Linux PCMCIA HOWTO David Hinds, dhinds@hyper.stanford.edu v2.5, 19 February 1998 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 . An HTML version is at . 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 software is continually under development. 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 (dhinds@hyper.stanford.edu). 1.2. Copyright notice and disclaimer Copyright (c) 1998 David A. Hinds This document may be reproduced or distributed in any form without my prior permission. Modified versions of this document, including translations into other languages, may be freely distributed, provided that they are clearly identified as such, and this copyright is included intact. This document may be included in commercial distributions without my prior consent. While it is not required, I would like to be informed of such usage. If you intend to incorporate this document in a published work, please contact me to make sure you have the latest available version. 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 major release of Card Services is version 3.0, and minor updates or bug fixes are numbered 3.0.1, 3.0.2, and so on. Source code for the latest version is available from hyper.stanford.edu in the /pub/pcmcia directory, as pcmcia- cs-3.0.?.tar.gz. There will usually be several versions here. I generally only keep the latest minor release for a given major release. New major releases may contain relatively untested code, so I also keep the latest version of the previous major release as a relatively stable fallback; the current fallback is 2.9.12. It is up to you to decide which version is more appropriate, but the CHANGES file will summarize the most important differences. hyper.stanford.edu is mirrored at sunsite.unc.edu (and all sunsite mirror sites) in /pub/Linux/kernel/pcmcia. If you do not feel up to compiling the PCMCIA drivers from scratch, pre-compiled drivers are included with current releases of most of the major Linux distributions, including Slackware, Red Hat, Caldera, and Yggdrasil, among others. 1.4. What systems are supported? This code should run on almost any Linux-capable laptop. Most common PCMCIA controllers are supported, including Intel, Cirrus, Vadem, VLSI, Ricoh, and Databook chips. Custom controllers used in IBM and Toshiba laptops are also supported. PCMCIA card docks for desktop systems should work as long as they are the type that plugs directly into the ISA bus, rather than SCSI-to-PCMCIA or IDE-to-PCMCIA adapters. CardBus bridge controllers that conform to the ``Yenta'' register specification (including TI, Cirrus, SMC, O2Micro, Omega Micro, and Ricoh chips) are supported, though support for 32-bit CardBus cards is still somewhat experimental. Drivers prior to version 3.0 only support 16-bit cards in CardBus sockets. Due to the rapid pace of technological change for laptop hardware, new controllers appear frequently, and there may be delays between when a new model appears on the market, and when driver support becomes available. The Motorola 6AHC05GA controller used in some Hyundai laptops is not supported. The custom PCMCIA controller in the HP Omnibook 600 is unsupported. 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, a driver for ATA/IDE drive cards, and memory card drivers that should support most SRAM cards and some 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 (frame buffers, sound cards, etc) will not work until someone writes the appropriate drivers. 1.6. When will my new card be supported? Unfortunately, they usually don't pay me to write device drivers, so if you would like to have a driver for your favorite card, you are probably going to have to do at least some of the work. Ideally, I'd like to work towards a model like the Linux kernel, where I would be responsible mainly for the ``core'' PCMCIA code and other authors would contribute and maintain drivers for specific cards. The SUPPORTED.CARDS file mentions some cards for which driver work is currently in progress. I will try to help where I can, but be warned that debugging kernel device drivers by email is not particularly effective. Manufacturers interested in helping provide Linux support for their products can contact me about consulting arrangements. 1.7. Mailing lists and other information sources I used to maintain a database and mailing list of Linux PCMCIA users. More recently, I've turned my web page for Linux PCMCIA information into a ``HyperNews'' site, with a set of message lists for Linux PCMCIA issues. There are lists for installation and configuration issues, for different types of cards, and for PCMCIA programming and debugging. The Linux PCMCIA information page is at . Users can request email notification of new responses to particular questions, or notification for all new messages in a given category. I hope that this will become a useful repository of information, for questions that go beyond the scope of the HOWTO. There is a Linux mailing list devoted to laptop issues, the ``linux- laptop'' list. For more information, send a message containing the word ``help'' to majordomo@vger.rutgers.edu. To subscribe, send a message containing ``subscribe linux-laptop'' to the same address. This mailing list might be a good forum for discussion of Linux PCMCIA issues. The Linux Laptop Home Page at has links to many sites that have information about configuring specific types of laptops for Linux (and PCMCIA). There is also a searchable database of system configuration information. 1.8. Why don't you distribute PCMCIA binaries? For me, distributing binaries would be a significant hassle. It is complicated because some features can only be selected at compile time, and because the PCMCIA modules are somewhat dependent on having the ``right'' kernel configuration. So, I would probably need to distribute precompiled modules along with matching kernels. Beyond this, the greatest need for precompiled modules is when installing Linux on a clean system. This typically requires setting up PCMCIA so that it can be used in the installation process for a particular Linux distribution. Each Linux distribution has its own procedures, and it is not feasible for me to provide boot and root disks for even just the common combinations of drivers and distributions. PCMCIA is now a part of many of the major Linux distributions, including Red Hat, Caldera, Slackware, Yggdrasil, Craftworks, and Nascent Technology. 1.9. Why is the PCMCIA package so darned big? Well, first of all, it isn't actually that large. All the driver modules together take up about 200K of disk space. The utility programs add up to about 70K, and the stuff in /etc/pcmcia is about 30K. When running, the core PCMCIA modules take up 48K of system memory. The cardmgr daemon will generally be swapped out except when cards are inserted or removed. The total package size is not much different from DOS Card Services implementations. Compared to DOS ``point enablers'', this may still seem like a lot of overhead, especially for people that don't plan on using many of the features of PCMCIA, such as power management or hot swapping. Point enablers can be tiny because they generally support only one or a small set of cards, and also generally support a restricted set of PCMCIA controllers. If someone were to write a genuinely ``generic'' modem enabler, it would end up incorporating much of the functionality of Card Services, to handle cards from different vendors and the full range of PCMCIA controller variants. 2. Compilation and installation 2.1. Prerequisites and kernel setup Before starting, you should think about whether you really need to compile the PCMCIA package yourself. All common Linux distributions come with pre-compiled PCMCIA driver packages. Generally, you only need to install the drivers from scratch if you need a new feature of the current drivers, or if you've updated and/or reconfigured your kernel in a way that is incompatible with the drivers included with your Linux distribution. While compiling the PCMCIA package is not technically difficult, it does require some general Linux familiarity. The following things should be installed on your system before you start installing PCMCIA: · A 2.0.* or 2.1.* series kernel source tree. · An appropriate set of module utilities. · (Optional) the ``XForms'' X11 user interface toolkit. The current driver package actually works with most kernel versions back to 1.2.8. However, use with older kernels is deprecated, and backwards compatibility with very old kernels may go away at any time. You need to have a complete linux source tree for your kernel, not just an up-to-date kernel image, to compile the PCMCIA package. The PCMCIA modules contain some references to kernel source files. While you may want to build a new kernel to remove unnecessary drivers, installing PCMCIA does not require you to do so. Current ``stable'' kernel sources and patches are available from , or from . Development kernels can be found in the corresponding v2.1 subdirectories. Current module utilities can be found in the same locations. In the Linux source tree for 2.0 and 2.1 kernels, the Documentation/Changes file describes the versions of all sorts of other system components that are required for that kernel release. You may want to check through this and verify that your system is up to date, especially if you have updated your kernel. If you are using a 2.1 kernel, be sure that you are using the right combination of shared libraries and module tools. 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. Any drivers compiled into your kernel will only waste space. 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 1.2.X kernels, 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. In order to use a PCMCIA token ring adapter, your kernel should be configured with ``Token Ring driver support'' (CONFIG_TR) enabled, though you should leave CONFIG_IBMTR off. If you want to use a PCMCIA IDE adapter, your kernel should be configured with CONFIG_BLK_DEV_IDE_PCMCIA enabled, for 1.3.72 through 2.1.7 kernels. Older kernels do not support removeable IDE devices; newer kernels do not require a special configuration setting. 