At Tue, 27 Jul 2010 17:33:32 +0200, David Henningsson wrote:
2010-07-27 16:57, Jaroslav Kysela skrev:
A little off topic: hda-compiler . I'm playing with an idea to have the hda-intel driver behaviour description (patches) in a firmware file.
There seem to be more than one thought in that area. Recently there has been some discussion (at least on Ubuntu Developer Summit) whether the device-tree[1] structure could be used in this area as well. Since we would then have separate device-tree files, we could update them independent of the kernel.
Did it come from Andy? I've heard the idea to use OF from Grant in the last year, and yes, this is feasible. But I'm not sure how much gain we'd get in the end.
For new devices, except for a few ones like AD or Conexant, we usually write the generic tree parser so that BIOS information can be parsed dynamically. If BIOS information is broken or insufficient, we can add some hints for correction, via sysfs for debugging or statically in the code for production. And the rest of the problem is very specific to devices, and requires often some quirks in the parser itself. So, in this scenario, there is little room OF can help. We'd like rather to avoid the static data, no matter in which form.
Meanwhile, the deployment of OF can be helpful if we move the whole parser stuff to the user-space and push the parsed/compiled tree info into the kernel (i.e. "firmware"). In such a case, OF representation can be more flexible; and the kernel has already the infrastructure.
thanks,
Takashi