I made a kernel module and used the code below to try to make a /dev/mytimer entry.
#define DEVICE_NAME "mytimer"
#define MAJOR_NUM 61
static struct class *fc;
fc = class_create(THIS_MODULE, DEVICE_NAME);
device_create(fc, NULL, MAJOR_NUM, "%s", DEVICE_NAME);
I don't see my module in /dev as /dev/mytimer...
But when I lsmod, I see it in the list as entry mytimer.
Where and how do I find my module? Is there anyway to put it in /dev?
Thanks!
Automatic creation of device nodes was something the devfs was responsible for. However it was eventually removed due to concerns about implementing device naming policy in the kernel. The modern way to create device nodes is using udev which can respond to sys device events and create the device nodes on demand.
Otherwise manually creating device nodes with mknod on a static filesystem is your other option.
Related
I have a kernel module that would like to send pre-fabricated ethernet frames from user space such as custom ARP, and other protocols (I'm trying to bypass tcp/ip stack on linux and create custom one for my needs). Frames are valid and complete with all necessary things. The only part that remains is to send them somehow to the queue on eth0 interface. What is the best solution to do this?
For snatching incoming packets I am using netfilter API with the earliest hook possible. I can not use raw sockets from user space due to the need of sudo and also due to my custom requirements.
Edit: I was able to achieve my goals with dev_queue_xmit(). However, I am still wondering if there is another solution that accesses the driver directly.
static void SendFrame(void)
{
struct sk_buff* skb = dev_alloc_skb(1518);
skb->dev = __dev_get_by_name(&init_net, "eth0");
skb_reserve(skb, NET_IP_ALIGN);
skb->data = skb_put(skb, ethFrameBytes);
memcpy(skb->data, pEthFrame, ethFrameBytes);
if (dev_queue_xmit(skb) != NET_XMIT_SUCCESS)
{
printk(KERN_ERR, KERN_ERR "Error: unable to send the frame\n");
}
}
I'm trying to run a full ADTF configuration from my own C++ command-line application using the ADTF SDK. ADTF version: 2.9.1 (pretty old).
Here's what I have (want) to do:
Load manifest file
Load globals-xml
Load config-xml
2 & 3 are done, using the session-manager service - see ISessionManager interface: https://support.digitalwerk.net/adtf/v2/adtf_sdk_html_docs/classadtf_1_1_i_session_manager.html , functions LoadGlobalsFromFile & LoadConfigFromFile.
The problem is that I don't know how to do point 1: currently, instead of loading a manifest, I manually load the list of services myself using _runtime->RegisterPlugin, _runtime->CreateInstance and _runtime->RegisterObject.
What I've managed to do is to load only the namespace service and use the INamespace interface which has a method for loading manifest files: https://support.digitalwerk.net/adtf/v2/adtf_sdk_html_docs/classadtf_1_1_i_namespace.html - see ImportFile with ui32ImportFlags = CF_IMPORT_MANIFEST.
But this only loads the manifest settings into the namespace, it doesn't actually instantiate the services. I could do it manually, by:
Do _runtime->RegisterPlugin for every url under
root/plugins/ in the namespace
Do _runtime->CreateInstance for every objectid under
root/services/ in the namespace
But I want this to be more robust and I'm hoping there's already a service that handles the populated namespace subsequently and does these actions. Is there such a service?
Note: if you know how this could be done in ADTF3 that might also be of help for me, so don't hesitate to answer/comment
UPDATE
See "Flow of the system" on this page: https://support.digitalwerk.net/adtf/v2/adtf_sdk_html_docs/page_service_layer.html
Apparently the runtime instance itself handles the manifest file (see run-levels shutdown & kernel) but I don't know how I'm supposed to tell it where it is.
I've tried setting the command-line arguments to be count = 2 and the 2nd = manifest file path when instantiating cRuntime. It doesn't work :).
In ADTF3 you can just use the supplied cADTFSystem class to initiate an ADTF system and then use the ISessionManager interface to load a session of your choice.
Found the answer, not exactly what I expected though. I tried debugging adtf_runtime.exe to find out what arguments it passes to cRuntime.
The result is indeed similar to what I've suspected (and actually tried):
arg1 = adtf_runtime.exe (argv[0] in adtf_runtime)
arg2 = full path to manifest file (e.g. $(ADTF_DIR)\bin\adtf_devenv.manifest)
arg3 = basename of manifest file, without extension (e.g. "adtf_devenv")
While this suggested that cRuntime indeed is responsible with loading and handling the manifest, it turned out to be NOT quite so, passing the same arguments to it did not do the job. The answer came when I noticed that adtf_runtime.exe was actually using an extension of cRuntime called cRuntimeEx which is NOT part of the SDK (at least I haven't found it).
This class IS among the exported symbols of the ADTF SDK library, i.e. a "dumpbin /symbols adtfsdk_290.lib" renders at some point:
public: __cdecl adtf::cRuntimeEx::cRuntimeEx(int,char const * *
const,class ucom::IException * *)
but it is NOT part of the SDK (you won't find a header file defining it).
