XMEGA Bootloader not able to start application

[cmcraeslo]

Hey guys.

I'm working on my own bootloader and I'm having problems jumping from the bootloader to application properly. I'm able to flash the application properly (If I set the BOOTRST to APPLICATION it works), but when I run the app from bootloader, it just doesn't work.

I'm using TCC0 timer in my bootloader and I disable it before jumping to 0x0. Even if I don't use the timers altogether, it still doesn't work.

There are many suggestions over the internet, I tried them all, but none of them worked for me.

Currently, I have this for going into the app:

Code: [Select]

CCP = CCP_IOREG_gc;
PMIC.CTRL = 0;
TCC0.INTCTRLA = 0;
asm("jmp 0x0");


I also tried enabling the watchdog and then checking for the RST.STATUS & WD first thing after booting:

When I want to start the application:

Code: [Select]

CCP = CCP_IOREG_gc;
WDT.CTRL = WDT_ENABLE_bm | WDT_CEN_bm | WDT_PER_8CLK_gc;
while(WDT.STATUS & WDT_SYNCBUSY_bm);

And then, first thing in main():

Code: [Select]

if (RST.STATUS & RST_WDRF_bm)
{
  asm("jmp 0x0");
}
This is driving me crazy

Thanks

[ataradov]

I'm not sure if "jmp #0" is appropriate for all situations. Try actual C way:

Code: [Select]

  void (*reset_vector)(void) = 0;
  reset_vector();


[krho]

I'm using xboot and I've looked at the code and at the end it also executes `jmp 0`. I'd say that you have something wrong with your fuses. Do you have a debugger to check where it's stuck? This would help you to find this in notime. Atmel ICE is pretty cheap.

[cmcraeslo]

I do have ICE.

Not sure which thing worked, but this is the way i have it now and it works. Hopefully someone will find this helpful.

If I want to run the app, I reset it via WD:

Code: [Select]

cli();
CCP = CCP_IOREG_gc;
RST.STATUS = 0;
CCP = CCP_IOREG_gc;
PMIC.CTRL = 0;
CCP = CCP_IOREG_gc;
WDT.CTRL = WDT_ENABLE_bm | WDT_CEN_bm | WDT_PER_512CLK_gc;
while(WDT.STATUS & WDT_SYNCBUSY_bm);
while(1);

and then first thing in the bootloader:

Code: [Select]

if (RST.STATUS & RST_WDRF_bm && !(RST.STATUS & RST_PDIRF_bm))
{
CCP = CCP_IOREG_gc;
RST.STATUS = 0;
CCP = CCP_IOREG_gc;
PMIC.CTRL = 0;
CCP = CCP_IOREG_gc;
cli();
SP_LockSPM();
asm("jmp 0x0");
while(1);
}