docs: networking: convert arcnet.txt to ReST

- add SPDX header;
- use document title markup;
- add notes markups;
- mark code blocks and literals as such;
- mark tables as such;
- adjust identation, whitespaces and blank lines;
- add to networking/index.rst.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 594 insertions, 0 deletions

diff --git a/Documentation/networking/arcnet.rst b/Documentation/networking/arcnet.rst
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+.. SPDX-License-Identifier: GPL-2.0
+
+======
+ARCnet
+======
+
+.. note::
+
+   See also arcnet-hardware.txt in this directory for jumper-setting
+   and cabling information if you're like many of us and didn't happen to get a
+   manual with your ARCnet card.
+
+Since no one seems to listen to me otherwise, perhaps a poem will get your
+attention::
+
+		This driver's getting fat and beefy,
+		But my cat is still named Fifi.
+
+Hmm, I think I'm allowed to call that a poem, even though it's only two
+lines.  Hey, I'm in Computer Science, not English.  Give me a break.
+
+The point is:  I REALLY REALLY REALLY REALLY REALLY want to hear from you if
+you test this and get it working.  Or if you don't.  Or anything.
+
+ARCnet 0.32 ALPHA first made it into the Linux kernel 1.1.80 - this was
+nice, but after that even FEWER people started writing to me because they
+didn't even have to install the patch.  <sigh>
+
+Come on, be a sport!  Send me a success report!
+
+(hey, that was even better than my original poem... this is getting bad!)
+
+
+.. warning::
+
+   If you don't e-mail me about your success/failure soon, I may be forced to
+   start SINGING.  And we don't want that, do we?
+
+   (You know, it might be argued that I'm pushing this point a little too much.
+   If you think so, why not flame me in a quick little e-mail?  Please also
+   include the type of card(s) you're using, software, size of network, and
+   whether it's working or not.)
+
+   My e-mail address is: apenwarr@worldvisions.ca
+
+These are the ARCnet drivers for Linux.
+
+This new release (2.91) has been put together by David Woodhouse
+<dwmw2@infradead.org>, in an attempt to tidy up the driver after adding support
+for yet another chipset. Now the generic support has been separated from the
+individual chipset drivers, and the source files aren't quite so packed with
+#ifdefs! I've changed this file a bit, but kept it in the first person from
+Avery, because I didn't want to completely rewrite it.
+
+The previous release resulted from many months of on-and-off effort from me
+(Avery Pennarun), many bug reports/fixes and suggestions from others, and in
+particular a lot of input and coding from Tomasz Motylewski.  Starting with
+ARCnet 2.10 ALPHA, Tomasz's all-new-and-improved RFC1051 support has been
+included and seems to be working fine!
+
+
+Where do I discuss these drivers?
+---------------------------------
+
+Tomasz has been so kind as to set up a new and improved mailing list.
+Subscribe by sending a message with the BODY "subscribe linux-arcnet YOUR
+REAL NAME" to listserv@tichy.ch.uj.edu.pl.  Then, to submit messages to the
+list, mail to linux-arcnet@tichy.ch.uj.edu.pl.
+
+There are archives of the mailing list at:
+
+	http://epistolary.org/mailman/listinfo.cgi/arcnet
+
+The people on linux-net@vger.kernel.org (now defunct, replaced by
+netdev@vger.kernel.org) have also been known to be very helpful, especially
+when we're talking about ALPHA Linux kernels that may or may not work right
+in the first place.
+
+
+Other Drivers and Info
+----------------------
+
+You can try my ARCNET page on the World Wide Web at:
+
+	http://www.qis.net/~jschmitz/arcnet/
+
+Also, SMC (one of the companies that makes ARCnet cards) has a WWW site you
+might be interested in, which includes several drivers for various cards
+including ARCnet.  Try:
+
+	http://www.smc.com/
+
+Performance Technologies makes various network software that supports
+ARCnet:
+
+	http://www.perftech.com/ or ftp to ftp.perftech.com.
