Writing a User-level EISA Device Driver

Writing a User-level EISA Device Driver

A typical application for a user-level EISA-bus device driver is to handle data acquisition hardware (that is, hardware that reads large amounts of data into device memory). Because the device memory is available to the user program directly (it is "mmapped" into the address space of the user program), the user program can avoid copying the data into host memory and can process the data in the device memory instead. However, on some systems, this PIO access may have substantially lower performance than DMA-based kernel drivers.

User-level EISA Special Files
Using the mmap Operating System Function