[yocto] System recovery

[Martin Townsend]

On Wed, May 9, 2018 at 11:21 AM, Enrico Bonomi
<enrico.bonomi92 at gmail.com> wrote:
> Hi Martin,
>
> I'm newbie in yocto, but i used IMAGE_FSTYPES ="sdcard" to boot the system
> from SD card. What i want to obtain is to replace the broken file system
> that is located on the NAND with another one that works. A kind of recovery
> partition. is it possible from SD or should i create a recovery partition
> over the NAND?
>
> thanks
>
> Enrico
>
> 2018-05-09 11:25 GMT+02:00 Martin Townsend <mtownsend1973 at gmail.com>:
>>
>> Hi Enrico,
>>
>> UBI is only designed to work on raw NAND using the MTD subsystem.  MMC
>> will be a standard block device as the SD card will have Flash
>> Translation layer. See the excellent MTD website for more info
>> http://www.linux-mtd.infradead.org/doc/ubi.html
>>
>> In Yocto I believe you can use "sdcard" in the IMAGE_FSTYPES for a
>> flashable image for SD cards that can be used with U-Boot.
>>
>> -Martin.
>>
>>
>> On Wed, May 9, 2018 at 9:31 AM, Enrico Bonomi <enrico.bonomi92 at gmail.com>
>> wrote:
>> > Hi,
>> >
>> > I work with Yocto Poky 1.7.3 on an imx6 dual lite SOM. I recently came
>> > across a problem with a preexisting system. Infact in a couple of cases,
>> > after about one year of work with no problems, file system results
>> > corrupted
>> > and the machine can't work. So i decide to implement a recovery system
>> > that
>> > can intervene in theese cases. An sd card is mounted on my board, so i
>> > think
>> > that i can use it to act this process. Using gparted i create a
>> > partition on
>> > sd card that can store my recovery file system.
>> > This partition starts at block 1581056 (so 0x00182000), every block has
>> > a
>> > size of 512 bytes and the file system size is 370262016 bytes (so
>> > 0x1611c000) that are 723168 blocks (so 0x000b08e0).
>> > In the u-boot i do the following instructions:
>> >
>> > nand erase.part rootfs
>> > ubi part rootfs
>> > ubi create rootfs
>> > mmc dev 0
>> > mmc read 12000000 0x00182000  0x000b08e0
>> > ubi write 12000000 rootfs 0x1611c000
>> > ubifsmount ubi0:rootfs
>> >
>> > and this instruction results in the following errors:
>> >
>> > UBIFS error (pid 0): ubifs_read_node: bad node type (0 but expected 6)
>> > UBIFS error (pid 0): ubifs_read_node: bad node at LEB 0:0
>> > UBIFS error (pid 0): ubifs_mount: Error reading superblock on volume
>> > 'ubi0:rootfs' errno=-22!
>> >
>> > ubifsmount - mount UBIFS volume
>> >
>> > Usage:
>> > ubifsmount <volume-name>
>> >    - mount 'volume-name' volume
>> >
>> > the strange thing is that when i first program all new devices i use the
>> > following instruction:
>> >
>> > tftpboot prall
>> >
>> > and prall is the compiled of a txt file which, when programming file
>> > system
>> > use the same instructions, obviously except for
>> >
>> > tftp 12000000 rootfs.ubifs
>> >
>> > instead of my mmc instructions, and
>> >
>> > ubi write 12000000 rootfs ${filesize}
>> >
>> > but from what i understand the "filesize" variable is set from the tftp
>> > instruction
>> >
>> > Where do i fail?
>> >
>> > Thanks
>> >
>> > Enrico
>> >
>> > --
>> > _______________________________________________
>> > yocto mailing list
>> > yocto at yoctoproject.org
>> > https://lists.yoctoproject.org/listinfo/yocto
>> >
>
>

You forgot to reply to all so added the Yocto mailing list back in again.

You can create multiple images by specifying ubi and sdcard in
IMAGE_FSTYPES and then flash ubi to the raw NAND and then the sdcard
image to the SD then write the logic to perform the switch.

-Martin.