Downgrade firmware on AR120

You can try to login to bootrom and set up the previous version as first at boot up. You can check the upgrade guide - the section that refers to bootrom - to understand how the settings should be made. Check the link below, chapter 6.

http://support.huawei.com/enterprise/en/doc/EDOC1000136580?idPath=7919710|21432787|7923148|22318718|6078839


Step 9 Enter 4 to set the loaded system software as the startup program.

Enter your choice(1-7):4
Startup Select

1. Display Startup
2. Set Boot File
3. Set Config File
4. Startupfile Check Manage
5. Set Startup Waiting Time
0. return

Enter your choice(0-5):2
Select Boot File

1. Flash
0. Return


Enter your choice(0-3):1
NOTE: Boot file must be .cc or .CC

Current boot file: flash:/AR1220-V200R008C50SPC500.cc
Press ENTER directly for no change.
Or, please input the new file name: flash:/AR1220-V200R008C50SPC500.cc
Save the bootfile name: flash:/ AR1220-V200R008C50SPC500.cc ? Yes or No(Y/N)y
Save load state word...OK!

Startup Select

1. Display Startup
2. Set Boot File
3. Set Config File
4. Startupfile Check Manage
5. Set Startup Waiting Time
0. return

Enter your choice(0-5):0

Hi.

Did not help. Look at my actions. The router still reboots. Please help me.

Loading Kernel Image ... OK

## Transferring control to Linux (at address 81008000) ...
Starting kernel ...

[ 1.890000] uiParaBase df409870
[ 1.930000] uiParaBase 46812379
[ 1.970000] g_sysled_gpio 18 sysNum 18 sysled_gpio DF080000
[ 2.040000] sys_led_irq init ok
INIT: version 2.88 booting
Starting udev
-n Starting Bootlog daemon:
bootlogd.
Now gigahome init......

HSAN init chip successfully ...!
SPI initializing......set frequency to 4000000
hi_module_init.sh

bootloader creation Data : Jun 6 2017, 18:36:45

Initializing I2C Bus:OK

Initializing SPI Bus:OK

Initializing EEPROM:OK
Press Ctrl+B to break auto startup ... 1

Enter Password:************
Default Password,Please Set New Password.
BootLoader Menu

1. Default Startup
2. Serial Menu
3. Network Menu
4. Startup Select
5. File Manager
6. Reboot
7. Password Manager

Enter your choice(1-7):4
Startup Select

1. Display Startup
2. Set Boot File
3. Set Config File
4. Startupfile Check Manage
5. Set Startup Waiting Time
0. Return

Enter your choice(0-5):2
Select Boot File

1. flash
0. Return

Enter your choice(0-1):1
NOTE: Boot file must be .cc or .CC

Current boot file: flash:/AR120-V200R008C50SPC500PWE.cc
Press ENTER directly for no change.
Or, please input the new file name: flash:/AR120-V200R007C00SPCb00.cc
Save the boot file name: flash:/AR120-V200R007C00SPCb00.cc ? Yes or No(Y/N)y
Save load state word...OK!

Startup Select

1. Display Startup
2. Set Boot File
3. Set Config File
4. Startupfile Check Manage
5. Set Startup Waiting Time
0. Return

Enter your choice(0-5):0
BootLoader Menu

1. Default Startup
2. Serial Menu
3. Network Menu
4. Startup Select
5. File Manager
6. Reboot
7. Password Manager

Enter your choice(1-7):1
Boot from CurrentPart=0,CurDiskFlag :1

Now boot from flash:/AR120-V200R007C00SPCb00.cc, please wait...

Get Boot ...
Get kernel ...
Get rootfs ...
Boot vesion[0xa2] is not the same[0x8d],need update.

Kernel vesion[0x303130] is not the same[0x303830], need update.

Rootfs vesion[0x37b2981f] is not the same[0x363732], need update.

Update boot.

Update Boot Successfully.
Update kernel.

Update Kernel Successfully.
Update rootfs.

