ALTERA_AVGEN(4FREEBSD) - Linux man page online | Special files

Driver for generic Altera Avalon-bus-attached, memory-mapped devices.

August 18, 2012
ALTERA_AVGEN(4) BSD Kernel Interfaces Manual ALTERA_AVGEN(4)


altera_avgen — driver for generic Altera Avalon-bus-attached, memory-mapped devices


device altera_avgen In /boot/device.hints:"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"


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 sup‐ ported, 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 operations; 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.


mmap(2), open(2), read(2), write(2)


The altera_avgen device driver first appeared in FreeBSD 10.0.


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.


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
This manual Reference Other manuals
altera_avgen(4freebsd) referred by
refer to mmap(2) | open(2) | read(2) | write(2)
Download raw manual
Index BSD Kernel Interfaces Manual (+773) BSD (+3984) № 4 (+981)
Go top