If you wish to use the mtd nandsim device as a simulator for testing yaffs, you can follow these steps:

1) Make sure you have a recent 2.6 kernel with a recent MTD tree. (If you ask the MTD folk, they'll tell you to run the mtd patchin script from the latest cvs version of MTD.)

2) Configure your kernel to enable the mtd nand support and nandsim driver. Make sure that the following are set in .config:

CONFIG_MTD=m
CONFIG_MTD_CHAR=m
CONFIG_MTD_BLOCK=m
CONFIG_MTD_NAND=m
CONFIG_MTD_NAND_NANDSIM=m

You can set them to 'y' rather than 'm' if you don't want the modules form.

3) make and install your kernel and modules in the usual way, then boot.

4) To use the nandsim, you need to load some MTD modules, unless you've configured MTD into the kernel:

modprobe mtdblock
modprobe mtdchar
modprobe nandsim

5) Verify that the nandsim device has loaded properly:

cat /proc/mtd

You will see something like

dev: size erasesize name
mtd0: 00800000 00002000 "NAND simulator partition"

If everything went well.

6) what the nand device is called will depend on your Linux distro, and whether you are using devfs or udev, but the '0', or whatever mtd reports as the device associated with the simulator, in the above will show up in the name. On my ubuntu system, if /proc/mtd reports 'mtd0' then the block device is /dev/mtdblock0 and the char device is /dev/mtd0.

7) You can mount yaffs on the nandsim in the usual way. I have /mnt/nand as the directory I mount on, so I would mount using

mount -t yaffs /dev/mtdblock0 /mnt/nand

If you find any errors in this, please let me know. It wll eventually find its way into the yaffs documentation.

Marty