Environment Variables¶

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.

LibGL environment variables¶

LIBGL_DEBUG: If defined debug information will be printed to stderr. If set to verbose additional information will be printed.
LIBGL_DRIVERS_PATH: colon-separated list of paths to search for DRI drivers
LIBGL_ALWAYS_INDIRECT: if set to true, forces an indirect rendering context/connection.
LIBGL_ALWAYS_SOFTWARE: if set to true, always use software rendering
LIBGL_NO_DRAWARRAYS: if set to true, do not use DrawArrays GLX protocol (for debugging)
LIBGL_SHOW_FPS: print framerate to stdout based on the number of glXSwapBuffers calls per second.
LIBGL_DRI2_DISABLE: disable DRI2 if set to true.
LIBGL_DRI3_DISABLE: disable DRI3 if set to true.

Core Mesa environment variables¶

MESA_NO_ASM

if set, disables all assembly language optimizations

MESA_NO_MMX

if set, disables Intel MMX optimizations

MESA_NO_3DNOW

if set, disables AMD 3DNow! optimizations

MESA_NO_SSE

if set, disables Intel SSE optimizations

MESA_NO_ERROR

if set to 1, error checking is disabled as per KHR_no_error. This will result in undefined behavior for invalid use of the API, but can reduce CPU use for apps that are known to be error free.

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. 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 behavior to just set MESA_DEBUG to 1:

silent: turn off debug messages. Only useful for debug builds.
flush: flush after each drawing command
incomplete_tex: extra debug messages when a texture is incomplete
incomplete_fbo: extra debug messages when a FBO is incomplete
context: create a debug context (see GLX_CONTEXT_DEBUG_BIT_ARB) and print error and performance messages to stderr (or MESA_LOG_FILE).

MESA_LOG_FILE

specifies a file name for logging all errors, warnings, etc., rather than stderr

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. Note that this will override extensions override configured using driconf.

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.

MESA_GL_VERSION_OVERRIDE

changes the value returned by glGetString(GL_VERSION) and possibly the GL API type.

The format should be MAJOR.MINOR[FC|COMPAT]
FC is an optional suffix that indicates a forward compatible context. This is only valid for versions >= 3.0.
COMPAT is an optional suffix that indicates a compatibility context or GL_ARB_compatibility support. This is only valid for versions >= 3.1.
GL versions <= 3.0 are set to a compatibility (non-Core) profile
GL versions = 3.1, depending on the driver, it may or may not have the ARB_compatibility extension enabled.
GL versions >= 3.2 are set to a Core profile
Examples:

2.1
select a compatibility (non-Core) profile with GL version 2.1.

3.0
select a compatibility (non-Core) profile with GL version 3.0.

3.0FC
select a Core+Forward Compatible profile with GL version 3.0.

3.1
select GL version 3.1 with GL_ARB_compatibility enabled per the driver default.

3.1FC
select GL version 3.1 with forward compatibility and GL_ARB_compatibility disabled.

3.1COMPAT
select GL version 3.1 with GL_ARB_compatibility enabled.

X.Y
override GL version to X.Y without changing the profile.

X.YFC
select a Core+Forward Compatible profile with GL version X.Y.

X.YCOMPAT
select a Compatibility profile with GL version X.Y.
Mesa may not really implement all the features of the given version. (for developers only)

MESA_GLES_VERSION_OVERRIDE

changes the value returned by glGetString(GL_VERSION) for OpenGL ES.

The format should be MAJOR.MINOR
Examples: 2.0, 3.0, 3.1
Mesa may not really implement all the features of the given version. (for developers only)

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)

MESA_GLSL_CACHE_DISABLE

if set to true, disables the GLSL shader cache. If set to false, enables the GLSL shader cache when it is disabled by default.

