Character Device Driver from Scratch

spatlou

HEADER FILE>

RCS file: header.h,v
Working file: header.h
head: 1.6
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total revisions: 6;	selected revisions: 6
description:
This si the base header file
----------------------------
revision 1.6
date: 2014/11/16 08:56:59;  author: root;  state: Exp;  lines: +1 -0
Included moduleparam.h
for module_param() macro.
----------------------------
revision 1.5
date: 2014/11/16 08:11:22;  author: root;  state: Exp;  lines: +2 -0
Includec cdev.h and slab.h for struct cdev and kmalloc()
----------------------------
revision 1.4
date: 2014/11/16 07:54:24;  author: root;  state: Exp;  lines: +8 -0
Defined the macros for MINORNO and NOD.
----------------------------
revision 1.3
date: 2014/11/09 10:26:03;  author: root;  state: Exp;  lines: +8 -0
Defined the Macreos
MAJORNO and DEVNAME
----------------------------
revision 1.2
date: 2014/11/09 10:01:54;  author: root;  state: Exp;  lines: +1 -0
Included fs.h
----------------------------
revision 1.1
date: 2014/11/09 09:36:05;  author: root;  state: Exp;
Initial revision
=============================================================================

DECELERATIONS File

RCS file: declerations.h,v
Working file: declerations.h
head: 1.7
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total revisions: 7;	selected revisions: 7
description:
This file would contsin all the decleration for our driver.
----------------------------
revision 1.7
date: 2014/11/16 09:06:43;  author: root;  state: Exp;  lines: +1 -1
declared new_dev for using with multiple devices.
----------------------------
revision 1.6
date: 2014/11/16 08:44:44;  author: root;  state: Exp;  lines: +1 -1
defined struct file_operations
----------------------------
revision 1.5
date: 2014/11/16 08:12:09;  author: root;  state: Exp;  lines: +13 -0
Gave the decleration for struct ScullDev and struct ScullQset.
----------------------------
revision 1.4
date: 2014/11/16 07:55:39;  author: root;  state: Exp;  lines: +4 -2
declared variables minorno, nod, dev.
removed the decleration of struct file_operations
----------------------------
revision 1.3
date: 2014/11/09 10:26:54;  author: root;  state: Exp;  lines: +3 -0
gave the prototype for initialization().
----------------------------
revision 1.2
date: 2014/11/09 10:17:58;  author: root;  state: Exp;  lines: +1 -1
declared exters struct file_operations
----------------------------
revision 1.1
date: 2014/11/09 10:10:26;  author: root;  state: Exp;
Initial revision
=============================================================================

INITIALIZATION FILE

RCS file: init.c,v
Working file: init.c
head: 1.17
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total revisions: 17;	selected revisions: 17
description:
Initialization function.
----------------------------
revision 1.17
date: 2014/11/16 09:09:35;  author: root;  state: Exp;  lines: +2 -2
*** empty log message ***
----------------------------
revision 1.16
date: 2014/11/16 09:08:31;  author: root;  state: Exp;  lines: +1 -1
declared lv.
----------------------------
revision 1.15
date: 2014/11/16 09:07:07;  author: root;  state: Exp;  lines: +20 -15
Multiple devices.
registering, allocating, initializing and adding for all devices.
----------------------------
revision 1.14
date: 2014/11/16 08:58:47;  author: root;  state: Exp;  lines: +1 -0
Diaplaying nod.
----------------------------
revision 1.13
date: 2014/11/16 08:57:27;  author: root;  state: Exp;  lines: +4 -2
using macro module_param() for accepting module parameters.
accepting nod here.
----------------------------
revision 1.12
date: 2014/11/16 08:32:08;  author: root;  state: Exp;  lines: +6 -4
testing our driver using cdev.
fetching device id from cdev.
----------------------------
revision 1.11
date: 2014/11/16 08:25:40;  author: root;  state: Exp;  lines: +9 -0
initialized the device specific structure cdev.
also added it to the device table.
----------------------------
revision 1.10
date: 2014/11/16 08:13:07;  author: root;  state: Exp;  lines: +1 -0
defined ScullDev.
----------------------------
revision 1.9
date: 2014/11/16 08:11:39;  author: root;  state: Exp;  lines: +9 -2
Allocated space on the scull device for IO.
----------------------------
revision 1.8
date: 2014/11/16 07:54:46;  author: root;  state: Exp;  lines: +12 -4
registered the driver usig alloc_chrdev_region()
Fetched the majorno and minorno using macros MAJOR and MINOR respectively.
----------------------------
revision 1.7
date: 2014/11/09 10:27:38;  author: root;  state: Exp;  lines: +1 -0
*** empty log message ***
----------------------------
revision 1.6
date: 2014/11/09 10:26:21;  author: root;  state: Exp;  lines: +7 -3
Implemented initialization() that initializes all the variables to default values from Macros.
----------------------------
revision 1.5
date: 2014/11/09 10:17:46;  author: root;  state: Exp;  lines: +1 -2
Declared struct file_operations.
----------------------------
revision 1.4
date: 2014/11/09 10:09:05;  author: root;  state: Exp;  lines: +2 -1
*** empty log message ***
----------------------------
revision 1.3
date: 2014/11/09 10:03:49;  author: root;  state: Exp;  lines: +1 -0
Printing maojr no.
----------------------------
revision 1.2
date: 2014/11/09 10:02:06;  author: root;  state: Exp;  lines: +13 -0
Registering the driver with the kernel using register_chrdev().
Obtaining major no.
----------------------------
revision 1.1
date: 2014/11/09 09:36:05;  author: root;  state: Exp;
Initial revision
=============================================================================

spatlou

CLEANUP FILE

RCS file: cleanup.c,v
Working file: cleanup.c
head: 1.10
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total revisions: 10;	selected revisions: 10
description:
This is the cleanup function.
----------------------------
revision 1.10
date: 2014/11/16 09:08:56;  author: root;  state: Exp;  lines: +1 -1
*** empty log message ***
----------------------------
revision 1.9
date: 2014/11/16 09:07:33;  author: root;  state: Exp;  lines: +4 -2
using cdev_del() for deleting device mapping foe all devices.
----------------------------
revision 1.8
date: 2014/11/16 08:26:38;  author: root;  state: Exp;  lines: +1 -0
deleting the device definition from device table using cdev_del()
----------------------------
revision 1.7
date: 2014/11/16 08:11:53;  author: root;  state: Exp;  lines: +1 -0
freeing memory using kfree()
----------------------------
revision 1.6
date: 2014/11/16 07:55:24;  author: root;  state: Exp;  lines: +1 -1
Unregistered tghe driver using unregister_chrdev_region()
----------------------------
revision 1.5
date: 2014/11/09 10:26:51;  author: root;  state: Exp;  lines: +1 -1
*** empty log message ***
----------------------------
revision 1.4
date: 2014/11/09 10:11:58;  author: root;  state: Exp;  lines: +3 -1
*** empty log message ***
----------------------------
revision 1.3
date: 2014/11/09 10:11:06;  author: root;  state: Exp;  lines: +1 -0
Declered majorno.
----------------------------
revision 1.2
date: 2014/11/09 10:09:11;  author: root;  state: Exp;  lines: +1 -0
*** empty log message ***
----------------------------
revision 1.1
date: 2014/11/09 09:36:05;  author: root;  state: Exp;
Initial revision
=============================================================================