+
+Novell makes a networking stack for DOS which includes ARCnet drivers.  Try
+FTPing to ftp.novell.com.
+
+You can get the Crynwr packet driver collection (including arcether.com, the
+one you'll want to use with ARCnet cards) from
+oak.oakland.edu:/simtel/msdos/pktdrvr. It won't work perfectly on a 386+
+without patches, though, and also doesn't like several cards.  Fixed
+versions are available on my WWW page, or via e-mail if you don't have WWW
+access.
+
+
+Installing the Driver
+---------------------
+
+All you will need to do in order to install the driver is::
+
+	make config
+		(be sure to choose ARCnet in the network devices
+		and at least one chipset driver.)
+	make clean
+	make zImage
+
+If you obtained this ARCnet package as an upgrade to the ARCnet driver in
+your current kernel, you will need to first copy arcnet.c over the one in
+the linux/drivers/net directory.
+
+You will know the driver is installed properly if you get some ARCnet
+messages when you reboot into the new Linux kernel.
+
+There are four chipset options:
+
+ 1. Standard ARCnet COM90xx chipset.
+
+This is the normal ARCnet card, which you've probably got. This is the only
+chipset driver which will autoprobe if not told where the card is.
+It following options on the command line::
+
+ com90xx=[<io>[,<irq>[,<shmem>]]][,<name>] | <name>
+
+If you load the chipset support as a module, the options are::
+
+ io=<io> irq=<irq> shmem=<shmem> device=<name>
+
+To disable the autoprobe, just specify "com90xx=" on the kernel command line.
+To specify the name alone, but allow autoprobe, just put "com90xx=<name>"
+
+ 2. ARCnet COM20020 chipset.
+
+This is the new chipset from SMC with support for promiscuous mode (packet
+sniffing), extra diagnostic information, etc. Unfortunately, there is no
+sensible method of autoprobing for these cards. You must specify the I/O
+address on the kernel command line.
+
+The command line options are::
+
+ com20020=<io>[,<irq>[,<node_ID>[,backplane[,CKP[,timeout]]]]][,name]
+
+If you load the chipset support as a module, the options are::
+
+ io=<io> irq=<irq> node=<node_ID> backplane=<backplane> clock=<CKP>
+ timeout=<timeout> device=<name>
+
+The COM20020 chipset allows you to set the node ID in software, overriding the
+default which is still set in DIP switches on the card. If you don't have the
+COM20020 data sheets, and you don't know what the other three options refer
+to, then they won't interest you - forget them.
+
+ 3. ARCnet COM90xx chipset in IO-mapped mode.
+
+This will also work with the normal ARCnet cards, but doesn't use the shared
+memory. It performs less well than the above driver, but is provided in case
+you have a card which doesn't support shared memory, or (strangely) in case
+you have so many ARCnet cards in your machine that you run out of shmem slots.
+If you don't give the IO address on the kernel command line, then the driver
+will not find the card.
+
+The command line options are::
+
+ com90io=<io>[,<irq>][,<name>]
+
+If you load the chipset support as a module, the options are:
+ io=<io> irq=<irq> device=<name>
+
+ 4. ARCnet RIM I cards.
+
+These are COM90xx chips which are _completely_ memory mapped. The support for
+these is not tested. If you have one, please mail the author with a success
+report. All options must be specified, except the device name.
+Command line options::
+
+ arcrimi=<shmem>,<irq>,<node_ID>[,<name>]
+
+If you load the chipset support as a module, the options are::
+
+ shmem=<shmem> irq=<irq> node=<node_ID> device=<name>
+
+
+Loadable Module Support
+-----------------------
+
+Configure and rebuild Linux.  When asked, answer 'm' to "Generic ARCnet
+support" and to support for your ARCnet chipset if you want to use the
+loadable module. You can also say 'y' to "Generic ARCnet support" and 'm'
+to the chipset support if you wish.
+
+::
+
+	make config
+	make clean
+	make zImage
+	make modules
+
+If you're using a loadable module, you need to use insmod to load it, and
+you can specify various characteristics of your card on the command
+line.  (In recent versions of the driver, autoprobing is much more reliable
+and works as a module, so most of this is now unnecessary.)
