about using UBI on MLC Nand flash

[Marteo Tim]

I noticed that UBI need to write 2 times at 1st page in 1 block, one
for EC header, and the other for VID header. But it is not suitable
for MLC NAND flash, which only can write once per page. And by
default, MTD's nand_write can only write page-aligned data.
Although we can set the module parameter vid_hdr_offsets to the 2nd
page, but it will occupy more flash space. It is in a dilemma. :(

marteo