25.2.1 Exit Boot Services Event
UEFI Drivers for network interface controllers that perform DMA operations to a
buffer in system memory in response to a received packet must create an Exit
Boot Services Event in the Driver Binding Protocol Start()
function. The
notification function associated with this Exit Boot Services Event must update
the network interface controller hardware to disable all further DMA activity.
This guarantees that after ExitBootServices()
is called, that the receive
resources allocated to network driver are freed for OS usage.
Caution: If the network interface controller performs DMA due to received packets into system memory after ExitBootServices() is called, the DMA operations may corrupt memory that is now owned by the operating system.