Problem with oprom_checknodeid() during DR (4474330)

A panic can occur under certain circumstances when the /dev/openprom interface accesses the PROM device tree after a DR disconnect. The openprom driver caches node information that can become invalid after a DR disconnect. As a result, OpenBoot PROM can be passed a bad node address.

Workaround: To minimize the possibility of encountering this situation, discontinue using applications, such as prtconf, that use the /dev/openprom interface during or immediately before or after a DR disconnect operation. Note that picld(1M) uses the /dev/openprom driver.