This patch switches the MINIX3 ethernet driver stack from a port-based

model to an instance-based model. Each ethernet driver instance is now
responsible for exactly one network interface card. The port field in
/etc/inet.conf now acts as an instance field instead.

This patch also updates the data link protocol. This update:
- eliminates the concept of ports entirely;
- eliminates DL_GETNAME entirely;
- standardizes on using m_source for IPC and DL_ENDPT for safecopies;
- removes error codes from TASK/STAT replies, as they were unused;
- removes a number of other old or unused fields;
- names and renames a few other fields.

All ethernet drivers have been changed to:
- conform to the new protocol, and exactly that;
- take on an instance number based on a given "instance" argument;
- skip that number of PCI devices in probe iterations;
- use config tables and environment variables based on that number;
- no longer be limited to a predefined maximum of cards in any way;
- get rid of any leftover non-safecopy support and other ancient junk;
- have a correct banner protocol figure, or none at all.

Other changes:
* Inet.conf is now taken to be line-based, and supports #-comments.
  No existing installations are expected to be affected by this.
* A new, select-based asynchio library replaces the old one.
  Kindly contributed by Kees J. Bot.
* Inet now supports use of select() on IP devices.
  Combined, the last two changes together speed up dhcpd
  considerably in the presence of multiple interfaces.
* A small bug has been fixed in nonamed.

man/man8/inet.8

@@ -39,7 +39,7 @@ It tells that network 0 (the one containing devices
 and
 .BR udp0 )
 uses the ethernet device driver handled
-by task "DP8390" at port 0.  This network is marked as the default
+by driver "DP8390" instance 0.  This network is marked as the default
 network, so most programs use it through the unnumbered devices like
 .B /dev/tcp
 or
@@ -47,21 +47,20 @@ or
 Network 1 is a Pseudo IP network that can be used for
 a serial IP over a modem for instance.
 .PP
-The configuration file may look like a common configuration file as
-described by
-.BR configfile (5),
-but it is currently just a simple subset allowing only what you see here.
+The configuration file uses a simple line-based format.
+Each network definition has to be fully on its own line.
+Empty lines and lines that start with a `#' symbol are ignored.
 The following network definitions are possible:
 .PP
 .BI eth N
-.I task port
+.I driver instance
 .RI { options };
 .RS
 This sets up an ethernet with device name
 .BI /dev/eth N\fR,
-built on the given ethernet device driver at the given port at that driver.
-(If a network driver manages two network
-cards then they are at port 0 and 1.)
+built on the given ethernet device driver with the given instance number.
+(If there are two network cards of the same type
+then they will be managed by instance 0 and 1 of the corresponding driver.)
 .br
 .RE
 .PP