Ever found the keyboard backlight annoying? It keeps turnning on when booting Windows, and there is no configuration to disable it permanently in any Lenovo Utilities.
Just did some reverse engineering to find how to control keyboard backlight programmatically. The principal is simple, use \\.\EnergyDrv device exposed by Lenovo ACPI energy management driver. It is capable of controlling all keyboard backlight levels. Also other capabilities available . See code:
fprintf(stderr,"Error: Failed to get capability!\n");
break;
}
if((cap>>1)!=3){
fprintf(stderr,"Error: Auto-level not supported!\n");
break;
}
/* status */
uint32_t status=get_backlight_status(drv_handle);
if(status==(uint32_t)-1){
break;
}
if((status&1)!=1){
fprintf(stderr,"Error: Failed to get current status!\n");
break;
}
status=status>>1;
if((status&0x8000)!=0x8000){
fprintf(stderr,"Error: Cannot set backlight when keyboard is disabled!\n");
break;
}
intcurr_level=-1;
switch(status&0x7fff){
case0:
curr_level=0;
break;
case1:
curr_level=1;
break;
case2:
curr_level=2;
break;
case3:
curr_level=3;
break;
}
printf("Current level: %d\n",curr_level);
set_backlight_level(drv_handle,level);
printf("Finished setting level: %d\n",level);
}while(FALSE);
/* close */
CloseHandle(drv_handle);
return0;
}
Should built and run on any C99 compilers. Run with <app.exe> [0|1|2|3]. You can add it to task scheduler to disable keyboard backlight on startup.
Also checked other approaches. The usb/hid way does not work on an ideapad. The Keyboard_Core.dll hack also does not work, I cannot find the file in drivers.
Just downloaded and tried Visual Studio 2012(with update 2, version 11.0.60315.01). The Windows XP targeting is available(actually already available in update 1):
The executable generated by the original VS2012 toolchain does not run under Windows XP. A error message box is shown:
In update 1, the static and dynamic link libraries for the CRT, STL and MFC have been updated in-place to add runtime support for Windows XP and Windows Server 2003. And the runtime version is upgraded to 11.0.51106.1 from 11.0.50727.1.
Except the library update, there’s none real difference when selecting “v110” or “v110_xp” toolchain. I wrote a simple HelloWorld application and compare the two generated binary.
The first difference represents the timestamps of the two binary. The other two differences standard for “Operating System Version” and “Subsystem Version”. We have 5.1 for Windows XP, 6.0 for Windows Vista and later. That’s all. And we can easily build a Windows XP binary from the command line with only one additional linker switch:
1
# cl hello.cpp /link /subsystem:console,5.01
I also built a simple MFC application(dynamic link to MFC) with Windows XP target in VS2012. It runs fine under Windows XP with MFC DLLs copied in the same directory. From VS2010, the SxS assembly is not used any more. All you need to do is copy the dependent DLLs to the application directory and run.
a) Setup Perl environment, add %Perl%/bin to %PATH%.
b) Also add awk, path tools to %PATH%.
c) Decompress the apache source code to %Apache%, D:Apache maybe.
d) Decompress the zlib into srclib subdirectory named zlib.
e) Decompress the openssl into srclib subdirectory named openssl.
f) Now the source tree should look like:
l) Build Apache using command line:
Now you can buid Apache by:
1
# nmake -f Makefile.win _apache[d|r]
And install Apache by:
1
# nmake -f Makefile.win install[d|r]
m) Build Apache using Visual Studio 2005:
There’s also a flaw in the *.vcproj conversion of *.dsp through Visual Studio 2005. We must run a perl script to fix it first:
1
# perl srclibaprbuildcvtdsp.pl -2005
Now, everything are OK. In Visual Studio 2005, open the Apache.dsw and convert all *.dsp files to *.vcproj files. Then build the project “BuildBin”. The project “InstallBin” project will distribute all the project in the Apache solution.
4. Debugging with Visual Studio 2005
It’s quite simple. After build the project “InstallBin”, open the property page of the “httpd” project. Switch to “Debugging” tab, change the Command value into your binary of installed directory. Now, add breakpoints, and press F5 to start your tracing or debugging.
第一个概念叫做invalid region. 当一个被遮盖的窗口被重新显示的时候, 实际上要重画的只是被遮盖的部分. 而这些被遮盖的需要重画的部分就叫做invalid region. windows 会给窗口发WM_PAINT 消息来让窗口重画. 在代码中ps 变量(PAINTSTRUCT 结构)的rcPaint 域实际上包含了这个invalid region 的信息. 当我们调用BeginPaint() 的时候,实际上把这个invalid region 给validate 了. 不然的话, windows 检测到还有invalid region 没被重画就会不断的发送WM_PAINT 消息, CPU 会100% 的.
. See code:
