Nirmala Venkat at 09:48, 22 October 2020

2020-10-22T09:48:49Z

Nirmala Venkat: Created page with " {| style="border-spacing:0;" | style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| '''Visual cue :''' | style="bo..."

2020-09-23T11:23:18Z

Created page with " {| style="border-spacing:0;" | style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| '''Visual cue :''' | style="bo..."

New page

{| style="border-spacing:0;"
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| '''Visual cue :'''
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| '''Narration :'''

|-
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Slide 1:

Welcome slide:
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Welcome to the spoken tutorial on''' Registering a Character Device Number.'''

|-
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Slide 2:

Learning objectives:
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| In this tutorial, we will learn how to

* Dynamically allocate the '''major''' and '''minor '''numbers to a''' device. '''
* Register a new '''character device '''inside the '''kernel.'''

|-
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Slide 3:

System Requirements:
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| To record this tutorial, I am using,

* '''VirtualBox''' version '''5.2.'''
* '''Ubuntu Linux 18.04 LTS''' operating system.
* '''Linux kernel '''version''' 5.0.0-31 generic '''and
* '''gedit text editor'''

|-
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Slide 4:

Prerequisites:
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| To follow this tutorial, you should be familiar with:

* '''C programming language '''and
* Basics of''' Linux kernel'''

If not, then go through the '''C/C++''' and '''Linux''' spoken tutorials on this website.

|-
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Slide 5:

'''Device file''' in '''Linux'''.
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| * Each '''device''' is represented as a '''file''' in '''Linux'''.
* The '''device files''' are located under the '''dev directory.'''
* Each '''device file''' in''' Linux''' has a unique number associated with it.

|-
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"|
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Let us see some of the device''' files''' that are already present in the '''Linux''' system.

|-
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Open the''' terminal'''
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Open the''' '''terminal by pressing''' Alt+Ctrl+T''' keys simultaneously.

Press the '''Enter''' key after every command.

|-
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Type >> '''ls -l /dev/tty* | head -5'''

Show the '''output'''
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Let us see about the specific device files such as '''serial character device files. '''

Type the command as shown here.

|-
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Highlight numbers '''4, 1'''

Highlight '''4'''
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Here, 4 and 1 indicate the '''major''' and '''minor''' numbers of '''tty1 device'''.

The '''major''' number indicates the driver associated with the '''device'''.

It indicates that the''' tty0 '''and '''tty1 serial ports '''are managed by the '''driver''' 4.
|-
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Highlight''' 0, 1'''

| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Inside the '''driver''', each '''device''' is identified by the unique number.

The''' tty0 '''and '''tty1 '''have different '''minor''' numbers 0 and 1 as shown here.

The '''driver''' uses the''' minor''' number to distinguish individual physical or logical '''devices'''.

Using these '''minor''' numbers, the '''driver 4 '''is able to differentiate these''' devices'''.

|-
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Slide 6 :

Internal representation of device number
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| * The '''kernel''' uses the '''dev_t type variable '''to hold '''major''' and '''minor''' numbers.
* The size of the '''dev_t''' is''' 32-bit.'''
* '''12 bits''' are used for '''major''' numbers and '''20 bits''' are used for '''minor''' numbers.
|-
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Point to the '''folder''' and''' file''' in '''desktop'''

Point to the '''files.'''

| style="border-top:1pt solid #000000;border-bottom:0.5pt solid #000000;border-left:0.5pt solid #000000;border-right:0.5pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Go to the '''DeviceDriver '''folder in the desktop which we have created earlier.

I have created a directory''' '''named''' RegisterDevice.'''

In this directory, I have saved '''simple_driver dot c''' and '''Makefile'''.

I will use these''' '''files for demonstration.

|-
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Slide :

Code''' files: '''
| style="border:1pt solid #000000;padding:0.176cm;"| * The files used in this tutorial are available in the '''Code Files '''link on this tutorial page.
* Please download and extract them
* Make a copy and then use them while practising
|-
| style="border:0.5pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Type >> '''cd Desktop/DeviceDriver/RegisterDevice'''
| style="border:0.5pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Switch back to the''' '''terminal'''.'''

Go to the directory''' RegisterDevice '''as shown here.

|-
| style="border:0.5pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Type >> '''gedit simple_driver.c'''
| style="border:0.5pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Let us open the file''' simple_driver dot c.'''

Type '''gedit space simple_driver dot c.'''

