Hi,

this post describes creating an virtual mtd device by nandsim with multiple partitions.

First of all install the mtd and ubi related tools. On debian install the mtd-utils package.

root@debdev ~# apt-get -y install  mtd-utils

I want to emulate an “NAND device: Manufacturer ID: 0x98, Chip ID: 0xd1 (Toshiba NAND 128MiB 3,3V 8-bit)” which is used in hikvisions IP cameras. The NAND device has 128MiB space with aa erasesize of 128KiB. To get the parameter for the nandsim kernel module I looked into the kernel source tree linux-source-4.7/drivers/mtd/nand_ids.c (Source: Kernel Sources www.kernel.org).

{"TC58NVG0S3E 1G 3.3V 8-bit",
                { .id = {0x98, 0xd1, 0x90, 0x15, 0x76, 0x14, 0x01, 0x00} },
                  SZ_2K, SZ_128, SZ_128K, 0, 8, 64, NAND_ECC_INFO(1, SZ_512),
                  2 },

To Create a mtd device with just one partition load nandsim with

root@debdev ~# modprobe nandsim first_id_byte=0x98 second_id_byte=0xd1 third_id_byte=0x90 fourth_id_byte=0x15
root@debdev ~# cat /proc/mtd
dev:    size   erasesize  name
mtd0: 08000000 00020000 "NAND simulator partition 0"

Check dmesg for details

root@debdev ~# dmesg
[   86.117813] nand: device found, Manufacturer ID: 0x98, Chip ID: 0xd1
[   86.117823] nand: Toshiba NAND 128MiB 3,3V 8-bit
[   86.117835] nand: 128 MiB, SLC, erase size: 128 KiB, page size: 2048, OOB size: 64
[   86.117874] flash size: 128 MiB
[   86.117884] page size: 2048 bytes
[   86.117892] OOB area size: 64 bytes
[   86.117901] sector size: 128 KiB
[   86.117910] pages number: 65536
[   86.117919] pages per sector: 64
[   86.117927] bus width: 8
[   86.117935] bits in sector size: 17
[   86.117943] bits in page size: 11
[   86.117951] bits in OOB size: 6
[   86.117960] flash size with OOB: 135168 KiB
[   86.117969] page address bytes: 4
[   86.117977] sector address bytes: 2
[   86.117985] options: 0x8

To delete the device, unload the kernel module

 
root@debdev ~# rmmod nandsim

To create multiple partitions add the parts parameter to the modprobe command. The parts parameter accept a comma seperated list of partition sizes. Size is not the size in bytes. The partitons size is the parts parameter multiplied with the Sectorsize/Erasesize of the device. An example:

root@debdev ~# modprobe nandsim first_id_byte=0x98 second_id_byte=0xd1 third_id_byte=0x90 fourth_id_byte=0x15 parts=4,8

• Partition 0 – 4 x 128KiB = 512KiB
• Partition 1 – 8 x 128KiB = 1MiB
• Partition 2  – The Rest of the device.

 
root@debdev ~# cat /proc/mtd
dev:    size   erasesize  name
mtd0: 00080000 00020000 "NAND simulator partition 0"
mtd1: 00100000 00020000 "NAND simulator partition 1"
mtd2: 07e80000 00020000 "NAND simulator partition 2"
root@debdev:~# mtdinfo
Count of MTD devices:           3
Present MTD devices:            mtd0, mtd1, mtd2
Sysfs interface supported:      yes

Or detailed info with

 
root@debdev:~# mtdinfo --all

Michael