HTC Vision/T-Mobile G2 Overclock Module
After two nights of mostly guesswork, I have managed to create an overclocking kernel module for the HTC Vision. The result? I have been able to not only overclock the MSM7x30 in this phone to 1GHz, the stock speed of the higher "binned" but identical 8x55 used in the Desire HD, I have been able to push the processor in my G2 significantly further, up to 1.42GHz! Benchmark scores are very, very high, and the improved CPU performance is in line with what you'd expect from such a high clock frequency. All of this is possible without permanent root (and the ability to flash kernels) because we are using a kernel module and not flashing an actual kernel.
Binary (OTA 11/03): http://dl.dropbox.com/u/36553/vision_oc-g9ab3677.ko
Binary (original stock ROM): http://dl.dropbox.com/u/36553/vision_oc.ko
This kernel module is distributed under the terms of the GNU GPLv2.
To use it on a T-Mobile G2 on the stock 18.104.22.168 kernel, copy vision_oc.ko to /data/local and run this command as root:
This will overclock your phone to the default 1017.6MHz, which is on par with the 8x55. To overclock even higher (or lower), run the following command:
insmod /data/local/vision_oc.ko pll2_l_val=53
Where pll2_l_val*19.2 equals the speed (in MHz) that you're overclocking to. For example, 53*19.2 corresponds to 1017.6MHz, while setting pll2_l_val=74 will overclock you to slightly over 1420MHz: insmod /data/local/vision_oc.ko pll2_l_val=74 (this is 1.42GHz - be careful! I ran into freezing issues somewhere between 76 and 80, so I figured 74 was stable for my G2, and I've been running it at that all day. If it freezes try 73, 72, etc. Every phone is unique - your mileage may vary. You may even be able to get higher than me.)
If you ever want to change the speed of your overclock without rebooting, run the following command:
Then run one of the above commands. It's important to note that using a value of 42 (good number ) for pll2_l_val will make your phone run at 806.4MHz again. Rebooting the phone will reset your root access and your overclock (of course, you probably already knew this). Voltages can also be tweaked for the highest frequency (to know how to do this, read the README link below).
If there's ever an OTA or if you flash a custom kernel, you'll need a recompiled version of the kernel module, and with different addresses. Any kernel dev can easily do this using the documentation below.
To use it on another device (such as an HTC Desire Z, if it runs a different kernel, or even an HTC Desire HD or 8x55 myTouch) running a different kernel, you must re-compile the kernel module from source and refer to the instructions here to modify it (or the installation process) accordingly: http://github.com/coolbho3k/vision_o.../master/README
If you're going to be overclocking, SetCPU sleep/battery/battery temperature profiles can be tremendously helpful.
Want to donate? Buy SetCPU from the Android Market, or there's a donate link in my signature.
Video and screenshots