MESA_GLSL_CACHE_MAX_SIZE

if set, determines the maximum size of the on-disk cache of compiled GLSL programs. Should be set to a number optionally followed by K, M, or G to specify a size in kilobytes, megabytes, or gigabytes. By default, gigabytes will be assumed. And if unset, a maximum size of 1GB will be used.

Note

A separate cache might be created for each architecture that Mesa is installed for on your system. For example under the default settings you may end up with a 1GB cache for x86_64 and another 1GB cache for i386.

MESA_GLSL_CACHE_DIR

if set, determines the directory to be used for the on-disk cache of compiled GLSL programs. If this variable is not set, then the cache will be stored in $XDG_CACHE_HOME/mesa_shader_cache (if that variable is set), or else within .cache/mesa_shader_cache within the user’s home directory.

MESA_GLSL

shading language compiler options

MESA_NO_MINMAX_CACHE

when set, the minmax index cache is globally disabled.

MESA_SHADER_CAPTURE_PATH

see Capturing Shaders

MESA_SHADER_DUMP_PATH and MESA_SHADER_READ_PATH

see Experimenting with Shader Replacements

MESA_VK_VERSION_OVERRIDE

changes the Vulkan physical device version as returned in VkPhysicalDeviceProperties::apiVersion.

The format should be MAJOR.MINOR[.PATCH]
This will not let you force a version higher than the driver’s instance version as advertised by vkEnumerateInstanceVersion
This can be very useful for debugging but some features may not be implemented correctly. (For developers only)

MESA_VK_WSI_PRESENT_MODE

overrides the WSI present mode clients specify in VkSwapchainCreateInfoKHR::presentMode. Values can be fifo, relaxed, mailbox or immediate.

MESA_VK_ABORT_ON_DEVICE_LOSS

causes the Vulkan driver to call abort() immediately after detecting a lost device. This is extremely useful when testing as it prevents the test suite from continuing on with a lost device.

MESA_VK_ENABLE_SUBMIT_THREAD

for Vulkan drivers which support real timeline semaphores, this forces them to use a submit thread from the beginning, regardless of whether or not they ever see a wait-before-signal condition.

MESA_LOADER_DRIVER_OVERRIDE

chooses a different driver binary such as etnaviv or zink.

NIR passes environment variables¶

The following are only applicable for drivers that uses NIR, as they modify the behavior for the common NIR_PASS and NIR_PASS_V macros, that wrap calls to NIR lowering/optimizations.

NIR_DEBUG: a comma-separated list of debug options to apply to NIR shaders. Use NIR_DEBUG=help to print a list of available options.
NIR_SKIP: a comma-separated list of optimization/lowering passes to skip.

Mesa Xlib driver environment variables¶

The following are only applicable to the Mesa Xlib software driver. See the Xlib software driver page for details.

MESA_RGB_VISUAL: specifies the X visual and depth for RGB mode
MESA_BACK_BUFFER: specifies how to implement the back color buffer, either pixmap or ximage
MESA_XSYNC: enable synchronous X behavior (for debugging only)
MESA_GLX_FORCE_ALPHA: if set, forces RGB windows to have an alpha channel.
MESA_GLX_DEPTH_BITS: specifies default number of bits for depth buffer.
MESA_GLX_ALPHA_BITS: specifies default number of bits for alpha channel.

Intel driver environment variables¶

INTEL_BLACKHOLE_DEFAULT

if set to 1, true or yes, then the OpenGL implementation will default GL_BLACKHOLE_RENDER_INTEL to true, thus disabling any rendering.

