[9fans] how to burn iso

[erik quanstrom]

#!/bin/rc
# burn a CD from ISO-9660 image on $home/cd.iso
# version 0.03
rfork e
t1 =`{date}
kill cdfs | rc
kill 9660srv | rc
cdfs -d /dev/sdD0
cp $home/cd.iso /mnt/cd/wd || echo CD BURNING ERROR
t2 =`{date}
echo begin: $t1
echo end: $t2
# -eof-

the key bit to understand is that cdfs is the only part of the system
that knows how to send special scsi commands for talking to dvd+/+/i
or blu-ray-* or cd-* devices. it uses the raw interface to inject the
commands directly. neither the disk drivers nor the sd system
know anything about cdroms, except that they are removable.

- erik

[Rudolf Sykora]

Post by erik quanstrom

#!/bin/rc
# burn a CD from ISO-9660 image on $home/cd.iso
# version 0.03
rfork e
t1 =`{date}
kill cdfs | rc
kill 9660srv | rc
cdfs -d /dev/sdD0
cp $home/cd.iso  /mnt/cd/wd || echo CD BURNING ERROR
t2 =`{date}
echo begin: $t1
echo end: $t2
# -eof-

the key bit to understand is that cdfs is the only part of the system
that knows how to send special scsi commands for talking to dvd+/+/i
or blu-ray-* or cd-* devices.  it uses the raw interface to inject the
commands directly.  neither the disk drivers nor the sd system
know anything about cdroms, except that they are removable.
- erik

I am still lost.
My current understanding is that I need as if 3 different views on a CD:
-- if audio CD is to be written, I need to follow some structure in
which audio tracks should be written, so that other audio readers
understand it,
-- if data files are to be written, I first need some filesystem
(iso9660) on the CD and then write the data files into this
filesystem,
-- if I have an ISO image, I'd expect that this is, without any
translation, just somehow raw-copied to the CD (similarly to a way a
dd command works).

While writing to cd/wa may solve the audio case, I don't understand
how the data file vs ISO is coped with, as the example just writes an
ISO to cd/wd...

Thanks for explanation!

Ruda

PS.: also, the example doesn't fixate the disk. Should it? Shouldn't
it? (Why is this (un)needed?)

[Russ Cox]

Post by Rudolf Sykora
-- if audio CD is to be written, I need to follow some structure in
which audio tracks should be written, so that other audio readers
understand it,
-- if data files are to be written, I first need some filesystem
(iso9660) on the CD and then write the data files into this
filesystem,
-- if I have an ISO image, I'd expect that this is, without any
translation, just somehow raw-copied to the CD (similarly to a way a
dd command works).
While writing to cd/wa may solve the audio case, I don't understand
how the data file vs ISO is coped with, as the example just writes an
ISO to cd/wd...

cdfs only provides the 'ISO image raw-copied to the CD' case.
You have an ISO image, so the scripts that have been posted
will do the burn to the CD.

If data files are to be written, you have the order of operations
backward: you don't start with a file system on the CD and then
write the files to that file system, because the CD is write-once
and the file system is not really set up for that. Instead, you
create an ISO image from the files you care about and then
you write that directly to the CD.

Russ

[Peter A. Cejchan]

Post by Rudolf Sykora
PS.: also, the example doesn't fixate the disk. Should it? Shouldn't
it? (Why is this (un)needed?)

I don't know. I do not use isofs anymore. I rather write a tar file to
raw CD. Maybe I am crazy, but it works fine for me, at least for
backup.

[erik quanstrom]

Post by Peter A. Cejchan

Post by Rudolf Sykora
PS.: also, the example doesn't fixate the disk. Should it? Shouldn't
it? (Why is this (un)needed?)

I don't know. I do not use isofs anymore. I rather write a tar file to
raw CD. Maybe I am crazy, but it works fine for me, at least for
backup.

it's going to depend if you need session/track support or not.
this is a function of the media. certain media types require session
closing.

i think direct access might accidentally work for the first track on
media. i wouldn't feel comfortable depending on this though.
as i have confused cd-r for dvd+r media before.

- erik

[erik quanstrom]

Post by Rudolf Sykora
I am still lost.
-- if audio CD is to be written, I need to follow some structure in
which audio tracks should be written, so that other audio readers
understand it,
-- if data files are to be written, I first need some filesystem
(iso9660) on the CD and then write the data files into this
filesystem,
-- if I have an ISO image, I'd expect that this is, without any
translation, just somehow raw-copied to the CD (similarly to a way a
dd command works).
While writing to cd/wa may solve the audio case, I don't understand
how the data file vs ISO is coped with, as the example just writes an
ISO to cd/wd...
Thanks for explanation!
Ruda
PS.: also, the example doesn't fixate the disk. Should it? Shouldn't
it? (Why is this (un)needed?)

fixation is a feature provided by cdfs. it happens when you remove
wa/wd. fixation depends on the type of media.

cdfs also deals with writing data or audio tracks.

9660srv serves 9660 file systems. this doesn't have anything to do
with the storage media, so 9660srv will be able to serve an iso on
cd or in a ramfs.

mk9660 makes 9660 file systems that are directly writable to cdfs'
wd file.

- erik