https://www.emblogic.com/blog/10/regarding-char-device-registration/ Embedded System and ARM Training Mon, 07 Oct 2013 04:00:03 +0000 hourly 1 http://wordpress.org/?v=3.9.1 https://www.emblogic.com/blog/10/regarding-char-device-registration/#comment-60 Tue, 05 Oct 2010 11:01:55 +0000 http://emblogic.org/blog/?p=182#comment-60 A call to register_chrdev() actually registers 0-255 minor numbers for a given major no and sets up default cdev structure for each.

]]> https://www.emblogic.com/blog/10/regarding-char-device-registration/#comment-59 Tue, 05 Oct 2010 06:25:32 +0000 http://emblogic.org/blog/?p=182#comment-59 register_chrdev() function internally automatically initialises cdev…ie it adds pointer oof file operations to the cdev structure element ops, but when we are using scull, cdev is not a global structure but it is taken as an element of scull_dev structure, so as to include attrbutes of device in the scull structure itself. In this case we have to manually initialise cdev object, which is inside scull, using register_chrdev_region…

]]> https://www.emblogic.com/blog/10/regarding-char-device-registration/#comment-58 Mon, 04 Oct 2010 15:56:57 +0000 http://emblogic.org/blog/?p=182#comment-58 u askd a gd questn…i think d reason behind this is ,whnevr we have to implement scull,we need various kind of operations (read,write,lseek etc)..and to make a pointer to such structure,struct file_operations (which keeps all such function pointers)…we must initialize cdev…so dat we cn access all those functions….to implement scull..

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