We were in fact talking past each other

We were in fact talking past each other

Posted Jun 6, 2008 14:49 UTC (Fri) by dwmw2 (subscriber, #2063)
In reply to: We were in fact talking past each other by PaulMcKenney
Parent article: Moving the firmware out

The main point I am trying to make -- which you appear to agree with -- is that there is good and sufficient motivation to provide users with some mechanism that automatically matches up the Linux-kernel driver with the corresponding device firmware. This is I believe that point that Dave Miller was getting at in the original article.

It's not particularly hard to do this -- and we get it right in many situations already, where the firmware is either in ROM/Flash or extracted from a Windows or other driver -- and thus we have to cope with the various versions we might encounter. You work out what version of the firmware you have, and you cope accordingly.

Alternatively, for firmware which can be shipped in the linux-firmware tree, we can actually ship both old and new versions simultaneously by appending a version number to the filename (think of it a bit like an soname in libraries). That makes it easier, because older kernels would continue to request and use the older firmware blobs.

I don't think it's a particularly serious concern. The firmware blobs just don't change that often -- they're a black box which we can't tweak for ourselves, and if we're really lucky the manufacturer might throw and improved version over the wall occasionally, but it isn't anywhere near as frequent as we'd like.

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If we're really lucky the firmware is generated at build time from the 
GPLed source :) I doubt you're moving the sym53c8xx firmware; it's not a 
blob (it has actual comments and everything).

That is certainly the best case -- very nice when it works out this way!