David Young asked;
but the decision was made weighing "the rootfs is seldom written beyond configuration mods by administrators." Software ECC is always calc'ed and verified, block write is counted and recorded inside NAND spare fields.How do you handle the bad blocks that develop as the device "wears" ?
The answer is "by manual intervention," just like good-old-days Winchester style hard disk drive bad sector management practice. I wrote a cmdline tool to manage bad block list and relocate block contents. In principle we neglect the whole NAND woe/buzz to happen due to the above mentioned rational. "this tools may cause hazardous results to hurt you, trained service personel only, or don't use this." If I have chose MMC/SD/CF media to go, I would build vnd on a large file on the FAT filesys and forget how good/bad to gauge badblock and wear-leveling schemes inside. Toru Nishimura/ALKYL Technology