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, as they will just take up space. If you want to modularize a driver that is needed for a PCMCIA device, you must modify /etc/pcmcia/config to specify what modules need to be loaded for what card types. For example, if the serial driver is modularized, then the serial device definition should be: device "serial_cs" class "serial" module "misc/serial", "serial_cs" This package includes an X-based card status utility called cardinfo. This utility is based on a freely distributed user interface toolkit called the XForms Library. This library is available as a separate package with most Linux distributions. If you would like to build cardinfo, you should install XForms and all the normal X header files and libraries before configuring the PCMCIA package. 2.2. Installation Here is a synopsis of the installation process: · Unpack pcmcia-cs-3.0.?.tar.gz in /usr/src. · Run ``make config'' in the new pcmcia-cs-3.0.? directory. · Run ``make all'', then ``make install''. · Customize the PCMCIA startup script and the option files in /etc/pcmcia for your site. If you plan to install any contributed client drivers not included in the core PCMCIA distribution, unpack each of them in the top-level directory of the PCMCIA source tree. Then follow the normal build instructions. The extra drivers will be compiled and installed automatically. Running ``make config'' prompts for a few configuration options, and checks out your system to verify that it satisfies all prerequisites for installing PCMCIA support. In most cases, you'll be able to just accept all the default configuration options. Be sure to carefully check the output of this command in case there are problems. If you are compiling the PCMCIA package for installation on another machine, specify an alternate target directory when prompted by the configure script. This should be an absolute path. All the PCMCIA tools will be installed relative to this directory. You will then be able to tar this directory tree and copy to your target machine, and unpack relative to its root directory to install everything in the proper places. If you are cross compiling on another machine, you may want to specify alternate names for the compiler and linker. This may also be helpful on mixed a.out and ELF systems. The script will also prompt for additional compiler flags for debugging. Some of the support utilities (cardctl and cardinfo) can be compiled either in ``safe'' or ``trusting'' forms. The ``safe'' forms prevent non-root users from modifying card configurations. The ``trusting'' forms permit ordinary users to issue commands to suspend and resume cards, reset cards, and change the current configuration scheme. The configuration script will ask if you want the utilities compiled as safe or trusting: the default is to be safe. There are a few kernel configuration options that affect the PCMCIA tools. The configuration script can deduce these from the running kernel (the most common case). Alternatively, if you are compiling for installation on another machine, it can read the configuration from a kernel source tree, or each option can be set interactively. 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//pcmcia. The cardmgr and cardctl programs are installed in /sbin. If cardinfo is built, it is installed in /usr/bin/X11. Configuration files will be installed in the /etc/pcmcia directory. If you are installing over an older version, your old config scripts will be backed up before being replaced. The saved scripts will be given extensions like *.~1~, *.~2~, and so on. 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. In a few cases, the probe command will be unable to determine your controller type automatically. If you have a Halikan NBD 486 system, it has a TCIC-2 controller at an unusual location: you'll need to edit rc.pcmcia to load the tcic module, and also set the PCIC_OPTS parameter to ``tcic_base=0x02c0''. 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. If this happens, edit rc.pcmcia and set PCIC to i82365, and PCIC_OPTS to ``wakeup=1''. 2.3. Post-installation for systems using BSD init scripts Some Linux distributions, including Slackware, use a BSD arrangement for system startup scripts. If /etc/rc.d/rc.M exists, your system is in this group. The script rc.pcmcia, installed in /etc/rc.d, controls starting up and shutting down the PCMCIA system. ``make install'' 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 the PCMCIA startup script, like: /etc/rc.d/rc.pcmcia start It does not really matter where you insert this line, as long as the PCMCIA drivers are started after syslogd. 2.4. Post-installation for systems using System V init scripts Red Hat, Caldera, and Debian Linux have a System V-ish arrangement for system startup files. If you have a directory called /etc/init.d or /etc/rc.d/init.d, then your system is in this group. The rc.pcmcia script will be installed as /etc/rc.d/init.d/pcmcia, or /etc/init.d/pcmcia, as appropriate. There is no need to edit any of the startup scripts to enable PCMCIA: it will happen automatically. If the /etc/sysconfig directory exists, then a separate configuration file, /etc/sysconfig/pcmcia, will be created for startup options. If you need to change any module options (like the PCIC= or PCIC_OPTS= settings), edit this config file rather than the actual PCMCIA startup script. This file will not be overwritten by subsequent installs. Some previous releases used the /etc/sysconfig/pcmcia-scripts directory in place of /etc/pcmcia on these platforms. The current release instead uses /etc/pcmcia for all systems, and will move an existing /etc/sysconfig/pcmcia-scripts to /etc/pcmcia. 2.5. Socket driver options Some PCMCIA controllers have optional features that may or may not be implemented in a particular system. In some cases, it is impossible for the socket driver to detect if these features are implemented. Check the man page for your socket driver to see what optional features may be present for your controller. 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 card recognition problems, 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: · Cirrus controllers have numerous configurable timing parameters. The most important seems to be the cmd_time flag, which determines the length of PCMCIA bus cycles. Fast 486 systems (i.e., DX4-100) seem to often benefit from increasing this from 6 (the default) to 12 or 16. · The Cirrus PD6729 PCI controller has the fast_pci flag, which should be set if the PCI bus speed is greater than 25 MHz. · 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. However, I have yet to hear of a laptop that needs this. · The pcmcia_core module has the cis_speed parameter for changing the memory speed used for accessing a card's Card Information Structure (CIS). On some systems with fast bus clocks, increasing this parameter (i.e., slowing down card accesses) may be beneficial for card recognition problems. · This isn't a timing issue, but if you have more than one ISA-to- PCMCIA controller in your system or extra sockets in a docking station, the i82365 module should be loaded with the extra_sockets parameter set to 1. This should not be necessary for PCI-to-PCMCIA or PCI-to-CardBus bridges 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 PCIC_OPTS="cmd_time=12" # Put pcmcia_core options here CORE_OPTS="cis_speed=500" Here are some timing settings for specific systems: · On the ARM Pentium-90 or Midwest Micro Soundbook Plus, use ``freq_bypass=1 cmd_time=8''. · On a Midwest Micro Soundbook Elite, use ``cmd_time=12''. · On a Gateway Liberty, try ``cmd_time=16''. 2.6. System resource settings Card Services should automatically avoid allocating IO ports and interrupts already in use by other standard devices. It will also attempt to detect conflicts with unknown devices, but this is not completely reliable. In some cases, you may need to explicitly exclude resources for a device in /etc/pcmcia/config.opts. Here are some resource settings for specific laptop types. · On the AMS SoundPro, exclude irq 10. · On some AMS TravelPro 5300 models, use memory 0xc8000-0xcffff. · On the BMX 486DX2-66, exclude irq 5, irq 9. · On the Chicony NB5, use memory 0xda000-0xdffff. · On the Compaq Presario 1020, exclude port 0x2f8-0x2ff, irq 3, irq 5. · On the HP Omnibook 4000C, exclude port 0x300-0x30f. · On the Micron Millenia Transport, exclude irq 5, irq 9. · On the NEC Versa M, exclude irq 9, port 0x2e0-2ff. · On the NEC Versa P/75, exclude irq 5, irq 9. · On the NEC Versa S, exclude irq 9, irq 12. · On the NEC Versa 6000 series, exclude port 0x300-0x33f, irq 9, irq 10. · On the ProStar 9200, Altima Virage, and Acquiline Hurricane DX4-100, exclude irq 5, port 0x330-0x35f. Maybe use memory 0xd8000-0xdffff. · On the Siemens Nixdorf SIMATIC PG 720C, use memory 0xc0000-0xcffff, port 0x300-0x3bf. · On the TI TravelMate 5000, use memory 0xd4000-0xdffff. · On the Toshiba T4900 CT, exclude irq 5, port 0x2e0-0x2e8, port 0x330-0x338. · On the Twinhead 5100, HP 4000, Sharp PC-8700 and PC-8900, exclude irq 9 (sound), irq 12. · On an MPC 800 Series, exclude irq 5, port 0x300-0x30f for the CD- ROM. 3. Resolving installation and configuration problems This section describes some of the most common failure modes for the PCMCIA subsystem. Try to match your symptoms against the examples. This section only describes ``general failures'' that are not specific to a particular card or driver. It is nearly impossible to debug PCMCIA driver problems encountered when attempting to install Linux via a PCMCIA device. Even if you can identify the problem based on its symptoms, installation disks are difficult to modify, especially without access to a running Linux system. Customization of installation disks is completely dependent on the choice of Linux distribution, and is beyond the scope of this document. In general, the best course of action is to install Linux using some other means, obtain the latest PCMCIA drivers, and then debug the problem if it persists. 