Linux Loadable Kernel Module HOWTO

Bryan Henderson

18 August 2001

Table of Contents

1. Preface

2. Introduction to Linux Loadable Kernel Modules

2.1. Terminology

2.2. History of Loadable Kernel Modules

2.3. The Case For Loadable Kernel Modules

2.4. What LKMs Can't Do

2.5. What LKMs Are Used For

3. Making Loadable Kernel Modules

4. LKM Utilities

5. How To Insert And Remove LKMs

5.1. Could Not Find Kernel Version...

5.2. Intelligent Loading Of LKMs - Modprobe

5.3. Automatic LKM Loading and Unloading

5.3.1. Automatic Loading

5.3.1.1. Kerneld

5.3.1.2. Kernel Module Loader

5.3.2. Automatic Unloading - Autoclean

5.3.2.1. The Autoclean Flag

5.3.2.2. Removing The Autoclean LKMs

5.4. /proc/modules

5.5. Where Are My LKM Files On My System?

6. LKM - Base Kernel Compatibility

6.1. An LKM Must Match The Base Kernel

6.2. If You Run Multiple Kernels

7. How To Boot Without A Disk Device Driver

8. About Module Parameters

9. Persistent Data

10. Technical Details

10.1. How They Work

10.2. The .modinfo Section

10.3. The __ksymtab And .kstrtab Sections

10.4. Ksymoops Symbols

10.5. Other Symbols

10.6. Linux internals

11. Writing Your Own Loadable Kernel Module

11.1. bug in hello.c

11.2. Rubini: Linux Device Drivers

11.3. Improving On Use Counts

12. Related Documentation

13. Individual Modules

13.1. Executable Interpreters

13.1.1. binfmt_aout: executable interpreter for a.out format

13.1.2. binfmt_elf: executable interpreter for ELF format

13.1.3. binfmt_java: executable interpreter for Java bytecode

13.2. Block Device Drivers

13.2.1. floppy: floppy disk driver

13.2.2. loop: loop device driver

13.2.3. linear: linear (non-RAID) disk array device driver

13.2.4. raid0: RAID-0 device driver

13.2.5. rd: ramdisk device driver

13.2.6. xd: XT disk device driver

13.3. SCSI Drivers

13.3.1. scsi_mod: SCSI mid-level driver

13.3.2. sd_mod: SCSI high-level driver for disk devices

13.3.3. st: SCSI high-level driver for tape devices

13.3.4. sr_mod: SCSI high-level driver for CD-ROM drives

13.3.5. sg: SCSI high-level driver for generic SCSI devices

13.3.6. wd7000: SCSI low-level driver for 7000FASST

13.3.7. aha154x: SCSI low-level driver for Adaptec AHA152X/2825

13.3.8. aha1542: SCSI low-level driver for Adaptec AHA1542

13.3.9. aha1740: SCSI low-level driver for Adaptec AHA1740 EISA

13.3.10. aic7xxx: SCSI low-level driver for Adaptec AHA274X/284X/294X

13.3.11. advansys: SCSI low-level driver for AdvanSys/Connect.com

13.3.12. in2000: SCSI low-level driver for Always IN2000

13.3.13. BusLogic: SCSI low-level driver for BusLogic

13.3.14. dtc: SCSI low-level driver for DTC3180/3280

13.3.15. eata: SCSI low-level driver for EATA ISA/EISA

13.3.16. eata_dma: SCSI low-level driver for EATA-DMA

13.3.17. eata_pio: SCSI low-level driver for EATA-PIO

13.3.18. fdomain: SCSI low-level driver for Future Domain 16xx

13.3.19. NCR5380: SCSI low-level driver for NCR5380/53c400

13.3.20. NCR53c406a: SCSI low-level driver for NCR53c406a

13.3.21. 53c7,8xx.o: SCSI low-level driver for NCR53c7,8xx

13.3.22. ncr53c8xx: SCSI low-level driver for PCI-SCS NCR538xx family

13.3.23. ppa: low-level SCSI driver for IOMEGA parallel port ZIP drive

13.3.24. pas16: SCSI low-level driver for PAS16

13.3.25. qlogicfas: SCSI low-level driver for Qlogic FAS

13.3.26. qlogicisp: SCSI low-level driver for Qlogic ISP

13.3.27. seagate: SCSI low-level driver for Seagate, Future Domain

13.3.28. t128: SCSI low-level driver for Trantor T128/T128F/T228

13.3.29. u14-34f: SCSI low-level driver for UltraStor 14F/34F

13.3.30. ultrastor: low-level SCSI driver for UltraStor

13.4. Network Device Drivers

13.4.1. bsd_comp: optional BSD compressor for PPP

13.4.2. slhc: SLHC compressor for PPP

13.4.3. 8390: General NS8390 Ethernet driver core

13.4.4. dummy: Dummy network interface driver

13.4.5. eql: serial line load balancer

13.4.6. dlci: frame relay DLCI driver

13.4.7. sdla: Sangoma S502A FRAD driver

13.4.8. plip: PLIP network interface driver

13.4.9. ppp: PPP network protocol driver

13.4.10. slip: SLIP network protocol driver

13.4.11. baycom: BAYCOM AX.25 amateur radio driver

