[KrypteX]

I would like to see a good explanation for the various reset methods used before and after flashing a new build on Atheros, Broadcom, Ralink.
I've been reading various reset methods and there's no consensus for which is the good way. For example, this Broadcom post considers that Erase nvram from CLI (telnet or SSH) is "superior/better" than Reset to Factory Defaults from Webgui, at least for Broadcom
http://www.dd-wrt.com/phpBB2/viewtopic.php?p=953285#953285

Why is this and is this valid for Atheros and/or Ralink ?

Please someone explain to me the differences between:
1. Erase nvram from CLI (Telnet or SSH)
2. Reset Factory Defaults from Webgui
3. Reset Button on the back of router, pushed for more than 10 seconds
4. 30/30/30 reset

Thanks !

[Murrkf]

There is info about this in PART 2 of the peacock announcement. I think there is a link at the end of the current peacock annnouncement.

[KrypteX]

[redhawk0]

Seems to be router specific too...for example...never do an "erase nvram" from the CLI on an RT-N16...(if you've upgraded to K3.x)...the unit really only has 64K nvram...but it reports 128k in the CLI...and 256k in the web GUI...well...if the erase nvram command is done...it tries to erase more than the actual 64k.

I've learned to use the Web GUI reset only on this unit.

Now...on some units if you use the reset on the Web GUI...it doesn't clear out all the variables for the VAP....but from the CLI it does. I've seen my Ralink unit clear all nvram except the dd-wrt style color variable.

I've seen where the reset button doesn't clear anything...but most older units it still does.

Its hit or miss...you have to try each method...and once you find what works for your unit...stick with it.

sorry...can't give you a more "official" answer than that.

redhawk

[tsynik]

[Murrkf]

If you read the ten plus pages of peacock 2, there is relevant info. Not clear, but relevant.

[jheide44]

i'll agree with redhawk0 it appears to be device specific... not exactly sure when it all changed 30-30-30 was all you needed "back in the day" (even if the actual hardware responded slightly differently to the reset button press, a 30-30-30 would cover all the bases)

these days what works on one unit could soft brick another, etc.


here are/were Kong's thoughts on the 30-30-30 reset
http://www.dd-wrt.com/forum/viewtopic.php?p=952595#952595

that was from a short while ago on the BCM ARM device new WiFi driver page (after debate that someone believed no reset of any kind was ever needed)

[KrypteX]

Thanks guys for your replles. Now I'm really puzzled about this whole RESET before and after thing.
There is a LOT of conflicting info on the forum and on the Wiki, that's a fact.
I'll quote Kong's post here, since it's relevant IMO
http://www.dd-wrt.com/forum/viewtopic.php?p=952595#952595
"30/30/30 is the biggest bullshit I have ever read since I started developing 5 years ago. I have not seen a single device including my older K26 units, that would do what you expect it to do:-)

Even among the same family of devices there are differences, e.g. some netgear units will reset, when they first notice a pressed button, some will just wait until you release the button. Some will not reset our nvram settings. Uboot devices don't even know about our nvram partition etc. since they originally work completely different ...

There are probably a few units out there were the timing fits so it executes cfe reset procedure and then dd-wrt reset procedure, but I don't know what the third 30 should do:-)

The only thing that is consistent among all devices (if reset button in dd-wrt is functional for a certain device), is that reset is performed if dd-wrt is in running state and you press the reset button. If dd-wrt is up and running and you press the button it will reset it's config, but it will not clear out special vars, we have marked as protected.

Same thing is done by webif.

Erase nvram is a bit special as it cleans the whole flash area, which can cause issues, if the port is incomplete and does not recreate all factory params. Erase nvram works on all the devices I have ported and is able to fully remove all shit, that might have been set by "broken" firmwares and I have seen fw that mess with vars that they should not mess with, including oem fws."

To simplify, my understanding is that pushing the Reset button on the back of router (for 10+ seconds) is equivalent to "Reset to Factory Defaults" from Webgui. This will only reset the config, but will not clear out special vars. Right ?
OTOH, doing "erase nvram && reboot" from CLI will clean the whole nvram area (but can cause issues...) Right ?

So maybe it's a good idea to "erase nvram" from time-to-time, when something special changes in the DD-WRT firmware (new driver, new nvram-related mods/quirks, etc). I have never done "erase nvram" since I have my routers... should I have done it, at least when going from factory firmware to DD-WRT ?

[Murrkf]

With regard to older units, 30-30-30 was the only reliable way to clear the Nvram. Although kong might not be able to understand what the third reset did, it definitely did something. You could see it in the flashing lights that about 20-25 seconds in to the third 30, the lights would start to flash differently and you would know that the router was reset. Ah discussed in the peacock part 2, it was simple, and it worked. Always.

Other methods SOMETIMES worked with older routers, but it was very important that it always worked. Failing to clear the Nvram before flashing to a different build would often brick routers. Often. A lot! Kong was not around in those days of constant bricks. Neither were most of you. But once people started doing the 30-30-30 reset, bricks went from common to rare. It was one of the reasons that I wrote the peacock announcement.

Now that middle 30 has always been controversial. Even LOM who has been pretty much infallible in his advise, said that it wasn't fully needed, and most of us cut a corner there, but that was because you could tell if the Nvram had been properly reset but the password page, which you looked for coming up before you flashed.

I cannot comment on new routers or why 30-30-30 reset is not to be done, or which it should not be done, other than what I have been told, and updated to the current peacock announcement.

[KrypteX]

Murrkf, you are right indeed, 30/30/30 reset seems to do something different than the Restore to Factory Defaults in webgui. And it's definitely NOT placebo.
I've noticed this on my WNDR3800, which is very interesting to see how it behaves on pushing the reset button.

Let me explain in detail how my WNDR3800 behaves when doing the 30/30/30...
First of all, I think 30/30/30 seconds it's not a good idea for this router because the first 30 is simply NOT enough.
So, this is the sequence I've observed...

1. First 30 seconds: keep pushing the button and around 25 seconds in the LEDs blink a couple of times and then it seems to start loading or working, the power LED blinks, the LAN led blinks a couple more times, etc. I think it's not the best idea to let go of the reset button at this stage (around the 30 second mark). So I keep pushing it and somewhere around the 40 second mark the power button starts blinking orange, then around 45 seconds in it starts blinking green.

2. 2nd 30 sec: keeping the button pushed, I disconnect power from the router and I usually not wait the entire 30 seconds, but only 10-20 seconds (supposedly it's enough for the residual charges to discharghe...)

3. 3rd 30 sec: still keeping the button pushed, I connect the power back on and wait until the orange and then the green power light blinks. This time around it takes 35 seconds, not 50 as it took in the first part.... which is strange.
I think something important happens when connecting the power back with the reset button already pushed.... here's when the nvram is erased, I guess.

So yeah, 30/30/30 is inherently different compared to the regular Restore to Factory Defaults.

[redhawk0]

Another thing too to remember...when the 30/30/30 process was developed..it was for the Linky WRT-XXXX units...BrainSlayer initially developed this firmware on those models specifically. hense the project name dd-wrt (dd is the license plate designator for Dresden Ger....wrt came from the Linksys WRT54G model)

It was later that other broadcom units started hitting the market, newer Linksys (Cisco), Asus, Buffalo, Netgear...etc....then finally Atheros, x86, Ralink...etc

When these makes/models began support by BrainSlayer...some of the original processes for resetting them carried over...but some/many did not accept the 30/30/30 very kindly.

So...I think we're back to square one with this topic...if it works on your specific router...stick with it...if it doesn't...use any of the 4 methods to perform resets...and stick with it...once confirmed to work.

Its hit or miss from brand to brand and model to model.

my two cents.

redhawk

[jheide44]

speaking of the old days & device specific responses once again I agree with the ^^group^^

(got to dance with the one that brung ya, or stick to what works for your specific hardware)



to Murrkf's point on the reset button... I was just playing with a Dell TrueMobile 2300 v1, last week (k24 vint firmware).

While initial flashing to DD-WRT the stock firmware displayed for the end user during firmware upgrade something like this (paraphrase below)

"if unit did't respond after firmware update (the user was instructed) to reboot computer and try again. if still no response from router... unplug power wait X seconds, then press & hold reset while plugging power back in... then continue to hold the reset button for XX (maybe 30) seconds"

so perhaps the 30-30-30 was just good advice for covering "all the bases" (especially on those old/early supported devices).



another observation:
I've also seen a couple broadcom units where the CLI/telnet "nvram erase && reboot" had no impact (on k26 firmware if i recall). (I'd have to re-create before guessing which device/firmware that fact pattern that observation came from)

[Unixworld]

Very good thread, Kryptex !
I have been *that close* to start it myself, actually !

Well, you know - especially when one is new to DD-WRT,
threads like Peacock's (with all my due respect !) are very confusing
for novices and experienced alike.

The information there dates back to 2009,
and as we all know - giant leaps forward do happen in the
IT/hardware-sector, just in 5 years terms.

Perhaps the Devs would join here, and give us all
updated info about what's to be done these days ?
Well, at least the most important stuff, of course,
not router-specific.

So, we all get when to use "erase nvram" - on ARM only,
between major versions changes, never ? Right ?
And they explain in "users's language" what erasing nvram
does, what all users should follow, regardless of router
brand and model - what extra caution has to be paid
when and where.

Some novice-thoughts !
May you all stay healthy,

Cheers

[stoney li]

For ASUS ARM router, be careful to use "erase nvram" command. It seems to create intermittent wifi disconnection for the new 26xxx release. The command might erase too much info from NVRAM.

[mac913]