|author||Brian Paul <email@example.com>||2009-01-08 16:15:31 -0700|
|committer||Brian Paul <firstname.lastname@example.org>||2009-01-08 16:15:31 -0700|
docs: updated Cell docs, from gallium-0.2 branch
Diffstat (limited to 'docs')
1 files changed, 57 insertions, 15 deletions
diff --git a/docs/cell.html b/docs/cell.html
index f9915d67e54..7fbbba7c7e0 100644
@@ -6,7 +6,7 @@
-<H1>Mesa Cell Driver</H1>
+<H1>Mesa/Gallium Cell Driver</H1>
@@ -23,18 +23,19 @@ Two phases are planned.
First, to implement the framework for parallel rasterization using the Cell
SPEs, including texture mapping.
Second, to implement a full-featured OpenGL driver with support for GLSL, etc.
+The second phase is now underway.
-The Cell driver source code is on the <code>gallium-0.1</code> branch of the
+The latest Cell driver source code is on the <code>gallium-0.2</code> branch
+of the Mesa git repository.
After you've cloned the repository, check out the branch with:
- git-checkout -b gallium-0.1 origin/gallium-0.1
+ git-checkout -b gallium-0.2 origin/gallium-0.2
To build the driver you'll need the IBM Cell SDK (version 2.1 or 3.0).
@@ -43,12 +44,13 @@ or the Cell Simulator (untested, though).
-If using Cell SDK 3.0, first edit configs/linux-cell and add
-<code>-DSPU_MAIN_PARAM_LONG_LONG</code> to the SPU_CFLAGS.
+If using Cell SDK 2.1, see the configs/linux-cell file for some
To compile the code, run <code>make linux-cell</code>.
+To build in debug mode, run <code>make linux-cell-debug</code>.
@@ -60,7 +62,7 @@ directory that contains <code>libGL.so</code>.
Verify that the Cell driver is being used by running <code>glxinfo</code>
and looking for:
- OpenGL renderer string: Gallium 0.1, Cell on Xlib
+ OpenGL renderer string: Gallium 0.2, Cell on Xlib
@@ -77,21 +79,61 @@ SPU local store as needed.
Similarly, textures are tiled and brought into local store as needed.
+As of October 2008, the driver runs quite a few OpenGL demos.
+Features that work include:
+<li>Point/line/triangle rendering, glDrawPixels
+<li>2D, NPOT and cube texture maps with nearest/linear/mipmap filtering
+<li>Dynamic SPU code generation for fragment shaders, but not complete
+<li>Dynamic SPU code generation for fragment ops (blend, Z-test, etc), but not complete
+<li>Dynamic PPU/PPC code generation for vertex shaders, but not complete
-More recently, vertex transformation has been parallelized across the SPUs
+Performance has recently improved with the addition of PPC code generation
+for vertex shaders, but the code quality isn't too great yet.
+Another bottleneck is SwapBuffers. It may be the limiting factor for
+many simple GL tests.
-As of February 2008 the driver supports smooth/flat shaded triangle rendering
-with Z testing and simple texture mapping.
-Simple demos like gears run successfully.
-To test texture mapping, try progs/demos/texcyl (press right mouse button for
+The CELL_DEBUG env var can be set to a comma-separated list of one or
+more of the following debug options:
+<li><b>checker</b> - use a different background clear color for each SPU.
+ This lets you see which SPU is rendering which screen tiles.
+<li><b>sync</b> - wait/synchronize after each DMA transfer
+<li><b>asm</b> - print generated SPU assembly code to stdout
+<li><b>fragops</b> - emit fragment ops debug messages
+<li><b>fragopfallback</b> - don't use codegen for fragment ops
+<li><b>cmd</b> - print SPU commands as their received
+<li><b>cache</b> - print texture cache statistics when program exits
+Note that some of these options may only work for linux-cell-debug builds.
+If the GALLIUM_NOPPC env var is set, PPC code generation will not be used
+and vertex shaders will be run with the TGSI interpreter.
+If the GALLIUM_NOCELL env var is set, the softpipe driver will be used
+intead of the Cell driver.
+This is useful for comparison/validation.