1 / 10

DEVICE DRIVER

DEVICE DRIVER. VINOD KAMATH CS691X PROJECT WORK. Introduction. How to write/install device drivers Systems, Kernel Programming Character, Block and Network devices. Tasks involved. Building and Running modules Character device drivers. Building device driver module.

dillian
Télécharger la présentation

DEVICE DRIVER

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. DEVICE DRIVER VINOD KAMATH CS691X PROJECT WORK

  2. Introduction • How to write/install device drivers • Systems, Kernel Programming • Character, Block and Network devices

  3. Tasks involved • Building and Running modules • Character device drivers

  4. Building device driver module • Module vs. Applications • Appln - single task • Module - register for future • Compiling and Loading • ___KERNEL__, MODULE • insmod,rmmod • Global var-Symtab • Do in Kernel space (not User space) • response time; block/network devs

  5. Character device drivers • Scull - Simple Char. Util. for Loading Localities • Acts on mem. Area as though it is a device • Demonstrate interface betn. Kernel and Char drivers • n devices for n mem. areas • Major/Minor no.- (un)register chr_dev

  6. Design and implementation of Scull • File operations/structure • Device id. By file structure • Kenerl uses file ops. To access driver’s functions • Open and Close • Initialize device, usage count, • Memory • Device-memory Link List • Read and Write • Transfer data from Kernel-User • Testing/Debugging • cp, cat, dd wls-l > dev/scull0

  7. Examples-Hello World • #define MODULE • #include <linux/module.h> • int init_module (void) {printk(“<1>Hello, World\n”); return 0} • void cleanup_module {printk(“<1>Goodbye, cruel World\n”);}

  8. Examples-Scull • #define MODULE, __KERNEL__ • #include <linux/module.h>…. • Struct file_operations d0_fops = {r,w,o,c } • int init_module (void) {malloc, reg do_fops} • void cleanup_module (unreg, free...);l

  9. Conclusions • Writing device drivers is not for faint heart/Adventure • Very careful with Kernel codes

  10. Future work • Try Advanced drivers, Scheduling • Understand principle for multi user

More Related