eudyptula

task01/Makefile

@@ -0,0 +1,9 @@
+ifneq ($(KERNELRELEASE),)
+	obj-m  := task01.o
+else
+	KDIR ?= /lib/modules/`uname -r`/build
+
+default:
+	$(MAKE) -C $(KDIR) M=$$PWD
+
+endif

task01/task 01.txt

@@ -0,0 +1,38 @@
+This is Task 01 of the Eudyptula Challenge
+------------------------------------------
+
+Write a Linux kernel module, and stand-alone Makefile, that when loaded
+prints to the kernel debug log level, "Hello World!"  Be sure to make
+the module unloadable as well.
+
+The Makefile should build the kernel module against the source for the
+currently running kernel, or, use an environment variable to specify
+what kernel tree to build it against.
+
+Please show proof of this module being built, and running, in your
+kernel.  What this proof is is up to you.  I'm sure you can come up with
+something.  Also be sure to send the kernel module you wrote, along with
+the Makefile you created to build the module.
+
+Remember to use your ID assigned in the Subject: line when responding to
+this task, so that I can figure out who to attribute it to.  You can
+just respond to the task with the answers and all should be fine.
+
+If you forgot, your id is "4f92b3aee379".  But of course you have not
+forgotten that yet, you are better than that.
+
+
+Some points
+------------------------------------------
+- Write a Linux Kernel Module (LKM) which prints “Hello World!” to the kernel debug log (when loaded)
+- Stand-alone Makefile
+- Make the module unloadable as well
+- Makefile - make to the current running kernel.
+- Send the LKM and the Makefile
+- Put "4f92b3aee379" in the subject or just respond the task
+
+Reference
+------------------------------------------
+http://www.acm.uiuc.edu/sigops/lkm_tut/pratap-lkm.txt
+http://www.thegeekstuff.com/2013/07/write-linux-kernel-module/
+https://www.kernel.org/doc/Documentation/kbuild/

task01/task01.c

@@ -0,0 +1,25 @@
+/* This lkm is modified from:
+ * http://www.tldp.org/LDP/lkmpg/2.6/html/x121.html
+ */
+
+/* linux/module.h - for the module
+ * linux/kernel.h - macros for printk
+ */
+#include <linux/module.h>
+#include <linux/kernel.h>
+
+/* Entry point of the lkm.
+ * This is executed as soon as the lkm is loaded.
+ * Priority of printk - from linux/kernel.h
+ * http://web.cecs.pdx.edu/~jrb/ui/linux/driver4.txt
+ */
+int init_module(void)
+{
+	printk(KERN_DEBUG "Hello World!\n");
+}
+/* Exit point of the lkm.
+ * This is executed as soon as the lkm is unloaded and undo
+ * everthing did in init_module.
+ */
+void cleanup_module(void)
+{}

task02/references.txt

@@ -0,0 +1,20 @@
+'make menuconfig' - menu para configuração do .config antes de compilar o kernel.
+apt-get install libncurses5 ncurses (ou libncurses5-dev)
+
+Sobre algumas configurações do kernel
+http://www.tldp.org/HOWTO/SCSI-2.4-HOWTO/kconfig.html
+
+Instalação completa []
+
+0) git clone git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git
+1) make localmodconfig - configurações padrão e compila baseado nelas
+2) make
+3) make modules
+4) make modules_install
+5) make install
+
+Referencias:
+[1] http://www.wikihow.com/Compile-the-Linux-Kernel
+[2] http://www.cyberciti.biz/tips/compiling-linux-kernel-26.html
+[3] http://www.thegeekstuff.com/2013/06/compile-linux-kernel/
+[4] http://kernelnewbies.org/KernelBuild

