4 ms·

The GL calls are marshalled across to the VideoCore firmware. The VideoCore firmware has essentially a function for each GL entry point. The shader compiler i

The GL calls are marshalled across to the VideoCore firmware. The VideoCore firmware has essentially a function for each GL entry point. The shader compiler is in the VideoCore firmware. The QPU code fragments are generated by a pull on a data flow representation in the firmware.

nitrogen 14y ago
Thanks! I suppose that's not too surprising; I've yet to hear of anybody open sourcing their core OpenGL implementation (is there even an open implementation other than Mesa?). It would be fun, in a sense, to have raw access to the VideoCore components without any existing firmware. Judging from this comment[0] of yours that I found on a Google search, I'm not the first to think so. Now, as I've said before, if the RPi gets solid USB host and isochronous transfer support (for e.g. Kinect, USB audio devices), then it will be unbeatable. [0] http://www.raspberrypi.org/phpBB3/viewtopic.php?f=33&t=6188&start=50 http://www.raspberrypi.org/phpBB3/viewtopic.php?f=33&t=6...
- hermanhermitage 14y ago
  It's possible to splice into the current blob by using /dev/mem to access the GPU partitioned memory. This lets you hot patch the VideoCore firmware (quite tricky as its running ThreadX OS), or you can hunt down QPU fragments generated by shaders. I have a plan to release an Architecture/Programming guide and will be recruiting more hands shortly for tools like LLVM etc. But today let's celebrate the great work the foundation have done opening up the user land!
  - comex 14y ago
    Just commenting to say thanks for working on this. A barebones open source firmware would be very cool to see.
makomk 14y ago
It certainly appears so, though that didn't stop Liz from spreading misinformation as usual when one of the developers of an actual open-source driver for an ARM GPU correctly pointed this out: http://www.raspberrypi.org/archives/2221#comment-34981 http://www.raspberrypi.org/archives/2221#comment-34981 The RasPi foundation is staying as classy as ever.
- hermanhermitage 14y ago
  Sour grapes from Luc I would say. The Lima project is tainted by breaches of the Mali license agreement and side channel information leaked out despite NDA. They need to start again with a Chinese wall. (Edit: According to rumours in the pubs around ARM headquarters)

nitrogen 14y ago

Thanks! I suppose that's not too surprising; I've yet to hear of anybody open sourcing their core OpenGL implementation (is there even an open implementation other than Mesa?). It would be fun, in a sense, to have raw access to the VideoCore components without any existing firmware. Judging from this comment[0] of yours that I found on a Google search, I'm not the first to think so. Now, as I've said before, if the RPi gets solid USB host and isochronous transfer support (for e.g. Kinect, USB audio devices), then it will be unbeatable. [0] http://www.raspberrypi.org/phpBB3/viewtopic.php?f=33&t=6188&start=50 http://www.raspberrypi.org/phpBB3/viewtopic.php?f=33&t=6...

hermanhermitage 14y ago
It's possible to splice into the current blob by using /dev/mem to access the GPU partitioned memory. This lets you hot patch the VideoCore firmware (quite tricky as its running ThreadX OS), or you can hunt down QPU fragments generated by shaders. I have a plan to release an Architecture/Programming guide and will be recruiting more hands shortly for tools like LLVM etc. But today let's celebrate the great work the foundation have done opening up the user land!
- comex 14y ago
  Just commenting to say thanks for working on this. A barebones open source firmware would be very cool to see.

makomk 14y ago

It certainly appears so, though that didn't stop Liz from spreading misinformation as usual when one of the developers of an actual open-source driver for an ARM GPU correctly pointed this out: http://www.raspberrypi.org/archives/2221#comment-34981 http://www.raspberrypi.org/archives/2221#comment-34981 The RasPi foundation is staying as classy as ever.

hermanhermitage 14y ago
Sour grapes from Luc I would say. The Lima project is tainted by breaches of the Mali license agreement and side channel information leaked out despite NDA. They need to start again with a Chinese wall. (Edit: According to rumours in the pubs around ARM headquarters)