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| <h1>The Mesa 3D Graphics Library</h1> |
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| <h1>Environment Variables</h1> |
| |
| <p> |
| Normally, no environment variables need to be set. Most of the environment |
| variables used by Mesa/Gallium are for debugging purposes, but they can |
| sometimes be useful for debugging end-user issues. |
| </p> |
| |
| |
| <h2>LibGL environment variables</h2> |
| |
| <ul> |
| <li>LIBGL_DEBUG - If defined debug information will be printed to stderr. |
| If set to 'verbose' additional information will be printed. |
| <li>LIBGL_DRIVERS_PATH - colon-separated list of paths to search for DRI drivers |
| <li>LIBGL_ALWAYS_INDIRECT - forces an indirect rendering context/connection. |
| <li>LIBGL_ALWAYS_SOFTWARE - if set, always use software rendering |
| <li>LIBGL_NO_DRAWARRAYS - if set do not use DrawArrays GLX protocol (for debugging) |
| <li>LIBGL_SHOW_FPS - print framerate to stdout based on the number of glXSwapBuffers |
| calls per second. |
| <li>LIBGL_DRI3_DISABLE - disable DRI3 if set (the value does not matter) |
| </ul> |
| |
| |
| |
| <h2>Core Mesa environment variables</h2> |
| |
| <ul> |
| <li>MESA_NO_ASM - if set, disables all assembly language optimizations |
| <li>MESA_NO_MMX - if set, disables Intel MMX optimizations |
| <li>MESA_NO_3DNOW - if set, disables AMD 3DNow! optimizations |
| <li>MESA_NO_SSE - if set, disables Intel SSE optimizations |
| <li>MESA_DEBUG - if set, error messages are printed to stderr. For example, |
| if the application generates a GL_INVALID_ENUM error, a corresponding error |
| message indicating where the error occurred, and possibly why, will be |
| printed to stderr.<br> |
| |
| For release builds, MESA_DEBUG defaults to off (no debug output). |
| |
| MESA_DEBUG accepts the following comma-separated list of named |
| flags, which adds extra behaviour to just set MESA_DEBUG=1: |
| <ul> |
| <li>silent - turn off debug messages. Only useful for debug builds.</li> |
| <li>flush - flush after each drawing command</li> |
| <li>incomplete_tex - extra debug messages when a texture is incomplete</li> |
| <li>incomplete_fbo - extra debug messages when a fbo is incomplete</li> |
| <li>context - create a debug context (see GLX_CONTEXT_DEBUG_BIT_ARB) and |
| print error and performance messages to stderr (or MESA_LOG_FILE).</li> |
| </ul> |
| <li>MESA_LOG_FILE - specifies a file name for logging all errors, warnings, |
| etc., rather than stderr |
| <li>MESA_TEX_PROG - if set, implement conventional texture env modes with |
| fragment programs (intended for developers only) |
| <li>MESA_TNL_PROG - if set, implement conventional vertex transformation |
| operations with vertex programs (intended for developers only). |
| Setting this variable automatically sets the MESA_TEX_PROG variable as well. |
| <li>MESA_EXTENSION_OVERRIDE - can be used to enable/disable extensions. |
| A value such as "GL_EXT_foo -GL_EXT_bar" will enable the GL_EXT_foo extension |
| and disable the GL_EXT_bar extension. |
| <li>MESA_EXTENSION_MAX_YEAR - The GL_EXTENSIONS string returned by Mesa is sorted |
| by extension year. |
| If this variable is set to year X, only extensions defined on or before year |
| X will be reported. |
| This is to work-around a bug in some games where the extension string is |
| copied into a fixed-size buffer without truncating. |
| If the extension string is too long, the buffer overrun can cause the game |
| to crash. |
| This is a work-around for that. |
| <li>MESA_GL_VERSION_OVERRIDE - changes the value returned by |
| glGetString(GL_VERSION) and possibly the GL API type. |
| <ul> |
| <li> The format should be MAJOR.MINOR[FC] |
| <li> FC is an optional suffix that indicates a forward compatible context. |
| This is only valid for versions >= 3.0. |