task02/response_task02.txt

@@ -0,0 +1,41 @@
+Hello, this is the proof...
+
+Linux mint using real machines
+
+==[ OLD LINUX KERNEL
+
+user-pc ~ # uname -a
+Linux user-pc 3.11.0-12-generic #19-Ubuntu SMP Wed Oct 9 16:20:46 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux
+
+user-pc ~ # dmesg
+[    0.000000] Initializing cgroup subsys cpuset
+[    0.000000] Initializing cgroup subsys cpu
+[    0.000000] Initializing cgroup subsys cpuacct
+[    0.000000] Linux version 3.11.0-12-generic (buildd@allspice) (gcc version 4.8.1 (Ubuntu/Linaro 4.8.1-10ubuntu7) ) #19-Ubuntu SMP Wed Oct 9 16:20:46 UTC 2013 (Ubuntu 3.11.0-12.19-generic 3.11.3)
+
+user-pc ~ # ls -la /boot/ | grep `uname -r`
+-rw-r--r--  1 root root  1005798 Out  9  2013 abi-3.11.0-12-generic
+-rw-r--r--  1 root root   163251 Out  9  2013 config-3.11.0-12-generic
+-rw-r--r--  1 root root 26635969 Jan 21 10:20 initrd.img-3.11.0-12-generic
+-rw-------  1 root root  3285893 Out  9  2013 System.map-3.11.0-12-generic
+-rw-r--r--  1 root root  5600016 Jan 20 11:51 vmlinuz-3.11.0-12-generic
+
+==[ NEW LINUX KERNEL
+
+The kernel downloaded from kernel.org git, downloaded in July 10th.
+
+user-pc user # uname -a
+Linux user-pc 3.16.0-rc4-00042-g4f440cd-dirty #2 SMP Thu Jul 10 13:07:00 BRT 2014 x86_64 x86_64 x86_64 GNU/Linux
+
+user-pc ~ # dmesg
+[    0.000000] Initializing cgroup subsys cpuset
+[    0.000000] Initializing cgroup subsys cpu
+[    0.000000] Initializing cgroup subsys cpuacct
+[    0.000000] Linux version 3.16.0-rc4-00042-g4f440cd-dirty (root@user-pc) (gcc version 4.8.1 (Ubuntu/Linaro 4.8.1-10ubuntu9) ) #2 SMP Thu Jul 10 13:07:00 BRT 2014
+
+user-pc user # ls -la /boot/ | grep `uname -r`
+-rw-r--r--  1 root root   110645 Jul 10 13:09 config-3.16.0-rc4-00042-g4f440cd-dirty
+-rw-r--r--  1 root root 20405424 Jul 10 13:09 initrd.img-3.16.0-rc4-00042-g4f440cd-dirty
+-rw-r--r--  1 root root  3397420 Jul 10 13:09 System.map-3.16.0-rc4-00042-g4f440cd-dirty
+-rw-r--r--  1 root root  5774704 Jul 10 13:09 vmlinuz-3.16.0-rc4-00042-g4f440cd-dirty
+

task02/task02.txt

@@ -0,0 +1,60 @@
+This is Task 02 of the Eudyptula Challenge
+------------------------------------------
+
+Now that you have written your first kernel module, it's time to take
+off the training wheels and move on to building a custom kernel.  No
+more distro kernels for you.  For this task you must run your own
+kernel.  And use git!  Exciting, isn't it?  No?  Oh, ok...
+
+The tasks for this round are:
+  - Download Linus's latest git tree from git.kernel.org (you have to
+    figure out which one is his.  It's not that hard, just remember what
+    his last name is and you should be fine.)
+  - Build it, install it, and boot it.  You can use whatever kernel
+    configuration options you wish to use, but you must enable
+    CONFIG_LOCALVERSION_AUTO=y.
+  - Show proof of booting this kernel.  Bonus points if you do it on a
+    "real" machine, and not a virtual machine (virtual machines are
+    acceptable, but come on, real kernel developers don't mess around
+    with virtual machines, they are too slow.  Oh yeah, we aren't real
+    kernel developers just yet.  Well, I'm not anyway, I'm just a
+    script...)  Again, proof of running this kernel is up to you, I'm
+    sure you can do well.
+
+Hint, you should look into the 'make localmodconfig' option, and base
+your kernel configuration on a working distro kernel configuration.
+Don't sit there and answer all 1625 different kernel configuration
+options by hand, even I, a foolish script, know better than to do that!
+
+After doing this, don't throw away that kernel, git tree, and
+configuration file.  You'll be using it for later tasks.  A working
+kernel configuration file is a precious thing, all kernel developers
+have one they have grown and tended to over the years.  This is the
+start of a long journey with yours.  Don't discard it like was a broken
+umbrella, it deserves better than that.
+
+Remember to use your ID assigned in the subject line when responding to
+this task, so that I can figure out who to attribute it to.
+
+If you forgot, your id is "4f92b3aee379".  But why do I repeat myself?
+Of course you know your id, you made it through the first task just fine
+with it.
+
+
+Some points
+------------------------------------------
+- Build a custom kernel using Linus's latest git tree from git.kernel.org.
+- Build it, install it, and boot it. Use CONFIG_LOCALVERSION_AUTO=y
+- If I install in real machine, I'll gain extra points
+- Look into the 'make localmodconfig'
+- Don't throw away the kernel, it'll be using for later tasks.
+
+Reference
+------------------------------------------
+http://www.acm.uiuc.edu/sigops/lkm_tut/pratap-lkm.txt
+http://www.thegeekstuff.com/2013/07/write-linux-kernel-module/
+https://www.kernel.org/doc/Documentation/kbuild/
+
+Compilando kernel com suporte a dpkg
+http://www.youtube.com/watch?v=bSS7oJ7n6f0
+http://www.youtube.com/watch?v=3Pf9D9hvlb0

