intel_hal.so

[Olivier Galibert]

On Thu, Sep 28, 2006 at 12:50:37PM +0300, Daniel Stone wrote:
> It's not difficult to find.
> 
> daniels at endtroducing:~/x/mesa/Mesa/src/mesa/drivers/dri/i965% grep intel_hal *
> [answer elided, I'm not doing your homework for you]

Made me curious.  Two functions are used in the 3D code:

- intel_hal_wm_pass, a fragment program optimizer.  Probably pure
  software, but written with knowledge of the hardware
  characteristics.  Dunno what the win is, but in any case you can
  live without it.  The perfect place to cheat, sorry, I mean optimize
  the rendering on some specific games and bechmarks as has happened
  from time to time in the video card world.

- intel_hal_recalculate_urb_fence, a function to compute the placement
  of the different parts of a shader in the 256-entries block of the
  card, if I understand it correctly.  If absent a perfectly reasonable
  function is used.  Dunno what the hal can win there, maybe some better
  adaptability of the sizes to get larger programs to run.  Not sure.
  Not critical in any way that I can see.  Maybe needed to fit some
  unusual results of the program optimizer.


Also, there was a long time ago another call in the 2D code but it has
never been (or been purged by dropping a branch) in the driver git,
it's just findable in the now-removed tgz of the driver there once was
on the intel page.  intel_hal_set_content_protection probably turns on
Macrovision on a specific screen.  Stragely, it turns it on
systematically, while:

- users may or may not want it (usually not, let's be realistic)

- Macrovision probably does not want it, since you have to pay a
  license to turn the protection on on DVDs, AFAIK.  So they'd
  definitively only want it on if they've been paid for it.

Probably explains why it's gone now.

  OG.