Before November 1997, the software for Linux didn't support ATAPI cd-writers. As a result, the current release of the HOWTO concentrates on dealing with SCSI devices.
The good news is, that dealing with ATAPI devices is much easier and you
can still use this HOWTO if you just forget about the "generic SCSI devices".
To find out how to address ATAPI devices you can issue the command
cdrecord -scanbus.
Future versions of this HOWTO will contain more details of dealing with ATAPI cd-writers.
Shut down your computer, switch it off and hook CD writer to the SCSI-bus.
Make sure the SCSI-bus is properly terminated and choose a free SCSI-ID for the writer. Look at the Linux SCSI-HOWTO if you're not sure. If you're completly clueless, ask an expert.
Switch the power on again and check the messages that the BIOS of the SCSI-controller prints immediatly after switching the power on. If it doesn't recognize you writer, go back to step (b). You should see a message like
In contrast to other rumors, the Linux-kernel does _not_ require a patch in
order to write to CDs. Although the file drivers/scsi/scsi.c from
the kernel-sources contains the lines
case TYPE_WORM:
case TYPE_ROM:
SDpnt->writeable = 0;
this does only mean that that CDs and WORMs are not writeable through the
standard-devices /dev/sda-/dev/sdh - which is ok.
Instead of using these devices the writing of CDs is done through the so called generic SCSI-devices which permit nearly everything - even writing to CDs.
The Linux SCSI-HOWTO says about generic SCSI-devices:
The Generic SCSI device driver provides an interface for sending SCSI commands to all SCSI devices - disks, tapes, CDROMs, media changer robots, etc.
Speaking of the generic devices as interfaces means that they provide an alternate way of accessing SCSI-hardware than through the standard devices.
This alternate way is required because the standard devices are designed to read data block-wise from a disk, tape or cd-rom. Compared to this, driving a cd-writer (or a scanner) is more exotic, e.g commands to position the laser must be transmitted. To have a clean (and therefore fast) implementation of standard-devices, all such exotic actions must be done through the generic SCSI devices.
As everthing can be done to SCSI-hardware through the generic devices they are not fixed to a certain purpose - therefore the name generic.
Goto the /dev-directory and check for generic SCSI devices;
ls-command should show sga-sgh:
bash> cd /dev
bash> ls -l sg*
crw------- 1 root sys 21, 0 Jan 1 1970 sga
crw------- 1 root sys 21, 1 Jan 1 1970 sgb
crw------- 1 root sys 21, 2 Jan 1 1970 sgc
crw------- 1 root sys 21, 3 Jan 1 1970 sgd
crw------- 1 root sys 21, 4 Jan 1 1970 sge
crw------- 1 root sys 21, 5 Jan 1 1970 sgf
crw------- 1 root sys 21, 6 Jan 1 1970 sgg
crw------- 1 root sys 21, 7 Jan 1 1970 sgh
If you don't have those device-files then create them by using
the /dev/MAKEDEV-script:
bash> cd /dev/
bash> ./MAKEDEV sg
Now the device-files should show up.
The Linux-kernel needs a module that lends it the ability to deal with
generic SCSI devices. If your running kernel has this feature, it should
be listed in the pseudo-file /proc/devices:
bash> cat /proc/devices
Character devices:
1 mem
2 pty
3 ttyp
4 ttyp
5 cua
7 vcs
21 sg <----- stands for "SCSI Generic device"
30 socksys
Block devices:
2 fd
7 loop <----- we even can use the loop-devices
8 sd
11 sr <----- stands for "SCSI cd-Rom"
Maybe you have to issue the commands insmod sg, insmod
loop or insmod sr_mod to load the modules into the
kernel. Check again after you've tried this.
If one of them doesn't succeed, you must re-configure your kernel and re-compile it.
bash> cd /usr/src/linux
bash> make config
[..]
*
* Additional Block Devices
*
Loopback device support (CONFIG_BLK_DEV_LOOP) [M/n/y/?] M
[..]
*
* SCSI support
*
SCSI support (CONFIG_SCSI) [Y/m/n/?] Y
*
* SCSI support type (disk, tape, CD-ROM)
*
SCSI disk support (CONFIG_BLK_DEV_SD) [Y/m/n/?] Y
SCSI tape support (CONFIG_CHR_DEV_ST) [M/n/y/?] M
SCSI CD-ROM support (CONFIG_BLK_DEV_SR) [M/n/y/?] M
SCSI generic support (CONFIG_CHR_DEV_SG) [M/n/y/?] M
[..]
