If you have an Android 4.x phone and use Wi-Fi tethering, you may have
noticed that it uses 802.11g channel 6 and there is no configuration option
to change it. For some reason Google engineers decided to hardcode this setting
when HAVE_HOSTAPD functionality was added in ICS release. The hostapd
configuration is in /data/misc/wifi/hostapd.conf. But this file is rewritten
when starting Wi-Fi hotspot so changing it won't help. What has to be changed
is SoftapController.cpp that is used to build
/system/bin/netd binary. Currently the SoftapController::setSoftap() API call
ignores argv (channel) if HAVE_HOSTAPD is defined. Proper fix would be to
check if argv is supplied and write it to hostapd.conf. That would require
the tethering app to supply channel argument and have a configuration option
I was going through my old archives and found an intro that I wrote in 1997
and never quite finished. I decided to release the source code. This is some
hardcore stuff written entirely in assembly. Lots of tweaks and optimizations
packed in ~2KB self modifying executable doing environment mapping shading, z
buffering, and rotating tori that was all the rage back in the day.
There have been some reports of patch freezing the box while changing the
frequencies. This has been identified to be a hardware issue. Older revision
laptops have clockgen chip ICS932S421BGLF and don't have any issues with
frequency scaling or overclocking. Newer ones have ICS9248BF-96 (which in
reality is a SLG84605) and will exhibit random lockups while changing
frequencies. They also don't overclock that well. See this post confirming the issue.
Managed to get PowerNow! working in Linux. I downloaded DSDT from ACPI,
disassembled with iasl, fixed 2 errors and 1 warning, added _PSS table with 5
P-States - 1200MHz@0.9V, 1100MHz@0.85V, 1000MHz@0.8V, 900MHz@0.75V, 800MHz@0.7V.
Compiled the DSDT table with iasl compiler and compiled it into kernel. See
this guide on details how to incorporate
custom DSDT table in kernel. Next step was to modify powernow-k8 Linux module
to work with these P-States. powernow-k8 module has restrictions regarding
allowed frequencies. In short - it just would not work with frequencies this
low. Also there was a bug in powernow-k8 module that prevented voltages lower
than 0.8V from working.
I bought the Gateway LT3103u Mini-Laptop for $399.99. iFirst thing I did
was to wipe the preinstalled Windows Vista Basic and Acer eRecovery partition
and install dual boot Windows XP and Gentoo Linux. For some reason Gateway
decided to disable AMD PowerNow! in BIOS/ACPI, making power saving in Linux
impossible. Windows though is different story, thanks to RightMark CPU Clock Utility. I
configured it to use processor P-states and even slightly undervolt (0.7V vs
default 0.9V) when in lowest P-state with CPU at 800MHz. Granted it was a pain
in the ass to set this up so that unprivileged user can use it - see
this post for information on how to set up RMClock to run as service.
Also installing latest AMD Chipset and VGA drivers from Gateway site made a huge
difference in power saving department. I think installing WebCam and SDCard
drivers also made some difference allowing USB devices to power down when not in
Finished video patching code for nkpatcher. The patch allows Xbox to be
connected to VGA monitor and/or autoconvert 480i resolution games to 480p
From version 10 to version 10-vga10: * Added force RGB video feature. This will patch kernel system call AvSetDisplayMode to configure GPU for RGB signal. It will also patch Conexant and Focus registers to configure video encoder to send bi-level sync with correct colors. Xcalibur video encoder is not supported. Intended for connecting the Xbox to VGA monitor. Connect AV pack Y output to monitor green input, Pr to monitor red input and Pb to monitor blue input. The monitor must support sync on green. Special sync separator circuit is required if the monitor does not support sync on green signal. * Added feature to convert 480i video modes to 480p. This will patch kernel system call AvSetDisplayMode so that it sets video mode 480p, if mode 480i is requested. Enhances graphics quality for applications that run in 480i video mode only. Note that this feature will be active even if 480p video mode is disabled in msdash. Video patching will be done only if HDTV AV pack is detected.