INTEL_DEBUG

a comma-separated list of named flags, which do various things:

ann: annotate IR in assembly dumps
aub: dump batches into an AUB trace for use with simulation tools
bat: emit batch information
blit: emit messages about blit operations
blorp: emit messages about the blorp operations (blits & clears)
buf: emit messages about buffer objects
clip: emit messages about the clip unit (for old gens, includes the CLIP program)
color: use color in output
cs: dump shader assembly for compute shaders
do32: generate compute shader SIMD32 programs even if workgroup size doesn’t exceed the SIMD16 limit
fs: dump shader assembly for fragment shaders
gs: dump shader assembly for geometry shaders
hex: print instruction hex dump with the disassembly
l3: emit messages about the new L3 state during transitions
no8: don’t generate SIMD8 fragment shader
no16: suppress generation of 16-wide fragment shaders. useful for debugging broken shaders
nocompact: disable instruction compaction
nodualobj: suppress generation of dual-object geometry shader code
nofc: disable fast clears
norbc: disable single sampled render buffer compression
optimizer: dump shader assembly to files at each optimization pass and iteration that make progress
perf: emit messages about performance issues
perfmon: emit messages about AMD_performance_monitor
reemit: mark all state dirty on each draw call
sf: emit messages about the strips & fans unit (for old gens, includes the SF program)
shader_time: record how much GPU time is spent in each shader
spill_fs: force spilling of all registers in the scalar backend (useful to debug spilling code)
spill_vec4: force spilling of all registers in the vec4 backend (useful to debug spilling code)
submit: emit batchbuffer usage statistics
sync: after sending each batch, emit a message and wait for that batch to finish rendering
tcs: dump shader assembly for tessellation control shaders
tes: dump shader assembly for tessellation evaluation shaders
tex: emit messages about textures.
urb: emit messages about URB setup
vs: dump shader assembly for vertex shaders

INTEL_MEASURE

Collects GPU timestamps over common intervals, and generates a CSV report to show how long rendering took. The overhead of collection is limited to the flushing that is required at the interval boundaries for accurate timestamps. By default, timing data is sent to stderr. To direct output to a file:

INTEL_MEASURE=file=/tmp/measure.csv {workload}

To begin capturing timestamps at a particular frame:

INTEL_MEASURE=file=/tmp/measure.csv,start=15 {workload}

To capture only 23 frames:

INTEL_MEASURE=count=23 {workload}

To capture frames 15-37, stopping before frame 38:

INTEL_MEASURE=start=15,count=23 {workload}

Designate an asynchronous control file with:

INTEL_MEASURE=control=path/to/control.fifo {workload}

As the workload runs, enable capture for 5 frames with:

$ echo 5 > path/to/control.fifo

Enable unbounded capture:

$ echo -1 > path/to/control.fifo

and disable with:

$ echo 0 > path/to/control.fifo

Select the boundaries of each snapshot with:

INTEL_MEASURE=draw: Collects timings for every render (DEFAULT)
INTEL_MEASURE=rt: Collects timings when the render target changes
INTEL_MEASURE=batch: Collects timings when batches are submitted
INTEL_MEASURE=frame: Collects timings at frame boundaries

With INTEL_MEASURE=interval=5, the duration of 5 events will be combined into a single record in the output. When possible, a single start and end event will be submitted to the GPU to minimize stalling. Combined events will not span batches, except in the case of INTEL_MEASURE=frame.

INTEL_NO_HW

if set to 1, true or yes, prevents batches from being submitted to the hardware. This is useful for debugging hangs, etc.

INTEL_PRECISE_TRIG

if set to 1, true or yes, then the driver prefers accuracy over performance in trig functions.

INTEL_SHADER_ASM_READ_PATH

if set, determines the directory to be used for overriding shader assembly. The binaries with custom assembly should be placed in this folder and have a name formatted as sha1_of_assembly.bin. The sha1 of a shader assembly is printed when assembly is dumped via corresponding INTEL_DEBUG flag (e.g. vs for vertex shader). A binary could be generated from a dumped assembly by i965_asm. For INTEL_SHADER_ASM_READ_PATH to work it is necessary to enable dumping of corresponding shader stages via INTEL_DEBUG. It is advised to use nocompact flag of INTEL_DEBUG when dumping and overriding shader assemblies. The success of assembly override would be signified by “Successfully overrode shader with sha1 <sha1>” in stderr replacing the original assembly.