Let us see the code.

|-
| style="border:0.5pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Highlight '''header files'''

Highlight '''fs.h'''
| style="border:0.5pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| We have to include these '''header files''' at the start of the '''program'''.

The purpose of each '''header file''' is mentioned here.

'''fs.h''' contains the required functions to register a '''character device number.'''

|-
| style="border:0.5pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Highlight''' device_num'''
| style="border:0.5pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| '''device_num '''is a '''dev_t type '''variable.

It will hold the '''major''' and '''minor''' number of a '''device'''.

|-
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"|
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Let us see how to register a''' character device number dynamically.'''

|-
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Highlight '''alloc_chrdev_region()'''

| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| '''alloc_chrdev_region''' '''function''' will dynamically allocate the '''major '''number to the '''device'''.

The''' kernel '''will find the unused '''major''' number and assign it to a '''device'''.

This function returns a value less than zero on failure.

|-
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Highlight '''dev '''

Highlight '''firstminor'''

Highlight '''count '''

Highlight '''name'''
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Let us see the parameters of this '''function'''.
'''dev '''is the variable that holds the '''device '''number.

'''firstminor '''specifies the starting '''minor''' number which is '''0.'''

'''count '''specifies the number of supported '''devices'''.

'''name''' is a '''device''' name used to identify the '''device.'''
|-
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Highlight '''0'''
Highlight '''alloc_chrdev_region()'''

'''my_device.'''
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| In this program, we allocate a '''minor''' number starting from '''0'''.

This '''function''' will register one device with the name '''my_device.'''

|-
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Highlight''' printk messages'''

| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| '''printk function '''will be executed to indicate the success or failure of the''' function.'''

|-
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Highlight '''MAJOR(dev_t dev)'''

Highlight '''MINOR(dev_t dev)'''

Highlight '''macros'''
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| '''MAJOR''' '''macro''' is used to extract the '''major''' number from the '''dev_t variable.'''

Similarly, '''MINOR''' '''macro''' is used to extract the '''minor''' number from the '''dev_t variable.'''

It will print the '''major''' and '''minor''' numbers of '''my_device '''using these '''macros'''.

|-
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Highlight '''Unregister_chrdev_region()'''
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| '''unregister_chrdev_region() '''function is used to remove a''' device number''' from''' kernel.'''

You should free the''' device numbers '''when they are no longer in use.

|-
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Highlight '''dev_t '''

Highlight '''count'''
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| '''dev_t '''specifies the''' '''beginning of device number range to be freed.

'''count '''represents the number of devices to unregister.
|-
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Highlight '''unregister_chrdev_region()'''

Highlight '''printk()'''
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| This function will unregister '''my_device '''from the''' kernel'''.

When the '''driver '''is unloaded, these messages will be printed in the '''kernel''' '''log level. '''

Save the file and close the window.

|-
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Show the '''terminal'''
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Switch back to the '''terminal'''
|-
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| <nowiki>Type << </nowiki>'''gedit Makefile'''

Type >> '''clear'''
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| To compile the '''driver''', we need to create a '''Makefile'''.

Type '''gedit''' space '''Makefile'''.

Type the''' code '''as shown or you can make use of the downloaded''' Makefile'''.

Save and close the file'''.'''

|-
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Open the '''terminal '''

Type >> '''sudo su'''
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Let us compile the '''driver'''.

Type '''sudo''' '''space''' '''su '''to be a '''superuser''' and type the system password.

|-
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Type >> '''make all '''

Type >>''' clear'''
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Type '''make space all'''

Clear the screen.

|-
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Type >> '''insmod space simple_driver.ko'''

Type >> '''clear'''
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Let us load the '''simple_driver dot ko''' into the '''kernel.'''

Type''' insmod space simple_driver dot ko.'''

Clear the screen.

|-
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"|
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Let us see the loaded''' printk messages''' of the '''driver'''.

|-
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Type >>''' dmesg | grep simple_driver '''

Highlight '''major''' and '''minor''' number
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Type''' dmesg space pipe space grep simple_driver.'''

We can see the '''major''' and '''minor''' number of '''my_device '''

It indicates that the '''my_device''' is registered inside the '''kernel '''successfully.

|-
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Type >> '''clear'''
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Clear the screen

|-
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Type >> '''cat /proc/devices | grep my_device'''

Highlight '''devices'''
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Let us check whether our '''device''' appears in the''' proc file''' system or not.

Type''' '''the command as shown here.

This file displays the various '''devices '''currently configured in the '''kernel'''.
|-
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Highlight''' my_device with number'''
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Here, you can see the '''my_device''' with its '''major''' number.

