Provided by: freebsd-manpages_7.2-1_all
BUS_READ_IVAR, BUS_WRITE_IVAR - manipulate bus-specific device instance
BUS_READ_IVAR(device_t dev, device_t child, int index,
BUS_WRITE_IVAR(device_t dev, device_t child, int index, uintptr_t value);
These two methods manage a bus specific set of instance variables of a
child device. The intention is that each different type of bus defines a
set of appropriate instance variables (such as ports and irqs for ISA bus
This information could be given to the child device as a struct but that
makes it hard for a bus to add or remove variables without forcing an
edit and recompile for all drivers which may not be possible for vendor
supplied binary drivers.
Zero is returned on success, otherwise an appropriate error is returned.
This manual page was written by Doug Rabson.