spatlou

RCS file: header.h,v
Working file: header.h
head: 1.11
branch:
locks: strict
access list:
symbolic names:
keyword substitution: kv
total revisions: 11;	selected revisions: 11
description:
This is the base header file for our Characrer driver.
All the headers and Mocros will be put here.
----------------------------
revision 1.11
date: 2015/02/07 05:04:59;  author: root;  state: Exp;  lines: +0 -13
*** empty log message ***
----------------------------
revision 1.10
date: 2015/02/05 09:08:58;  author: root;  state: Exp;  lines: +1 -0
Included uaccess.h
----------------------------
revision 1.9
date: 2015/02/02 08:03:04;  author: root;  state: Exp;  lines: +1 -0
included kernel.h
----------------------------
revision 1.8
date: 2015/01/29 08:35:52;  author: root;  state: Exp;  lines: +2 -2
*** empty log message ***
----------------------------
revision 1.7
date: 2015/01/29 08:33:59;  author: root;  state: Exp;  lines: +17 -0
Difuned macros
DEVIE_SIZE, DATA_SIZE, QSET_SIZE, QUANTUM_SIZE
----------------------------
revision 1.6
date: 2015/01/29 08:17:49;  author: root;  state: Exp;  lines: +1 -0
Included moduleparam.h
----------------------------
revision 1.5
date: 2015/01/29 07:54:59;  author: root;  state: Exp;  lines: +1 -0
Included cdev.h
----------------------------
revision 1.4
date: 2015/01/27 11:25:35;  author: root;  state: Exp;  lines: +1 -0
Included linux/slab.h for kmalloc() and kfree()
----------------------------
revision 1.3
date: 2015/01/27 10:57:07;  author: root;  state: Exp;  lines: +8 -0
Defined macros
MINORNO and NOD
----------------------------
revision 1.2
date: 2015/01/25 06:56:36;  author: root;  state: Exp;  lines: +9 -0
Included fs.h
Gave macros
MAJORNO, DEVNAME
----------------------------
revision 1.1
date: 2015/01/25 06:08:28;  author: root;  state: Exp;
Initial revision
=============================================================================

spatlou

RCS file: declerations.h,v
Working file: declerations.h
head: 1.11
branch:
locks: strict
access list:
symbolic names:
keyword substitution: kv
total revisions: 11;	selected revisions: 11
description:
This header file would contain all the declerations and function prototypes.
----------------------------
revision 1.11
date: 2015/02/07 04:50:37;  author: root;  state: Exp;  lines: +1 -0
Gave the prototype for dev_trim()
----------------------------
revision 1.10
date: 2015/02/01 07:59:25;  author: root;  state: Exp;  lines: +1 -0
gave prototype for dev_release()
----------------------------
revision 1.9
date: 2015/02/01 07:56:52;  author: root;  state: Exp;  lines: +1 -0
gave the prototype for dev_open()
----------------------------
revision 1.8
date: 2015/02/01 06:45:26;  author: root;  state: Exp;  lines: +1 -1
declared newdev
----------------------------
revision 1.7
date: 2015/01/31 05:10:12;  author: root;  state: Exp;  lines: +1 -0
Declared struct cdev inside struct Dev.
----------------------------
revision 1.6
date: 2015/01/31 04:44:06;  author: root;  state: Exp;  lines: +1 -1
*** empty log message ***
----------------------------
revision 1.5
date: 2015/01/31 04:40:37;  author: root;  state: Exp;  lines: +13 -1
gave the decleration for struct Dev and Struct Qset
Declared extern pointers for these.
----------------------------
revision 1.4
date: 2015/01/31 04:26:36;  author: root;  state: Exp;  lines: +2 -4
Declared variables minorno, nod.
Removed decleration for file_operations
----------------------------
revision 1.3
date: 2015/01/25 07:02:31;  author: root;  state: Exp;  lines: +2 -2
Removed the definition of struct file_operations.
----------------------------
revision 1.2
date: 2015/01/25 07:01:54;  author: root;  state: Exp;  lines: +1 -1
*** empty log message ***
----------------------------
revision 1.1
date: 2015/01/25 07:01:09;  author: root;  state: Exp;
Initial revision
=============================================================================

spatlou

RCS file: file_opr.h,v
Working file: file_opr.h
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total revisions: 0
description:
Containssystem call mappings to driver routines.
mapped open and release.
=============================================================================

spatlou

RCS file: init.c,v
Working file: init.c
head: 1.12
branch:
locks: strict
access list:
symbolic names:
keyword substitution: kv
total revisions: 12;	selected revisions: 12
description:
This is the Initialization function for the Character Driver.
This will initilaize, register the driver with the kernel and the kernel table.
This will also initializa the devices.
----------------------------
revision 1.12
date: 2015/02/01 07:01:40;  author: root;  state: Exp;  lines: +2 -2
Cross check for adding device attributes to device table.
by fetching device if from struct cdev.
----------------------------
revision 1.11
date: 2015/02/01 06:49:00;  author: root;  state: Exp;  lines: +4 -0
*** empty log message ***
----------------------------
revision 1.10
date: 2015/02/01 06:47:25;  author: root;  state: Exp;  lines: +2 -2
Declared the loop variable
----------------------------
revision 1.9
date: 2015/02/01 06:45:36;  author: root;  state: Exp;  lines: +20 -13
Initialized for nod number of devices.
nod value is accepted as module parameter using macro module_param()
----------------------------
revision 1.8
date: 2015/01/31 05:10:34;  author: root;  state: Exp;  lines: +13 -0
Initialized the device specific structure struct cdev using cdev_init()
mapped owner and ops fields.
add this to the device table using cdev_add().
----------------------------
revision 1.7
date: 2015/01/31 04:41:19;  author: root;  state: Exp;  lines: +19 -4
allocated space on the device according to struct Dev using kmalloc()
----------------------------
revision 1.6
date: 2015/01/31 04:27:01;  author: root;  state: Exp;  lines: +12 -5
Registering driver using alloc_chrdev_region()
----------------------------
revision 1.5
date: 2015/01/25 07:07:04;  author: root;  state: Exp;  lines: +3 -3
Printing major no.
----------------------------
revision 1.4
date: 2015/01/25 07:05:28;  author: root;  state: Exp;  lines: +1 -1
*** empty log message ***
----------------------------
revision 1.3
date: 2015/01/25 07:04:22;  author: root;  state: Exp;  lines: +1 -0
Declared fops.
----------------------------
revision 1.2
date: 2015/01/25 06:56:59;  author: root;  state: Exp;  lines: +29 -1
Trying to register the driver using register_chrdev()
and obtain the najor no.
----------------------------
revision 1.1
date: 2015/01/25 06:08:28;  author: root;  state: Exp;
Initial revision
=============================================================================

spatlou

RCS file: exit.c,v
Working file: exit.c
head: 1.8
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locks: strict
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total revisions: 8;	selected revisions: 8
description:
This is the cleanup function.
This will unregister and deinitialize our device
It will remove the driver from the kernel.
----------------------------
revision 1.8
date: 2015/02/01 06:46:06;  author: root;  state: Exp;  lines: +4 -1
deleting nod number of devices.
----------------------------
revision 1.7
date: 2015/01/31 05:11:22;  author: root;  state: Exp;  lines: +2 -1
remeve the device description from the device table.
using cdev_del()
----------------------------
revision 1.6
date: 2015/01/31 04:44:47;  author: root;  state: Exp;  lines: +1 -1
*** empty log message ***
----------------------------
revision 1.5
date: 2015/01/31 04:41:43;  author: root;  state: Exp;  lines: +1 -0
freed allocated space using kfree()
----------------------------
revision 1.4
date: 2015/01/31 04:27:14;  author: root;  state: Exp;  lines: +1 -1
Unregistering using unregister_chrdev_region()
----------------------------
revision 1.3
date: 2015/01/25 07:03:30;  author: root;  state: Exp;  lines: +1 -0
*** empty log message ***
----------------------------
revision 1.2
date: 2015/01/25 06:57:22;  author: root;  state: Exp;  lines: +2 -0
unregistering the driver using unregister_chrdev().
----------------------------
revision 1.1
date: 2015/01/25 06:08:28;  author: root;  state: Exp;
Initial revision
=============================================================================

spatlou

RCS file: dev_open.c,v
Working file: dev_open.c
head: 1.5
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total revisions: 5;	selected revisions: 5
description:
This is the driver routing for opening the device.
Just checking for the mappings right now.
----------------------------
revision 1.5
date: 2015/02/07 05:00:01;  author: root;  state: Exp;  lines: +10 -1
*** empty log message ***
----------------------------
revision 1.4
date: 2015/02/07 04:49:32;  author: root;  state: Exp;  lines: +37 -1
Checking , if the device is being opened in the wroteonly mode , then trimming it.
Implementing dev_trim()
----------------------------
revision 1.3
date: 2015/02/07 04:39:51;  author: root;  state: Exp;  lines: +1 -0
Included declerations.h
----------------------------
revision 1.2
date: 2015/02/07 04:38:48;  author: root;  state: Exp;  lines: +26 -1
Implementing open
----------------------------
revision 1.1
date: 2015/02/01 07:57:03;  author: root;  state: Exp;
Initial revision
=============================================================================