3.1. Base PCMCIA kernel modules do not load Symptoms: · Kernel version mismatch errors are reported when the PCMCIA startup script runs. · After startup, lsmod does not show any PCMCIA modules. · cardmgr reports ``no pcmcia driver in /proc/devices'' in the system log. Kernel modules contain version information that is checked against the current kernel when a module is loaded. The type of checking depends on the setting of the CONFIG_MODVERSIONS kernel option. If this is false, then the kernel version number is compiled into each module, and insmod checks this for a match with the running kernel. If CONFIG_MODVERSIONS is true, then each symbol exported by the kernel is given a sort of checksum. These codes are all compared against the corresponding codes compiled into a module. The intent was for this to make modules less version-dependent, because the checksums would only change if a kernel interface changed, and would generally stay the same across minor kernel updates. In practice, the checksums have turned out to be even more restrictive, because many kernel interfaces depend on compile-time kernel option settings. Also, the checksums turned out to be an excessively pessimistic judge of compatibility. Some of the PCMCIA modules require kernel services that may or may not be present, depending on kernel configuration. For instance, the SCSI card drivers require that the kernel be configured with SCSI support, and the network drivers require a networking kernel. If a kernel lacks a necessary feature, insmod may report undefined symbols and refuse to load a module. The practical upshot of this is that kernel modules are closely tied to both the kernel version, and the setting of many kernel configuration options. Generally, a set of modules compiled for one 2.0.31 kernel will not load against some other 2.0.31 kernel unless special care is taken to ensure that the two were built with similar configurations. This makes distribution of precompiled kernel modules a tricky business. You have several options: · If you obtained precompiled drivers as part of a Linux distribution, verify that you are using an unmodified kernel as supplied with that distribution. If you intend to use precompiled modules, you generally must stick with the corresponding kernel. · If you have reconfigured or upgraded your kernel, you will probably need to compile and install the PCMCIA package from scratch. This is easily done if you already have the kernel source tree installed. See the PCMCIA-HOWTO for detailed instructions. · In some cases, incompatibilities in other system components can prevent correct loading of kernel modules. If you have upgraded your own kernel, pay attention to the ``minimal requirements'' for module utilities and binutils listed in the Documentation/Changes file in the kernel source code tree. 3.2. Interrupt scan failures Symptoms: · The system locks up when the PCMCIA drivers are loaded, even with no cards present. · The system log shows a successful PCMCIA controller probe just before the lock-up, but does not show interrupt probe results. After identifying the PCMCIA controller, the socket driver probes for free interrupts. The probe involves programming the controller for each apparently free interrupt, then generating a ``soft'' interrupt, to see if the interrupt can be detected correctly. In some cases, probing a particular interrupt can interfere with another system device. The reason for the probe is to identify interrupts which appear to be free (i.e., are not reserved by any other Linux device driver), yet are either not physically wired to the PCMCIA controller, or are connected to another device that does not have a driver. There are two ways to proceed: · The interrupt probe can be restricted to a list of interrupts using the irq_list parameter for the socket drivers. For example, ``irq_list=5,9,10'' would limit the scan to three interrupts. All PCMCIA devices will be restricted to using these interrupts (assuming they pass the probe). You may need to use trial and error to find out which interrupts can be safely probed. · The interrupt probe can be disabled entirely by loading the socket driver with the ``do_scan=0'' option. In this case, a default interrupt list will be used, which avoids interrupts already allocated for other devices. In either case, the probe options can be specified using the PCIC_OPTS definition in the PCMCIA startup script, for example: PCIC_OPTS="irq_list=5,9,10" 3.3. Memory probe failures Symptoms: · The core drivers load correctly when no cards are present, with no errors in the system log. · The system freezes and/or reboots as soon as any card is inserted, before any beeps are heard. Or alternately: · All card insertions generate a high beep followed by a low beep. · All cards are identified as ``anonymous memory cards''. · The system log reports that various memory ranges have been excluded. The core modules perform a memory scan at the time of first card insertion. This scan can potentially interfere with other memory mapped devices. Also, pre-3.0.0 driver packages perform a more aggressive scan than more recent drivers. The memory window is defined in /etc/pcmcia/config.opts. The default window is large, so it may help to restrict the scan to a narrower range. Reasonable ranges to try include 0xd0000-0xdffff, 0xc0000-0xcffff, 0xc8000-0xcffff, or 0xd8000-0xdffff. If you have DOS or Windows PCMCIA drivers, you may be able to deduce what memory region those drivers use. Note that DOS memory addresses are often specified in ``segment'' form, which leaves off the final hex digit (so an absolute address of 0xd0000 might be given as 0xd000). Be sure to add the extra digit back when making changes to /etc/pcmcia/config.opts. 3.4. Failure to detect card insertions and removals Symptoms: · Cards are detected and configured properly if present at boot time. · The drivers do not respond to insertion and removal events, either by recording events in the system log, or by beeping. 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. If a device is inactive at probe time, its interrupt may also appear to be available. In these cases, the socket driver may pick an interrupt that is used by another device. With the i82365 and tcic drivers, the irq_list option can be used to limit the interrupts that will be tested. This list limits the set of interrupts that can be used by PCMCIA cards as well as for monitoring card status changes. The cs_irq option can also 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 for card status changes once per second. This option should also be used if your system has a shortage of interrupts available for use by PCMCIA cards. Especially for systems with more than one PCMCIA controller, there is little point in dedicating interrupts for monitoring card status changes. All these options should be set in the PCIC_OPTS= line in either /etc/rc.d/rc.pcmcia or /etc/sysconfig/pcmcia, depending on your site setup. 3.5. Resource conflict between two cards Symptoms: · Two cards each work fine when used separately. · When both cards are inserted, only one works. This usually indicates a resource conflict with a system device that Linux does not know about. PCMCIA devices are dynamically configured, so, for example, interrupts are allocated as needed, rather than specifically assigned to particular cards or sockets. Given a list of resources that appear to be available, cards are assigned resources in the order they are configured. In this case, the card configured last is being assigned a resource that in fact is not free. Check the system log to see what resources are used by the non-working card. Exclude these in /etc/pcmcia/config.opts, and restart the cardmgr daemon to reload the resource database. 3.6. Device configuration does not complete Symptoms: · When a card is inserted, exactly one high beep is heard. · Subsequent card insertions and removals may be ignored. This indicates that the card was identified successfully, however, cardmgr has been unable to complete the configuration process for some reason. The most likely reason is that a step in the card setup script has blocked. A good example would be the network script blocking if a network card is inserted with no actual network hookup present. To pinpoint the problem, you can manually run a setup script to see where it is blocking. The scripts are in the /etc/pcmcia directory. They take two parameters: a device name, and an action. The cardmgr daemon records the configuration commands in the system log. For example, if the system log shows that the command ``./network start eth0'' was the last command executed by cardmgr, the following commands would trace the script: cd /etc/pcmcia sh -x ./network start eth0 4. Usage and features 4.1. Tools for configuring and monitoring PCMCIA devices If the modules are all loaded correctly, the output of the lsmod command should look like the following, when no cards are inserted: Module Size Used by ds 5640 2 i82365 15452 2 pcmcia_core 30012 3 [ds i82365] The system log should also include output from the socket driver describing the host controller(s) found and the number of sockets detected. 4.1.1. The cardmgr configuration daemon The cardmgr daemon is responsible for monitoring PCMCIA sockets, loading client drivers when needed, and running user-level scripts in response to card insertions and removals. It records its actions in the system log, but also uses beeps to signal card status changes. The tones of the beeps indicate success or failure of particular configuration steps. Two high beeps indicate that a card was identified and configured successfully. A high beep followed by a low beep indicates that a card was identified, but could not be configured for some reason. One low beep indicates that a card could not be identified. Cardmgr records device information for each socket in /var/run/stab. Here is a sample /var/run/stab listing: Socket 0: Adaptec APA-1460 SlimSCSI 0 scsi aha152x_cs 0 sda 8 0 0 scsi aha152x_cs 1 scd0 11 0 Socket 1: Serial or Modem Card 1 serial serial_cs 0 ttyS1 5 65 For the lines describing devices, the first field is the socket, the second is the device class, the third is the driver name, the fourth is used to number multiple devices associated with the same driver, the fifth is the device name, and the final two fields are the major and minor device numbers for this device (if applicable). The cardmgr daemon configures cards based on a database of known card types kept in /etc/pcmcia/config. This file describes the various client drivers, then describes how to identify various cards, and which driver(s) belong with which cards. The format of this file is described in the pcmcia(5) man page. 4.1.2. The cardctl and cardinfo utilities The cardctl command can be used to check the status of a socket, or to see how it is configured. It can also be used to alter the configuration status of a card. Here is an example of the output of the ``cardctl config'' command: Socket 0: Socket 1: Vcc = 5.0, Vpp1 = 0.0, Vpp2 = 0.0 Card type is memory and I/O IRQ 3 is dynamic shared, level mode, enabled Speaker output is enabled Function 0: Config register base = 0x0800 Option = 0x63, status = 0x08 I/O window 1: 0x0280 to 0x02bf, auto sized I/O window 2: 0x02f8 to 0x02ff, 8 bit The ``cardctl suspend'' and ``cardctl resume'' commands can be used to shut down a card without unloading its associated drivers. The ``cardctl reset'' command attempts to reset and reconfigure a card. ``cardctl insert'' and ``cardctl eject'' mimic the actions performed when a card is physically inserted or ejected, including loading or unloading drivers, and configuring or shutting down devices. If you are running X, the cardinfo utility produces a graphical display showing the current status of all PCMCIA sockets, similar in content to ``cardctl config''. It also provides a graphical interface to most other cardctl functions. 