| <li> GL versions < 3.0 are set to a compatibility (non-Core) profile |
| <li> GL versions = 3.0, see below |
| <li> GL versions > 3.0 are set to a Core profile |
| <li> Examples: 2.1, 3.0, 3.0FC, 3.1, 3.1FC |
| <ul> |
| <li> 2.1 - select a compatibility (non-Core) profile with GL version 2.1 |
| <li> 3.0 - select a compatibility (non-Core) profile with GL version 3.0 |
| <li> 3.0FC - select a Core+Forward Compatible profile with GL version 3.0 |
| <li> 3.1 - select a Core profile with GL version 3.1 |
| <li> 3.1FC - select a Core+Forward Compatible profile with GL version 3.1 |
| </ul> |
| <li> Mesa may not really implement all the features of the given version. |
| (for developers only) |
| </ul> |
| <li>MESA_GLES_VERSION_OVERRIDE - changes the value returned by |
| glGetString(GL_VERSION) for OpenGL ES. |
| <ul> |
| <li> The format should be MAJOR.MINOR |
| <li> Examples: 2.0, 3.0, 3.1 |
| <li> Mesa may not really implement all the features of the given version. |
| (for developers only) |
| </ul> |
| <li>MESA_GLSL_VERSION_OVERRIDE - changes the value returned by |
| glGetString(GL_SHADING_LANGUAGE_VERSION). Valid values are integers, such as |
| "130". Mesa will not really implement all the features of the given language version |
| if it's higher than what's normally reported. (for developers only) |
| <li>MESA_GLSL - <a href="shading.html#envvars">shading language compiler options</a> |
| <li>MESA_NO_MINMAX_CACHE - when set, the minmax index cache is globally disabled. |
| </ul> |
| |
| |
| <h2>Mesa Xlib driver environment variables</h2> |
| |
| <p> |
| The following are only applicable to the Mesa Xlib software driver. |
| See the <a href="xlibdriver.html">Xlib software driver page</a> for details. |
| </p> |
| <ul> |
| <li>MESA_RGB_VISUAL - specifies the X visual and depth for RGB mode |
| <li>MESA_CI_VISUAL - specifies the X visual and depth for CI mode |
| <li>MESA_BACK_BUFFER - specifies how to implement the back color buffer, |
| either "pixmap" or "ximage" |
| <li>MESA_GAMMA - gamma correction coefficients for red, green, blue channels |
| <li>MESA_XSYNC - enable synchronous X behavior (for debugging only) |
| <li>MESA_GLX_FORCE_CI - if set, force GLX to treat 8bpp visuals as CI visuals |
| <li>MESA_GLX_FORCE_ALPHA - if set, forces RGB windows to have an alpha channel. |
| <li>MESA_GLX_DEPTH_BITS - specifies default number of bits for depth buffer. |
| <li>MESA_GLX_ALPHA_BITS - specifies default number of bits for alpha channel. |
| </ul> |
| |
| |
| <h2>i945/i965 driver environment variables (non-Gallium)</h2> |
| |
| <ul> |
| <li>INTEL_NO_HW - if set to 1, prevents batches from being submitted to the hardware. |
| This is useful for debugging hangs, etc.</li> |
| <li>INTEL_DEBUG - a comma-separated list of named flags, which do various things: |
| <ul> |
| <li>tex - emit messages about textures.</li> |
| <li>state - emit messages about state flag tracking</li> |
| <li>blit - emit messages about blit operations</li> |
| <li>miptree - emit messages about miptrees</li> |
| <li>perf - emit messages about performance issues</li> |
| <li>perfmon - emit messages about AMD_performance_monitor</li> |
| <li>bat - emit batch information</li> |
| <li>pix - emit messages about pixel operations</li> |
| <li>buf - emit messages about buffer objects</li> |
| <li>fbo - emit messages about framebuffers</li> |
| <li>fs - dump shader assembly for fragment shaders</li> |
| <li>gs - dump shader assembly for geometry shaders</li> |
| <li>sync - after sending each batch, emit a message and wait for that batch to finish rendering</li> |
| <li>prim - emit messages about drawing primitives</li> |
| <li>vert - emit messages about vertex assembly</li> |
| <li>dri - emit messages about the DRI interface</li> |
| <li>sf - emit messages about the strips & fans unit (for old gens, includes the SF program)</li> |
