Can 256K erase blocks work with JFFS2?

[Marc Singer <elf@buici.com>]

In struggling through final steps in proving a new kernel port, I'm
trying to mount a root filesystem so I can see a shell prompt.  I've
got a mapping driver with partitions that appears to work correctly.
Yet, I'm concerned that the very large erase block size could be
causing problems.

When creating the jffs2 filesystem, if I set the erase block size to
256 then the filesystem created is twice the size of my total flash
capacity--can't use it.  The default of 64 produces a modest
filesystem of 5MB.

I'm pretty sure of the erase size.  There are two StrataFlash
28F640J3A chips wired for a 32 bit data bus.  Each has 8MBytes
organized in 64 blocks.  Moreover, empirical evidence shows that the
erase size of 256K.

The kernel will mount the filesystem as rootm but I don't get a shell.
I'm reasonably confident that the root is good because it has worked
when mounted over NFS.  This new system uses the same CPU, but doesn't
yet have a working network driver.

So, I'm asking if I have a snowball's chance in hades with this.  Or,
should I start working on other means of mounting a root filesystem?

TIA