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

From: Yves Vandervennet
Date: Fri Feb 17 2017 - 17:29:23 EST


Moritz,

whatever solution we decide to go with has to work with other OS'es. The
last thing we want to do is to have wrappers that are Linux specific.

Yves

On Wed, 15 Feb 2017, Moritz Fischer wrote:

>>Hi Jason,
>>
>>On Wed, Feb 15, 2017 at 12:37 PM, Jason Gunthorpe
>><jgunthorpe@xxxxxxxxxxxxxxxxxxxx> wrote:
>>> On Wed, Feb 15, 2017 at 12:07:15PM -0800, matthew.gerlach@xxxxxxxxxxxxxxx wrote:
>>>
>>>> The format of the meta data associated with a fpga bitstream is certainly a
>>>> subject on its own. HTTP style plain text is definately easy to understand
>>>> and more importantly it is extendable. On the other hand, it seems
>>>> dangerous to be doing a lot of string parsing in the kernel.
>>>
>>> It is fairly close to binary parsing.. The process is
>>>
>>> - Find the first occurance of \n\n, must be less than XX bytes
>>> - Memcpy that from the sg list into a linear buffer
>>> - Replace all \n with \0
>>>
>>> To access a key:
>>> - Case insensitive search for START + "Key: " or \0 + "Key: "
>>> - Return as a string the part after the match
>>>
>>> This isn't the sort of string parsing that typically gets you into
>>> trouble. If we can't code the above correctly then we will screw up
>>> safe binary parsing of strings too :)
>>
>>Well I don't know ;-) With something fdt based we already have parsers there,
>>compilers are already in tree. I'll take another look at the u-boot
>>code, I think their
>>FIT (Flattened Image Tree) would be a fairly good match for what we're
>>trying to do.
>>
>>Cheers,
>>Moritz
>>--
>>To unsubscribe from this list: send the line "unsubscribe linux-fpga" in
>>the body of a message to majordomo@xxxxxxxxxxxxxxx
>>More majordomo info at http://vger.kernel.org/majordomo-info.html
>>