Linux PCMCIA HOWTO
David Hinds,
[email protected]
v1.33, 9 April 1995
This document describes how to install and use PCMCIA Card Services
for Linux, and answers some frequently asked questions. The latest
version of this document can always be found at cb-iris.stanford.edu
in /pub/pcmcia/doc.
1. General information and hardware requirements
1.1. Introduction
Card Services for Linux is a complete PCMCIA support package. It
includes a set of loadable kernel modules that implement a version of
the PCMCIA Card Services applications program interface, a set of
client drivers for specific cards, and a card manager daemon that can
respond to card insertion and removal events, loading and unloading
drivers on demand. It supports ``hot swapping'' of PCMCIA cards, so
cards can be inserted and ejected at any time.
This is beta software. It probably contains bugs, and should be used
with caution. I'll do my best to fix problems that are reported to
me, but if you don't tell me, I may never know. If you use this code,
I hope you will send me your experiences, good or bad!
If you have any suggestions for how this document could be improved,
please let me know (
[email protected]).
1.2. Copyright notice and disclaimer
Copyright (c) 1995 David A. Hinds
This document may be reproduced or distributed in any form without my
prior permission. Parts of this document may be distributed, provided
that this copyright message and a pointer to the complete document are
included. Specifically, it may be included in commercial
distributions without my prior consent. However, I would like to be
informed of such usage.
This document may be translated into any language, provided this
copyright statement is left intact.
This document is provided ``as is'', with no explicit or implied
warranties. Use the information in this document at your own risk.
1.3. What is the latest version, and where can I get it?
The current release of Card Services is version 2.5.1.
The latest version is always available from cb-iris.stanford.edu in
the /pub/pcmcia directory. There will sometimes be several versions
here. In that case, the oldest version should be more stable, and
newer versions generally contain more experimental code. It is up to
you to decide which version is more appropriate, but the CHANGES file
will summarize the most important differences.
cb-iris.stanford.edu is mirrored at sunsite.unc.edu in
/pub/Linux/kernel/pcmcia. I'll also try to upload major releases to
tsx-11.mit.edu under /pub/linux/laptops/pcmcia/drivers now and then.
1.4. What systems are supported?
This code should run on almost any Linux-capable laptop. All common
PCMCIA controllers are supported, including Intel, Cirrus, Vadem,
VLSI, and Databook chips. Custom controllers used in IBM and Toshiba
laptops are also supported. Several people use the package on desktop
systems with PCMCIA card adapters.
The Motorola 6AHC05GA controller used in some Hyundai laptops is not
supported.
1.5. What PCMCIA cards are supported?
The current release includes drivers for a variety of ethernet cards,
a driver for modem and serial port cards, several SCSI adapter
drivers, and a simple memory card driver that should support most SRAM
cards and read-only access to Flash cards. The SUPPORTED.CARDS file
included with each release of Card Services lists all cards that are
known to work in at least one actual system.
The likelihood that a card not on the supported list will work depends
on the type of card. Essentially all modems should work with the
supplied driver. Some network cards may work if they are OEM versions
of supported cards. Other types of IO cards (hard drives, sound
cards, etc) will not work until someone writes the appropriate
drivers.
1.6. When will card X be supported?
Unfortunately, they don't pay me to write device drivers, so if you'd
like to have a driver for your favorite card, you're probably going to
have to do some of the work on your own. The SUPPORTED.CARDS file
mentions some cards for which driver work is currently in progress. I
will try to help where I can.
1.7. Mailing list
I maintain a database and mailing list of Linux PCMCIA users. This is
used to announce new releases of the PCMCIA package. If you would
like to be included, send me the following:
o Your name and email address
o What kind of laptop are you using?
o What PCMCIA controller is reported by the probe command?
o What PCMCIA cards are you using?
o Any special settings you use: compilation options, irq and port
settings, /etc/pcmcia/config entries, insmod options, etc.
2. Compilation, installation, and configuration
2.1. Prerequisites and kernel setup
For the latest version, you will need to have kernel version 1.1.93 or
higher, or kernel 1.2.0 or higher. There are no kernel patches
specifically for PCMCIA support. You'll also need to have a
relatively recent set of module utilities. If your man page for
insmod describes the [symbol=value ...] syntax, your utilities are
current enough.