RCS file: dev_release.c,v
Working file: dev_release.c
head: 1.1
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total revisions: 1;	selected revisions: 1
description:
This is the driver routing for closing the device.
----------------------------
revision 1.1
date: 2015/02/01 08:01:22;  author: root;  state: Exp;
Initial revision
=============================================================================

spatlou

RCS file: header.h,v
Working file: header.h
head: 1.14
branch:
locks: strict
access list:
symbolic names:
keyword substitution: kv
total revisions: 14;	selected revisions: 14
description:
This is the base header file for our Characrer driver.
All the headers and Mocros will be put here.
----------------------------
revision 1.14
date: 2015/02/08 10:22:39;  author: root;  state: Exp;  lines: +1 -0
Included uaccess.h
----------------------------
revision 1.13
date: 2015/02/08 08:26:51;  author: root;  state: Exp;  lines: +6 -0
Defined Macros
QUANTUM_SIZE, QSET_SIZE
----------------------------
revision 1.12
date: 2015/02/08 07:21:51;  author: root;  state: Exp;  lines: +0 -3
Included string.h
----------------------------
revision 1.11
date: 2015/02/07 05:04:59;  author: root;  state: Exp;  lines: +0 -13
*** empty log message ***
----------------------------
revision 1.10
date: 2015/02/05 09:08:58;  author: root;  state: Exp;  lines: +1 -0
Included uaccess.h
----------------------------
revision 1.9
date: 2015/02/02 08:03:04;  author: root;  state: Exp;  lines: +1 -0
included kernel.h
----------------------------
revision 1.8
date: 2015/01/29 08:35:52;  author: root;  state: Exp;  lines: +2 -2
*** empty log message ***
----------------------------
revision 1.7
date: 2015/01/29 08:33:59;  author: root;  state: Exp;  lines: +17 -0
Difuned macros
DEVIE_SIZE, DATA_SIZE, QSET_SIZE, QUANTUM_SIZE
----------------------------
revision 1.6
date: 2015/01/29 08:17:49;  author: root;  state: Exp;  lines: +1 -0
Included moduleparam.h
----------------------------
revision 1.5
date: 2015/01/29 07:54:59;  author: root;  state: Exp;  lines: +1 -0
Included cdev.h
----------------------------
revision 1.4
date: 2015/01/27 11:25:35;  author: root;  state: Exp;  lines: +1 -0
Included linux/slab.h for kmalloc() and kfree()
----------------------------
revision 1.3
date: 2015/01/27 10:57:07;  author: root;  state: Exp;  lines: +8 -0
Defined macros
MINORNO and NOD
----------------------------
revision 1.2
date: 2015/01/25 06:56:36;  author: root;  state: Exp;  lines: +9 -0
Included fs.h
Gave macros
MAJORNO, DEVNAME
----------------------------
revision 1.1
date: 2015/01/25 06:08:28;  author: root;  state: Exp;
Initial revision
=============================================================================

spatlou

RCS file: declerations.h,v
Working file: declerations.h
head: 1.15
branch:
locks: strict
access list:
symbolic names:
keyword substitution: kv
total revisions: 15;	selected revisions: 15
description:
This header file would contain all the declerations and function prototypes.
----------------------------
revision 1.15
date: 2015/02/08 10:05:54;  author: root;  state: Exp;  lines: +1 -0
Gave the prototype for creat_quantums()
----------------------------
revision 1.14
date: 2015/02/08 09:48:14;  author: root;  state: Exp;  lines: +1 -0
Gave the prototype for creat_qste();
----------------------------
revision 1.13
date: 2015/02/08 08:28:52;  author: root;  state: Exp;  lines: +4 -0
gave the definition for quantum_size, qset_size.
----------------------------
revision 1.12
date: 2015/02/08 07:22:23;  author: root;  state: Exp;  lines: +1 -0
gave the prototype for write routine.
----------------------------
revision 1.11
date: 2015/02/07 04:50:37;  author: root;  state: Exp;  lines: +1 -0
Gave the prototype for dev_trim()
----------------------------
revision 1.10
date: 2015/02/01 07:59:25;  author: root;  state: Exp;  lines: +1 -0
gave prototype for dev_release()
----------------------------
revision 1.9
date: 2015/02/01 07:56:52;  author: root;  state: Exp;  lines: +1 -0
gave the prototype for dev_open()
----------------------------
revision 1.8
date: 2015/02/01 06:45:26;  author: root;  state: Exp;  lines: +1 -1
declared newdev
----------------------------
revision 1.7
date: 2015/01/31 05:10:12;  author: root;  state: Exp;  lines: +1 -0
Declared struct cdev inside struct Dev.
----------------------------
revision 1.6
date: 2015/01/31 04:44:06;  author: root;  state: Exp;  lines: +1 -1
*** empty log message ***
----------------------------
revision 1.5
date: 2015/01/31 04:40:37;  author: root;  state: Exp;  lines: +13 -1
gave the decleration for struct Dev and Struct Qset
Declared extern pointers for these.
----------------------------
revision 1.4
date: 2015/01/31 04:26:36;  author: root;  state: Exp;  lines: +2 -4
Declared variables minorno, nod.
Removed decleration for file_operations
----------------------------
revision 1.3
date: 2015/01/25 07:02:31;  author: root;  state: Exp;  lines: +2 -2
Removed the definition of struct file_operations.
----------------------------
revision 1.2
date: 2015/01/25 07:01:54;  author: root;  state: Exp;  lines: +1 -1
*** empty log message ***
----------------------------
revision 1.1
date: 2015/01/25 07:01:09;  author: root;  state: Exp;
Initial revision
=============================================================================

spatlou

RCS file: declerations.h,v
Working file: declerations.h
head: 1.15
branch:
locks: strict
access list:
symbolic names:
keyword substitution: kv
total revisions: 15;	selected revisions: 15
description:
This header file would contain all the declerations and function prototypes.
----------------------------
revision 1.15
date: 2015/02/08 10:05:54;  author: root;  state: Exp;  lines: +1 -0
Gave the prototype for creat_quantums()
----------------------------
revision 1.14
date: 2015/02/08 09:48:14;  author: root;  state: Exp;  lines: +1 -0
Gave the prototype for creat_qste();
----------------------------
revision 1.13
date: 2015/02/08 08:28:52;  author: root;  state: Exp;  lines: +4 -0
gave the definition for quantum_size, qset_size.
----------------------------
revision 1.12
date: 2015/02/08 07:22:23;  author: root;  state: Exp;  lines: +1 -0
gave the prototype for write routine.
----------------------------
revision 1.11
date: 2015/02/07 04:50:37;  author: root;  state: Exp;  lines: +1 -0
Gave the prototype for dev_trim()
----------------------------
revision 1.10
date: 2015/02/01 07:59:25;  author: root;  state: Exp;  lines: +1 -0
gave prototype for dev_release()
----------------------------
revision 1.9
date: 2015/02/01 07:56:52;  author: root;  state: Exp;  lines: +1 -0
gave the prototype for dev_open()
----------------------------
revision 1.8
date: 2015/02/01 06:45:26;  author: root;  state: Exp;  lines: +1 -1
declared newdev
----------------------------
revision 1.7
date: 2015/01/31 05:10:12;  author: root;  state: Exp;  lines: +1 -0
Declared struct cdev inside struct Dev.
----------------------------
revision 1.6
date: 2015/01/31 04:44:06;  author: root;  state: Exp;  lines: +1 -1
*** empty log message ***
----------------------------
revision 1.5
date: 2015/01/31 04:40:37;  author: root;  state: Exp;  lines: +13 -1
gave the decleration for struct Dev and Struct Qset
Declared extern pointers for these.
----------------------------
revision 1.4
date: 2015/01/31 04:26:36;  author: root;  state: Exp;  lines: +2 -4
Declared variables minorno, nod.
Removed decleration for file_operations
----------------------------
revision 1.3
date: 2015/01/25 07:02:31;  author: root;  state: Exp;  lines: +2 -2
Removed the definition of struct file_operations.
----------------------------
revision 1.2
date: 2015/01/25 07:01:54;  author: root;  state: Exp;  lines: +1 -1
*** empty log message ***
----------------------------
revision 1.1
date: 2015/01/25 07:01:09;  author: root;  state: Exp;
Initial revision
=============================================================================

RCS file: file_opr.h,v
Working file: file_opr.h
head:
branch:
locks: strict
access list:
symbolic names:
keyword substitution: kv
total revisions: 0
description:
Containssystem call mappings to driver routines.
mapped open and release.
=============================================================================

