Move all firmware files to subdirectory

firmware/components/fatal/CMakeLists.txt

@@ -0,0 +1,5 @@
+idf_component_register(
+  SRCS "fatal.c"
+  INCLUDE_DIRS "."
+  REQUIRES log
+)

firmware/components/fatal/fatal.c

@@ -0,0 +1,16 @@
+/*
+ * SPDX-License-Identifier: AGPL-3.0-only
+ * Copyright (c) Camden Dixie O'Brien
+ */
+
+#include "fatal.h"
+
+#include "esp_log.h"
+
+#define TAG "Fatal"
+
+void _fatal(const char *func, const char *file, unsigned line)
+{
+	ESP_LOGE(TAG, "%s() @ %s:%u", func, file, line);
+	while (1) { }
+}

firmware/components/fatal/fatal.h

@@ -0,0 +1,21 @@
+/*
+ * SPDX-License-Identifier: AGPL-3.0-only
+ * Copyright (c) Camden Dixie O'Brien
+ *
+ * Fatal error module.
+ *
+ * This small module provides the FATAL() macro, intended to be used
+ * to signal a fatal error. This prompts a system restart.
+ */
+
+#ifndef FATAL_H
+#define FATAL_H
+
+/**
+ * Signals a fatal error.
+ */
+#define FATAL() _fatal(__func__, __FILE__, __LINE__)
+
+void _fatal(const char *func, const char *file, unsigned line);
+
+#endif