You need to have a complete linux source tree for your kernel, not
just an up-to-date kernel image, when you compile the PCMCIA package.
The PCMCIA modules contain some references to kernel source files.
Current kernel sources and patches are available from sunsite.unc.edu
in /pub/Linux/kernel/v1.1, or from tsx-11.mit.edu in
/pub/linux/sources/system/v1.1. Current module utilities can be found
in the same places, in the file modules-1.1.87.tgz.
When configuring your kernel, if you plan on using a PCMCIA ethernet
card, you should turn on networking support but turn off the normal
Linux network card drivers, including the ``pocket and portable
adapters''. The PCMCIA network card drivers are all implemented as
loadable modules. All of the PCMCIA net drivers except the 3Com 3c589
driver depend on the 8390.o driver module which is part of the Linux
kernel.
If you want to use SLIP, PPP, or PLIP, you do need to either configure
your kernel with these enabled, or use the loadable module versions of
these drivers. There is an unfortunate deficiency in the kernel
config process, in that it is not possible to set configuration
options (like SLIP compression) for a loadable module, so it is
probably better to just link SLIP into the kernel if you need it.
If you will be using a PCMCIA SCSI adapter, you should enable
CONFIG_SCSI when configuring your kernel. Also, enable any top level
drivers (SCSI disk, tape, cdrom, generic) that you expect to use. All
low-level drivers for particular host adapters should be disabled.
There is currently a bad interaction between the SCSI modules and
CONFIG_MODVERSIONS, so you will need to disable this option if you
plan to use one of these cards.
For recent kernels, you must explicitly do ``make modules'' followed
by ``make modules_install'' in /usr/src/linux to build the loadable
driver modules. They will be installed under /lib/modules.
2.2. Installation
Starting with release 2.4.8, this package includes an X-based card
status utility called cardinfo. This utility is based on a public
domain user interface toolkit called the Forms Library, which you will
need to install before building cardinfo. A binary distribution is on
cb-iris.stanford.edu in /pub/pcmcia/extras/bxform-0.61.tgz. There is
a small bug in the Makefile: the line that starts with ``ln -s''
should have ``; fi'' added to the end.
Unpack the pcmcia-cs-2.5.1.tgz package in a convenient location, like
/usr/src.
Make sure the definitions in make.options are consistent with your
site setup. Running ``make prereq'' will check your system
configuration to verify that it satisfies all prerequisites for
installing PCMCIA support.
Running ``make all'' followed by ``make install'' will build and then
install the kernel modules and utility programs. Kernel modules are
installed under /lib/modules/<version>/pcmcia. The cardmgr and
cardctl programs are installed in /sbin. If cardinfo is built, it is
installed in /usr/bin/X11.
Configuration files are kept in the /etc/pcmcia directory: do ``make
install-etc'' to set up this directory. If you are installing over an
older version, the new config files will be installed with a ``.N''
suffix -- you should replace or update your existing files by hand.
Finally, ``make install-man'' will install man pages for all the
loadable modules and programs.
If you don't know what kind of PCMCIA controller chip you have, you
can use the probe utility in the cardmgr/ subdirectory to determine
this. There are two major types: the Databook TCIC-2 type and the
Intel i82365SL-compatible type.
A user-level daemon processes card insertion and removal events. This
is called cardmgr. It is similar in function to Barry Jaspan's
pcmciad in earlier PCMCIA releases. Cardmgr reads a configuration
file describing known PCMCIA cards from /etc/pcmcia/config. This file
also specifies what resources can be allocated for use by PCMCIA
devices, and may need to be customized for your system. See the
pcmcia man page for more information about this file.
The script rc.pcmcia, installed in /etc/rc.d, controls starting up and
shutting down the PCMCIA system. ``make install-etc'' will use the
probe command to determine your controller type and modify rc.pcmcia
appropriately. You should add a line to your system startup file
/etc/rc.d/rc.M to invoke this:
/etc/rc.d/rc.pcmcia start
If you are using a PCMCIA ethernet card, you should not try to
configure it in /etc/rc.d/rc.inet1, since the card may not be present
when this script is executed. Comment out everything except the
loopback stuff in rc.inet1 and instead edit the /etc/pcmcia/network
script to match your local network setup. This script will be
executed only when your ethernet card is actually present.
