main.c

#include <stdio.h>
#include <stddef.h>
#include <stdbool.h>
#include <string.h>

#include "mxc_config.h"
#include "mxc_sys.h"
#include "mxc_delay.h"
#include "flc.h"
#include "icc.h"
#include "crc.h"
#include "board.h"
#include "led.h"
#include "ff.h"
#include "crc16-ccitt.h"


#define GPIO_PORT_IN                PORT_1
#define GPIO_PIN_IN                 PIN_6


#define PARTITION_START (0x10000000 + 64 * 1024)
#define PARTITION_END (0x10000000 + 512 * 1024 - 1) /* TODO: check if 1 MB also works. Might have to enable the second bank */
//#define PARTITION_END (0x10000000 + 1024 * 1024 - 1)

extern void run_usbmsc(void);

DIR dir;
FATFS FatFs;

bool mount(void)
{
    FRESULT res;
    res=f_mount(&FatFs,"/",0);
    if(res != FR_OK) {
        printf("f_mount error %d\n", res);
        return false;
    }

    res = f_opendir(&dir, "0:");
    if(res != FR_OK) {
        printf("f_opendir error %d\n", res);
        return false;
    }

    return true;
}

bool check_integrity(void)
{
    FIL file;
    UINT readbytes;
    char *filename = "card10.bin";
    uint8_t data[512];
    FRESULT res;

    res=f_open(&file, filename, FA_OPEN_EXISTING|FA_READ);
    if(res != FR_OK) {
        printf("f_open error %d\n", res);
        return false;
    }

    uint16_t crcval = 0;
    do {
        res = f_read(&file, data, sizeof(data), &readbytes);
        if(res != FR_OK) {
            printf("f_read error %d\n", res);
            crcval = 1; // Make sure to fail the test
            break;
        }
        crcval = crc16_ccitt(crcval, data, readbytes);
    } while (readbytes == sizeof(data));

    f_close(&file);

    if(crcval == 0) {
        return true;
    } else {
        printf("CRC check failed. Final CRC: %d\n", crcval);
        return false;
    }
}

bool is_update_needed(void)
{
    FIL file;
    UINT readbytes;
    char *filename = "card10.bin";
    uint8_t data[512];
    FRESULT res;

    res=f_open(&file, filename, FA_OPEN_EXISTING|FA_READ);
    if(res != FR_OK) {
        printf("f_open error %d\n", res);
        return false;
    }

    uint8_t *partition = (uint8_t *)(intptr_t)PARTITION_START;
    bool different = false;
    do {
        res = f_read(&file, data, sizeof(data), &readbytes);
        if(res != FR_OK) {
            printf("f_read error %d\n", res);
            break; /* Going to return false, don't want to use this file */
        }
        if(memcmp(partition, data, readbytes)) {
            different = true;
            break;
        }
        partition += readbytes;
    } while (readbytes == sizeof(data));

    f_close(&file);

    return different;
}

void erase_partition(void)
{
    int ret = FLC_MultiPageErase(PARTITION_START, PARTITION_END);
    if(ret != E_NO_ERROR) {
        printf("FLC_MultiPageErase failed with %d\n", ret);
        while(1);
    }
}

void flash_partition(void)
{
    FIL file;
    UINT readbytes;
    char *filename = "card10.bin";
    uint8_t data[512];
    FRESULT res;

    res=f_open(&file, filename, FA_OPEN_EXISTING|FA_READ);
    if(res != FR_OK) {
        printf("f_open error %d\n", res);
        while(1);
    }

    uint32_t partition = PARTITION_START;

    ICC_Disable();
    do {
        res = f_read(&file, data, sizeof(data), &readbytes);
        if(res != FR_OK) {
            printf("f_read error %d\n", res);
            break; /* Going to return false, don't want to use this file */
        }
        int ret = FLC_Write(partition, readbytes, (uint32_t *)data); /* wild cast. not sure if this works */
        if(ret != E_NO_ERROR) {
            printf("FLC_Write failed with %d\n", ret);
            while(1);
        }
        partition += readbytes;
    } while (readbytes == sizeof(data));
    ICC_Enable();

    f_close(&file);
}

static inline void boot(const void * vtable){
    SCB->VTOR = (uintptr_t) vtable;

	// Reset stack pointer & branch to the new reset vector.
	__asm(  "mov r0, %0\n"
			"ldr sp, [r0]\n"
			"ldr r0, [r0, #4]\n"
			"bx r0\n"
			:
			: "r"(vtable)
			: "%sp", "r0");
};


/******************************************************************************/
int main(void)
{

    printf("\n\nBootloader\n");
    // If the button is pressed, we go into MSC mode.
    if (PB_Get(0) || PB_Get(1)) {
        run_usbmsc();

        // If we return, don't try to boot. Maybe rather trigger a software reset.
        // Reason: Not sure in which state the USB peripheral is and what kind
        // of interrupts are active.
        while(1);
    }


    if(mount()) {
        if(check_integrity()) {
            printf("Found valid application image\n");
            if(is_update_needed()) {
                printf("Trying to update application from external flash\n");
                MXC_FLC0->clkdiv = 54;
                erase_partition();
                flash_partition();
            } else {
                printf("No update needed\n");
            }
        } else {
            printf("Integrity check failed\n");
        }
    } else {
        printf("Failed to mount the external flash\n");
    }


    printf("Trying to boot\n");
    // boot partition
    boot((uintptr_t *) PARTITION_START);

    while (1) {
        // Should never be reached.
    }
}

/******************************************************************************/
void SysTick_Handler(void)
{
    mxc_delay_handler();
}