root/Documentation/cdrom/cm206

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This is the readme file for the driver for the Philips/LMS cdrom drive
cm206 in combination with the cm260 host adapter card. 

                                (c) 1995 David A. van Leeuwen
   
Features as of version 0.33
---------------------------
- Full audio support, that is, both  workman, workbone and cdp work
  now reasonably. Reading TOC still takes some time. xmcd has been
  reported to run successfully. 
- Made auto-probe code a little better, i hope

Features as of version 0.28
---------------------------
- Full speed stransfer rate (300 kB/s).
- Minimum kernel memory usage for buffering (less than 3 kB).
- Multisession support.
- Tray locking.
- Statistcics of driver accessible to the user.
- Module support.
- Auto-probing of adapter card's base port and irq line,
  also configurable at boot time or module load time.

Features still lacking
----------------------
- cm205ms+cm250 support. (I do have cm205ms docs now. I still have to
  study Kai Petzke's cm205 drives to understand the workings of the
  cm250 adapter card. Don't bet on me, write a driver yourself!)


Decide how you are going to use the driver. There are two
options:

   (a) installing the driver as a resident part of the kernel
   (b) compiling the driver as a loadable module

   Further, you must decide if you are going to specify the base port
   address and the interrupt request line of the adapter card cm260 as
   boot options for (a), module parameters for (b), use automatic
   probing of these values, or hard-wire your adaptor cards settings
   into the source code. If you don't care, you can choose for
   autoprobing, which is the default. In that case you can move on to
   the next step.

Compiling the kernel
--------------------
1) move to /usr/src/linux and do a 

        make config

   If you have chosen for option (a), answer yes to CONFIG_CM206 and
   CONFIG_ISO9660_FS.

   If you have chosen for option (b), answer yes to CONFIG_MODVERSIONS
   and no (!) to CONFIG_CM206 and CONFIG_ISO9660_FS. 

2) then do a 
        
        make dep; make clean; make zImage; make modules

3) do the usual things to install a new image (backup the old one, run
   `rdev -R zImage 1', copy the new image in place, run lilo).  Might
   be `make zlilo'.

Using the driver as a module
----------------------------
If you will only seldomly use the cd-rom driver, you can choose for
option (b), install as a loadable module. You may have to re-compile
the module when you upgrade the kernel to a new version. Read the file
`README.modules' in /usr/src/linux. To install the module, you use the 
command, as root

        insmod /usr/src/linux/modules/cm206.o

You can specify the base address on the command line as well as the irq 
line to be used, e.g.

        insmod /usr/src/linux/modules/cm206.o cm206=0x300,11

The order of base port and irq line don't matter; you may specify only
one, the other will have the value of the compiled-in default.  You
may also have to install the file-system module `iso9660.o', if you
didn't compile that into the kernel. (If you use `tcsh' as shell, you
might consider defining

        alias listinstalledmodules 'cat /proc/modules | awk \{print\$1\}'
        complete rmmod          'p/1/`listinstalledmodules`/'
        alias listcompiledmodules '(cd /usr/src/linux/modules; \ls -o *.o)'
        alias insmod            'insmod /usr/src/linux/modules/\!:1 \!:2*'
        complete insmod         'p/1/`listcompiledmodules`/'

which makes typing insmod and rmmod somewhat easier.)

Using the driver as part of the kernel
--------------------------------------
If you have chosen for option a, you can specify the base-port
address and irq on the lilo boot command line, e.g.:

        LILO: linux cm206=0x340,11

This assumes that your linux kernel image keyword is `linux'. 
If you may specify either IRQ (3--11) or base port (0x300--0x370),
auto probing is turned off for both settings, thus setting the 
other value to the compiled-in default.

If module parameters and LILO config options don't work
-------------------------------------------------------
If autoprobing does not work, you can hard-wire the default values
of the base port address (CM206_BASE) and interrupt request line
(CM206_IRQ) into the file ./include/linux/cm206.h. Change
the defines of CM206_IRQ and CM206_BASE.



Mounting the cdrom
------------------
1) Make sure that there is the right device installed in /dev.

        mknod /dev/cm206cd b 32 0

2) Make sure there is a mount point, e.g., /cdrom 

        mkdir /cdrom

3) mount using a command like this (run as root):

        mount -rt iso9660 /dev/cm206cd /cdrom

4) For user-mounts, add a line in /etc/fstab

        /dev/cm206cd      /cdrom     iso9660    ro,noauto,user

   This will allow users to give the commands

        mount /cdrom
        umount /cdrom

If things don't work
--------------------

- Try to do a `tail /var/adm/messages' to find out if the driver
  said anything about what is going wrong during the initialization.

- Try to do a `dd if=/dev/cm206cd | od -tc | less' to read from the
  CD.

- Look in the /proc directory to see if `cm206' shows up under
  one of `interrupts', `ioports', `devices' or `modules' (if
  applicable). 


DISCLAIMER 
---------- 
I cannot guarantee that this driver works, or that the hardware will
not be harmed, although i consider it most unlikely. 

I hope that you'll find this driver in some way useful. 

                                        David van Leeuwen
                                        david@tm.tno.nl

Note for Linux CDROM vendors
-----------------------------
You are encouraged to include this driver on your Linux CDROM. If
you do, you might consider sending me a free copy of that cd-rom.
You can contact me through my e-mail address, david@tm.tno.nl. 
If this driver is compiled into a kernel to boot off a cdrom, 
you should actually send me a free copy of that cd-rom. 

Copyright
---------
The copyright of the cm206 driver for Linux is 

    (c) 1995 David A. van Leeuwen

The driver is released, like most Linux software, under the conditions 
of the GNU general public license.

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