Practically speaking, it seems the convention is to only have one
packet pending and not rely upon any mechanism to associate returned
txbuf with txqueue.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Remove the concept of shutdown exit flags, and replace it with a
counter used to keep track of exposed interfaces that require devices
to remain active.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Add a new network driver that consumes the EFI Simple Network
Protocol. Also add a bus driver that can find the Simple Network
Protocol that iPXE was loaded from; the resulting behavior is similar
to the "undionly" driver for BIOS systems.
Signed-off-by: Michael Brown <mcb30@ipxe.org>