4.1.3. Inserting and ejecting cards 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. 4.1.4. Card Services and Advanced Power Management Card Services can be compiled with support for APM (Advanced Power Management) if you've installed this package on your system. APM is incorporated into 1.3.46 and later kernels. It is currently being maintained by Rick Faith (faith@cs.unc.edu), and APM tools can be obtained from . 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. Some drivers, notably the PCMCIA SCSI drivers, cannot recover from a suspend/resume cycle. When using a PCMCIA SCSI card, use ``cardctl eject'' prior to suspending the system. 4.1.5. Shutting down the PCMCIA system 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 be incomplete, and some kernel modules may not be unloaded. To avoid this, use ``cardctl eject'' to shut down all sockets before invoking rc.pcmcia. The exit status of the cardctl command will indicate if any sockets could not be shut down. 4.2. Overview of the PCMCIA configuration scripts Each PCMCIA device has an associated ``class'' that describes how it should be configured and managed. Classes are associated with device drivers in /etc/pcmcia/config. There are currently five IO device classes (network, SCSI, cdrom, fixed disk, and serial) and two memory device classes (memory and FTL). For each class, there are two scripts in /etc/pcmcia/config: a main configuration script (i.e., /etc/pcmcia/scsi for SCSI devices), and an options script (i.e., /etc/pcmcia/scsi.opts). The main script for a device will be invoked to configure that device when a card is inserted, and to shut down the device when the card is removed. For cards with several associated devices, the script will be invoked for each device. The config scripts start by extracting some information about a device from /var/run/stab. Each script constructs a ``device address'', that uniquely describes the device it has been asked to configure, in the ADDRESS shell variable. This is passed to the *.opts script, which should return information about how a device at this address should be configured. For some devices, the device address is just the socket number. For others, it includes extra information that may be useful in deciding how to configure the device. For example, network devices pass their hardware ethernet address as part of the device address, so the network.opts script could use this to select from several different configurations. The first part of all device addresses is the current PCMCIA ``scheme''. This parameter is used to support multiple sets of device configurations based on a single external user-specified variable. One use of schemes would be to have a ``home'' scheme, and a ``work'' scheme, which would include different sets of network configuration parameters. The current scheme is selected using the ``cardctl scheme'' command. The default if no scheme is set is ``default''. As a general rule, when configuring Linux for a laptop, PCMCIA devices should only be configured from the PCMCIA device scripts. Do not try to configure a PCMCIA device the same way you would configure a permanently attached device. However, some Linux distributions provide PCMCIA packages that are hooked into those distributions' own device configuration tools. In that case, some of the following sections may not apply; ideally, this will be documented in the distribution. 4.3. PCMCIA network adapters Linux ethernet-type network interfaces normally have names like eth0, eth1, and so on. Token-ring adapters are handled similarly, however they are named tr0, tr1, and so on. The ifconfig command is used to view or modify the state of a network interface. A peculiarity of Linux is that network interfaces do not have corresponding device files under /dev, so do not be surprised when you do not find them. When a PCMCIA ethernet card is detected, it will be assigned the first free interface name, which will probably be eth0. Cardmgr will run the /etc/pcmcia/network script to configure the interface. Do not configure your PCMCIA ethernet card 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. Instead, edit the /etc/pcmcia/network.opts file to match your local network setup. The network and network.opts scripts will be executed only when your ethernet card is actually present. If your system has an automatic network configuration procedure, it may or may not be PCMCIA-aware. Consult the documentation of your Linux distribution to determine if PCMCIA network devices should be configured with the automatic tools, or by editing network.opts. The device address passed to network.opts consists of four comma- separated fields: the scheme, the socket number, the device instance, and the card's hardware ethernet address. The device instance is used to number devices for cards that have several network interfaces, so it will usually be 0. If you have several network cards used for different purposes, one option would be to configure the cards based on socket position, as in: case "$ADDRESS" in *,0,*,*) # definitions for network card in socket 0 ;; *,1,*,*) # definitions for network card in socket 1 ;; esac Alternatively, they could be configured using their hardware addresses, as in: case "$ADDRESS" in *,*,*,00:80:C8:76:00:B1) # definitions for a D-Link card ;; *,*,*,08:00:5A:44:80:01) # definitions for an IBM card esac 4.3.1. Network device parameters The following parameters can be defined in network.opts: IF_PORT Specifies the ethernet transceiver type, for cards that do not autodetect. See ``man ifport'' for transceiver names. BOOTP A boolean (y/n) value: indicates if the host's IP address and routing information should be obtained using the BOOTP protocol. IPADDR The IP address for this interface. NETMASK, BROADCAST, NETWORK Basic network parameters: see the networking HOWTO for more information. GATEWAY The IP address of a gateway for this host's subnet. Packets with destinations outside this subnet will be routed to this gateway. DOMAIN The network domain name for this host, to be used in creating /etc/resolv.conf. DNS_1, DNS_2, DNS_3 Host names or IP addresses for nameservers for this interface, to be added to /etc/resolv.conf MOUNTS A list of NFS mount points to be mounted for this interface. IPX_FRAME, IPX_NETNUM For IPX networks: the frame type and network number, passed to the ipx_interface command. For example: case "$ADDRESS" in *,*,*,*) IF_PORT="10base2" BOOTP="n" IPADDR="10.0.0.1" NETMASK="255.255.255.0" NETWORK="10.0.0.0" BROADCAST="10.0.0.255" GATEWAY="10.0.0.1" DOMAIN="domain.org" DNS_1="dns1.domain.org" ;; esac To automatically mount and unmount NFS filesystems, first add all these filesystems to /etc/fstab, but include noauto in the mount options. In network.opts, list the filesystem mount points in the MOUNTS variable. It is especially important to use either cardctl or cardinfo to shut down a network card when NFS mounts are configured this way. It is not possible to cleanly unmount NFS filesystems if a network card is simply ejected without warning. In addition to the usual network configuration parameters, the network.opts script can specify extra actions to be taken after an interface is configured, or before an interface is shut down. If network.opts defines a shell function called start_fn, it will be invoked by the network script after the interface is configured, and the interface name will be passed to the function as its first (and only) argument. Similarly, if it is defined, stop_fn will be invoked before shutting down an interface. The transceiver type can be selected using the IF_PORT setting. This can either be a numeric value as in previous PCMCIA releases, or a keyword identifying the transceiver type. All the network drivers default to either autodetect the interface if possible, or 10baseT otherwise. The ifport command can be used to check or set the current transceiver type. For example: # ifport eth0 10base2 # # ifport eth0 eth0 2 (10base2) Current releases of the 3c589 driver attempt to autodetect the network connection, but this doesn't seem to be completely functional yet. For autodetection to work, the network cable should be connected to the card when the card is configured. Alternatively, once the network is connected, you can force the driver to check the connection with: ifconfig eth0 down up 4.3.2. Comments about specific cards · With IBM CCAE and Socket EA cards, you need to pick the transceiver type (10base2, 10baseT, AUI) when the network device is configured. Make sure that the transceiver type reported in the system log matches your connection. · The drivers for SMC, Megahertz, Ositech, and 3Com cards should autodetect the attached network type (10base2 or 10baseT). Setting the transceiver type when the driver is loaded serves to define the card's ``first guess''. · 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. · If you have trouble with an IBM CCAE, NE4100, Thomas Conrad, or Kingston adapter, try increasing the memory access time with the mem_speed=# option to the pcnet_cs module. An example of how to do this is given in the standard config.opts file. Try speeds of up to 1000 (in nanoseconds). · For the New Media Ethernet adapter, on some systems, it may be necessary to increase the IO port access time with the io_speed=# option when the pcmcia_core module is loaded. Edit CORE_OPTS in the startup script to set this option. · The multicast support in the New Media Ethernet driver is incomplete. The latest driver will function with multicast kernels, but will ignore multicast packets. Promiscuous mode should work properly. · The driver used by the IBM and 3Com token ring adapters seems to behave very badly if the cards are not connected to a ring when they get initialized. Always connect these cards to the net before they are powered up. This driver also requires free IO ports in the range of 0xa20-0xa27. On some systems, the automatic IO port conflict checker will incorrectly determine that this port range is unavailable. In that case, the port check can be disabled by loading the pcmcia_core module with probe_io=0. · Newer Linksys and D-Link cards have a unique way of selecting the transceiver type that isn't handled by the Linux drivers. One workaround is to boot DOS and use the vendor-supplied utility to select the transceiver, then warm boot Linux. I am looking for beta testers for a Linux utility to perform this function. · For WaveLAN wireless network adapters, Jean Tourrilhes (jt@hplb.hpl.hp.com) has put together a wireless HOWTO at . 