Плату как отключаете - просто питание убираете ? ubifs теоретически устойчива к сбоям питания но практически работу системы надо завершать корректно - halt или poweroff

Процессор должен получать запрет на запись при граничном питании. Используется ли это программно?

ubi->bad_allowed = 0; // sasa

По поводу убута ...

Надо не только загрузчик настраивать.

CPU: Freescale i.MX6SOLO rev1.1 at 792 MHz
Reset cause: POR
Board: SK-iMX6S
DRAM: 512 MiB
Setup enet clock OK
NAND: 2048 MiB
MMC: FSL_SDHC: 0, FSL_SDHC: 1
*** Warning - bad CRC, using default environment

Net: FEC
Hit any key to stop autoboot: 0
UBI: attaching mtd1 to ubi0
UBI: physical eraseblock size: 1048576 bytes (1024 KiB)
UBI: logical eraseblock size: 1032192 bytes
UBI: smallest flash I/O unit: 8192
UBI: VID header offset: 8192 (aligned 8192)
UBI: data offset: 16384
UBI: fixable bit-flip detected at PEB 11
UBI error: ubi_io_read: error -74 while reading 1032192 bytes from PEB 11:16384, read 1032192 bytes
UBI error: ubi_init: cannot attach mtd1
UBI error: ubi_init: UBI error: cannot initialize UBI, error -74
UBI init error 74
UBIFS error (pid 0): ubifs_get_sb: cannot open "ubi0:kernelfs", error -19
UBIFS error (pid 0): ubifs_mount: Error reading superblock on volume 'ubi0:kernelfs' errno=-19!

ubifsmount - mount UBIFS volume

Usage:
ubifsmount <volume-name>
- mount 'volume-name' volume
UBIFS not mounted, use ubifs mount to mount volume first!
ubifsload - load file from an UBIFS filesystem

Usage:
ubifsload <addr> <filename> [bytes]
- load file 'filename' to address 'addr'
Wrong Image Format for bootm command
ERROR: can't get kernel image!
SK-iMX6S >

U-Boot 2014.04 (Feb 19 2015 - 09:49:58)

CPU: Freescale i.MX6SOLO rev1.1 at 792 MHz
CPU: Temperature 27 C, calibration data: 0x58d5115f
Reset cause: POR
Board: SK-iMX6-OEM
DRAM: 512 MiB
NAND: 1024 MiB
MMC: FSL_SDHC: 0, FSL_SDHC: 1
*** Warning - bad CRC, using default environment

Net: FEC
Normal Boot
Hit any key to stop autoboot: 0
UBI: attaching mtd1 to ubi0
UBI: physical eraseblock size: 1048576 bytes (1024 KiB)
UBI: logical eraseblock size: 1032192 bytes
UBI: smallest flash I/O unit: 8192
UBI: VID header offset: 8192 (aligned 8192)
UBI: data offset: 16384
UBI error: do_sync_erase: cannot erase PEB 76, error -5
UBI error: erase_worker: failed to erase PEB 76, error -5
UBI: reserve more 1 PEBs
UBI: mark PEB 76 as bad
UBI error: do_sync_erase: cannot erase PEB 305, error -5
UBI error: erase_worker: failed to erase PEB 305, error -5
UBI: reserve more 1 PEBs
UBI: mark PEB 305 as bad
UBI error: do_sync_erase: cannot erase PEB 409, error -5
UBI error: erase_worker: failed to erase PEB 409, error -5
UBI: reserve more 1 PEBs
UBI: mark PEB 409 as bad
UBI: attached mtd1 to ubi0
UBI: MTD device name: "mtd=1"
UBI: MTD device size: 512 MiB
UBI: number of good PEBs: 509
UBI: number of bad PEBs: 3
UBI: max. allowed volumes: 128
UBI: wear-leveling threshold: 4096
UBI: number of internal volumes: 1
UBI: number of user volumes: 1
UBI: available PEBs: 12
UBI: total number of reserved PEBs: 500
UBI: number of PEBs reserved for bad PEB handling: 5
UBI: max/mean erase counter: 8194/18
UBIFS: recovery needed
UBI error: ubi_io_read: error -74 while reading 688128 bytes from PEB 17:360448, read 688128 bytes
UBIFS error (pid 0): ubifs_recover_leb: corrupt empty space at LEB 11:344064
UBIFS error (pid 0): ubifs_scanned_corruption: corrupted data at LEB 11:344064
UBIFS error (pid 0): ubifs_recover_leb: LEB 11 scanning failed
UBIFS error (pid 0): ubifs_mount: Error reading superblock on volume 'ubi0:rootfs' errno=-117!

ubifsmount - mount UBIFS volume

Usage:
ubifsmount <volume-name>
- mount 'volume-name' volume
UBIFS not mounted, use ubifs mount to mount volume first!
ubifsload - load file from an UBIFS filesystem

Usage:
ubifsload <addr> <filename> [bytes]
- load file 'filename' to address 'addr'
UBIFS not mounted, use ubifs mount to mount volume first!
ubifsload - load file from an UBIFS filesystem

Usage:
ubifsload <addr> <filename> [bytes]
- load file 'filename' to address 'addr'
Bad Linux ARM zImage magic!
u-boot >