It indicates that '''my_device '''is registered inside the '''kernel''' successfully.

|-
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Type >>''' clear'''
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Clear the screen'''.'''

|-
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Type >> '''rmmod simple_driver.ko '''

| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Let us unload a''' module''' from the kernel.

Type''' rmmod space simple_driver dot ko'''

|-
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Type >>''' dmesg | grep simple_driver '''

Highlight '''printk'''

Type >> '''clear'''
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Let us see the unloaded''' printk messages''' of the '''driver'''.

Type the command as shown here.

It indicates that the '''my_device''' is unregistered from the '''kernel '''successfully.

Clear the screen.

|-
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Type >> '''make clean'''

Type >> '''clear'''
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Type '''make space clean.'''

It removes all '''objects''' '''files '''created after the '''compilation.'''

Clear the screen.

|-
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Type >> '''exit'''
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| To be''' '''a regular user''', '''type '''exit.'''

|-
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"|
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| With this, we come to the end of this tutorial. Let us summarize.

|-
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Slide :

Summary
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| In this tutorial, we learned how to

* Dynamically allocate the '''major''' and '''minor '''numbers to a device'''.'''
* Register a new character device inside the kernel.

|-
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Slide :

Assignment :
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| As an assignment

# Open the''' simple_driver.c '''file.
# Allocate the device number using the '''kernel function.'''
# Change the name of the '''device'''.
# Compile and load the '''driver''' into the '''kernel'''.
# See the registered device in the '''procfs'''
# Unload the driver from the''' kernel'''.

|-
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Slide :

About Spoken Tutorial Project:
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| * The video at the following link summarizes the Spoken Tutorial project.

* Please download and watch it.
|-
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Slide :

Spoken Tutorial workshops:
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| The''' Spoken Tutorial Project''' Team:

* conducts workshops and gives certificates.
* For more details, please write to us.

|-
| style="border:1pt solid #000000;padding:0.176cm;"| Slide :

Forum questions :
| style="border:1pt solid #000000;padding:0.176cm;"| * Please post your timed queries in this forum

|-
| style="border:1pt solid #000000;padding:0.176cm;"| Slide :

Forum for specific questions :
| style="border:1pt solid #000000;padding:0.176cm;"| * Do you have any general or technical questions on Embedded Linux Device Driver?
* Please visit the FOSSEE forum and post your question.
|-
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Slide :

Acknowledgment:
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| The Spoken Tutorial project is funded by MHRD, Government of India.

|-
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Slide :
Thank you slide:
| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| This tutorial has been contributed by FOSSEE and Spoken Tutorial Project, IIT Bombay.

This is Mayuri Panchakshari from IIT Bombay signing off.

Thanks for watching.

|}

Embedded-Linux-Device-Driver/C3/Registering-a-Character-Device-Number/English - Revision history

Nancyvarkey at 10:02, 30 October 2020

Nirmala Venkat at 09:48, 22 October 2020

Nirmala Venkat: Created page with " {| style="border-spacing:0;" | style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| '''Visual cue :''' | style="bo..."

@@ Line 57: / Line 57: @@
 | style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Open the''' '''terminal by pressing''' Alt+Ctrl+T''' keys simultaneously.
-Press the '''Enter''' key after every command.
+Press '''Enter''' key after every command.
 |-
@@ Line 165: / Line 165: @@
 Highlight '''name'''
-| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Let us see the parameters of this '''function'''.
+| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Let us see the parameters of this function.
 '''dev '''is the variable that holds the '''device '''number.
@@ Line 180: / Line 180: @@
 | style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| In this program, we allocate a '''minor''' number starting from '''0'''.
-This '''function''' will register one device with the name '''my_device.'''
+This function will register one device with the name '''my_device.'''
 |-
 | style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| Highlight''' printk messages'''
-| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| '''printk function '''will be executed to indicate the success or failure of the''' function.'''
+| style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| '''printk function '''will be executed to indicate the success or failure of the function.
 |-
@@ Line 400: / Line 400: @@
 | style="border:1pt solid #000000;padding-top:0cm;padding-bottom:0cm;padding-left:0.206cm;padding-right:0.191cm;"| This tutorial has been contributed by FOSSEE and Spoken Tutorial Project, IIT Bombay.
-This is Mayuri Panchakshari from IIT Bombay signing off.
+This is Usha from IIT Bombay signing off.
 Thanks for watching.
 |}