4.3.3. Diagnosing problems with network adapters · Is your card recognized as an ethernet card? Check the system log 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''. · 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 the system log), and try excluding these in /etc/pcmcia/config.opts to force the card to use something different. · 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. · If you get messages like ``network unreachable'' when you try to access the network, then you have probably set up /etc/pcmcia/network.opts incorrectly. On the other hand, mis- configured cards will usually fail silently. · To diagnose problems in /etc/pcmcia/network.opts, start by trying to ping other systems on the same subnet using their IP addresses. Then try to ping your gateway, and then machines on other subnets. Ping machines by name only after trying these simpler tests. · 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.opts script. Make sure your drop cable, ``T'' jack, terminator, etc are working. 4.4. PCMCIA serial and modem devices Linux serial devices are accessed via the /dev/cua* and /dev/ttyS* special device files. The ttyS* devices are for incoming connections, such as directly connected terminals. The cua* devices are for outgoing connections, such as modems. Each physical serial port has both a ttyS and a cua device file: it is up to you to pick the appropriate device for your application. The configuration of a serial device can be examined and modified with the setserial command. When a PCMCIA serial or modem card is detected, it will be assigned to the first available serial device slot. This will usually be /dev/ttyS1 (cua1) or /dev/ttyS2 (cua2), depending on the number of built-in serial ports. The ttyS* device is the one reported in /var/run/stab. The default serial device option script, /etc/pcmcia/serial.opts, will link the corresponding cua* device file to /dev/modem as a convenience. Do not try to use /etc/rc.d/rc.serial to configure a PCMCIA modem. This script should only be used to configure non-removable devices. Modify /etc/pcmcia/serial.opts if you want to do anything special to set up your modem. Also, do not try to change the IO port and interrupt settings of a PCMCIA serial device using setserial. This would tell the serial driver to look for the device in a different place, but would not change how the card hardware is actually configured. The serial configuration script allows you to specify other setserial options, as well as whether a line should be added to /etc/inittab for this port. The device address passed to serial.opts has three comma-separated fields: the first is the scheme, the second is the socket number, and the third is the device instance. The device instance may take several values for cards that support multiple serial ports, but for single-port cards, it will always be 0. If you commonly use more than one PCMCIA modem, you may want to specify different settings based on socket position, as in: case "$ADDRESS" in *,0,*) # Options for modem in socket 0 LINK=/dev/modem0 ;; *,1,*) # Options for modem in socket 1 LINK=/dev/modem1 ;; esac If a PCMCIA modem is already configured when Linux boots, it may be incorrectly identified as an ordinary built-in serial port. This is harmless, however, when the PCMCIA drivers take control of the modem, it will be assigned a different device slot. It is best to either parse /var/run/stab or use /dev/modem, rather than expecting a PCMCIA modem to always have the same device assignment. If you configure your kernel to load the basic Linux serial port driver as a module, you must edit /etc/pcmcia/config to indicate that this module must be loaded. Edit the serial device entry to read: device "serial_cs" class "serial" module "misc/serial", "serial_cs" 4.4.1. Serial device parameters The following parameters can be defined in serial.opts: LINK Specifies a path for a symbolic link to be created to the ``dialout'' or /dev/cua* device. SERIAL_OPTS Specifies options to be passed to the setserial command. INITTAB If specified, this will be used to construct an inittab entry for the device. For example: case "$ADDRESS" in *,*,*,*) LINK="/dev/modem" SERIAL_OPTS="" INITTAB="/sbin/getty" 4.4.2. Diagnosing problems with serial devices · Is your card recognized as a modem? Check the system log 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 ``3.6'' for details. · Is the modem configured successfully by serial_cs? Again, check the system log 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.opts and exclude the port range that was allocated for the modem. · Is there an interrupt conflict? If the system log 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.opts to exclude this interrupt. · If the modem seems to work only very, very slowly, this is an almost certain indicator of an interrupt conflict. · 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 or PPP until you are sure you can make simple connections. If simple things work but SLIP does not, your problem is most likely with SLIP, not with PCMCIA. · If you get kernel messages indicating that the serial_cs module cannot be loaded, it means that your kernel does not have serial device support. If you have compiled the serial driver as a module, you must modify /etc/pcmcia/config to indicate that the serial module should be loaded before serial_cs. 4.5. PCMCIA SCSI adapters All the currently supported PCMCIA SCSI cards are work-alikes of one of the following ISA bus cards: the Qlogic, the Adaptec AHA-152X, or the Future Domain TMC-16x0. The PCMCIA drivers are built by linking some PCMCIA-specific code (in qlogic_cs.c, toaster_cs.c, or fdomain_cs.c) with the normal Linux SCSI driver. When a new SCSI host adapter is detected, the SCSI drivers will probe for devices. Check the system log to make sure your devices are detected properly. New SCSI devices will be assigned to the first available SCSI device files. The first SCSI disk will be /dev/sda, the first SCSI tape will be /dev/st0, and the first CD-ROM will be /dev/scd0. With 1.3.X and later kernels, the PCMCIA core drivers are able to find out from the kernel which SCSI devices are connected to a card. They will be listed in /var/run/stab, and the SCSI configuration script, /etc/pcmcia/scsi, will be called once for each attached device, to either configure or shut down that device. The default script does not take any actions to configure SCSI devices, but will properly unmount filesystems on SCSI devices when a card is removed. With 1.2.X kernels, the PCMCIA drivers cannot automatically deduce which devices are associated with a particular SCSI adapter. Instead, if you have one normal SCSI device configuration, you may list these devices in /etc/pcmcia/scsi.opts. For example, if you normally have a SCSI disk and a CD-ROM, you would use: # For 1.2 kernels: list of attached devices SCSI_DEVICES="sda scd0" The device addresses passed to scsi.opts are complicated, because of the variety of things that can be attached to a SCSI adapter. Addresses consist of either six or seven comma-separated fields: the current scheme, the device type, the socket number, the SCSI channel, ID, and logical unit number, and optionally, the partition number. The device type will be ``sd'' for disks, ``st'' for tapes, ``sr'' for CD-ROM devices, and ``sg'' for generic SCSI devices. For most setups, the SCSI channel and logical unit number will be 0. For disk devices with several partitions, scsi.opts will first be called for the whole device, with a five-field address. The script should set the PARTS variable to a list of partitions. Then, scsi.opts will be called for each partition, with the longer seven-field addresses. If your kernel does not have a top-level driver (disk, tape, etc) for a particular SCSI device, then the device will not be configured by the PCMCIA drivers. As a side effect, the device's name in /var/run/stab will be something like ``sd#nnnn'' where ``nnnn'' is a four-digit hex number. This happens when cardmgr is unable to translate a SCSI device ID into a corresponding Linux device name. It is possible to modularize the top-level SCSI drivers so that they are only loaded when a PCMCIA SCSI adapter is detected. To do so, you need to edit /etc/pcmcia/config to tell cardmgr which extra modules need to be loaded when your adapter is configured. For example: device "aha152x_cs" class "scsi" module "scsi/scsi_mod", "scsi/sd_mod", "aha152x_cs" would say to load the core SCSI module and the top-level disk driver module before loading the regular PCMCIA driver module. The PCMCIA Configure script will not automatically detect modularized SCSI modules, so you will need use the manual configure option to enable SCSI support. Always turn on SCSI devices before powering up your laptop, or before inserting the adapter card, so that the SCSI bus is properly terminated when the adapter is configured. Also be very careful about ejecting a SCSI adapter. Be sure that all associated SCSI devices are unmounted and closed before ejecting the card. The best way to ensure this is to use either cardctl or cardinfo to request card removal before physically 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. There is a potential complication when using these cards that does not arise with ordinary ISA bus adapters. The SCSI bus carries a ``termination power'' signal that is necessary for proper operation of ordinary passive SCSI terminators. PCMCIA SCSI adapters do not supply termination power, so if it is required, an external device