[Yaffs] yaffs2 questions

Hi all ,
This is my first mail to the yaffs group. I am learning yaffs file
system and i have some doubts trying to understand checkpointing and
how yaffs copes without having a on-disk format.

1. On mounting how is the starting of the checkpoint block located. I
guess it should be at a fixed location on flash as we cant scan for
the checkpoint start block. Then if we use the same block for
checkpoint wont it hurt the wear of that particular block?
2. Is the checkpoint information stored contiguously on the flash or
is it scattered ?
3. Where is the super block stored on the flash?
4. When we open an existing file how do we get the tnode information?
When checkpointing does the tnode structure of all files also
checkpointed?
5. Roughly how much RAM will be needed for a 512 GB flash assuming it
stores 1000 files with size of 500MB each.

Thanks in advance for clearing my doubts.
mugunthan