2.3. Site-specific configuration options
Card Services should automatically avoid allocating IO ports and
interrupts already in use by other standard devices. This should work
for any devices that have Linux drivers, like serial and parallel
ports, IDE drives, and some sound cards. If a device is unsupported
by Linux, you may need to explicitly exclude the resources it uses in
/etc/pcmcia/config.
Some PCMCIA controllers have optional features that may or may not be
implemented in a particular system. It is generally impossible for a
socket driver to detect if these features are implemented. Check the
man page for your driver to see what optional features may be enabled.
The low level socket drivers, tcic and i82365, have numerous bus
timing parameters that may need to be adjusted for systems with
particularly fast processors. Symptoms of timing problems include
lock-ups under heavy loads, high error rates, or poor device
performance. Check the corresponding man pages for more details, but
here is a brief summary:
o Cirrus controllers have numerous configurable timing parameters.
The most important is the freq_bypass flag which changes the
multiplier for the PCMCIA bus clock to slow down all operations.
o The Cirrus CL6729 PCI controller has the fast_pci flag, which
should be set if the PCI bus speed is greater than 25 MHz.
o For Vadem VG-468 controllers and Databook TCIC-2 controllers, the
async_clock flag changes the relative clocking of PCMCIA bus and
host bus cycles. Setting this flag adds extra wait states to some
operations.
All these options should be configured by modifying the top of
/etc/rc.d/rc.pcmcia. For example:
# Should be either i82365 or tcic
PCIC=i82365
# Put socket driver timing parameters here
OPTS="async_clock=1"
On some systems using Cirrus controllers, including the NEC Versa M,
the BIOS puts the controller in a special suspended state at system
startup time. On these systems, the probe command will fail to find
any known PCMCIA controller. In this case, edit /etc/rc.pcmcia by
hand as follows:
# Should be either i82365 or tcic
PCIC=i82365
# Put socket driver timing parameters here
OPTS="wakeup=1"
2.4. Can I install Linux via NFS with a PCMCIA network card?
I've created a set of 1.44MB boot and root disks with PCMCIA support
for the Slackware 2.1 distribution. The files are pcboot14.gz and
pcroot14.gz on cb-iris.stanford.edu and sunsite.unc.edu (see section
``1.3''). The root disk includes cardmgr, the core PCMCIA modules,
and all the network drivers. As for how to use these, you should
familiarize yourself with the Slackware installation instructions,
available from the usual FTP sites. The PCMCIA drivers will be loaded
automatically, and installation will be the same as for a non-PCMCIA
net card. Note that Slackware root disks do not include any normal
user-level network utilities (ftp, telnet, etc). They only include
enough network support to establish an NFS mount.
After installation is complete, you'll have a non-PCMCIA setup on your
root disk. It is possible to copy things from the boot and root disks
to get a working network setup, but it is tricky to put everything in
the right places by hand. First, with the boot disk mounted on /mnt,
do:
cp /mnt/vmlinuz /linuz
rootflags /vmlinuz 1
lilo
Then, with the root disk mounted on /mnt, do:
cp /mnt/sbin/cardmgr /sbin
(cd /mnt ; tar cf - etc/pcmcia lib/modules) | (cd / ; tar xf -)
Edit /etc/pcmcia/config and un-comment the ``start'' and ``stop''
commands for the net cards, and edit /etc/pcmcia/network to conform to
your network setup.
Alternatively, if your install server has a current set of source
files, you can copy current kernel sources, pcmcia sources, and module
utilities to your hard disk while it is NFS mounted. Then, after
rebooting, build a new kernel and install the PCMCIA software as
normal.
2.5. Why doesn't my system respond to card insertions?
In most cases, the socket driver (i82365 or tcic) will automatically
probe and select an appropriate interrupt to signal card status
changes. The automatic interrupt probe doesn't work on some Intel-
compatible controllers, including Cirrus chips and the chips used in
some IBM ThinkPads. In these cases, the i82365 driver may pick an
interrupt that is used by another device.
With the i82365 driver, the irq_mask option can be used to limit the
interrupts that will be tested. This mask limits the set of
interrupts that can be used by PCMCIA cards as well as for monitoring
card status changes. For the tcic driver, the cs_irq option can be
used to explicitly set the interrupt to be used for monitoring card
status changes.
