Bad Block On NAND

Umpa · 10-14-2009, 03:40 AM

Hi, after trying to recover from a banner brick I tried to use bootmii to reflash the nand, it failed saying that the image was from another wii. I fixed the issue with a little app that patched my nand.bin file.

Thing is bootmii now reports a bad block when backing up my system, it never did this before. Might this be just a weak sector in the chip, or is this just some corruption ?

If weak part of chip - how common is this and have you got any ?

Favs · 10-14-2009, 03:46 AM

Did it work or is it preventing you from reflashing your NAND and having a bad block is normal, I only had two when I backed up my NAND.

Umpa · 10-14-2009, 03:49 AM

Hi fav,

All is fine, it worked a treat I was just wondering that all, it now reports all the blocks as good - so I dont know what to make of it.

Favs · 10-14-2009, 03:57 AM

Ok found this on the bootmii website if your interested.

Why do I have all of these "bad blocks"? Can I fix them?
This is completely normal; in order to bring down the price of NAND flash chips, all manufacturers will allow chips to leave the factory with a small number of bad blocks. It's similar to bad pixels in LCD panels -- it would be too expensive to throw away the whole panel (or in this case, the whole chip) due to a few bad pixels. With NAND flash, software usually remaps these blocks so you don't even notice, but BootMii works at the lowest level possible so we have to take these into consideration when writing our code. There are 4096 blocks; according to the flash chip manufacturer, at least 4016 blocks are valid (in other words, up to 80 blocks may be bad).

Umpa · 10-14-2009, 02:47 PM

Hey thanx dude,

I figured that because i did not have any to start with and then I did, that I might have caused it - but not to worry they all show up as green now - lol

cheers

Ump..