From 44afcc8cbed5f746dbe6eec8093f1bc5cdfd5eef Mon Sep 17 00:00:00 2001
From: Aidan MacDonald <amachronic@protonmail.com>
Date: Sun, 21 Dec 2025 20:01:54 +0000
Subject: [PATCH] firmware: add build rules for RegGen-generated headers

Change-Id: I86ff1a39aec1ee428abd6464483ae3732fdf9196
---
 firmware/firmware.make      |  3 +++
 firmware/reggen/SOURCES     |  1 +
 firmware/reggen/reggen.make | 27 +++++++++++++++++++++++++++
 tools/tools.make            |  4 ++++
 4 files changed, 35 insertions(+)
 create mode 100644 firmware/reggen/SOURCES
 create mode 100644 firmware/reggen/reggen.make

diff --git a/firmware/firmware.make b/firmware/firmware.make
index b840c90ba8..98c2c3bb27 100644
--- a/firmware/firmware.make
+++ b/firmware/firmware.make
@@ -14,6 +14,9 @@ INCLUDES += -I$(FIRMDIR)/libc/include
 endif
 
 include $(FIRMDIR)/asm/asm.make
+ifneq ($(filter reggen,$(TOOLSET)),)
+  include $(FIRMDIR)/reggen/reggen.make
+endif
 
 FIRMLIB_SRC += $(call preprocess, $(FIRMDIR)/SOURCES)
 FIRMLIB_OBJ := $(call c2obj, $(FIRMLIB_SRC))
diff --git a/firmware/reggen/SOURCES b/firmware/reggen/SOURCES
new file mode 100644
index 0000000000..dfd8c956b1
--- /dev/null
+++ b/firmware/reggen/SOURCES
@@ -0,0 +1 @@
+// Intentionally empty file.
diff --git a/firmware/reggen/reggen.make b/firmware/reggen/reggen.make
new file mode 100644
index 0000000000..5f1c075fb0
--- /dev/null
+++ b/firmware/reggen/reggen.make
@@ -0,0 +1,27 @@
+#             __________               __   ___.
+#   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+#   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+#   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+#   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+#                     \/            \/     \/    \/            \/
+# $Id$
+#
+
+REGGEN_SRC := $(call preprocess, $(FIRMDIR)/reggen/SOURCES)
+
+REGGEN_STAMP := $(foreach regs,$(REGGEN_SRC),$(notdir $(regs)))
+REGGEN_STAMP := $(patsubst %.regs,$(BUILDDIR)/regs/%/_stamp,$(REGGEN_STAMP))
+
+$(BUILDDIR)/regs/%/_stamp: $(FIRMDIR)/reggen/%.regs $(TOOLSDIR)/reggen
+	$(SILENT)rm -rf $(@D)
+	$(SILENT)mkdir -p $(@D)
+	$(call PRINTS,REGGEN $(subst $(ROOTDIR)/,,$<))$(TOOLSDIR)/reggen $< -rh reggen.h -ig $(subst -,_,$*) -o $(@D)
+	$(SILENT)touch $@
+
+# 'touch' header to propagate dependency on reggen.h through to
+# users of the generated headers. Might be a better way to do
+# this, but this seems to be adequate.
+$(BUILDDIR)/regs/%.h: $(REGGEN_STAMP) $(FIRMDIR)/export/reggen.h
+	$(SILENT)touch $@
+
+CLEANOBJS += $(BUILDDIR)/regs
diff --git a/tools/tools.make b/tools/tools.make
index 00cb431078..5fd8e80cc3 100644
--- a/tools/tools.make
+++ b/tools/tools.make
@@ -41,6 +41,10 @@ $(TOOLSDIR)/convttf: $(TOOLSDIR)/convttf.c
 	$(SILENT)$(HOSTCC) $(TOOLSFLAGS) -lm -O2 -Wall -g $+ -o $@ \
 		`pkg-config --cflags --libs freetype2`
 
+$(TOOLSDIR)/reggen: $(wildcard $(TOOLSDIR)/reggen_src/*.c)
+	$(call PRINTS,CC $(@F))
+	$(SILENT)$(HOSTCC) $(TOOLSFLAGS) -Wall -Wextra -O2 -g -o $@ $+
+
 # implicit rule for simple tools
 $(TOOLSDIR)/%: $(TOOLSDIR)/%.c
 	$(call PRINTS,CC $(subst $(ROOTDIR)/,,$@))