+
+For example::
+
+	cd /usr/src/linux/modules
+	insmod arcnet.o
+	insmod com90xx.o
+	insmod com20020.o io=0x2e0 device=eth1
+
+
+Using the Driver
+----------------
+
+If you build your kernel with ARCnet COM90xx support included, it should
+probe for your card automatically when you boot. If you use a different
+chipset driver complied into the kernel, you must give the necessary options
+on the kernel command line, as detailed above.
+
+Go read the NET-2-HOWTO and ETHERNET-HOWTO for Linux; they should be
+available where you picked up this driver.  Think of your ARCnet as a
+souped-up (or down, as the case may be) Ethernet card.
+
+By the way, be sure to change all references from "eth0" to "arc0" in the
+HOWTOs.  Remember that ARCnet isn't a "true" Ethernet, and the device name
+is DIFFERENT.
+
+
+Multiple Cards in One Computer
+------------------------------
+
+Linux has pretty good support for this now, but since I've been busy, the
+ARCnet driver has somewhat suffered in this respect. COM90xx support, if
+compiled into the kernel, will (try to) autodetect all the installed cards.
+
+If you have other cards, with support compiled into the kernel, then you can
+just repeat the options on the kernel command line, e.g.::
+
+	LILO: linux com20020=0x2e0 com20020=0x380 com90io=0x260
+
+If you have the chipset support built as a loadable module, then you need to
+do something like this::
+
+	insmod -o arc0 com90xx
+	insmod -o arc1 com20020 io=0x2e0
+	insmod -o arc2 com90xx
+
+The ARCnet drivers will now sort out their names automatically.
+
+
+How do I get it to work with...?
+--------------------------------
+
+NFS:
+	Should be fine linux->linux, just pretend you're using Ethernet cards.
+	oak.oakland.edu:/simtel/msdos/nfs has some nice DOS clients.  There
+	is also a DOS-based NFS server called SOSS.  It doesn't multitask
+	quite the way Linux does (actually, it doesn't multitask AT ALL) but
+	you never know what you might need.
+
+	With AmiTCP (and possibly others), you may need to set the following
+	options in your Amiga nfstab:  MD 1024 MR 1024 MW 1024
+	(Thanks to Christian Gottschling <ferksy@indigo.tng.oche.de>
+	for this.)
+
+	Probably these refer to maximum NFS data/read/write block sizes.  I
+	don't know why the defaults on the Amiga didn't work; write to me if
+	you know more.
+
+DOS:
+	If you're using the freeware arcether.com, you might want to install
+	the driver patch from my web page.  It helps with PC/TCP, and also
+	can get arcether to load if it timed out too quickly during
+	initialization.  In fact, if you use it on a 386+ you REALLY need
+	the patch, really.
+
+Windows:
+	See DOS :)  Trumpet Winsock works fine with either the Novell or
+	Arcether client, assuming you remember to load winpkt of course.
+
+LAN Manager and Windows for Workgroups:
+	These programs use protocols that
+	are incompatible with the Internet standard.  They try to pretend
+	the cards are Ethernet, and confuse everyone else on the network.
+
+	However, v2.00 and higher of the Linux ARCnet driver supports this
+	protocol via the 'arc0e' device.  See the section on "Multiprotocol
+	Support" for more information.
+
+	Using the freeware Samba server and clients for Linux, you can now
+	interface quite nicely with TCP/IP-based WfWg or Lan Manager
+	networks.
+
+Windows 95:
+	Tools are included with Win95 that let you use either the LANMAN
+	style network drivers (NDIS) or Novell drivers (ODI) to handle your
+	ARCnet packets.  If you use ODI, you'll need to use the 'arc0'
+	device with Linux.  If you use NDIS, then try the 'arc0e' device.
+	See the "Multiprotocol Support" section below if you need arc0e,
+	you're completely insane, and/or you need to build some kind of
+	hybrid network that uses both encapsulation types.