must supply it. Some external SCSI devices may be configured to supply termination power. Others, such as the Zip Drive and the Syquest EZ- Drive, use active terminators that do not depend on it. In some cases, it may be necessary to use a special terminator block such as the APS SCSI Sentry 2, which has an external power supply. When configuring your SCSI device chain, be aware of whether or not any of your devices require or can provide termination power. The Adaptec APA-460 SlimSCSI adapter is not supported. This card was originally sold under the Trantor name, and when Adaptec merged with Trantor, they continued to sell the Trantor card with an Adaptec label. The APA-460 is not compatible with any existing Linux driver. I'm not sure how hard it would be to write a driver; I don't think anyone has been able to obtain the technical information from Adaptec. The (unsupported) Trantor SlimSCSI can be identified by the following: Trantor / Adaptec APA-460 SlimSCSI FCC ID: IE8T460 Shipped with SCSIworks! driver software The (supported) Adaptec SlimSCSI can be identified by the following: Adaptec APA-1460 SlimSCSI FCC ID: FGT1460 P/N: 900100 Shipped with EZ-SCSI driver software 4.5.1. SCSI device parameters The following parameters can be defined in scsi.opts: DO_FSTAB A boolean (y/n) setting: specifies if an entry should be added to /etc/fstab for this device. DO_FSCK A boolean (y/n) setting: specifies if the filesystem should be checked before being mounted, with ``fsck -Ta''. DO_MOUNT A boolean (y/n) setting: specifies if this device should be automatically mounted at card insertion time. FSTYPE, OPTS, MOUNTPT The filesystem type, mount options, and mount point to be used for the fstab entry and/or mounting the device. For example, here is a script for configuring a disk device at SCSI ID 3, with two partitions, and a CD-ROM at SCSI ID 6: case "$ADDRESS" in *,sd,*,0,3,0) # This device has two partitions... PARTS="1 2" ;; *,sd,*,0,3,0,1) # Options for partition 1: # update /etc/fstab, and mount an ext2 fs on /usr1 DO_FSTAB="y" ; DO_FSCK="y" ; DO_MOUNT="y" FSTYPE="ext2" OPTS="" MOUNTPT="/usr1" ;; *,sd,*,0,3,0,2) # Options for partition 2: # update /etc/fstab, and mount an MS-DOS fs on /usr2 DO_FSTAB="y" ; DO_FSCK="y" ; DO_MOUNT="y" FSTYPE="msdos" OPTS="" MOUNTPT="/usr2" ;; *,sr,*,0,6,0) # Options for CD-ROM at SCSI ID 6 PARTS="" DO_FSTAB="y" ; DO_FSCK="n" ; DO_MOUNT="y" FSTYPE="iso9660" OPTS="ro" MOUNTPT="/cdrom" ;; esac 4.5.2. Diagnosing problems with SCSI adapters · With the aha152x_cs driver (used by Adaptec, New Media, and a few others), it seems that SCSI disconnect/reconnect support is a frequent source of trouble with tape drives. To disable this ``feature,'' add the following to /etc/pcmcia/config.opts: module "aha152x_cs" opts "reconnect=0" · If you have compiled SCSI support as modules (CONFIG_SCSI is ``m''), when configuring PCMCIA, you must explicitly specify that you want the SCSI drivers to be built. You must also modify /etc/pcmcia/config to load the SCSI modules before the appropriate *_cs driver is loaded. · If you get ``aborting command due to timeout'' messages when the SCSI bus is probed, you almost certainly have an interrupt conflict. 4.6. PCMCIA memory cards The memory_cs driver handles all types of memory cards, as well as providing direct access to the PCMCIA memory address space for cards that have other functions. When loaded, it creates a combination of character and block devices. See the man page for the module for a complete description of the device naming scheme. Block devices are used for disk-like access (creating and mounting filesystems, etc). The character devices are for "raw" unbuffered reads and writes at arbitrary locations. The device address passed to memory.opts consists of two fields: the scheme, and the socket number. The options are applied to the first common memory partition on the corresponding memory card. Some older memory cards, and most simple static RAM cards, lack a ``Card Information Structure'' (CIS), which is the scheme PCMCIA cards use to identify themselves. Normally, cardmgr will assume that any card that lacks a CIS is a simple memory card, and load the memory_cs driver. Thus, a common side effect of a general card identification problem is that other types of cards may be misdetected as memory cards. The memory_cs driver uses a heuristic to guess the capacity of these cards. The heuristic does not work for write protected cards, and may make mistakes in some other cases as well. If a card is misdetected, its size should then be explicitly specified when using commands such as dd or mkfs. 4.6.1. Memory device parameters The following parameters can be specified in memory.opts: DO_FSTAB A boolean (y/n) setting: specifies if an entry should be added to /etc/fstab for this device. DO_FSCK A boolean (y/n) setting: specifies if the filesystem should be checked before being mounted, with ``fsck -Ta''. DO_MOUNT A boolean (y/n) setting: specifies if this device should be automatically mounted at card insertion time. FSTYPE, OPTS, MOUNTPT The filesystem type, mount options, and mount point to be used for the fstab entry and/or mounting the device. Here is an example of a script that will automatically mount memory cards based on which socket they are inserted into: case "$ADDRESS" in *,0,0) # Mount filesystem, but don't update /etc/fstab DO_FSTAB="n" ; DO_FSCK="y" ; DO_MOUNT="y" FSTYPE="ext2" ; OPTS="" MOUNTPT="/mem0" ;; *,1,0) # Mount filesystem, but don't update /etc/fstab DO_FSTAB="n" ; DO_FSCK="y" ; DO_MOUNT="y" FSTYPE="ext2" ; OPTS="" MOUNTPT="/mem1" ;; esac 4.6.2. Using flash memory cards The device address passed to ftl.opts consists of three or four fields: the scheme, the socket number, the region number, and optionally, the partition number. Most flash cards have just one flash memory region, so the region number will generally always be zero. To use a flash memory card as an ordinary disk-like block device, first create an FTL, or ``flash translation layer'', partition on the device with the ftl_format command. This layer hides the device- specific details of flash memory programming and make the card look like a simple block device. For example: ftl_format -i /dev/mem0c0c Note that this command accesses the card through the ``raw'' memory card interface. Once formatted, the card can be accessed as an ordinary block device via the ftl_cs driver. For example: mke2fs /dev/ftl0c0 mount -t ext2 /dev/ftl0c0 /mnt Device naming for FTL devices is tricky. Minor device numbers have three parts: the card number, the region number on that card, and optionally, the partition within that region. A region can either be treated as a single block device with no partition table (like a floppy), or it can be partitioned like a hard disk device. The ``ftl0c0'' device is card 0, common memory region 0, the entire region. The ``ftl0c0p1'' through ``ftl0c0p4'' devices are primary partitions 1 through 4 if the region has been partitioned. There are two major formats for flash memory cards: the FTL style, and the Microsoft Flash File System. The FTL format is generally more flexible because it allows any ordinary high-level filesystem (ext2, ms-dos, etc) to be used on a flash card as if it were an ordinary disk device. The FFS is a completely different filesystem type. Linux cannot currently handle cards formated with FFS. 4.7. PCMCIA ATA/IDE card drives ATA/IDE drive support requires a 1.3.72 or higher kernel. The PCMCIA- specific part of the driver is fixed_cs. Be sure to use cardctl or cardinfo to shut down an ATA/IDE card before ejecting it, as the driver has not been made ``hot-swap-proof''. The device addresses passed to fixed.opts consist of either three or four fields: the current scheme, the socket number, the drive's serial number, and an optional partition number. The ide_info can be used to obtain an IDE device's serial number. As with SCSI devices, fixed.opts is first called for the entire device. If fixed.opts returns a list of partitions in the PARTS variable, the script will then be called for each partition. 4.7.1. ATA/IDE fixed-disk device parameters The following parameters can be specified in fixed.opts: DO_FSTAB A boolean (y/n) setting: specifies if an entry should be added to /etc/fstab for this device. DO_FSCK A boolean (y/n) setting: specifies if the filesystem should be checked before being mounted, with ``fsck -Ta''. DO_MOUNT A boolean (y/n) setting: specifies if this device should be automatically mounted at card insertion time. FSTYPE, OPTS, MOUNTPT The filesystem type, mount options, and mount point to be used for the fstab entry and/or mounting the device. Here is an example fixed.opts file to mount the first partition of any ATA/IDE card on /mnt. case "$ADDRESS" in *,*,*) PARTS="1" ;; *,*,*,1) DO_FSTAB="y" ; DO_FSCK="y" ; DO_MOUNT="y" FSTYPE="msdos" OPTS="" MOUNTPT="/mnt" ;; esac 4.7.2. Diagnosing problems with ATA/IDE adapters · Some IDE drives violate the PCMCIA specification by requiring a longer time to spin up than the maximum allowed card setup time. To use these cards, load the pcmcia_core module with: CORE_OPTS="unreset_delay=400" · To use an ATA/IDE CD-ROM device, your kernel must be compiled with CONFIG_BLK_DEV_IDECD enabled. This will normally be the case for standard kernels, however it is something to be aware of if you compile a custom kernel. 4.8. Multifunction cards Starting with the 1.3.73 Linux kernel, a single interrupt can be shared by several drivers, such as the serial driver and an ethernet driver. When using a multifunction card under a newer kernel, all card functions can be used without loading and unloading drivers. Simultaneous use of two card functions is ``tricky'' and various hardware vendors have implemented interrupt sharing in their own incompatible (and sometimes proprietary) ways. The drivers for some cards (Ositech Jack of Diamonds, 3Com 3c562, Linksys) properly support simultaneous access, but others (Megahertz in particular) do not. Earlier kernels do not support interrupt sharing between different device drivers, so it is not possible for the PCMCIA drivers to configure this card for simultaneous ethernet and modem access. The ethernet and serial drivers are both loaded automatically. However, the ethernet driver ``owns'' the card interrupt by default. To use the modem, you can unload the ethernet driver and reconfigure the serial port by doing something like: ifconfig eth0 down rmmod 3c589_cs setserial /dev/modem autoconfig auto_irq setserial /dev/modem The second setserial should verify that the port has been configured to use the interrupt previously used by the ethernet driver. 