From d06a388e59c6a0b49634e3490be529358b3bf5b4 Mon Sep 17 00:00:00 2001
From: Bryan Forbes <bryan@reigndropsfall.net>
Date: Sun, 20 Sep 2026 14:06:28 -0500
Subject: [PATCH] fix(python-evdev): build ecodes.py on host

The build for `python-evdev` relies on generating, compiling, and
importing a C extension module called `_ecodes` during the build process
to then generate a static `ecodes` Python module. If that fails,
`ecodes_runtime` is copied to `ecodes` and importing it at runtime
builds the static dicts on the fly. The problem is that when
cross-compiling, the `_ecodes` module is built for the target and may
not be importable on the host, so the build falls back to
`ecodes_runtime`. For smaller ARM boards build on x86_64, this can
cause a large runtime cost when importing `ecodes` because the
structures are built on the fly instead of being pre-built.

This change adds a host build of `python-evdev` to generate `_ecodes.so`
for the host (which allows the static `ecodes.py` to be generated), and
the target uses the generated `ecodes.py` from the host build instead of
falling back to `ecodes_runtime.py`. The host build uses the same
headers as the target build, so the generated `ecodes.py` is valid for
the target.
---
 package/python-evdev/python-evdev.mk | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/package/python-evdev/python-evdev.mk b/package/python-evdev/python-evdev.mk
index 169055ab27f..35e89def8de 100644
--- a/package/python-evdev/python-evdev.mk
+++ b/package/python-evdev/python-evdev.mk
@@ -11,8 +11,31 @@ PYTHON_EVDEV_SETUP_TYPE = setuptools
 PYTHON_EVDEV_LICENSE = Revised BSD License
 PYTHON_EVDEV_LICENSE_FILES = LICENSE
 
+# batocera - Build python-evdev for the host so we get a generated ecodes.py with
+# static dicts instead of using ecodes_runtime.py (which builds the dicts on the fly
+# when it is first imported)
+PYTHON_EVDEV_DEPENDENCIES = host-python-evdev
+
 PYTHON_EVDEV_BUILD_OPTS = \
 	-C--build-option=build_ecodes \
 	-C--build-option=--evdev-headers=$(STAGING_DIR)/usr/include/linux/input.h:$(STAGING_DIR)/usr/include/linux/input-event-codes.h:$(STAGING_DIR)/usr/include/linux/uinput.h
 
+# batocera - Build with the headers in staging so the generated ecodes.py is for the target
+HOST_PYTHON_EVDEV_BUILD_OPTS = \
+	-C--build-option=build_ecodes \
+	-C--build-option=--evdev-headers=$(STAGING_DIR)/usr/include/linux/input.h:$(STAGING_DIR)/usr/include/linux/input-event-codes.h:$(STAGING_DIR)/usr/include/linux/uinput.h
+
+# batocera - For cross-compilation, we need to install the ecodes.py that was generated on
+# the host because the target generation will fail due to the evdev build process trying to
+# import the target ecodes.so. Since both the host and the target build with the same headers,
+# the source of the module will be the same and the host build process will generate
+# a static ecodes.py (rather than copy the dynamic ecodes_runtime.py).
+define PYTHON_EVDEV_INSTALL_ECODES_MODULE
+	$(INSTALL) -m 0644 $(HOST_DIR)/usr/lib/python$(PYTHON3_VERSION_MAJOR)/site-packages/evdev/ecodes.py \
+		$(TARGET_DIR)/usr/lib/python$(PYTHON3_VERSION_MAJOR)/site-packages/evdev
+endef
+PYTHON_EVDEV_POST_INSTALL_TARGET_HOOKS += PYTHON_EVDEV_INSTALL_ECODES_MODULE
+
 $(eval $(python-package))
+# batocera - add a host package for python-evdev so we can generate the ecodes.py module on the host
+$(eval $(host-python-package))