Bootloader loading kernel, not yet jumping to it

src/modules/main/main.c

@@ -0,0 +1,4 @@
+__attribute__((used))
+int kernel_main() {
+    return 42;
+}

src/modules/main/module.mk

@@ -0,0 +1,2 @@
+MOD_NAME := main
+include modules.mk