task03/0001-Makefile-Modification-for-Eudyptula-Challenge-task03.patch

@@ -0,0 +1,29 @@
+From f60e32cd71c1f3018a42ed3429b16299f1e191b1 Mon Sep 17 00:00:00 2001
+From: Raphael Campos <[email protected]>
+Date: Tue, 15 Jul 2014 08:10:17 -0300
+Subject: [PATCH 1/1] Makefile: Modification for Eudyptula Challenge task03
+
+EXTRAVERSION field modification to show "-eudyptula" in the version
+string.
+
+Signed-off-by: Raphael Campos <[email protected]>
+---
+ Makefile | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/Makefile b/Makefile
+index f3c543d..28be911 100644
+--- a/Makefile
++++ b/Makefile
+@@ -1,7 +1,7 @@
+ VERSION = 3
+ PATCHLEVEL = 16
+ SUBLEVEL = 0
+-EXTRAVERSION = -rc5
++EXTRAVERSION = -eudyptula
+ NAME = Shuffling Zombie Juror
+
+ # *DOCUMENTATION*
+-- 
+1.8.3.2
+

task03/references.txt

@@ -0,0 +1,34 @@
+Dar uma olhada rápida nas referências a seguir. Referências obtidas em Documentation/SubmittingPatches	
+
+http://www.ozlabs.org/~akpm/stuff/tpp.txt
+http://linux.yyz.us/patch-format.html
+
+[url:http://www.linuxchix.org/content/courses/kernel_hacking/lesson9
+] - básico sobre patch e diff
+Referencia que ensina de forma rápida a usar os comandos 'diff' e 'patch'.
+
+[url:http://linux.koolsolutions.com/2011/02/26/howto-create-and-submit-your-first-linux-kernel-patch/] - sobre git/patch
+# git config --add user.name "Raphael Campos"
+# git config --add user.email "[email protected]"
+# git branch task03	-- cria um novo branch que irá conter as alterações
+# git checkout task03	-- muda para este branch
+# git branch		-- lista para ver se esta no branch correta
+... realiza as alterações necessárias ...
+# git commit -a
+... comentar sobre o patch: linha 1 será o subject, linha em branco, linha 2 será a descrição.
+# git diff 		-- verificar alteração antes de criar o patch
+# git format-patch -s -n master..task03 -- criar um patch e salva no ./ baseado nas alterações realizadas.
+# scripts/checkpatch.pl 0001-x86-Fix-reboot-problem-on-VersaLogic-Menlow-boards.patch
+
+# make M=drivers/staging/comedi/	-- compilando os arquivos de um dir especifico. No qual o arquivo foi alterado
+
+# git log	-- mostra as alterações
+# git show 	-- mostra o patch.
+#./scripts/get_maintainer.pl --file drivers/hid/hid-ezkey.c 	-- mostra os manteners.
+# git blame drivers/hid/hid-ezkey.c
+# git show f425458e
+
+Referência muito boa sobre o assunto. Tudo sobre patch.
+https://www.youtube.com/watch?v=LLBrBBImJt4
+
+Ponto de partida - Documentation/HOWTO

