Asus RT-N66u with TomatoUSB firmware

[RMerlin]

When the new stock RT-N66 firmware that increases NVRAM to 64 KB comes out later this summer, will this increase in NVRAM be permanent or will the NVRAM size go back to 32 KB when the router is flashed with earlier versions of stock firmware or flashed with a non-ASUS firmware (like Shibby’s TomatoUSB)?

Reverting to an older firmware or flashing a third party firmware will make you lose all your settings, and only report 32K available. Tomato devs will have to implement changes in their firmware to also address 64 KB of nvram.

 

[sirozha]

Reverting to an older firmware or flashing a third party firmware will make you lose all your settings, and only report 32K available. Tomato devs will have to implement changes in their firmware to also address 64 KB of nvram.

So, is NVRAM a partition in the flash memory? I thought it was a dedicated chip that ASUS originally partitioned for 32 KB and now they are expanding this partition to 64 KB, so as soon as the partition is expanded to 64 KB, NVRAM stays at 64 KB. You don’t really need to have any firmware loaded for NVRAM to retain its size, do you?

When you erase NVRAM, you format it, but you don’t repartition it, do you?

Thanks in advance for clarifying this for me.

 

[RMerlin]

There's 32 MB of NAND (flash) memory total. It's split in a few partitions:

- Bootloader (aka CFE, aka pmon)
- Linux (the kernel)
- rootfs (The firmware filesystem)
- jffs (this will always use all the remaining space left after roofs has taken what it needs)
- nvram (fixed at 128 KB)

The nvram partition size has always been 128 KB, but the firmware was only accessing the first 32 KB. The newer version will access 64 KB of it. So if you revert to an older firmware, it will go back to only accessing the first 32 KB, ignoring all the remaining space.

 

[sirozha]

There's 32 MB of NAND (flash) memory total. It's split in a few partitions:

- Bootloader (aka CFE, aka pmon)
- Linux (the kernel)
- rootfs (The firmware filesystem)
- jffs (this will always use all the remaining space left after roofs has taken what it needs)
- nvram (fixed at 128 KB)

The nvram partition size has always been 128 KB, but the firmware was only accessing the first 32 KB. The newer version will access 64 KB of it. So if you revert to an older firmware, it will go back to only accessing the first 32 KB, ignoring all the remaining space.

So, does this mean that there’s no sense in waiting for the new ASUS stock firmware that can access 64 KB of NVRAM if one is going to run TomatoUSB on this router?

 

[RMerlin]

So, does this mean that there’s no sense in waiting for the new ASUS stock firmware that can access 64 KB of NVRAM if one is going to run TomatoUSB on this router?

Correct. You won't have 64 KB nvram under Tomato until its developers implement it in their code (probably by looking at Asus's GPL code), or someone comes up with an updated CFE (which, so far, doesn't seem to be the direction taken by Asus).

 

[sirozha]

Correct. You won't have 64 KB nvram under Tomato until its developers implement it in their code (probably by looking at Asus's GPL code), or someone comes up with an updated CFE (which, so far, doesn't seem to be the direction taken by Asus).

What are the benefits of having larger NVRAM? Is 34 KB limiting the number of features that can be packed in the firmware due to not having enough space to save all settings?

 

[RMerlin]

What are the benefits of having larger NVRAM? Is 34 KB limiting the number of features that can be packed in the firmware due to not having enough space to save all settings?

nvram is where settings are stored. A typical configured RT-N66U (with only Asus's features) only has about 2 KB of space left. Every port forward and DHCP reservation will take up space, meaning you can easily run out of nvram space over time. At that point, you will end up either with a crashed router (requiring a factory default reset), or your entire configuration being wiped out.

When it comes to third party firmwares like Tomato the issue is much worse. It prevents these from using the nvram to store additional data, such as OpenVPN SSL certificates and such. So while there is plenty of NAND space to put code, there isn't enough space to actually store the settings needed by additional features.

 

[sirozha]

Thanks a lot!

 

[RMerlin]

I updated the OP with the URL to the new Github repo where I am publishing my work:

https://github.com/RMerl/asuswrt-merlin

 

[piotrpiano]

Greetings!

