Re: [avr-gcc-list] bootloader problem

[Bob Paddock]

On Wednesday 26 January 2005 09:07 pm, Lee Terry wrote:

> I wrote a bootloader for mega128, and here are the problems.
>
> 1. BOOTRST programmed
>    I upload an application, then jump to 0x0, bootloader section starts
> again. Below is the code I use when jumping to the app.
>
>     boot_spm_busy_wait();
>     __boot_rww_enable();
>     MCUCR = (1<<IVCE);
>     MCUCR = (0<<IVSEL);
>     asm volatile("cli"::);
>     asm volatile("jmp 0x0000" ::);

Make sure you have rampz set to zero.

The datasheets says it will come up zero but in extensive testing I found
that is not the case.   In my case when it came up non-zero the application 
would not start.


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