panic: move to separate file, add KASSERT macro

kernel/panic.c

@@ -0,0 +1,46 @@
+/* See the end of this file for copyright and license terms. */
+
+#include <arch/cpufunc.h>
+
+#include <gay/cdefs.h>
+#include <gay/config.h>
+#include <gay/kprintf.h>
+
+#include <stdarg.h>
+
+__noreturn
+void panic(const char *fmt, ...)
+{
+	va_list args;
+	va_start(args, fmt);
+
+	disable_intr();
+
+	kprintf("Kernel panic: ");
+	if (fmt == nil)
+		kprintf("(nil)\n");
+	else
+		kvprintf(fmt, args);
+
+	kprintf("\nKernel version: %s\nSystem halted", GAY_VERSION_STR);
+
+	/* no need for va_end() here i guess */
+	while (1) {
+		halt();
+		disable_intr();
+	}
+}
+
+/*
+ * This file is part of GayBSD.
+ * Copyright (c) 2021 fef <owo@fef.moe>.
+ *
+ * GayBSD is nonviolent software: you may only use, redistribute, and/or
+ * modify it under the terms of the Cooperative Nonviolent Public License
+ * (CNPL) as found in the LICENSE file in the source code root directory
+ * or at <https://git.pixie.town/thufie/npl-builder>; either version 7
+ * of the license, or (at your option) any later version.
+ *
+ * GayBSD comes with ABSOLUTELY NO WARRANTY, to the extent
+ * permitted by applicable law.  See the CNPL for details.
+ */