OneNAND
The OneNAND is a highly reliable embedded memory targeted for both consumer electronic, and next generation mobile phone market. With accumulated NAND flash technologies over the last decade, the company designs an ideal single memory chip based on NAND architecture integrating SRAM buffers and logic interface. The OneNAND takes both advantages from high-speed data read function of NOR flash and the advanced data storage function of NAND flash.
| Application Requires | NAND | OneNAND | NOR |
| Fast Random Read | o | ||
| Fast Sequential Read | o | o | o |
| Fast Write/Program | o | o | |
| Multi Block Erase | o (Max 64 blocks) | o | |
| Erase Suspend/Resume | o | o | |
| Copyback | o (EDC) | o (ECC) | |
| Lock/Unlock/Lock-Tight | o | o | |
| ECC | External (Hardware/Software) | Internal | X |
| Scalablity | o | o |
JFFS2 on OneNAND
It has the same behavior of bare NAND
JFFS2 specific information
JFFS2 Out of Band usage
JFFS2 uses the default autoplacement scheme. The only JFFS2 specific usage of the oob area is the storage of the cleanmarker
Nand chips with 1048 byte pagesize and 32 byte OOB size
Nand chips with 2048 byte pagesize and 64 byte OOB size
| Offset | Content | Comment |
| 0x02 | Clean marker byte 0 | This byte indicates that a block was erased under JFFS2 control. If the page was successfully erased this byte in the first page of a block is programmed to 0x85. In the remaining pages this byte is reserved |
| 0x03 | Clean marker byte 1 | This byte indicates that a block was erased under JFFS2 control. If the page was successfully erased this byte in the first page of a block is programmed to 0x19. In the remaining pages this byte is reserved |
| 0x04 | Clean marker byte 2 | This byte indicates that a block was erased under JFFS2 control. If the page was successfully erased this byte in the first page of a block is programmed to 0x03. In the remaining pages this byte is reserved |
| 0x0e | Clean marker byte 3 | This byte indicates that a block was erased under JFFS2 control. If the page was successfully erased this byte in the first page of a block is programmed to 0x20. In the remaining pages this byte is reserved |
| 0x0f | Clean marker byte 4 | This byte indicates that a block was erased under JFFS2 control. If the page was successfully erased this byte in the first page of a block is programmed to 0x08. In the remaining pages this byte is reserved |
| 0x12 | Clean marker byte 5 | This byte indicates that a block was erased under JFFS2 control. If the page was successfully erased this byte in the first page of a block is programmed to 0x00. In the remaining pages this byte is reserved |
| 0x13 | Clean marker byte 6 | This byte indicates that a block was erased under JFFS2 control. If the page was successfully erased this byte in the first page of a block is programmed to 0x00. In the remaining pages this byte is reserved |
| 0x14 | Clean marker byte 7 | This byte indicates that a block was erased under JFFS2 control. If the page was successfully erased this byte in the first page of a block is programmed to 0x00. In the remaining pages this byte is reserved |
UBI on OneNAND
You can use the UBI on OneNAND
Here's full sequences of UBI on OneNAND.onenand partitions
Muxed OneNAND 128MB 1.8V 16-bit (0x30)
Scanning device for bad blocks
Bad eraseblock 4 at 0x00080000
Bad eraseblock 32 at 0x00400000
Bad eraseblock 1008 at 0x07e00000
Creating 6 MTD partitions on "onenand":
0x00000000-0x00020000 : "X-Loader + U-Boot"
0x00020000-0x00040000 : "params"
0x00040000-0x00240000 : "kernel"
0x00240000-0x01240000 : "rootfs"
0x01240000-0x03240000 : "filesystem00"
0x03240000-0x08000000 : "filesystem01"
/ # /mtd-utils/eraseall /dev/mtd3
Erasing onenand_erase: attempt to erase a bad block at addr 0x00400000
Erasing 128 Kibyte @ 1c0000 -- 10 % complete.
