Erik Olieman / FreescaleIAP

IAP code for Freescale platforms

Dependents:   JRO_DDSv2 18_PT1000 RDA5807M-FM-Radio flashaccess ... more

K22F

Due to the default clock setup of the K22F, flash write access is there disabled. In the future I might add a workaround, but for now see: https://developer.mbed.org/questions/52738/Error-with-FreescaleIAP-code-with-K22F/

Be careful with which flash you are erasing/overwriting!

Example code:

#include "mbed.h"
#include "FreescaleIAP.h"


int main() {
    int address = flash_size() - SECTOR_SIZE;           //Write in last sector
    
    int *data = (int*)address;
    printf("Starting\r\n"); 
    erase_sector(address);
    int numbers[10] = {0, 1, 10, 100, 1000, 10000, 1000000, 10000000, 100000000, 1000000000};
    program_flash(address, (char*)&numbers, 40);        //10 integers of 4 bytes each: 40 bytes length
    printf("Resulting flash: \r\n");
    for (int i = 0; i<10; i++)
        printf("%d\r\n", data[i]);
    
    printf("Done\r\n\n");
        

    while (true) {
    }
}

For an example on using this for a bootloader, check out: http://developer.mbed.org/users/Sissors/code/Bootloader_K64F/

If you want to permanently store a variable between resets, you can run into the problem of how to define the value the first time. Since the mbed drag-and-drop loader seems to issue a full-chip erase, you cannot first upload a program to set the initial value, and then switch to the regular program: The full-chip erase will also erase your initial value. One option is to use the same statements as used in the bootloader example to force it to program initial values for your variables on your memory address. This should work fine, however it is target dependent where you want to program it (generally your last sector), so it makes for a less nice example program. You can also try to detect if it is the initial run by looking at the state of the flash, by default this is all '1's. The following example does this:

#include "mbed.h"
#include "FreescaleIAP.h"

int main() {    
    
    int address = flash_size() - SECTOR_SIZE;           //Write in last sector
    int *data = (int*)address;
    
    //By default flash is initialized at 0xFF, this is signed -1, so now we know
    //the program runs for the first time. You of course need to make sure your program
    //never writes -1 to this variable if you use this method
    
    //Alternatively you could also do the same, but with a seperate "initial run" variable added,
    //so your other variables can take any value
    if (data[0] == -1) {
        printf("Initial run\r\n");
        printf("Writing 42 and 42\r\n");
        erase_sector(address);
        int newvalues[2] = {42, 42};
        program_flash(address,(char*) newvalues, 8);     //Two integers of 4 bytes = 8 bytes
        while(1);
    }
    printf("Current = %d and %d, new is %d and %d\r\n", data[0], data[1], data[0]+1, data[1]-1);
    int newvalues[2] = {data[0]+1, data[1]-1};
    erase_sector(address);
    program_flash(address, (char*) newvalues, 8);
    while(1);
}