Hi Detlev,
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.
I did create a new command "dfu" that activates the controller and DFU. I than used the GPBR register of the AT91 to make u-boot know that it has to activate DFU by script. Basically the value of the GPBR register either tells u-boot to wait for TFTP or DFU ways to upgrade.
About the way it currently works :
- I start u-boot
- I issue the dfuinit command (new)
- 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?
Since I wasn't familiar with DFU either I asked. I implemented it basically on the go, so while I was reading the spec. Along the way I found some items which I found not very logical for u-boot. DFU states that the device should expose the normal descriptors + a DFU descriptor. I don't do that in my application. Instead I have another way to reset my application and tel u-boot to go in DFU mode. I however implemented the DFU driver in u-boot such way that it does work with dfu-utils without any issues.
Also I upload the full application to RAM first before storing it in NAND. On my board this has some limits. The RAM is 128M and NAND 256M, so I can not flash the whole NAND yet. The Openmoko driver implements a method that allows that, which can be added later of course.
I tested it the whole week and use it now as my main way to upgrade my application. Haven't seen it fail once so far, so it looks good.
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 :)
Great. I hope I can post it and that it will be maintained. It really is a nice feature I think.
If anyone is interested in helping me out posting the changes it would be very much appreciated.
What help do you need?
I'm on a real deadline for my project. I have to go on business trip end of next week and very limited in time. I finished u-boot for my companies products and I can post a full diff of it. I was hoping someone could help me out testing the patch on their board (either sam9g45 or using at91_udc ) and help me to post the changes to u-boot. I can also post a full diff the the forum, but it's rather large I think. I never posted changes before, so I have no idea yet how to do it. I know there's reading info about it, but had no time yet to look into it (shame on me :-) ).
Best regards, Marcel