Hi I am trying to study PCI device in gem5 system. I am trying to use a ready device from gem5 /dev folder. However, I am not sure how to use the PCI device. Is there anyone can give me some hits about the software driver or hardware configuration. THANKS.
The file is in /gem5/src/dev/pci/CopyEngine.py
The version is 22.
thanks.
Liu
example or some hints
Related
We made a motherboard. A PCIe switch (1 upstream port, 4 downstream ports) is used. Each downstream port directly leads to a PCIe slot.
There is a problem that has been plagued for a long time. The No. 2 slot does not recognize the device and has this problem on multiple motherboards.
We checked the power supply and wiring of slot 2 and everything worked fine. And carefully checked the PCB design and layout, slot 2 is no different from other slots.
At present, the hardware has not found any doubts, so I wonder if I can get further fault information through the operating system.
Can I get the details of the device enumeration by opening some configuration of the operating system or by kernel debugging?
1) I've used UEFI Shell V2.2 to see that the No.2 slot device is online and can be read out the configuration space. However, after entering Windows, the No.2 slot device is still not visible in the device manager. I tried to refresh the device by right-clicking on the device manager and the No.2 slot device appeared! By running the test application, it's found that the board is operating normally.
2) I did a comparative experiment and plugged a Samsung PCIe SSD into slot 2. The device would display properly whether in the EFI shell or in Windows.
I'm using beaglebone black (Debian OS, MySQL are installed).
After unplugging supply power and not using 24 hours.
I can't start my beaglebone.
It's only birght LED D4 and power LED.
How can i start my OS?
I just try to use usb cable and access to beaglebone at 192.168.7.2. but request time out.
The most likely issue is that the operating system has become corrupted by the unexpected shutdown. The same thing can happen with a regular computer and has happened with my own beaglebone black when I pulled the power plug while testing some circuits. I would suggest trying to boot off of an SD card. If you have anything on there you want to save, you can use the live SD card OS to retrieve the data from the embedded flash. If the SD card also doesnt boot, then you may have a hardware issue and a serial to USB cable plugged into the debug header would probably be needed to try and get more information as to why it is not booting.
Is it possible to send an ASCII code on an external device through USB port using IOS API? I assume that it is possible through bluetooth connection, but I'm not sure through USB connector. Any thoughts?
I would appreciate if someone could put me in the right direction.
Thanking you in advance
That largely depends on the level of sophistication of this "external device". If this external device is just a bare metal embedded device without some sort of operating system you definitely need MFI.
Otherwise, you can run a usbmuxd server (e.g. on Raspberry PI with Linux) to establish a connection via USB. Usbmuxd is basically the technology that Apple uses to communicate between iOS devices and Desktop apps such as iTunes or Xcode. And yes, it is App Store compliant, e.g., Duet Display uses this approach to make an iPad a secondary display for your Desktop via USB.
There are several open source libraries that provide a high level API, e.g., PeerTalk or DarkLightning.
I am pretty new to Linux so I apologize if I will ask some really simple stuff.
I am working on a custom board with SAM9G25 and Angstrom distribution as operating system.
The board as to act as a USB Device (Mass storage device), when will be connected to a Host computer. Right now I am simply enabling and removing the g_mass_storage module and the things are working fine.
In the final version, I need to manage the g_mass_storage module according to the connection and disconnection of a USB cable. I tought to use VBUS as an interrupt (also polling will be fine).
Here it comes my problem.
Since the VBUS GPIO is handled by the USB driver i cannot read it's status from userspace. I only see an interrupt count in /proc/interrupt.
I am asking if there is a way to get an interrupt (from the Driver) or to be able to read the VBUS GPIO value when the usb cable is connected/disconnected from the system.
I apreciate any kind of help.
I know this is a bit old, but I found the same problem, and found from userspace you can view the connection status from the udc sys class device. For example, on my architecture the status of USB can be viewed from:
/sys/class/udc/ci_hdrc.0/status
PC connection: configured
Power adapter: powered
Disconnected: not attached
I've read the AM335x architecture can be observed from:
/sys/class/udc/musb-hdrc.0.auto/current_speed
Best of luck
As part of a BlackBerry project I'm working on I need the ability to store data. As per RIM's documentation, on handsets running v5 or later OS, we can use the SQLite database versus the more typical PersistenceStore methods.
What I noticed is when my handset (A Torch 2) is plugged-in via the USB cable - so that I can run code through the debugger - the "SDCard/" and the "store/" are no longer available (both of these are NO longer enumerated when calling FileSystemRegistry.listRoots). Only "system/" is available, but as it's a read-only file system this does me little good.
I need a read/write file system that will be available even if the handset is attached to a PC.
It's worth noting that when I plug my handset in I get a dialog that asks how I want this connected: Sync Media, Mass storage device, or Charge Only are the 3 options. It does not matter which I choose ... the effects are the same in that only "system/" is available for a file system.
Any advice or help is greatly appreciated.
-------------------------------------- UPDATE --------------------------------------
I spoke with RIM's developer tech support on this issue and was simply informed this is a FAD. Their advice was
"This is not a bug, it is how the device is meant to function. You can
listen for when the device is connected via USB and the data
unavailable using SystemListener2."
As such it appears all we can do is alert the user to the fact that by plugging their handsets into the USB cables whatever functionaltiy you might require in your application that would include the file system will temporarily be unavailable. It might be functions as designed but I hope at some point they'll improve the design.
I'm afraid to say I struggled briefly with this and then gave up.
In my experience RIM mounts the SD card on the pc filesystem when you connect it via USB no matter what you do.
If you "eject" your device from the machine you should be able to access the sd card.