z8530drv.txt

《嵌入式系统设计与实例开发实验教材二源码》Linux内核移植与编译实验

This is a subset of the documentation. To use this driver you MUST have the
full package from:

Internet:
=========

1. ftp://ftp.ccac.rwth-aachen.de/pub/jr/z8530drv-utils_3.0-3.tar.gz

2. ftp://ftp.pspt.fi/pub/ham/linux/ax25/z8530drv-utils_3.0-3.tar.gz

Please note that the information in this document may be hopelessly outdated.
A new version of the documentation, along with links to other important
Linux Kernel AX.25 documentation and programs, is available on
http://yaina.de/jreuter

-----------------------------------------------------------------------------


	 SCC.C - Linux driver for Z8530 based HDLC cards for AX.25      

   ********************************************************************

        (c) 1993,2000 by Joerg Reuter DL1BKE <[e-mail]>

        portions (c) 1993 Guido ten Dolle PE1NNZ

        for the complete copyright notice see >> Copying.Z8530DRV <<

   ******************************************************************** 


1. Initialization of the driver
===============================

To use the driver, 3 steps must be performed:

     1. if compiled as module: loading the module
     2. Setup of hardware, MODEM and KISS parameters with sccinit
     3. Attach each channel to the Linux kernel AX.25 with "ifconfig"

Unlike the versions below 2.4 this driver is a real network device
driver. If you want to run xNOS instead of our fine kernel AX.25
use a 2.x version (available from above sites) or read the
AX.25-HOWTO on how to emulate a KISS TNC on network device drivers.


1.1 Loading the module
======================

(If you're going to compile the driver as a part of the kernel image,
 skip this chapter and continue with 1.2)

Before you can use a module, you'll have to load it with

	insmod scc.o

please read 'man insmod' that comes with modutils.

You should include the insmod in one of the /etc/rc.d/rc.* files,
and don't forget to insert a call of sccinit after that. It
will read your /etc/z8530drv.conf.

1.2. /etc/z8530drv.conf
=======================

To setup all parameters you must run /sbin/sccinit from one
of your rc.*-files. This has to be done BEFORE you can
"ifconfig" an interface. Sccinit reads the file /etc/z8530drv.conf
and sets the hardware, MODEM and KISS parameters. A sample file is
delivered with this package. Change it to your needs.

The file itself consists of two main sections.

1.2.1 configuration of hardware parameters
==========================================

The hardware setup section defines the following parameters for each
Z8530:

chip    1
data_a  0x300                   # data port A
ctrl_a  0x304                   # control port A
data_b  0x301                   # data port B
ctrl_b  0x305                   # control port B
irq     5                       # IRQ No. 5
pclock  4915200                 # clock
board   BAYCOM                  # hardware type
escc    no                      # enhanced SCC chip? (8580/85180/85280)
vector  0                       # latch for interrupt vector
special no                      # address of special function register
option  0                       # option to set via sfr


chip	- this is just a delimiter to make sccinit a bit simpler to
	  program. A parameter has no effect.

data_a  - the address of the data port A of this Z8530 (needed)
ctrl_a  - the address of the control port A (needed)
data_b  - the address of the data port B (needed)
ctrl_b  - the address of the control port B (needed)

irq     - the used IRQ for this chip. Different chips can use different
          IRQs or the same. If they share an interrupt, it needs to be
	  specified within one chip-definition only.

pclock  - the clock at the PCLK pin of the Z8530 (option, 4915200 is
          default), measured in Hertz

board   - the "type" of the board:

	   SCC type                 value
	   ---------------------------------
	   PA0HZP SCC card          PA0HZP
	   EAGLE card               EAGLE
	   PC100 card               PC100
	   PRIMUS-PC (DG9BL) card   PRIMUS
	   BayCom (U)SCC card       BAYCOM

escc    - if you want support for ESCC chips (8580, 85180, 85280), set
          this to "yes" (option, defaults to "no")

vector  - address of the vector latch (aka "intack port") for PA0HZP
          cards. There can be only one vector latch for all chips!
	  (option, defaults to 0)

special - address of the special function register on several cards.
          (option, defaults to 0)

option  - The value you write into that register (option, default is 0)

You can specify up to four chips (8 channels). If this is not enough,
just change

	#define MAXSCC 4

to a higher value.

