KBOOT ROM never executes application, bootloops

[xxxajk]

As the title says, just reenters ROM after timeout.

MKE16F512VLH16

K1.5.1 ROM

BCA:

0x3c0: 6b 63 66 67 ff ff ff ff ff ff ff ff ff ff ff ff
0x3d0: ff ff e8 03 ff ff ff ff ff ff ff ff ff ff ff ff
0x3e0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
0x3f0: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff

Flash configuration field:

0x400: ff ff ff ff ff ff ff ff ff ff ff ff de fb ff ff

                                            ^^

                                           ||

                                      boot from rom

If I disable ROM and only enable with BOOT0 pin, the application runs as expected.

Two quesions to help resolve the issue:

Is there something the ROM configs that is causing a fault in my start up code? I can post my start up code if required.

Does Zeroing RAM at start up of app cause the fault?

[xxxajk]

Flash configuration field:

0x400: ff ff ff ff ff ff ff ff ff ff ff ff de fb ff ff

                                               ^^

                                              ||

                                         boot from rom

Was off-by one. Anyway....

[jorge_a_vazquez · Accepted solution]

Hi Andrew

Actually, your application is executing after timeout, the problem is that the WDOG interrupt is happening and you get into the ROM bootloader again.

There is a Errata in this chip about the WDOG, please check the following link: https://www.nxp.com/docs/en/errata/Kinetis_E_0N79P.pdf 

So, when you boot from the ROM bootloader and then jump to the application, you need a delay before you continuing your program execution. I added a little delay in the Reset Handler, so now my application can run without problems.

void ResetISR(void) {
     unsigned int i=100;
         while(i--){}
    // Disable interrupts
    __asm volatile ("cpsid i");
#if defined (__USE_CMSIS)
// If __USE_CMSIS defined, then call CMSIS SystemInit code
    SystemInit();
...‍‍‍‍‍‍‍‍‍

Inside the SystemInit you will find the WDOG disable.

Hope this could help you,

Best Regards

Jorge Alcala

[xxxajk]

Thanks so much!

I'll have the MCU do other set up during this time, if possible, instead of the simple loop.

Also FWIW I'm not using any tools from NXP/Freescale or anyone else, but I now get the gist of what needs to be done.