This reverts commit fc5f6c9de2.

Reverted commit breaks the much more common case of changing the debug
options in subsequent builds without any code changes.

safe dropping of the netdev ref by the driver while other refs still
exist.

Add netdev_irq() method.  Net device open()/close() methods should no
longer enable or disable IRQs.

Remove rx_quota; it wasn't used anywhere and added too much complexity
to implementing correct interrupt-masking behaviour in pxe_undi.c.

This reverts commit 3487640397.

This reverts commit 68add6e814.

This reverts commit a4bea78974.

This reverts commit 3414fd8df8.

This reverts commit 636bd2cd0a.

This reverts commit 7297f04481.

This reverts commit 5ce16b03a1.

not apply DHCP options in dhcp_configure_netdev().

Documented non-blocking nature of PXENV_FILE_READ.

Changed FileName field in PXENV_FILE_OPEN to be a SEGOFF16, to avoid a
fixed 256-byte length limit on URLs.

below _text.  This should help with the gPXE-on-gPXE-via-PXE case.

posix_io.c and this PXE error makes more sense in this context.

the Etherboot partition.

This version uses the gPXE driver API rather than the legacy wrapper API.