DRI environment variables¶

DRI_NO_MSAA: disable MSAA for GLX/EGL MSAA visuals

EGL environment variables¶

Mesa EGL supports different sets of environment variables. See the Mesa EGL page for the details.

Gallium environment variables¶

GALLIUM_HUD: draws various information on the screen, like framerate, CPU load, driver statistics, performance counters, etc. Set GALLIUM_HUD to help and run e.g. glxgears for more info.
GALLIUM_HUD_PERIOD: sets the HUD update rate in seconds (float). Use zero to update every frame. The default period is 1/2 second.
GALLIUM_HUD_VISIBLE: control default visibility, defaults to true.
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.
GALLIUM_HUD_SCALE: Scale HUD by an integer factor, for high DPI displays. Default is 1.
GALLIUM_HUD_DUMP_DIR: specifies a directory for writing the displayed HUD values into files.
GALLIUM_DRIVER: useful in combination with LIBGL_ALWAYS_SOFTWARE`=`true for choosing one of the software renderers softpipe or llvmpipe.
GALLIUM_LOG_FILE: specifies a file for logging all errors, warnings, etc. rather than stderr.
GALLIUM_PIPE_SEARCH_DIR: specifies an alternate search directory for pipe-loader which overrides the compile-time path based on the install location.
GALLIUM_PRINT_OPTIONS: if non-zero, print all the Gallium environment variables which are used, and their current values.
GALLIUM_DUMP_CPU: if non-zero, print information about the CPU on start-up
TGSI_PRINT_SANITY: if set, do extra sanity checking on TGSI shaders and print any errors to stderr.
DRAW_FSE: Enable fetch-shade-emit middle-end even though its not correct (e.g. for softpipe)
DRAW_NO_FSE: Disable fetch-shade-emit middle-end even when it is correct
DRAW_USE_LLVM: if set to zero, the draw module will not use LLVM to execute shaders, vertex fetch, etc.
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.

Clover environment variables¶

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.
CLOVER_EXTRA_COMPILE_OPTIONS: allows specifying additional compiler options. Specified options are appended after the options set by the OpenCL program in clCompileProgram.
CLOVER_EXTRA_LINK_OPTIONS: allows specifying additional linker options. Specified options are appended after the options set by the OpenCL program in clLinkProgram.

Softpipe driver environment variables¶

SOFTPIPE_DEBUG

a comma-separated list of named flags, which do various things:

vs: Dump vertex shader assembly to stderr
fs: Dump fragment shader assembly to stderr
gs: Dump geometry shader assembly to stderr
cs: Dump compute shader assembly to stderr
no_rast: rasterization is disabled. For profiling purposes.
use_llvm: the softpipe driver will try to use LLVM JIT for vertex shading processing.
use_tgsi: if set, the softpipe driver will ask to directly consume TGSI, instead of NIR.

LLVMpipe driver environment variables¶

LP_NO_RAST: if set LLVMpipe will no-op rasterization
LP_DEBUG: a comma-separated list of debug options is accepted. See the source code for details.
LP_PERF: a comma-separated list of options to selectively no-op various parts of the driver. See the source code for details.
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.

VMware SVGA driver environment variables¶

:envvar`SVGA_FORCE_SWTNL`: force use of software vertex transformation
:envvar`SVGA_NO_SWTNL`: don’t allow software vertex transformation fallbacks (will often result in incorrect rendering).
:envvar`SVGA_DEBUG`: for dumping shaders, constant buffers, etc. See the code for details.
:envvar`SVGA_EXTRA_LOGGING`: if set, enables extra logging to the vmware.log file, such as the OpenGL program’s name and command line arguments.
:envvar`SVGA_NO_LOGGING`: if set, disables logging to the vmware.log file. This is useful when using Valgrind because it otherwise crashes when initializing the host log feature.

See the driver code for other, lesser-used variables.