task03/response_task03.txt

@@ -0,0 +1,50 @@
+Hello, this is the proof...
+
+Linux mint (with kernel from task02) using real machine
+
+==[ OLD LINUX KERNEL
+
+user-pc ~ # uname -a
+Linux user-pc 3.16.0-rc4-00042-g4f440cd-dirty #2 SMP Thu Jul 10 13:07:00 BRT 2014 x86_64 x86_64 x86_64 GNU/Linux
+
+user-pc ~ # dmesg
+[    0.000000] Initializing cgroup subsys cpuset
+[    0.000000] Initializing cgroup subsys cpu
+[    0.000000] Initializing cgroup subsys cpuacct
+[    0.000000] Linux version 3.16.0-rc4-00042-g4f440cd-dirty (root@user-pc) (gcc version 4.8.1 (Ubuntu/Linaro 4.8.1-10ubuntu9) ) #2 SMP Thu Jul 10 13:07:00 BRT 2014
+
+user-pc ~ # ls -la /boot/ | grep `uname -r`
+-rw-r--r--  1 root root  3397420 Jul 10 13:09 System.map-3.16.0-rc4-00042-g4f440cd-dirty
+-rw-r--r--  1 root root   110645 Jul 10 13:09 config-3.16.0-rc4-00042-g4f440cd-dirty
+-rw-r--r--  1 root root 20405424 Jul 10 13:09 initrd.img-3.16.0-rc4-00042-g4f440cd-dirty
+-rw-r--r--  1 root root  5774704 Jul 10 13:09 vmlinuz-3.16.0-rc4-00042-g4f440cd-dirty
+
+==[ NEW LINUX KERNEL
+
+The kernel downloaded from kernel.org git, downloaded in July 15th.
+
+user-pc user # uname -a
+Linux user-pc 3.16.0-eudyptula-dirty #2 SMP Tue Jul 15 08:51:07 BRT 2014 x86_64 x86_64 x86_64 GNU/Linux
+
+user-pc ~ # dmesg
+[    0.000000] Initializing cgroup subsys cpuset
+[    0.000000] Initializing cgroup subsys cpu
+[    0.000000] Initializing cgroup subsys cpuacct
+[    0.000000] Linux version 3.16.0-eudyptula-dirty (root@user-pc) (gcc version 4.8.1 (Ubuntu/Linaro 4.8.1-10ubuntu9) ) #2 SMP Tue Jul 15 08:51:07 BRT 2014
+
+user-pc linux # ls -al /boot/ | grep `uname -r`
+-rw-r--r--  1 root root   110710 Jul 15 08:54 config-3.16.0-eudyptula-dirty
+-rw-r--r--  1 root root 20406948 Jul 15 08:55 initrd.img-3.16.0-eudyptula-dirty
+-rw-r--r--  1 root root  3397539 Jul 15 08:54 System.map-3.16.0-eudyptula-dirty
+-rw-r--r--  1 root root  5774160 Jul 15 08:54 vmlinuz-3.16.0-eudyptula-dirty
+
+
+==[ PATCH
+
+The patch was build using git, as show below:
+
+user-pc user # git branch task03
+user-pc user # git checkout task03
+... Makefile changes ...
+user-pc user # git commit -a
+user-pc user # git format-patch -s -n master..task03

task03/task03.txt

@@ -0,0 +1,36 @@
+This is Task 03 of the Eudyptula Challenge
+------------------------------------------
+
+Now that you have your custom kernel up and running, it's time to modify
+it!
+
+The tasks for this round are:
+  - Take the kernel git tree from Task 02 and change the Makefile to
+    modify the EXTRAVERSION field.  Do this in a way that the
+    running kernel (after modifying the Makefile, rebuilding, and
+    rebooting) has the characters "-eudyptula" in the version string.
+  - Show proof of booting this kernel.  Extra cookies when you provide
+    creative examples, especially if done in interpretive dance at your
+    local pub.
+  - Send a patch that shows the Makefile modified.  Do this in a manner
+    that would be acceptable for merging in the kernel source tree.
+    (Hint, read the file Documentation/SubmittingPatches and follow the
+    steps there.)
+
+Remember to use your ID assigned in the subject line when responding to
+this task, so that I can figure out who to attribute it to.
+
+If you forgot, your id is "4f92b3aee379".  Surely I don't need to keep
+saying this right?  I know, _you_ wouldn't forget, but someone else, of
+course they would, so I'll just leave it here for those "others."
+
+Some points
+------------------------------------------
+- Take the kernel git tree from Task 02
+- Change the Makefile to modify the EXTRAVERSION field (-eudyptula)
+- Show a proof of booting the kernel
+- Extra cookies when you provide creative examples, especially if done in interpretive dance at your local pub. (?!)
+- Send a patch that shows the Makefile modified (read Documentation/SubmittingPatches)
+
+Reference
+------------------------------------------

task04/coding_style.c

@@ -0,0 +1,40 @@
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+
+int do_work(int *my_int, int retval)
+{
+	int x;
+	int y = *my_int;
+	int z;
+
+	for (x = 0; x < *my_int; ++x)
+		udelay(10);
+
+	if (y < 10)
+		/* That was a long sleep, tell userspace about it */
+		pr_warn("We slept a long time!");
+
+	z = x * y;
+
+	return z;
+}
+
+int my_init(void)
+{
+	int x = 10;
+
+	x = do_work(&x, x);
+
+	return x;
+}
+
+void my_exit(void)
+{
+	return 0;
+}
+
+module_init(my_init);
+module_exit(my_exit);
+