Kernel Module Internals

• __register_chrdev_region
  • The first and foremost functioni called by kernel module to ask kernel to add this module to it kernel iinternal structure
  • What are the structs?
    • char_device_struct (char_dev.c)
      • Creates a mojor number for this module and creates a new struct for this module add it to the linked list of all char dev structs chrdevs

        #define CHRDEV_MAJOR_HASH_SIZE 255
        static struct char_device_struct {
          struct char_device_struct *next;
          unsigned int major;
          unsigned int baseminor;
          int minorct;
          char name[64];
          struct cdev *cdev;		/* will die */
        } *chrdevs[CHRDEV_MAJOR_HASH_SIZE];
        

• class_create
  • creaees a class with char device namein /sys/class