Next | Prev | Up | Top | Contents | Index

User-level EISA Special Files

IRIX Release 5.x contains special files in the /dev/eisa directory that allow a user-level program to map arbitrary EISA or ISA devices into its address space. These files can be used to write a user-level memory-mapped device driver. The driver uses the mmap() system call to map the card's address space into user-level program address space. Then the driver can access the card through simple loads and stores of program variables.

The special device files found in the /dev/eisa directory are:

eisaAio

EISA-bus adapter's 64 KB I/O address space

eisaAmem

EISA-bus adapter's 112 MB memory address space
Where A is the specific EISA-bus adapter.

An Indigo2 system has a single EISA-bus slot, so its special device files are limited to eisa0io and eisa0mem.


Next | Prev | Up | Top | Contents | Index