Among its methods you'll also find this:
protected: long __cdecl adtf::cRuntimeEx::LoadManifest(class adtf_util::cString const &,class std::set,class std::allocator > *,class ucom::IException * *)
Voila. And thus, unfortunately, I cannot achieve what I wanted in a robust fashion. :)
I ended up manually implementing the manifest-loading logic, since cRuntimeEx is not made available within the SDK. Something along these lines:
Use a cDOM instance to load the manifest file
Call FindNodes("/adtf:manifest/environment/variable") to find the environment-variables that need to be set and set them using "cSystem::SetEnvVariable"
Call FindNodes("/adtf:manifest/dependencies/platform") to find library dependencies and use cDynamicLinkage::Load to load the libraries that target the current platform (win32/linux)
Call FindNodes("/adtf:manifest/plugins/plugin") to find the services to be loaded using _runtime->RegisterPlugin (you may also handle "optional" attribute)
Call FindNodes("/adtf:manifest/services/service") to find the services that need to be created using _runtime->CreateInstance and _runtime->RegisterObject (you may also handle "optional" attribute)
And, finally, call FindNodes("/adtf:manifest/manifests/manifest") to (recursively) load child-manifests (you may also handle "optional" attribute)
The only thing you need to do is start the adtf launcher with the meta files (manifest. This works for adtf 2 as well as for adtf 3. It can be done (console) application. If you also want to do a little bit more in adtf 3, you can use adtf control instead of adtf launcher with its scripting interface (see the scripts under examples)
I have to create a particular simulation for a college project. The simulation should feature several mobile nodes cyclically switch between 802.11 access point and station modes. While in station mode, nodes should read the SSIDs of access points around them, and then they should change their SSID in AP mode accordingly. There is no need for connections or data exchange between the nodes beside the SSID reading.
Now, I've been through Omnet/Inet tutorials/documentation (all two of them), and I feel pretty much stuck.
What I could use right now is someone confirming my understanding of the framework giving me some directions on how exactly I should proceed.
From what I understand is Inet does not implement any direct/easy way to do what I'm trying to do. Most examples have fixed connections declared in NED files and hosts with a fixed status (AP or STA) defined in the .ini file.
So my question is basically how do I do that: do I need to extend a module (say, wirelessHost), modifying its runtime behaviour, or should I implement a new application (like UDPApp) to have my node read other SSIDs and change his accordingly? And what is the best way to access an host's SSID?
You may utilize two radios for each mobile node e.g. **.mobilenode[*].numRadios = 2 (see also example in /inet/examples/wireless/multiradio/).
The first radio operates as AP **.mobilenode[*].wlan[0].mgmtType = "Ieee80211MgmtAPSimplified" which has to adapt its SSID.
The second radio serves as STA **.mobilenode[*].wlan[1].mgmtType = "Ieee80211MgmtSTA". Now, you have to sub-class Ieee80211AgentSTA which handles the SSID scanning procedure and has to change the first radio's SSID upon new SSID detection. Then you utilize the adopted sub-class within the simulation. Finally, active scanning has to be activated **.mobilenode[*].wlan[1].agent.activeScan = true.
I have just started on libusbdotnet. I have downloaded the sample code from http://libusbdotnet.sourceforge.net/V2/Index.html.
I am using a JetFlash 4GB Flash drive (a libusb-win32 filter driver was added for this drive).
The ShowInfo code works perfectly, and I can see my device info with two endpoints. Following is the device info from pastebin
http://pastebin.com/2Jdph6bY
However, the ReadOnly sample code does not work.
http://pastebin.com/hNZaEt8N
My code is almost same as that from the libsubdotnet website. I have only changed the endpoint that UsbEndpointReader uses. I have changed it from Ep01 to Ep02, because I read that the first endpoint is a control endpoint used for configuration, access control and similar stuff.
UsbEndpointReader reader = MyUsbDevice.OpenEndpointReader(ReadEndpointID.Ep02);
I always get the message "No more bytes!".
I thought that this is because of the absence of data, so I used the ReadWrite sample code.
http://pastebin.com/NiN5w9Jt
But here I also get "No more bytes!" message.
Interestly, the line
ec = writer.Write(Encoding.Default.GetBytes(cmdLine), 2000, out bytesWritten);
executes without errors.
Can pen drives be used for read write operations? Or is something wrong with the code?
A USB thumb drive implements the USB mass storage device class, which is a subset of SCSI. The specification is here.
You're not going to get anything sensible by just reading from an endpoint - you have to send the appropriate commands to get any response.
You have not chosen an easy device class to begin your exploration of USB - you may be better starting with something easier - a HID class device, perhaps (Mouse/Keyboard) though Windows does have enhanced security around mice and keyboards which may prevent you installing a filter.
If you meddle with the filesystem on the USB stick while it's mounted as a drive by Windows, you'll almost certainly run into cache-consistency problems, unless you're extremely careful about what kind of access you allow Windows to do.
I need to configure USB OTG on iMX31 for device mode. We need a raw channel between the host and target and usb seems to be the best suited. However I haven't been able to correctly configure the OTG controller. I dont know what I am missing. I have performed the steps mentioned in section 32.14.1 of iMX31 Reference Manual. I have also configured PORTSC1 register for ULPI.
Can any one help me out here? any poineters/code/any thing that can help me is welcome.
Thanks
The litekit is supported by the vanilla Linux kernel.
It's pretty easy to declare the OTG for device mode. You just need to declare it as device when you register your device:
static struct fsl_usb2_platform_data usb_pdata = {
.operating_mode = FSL_USB2_DR_DEVICE,
.phy_mode = FSL_USB2_PHY_ULPI,
};
Register code:
mxc_register_device(&mxc_otg_udc_device, &usb_pdata);
Don't forget to configure the pads for the physical ULPI lines, and eventually make the initial transactions for your transceiver.
You can find all the necessary code as I did it for the moboard platform and the marxbot board file.