RCS file: init.c,v
Working file: init.c
head: 1.15
branch:
locks: strict
access list:
symbolic names:
keyword substitution: kv
total revisions: 15;	selected revisions: 15
description:
This is the Initialization function for the Character Driver.
This will initilaize, register the driver with the kernel and the kernel table.
This will also initializa the devices.
----------------------------
revision 1.15
date: 2015/02/08 08:29:50;  author: root;  state: Exp;  lines: +1 -1
*** empty log message ***
----------------------------
revision 1.14
date: 2015/02/08 08:29:11;  author: root;  state: Exp;  lines: +1 -0
Defined quantum_size, qset_size.
----------------------------
revision 1.13
date: 2015/02/08 08:27:25;  author: root;  state: Exp;  lines: +5 -1
INitialized quantum_size and Qset_size
----------------------------
revision 1.12
date: 2015/02/01 07:01:40;  author: root;  state: Exp;  lines: +2 -2
Cross check for adding device attributes to device table.
by fetching device if from struct cdev.
----------------------------
revision 1.11
date: 2015/02/01 06:49:00;  author: root;  state: Exp;  lines: +4 -0
*** empty log message ***
----------------------------
revision 1.10
date: 2015/02/01 06:47:25;  author: root;  state: Exp;  lines: +2 -2
Declared the loop variable
----------------------------
revision 1.9
date: 2015/02/01 06:45:36;  author: root;  state: Exp;  lines: +20 -13
Initialized for nod number of devices.
nod value is accepted as module parameter using macro module_param()
----------------------------
revision 1.8
date: 2015/01/31 05:10:34;  author: root;  state: Exp;  lines: +13 -0
Initialized the device specific structure struct cdev using cdev_init()
mapped owner and ops fields.
add this to the device table using cdev_add().
----------------------------
revision 1.7
date: 2015/01/31 04:41:19;  author: root;  state: Exp;  lines: +19 -4
allocated space on the device according to struct Dev using kmalloc()
----------------------------
revision 1.6
date: 2015/01/31 04:27:01;  author: root;  state: Exp;  lines: +12 -5
Registering driver using alloc_chrdev_region()
----------------------------
revision 1.5
date: 2015/01/25 07:07:04;  author: root;  state: Exp;  lines: +3 -3
Printing major no.
----------------------------
revision 1.4
date: 2015/01/25 07:05:28;  author: root;  state: Exp;  lines: +1 -1
*** empty log message ***
----------------------------
revision 1.3
date: 2015/01/25 07:04:22;  author: root;  state: Exp;  lines: +1 -0
Declared fops.
----------------------------
revision 1.2
date: 2015/01/25 06:56:59;  author: root;  state: Exp;  lines: +29 -1
Trying to register the driver using register_chrdev()
and obtain the najor no.
----------------------------
revision 1.1
date: 2015/01/25 06:08:28;  author: root;  state: Exp;
Initial revision
=============================================================================

spatlou

RCS file: exit.c,v
Working file: exit.c
head: 1.8
branch:
locks: strict
access list:
symbolic names:
keyword substitution: kv
total revisions: 8;	selected revisions: 8
description:
This is the cleanup function.
This will unregister and deinitialize our device
It will remove the driver from the kernel.
----------------------------
revision 1.8
date: 2015/02/01 06:46:06;  author: root;  state: Exp;  lines: +4 -1
deleting nod number of devices.
----------------------------
revision 1.7
date: 2015/01/31 05:11:22;  author: root;  state: Exp;  lines: +2 -1
remeve the device description from the device table.
using cdev_del()
----------------------------
revision 1.6
date: 2015/01/31 04:44:47;  author: root;  state: Exp;  lines: +1 -1
*** empty log message ***
----------------------------
revision 1.5
date: 2015/01/31 04:41:43;  author: root;  state: Exp;  lines: +1 -0
freed allocated space using kfree()
----------------------------
revision 1.4
date: 2015/01/31 04:27:14;  author: root;  state: Exp;  lines: +1 -1
Unregistering using unregister_chrdev_region()
----------------------------
revision 1.3
date: 2015/01/25 07:03:30;  author: root;  state: Exp;  lines: +1 -0
*** empty log message ***
----------------------------
revision 1.2
date: 2015/01/25 06:57:22;  author: root;  state: Exp;  lines: +2 -0
unregistering the driver using unregister_chrdev().
----------------------------
revision 1.1
date: 2015/01/25 06:08:28;  author: root;  state: Exp;
Initial revision
=============================================================================

RCS file: dev_open.c,v
Working file: dev_open.c
head: 1.5
branch:
locks: strict
access list:
symbolic names:
keyword substitution: kv
total revisions: 5;	selected revisions: 5
description:
This is the driver routing for opening the device.
Just checking for the mappings right now.
----------------------------
revision 1.5
date: 2015/02/07 05:00:01;  author: root;  state: Exp;  lines: +10 -1
*** empty log message ***
----------------------------
revision 1.4
date: 2015/02/07 04:49:32;  author: root;  state: Exp;  lines: +37 -1
Checking , if the device is being opened in the wroteonly mode , then trimming it.
Implementing dev_trim()
----------------------------
revision 1.3
date: 2015/02/07 04:39:51;  author: root;  state: Exp;  lines: +1 -0
Included declerations.h
----------------------------
revision 1.2
date: 2015/02/07 04:38:48;  author: root;  state: Exp;  lines: +26 -1
Implementing open
----------------------------
revision 1.1
date: 2015/02/01 07:57:03;  author: root;  state: Exp;
Initial revision
=============================================================================

RCS file: dev_release.c,v
Working file: dev_release.c
head: 1.1
branch:
locks: strict
access list:
symbolic names:
keyword substitution: kv
total revisions: 1;	selected revisions: 1
description:
This is the driver routing for closing the device.
----------------------------
revision 1.1
date: 2015/02/01 08:01:22;  author: root;  state: Exp;
Initial revision
=============================================================================

spatlou

RCS file: dev_write.c,v
Working file: dev_write.c
head: 1.14
branch:
locks: strict
access list:
symbolic names:
keyword substitution: kv
total revisions: 14;	selected revisions: 14
description:
Implementing this driver routine for the purpose of writing.
Just checking mappings for now.
----------------------------
revision 1.14
date: 2015/02/08 10:23:59;  author: root;  state: Exp;  lines: +3 -0
*** empty log message ***
----------------------------
revision 1.13
date: 2015/02/08 10:21:57;  author: root;  state: Exp;  lines: +7 -1
Created quantums.
Implemented writing in 1 quantum
----------------------------
revision 1.12
date: 2015/02/08 10:06:04;  author: root;  state: Exp;  lines: +51 -1
*** empty log message ***
----------------------------
revision 1.11
date: 2015/02/08 09:49:44;  author: root;  state: Exp;  lines: +1 -1
*** empty log message ***
----------------------------
revision 1.10
date: 2015/02/08 09:49:20;  author: root;  state: Exp;  lines: +1 -0
*** empty log message ***
----------------------------
revision 1.9
date: 2015/02/08 09:48:27;  author: root;  state: Exp;  lines: +38 -1
Created Qset arrays.
----------------------------
revision 1.8
date: 2015/02/08 08:46:09;  author: root;  state: Exp;  lines: +1 -1
*** empty log message ***
----------------------------
revision 1.7
date: 2015/02/08 08:45:36;  author: root;  state: Exp;  lines: +1 -1
*** empty log message ***
----------------------------
revision 1.6
date: 2015/02/08 08:44:18;  author: root;  state: Exp;  lines: +16 -10
*** empty log message ***
----------------------------
revision 1.5
date: 2015/02/08 08:33:08;  author: root;  state: Exp;  lines: +7 -0
*** empty log message ***
----------------------------
revision 1.4
date: 2015/02/08 08:31:09;  author: root;  state: Exp;  lines: +6 -1
*** empty log message ***
----------------------------
revision 1.3
date: 2015/02/08 08:27:42;  author: root;  state: Exp;  lines: +53 -0
*** empty log message ***
----------------------------
revision 1.2
date: 2015/02/08 07:23:34;  author: root;  state: Exp;  lines: +0 -2
*** empty log message ***
----------------------------
revision 1.1
date: 2015/02/08 07:22:50;  author: root;  state: Exp;
Initial revision
=============================================================================

