Yes, and what is it used for?Micron M25P80 Serial Flash Embedded Memory.
#backup:
nanddump --file /mnt/sda1/mtd11.dmp /dev/mtd11
#and then to write it back:
flash_erase /dev/mtd11 0 0
nandwrite -p /dev/mtd11 /mnt/sda1/mtd11.dmp
Thank you.
Ok. But after that how can I restore it?
I am sorry if I ask too simple questions but it is difficult for me to find a person who can help me.
I think, I now understand, why Netgear and other manufactures continue using NVRAM partitions for keeping the essential settings. The answer is simple: to survive firmware upgrades, otherwise if all the settings are kept as uci configs, users will have to reconfigure or restore settings from backup every time they upgrade fw, which leads to broken user experience and customer dissatisfaction.
Thank you very much for support.Don't do it if you don't need to and don't know what you do.
Use the GUI backup and restore to start with, and only use nandwrite when you have the need:
https://forum.openwrt.org/t/dump-and-write-back-mtd/30180/2
Code:#backup: nanddump --file /mnt/sda1/mtd11.dmp /dev/mtd11 #and then to write it back: flash_erase /dev/mtd11 0 0 nandwrite -p /dev/mtd11 /mnt/sda1/mtd11.dmp
Re: R7800 Resetting to Default Config
HI,
I have moved on to a new router after this fiasco but I tried an experiment today and wanted to share it to anyone with one of these boat anchors (kinda light for that job so "paper weight" is probably more appropriate). I opened up my r8700, took off the shielding, found the chip and held some pressure on it while heating it with a butane torch ($1.00 from Menards). I plugged it all in and confiured it. I was able to re-boot several times and it retained the settings. I am going to put it in to service tonight. I'll update this thread one way or the other.
Jim
Message 69 of 71
Original link: https://community.netgear.com/t5/Ni...to-default-configurations/m-p/1913254#M157881Re: R7800 Resetting to Default Config
Good Evening,
It's been a week since I "torched" the flash memory chip on the underside of my r7800 and it has been rock solid. I have rebooted it several times and it holds my config (passwords, wifi names, reserved ip's). I have backed up and restored configs. Try it at your own risk, but I had nothing to lose.
Jim
Message 71 of 71
If that's the case, then we still need some explanation on why it affects data retention of only a specific partition. Anyway, we need more evidence. A gas torch is the worst tool I can imagine of to heat-up a PCB. It is absolutely possible, that the cold contact is somewhere near the chip itself, and by using a torch he might've unintentionally refreshed the soldering of all the surrounding discrete SMD components, effectively eliminating the real root cause.On NG community forum, there are two very interesting posts confirming that the problem is linked with the flash microchip.
However, might not be the chip itself, but the soldering...
Here are the posts:
And
Original link: https://community.netgear.com/t5/Ni...to-default-configurations/m-p/1913254#M157881
I made a little script called nvram-utils.
To install:
- Connect to the router with ssh or telnet
- Go to the directory you want to install the script (I recommend /opt/scripts):
If directory does not exist use:Code:cd /opt/scripts
Code:mkdir -p /opt/scripts; cd /opt/scripts
- Copy and paste the following code:
Code:wget https://tinyurl.com/nvram-utils && chmod +x nvram-utils
Now the script is installed.
Usage:
- /opt/scripts/nvram-utils backup
- To backup the current settings to be able to restore with the boot fix.
- If you have an external drive labeled ‘optware’, it will save a copy to it with a timestamp in /mnt/optware/nvram_backups/ in binary and text formats.
- /opt/scripts/nvram-utils bootfix install
- To install the boot fix (init.d and rc.d) to restore saved settings from backup at early boot stage.
- THIS WILL PREVENT THE ABILITY TO DO A FACTORY RESET as the backup settings will always be restored. To prevent that, you need to access the root file system (telnet or ssh) and either:
- remove /nvram_backup (rm /nvram_backup and confirm), or
- uninstall the boot fix (see next command)
- /opt/scripts/nvram-utils bootfix uninstall
- To uninstall the boot fix
That’s it. I threw that quickly without much testing. It is basic and to help people having the settings reset at reboot or restore from web GUI problem.
Thanks to @kamoj who helped with the boot fix.
After installing the most recent Voxel firmware and/or installing various Kamoj betas, I discovered that nvram-utils is no longer installed in my router. The only file in opt/scripts is "firewall-start-bwusage.sh".
Can you tell me what events necessitate reinstallation of the script?
Any firmware flash is removing the utility.
To reinstall, just follow install steps.
About the necessity to have the script installed or not:
The script is never necessary (except people encountering the problem with nvram not sticking after reboots), but it helps to do backups of settings and be more prepared if problems happen.
Got it. Does a firmware flash also remove the backed up configuration data? At the moment, I'm using the utility simply to save my configuration settings. It is "safe hex." Fortunately, none of the recent (post 74.3SF) reboots necessitated by updated Voxel and Kamoj firmwares has resulted in any loss of my settings.
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