Re: [RFC 7/8] fpga-region: add sysfs interface

From: Alan Tull
Date: Wed Feb 15 2017 - 17:42:24 EST

On Wed, Feb 15, 2017 at 3:36 PM, Moritz Fischer
<moritz.fischer@xxxxxxxxx> wrote:
> Jason,
> On Wed, Feb 15, 2017 at 1:15 PM, Jason Gunthorpe
> <jgunthorpe@xxxxxxxxxxxxxxxxxxxx> wrote:
>> On Wed, Feb 15, 2017 at 12:54:27PM -0800, Moritz Fischer wrote:
>>> Well I don't know ;-) With something fdt based we already have
>>> parsers there,
>> Not sure.. How does incbin work in DTB?
>> We have the FPGA in a s/g list so we cannot pass the entire file to
>> libfdt - is that consistent with incbin?
> Well you could attach the (for lack of better word) blob to the beginning,
> instead of doing incbin
>> Can we force a specific alignment for the included data?
> I'd say probably, but haven't checked.
>> How complex will the userspace tool be to make the image?
> Userspace can be as complex as it needs to be, imho, if it makes
> kernel space easier & safer.
> I'll need to do some more reading over the weekend before I can make
> more sensible comments :)
> Thanks,
> Moritz

Another thought I have about this is that adding the header to
bitstreams can be a piece of independence from DT for systems that
aren't already using DT. This includes x86 in Linux. It also
includes other OS's that aren't using DT, they can reuse the same
image files without having to add dtc. As much as I like DT, it is
something I'm having to think about.