[U-Boot] {Spam?} u-boot-usb DFU working but need some ideas

[Detlev Zundel]

Hi Marcel,

> I finally got things working well with my SAM9G45 USB devcie controller and 
> continued to implement DFU for it. 
> I implemented it using the new gadget layer and should be compatible with the 
> at91_udc driver.

Excellent, congratulations!

> I have managed to get DFU working in such way that it transfers the file to 
> RAM.  There's still a lot to do, but most things are in place and working 
> well. Basically after transfer to RAM,  a u-boot script can handle additional 
> actions, so I'm in doubt about the following :
>
> The DFU implementation I used as a basis came from openmoko. This implements 
> directly flashing the device.
> However, my thought is that it's much better to just write the file to RAM and 
> let a script in u-boot handle what should happen with it (verify, boot, flash)
> The DFU spec seems to handle this with the bitManifestationTolentant bit, but 
> the current dfu-utils don't use this bit (that can be updated of course, which 
> I already did).

I am not too familiar with the DFU spec, but I agree with regards to the
scripting.  I can envision usage scenarios where the downloaded files
are written to other storage media, so I would much rather leave that up
to the U-Boot script interpreter.

> About the way it currently works :
> 1) I start u-boot
> 2) I issue the dfuinit command (new)
> 3) the host can now download a file to RAM.
> Any thoughts on what would be the most preferred way to do this ?

This sequence sounds absolutely feasible.  What exactly is your
question?

> Additionally I think I will implement this as a composite driver so that both 
> (usb)CDC and DFU are available via USB. I have both working, but currently 
> must select it at compile time.
> My current implementation basically is just DFU as it assumes the application 
> (not u-boot) to be the firmware to be updated, so no need to switch on 
> descriptor layer level.
>
> Any reply on this would be nice, even if my above thoughts are in line.
> I hope to be able to post my changes in 1-2 weeks. After that my time is 
> extremely limited due to long time travel.

I'm really looking forward to getting DFU support into U-Boot - having
lobbyied for it quite a while :)

> If anyone is interested in helping me out posting the changes it would
> be very much appreciated.

What help do you need?

Cheers
  Detlev

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