Joerg Reuter, DL1BKE, jreuter@lykos.tng.oche.de has developed generic
support for Z8530 SCC based cards. His driver is configurable to support a
range of different types of cards and present an interface that looks like a
KISS TNC so you can treat it as though it were a KISS TNC.
While the kernel driver is included in the standard kernel distribution, Joerg distributes more recent versions of his driver with the suite of configuration tools that you will need to obtain as well.
You can obtain the configuration tools package from:
db0bm.automation.fh-aachen.de
/incoming/dl1bke/
or:
insl1.etec.uni-karlsruhe.de
/pub/hamradio/linux/z8530/
or:
ftp.ucsd.edu
/hamradio/packet/tcpip/linux
/hamradio/packet/tcpip/incoming/
You will find multiple versions, choose the one that best suits the kernel you intend to use:
z8530drv-2.4.dl1bke.tar.gz 2.0.* z8530drv-utils-3.0.tar.gz 2.1.6 or greater
The following command were what I used to compile and install the package for kernel version 2.0.25:
# cd /usr/src
# gzip -dc z8530drv-2.4.dl1bke.tar.gz | tar xvpofz -
# cd z8530drv
# make clean
# make dep
# make module # If you want to build the driver as a module
# make for_kernel # If you want the driver to built into your kernel
# make install
After the above is complete you should have three new programs installed
in your /sbin directory: gencfg, sccinit and
sccstat. It is these programs that you will use to configure the
driver for your card.
You will also have a group of new special device files created in your
/dev called scc0 .. scc7. These will be used
later and will be the `KISS' devices you will end up using.
If you chose to 'make for_kernel' then you will need to recompile your
kernel. To ensure that you include support for the z8530 driver you must be
sure to answer `Y' to:
`Z8530 SCC kiss emulation driver for AX.25' when asked during a
kernel `make config'.
If you chose to 'make module' then the new scc.o will have been
installed in the appropriate /lib/modules directory and you do
not need to recompile your kernel. Remember to use the insmod command
to load the module before your try and configure it.
The z8530 SCC driver has been designed to be as flexible as possible so as to support as many different types of cards as possible. With this flexibility has come some cost in configuration.
There is more comprehensive documentation in the package and you should
read this if you have any problems. You should particularly look at
doc/scc_eng.doc or doc/scc_ger.doc for more detailed
information. I've paraphrased the important details, but as a result there
is a lot of lower level detail that I have not included.
The main configuration file is read by the sccinit program and is
called /etc/z8530drv.rc. This file is broken into two main stages:
Configuration of the hardware parameters and channel configuration. After
you have configured this file you need only add:
# sccinit
into the rc file that configures your network and the driver will
be initialised according to the contents of the configuration file. You must
do this before you attempt to use the driver.
The first section is broken into stanzas, each stanza representing an 8530
chip. Each stanza is a list of keywords with arguments. You may specify up
to four SCC chips in this file by default. The #define MAXSCC 4 in
scc.c can be increased if you require support for more.
The allowable keywords and arguments are:
the chip keyword is used to separate stanzas. It will
take anything as an argument. The arguments are not used.
this keyword is used to specify the address of the data port for the z8530 channel `A'. The argument is a hexadecimal number e.g. 0x300
this keyword is used to specify the address of the control port for the z8530 channel `A'. The arguments is a hexadecimal number e.g. 0x304
this keyword is used to specify the address of the data port for the z8530 channel `B'. The argument is a hexadecimal number e.g. 0x301
this keyword is used to specify the address of the control port for the z8530 channel `B'. The arguments is a hexadecimal number e.g. 0x305
this keyword is used to specify the IRQ used by the 8530 SCC described in this stanza. The argument is an integer e.g. 5
this keyword is used to specify the frequency of the clock at the PCLK pin of the 8530. The argument is an integer frequency in Hz which defaults to 4915200 if the keyword is not supplied.
the type of board supporting this 8530 SCC. The argument is a character string. The allowed values are:
the PA0HZP SCC Card
the Eagle card
the DRSI PC100 SCC card
the PRIMUS-PC (DG9BL) card
BayCom (U)SCC card
this keyword is optional and is used to enable support for the Extended SCC chips (ESCC) such as the 8580, 85180, or the 85280. The argument is a character string with allowed values of `yes' or `no'. The default is `no'.
this keyword is optional and specifies the address of the vector latch (also known as "intack port") for PA0HZP cards. There can be only one vector latch for all chips. The default is 0.
this keyword is optional and specifies the address of the special function register on several cards. The default is 0.
this keyword is optional and defaults to 0.