RCS file: writer.c,v
Working file: writer.c
head: 1.4
branch:
locks: strict
access list:
symbolic names:
keyword substitution: kv
total revisions: 4;	selected revisions: 4
description:
This is an application for testing our driver.
This application will open the device for writing..
----------------------------
revision 1.4
date: 2015/02/08 07:24:48;  author: root;  state: Exp;  lines: +1 -1
Declared count.
----------------------------
revision 1.3
date: 2015/02/08 07:22:36;  author: root;  state: Exp;  lines: +7 -2
Application is now writing into the device.
----------------------------
revision 1.2
date: 2015/02/01 07:27:01;  author: root;  state: Exp;  lines: +1 -0
Included fcntl.h
----------------------------
revision 1.1
date: 2015/02/01 07:26:00;  author: root;  state: Exp;
Initial revision
=============================================================================

spatlou

RCS file: header.h,v
Working file: header.h
head: 1.2
branch:
locks: strict
	root: 1.2
access list:
symbolic names:
keyword substitution: kv
total revisions: 2;	selected revisions: 2
description:
Base header for the driver.
Included init.h and module.h
Described module license.
----------------------------
revision 1.2	locked by: root;
date: 2015/06/06 11:44:14;  author: root;  state: Exp;  lines: +1 -0
included fs.h
----------------------------
revision 1.1
date: 2015/06/06 11:05:10;  author: root;  state: Exp;
Initial revision
=============================================================================

RCS file: declerations.h,v
Working file: declerations.h
head: 1.2
branch:
locks: strict
	root: 1.2
access list:
symbolic names:
keyword substitution: kv
total revisions: 2;	selected revisions: 2
description:
This header file contains all the declerations
----------------------------
revision 1.2	locked by: root;
date: 2015/06/06 11:57:45;  author: root;  state: Exp;  lines: +1 -1
devlared dev
----------------------------
revision 1.1
date: 2015/06/06 11:44:29;  author: root;  state: Exp;
Initial revision
=============================================================================

RCS file: init.c,v
Working file: init.c
head: 1.3
branch:
locks: strict
	root: 1.3
access list:
symbolic names:
keyword substitution: kv
total revisions: 3;	selected revisions: 3
description:
Just Inserted module
----------------------------
revision 1.3	locked by: root;
date: 2015/06/06 11:57:53;  author: root;  state: Exp;  lines: +6 -6
registering the driver using alloc_chrdev_region()
----------------------------
revision 1.2
date: 2015/06/06 11:44:29;  author: root;  state: Exp;  lines: +12 -0
registered the driver using register_chrdev()
\.
----------------------------
revision 1.1
date: 2015/06/06 11:05:10;  author: root;  state: Exp;
Initial revision
=============================================================================

RCS file: cleanup.c,v
Working file: cleanup.c
head: 1.3
branch:
locks: strict
	root: 1.3
access list:
symbolic names:
keyword substitution: kv
total revisions: 3;	selected revisions: 3
description:
Just identifying the cleanup function
----------------------------
revision 1.3	locked by: root;
date: 2015/06/06 11:58:08;  author: root;  state: Exp;  lines: +1 -1
unregister using unregister_chrdev_region()
----------------------------
revision 1.2
date: 2015/06/06 11:44:43;  author: root;  state: Exp;  lines: +2 -0
unregister_chrdev()
----------------------------
revision 1.1
date: 2015/06/06 11:05:10;  author: root;  state: Exp;
Initial revision
=============================================================================

spatlou

RCS file: header.h,v
Working file: header.h
head: 1.5
branch:
locks: strict
	root: 1.5
access list:
symbolic names:
keyword substitution: kv
total revisions: 5;	selected revisions: 5
description:
This is the base header file.
Included init.h, module.h and
declared Licence.
----------------------------
revision 1.5	locked by: root;
date: 2015/09/12 05:32:28;  author: root;  state: Exp;  lines: +1 -0
Included slab.h
----------------------------
revision 1.4
date: 2015/09/12 05:04:30;  author: root;  state: Exp;  lines: +12 -0
Declared macros
MINORNO
NOD
----------------------------
revision 1.3
date: 2015/09/12 04:44:43;  author: root;  state: Exp;  lines: +1 -0
Included fs.h
----------------------------
revision 1.2
date: 2015/09/12 04:43:07;  author: root;  state: Exp;  lines: +9 -0
Declared macros DEVNAME and MAJORNO
----------------------------
revision 1.1
date: 2015/09/05 05:32:58;  author: root;  state: Exp;
Initial revision
=============================================================================

spatlou

RCS file: operations.h,v
Working file: operations.h
head: 1.1
branch:
locks: strict
	root: 1.1
access list:
symbolic names:
keyword substitution: kv
total revisions: 1;	selected revisions: 1
description:
Declared file operations
----------------------------
revision 1.1	locked by: root;
date: 2015/09/12 04:43:21;  author: root;  state: Exp;
Initial revision
=============================================================================

RCS file: declerations.h,v
Working file: declerations.h
head: 1.3
branch:
locks: strict
	root: 1.3
access list:
symbolic names:
keyword substitution: kv
total revisions: 3;	selected revisions: 3
description:
This header file would contain all declerations and prototypes
----------------------------
revision 1.3	locked by: root;
date: 2015/09/12 05:32:01;  author: root;  state: Exp;  lines: +11 -0
Defined and declared the device structure Dev
----------------------------
revision 1.2
date: 2015/09/12 05:04:16;  author: root;  state: Exp;  lines: +2 -1
Declared minorno and nod.
----------------------------
revision 1.1
date: 2015/09/12 04:42:40;  author: root;  state: Exp;
Initial revision
=============================================================================

spatlou

RCS file: init.c,v
Working file: init.c
head: 1.10
branch:
locks: strict
	root: 1.10
access list:
symbolic names:
keyword substitution: kv
total revisions: 10;	selected revisions: 10
description:
Initialization Function.
Checking for mapping.
Saying Hello to kernel.
----------------------------
revision 1.10	locked by: root;
date: 2015/09/12 05:32:56;  author: root;  state: Exp;  lines: +12 -1
allocating memory for device using kmalloc()
----------------------------
revision 1.9
date: 2015/09/12 05:17:50;  author: root;  state: Exp;  lines: +2 -0
Accepting module parameters using module_param()
----------------------------
revision 1.8
date: 2015/09/12 05:11:12;  author: root;  state: Exp;  lines: +1 -0
*** empty log message ***
----------------------------
revision 1.7
date: 2015/09/12 05:10:46;  author: root;  state: Exp;  lines: +1 -1
*** empty log message ***
----------------------------
revision 1.6
date: 2015/09/12 05:09:58;  author: root;  state: Exp;  lines: +3 -0
Printing major and minor numbers.
----------------------------
revision 1.5
date: 2015/09/12 05:04:58;  author: root;  state: Exp;  lines: +13 -3
Registering the driver using alloc_chrdev_region()
----------------------------
revision 1.4
date: 2015/09/12 04:45:42;  author: root;  state: Exp;  lines: +1 -0
Included declerations.h
----------------------------
revision 1.3
date: 2015/09/12 04:43:45;  author: root;  state: Exp;  lines: +11 -1
Registering the driver using register_chrdev()
----------------------------
revision 1.2
date: 2015/09/05 05:35:19;  author: root;  state: Exp;  lines: +1 -1
*** empty log message ***
----------------------------
revision 1.1
date: 2015/09/05 05:32:58;  author: root;  state: Exp;
Initial revision
=============================================================================

