initial hello

hello/Makefile

@@ -0,0 +1,15 @@
+ifneq ($(KERNELRELEASE),)
+  obj-m := hello.o
+else
+  KERNELDIR ?= /usr/src/linux-headers-4.19.66-v7+
+  PWD := $(shell pwd)
+
+default:
+	$(MAKE) -C $(KERNELDIR) M=$(PWD) modules
+
+.PHONY: clean
+clean:
+	rm -rf *.o *~ core .depend .*.cmd *.ko *.mod.c .tmp_versions modules.order Module.symvers
+
+endif
+

hello/hello.c

@@ -0,0 +1,20 @@
+/*                                                     
+ * $Id: hello.c,v 1.5 2004/10/26 03:32:21 corbet Exp $ 
+ */                                                    
+#include <linux/init.h>
+#include <linux/module.h>
+MODULE_LICENSE("GPL");
+
+static int hello_init(void)
+{
+	printk(KERN_ALERT "Hello, world\n");
+	return 0;
+}
+
+static void hello_exit(void)
+{
+	printk(KERN_ALERT "Goodbye, cruel world\n");
+}
+
+module_init(hello_init);
+module_exit(hello_exit);