| <li>stats - enable statistics counters. you probably actually want perfmon or intel_gpu_top instead.</li> |
| <li>urb - emit messages about URB setup</li> |
| <li>vs - dump shader assembly for vertex shaders</li> |
| <li>clip - emit messages about the clip unit (for old gens, includes the CLIP program)</li> |
| <li>aub - dump batches into an AUB trace for use with simulation tools</li> |
| <li>shader_time - record how much GPU time is spent in each shader</li> |
| <li>no16 - suppress generation of 16-wide fragment shaders. useful for debugging broken shaders</li> |
| <li>blorp - emit messages about the blorp operations (blits & clears)</li> |
| <li>nodualobj - suppress generation of dual-object geometry shader code</li> |
| <li>optimizer - dump shader assembly to files at each optimization pass and iteration that make progress</li> |
| <li>ann - annotate IR in assembly dumps</li> |
| <li>no8 - don't generate SIMD8 fragment shader</li> |
| <li>vec4 - force vec4 mode in vertex shader</li> |
| <li>spill_fs - force spilling of all registers in the scalar backend (useful to debug spilling code)</li> |
| <li>spill_vec4 - force spilling of all registers in the vec4 backend (useful to debug spilling code)</li> |
| <li>cs - dump shader assembly for compute shaders</li> |
| <li>hex - print instruction hex dump with the disassembly</li> |
| <li>nocompact - disable instruction compaction</li> |
| <li>tcs - dump shader assembly for tessellation control shaders</li> |
| <li>tes - dump shader assembly for tessellation evaluation shaders</li> |
| <li>l3 - emit messages about the new L3 state during transitions</li> |
| <li>do32 - generate compute shader SIMD32 programs even if workgroup size doesn't exceed the SIMD16 limit</li> |
| <li>norbc - disable single sampled render buffer compression</li> |
| </ul> |
| <li>INTEL_PRECISE_TRIG - if set to 1, true or yes, then the driver prefers |
| accuracy over performance in trig functions.</li> |
| </ul> |
| |
| |
| <h2>Radeon driver environment variables (radeon, r200, and r300g)</h2> |
| |
| <ul> |
| <li>RADEON_NO_TCL - if set, disable hardware-accelerated Transform/Clip/Lighting. |
| </ul> |
| |
| |
| <h2>EGL environment variables</h2> |
| |
| <p> |
| Mesa EGL supports different sets of environment variables. See the |
| <a href="egl.html">Mesa EGL</a> page for the details. |
| </p> |
| |
| |
| <h2>Gallium environment variables</h2> |
| |
| <ul> |
| <li>GALLIUM_HUD - draws various information on the screen, like framerate, |
| cpu load, driver statistics, performance counters, etc. |
| Set GALLIUM_HUD=help and run e.g. glxgears for more info. |
| <li>GALLIUM_HUD_PERIOD - sets the hud update rate in seconds (float). Use zero |
| to update every frame. The default period is 1/2 second. |
| <li>GALLIUM_HUD_VISIBLE - control default visibility, defaults to true. |
| <li>GALLIUM_HUD_TOGGLE_SIGNAL - toggle visibility via user specified signal. |
| Especially useful to toggle hud at specific points of application and |
| disable for unencumbered viewing the rest of the time. For example, set |
| GALLIUM_HUD_VISIBLE to false and GALLIUM_HUD_TOGGLE_SIGNAL to 10 (SIGUSR1). |
| Use kill -10 <pid> to toggle the hud as desired. |
| <li>GALLIUM_HUD_DUMP_DIR - specifies a directory for writing the displayed |
| hud values into files. |
| <li>GALLIUM_DRIVER - useful in combination with LIBGL_ALWAYS_SOFTWARE=1 for |
| choosing one of the software renderers "softpipe", "llvmpipe" or "swr". |
| <li>GALLIUM_LOG_FILE - specifies a file for logging all errors, warnings, etc. |
| rather than stderr. |
| <li>GALLIUM_PRINT_OPTIONS - if non-zero, print all the Gallium environment |
| variables which are used, and their current values. |
| <li>GALLIUM_DUMP_CPU - if non-zero, print information about the CPU on start-up |