If you can't find an interrupt number that works, there is also a
polled status mode: both i82365 and tcic will accept a
poll_interval=100 option, to poll once per second.
3. Usage and features
3.1. How do I tell if it is working?
The cardmgr daemon normally beeps when a card is inserted, and the
tone of the beeps indicates the status of the newly inserted card.
Two high beeps indicate the card was identified and configured
successfully. A high beep followed by a lower beep indicates that the
card was identified, but could not be configured for some reason. One
low beep indicates that the card could not be identified.
If you are running X, the new cardinfo utility produces a slick
graphical display showing the current status of all PCMCIA sockets.
If the modules are all loaded correctly, the output of the lsmod
command should look like the following, with no cards inserted:
Module: #pages: Used by:
ds 2
i82365 2
pcmcia_core 4 [ds i82365]
All the PCMCIA modules and the cardmgr daemon send status messages to
the system log. This will usually be /usr/adm/messages. This file
should be the first place you look when tracking down a problem. When
submitting a bug report, you should always include the contents of
this file. Cardmgr also records some current device information for
each socket in /etc/stab.
3.2. How do I tell cardmgr how to identify a new card?
Assuming that your card is supported by an existing driver, all that
needs to be done is to add an entry to /etc/pcmcia/config to tell
cardmgr how to identify the card, and which driver(s) need to be
linked up to this card. Check the man page for pcmcia for more
information about the config file format. If you insert an unknown
card, cardmgr will normally record some identification information in
/usr/adm/messages that can be used to construct the config entry.
Here is an example of how cardmgr will report an unsupported card in
/usr/adm/messages.
cardmgr[460]: unsupported card in socket 1
cardmgr[460]: version info: "MEGAHERTZ", "XJ2288", "V.34 PCMCIA MODEM"
The corresponding entry in /etc/pcmcia/config would be:
card "Megahertz XJ2288 V.34 Fax Modem"
version "MEGAHERTZ", "XJ2288", "V.34 PCMCIA MODEM"
bind "serial_cs"
You can use ``*'' to match strings that don't need to match exactly,
like version numbers. When making new config entries, be careful to
copy the strings exactly, preserving case and blank spaces. Also be
sure that the config entry has the same number of strings as are
reported in the log file.
After editing /etc/pcmcia/config, you can signal cardmgr to reload the
file with:
kill -HUP `cat /var/run/cardmgr.pid`
If you do set up an entry for a new card, please send me a copy so
that I can include it in sample.config.
3.3. How do I control which interrupts and ports are used by a
device?
In theory, it should not really matter which interrupt is allocated to
which device, as long as two devices are not configured to use the
same interrupt. At the top of /etc/pcmcia/config you'll find a place
for excluding interrupts that are used by non-PCMCIA devices.
The ibmcc_cs, de650_cs, 3c589_cs, and serial_cs drivers each have a
parameter called irq_mask for specifying which interrupts they may try
to allocate. Each bit of irq_mask corresponds to one irq line: bit 0
is irq 0, bit 1 is irq 1, and so on. So, a mask of 0x1100 would
correspond to irq 8 and irq 12. To limit a driver to use only one
specific interrupt, its irq_mask should have only one bit set. These
driver options should be set in your /etc/pcmcia/config file. For
example:
device "serial_cs"
module "serial_cs" opts "irq_mask=0x1100"
...
would specify that the serial driver should only use irq 8 or irq 12.
Note that Card Services will never allocate an interrupt that is
already in use by another device, or an interrupt that is excluded in
the config file.
There is no way to directly specify the I/O addresses for a PCMCIA
card to use. The /etc/pcmcia/config file allows you to specify ranges
of ports available for use by all PCMCIA devices.
After modifying /etc/pcmcia/config, you can restart cardmgr with
``kill -HUP''.
3.4. When is it safe to insert or eject a PCMCIA card?
In theory, you can insert and remove PCMCIA cards at any time.
However, it is a good idea not to eject a card that is currently being
used by an application program. Kernels older than 1.1.77 would often
lock up when serial/modem cards were ejected, but this should be fixed
now.