RCS file: clean.c,v
Working file: clean.c
head: 1.7
branch:
locks: strict
	root: 1.7
access list:
symbolic names:
keyword substitution: kv
total revisions: 7;	selected revisions: 7
description:
This is the cleanup function.
Checking for mapping.
----------------------------
revision 1.7	locked by: root;
date: 2015/09/12 05:32:35;  author: root;  state: Exp;  lines: +1 -0
freeing the space using kfree()
----------------------------
revision 1.6
date: 2015/09/12 05:06:13;  author: root;  state: Exp;  lines: +1 -0
*** empty log message ***
----------------------------
revision 1.5
date: 2015/09/12 05:05:50;  author: root;  state: Exp;  lines: +1 -1
*** empty log message ***
----------------------------
revision 1.4
date: 2015/09/12 05:04:40;  author: root;  state: Exp;  lines: +3 -2
unregistering the driver using unregister_chrdev_region()
----------------------------
revision 1.3
date: 2015/09/12 04:46:35;  author: root;  state: Exp;  lines: +1 -0
Included declerations.h
----------------------------
revision 1.2
date: 2015/09/12 04:43:30;  author: root;  state: Exp;  lines: +1 -0
Unregistering the driver using unregister_chrdev()
----------------------------
revision 1.1
date: 2015/09/05 05:32:58;  author: root;  state: Exp;
Initial revision
=============================================================================

spatlou

RCS file: header.h,v
Working file: header.h
head: 1.7
branch:
locks: strict
   root: 1.7
access list:
symbolic names:
keyword substitution: kv
total revisions: 7;   selected revisions: 7
description:
This is the header file for Character Device Driver.
Included init.h and module.h
----------------------------
revision 1.7   locked by: root;
date: 2015/11/26 10:50:20; author: root; state: Exp; lines: +4 -0
Defined Macro DEBUG for controlling the debug and printk statements.
----------------------------
revision 1.6
date: 2015/11/26 10:45:38; author: root; state: Exp; lines: +1 -0
Included slab.h for kmalloc()
----------------------------
revision 1.5
date: 2015/11/26 10:30:08; author: root; state: Exp; lines: +14 -0
Defined macros for MAJORNO, MINORNO, NOD.
----------------------------
revision 1.4
date: 2015/11/20 11:10:36; author: root; state: Exp; lines: +1 -0
Included fs.h
----------------------------
revision 1.3
date: 2015/11/20 11:09:11; author: root; state: Exp; lines: +4 -0
Defined a macro for DEVNAME
----------------------------
revision 1.2
date: 2015/11/20 11:01:47; author: root; state: Exp; lines: +2 -0
Introduced License.
----------------------------
revision 1.1
date: 2015/11/20 10:04:12; author: root; state: Exp;
Initial revision
=============================================================================

RCS file: declerations.h,v
Working file: declerations.h
head: 1.3
branch:
locks: strict
   root: 1.3
access list:
symbolic names:
keyword substitution: kv
total revisions: 3;   selected revisions: 3
description:
Defined majorno
----------------------------
revision 1.3   locked by: root;
date: 2015/11/26 10:43:47; author: root; state: Exp; lines: +11 -0
Defined the device epresentation structure struct Dev
Defined struct Qset as well.
Defined a pointer to struct Dev.
----------------------------
revision 1.2
date: 2015/11/26 10:29:34; author: root; state: Exp; lines: +2 -1
defined minorno, nod devid.
----------------------------
revision 1.1
date: 2015/11/20 11:08:42; author: root; state: Exp;
Initial revision
=============================================================================

spatlou

RCS file: init.c,v
Working file: init.c
head: 1.8
branch:
locks: strict
   root: 1.8
access list:
symbolic names:
keyword substitution: kv
total revisions: 8;   selected revisions: 8
description:
This si the initialization function for the driver.
Just Given printk()
----------------------------
revision 1.8   locked by: root;
date: 2015/11/26 10:50:41; author: root; state: Exp; lines: +9 -0
Using the DEBUG macro for printk()
----------------------------
revision 1.7
date: 2015/11/26 10:47:07; author: root; state: Exp; lines: +1 -1
Included declerations.h and removed file_opr.h
----------------------------
revision 1.6
date: 2015/11/26 10:46:19; author: root; state: Exp; lines: +1 -1
*** empty log message ***
----------------------------
revision 1.5
date: 2015/11/26 10:44:59; author: root; state: Exp; lines: +7 -0
Allocating the space for SCULL using kmalloc()
----------------------------
revision 1.4
date: 2015/11/26 10:35:17; author: root; state: Exp; lines: +4 -1
Ectracting the major and minor numbers from the dev_t type variable using MAJOR and MINOR macros.
Printing the major and minor numbers.
----------------------------
revision 1.3
date: 2015/11/26 10:31:09; author: root; state: Exp; lines: +15 -3
Registering the driver using alloc_chrdev_region().
----------------------------
revision 1.2
date: 2015/11/20 11:09:40; author: root; state: Exp; lines: +4 -0
Registering driver using register_chrdev()
----------------------------
revision 1.1
date: 2015/11/20 10:05:00; author: root; state: Exp;
Initial revision
=============================================================================

spatlou

RCS file: clean.c,v
Working file: clean.c
head: 1.5
branch:
locks: strict
   root: 1.5
access list:
symbolic names:
keyword substitution: kv
total revisions: 5;   selected revisions: 5
description:
This is the cleanup file for Driver.
Just given Printk()
----------------------------
revision 1.5   locked by: root;
date: 2015/11/26 10:44:44; author: root; state: Exp; lines: +1 -0
deallocating the momory using kfree()
----------------------------
revision 1.4
date: 2015/11/26 10:30:53; author: root; state: Exp; lines: +1 -1
Unregistering the driver using unregister_chrdev_region()
----------------------------
revision 1.3
date: 2015/11/20 11:11:03; author: root; state: Exp; lines: +1 -1
*** empty log message ***
----------------------------
revision 1.2
date: 2015/11/20 11:09:26; author: root; state: Exp; lines: +2 -0
unregistering the driver using unregister_chrdev()
----------------------------
revision 1.1
date: 2015/11/20 10:04:39; author: root; state: Exp;
Initial revision
=============================================================================

ra9501576600

Can someone please explain Character driver theoratically in detail.....

ra9501576600

What steps are performed by OS, when we insert a device driver into kernel ?

spatlou

url for Downloading kernel

https://mirrors.edge.kernel.org/pub/linux/kernel/v4.x/

spatlou

Impoetant files at /lib/modules/4.13.12/build

Makefile

Kbuild

Kconfig

vmlinux

spatlou

http://www.emblogic.com/members/document_view/1258

Please use this url for kernel compilation

spatlou

@page { margin: 0.79in }
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p { margin-bottom: 0.1in; line-height: 120% }

RCS file: declerations.h,v
Working file: declerations.h
head: 1.1
branch:
locks: strict
	root: 1.1
access list:
symbolic names:
keyword substitution: kv
total revisions: 1;	selected revisions: 1
description:
declared constants 
MINORNO, NOD and DEVNAME . these will be used as default values.
declared extern devid for identifying device driver and device
declared minorno and nod . for internal bookkeeping by the driver.
----------------------------
revision 1.1	locked by: root;
date: 2019/10/05 09:20:12;  author: root;  state: Exp;
Initial revision
=============================================================================

spatlou

@page { margin: 0.79in }
pre.cjk { font-family: "DejaVu Sans Mono", monospace }
p { margin-bottom: 0.1in; line-height: 120% }

RCS file: headers.h,v
Working file: headers.h
head: 1.2
branch:
locks: strict
	root: 1.2
access list:
symbolic names:
keyword substitution: kv
total revisions: 2;	selected revisions: 2
description:
included linux/init.h and linux/modules.h for printk()
----------------------------
revision 1.2	locked by: root;
date: 2019/10/05 09:25:33;  author: root;  state: Exp;  lines: +2 -1
Included fs.h for alloc......
----------------------------
revision 1.1
date: 2019/10/05 07:06:04;  author: root;  state: Exp;
Initial revision
=============================================================================

spatlou

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RCS file: cleanup.c,v
Working file: cleanup.c
head: 1.1
branch:
locks: strict
	root: 1.1
access list:
symbolic names:
keyword substitution: kv
total revisions: 1;	selected revisions: 1
description:
static void __exit cleanup(void)
return type is static void as there is no one to capture drivers exit code after the driver would be pulled out
__exit
1: Identifies this as cleaup function
2: it could not be invoked from within the driver
3: it runs once in the lifetime of device
4: releases all resources used immediately
....
module_exit(cleanup);
module_exit() is a macro that will run upon driver exit.
it will be invoked when rmmod command will be given
ITs argument id a function called cleanup #:wq
----------------------------
revision 1.1	locked by: root;
date: 2019/10/05 09:21:54;  author: root;  state: Exp;
Initial revision
=============================================================================

spatlou

@page { margin: 0.79in }
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p { margin-bottom: 0.1in; line-height: 120% }