WGL environment variables¶

WGL_SWAP_INTERVAL: to set a swap interval, equivalent to calling wglSwapIntervalEXT() in an application. If this environment variable is set, application calls to wglSwapIntervalEXT() will have no effect.

VA-API environment variables¶

VAAPI_MPEG4_ENABLED: enable MPEG4 for VA-API, disabled by default.

VC4 driver environment variables¶

VC4_DEBUG

a comma-separated list of named flags, which do various things:

cl: dump command list during creation
qpu: dump generated QPU instructions
qir: dump QPU IR during program compile
nir: dump NIR during program compile
tgsi: dump TGSI during program compile
shaderdb: dump program compile information for shader-db analysis
perf: print during performance-related events
norast: skip actual hardware execution of commands
always_flush: flush after each draw call
always_sync: wait for finish after each flush
dump: write a GPU command stream trace file (VC4 simulator only)

RADV driver environment variables¶

RADV_DEBUG

a comma-separated list of named flags, which do various things:

llvm: enable LLVM compiler backend
allbos: force all allocated buffers to be referenced in submissions
checkir: validate the LLVM IR before LLVM compiles the shader
forcecompress: Enables DCC,FMASK,CMASK,HTILE in situations where the driver supports it but normally does not deem it beneficial.
hang: enable GPU hangs detection and dump a report to $HOME/radv_dumps_<pid>_<time> if a GPU hang is detected
img: Print image info
info: show GPU-related information
invariantgeom: Mark geometry-affecting outputs as invariant. This works around a common class of application bugs appearing as flickering.
metashaders: dump internal meta shaders
noatocdithering: disable dithering for alpha to coverage
nobinning: disable primitive binning
nocache: disable shaders cache
nocompute: disable compute queue
nodcc: disable Delta Color Compression (DCC) on images
nodisplaydcc: disable Delta Color Compression (DCC) on displayable images
nodynamicbounds: do not check OOB access for dynamic descriptors
nofastclears: disable fast color/depthstencil clears
nohiz: disable HIZ for depthstencil images
noibs: disable directly recording command buffers in GPU-visible memory
nomemorycache: disable memory shaders cache
nongg: disable NGG for GFX10+
nonggc: disable NGG culling on GPUs where it’s enabled by default (GFX10.3+ only).
nooutoforder: disable out-of-order rasterization
notccompatcmask: disable TC-compat CMASK for MSAA surfaces
noumr: disable UMR dumps during GPU hang detection (only with RADV_DEBUG`=``hang`)
novrsflatshading: disable VRS for flat shading (only on GFX10.3+)
preoptir: dump LLVM IR before any optimizations
prologs: dump vertex shader prologs
shaders: dump shaders
shaderstats: dump shader statistics
spirv: dump SPIR-V
startup: display info at startup
syncshaders: synchronize shaders after all draws/dispatches
vmfaults: check for VM memory faults via dmesg
zerovram: initialize all memory allocated in VRAM as zero

RADV_FORCE_FAMILY

create a null device to compile shaders without a AMD GPU (e.g. VEGA10)

RADV_FORCE_VRS

allow to force per-pipeline vertex VRS rates on GFX10.3+. This is only forced for pipelines that don’t explicitely use VRS or flat shading. The supported values are 2x2, 1x2 and 2x1. Only for testing purposes.

RADV_PERFTEST

a comma-separated list of named flags, which do various things:

bolist: enable the global BO list
cswave32: enable wave32 for compute shaders (GFX10+)
dccmsaa: enable DCC for MSAA images
force_emulate_rt: forces ray-tracing to be emulated in software, even if there is hardware support.
gewave32: enable wave32 for vertex/tess/geometry shaders (GFX10+)
localbos: enable local BOs
nosam: disable optimizations that get enabled when all VRAM is CPU visible.
pswave32: enable wave32 for pixel shaders (GFX10+)
nggc: enable NGG culling on GPUs where it’s not enabled by default (GFX10.1 only).
rt: enable rt extensions whose implementation is still experimental.
sam: enable optimizations to move more driver internal objects to VRAM.