3.5. How do I unload PCMCIA drivers?
To unload the entire PCMCIA package, invoke rc.pcmcia with:
/etc/rc.d/rc.pcmcia stop
This script will take several seconds to run, to give all client
drivers time to shut down gracefully. If a PCMCIA device is currently
in use, the shutdown will fail.
3.6. How does Card Services deal with suspend/resume?
Card Services can be compiled with support for APM (Advanced Power
Management) if you've installed this package on your system. The
current release of Stephen Rothwell's APM support package is version
0.5. Unlike the 0.4 release, 0.5 does not require a special patch to
work with PCMCIA. The PCMCIA modules will automatically be configured
for APM if a compatible version is detected on your system.
Without resorting to APM, you can do ``cardctl suspend'' before
suspending your laptop, and ``cardctl resume'' after resuming, to
properly shut down and restart your PCMCIA cards. This will not work
with a PCMCIA modem that is in use, because the serial driver isn't
able to save and restore the modem operating parameters.
APM seems to be unstable on some systems. If you experience trouble
with APM and PCMCIA on your system, try to narrow down the problem to
one package or the other before reporting a bug.
3.7. How do I turn off a PCMCIA card without ejecting it?
Use either the cardctl or cardinfo command. ``cardctl suspend #''
will suspend one socket, and turn off its power. The corresponding
resume command will wake up the card in its previous state.
4. Problems with specific cards
4.1. Why doesn't my modem work?
That's a broad question, but here's a quick troubleshooting guide.
o Is your card recognized as a modem? Check /usr/adm/messages and
make sure that cardmgr identifies the card correctly and starts up
the serial_cs driver. If it doesn't, you may need to add a new
entry to your /etc/pcmcia/config file so that it will be identified
properly. See section ``3.2'' for details.
o Is the modem configured successfully by serial_cs? Again, check
/usr/adm/messages and look for messages from the serial_cs driver.
If you see ``register_serial() failed'', you may have an I/O port
conflict with another device. Another tip-off of a conflict is if
the device is reported to be an 8250; most modern PCMCIA modems
should be identified as 16550A UART's. If you think you're seeing
a port conflict, edit /etc/pcmcia/config and exclude the port range
that was allocated for the modem.
o Is there an interrupt conflict? If /usr/adm/messages looks good,
but the modem just doesn't seem to work, try using setserial to
change the irq to 0, and see if the modem works. This causes the
serial driver to use a slower polled mode instead of using
interrupts. If this seems to fix the problem, it is likely that
some other device in your system is using the interrupt selected by
serial_cs. You should add a line to /etc/pcmcia/config to exclude
this interrupt.
o Make sure your problem is really a PCMCIA one. It may help to see
if the card works under DOS with the vendor's drivers. Also, don't
test the card with something complex like SLIP until you are sure
you can make simple connections. If simple things work but SLIP
does not, your problem is with SLIP, not with PCMCIA.
4.2. Why does my Megahertz modem sometimes fail to work?
Earlier versions of the PCMCIA drivers often failed to properly
initialize some Megahertz modems, specifically the 2144 model. This
problem should be fixed in current releases.
I've also received one report from someone with a newer Megahertz
modem that has a 16550-type UART. He says that he wasn't able to get
this modem to work under Linux with cu until he configured the modem
with:
echo 'ATS=QV1X4&C1&D2S95=2W1&K3S36=7S95=255' > /dev/modem
This initialization string was supplied by Megahertz tech support.
4.3. Why doesn't my ethernet card work?
Here's another quick troubleshooting guide.
o Is your card recognized as an ethernet card? Check
/usr/adm/messages and make sure that cardmgr identifies the card
correctly and starts up one of the network drivers. If it doesn't,
your card might still be usable if it is compatible with a
supported card. This will be most easily done if the card claims
to be "NE2000 compatible".
o Is the card configured properly? If you are using a supported
card, and it was recognized by cardmgr, but still doesn't work,
there might be an interrupt or port conflict with another device.
