saveenv & erase with bad blocks present

[Boulais, Marc-Andre]

Hi,
I have flashed Barebox-2015.02.0 on my omap4 setup (using the Barebox update command) and I am now trying to modify the environment from the Barebox prompt. I have modified the env/config file and I would like to save my changes to NAND. 

For this task, I call the "saveenv" command and I get this result:

barebox at Phytec phyCORE-OMAP4460:/ saveenv
saving environment
saveenv: No space left on device

The "devinfo" command indicates to me that the /dev/nand0.bareboxenv partition is 128 Kb. 
Just to be sure, I erase it and get the following error:

barebox at Phytec phyCORE-OMAP4460:/ erase /dev/nand0.bareboxenv.bb
nand: nand_erase_nand: attempt to erase a bad block at page 0x00000140
erase: I/O error

So I guess I am a bit confused here. 
1) Is "saveenv" the right command to save my changes to the environment ?
2) How can I erase a NAND partition that has bad blocks ?
3) Can bad blocks be marked by software or are they all marked by the manufacturer ?

Many thanks,