+
+OS/2:
+	I've been told it works under Warp Connect with an ARCnet driver from
+	SMC.  You need to use the 'arc0e' interface for this.  If you get
+	the SMC driver to work with the TCP/IP stuff included in the
+	"normal" Warp Bonus Pack, let me know.
+
+	ftp.microsoft.com also has a freeware "Lan Manager for OS/2" client
+	which should use the same protocol as WfWg does.  I had no luck
+	installing it under Warp, however.  Please mail me with any results.
+
+NetBSD/AmiTCP:
+	These use an old version of the Internet standard ARCnet
+	protocol (RFC1051) which is compatible with the Linux driver v2.10
+	ALPHA and above using the arc0s device. (See "Multiprotocol ARCnet"
+	below.)  ** Newer versions of NetBSD apparently support RFC1201.
+
+
+Using Multiprotocol ARCnet
+--------------------------
+
+The ARCnet driver v2.10 ALPHA supports three protocols, each on its own
+"virtual network device":
+
+	======  ===============================================================
+	arc0	RFC1201 protocol, the official Internet standard which just
+		happens to be 100% compatible with Novell's TRXNET driver.
+		Version 1.00 of the ARCnet driver supported _only_ this
+		protocol.  arc0 is the fastest of the three protocols (for
+		whatever reason), and allows larger packets to be used
+		because it supports RFC1201 "packet splitting" operations.
+		Unless you have a specific need to use a different protocol,
+		I strongly suggest that you stick with this one.
+
+	arc0e	"Ethernet-Encapsulation" which sends packets over ARCnet
+		that are actually a lot like Ethernet packets, including the
+		6-byte hardware addresses.  This protocol is compatible with
+		Microsoft's NDIS ARCnet driver, like the one in WfWg and
+		LANMAN.  Because the MTU of 493 is actually smaller than the
+		one "required" by TCP/IP (576), there is a chance that some
+		network operations will not function properly.  The Linux
+		TCP/IP layer can compensate in most cases, however, by
+		automatically fragmenting the TCP/IP packets to make them
+		fit.  arc0e also works slightly more slowly than arc0, for
+		reasons yet to be determined.  (Probably it's the smaller
+		MTU that does it.)
+
+	arc0s	The "[s]imple" RFC1051 protocol is the "previous" Internet
+		standard that is completely incompatible with the new
+		standard.  Some software today, however, continues to
+		support the old standard (and only the old standard)
+		including NetBSD and AmiTCP.  RFC1051 also does not support
+		RFC1201's packet splitting, and the MTU of 507 is still
+		smaller than the Internet "requirement," so it's quite
+		possible that you may run into problems.  It's also slower
+		than RFC1201 by about 25%, for the same reason as arc0e.
+
+		The arc0s support was contributed by Tomasz Motylewski
+		and modified somewhat by me.  Bugs are probably my fault.
+	======  ===============================================================
+
+You can choose not to compile arc0e and arc0s into the driver if you want -
+this will save you a bit of memory and avoid confusion when eg. trying to
+use the "NFS-root" stuff in recent Linux kernels.
+
+The arc0e and arc0s devices are created automatically when you first
+ifconfig the arc0 device.  To actually use them, though, you need to also
+ifconfig the other virtual devices you need.  There are a number of ways you
+can set up your network then:
+
+
+1. Single Protocol.
+
+   This is the simplest way to configure your network: use just one of the
+   two available protocols.  As mentioned above, it's a good idea to use
+   only arc0 unless you have a good reason (like some other software, ie.
+   WfWg, that only works with arc0e).
+
+   If you need only arc0, then the following commands should get you going::
+
+	ifconfig arc0 MY.IP.ADD.RESS
+	route add MY.IP.ADD.RESS arc0
+	route add -net SUB.NET.ADD.RESS arc0
+	[add other local routes here]
+
+   If you need arc0e (and only arc0e), it's a little different::
+
+	ifconfig arc0 MY.IP.ADD.RESS
+	ifconfig arc0e MY.IP.ADD.RESS
+	route add MY.IP.ADD.RESS arc0e
+	route add -net SUB.NET.ADD.RESS arc0e
+
+   arc0s works much the same way as arc0e.