Find out what resources the card is using (from /usr/adm/messages),
and try excluding these in /etc/pcmcia/config to force the card to
use something different.
o With Socket EA and 3Com 3c589 cards, you need to pick the
transceiver type (10base2, 10baseT, AUI) when the driver module is
loaded. Make sure that the transceiver type reported in
/usr/adm/messages matches your connection.
o The Farallon EtherWave is actually based on the 3Com 3c589, with a
special transceiver. Though the EtherWave uses 10baseT-style
connections, its transceiver requires that the 3c589 be configured
in 10base2 mode.
o Make sure your problem is really a PCMCIA one. It may help to see
see if the card works under DOS with the vendor's drivers. Double
check your modifications to the /etc/pcmcia/network script. Make
sure your drop cable, ``T'' jack, terminator, etc are working.
o If your card seems to be configured properly, but sometimes locks
up, particularly under high load, you may need to try changing your
socket driver timing parameters. See section ``2.3'' for more
information.
4.4. How do I select the transceiver type for my 3c589 card?
It would be nice if the driver could autodetect the difference between
a 10baseT and a 10base2 connection, but I don't know how to do that.
For now, you need to edit /etc/pcmcia/config and add an if_ports=#
option to the 3c589_cs module definition. Check the tc589_cs man page
for more details, but to select 10base2 (also known as BNC, or thin
net, or coax), change:
module "3c589_cs"
to:
module "3c589_cs" opts "if_port=3"
4.5. My network performance stinks. What can I do?
If you have an NE4100 or IBM CCAE adapter, increase the memory access
time with the mem_speed=# option to the ibmcc_cs module definition.
Try speeds of up to 1000 (in nanoseconds).
For other cards, you may need to try changing your socket driver
timing parameters. Check the man page for your socket driver (i82365
or tcic) to see what parameters are available.
4.6. How do I add support for an NE2000-compatible ethernet card?
First, see if the card is already recognized by cardmgr. Some cards
not listed in SUPPORTED.CARDS are actually OEM versions of cards that
are supported. If you find a card like this, let me know so I can add
it to the list.
If it is not recognized, cardmgr will normally bind the ``memory
card'' driver to the card. Check your system log to verify this,
because you'll need to use this driver. You will also need to know
your card's hardware ethernet address. This address is a series of
six two-digit hex numbers, often printed on the card itself. If it is
not printed on the card, you may be able to use a DOS driver to
display the address. In any case, once you know it, run:
dd if=/dev/pcmem0a count=20 | od -Ax -t x1
and search the output for your address. Record the hex offset of the
first byte of the address. Now, edit modules/de650_cs.c and find the
hw_info structure. You'll need to create a new entry for your card.
The first field is the offset multiplied by two. The next three
fields are the first three bytes of the hardware address. The final
field is just a descriptive name.
After editing de650_cs, install the new module. Edit
/etc/pcmcia/config and create an entry for your card. See section
``3.2'' for details. And please send me copies of your new hw_info
and config entries.
4.7. How do I use my PCMCIA floppy interface?
The PCMCIA floppy interface used in the Compaq Aero and a few other
laptops is not yet supported by this package. If your laptop can
initialize this card before Linux boots, you should be able to use it
by telling Card Services to ignore that socket. Note that you will
not be able to hot swap this card.
To configure Card Services to ignore a socket, use the ignore=#
parameter when you load the i82365 or tcic driver. See the man pages
for more details.
4.8. What's up with support for Xircom cards?
Xircom does not share technical information about its cards without a
non-disclosure agreement. This means that it is not really possible
to develop freely distributable drivers for Xircom cards without doing
legally dubious things like reverse engineering DOS drivers. Unless
their policy changes, it is doubtful that Linux drivers for Xircom
products will ever become available.
4.9. What's up with support for SCSI adapters?
The Qlogic FastSCSI and New Media Bus Toaster cards now work under
Card Services. As of 1.1.81, the Linux kernel supports loadable SCSI
driver modules, but you should try to use the latest available kernel.
The PCMCIA driver modules for these cards are built by linking some
PCMCIA-specific code (in qlogic_cs.c and toaster_cs.c) with a normal
Linux SCSI driver. The Qlogic PCMCIA driver links with the normal
QLogic driver; the Bus Toaster driver links with the Adaptec 152x
driver. Pre-1.2.2 kernels require a patch for the Adaptec driver to
make it PCMCIA-ready: the patch should be available from all the FTP
sites mirroring cb-iris.stanford.edu.