13.4.12. strip: STRIP (Metricom starmode radio IP) driver

13.4.13. wavelan: WaveLAN driver

13.4.14. wic: WIC Radio IP bridge driver

13.4.15. scc: Z8530 SCC kiss emulation driver

13.4.16. 3c501: 3COM 3c501 Ethernet driver

13.4.17. 3c503: 3COM 3c503 driver

13.4.18. 3c505: 3COM 3c505 driver

13.4.19. 3c507: 3COM 3c507 driver

13.4.20. 3c509: 3COM 3c509/3c579 driver

13.4.21. 3c59x: 3COM 3c590 series "Vortex" driver

13.4.22. wd: Western Digital/SMC WD80*3 driver

13.4.23. smc-ultra: SMC Ultra/EtherEZ driver

13.4.24. smc9194: SMC 9194 driver

13.4.25. at1700: AT1700 driver

13.4.26. e2100: Cabletron E21xx driver

13.4.27. depca: DEPCA, DE10x, DE200, DE201, DE202, DE422 driver

13.4.28. ewrk3: EtherWORKS 3 (DE203, DE204, DE205) driver

13.4.29. eexpress: EtherExpress 16 driver

13.4.30. eepro: EtherExpressPro driver

13.4.31. fmv18k: Fujitsu FMV-181/182/183/184 driver

13.4.32. hp-plus: HP PCLAN+ (27247B and 27252A) driver

13.4.33. hp: HP PCLAN (27245, 27xxx) driver

13.4.34. hp100: HP 10/100VG PCLAN (ISA, EISA, PCI) driver

13.4.35. eth16i: ICL EtherTeam 16i/32 driver

13.4.36. ne: NE2000/NE1000 driver

13.4.37. ni52: NI5210 driver

13.4.38. ac3200: Ansel Communications EISA 3200 driver

13.4.39. apricot: Apricot Xen-II on board ethernet driver

13.4.40. de4x5: DE425, DE434, DE435, DE450, DE500 driver

13.4.41. tulip: DECchip Tulip (dc21x4x) PCI driver

13.4.42. dgrs: Digi Intl RightSwitch SE-X driver

13.4.43. de600: D-Link DE600 pocket adapter driver

13.4.44. de620: D-Link DE620 pocket adapter driver

13.4.45. ibmtr: Tropic chipset based token ring adapter driver

13.4.46. arcnet: ARCnet driver

13.4.47. isdn: basic ISDN functions

13.4.48. icn: ICN 2B and 4B driver

13.4.49. pcbit: PCBIT-D driver

13.4.50. teles: Teles/NICCY1016PC/Creatix driver

13.5. CDROM Device Drivers

13.5.1. axtcd: Aztech/Orchid/Okano/Wearnes/TXC/CDROM driver

13.5.2. gscd: Goldstar R420 CDROM driver

13.5.3. sbpcd: Sound Blaster CDROM driver

13.5.4. mcd: Mitsumi CDROM driver

13.5.5. mcdx: Mitsumi XA/MultiSession driver

13.5.6. optcd: Optics Storage DOLPHIN 8000AT CDROM driver

13.5.7. cm206: Philips/LMS CM206 CDROM driver

13.5.8. sjcd: Sanyo CDR-H94A CDROM driver

13.5.9. isp16: ISP16/MAD16/Mozart soft configurable cdrom driver

13.5.10. cdu31a: Sony CDU31A/CDU33A CDROM driver

13.5.11. sonycd535: Sony CDU535 CDROM driver

13.6. Filesystem Drivers

13.6.1. minix: Minix filesystem driver

13.6.2. ext: "Extended" filesystem driver

13.6.3. ext2: "Second extended" filessystem driver

13.6.4. xiafs: xiafs filesystem driver

13.6.5. fat: DOS FAT filesystem functions

13.6.6. msdos: MSDOS filesystem driver

13.6.7. vfat: VFAT (Windows-95) filesystem driver

13.6.8. umsdos: UMSDOS filesystem driver

13.6.9. nfs: NFS filesystem driver

13.6.10. smbfs: SMB filesystem driver

13.6.11. ncpfs: NCP (Netware) filesystem driver

13.6.12. isofs: ISO 9660 (CDROM) filesystem driver

13.6.13. hpfs: OS/2 HPFS filesystem driver

13.6.14. sysv: System V and Coherent filesystem driver

13.6.15. affs: Amiga FFS filesystem driver

13.6.16. ufs: UFS filesystem driver

13.7. Miscellaneous Device Driver

13.7.1. misc: device driver for "miscellaneous" character devices

13.8. Serial Device Drivers

13.8.1. serial: serial communication port (UART) device driver

13.8.2. cyclades: Cyclades async mux device driver

13.8.3. stallion: Stallion EasyIO or EC8/32 device driver

13.8.4. istallion: Stallion EC8/64, ONboard, Brumby device driver

13.8.5. riscom8: SDL RISCom/8 card device driver

13.9. Parallel Device Drivers

13.9.1. lp: Parallel printer device driver

13.10. Bus Mouse Device Drivers

13.10.1. atixlmouse: ATIXL busmouse driver

13.10.2. busmouse: Logitech busmouse driver

13.10.3. msbusmouse: Microsoft busmouse driver

13.10.4. psaux: PS/2 mouse (aka "auxiliary device") driver

13.11. Tape Device Drivers

13.11.1. ftape: floppy tape (QIC-80/Travan) device driver

13.12. Watchdog Timers

13.12.1. WDT: WDT Watchdog timer device driver

13.12.2. softdog: Software Watchdog Timer

13.12.3. pcwd: Berkshire Products PC Watchdog Driver

13.13. Sound Device Drivers

14. Maintenance Of This Document

15. History

16. Copyright