5. Advanced topics 5.1. Resource allocation for PCMCIA devices 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. In /etc/pcmcia/config.opts you'll find a place for excluding interrupts that are used by non-PCMCIA devices. Similarly, there is no way to directly specify the I/O addresses for a PCMCIA card to use. The /etc/pcmcia/config.opts file allows you to specify ranges of ports available for use by all PCMCIA devices, or to exclude ranges that conflict with other devices. After modifying /etc/pcmcia/config.opts, you can restart cardmgr with ``kill -HUP''. The interrupt used to monitor card status changes is chosen by the low-level socket driver module (i82365 or tcic) before cardmgr parses /etc/pcmcia/config, so it is not affected by changes to this file. To set this interrupt, use the cs_irq= option when the socket driver is loaded, by setting the PCIC_OPTS variable in /etc/rc.d/rc.pcmcia. All the client card drivers have a parameter called irq_list for specifying which interrupts they may try to allocate. These driver options should be set in your /etc/pcmcia/config file. For example: device "serial_cs" module "serial_cs" opts "irq_list=8,12" ... would specify that the serial driver should only use irq 8 or irq 12. Regardless of irq_list settings, 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. 5.2. How can I have separate device setups for home and work? This is fairly easy using PCMCIA ``scheme'' support. Use two configuration schemes, called ``home'' and ``work''. Here is an example of a network.opts script with scheme-specific settings: case "$ADDRESS" in work,*,*,*) # definitions for network card in work scheme ... ;; home,*,*,*|default,*,*,*) # definitions for network card in home scheme ... ;; esac The first part of a PCMCIA device address is always the configuration scheme. In this example, the second ``case'' clause will select for both the ``home'' and ``default'' schemes. So, if the scheme is unset for any reason, it will default to the ``home'' setup. Now, to choose between the two sets of settings, run either: cardctl scheme home or cardctl scheme work The cardctl command does the equivalent of shutting down all your cards and restarting them. The command can be safely executed whether or not the PCMCIA system is loaded, but the command may fail if you are using other PCMCIA devices at the time (even if their configurations are not explicitly dependant on the scheme setting). To find out the current PCMCIA scheme setting, run: cardctl scheme 5.3. Booting from a PCMCIA device Having the root filesystem on a PCMCIA device is tricky because the Linux PCMCIA system is not designed to be linked into the kernel. Its core components, the loadable kernel modules and the user mode cardmgr daemon, depend on an already running system. The kernel's ``initrd'' facility works around this requirement by allowing Linux to boot using a temporary ram disk as a minimal root image, load drivers, and then re-mount a different root filesystem. The temporary root can configure PCMCIA devices and then re-mount a PCMCIA device as root. The initrd image absolutely must reside on a bootable device: this generally cannot be put on a PCMCIA device. This is a BIOS limitation, not a kernel limitation. It is useful here to distinguish between ``boot-able'' devices (i.e., devices that can be booted), and ``root-able'' devices (i.e., devices that can be mounted as root). ``Boot-able'' devices are determined by the BIOS, and are generally limited to internal floppy and hard disk drives. ``Root-able'' devices are any block devices that the kernel supports once it has been loaded. The initrd facility makes more devices ``root-able'', not ``boot-able''. Some Linux distributions will allow installation to a device connected to a PCMCIA SCSI adapter, as an unintended side-effect of their support for installs from PCMCIA SCSI CD-ROM devices. However, at present, no Linux installation tools support configuring an appropriate ``initrd'' to boot Linux with a PCMCIA root filesystem. Setting up a system with a PCMCIA root thus requires that you use another Linux system to create the ``initrd'' image. If another Linux system is not available, another option would be to temporarily install a minimal Linux setup on a non-PCMCIA drive, create an initrd image, and then reinstall to the PCMCIA target. The Linux Bootdisk-HOWTO has some general information about setting up boot disks but nothing specific to initrd. The main initrd document is included with recent kernel source code distributions, in linux/Documentation/initrd.txt. Before beginning, you should read this document. A familiarity with lilo is also helpful. Using initrd also requires that you have a kernel compiled with CONFIG_BLK_DEV_RAM and CONFIG_BLK_DEV_INITRD enabled. This is an advanced configuration technique, and requires a high level of familiarity with Linux and the PCMCIA system. Be sure to read all the relevant documentation before starting. The following cookbook instructions should work, but deviations from the examples will quickly put you in uncharted and ``unsupported'' territory, and you will be on your own. This method absolutely requires that you use a PCMCIA driver release of 2.9.5 or later. Older PCMCIA packages or individual components will not work in the initrd context. Do not mix components from different releases. 5.3.1. The pcinitrd helper script The pcinitrd script creates a basic initrd image for booting with a PCMCIA root partition. The image includes a minimal directory heirarchy, a handful of device files, a few binaries, shared libraries, and a set of PCMCIA driver modules. When invoking pcinitrd, you specify the driver modules that you want to be included in the image. The core PCMCIA components, pcmcia_core and ds, are automatically included. As an example, say that your laptop uses an i82365-compatible PCMCIA host controller, and you want to boot Linux with the root filesystem on a hard drive attached to an Adaptec SlimSCSI adapter. You could create an appropriate initrd image with: pcinitrd -v initrd pcmcia/i82365.o pcmcia/aha152x_cs.o To customize the initrd startup sequence, you could mount the image using the ``loopback'' device with a command like: mount -o loop -t ext2 initrd /mnt and then edit the linuxrc script. The PCMCIA configuration files will be installed under /etc in the image, and can also be customized. See the man page for pcinitrd for more information. 5.3.2. Creating an initrd boot floppy After creating an image with pcinitrd, you can create a boot floppy by copying the kernel, the compressed initrd image, and a few support files for lilo to a clean floppy. In the following example, we assume that the desired PCMCIA root device is /dev/sda1: mke2fs /dev/fd0 mount /dev/fd0 /mnt mkdir /mnt/etc /mnt/boot /mnt/dev cp -a /dev/fd0 /dev/sda1 /mnt/dev cp [kernel-image] /mnt/vmlinuz gzip < [initrd-image] > /mnt/initrd Create /mnt/etc/lilo.conf with the contents: boot=/dev/fd0 compact image=/vmlinuz label=linux initrd=/initrd read-only root=/dev/sda1 Finally, invoke lilo with: lilo -r /mnt When lilo is invoked with -r, it performs all actions relative to the specified alternate root directory. The reason for creating the device files under /mnt/dev was that lilo will not be able to use the files in /dev when it is running in this alternate-root mode. 5.3.3. Installing an initrd image on a non-Linux drive One common use of the initrd facility would be on systems where the internal hard drive is dedicated to another operating system. The Linux kernel and initrd image can be placed in a non-Linux partition, and lilo or LOADLIN can be set up to boot Linux from these images. Assuming that you have a kernel has been configured for the appropriate root device, and an initrd image created on another system, the easiest way to get started is to boot Linux using LOADLIN, as: LOADLIN initrd= Once you can boot Linux on your target machine, you could then install lilo to allow booting Linux directly. For example, say that /dev/hda1 is the non-Linux target partition and /mnt can be used as a mount point. First, create a subdirectory on the target for the Linux files: mount /dev/hda1 /mnt mkdir /mnt/linux cp [kernel-image] /mnt/linux/vmlinuz cp [initrd-image] /mnt/linux/initrd In this example, say that /dev/sda1 is the desired Linux root partition, a SCSI hard drive mounted via a PCMCIA SCSI adapter. To install lilo, create a lilo.conf file with the contents: boot=/dev/hda map=/mnt/linux/map compact image=/mnt/linux/vmlinuz label=linux root=/dev/sda1 initrd=/mnt/linux/initrd read-only other=/dev/hda1 table=/dev/hda label=windows The boot= line says to install the boot loader in the master boot record of the specified device. The root= line identifies the desired root filesystem to be used after loading the initrd image, and may be unnecessary if the kernel image is already configured this way. The other= section is used to describe the other operating system installed on /dev/hda1. To install lilo in this case, use: lilo -C lilo.conf Note that in this case, the lilo.conf file uses absolute paths that include /mnt. I did this in the example because the target filesystem may not support the creation of Linux device files for the boot= and root= options. 6. Dealing with unsupported cards 6.1. Configuring unrecognized cards 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 the system log 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. Beware that you can specify just about any driver for a card, but if you're just shooting in the dark, there is not much reason to expect this to be productive. You may get lucky and find that your card is supported by an existing driver. However, the most likely outcome is that the driver won't work, and may have unfortunate side effects like locking up your system. Unlike most ordinary device drivers, which probe for an appropriate card, the probe for a PCMCIA device is done by cardmgr, and the driver itself may not do much validation before attempting to communicate with the device. 