RCS file: initFunc.c,v
Working file: initFunc.c
head: 1.6
branch:
locks: strict
	root: 1.6
access list:
symbolic names:
keyword substitution: kv
total revisions: 6;	selected revisions: 6
description:
static: scope is local
returns int
// __init: 
// 1 - this is the initialization function
// 2 - it could not be invoked from within the kernel
// 3 - it will run only once in the lifeting of the device
// 4 - it will release all resources including memory when it will finish
----------------------------
revision 1.6	locked by: root;
date: 2019/10/05 09:21:54;  author: root;  state: Exp;  lines: +13 -7
Registered driver using alloc_chrdev_region()
declared devid and nod as globals.
assigned these vars from conctants. This needs to be done as these values will keep changing but we need to mantain the default values also for reset operastions.
Must check the return value from alloc..... and report error if needed.
----------------------------
revision 1.5
date: 2019/10/05 09:00:23;  author: root;  state: Exp;  lines: +9 -1
Trying to register device usinf alloc_chrdev_region()
----------------------------
revision 1.4
date: 2019/10/05 08:52:56;  author: root;  state: Exp;  lines: +5 -4
We need to do device driver registration into the kernel devic table
----------------------------
revision 1.3
date: 2019/10/05 06:45:08;  author: root;  state: Exp;  lines: +3 -5
module_init(initFunc);//is a macro, it is entry point for the driver.
//The argument to module_init() is the initialization function
//When the driver is inserted into kernel, This is always the first function to run
----------------------------
revision 1.2
date: 2019/10/05 06:40:41;  author: root;  state: Exp;  lines: +4 -8
// Symbol Table:
// exported symbols which work as globals in the kernel
// one of the symbol placed ion the symbol table is printk()
----------------------------
revision 1.1
date: 2019/10/05 06:37:43;  author: root;  state: Exp;
Initial revision
=============================================================================

spatlou

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p { margin-bottom: 0.1in; line-height: 120% }

#! /bin/bash

for file in $(ls *.h) $(ls *.c)
do
	ci $file
done
for file in $(ls *.h,v) $(ls *.c,v)
do
	co $file
done

removecdd()
{
	read -n1 -p "Do you want to remove driver(y/n)?" resp
	if [ $resp = 'y' ]
	then
		rmmod mycdd
		lsmod
		read
		dmesg
		read
	fi
}
insertcdd()
{
	read -n1 -p "Do you want to insert driver(y/n)?" resp
	if [ $resp = 'y' ]
	then
		insmod ./modules/mycdd.ko
		lsmod
		read
		dmesg
		read
	fi
}

echo
read -n1 -p "Do you want to build driver(y/n)?" resp
if [ $resp = 'y' ]
then
	if ( make )
	then
		insertcdd
		removecdd
	else
		echo "make Failed."
		read
	fi
else
	echo "Fine Chill"
fi

read -n1 -p "Do you want to edit driver further(y/n)?" resp
if [ $resp = 'y' ]
then
	for file in $(ls *.h,v) $(ls *.c,v)
	do
		co -l $file
	done
fi

spatlou

insertcdd()
{
	read -n1 -p "Do you want to insert driver(y/n)?" resp
	if [ $resp = 'y' ]
	then
		insmod ./modules/mycdd.ko
		lsmod
		read
		dmesg
		read

		cat /proc/devices

	fi
}

spatlou

@page { margin: 0.79in }
pre.cjk { font-family: "DejaVu Sans Mono", monospace }
p { margin-bottom: 0.1in; line-height: 120% }

RCS file: ./initFunc.c,v
Working file: ./initFunc.c
head: 1.8
branch:
locks: strict
	root: 1.8
access list:
symbolic names:
keyword substitution: kv
total revisions: 8;	selected revisions: 8
description:
static: scope is local
returns int
// __init: 
// 1 - this is the initialization function
// 2 - it could not be invoked from within the kernel
// 3 - it will run only once in the lifeting of the device
// 4 - it will release all resources including memory when it will finish
----------------------------
revision 1.8	locked by: root;
date: 2019/10/05 11:03:12;  author: root;  state: Exp;  lines: +7 -7
declared global pointer for Dev
allocated space for Dev using kmalloc()
Checked for arrors
----------------------------
revision 1.7
date: 2019/10/05 10:44:15;  author: root;  state: Exp;  lines: +9 -0
//Allocate some space for our simulated device in kernel space
//      static __always_inline void *kmalloc(
//              size_t size,: no of bytes to allocate 
//              gfp_t flags): this is an enforcing flag.
//              ensures that the memory be allocated in kernel space 
//              and in page alogned
----------------------------
revision 1.6
date: 2019/10/05 09:21:54;  author: root;  state: Exp;  lines: +13 -7
Registered driver using alloc_chrdev_region()
declared devid and nod as globals.
assigned these vars from conctants. This needs to be done as these values will keep changing but we need to mantain the default values also for reset operastions.
Must check the return value from alloc..... and report error if needed.
----------------------------
revision 1.5
date: 2019/10/05 09:00:23;  author: root;  state: Exp;  lines: +9 -1
Trying to register device usinf alloc_chrdev_region()
----------------------------
revision 1.4
date: 2019/10/05 08:52:56;  author: root;  state: Exp;  lines: +5 -4
We need to do device driver registration into the kernel devic table
----------------------------
revision 1.3
date: 2019/10/05 06:45:08;  author: root;  state: Exp;  lines: +3 -5
module_init(initFunc);//is a macro, it is entry point for the driver.
//The argument to module_init() is the initialization function
//When the driver is inserted into kernel, This is always the first function to run
----------------------------
revision 1.2
date: 2019/10/05 06:40:41;  author: root;  state: Exp;  lines: +4 -8
// Symbol Table:
// exported symbols which work as globals in the kernel
// one of the symbol placed ion the symbol table is printk()
----------------------------
revision 1.1
date: 2019/10/05 06:37:43;  author: root;  state: Exp;
Initial revision
=============================================================================

spatlou

The kernel headers for device drivers development are found at this path

/usr/src/kernels/linux-4.13.12/include/linux

nikeshkumarvedik

when i insert module insmod module_name it give segmentation fault. After when i tried to remove module it error "rmmod: ERROR: Module cdd132 is in use"

inserting a module error

[root@localhost modules]# insmod cdd132.ko

Segmentation fault

[root@localhost modules]#

removing module error

[root@localhost modules]# rmmod cdd132

rmmod: ERROR: Module cdd132 is in use

[root@localhost modules]#

dhananjay.patel

My device driver is working proper. But i am facing a warning message while compiling the driver

Please See:

make[1]: Entering directory '/usr/src/kernels/linux-5.5.10'

CC [M] /home/fedora/Desktop/Driver_File/10.writemap/init.o

CC [M] /home/fedora/Desktop/Driver_File/10.writemap/clean.o

CC [M] /home/fedora/Desktop/Driver_File/10.writemap/opendev.o

In file included from ./include/linux/printk.h:7,

from ./include/linux/kernel.h:15,

from ./include/linux/list.h:9,

from ./include/linux/module.h:12,

from /home/fedora/Desktop/Driver_File/10.writemap/headers.h:2,

from /home/fedora/Desktop/Driver_File/10.writemap/opendev.c:1:

/home/fedora/Desktop/Driver_File/10.writemap/opendev.c: In function ‘openDev’:

./include/linux/kern_levels.h:5:18: warning: too many arguments for format [-Wformat-extra-args]

5 | #define KERN_SOH "\001" /* ASCII Start Of Header */

| ^~~~~~

./include/linux/kern_levels.h:14:19: note: in expansion of macro ‘KERN_SOH’

14 | #define KERN_INFO KERN_SOH "6" /* informational */

| ^~~~~~~~

/home/fedora/Desktop/Driver_File/10.writemap/opendev.c:11:10: note: in expansion of macro ‘KERN_INFO’

11 | printk(KERN_INFO "ERROR : container_of() failure\n",__func__);

| ^~~~~~~~~

./include/linux/kern_levels.h:5:18: warning: too many arguments for format [-Wformat-extra-args]

5 | #define KERN_SOH "\001" /* ASCII Start Of Header */

| ^~~~~~

./include/linux/kern_levels.h:14:19: note: in expansion of macro ‘KERN_SOH’

14 | #define KERN_INFO KERN_SOH "6" /* informational */

| ^~~~~~~~

/home/fedora/Desktop/Driver_File/10.writemap/opendev.c:19:11: note: in expansion of macro ‘KERN_INFO’

19 | printk(KERN_INFO "ERROR : trimDev() failure\n",__func__);

| ^~~~~~~~~

CC [M] /home/fedora/Desktop/Driver_File/10.writemap/releasedev.o

CC [M] /home/fedora/Desktop/Driver_File/10.writemap/trimdev.o

CC [M] /home/fedora/Desktop/Driver_File/10.writemap/writedev.o

LD [M] /home/fedora/Desktop/Driver_File/10.writemap/cdd131.o

Building modules, stage 2.

