in situ MTD upgrade from userspace (kernel, CRAMFS, YAFFS)

[David Wuertele]

> 1.  There are many other processes running at the time of the upgrade.
>     They are running out of CRAMFS.  As I overwrite the CRAMFS
>     partition, is it possible that my write could get corrupted?
>     Perhaps by crashing programs that inadvertently do weird syscalls?

Corollary question:

  As my own userspace process overwrites the CRAMFS block that
  contains that process's program, how can I ensure that the process
  doesn't get hosed until after it has a chance to reboot the system?