The Linux SCSI Generic (sg) HOWTO
Douglas Gilbert
dgilbert@interlog.com
Copyright © 2001, 2002 by Douglas Gilbert
2002-05-03
| Revision History | ||
|---|---|---|
| Revision 1.2 | 2002-05-03 | Revised by: dpg |
| ENOMEM, EPERM; DRIVER_SENSE->CHECK_CONDITION | ||
| Revision 1.1 | 2002-01-26 | Revised by: dpg |
| corrections, host_status, odd dxfer_len | ||
| Revision 1.0 | 2001-12-21 | Revised by: dpg |
| original, displace SCSI-PROGRAMMING-HOWTO | ||
This HOWTO describes the SCSI Generic driver (sg) found in the Linux 2.4 production series of kernels. It focuses on the the interface and characteristics of the driver that application writers may need to know. The driver's theory of operations is covered and some brief examples are included.
- Table of Contents
- 1. Introduction
- 2. What the sg driver does
- 3. Identifying the version of the SG driver
- 4. Interface
- 5. Theory of operation
- 6. The sg_io_hdr_t structure in detail
-
- 6.1. interface_id
- 6.2. dxfer_direction
- 6.3. cmd_len
- 6.4. mx_sb_len
- 6.5. iovec_count
- 6.6. dxfer_len
- 6.7. dxferp
- 6.8. cmdp
- 6.9. sbp
- 6.10. timeout
- 6.11. flags
- 6.12. pack_id
- 6.13. usr_ptr
- 6.14. status
- 6.15. masked_status
- 6.16. msg_status
- 6.17. sb_len_wr
- 6.18. host_status
- 6.19. driver_status
- 6.20. resid
- 6.21. duration
- 6.22. info
- 7. System calls
-
- 7.1. open()
- 7.2. write()
- 7.3. read()
- 7.4. poll()
- 7.5. close()
- 7.6. mmap()
- 7.7. fcntl(sg_fd, F_SETFL, oflags | FASYNC)
- 7.8. Errors reported in errno
- 8. Ioctl()s
-
- 8.1. SG_IO
- 8.2. SG_GET_ACCESS_COUNT
- 8.3. SG_SET_COMMAND_Q (and _GET_)
- 8.4. SG_SET_DEBUG
- 8.5. SG_EMULATED_HOST
- 8.6. SG_SET_KEEP_ORPHAN (and _GET_)
- 8.7. SG_SET_FORCE_LOW_DMA
- 8.8. SG_GET_LOW_DMA
- 8.9. SG_NEXT_CMD_LEN
- 8.10. SG_GET_NUM_WAITING
- 8.11. SG_SET_FORCE_PACK_ID
- 8.12. SG_GET_PACK_ID
- 8.13. SG_GET_REQUEST_TABLE
- 8.14. SG_SET_RESERVED_SIZE (and _GET_ )
- 8.15. SG_SCSI_RESET
- 8.16. SG_GET_SCSI_ID
- 8.17. SG_GET_SG_TABLESIZE
- 8.18. SG_GET_TIMEOUT
- 8.19. SG_SET_TIMEOUT
- 8.20. SG_SET_TRANSFORM
- 8.21. SG_GET_TRANSFORM
- 8.22. Sg ioctls removed in version 3
- 8.23. SCSI_IOCTL_GET_IDLUN
- 8.24. SCSI_IOCTL_GET_PCI
- 8.25. SCSI_IOCTL_PROBE_HOST
- 8.26. SCSI_IOCTL_SEND_COMMAND
- 9. Direct and Mmap-ed IO
-
- 9.1. Direct IO
- 9.2. Mmap-ed IO
- 10. Driver and module initialization
- 11. Sg and the "proc" file system
-
- 11.1. /proc/debug
- 12. Asynchronous usage of sg
- A. Sg3_utils package
- B. sg_header, the original sg control structure
- C. Programming example
- D. Debugging
- E. Other references
| Next | ||
| Introduction |
