Kernel Data Structures and Declarations

The interface objects used by device drivers are summarized in Table A-2. .

Device Driver Interface Objects

Name	Summary	Discussed	Versions
buf(D4)	Block read/write request structure.	page 183	SV*, 5.3*
eisa_dma_cb(D4)	DMA command block for EISA slave DMA.	page 446	5.3
eisa_dma_buf(D4)	DMA command buffer for EISA slave DMA.	page 446	5.3
errnos(D5)	Error numbers valid for driver use.		SV*, 5.3
iovec(D4)	Describes an I/O buffer segment to the read or write entry points.	page 182	SV, 5.3
signals(D5)	Lists signal numbers valid for driver use.		SV*, 5.3
uio(D4)	Describes an I/O request to the read or write entry points.	page 182	SV*, 5.3

Note: The following data structures used in SVR4 drivers are not used in IRIX: dma_buf and dma_cb. The eisa_dma_buf and eisa_dma_cb structures are similar but are used only in EISA drivers. The interface objects used by STREAMS drivers are summarized in Table A-3

STREAMS Driver Interface Objects

Name	Summary	Discussed	Versions
copyreq(D4)	Copy request structure.		SV, 5.3
copyresp(D4)	Copy response structure.		SV, 5.3
datab(D4)	Message data block.		SV, 5.3
free_rtn(D4)	Describes a message-free routine.		SV, 5.3
iocblk(D4)	Describes ioctl() data or response.		SV, 5.3
linkblk(D4)	Describes multiplexed link.		SV, 5.3
module_info(D4)	Describes module attributes.		SV, 5.3
msgb(D4)	Describes all or part of a message.		SV, 5.3
qinit(D4)	Points to handlers and parameters for a queue.		SV, 5.3
queue(D4)	Describes a queue of messages.		SV, 5.3
streamtab(D4)	Points to the queues handled by a driver.		SV, 5.3
stroptions(D4)	Lists stream-head options.		SV, 5.3