The Adaptec SlimSCSI adapter is not currently supported. This card
was originally sold under the Trantor name, and is not compatible with
any of the existing Adaptec drivers for Linux. I'm not sure how hard
it would be to write a driver; I don't think anyone has obtained the
technical information from Adaptec.
Be very careful about ejecting a SCSI adapter. Be sure that all
associated SCSI devices are unmounted and closed before ejecting the
card. For now, all SCSI devices should be powered up before plugging
in a SCSI adapter, and should stay connected until after you unplug
the adapter and/or power down your laptop.
Roger Pao (
[email protected]) adds:
Make sure there is a device capable of supplying termination power
both to the terminating target device and to the PCMCIA SCSI card.
This is vitally important as most PCMCIA SCSI cards do not supply
termination power to its own terminators nor to the SCSI bus. This is
usually to save laptop battery power and to isolate the laptop from
the SCSI bus.
For a recommendation, the APS SCSI Sentry 2 ($100) is an external
Centronics active terminator block (male on one end, female on the
other) which uses an external power supply (115/230VAC) to supply
termination power (5VDC 2.0A) to its own active terminator and to the
PCMCIA SCSI card's terminators (be it active or passive). For more
details, APS Technical Support can be reached at 800-334-7550.
5. Debugging tips and programming information
5.1. How can I submit a helpful bug report?
Here are some things that should be included in all bug reports:
o Your system type, and the output of the probe command
o What PCMCIA cards you are using
o Your Linux kernel version, and PCMCIA version
o Any changes you've made to the startup files in /etc/pcmcia
o Contents of /usr/adm/messages, even if you don't see anything that
looks interesting.
The make.options file includes a few choices for building the kernel
modules with various kinds of debugging code turned on. This may or
may not be useful, depending on your problem. It is probably better
to only turn on the really verbose debugging if I ask you to.
If your problem involves a kernel fault, the register dump from the
fault is only useful if you can track down the fault address, EIP. If
it is in the main kernel, look up the address in zSystem.map to
identify the function at fault. If the fault is in a loadable module,
it is a bit harder to trace. With the current module tools, ``ksyms
-m'' will report the base address of each loadable module. Pick the
module that contains the EIP address, and subtract its base address
from EIP to get an offset inside that module. Then, run gdb on that
module, and look up the offset with the list command. This will only
work if you've compiled that module with -g to include debugging
information.
Send bug reports to
[email protected]. I prefer to handle
bug reports by email -- please avoid calling me at home or at work.
5.2. Low level PCMCIA debugging aids
The PCMCIA modules contain a lot of conditionally-compiled debugging
code. The make.options file shows how to enable this code. A module
compiled with PCMCIA_DEBUG set will have a parameter, pc_debug, that
controls the verbosity of debugging output. This can be adjusted when
the module is loaded, so output can be controlled on a per-module
basis without recompiling.
There are a few debugging tools in the debug_tools/ subdirectory of
the PCMCIA distribution. The dump_tcic and dump_i365 utilities
generate complete register dumps of the PCMCIA controllers, and decode
a lot of the register information. They are most useful if you have
access to a datasheet for the corresponding controller chip. The
dump_tuples utility lists a card's CIS (Card Information Structure),
and decodes some of the important bits. And the dump_cisreg utility
displays a card's local configuration registers.
The pcmem_cs memory card driver is also sometimes useful for
debugging. It can be bound to any PCMCIA card, and does not interfere
with other drivers. It can be used to directly access any card's
attribute memory or common memory.
5.3. How do I write a Card Services driver for card X?
The Linux PCMCIA Programmer's Guide is the best documentation for the
Linux PCMCIA interface. The latest version is always available from
cb-iris.stanford.edu in /pub/pcmcia/doc.
For devices that are close relatives of normal ISA devices, you'll
probably be able to use parts of existing Linux drivers. In some
cases, the biggest stumbling block will be modifying an existing
driver so that it can handle adding and removing devices after boot
time. Of the current drivers, the memory card driver is the only
``self-contained'' driver that does not depend on other parts of the
Linux kernel to do most of the dirty work.
I've written a skeleton driver with lots of comments that explains a
lot of how a driver communicates with Card Services; you'll find this
in the PCMCIA source distribution in modules/skeleton.c.
