special(7S)

NAME | DESCRIPTION | ATTRIBUTES | SEE ALSO | NOTES

NAME

special- special files

DESCRIPTION

This manual page describes special files related to the devices supported by ChorusOS. Special files normally reside in the /dev directory, which is mounted at boot time.

See sysadm.ini(4CC) for a list of examples of special file creation using the mknod(1M) command.

Generic Devices

The following special files are not specific to any hardware device and are present on all platforms.

/dev/console

Provides access to the system console regardless of its real location.

/dev/mem

Provides access to the physical memory of the system.

/dev/kmem

Provides access to the kernel memory of the system.

/dev/zero

Is a source of zeroed unnamed memory. Reads from a zero special file always return a buffer full of zeroes. The file is of infinite length. Writes to a zero special file are always successful, but the data written to it is ignored.

Peripheral Devices

By convention, special file names for storage devices follow the form /dev/rsuffix for raw (character) mode and /dev/suffix for buffered (block) mode.

The suffix is made up of:

• A string of letters referring to the device driver name, such as sd for a SCSI disk, rd for a RAM disk, hd for an IDE disk or flash for flash,

• Followed by a digit representing the disk unit number, such as 0, 1, 2 and so forth,

• Terminated by a single letter referring to the partition, such as a, b, ... h.

Special file names for devices related to networking include:

/dev/bpfN

Provides access to a Berkeley Packet Filter; see bpf(7S).

/dev/ptypM

Provides access to a master pseudo-tty device.

/dev/tty0M

Provides access to a tty (Teletype) character device.

/dev/ttypM

Provides access to a slave pseudo-tty device.

Where N is a digit, such as 0, 1, 2 and so forth, and M is a digit, such as 1, 2, 3 and so forth.

ATTRIBUTES

See attributes(5) for descriptions of the following attributes:

ATTRIBUTE TYPE	ATTRIBUTE VALUE
Interface Stability	Evolving

SEE ALSO

mknod(1M), sysadm.ini(4CC)

NOTES

Unlike earlier releases that used special device driver files created on the host, this release only allows you create special files on the target.

Previous releases allowed you to create special files on the host because no /dev directory was available at boot time. As ChorusOS systems in this release mount a /dev directory at boot time, it is no longer necessary to create special files on the host.

ChorusOS 4.0  Last Revised December 1999

NAME | DESCRIPTION | ATTRIBUTES | SEE ALSO | NOTES