3,c0,0\n" /*设置页表基址寄存器*/ "mvn r0,#0\n" "mcr p15,0,r0,c3,c0,0\n" /*域访问控制寄存器设为0xffffffff，不进行权限检查*/ //对于控制寄存器，先读入其值，在此基础上修改感兴趣的位，然后写入 "mrc p15,0,r0,c1,c0,0\n" "bic r0,r0,#0x3000\n" "bic r0,r0,#0x0300\n" "bic r0,r0,#0x0087\n" "orr r0,r0,#0x0002\n" "orr r0,r0,#0x0004\n" "orr r0,r0,#0x1000\n" "orr r0,r0,#0x0001\n" "mcr p15,0,r0,c1,c0,0\n" : :"r"(ttb)); }