NAME
devinfo
,
devinfo_init
, devinfo_free
,
devinfo_handle_to_device
,
devinfo_handle_to_resource
,
devinfo_handle_to_rman
,
devinfo_foreach_device_child
,
devinfo_foreach_device_resource
,
devinfo_foreach_rman_resource
,
devinfo_foreach_rman
—
device and resource information utility
library
LIBRARY
library “libdevinfo”
SYNOPSIS
#include
<devinfo.h>
int
devinfo_init
(void);
void
devinfo_free
(void);
struct devinfo_dev *
devinfo_handle_to_device
(devinfo_handle_t
handle);
struct devinfo_res *
devinfo_handle_to_resource
(devinfo_handle_t
handle);
struct devinfo_rman *
devinfo_handle_to_rman
(devinfo_handle_t
handle);
int
devinfo_foreach_device_child
(struct
devinfo_dev *parent, int (*fn)(struct devinfo_dev
*child, void *arg), void *arg);
int
devinfo_foreach_device_resource
(struct
devinfo_dev *dev, int (*fn)(struct devinfo_dev *dev,
struct devinfo_res *res, void *arg), void
*arg);
int
devinfo_foreach_rman_resource
(struct
devinfo_rman *rman, int (*fn)(struct devinfo_res *res,
void *arg), void *arg);
int
devinfo_foreach_rman
(int (*fn)(struct
devinfo_rman *rman, void *arg), void *arg);
DESCRIPTION
Thedevinfo
library provides access to the kernel's
internal device hierarchy and to the I/O resource manager. The library uses a
sysctl(3) interface to obtain a snapshot of the kernel's state, which
is then made available to the application.
Due to the fact that the information may be logically arranged in a number of different fashions, the library does not attempt to impose any structure on the data.
Device, resource, and resource manager information is returned in
data structures defined in
<devinfo.h>
:
struct devinfo_dev { devinfo_handle_t dd_handle; /* device handle */ devinfo_handle_t dd_parent; /* parent handle */ char *dd_name; /* name of device */ char *dd_desc; /* device description */ char *dd_drivername; /* name of attached driver */ char *dd_pnpinfo; /* pnp info from parent bus */ char *dd_location; /* Where bus thinks dev at */ uint32_t dd_devflags; /* API flags */ uint16_t dd_flags; /* internal dev flags */ device_state_t dd_state; /* attachment state of dev */ }; struct devinfo_rman { devinfo_handle_t dm_handle; /* resource manager handle */ u_long dm_start; /* resource start */ u_long dm_size; /* resource size */ char *dm_desc; /* resource description */ }; struct devinfo_res { devinfo_handle_t dr_handle; /* resource handle */ devinfo_handle_t dr_rman; /* resource manager handle */ devinfo_handle_t dr_device; /* owning device */ u_long dr_start; /* region start */ u_long dr_size; /* region size */ };
The devinfo_handle_t values can be used to look up the correspondingly referenced structures.
devinfo_init
()
takes a snapshot of the kernel's internal device and resource state. It
returns nonzero if after a number of retries a consistent snapshot cannot be
obtained. devinfo_init
() must be called before any
other functions can be used.
devinfo_free
()
releases the memory associated with the snapshot. Any pointers returned by
other functions are invalidated by this, and
devinfo_init
() must be called again before using any
other functions.
devinfo_handle_to_device
(),
devinfo_handle_to_resource
()
and
devinfo_handle_to_rman
()
return pointers to devinfo_dev,
devinfo_res and devinfo_rman
structures respectively based on the devinfo_handle_t
passed to them. These functions can be used to traverse the tree from any
node to any other node. If
devinfo_handle_to_device
() is passed the constant
DEVINFO_ROOT_DEVICE
it will return the handle to the
root of the device tree.
devinfo_foreach_device_child
()
invokes its callback argument fn on every device which
is an immediate child of device. The
fn function is also passed arg,
allowing state to be passed to the callback function. If
fn returns a nonzero error value the traversal is
halted, and devinfo_foreach_device_child
() returns
the error value to its caller.
devinfo_foreach_device_resource
()
invokes its callback argument fn on every resource
which is owned by device. The fn
function is also passed device and
arg, allowing state to be passed to the callback
function. If fn returns a nonzero error value the
traversal is halted, and
devinfo_foreach_device_resource
() returns the error
value to its caller.
devinfo_foreach_rman_resource
()
invokes its callback argument fn on every resource
within the resource manager rman. The
fn function is also passed arg,
allowing state to be passed to the callback function. If
fn returns a nonzero error value the traversal is
halted, and devinfo_foreach_rman_resource
() returns
the error value to its caller.
devinfo_foreach_rman
()
invokes its callback argument fn on every resource
manager. The fn function is also passed
arg, allowing state to be passed to the callback
function. If fn returns a nonzero error value the
traversal is halted, and devinfo_foreach_rman
()
returns the error value to its caller.
SEE ALSO
HISTORY
The devinfo
library first appeared in
FreeBSD 5.0 and was imported into
DragonFly 2.1.
AUTHORS
Michael Smith <msmith@FreeBSD.org>
BUGS
This is the first implementation of the library, and the interface is still subject to refinement.
The interface does not report device classes or drivers, making it hard to sort by class or driver.