firmware flash could lock NXT ?

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firmware flash could lock NXT ?

Postby raph » Thu Jan 25, 2007 9:09 pm

Hi folks,

I am new to NXJ and didn't have enough time to review the code . Does each
Code: Select all
lejosdl demo.bin
actualy rewrite flash memory and could potentialy hang the device ?

See below a quotation of the libnxt library/bootloader primary source...

The main problem is that the SAM-BA firmware flashing utility, while useful, puts the flash chip under a lot of stress : the lock bits, which let firmwares write-protect themselves, are only guaranteed for about a hundred toggles. Each SAM-BA firmware flash results in two toggles of the lock bits of the first two pages of flash memory.

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Postby bbagnall » Sat Jan 27, 2007 9:01 pm

The lock bits was a concern for us too. Apparently there is a limit of something like 100 firmware uploads, then the lock bits might stop functioning and you've got a dead NXT on your hands.

Not to worry though, the 100 upload limit does not apply as long as you leave the NXT in firmware upload mode. However, basically every time you push the button on your NXT to put it in SAMBA mode/upload LEGO firmware it counts towards the 100. But you can keep uploading NXT programs forever without wearing out the lock bits.

Apparently the 100 number is a very conservative estimate, so it can probably go much higher than this. If you are worried, my suggestion is don't jump between LEGO firmware and NXT frequently.
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