| <li>TGSI_PRINT_SANITY - if set, do extra sanity checking on TGSI shaders and |
| print any errors to stderr. |
| <LI>DRAW_FSE - ??? |
| <LI>DRAW_NO_FSE - ??? |
| <li>DRAW_USE_LLVM - if set to zero, the draw module will not use LLVM to execute |
| shaders, vertex fetch, etc. |
| <li>ST_DEBUG - controls debug output from the Mesa/Gallium state tracker. |
| Setting to "tgsi", for example, will print all the TGSI shaders. |
| See src/mesa/state_tracker/st_debug.c for other options. |
| </ul> |
| |
| <h3>Clover state tracker environment variables</h3> |
| |
| <ul> |
| <li>CLOVER_EXTRA_BUILD_OPTIONS - allows specifying additional compiler and linker |
| options. Specified options are appended after the options set by the OpenCL |
| program in clBuildProgram. |
| <li>CLOVER_EXTRA_COMPILE_OPTIONS - allows specifying additional compiler |
| options. Specified options are appended after the options set by the OpenCL |
| program in clCompileProgram. |
| <li>CLOVER_EXTRA_LINK_OPTIONS - allows specifying additional linker |
| options. Specified options are appended after the options set by the OpenCL |
| program in clLinkProgram. |
| </ul> |
| |
| |
| <h3>Softpipe driver environment variables</h3> |
| <ul> |
| <li>SOFTPIPE_DUMP_FS - if set, the softpipe driver will print fragment shaders |
| to stderr |
| <li>SOFTPIPE_DUMP_GS - if set, the softpipe driver will print geometry shaders |
| to stderr |
| <li>SOFTPIPE_NO_RAST - if set, rasterization is no-op'd. For profiling purposes. |
| <li>SOFTPIPE_USE_LLVM - if set, the softpipe driver will try to use LLVM JIT for |
| vertex shading processing. |
| </ul> |
| |
| |
| <h3>LLVMpipe driver environment variables</h3> |
| <ul> |
| <li>LP_NO_RAST - if set LLVMpipe will no-op rasterization |
| <li>LP_DEBUG - a comma-separated list of debug options is accepted. See the |
| source code for details. |
| <li>LP_PERF - a comma-separated list of options to selectively no-op various |
| parts of the driver. See the source code for details. |
| <li>LP_NUM_THREADS - an integer indicating how many threads to use for rendering. |
| Zero turns off threading completely. The default value is the number of CPU |
| cores present. |
| </ul> |
| |
| <h3>VMware SVGA driver environment variables</h3> |
| <ul> |
| <li>SVGA_FORCE_SWTNL - force use of software vertex transformation |
| <li>SVGA_NO_SWTNL - don't allow software vertex transformation fallbacks |
| (will often result in incorrect rendering). |
| <li>SVGA_DEBUG - for dumping shaders, constant buffers, etc. See the code |
| for details. |
| <li>See the driver code for other, lesser-used variables. |
| </ul> |
| |
| |
| <h3>VA-API state tracker environment variables</h3> |
| <ul> |
| <li>VAAPI_MPEG4_ENABLED - enable MPEG4 for VA-API, disabled by default. |
| </ul> |
| |
| |
| <h3>VC4 driver environment variables</h3> |
| <ul> |
| <li>VC4_DEBUG - a comma-separated list of named flags, which do various things: |
| <ul> |
| <li>cl - dump command list during creation</li> |
| <li>qpu - dump generated QPU instructions</li> |
| <li>qir - dump QPU IR during program compile</li> |
| <li>nir - dump NIR during program compile</li> |
| <li>tgsi - dump TGSI during program compile</li> |
| <li>shaderdb - dump program compile information for shader-db analysis</li> |
| <li>perf - print during performance-related events</li> |
| <li>norast - skip actual hardware execution of commands</li> |
| <li>always_flush - flush after each draw call</li> |
| <li>always_sync - wait for finish after each flush</li> |
| <li>dump - write a GPU command stream trace file (VC4 simulator only)</li> |
| </ul> |
| </ul> |
| |
| |
| <p> |
| Other Gallium drivers have their own environment variables. These may change |
| frequently so the source code should be consulted for details. |
| </p> |
| |
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