Emulating a NAND flash device
A quick rundown on how to get started using the NAND flash emulator in the NetBSD kernel:
First, build a kernel with:
pseudo-device nandemulator flash* at flashbus? nand* at nandbus?
I created a new kernel config called "NAND" (on amd64):
include "arch/amd64/conf/GENERIC" pseudo-device nandemulator flash* at flashbus? nand* at nandbus?
Note that at the present time, all the parameters of the NAND emulator are
hardcoded, so to change anything you'll need to edit
sys/dev/nand/nandemulator.c and substitute the values you want.
Build and install the kernel, and boot from it. You'll notice the following items appear:
nandemulator0: NAND emulator nand0 at nandemulator0: ONFI NAND Flash nand0: vendor: NETBSD, model: NANDEMULATOR nand0: page size: 2048 bytes, spare size: 64 bytes, block size: 131072 bytes nand0: LUN size: 256 blocks, LUNs: 1, total storage size: 32 MB flash0 at nand0: NAND flash partition size 32 MB, offset 0 flash0: erase size 128 KB, page size 2048 bytes, write size 2048 bytes
You can then mount a chfs file system on the emulated flash device. The file system is created on the first mount:
# mount_chfs /dev/flash0 /mnt # ls -l /mnt # cp /netbsd /mnt # ls -l /mnt total 29216 -rwxr-xr-x 1 root wheel 14958233 Oct 13 16:29 netbsd # umount /mnt # mount_chfs /dev/flash0 /mnt # ls -l /mnt total 29216 -rwxr-xr-x 1 root wheel 14958233 Oct 13 16:29 netbsd # ls -l /mnt total 29216 -rwxr-xr-x 1 root wheel 14958233 Oct 13 16:29 netbsd # md5 /mnt/netbsd /netbsd MD5 (/mnt/netbsd) = 79184fe311657261e1744d77206716c8 MD5 (/netbsd) = 79184fe311657261e1744d77206716c8 # umount /mnt
Note: because this is using kernel memory and not real flash, nothing will be persistent across reboots!