FreeBSD Man Pages

devinfo(3)

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

     Device and Resource Information Utility Library (libdevinfo, -ldevinfo)

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

     The devinfo library provides access to the kernel's internal device hier-
     archy 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 num-
     ber 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>:
	       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 con-
     sistent 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.
     devstat(3)

HISTORY

     The devinfo library first appeared in FreeBSD 5.0.

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.

FreeBSD 5.4			April 19, 2001			   FreeBSD 5.4

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