I have been trying without success to configure a 32MB IDE flash
module to operate under Plan 9. The geometry is one of two options,
c=489, h=4, s=32 or c=31, h=32, s=32, the sector size is the normal
512 bytes and the full capacity is 62592 sectors. I can't convince
Plan 9 to accept the latter geometry and, in my rather ignorant state,
I believe that accessing parts (partitions) of the flash using the
former geometry is responsible for the I/O errors that occur.

I can read and write the entire image using dd(1), irrespective of
geometry and I have used disksim to build an image using the second
geometry, but installing this on the flash has not made it possible to
boot a Plan 9 kernel.

I'm not sure what I should try next, I would like to force a different
geometry on the sd(3) driver, but writing a new geometry to the ctl
file, in keeping with the documentation, just triggers an error.