[U-Boot] handling of NAND blocks which go bad

[tkoka]

I have a question about how u-boot handles NAND blocks going bad over
time, for example when uncorrectable ECC errors or erase failures are
encountered for blocks which are not already in the Bad Block Table.  I
know that u-boot properly skips already known bad blocks, but I can't
seem to find where new bad blocks are recorded in the BBT.  Can anyone
point me in the right direction?  Or confirm that this is not supported
in u-boot?  I am using a BSP from Freescale on a custom mx25 board, but
I cannot find this handling in the latest u-boot git either.

TIA