JB Bootloader and Kernel Questions...

Discussion in 'Samsung Galaxy Nexus' started by billyk, Aug 14, 2012.

  1. billyk

    billyk Member

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    Having less than a week's experience with rooting/ROMs (Vicious was my first ROM, Bugless Beast is my current ROM), I have a some questions, if I may...

    - Some of my boot times with BB are 3-4 minutes, others boots are super-fast. I know that JB Bootloader might fix this. If I flash JB Bootloader, will it complicate a move back to stock if I choose to do so? Do the majority of JB ROM users use this bootloader? Is it just a matter of copying it to my SDCard partition and then using ROM manager to flash it using the "Install New ROM from SD Card" (don't know any other way to flash a file).

    - Regarding kernels, do you have to use an alternate kernel to get the best battery life? I assume that when I flashed BB, it brought it's own kernel with it. If that's the case, do I flash a kernel only after I flash the ROM? Can I also use ROM Manager's "Install New ROM from SD Card" function to flash it? I looked up Franco's app, and noticed that the app will find the latest kernel and can flash it for you. But if using some other kernel, is ROM Manager the ticket for flashing?

    Thanks for your help and patience!
     
  2. cupfulloflol

    cupfulloflol Senior Member

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    The issue with long JB boot times seems to be due to file system checks. Meaning it is scanning your partitions for errors. If you aren't powering down properly, like say a crash or a battery pull, chances are next boot you will have a longer boot time. There are also times where you get hit with them even if you are properly shutting down. They should be pretty rare, perhaps 1/10 or 1/20, but they happen to everyone.

    I would assume I am in the minority of folks not using the JB bootloader. There are plenty of folks using the JB bootloader whom are hit with the long reboots, so I am not sold on it does anything worthwhile. A few devs I have seen discussing it, seem to not believe it is helpful either. It doesn't hurt to use it though, as you can go back to ICS if you want. There are many alleged fixes out there, none of which seem to be 100% solutions, to the problem.

    Kernels, do you have to use a different kernel for better battery life? No, not necessarily. Every device and every ROM can react a little differently to kernels and kernel settings. This requires a little bit of experimentation to see what works for you. I am a fan of custom kernels though, if for nothing else but the additional options they allow for (color adjustments for example).

    Three things to consider here with kernels as well. First make sure the kernel is for your device. Second make sure the kernel is for your particular OS, meaning if you are on a JB ROM you will need a kernel that is compatible with JB. Third, make sure you download the "update.zip" version of the kernel. Some kernel devs release the .img which is flashable via fastboot, which basically just means it won't be installable via ROM manager/custom recovery.

    Yes you should be able to use ROM Manager's Install rom from sdcard option to flash either of these. All this really does is automates the reboot into recovery, flash the file, then boot back into android process. It also can perform wipes and backups as well if you select them. I honestly haven't used ROM manager in quite some time though, so I can't really verify this for sure. You can flash Lean Kernel or Franco's kernel via this method too, they both release update.zip for their kernels (you mentioned Franco's app, both are in his app).

    Another note: Perhaps make a backup before the kernel flash if you choose to flash one, with the bootloader it really won't make a difference if you backup as you can't backup a bootloader.
     
  3. billyk

    billyk Member

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    Wow - thanks for all of that!
    I just got an education!
    Betcha this will help others as well.

    So maybe I'll be Franco's app. It seems to automate things a bit. One article I read from earlier this year that said the merely flashing that kernel (leaving all settings to default) improved performance significantly (up to 5x in benchmark tests). That's impressive. But, I wouldn't want to do that if it introduces any instability.
     
  4. cupfulloflol

    cupfulloflol Senior Member

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    Certain benchmarks can have the score fluctuate quite a bit just do to a single tweak. Will that tweak make a difference on the actual performance? Maybe and maybe not (more often probably not haha). I don't think the benchmarks are a great indication of performance. For example my phone could be much smoother than another person's phone, even though they scored 500 points higher on a benchmark. That said I do have two benchmark apps installed on my device, but I use them as stress test tools (to test stability of kernel and kernel settings) more than a performance test.

    I personally just give kernels the eyeball test. Which consists of me using the device as I normally would. Browse a few of my favorite sites, watch a video on youtube, play a couple games....etc Do I see lag where I used to not see lag? Are things smoother or at least on par with stock?

    I basically leave settings at default for a lot of things nowadays myself. Outside of color calibration, I don't touch a whole lot else anymore.
     
  5. billyk

    billyk Member

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    Thanks again!
    I'll still consider Franco's Kernel.
     
  6. dezymond

    dezymond Tech Support Mod
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    I used Franco's app for a bit and loved it. His kernel ran solid for me and never had an issue with it, I've moved onto another kernel since then, but will always have Franco's kernel as backup. But as Cup said, benchmarks aren't really going to show "real world" performance. Benchmark apps were made to really work your phone, something you'd probably never do on a daily basis and if so, rarely.

    And as for leaving kernel settings at default, I agree. The dev of these kernels know what they're doing and performance wise they know how to get the most out of their kernels. Remember kernels are just like ROMs. Each are a little different and some of us like certain kernels more than others. Franco's kernel is a great start, and for the time I ran it, never had a hiccup.
     
  7. tgyberg

    tgyberg Silver Member

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    Bunch of DF old timers in this thread! :p I've been using a franco.kernel nightly with linaro tweaks (did on ICS and now on JB) and man is it fast. Really good battery life as well!
     
  8. rjcapp

    rjcapp Member

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    Try jbsourcery ROM.

    Sent from my Galaxy Nexus using Droid Forums
     
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