Re: [RFC PATCH v2 0/1] FPGA subsystem core

[Michal Simek]

On 10/05/2013 01:49 AM, Jason Gunthorpe wrote:
> On Fri, Oct 04, 2013 at 04:33:41PM -0700, Greg Kroah-Hartman wrote:
> 
>>> I agree that the firmware interface makes sense when the use of the
>>> FPGA is an implementation detail in a fixed hardware configuration,
>>> but that is a fairly restricted use case all things considered.
>>
>> Ideally I thought this would be just like "firmware", you dump the file
>> to the FPGA, it validates it and away you go with a new image running in
>> the chip.
> 
> That is 99% of the use cases. The other stuff people are talking about
> is fringe.

yep.

> I've been doing FPGAs for > 10 years and I've never once used read back
> via the config bus. In fact all my FPGAs turn that feature off once
> they are loaded.
> 
> Partial reconfiguration is very specialized, and hard to use from a
> FPGA design standpoint.

And also from software point of view in connection to drivers handling.
It means tools supports partial reconfiguration and even Xilinx produce
TRD design where partial reconfiguration is used but it is long way
to go to get this work nicely.

> I also think it is sensible to focus this interface on simple SRAM
> FPGAs, not FLASH based stuff, or whatever complex device required a
> byte code interpreter (never heard of that before).

Agree.

Michal

-- 
Michal Simek, Ing. (M.Eng), OpenPGP -> KeyID: FE3D1F91
w: www.monstr.eu p: +42-0-721842854
Maintainer of Linux kernel - Microblaze cpu - http://www.monstr.eu/fdt/
Maintainer of Linux kernel - Xilinx Zynq ARM architecture
Microblaze U-BOOT custodian and responsible for u-boot arm zynq platform

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