lowinit.c

在ARM7和UC/OSII的平台上实现了GPS自动报站的功能,涉及GPS模块LEA_4S的驱动,位置速寻算法,语音芯片ISD4004的录放音驱动,LED页面管理等等.从启动代码到操作系统的移植以及到业

/****************************************************************
**                                                              *
**  FILE         :  LOWINIT.H                                   *
**  COPYRIGHT    :  (c) 2004 .Xiamen Yaxon NetWork CO.LTD       *
**                                                              *
**                                                              *
**            2004/10/21                                        *
****************************************************************/

#include "includes.h"
#include "bsp.h"


// The following functions must be write in ARM mode this function called directly
// by exception vector

void vec_reset_handler (void)
{
    SendFromUART_STR(USART1,(INT8U*) ("1EXC: Soft Reset!!\r\n"));
}

void vec_undef_handler (void)
{
    SendFromUART_STR(USART1,(INT8U*)("2EXC: Undef!!\r\n"));
}

void vec_swi_handler (void)
{
    SendFromUART_STR(USART1, (INT8U*) ("3EXC: SWI!!\r\n"));
}

void vec_prefetchabort_handler (INT32U addr)
{
    PrintFromUART(USART1,(char*) ("4EXC: Prefetch Abort!!\r\n"));
    
    //PrintFromUART(USART1,"\naddress=");
    SendFromUART_HEX(USART1,(INT32U)addr >>24);
    SendFromUART_HEX(USART1,(INT32U)addr>>16);
    SendFromUART_HEX(USART1,(INT32U)addr>>8);
    SendFromUART_HEX(USART1,(INT32U)addr);
}

void vec_dataabort_handler (void)
{
    PrintFromUART(USART1,(char*)  ("5EXC: Data Abort!!\r\n"));
    //PrintFromUART(USART1,"\naddress=");
    //SendFromUART_HEX(USART1,(INT32U)vecptr>>24);
    //SendFromUART_HEX(USART1,(INT32U)vecptr>>16);
    //SendFromUART_HEX(USART1,(INT32U)vecptr>>8);
    //SendFromUART_HEX(USART1,(INT32U)vecptr);    
    
}

void AT91F_Spurious_handler (void)
{
    SendFromUART_STR(USART1,(INT8U*) ("NOTE:  Entering Spurious!!\r\n"));
}

void AT91F_Default_IRQ_handler(void)
{
	PrintFromUART(USART1,(char*)  ("enter start IRQ interrupt!!\r\n"));
}

void AT91F_Default_FIQ_handler(void)
{
	PrintFromUART(USART1,(char*)  ("enter start FIQ interrupt!!\r\n"));
}

//*----------------------------------------------------------------------------
//* \fn    AT91F_LowLevelInit
//* \brief This function performs very low level HW initialization
//*         this function can be use a Stack, depending the compilation 
//*        optimization mode
//* Input Parameters
//* <Vector>  vector table Address determinate in Relative addressing
//* <InternalRam> Internal Address determinate in Relative addressing
//* Output Parameters 
//* <EBI address>
//*----------------------------------------------------------------------------
AT91_REG * AT91F_LowLevelInit( unsigned int * Vector, unsigned int * InternalRam)
{
    INT32U i;  
    
    AT91PS_EBI     pEbi;
    AT91PS_AIC     pAic;
	//-----------------------------------------------------------------------------
	// Speed up the Boot sequence
	//---------------------------
	// After reset, the number of wait states on chip select 0 is 8. All AT91 
	// Evaluation Boards fits fast flash memories, so that the number of wait 
	// states can be optimized to fast up the boot sequence.
	//-----------------------------------------------------------------------------
 	// set sandart Wait State
 	pEbi = AT91C_BASE_EBI ;
 	pEbi->EBI_CSR[0] = EBI_CSR_0 ;	

	//-----------------------------------------------------------------------------
	//  Set up EBI value
	//--------------------
	// After reset, All EBI register are setted at the default value 
	// The new value will be effective only after the remap command
	//-----------------------------------------------------------------------------
	// Load System pEbi Base address and CSR0 Init Value
	pEbi->EBI_CSR[1] = EBI_CSR_1 ;
	pEbi->EBI_CSR[2] = EBI_CSR_2 ;
	pEbi->EBI_CSR[3] = EBI_CSR_3 ;
	pEbi->EBI_CSR[4] = EBI_CSR_4 ;
	pEbi->EBI_CSR[5] = EBI_CSR_5 ;
	pEbi->EBI_CSR[6] = EBI_CSR_6 ;
	pEbi->EBI_CSR[7] = EBI_CSR_7 ;
	// 6 memory regions, standard read
	pEbi->EBI_MCR =	AT91C_EBI_ALE_2M;
	//-----------------------------------------------------------------------------
	// Reset the Interrupt Controller
	//-------------------------------
	// Normally, the code is executed only if a reset has been actually performed.
	// So, the AIC initialization resumes at setting up the default vectors.
	//-----------------------------------------------------------------------------
	// Load System pAic Base address 
	pAic = AT91C_BASE_AIC; 
	
	// Mask All interrupt
	pAic->AIC_IDCR = 0xFFFFFFFF;
	
	// Perform 8 End Of Interrupt Command to make sure AIC will not Lock out nIRQ 
	for (i=0;i < 8; i++)
	{
		AT91F_AIC_AcknowledgeIt(AT91C_BASE_AIC);
	}

	// Set up the default interrupts handler vectors
	pAic->AIC_SVR[0] = (int) AT91F_Default_FIQ_handler ;
	for (i=1;i < 31; i++)
	{
		pAic->AIC_SVR[i] = (int) AT91F_Default_IRQ_handler ;
	}
	pAic->AIC_SPU  = (int) AT91F_Spurious_handler ;
	
	//-----------------------------------------------------------------------------
	// Setup Exception Vectors in Internal RAM before Remap
	//-----------------------------------------------------
	// That's important to perform this operation before Remap in order to guarantee
	// that the core has valid vectors at any time during the remap operation.
	// Note: There are only 5 offsets as the vectoring is used.
	// Before Remap the internal RAM it's 0x300000
	// After  Remap the internal RAM it's 0x000000
	// Remap it's already executed it's no possible to write to 0x300000.
	//-----------------------------------------------------------------------------
	//  Copy the ARM exception vectors and indirect table

    
    
	for  (i=0;i < (8+5); i++ )
	{
	   *InternalRam++=*Vector++;
	}

	
	return ( &pEbi->EBI_RCR); 
}