[avr-chat] ATmega2561: bootloader can not write in application section

[Thomas Richter]

Hi,

why it is not possible for my bootloader application to write into 
application flash section?
I use ATmega2561. My code uses the AVR libc functionality (installed 
with WinAVR-20070122 package). To prevent protection mode I set all boot 
loader lock bits to "1".

Here the important parts of my code:

in main():
   {
     ...
   #if defined(__AVR_ATmega2561__)
     // no restrictions for SPM or (E)LPM accessing the Application Section
     boot_lock_bits_set_safe((1<<BLB12));  // please compare tables 149 
& 150 at pages 342, 343
     boot_lock_bits_set_safe((1<<BLB11));
     boot_lock_bits_set_safe((1<<BLB02));
     boot_lock_bits_set_safe((1<<BLB01));
   //  boot_lock_bits_set_safe(1<<LB2);    // no memory lock features 
enabled
   //  boot_lock_bits_set_safe(1<<LB1);
   #endif // __AVR_ATmega2561__
     ...
   }

The function to write my data (stored at gBuffer) one page into flash:
   uint8_t writeFlashPage(uint16_t waddr, pagebuf_t size)
   {
     uint32_t pagestart = (uint32_t)waddr; 
     uint32_t baddr = pagestart;
     uint16_t data;
     char *tmp = gBuffer;
     uint8_t  result = OK;

     // infront writing erase the flash page
     if (eraseFlashPage(waddr) == OK)
     {  // Erase Ok
       do {
         data = *tmp++;
         data |= *tmp++ << 8;
         boot_page_fill(baddr, data);  // call asm routine.

         baddr += 2;     // Select next word in memory
         size -= 2;      // Reduce number of bytes to write by two
       } while (size);       // Loop until all bytes written

       boot_page_write(pagestart);  // Store buffer in flash page
       boot_spm_busy_wait();   // Wait until the memory is written.
       boot_rww_enable();      // Re-enable the RWW section
     }
     else // erase was not possible
       result = NOK;

     return (result);
   }

The function to erase one flash page:
   uint8_t eraseFlashPage(uint16_t waddr)
   {
     uint32_t pagestart = (uint32_t)waddr; 
     uint16_t data      = 0;
     uint8_t  result    = OK;
     uint16_t i         = 0;

     boot_page_erase (pagestart); // erase the page
     boot_spm_busy_wait ();       // Wait until the memory is erased.

     for (i=0; i<SPM_PAGESIZE; i+=2) // over all words in memory
     {
   #if defined(RAMPZ)
        data = pgm_read_word_far(pagestart+i);
   #else
        data = pgm_read_word_near(pagestart+i);
   #endif
        if (data != 0xFFFF) result = NOK; // NOK
     }
     return (result);
   }

Thanks for any help.

Regards,
Thomas