entry.c

ARM入门的好帮手.包含了从简单到相对较复杂的程序.

//*-----------------------------------------------------------------------------
//*      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           : entry.c
//* Object              : Main loop of AT91EB42 test
//*
//* 1.0 17/07/00  PF    : Creation
//* 2.0 29/01/02  PFi   : Clean up.
//*                     : Boot Version 1.02
//*-----------------------------------------------------------------------------

#include "parts/m42800/lib_m42800.h"
#include "drivers/capture/capture.h"
#include "drivers/wait/wait.h"
#include "targets/eb42/eb42.h"
#include "clock_switching_driver.h"

extern void BootFts ( void ) ;
extern u_int BootLoad ( void ) ;
extern void wake_up_handler ( void ) ;
extern int fmu ( void ) ;
extern void mck_clock_speed (short target_source, u_int frequency_multiplier, u_int prescaler) ;

#define PLL         0x2     //* low frequency oscillator output => MCK
#define SLOW_OSC    0x0     //* PLL output =MCK

#define MUL_x3      0x3
#define MUL_x2      0x2
#define NO_MUL      0x1

/* Global Variable */
WaitDesc wait_desc = { &TC0_DESC, 0, 0, WAIT_DELAY, wake_up_handler } ;

typedef void (type_pt_angel(u_int clock)) ;

//*-------------------------------------------------------------------------------
//* Function Name           : BootEntry
//* Object                  : Entry point of boot
//* Input Parameters        : None
//* Output Parameters       : None
//* Functions called        : at91_pio_open, at91_pio_write
//*-------------------------------------------------------------------------------
void * main_boot ( void )
//* Begin
{
    u_int   i ;
    type_pt_angel  *pt_angel ;

    pt_angel = (type_pt_angel *)(0x1006000) ;

    //* -- Set up PIO
    at91_pio_open ( &PIOA_DESC, SW2_MASK, PIO_INPUT ) ;
    at91_pio_open ( &PIOB_DESC, (SW1_MASK|SW3_MASK|SW4_MASK), PIO_INPUT ) ;

    at91_pio_open ( &PIOB_DESC, LED_MASK, PIO_OUTPUT ) ;
    at91_pio_write (&PIOB_DESC, LED_MASK, LED_OFF ) ;


    //* Detect Master Clock
    wait_desc.mcki_khz = 32768 ;

    wait_desc.period = 50000 ;

    //* Once a Shot on each led
    for ( i=LED1 ; i <= LED8 ; i<<=1 )
    {
        at91_pio_write (&PIOB_DESC, i, LED_ON ) ;
        at91_wait_open ( &wait_desc ) ;
        at91_pio_write (&PIOB_DESC, i, LED_OFF ) ;
    }

    //* Light off all leds
    at91_pio_write (&PIOB_DESC, LED_MASK, LED_OFF ) ;

    //* If SW1 button pressed, Functional Test Software
    if (( at91_pio_read( &PIOB_DESC ) & SW1_MASK ) == 0 )
    {
        //* Light on all the leds
        at91_pio_write ( &PIOB_DESC, LED_MASK, LED_ON ) ;

        //* Expect S1 un-pressed
        while (( at91_pio_read (&PIOB_DESC ) & SW1_MASK) == 0 ) ;

        //* Light off all the leds unless led 1
        at91_pio_write ( &PIOB_DESC, (LED_MASK&~LED1), LED_OFF ) ;
        BootFts() ;
    } //* EndIf

    //* If SW2 button pressed, Load in SRAM
    if (( at91_pio_read ( &PIOA_DESC ) & SW2_MASK) == 0 )
    {
        //* Enable USART 1 & PIOB Clock
        at91_clock_open (US1_ID | US0_ID) ;
        at91_clock_open (PIOB_ID) ;

        //* Light on all the leds
        at91_pio_write ( &PIOB_DESC, LED_MASK, LED_ON  ) ;