MTD Erase failure: Input/output error
Erasing 128 Kibyte @ fe0000 -- 99 % complete.
There's one initial bad block, so we can't use this partition as block device such as cramfs
Load ubi module
/ # insmod /mtd-utils/ubi.ko mtd=3
Using /mtd-utils/ubi.ko
UBI: background thread "ubi_bgt0d" started, PID 192
UBI: empty MTD device detected
UBI: create volume table (copy #1)
UBI: create volume table (copy #2)
UBI: mean erase counter: 0
UBI: attached mtd3 to ubi0
UBI: MTD device name: "rootfs"
UBI: MTD device size: 16 MB
UBI: physical eraseblock size: 131072 bytes (128 KB)
UBI: logical eraseblock size: 126976 bytes
UBI: number of good PEBs: 127
UBI: number of bad PEBs: 1
UBI: smallest flash I/O unit: 2048
UBI: VID header offset: 2048 (aligned 2048)
UBI: data offset: 4096
UBI: max. allowed volumes: 124
UBI: wear-levelling threshold: 4096
UBI: number of internal volumes: 2
UBI: number of user volumes: 0
UBI: available PEBs: 122
UBI: total number of reserved PEBs: 5
UBI: number of PEBs reserved for bad PEB handling: 1
Create ubi volume
/ # /mtd-utils/ubimkvol -s 10485760 -N rootfs-cramfs -d 0
/ # cat /proc/mtd
dev: size erasesize name
mtd0: 00020000 00020000 "X-Loader + U-Boot"
mtd1: 00020000 00020000 "params"
mtd2: 00200000 00020000 "kernel"
mtd3: 01000000 00020000 "rootfs"
mtd4: 02000000 00020000 "filesystem00"
mtd5: 04dc0000 00020000 "filesystem01"
mtd6: 00a0d000 0001f000 "rootfs-cramfs" <- ubi partition
ubi parition, mtd6 is created.
copy cramfs image to ubi partition
/ # cp cramfs.img /dev/mtdblock6
mount cramfs and test
/ # mount -t cramfs /dev/mtdblock6 /tmp
/ # cd /tmp
/tmp # ls
bin dev lib proc tmp var
cramfs etc mnt sbin usr
/tmp # mount
/dev/mtdblock6 on /tmp type cramfs (ro)
create jffs2 ubi partition
/ # /mtd-utils/ubimkvol -s 4194304 -N rootfs-jffs2 -d 0
/ # cat /proc/mtd
dev: size erasesize name
mtd0: 00020000 00020000 "X-Loader + U-Boot"
mtd1: 00020000 00020000 "params"
mtd2: 00200000 00020000 "kernel"
mtd3: 01000000 00020000 "rootfs"
mtd4: 02000000 00020000 "filesystem00"
mtd5: 04dc0000 00020000 "filesystem01"
mtd6: 00a0d000 0001f000 "rootfs-cramfs"
mtd7: 0041e000 0001f000 "rootfs-jffs2"
ubi partition, mtd7 is created.
mount jffs2 and test
/ # mount -t jffs2 /dev/mtdblock7 /mnt
JFFS2 write-buffering enabled buffer (2048) erasesize (126976)
/ # mount
/dev/mtdblock6 on /tmp type cramfs (ro)
/dev/mtdblock7 on /mnt type jffs2 (rw)
/ # cd /mnt
/mnt # cat /proc/filesystems > filesystem
/mnt # cat filesystem
the contents of filesystem...
/mnt # cd ..
/ # umount /mnt
/ # mount -t jffs2 /dev/mtdblock7 /mnt
JFFS2 write-buffering enabled buffer (2048) erasesize (126976)
/ # cd /mnt
/mnt # cat filesystem
the same contents of filesystem...
Yaffs2
The yaffs2 can run on OneNAND
If your yaffs2 doesn't work, please check this patch
FAQ
Please see the OneNAND section in MTD FAQ's
References:
Experimental patches
Sync. Burst Block Read support
