init.c

基于AT91SAM9260的bootloader

//*----------------------------------------------------------------------------
//*         ATMEL Microcontroller Software Support  -  ROUSSET  -
//*----------------------------------------------------------------------------
//* The software is delivered "AS IS" without warranty or condition of any
//* kind, either express, implied or statutory. This includes without
//* limitation any warranty or condition with respect to merchantability or
//* fitness for any particular purpose, or against the infringements of
//* intellectual property rights of others.
//*----------------------------------------------------------------------------
//* File Name           : init.c
//* Object              : Low level initialisations written in C
//* Creation            : HIi   10/10/2003
//*
//*----------------------------------------------------------------------------
#include "main.h"

//*----------------------------------------------------------------------------
//* \fn    AT91F_DBGU_Printk
//* \brief This function is used to send a string through the DBGU channel (Very low level debugging)
//*----------------------------------------------------------------------------
void AT91F_DBGU_Printk(
	char *buffer) // \arg pointer to a string ending by \0
{
	while(*buffer != '\0') {
		while (!AT91F_US_TxReady((AT91PS_USART)AT91C_BASE_DBGU));
		AT91F_US_PutChar((AT91PS_USART)AT91C_BASE_DBGU, *buffer++);
	}
}

//*----------------------------------------------------------------------------
//* \fn    AT91F_DataAbort
//* \brief This function reports an Abort
//*----------------------------------------------------------------------------
void AT91F_SpuriousHandler() 
{
	AT91F_DBGU_Printk("-F- Spurious Interrupt detected\n\r");
	while (1);
}


//*----------------------------------------------------------------------------
//* \fn    AT91F_DataAbort
//* \brief This function reports an Abort
//*----------------------------------------------------------------------------
void AT91F_DataAbort() 
{
	AT91F_DBGU_Printk("-F- Data Abort detected\n\r");
	while (1);
}

//*----------------------------------------------------------------------------
//* \fn    AT91F_FetchAbort
//* \brief This function reports an Abort
//*----------------------------------------------------------------------------
void AT91F_FetchAbort()
{
	AT91F_DBGU_Printk("-F- Prefetch Abort detected\n\r");
	while (1);
}

//*----------------------------------------------------------------------------
//* \fn    AT91F_Undef
//* \brief This function reports an Abort
//*----------------------------------------------------------------------------
void AT91F_Undef() 
{
	AT91F_DBGU_Printk("-F- Undef detected\n\r");
	while (1);
}

//*----------------------------------------------------------------------------
//* \fn    AT91F_UndefHandler
//* \brief This function reports that no handler have been set for current IT
//*----------------------------------------------------------------------------
void AT91F_UndefHandler() 
{
	AT91F_DBGU_Printk("-F- Undef detected\n\r");
	while (1);
}

//*----------------------------------------------------------------------------
//* \fn    AT91F_LowLevelInit
//* \brief This function performs very low level HW initialization
//*----------------------------------------------------------------------------
void AT91F_LowLevelInit(void)
{
	// Disable all interrupts
	AT91F_AIC_DisableIt(AT91C_BASE_AIC, 0xFFFFFFFF);

	// Init Interrupt Controller
	AT91F_AIC_Open(
		AT91C_BASE_AIC,          // pointer to the AIC registers
		AT91C_AIC_BRANCH_OPCODE, // IRQ exception vector
		AT91F_UndefHandler,      // FIQ exception vector
		AT91F_UndefHandler,      // AIC default handler
		AT91F_SpuriousHandler,   // AIC spurious handler
		0);                      // Protect mode

	// Perform 8 End Of Interrupt Command to make sure AIC will not Lock out nIRQ 
	AT91F_AIC_AcknowledgeIt(AT91C_BASE_AIC);
	AT91F_AIC_AcknowledgeIt(AT91C_BASE_AIC);
	AT91F_AIC_AcknowledgeIt(AT91C_BASE_AIC);
	AT91F_AIC_AcknowledgeIt(AT91C_BASE_AIC);
	AT91F_AIC_AcknowledgeIt(AT91C_BASE_AIC);
	AT91F_AIC_AcknowledgeIt(AT91C_BASE_AIC);
	AT91F_AIC_AcknowledgeIt(AT91C_BASE_AIC);
	AT91F_AIC_AcknowledgeIt(AT91C_BASE_AIC);

	AT91F_AIC_SetExceptionVector((unsigned int *)0x0C, AT91F_FetchAbort);
	AT91F_AIC_SetExceptionVector((unsigned int *)0x10, AT91F_DataAbort);
	AT91F_AIC_SetExceptionVector((unsigned int *)0x4, AT91F_Undef);
	
	// Open PIO for DBGU
	AT91F_DBGU_CfgPIO();
	
	// Configure DBGU
	AT91F_US_Configure(
		(AT91PS_USART)AT91C_BASE_DBGU, // DBGU base address
		AT91C_MASTER_CLOCK,            // 100 MHz
		AT91C_US_ASYNC_MODE,           // mode Register to be programmed
		115200,                        // baudrate to be programmed
		0                              // timeguard to be programmed
	);

	// Enable Transmitter
	AT91F_US_EnableTx((AT91PS_USART)AT91C_BASE_DBGU);
	// Enable Receiver
	AT91F_US_EnableRx((AT91PS_USART)AT91C_BASE_DBGU);
}