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.\" Copyright (c) 2023-2024 Ian Marco Moffett and the Osmora Team.
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions are met:
.\"
.\" 1. Redistributions of source code must retain the above copyright notice,
.\" this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\" notice, this list of conditions and the following disclaimer in the
.\" documentation and/or other materials provided with the distribution.
.\" 3. Neither the name of Hyra nor the names of its
.\" contributors may be used to endorse or promote products derived from
.\" this software without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
.\" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
.\" LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
.\" POSSIBILITY OF SUCH DAMAGE.
.Dd Apr 29 2024
.Dt DEVICE 9
.Os Hyra
.Sh NAME
.Nm device - hyra device subsystem
.Sh SYNOPSIS
.In sys/device.h
.Sh DESCRIPTION
Devices registered with the kernel are represented by the device structure:
.Bd -literal
struct device {
dev_t major, minor;
size_t blocksize;
int(*write)(struct device *dev, struct sio_txn *sio);
int(*read)(struct device *dev, struct sio_txn *sio);
int(*ioctl)(struct device *dev, uint32_t cmd, uintptr_t arg);
...
TAILQ_ENTRY(device) link;
};
.Ed
Device instances are to be allocated with the
.Ft device_alloc()
function. These instances are registered with the kernel by the
.Ft device_create()
function.
The major number identifies the driver and the minor number identifies
the device itself. The major number must be allocated with the
.Ft device_alloc_major()
function.
If the device blocksize is greater than 1, this device is considered a block
device, otherwise if it is 1, it is considered a character device.
.Sh AUTHORS
.An Ian Moffett Aq Mt ian@osmora.org
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