RADV_TEX_ANISO

force anisotropy filter (up to 16)

RADV_THREAD_TRACE

enable frame based SQTT/RGP captures (eg. export RADV_THREAD_TRACE=100 will capture the frame #100)

RADV_THREAD_TRACE_BUFFER_SIZE

set the SQTT/RGP buffer size in bytes (default value is 32MiB, the buffer is automatically resized if too small)

RADV_THREAD_TRACE_CACHE_COUNTERS

enable/disable SQTT/RGP cache counters on GFX10+ (disabled by default)

RADV_THREAD_TRACE_INSTRUCTION_TIMING

enable/disable SQTT/RGP instruction timing (enabled by default)

RADV_THREAD_TRACE_TRIGGER

enable trigger file based SQTT/RGP captures (eg. export RADV_THREAD_TRACE_TRIGGER=/tmp/radv_sqtt_trigger and then touch /tmp/radv_sqtt_trigger to capture a frame)

ACO_DEBUG

a comma-separated list of named flags, which do various things:

validateir: validate the ACO IR at various points of compilation (enabled by default for debug/debugoptimized builds)
validatera: validate register assignment of ACO IR and catches many RA bugs
perfwarn: abort on some suboptimal code generation
force-waitcnt: force emitting waitcnt states if there is something to wait for
novn: disable value numbering
noopt: disable various optimizations
noscheduling: disable instructions scheduling
perfinfo: print information used to calculate some pipeline statistics
liveinfo: print liveness and register demand information before scheduling

radeonsi driver environment variables¶

AMD_DEBUG

a comma-separated list of named flags, which do various things:

nodcc: Disable DCC.
nodccclear: Disable DCC fast clear.
nodccmsaa: Disable DCC for MSAA
nodpbb: Disable DPBB.
nodfsm: Disable DFSM.
notiling: Disable tiling
nofmask: Disable MSAA compression
nohyperz: Disable Hyper-Z
no2d: Disable 2D tiling
info: Print driver information
tex: Print texture info
compute: Print compute info
vm: Print virtual addresses when creating resources
vs: Print vertex shaders
ps: Print pixel shaders
gs: Print geometry shaders
tcs: Print tessellation control shaders
tes: Print tessellation evaluation shaders
cs: Print compute shaders
noir: Don’t print the LLVM IR
nonir: Don’t print NIR when printing shaders
noasm: Don’t print disassembled shaders
preoptir: Print the LLVM IR before initial optimizations
gisel: Enable LLVM global instruction selector.
w32ge: Use Wave32 for vertex, tessellation, and geometry shaders.
w32ps: Use Wave32 for pixel shaders.
w32cs: Use Wave32 for computes shaders.
w64ge: Use Wave64 for vertex, tessellation, and geometry shaders.
w64ps: Use Wave64 for pixel shaders.
w64cs: Use Wave64 for computes shaders.
checkir: Enable additional sanity checks on shader IR
mono: Use old-style monolithic shaders compiled on demand
nooptvariant: Disable compiling optimized shader variants.
nowc: Disable GTT write combining
check_vm: Check VM faults and dump debug info.
reserve_vmid: Force VMID reservation per context.
nogfx: Disable graphics. Only multimedia compute paths can be used.
nongg: Disable NGG and use the legacy pipeline.
nggc: Always use NGG culling even when it can hurt.
nonggc: Disable NGG culling.
switch_on_eop: Program WD/IA to switch on end-of-packet.
nooutoforder: Disable out-of-order rasterization
dpbb: Enable DPBB.
dfsm: Enable DFSM.