Example for the BAYCOM USCC:
----------------------------

chip    1
data_a  0x300                   # data port A
ctrl_a  0x304                   # control port A
data_b  0x301                   # data port B
ctrl_b  0x305                   # control port B
irq     5                       # IRQ No. 5 (#)
board   BAYCOM                  # hardware type (*)
#
# SCC chip 2
#
chip    2
data_a  0x302
ctrl_a  0x306
data_b  0x303
ctrl_b  0x307
board   BAYCOM

An example for a PA0HZP card:
-----------------------------

chip 1
data_a 0x153
data_b 0x151
ctrl_a 0x152
ctrl_b 0x150
irq 9
pclock 4915200
board PA0HZP
vector 0x168
escc no
#
#
#
chip 2
data_a 0x157
data_b 0x155
ctrl_a 0x156
ctrl_b 0x154
irq 9
pclock 4915200
board PA0HZP
vector 0x168
escc no

A DRSI would should probably work with this:
--------------------------------------------
(actually: two DRSI cards...)

chip 1
data_a 0x303
data_b 0x301
ctrl_a 0x302
ctrl_b 0x300
irq 7
pclock 4915200
board DRSI
escc no
#
#
#
chip 2
data_a 0x313
data_b 0x311
ctrl_a 0x312
ctrl_b 0x310
irq 7
pclock 4915200
board DRSI
escc no

Note that you cannot use the on-board baudrate generator off DRSI
cards. Use "mode dpll" for clock source (see below).

This is based on information provided by Mike Bilow (and verified
by Paul Helay)

The utility "gencfg"
--------------------

If you only know the parameters for the PE1CHL driver for DOS,
run gencfg. It will generate the correct port addresses (I hope).
Its parameters are exactly the same as the ones you use with
the "attach scc" command in net, except that the string "init" must 
not appear. Example:

gencfg 2 0x150 4 2 0 1 0x168 9 4915200 

will print a skeleton z8530drv.conf for the OptoSCC to stdout.

gencfg 2 0x300 2 4 5 -4 0 7 4915200 0x10

does the same for the BAYCOM USCC card. In my opinion it is much easier
to edit scc_config.h... 


1.2.2 channel configuration
===========================

The channel definition is divided into three sub sections for each
channel:

An example for scc0:

# DEVICE

device scc0	# the device for the following params

# MODEM / BUFFERS

speed 1200		# the default baudrate
clock dpll		# clock source: 
			# 	dpll     = normal half duplex operation
			# 	external = MODEM provides own Rx/Tx clock
			#	divider  = use full duplex divider if
			#		   installed (1)
mode nrzi		# HDLC encoding mode
			#	nrzi = 1k2 MODEM, G3RUH 9k6 MODEM
			#	nrz  = DF9IC 9k6 MODEM
			#
bufsize	384		# size of buffers. Note that this must include
			# the AX.25 header, not only the data field!
			# (optional, defaults to 384)

# KISS (Layer 1)

txdelay 36              # (see chapter 1.4)
persist 64
slot    8
tail    8
fulldup 0
wait    12
min     3
maxkey  7
idle    3
maxdef  120
group   0
txoff   off
softdcd on                   
slip    off

The order WITHIN these sections is unimportant. The order OF these
sections IS important. The MODEM parameters are set with the first
recognized KISS parameter...

Please note that you can initialize the board only once after boot
(or insmod). You can change all parameters but "mode" and "clock" 
later with the Sccparam program or through KISS. Just to avoid 
security holes... 

(1) this divider is usually mounted on the SCC-PBC (PA0HZP) or not
    present at all (BayCom). It feeds back the output of the DPLL 
    (digital pll) as transmit clock. Using this mode without a divider 
    installed will normally result in keying the transceiver until 
    maxkey expires --- of course without sending anything (useful).

2. Attachment of a channel by your AX.25 software
=================================================

2.1 Kernel AX.25
================

To set up an AX.25 device you can simply type:

	ifconfig scc0 44.128.1.1 hw ax25 dl0tha-7

This will create a network interface with the IP number 44.128.20.107 
and the callsign "dl0tha". If you do not have any IP number (yet) you 
can use any of the 44.128.0.0 network. Note that you do not need 
axattach. The purpose of axattach (like slattach) is to create a KISS 
network device linked to a TTY. Please read the documentation of the 
ax25-utils and the AX.25-HOWTO to learn how to set the parameters of
the kernel AX.25.

2.2 NOS, NET and TFKISS
=======================

Since the TTY driver (aka KISS TNC emulation) is gone you need
to emulate the old behaviour. The cost of using these programs is
that you probably need to compile the kernel AX.25, regardless of whether
you actually use it or not. First setup your /etc/ax25/axports,
for example:

	9k6	dl0tha-9  9600  255 4 9600 baud port (scc3)
	axlink	dl0tha-15 38400 255 4 Link to NOS

Now "ifconfig" the scc device:

	ifconfig scc3 44.128.1.1 hw ax25 dl0tha-9