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Add fuse and lock bits reading #210

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Add fuse and lock bits reading #210

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30 changes: 25 additions & 5 deletions optiboot/bootloaders/optiboot/optiboot.c
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Original file line number Diff line number Diff line change
Expand Up @@ -567,11 +567,31 @@ int main(void) {
newAddress += newAddress; // Convert from word address to byte address
address = newAddress;
verifySpace();
}
else if(ch == STK_UNIVERSAL) {
// UNIVERSAL command is ignored
getNch(4);
putch(0x00);

/* STK500 Universal Command */
} else if(ch == STK_UNIVERSAL) {
#if defined(BIGBOOT) // real data
/* read fuse and lock bits; it takes additional 80 bytes */
uint8_t ucb1 = getch(); // universal command byte 1
uint8_t ucb2 = getch(); // universal command byte 2
getNch(2); // discard universal command byte 3-4
uint8_t ucr = 0; // response

/* mapping algorithm for function parameter, optimized to save a space:
ucb1(0x50), ucb2(0x00) -> GET_LOW_FUSE_BITS (0x0000)
ucb1(0x58), ucb2(0x00) -> GET_LOCK_BITS (0x0001)
ucb1(0x50), ucb2(0x08) -> GET_EXTENDED_FUSE_BITS(0x0002)
ucb1(0x58), ucb2(0x08) -> GET_HIGH_FUSE_BITS (0x0003)
*/
if((ucb1 & ~(0x08)) == 0x50 && (ucb2 & ~(0x08)) == 0x00) {
ucb1 = ((ucb1 & 0x08) ? 1 : 0) | (ucb2 >> 2);
ucr = boot_lock_fuse_bits_get((uint16_t)ucb1);
}
putch(ucr);
#else // universal command is ignored
getNch(4); // 4 bytes of data/command
putch(0x00); // response
#endif
}
/* Write memory, length is big endian and is in bytes */
else if(ch == STK_PROG_PAGE) {
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