r600 driver environment variables¶

R600_DEBUG

a comma-separated list of named flags, which do various things:

nocpdma: Disable CP DMA
nosb: Disable sb backend for graphics shaders
sbcl: Enable sb backend for compute shaders
sbdry: Don’t use optimized bytecode (just print the dumps)
sbstat: Print optimization statistics for shaders
sbdump: Print IR dumps after some optimization passes
sbnofallback: Abort on errors instead of fallback
sbdisasm: Use sb disassembler for shader dumps
sbsafemath: Disable unsafe math optimizations
nirsb: Enable NIR with SB optimizer
tex: Print texture info
nir: Enable experimental NIR shaders
compute: Print compute info
vm: Print virtual addresses when creating resources
info: Print driver information
fs: Print fetch shaders
vs: Print vertex shaders
gs: Print geometry shaders
ps: Print pixel shaders
cs: Print compute shaders
tcs: Print tessellation control shaders
tes: Print tessellation evaluation shaders
noir: Don’t print the LLVM IR
notgsi: Don’t print the TGSI
noasm: Don’t print disassembled shaders
preoptir: Print the LLVM IR before initial optimizations
checkir: Enable additional sanity checks on shader IR
nooptvariant: Disable compiling optimized shader variants.
testdma: Invoke SDMA tests and exit.
testvmfaultcp: Invoke a CP VM fault test and exit.
testvmfaultsdma: Invoke a SDMA VM fault test and exit.
testvmfaultshader: Invoke a shader VM fault test and exit.
nodma: Disable asynchronous DMA
nohyperz: Disable Hyper-Z
noinvalrange: Disable handling of INVALIDATE_RANGE map flags
no2d: Disable 2D tiling
notiling: Disable tiling
switch_on_eop: Program WD/IA to switch on end-of-packet.
forcedma: Use asynchronous DMA for all operations when possible.
precompile: Compile one shader variant at shader creation.
nowc: Disable GTT write combining
check_vm: Check VM faults and dump debug info.
unsafemath: Enable unsafe math shader optimizations

R600_DEBUG_COMPUTE

if set to true, various compute-related debug information will be printed to stderr. Defaults to false.

R600_DUMP_SHADERS

if set to true, NIR shaders will be printed to stderr. Defaults to false.

R600_HYPERZ

If set to false, disables HyperZ optimizations. Defaults to true.

R600_NIR_DEBUG

a comma-separated list of named flags, which do various things:

instr: Log all consumed nir instructions
ir: Log created R600 IR
cc: Log R600 IR to assembly code creation
noerr: Don’t log shader conversion errors
si: Log shader info (non-zero values)
reg: Log register allocation and lookup
io: Log shader in and output
ass: Log IR to assembly conversion
flow: Log control flow instructions
merge: Log register merge operations
nomerge: Skip register merge step
tex: Log texture ops
trans: Log generic translation messages

r300 driver environment variables¶

RADEON_DEBUG

a comma-separated list of named flags, which do various things:

info: Print hardware info (printed by default on debug builds
fp: Log fragment program compilation
vp: Log vertex program compilation
draw: Log draw calls
swtcl: Log SWTCL-specific info
rsblock: Log rasterizer registers
psc: Log vertex stream registers
tex: Log basic info about textures
texalloc: Log texture mipmap tree info
rs: Log rasterizer
fb: Log framebuffer
cbzb: Log fast color clear info
hyperz: Log HyperZ info
scissor: Log scissor info
msaa: Log MSAA resources
anisohq: Use high quality anisotropic filtering
notiling: Disable tiling
noimmd: Disable immediate mode
noopt: Disable shader optimizations
nocbzb: Disable fast color clear
nozmask: Disable zbuffer compression
nohiz: Disable hierarchical zbuffer
nocmask: Disable AA compression and fast AA clear
use_tgsi: Request TGSI shaders from the state tracker
notcl: Disable hardware accelerated Transform/Clip/Lighting

Other Gallium drivers have their own environment variables. These may change frequently so the source code should be consulted for details.