C++ (Cpp) MMUInit Examples

Example #1

File: usb_dev_bulk.c Project: OS-Project/Divers

/*
** Function to setup MMU. This function Maps three regions (1. DDR
** 2. OCMC and 3. Device memory) and enables MMU.
*/
void MMUConfigAndEnable(void)
{
    /*
    ** Define DDR memory region of AM335x. DDR can be configured as Normal
    ** memory with R/W access in user/privileged modes. The cache attributes
    ** specified here are,
    ** Inner - Write through, No Write Allocate
    ** Outer - Write Back, Write Allocate
    */
    REGION regionDdr = {
                        MMU_PGTYPE_SECTION, START_ADDR_DDR, NUM_SECTIONS_DDR,
                        MMU_MEMTYPE_NORMAL_NON_SHAREABLE(MMU_CACHE_WT_NOWA,
                                                     MMU_CACHE_WB_WA),
                        MMU_REGION_NON_SECURE, MMU_AP_PRV_RW_USR_RW,
                        (unsigned int*)pageTable
                       };
    /*
    ** Define OCMC RAM region of AM335x. Same Attributes of DDR region given.
    */
    REGION regionOcmc = {
                         MMU_PGTYPE_SECTION, START_ADDR_OCMC, NUM_SECTIONS_OCMC,
                         MMU_MEMTYPE_NORMAL_NON_SHAREABLE(MMU_CACHE_WT_NOWA,
                                                      MMU_CACHE_WB_WA),
                         MMU_REGION_NON_SECURE, MMU_AP_PRV_RW_USR_RW,
                         (unsigned int*)pageTable
                        };

    /*
    ** Define Device Memory Region. The region between OCMC and DDR is
    ** configured as device memory, with R/W access in user/privileged modes.
    ** Also, the region is marked 'Execute Never'.
    */
    REGION regionDev = {
                        MMU_PGTYPE_SECTION, START_ADDR_DEV, NUM_SECTIONS_DEV,
                        MMU_MEMTYPE_DEVICE_SHAREABLE,
                        MMU_REGION_NON_SECURE,
                        MMU_AP_PRV_RW_USR_RW  | MMU_SECTION_EXEC_NEVER,
                        (unsigned int*)pageTable
                       };

    /* Initialize the page table and MMU */
    MMUInit((unsigned int*)pageTable);

    /* Map the defined regions */
    MMUMemRegionMap(&regionDdr);
    MMUMemRegionMap(&regionOcmc);
    MMUMemRegionMap(&regionDev);

    /* Now Safe to enable MMU */
    MMUEnable((unsigned int*)pageTable);
}

Example #2

File: target.c Project: leeminghao/lj-os

/*
 *==============================================================================================
 * 函数名称：TargetInit
 * 功能描述：初始化目标板，完成以下功能：
 *           1. 时钟初始化
 *           2. mmu初始化
 *           3. 串口初始化
 *           4. 串口初始化
 * 传    参：void
 * 返 回 值：void
 *==============================================================================================
 */
 void
 TargetInit( void )
 {
 	U32		i;
 	U8		key;
 	U32		mpllVal = 0;
 	
 	i		= 2;						/* 使用400MHz主频                                      */
 	switch ( i )
 	{
 		case 0:							/* 200MHz */
 			key = 12;
 			mpllVal = (92 << 12) | (4 << 4) | (1);
 			break;
 			
 		case 1:							/* 300MHz */
 			key = 14;
 			mpllVal = (67 << 12) | (1 << 4) | (1);
 			break;
 			
 		case 2:							/* 400MHz */
 			key = 14;
 			mpllVal = (92 << 12) | (1 << 4) | (1);
 			break;
 			
 		case 3:							/* 440MHz */
 			key = 14;
 			mpllVal = (102 << 12) | (1 << 4) | (1);
 			break;
 			
 		default:						/* 默认使用400MHz */
 			key = 14;
 			mpllVal = (92 << 12) | (1 << 4) | (1);
 			break;
 	}
 	
 	ChangeMPLLValue( (mpllVal >> 12) & 0xff, (mpllVal >> 4) & 0x3f, mpllVal & 3 );	/* 时钟初始化 */
 	ChangeClockDivider( key, 12 );
 	
 	MMUDisableICache( );				
 	MMUDisableDCache( );
 	MMUInit( );							/* MMU初始化                                           */
 	
 	PortInit( );						/* 端口初始化                                          */
 	
 	UartSelect( 0 );					/* 串口选择                                            */
 	UartInit( 0, 115200 );				/* 串口初始化                                          */
 }