Some example configurations for the more popular cards are as follows:
chip 1
data_a 0x300
ctrl_a 0x304
data_b 0x301
ctrl_b 0x305
irq 5
board BAYCOM
#
# SCC chip 2
#
chip 2
data_a 0x302
ctrl_a 0x306
data_b 0x303
ctrl_b 0x307
board BAYCOM
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
chip 1
data_a 0x303
data_b 0x301
ctrl_a 0x302
ctrl_b 0x300
irq 7
pclock 4915200
board DRSI
escc no
If you already have a working configuration for your card under NOS, then you can use the gencfg command to convert the PE1CHL NOS driver commands into a form suitable for use in the z8530 driver configuration file.
To use gencfg you simply invoke it with the same parameters as you used for the PE1CHL driver in NET/NOS. For example:
# gencfg 2 0x150 4 2 0 1 0x168 9 4915200
The Channel Configuration section is where you specify all of the other parameters associated with the port you are configuring. Again this section is broken into stanzas. One stanza represents one logical port, and therefore there would be two of these for each one of the hardware parameters stanzas as each 8530 SCC supports two ports.
These keywords and arguments are also written to the /etc/z8530drv.rc
file and must appear after the hardware parameters section.
Sequence is very important in this section, but if you stick with the suggested sequence it should work ok. The keywords and arguments are:
this keyword must be the first line of a port definition and
specifies the name of the special device file that the rest of the
configuration applies to. e.g. /dev/scc0
this keyword specifies the speed in bits per second of the
interface. The argument is an integer: e.g. 1200
this keyword specifies where the clock for the data will be sourced. Allowable values are:
normal halfduplex operation
MODEM supplies its own Rx/Tx clock
use fullduplex divider if installed.
this keyword specifies the data coding to be used. Allowable
arguments are: nrzi or nrz
this keyword specifies the number of receive buffers to allocate memory for. The argument is an integer, e.g. 8.
this keyword specifies the number of transmit buffers to allocate memory for. The argument is an integer, e.g. 8.
this keyword specifies the size of the receive and transmit
buffers. The arguments is in bytes and represents the total length of the
frame, so it must also take into account the AX.25 headers and not just the
length of the data field. This keyword is optional and default to 384
the KISS transmit delay value, the argument is an integer in mS.
the KISS persist value, the argument is an integer.
the KISS slot time value, the argument is an integer in mS.
the KISS transmit tail value, the argument is an integer in mS.
the KISS full duplex flag, the argument is an integer.
1==Full Duplex, 0==Half Duplex.
the KISS wait value, the argument is an integer in mS.
the KISS min value, the argument is an integer in S.
the KISS maximum keyup time, the argument is an integer in S.
the KISS idle timer value, the argument is an integer in S.
the KISS maxdef value, the argument is an integer.
the KISS group value, the argument is an integer.
the KISS txoff value, the argument is an integer in mS.
the KISS softdcd value, the argument is an integer.
the KISS slip flag, the argument is an integer.
To use the driver you simply treat the /dev/scc* devices just as
you would a serial tty device with a KISS TNC connected to it. For example,
to configure Linux Kernel networking to use your SCC card you could use
something like:
# axattach -s 4800 /dev/scc0 VK2KTJ
You can also use NOS to attach to it in precisely the same way. From JNOS for example you would use something like:
attach asy scc0 0 ax25 scc0 256 256 4800
To assist in the diagnosis of problems you can use the sccstat program to display the current configuration of an SCC device. To use it try:
# sccstat /dev/scc0
you will displayed a very large amount of information relating to the
configuration and health of the /dev/scc0 SCC port.
The sccparam command allows you to change or modify a configuration
after you have booted. Its syntax is very similar to the NOS param
command, so to set the txtail setting of a device to 100mS you
would use:
# sccparam /dev/scc0 txtail 0x8