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Ifdefs to disable APPCHECKSUM on tiny85 #3

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Ifdefs to disable APPCHECKSUM on tiny85 #3

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8 changes: 4 additions & 4 deletions firmware/bootloaderconfig.h
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Original file line number Diff line number Diff line change
Expand Up @@ -174,15 +174,15 @@ these macros are defined, the boot loader uses them.
# define MCUCSR MCUSR
#endif

#define APPCHECKSUM
//#define APPCHECKSUM

/* tiny85 Architecture Specifics */
#ifdef __AVR_ATtiny85__
# define TINY85MODE

# ifndef APPCHECKSUM
# define APPCHECKSUM
# endif
//# ifndef APPCHECKSUM
//# define APPCHECKSUM
//# endif

// number of bytes before the boot loader vectors to store the tiny application vector table
# define TINYVECTOR_RESET_OFFSET 4
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10 changes: 9 additions & 1 deletion firmware/main.c
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Original file line number Diff line number Diff line change
Expand Up @@ -164,17 +164,21 @@ static void writeWordToPageBuffer(uint16_t data)
data = 0xC000 + (BOOTLOADER_ADDRESS/2) - 1;

// write 2's complement of checksum
#ifdef APPCHECKSUM
if(CURRENT_ADDRESS == BOOTLOADER_ADDRESS - APPCHECKSUM_POSITION)
data = (uint8_t)(~checksum + 1);
#endif

if(CURRENT_ADDRESS == BOOTLOADER_ADDRESS - TINYVECTOR_RESET_OFFSET)
data = vectorTemp[0] + ((FLASHEND + 1) - BOOTLOADER_ADDRESS)/2 + 2 + RESET_VECTOR_OFFSET;

if(CURRENT_ADDRESS == BOOTLOADER_ADDRESS - TINYVECTOR_USBPLUS_OFFSET)
data = vectorTemp[1] + ((FLASHEND + 1) - BOOTLOADER_ADDRESS)/2 + 1 + USBPLUS_VECTOR_OFFSET;

#ifdef APPCHECKSUM
// only calculate checksum when we are writing new data to flash (ignore when writing vectors after bootloader programming)
checksum += (uint8_t)(data/256) + (uint8_t)(data);
#endif

// clear page buffer as a precaution before filling the buffer on the first page
// TODO: maybe clear on the first byte of every page?
Expand Down Expand Up @@ -544,7 +548,9 @@ static inline void tiny85FlashInit(void)

// TODO: necessary to reset CURRENT_ADDRESS?
CURRENT_ADDRESS = 0;
checksum = 0;
# ifdef APPCHECKSUM
checksum = 0;
# endif
}

static inline void tiny85FlashWrites(void)
Expand All @@ -557,7 +563,9 @@ static inline void tiny85FlashWrites(void)
eraseApplication();
sei();

#ifdef APPCHECKSUM
checksum = 0;
#endif
eraseRequested = 0;
}
#endif
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