MODPOST 1 modules

spatlou

headers.h

MODULE_LICENSE("GPL");

MODULE_AUTHOR("Ramans");

declerations.h

#define DDNAME

extern dev_t devid;

extern unsigned int majorNo, minorNo, nod;

init.h

// extern int alloc_chrdev_region(dev_t *, unsigned, unsigned, const char *);

clean.c

// extern void unregister_chrdev_region(dev_t, unsigned);

nikeshkumarvedik

Facing error while compiling

[root@localhost file_operation]# make

make -C /lib/modules/5.2.17-200.fc30.x86_64/build M=/home/nikesh/device_driver/file_operation modules

make[1]: Entering directory '/usr/src/kernels/5.2.17-200.fc30.x86_64'

CC [M] /home/nikesh/device_driver/file_operation/init.o

CC [M] /home/nikesh/device_driver/file_operation/exit.o

CC [M] /home/nikesh/device_driver/file_operation/deviceOpen.o

In file included from ./include/linux/init.h:5,

from /home/nikesh/device_driver/file_operation/headers.h:1,

from /home/nikesh/device_driver/file_operation/deviceOpen.c:1:

/home/nikesh/device_driver/file_operation/deviceOpen.c: In function ‘deviceOpen’:

./include/linux/compiler.h:345:38: error: call to ‘__compiletime_assert_16’ declared with attribute error: pointer type mismatch in container_of()

345 | _compiletime_assert(condition, msg, __compiletime_assert_, __LINE__)

| ^

./include/linux/compiler.h:326:4: note: in definition of macro ‘__compiletime_assert’

326 | prefix ## suffix(); \

| ^~~~~~

./include/linux/compiler.h:345:2: note: in expansion of macro ‘_compiletime_assert’

345 | _compiletime_assert(condition, msg, __compiletime_assert_, __LINE__)

| ^~~~~~~~~~~~~~~~~~~

./include/linux/build_bug.h:39:37: note: in expansion of macro ‘compiletime_assert’

39 | #define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)

| ^~~~~~~~~~~~~~~~~~

./include/linux/kernel.h:988:2: note: in expansion of macro ‘BUILD_BUG_ON_MSG’

988 | BUILD_BUG_ON_MSG(!__same_type(*(ptr), ((type *)0)->member) && \

| ^~~~~~~~~~~~~~~~

/home/nikesh/device_driver/file_operation/deviceOpen.c:16:9: note: in expansion of macro ‘container_of’

16 | ldev = container_of(finode->i_cdev, Dev, c_dev);

| ^~~~~~~~~~~~

make[2]: *** [scripts/Makefile.build:279: /home/nikesh/device_driver/file_operation/deviceOpen.o] Error 1

make[1]: *** [Makefile:1601: _module_/home/nikesh/device_driver/file_operation] Error 2

make[1]: Leaving directory '/usr/src/kernels/5.2.17-200.fc30.x86_64'

make: *** [Makefile:12: default] Error 2

spatlou

The bug seems to be here:

16 | ldev = container_of(finode->i_cdev, Dev, c_dev);

Dev is what?

either you should use struct Dev or typedef struct to Dev

torshadas20494

Error:

make -C /lib/modules/5.4.5-300.fc31.x86_64/build M=/home/torshadas/Documents/Torsha/Device_Driver/01CDD modules

make[1]: Entering directory '/usr/src/kernels/5.4.5-300.fc31.x86_64'

Building modules, stage 2.

MODPOST 1 modules

ERROR: "myModule" [/home/torshadas/Documents/Torsha/Device_Driver/01CDD/cddMyTest.ko] undefined!

make[2]: *** [scripts/Makefile.modpost:94: __modpost] Error 1

make[1]: *** [Makefile:1609: modules] Error 2

make[1]: Leaving directory '/usr/src/kernels/5.4.5-300.fc31.x86_64'

make: *** [Makefile:12: default] Error 2

torshadas20494

Line 1609

in Makefile

$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost

vermaabhinav30

ERROR

Address of driver is coming out 0x00000000 in Modules.symvers file.

0x00000000 myModule /home/abhinavverma/Emblogic/CDD_FROM_SCRATCH/cddMyDev EXPORT_SYMBOL

nikeshkumarvedik

the answer of above bug container_of issue is it's kernel issue not an code issue

-#define container_of(ptr, type, member) ({			\
-	const typeof( ((type *)0)->member ) *__mptr = (ptr);	\
-	(type *)( (char *)__mptr - offsetof(type,member) );})
+#define container_of(ptr, type, member) ({				\
+	void *__mptr = (void *)(ptr);					\
+	BUILD_BUG_ON_MSG(!__same_type(*(ptr), ((type *)0)->member) &&	\
+			 !__same_type(*(ptr), void),			\
+			 "pointer type mismatch in container_of()");	\
+	((type *)(__mptr - offsetof(type, member))); })

ritde1

Observed the following error, after trying to compile kernel:
BTF: .tmp_vmlinux.btf: pahole (pahole) is not available
Failed to generate BTF for vmlinux.
Try to Disable CONFIG_DEBUG_INFO_BTF

Solution that worked for me:

1. Disabled "Generate BTF typeinfo" in menucongif->kernel hacking->compile time checks and compiler options.

Location: │

│ -> Kernel hacking

│ -> Compile-time checks and compiler options │

│ (1) -> Compile the kernel with debug info (DEBUG_INFO [=y])

Questions:
1-> What is pahole?

2-> What is BTF?

ritde1

1-> What is the linux booting process?
2-> What is grub(grand unified boot-loader)?

3-> What is the difference between Windows boot loader and GRUB?

4-> What is MBR, how is it different from GRUB?

5-> Why does dual boot fail, OS gets corrupted while using Windows boot manager and not GRUB(Works perfectly with GRUB)?

adarshkr55

>>how to resolve this problem

/bin/sh: openssl: command not found

make[1]: *** [certs/Makefile:63: certs/signing_key.pem] Error 127

make: *** [Makefile:1805: certs] Error 2

>> i install openssl but not resolved and give same error again again..

any one can suggest what's actually happen

rahul

@adarshkr55

yum install openssl-devel

above command will work.

If openssl of lowaer version is already installd. Then you may also find this error.

Check first openssl version on your system. If you have openssl of lowaer version then remove it first.

After that install again openssl

Note for kernal 5.10.8 you must install OpenSSL 1.1.1f of this version

To install this yum install openssl-devel

After installing you can continue the installation process.

rahul

I compiled and loaded basic device driver in kernel. I got following massage.

[ 1458.766784] cdd150: loading out-of-tree module taints kernel. // Need elobotation

[ 1458.766792] cdd150: module license 'unspecified' taints kernel.   // Need elobotation
[ 1458.766794] Disabling lock debugging due to kernel taint             // Need elobotation
[ 1458.766854] cdd150: module verification failed: signature and/or required key missing - tainting kernel // Need elobotation
[ 1458.768004] Heloo Kernel !
[ 1609.859521] Bye for now

I noted one thing that when i load device driver using insmod printk does not print in log

If i do rmmod then it print both massage hello kernel and bye for now

Why massage does not printed as device driver is loaded.

abdulrehmanjmi

After inserting dd_hello.ko file

when dmesg it, it shows these lines

[1934.159364] intel ips 0000:00:1f.6: ME failed to update for more than 1s, likely hung
[1934.159364] intel ips 0000:00:1f.6: ME failed to update for more than 1s, likely hung

[1934.159364] intel ips 0000:00:1f.6: ME failed to update for more than 1s, likely hung

Bye Now
[1934.159364]  intel ips 0000:00:1f.6: ME failed to update for more than 1s, likely hung
[1934.159364]  intel ips 0000:00:1f.6: ME failed to update for more than 1s, likely hung
[1934.159364]  intel ips 0000:00:1f.6: ME failed to update for more than 1s, likely hung

Hello Kernel
[1934.159364] intel ips 0000:00:1f.6: ME failed to update for more than 1s, likely hung
[1934.159364] intel ips 0000:00:1f.6: ME failed to update for more than 1s, likely hung

ritde1

Initialization Algorithm:

1-> Register device

2-> Get memory for Scull device

3-> Set memory to null using memset

4-> Initialize Device

5-> Get Device Status

Character Device Driver from Scratch

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