diff --git a/software/CMakeLists.txt b/software/CMakeLists.txt
new file mode 100644
index 0000000..b7c40a4
--- /dev/null
+++ b/software/CMakeLists.txt
@@ -0,0 +1,7 @@
+cmake_minimum_required(VERSION 3.20.0)
+
+find_package(Zephyr)
+project(cryosnom1)
+include_directories("../firmware")
+
+target_sources(app PRIVATE src/main.c)
diff --git a/software/Kconfig b/software/Kconfig
new file mode 100644
index 0000000..1f47670
--- /dev/null
+++ b/software/Kconfig
@@ -0,0 +1,3 @@
+mainmenu "CryoSNOM 1"
+
+source "Kconfig.zephyr"
diff --git a/software/mk.sh b/software/mk.sh
new file mode 100755
index 0000000..efa3a0d
--- /dev/null
+++ b/software/mk.sh
@@ -0,0 +1,7 @@
+#!/bin/sh
+
+set -x
+
+mkdir -p build
+cd build
+cmake $(cat ../../firmware/overlay.config) -DDTC_OVERLAY_FILE=../firmware/overlay.dts -DBOARD=litex_vexriscv .. && make -j7
diff --git a/software/prj.conf b/software/prj.conf
new file mode 100644
index 0000000..1186b44
--- /dev/null
+++ b/software/prj.conf
@@ -0,0 +1,3 @@
+CONFIG_LOG=y
+CONFIG_LOG_BUFFER_SIZE=1024
+CONFIG_LOG_PRINTK=y
diff --git a/software/src/main.c b/software/src/main.c
new file mode 100644
index 0000000..032fa68
--- /dev/null
+++ b/software/src/main.c
@@ -0,0 +1,23 @@
+#include <zephyr/zephyr.h>
+#include <zephyr/kernel.h>
+#include <zephyr/logging/log.h>
+#include "pin_io.h"
+
+void
+main(void)
+{
+	uint32_t out_pins = 0;
+	uint32_t in_pin;
+
+	LOG_PRINTK("hello, world\n");
+	for (;;) {
+		k_sleep(K_MSEC(1000));
+		*dac_ctrl[0] = out_pins;
+		out_pins++;
+		if (out_pins == 7)
+			out_pins = 0;
+		in_pin = *dac_miso[0];
+
+		LOG_PRINTK("out: %d; in: %d\n", out_pins, in_pin);
+	}
+}