Re: [Libusbx-devel] [PATCH] Samples: Add FX2/FX3 firmware upload to RAM

[Markus <li...@ne...>]

Hi Pete,

my answers became a bit longer than intended. Here's my 5 cent,
but generally, I'd leave the decision to you:

> Now, this being said, I don't have that much of an issue bumping the
> limit, but 4K seems awfully large for a file path. Would 512 bytes
> be OK with you?

I'm perfectly ok with that.
 
> >Furthermore, as the FX3 files are expected to come as an .img
> >file, I'd suggest not to use "data.bin" as default file name
> >(I'd rather opt for no default filename at all for FX2/FX3).
> 
> And the FX2 ones come as .bix, so if we wanted to satisfy everyone,
> we'd need a .bin for the mass storage dump, .bix for FX2 and .img
> for FX3, plus the logic that goes with it. Except it's a sample, so
> we might as well keep things simple.
> 
> Likewise, you'll see that I reused the data.bin section we already
> had for the -b option, which was optional, so that's the reason why
> it's still optional for the FXes. If you think it's preferable, I
> can make the filename mandatory of all of -b|f|g, but I didn't see
> it as a major point and it helped minimizing the diff.

I see what you mean. But from a usability standpoint I would opt 
for mentioning at least the suffix the firmware is expected to
have for a given Cypress board. This relieves the forum from
answering basic questions on the one hand and saves firmware
developers from reading the xusb code for understanding the transfer.

So I would at least mention the designated firmware file suffix
in the command description.

For the FX3, I did some searching myself until it was clear to 
me that only the Cypress generated .img file format is supported 
due to the preamble it provides [2].

I consider mandatory filenames more sensible than a random one, as said.

> >As for upload vs. download, this seems to be a matter of taste.
> > From my experience, the hardware development crowd tends to
> >prefer download when flashing firmware to a device.
> 
> I'd say you should always consider users who aren't familiar with
> the operation first and foremost, as they're the ones for whom the
> terminology will matter.
> 
> If it goes from PC to an external device, and the program that is
> run by the end user to perform the data transfer executes on the PC
> (or, in a more general manner, if the environment where the end user
> is going to actively perform actions is not the target), then, as
> far as I'm concerned, it should logically be labelled as an upload.
     
I don't have much of a preference here, since both parties arguments 
are valid in my opinion.

The final reason I chose download in favor of upload was that
the Cypress docs do so as well [1].

All the best,
/Markus


[1] "Getting Started with FX3 SDK.pdf" (as part of the SDK install)
[2] http://www.cypress.com/?app=forum&id=167&rID=53996