        //* Expect S2 un-pressed
        while (( at91_pio_read ( &PIOA_DESC ) & SW2_MASK) == 0 ) ;

        //* Light off all the leds unless led 2
        at91_pio_write ( &PIOB_DESC, (LED_MASK&~LED2), LED_OFF ) ;
        return (void *)BootLoad () ;

        //* disable USART 1
        at91_clock_close (US1_ID ) ;
        at91_pio_write ( &PIOB_DESC, LED2, LED_OFF ) ;
    }//* EndIf


    //* ----------------------------------------------
    //* If SW3 button pressed, Load the Flash_uploader
    //* ----------------------------------------------
    if (( at91_pio_read( &PIOB_DESC ) & SW3_MASK ) == 0 )
    {
        //* Light on all the leds
        at91_pio_write ( &PIOB_DESC, LED_MASK, LED_ON ) ;

        //* Expect S3 un-pressed
        while (( at91_pio_read (&PIOB_DESC ) & SW3_MASK) == 0 ) ;

        //* Light off all the leds unless led 3
        at91_pio_write ( &PIOB_DESC, (LED_MASK&~LED3), LED_OFF ) ;

        fmu();

    } //* EndIf


    //* -------------------------------------
    //* If SW4 button pressed, ShutDown Mode
    //* -------------------------------------
    if (( at91_pio_read( &PIOB_DESC ) & SW4_MASK ) == 0 )
    {
        //* Light on all the leds
        at91_pio_write ( &PIOB_DESC, LED_MASK, LED_ON ) ;

        //* Expect S3 un-pressed
        while (( at91_pio_read (&PIOB_DESC ) & SW4_MASK) == 0 ) ;

        // Turn off all peripheral clocks except PIOB and TC0
        at91_clock_set_mode ( PS_ALL_PERIPH_INACTIVE ) ;
        at91_clock_open ( PIOB_ID ) ;
        at91_clock_open ( TC0_ID ) ;

        //* Light off all the leds unless led 3
        at91_pio_write ( &PIOB_DESC, (LED_MASK&~LED4), LED_OFF ) ;

        //* Switch the Master Clock to 32,768KHz (Slow Clock)
        mck_clock_speed ( SLOW_OSC, NO_MUL, PMC_PRES_NONE ) ;

        for (;;)
        {
            at91_pio_write ( &PIOB_DESC, (LED4), LED_OFF ) ;
            wait_desc.period = 5000 ;
            at91_wait_open ( &wait_desc ) ;
            at91_wait_open ( &wait_desc ) ;
            at91_pio_write ( &PIOB_DESC, (LED4), LED_ON ) ;
            at91_pio_write ( &PIOB_DESC, (LED4), LED_ON ) ;

            if (( at91_pio_read( &PIOB_DESC ) & SW4_MASK ) == 0 )
            {
                //* Switch the Master Clock to 32,768MHz
                mck_clock_speed ( PLL, 1000, PMC_PRES_NONE) ;

                //* Re-enable USART0 Clock
                at91_clock_open ( US0_ID ) ;

                //* Branch Angel in Flash
                pt_angel ( wait_desc.mcki_khz ) ;
            }

        }

     } //* EndIf


    //* Light on the led 1
    at91_pio_write (&PIOB_DESC, LED1, LED_ON ) ;

    //* Enable USART0 Clock
    at91_clock_open ( US0_ID ) ;

    //* Branch Angel in Flash
    pt_angel ( wait_desc.mcki_khz ) ;

//* End
}

/*-------------------------------------------------------------------------------*/
/* Function Name           : BootEntry                                           */
/* Object                  : Entry point of boot                                 */
/* Input Parameters        : None                                                */
/* Output Parameters       : None                                                */
/* Functions called        : at91_pio_open, at91_pio_write                       */
/*-------------------------------------------------------------------------------*/
int main ( void )
/* Begin */
{
 void (*next)(void);
   next =  (void (*)(void)) main_boot();
   (*next)();
}