+
+
+2. More than one protocol on the same wire.
+
+   Now things start getting confusing.  To even try it, you may need to be
+   partly crazy.  Here's what *I* did. :) Note that I don't include arc0s in
+   my home network; I don't have any NetBSD or AmiTCP computers, so I only
+   use arc0s during limited testing.
+
+   I have three computers on my home network; two Linux boxes (which prefer
+   RFC1201 protocol, for reasons listed above), and one XT that can't run
+   Linux but runs the free Microsoft LANMAN Client instead.
+
+   Worse, one of the Linux computers (freedom) also has a modem and acts as
+   a router to my Internet provider.  The other Linux box (insight) also has
+   its own IP address and needs to use freedom as its default gateway.  The
+   XT (patience), however, does not have its own Internet IP address and so
+   I assigned it one on a "private subnet" (as defined by RFC1597).
+
+   To start with, take a simple network with just insight and freedom.
+   Insight needs to:
+
+	- talk to freedom via RFC1201 (arc0) protocol, because I like it
+	  more and it's faster.
+	- use freedom as its Internet gateway.
+
+   That's pretty easy to do.  Set up insight like this::
+
+	ifconfig arc0 insight
+	route add insight arc0
+	route add freedom arc0	/* I would use the subnet here (like I said
+					to to in "single protocol" above),
+					but the rest of the subnet
+					unfortunately lies across the PPP
+					link on freedom, which confuses
+					things. */
+	route add default gw freedom
+
+   And freedom gets configured like so::
+
+	ifconfig arc0 freedom
+	route add freedom arc0
+	route add insight arc0
+	/* and default gateway is configured by pppd */
+
+   Great, now insight talks to freedom directly on arc0, and sends packets
+   to the Internet through freedom.  If you didn't know how to do the above,
+   you should probably stop reading this section now because it only gets
+   worse.
+
+   Now, how do I add patience into the network?  It will be using LANMAN
+   Client, which means I need the arc0e device.  It needs to be able to talk
+   to both insight and freedom, and also use freedom as a gateway to the
+   Internet.  (Recall that patience has a "private IP address" which won't
+   work on the Internet; that's okay, I configured Linux IP masquerading on
+   freedom for this subnet).
+
+   So patience (necessarily; I don't have another IP number from my
+   provider) has an IP address on a different subnet than freedom and
+   insight, but needs to use freedom as an Internet gateway.  Worse, most
+   DOS networking programs, including LANMAN, have braindead networking
+   schemes that rely completely on the netmask and a 'default gateway' to
+   determine how to route packets.  This means that to get to freedom or
+   insight, patience WILL send through its default gateway, regardless of
+   the fact that both freedom and insight (courtesy of the arc0e device)
+   could understand a direct transmission.
+
+   I compensate by giving freedom an extra IP address - aliased 'gatekeeper' -
+   that is on my private subnet, the same subnet that patience is on.  I
+   then define gatekeeper to be the default gateway for patience.
+
+   To configure freedom (in addition to the commands above)::
+
+	ifconfig arc0e gatekeeper
+	route add gatekeeper arc0e
+	route add patience arc0e
+
+   This way, freedom will send all packets for patience through arc0e,
+   giving its IP address as gatekeeper (on the private subnet).  When it
+   talks to insight or the Internet, it will use its "freedom" Internet IP
+   address.
+
+   You will notice that we haven't configured the arc0e device on insight.
+   This would work, but is not really necessary, and would require me to
+   assign insight another special IP number from my private subnet.  Since
+   both insight and patience are using freedom as their default gateway, the
+   two can already talk to each other.
+
+   It's quite fortunate that I set things up like this the first time (cough
+   cough) because it's really handy when I boot insight into DOS.  There, it
+   runs the Novell ODI protocol stack, which only works with RFC1201 ARCnet.
