[Captivate Android Development] glitterballs:
Most of what is below is still accurate, but see this post for links to the kernel download and important infoshttp://xdaforums.com/showpost.php?p=12397646&postcount=580

1-18-11

v.4 - GB’s Impressive Sounding Name Kernel

* As always, many, many thanks to xcaliburinhand.

* Consolidating Steam and Voodoo/CWM kernels into one thread. The two kernels are the same except for recovery, and jfs support in the Steam kernel.

* Started using a proper changelog

* Implemented Impressive Sounding Name Technology AND Dynamic Naming Technology patches; next update to include Dramatic Use of Imagery, with possible Reference to Mythical Creatures patch.

* Cherry-picked some recent commits not included in JPX source. (Will post source this evening, I hadn’t planned on releasing this just yet, but it seems as though it’s already being packaged into a ROM so might as well, right?)

* CONFIG_ARM_THUMBEE=y, enables ThumbEE processor mode, should give some minor JIT performance improvement.

* config_hz=100. With this value, kernel hz = user hz which eliminates HZ <--> USER_HZ conversions. It should also slightly increase battery life without affecting performance.

* Increased default overclock to 1280 MHz. Your may want to revise your undervolt settings, 1280MHz runs at the same voltage as 1200MHz did/does, so you **may** not be able to undervolt as much at 1280. (Yes, I previously said I wouldn’t go past 1200MHz, but, I feel ok going to 1280 since the voltage hasn’t changed and it’s still well below the max vdd_arm.) Use voltage control or setCPU to limit clock speed if you don’t want to use this. Delete your Voltage Control boot settings before booting this kernel. I’m currently using Voltage Control 3.0a.

* Added Voodoo Sound. I hadn’t really planned on it but there were a lot of requests for it.

* Removed i9000 splash screen and replaced with an old familiar one.

* Want lower screen brightness? I know Hardcore did tinkering with the kernel source to do this, but I really like Screen Filter, it even has a Tasker plugin.

* From previous versions: Backlightnotification 2.3, Voodoo color/video fixes re-enabled against my better judgment and even though single-blind testers couldn't tell me which kernels had it and which did not. .

Downloads of v.4 - The file you want is something like rGB-v.4-011811-XXXXX.zip/tar

By clicking any of these links, you agree to flash delete your Dalvik cache and remove any oc/uv boot settings you have before booting. v.4 ClockworkMod zip at the bottom of this post, tar files of Voodoo5/CWM and Steam below for those of you who like to use Odin.

tar of v.4 with Voodoo5 & CWM recovery

tar of v.4 with Steam recovery

Credits

Xcaliburinhand, supercurio, raspdeep, SztupY, sorry if I forgot anyone else.

Stuff I wrote a while ago and may or may not be accurate any more.

1-6-11

This seems to be stable again. Started over from scratch and added in BLN 2.3. Everyone who was affected by charging problems with the previous kernels has not had a shutdown over the last two days of testing. Hopefully we're good again.

1-4-11

Closed testing on newer kernels until I'm fairly confident the issue is resolved again. I had still been getting intermittent reports of charger instability from the reoriented-balls-1-3-11-ocuv-bln23.zip (#47) kernel. Anyone affected by this please switch back to the 'f' builds below, which is the last known rock solid (I think) version.

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This kernel is fast, and this kernel is stable. It's overclocked by default to 1.2GHz, but if you don't want to overclock at all, just install either setCPU or download xan's app which I have attached to this post and set the max clock speed to 1.0GHz. This kernel supports init.d scripts, so you have save your settings and have them load at boot.

1100-1200+ Quadrant score on RFS at 1GHz. 1500-1700+ on /data, /dbdata, and /cache on ext4. ~14.1 Linpack at 1GHz. Compare that to any other kernel available here at the same speed and I think you'll see this one comes out on top. I'm not doing this for donations, I just want to my experience with the phone as good as possible. Since this is a Voodoo 5 kernel, you can also make /system ext4 as well for an even smoother experience. This kernel has great battery life and is very stable as well. And when I say stable, I mean, you can use the phone however you want to, you don't have to do any workarounds to keep it from freezing. (edit - as long as you're using one of the build f kernels it seems...) Although, as always, if you aren't 100% satisfied with any of my products, I will give you a full refund.

