freebsd man page for altera_avgen

Query: altera_avgen

OS: freebsd

Section: 4

Format: Original Unix Latex Style Formatted with HTML and a Horizontal Scroll Bar

ALTERA_AVGEN(4) 					   BSD Kernel Interfaces Manual 					   ALTERA_AVGEN(4)

NAME
altera_avgen -- driver for generic Altera Avalon-bus-attached, memory-mapped devices
SYNOPSIS
device altera_avgen In /boot/device.hints: hint.altera_avgen.0.at="nexus0" hint.altera_avgen.0.maddr=0x7f00a000 hint.altera_avgen.0.msize=20 hint.altera_avgen.0.width=4 hint.altera_avgen.0.fileio="rw" hint.altera_avgen.0.devname="berirom"
DESCRIPTION
The altera_avgen device driver provides generic support for memory-mapped devices on the Altera Avalon bus. device.hints entries configure the address, size, I/O disposition, and /dev device node name that will be used. The open(2), read(2), write(2), and mmap(2) system calls (and variations) may be used on altera_avgen device nodes, subject to constraints imposed using device.hints entries. Although reading and writing mapped memory is supported, altera_avgen does not currently support directing device interrupts to userspace. A number of device.hints sub-fields are available to configure altera_avgen device instances: maddr base physical address of the memory region to export; must be aligned to width msize length of the memory region export; must be aligned to width width Granularity at which read(2) and write(2) operations will be performed. Larger requests will be broken down into width -sized oper- ations; smaller requests will be rejected. I/O operations must be aligned to width. fileio allowed file descriptor operations; r authorizes read(2); w authorizes write(2). mmapio allowed mmap(2) permissions; w authorizes PROT_WRITE; r authorizes PROT_READ; x authorizes PROT_EXEC. devname specifies a device name relative to /dev. devunit specifies a device unit number; no unit number is used if this is unspecified.
SEE ALSO
mmap(2), open(2), read(2), write(2)
HISTORY
The altera_avgen device driver first appeared in FreeBSD 10.0.
AUTHORS
The altera_avgen device driver and this manual page were developed by SRI International and the University of Cambridge Computer Laboratory under DARPA/AFRL contract (FA8750-10-C-0237) (``CTSRD''), as part of the DARPA CRASH research programme. This device driver was written by Robert N. M. Watson.
BUGS
altera_avgen is intended to support the writing of userspace device drivers; however, it does not permit directing interrupts to userspace, only memory-mapped I/O. altera_avgen supports only a nexus bus attachment, which is appropriate for system-on-chip busses such as Altera's Avalon bus. If the target device is off of another bus type, then additional bus attachments will be required.
BSD
August 18, 2012 BSD
Related Man Pages
ct(4) - debian
device(9) - debian
device.hints(5) - freebsd
atse(4) - freebsd
gpiobus(4) - freebsd
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