+   In this mode it would be impossible for insight to communicate directly
+   with patience, since the Novell stack is incompatible with Microsoft's
+   Ethernet-Encap.  Without changing any settings on freedom or patience, I
+   simply set freedom as the default gateway for insight (now in DOS,
+   remember) and all the forwarding happens "automagically" between the two
+   hosts that would normally not be able to communicate at all.
+
+   For those who like diagrams, I have created two "virtual subnets" on the
+   same physical ARCnet wire.  You can picture it like this::
+
+
+	  [RFC1201 NETWORK]                   [ETHER-ENCAP NETWORK]
+      (registered Internet subnet)           (RFC1597 private subnet)
+
+			     (IP Masquerade)
+	  /---------------\         *            /---------------\
+	  |               |         *            |               |
+	  |               +-Freedom-*-Gatekeeper-+               |
+	  |               |    |    *            |               |
+	  \-------+-------/    |    *            \-------+-------/
+		  |            |                         |
+	       Insight         |                      Patience
+			   (Internet)
+
+
+
+It works: what now?
+-------------------
+
+Send mail describing your setup, preferably including driver version, kernel
+version, ARCnet card model, CPU type, number of systems on your network, and
+list of software in use to me at the following address:
+
+	apenwarr@worldvisions.ca
+
+I do send (sometimes automated) replies to all messages I receive.  My email
+can be weird (and also usually gets forwarded all over the place along the
+way to me), so if you don't get a reply within a reasonable time, please
+resend.
+
+
+It doesn't work: what now?
+--------------------------
+
+Do the same as above, but also include the output of the ifconfig and route
+commands, as well as any pertinent log entries (ie. anything that starts
+with "arcnet:" and has shown up since the last reboot) in your mail.
+
+If you want to try fixing it yourself (I strongly recommend that you mail me
+about the problem first, since it might already have been solved) you may
+want to try some of the debug levels available.  For heavy testing on
+D_DURING or more, it would be a REALLY good idea to kill your klogd daemon
+first!  D_DURING displays 4-5 lines for each packet sent or received.  D_TX,
+D_RX, and D_SKB actually DISPLAY each packet as it is sent or received,
+which is obviously quite big.
+
+Starting with v2.40 ALPHA, the autoprobe routines have changed
+significantly.  In particular, they won't tell you why the card was not
+found unless you turn on the D_INIT_REASONS debugging flag.
+
+Once the driver is running, you can run the arcdump shell script (available
+from me or in the full ARCnet package, if you have it) as root to list the
+contents of the arcnet buffers at any time.  To make any sense at all out of
+this, you should grab the pertinent RFCs. (some are listed near the top of
+arcnet.c).  arcdump assumes your card is at 0xD0000.  If it isn't, edit the
+script.
+
+Buffers 0 and 1 are used for receiving, and Buffers 2 and 3 are for sending.
+Ping-pong buffers are implemented both ways.
+
+If your debug level includes D_DURING and you did NOT define SLOW_XMIT_COPY,
+the buffers are cleared to a constant value of 0x42 every time the card is
+reset (which should only happen when you do an ifconfig up, or when Linux
+decides that the driver is broken).  During a transmit, unused parts of the
+buffer will be cleared to 0x42 as well.  This is to make it easier to figure
+out which bytes are being used by a packet.
+
+You can change the debug level without recompiling the kernel by typing::
+
+	ifconfig arc0 down metric 1xxx
+	/etc/rc.d/rc.inet1
+
+where "xxx" is the debug level you want.  For example, "metric 1015" would put
+you at debug level 15.  Debug level 7 is currently the default.
+
+Note that the debug level is (starting with v1.90 ALPHA) a binary
+combination of different debug flags; so debug level 7 is really 1+2+4 or
+D_NORMAL+D_EXTRA+D_INIT.  To include D_DURING, you would add 16 to this,
+resulting in debug level 23.
+
+If you don't understand that, you probably don't want to know anyway.
+E-mail me about your problem.
+
+
+I want to send money: what now?
+-------------------------------
+
+Go take a nap or something.  You'll feel better in the morning.