What this kernel is -

Kernel for 2.2.1 ROMs, (may work on 2.2, but I haven't personally tested it), built from JPX source, with Supercurio's Voodoo 5, overclocked by default to 1.2GHz with raspdeep's code, and Neldar's backlight notification enabled, and re-oriented with xcaliburinhand's code. The undervolting code has been fixed to keep your phone from dying while charging. I'll not be supporting anything beyond 1.2GHz. I hardly use 1.2GHz myself, and from what I've read, many users (but obviously not all) have stability issues with anything much beyond that. This post from one of the senior Android engineers at Google also struck a nerve with me, and is also part of the reason I'll not support anything past 1.2GHz. Samsung actually wrote most of the code for 1.2GHz into the kernel source but had it commented out, so I don't have a problem providing software that will allow users to push it to that level.

Again, for voltage control, use xan's app. I've attached an older version of the app as I'm not sure if the newer one is backwards compatible with the 'older' methods of power management.

Also, standard disclaimers about how if this blows up your phone or tells your girlfriend she's getting fat, it's not my fault. I've had this kernel on my phone for a couple days, so none of that should happen.

How to install - Either flash in ClockworkMod, or use Neldar's really awesome kernel flashing app.

gb-reorient-12-23-build-f.zip is a zip tarred zImage. Unzip, then flash the tar with Odin, or extract the zImage and flash it with Heimdall or Neldar's kernel flashing app.

gb-reorient-fixed-ocuv-f-cwm.zip is a ClockworkMod flashable kernel.

Some thoughts on undervolting

The whole point of undervolting is to safely do the same amount of work with your CPU while using less energy (ie more battery life). Your phone is idle most of the time, so you can the most from undervolting lower frequencies more. Undervolting is safe WHEN you find the settings that work for your phone. Generally, -75mV seems to be stable for everyone. If you want to push it further, go ahead, but realize that if you push it too far, you phone will freeze, and you'll have to pull the battery. Relatively harmless, but, be aware it can happen. Personally, my phone is perfectly stable at the following settings (from 100MHz to 1000MHz) -125mV, -100mV, -100mV, -100mV, -75mV. These settings may not work for your phone. You might find that you can get by with undervolting a little more, but your system will freeze randomly, so if that happens, don't undervolt as aggresively. So, for example, I found that I can usually get by with -150, -125, -125, -125, -100, but every once in a while the phone will freeze up. And since I want a stable system, I've backed down from that. I can't tell you what to do though, but keep in mind that undervolting too much may lead to system instability.

- If you still want to try to find a oc/uv kernel which works for you, don't undervolt at all and tell me if it still happens with kernel #7 (12-23 build from my other thread). As far as I know, no one has had an issue with charger instability on that kernel. If it does still happen, I need to know the kernel version # and for good measure, the production code under your battery (can someone tell me what the name for this is again, I don't feel like shutting off my phone to check), it will be a number like 08.10, 10.10, etc.

- If even with the 12/23 build f kernels and not undervolting at all, you're still get shutdowns when charging, you probably want to get a different kernel. If you insist upon using that one anyway, try charging via USB instead of the wall outlet, it seemed to happen less frequently on older kernels, and I haven't had a charge death in weeks now, so, I'm good at least.

- See if your phone is one of the ones being recalled. If your phone is under recall and these don't work for you, I'm not sure what else I can do.

- These fixes work for me and a lot other people who had the same problem with other oc/uv kernels. Like I said, we're running these out of spec, so a few unlucky souls might not have phones that can handle this. Or maybe some of these kernels have been sprinkled with pixie dust and others haven't. If you find a different kernel that works for you by all means use it. It's all about choice people.