USB MSD Run time DFU

gregoire · ‎2012-04-18

Posted on April 18, 2012 at 14:05

Hi,

I am trying to implement a new project to combine MSD Mass Storage Device with DFU capabilities.

I First play with both MSD ST's example and DFU ST's example separetely.

Then I made a project with Both capabilities combined together.

I simply go from DFU to MSD, or MSD to DFU thanks to a delay.

To do so : I disconnect my USB, set the appropriate PID and initialize a new MSD connection or DFU connection respectively. Thus my host (PC) load the appropriate driver.

Everything work properly.

However, I would like to be in MSD mode by default and enter DFU mode thanks to a software command.

I saw that the Detach DFU command would correspond.

However I am a little confuse about how to do so.

I would be very pleased with any advise,

Thanks in advance

Regards,

Greg

gregoire · ‎2012-04-19

Posted on April 19, 2012 at 10:36

Hi,

I find that I should either use the composite device capabilities or use the DFU run-time capabilities.

I have a few questions :

1) If I use the composite device capabilities.

The Host PC will load a driver for each declared interfaces.

But the PID is described en the desc.c file once. How to provide the Host different PID ?

2) Using run-time DFU

I begin with the MSD ST's example.

And I try to add the run-time DFU interface and functional descriptor.

I m not sure about where it should go...

I tried once in the desc.c file in /* USB Standard Device Descriptor */

or once in the usbd_msc_core.c in /* USB Mass storage device Configuration Descriptor */

I add this :

// Run-Time DFU Interface Descriptor taken from the

// USB Device Firmware Upgrade Specification, Rev. 1.1

//

0x09, // bLength

0x04, // bDescriptorType

0x00, // bInterfaceNumber

0x00, // bAlternateSetting

0x00, // bNumEndpoints

0xFE, // bInterfaceClass: Application Specific Class

0x01, // bInterfaceSubClass: Device Firmware Update

0x01, // bInterfaceProtocol: Runtime protocol

0x00, // iInterface

0x09, // bLength

0x21, // bDescriptorType: DFU_FUNCTIONAL

0x0B, // bmAttributes: WillDetach, CanUpload, bitCanDownload

0xff, 0x00, // wDetachTimeOut: 255 ms

0x00, 0x04, // wTransferSize: 1024 byte

0x00, 0x01 // bcdDFUVersion

As I told you before,

I want to send a software command to enter DFU.

If anyone could have a look,

It would be very appreciated...

Thanks,

Greg

alok472 · ‎2012-04-20

Posted on April 21, 2012 at 05:14

I guess the example from ST provide this capability already. DFU -> MSD and Back. Can you pls re-check ? i am not so sure

For Composite device, only 1 PID needs to be provided in Device Desc and composite device implementation is done using Configuration Desc. Using this, the Host becomes DFU capable MSD device.

harinath · ‎2012-05-02

Posted on May 03, 2012 at 03:23

Though i could not clarify things in this post, i would like to point you to an firmware source example code available from ST

http://www.st.com/internet/evalboard/product/250367.jsp

Donwload iNEMO GUI and firmware. The firmware has both options enabled, Hardware DFU mode and software DFU mode when the device connected to USB of computer.

I guess you are particularly asking for MSD case. If it is so, ignore my reply.

gregoire · ‎2012-05-09

Posted on May 09, 2012 at 14:26

Hi alkom andothers,

You are right that it already support it.

However I can t see how to launch a detach request to get in DFU when my MSD works.

My PC see it as a Mass storage device and load the driver,

Thus the DFUSE does not recognize my board.

Consequently, I m not able to do anything linked with DFU...

Any Idea about how I should proceed ?

Thanks in advance,

Greg