{"id":24,"date":"2015-12-20T19:57:33","date_gmt":"2015-12-20T18:57:33","guid":{"rendered":"http:\/\/blog.brunocsmartin.fr\/?p=24"},"modified":"2016-01-27T15:47:04","modified_gmt":"2016-01-27T14:47:04","slug":"about-linux-modules","status":"publish","type":"post","link":"https:\/\/blog.brunocsmartin.fr\/index.php\/2015\/12\/20\/about-linux-modules\/","title":{"rendered":"About Linux Modules"},"content":{"rendered":"

Create a SD card image :
\n– get the last Raspbian image ont the website :\u00a0https:\/\/www.raspberrypi.org\/downloads\/raspbian\/<\/a>
\n– get the last applePi-Baker :\u00a0http:\/\/www.tweaking4all.com\/hardware\/raspberry-pi\/macosx-apple-pi-baker\/<\/a>
\n– unzip the image, connect the SD card and launch applePi-Baker<\/p>\n

Connect the rpi using usb serial connexion :
\n– install the PL2303 driver
\n– install minicom
\n– connect the usb serial adapter to the rpi and ti the mac, check in dev (\/dev\/tty.usbserial)
\n– launch \u00ab\u00a0minicom -s\u00a0\u00bb in a terminal and enter the device address<\/p>\n

minicom -s<\/pre>\n
– login : pi, password : raspberry
\n– activate root account :<\/p>\n
sudo passwd root<\/pre>\n
– exit and log with root<\/p>\n
Expand Filesystem:
\n– launch raspi-config<\/p>\n
raspi-config<\/pre>\n
– choose \u00ab\u00a01 Expand Filesystem\u00a0\u00bb
\n– reboot<\/p>\n
Get the module development environment :<\/p>\n
\r\napt-get install rpi-update\r\nrpi-update\r\n<\/pre>\n
– get the kernel version :<\/p>\n
uname -r<\/pre>\n
– download corresponding package at https:\/\/www.niksula.hut.fi\/~mhiienka\/Rpi\/linux-headers-rpi\/
\n– install with dpkg :<\/p>\n
dpkg -i linux-headers...<\/pre>\n
Try module compilation :
\n– create hello.c file containing :<\/p>\n
\r\n\r\n\/*\r\n* hello.c - The simplest kernel module.\r\n*\/\r\n#include "linux\/module.h" \/\/ included for all kernel modules\r\n#include "linux\/kernel.h" \/\/ included for KERN_INFO\r\n#include "linux\/init." \/\/ included for __init and __exit macros\r\n\r\nMODULE_LICENSE("GPL");\r\nMODULE_AUTHOR("Martin");\r\nMODULE_DESCRIPTION("A Simple Hello World module");\r\n\r\nstatic int __init hello_init(void)\r\n{\r\n    printk(KERN_INFO "Hello world!\\n");\r\n    return 0; \/\/ Non-zero return means that the module couldn't be loaded.\r\n}\r\n\r\nstatic void __exit hello_cleanup(void)\r\n{\r\n    printk(KERN_INFO "Cleaning up module.\\n");\r\n}\r\n\r\nmodule_init(hello_init);\r\nmodule_exit(hello_cleanup);\r\n<\/pre>\n
– create Makefile file containing :<\/p>\n
\r\nobj-m += hello.o\r\nKDIR := \/lib\/modules\/$(shell uname -r)\/build\r\nPWD := $(shell pwd)\r\n\r\nall:\r\n    make -C $(KDIR) M=$(PWD) modules\r\n\r\nclean:\r\n\u00a0\u00a0 \u00a0make -C $(KDIR) M=$(PWD) clean\r\n<\/pre>\n
– try to load and unload the module :<\/p>\n
\r\ninsmod hello.ko\r\nrmmod hello.ko\r\n<\/pre>\n
– check the results through the kernel messages :
\n>dmesg | tail -20<\/p>\n
– it should be written something like :<\/p>\n
\r\n[ 2831.586831] Hello world.\r\n[ 2846.286438] Goodbye world.\r\n<\/pre>\n
– And it’s good !<\/p>\n
Install the new driver so it will be loaded at start up :
\n– copy the .ko file to the appropropriate directory : \/lib\/modules\/`uname -r`\/kernel\/drivers\/gpio
\n– run depmod
\n>depmod
\n– and reboot
\n>shutdown -r now<\/p>\n
For the raspberry, the serial connexion is limited and graphical interface is not supplied. So create a ssh server is a good way to use geany for example. As I use a wifi connexion, the ssh server will hang up soon as you are connected so. To get rid of this, add the following lines at the end of \/etc\/ssh\/sshd_config :<\/p>\n
KeepAlive yes\r\nClientAliveInterval 60<\/pre>\n
Ok ?<\/p>\n","protected":false},"excerpt":{"rendered":"
Create a SD card image : – get the last Raspbian image ont the website :\u00a0https:\/\/www.raspberrypi.org\/downloads\/raspbian\/ – get the last applePi-Baker :\u00a0http:\/\/www.tweaking4all.com\/hardware\/raspberry-pi\/macosx-apple-pi-baker\/ – unzip the image, connect the SD card and launch applePi-Baker Connect the rpi using usb serial connexion : – install the PL2303 driver – install minicom – connect the usb serial adapter … Continuer la lecture de About Linux Modules<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-24","post","type-post","status-publish","format-standard","hentry","category-non-classe"],"_links":{"self":[{"href":"https:\/\/blog.brunocsmartin.fr\/index.php\/wp-json\/wp\/v2\/posts\/24"}],"collection":[{"href":"https:\/\/blog.brunocsmartin.fr\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.brunocsmartin.fr\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.brunocsmartin.fr\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.brunocsmartin.fr\/index.php\/wp-json\/wp\/v2\/comments?post=24"}],"version-history":[{"count":8,"href":"https:\/\/blog.brunocsmartin.fr\/index.php\/wp-json\/wp\/v2\/posts\/24\/revisions"}],"predecessor-version":[{"id":39,"href":"https:\/\/blog.brunocsmartin.fr\/index.php\/wp-json\/wp\/v2\/posts\/24\/revisions\/39"}],"wp:attachment":[{"href":"https:\/\/blog.brunocsmartin.fr\/index.php\/wp-json\/wp\/v2\/media?parent=24"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.brunocsmartin.fr\/index.php\/wp-json\/wp\/v2\/categories?post=24"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.brunocsmartin.fr\/index.php\/wp-json\/wp\/v2\/tags?post=24"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}