Update Rootfs Successfully.System will reboot......
INIT: Switching to runlevel: 6
INIT: Pid 1016 [id si] seems to hang
-n Stopping syslogd/klogd:
no syslogd found; none killed
Unmounting remote filesystems...
Unmounting local filesystems...
-n Rebooting...
[ 145.180000] Restarting system.


Hi-Boot 2015.09 ( 2016-09-12 - 16:33:44 )
pcb_ver 0x2!board_id 0x11e!
debug_serial 0!serial_baud 9600
BDIF_GetBoardType: 0x11e OK

Initializing GPIO:OK

chipid 0x56102110!
Initializing I2C Bus:OK

Initializing TIMER:OK

Initializing PCA9555:OK

Initializing PCA9555:OK

Initializing Serial LED:OK

Initializing LED:OK

chipid 0x56102110!

boardinfo:0x402911e0!

LoadFailTimes :0x2
find kernel desc at [0x1f40000]!

Boot from KERNEL2...commandline: ro rootfstype=squashfs mtdparts=hi_nfc:256K(boot),8M(boota),8M(bootb),10M(kernela),10M(kernelb),20M(rootfsa),20M(rootfsb),15M(misc),5M(dfx),-(system) console=ttyAMA0,9600 root=/dev/mtdblock6 isolcpus=1 mem=490M bsp_rsv_base=0x9fe00000 OK
Loading Kernel Image ... OK

## Transferring control to Linux (at address 81008000) ...
Starting kernel ...

[ 1.890000] uiParaBase df209870
[ 1.930000] uiParaBase 46812379
[ 1.970000] g_sysled_gpio 18 sysNum 18 sysled_gpio DF080000
[ 2.030000] sys_led_irq init ok
INIT: version 2.88 booting
Starting udev
-n Starting Bootlog daemon:
bootlogd.
Now gigahome init......

HSAN init chip successfully ...!
hi_module_init.sh

bootloader creation Data : Sep 13 2016, 16:43:36

Initializing I2C Bus:OK

Initializing SPI Bus:OK
Press Ctrl+B to break auto startup ... 0
Boot from CurrentPart=1,CurDiskFlag :1

Now boot from flash:/AR120-V200R007C00SPCb00.cc, please wait...

Get Boot ...
Get kernel ...
Get rootfs ...
Boot vesion[0xa2] is not the same[0x8d],need update.

Backup bak-boot.

Update Boot Successfully.
Kernel vesion[0x303130] is not the same[0x303830], need update.

Backup bak-kernel.
Update Kernel Successfully.
Rootfs vesion[0x37b2981f] is not the same[0x363732], need update.

Backup bak-rootfs.
Update Rootfs Successfully.
dont support card

Save load state word...OK!
[ 44.640000] watchdog watchdog0: watchdog did not stop!

5610 end
INIT: Entering runlevel: 3
-n Starting syslogd/klogd:
done
-n Stopping Bootlog daemon:
bootlogd.

*********EVM Init(Version:D20150601B02)*********
EVM Init start 3 app(s)......ok.
EVM Init add default link between ar and veth1......Fail, ret is 0xc0000192.
EVM Devm Qmp Init......Ok.
DEVM compile :Jun 7 2016 20:29:13.
EVM Devm host init......ok.
chardev: opening backend "socket" failed
EVM Appm start nc server......ok.
EVM Appm execute monitor(0)......Ok.
EVM Appm Qmp init......ok.

Create monitor process
BSP Monitor Root Sep 12 2016 16:53:30
Initializing SPI Bus:OK
FLASH_CreateFlashFile /mnt/misc/flashfile
fopen: No such file or directory

read /mnt/db/framemtype.bin error, FILE[/home/liujie/code/v2r7/br_V200R007C00SPC_Maintain/product/ar/app/mpu/sysadm/devdb/devdb_main.c], line[276]

devdb load db file fail
EVM Sysm going to initialize......
EVM Sysm Qmp init......ok.
chardev: opening backend "socket" failed
Ч [ 51.110000] Restarting system.

AR129CGVW-L is supported upon V200R008, it can't be downgrade to V2R7.
the recommended version of this type is V200R008C50SPC500.

This device can't be downgraded

It better to use bootrom guide and set as startup the V200R008 software version