From a7456a885ecaa3832cfc4576fa35288e62548e4e Mon Sep 17 00:00:00 2001
From: Bdale Garbee <bdale@gag.com>
Date: Mon, 6 Jan 2025 02:07:10 -0700
Subject: [PATCH] add devicetree overlay to append cmdline, use it to make gpio
 commands persist

---
 Makefile                         | 18 ++++++++++++++++++
 debian/quantimotor.install       |  2 ++
 devicetree/Makefile              |  9 +++++++++
 devicetree/append_cmdline.dts    | 16 ++++++++++++++++
 devicetree/raspi-firmware-custom |  1 +
 5 files changed, 46 insertions(+)
 create mode 100644 Makefile
 create mode 100644 devicetree/Makefile
 create mode 100644 devicetree/append_cmdline.dts
 create mode 100644 devicetree/raspi-firmware-custom

diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..435bf46
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,18 @@
+# Top level Makefile for the QuantiMotor software Debian package
+# Copyright 2025 Bdale Garbee <bdale@gag.com>, GPL-3+
+
+SUBDIRS := devicetree
+SUBDIRS-clean := $(addsuffix -clean,$(SUBDIRS))
+
+all: $(SUBDIRS)
+
+clean: $(SUBDIRS-clean)
+
+$(SUBDIRS):
+	$(MAKE) -C $@
+
+$(SUBDIRS-clean):
+	$(MAKE) -C $(subst -clean,,$@) clean
+
+.Suffixes:
+.PHONY: all clean $(SUBDIRS) $(SUBDIRS-clean)
diff --git a/debian/quantimotor.install b/debian/quantimotor.install
index c1c1c8f..c541b3a 100644
--- a/debian/quantimotor.install
+++ b/debian/quantimotor.install
@@ -1,2 +1,4 @@
 bcm2837-rpi-zero-2-w.dtb usr/share/quantimotor
 z99-quantimotor etc/kernel/postinst.d
+devicetree/append_cmdline.dtbo boot/firmware/overlays
+devicetree/raspi-firmware-custom etc/default
diff --git a/devicetree/Makefile b/devicetree/Makefile
new file mode 100644
index 0000000..4957e57
--- /dev/null
+++ b/devicetree/Makefile
@@ -0,0 +1,9 @@
+all: append_cmdline.dtbo
+
+append_cmdline.dtbo: append_cmdline.dts
+	dtc -I dts -O dtb -o $@ $<
+
+clean:
+	rm -f append_cmdline.dtbo
+
+.PHONY: clean
diff --git a/devicetree/append_cmdline.dts b/devicetree/append_cmdline.dts
new file mode 100644
index 0000000..3f9509f
--- /dev/null
+++ b/devicetree/append_cmdline.dts
@@ -0,0 +1,16 @@
+/dts-v1/;
+/plugin/;
+
+/ {
+        compatible = "brcm,bcm2835";
+
+        fragment@0 {
+                target = <&chosen>;
+                frag0:  __overlay__ {
+                };
+        };
+
+		__overrides__ {
+			append = <&frag0>, "bootargs";
+		};
+};
diff --git a/devicetree/raspi-firmware-custom b/devicetree/raspi-firmware-custom
new file mode 100644
index 0000000..3bb3f67
--- /dev/null
+++ b/devicetree/raspi-firmware-custom
@@ -0,0 +1 @@
+dtoverlay=append_cmdline,append=pinctrl_bcm2835.persist_gpio_outputs=y
-- 
2.47.2