diff --git a/docs/envvars.html b/docs/envvars.html
index 8c4597c9c76..4eff7065df0 100644
--- a/docs/envvars.html
+++ b/docs/envvars.html
@@ -253,6 +253,25 @@ for details.
+
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)
+
+
+
+
Other Gallium drivers have their own environment variables. These may change
frequently so the source code should be consulted for details.