[Yaffs] When are Block Summaries written?

All:


Our system will not have the unmount() function, since there will be no
'power down' sequence, but data can still be written to a file system at
certain times. I was reading in How Yaffs Works, section 13.6 talks about
Block summaries that were introduced to speed up mount times, but it does
not state when these summaries are written, I do see that Checkpoints are
written for a file system when 'sync() is called. Is this also when the
Block Summaries are written out also?

Thanks

Chris