CFE questions

Discussion in 'Asuswrt-Merlin' started by edsyl, Jan 8, 2013.

  1. edsyl

    edsyl Occasional Visitor

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    Merlin:
    I am not a CFE expert, nor do I want to be...lol

    I have been doing my reading about the ASUS implementation still being a 32K NVRAM version, but with a virtual 64K support?

    This puzzles me and I was wondering if you could clear this point up and whether or not I need to be concerned about this?

    What are the advantages/disadvantages of a 32K vs 64K CFE implementation?
    Does the ASUS implementation suffer at all for it still being 32K for the 66U?

    Thanks in advance for all the efforts,
    Regards
    Ed
     
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  3. Pierino

    Pierino Very Senior Member

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  4. edsyl

    edsyl Occasional Visitor

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    Think of it as the BIOS of a router. It's the first piece of code that gets run at power on time, it initializes basic hardware, allows recovery and such, before transferring control to the Linux kernel, which in turns will boot the actual firmware.


    OK but what does a 64K version DO for me as a user of this router?
    And does Merlin's version need it or would it even matter?
    Regards
    Ed
     
  5. Pierino

    Pierino Very Senior Member

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    If you are sticking with asus fw or Merlin's then you don't need to do anything. As long as you are running a version newer than .220(not positive) you for all intents and purposes have 64k nvram.

    I converted mine because I like dd-wrt, which I run on my linksys e3000, I tried it with the rt-n66u but found Merlin's better.
    Although I have not tried the very latest dd-wrt on it.
     
  6. RMerlin

    RMerlin Part of the Furniture

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    Basically, Asuswrt, Asuswrt-Merlin and Tomato (those that included the code for this) will manually address the whole 64 KB of NVRAM, while other firmwares like DD-WRT will only access what is initialized by the CFE. The firmware-based fix isn't virtualized, it's just manually extending to the full 64 KB.

    In Asuswrt-Merlin's case, the only reason why you might want the upgraded CFE would be if you needed the CFE to be able to use some modified settings. For example, if you were overclocking your router. But for 99% of users, there is no point in upgrading the CFE if using Asuswrt/Asuswrt-Merlin/Tomato.
     
  7. Pierino

    Pierino Very Senior Member

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    What he said. :D
     
  8. jsmiddleton4

    jsmiddleton4 Senior Member

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    The CFE thing is not necessary at this time. But I personally wanted to make sure it would not ever present itself as a problem so I updated it.

    If you read the CFE Bootloader thread in the regular 66U forum you'll see time and time again folks saying, "Hey, that wasn't too hard..."

    And it isn't. The steps are spelled out quite clearly and are step by step.

    Is it critically valuable to do? No, it isn't.

    Is it nice to know its done and I'm moving on and don't have to take note of the cfe bootloader 64K bug? Yes, it is.

    Your call of course.
     
  9. RogerSC

    RogerSC Very Senior Member

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    No it isn't difficult, but if you make a mistake, or the router software doesn't work exactly as expected (unlikely, but it happens), the stakes are high. So I think that the risk factor is what is being emphasized in those postings, that if you don't understand exactly what needs to be done and make a simple mistake, or are just unlucky, you're really hosed.
     
    Last edited: Jan 8, 2013
  10. edsyl

    edsyl Occasional Visitor

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    Thanks to all for replying. Very helpful.

    It is still not clear to me just WHAT having the CFE 64K 'enabled' (not even sure that is the appropriate adjective) does for me. That is the missing piece.
    So essentially it comes down to feature sets of ASUS, Merlin, and DD-WRT?
    If I want dd-wrt then I will need to use the 64K CFE updated to be able to install the build that need it?

    Regards
    Ed
     
  11. KevTech

    KevTech Senior Member

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    The issue with dd-wrt is if you update the CFE to 64K you can not use regular builds of dd-wrt or you will brick your router.

    You can only use the 64K builds if you have updated.

    If you have not updated then you can not use the 64K dd-wrt builds or, once again, you will brick the router.

    This is not an issue on stock or Merlins.
     
  12. jsmiddleton4

    jsmiddleton4 Senior Member

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    "the stakes are high"

    Really? A 130 dollar routers is "high stakes"?
     
  13. RMerlin

    RMerlin Part of the Furniture

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    Try having no Internet access in a house with a few kids for more than 24 hours. :)
     
  14. edsyl

    edsyl Occasional Visitor

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    Above and Beyond the Call of Duty....LOL


    Or is that NO Call of Duty

    Regards
    ED
     
  15. edsyl

    edsyl Occasional Visitor

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    So if this 64K CFE is so fraught with bricking, why even bother, I still do not understand the advantages of this larger CFE?
    Regards
    Ed
     
  16. RMerlin

    RMerlin Part of the Furniture

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    Some people are running DD-WRT, which makes it pretty much essential to be able to do so.

    There are also people who did it because they just like tinkering, and considered it a learning experience.
     
  17. mromero

    mromero Regular Contributor

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    I would say that fixing your modem's CFE is to make it be the way it was designed to be - having 64K NVRAM addressable by any firmware, be it DDWRT, Tomato, Asus and Merlin's version of Asus.

    The latest Asus / Merlin / Tomato are hacked to make the software see the 64K NVRAM you paid for.

    Using current or older DDWRT a router that has not had its CFE "fixed" will lead to problems.

    Some folks like myself do not want to be trying to remember if the CFE on this or that modem is OK - fix it now to avoid any potential problems down the road.

    For most people, leaving the router with the old CFE will not pose any problem so long as they use stock ASUS or Merlin's version. I do not want to have an oddball router in my stock ;o)
     
    Last edited: Jan 8, 2013
  18. jsmiddleton4

    jsmiddleton4 Senior Member

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    So at this point with the group of people who would consider updating the CFE and have been updating the firmware to any number of variations, that group of people doesn't have more than one router laying around?

    Updating the CFE is not that big a deal and the steps are so spelled out clearly that it is not big a deal nor is it that risky.
     
  19. edsyl

    edsyl Occasional Visitor

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    Thanks all!
    REgards
    Ed
     
  20. RogerSC

    RogerSC Very Senior Member

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    Personally, I hate having to throw away a nice router that's working really well and cost me $170 (plus tax *smile*). I took that risk when I upgraded, but I've been working with hardware and software for a LOT of years and knew where the risks were before I started.

    You can sneer about your $130 if you want, that's up to you. I get attached to things that work well and hate to see them go because of my mistake(s).
     
  21. jsmiddleton4

    jsmiddleton4 Senior Member

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    So that's how you frame it Roger. Either its "high stakes" or I'm "snearing"?

    Wow.

    As mromero pointed out in the thread about updating the CFE it is simple. It is simple because the work others have done to make it such.

    The process has been over dramatized by yourself.

    Do or do not update the CFE. It doesn't matter to me.

    However the process and steps are not difficult and if I can follow them and succeed, pert near everyone can.
     

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