I am trying to disable power management in Linux for Zynq Ultrascale devices. Looking at the kernel, it is enabled by default. When I set CONFIG_PM=n and build the kernel, it doesn't take effect. Also I wish to know if there is any dependency on other mdoules like CONFIG_SUSPEND ?
I tried disabling both of the above parameters by setting CONFIG_PM=n and CONFIG_SUSPEND=n in my kernel.cfg. But it throws out a big blob of error which is very difficult for me as a entry level embedded linux engineer to understand. Can someone shine some light on this.
Edit:
Based on the suggestion from #sawdust. I tried to do the kernel changes using menuconfig. Then the petalinux-build breaks. I am a newbie and it is a bit difficult to understand from the log, why it breaks.
Will be great to have some experienced eyes look over the build log and suggest why it fails.
https://gist.github.com/cody70b/b866dce72ae7080981edbc2ffbc4f8e9
Related
What follows is really a learning exercise and not necessarily a search for a production solution. I've recently done a bunch of reading about Windows driver development and am looking for a first good exercise in practical application before potentially proceeding toward a future win10 mobile device family project.
Just to get my feet wet with win10 driver development, I was thinking it would be interesting to develop (and then publish) a filesystem driver project that implemented a dumb Windows equivalent of /dev/null or /dev/random - really, any virtual device that I can read a stream of data from.
I haven't done much Windows development in the past, but after reading through a couple books on Safari I've landed on MS's driver samples GitHub page, which seems like a good start, but doesn't seem to provide a clear way forward from what I've read so far.
Right now I'm still casting about with web searches and would sure appreciate some guidance in how to proceed toward this goal (references, reading materials, etc) I'll be happy to publish whatever silly project(s) I wind up generating for others to learn from in the future.
One of the best way to start Windows driver development is with toaster sample . It will provide you basic workable understanding of Windows driver development. You will be able to understand basics for writing bus driver, function driver and filter drivers(upper, lower) in Windows.
I am facing a performance issue on my embedded box which is x86 based. I have installed valgrind on it, but so far it looks that it gives the performance data for application program but if I want to check the performance data for the kernel drivers, how can I do that?
Is there any tool which can help do that, by rebuilding the kernel with some options or anything..
Really appreciate any help!!
Have a look at perf. Apparently there is also some effort going on to implement a callgrind converter.
As part of the work I've been doing to answer this question about the technical workings of a glitch in Pokémon Red, I've been looking for a way to use a standard debugger to debug a Game Boy ROM. Although many of the emulators I've found have some support for debugging, nothing I've found so far has been helpful.
As a background, as of now I have tried to use the Visual Boy Advance built-in features to do debugging, but they aren't particularly useful for what I'm trying to do. VBA lacks the ability to set breakpoints, and since it steps forward at the level of frames rather than instructions I'm unable to see how the code is executing when I actually need it to. Although VBA says that it supports GDB debugging, I have been completely unable to get it working. I tried cross-compiling GDB for ARM as per the instructions, but could not get GDB to connect to the emulator (it would recognize that there was a program to connect to, but reported that the protocol had been violated). I repeated this with similar success in both Windows with Cygwin and on Ubuntu Linux. A friend and I tried to use Insight/GDB, but ran into exactly the same problems.
I also tried to use the NO$GBA debugger, but it refused to load my ROM for Pokémon Red (and then insulted me by saying that nothing I could try to do would fix it, as the file was just flat-out wrong).
Additionally, I tried downloading this version of Visual Boy Advance that claims to have a debugger in it, but for some reason I can't get it to enable the debugger. Pressing F11 as per its instructions has no effect whatsoever.
I believe that I've done my due diligence trying to get a debugger working, and I'm surprised that not a single one of them has worked. Does anyone know of a simple, straightforward way to debug Game Boy games using standard debugging techniques? I'm interested mostly in being able to put in memory write breakpoints (to see what routine is clobbering certain parts of memory). I would really appreciate it if someone with first-hand experience doing this could provide details on how to do this, as online resources on the subject seem pretty limited.
If you just want to debug your old gameboy games you can also use bgb which has several debugging options such as tracing, breakpoints, profiler and a lot more.
No$GBA is for GBA games; you want NO$GMB. Note that it's very buggy, and without a registered version (which may be impossible to get legitimately) rather crippled.
bgb is free and is very similar to No$GMB, but even buggier.
VBA is supposed to have a debugger, but there are a million different versions out there, so good luck finding the right one.
Check out the site GbaDev.org and look on the forums. This is the best spot on the web for GBA or even GBC questions. I can tell you that there are many versions of VBA and no$ out and about. The No$ you want was technically a pay for version, but Martin Korth hasn't been answering emails or anything for years now and I'm not sure of its status anymore. I can also answer some questions for you personally if you'd like or help you with the debugger.