Shibby's Tomato v.095 released!

http://tomato.groov.pl/?dir=K26RT-N

Changelog:
- fix working PS3 with minidlna
- fix [bwlimit] link on overview-devices page
- fix „ug” bug with running shell scripts on RT-N66u
- remove garbage from Router Name
- enable USB Support by default
- enable SD Card support for RT-N66u by default
- samba security fix – „root” credential remote code execution
- wl_mitigation disabled by default

- VLAN:
experimental VLAN/VID mapping GUI (allows creating VLANs with 802.1Q tags larger than 15 via GUI)
allow DMZ-style forwarding to alternative LAN bridges
- PPTP:
allow specify ‘custom’ config/settings
dnsmasq to answer DNS queries on pppX interfaces
- MultiSSID: some minor fixes

 

[angelsanges]

Greetings!

Shibby's Tomato v.095 released!

http://tomato.groov.pl/?dir=K26RT-N

Changelog:
- fix working PS3 with minidlna
- fix [bwlimit] link on overview-devices page
- fix „ug” bug with running shell scripts on RT-N66u
- remove garbage from Router Name
- enable USB Support by default
- enable SD Card support for RT-N66u by default
- samba security fix – „root” credential remote code execution
- wl_mitigation disabled by default

- VLAN:
experimental VLAN/VID mapping GUI (allows creating VLANs with 802.1Q tags larger than 15 via GUI)
allow DMZ-style forwarding to alternative LAN bridges
- PPTP:
allow specify ‘custom’ config/settings
dnsmasq to answer DNS queries on pppX interfaces
- MultiSSID: some minor fixes

it is with latest asus drivers for wireless?

 

[xrecar]

like the firmware, but...

Just my experience, but has anyone else notice the signal difference between stock(112) and tomato? I bumped up the tx power to 80, but anything over seems to make it worse. I guess I'll be keeping to stock just for the signal strength alone.

 

[piotrpiano]

it is with latest asus drivers for wireless?

It's with the 5.100.138.20, introduced in v 093. Not sure if it's "the newest" but it's pretty new

 

[piotrpiano]

Just my experience, but has anyone else notice the signal difference between stock(112) and tomato? I bumped up the tx power to 80, but anything over seems to make it worse. I guess I'll be keeping to stock just for the signal strength alone.

Which Tomato version? Weaker signal strength was reported in Shibby's review of RT-N66u some time ago but it was before the newer broadcom driver 5.100.138.20 was used in v. 093.

 

[jyavenard]

Greetings!

Shibby's Tomato v.095 released!

Did you try it?

If it's built on the source code he released a couple of days ago, it wouldn't boot on any non-linksys hardware.

 

[jyavenard]

It's with the 5.100.138.20, introduced in v 093. Not sure if it's "the newest" but it's pretty new

It's the latest version available. Same as stock asus 112 firmware.

However, it was an incomplete update of the drivers... one of the utility didn't get updated.

I'm about to push a fix

 

[piotrpiano]

Did you try it?

If it's built on the source code he released a couple of days ago, it wouldn't boot on any non-linksys hardware.

No, I didn't yet... And I am afraid I won't be able to until next week due to lack of time. But one of the users of the openlinksys forums (Polish) already reported 095 working on an Rt-n16.
Plus, Shibby's signature over there clearly says: Asus RT-N66u + Tomato v1.28 K26USB RT-N5x-095

Maybe you could join Openlinksys thread and clarify your doubts directly with Shibby...? He speaks pretty good English
http://www.openlinksys.info/forum/viewthread.php?thread_id=11624&rowstart=4900

 

[jyavenard]

Maybe you could join Openlinksys thread and clarify your doubts directly with Shibby...? He speaks pretty good English

I'm already in talk with Shibby, and I can confirm that 095 contains the fixes required to work with the RT-N66.

(FYI: I'm the author of the required fixes)

 

[HHawk]

I'm already in talk with Shibby, and I can confirm that 095 contains the fixes required to work with the RT-N66.

(FYI: I'm the author of the required fixes)

Forgive my ignorance, but what is the difference between Shibby's and Toastman's versions?

Also, I ordered a RT-N66 today to replace one of RT-N16 (which has problems), what is the recommended setting for the "Transmit Power" for the RT-N66 with either of these Tomato firmwares?

If I recall correctly I RT-N16 set at around 60 or 65 mW in the GUI.

 

[richto]

I need a pre-shared key IPSEC VPN to connect my home network to Azure - is the Tomato USB firmware any good for that?