Nand 플래시 저장 영역 백업

온보드 Linux 버전 2.6.26.5 임베디드 시스템. 장치는 전체 그래픽 커널을 사용합니다. 파일 시스템은 NAND 플래시 메모리인 Hynix NAND 32MiB 3,3V 8비트에 저장됩니다.

# printenv
baudrate=115200
ethaddr=FF:FF:FF:FF:FF:FF
netmask=255.255.255.0
ipaddr=192.168.1.1
serverip=192.168.1.100
bootfile=firetux.kernel
bootcmd1=setenv bootargs ${bootargs} && nboot 0x20200000 0 ${image_addr} && bootm 0x20200000
bootcmd2=setenv bootargs ${bootargs} && tftpboot 20200000 firetux.kernel && bootm 20200000
phymode=auto
mtdids=nand0=gen_nand
unlock=yes
verify=y
update.uboot=echo Update u-boot && tftpboot 0x20000000 nandboot.flash && nand erase 0x0 0x03ffff && nand write.jffs2 0x20000000 0x0 ${filesize}
update.kernel=echo Update kernel && tftpboot 0x20000000 uImage && nand erase 0x80000 0x180000 && nand write.jffs2 20000000 0x80000 0x180000
update.romimg=echo Update RomImage && tftpboot 0x20000000 romimage.img && nand erase 0x80000 0x13e0000&& nand write.jffs2 20000000 0x80000 ${filesize}
update.halfimg=echo Update HalfImage && tftpboot 0x20000000 recovery.img && nand erase 0x1460000 0x700000&& nand write.jffs2 20000000 0x1460000 ${filesize}
eraseenv=echo Erase Environment && nand erase 0x60000 0x20000
HwModel=Hw_Model=NXPi02
bootcmd=run bootcmd1
halfImage=half_image=0
cy_boot_code_ver=1.0.1 (Oct  6 2011 - 20:04:00)
RouterMode=Router_Mode=0
stdin=serial
stdout=serial
stderr=serial
bootcmd=run bootcmd1
image_addr=0x80000
bootargs=console=ttyS1,115200n8 rootfstype=squashfs noalign half_image=0 verify=y Hw_Model=NXPi02 Router_Mode=0
ethact=ETN1
bootdelay=3

NAND 메모리(NVRAM)의 일부 영역은 U-boot에서 백업해야 하며, 직렬 인터페이스(UART)를 통해 보드에 연결되어 있어 네트워크 연결이 불가능합니다. U-boot에는 낸드 메모리 관리를 위한 몇 가지 옵션이 있습니다.

# help nand
nand info - show available NAND devices
nand device [dev] - show or set current device
nand read - addr off|partition size
nand write - addr off|partition size
    read/write 'size' bytes starting at offset 'off'
    to/from memory address 'addr', skipping bad blocks.
nand erase [clean] [off size] - erase 'size' bytes from
    offset 'off' (entire device if not specified)
nand bad - show bad blocks
nand dump[.oob] off - dump page
nand scrub - really clean NAND erasing bad blocks (UNSAFE)
nand markbad off - mark bad block at offset (UNSAFE)
nand biterr off - make a bit error at offset (UNSAFE)

특히,nand dump[.oob] off - dump page

무엇이 옳고 그른가오프셋 주소이것을 위해? 덤프할 파티션의 크기가 지정되지 않았습니다. 전체 NVRAM을 덤프해야 합니다.

장치가 커널 이미지를 로드한 후 11개의 MTD 파티션이 생성됩니다.

Creating 11 MTD partitions on "gen_nand":
0x00000000-0x00060000 : "u-boot"
0x00060000-0x00080000 : "u-bootenv"
0x00080000-0x01460000 : "ROMIMAGE"
0x01460000-0x01b60000 : "HALFIMAGE"
0x00200000-0x01460000 : "LINUX_ROOTFS"
0x01b60000-0x01d60000 : "HS_FW"
0x01d60000-0x01e60000 : "FPAR"
0x01e60000-0x01ee0000 : "SNOM"
0x01ee0000-0x01f00000 : "EEPROM"
0x01f00000-0x01f80000 : "NVRAM"
0x01f80000-0x02000000 : "CA_DATA"

0x01f00000nvram 오프셋 주소 인가요 ? nvram 크기는 어떻게 되나요? 0x80000인가요? U-boot에는 명령도 있습니다 md - memory display.

=> help md
md - memory display
Usage:
md [.b, .w, .l] address [# of objects]
=>

md.b 0x01f00000 0x80000터미널에 nvram을 표시하는 명령을 사용해 보았 으나 아무 것도 출력되지 않고 터미널이 정지됩니다.

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편집: [추가됨]

# nand info

Device 0: NAND 32MiB 3,3V 8-bit, sector size 16 KiB
# nand device nand0
Device 0: NAND 32MiB 3,3V 8-bit... is now current device
# nand read 0x20000000 NVRAM

NAND read: mtdparts variable not set, see 'help mtdparts'
incorrect device type in NVRAM
'NVRAM' is not a number
# nand read 0x20000000 0x01f00000 0x00080000

NAND read: device 0 offset 0x1f00000, size 0x80000
 524288 bytes read: OK

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BusyBox v1.10.2 (2015-09-06 10:58:05 CST) built-in shell (ash)
Enter 'help' for a list of built-in commands.

/bin/sh: can't access tty; job control turned off
# help

Built-in commands:
-------------------
    . : [ [[ alias bg break cd chdir continue echo eval exec exit
    export false fg hash help jobs let local pwd read readonly return
    set shift source test times trap true type ulimit umask unalias
    unset wait

# ext4write LINUX_ROOTFS /NVRAM.img 0x20000000 0x00080000
/bin/sh: ext4write: not found