great, read that already. but for me it makes not much sense that stock firmware is working when there are bad sectors on the memory... anyway router is going back to amzn.
Joined: 18 Mar 2014 Posts: 12904 Location: Netherlands
Posted: Fri Nov 05, 2021 11:06 Post subject:
When firmware is made the compiler has no knowledge of bad sectors but the first part of the boot firmware has to be written on a known good flash part otherwise it will not run
The Netgear firmware (the first part of the boot process) is either smaller or has knowledge about bad blocks and works around that
Watching the serial output while booting stock fw will identify the bad blocks. Mine were the same as the openwrt guide. My 2nd flashed via GUI without issues. I haven't tried compiling myself to avoid them, as I'm not prepared to dive in that deep.
Joined: 30 Jun 2014 Posts: 61 Location: California
Posted: Fri Nov 05, 2021 19:31 Post subject:
If you can't return the router, you could try the procedure described on the Openwrt forum. No build or compiling required, but you do need to edit a binary file.
As I understand it, there are two sections in the factory.img file, the kernel and the rootfs, separated by padding with zeroes. The install expects the rootfs to be at a specific memory location. Bad blocks will push the rootfs into the wrong spot. Determine the number of bad blocks ( dmseg | grep bad ) and the block size (128k?). Remove that amount of zero padding between the kernel and rootfs, and you are good to go.
i will, i've been familiar with wrt (openwrt and dd-wrt) since 2006 starting with FON2100 going over several other devices, never had issues like that.
next time i will hook up my serial console and look deeper into it.
i will, i've been familiar with wrt (openwrt and dd-wrt) since 2006 starting with FON2100 going over several other devices, never had issues like that.
next time i will hook up my serial console and look deeper into it.
Post updates if you do. I identified the bad blocks on mine to confirm the issue, but wasn't ready to invest the time figuring out how to work around them. Since my bad blocks matched those in the Open-wrt forum, I've wondered if others are the same as well, and if skipping these blocks on unaffected devices would cause issues. If not problematic, could the fix be incorporated into the official builds (if the bad blocks are indeed in the same place)?
Joined: 16 Nov 2015 Posts: 6445 Location: UK, London, just across the river..
Posted: Fri Nov 05, 2021 20:20 Post subject:
i believe, bad blocks marking was implemented in the new age DDWRT firmwares...already...
if im not wrong... _________________ Atheros
TP-Link WR740Nv1 ---DD-WRT 55630 WAP
TP-Link WR1043NDv2 -DD-WRT 55723 Gateway/DoT,Forced DNS,Ad-Block,Firewall,x4VLAN,VPN
TP-Link WR1043NDv2 -Gargoyle OS 1.15.x AP,DNS,QoS,Quotas
Qualcomm-Atheros
Netgear XR500 --DD-WRT 55779 Gateway/DoH,Forced DNS,AP Isolation,4VLAN,Ad-Block,Firewall,Vanilla
Netgear R7800 --DD-WRT 55819 Gateway/DoT,AD-Block,Forced DNS,AP&Net Isolation,x3VLAN,Firewall,Vanilla
Netgear R9000 --DD-WRT 55779 Gateway/DoT,AD-Block,AP Isolation,Firewall,Forced DNS,x2VLAN,Vanilla
Broadcom
Netgear R7000 --DD-WRT 55460 Gateway/SmartDNS/DoH,AD-Block,Firewall,Forced DNS,x3VLAN,VPN
NOT USING 5Ghz ANYWHERE
------------------------------------------------------
Stubby DNS over TLS I DNSCrypt v2 by mac913
i believe, bad blocks marking was implemented in the new age DDWRT firmwares...already...
if im not wrong...
If it has been implemented, it's not working correctly on these devices. The serial console shows no attempt of DD-WRT skipping the bad blocks. It with the stock firmware.
I do not know if it works but I think you first have get it to run before it can detect bad blocks and that is just the point you cannot get it to run
So if you already have it running then it might detect bad blocks which are surfacing on subsequent upgrades?
So if I edit the factory to DD-WRT file and get it running, the upgrade files should work. Is this correct? I'm more likely to give it a try at some point if I don't need to edit files for each upgrade as well. It's currently doing well as my primary router on DumaOS. Hybrid VPN has been decent once I figured out it's quirks. I'd love have ad blocking back though, and using vlans to have a separate VPN network across all APs makes connecting devices to the VPN extremely easy.
Joined: 18 Mar 2014 Posts: 12904 Location: Netherlands
Posted: Sat Nov 06, 2021 8:40 Post subject:
mwbuss8 wrote:
egc wrote:
I do not know if it works but I think you first have get it to run before it can detect bad blocks and that is just the point you cannot get it to run
So if you already have it running then it might detect bad blocks which are surfacing on subsequent upgrades?
So if I edit the factory to DD-WRT file and get it running, the upgrade files should work. Is this correct? I'm more likely to give it a try at some point if I don't need to edit files for each upgrade as well. It's currently doing well as my primary router on DumaOS. Hybrid VPN has been decent once I figured out it's quirks. I'd love have ad blocking back though, and using vlans to have a separate VPN network across all APs makes connecting devices to the VPN extremely easy.
I think/hope so, so if you get it to run with the trick described on OpenWRT it should upgrade again.
I do not know if it works but I think you first have get it to run before it can detect bad blocks and that is just the point you cannot get it to run
So if you already have it running then it might detect bad blocks which are surfacing on subsequent upgrades?
So if I edit the factory to DD-WRT file and get it running, the upgrade files should work. Is this correct? I'm more likely to give it a try at some point if I don't need to edit files for each upgrade as well. It's currently doing well as my primary router on DumaOS. Hybrid VPN has been decent once I figured out it's quirks. I'd love have ad blocking back though, and using vlans to have a separate VPN network across all APs makes connecting devices to the VPN extremely easy.
I think/hope so, so if you get it to run with the trick described on OpenWRT it should upgrade again.
Please let me know if that indeed works when you try it
It'll probably be a while before I get a chance to try, but I'll definitely post when/if I do. Fortunately, it's pretty easy to open, so I can see what's happening via serial. Last time I tried serial was the only way I could boot into recovery mode anyway.
