From dcf72ff8e2aa724b82ada89ad068b9308ed97a54 Mon Sep 17 00:00:00 2001
From: Krystine Sherwin <93062060+KrystalDelusion@users.noreply.github.com>
Date: Mon, 7 Jul 2025 11:27:37 +1200
Subject: [PATCH] Document tests/functional prereqs

---
 .../extending_yosys/test_suites.rst            | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/docs/source/yosys_internals/extending_yosys/test_suites.rst b/docs/source/yosys_internals/extending_yosys/test_suites.rst
index 3e5f45b94..6627fdbdd 100644
--- a/docs/source/yosys_internals/extending_yosys/test_suites.rst
+++ b/docs/source/yosys_internals/extending_yosys/test_suites.rst
@@ -14,6 +14,24 @@ compiler versions.  For up to date information, including OS versions, refer to
 .. _Yosys Git repo: https://github.com/YosysHQ/yosys
 .. _the git actions page: https://github.com/YosysHQ/yosys/actions
 
+Functional backend testing
+--------------------------
+
+Testing of the functional backend is controlled by the
+``ENABLE_FUNCTIONAL_TESTS`` make variable.  Setting it to a value of ``1``,
+either when calling ``make test`` or in your ``Makefile.conf`` file, will enable
+these additional tests.
+
+.. note::
+
+   The functional backend tests requires additional prerequisites to be
+   installed:
+
+   - racket and z3, available via ``apt-get`` or similar.
+   - pytest and pytest-xdist, available via ``pip``; pytest-xdist-gnumake is
+     also recommended.
+   - rosette, available via ``raco`` (after installing racket).
+
 .. todo:: are unit tests currently working
 
 ..