The Kernel - BeagleBone - page 508

Solution

Example 7-4 shows a patch file that you can use on the kernel.

Example 7-4. Simple kernel patch file (hello.patch)
From eaf4f7ea7d540bc8bb57283a8f68321ddb4401f4 Mon Sep 17 00 : 00 : 00 2001
From : Jason Kridner < jdk @ ti . com >
Date : Tue , 12 Feb 2013 02 : 18 : 03 + 0000
Subject : [ PATCH ] hello : example kernel modules

---
hello / Makefile | 7 +++++++
hello / hello . c | 18 ++++++++++++++++++
2 files changed , 25 insertions (+), 0 deletions (-)
create mode 100644 hello / Makefile
create mode 100644 hello / hello . c

diff -- git a / hello / Makefile b / hello / Makefile
new file mode 100644
index 0000000..4 b23da7
--- / dev / null
+++ b / hello / Makefile
@@ - 0 , 0 + 1 , 7 @@
+ obj - m := hello . o
+
+ PWD := $ ( shell pwd )
+ KDIR := $ { PWD }/..
+
+ default :
+ make - C $ ( KDIR ) SUBDIRS = $ ( PWD ) modules
diff -- git a / hello / hello . c b / hello / hello . c
new file mode 100644
index 0000000..157 d490
--- / dev / null
+++ b / hello / hello . c
@@ - 0 , 0 + 1 , 22 @@
+ # include < linux / module . h >

/* Needed by all modules */

+ # include < linux / kernel . h > /* Needed for KERN_INFO */

+ # include < linux / init . h > /* Needed for the macros */

+
+ static int __init hello_start ( void )
+{
+ printk ( KERN_INFO "Loading hello module... \n " );

+ printk ( KERN_INFO "Hello, World! \n " );