USB device: Switch between "mass storage" and "serial class"

fs-support_MK · Nov 23rd 2009

By default the USB device interface of all boards is configured to run active sync (serial). If you intend to access the board as regular mass storage device you can arrange this by simple changing a registry value.

Mass Storage Device

Code

[HKEY_LOCAL_MACHINE\Drivers\USB\FunctionDrivers]
"DefaultClientDriver"="Mass_Storage_Class"

Active Sync

Code

[HKEY_LOCAL_MACHINE\Drivers\USB\FunctionDrivers]
"DefaultClientDriver"="Serial_Class"

Festus · Mar 20th 2014

Hello,

is it possible to change the the usb device client during runtime?

I read something about DeviceIoControl and IOCTL_UFN_CHANGE_CURRENT_CLIENT but when I try to use this,
the board reboots automatically...

Another question:
When I use Mass_Storage_Device_Class, the PicoMOD is recognized on a connected PC when I plug in a SD card to the PicoMOD and then the PC shows the contents of the SD card. Is it also possible that I show the contents of FFSDISK?

Festus · Mar 20th 2014

FYI, here is a link where the switching is described:
http://nicolasbesson.blogspot.…ion-profile-switcher.html

fs-support_ZU · Mar 20th 2014

Hello,

thanks for the inforamtion above. The used mass storeage is selected by:

Code

[HKEY_LOCAL_MACHINE\Drivers\USB\FunctionDrivers\Mass_Storage_Class]
"DeviceName"="DSK1:"

Try to find the "Devicename" of ffsdisk by "storage manger" (control panel/registry) or storage manger API.

Festus · Mar 20th 2014

Thanks,

I will test it.

Do you know if changing the functiondriver on the fly (without) reboot is possible on the PicoMOD boards?

fs-support_ZU · Mar 20th 2014

Hello,

Code

Do you know if changing the functiondriver on the fly (without) reboot is possible on the PicoMOD boards?

Hm, i thought you test this "link" already. I did not test it until now.

You may also test "DeactivateDevice(..."UFN1":...) -> configure Registry -> ActivateDevice(..."UFN1":...).

Festus · Mar 20th 2014

Hi,

as I wrote above, I tried the link but the PicoMOD always performs a reboot.

I also tested your suggestion (DeactivateDevice -> ActivateDevice) but with the same result.
After I call DeactivateDevice, the PicoMOD performs a reboot.

fs-support_ZU · Mar 20th 2014

Sorry,
i thought the your "post with the link" is the "solution for the previous post". The reboot may occur because the IO controls are not implemented. But i have no idea why "DeactivateDevice" fails. Any details?

Festus · Mar 20th 2014

Here is my code (C#):

Code

string searchParamString = "UFN*";
DeviceSearchType searchType = DeviceSearchType.DeviceSearchByDeviceName;
DEVMGR_DEVICE_INFORMATION pdi = new DEVMGR_DEVICE_INFORMATION();
pdi.dwSize = (uint)System.Runtime.InteropServices.Marshal.SizeOf(typeof(DEVMGR_DEVICE_INFORMATION));
IntPtr searchParam = Marshal.AllocHGlobal(searchParamString.Length);
searchParam = Marshal.StringToBSTR(searchParamString);
IntPtr device = Win32Methods.FindFirstDevice(searchType, searchParam, ref pdi);
Win32Methods.DeactivateDevice(pdi.hDevice);

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The reboot occurs in the last code line. I also compared pdi.hDevice with the Hnd Registry entry under HKLM\Drivers\Active both are the same.

fs-support_ZU · Mar 21st 2014

Hello,

Quote

I also compared pdi.hDevice with the Hnd Registry entry under HKLM\Drivers\Active both are the same.

So everything seems to be right.

Quote

The reboot occurs in the last code line.

Do you see any "reboot reason" in the debug output after reboot? From where do you know that the reboot occur in the last line? Do you debug vai Ethernet:-)?

Festus · Mar 21st 2014

RestartReason: Watchdog

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