I was able to go to the no$ main website, download the windows version of no$gmb, and use it to debug when run in B/W mode - should be sufficient for you needs. F12 opens roms, F2 toggles break points, space traces, F3 steps over, Ctrl-G takes you to an address (or symbol), and Ctrl_B allows conditional break points (by far the most powerful feature for you to use.) For instance, (3000)! would set a read/write breakpoint on address 0x3000. (0300..03003)! sets on a range. As you are looking for specific address changes, this is what you want.
VBA-M has a bunch of debugging tools under "Tools" menu, including memory & tile inspectors and a disassembler. It even has support for GDB. I didn't test with any frontends like gdbgui, or VSCode's GDB support, so YMMV, but the other built-in tools look pretty decent.
Go to the releases section for a build for your platform (arch linux also has it in AUR, for easy install in package manager.)
Here it is running some of the tools on a Mac:
I'm trying to create a windows driver that allows a standard TCP/IP socket to be used like a COM Port. I am aware of a number of existing products that do just this, but can find no reference material as to how it's actually done! I understand some of the concepts of windows drivers (bus/function/filter drivers, driver stacks, etc), and have tried reading a book on WDF, but I'm still not 100% sure on where I start if there is no actual backing hardware. If anyone has any links/pointers that will help, it would be much appreciated.
Kazar
Take a look at the com0com project. They also offer an com2tcp driver. As it is open source you can go through the sources and get an idea of how it's done.
Actually this is not a driver, but an app, so it might be less helpful in your task to learn something about driver development, but anyway could be a good starter for some technical insight.
I'd like to write a packet sniffer and editor for Windows. I want to able to see the contents of all packets entering and leaving my system and possibly modify them. Any language is fine but I'd like it to run fast enough that it won't burden the system.
I've read a little about WinPcap but the documentation claims that you can't use WinPcap to create a firewall because it can't drop packets. What tools will help me write this software?
Been there, done that :-) Back in 2000 my first Windows program ever was a filter hook driver.
What I did was implementing the filter hook driver and writing a userspace application that prepared a filter table on what to allow and what to disallow. When you get around your initial set of blue screens (see below for my debug tip in kernel mode) the filter mode driver is quite easy to use ... it gives each packet to a function you wrote and depending on the return code drops it or lets it pass.
Unfortunatley packets at that level are QUITE raw, fragments are not reassembled and it looks more like the "network card" end of things (but no ethernet headers anymore). So you'll have quite a bad time decoding the packets to filter with that solution.
There also is the firewall hook driver, as discussed in this codeproject article.
If you are on Vista or Server 2008 you'd better have a look at WFP (Windows Filtering Platform) instead, that seems to be the mandated API of the day for writing firewalls.
I don't know about it other than google turing it up some minutes ago when I googled for the filter hook driver.
Update: Forgot the debug tip:
Sysinternals DbgView shows kernel-mode DbgPrint output, and more important - it can also read them from the dump file your last blue screen produced. So sprinkle your code with dbgprint and if it bluescreens just load the dump into dbgview to see what happened before it died ... VERY useful. Using this I managed without having a kernel debugger.
I'm pretty sure you'd need to write a filter driver. http://en.wikipedia.org/wiki/Filter_driver I don't know much more than that :). It would definitely be a C/C++ Win32 app and you'd likely being doing some kernel side work. Start by downloading the DDK and finding some of the sample filter drivers.
If you just want to monitor what goes in and out of IIS, consider an ISAPI filter. Still C/C++ in Win32, but relatively easier than writing a device driver.
C# code to do this is here
I actually did this, several years ago. I'm hazy on the details at this point, but I had to develop a filter/pass-thru/intermediate driver using the Windows DDK. I got a lot of good information from pcausa. Here's a url which points to their product that does this: http://www.pcausa.com/pcasim/Default.htm
If you're doing this for practical reasons, and not just for fun, then you should take a look at Microsoft Network Monitor. The home page talks about the version 3.3 beta, but you can download version 3.2 from the Downloads page. There is also an SDK for NM, and the ability to write parsers for your own network protocols.
There's a question you need to ask which you don't know you need to ask; do you want to know which applications sockets belong to? or are you happy to be restricted to the IP:port quad for a connection?
If you want to know applications, you need to write a TDI filter driver, but that makes handling the receive almost impossible, since you can't block on the receive path.
If you're happy with IP:port, go in at the NDIS level, and I believe you can block on receive to your hearts content.
A word of warning; if you have no prior kernel experience, writing either of these drivers (although TDI is significantly harder) will take about two years, full time.
this:
TdiFw is a simple TDI-Based Open Source Personal Firewall for Windows NT4/2000/XP/2003
http://tdifw.sourceforge.net/
may help you