firmware/libboard/common/source/board_cstartup_gnu.c

/* ----------------------------------------------------------------------------
 *         ATMEL Microcontroller Software Support
 * ----------------------------------------------------------------------------
 * Copyright (c) 2010, Atmel Corporation
 * Copyright (C) 2017, Harald Welte <laforge@gnumonks.org>
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * - Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the disclaimer below.
 *
 * Atmel's name may not be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * DISCLAIMER: THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
 * DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
 * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 * ----------------------------------------------------------------------------
 */

/*----------------------------------------------------------------------------
 *        Headers
 *----------------------------------------------------------------------------*/

#include "board.h"
#include "board_lowlevel.h"

/*----------------------------------------------------------------------------
 *        Exported variables
 *----------------------------------------------------------------------------*/

/* Stack Configuration */  
#define STACK_SIZE       0x900     /** Stack size (in DWords) */
__attribute__ ((aligned(8),section(".stack")))
uint32_t pdwStack[STACK_SIZE] ;     

/* Initialize segments */
extern uint32_t _sfixed;
extern uint32_t _efixed;
extern uint32_t _etext;
extern uint32_t _srelocate;
extern uint32_t _erelocate;
extern uint32_t _szero;
extern uint32_t _ezero;


/*----------------------------------------------------------------------------
 *        ProtoTypes
 *----------------------------------------------------------------------------*/

/** \cond DOXYGEN_SHOULD_SKIP_THIS */
extern int main( void ) ;
/** \endcond */
void ResetException( void ) ;

/*------------------------------------------------------------------------------
 *         Exception Table
 *------------------------------------------------------------------------------*/

__attribute__((section(".vectors")))
IntFunc exception_table[] = {

    /* Configure Initial Stack Pointer, using linker-generated symbols */
    (IntFunc)(&pdwStack[STACK_SIZE-1]),
    ResetException,

    NMI_Handler,
    HardFault_Handler,
    MemManage_Handler,
    BusFault_Handler,
    UsageFault_Handler,
    0, 0, 0, 0,         /* Reserved */
    SVC_Handler,
    DebugMon_Handler,
    0,                  /* Reserved  */
    PendSV_Handler,
    SysTick_Handler,

    /* Configurable interrupts  */
    SUPC_IrqHandler,    /* 0  Supply Controller */
    RSTC_IrqHandler,    /* 1  Reset Controller */
    RTC_IrqHandler,     /* 2  Real Time Clock */
    RTT_IrqHandler,     /* 3  Real Time Timer */
    WDT_IrqHandler,     /* 4  Watchdog Timer */
    PMC_IrqHandler,     /* 5  PMC */
    EEFC_IrqHandler,    /* 6  EEFC */
    IrqHandlerNotUsed,  /* 7  Reserved */
    UART0_IrqHandler,   /* 8  UART0 */
    UART1_IrqHandler,   /* 9  UART1 */
    SMC_IrqHandler,     /* 10 SMC */
    PIOA_IrqHandler,    /* 11 Parallel IO Controller A */
    PIOB_IrqHandler,    /* 12 Parallel IO Controller B */
    PIOC_IrqHandler,    /* 13 Parallel IO Controller C */
    USART0_IrqHandler,  /* 14 USART 0 */
    USART1_IrqHandler,  /* 15 USART 1 */
    IrqHandlerNotUsed,  /* 16 Reserved */
    IrqHandlerNotUsed,  /* 17 Reserved */
    MCI_IrqHandler,     /* 18 MCI */
    TWI0_IrqHandler,    /* 19 TWI 0 */
    TWI1_IrqHandler,    /* 20 TWI 1 */
    SPI_IrqHandler,     /* 21 SPI */
    SSC_IrqHandler,     /* 22 SSC */
    TC0_IrqHandler,     /* 23 Timer Counter 0 */
    TC1_IrqHandler,     /* 24 Timer Counter 1 */
    TC2_IrqHandler,     /* 25 Timer Counter 2 */
    TC3_IrqHandler,     /* 26 Timer Counter 3 */
    TC4_IrqHandler,     /* 27 Timer Counter 4 */
    TC5_IrqHandler,     /* 28 Timer Counter 5 */
    ADC_IrqHandler,     /* 29 ADC controller */
    DAC_IrqHandler,     /* 30 DAC controller */
    PWM_IrqHandler,     /* 31 PWM */
    CRCCU_IrqHandler,   /* 32 CRC Calculation Unit */
    ACC_IrqHandler,     /* 33 Analog Comparator */
    USBD_IrqHandler,    /* 34 USB Device Port */
    IrqHandlerNotUsed   /* 35 not used */
};

#if defined(BOARD_USB_DFU) && defined(APPLICATION_dfu)
#include "usb/device/dfu/dfu.h"
static void BootIntoApp(void)
{
	unsigned int *pSrc;
	void (*appReset)(void);

	pSrc = (unsigned int *) ((unsigned char *)IFLASH_ADDR + BOARD_DFU_BOOT_SIZE);
	/* set vector table to application vector table (store at the beginning of the application) */
	SCB->VTOR = (unsigned int)(pSrc);
	/* set stack pointer to address provided in the beginning of the application (loaded into a register first) */
	__asm__ volatile ("MSR msp,%0" : :"r"(*pSrc));
	/* start application (by jumping to the reset function which address is stored as second entry of the vector table) */
	appReset = (void(*)(void))pSrc[1];

	g_dfu->state = DFU_STATE_appIDLE;

	appReset();
}
#endif

/**
 * \brief This is the code that gets called on processor reset.
 * To initialize the device, and call the main() routine.
 */
void ResetException( void )
{
    uint32_t *pSrc, *pDest ;

    /* Low level Initialize */
    LowLevelInit() ;


#if defined(BOARD_USB_DFU) && defined(APPLICATION_dfu)
    /* we are before the text segment has been relocated, so g_dfu is
     * not initialized yet */
    g_dfu = &_g_dfu;
    if ((g_dfu->magic != USB_DFU_MAGIC) && !USBDFU_OverrideEnterDFU()) {
        /* start application if valid
         * the application starts with the vector table
         * the first entry in the vector table is the initial stack pointer (SP) address
         * the stack will be placed in RAM, which begins at 0x2000 0000
         * there is up to 48 KB of RAM (0xc000)
         * since the stack grown "downwards" it should start at the end of the RAM: max 0x2000 c000
         * if the SP is not in this range (e.g. flash has been erased) there is no valid application
         * the second entry in the vector table is the reset address, corresponding to the application start
         */
        if (((*((uint32_t*)(IFLASH_ADDR+BOARD_DFU_BOOT_SIZE)))&0xFFFF0000)==0x20000000) {
            UART_Exit();
            __disable_irq();
            BootIntoApp();
            /* Infinite loop */
            while ( 1 ) ;
        }
    }
#endif

    /* Initialize the relocate segment */
    pSrc = &_etext ;
    pDest = &_srelocate ;

    if ( pSrc != pDest )
    {
        for ( ; pDest < &_erelocate ; )
        {
            *pDest++ = *pSrc++ ;
        }
    }

    /* Clear the zero segment */
    for ( pDest = &_szero ; pDest < &_ezero ; )
    {
        *pDest++ = 0;
    }

    /* Set the vector table base address */
    pSrc = (uint32_t *)&_sfixed;
    SCB->VTOR = ( (uint32_t)pSrc & SCB_VTOR_TBLOFF_Msk ) ;
    
    if ( ((uint32_t)pSrc >= IRAM_ADDR) && ((uint32_t)pSrc < IRAM_ADDR+IRAM_SIZE) )
    {
	    SCB->VTOR |= 1 << SCB_VTOR_TBLBASE_Pos ;
    }

    /* App should have disabled interrupts during the transition */
    __enable_irq();

    /* Branch to main function */
    main() ;

    /* Infinite loop */
    while ( 1 ) ;
}