1 files changed, 24 insertions, 0 deletions

diff --git a/users/drashna/rules.mk b/users/drashna/rules.mk
index b7523a436..2ae01c62e 100644
--- a/users/drashna/rules.mk
+++ b/users/drashna/rules.mk
@@ -66,3 +66,27 @@ ifeq ($(strip $(PIMORONI_TRACKBALL_ENABLE)), yes)
     SRC += pimoroni_trackball.c
     QUANTUM_LIB_SRC += i2c_master.c
 endif
+
+
+ifeq ($(strip $(SPLIT_KEYBOARD)), yes)
+    ifneq ($(strip $(SPLIT_TRANSPORT)), custom)
+        SPLIT_TRANSPORT = custom
+        QUANTUM_LIB_SRC += drashna_transport.c
+        OPT_DEFS += -DDRASHNA_CUSTOM_TRANSPORT
+        # Unused functions are pruned away, which is why we can add multiple drivers here without bloat.
+        ifeq ($(PLATFORM),AVR)
+            ifneq ($(NO_I2C),yes)
+                QUANTUM_LIB_SRC += i2c_master.c \
+                                   i2c_slave.c
+            endif
+        endif
+
+        SERIAL_DRIVER ?= bitbang
+        OPT_DEFS += -DSERIAL_DRIVER_$(strip $(shell echo $(SERIAL_DRIVER) | tr '[:lower:]' '[:upper:]'))
+        ifeq ($(strip $(SERIAL_DRIVER)), bitbang)
+            QUANTUM_LIB_SRC += serial.c
+        else
+            QUANTUM_LIB_SRC += serial_$(strip $(SERIAL_DRIVER)).c
+        endif
+    endif
+endif