ISO9660 cdrom filesystem (CONFIG_ISO9660_FS) [Y/m/n/?] M
Please note that I omitted the not-so-important questions.
If you have questions regarding to this the Linux Kernel-HOWTO is the suggested reading. Furthermore your Linux-distribution should ship with some documentation about this issue.
Don't panic if the Linux-kernel prints the messages faster than you can
read them, at least the initialization of SCSI-devices can be re-displayed
with the command dmesg:
scsi0 : NCR53c{7,8}xx (rel 17)
scsi : 1 host.
scsi0 : target 0 accepting period 100ns offset 8 10.00MHz
scsi0 : setting target 0 to period 100ns offset 8 10.00MHz
Vendor: FUJITSU Model: M1606S-512 Rev: 6226
Type: Direct-Access ANSI SCSI
Detected scsi disk sda at scsi0, channel 0, id 0, lun 0
Vendor: NEC Model: CD-ROM DRIVE:84 Rev: 1.0a
Type: CD-ROM ANSI SCSI
Detected scsi CD-ROM sr0 at scsi0, channel 0, id 4, lun 0
scsi : detected 1 SCSI disk total.
SCSI device sda: hdwr sector= 512 bytes. Sectors= 2131992
Shown above is only that part of the initialization-messages that report the detection of physically present SCSI-devices.
Goto the /dev-directory and check for loopback devices.
It's not critical if you don't have those devices, but it's convenient if
you do (see 3.5). If you already have them, the ls-command should
show loop0-loop7:
bash> cd /dev
bash> ls -l loop*
brw-rw---- 1 root disk 7, 0 Sep 23 17:15 loop0
brw-rw---- 1 root disk 7, 1 Sep 23 17:15 loop1
brw-rw---- 1 root disk 7, 2 Sep 23 17:15 loop2
brw-rw---- 1 root disk 7, 3 Sep 23 17:15 loop3
brw-rw---- 1 root disk 7, 4 Sep 23 17:15 loop4
brw-rw---- 1 root disk 7, 5 Sep 23 17:15 loop5
brw-rw---- 1 root disk 7, 6 Sep 23 17:15 loop6
brw-rw---- 1 root disk 7, 7 Sep 23 17:15 loop7
If you don't have those device-files, then create them by using the
/dev/MAKEDEV-script:
bash> cd /dev/
bash> ./MAKEDEV loop
The last command only succeeds if you have the loop-module in your
kernel (see 2.4 for handling of modules). If insmod loop does not
help, you must wait until the new kernel is properly installed (see 2.5).
The following package is required to generate prototypes of CD-Rs:
ftp://tsx-11.mit.edu/pub/linux/packages/mkisofs/ (mkisofs)ftp://ftp.ge.ucl.ac.uk/pub/mkhfs (mkhybrid)
Depending on the model of your cd-writer (see 1.3), one of the following software for writing prototypes to CD-Rs is required:
ftp://ftp.fokus.gmd.de/pub/unix/cdrecord/ (cdrecord)ftp://sunsite.unc.edu/pub/Linux/utils/disk-management/ (cdwrite)
Please use the nearest mirrors of these ftp-Servers or get them from a CD.
Be absolutly sure you have version 2.0 of cdwrite or newer. No
older version and especially no beta-versions will work properly! Don't
trust the man-page of (old) mkisofs which states you need version
1.5 of cdwrite.
For information about ports of cdwrite to Irix and AIX visit the URL
http://lidar.ssec.wisc.edu/~forrest/
If you are using a kernel prior to release 2.0.31, you may want to patch
mkisofs to get along a bug in the Linux filesystem code. The
Debian-Distribution ships a patch for release 1.05 of mkisofs
(1.11 should work, too) of mkisofs that adds the option '-K' to it
(see 3.4); it's available from
ftp://ftp.debian.org/pub/debian/bo/source/otherosfs/mkisofs_1.11-1.diff.gz
This patch is only necassary if you want to mount the CD-image via the loopback-device (see 3.5.).
X-CD-Roast is full X based CD-Writer-Program, and it is the successor of
the cdwtools-0.93. It's available from
http://www.fh-muenchen.de/home/ze/rz/services/projects/xcdroast/e_overview.html
Currently X-CD-Roast is based on a patched version of cdwrite-2.0 and thus comes with exactly the same features (see 1.4). Future versions may be based on the alternate cdrecord software.