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 the standard config file. 6.2. Adding 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 your card is not recognized, follow the instructions in section ``3.6'' to create a config entry for your card, and bind the card to the pcnet_cs driver. Restart cardmgr to use the updated config file. If the pcnet_cs driver says that it is unable to determine your card's hardware ethernet address, then edit your new config entry to bind the card to the memory card driver, memory_cs. Restart cardmgr to use the new updated config file. You will 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/mem0a count=20 | od -Ax -t x1 and search the output for your address. Only the even bytes are defined, so ignore the odd bytes in the dump. Record the hex offset of the first byte of the address. Now, edit modules/pcnet_cs.c and find the hw_info structure. You'll need to create a new entry for your card. The first field is the memory offset. The next three fields are the first three bytes of the hardware address. The final field contains some flags for specific card features; to start, try setting it to 0. After editing pcnet_cs.c, compile and install the new module. Edit /etc/pcmcia/config again, and change the card binding from memory_cs to pcnet_cs. Follow the instructions for reloading the config file, and you should be all set. Please send me copies of your new hw_info and config entries. If you can't find your card's hardware address in the hex dump, as a method of last resort, it is possible to ``hard-wire'' the address when the pcnet_cs module is initialized. Edit /etc/pcmcia/config.opts and add a hw_addr= option, like so: module "pcnet_cs" opts "hw_addr=0x00,0x80,0xc8,0x01,0x02,0x03" Substitute your own card's hardware address in the appropriate spot, of course. Beware that if you've gotten this far, it is very unlikely that your card is genuinely NE2000 compatible. In fact, I'm not sure if there are any cards that are not handled by one of the first two methods. 6.3. PCMCIA floppy interface cards The PCMCIA floppy interface used in the Compaq Aero and a few other laptops is not yet supported by this package. The snag in supporting the Aero floppy is that the Aero seems to use a customized PCMCIA controller to support DMA to the floppy. Without knowing exactly how this is done, there isn't any way to implement support under Linux. If the floppy adapter card is present when an Aero is booted, the Aero BIOS will configure the card, and Linux will identify it as a normal floppy drive. When the Linux PCMCIA drivers are loaded, they will notice that the card is already configured and attached to a Linux driver, and this socket will be left alone. So, the drive can be used if it is present at boot time, but the card is not hot swappable. 6.4. What's up with support for Xircom cards? A driver for Xircom ethernet and ethernet/modem cards is included in the current PCMCIA package, thanks to the work of Werner Koch. I've set up a HyperNews forum specifically for discussion of Xircom driver development, at . For a long time, Xircom cards were not supported because Xircom had a company policy of not disclosing technical information about their cards. However, they have relaxed their rules, and now, they do distribute driver information. 7. Debugging tips and programming information 7.1. Submitting useful bug reports The best way to submit bug reports is to use the HyperNews message lists on the Linux PCMCIA information site. That way, other people can see current problems (and fixes or workarounds, if available). Here are some things that should be included in all bug reports: · Your system type, and the output of the probe command. · What PCMCIA cards you are using. · Your Linux kernel version, and PCMCIA driver version. · Any changes you have made to the startup files in /etc/pcmcia, or to the PCMCIA startup script. · All PCMCIA-related messages in your system log file. All the PCMCIA modules and the cardmgr daemon send status messages to the system log. This will usually be something like /var/log/messages or /usr/adm/messages. This file should be the first place to look when tracking down a problem. When submitting a bug report, always include the contents of this file. If you are having trouble finding your system messages, check /etc/syslogd.conf to see how different classes of messages are handled. Before submitting a bug report, please check to make sure that you are using an up-to-date copy of the driver package. While it is somewhat gratifying to read bug reports for things I've already fixed, it isn't a particularly constructive use of my time. 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 System.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. If you do not have web access, bug reports can be sent to me at dhinds@hyper.stanford.edu. However, I prefer that bug reports be posted to my web site, so that they can be seen by others. 7.2. Low level PCMCIA debugging aids The PCMCIA modules contain a lot of conditionally-compiled debugging code. Most of this code is under control of the PCMCIA_DEBUG preprocessor define. If this is undefined, debugging code will not be compiled. If set to 0, the code is compiled but inactive. Larger numbers specify increasing levels of verbosity. Each module built with PCMCIA_DEBUG defined will have an integer parameter, pc_debug, that controls the verbosity of its 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 memory_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. 7.3. Writing Card Services drivers for new cards The Linux PCMCIA Programmer's Guide is the best documentation for the Linux PCMCIA interface. The latest version is always available from hyper.stanford.edu in /pub/pcmcia/doc, or on the web at . 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. In many cases, the largest barrier to supporting a new card type is obtaining technical information from the manufacturer. It may be difficult to figure out who to ask, or to explain exactly what information is needed. However, with a few exceptions, it is very difficult if not impossible to implement a driver for a card without technical information from the manufacturer. 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. 7.4. Guidelines for PCMCIA client driver authors I have decided that it is not really feasible for me to distribute all PCMCIA client drivers as part of the PCMCIA package. Each new driver makes the main package incrementally harder to maintain, and including a driver inevitably transfers some of the maintenance work from the driver author to me. Instead, I will decide on a case by case basis whether or not to include contributed drivers, based on user demand as well as maintainability. For drivers not included in the core package, I suggest that driver authors adopt the following scheme for packaging their drivers for distribution. Driver files should be arranged in the same directory scheme used in the PCMCIA source distribution, so that the driver can be unpacked on top of a complete PCMCIA source tree. A driver should include source files (in ./modules/), a man page (in ./man/), and configuration files (in ./etc/). The top level directory should also include a README file. The top-level directory should include a makefile, set up so that ``make -f ... all'' and ``make -f ... install'' compile the driver and install all appropriate files. If this makefile is given an extension of .mk, then it will automatically be invoked by the top-level Makefile for the all and install targets. Here is an example of how such a makefile could be constructed: # Sample Makefile for contributed client driver FILES = sample_cs.mk README.sample_cs \ modules/sample_cs.c modules/sample_cs.h \ etc/sample etc/sample.opts man/sample_cs.4 all: $(MAKE) -C modules MODULES=sample_cs.o install: $(MAKE) -C modules install-modules MODULES=sample_cs.o $(MAKE) -C etc install-clients CLIENTS=sample $(MAKE) -C man install-man4 MAN4=sample_cs.4 dist: tar czvf sample_cs.tar.gz $(FILES) This makefile uses install targets defined in 2.9.10 and later versions of the PCMCIA package. This makefile also includes a ``dist'' target for the convenience of the driver author. You would probably want to add a version number to the final package filename (for example, sample_cs-1.5.tar.gz). A complete distribution could look like: sample_cs.mk README.sample_cs modules/sample_cs.c modules/sample_cs.h etc/sample etc/sample.opts man/sample_cs.4 With this arrangement, when the contributed driver is unpacked, it becomes essentially part of the PCMCIA source tree. It can make use of the PCMCIA header files, as well as the machinery for checking the user's system configuration, and automatic dependency checking, just like a ``normal'' client driver. I will accept client drivers prepared according to this specification and place them in the /pub/pcmcia/contrib directory on my FTP server, hyper.stanford.edu. The README in this directory will describe how to unpack a contributed driver. The PCMCIA client driver interface has not changed much over time, and has almost always preserved backwards compatibility. A client driver will not normally need to be updated for minor revisions in the main PCMCIA package. I will try to notify authors of contributed drivers of changes that require updates to their drivers. 7.5. Guidelines for Linux distribution maintainers If your distribution has system configuration tools that you would like to be PCMCIA-aware, please use the *.opts files in /etc/pcmcia for your ``hooks.'' These files will not be modified if a user compiles and installs a new release of the PCMCIA package. If you modify the main configuration scripts, then a fresh PCMCIA install will silently overwrite your custom scripts and break the connection with your configuration tools. Contact me if you are not sure how to write an appropriate option script. It is helpful for users (and for me) if you can document how your distribution deviates from the PCMCIA package as described in this document. In particular, please document changes to the startup script and configuration scripts. When building PCMCIA for distribution, you should consider including contributed drivers that are not part of the main PCMCIA package. For reasons of maintainability, I am trying to limit the core package size, by only adding new drivers if I think they are of particularly broad interest. Other drivers will be distributed separately, as described in the previous section. The split between integral and separate drivers is somewhat arbitrary and partly historical, and should not imply a difference in quality.